Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

Transcription

1 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Web Report #4129 Subject Area: Water Quality

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3 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

4 About the Water Research Foundation The Water Research Foundation (formerly Awwa Research Foundation or AwwaRF) is a member-supported, international, 501(c)3 nonprofit organization that sponsors research to enable water utilities, public health agencies, and other professionals to provide safe and affordable drinking water to consumers. The Foundation s mission is to advance the science of water to improve the quality of life. To achieve this mission, the Foundation sponsors studies on all aspects of drinking water, including resources, treatment, distribution, and health effects. Funding for research is provided primarily by subscription payments from close to 1,000 water utilities, consulting firms, and manufacturers in North America and abroad. Additional funding comes from collaborative partnerships with other national and international organizations and the U.S. federal government, allowing for resources to be leveraged, expertise to be shared, and broad-based knowledge to be developed and disseminated. From its headquarters in Denver, Colorado, the Foundation s staff directs and supports the efforts of more than 800 volunteers who serve on the board of trustees and various committees. These volunteers represent many facets of the water industry, and contribute their expertise to select and monitor research studies that benefit the entire drinking water community. The results of research are disseminated through a number of channels, including reports, the Web site, Webcasts, conferences, and periodicals. For its subscribers, the Foundation serves as a cooperative program in which water suppliers unite to pool their resources. By applying Foundation research findings, these water suppliers can save substantial costs and stay on the leading edge of drinking water science and technology. Since its inception, the Foundation has supplied the water community with more than $460 million in applied research value. More information about the Foundation and how to become a subscriber is available on the Web at

5 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Prepared by: Patrick J. Evans, Eva M. Opitz, Phillippe A. Daniel, and Chris R. Schulz CDM S.E. Eastgate Way, Ste 100, Bellevue, WA Jointly sponsored by: Water Research Foundation 6666 West Quincy Avenue, Denver, CO and Department of Defense 1400 Defense Pentagon, Washington, DC Published by:

6 DISCLAIMER This study was jointly funded by the Water Research Foundation (Foundation) and Department of Defense (DOD). The Foundation and DOD assume no responsibility for the content of the research study reported in this publication or for the opinions or statements of fact expressed in the report. The mention of trade names for commercial products does not represent or imply the approval or endorsement of the Foundation or DOD. This report is presented solely for informational purposes. Copyright 2010 by Water Research Foundation and Department of Defense ALL RIGHTS RESERVED. No part of this publication may be copied, reproduced or otherwise utilized without permission.

7 CONTENTS LIST OF TABLES... ix LIST OF FIGURES... xi FOREWORD... xv ACKNOWLEDGMENTS... xvii EXECUTIVE SUMMARY... xix CHAPTER 1 INTRODUCTION... 1 CHAPTER 2 OVERVIEW OF BIOLOGICAL DRINKING WATER TREATMENT... 3 History and Impetus for Use... 3 General Types of Processes... 4 Slow Sand Filtration... 4 Rapid Biological Filtration (RBF)... 4 Ozone-Enhanced Biological Filtration (OEBF)... 4 Granular Activated Carbon Biological Adsorption (GBA)... 5 Biological Perchlorate/Nitrate Process (BPNP)... 5 Other Processes... 5 CHAPTER 3 METHODS... 7 General Approach... 7 Electronic Survey... 7 General Electronic Survey Questions... 8 Electronic Survey Case Studies... 8 Telephone Case Studies CHAPTER 4 ELECTRONIC SURVEY RESULTS AND DISCUSSION Electronic Survey Demographics Use and Acceptance of Biological Treatment Use and Acceptance among Different Professions Barriers to Acceptance Overcoming Acceptance Barriers General Attributes of Biological Treatment Contaminant Removal Finished Water Quality Levels of Effort Required for Design and Operations Additional Regulator Perspectives Additional Consultant, Academic, and Vendor Perspectives Electronic Survey Case Studies Plant Demographics and Characteristics Source Water Type and Quality v

8 vi Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Process Types and Distribution Process Attributes CHAPTER 5 TELEPHONE CASE STUDIES Locations City of Salem, Oregon: Slow Biological Filtration Background Rationale for Process Selection Design and Operating Parameters Performance Regulatory Perspectives Public Perception Greater Cincinnati Water Works: Rapid Biological Filtration and GAC Background Rationale for Process Selection Design and Operating Parameters Performance Regulatory Perspectives Public Perception Los Angeles Department of Water and Power: Ozone Enhanced Biological filtration (Anthracite) Background Rationale for Process Selection Design and Operating Parameters Performance Regulatory Perspectives Public Perception Henrico y: Ozone Enhanced Biological filtration (GAC) Background Rationale for Process Selection Design and Operating Parameters Performance Regulatory Perspectives Public Perception Santa Clara Valley Water District: Ozone Enhanced Biological filtration (GAC) Background Rationale for Process Selection Design and Operating Parameters Performance Regulatory Perspectives Public Perception Arlington, Texas: Ozone Enhanced Biological filtration (GAC) Background Rationale for Process Selection Design and Operating Parameters Performance Regulatory Perspectives... 62

9 Contents vii Public Perception France: Biological Denitrification Overview Background Rationale for Process Selection Design and Operating Parameters Performance Regulatory Perspectives Public Perception Western Municipal Water District: Biological Denitrification Background Rationale for Process Selection Design and Operating Parameters Performance (pilot plant data) Regulatory Perspectives Public Perception CHAPTER 6 WORKSHOP Introduction Definitions and Terminology Article Development Article Manuscript Research Roadmap What is n Identified Research Topics CHAPTER 7 CONCLUSIONS AND RECOMMENDATIONS Conclusions General Survey Electronic Case Studies Telephone Case Studies Recommendations CHAPTER 8 RECOMMENDATIONS TO UTILITIES APPENDIX A SURVEY QUESTIONS APPENDIX B COMPLETE SURVEY DATA APPENDIX C CONTACTS LIST APPENDIX D WORKSHOP AGENDA APPENDIX E WORKSHOP ATTENDEES APPENDIX F BIOLOGICAL DRINKING WATER TREATMENT EXPERT WORKSHOP PRESENTATION ON THE SURVEY RESULTS...251

10 viii Biological Drinking Water Treatment Perceptions and Actual Experiences in North America APPENDIX G WATER RESEARCH FOUNDATION BIOLOGICAL TREATMENT PROJECTS REFERENCES ABBREVIATIONS

11 LIST OF TABLES 5.1 Monitoring Parameters Classification of Biological Drinking Water Treatment Processes...75 ix

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13 LIST OF FIGURES 3.1 Drinking water treatment process selection decision tree Survey response statistics U.S. survey demographics Characterize the extent to which aerobic (A) and anoxic (B) biological water treatment processes are used Do you believe that biological water treatment processes are generally accepted by the drinking water industry, i.e., the same as conventional treatment? How should aerobic (A) or anoxic/anaerobic (B) processes be implemented? How difficult is it to gain acceptance of biological treatment processes when compared to conventional treatment? What do you think is the likelihood of acceptance for anoxic or anaerobic biological treatment processes for perchlorate/nitrate removal in drinking water treatment plants within the next 5 to 7 years? What do you think are the most significant barriers to acceptance of any type of biological treatment process in drinking water treatment plants? What do you think are the most significant barriers to future acceptance of anoxic or anaerobic biological treatment process (e.g., for treatment of perchlorate or nitrate) in drinking water treatment plants? What methods do you think will be most helpful to gain acceptance of biological treatment processes? How will additional research promote acceptance of aerobic (A) or anoxic/ anaerobic (B) biological processes for drinking water? In your own opinion, list research priorities for biological drinking water treatment Choose up to three contaminants that you believe are especially suitable for removal by aerobic biological treatment Choose up to three contaminants that you believe are especially suitable for removal by anoxic/anaerobic biological treatment Choose up to three contaminants that you believe are especially suitable for removal by conventional treatment xi

14 xii Biological Drinking Water Treatment Perceptions and Actual Experiences in North America 4.16 With respect to finished water quality, compare aerobic (A) and anoxic/ anaerobic (B) biological processes to conventional treatment processes Characterize each process with respect to the required level of effort In your own opinion, how significant are the following operational concerns associated with any type of biological treatment process? Does your agency prohibit biological treatment processes for drinking water? How many drinking water plants are currently permitted in your state that include the following processes? Are there any special permits or approvals required for the following biological treatment processes? What are the requirements for operation of each process? Does your agency require a higher plant operator classification for biological processes as compared to conventional treatment processes? Are you aware of any requirement for a disinfectant residual such as free chlorine downstream of any biological process? Does your agency have guidance documents for the design of biological processes? Percentage of consultants, academics, and vendors having conducted at least 1 project for each project type and process type Percentage of consultants, academics, and vendors having conducted at least 10 projects for each project type and process type What pre-design studies do you typically perform on drinking water treatment projects? What types of guidance documents do you use for designing the following drinking water treatment processes? For each type of treatment process, what do you as a consultant consider to be a typical unit cost range (in $US/gallons per day, $/gpd) for estimating the normalized capital cost for the biological treatment process component? For each type of treatment process (i.e., each row), what do you as a consultant consider to be a typical or rule-of-thumb unit cost range (in $US/million gallons, $/mg) for estimating the normalized operating and maintenance costs for the biological treatment process? What is the capacity for this water treatment plant?...32

15 List of Figures xiii 4.33 What is the population served for this water treatment plant? What type of water source(s) is used for this treatment plant? a Characterize the average source water quality for this water treatment plant for the following parameters b Characterize the average source water quality for this water treatment plant for the following parameters Distribution of water treatment plants based on the process selection decision tree Was the biological water treatment process designed as a "managed" or "incidental" process? Choose one or more contaminants removed by the aerobic biological process Choose one or more contaminants removed by the anoxic/anaerobic biological process How does the biological drinking water treatment process impact water quality in the distribution system? What is your final disinfectant? What dose do you need to achieve your target disinfectant residual? What is your target disinfectant residual leaving the plant? What type of wash water is used to backwash the biological water treatment process? What is the average backwash frequency for the process? Choose one or more approaches currently used to produce biologically stable water leaving the plant Choose one or more approaches currently used to maintain biologically stable water in the distribution system What tools or water quality parameters are used or should be used to monitor and control the biological process? Does having a biological process trigger the need for additional plant operators over a conventional treament process? Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes?...44

16 xiv Biological Drinking Water Treatment Perceptions and Actual Experiences in North America 4.51 What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? What percent of the time is the biological water treatment process in continuous operation? How is performance of the biological water treatment process impacted by taking it off-line for an extended period (i.e., > 1 week)? List three source water quality parameters that most significantly impact performance of the biological process What plant operating conditions impact performance of the biological process? How significant are the following operational concerns for your biological treatment process? Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? Based on plant operations, what is the optimal ozone dose or ozone: TOC ratio for optimizing biological filtration performance? What is the empty bed contact time for the GBA process? How was the RBF process introduced into the water treatment process train? What treatment processes were considered or are being used for perchlorate and nitrate treatment for meeting water quality and treatment objectives Organization of Biological Processes for Drinking Water Treatment...74

17 FOREWORD The Water Research Foundation (Foundation) is a nonprofit corporation that is dedicated to the implementation of a research effort to help utilities respond to regulatory requirements and traditional high-priority concerns of the industry. The research agenda is developed through a process of consultation with subscribers and drinking water professionals. Under the umbrella of a Strategic Research Plan, the Research Advisory Council prioritizes the suggested projects based upon current and future needs, applicability, and past work; the recommendations are forwarded to the Board of Trustees for final selection. The Foundation also sponsors research projects through the unsolicited proposal process; the Collaborative Research, Research Applications, and Tailored Collaboration programs; and various joint research efforts with organizations such as the U.S. Environmental Protection Agency, the U.S. Bureau of Reclamation, and the Association of California Water Agencies. This publication is a result of one of these sponsored studies, and it is hoped that its findings will be applied in communities throughout the world. The following report serves not only as a means of communicating the results of the water industry's centralized research program but also as a tool to enlist the further support of the nonmember utilities and individuals. Projects are managed closely from their inception to the final report by the Foundation's staff and large cadre of volunteers who willingly contribute their time and expertise. The Foundation serves a planning and management function and awards contracts to other institutions such as water utilities, universities, and engineering films. The funding for this research effort comes primarily from the Subscription Program, through which water utilities subscribe to the research program and make an annual payment proportionate to the volume of water they deliver and consultants and manufacturers subscribe based on their annual billings. The program offers a cost-effective and fair method for funding research in the public interest. A broad spectrum of water supply issues is addressed by the Foundation's research agenda: resources, treatment and operations, distribution and storage, water quality and analysis, toxicology, economics, and management. The ultimate purpose of the coordinated effort is to assist water suppliers to provide the highest possible quality of water economically and reliably. The true benefits are realized when the results are implemented at the utility level. The Foundation's trustees are pleased to offer this publication as a contribution toward that end. Roy Wolfe, Ph.D. Chair, Board of Trustees Water Research Foundation Robert C. Renner, P.E. Executive Director Water Research Foundation xv

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19 ACKNOWLEDGMENTS The authors gratefully acknowledge the input and guidance from the Project Advisory Committee (PAC) which included Eva Nieminski (Utah Department of Environmental Quality), Mark LeChevallier (American Water), Anne Camper (Montana State University) Ed Bouwer (Johns Hopkins University) and Jan Kool (HGL). We also appreciate very much the support of the Water Research Foundation project manager John Albert and early project support from Frank Blaha of the Foundation. This project was co-funded by the Department of Defense Environmental Security Technology Certification Program (ESTCP) and we gratefully acknowledge the support of Jeff Marqusee and Andrea Leeson of ESTCP. The authors appreciate the help of the following CDM staff: Charlie Anderson, June Gibbs, Carl Johnson, Pam Salter, Shilpa Shivakumar, Amy Skerly, and Jacqueline Wesley. We express our gratitude to all of the people who took the time to complete the on-line survey. In addition, we would like to specifically acknowledge the additional time and effort contributed by the following people and organizations in participating in the telephone surveys: Jess Brown, Carollo Engineers, Sarasota, Florida Johanna Castro, Santa Clara Valley Water District, San Jose, California Jeff Davidson, Ohio EPA, Dayton, Ohio Richard Haberman, California Department of Public Health, Fresno, California Julie Hunt, Arlington Water Utilities, Arlington, Texas Johanna Léger, Veolia Eau, Saint Maurice, France David Leland, Oregon Health Division, Portland, Oregon Catherine Ma, California Department of Public Health, Richmond, California Doug Meyer, Virginia Department of Health, Henrico, Virginia Russell Navratil, Henrico y Water Treatment Facility, Henrico, Virginia Tim Sherman, City of Salem, Oregon Gary Stolarik, Los Angeles Department of Power and Water, Los Angeles, California Jeff Swertfeger, Greater Cincinnati Water Works, Cincinnati, Ohio Jeffrey Vogt, Greater Cincinnati Water Works, Cincinnati, Ohio xvii

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21 EXECUTIVE SUMMARY OBJECTIVES This report presents the results of a research project jointly funded by the Water Research Foundation and the Department of Defense (DoD) Environmental Security Technology Certification Program (ESTCP). In general, the Foundation s interest was focused on use of biological drinking water treatment to produce biologically stable water. The DoD ESTCP was particularly interested in the acceptance of anoxic biological drinking water processes for treatment of perchlorate. The research project involved an electronic survey and follow-up case studies. The joint objectives of this research project were to: Quantify and characterize the use of biological drinking water treatment in North America. Identify challenges and solutions with regard to technology acceptance. Characterize various types of biological treatment processes with respect to design, operations, and performance. Identify methods by which acceptance and use of biological treatment of drinking water can be increased. BACKGROUND Increasing demands for high quality drinking water result in the need for treatment technologies that are capable of meeting these demands in a cost-effective manner. Biological drinking water treatment is one technology that has the potential to address many of these needs. This technology is based on the ability of microorganisms specifically non-pathogenic bacteria to efficiently catalyze the biochemical oxidation or reduction of drinking water contaminants and produce biologically stable water (i.e., finished water that does not support growth of microorganisms in the distribution system). Biological drinking water treatment is often used in combination with other chemical and chemical processes including ozonation and filtration. It is not new, but the awareness of this technology is limited. Additionally, many questions remain regarding its applicability, capabilities, reliability, and safety of the technology. Increased acceptance and use of biological drinking water treatment is dependent on answering these questions. APPROACH An on-line electronic survey and telephone interviews were used to gather data. The online electronic survey included general questions directed toward all recipients, specific questions directed toward individual professional groups, and optional case study questions. The electronic survey was web-based and designed to gather perceptions and direct experience regarding biological drinking water treatment use and acceptance. Perspectives and experiences of different professional groups were of interest and survey recipients included utility, regulator, consultant, academic, and vendor professionals. xix

22 xx Biological Drinking Water Treatment Perceptions and Actual Experiences in North America All survey recipients were given an opportunity to provide case studies on pilot-scale or full-scale biological drinking water treatment systems. A decision tree was used to ascertain what general type of drinking water treatment process was being used and whether it was conventional or biological. Standard terminology for biological treatment processes was developed and used in this assessment. The biological treatment process categories included ozone-enhanced biological filtration (OEBF), rapid biological filtration (RBF), granular activated carbon biological adsorption (GBA), slow biological filtration (SBF), and biological perchlorate/nitrate processes (BPNP). Once the case study processes were categorized, several questions were asked. Additional case studies were conducted via telephone interviews and multiple stakeholders were interviewed including utility managers and operators, regulators, and consultants in order to obtain multiple perspectives. RESULTS/CONCLUSIONS Biological treatment is of great interest to the drinking water industry based on the response to this survey. However, the perceived use and acceptance of biological drinking water treatment varied greatly among different professional groups. Utility and regulatory professionals believed biological drinking water treatment was used to a much lesser extent than consultant and academic professionals. The differences in perception among different professionals appear to be attributable to varying degrees of awareness and/or appreciation of the process that is compounded by a lack of standard process definitions and terminology. Clearly there is a need for standardization of terminology and process definitions in the field of biological drinking water treatment. Also, the divergence of opinions and the high level of Don t responses suggest a lack of a shared knowledge base and a need for educational outreach efforts. People are drawing conclusions based on different understandings of the processes, which are shaped by a lack of information, rather than the processes themselves. With respect to acceptance of biological processes, utility and regulator professionals weighed public health protection very strongly compared to other concerns, for example environmental footprint. Consultant and academic professionals believed biological processes are safe and demonstrated a greater willingness to embrace their use. Nevertheless, most professionals in all groups considered acceptance of biological drinking water treatment to be low and not easy to increase when compared to conventional treatment. Utility professionals considered permitting and regulations, public perception, insufficient full-scale experience, potential public health risks, reliance on/use of microorganisms, and operator training/certification to be the most significant barriers. Of these potential barriers, insufficient full-scale experience was most consistently considered by all professionals to be the most significant issue. The lack of a unified understanding and definition of biological drinking water treatment can also be considered as a potential barrier to acceptance. Most professionals in all categories considered the need for more full-scale systems, regulatory acceptance documents, and industry research to be effective tools for overcoming acceptance barriers. Research was also listed as having a high impact on technology acceptance and contaminant removal was most frequently cited as a research priority followed by safety. Research into contaminant removal was considered to be particularly important with respect to high profile contaminants such as endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care products (PPCPs).

23 Executive Summary xxi Based on responses from the general survey, aerobic biological treatment was considered most suitable for treatment of assimilable organic carbon (AOC), biodegradable dissolved organic carbon (BDOC), total organic carbon (TOC) and DBP disinfection by-product (DBP) precursors, and taste and odor compounds. Anoxic biological drinking water treatment was considered most suitable for treatment of perchlorate, nitrate, and nitrite. Conventional drinking water treatment was considered most suitable for treatment of iron/manganese, turbidity/particle counts, and heterotrophic bacteria/total coliforms, but also for TOC/DBP precursors, taste and odor compounds, and color. Finished water generated by biological processes was generally considered by professionals to be not equivalent to that generated by conventional processes. On the other hand, the case studies indicated that biological drinking water treatment processes are capable of treating a broader group of contaminants and with better performance than is perceived by many professionals in the general survey. Removal of TOC and DBP precursors, AOC/BDOC, taste and odor compounds, iron/manganese, turbidity/particle counts, and color was shown to be greater in the aerobic biological treatment case studies relative to the general survey perceptions. In addition, removals of many of these constituents were similar to or better than removals by conventional treatment processes. Perceptions and reality were more consistent for anoxic biological treatment processes. Perchlorate, nitrate, and nitrite were considered most suitable for removal by this process both in the general survey and in the case studies. In general the case studies indicated that biological processes had positive or neutral effects on finished water quality. Very few negative effects were observed. Positive perspectives from the survey respondents who completed the case studies contrast to the less positive perspectives of the drinking water industry observed in the general survey. The levels of operational concerns for biological drinking water treatment expressed in the case studies were generally none, low, or moderate. The general survey responses indicated greater operational concerns further illustrating the gap between perceived and actual concerns of biological treatment the concerns were perceived to be greater than they are in reality. In the general survey, perceived operational concerns associated with biological drinking water treatment included bacterial sloughing/breakthrough, pathogen or contaminant breakthrough, and unknown/changing regulatory conditions. These concerns were considered to be significant by all professional groups including regulatory professionals. Operational strategies including backwashing varied widely among the case studies indicating that generalizations regarding operations may not be possible based on the current understanding of the processes. A lack of direct monitoring of biological process parameters (e.g., bacterial concentrations or activity) complicates the development of operational guidelines because the necessary data are not being collected. Significant uncertainty among utility professions existed with respect to design, operations and maintenance, training, staffing, and regulatory requirements for biological drinking water treatment. Electronic case study survey questions were designed to determine the general type of drinking water treatment process being used. The process selection decision tree used in this determination was a useful means of categorizing biological drinking water treatment processes (i.e., OEBF, RBF, GBA, SBF, BPNP). Based on the telephone case studies biological drinking water treatment is being used in numerous locations across North America and Europe. The manner in which it is implemented and used varies:

24 xxii Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Incidental approach (e.g., discontinuing chlorine upstream of a filter to reduce DBPs). Managed approach (e.g., design and operate the process with the intent of optimizing or promoting biological activity). Biological processes have not been optimized within many, if not most, of the treatment plants underlining the need for monitoring and control tools. There is a significant opportunity for improving the removal of regulated and un-regulated substances. Nevertheless, performance of these biological processes was generally good and provided high quality finished water in the distribution system. Generally, problematic operational issues were not encountered. Therefore, these telephone case studies confirmed and expanded upon the positive attributes of biological drinking water treatment identified in the electronic case studies. APPLICATIONS/RECOMMENDATIONS Utilities should consider re-assessing the role of biological processes for optimizing their treatment plants. First, use the process selection decision tree developed for this survey to categorize the drinking water treatment process. Second, develop an applied understanding of biological treatment processes and microbiology to increase awareness. With this enhanced understanding utilities will be in a better position to monitor beneficial biological processes in their plants and assess the biological significance of these processes. Third, determine what monitoring and control tools merit use for biological process optimization. Fourth, consider completing case studies, papers, and presentations on the process. Education and outreach is highly recommended with a particular focus on benefits, technology acceptance, design considerations, operational requirements, and performance. For those utilities that do not currently have a biological treatment process, consider the potential benefits of biological treatment and identify retrofits or changes in operational procedures that would be required to initiate biological treatment. Additional recommendations include: Develop additional case studies on aerobic drinking water treatment plants with a focus on dispelling many of the misconceptions about biological drinking water treatment. As full-scale anoxic BPNP plants are commissioned in the U.S., case studies should be developed to detail technology performance for drinking water treatment. Develop regulatory acceptance documents for biological drinking water treatment. Create clear and consistent terminology and process definitions for biological drinking water treatment. The terms used in this report (OEBF, RBF, GBA, SBF, and BPNP) may be used as an initial platform for development of such terminology. Continue and expand biological drinking water treatment research in the areas of contaminant removal, safety, and monitoring and control. Develop new on-line monitoring tools and laboratory methods to optimize biological treatment processes in full-scale operation.

25 Executive Summary xxiii Expand education and outreach efforts to familiarize drinking water professionals with the benefits of biological drinking water treatment and to assuage perceived technology acceptance concerns. RESEARCH PARTNERS This project was co-funded by the Department of Defense Environmental Security Technology Certification Program (ESTCP). PARTICIPANTS In addition to the hundreds of people who took the time to complete the on-line survey, the following organizations contributed valuable information and time for the telephone case studies: Arlington Water Utilities California Department of Public Health Carollo Engineers City of Salem, Oregon Greater Cincinnati Water Works Henrico y Water Treatment Facility Los Angeles Department of Power and Water Ohio EPA Oregon Health Division Santa Clara Valley Water District Veolia Eau Virginia Department of Health

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27 CHAPTER 1 INTRODUCTION Increasing demands for high quality drinking water result in the need for treatment technologies that are capable of meeting these demands in a cost-effective manner. Awareness of the health risks associated with endocrine disrupting compounds (EDCs) including pharmaceutical and personal care products (PPCPs) has brought a sense of urgency. In addition to desiring drinking water treatment processes to be more cost-effective, there is a growing demand that these processes be more energy efficient and more sustainable. Biological drinking water treatment is one technology that has the potential to further many of these objectives. This technology is based on the ability of microorganisms specifically non-pathogenic bacteria to efficiently catalyze the biochemical oxidation or reduction of drinking water contaminants and produce biologically stable water (i.e., finished water that does not support growth of microorganisms in the distribution system [Rittmann and Snoeyink, 1984]). Biological drinking water treatment is often used in combination with other chemical and chemical processes including ozonation and filtration. It is not new, but the awareness of this technology is limited. Additionally, many questions remain regarding the applicability, capabilities, reliability, and safety of biological treatment processes. Greater acceptance and increased use of biological drinking water treatment is dependent on answering these questions. This report presents the results of a research project jointly funded by the Water Research Foundation and the Department of Defense (DoD) Environmental Security Technology Certification Program (ESTCP). In general the Foundation s interest was focused on use of biological drinking water treatment to produce biologically stable water. The DoD ESTCP was particularly interested in the acceptance of anoxic biological drinking water processes for treatment of perchlorate. The research project involved an electronic survey and follow-up case studies. The joint objectives of this research project were to: Quantify and characterize the use of biological drinking water treatment in North America. Identify challenges and solutions with regard to technology acceptance. Characterize various types of biological treatment processes with respect to design, operations, and performance. Identify methods by which acceptance and use of biological treatment of drinking water can be increased. 1

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29 CHAPTER 2 OVERVIEW OF BIOLOGICAL DRINKING WATER TREATMENT HISTORY AND IMPETUS FOR USE Biological drinking water treatment processes involve the use of non-pathogenic bacteria to remove contaminants from water. These processes have been used since the 1800s in the form of slow sand filtration and possibly as early as 4000 B.C.E. in the form of carbon filtration (U.S. EPA, 2000). Biological drinking water treatment processes originating with slow sand filtration appear to have originated in Europe but are now used in North America and elsewhere. These original processes are fundamentally based upon physical filtration, but rely on biological activity to supplement and enhance the physical removal process. An important distinction between biological and conventional treatment processes that include filtration in the process train is the maintenance of a disinfectant residual throughout filter. If a disinfectant is not used upstream of a filter, or if the disinfectant dose is sufficiently low to prevent a disinfectant residual at the filter outlet, then it is likely that heterotrophic bacteria will grow in the form of a biofilm on at least part of the filter bed. These bacteria are most commonly nonpathogenic bacteria that can beneficially enhance filter performance (Burr et al., 2000). The same concepts apply to granular activated carbon (GAC) contactors where bacterial biofilms will grow on the GAC media in the absence of a disinfectant residual. These bacteria can also enhance performance of these contactors, and potentially extend the adsorptive capacity of the GAC media through removal of biodegradable organic compounds. The impetus for use of biological drinking water treatment processes is to produce high quality water in a cost-effective and sustainable manner. To list a few benefits, biological treatment processes can: Increase water stability in the distribution system by reducing assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC), Reduce the potential for disinfection by-products (DBPs) by reducing dissolved organic carbon (DOC) concentrations, Remove specific contaminants such as nitrate and perchlorate, and Possibly decrease costs and/or environmental footprint by reducing energy requirements. For the past two to three decades, ozonation has been implemented in combination with biological filtration the latter for removing BDOC generated by the ozonation process to reduce the risk of DBP formation and biofilm regrowth in the distribution system. Even more recently full-scale anoxic processes for biological destruction of nitrate and perchlorate in groundwater and production of drinking water are being implemented in the U.S. Many if not most of these processes involve a combination of physical, chemical, and biological contaminant removal mechanisms and are not solely biological treatment processes. Rather, biological removal mechanisms are an integral part of the overall drinking water treatment process. 3

30 4 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America GENERAL TYPES OF PROCESSES Many different processes have been developed and implemented for biological drinking water treatment and have been described previously (Bouwer and Crowe, 1988; Urfer et al., 1997; Weiss et al., 2004). These processes are summarized below and were included in the utility survey developed under this project. Slow Sand Filtration Slow sand filtration involves very low filtration rates (e.g., 0.04 to 0.10 gpm/ft 2 ) through sand media without pre-oxidation or pre-disinfection (ASCE and Awwa, 2005). During initial operation of these filters, the separation of organic matter and other solids generates a layer of biological matter on the surface of the filter media. Once established, this layer is the predominant filtering mechanism. This top biologically active layer is called the schmutzdecke. The schmutzdecke supports the biological matter that works as the primary biofiltration process to remove BDOC, pathogenic microorganisms, and particulates (Page et al., 2006). Maintenance involves periodic scraping and removal of the top layer of sand. Since the biologically active schmutzdecke is an integral part of this process, slow sand filtration might be more accurately called slow biological filtration (SBF), which is the term used in this report. Rapid Biological Filtration (RBF) Rapid biological filtration involves use of granular media (e.g., sand, anthracite) and a relatively high surface loading rate of 2 to 10 gpm/ft 2 (ASCE and Awwa, 2005). Operation involves either exclusive addition of a disinfectant downstream of the filter or limitation of upstream disinfection to prevent maintenance of a disinfectant residual through the filter bed. Bacteria grow as a biofilm on the media throughout the filter bed depth rather than as a schmutzdecke on top of the filter. The filters can be designed to operate in gravity or pressure modes. Coagulants or flocculants may be added upstream of the RBF. The RBF can either be operated in direct filtration mode or a sedimentation process can be included between the coagulation/flocculation and RBF processes. A pre-oxidant such as permanganate or ozone can be used and use of ozone is specifically addressed below. Ozone-Enhanced Biological Filtration (OEBF) Ozone-enhanced biological filtration is a subset of RBF and involves ozonation to oxidize natural organic matter (NOM) in order to make it amenable to biodegradation in the RBF (Westerhoff et al., 2005). Ozone can also precede the granular activated carbon biological adsorption (GBA) process described below. Biological filtration downstream of ozonation is often practiced since the ozonation process generates BDOC and AOC that could stimulate regrowth in the distribution system if not reduced. Over 300 ozone systems are currently in operation in the U.S. for producing drinking water; the majority of these include a post-ozone biological filtration step so are defined in this report as OEBF systems.

31 Chapter 2: Overview of Biological Drinking Water Treatment 5 Granular Activated Carbon Biological Adsorption (GBA) GAC is well known and widely used for removal of DOC in general and specific organic contaminants. GAC also supports biofilm growth and may support higher bacterial concentrations than sand or anthracite. GBA involves integration of both physical adsorption and biodegradation processes to increase the overall removal of DOC and/or specific contaminants. GBA can also extend the adsorptive capacity and service life of GAC by relying on the bacterial population within the bed to remove BDOC, thereby decreasing change-out frequency of the GAC bed and associated costs. Biological Perchlorate/Nitrate Process (BPNP) Perchlorate and nitrate are capable of being anoxically or anaerobically biodegraded to chloride and nitrogen gas, respectively. The process involves addition of an electron donor such as acetic acid (i.e., vinegar) plus nutrients (e.g., phosphate) to water to promote biochemical reduction of perchlorate and/or nitrate. Perchlorate and nitrate serve as the terminal electron acceptors for respiration by these bacteria. Thus BPNP differs from the preceding biological drinking water treatment processes that are aerobic and employ aerobic bacteria that use oxygen as a terminal electron acceptor for respiration. BPNP can be employed in various configurations including packed beds, fluidized beds, and membrane systems. BPNP is followed by an aeration process to promote aerobic biodegradation of BDOC/AOC in combination with a filtration process (e.g., RBF) to remove turbidity. Other Processes Variations and combinations of the above processes are possible. In addition, riverbank filtration is used for treatment of surface water (Weiss et al., 2004).

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33 CHAPTER 3 METHODS GENERAL APPROACH An on-line electronic survey and telephone interviews were used to gather data. The online electronic survey included general questions directed toward all recipients, specific questions directed toward individual professional groups, and optional case study questions. Telephone interviews were used to develop more detailed case studies. ELECTRONIC SURVEY The electronic general survey was web-based and designed to gather perceptions and direct experiences regarding biological drinking water treatment use and acceptance. Perspectives and experiences of different professional groups were of interest and survey recipients included utility, regulator, consultant, academic, and vendor professionals. A list of survey recipients was compiled from multiple information sources including the U.S. EPA Safe Drinking Water Information System (SDWIS), the Interstate Technology & Regulatory Council (ITRC) Perchlorate Team, and institutional knowledge of practitioners and experts in the field. The following approach was used to communicate with the identified recipients: Formal letter sent to all identified potential respondents with a participation request and link to survey. The letter highlighted the importance of the survey, identified survey sponsors, and provided a web site for survey access. Follow-up postcard reminder sent to all identified targeted contacts two weeks after initial letter mailing. Another follow-up postcard reminder sent to all identified targeted contacts two weeks after the first post-card reminder. requests sent to all targeted contacts for which we had addresses. The requests provided information similar to the initial letter request. In addition, advertisement of the survey was conducted using various forums including the Water Research Foundation website, the ESTCP website, the CDM website, and Safe Drinking Water News. The total number of targeted survey recipients was 4,186 including 3,905 U.S. utilities and 23 international utilities. The remaining recipients included 91 regulators, 71 consultants, 47 DoD and industry professionals, 37 academics, and 12 vendors. The survey was implemented using the commercial web-based survey tool Survey Monkey. The survey was launched in May 2008 and taken off-line in June

34 8 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America General Electronic Survey Questions The complete survey is included in Appendix A. Questions directed to all survey recipients covered the following topics: General information on the respondents profession and geographic location. Use and acceptance of biological drinking water treatment. Barriers to acceptance including technical and regulatory aspects and methods for overcoming these barriers. Research needs. Perceptions on the ability of biological drinking water treatment to remove specific contaminants and provide high quality finished water. Level of effort required for design and operations. In addition to general location and profession questions, the basic (no case study) survey included 24 questions for consultants/academics/vendors, 16 questions for utility/dod representatives, and 22 questions for regulatory agencies representatives. Although some of the questions among these three groups were the same, other questions were based upon the survey recipient s self-identified professional area. For example, regulatory professionals were specifically asked additional questions addressing the topic of regulatory acceptance and permit requirements. Consultant, academic, and vendor professionals were specifically asked additional questions addressing the following topics: Experience with biological drinking water treatment. Tools and resources used to design systems. Technology costs. Electronic Survey Case Studies With the exception of respondents who represented the regulatory community, all survey recipients were given an opportunity to provide case studies on pilot-scale or full-scale biological drinking water treatment systems. First the design and operating capacity of the plant was determined along with source water characteristics. We hypothesized that some respondents offering to provide case studies may not be aware that they are using a biological drinking water treatment process. Therefore, a decision tree was used to ascertain what general type of drinking water treatment process was being used (Figure 3.1). The first question in the decision tree addressed whether an anoxic process for treating perchlorate or nitrate (BPNP) was being used. If the answer was yes the respondent was directed toward the BPNP survey questions. If the answer was no, then the process was either an aerobic biological drinking water treatment process or a conventional process. The next question was used to determine whether the process was one of these two categories. Maintaining a disinfectant residual across the filter or contactor was used as the basis for selection. If a disinfectant residual was maintained across the filter or contactor the process was concluded to be conventional and no additional case study questions were asked of the respondent (the respondent was given the opportunity to provide another case study however). If a disinfectant residual was not maintained across the filter or contactor the

35 Chapter 3: Methods 9 Figure 3.1 Drinking water treatment process selection decision tree process was concluded to be an aerobic biological drinking water treatment process. The remaining questions in the decision tree were used to determine which general type of aerobic biological drinking water treatment process was being used as illustrated in Figure 3.1. Once the case study processes were categorized several questions were asked. Many of the questions were common to all of the processes and included the following topics: Process implementation was the process managed or incidental? Capability and performance with regard to removal of specific contaminants.

36 10 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Finished water quality. Design and operations considerations. Monitoring strategies. Process stability. Operational concerns. Process-specific questions (e.g., ozone dose for OEBF process). TELEPHONE CASE STUDIES Additional case studies were conducted via telephone interviews and the following utilities practicing biological drinking water treatment and associated stakeholders were interviewed: Arlington Water Utilities California Department of Public Health Carollo Engineers City of Salem, Oregon Greater Cincinnati Water Works Henrico y Water Treatment Facility Los Angeles Department of Power and Water Ohio EPA Oregon Health Division Santa Clara Valley Water District Veolia Eau Virginia Department of Health In addition to evaluating multiple biological drinking water treatment processes (i.e., SBF, RBF, GBA, OEBF, and BPNP), multiple stakeholders were interviewed including utility managers and operators, regulators, and consultants in order to get a variety of perspectives. Interviews focused on selection, implementation, and operation of the process from technology acceptance, design and operations, and performance perspectives.

37 CHAPTER 4 ELECTRONIC SURVEY RESULTS AND DISCUSSION This section presents results of the electronic survey including electronic case studies. Supplemental figures and tables including complete survey responses are presented in Appendix B. ELECTRONIC SURVEY DEMOGRAPHICS Out of the 4,186 people who were directly contacted about the survey, 467 people completed at least one of the technology acceptance questions for an overall response rate of 11 percent. Figure 4.1 illustrates the number of responses and the response rate by profession. Utility professionals represented the greatest number of responses (N=357) with an overall response rate of nine percent. Other professional groups had fewer representatives but the response rates were greater and ranged from 28 to 59 percent. In part because utilities represented the majority of survey respondents, survey results for each professional category were determined individually. s % 60% 50% 40% 30% 20% 10% 0% Rate s Rate Figure 4.1 Survey response statistics The results of this survey are mainly representative of North American experience and perceptions. Survey respondents were primarily from the U.S. with only eleven international respondents. Figure 4.2 illustrates that geographic response across the U.S. was well distributed and all states except Montana were represented. Eighteen states had ten or more respondents. Internationally, Canada (N=5), The Netherlands (N=3), Germany (N=1), Italy (N=1), and Switzerland (N=1) were represented. 11

38 12 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Figure 4.2 U.S. survey demographics USE AND ACCEPTANCE OF BIOLOGICAL TREATMENT Use and Acceptance among Different Professions Assessing the actual use of biological drinking water treatment is complicated by the fact that concrete definitions of this process do not exist. Additionally, biological drinking water treatment is typically not a distinct process rather it is an integral component of another process such as granular media filtration or GAC adsorption. These considerations can lead to a wide array of opinions regarding the extent of biological drinking water treatment use as illustrated in Figure 4.3. These opinions can be based on varying degrees of scientific understanding of the process, varying levels and type of experience in the drinking water industry and varying perceptions of what constitutes biological drinking water treatment. Half or more of academic and consulting professionals believe the extent of aerobic biological drinking water use is wideto-moderate compared to about ten percent of utility and regulator professionals (Figure 4.3a). Clearly, the utility/regulator professionals have vastly different perceptions regarding the use of aerobic biological drinking water treatment when compared to the academic/consultant professionals. Anoxic biological drinking water treatment, on the other hand, is generally considered to be used to a limited extent or not at all (Figure 4.3b). Acceptance of biological drinking water treatment is a wide arching and important topic relevant to increasing technology use. Acceptance involves multiple stakeholders including various utility professionals (managers, engineers, operators, etc.), regulators, consultants, and the general public. These and other stakeholders have varying criteria with which they use to determine acceptance of any technology. An overarching criterion is public safety. Nevertheless, broad technology acceptance by all stakeholders is necessary to increase use.

39 Chapter 4: Electronic Survey Results and Discussion 13 ACADEMICS A: Aerobic VENDORS B: Anoxic CONSULTANTS DoD VENDORS CONSULTANTS DoD UTILITIES UTILITIES REGULATORS REGULATORS ACADEMICS 0% 20% 40% 60% 80% 100% 0% 20% 40% 60% 80% 100% Moderate to Wide Use No to Limited Use Figure 4.3 Characterize the extent to which aerobic (A) and anoxic (B) biological water treatment processes are used. The survey results clearly indicate that biological drinking water treatment is generally not accepted on an equal basis with conventional treatment (Figure 4.4). Interestingly, utility professionals rated technology acceptance the highest of all groups even though they considered biological drinking water treatment to be used only to a limited extent or not at all (Figure 4.3a). Significant numbers of utility, regulator, and DoD professionals also were uncertain with respect to the issue of acceptance (i.e., answered Don t know). Utilities Consultants Regulators Academics DoD Vendors 0% 20% 40% 60% 80% 100% Yes know No Figure 4.4 Do you believe that biological water treatment processes are generally accepted by the drinking water industry, i.e., the same as conventional treatment? Barriers to Acceptance Lack of technology acceptance and uncertainty with respect to the potential for acceptance are understandable impediments to increased technology use. Understanding the reasons for not accepting biological drinking water treatment is important with respect to increasing acceptance. Figure 4.5 clearly illustrates the different perspectives of utility/regulator compared to academic/consultant/vendor professionals. Utilities and regulators take a conservative viewpoint because of their responsibilities for protection of human health and possibly because of uncertainty regarding technology performance. Academics and consultants, on the other hand, believe biological drinking water treatment is safe and offers a green upside and should be implemented preferentially. Similar patterns were observed for aerobic and anoxic processes.

40 14 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America VENDORS ACADEMICS CONSULTANTS DoD UTILITIES REGULATORS A: Aerobic VENDORS ACADEMICS CONSULTANTS DoD UTILITIES REGULATORS B: Anoxic/Anaerobic 0% 20% 40% 60% 80% 100% 0% 20% 40% 60% 80% 100% implemented preferentially since they represent a green technology implemented cautiously due to concerns over uncertain public health impacts Figure 4.5 How should aerobic (A) or anoxic/anaerobic (B) processes be implemented? When asked a question regarding the level of difficulty for gaining acceptance of biological drinking water treatment, consultant and regulator professionals responses were similar and indicated that it was moderate to difficult (Figure 4.6). These answers contrast to utility professionals where nearly half of the respondents did not know. Very few professionals in any group considered gaining acceptance easy. Academic and vendor professionals considered gaining acceptance the most difficult. In contrast, when asked what the likelihood of gaining acceptance for anoxic biological drinking water treatment within the next 5 to 7 years, professional groups are more optimistic regarding technology acceptance (Figure 4.7). For example, almost twice as many utility and consultant professionals considered the likelihood of gaining acceptance for anoxic biological drinking water treatment acceptance strong to moderate (Figure 4.7) compared to the numbers of these same professionals who thought gaining acceptance of any type of biological drinking water treatment (i.e., aerobic or anoxic) was easy to moderate (Figure 4.6). This result was unexpected since aerobic biological drinking water treatment is already in use in North America, whereas no permitted anoxic perchlorate or nitrate biological drinking water treatment systems currently exist. Nevertheless, this result is encouraging and suggests that many professionals are becoming increasingly aware and sophisticated with regard to emerging biological drinking water treatment technologies such as anoxic biological nitrate and perchlorate treatment. ACADEMICS VENDORS CONSULTANTS REGULATORS UTILITIES DoD 0% 20% 40% 60% 80% 100% Easy Moderate Difficult know Figure 4.6 How difficult is it to gain acceptance of biological treatment processes when compared to conventional treatment?

41 Chapter 4: Electronic Survey Results and Discussion 15 VENDORS ACADEMICS CONSULTANTS DOD REGULATORS UTILITIES Strong likelihood Not likely 0% 20% 40% 60% 80% 100% Moderate likelihood Don t know Figure 4.7 What do you think is the likelihood of acceptance for anoxic or anaerobic biological treatment processes for perchlorate/nitrate removal in drinking water treatment plants within the next 5 to 7 years? Many potential barriers to technology acceptance exist and survey recipients were given eleven options to consider as indicated in Figure Data presented in this figure were consolidated from detailed data presented in Appendix B. The survey results indicate a lack of consensus among the different professions. In addition, the prevalence of hollow symbols indicates a lack of consensus within each profession. With respect to general biological drinking water treatment (Figure 4.8), utility professionals considered permitting and regulations, public perception, insufficient full-scale experience, potential public health risks, and operator training/certification to be the most significant barriers. Reliance on/use of microorganisms was also considered to be a potential barrier but with less consensus. No barrier was considered by utility professionals as a group to be of low or no significance. Of these potential barriers, insufficient full-scale experience was most consistently considered by all professions to be one of the most significant barriers. Other barriers often elicited very different responses. For example, permitting and regulations were considered to be of high significance by utilities, moderate significance by consultants, and low significance by regulators. Potential public health risks were considered by utilities and regulators to be of high significance while consultants considered these risks to be low. These differences of opinions among professions can indicate a difference in priorities but also can indicate a difference in technology understanding or awareness. Thus in addition to these specific acceptance barriers, developing of a unified understanding of biological drinking water treatment can also be considered as a potential barrier to acceptance. 1 The color of the symbols represents the choice selected most frequently (e.g., High, Moderate, None to Low, or Don t know ). The type of symbol (i.e., solid or hollow) represents the degree of consensus on the selected choice within each profession. Solid symbols indicate ten or greater percentage points between the most frequently selected choice and the next choice. Hollow symbols represent less than a ten percentage point spread between the top two choices. Presence of two or more adjacent symbols represents equal response frequencies.

42 16 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Permitting and regulations Public perception Industry acceptance Design guidance or standards Not enough full-scale experience Reliability Reliance on/use of microorganisms Potential public health risks Maintenance Operator training/certification Cost UTILITIES REGULATORS CONSULTANTS Degree of Consensus High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) Rating None to Moderate Low Figure 4.8 What do you think are the most significant barriers to acceptance of any type? High Don t know Permitting and regulations Public perception Industry acceptance Design guidance or standards Not enough full-scale experience Reliability Reliance on/use of microorganisms Potential public health risks Maintenance Operator training/certification Cost UTILITIES REGULATORS CONSULTANTS Degree of Consensus High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) Rating None to Moderate Low Figure 4.9 What do you think are the most significant barriers to future acceptance of anoxic or anaerobic biological treatment process (e.g., for treatment of perchlorate or nitrate) in drinking water treatment plants? High Don t know

43 Chapter 4: Electronic Survey Results and Discussion 17 Technology acceptance barriers for future acceptance anoxic biological drinking water treatment for nitrate or perchlorate were considered to be greater when compared to biological treatment in general (Figure 4.9). Permitting/regulations and insufficient full-scale experience were consistently cited by all professions as being the most significant barriers. Utility professionals considered nearly all of the listed barriers to be highly significant. The greater significance of technology acceptance barriers for anoxic biological drinking water treatment is expected since this technology is not currently implemented at full-scale in North America. Survey recipients were given an opportunity to list any other technology acceptance issues that had not been addressed in the survey. The verbatim responses are listed in Appendix B. The most common theme in these responses was a general lack of process understanding and a desire for more education and outreach. One particular response highlighted this theme: Education and outreach about the processes is extremely important. Getting the current and future research circulated and understood by Engineers and Water System Managers/Operators is essential. This response highlights the lack of a common technical understanding among different professions as borne out by the variant responses by different professions. Overcoming Acceptance Barriers Various means of overcoming technology acceptance barriers were evaluated in the survey. Figure 4.10 illustrates that industry research, more full-scale systems, and regulatory guidance documents were considered by most professional groups to be useful tools for increasing technology acceptance. Operator training workshops/seminars were also considered by utilities to be valuable. All professional groups had firm opinions regarding which tools should be used since the rate of Don t know responses was very low. Industry research More full scale systems Operator training workshops/seminars Public education Regulatory guidance documents Don t know 0% 20% 40% 60% 80% 100% UTILITIES REGULATORS CONSULTANTS ACADEMICS VENDORS DoD Figure 4.10 What methods do you think will be most helpful to gain acceptance of biological treatment processes?

44 18 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America These results are generally consistent with the perceived barriers illustrated in Figure 4.8 with a few exceptions. Many professional groups listed public perception as being a significant barrier but public education was generally not considered to be a useful tool to overcoming this barrier. The reason is likely attributable to the general public s desire for safe water but not necessarily wanting to know the technical details about how it is treated. The different professional groups also have a vested interest and responsibility for providing safe water. Their highlighting of industry research as a tool for overcoming technology acceptance barrier is linked with a desire to focus that research on safety of biological drinking water treatment as discussed below. Therefore, the listing of public perception as a significant barrier by professional groups is more likely to be representative of the need for a safe water supply rather than public perception of biological drinking water treatment per se. Another interesting difference between perceived barriers and recommendations for overcoming these barriers was associated with the regulatory professionals. Most respondents in this group indicated that permitting and regulations were not significant barriers (Figure 4.8) yet indicated that regulatory guidance documents were needed (Figure 4.10). The apparent conflict between these responses may be attributable to the thought that sufficient regulations are in place for biological filtration but specific regulatory guidance documents are lacking. Industry research was listed as being one of the approaches to overcome technology acceptance barriers. Most professional groups listed research as having a high impact on technology acceptance (Figure 4.11). Verbatim research priorities were solicited from survey recipients and are documented in Appendix B. These verbatim research priorities were categorized as shown in Figure 4.12 where contaminant removal was the number one priority. Contaminant removal was further parsed as shown in the inset to Figure EDCs and PPCPs were the most highly ranked contaminant removal research priority followed closely by parameters associated with biological stability and DBP precursors. The second highest research need was safety. As mentioned previously, the need for safe water and protection of public health drives this research need. Don t know was the third most frequent response indicating a general lack of awareness and understanding of biological drinking water treatment. ACADEMICS VENDORS CONSULTANTS REGULATORS UTILITIES DoD A: Aerobic ACADEMICS VENDORS CONSULTANTS REGULATORS UTILITIES DoD B: Anoxic/Anaerobic 0% 20% 40% 60% 80% 100% 0% 20% 40% 60% 80% 100% High impact Medium impact Low impact know Figure 4.11 How will additional research promote acceptance of aerobic (A) or anoxic/anaerobic (B) biological processes for drinking water?

45 Chapter 4: Electronic Survey Results and Discussion 19 Contaminant removal Safety know Cost Monitoring and control Downstream treatment incl disinfection training/education Reliability Pathogens O&M Water conditions Biological Activity Public acceptance Pilot studies Full scale Residuals Finished water/ distribution system quality Clogging/backwash Potential problems Optimization Process configurations Design Water re use Nutrients As pretreatment Bench tests Flexibility Startup Low temperatures Pretreatment Bacterial sloughing Anaerobic processes EDC/PPCP TOC/AOC/NOM General DBP T&O Nitrate/nitrite Pathogens Algae, Algal toxins Iron/Manganese Particles Arsenic Ammonia MTBE Bromate Perchlorate 0% 5% 10%15%20%25% 0% 5% 10% 15% 20% 25% Figure 4.12 In your own opinion, list research priorities for biological drinking water treatment. Research will thus play an important role in increasing technology acceptance through demonstrating process safety and contaminant removal attributes. However, research alone will be insufficient to increase technology acceptance. Education and outreach are necessary to provide a common and unified understanding of biological drinking water treatment among different industry professional groups. Part of this education and outreach will include development of regulatory and technical guidance documents. Finally, full-scale systems of aerobic biological drinking water treatment are operating in North America today and case studies are a cost-effective tool to disseminate successes and challenges. Anoxic biological treatment of perchlorate and nitrate in drinking water is not practiced today in North America and thus installation of the first full-scale systems will facilitate technology acceptance. GENERAL ATTRIBUTES OF BIOLOGICAL TREATMENT Contaminant Removal Several general attributes of biological drinking water treatment were assessed in the survey and Figures 4.13 through 4.15 illustrate the opinions regarding applicable contaminants for aerobic biological treatment, anoxic biological treatment, and conventional treatment, respectively. s among the different professional groups were generally consistent.

46 20 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Aerobic biological drinking water treatment was considered most suitable for treatment of AOC/BDOC, TOC and DBP precursors, and taste and odor compounds with vendor and academic professional groups also including EDC/PPCPs (Figure 4.13). Anoxic biological drinking water treatment was considered most suitable for treatment of perchlorate, nitrate, and nitrite with academic professions also including bromate and vendors also including taste and odor compounds (Figure 4.14). Conventional drinking water treatment was considered most suitable for treatment of iron/manganese, turbidity/particle counts, and HPC bacteria/total coliforms, but also for TOC/EDC precursors, taste and odor compounds, and color (Figure 4.15). These data suggest a general technical understanding that aerobic biological drinking water treatment is most commonly used to address biological stability and that anoxic biological drinking water treatment has the potential to treat perchlorate, nitrate, and nitrite. However, certain misunderstandings also exist 20 percent or more of DoD, utility, and vendor professional groups incorrectly believed that aerobic biological treatment can remove perchlorate, nitrate, and nitrite from drinking water. The data did suggest a belief that biological processes may have promise with respect to improved treatment of EDCs/PPCPs when compared to conventional treatment processes. TOC/DBP precursors AOC/BDOC Taste and odor EDC/PPCPs Perchlorate/nitrate/nitrite Iron/manganese Turbidity/particle counts HPC bacteria/total coliform Bromate Color 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% UTILITIES REGULATORS CONSULTANTS ACADEMICS VENDORS DoD Figure 4.13 Choose up to three contaminants that you believe are especially suitable for removal by aerobic biological treatment.

47 Chapter 4: Electronic Survey Results and Discussion 21 TOC/DBP precursors AOC/BDOC Taste and odor EDC/PPCPs Perchlorate/nitrate/nitrite Iron/manganese Turbidity/particle counts HPC bacteria/total coliform Bromate Color 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% UTILITIES REGULATORS CONSULTANTS ACADEMICS VENDORS DoD Figure 4.14 Choose up to three contaminants that you believe are especially suitable for removal by anoxic/anaerobic biological treatment. TOC/DBP precursors AOC/BDOC Taste and odor EDC/PPCPs Perchlorate/nitrate/nitrite Iron/manganese Turbidity/particle counts HPC bacteria/total coliform Bromate Color 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% UTILITIES REGULATORS CONSULTANTS ACADEMICS VENDORS DoD Figure 4.15 Choose up to three contaminants that you believe are especially suitable for removal by conventional treatment.

48 22 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Finished Water Quality A biological treatment process is typically only one part of a complete process train. Other elements of the process train may include coagulation, pre-oxidation, sedimentation, disinfection, etc. Assessing the specific impacts of biological treatment on finished water quality is thus difficult. Nevertheless, survey recipients were asked to compare finished water quality attributable to biological treatment processes (i.e., aerobic and anoxic) and conventional processes (Figure 4.16). Utility, regulatory, and DoD professional groups had a wide variety of opinions but 50 percent or more did not know how these processes impacted finished water quality. About 40 percent of consultant, vendor, and academic professional groups considered finished water from aerobic biological drinking water treatment to be currently equivalent to conventionally treated water. Consultant and academic professional groups were less certain with respect to anoxic biological drinking water treatment. Contrary to the consensual understanding regarding contaminant removal, there is a lack of consensus regarding the ability of biological drinking water treatment to produce high quality finished water. ACADEMICS VENDORS CONSULTANTS REGULATORS UTILITIES DoD A: Aerobic ACADEMICS VENDORS CONSULTANTS REGULATORS UTILITIES DoD B: Anoxic/Anaerobic 0% 20% 40% 60% 80% 100% 0% 20% 40% 60% 80% 100% Currently equivalent Expected to be equivalent in 5 10 yrs Not expected to be equivalent in the near future Figure 4.16 With respect to finished water quality; compare aerobic (A) and anoxic/anaerobic (B) biological processes to conventional treatment processes. Levels of Effort Required for Design and Operations Levels of effort needed for design and operations of biological treatment were evaluated and compared to analogous needs for conventional treatment. A clear distinction between the biological processes (i.e., both aerobic and anoxic) and conventional treatment existed from the utility perspective (Figure 4.17 and Appendix B). Most utility professionals did not know what level of effort was required for design and operation of biological treatment processes with the exception of training requirements which were considered to be high. In comparison, this group considered the levels of effort needed for conventional treatment processes to be moderate. Overall these responses indicate a high level of uncertainty regarding design and operating requirements for biological drinking water treatment processes.

49 Chapter 4: Electronic Survey Results and Discussion 23 Aerobic Biological Treatment DoD Utilities Regulators Consultants Vendors Academics Design Operations and maintenance Training Operator certification Staffing Anoxic/Anaerobic Biological Treatment DoD Utilities Regulators Consultants Vendors Academics Design Operations and maintenance Training Operator certification Staffing Conventional Treatment DoD Utilities Regulators Consultants Vendors Academics Design Operations and maintenance Training Operator certification Staffing Degree of Consensus High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) Rating None to Moderate Low Figure 4.17 Characterize each process with respect to the required level of effort. High Don t know Consultant professionals considered the levels of effort for aerobic biological drinking water treatment processes to be similar to that for conventional processes. Consultant professionals considered design requirements for anoxic biological drinking water treatment processes to require a high level of effort compared to the aerobic processes. Consultants are generally the professionals who design drinking water treatment processes and their responses are consistent with current design concepts for these processes. Historically, aerobic biological drinking water treatment processes have generally been designed using similar if not identical concepts for conventional processes such as granular media filtration and granular activated carbon adsorption. Thus it is understandable that consultant professionals would consider the

50 24 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America design level of effort for an aerobic biological drinking water treatment process to be similar to that for a conventional process. On the other hand, an anoxic biological drinking water treatment process also includes electron donor feed to promote biodegradation of nitrate or perchlorate. This process is distinctly different and less common than an aerobic biological process. Understandably the level of effort needed for the anoxic process was rated as high. Specific operational issues were explored as illustrated in Figure 4.18 (see also Appendix B). Almost all professional groups considered bacterial sloughing/breakthrough, pathogen or contaminant breakthrough, and unknown/changing regulatory conditions to be highly significant issues. Interestingly, most regulatory professionals did not know whether unknown/changing regulatory conditions were significant. Utility and regulatory professionals were generally more concerned than most other professional groups about process instability, process inflexibility, and post-treatment/disinfection. DoD Utilities Regulators Consultants Vendors Academics Process instability Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory conditions Degree of Consensus High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) Rating None to Moderate Low Figure 4.18 In your own opinion, how significant are the following operational concerns associated with any type of biological treatment process? High Don t know ADDITIONAL REGULATOR PERSPECTIVES Regulatory professionals were asked additional questions to gain insight into their perspectives. Respondents in this group were all from a state agency in 24 states no responses were received from U.S. EPA headquarters or regional offices based on respondents who provided contact information. Most respondents indicated their states did not prohibit biological treatment processes for drinking water (Figure 4.19). Respondents from three states Alabama, Kentucky, and New Jersey did state their agencies prohibited biological treatment. These individuals were contacted to determine the basis for their response.

51 Chapter 4: Electronic Survey Results and Discussion % 80% 60% 40% 20% 0% Yes No know Figure 4.19 Does your agency prohibit biological treatment processes for drinking water? The respondent from New Jersey indicated that he had considered anoxic biological drinking water treatment of perchlorate and nitrate specifically when answering the question. He clarified that he was well aware that aerobic biological treatment was approved and used as a polishing step in New Jersey (e.g., following ozonation). Thus, he made a distinction between biological treatment and polishing and this distinction was important with respect to regulatory acceptance. The primary reason he stated that anoxic biological treatment of drinking water was banned in New Jersey was that lack of systems in operation. He also indicated that bacterial sloughing was his major concern for a biological process. The respondent from Alabama had a similar perspective to the respondent from New Jersey he was specifically addressing the lack of permitted anoxic biological drinking water treatment systems for perchlorate and nitrate. The respondent from Kentucky indicated that no specific regulations banned biological drinking water treatment, however there was a consensus that biological systems are not allowed by the agency. The major reason given was a lack of experience and concern regarding risks. There was a concern that biological systems may become unstable and pose some hazards. A desire was expressed for education and outreach to increase the understanding of and experience with this technology. While biological treatment was indicated as being prohibited in Kentucky, there is no specific requirement for maintaining a disinfectant residual through media filtration systems. The respondent recognized that bacteria can grow on media filters in the absence of a disinfectant residual. Thus a distinction was made between biological treatment and media filters operated in the absence of a disinfectant. This distinction highlights the need for standardization of terminology and process definitions in the field of biological drinking water treatment. While 81 percent of regulatory professionals indicated their states did not prohibit biological treatment, 48 to 65 percent of these respondents stated that no aerobic biological treatment plants (i.e., OEBF, RBF, SBF, or GBA) were permitted in their respective states (Figure 4.20). These data suggest one of two possibilities: A) many states that allow biological treatment do not have any permitted facilities, or B) regulators in many states are not aware of permitted biological treatment facilities in their states. These regulatory professionals were very aware of permitted conventional treatment plants in their respective states the number of Don t know responses was similar for conventional and biological treatment plants. Nevertheless, OEBF and GBA were the two types of aerobic biological drinking water treatment processes that were most commonly permitted based on a significant percentage of 1-10 responses. While no drinking water treatment plants are currently permitted in the United States for anoxic treatment of perchlorate or nitrate (BPNP), one regulator in California thought that six to ten such plants were currently permitted for drinking water treatment.

52 26 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Biological perchlorate/nitrate removal GAC biological adsorption (GBA) Slow biological filtration (RBF) Rapid biological filtration (SBF) Ozone enhanced biological filtration (OEBF) Conventional treatment process (CTP) 0% 20% 40% 60% 80% 100% > None know Figure 4.20 How many drinking water plants are currently permitted in your state that include the following processes? Approximately equal numbers of regulatory professionals did and did not consider that special permit requirements existed for biological drinking water treatment processes (Figure 4.21). About twenty percent of these professionals did not know whether special requirements existed for aerobic processes. Little difference in these results among the various processes was observed. These results indicate that either states have very different permit requirements or regulatory professionals understanding of permit requirements varies. Permit requirements for biological drinking water treatment processes generally were better understood and more stringent when compared to those for conventional treatment processes (Figure 4.22, Appendix B). About 40 percent of regulatory professionals did not know what specific permit requirements were for biological treatment processes compared to about ten percent for conventional treatment processes (Appendix B). When the Don t know responses were excluded, all requirements with the exception of standard monthly operating reports were required more often for biological drinking water treatment processes than for conventional treatment processes (Figure 4.22). However, only 13 percent of regulatory professionals stated that a higher operator classification was required for biological drinking water treatment plants than for conventional treatment plants (Figure 4.23). When regulatory professionals were asked whether a disinfectant residual was required downstream of any biological process responses were highly varied (Figure 4.24). Verbatim comments indicated that a chlorine residual of 0.2 mg/l in the distribution system was required which is a requirement of U.S. EPA s Total Coliform Rule (TCR). Thus no regulatory professionals appeared to require or were aware of any requirement for a disinfectant residual immediately downstream of a biological process in addition to what is required by the TCR. Most respondents indicated that regulatory guidance documents for biological drinking water treatment did not exist in their agency or were not aware of any such documents (Figure 4.25). The results of the survey questions directed specifically at regulatory professionals reinforce the need for greater educational outreach and guidance on biological drinking water treatment.

53 Chapter 4: Electronic Survey Results and Discussion 27 Ozone enhanced biological filtration (OEBF) Rapid biological filtration (RBF) Slow biological filtration (SBF) Granular activated carbon biological adsorption (GBA) Biological perchlorate/nitrate removal (BPNP) 0% 20% 40% 60% 80% 100% Yes know No Figure 4.21 Are there any special permits or approvals required for the following biological treatment processes? Standard monthly operating report Bench scale/laboratory testing Pilot plant study Full scale demonstration Operating data from other fullscale water treatment plants 0% 20% 40% 60% 80% 100% Percentage of "Yes" responses when " know" respones are excluded Aerobic biological process Anaerobic/anoxic biological treatment process Conventional treatment process Figure 4.22 What are the requirements for operation of each process?

54 28 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America 80% 60% 40% 20% 0% Yes No know Figure 4.23 Does your agency require a higher plant operator classification for biological processes as compared to conventional treatment processes? 50% 80% 40% 30% 20% 10% 60% 40% 20% 0% Yes No know 0% Yes No know Figure 4.24 Are you aware of any requirement for a disinfectant residual such as free chlorine downstream of any biological process? Figure 4.25 Does your agency have guidance documents for the design of biological processes? ADDITIONAL CONSULTANT, ACADEMIC, AND VENDOR PERSPECTIVES Consultant, academic, and vendor professionals generally had a greater level of experience with conventional treatment processes as compared to biological treatment processes which was expected (Figure 4.26, Appendix B). Greater than 25 percent of these professionals had experience with at least one biological drinking water project involving research, study (i.e., bench, pilot, or full-scale) or design aspects. On the other hand, two percent or fewer of these professionals had experience with more than ten such projects involving RBF, OEBF, or GBA biological drinking water treatment processes (Figure 4.27). Thirteen to 21 percent of these professionals had such experience with more than ten conventional treatment processes. While the experience with biological treatment processes exists among these professionals, it is limited.

55 Chapter 4: Electronic Survey Results and Discussion 29 Research Bench/Pilot Design Construction Support Equipment Supply 0% 20% 40% 60% 80% Conventional treatment process (CTP) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Rapid biological filtration (RBF) Biological perchlorate/nitrate process (BPNP) Slow biological filtration (SBF) Figure 4.26 Percentage of consultants, academics, and vendors having conducted at least 1 project for each project type and process type. Research Bench/Pilot Design Construction Support Equipment Supply Conventional treatment process (CTP) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Rapid biological filtration (RBF) Biological perchlorate/nitrate process (BPNP) 0% 5% 10% 15% 20% 25% Slow biological filtration (SBF) Figure 4.27 Percentage of consultants, academics, and vendors having conducted at least 10 projects for each project type and process type.

56 30 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Consultant professionals were queried about the pre-design studies that were conducted and available guidance documents that were used for conventional and biological drinking water treatment processes (Figures 4.28 and 4.29). The types of pre-design studies used for conventional and aerobic biological treatment processes were very similar. However, fewer predesign studies of all types were indicated as being conducted for anoxic biological treatment processes. This result is likely associated with the relative unfamiliarity with these processes and a lack of established pre-design procedures. A greater disparity between conventional and aerobic biological treatment processes was observed with respect to available guidance documents. While academic research articles, U.S. EPA guidance documents, and Water Research Foundation reports were used to similar extents for conventional and aerobic biological treatment process design, consultant-developed design tools, vendor design documents, industry text books, and state guidance documents were used much less for aerobic biological treatment process design. Guidance documents for anoxic biological process design were used to an even lesser extent or, more likely, were unavailable. Thus for aerobic biological drinking water treatment process design, while similar pre-design studies were conducted, a relative lack of guidance documents exists potentially limiting greater implementation of this technology. Laboratory study Pilot plant study Literature search Process alternatives desk top evaluation Full scale performance at facility Full scale performance at other facility 0% 20% 40% 60% Conventional Treatment Processes Other Biological Processes (SBF/RBF/GBA/OEBF) Biological Perchlorate/Nitrate Process (BPNP) Figure 4.28 What pre-design studies do you typically perform on drinking water treatment projects? Academic research articles Consultant developed design tools Vendor design documents Industry textbooks State guidance documents U.S. EPA guidance documents ESTCP cost and performance reports Water Research Foundation reports None Conventional treatment processes Other biological processes (SBF/RBF/GBA/OEBF) Biological perchlorate/nitrate process (BPNP) 0% 10% 20% 30% 40% 50% 60% Figure 4.29 What types of guidance documents do you use for designing the following drinking water treatment processes?

57 Chapter 4: Electronic Survey Results and Discussion 31 Relative technology costs are difficult to assess with a broad survey because costs are highly dependent on specific process configurations and site infrastructure requirements. Nevertheless, consultant professionals were asked to provide estimates of typical unit capital and operating/maintenance costs for various treatment plants. The vast majority of consultant professionals were not able to provide these costs (Figures 4.30 and 4.31). The percentage of consultant professionals who were not able to provide costs for conventional treatment processes was slightly less than the percentages for the biological treatment processes reinforcing the challenges associated with estimating generic process costs. For the respondents who did provide typical capital costs, most consultant professionals considered conventional treatment processes to be more expensive than biological treatment processes (Figure 4.30). No apparent trends for typical operating and maintenance costs were observed (Figure 4.31). Slow biological filtration (SBF) Rapid biological filtration (RBF) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Biological perchlorate/nitrate process (BPNP) Conventional treatment process (CTP) Less than 0.10 per gpd $0.10 $0.20 per gpd $0.21 to $.50 per gpd Greater than $1.00 per gpd $0.51 to $1.00 per gpd 0% 10% 20% 30% 40% 50% 60% 70% Figure 4.30 For each type of treatment process, what do you as a consultant consider to be a typical unit cost range (in $US/gallons per day, $/gpd) for estimating the normalized capital cost for the biological treatment process component? Slow biological filtration (SBF) Rapid biological filtration (RBF) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Biological perchlorate/nitrate process (BPNP) Conventional treatment process (CTP) 0% 20% 40% 60% 80% Less than $50/million gallons (mg) $51 to 100/mg $101 to 150/mg $151 to 200/mg $201 to 250/mg $251 to 300/mg $301 to 350/mg Greater than $350/mg Figure 4.31 For each type of treatment process (i.e., each row), what do you as a consultant consider to be a typical or rule-of-thumb unit cost range (in $US/million gallons, $/mg) for estimating the normalized operating and maintenance costs for the biological treatment process?

58 32 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America ELECTRONIC SURVEY CASE STUDIES Plant Demographics and Characteristics A total of 77 electronic case studies were initiated by survey recipients. However, all questions in each case study were not answered. All case studies were for treatment plants in the U.S. except for two in Canada. The SDWIS database used to solicit participation in the survey was restricted to utilities serving 10,000 people or more. Figures 4.32 and 4.33 show that the median capacity for treatment plants included in the survey was between 11 and 50 million gallons per day (mgd). A bimodal distribution for the population served was observed: about 30 percent of the case studies represented plants serving 10,000 to 50,000 people and about 50 percent of the case studies represented plants serving over 100,000 people. Capacity <1 mgd 6 10 mgd mgd > 200 mgd Population Served < > know 0% 10% 20% 30% 40% 50% Design Curent Operation Figure 4.32 What is the capacity for this water treatment plant? 0% 10% 20% 30% 40% 50%60% Curent Operation Design Figure 4.33 What is the population served for this water treatment plant? Source Water Type and Quality Most case studies (73 percent) were based on surface water supplies treating water from reservoir/lake supplies (Figure 4.34). The case studies represented a broad range of source water qualities, as illustrated by the graphs in Figure Of particular interest was the broad range of TOC concentrations and temperature conditions. TOC is of particular interest for biological treatment since it can promote biological instability in distribution systems (e.g., biofilm growth, chlorine residual decay) after a pre-oxidation step such as ozonation. Temperature is also of interest because it impacts biological process efficiency. Reservoir/lake River/Stream Groundwater Groundwater under direct 0% 10% 20% 30% 40% 50% Figure 4.34 What type of water source(s) is used for this treatment plant?

59 Chapter 4: Electronic Survey Results and Discussion 33 Maximum source water temperature 0% 20% 40% 60% 80% 100% < 40 Deg F Deg F Deg F Deg F Deg F > 80 Deg F Minimum source water temperature 0% 20% 40% 60% 80% 100% < 40 Deg F Deg F Deg F Deg F Deg F > 80 Deg F TOC 0% 20% 40% 60% 80% 100% < 2 mg/l 2 4 mg/l 4 6 mg/l > 6 mg/l Unknown Turbidity 0% 20% 40% 60% 80% 100% < 10 NTU NTU > 50 NTU Unknown ph 0% 20% 40% 60% 80% 100% < > 8 Unknown Alkalinity 0% 20% 40% 60% 80% 100% < 50 mg/l mg/l > 100 mg/l Unknown Figure 4.35a Characterize the average source water quality for this water treatment plant for the following parameters.

60 34 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Threshold odor number 0% 20% 40% 60% 80% 100% < >10 Total Fe 0% 20% 40% 60% 80% 100% <= 0.15 mg/l > 0.15 and <= 0.3 mg/l > 0.3 and <= 1 mg/l Total Mn 0% 20% 40% 60% 80% 100% <= mg/l > and <= 0.05 mg/l > > 0.05 mg/l Unknown Total Nitrate/Nitrite 0% 20% 40% 60% 80% 100% < 1 mg N/L > 1 and < 10 mg N/L > 10 mg N/L Unknown Perchlorate 0% 20% 40% 60% 80% 100% <=4 ug/l > 4 and <= 22 ug/l > 22 ug/l Unknown Bromide 0% 20% 40% 60% 80% 100% <= 0.05 mg/l > 0.05 and <= 0.1 mg/l > 0.1 mg/l Unknown Figure 4.35b Characterize the average source water quality for this water treatment plant for the following parameters.

61 Chapter 4: Electronic Survey Results and Discussion 35 Process Types and Distribution The case studies included a series of questions designed to categorize each drinking water treatment process. Figure 3.1 illustrated the process selection decision tree that was used by the survey for this categorization. Fifteen percent of the case studies were in the BPNP category (Figure 4.36) and 39 percent of the water treatment plants were concluded to be conventional non-biological treatment processes. The remaining case study respondents (45 percent) 2 were concluded to have an aerobic biological treatment process (e.g., OEBF, GBA 3, SBF, or RBF). In the following sections the number of case studies per process type varied depending on the actual question asked. The minimum number of case study question responses was three for all process types with the exception of the SBF process. The SBF process questions generally had only one case study response. Non-Biological (Conventional) Ozone-enhanced biological filtration (OEBF) Rapid biological filtration (RBF) Biological perchlorate/nitrate process (BPNP) GAC biological adsorption (GBA) Slow biological filtration (SBF) 28 Plants 19 Plants 8 Plants 11 Plants 3 Plants 2 Plants Figure 4.36 Distribution of water treatment plants based on the process selection decision tree. Process Attributes 0% 10% 20% 30% 40% The case study respondents were asked general questions pertaining to all biological treatment processes and specific questions pertaining to individual processes. One of the questions pertained to whether the process was a managed or incidental process. A managed process was considered to be one that was designed and/or operated intentionally as a biological process with a focus on promoting biological treatment performance. An incidental process was considered to be one that was not designed or operated as a biological process, but instead with a focus on conventional treatment performance parameters (e.g., turbidity and particle removal for filtration, adsorption for GAC contactors). The OEBF, RBF, and SBF processes were generally considered to be managed processes whereas the GBA process was considered to be an incidental process (Figure 4.37). This result indicates that the most utilities and consultants who provided case studies and are responsible for design and operating biological filtration processes (i.e., OEBF, RBF, and SBF) have a clear appreciation of the role that biology can play in drinking water treatment. This result contrasts to the high number of Don t know responses from utility professionals in the general survey (i.e., non-case study questions). The GBA process was unique in that it was considered exclusively to be an incidental biological process. Thus GBA processes appear to be less understood or appreciated than biological filtration 2 The total is less than 100 percent due to rounding. 3 The decision tree process lumped GAC contactors with pre-ozonation into the OEBF category. Therefore, the GBA response rate is less than the total number of aerobic biological drinking water treatment case studies that use GAC.

62 36 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America processes. One reason may be that GBA is a complex process involving both adsorption and biodegradation, with no practical method to attribute treatment performance to a particular mechanism. Consequently, utility professionals do not appear to focus on the biological contaminant removal capabilities of post-filtration GAC contactors. Since GAC has been demonstrated to generally support greater concentrations of bacteria, greater focus on the GBA process appears to be warranted. 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Figure 4.37 Was the biological water treatment process designed as a "managed" or "incidental" process? Target Contaminant Removal and Performance Managed Incidental know Ozone enhanced biological filtration (OEBF) Rapid biological filtration (RBF) GAC biological adsorption (GBA) Slow biological filtration (SBF) Contaminant removal by each process was determined for each case study and results were compared to those from the general survey previously presented in Figures 4.13 through The comparison presented in Figure 4.38 highlights some distinct differences between contaminants that are actually removed by biological treatment processes and the perceptions of what can be removed. While there were differences among the OEBF, RBF, and GBA case study results, the overall observation was that TOC and DBP precursors, AOC/BDOC, taste and odor compounds, iron/manganese, turbidity/particle counts, and color removals were shown to be greater in the case studies relative to the general survey perceptions. In addition, removals of many of these constituents were similar to or better than removals by conventional treatment processes. For example, about 50 percent of general survey respondents considered removal of TOC/DBP precursor to be suitable for both aerobic biological treatment and conventional treatment processes. This contaminant group was listed as one of the contaminants removed in over 90 percent of the case studies for OEBF, RBF, and GBA. In another example, removal of turbidity/particle counts was cited by 67 to 75 percent of the OEBF, RBF, and GBA case studies. In the general survey only 11 percent of respondents stated this was suitable for removal by aerobic biological processes and 85 percent stated it was suitable for removal by conventional treatment processes. Thus, the perception is that aerobic biological treatment is not suitable for removal of turbidity/particle counts, whereas plant operational experience demonstrates that this process is comparable to conventional treatment processes. While only one case study was provided for SBF, it did indicate that the process was used primarily for iron/manganese removal which is also contrary to the perception about the applicability of aerobic biological treatment for removal of these contaminants. Perceptions and reality were more in line with each other for anoxic biological

63 Chapter 4: Electronic Survey Results and Discussion 37 treatment processes. Perchlorate/nitrate/nitrite was considered most suitable for removal by this process both in the general survey and in the case study (Figure 4.39). In addition to removal of specific contaminants outlined above, positive and negative impacts of the individual biological treatment processes on finished water quality were assessed. Detailed data are presented in Appendix B; the results are summarized in Figure Impacts of various processes on finished water quality were almost exclusively positive, neutral, or unknown. The only case where a majority of respondents indicated negative impacts occurred was for BPNP and disinfectant demand. This result is associated with the addition of an electron donor (e.g., acetic acid or vinegar) as part of the process and may indicate insufficient optimization of downstream aerobic biological stabilization. Otherwise, the OEBF, RBF, BPNP, and SBF case studies indicated positive or neutral effects on finished water quality. These results contrast to the perceived concerns of biological treatment processes on finished water quality that were identified in the general survey (e.g., Figure 4.16). Effects of the GBA process on finished water quality were generally unknown indicating a need for further research. This result is consistent with the general view of GBA as an incidental biological treatment process (see Figure 4.37). Total organic carbon / disinfection by product precursors Assimilable organic carbon / biodegradable dissolved organic carbon (AOC/BDOC) Taste and odor compounds Endocrine disrupting compounds, pharmaceuticals, and personal care products, etc. Perchlorate/nitrate/nitrite Iron/manganese Turbidity/particle counts HPC bacteria/total coliform Bromate Color 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Aerobic biological processes General Survey Conventional treatment processes General Survey OEBF Case Studies RBF Case Studies GBA Case Studies SBF Case Study Figure 4.38 Choose one or more contaminants removed by the aerobic biological process.

64 38 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Total organic carbon / disinfection by product precursors Assimilable organic carbon / biodegradable dissolved organic carbon (AOC/BDOC) Taste and odor compounds Endocrine disrupting compounds, pharmaceuticals, and personal care products, etc. Perchlorate/nitrate/nitrite Iron/manganese Turbidity/particle counts HPC bacteria/total coliform Bromate Color 0% 50% 100% Anaerobic/anoxic biological processes General Survey Conventional treatment processes General Survey BPNP Case Studies Figure 4.39 Choose one or more contaminants removed by the anoxic/anaerobic biological process. Chlorine/chloramine disinfectant residuals Chlorine/chloramine demand and residual decay rates Total coliform positives HPC bacterial concentrations Biofilm levels AOC/BDOC concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration OEBF RBF GBA Degree of Consensus Negative Impact Rating No Change Positive Impact Don t know High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) Figure 4.40 How does the biological drinking water treatment process impact water quality in the distribution system?

65 Chapter 4: Electronic Survey Results and Discussion 39 Design and Operational Considerations Several design and operational parameters were queried as part of the case studies. Disinfection requirements were initially evaluated and the findings are illustrated in Figures 4.41 through Free chlorine was the most common disinfectant but combined chlorine was also used (Figure 4.41). No major differ-ences among the aerobic biological treatment processes were observed. The anoxic 100% 80% 60% 40% 20% 0% Chlorine Combined chlorine (e.g., chloramine) Other OEBF RBF BPNP GBA SBF Figure 4.41 What is your final disinfectant? process (i.e., BPNP) case studies were pilot studies and ultraviolet disinfection was used in addition to chlorine in one case thus leading to the Other response. The required disinfectant dose and residual were variable among the various case studies (Figures 4.42 and 4.43). The OEBF process has the broadest ranges of responses which is partially an effect of having the greatest number of case studies. The median dose for OEBF was > 3.0 mg/l and the median response of 29% was shared by the 1.6-to-2.0 mg/l and > 2.5 mg/l residual concentrations. An apparent bimodal distribution of the RBF and GBA data was observed. Doses > 3.0 mg/l were indicated but the median doses were 1.0 to 1.5 mg/l. Target residual concentrations were similarly distributed albeit at lower concentrations than the applied doses. Limited conclusions regarding SBF can be made because only one case study was contributed, but the data are not inconsistent with the data for the other processes. The BPNP case study data were also similar to the other processes however and a significant number of Don t know responses were supplied due to less experience with this process. No clear distinctions among the various processes with respect to disinfectant demand and target residual concentration can be ascertained. Dose (mg/l) < 0.5 mg/l mg/l mg/l mg/l mg/l mg/l > 3.0 mg/l know Disenfectant Residual (mg/l) < 0.5 mg/l mg/l mg/l mg/l mg/l > 2.5 mg/l know 0% 20% 40% 60% 80% 100% OEBF RBF BPNP GBA SBF Figure 4.42 What dose do you need to achieve your target disinfectant residual? 0% 20% 40% 60% 80%100% OEBF RBF BPNP GBA SBF Figure 4.43 What is your target disinfectant residual leaving the plant?

66 40 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Backwashing the processes (i.e., except for the SBF and the BPNP fluidized bed bioreactor process) was conducted using different approaches (Figure 4.44). Most OEBF processes were backwashed with chlorinated or chloraminated wash water and to a lesser extent with non-chlorinated or intermittently chlorinated wash water. The RBF case studies indicated that chlorinated or chloraminated wash water was used to backwash at least intermittently. The GBA case studies indicated that non-chlorinated wash water was used for backwash most commonly. The BPNP case studies were variable with respect to backwash requirements. Thus a variety of backwash strategies are used for biological treatment processes and no single approach appears to be appropriate or gained acceptance. OEBF RBF GBA BPNP Chlorinated/chloraminated Chlorinated intermittently Non chlorinated know Not applicable 0% 20% 40% 60% 80% 100% Figure 4.44 What type of wash water is used to backwash the biological water treatment process? Backwashing frequency was also variable for each process and among the different processes (Figure 4.45). The frequency ranged from a low of 12 to 48 hours to a high of greater than 168 hours (i.e., weekly). No single backwash frequency was uniformly applied to any process. For example, the backwash frequency for the OEBF process was evenly distributed among the 12-to-48 hour, 49-to-72 hour, and 73-to-168 hour ranges. The variation in backwash frequency is in part attributable to variations in source water quality as illustrated in Figures 4.34 and These variations result in differing contaminant loading rates to the filters. The variation in backwash frequency is also likely to be attributable to variations in designs and operational strategies. However, as discussed below, it is unlikely that these variations are attributable to operational strategies that are directed towards optimizing biological activity and contaminant removal. Thus no definitive conclusions regarding appropriate backwash frequency of these biological processes can be made. Less than once every 12 hours Once every hours Once every hours Once every hours OEBF RBF BPNP GBA Greater than every 168 hours know Not applicable 0% 20% 40% 60% 80% Figure 4.45 What is the average backwash frequency for the process?

67 Chapter 4: Electronic Survey Results and Discussion 41 One of the main objectives of biological treatment today is the production of biologically stable water yet very few plants actually monitor AOC/BDOC. Case study respondents were queried with respect to methods in use to stabilize water leaving the water treatment plant and in the distribution system (Figures 4.46 and 4.47). Several methods were used to stabilize water leaving the water treatment plant but no single method was applicable to all biological treatment processes. Methods that were used by 50 percent or more of the respondents for a given process included: optimization of corrosion control, monitoring of AOC/BDOC, provision of advanced treatment such as UV or membranes, use of media filtration, increasing the disinfectant dose, and optimization of the empty bed contact time. Insufficient experience with anoxic processes (i.e., BPNP) exists thus the high percentage of Don t know responses. Surprisingly, minimization of electron donor residuals in finished water was not universally chosen as a suitable method for the BPNP case studies. Disinfection of new or repaired pipelines prior to placement into service was universally used in the aerobic biological filtration case studies as a method to maintain stable water in the distribution system (Figure 4.47). Other methods that were used to a large extent (i.e., greater than 50 percent), though not universally, included monitoring of HPC levels, increasing the disinfectant residual, increasing distribution system monitoring, and implementation of a strategic pipeline replacement program. Again, insufficient experience with BPNP led to a high percentage of Don t know responses. Optimize ozone dose (unique to OEBF) Aerate to increase dissolved oxygen Aerate to promote aerobic biodegradation Optimize empty-bed contact time for biological filtration Increase chlorine/chloramine disinfectant dose Increase chlorine:ammonia ratio Provide multi-media filtration downstream Provide advanced treatment (UV or membranes) downstream Monitor HPC levels downstream of filtration Monitor AOC/BDOC downstream of filtration Optimize corrosion control Minimize electron donor residuals in finished water know 0% 20% 40% 60% 80% 100% BPNP SBF GBA RBF OEBF Figure 4.46 Choose one or more approaches currently used to produce biologically stable water leaving the plant.

68 42 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America know Monitor AOC/BDOC in distribution system Monitor HPC levels in distribution system Change monitoring points Increase disinfectant residual Increase distribution monitoring Implement strategic pipeline replacement program Disinfect new or repaired pipelines prior to placing in service Increase flushing frequency in filtration system 0% 20% 40% 60% 80% 100% OEBF RBF GBA SBF BPNP Figure 4.47 Choose one or more approaches currently used to maintain biologically stable water in the distribution system. Monitoring of the biological treatment process was evaluated in the survey and summary results are presented in Figure Detailed results are presented in Appendix B. The only monitoring parameter that was used for all processes in most of the case studies was turbidity. For the aerobic processes, temperature was also monitored to a large extent. Parameters that are indicators of biological stability (e.g., AOC/BDOC, biofilm formation rate, and oxalic acids/ aldehydes) were not monitored and few if any of the case study respondents stated they should be monitored. This result contrasts to the results presented in Figure 4.46 where AOC/BDOC was listed as a method for managing production of biologically stable water. Of the listed direct measurements of biological activity (i.e., HPC bacteria, biomass concentration, ATP, and NADH fluorescence) only HPC was widely used. However, the GBA case studies indicated that this analysis could be used but was not required. On the other hand, some of the GBA case studies indicated that newer methods of biomass measurement such as ATP should be used. Additional monitoring tools indicated in verbatim responses to this question included haloacetic acids (HAA5s), total trihalomethanes (TTHM), and head loss. One verbatim response was, We do not do enough monitoring of our BAF process. The results from this survey support this statement by the case study respondent. Most monitoring methods were focused on the filtration process rather than the biological filtration process. Methods for monitoring and controlling the biological aspect of the biological treatment processes are generally not being used. A possible reason is a lack of sufficient understanding of what tools are available and how they can be used to optimize water treatment plant performance.

69 Chapter 4: Electronic Survey Results and Discussion 43 OEBF RBF GBA SBF BPNP Gas-phase ozone (on-line) NA NA NA NA Residual ozone (on-line) NA NA NA NA Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold AOC/BDOC Coliforms Opportunistic bacterial pathogens Heterotrophic bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Nitrate concentration (on-line) NA NA NA NA Perchlorate concentration (on-line) NA NA NA NA Chemical oxygen demand (COD) NA NA NA NA Specific electron donor concentration NA NA NA NA Perchlorate or nitrate reducing bacteria concentration NA NA NA NA Degree of Consensus High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) Could Be Used, But Not Required Figure 4.48 What tools or water quality parameters are used or should be used to monitor and control the biological process? Rating Should Be Used Are Used Don t Or NA The need for additional operators or higher operator classification was evaluated as part of the case studies. In most cases more operators were not required for the biological process compared to a conventional process (Figure 4.49). An exception was for the RBF case studies one case study of the three provided indicated more operators were required. Greater operator classification was not indicated as being required in any of the case studies (Figure 4.50). Thirteen percent of regulatory professionals indicated that a greater operator classification was required for a biological process (Figure 4.23). This regulatory requirement for greater operator classification apparently was limited to states where the cases studies were not located.

70 44 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America OEBF RBF BPNP GBA SBF 0% 20% 40% 60% 80% 100% No know Yes Figure 4.49 Does having a biological process trigger the need for additional plant operators over a conventional treament process? OEBF RBF BPNP GBA SBF 0% 50% 100% No know Yes Figure 4.50 Does having a biological process process in your water treatment plant require a higher plant operator classification than for conventional treatment processes? Several operational aspects were evaluated including startup time, effects of taking the process off line, changes in water quality, and other factors. The time to attain stable performance was generally within one month for the OEBF, RBF, and BPNP processes (Figure 4.51). The GBA and SBF processes generally took longer up to four months. Most of the processes described in the case studies were operational more than 90 percent of the time (Figure 4.52). One of the GBA plants operated seasonally. Many of the case study respondents indicated that they did not know how performance of the processes was affected by taking them off line for more than one week (Figure 4.53). Other respondents provided answers indicating that the stabilization time was quite variable and no clear correlations among process type and stabilization time were apparent. < 1 months 1 2 months 3 4 months 5 8 months 9 12 months > 12 months Unstable know 0% 20% 40% 60% 80% 100% OEBF RBF BPNP GBA SBF Figure 4.51 What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process?

71 Chapter 4: Electronic Survey Results and Discussion 45 Operates 100% of the time Operates > 95% of the time Operates > 90% of the time Operates > 50% of the time Operates seasonally Varies know 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% OEBF RBF BPNP GBA SBF Figure 4.52 What percent of the time is the biological water treatment process in continuous operation? Immediately Within 4 hours Within 5 to 24 hours Within 1 day to 1 week Within 1 week to 1 month Does not stabilize for several months know 0% 20% 40% 60% 80% 100% OEBF RBF BPNP GBA SBF Figure 4.53 How is performance of the biological water treatment process impacted by taking it off-line for an extended period (i.e., > 1 week)?

72 46 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Source water quality parameters were observed to have varying effects on the biological processes (Figure 4.54). Temperature was the main parameter that was cited as being significant by all processes except SBF. For the aerobic biological treatment case studies, other parameters that were cited as being significant included TOC and algae. Iron/manganese, ph, and dissolved oxygen were cited as being important by the single SBF case study. The anoxic BPNP case studies indicated temperature, nutrient levels, dissolved oxygen, and nitrate/perchlorate concentrations as being significant. Temperature Total organic carbon (TOC) Dissolved organic carbon (DOC) Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Algae Nutrient levels (nitrogen, phosphorus) Iron and manganese ph Dissolved oxygen Turbidity Nitrate or perchlorate concentrations (unique to BPNP) 0% 20% 40% 60% 80% 100% OEBF RBF GBA SBF BPNP Figure 4.54 List three source water quality parameters that most significantly impact performance of the biological process. Figure 4.55 summarizes the degree to which various operating conditions impacted the performance of the biological processes in the case studies. Appendix B provides detailed data upon which these conclusions are based. Whether the biological processes were operated continuously or intermittently was the single factor that was generally considered to affect all of the processes continuous operation improved performance and intermittent operation worsened performance. On the other hand, plant shutdown and media replacement both of which can be considered to be interruptions in operation just as intermittent operation did not yield consistent results. For example, media replacement resulted in improved RBF performance while intermittent operation resulted in worsened performance. Higher flow rates resulted in worse

73 Chapter 4: Electronic Survey Results and Discussion 47 GBA performance and lower flow rates resulted in better GBA performance as expected because of the reasonably expected positive effect of increased empty bed contact time on performance. However, higher flow rates improved RBF performance and lower flow rates resulted in no change. This result was unexpected. Flow rate and ozone did not have any effect on the OEBF process which was similarly unexpected. These unexpected results may be attributable to other parameters having stronger effects on process performance (e.g., temperature) which lead to obfuscation of effects by weaker parameters. Whatever the reasons, logically expected effects of many operating parameters on performance did not always appear to manifest themselves in a consistent manner across various processes. Backwashing strategy is another example. While chlorinated/chloraminated backwash water worsened performance of the OEBF and GBA processes, it improved performance of the RBF process. The reasons for the effect on the RBF process are not easily explained. The effects of the BPNP operating parameters electron donor and nutrient concentrations were as expected. OEBF RBF GBA SBF BPNP Higher ozone dose NA NA NA NA Lower ozone dose NA NA NA NA Higher flow rate Lower flow rate Chlorinated/chloraminated filter backwashing NA NA Non-chlorinated/non-chloraminated filter backwashing NA NA Resting filters after backwashing NA Continuous operation Intermittent operation Plant shut down Media replacement Increased electron donor concentration NA NA NA NA Decreased electron donor concentration NA NA NA NA Increased nutrient (N or P) concentration NA NA NA NA Decreased nutrient (N or P) concentration NA NA NA NA Filter backwashing (BPNP only) NA NA NA NA Filter bumping with air NA NA NA NA Filter bumping with nitrogen NA NA NA NA Degree of Consensus High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) Negative Impact Figure 4.55 What plant operating conditions impact performance of the biological process? Rating No Change Positive Impact Don t know

74 48 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Operational concerns were explored in the general survey and utility professionals expressed high levels of concern for seven out of nine listed concerns (Figure 4.18). The case studies which were prepared predominantly by utility professionals present a completely different picture (Figure 4.56). The level of concern was none-to-low for most of the same listed concerns with almost all of the remaining responses listed as moderate. The responses in the general survey represent perceived concerns whereas the responses in the case studies represent actual concerns. These data further illustrate the gap between perceived and actual concerns of biological treatment the concerns are perceived to be greater than they are in reality. A final question asked of all the case study respondents was whether nematodes were observed in the process. The results generally indicated that either it was not known or they were not observed (Figure 4.57). An exception was the RBF process where they were observed in 50 percent of the cases. OEBF RBF GBA SBF BPNP Process instability Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory conditions Degree of Consensus High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) Rating None to Moderate Low Figure 4.56 How significant are the following operational concerns for your biological treatment process? High Don t know 100% 80% 60% 40% 20% 0% Yes No know OEBF RBF BPNP GBA SBF Figure 4.57 Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system?

75 Chapter 4: Electronic Survey Results and Discussion 49 Additional Process-Specific Attributes Additional questions specific to each process type were posed in the case studies. The optimal ozone dose and optimal ozone-to-toc ratio was evaluated for the OEBF process (Figure 4.58). A dose of one-to-two mg/l and a ratio of 0.6-to-1.0 were most commonly considered to be optimal. However many respondents did not know the optimal ozone-to-toc ratio. The empty bed contact time for the GBA process varied from 5 to 20 minutes, but one-third of respondents did not know (Figure 4.59). A variety of reasons were given on how the RBF process was implemented within the plant process train, as shown in Figure With respect to BPNP process implementation, several biological and non-biological processes were considered for meeting water quality objectives and are also being used (Figure 4.61). Ozone Dose (mg/l) < 1 mg/l 1 to 2 mg/l 3-4 mg/l 5-6 mg/l >6 mg/l know Ozone:TOC Ratio < >1.0 know 0% 20% 40% 60% 80% 0% 20% 40% 60% Figure 4.58 Based on plant operations, what is the optimal ozone dose or ozone: TOC ratio for optimizing biological filtration performance? < 5 minutes 5-10 minutes minutes > 20 minutes know 0% 5% 10% 15% 20% 25% 30% 35% Figure 4.59 What is the empty bed contact time for the GBA process?

76 50 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Part of original design Stopped chlorination upstream of filter Retrofit filter (e.g. new media or deeper box) 0% 10% 20% 30% 40% 50% 60% Figure 4.60 How was the RBF process introduced into the water treatment process train Fluidized bed bioreactor Packed bed bioreactor Membrane bioreactor Membrane biofilm reactor Ion exchange Tailored granular activated carbon Water supply blending know 0% 20% 40% 60% Were considered Are being used Figure 4.61 What treatment processes were considered or are being used for perchlorate and nitrate treatment for meeting water quality and treatment objectives?

77 CHAPTER 5 TELEPHONE CASE STUDIES As a follow-up to the web-based survey, selected locations were identified to obtain additional information on the circumstances leading to biological treatment and experiences at these locations. Utility, regulatory, and consultant professionals were contacted via telephone for these surveys (Appendix C). LOCATIONS The following water utilities participated in the telephone survey phase: City of Salem, Oregon SBF Greater Cincinnati Water Works, Ohio RBF and GBA Los Angeles Department of Water and Power, California OEBF Henrico y, Virginia OEBF Santa Clara Valley Water District, California OEBF Arlington, Texas OEBF Various facilities, France BPNP Western Municipal Water District, California BPNP CITY OF SALEM, OREGON: SLOW BIOLOGICAL FILTRATION The City of Salem, Oregon, operates a 120 mgd surface water treatment plant consisting of slow sand filtration and chlorine disinfection. It is the largest slow sand filtration plant in the U.S. It serves a population of approximately 150,000. The source of water is the North Santiam River. Background In 1936, treatment consisted of an infiltration gallery followed by a sand trap. In 1954, the first slow sand filter was constructed. The City had considered several water sources at the time: the Willamette River, deep wells, and the North Santiam River. Rationale for Process Selection The high source water quality and land availability made the use of slow sand filtration the most cost-effective option. Design and Operating Parameters The plant has 3 SBFs. Each filter consists of a pair of 2.5-acre beds that are open and constructed as earthen basins with side slopes covered with high density polyethylene liner. The filter media consists of 36 inches of 0.25-to-0.33 mm effective size sand over 18 inches of graded gravel. The peak filtration rate is 0.12 gpm/ft 2. 51

78 52 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Staff converted the oldest slow sand filter to a roughing filter giving a peak filtration rate of 0.24 gpm/ ft 2. The roughing filter has the same media as the SBF and covers an area of five acres. The roughing filter has sloped sides with no liner. The roughing filter is used during those times when the raw water turbidity exceeds 10 NTU. This typically occurs two to eight weeks a year. Over the past 4 years the roughing filter has treated turbidity up to 30 NTU. Roughing filter effluent turbidity is always 2 NTU or less. In the last 10 years, a chemical treatment facility and small clarification basin were installed for use when source water turbidity exceeded 10 NTU. Operators used this facility for two years, but found that chemical dosing and residual handling was cumbersome. The use of the SBF without chemical addition has been much easier, reliable, and less costly. The only chemicals used at the SBF plant are for corrosion control (soda ash) and disinfection (NaOCl) of the filtered water. The filters are monitored continually for turbidity, head loss, and flow. All filters in operation are tested weekly for bacterial quality in the filtered water and daily during the ripening process. Raw water bacterial quality is monitored daily. The filters must meet a bacterial quality of less than 10 CFU/100 ml for total coliforms and non-detectable for E. coli prior to being placed in service. The goal is for turbidity to be below 0.5 NTU at all times. Performance Water Quality Filtered water turbidity is typically less than 0.1 NTU. Source water experiences some algae episodes. The algae are filamentous in nature and do not impair the production efficiency or quality of the water exiting the SBF. THMs and HAAs average less than 30 µg/l. Total and fecal coliforms are non-detect in the chlorinated finished water leaving the plant and in the distribution system. Operational Roughing filter run length is usually 2 to 4 weeks. Maximum headloss is about 5 ft. SBF is not put into production until the filtered water turbidity is less than 0.5 NTU. This usually takes two to seven days, depending upon the water temperature. SBF run lengths are typically eight to ten weeks at peak loading rates of 0.12 gpm/ft 2. Maximum headloss is about 5 ft. The SBFs are operated in a constant rate mode. It takes two operators 8 hours to clean and level a SBF cell (2.5 acres): one to drive the scraping machine and one to drive the truck next to the scraper to receive the scrapings. Each cleaning scrapes off 0.25 to 0.5 inches of sand. Regulatory Perspectives The Oregon Health Department has no concerns over SBF as it is one of the longest established water treatment processes.

79 Chapter 5: Telephone Case Studies 53 Public Perception Satisfaction with water quality is good. No particular concerns have been expressed over this biological treatment process which has been operational for over 50 years. GREATER CINCINNATI WATER WORKS: RAPID BIOLOGICAL FILTRATION AND GAC The Greater Cincinnati Water Works (GCWW) of Cincinnati, Ohio, operates the 220- mgd Richard Miller Treatment Plant, which is a surface water treatment plant consisting of coagulation, flocculation, sedimentation, biological sand filtration, GAC adsorption, and chlorination. It serves a population of about 1 million. The source of water is the Ohio River. A smaller groundwater plant is also operated but not included in this discussion. Background The source water has bromide levels that are low (<0.05 mg/l), moderate alkalinity (~75 mg/l), moderate TOC (~ 2 to 4 mg/l). In October 1992, GCWW added a new treatment process (GAC adsorption with post filtration contactors) and modified the existing process (discontinuing pre-chlorination before rapid sand filtration). Consequently, the rapid sand filters became biologically active as was evidenced by the reduction of total organic carbon (TOC) through the filters and the biomass levels on the media. In effect, GCWW has two biological treatment processes operated in series rapid biological filtration (RBF) and GAC biological adsorption (GBA). Rationale for Process Selection Concerns over synthetic organic chemicals associated with the vulnerability for spills on Ohio River and transport during spring run-off, coupled with anticipation of more stringent disinfection by-product (DBP) regulations stimulated extensive pilot and demonstration studies (EPA, 1982; Westerhoff and Miller, 1986). GAC was selected to provide a barrier to synthetic organic chemicals and to reduce DBP precursors. Post-filter adsorbers were chosen over a GAC filter cap to increase the EBCT to between 7 and 15 minutes and eliminate GAC-sand mixing (since the scale of the operation led GCWW to perform reactivation of GAC on-site). Design and Operating Parameters To minimize potential for dioxin formation during GAC reactivation and optimize DBP precursor removal instead of preformed DBPs removal, chlorination was discontinued upstream of the sand filters giving rise to two biological filtration processes operating at the GCWW. The design criteria for the 47 sand filters and 12 GAC contactors are as follows. The empty bed contact times of the sand filters and GAC contactors are at least 5 and 12 minutes, respectively. The maximum surface loading rate to the GAC contactors is 6.9 gpm/ft 2. The effective media sizes of the sand filters and the GAC contactors are 0.45 mm and 0.55 to 0.75 mm, respectively.

80 54 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America The utility regularly monitors turbidity, ph, particles, TOC, UV and chlorophyll a (seasonally along with MIB and geosmin). Backwashing the sand filters is based on head loss, turbidity and plant flow rate change. GAC contactors are backwashed based on head loss. Performance Water Quality In the years prior to the sand filters becoming biologically active, the filtered water turbidity after the sand filters averaged 0.13 NTU with no significant difference noted when the filters were converted to a biological mode. In the biological mode the average TOC removal across the biological sand filters ranged from 8 to 20 percent depending on water temperature with values from 0.6 to 31 o C. MIB removal averaged 80 percent and geosmin removal averaged 50 percent removal across the sand filters when appreciable amount of these compounds were present in the filter influent water. The filter effluent water seldom had perceptible musty or earthy odor. Turbidity reduction across GAC contactors is minor (0.10 to 0.07 NTU), however as a secondary filter the GAC contactors are successful in attenuating the filter ripening peaks that can occur with the sand filters. TOC values average approximately 1 mg/l and facilitate meeting a THM goal of less than 64 µg/l. Chlorine demand post-gac is monitored regularly. Based on a review of 7 years of data from 2002 to 2009, E. coli were rarely detected. The highest E. coli level onto the GAC was 4 per 100 ml. The highest post-filter GAC level (i.e., before chlorine addition) was 3 per 100 ml. No positive E. coli results were observed in samples after chlorination. Operational The sand filters are typically backwashed based on head loss (6 feet). Comparing filter run lengths before and after operation in a biological mode initially showed a slight decrease in filter run time, though further optimization virtually eliminated any appreciable difference. On rare occasions, filters are backwashed based on reaching 0.3 NTU, mostly due to algae breakthrough. The GAC contactors are lightly backwashed approximately every 10 days, though the frequency increases slightly during summer months. In addition, the GAC is regenerated on-site. On average, the contactors are regenerated 1.5 times per year. The frequency and scheduling of carbon reactivation is based on TOC and DBP precursor removal as well as optimizing energy costs (i.e., natural gas) and other expenses with reactivation. Regulatory Perspectives In general, the Ohio EPA relies on the Ten State Standards. Consequently there are no specific considerations for biofiltration (i.e., stopping chlorine addition prior to filtration) that are different from conventional treatment.

81 Chapter 5: Telephone Case Studies 55 Public Perception There was no resistance to implementing the biological treatment processes. The use of post-filter GAC was seen as a benefit to ensure higher levels of protection against potential contaminants. When the Associated Press story on pharmaceuticals in drinking water was released in 2008, GCWW was proactive in their communications strategy management of potential source water occurrences involved specific treatment processes (i.e., taking the storage reservoir off-line and GAC post-treatment). In addition, GCWW provided perspective as to the very low concentrations of pharmaceuticals that were detected in the source water. LOS ANGELES DEPARTMENT OF WATER AND POWER: OZONE ENHANCED BIOLOGICAL FILTRATION (ANTHRACITE) The Los Angeles Department of Water and Power operates a 600-mgd surface water treatment plant consisting of ozonation, coagulation, flocculation, filtration, and chlorination. The Los Angeles Aqueduct Filtration Plant (LAAFP) treats water from the eastern Sierra Nevada and water from the Sacramento Delta. Treated water from LAAFP is served throughout most of the San Fernando Valley and the western portion of Los Angeles. Some LAAFP water is also blended with groundwater. A portion of the LAAFP water is stored in large, as yet uncovered distribution reservoirs prior to being served to customers. The plant serves a population of roughly 3.0 million, about three-fourths of the City s residents. Background The source water blend has bromide levels that can vary from <0.05 mg/l to 0.25 mg/l, moderate alkalinity (80 to 120 mg/l), moderate TOC (~ 2 to 4 mg/l) and occasional episodes of turbid water. The LAAFP is a direct filtration plant (i.e., it includes no clarification process) and relies on ozone to enable high filtration rates well in excess of the California Department of Public Health (CDPH) maximum of 6 gpm/ft 2 (i.e., alternative limits may be applicable if pilot studies conducted). In 1999, pre-filter chlorination was discontinued plant-wide after a year-long evaluation of biofiltration. Rationale for Process Selection The ozone-direct filtration process was chosen as a cost-effective means of treating Owens River (Los Angeles Aqueduct) water. Awareness of ozonation by-products and the potential for bacterial regrowth in the distribution system stimulated interest in operating the LAAFP in biological treatment. A trial was conducted in which indicated that water quality benefits were realized without compromising operations. Design and Operating Parameters Ozone is applied to the water prior to adding ferric chloride and a cationic polymer for coagulation. A flocculation step precedes filtration. The design filtration rate is 13.5 gpm/ft 2 and

82 56 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America is among the highest used world-wide. The average filtration rate is 9 gpm/ft 2. The filter consists of 72 inches of 1.5 mm effective size anthracite coal. Performance In , LADWP conducted a year-long comparison of plant performance with and without chlorine being applied in front of the filters. One process train (one-fourth of the plant flow) was operated in a biological mode and compared to a normally operated train in parallel service. No chlorine was used in the backwash water. There was no attempt to make other process adjustments during the year other than rare use of pre-filter chlorine to both trains when ozone went down. Water Quality Turbidity was consistently below 0.1 NTU. Comparison of biological versus nonbiological filters showed virtually no difference in turbidity with an average of 0.07 NTU in either filter mode. Removal of chlorine resulted in a modest decrease in TOC (6%), THMFP (9%), HAAFP (9%) and AOC (25%). There was no significant change in filter run time. Operational Concerns expressed by operators prior to conversion focused on filtered water turbidity and run length, as well as plant aesthetics (i.e., odors and visual appearance). Comparing results for filters using chlorine versus those without chlorine showed roughly equivalent run lengths (17.7 versus 17.1 hours, respectively). Negative aesthetic impacts were minimal. Some brown floc or biological matter clings to basin walls since operators hose down the filters less frequently now that biofiltration is practiced. Regulatory Perspectives No concerns over biofiltration were expressed by the California Department of Public Health (then the Department of Health Services). Public Perception No specific concerns have been raised by customers regarding the use of biofiltration as an integral part of the treatment process. HENRICO COUNTY: OZONE ENHANCED BIOLOGICAL FILTRATION (GAC) Henrico y operates a 55-mgd surface water treatment plant consisting of coagulation, flocculation, sedimentation, ozonation, and filtration. The filter media includes GAC and sand. It serves a population of 260,000. The source of water is the James River.

83 Chapter 5: Telephone Case Studies 57 Background The source water is stable with low bromide (<0.05 mg/l), moderate alkalinity (~75 mg/l) moderate TOC (~ 2 to 4 mg/l) and occasional episodes of high turbidity and iron and manganese. The Henrico y Water Treatment Facility has been in operation since April Rationale for Process Selection Ozone was selected based on both disinfection and DBP control considerations. Intermediate ozone was selected as the application point to minimize disinfection interferences. GAC media was incorporated into the dual media filter design to enhance removal of biodegradable organic matter. Design and Operating Parameters The ozone system was designed to achieve 2-log Cryptosporidium inactivation with 2-log virus inactivation as the functional operating goal. The filter media design consists of 40 inches of GAC over 12 inches of sand. The design filtration rate is 4.5 gpm/ft 2 though the filters are typically operated at a rate of two gpm/ft 2. Potassium permanganate is added at the raw water pumping station periodically for oxidation of iron and manganese. For filtration, Henrico Conty has established a filtered water turbidity goal of <0.1 NTU (95% of the time) and monitors particles in 2 to 10 µm range for trends (on-line monitoring and grab samples). CT compliance is achieved using ozone at a dose of 1.5 times the regulatory CT requirement. Chloramine residual leaving the facility is 3.5 to 4.0 mg/l, using 4.75:1 chlorine-toammonia ratio. Total coliform and E. coli are monitored in raw, inlet, filtered, and finished water. Ammonia, nitrate and nitrite are also monitored in the distribution system. Performance Water Quality Filtered water turbidity is consistently below 0.1 NTU. Over 50 percent TOC reduction is realized through coagulation-sedimentation. The TOC is approximately 2 mg/l going onto filters with little further reduction across the filters. Total coliform and E. coli have all been historically non-detectable in filtered water. Total coliform and HPC (using R2A agar) are monitored at 150 distribution sites. The total coliform rate for 2008 was low (i.e., 0.04 percent), but at times has been close to 5 percent. High total coliform rates in the past have been associated with contaminated sampling taps (e.g., hose bibs). HPC varies from <1 to 1000 CFU/mL. No monitoring has been conducted for AOC or other biodegradable organic matter parameters. Operational Typical filter runs are 125 hours with little headloss accumulation. Filters are backwashed based on time in accordance with a regulatory requirement. The operating staff has modified backwash sequence to achieve some bed expansion. Chloraminated water is used for backwashing.

84 58 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America The GAC is currently 5 years old. Criteria for replacement are based on physical characteristics (i.e., effective size, uniformity coefficient and specific gravity). Current testing shows that the GAC effective size has decreased somewhat, but filter runs are still acceptably long. Currently staff is anticipating another 10 years before the GAC media will need to be replaced. Regulatory Perspectives The Virginia Department of Health has detailed design guidelines for water treatment plants yet is silent on biological filtration. Biofiltration is seen more as a minor, tangential treatment issue. Whenever there are any questions or concerns, they typically require operating data from other Virginia facilities, or they issue a provisional permit (i.e., pilot testing and one year of data). The original design did not receive much review originally nor 10 years ago during another design review with respect to biological filtration. Recently, as Henrico y has sought to increase the rate of their filters, some concern was expressed about optimizing the biological removal of organic matter to improve biostability. Studies have been on-going along with implementation of several measures for maintaining distribution system water quality (e.g., increasing chlorine-to-ammonia ratio during chloramine formation after filtration). Public Perception Satisfaction with water quality is high. There were no negative perceptions concerning use of biological processes. SANTA CLARA VALLEY WATER DISTRICT: OZONE ENHANCED BIOLOGICAL FILTRATION (GAC) The Santa Clara Valley Water District (SCVWD) operates three surface water treatment plants of 42-, 80-, and 100-mgd serving a population of 1.8 million people. The water source is the Sacramento-San Joaquin Delta along with some local reservoirs. Two of the treatment facilities (i.e., 42 mgd and 100 mgd) originally consisted of coagulation, flocculation, sedimentation, and filtration and were modified to add settled water ozone and add GAC in place of anthracite in the filters. Background The source water has bromide levels that can vary from 0.05 mg/l to 0.6 mg/l, moderate alkalinity (~75 mg/l), moderate TOC (~ 2.5 to 4.5 mg/l) and low levels of manganese. Episodic odors are associated with spring, summer, and fall conditions. After intensively studying options to reduce DBP concentrations, control tastes and odors, and provide some protection against trace contaminants, the SCVWD elected to implement an ozone-gac retrofit to their three treatment facilities. In 2004, modifications were completed at the 42-mgd and 100-mgd facilities. Modifications for the 75-mgd facility are being re-evaluated.

85 Chapter 5: Telephone Case Studies 59 Rationale for Process Selection The SCVWD desired a robust treatment process to address their anticipated water quality challenges. Coupling strong oxidation with adsorption and biodegradation was deemed desirable. As a consequence ozone was selected as a primary disinfectant-oxidant. The choice of GAC over sand media for filtration was based on: a) particle-turbidity performance, b) operationally acceptable filter production, c) biological stabilization relative to AOC, and d) buffer for removal of trace contaminants. Extensive pilot testing was conducted during the 1990s. Design and Operating Parameters Ozone is added to the settled water just prior to filtration. The ozone dose is set by meeting a 1-log Giardia inactivation goal. The GAC filters consist of 48 inches of 1.3 to 1.5 mm GAC over 10 inches of 0.65 mm sand. Chlorine is added at low doses to the raw water to suppress algal growth in the basins for the 42-mgd facility but not at the 100-mgd facility. Chlorine residual is not measureable at the filters for the 42-mgd facility, although some pre-filtration chlorine is added at the 100-mgd plant to catalyze manganese removal. Filters are backwashed based on head loss, time, and turbidity breakthrough. The plant is designed to allow filter backwashing with either chlorinated or de-chlorinated water. Turbidity, flow, and head loss are the major filter operating parameters and are identical to those being used at their 80-mgd conventional treatment plant without ozone or GAC. Run time is also used. No specific parameters are used for optimizing biological activity. Performance Water Quality Turbidity from the biofilters is consistently below 0.1 NTU. During pilot studies and special sampling in 2007 and 2009, observed AOC reductions of 50 to 75 percent. At the 100- mgd facility, now using trace pre-filtration chlorination, the AOC removal is approximately 20 to 25 percent. However, AOC is not of concern because total coliform levels are low. Consequently, SCVWD does not monitor AOC. Interestingly, staff observed better AOC removal at the 42-mgd facility when the backwash water was not de-chlorinated. The 100-mgd facility currently uses chloraminated water for backwashing. Operational GAC media performed better in terms of filter ripening at the 42-mgd facility and run length at the 100-mgd facility than the anthracite that it replaced. Ozone further increased filter run lengths with the GAC at the 100-mgd facility. After optimizing chemical dosing, ozone seems to have had a positive impact on filterability as compared to pre-chlorine with GAC at the 42- mgd plant. Biofiltration had slight impacts on backwash volumes, decreasing them from 200,000 gallons to 175,000 gallons per backwash at the 42-mgd plant. During the start-up of the 100-mgd plant, shorter filter runs were experienced due to turbidity breakthrough. There was inherent sensitivity associated with settled water ozone.

86 60 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Optimization led to use of higher filter aid polymer doses. The breakthrough was not attributed to biological activity in the filters. Regulatory Perspectives Regulatory agencies were involved throughout the decade of studies and deliberation that led to selection of the ozone-gac process. No concerns over biofiltration were expressed by the California Department of Public Health (then the Department of Health Services). Public Perception Generally, public perception in the SCVWD service area is driven by tastes and odors. Complaints have dropped significantly with addition of ozone and GAC. Since SCVWD does not serve water to individuals, but rather agencies that purchase water for service to their customers, the retail agencies were also involved in the deliberations. No specific concerns were raised by the retail customers regarding the use of biofiltration as an integral part of the treatment process. ARLINGTON, TEXAS: OZONE ENHANCED BIOLOGICAL FILTRATION (GAC) The City of Arlington, Texas, operates two treatment plants: the Pierce-Burch Water Treatment Plant (75 mgd) and the John F. Kubala Water Treatment Plant (65 mgd) serving an estimated population of 375,000 people. Both plants consist of conventional treatment with raw water and intermediate ozonation application points and a granular activated carbon (GAC) over sand filter media with a layer of support gravel. The primary water source for the Pierce Burch Water Treatment Plant is Lake Arlington and it is supplemented by the Tarrant Regional Water District s southeast Texas lakes; Cedar Creek and Richland Chambers. 4 The John F. Kubala Water Treatment Plant receives its water directly from the Tarrant Regional Water District pipelines that transport the southeast Texas supply to the Tarrant y, Texas customers. Background Faced with a long history of seasonal taste and odor episodes and the potential for lower THM and HAA regulatory limits, ozone was installed in 1999 at both facilities along with biofiltration primarily to help remove taste and odor (i.e., MIB and geosmin), iron and manganese, and turbidity, and to minimize disinfection by-product formation. Rationale for Process Selection Prior to making a final decision as to which advanced treatment technology to pursue, bench-scale and pilot-scale testing of enhanced coagulation, ozonation/sand filtration, and ozonation with GAC contactors was completed. The result was that the implementation of two- 4 Although Lake Arlington does not typically receive water from the Tarrant y U.S. Army Corps of Engineers Benbrook Lake, the Tarrant Regional Water District does have a contract with the Corps that allows them to withdraw water from Benbrook to supplement their Tarrant y supplies and on occasion they may divert Benbrook Lake waters to Lake Arlington.

87 Chapter 5: Telephone Case Studies 61 stage ozone with GAC/sand filters provided the most cost-effective method of meeting Arlington s water quality goals of eliminating taste and odor problems, reducing trihalomethanes to less than 40 µg/l, and providing another barrier against potential Crytosporidium contamination. Design and Operating Parameters Ozone is added to both the raw water and settled water (prior to filtration). The ozone doses are 0.5 mg/l and 3 mg/l, respectively in the raw and settled water. The dose in the raw water is primarily for the purpose of aiding coagulation and beginning the process of oxidizing iron and manganese in the raw water. The higher settled water ozone is based on CT disinfection requirements for Giardia and virus inactivation. No chlorine is added to the raw or settled water and ozone acts as the primary disinfectant. The Pierce Burch Water Treatment Plant filters are designed for a rate of 5.47 gpm/ft 2 and are backwashed based on head loss, filter run time, or turbidity breakthrough. The plant is designed to allow filter backwashing with either chlorinated or de-chlorinated filtered water. The original biofilter media design included 40 inches of GAC (effective size range of 1.0 to 1.2 mm) and 6 inches of sand (effective size of 0.45 to 0.55 mm). The original design included Leopold Universal type under drains with IMS Caps. The filters are currently undergoing rehabilitation to remove the IMS caps. 5 The John F. Kubala Water Treatment Plant filters are designed for a rate of 6.5 gpm/ft 2 and the filters are backwashed based on headloss, filter run time or turbidity breakthrough. The plant is designed to allow filter backwashing with either chlorinated or de-chlorinated water. The original biofilter media design included 48 inches of GAC (effective size range of 1.0 to 1.2 mm) and 8 inches of sand (effective size of 0.45 to 0.55 mm). The original biofilter design included the Leopold Universal type under drain with IMS Caps. Due to problems with the IMS caps, the John F. Kubala Water Treatment Plant filters have been modified to remove the IMS caps and they were replaced with a layer of support gravel. The new biofilter media configuration now includes 40 inches of GAC (effective size 1.0 to 1.2 mm) and 8 inches of sand (effective size 0.45 to 0.55 mm) over 12 inches of gravel. For both plants, turbidity, flow and head loss are the major filter operating parameters. Run time is also used. Non-chloraminated backwash water is used for encouraging biological activity. 5 Due to earlier failures of the IMS caps, four of the Pierce Burch Water Treatment Plant filters have already been rehabilitated. In those four filters the Leopold Universal under drains were removed and the newer low profile Leopold universal under drains were installed. For those four filters the media configuration consists of 36 inches of GAC (effective size 1.0 to 1.2 mm) and 8 inches of sand (effective size 0.45 to 0.55 mm) over 12 inches of gravel. The remaining sixteen Pierce Burch Water Treatment Plant filters that are currently undergoing rehabilitation will continue to use the original Leopold universal under drains with the IMS caps removed and a new media configuration of 31 inches of GAC (effective size 1.0 to 1.2 mm) and 9 inches of sand (effective size 0.45 to 0.55 mm) over 12 inches of gravel.

88 62 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Performance Water Quality Filtered water turbidity is typically below 0.1 NTU at both plants. THMs and HAAs average 10 µg/l. Tastes and odors have been minimized significantly since the implementation of biofiltration. While the ozone/biofiltration systems performed well for many years, recently observed performance disruptions and the detection of endocrine disrupting compounds in the raw water have prompted additional studies to identify potential modifications to enhance process performance. Operational Over the last few years, shorter filter runs have been experienced as well as clogging of filter underdrains related to biofouling of the IMS caps. Prior to the conversion from chloraminated backwash water to non-chloraminated filtered backwash water, periodic episodes of manganese breakthrough and post-precipitation of oxidized manganese were experienced as well as difficulty stabilizing the chloramine residuals in the distribution system. In addition, four of the filters at the Pierce Burch failed while using chloraminated backwash. However, the cause of failure was attributed to plugging of the IMS caps with biofilm and failure of the epoxy bonding the holddown rebar. These factors led to catastrophic failure of the underdrains during backwash. Regulatory Perspectives In permitting the ozone-gac modifications, the City of Arlington submitted all plans to the Texas Commission on Environmental Quality. Permitting was relatively simple and the agency expressed no unusual concerns. Approval was received and improvements were implemented. Public Perception Currently, the public perception of the Arlington tap water is that it is very good and when the City completes annual service level surveys for all categories of service provided to Arlington s citizens, the water quality receives high marks from the citizens. FRANCE: BIOLOGICAL DENITRIFICATION OVERVIEW 6 A number of facilities operate in France to remove nitrates from groundwater. 6 This information was obtained exclusively through an interview with Johanna Léger from Veolia Eau s Drinking Water Unit.

89 Chapter 5: Telephone Case Studies 63 Background Denitrification is the anoxic biochemical reduction of nitrate to nitrogen gas that proceeds according to the following steps: NO 3 - NO 2 - NO N 2 O N 2 Denitrification can be achieved using both heterotrophic and autotrophic bacteria. In a heterotrophic process, an organic carbon substrate, such as methanol, ethanol or acetic acid, is required as the bacteria food source. In an autotrophic process, an inorganic energy source such as sulphur, reduced sulphur species (e.g. thiosulphate) or hydrogen is required; the carbon needed for autotrophic bacterial growth is obtained from bicarbonate in the water. Rationale for Process Selection When all options to deliver water with limited nitrate concentration are exhausted (blending sources, connecting distribution networks, new water sources, etc.), two processes are currently used in France to remove nitrate from drinking water: a) physico-chemical process via ion exchange, and b) biological treatment. When implementing the physico-chemical process, the spent resin, or in the case of resin regeneration, concentrated brine requires additional treatment. Biological treatment results in destruction of nitrate rather than transfer to a resin or concentration in a brine. All three processes used for biological drinking water treatment by the three main water treatment companies in France (i.e., Veolia/OTV, Suez/Degrémont and Saur/Stéreau) are similar in the way that nitrate removal occurs water plus electron donor (e.g., acetic acid) and nutrients (e.g., phosphate salts) are conveyed through a reactor containing proprietary inert support media. The support media support growth of biomass and nitrate is biochemically reduced to gaseous nitrogen by serving as the terminal electron acceptor for bacterial respiration. Additional information on these processes is presented below. The water treatment plants that Veolia operates for biological nitrate removal were constructed in the 1990 s. At that time not a lot of information was available. Brittany, known for high concentrations of nitrates, was the location where initial pilot experiments were performed on low temperature surface water. The following information in this case study is based primarily on Veolia/OTV experiences. Design and Operating Parameters The Veolia/OTV process is called BioStyr and uses porous polystyrene support media. The Suez/Degrémont process is called Nitrazur DN and uses an expanded clay support media called Biolite. The Saur/Stéreau process is called Bionitracycle and limited information was available on this process. However, Saur/ Stéreau also market an aerobic biological process for wastewater treatment called Biolest that uses a pozzolanic biomass support media called Biozzolane. It is not known whether this media is used in the Bionitracycle process. All three processes require further downstream treatment such as removal of excess electron donor and filtration before water distribution. The Nitrazur and Bionitracycle biofilters are supplied with raw water from the bottom of the filters and treated water is recovered at the top of the filter. For the Veolia/OTV process,

90 64 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America water flows downstream, from top to bottom of the biofilters. The reported advantage of the Veolia/OTV process is that there are less problems of clogging of inlet filters at the bottom of the filters but the drawback is that degassing of N 2 can cause filter binding. To solve this problem, the filtration cycle is often stopped for a few moments in order to allow N 2 to degas. Temperature is a critical parameter biological treatment is less efficient in cold waters (< 3 C for Veolia/OTV process, 5 C in general). Decreases in efficiency are observed starting at a temperature lower that 8 C; at these temperatures, the reaction might not be complete and the transformation of NO 3 - to N 2 may not go to completion and NO 2 - may accumulate. Optimal ph is between 7 and 8.5 depending on the bacteria. For anaerobic conditions, inlet water preferably will have low dissolved oxygen (<5 mg/l) or the consumption of electron donor will increase to promote biochemical removal of oxygen. If oxygen is not removed denitrification will be prevented or inhibited and nitrite may accumulate. Phosphorus nutrient feed is necessary to ensure the biomass growth but the dosage must be controlled. Supplying phosphorus at too high a rate can result in an excess of biomass growth, shorter filter run times, potential difficulties for backwash, and possible excess biomass breakthrough. The height of the fixed bed in biofilter is between 1.0 and 2.5 meters and the support media are either plastic or mineral based as described above. The support media have a great specific area, a high number of macropores, a light density and high resistance to abrasion. Many parameters for plant operation are temperature dependent: the filter loading (kg NO 3 - /m 3 media/day) increases with temperature, from 2.7 at 3 to 5 C to 7 at > 11 C; the minimum required contact time decreases when temperature increases, from 27 minutes at 3 to 5 C to 6 minutes at > 16 C. The filtration velocity increases with temperature and depends on NO 3 - in raw water. For NO 3 - < 100 mg/l, the velocity varies from 4.5 m/h at 3 to 5 C to 9 m/h at 10 to 12 C. Performance Water Quality A number of water quality parameters are monitored as noted in Table 5.1. Monitoring Frequency Daily Table 5.1 Monitoring Parameters Parameter Raw water: NO 3 - Outlet of each biofilter: NO 3 -, NO 2 -, ethanol, head loss Blend of waters after biological treatment : NO 3 - Ozonated water: NO 3 -, O 3 residual Outlet of each second stage filter: NO 2 -, turbidity, head loss Blend of waters after second stage filtration: NO 2 -, turbidity, ethanol Treated water: disinfectant residual, taste and odors Twice a week Raw water: ph, Temperature, NH 4 +, organic matter, NO 2 - Outlet of each biofilter: ph, organic matter, turbidity, phosphorus Ozonated water: NH 4 +, NO 2 -, phosphorus Outlet of each second stage filter: NO 3 -, Treated water: NO 3 -, NO 2 -, NH 4 +, organic matter, turbidity

91 Chapter 5: Telephone Case Studies 65 Operational The biofilters must be backwashed about every 24h and 72h is the maximum or the filters may become excessively anaerobic and cause hydrogen sulfide production. The backwash procedure comprises three phases: air alone, air and water, water alone. A regular backwash must be efficient for biomass/sludge removal in order to prevent clogging of filter, aging of - sludge, NO 2 formation, and short-circuiting inside the filter. At the same time, it must not remove too much of the biomass in order to maintain the biological activity. The water that is used for backwash is treated water prior to chlorination. Considerations that enhance performance include: 1. Maintain stable and optimal conditions: Difficulties result when flow rate is unstable or when raw water quality varies. Preferable source water conditions are T > 5 C, turbidity < 4 NTU, and O 2 < 5 mg/l. Limit production stops to few hours (2h for Suez/Degrémont process, 4 to 5 h for Veolia/OTV process). Initial filter backwash and wasting of water for 30 minutes to 1 hour when filters are back into service in order to limit dead biomass detachment from the media and generation of turbidity. 2. Use precise equipment to control flow rate of raw water, flow rate of electron donor and nutrients, equal distribution of flow on filters, and to ensure efficient mixing of electron donor, nutrients, and raw water. 3. Strictly control applied doses of nutrients (carbon and phosphorus) in raw water: Sufficient dosage of carbon substrate to ensure a complete reaction and reduce the quantities of NO - 2 formed due to a lack of nutrient. Non-excessive dosage of substrates to control biomass production and growth and avoid biomass breakthrough, difficulties with filter backwash and unclogging, or carbon substrate breakthrough in treated water leading to bacterial re-growth in the distribution system. Regular control of carbon substrate injection system, concentration in raw water after injection, and residual at the outlet of biological treatment. Periodic check on carbon substrate concentration on each biofilter to ensure balance across filters. 4. Implement regular monitoring of head loss before and after backwash. Regulatory Perspectives Biological nitrate removal is acceptable for groundwater; however, legislation currently does not authorize biological nitrate removal from surface water. European legislation fixes the maximum nitrate concentration in drinking water at 50 mg/l as nitrate compared to 44 mg/l in the United States. Public Perception Not available, however these full-scale processes have been in place since the 1990s.

92 66 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America WESTERN MUNICIPAL WATER DISTRICT: BIOLOGICAL DENITRIFICATION The Western Municipal Water District serves western Riverside y in California and obtains water from a variety of sources including ground water. Among their facilities is a 6.5- mgd reverse osmosis facility, the Arlington Desalter. A biological denitrification pilot test using a fixed-bed bioreactor was conducted as a precursor to a full-scale design of a 3.6-mgd expansion. This case study is based on pilot test results and current activities related to design and permitting of the full-scale plant. WMWD serves over 24,000 retail customers and eight wholesale customers. The source of water for this facility is brackish groundwater from the Arlington Basin. Background Located east of Los Angeles and inland, salt build-up in the aquifer and limitations of the existing brine line 7 pose challenges for concentrate disposal from a reverse osmosis process. Thus alternatives are needed to reverse osmosis to provide potable water to this area. Rationale for Process Selection Driven by concerns over nitrate, engineering limitations and costs, WMWD evaluated expanded the existing Arlington reverse osmosis system or treating an existing by-pass flow with either ion exchange or biological treatment. A life-cycle cost assessment found the ion exchange and biological treatment process to be roughly comparable although the biological treatment capital costs were higher due to regulatory requirements for polishing filtration. On the other hand, the biological treatment process eliminates significant waste stream concerns and associated cost impacts. There is a possibility that with greater use of acetic acid, pricing will become more competitive, and that issue is significant because it accounts more than 80 percent of the operating costs. Design and Operating Parameters This facility will consist of a series of biofilters followed by polishing filters and chlorination. The use of polishing filters downstream of the biofilters was driven by regulatory concern over biomass entering the distribution system, even though the ripening period was short and was followed by chlorine disinfection (to achieve 4 log virus inactivation). Process control for acetic acid dosing is achieved by feed forward control logic. Influent dissolved oxygen and nitrate concentration are measured and used to determining dose the required acetic acid dose. Monitoring the shape of the fixed bed head loss curve provides insight as to nitrate removal. Backwashing needs to balance cleaning against over-cleaning. European practice is to remove media and clean annually due to mudball formation. The design approach for WMWD has been to provide sufficient flexibility in terms of air scour, surface wash and fluidization. 7 The brine line, also known as the Santa Ana Regional Interceptor (SARI), is used to transport waste water with high salt content directly to the Pacific Ocean.

93 Chapter 5: Telephone Case Studies 67 Performance (pilot plant data) Water Quality Nitrate was removed from levels of 70 mg/l to less than 5 mg/l during steady-state conditions (Brown and Safely, 2009). Turbidity of the fixed bed process was 0.3 NTU or less. During the ripening phase, turbidity could exceed 0.3 NTU for a maximum of 30 minutes. The media was analyzed and a full clone DNA analysis for the bacteria was conducted. No pathogenic organisms were found. Operational Pilot testing demonstrated that eliminating carry-over of organic donor was readily achievable. Optimizing backwashing is anticipated to be a challenge at full-scale. Regulatory Perspectives WMWD has received conditional approval from the California Department of Public Health (CDPH) for a full scale facility. CDPH requires polishing filtration after biological treatment to meet turbidity requirements which adds to the treatment costs. Public Perception No information was provided.

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95 CHAPTER 6 WORKSHOP INTRODUCTION A workshop on biological drinking water treatment was held at the Water Research Foundation in Denver, Colorado to promote technology acceptance and identify future research needs for biological drinking water treatment. It occurred on the afternoon of January 20 and the morning of January 21, 2010 and the workshop agenda is included in Appendix D. The workshop attendees included Foundation staff, utilities, academicians, consultants, regulators, and vendors and the final attendee list is included in Appendix E. A presentation on the survey results was presented to open the workshop. This presentation is included in Appendix F. Specific workshop objectives included: Achieve consensus on biological drinking water treatment definitions and terminology to promote greater technology acceptance. The outcome will be a consensus article to be published in OpFlow. Development of this article will be coordinated with the Awwa Committee on Biological Drinking Water Treatment. Develop a research roadmap that can be used by the Water Research Foundation Research Advisory Committee (RAC). This roadmap will affirm both areas which will yield significant additional insight/value to the field and those areas that will not. Workshop attendees were divided into individual groups that initially focused on terminology, aerobic treatment, anoxic treatment, monitoring and control, and safety. These groups were dynamic and exchanges of group members were conducted to foster active discussions. DEFINITIONS AND TERMINOLOGY Article Development A draft article on definitions and terminology for biological treatment of drinking water was presented to the entire group and discussed. This draft document was based in part on the process classification developed for the survey and previously presented in Figure 3.1. Subgroups of the workshop attendees convened and worked on refining the document during and after the workshop. The final article is presented below and will be submitted for publication in Opflow. Article Manuscript Biological Treatment of Drinking Water Introduction Biological treatment of drinking water, while not widely recognized in the U.S., is used to improve finished water quality. It has an extensive history of use in Europe and to some extent in Canada. In the U.S., biological treatment of drinking water is utilized, but the design criteria and operational optimization are 69

96 70 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America not well established. Biological drinking water treatment processes are often integrated into a treatment plant as one of several processes that are used to improve water quality and public health protection. The purpose of this article is to introduce biological drinking water treatment concepts and definitions as well as increase awareness of their potential to produce high quality water. Biological treatment is defined as a process that is partly or wholly dependent on biological mechanisms to achieve treatment objectives. Biological drinking water treatment processes often improve the biological stability of water in distribution systems. Biological stability of drinking water is a concept that refers to the potential for biofilm and/or pathogen growth in the distribution system the more biologically stable the finished water, the less the potential for biofilm and pathogen growth in the distribution system. Other purposes of biological treatment include removal of contaminants such as disinfection byproduct precursors, taste and odor compounds, pharmaceuticals, iron, manganese, ammonia, nitrate, and perchlorate. Biological drinking water treatment processes can be implemented in various configurations and combinations such as filtration processes, natural filtration processes, and bioreactor processes. Figure 6.1 and Table 6.1 provide an illustration of how these individual processes can be classified. Many of these processes are currently in use in North America and other parts of the world. Filtration Processes Biological filtration processes primarily employ physical and chemical mechanisms of contaminant removal and are supplemented and enhanced by biological mechanisms. These processes are quite common. Any granular media filter that does not maintain a disinfectant residual in the filter effluent (i.e., no pre-disinfectant is used or a pre-disinfectant is consumed within the filter) supports growth of microorganisms. The simple measurement of disinfectant residual in the filter effluent (i.e., prior to post-filter disinfection) characterizes whether the filter is considered biological active or not. If there is no residual the filter is considered biological. This biological activity can improve treatment performance and water quality. The degree to which biological activity contributes to treatment performance can vary. While biological activity may occur in the presence of a disinfectant residual, the contribution to overall treatment performance is negligible. Similarly, granular activated carbon (GAC) filters and filter caps typically do not carry a disinfectant residual across the GAC, since the GAC media rapidly consumes the disinfectant. Therefore, GAC filters are generally always biologically active. Determination of how much these biological mechanisms are contributing to contaminant removal is not always straightforward because these processes are primarily designed and operated based on physical mechanisms (e.g., filtration or adsorption). Several different filtration approaches are used today including slow sand filtration, rapid rate filtration, and GAC filtration.

97 Chapter 6: Workshop 71 Slow sand filtration Slow sand filtration along with natural filtration processes described below, is one of the oldest drinking water treatment processes. The slow sand filtration process involves use of small diameter sand with low surface loading rates and without chemical coagulation. The top of the sand surface becomes coated with a biologically active layer known as the schmutzdecke. This layer is periodically scraped off or harrowed to renew hydraulic capacity of the system and no backwash is employed. Slow sand filtration thus primarily employs physical and biological mechanisms for contaminant removal; however, the biological mechanism is more dominant than in the case of rapid rate filtration. Rapid rate filtration Rapid rate filtration employs larger diameter media (e.g., sand, anthracite, etc.) and greater surface loading rates (about 100 times higher) than the slow sand filtration process. A coagulant such as ferric chloride or alum is added upstream of the process to facilitate removal of turbidity and natural organic matter (NOM). The filter must be backwashed periodically using either chlorinated or nonchlorinated backwash water. Sometimes a pre-oxidant process using ozone, chlorine, chlorine dioxide or permanganate is employed. If no pre-oxidant residual is detected in the effluent of the filter, then the rapid rate filter is considered biologically active. Biological activity can be enhanced by using ozone as a pre-oxidant. Ozone oxidizes part of the NOM to simpler biodegradable organic compounds that are readily removed in the rapid rate filter. Other pre-oxidants, while not as powerful an oxidant as ozone, can oxidize NOM to a limited extent and facilitate removal of other contaminants such as dissolved iron. In all cases, unless a disinfectant residual is maintained through a rapid rate filter, microorganisms will grow on the media and remove at least some of the contaminants present in the water. Even in the presence of a disinfectant residual, microorganisms can grow albeit at a lower and possibly insignificant rate. Biologically enhanced rapid rate filtration thus integrates physical, chemical, and biological processes for contaminant removal and improved biological stability of the finished water. GAC filtration GAC is a common filter media used in drinking water treatment processes that has the additional property of adsorption when compared to other media such as sand or anthracite. GAC can also accumulate greater microbial biomass (or biofilm) on the activated carbon media compared to sand and anthracite media. The biomass plays an important role in biodegradation of contaminants and supplements GAC filtration. The lifetime of GAC (i.e., time between media replacement) can be extended by biological processes. Thus, GAC filtration employs both physical and biological processes for contaminant removal. GAC filtration can be designed as a GAC rapid rate filter, a mono-media deep-bed contactor, or as a filter cap on top of a sand or anthracite filter bed, depending on the contact time requirements to achieve removal of target contaminants. As with conventional rapid rate filters, upstream coagulants and oxidants are often employed to improve removal of

98 72 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America contaminants. GAC filters operated downstream of ozonation are often deemed biologically active carbon (BAC) filters, but since no residual is detected on the effluent of most GAC filters, GAC filters (with or without upstream ozonation) are biologically active filters. In some cases where the adsorptive capacity of the GAC is required in order to produce the desired filtered water quality, GAC is regenerated more frequently and the adsorptive mechanism may plays a more dominant role in treatment than the biological mechanism. Natural Filtration Processes Natural filtration processes are the oldest type of biological drinking water treatment and take advantage of the intrinsic characteristics of riverbanks, aquifers, and wetlands. These different configurations as discussed below are comprised of media (e.g., sand, silt, plants, etc.) that can both filter water and provide a surface for growth of microbial biofilms. These biofilms can promote biological contaminant oxidation and reduction depending on the geochemical characteristics of the aquifer. Two natural treatment approaches that are used today include riverbank filtration and aquifer filtration. Riverbank filtration Riverbank filtration, also called bank filtration, is extensively used in Europe and to a lesser, but not insignificant, extent in North America. The technology is based on use of wells to extract river water following passage through the riverbank and, depending on the distance between the wells and river the aquifer. The riverbank itself can support a biologically active layer somewhat analogous to the schmutzdecke. In addition, silts and sands underlying the riverbank (i.e., the aquifer) can filter water and support biofilms. Thus riverbank filtration is based on contaminant removal by physical and biological processes. Aquifer filtration Prior to extraction from a well, groundwater flows through the aquifer where it is subjected to natural biodegradation processes. Microorganisms present on aquifer media (e.g., sand, silt, etc.) are capable of oxidizing, reducing, or transforming various contaminants depending on the geochemistry of the aquifer and other factors. This process also plays an important role in further purification of treated wastewater when recharged into the aquifer. Aquifer filtration is thus based on physical and biological treatment mechanisms. Bioreactor Processes Bioreactor processes are distinguished from traditional biological filtration processes as they are designed for biological activity independently of the treatment objective of particulate removal. Bioreactor processes, which place more emphasis on biological contaminant removal compared to physical and chemical contaminant removal, are anticipated to play a more significant role in the years to come with the increasing emphasis on removal of emerging contaminants including anoxic biological treatment of perchlorate and nitrate and aerobic biological treatment of ammonia and other contaminants.

99 Chapter 6: Workshop 73 Anoxic biological treatment Perchlorate and nitrate can be biologically reduced to innocuous chloride ions and nitrogen gas, respectively. This process is currently used in Europe to treat drinking water sources contaminated with nitrate. The processes can include a variety of engineered configurations (e.g., packed or fixed bed, fluidized bed, membrane systems, etc.). Both heterotrophic and autotrophic processes have been used. Heterotrophic systems involve addition of a biodegradable organic carbon source called an electron donor (e.g., acetic acid) and nutrients (e.g., phosphoric acid) and autotrophic systems involve addition of an inorganic electron donor (e.g., hydrogen) and nutrients to promote anoxic biological reduction of nitrate to nitrogen gas or perchlorate to chloride ion. The reactor effluent is subsequently aerated and passed through an aerobic rapid rate filtration process to remove biodegradable organic carbon and suspended solids prior to entering the distribution system. Such processes have been demonstrated to be reliable through extensive pilot testing, are currently scheduled for construction in North America, and are anticipated to be producing drinking water within the next few years. These processes primarily employ biological mechanisms for contaminant destruction (e.g., perchlorate into chloride and oxygen) and/or transformation. Conclusions Biological treatment of drinking water is an integral component in many treatment plants in North America. Typically, biological mechanisms for contaminant removal work synergistically with well-established physical and chemical mechanisms. This powerful combination of biological, chemical, and physical mechanisms results in cost-effective processes for production of high quality water. Increasing demands for high quality water and sustainable processes for its production necessitate the best use of the available tools and treatment approaches including biological treatment.

100 74 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Figure 6.1 Organization of Biological Processes for Drinking Water Treatment

101 Chapter 6: Workshop 75 Table 6.1 Classification of Biological Drinking Water Treatment Processes Generalized Potential for Treatment Effectiveness Natural organic System Classification Biological stability (e.g., low assimilable organic carbon [AOC]) matter [NOM], taste & odor, microtoxins (e.g., geosmin) Synthetic organic compounds (e.g., pharmaceutical and personal care products [PPCPs]) Disinfection byproduct precursors Filtration Processes Inorganics (e.g., nitrate, perchlorate) Slow sand High Moderate Moderate Moderate Moderate filtration Rapid rate filtration a) Without preoxidation Moderate Low Low Low Low b) With preoxidation High High High Moderate Moderate GAC filtration a) Without preoxidation Moderate Moderate Moderate Moderate Low b) With preoxidation High High High High Low Natural Filtration Processes Riverbank High Moderate Moderate Moderate Low filtration Aquifer filtration High Moderate Moderate Moderate Low Bioreactor Processes Anoxic biological Low Low Low Low High treatment Note: The potentials for treatment effectiveness are solely intended to be used as a general guide and are not intended to be used for design. Actual treatment effectiveness is affected by many factors including the specific contaminant, source water quality and conditions, treatment process design and operation, and presence of specific strains of bacteria.

102 76 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America RESEARCH ROADMAP The workshop included extensive discussions on what is known about biological filtration (i.e., what should not be researched further) and on future directions for research. The first half-day included general discussions and the second half-day focused on development of research topics. Each of these research topic descriptions include: 1) title, 2) description, 3) justification, and 4) expected outcomes. This section presents a summary of the general discussions followed by the individual research topic descriptions. What is n As described in the article manuscript introduction, biological treatment is defined as a process that is partly or wholly dependent on biological mechanisms to achieve treatment objectives. The treatment process may be managed or incidental with respect to design, operations, and monitoring. We know how to design rapid rate filtration and GAC filters for multiple and concurrent treatment objectives, but the design process has limited consideration for biological activity and effects on water quality. We also know how to design anoxic processes for treatment of nitrate and perchlorate. Biological filtration is being used at many water treatment plants with limited operational guidance specific to biological filtration. Monitoring of these processes is also limited and is not specific to the biological processes. Anoxic biological treatment of nitrate and perchlorate is an exception in that it can be monitored and operated well however these processes are not yet operating at a full-scale in North America. Less is known about anoxic treatment of other contaminants. Gaining approval or acceptance of biological filtration by different industry professionals (e.g., utilities, regulators, consultants, etc.) is often challenging as was illustrated by the survey. Part of the challenge stems from the fact that current regulations do not distinguish between biological processes and physical-chemical processes. Additionally, there is a negative perception among some regulators and utilities toward biological processes in fact some states do not allow biological treatment. Part of this perception is based on general concerns regarding safety of the process. Identified Research Topics The research topic descriptions below cover various areas including sustainable technology evaluation and selection, design and operations, effects of source water quality on performance, downstream treatment, and process innovations. These topics were not prioritized and the order of presentation does not reflect any prioritization. In addition to the identified research topics, there is a general need for research and education programs that address technology approval and acceptance. These programs may include the following elements: Explore and evaluate possible design parameters, operation parameters, and monitoring tools that may require regulatory approval and compliance monitoring. Identify design parameters that potentially require regulatory approval. Identify water quality parameters that potentially require regulatory approval. Identifying operational and monitoring parameters that are necessary for compliance.

103 Chapter 6: Workshop 77 Develop education materials explaining the benefits of biological treatment. Create promotional materials specifying the benefits and limitations of biological treatment and describing the new tools. Develop regulatory acceptance documents through EPA or the Association of State Drinking Water Administrators (ASDWA). Developing a Comprehensive Technology Evaluation Framework Incorporating Sustainability Metrics Description: Develop a framework for evaluating the sustainability of different treatment processes to facilitate process selection. Test the framework by comparing several biological treatment processes against conventional processes. Justification/Need: Biological treatment processes likely have many benefits in providing sustainable production of high quality drinking water. However, there is no framework for making comparisons among treatment options, particularly with respect to sustainability. More systematic and comprehensive analyses are needed to better understand viable choices for utilities. Approach: Framework would be developed and tested against several biological treatment processes (e.g., biological stability, organic carbon, nitrate, perchlorate) and conventional processes for contaminant removal. Address parameters including: site, construction materials, energy, green house gas emissions, chemicals, residual streams, renewable resources, etc. Evaluate other environmental impacts, process stability, operator safety, operator training requirements, secondary benefits, costs, etc. Analysis will utilize various existing information sources (published and grey literature) and data collection. Expected Research Outcomes: Provide a basis for making sound decisions on process selection. Provide a basis for articulating the benefits of biological treatment to utilities, regulators and other stakeholders. Enumerate the hidden environmental and ecological costs of various process decisions.

104 78 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Benefits and Consequences of Converting Water Treatment Plants to Biological Filtration Objective: Develop a guidance manual for utilities and regulators to facilitate the conversion of conventionally operated unit processes and filters to biological mode. Justification/Need: Utilities currently lack information to fully consider the benefits and consequences of converting filters to a biological mode (i.e., filters without the continuous application of a disinfectant). Likewise, regulatory agencies lack adequate assurances that the conversion to biological filtration will occur without unintended negative consequences. For example, utilities have experienced loss of manganese control, proliferation of higher organisms, problematic growth of algae, increased mud ball formation and loss of filter productivity when converting. Approach: The project team will survey and review prior experiences from utilities that have converted filters. A workshop format should be considered to gather these data and experiences. Identify & partner w/utilities planning to convert to biological filtration. Based on results of survey, project team would engage the utility in performance goal setting, developing operating procedures, training, developing monitoring plans, communicating with regulators/stakeholders, and identifying opportunities for optimization. Expected Research Outcomes: A practical guidance manual that is based on the results of the project and addresses benefits and risks conversion along with methods to minimize these risks or mitigate their consequences.

105 Chapter 6: Workshop 79 Developing Design and Operational Guidelines for New Aerobic Biological Filters Description: The objective of this project will be to develop specific design and operational guidelines for new aerobic biological filters. Primary water quality objectives of these aerobic biological filters can include: Biological stability of finished water in the distribution system. Removal and/or prevention of the formation of specific contaminants including: o Ammonia o Manganese o Disinfection byproducts o Taste and odor o Pharmaceuticals and personal care products o Higher organisms Justification/Need: Current and planned research will develop targets and associated design/operational parameters for achieving biological stability in the distribution system. This research is focused on existing plants that have converted to biological filtration but are not necessarily designed or operated in the most optimal manner. New process designs and operational strategies, that cannot necessarily be implemented at existing plants, need to be developed and will be developed as part of this research. Design and operational guidelines for the specific contaminants listed above have not been developed. Previous research has demonstrated the efficacy for treatment of these specific contaminants. However full-scale treatment plants have not applied these results in practice. Therefore there is a need to develop detailed design and operational guidelines for new plants. Approach: Identification of specific water quality contaminants that are applicable for treatment. Develop water quality objectives and expected treatment performance. Specific process design parameters and recommended ranges. Develop operational guidelines. Integrate monitoring and control strategies developed in other Foundation projects. Bracket anticipated capital and operating costs. Expected Research Outcomes: This research will result in a practical guidance document that will allow utilities to design, build, and operate new aerobic biological filters for attainment of pressing water quality goals. The guidance, especially with respect to operational guidance, will also be applicable to existing biological filters.

106 80 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Linking Aerobic Biological Drinking Water Treatment Process Performance to Source and Pretreated Water Quality Description: This project will focus on directly and mechanistically linking source and pretreated water quality to biological drinking water treatment process ability to achieve improved drinking water biostability and/or removal of taste and odor compounds, disinfection byproduct precursors, PPCPs, etc. relative to conventional treatment processes. Based on the fundamental relationships that are revealed, practical recommendations such as source and pre-treated water quality controls /signals for assessing anticipated process performance and early warning of potential process upset will be provided. Justification/Need: Numerous case studies have demonstrated that aerobic biological drinking water treatment can contribute significant process performance benefits including improved drinking water biostability and removal of taste and odor compounds, disinfection byproduct precursors, PPCPs, etc. Recently, fundamental investigations of source and pretreated water quality have indicated that removal of specific contaminants by commonly utilized treatment processes potentially contributes to increased occurrence of other non-desirable compounds. To better evaluate the costs and benefits of implementing biological treatment to meet specific treatment performance goals, utilities need to be able to assess how variable source and pretreated water quality will impact the ability of biologically active drinking water treatment processes to achieve what are often multiple and concurrent performance targets. Approach: Conduct laboratory, pilot, or full-scale studies to understand the effects of source water quality and pretreatment on biological filtration performance. Develop a framework for assessing the effects of source water quality and pretreatment on biological filtration. Expected Research Outcomes: Both fundamental science and practical outcomes are expected. Specific measures of source and pretreated water quality that are directly and mechanistically linked to the performance of biologically active drinking water treatment processes will be identified. Where possible, practical approaches for measuring the identified source and pre-treated water quality metrics will be presented. A framework for assessing the potential vulnerability of biological drinking water treatment process performance to variable source and pre-treated water quality will be developed and its use demonstrated. The relative benefits and consequences of biologically active drinking water treatment process performance relative to conventional treatment performance in response to variable source and pre-treated water quality will also be evaluated.

107 Chapter 6: Workshop 81 Leveraging Existing Information on Anoxic Biological Processes Description: Summarize full-scale European experience on full-scale applications for nitrate removal. Compare and contrast current experiences to document performance of anoxic processes, water quality issues, and identify knowledge gaps. Justification/Need: A framework is needed for the wide spread acceptance of anoxic processes. Anoxic biological treatment is currently used successfully in Europe for production of drinking water. Establish a framework for current practices identify knowledge gaps and acceptance for wide spread water treatment. Need to document data for performance, monitoring, control, design criteria, operating experience, and cost. Triple-bottom line analysis is also needed. Approach: Conduct a literature review and case studies on existing full-scale plants including: o Full-scale European experience o Full-, demonstration-, pilot-scale North American experience o Proprietary and non-proprietary systems All relevant pilot and bench-scale studies should be included. Expected Research Outcomes: Synthesis document on the state of knowledge of the implementation of biological anoxic drinking water contaminants. The document will address quality of the water being treated, type of process being used, operations and design criteria, performance outcomes, unintended consequences, costs, downstream treatment requirements, and regulatory aspects. The document could be available electronically as an anoxic knowledgebase.

108 82 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Impacts of Biological Treatment Processes on Downstream Disinfection Project Description: Evaluate disinfection efficacy for organisms released by biological water treatment. Develop an approach to determine the disinfection dosing and/or contact time to show adequate disinfection of organisms. Use the data to document and demonstrate safety of biological treatment processes. Justification/Need: Some utilities and regulators have expressed concerns regarding the safety of biological filtration. Utility experience has shown apparent increases in undesirable organisms; however, the associated health risks are not fully understood. A better understanding is needed on how disinfection affects the viability of sloughed organisms in various physical forms (e.g., attached to particles, internalized in higher organisms, or aggregated in flocs). There is also a growing concern of aggregation and internalization (bacteria, protozoa). Approach: Characterize downstream disinfection requirements and performance in full-scale aerobic biological filters and anoxic bioreactors. Determine the effects of particle attachment, aggregation, and internalization on disinfection requirements. There should not be a focus on creating a list or speciation of the bacteria. Expected Research Outcomes: An understanding of how downstream disinfection impacts organisms released from aerobic biological filters and anoxic bioreactors. Data that can demonstrate the safety of currently required disinfection practices when implemented downstream of biological drinking water treatment processes and/or identification of required process modifications.

109 Chapter 6: Workshop 83 Identifying Performance Ranges for Biological Stability Following Anoxic Bioreactor Treatment Project Description: Develop biological stability goals for anoxic bioreactor processes. Develop guidance on the management of distribution systems receiving water from anoxic bioprocesses. Justification/Need: Past experience with aerobic biological filtration has provided a framework for assessing regrowth in the distribution systems. It is recognized that anoxic bioreactor processes that involve the addition of organic or inorganic electron donors may: o Lead to growth of biomass and release of microorganisms and microbial products in to treated water. o Result in breakthrough of unreacted donors which may represent a regrowth potential in the distribution system. The differences between aerobic biological filtration and anoxic bioreactor processes with respect to biological stability are not well understood. Approach: Monitor laboratory, pilot-scale, and full-scale systems to bracket the typical range of electron donor concentrations in the effluent. Evaluate other anoxic bioreactor contributors to biological instability including fermentation products, low oxidation-reduction potential, etc. Determine the regrowth potential based on the above parameters and determine whether electron donor concentration alone is sufficient to establish biological stability. Expected Research Outcomes: Identification of parameters and metrics for biological stability in anoxic bioreactor effluents. Guidance on when downstream treatment following anoxic bioreactor treatment is required.

110 84 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Downstream Treatment Following Anoxic Perchlorate & Nitrate Bioreactor Processes Description: Develop technical requirements and guidance for downstream treatment following anoxic perchlorate and nitrate treatment. Tailor guidance to specific bioreactor processes and for specific water quality requirements. Justification/Need: The first anoxic bioreactor systems are being designed and installed in California and have strict downstream treatment requirements. These requirements substantially add to the total treatment cost and plant footprint. The technical and regulatory requirements are conservative in part because these are the first full-scale anoxic treatment plants in the United States. Identification of cost-effective downstream treatment processes that are protective of human health is required to increase the acceptance of these processes. Approach: Characterize full-scale designs and operating configurations in Europe for downstream treatment requirements with respect to taste and odor, residual organics, disinfection byproducts, pathogens, etc. Evaluate performance of the various configurations operating in Europe and, if operating, newly installed systems in the U.S. Expected Research Outcomes: Documented performance of various treatment configurations that are implemented downstream of anoxic bioreactor processes. Design and operational guidance for downstream treatment.

111 Chapter 6: Workshop 85 The Next Generation of Biological Filtration Description: This project would seek to enhance the performance of biological filters through the addition of nutrients or other compounds to stimulate biological activity in increase treatment effectiveness. Justification/Need: For the most part biological filters have been a passive process where biological activity naturally occurs. It is known that cometabolism can enhance the removal otherwise poorly biodegraded products. In addition, some biological processes may lack essential nutrients (e.g., nitrogen, phosphorus, trace metals, etc.) for optimal performance. Approach: Literature review and case studies of existing systems. Provide theoretical basis for process improvement: catabolite repression, cometabolism, nutrient limitations, etc. Target candidate compounds. Evaluate biological processes that may lack essential nutrients (e.g., nitrogen, phosphorus, trace metals, etc.) for optimal performance. Evaluate seeding of biological filters with bacteria with specific capabilities. Expected Research Outcomes: New techniques and processes for optimized performance. New applications of biological filtration for recalcitrant compounds. Better understanding on what is limiting biological filter performance. Documentation of any adverse consequences.

112 86 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America The Next Generation of Biological Treatment: From Biological Filters to Dual Stage Bioreactor and Filtration Processes Description: Develop a new generation of treatment processes that combine an advanced filtration step with an upstream biological process. These new multiple-stage configurations allow optimization of the biological treatment aspect independently of turbidity removal, hence enabling optimum overall performance. Justification: In designing current biological filters engineers have to compromise between many objectives and process considerations. Turbidity removal considerations prevail above biological considerations. Similarly operators have to meet various objectives with their biological filters and are balancing various goals such as turbidity removal, nitrogen management considerations and biological stability objectives. Ultrafiltration and microfiltration have gained general acceptance and are being installed by many utilities to achieve higher turbidity and cryptosporidium removals. Also microfiltration and ultrafiltration are replacing conventional granular media filters as a pretreatment before reverse osmosis units for desalination (brackish and sea water) and wastewater reuse. However UF/MF performance with regards to AOC removal and biostability may not be as good in many cases as granular filters performance (due in part to the lack of biological treatment mechanisms is these processes). Approach: Conduct a literature review of two-stage bioreactor/membrane filter processes used. Identify promising configurations that warrant further evaluation. Conduct laboratory and pilot studies to demonstrate the utility and effectiveness of these novel treatment systems. Expected Research Outcomes: A documented review of novel multiple- stages treatment trains incorporating biological treatment steps and separate filtration steps (with a specific focus on membranes). Generation of hard data on the performance, benefits and shortcomings of these novel processes from pilot studies developed at utility sites.

113 Chapter 6: Workshop 87 Treatment of Multiple Contaminants Using Anoxic Bioreactor Processes Description: Development and validation of anoxic bioreactor treatment processes for contaminants other than perchlorate and nitrate. Development and validation of anoxic bioreactor treatment processes for simultaneous removal of multiple contaminants Justification/Need: Anoxic bioreactor processes have been demonstrated to be capable of treating perchlorate and nitrate and full-scale systems are being designed and built in the U.S. Other contaminants can potentially be treated using anoxic processes including bromate, arsenic, hexavalent chromium, selenium, uranium, and select PPCPs. Anoxic bioreactor processes can also treat multiple contaminants simultaneously. The design, operating, control, monitoring criteria and performance for these processes is not established. Approach: Conduct laboratory and pilot tests demonstrating the potential of anoxic bioreactor processes for treatment of multiple contaminants. Expected Research Outcomes: Guidance on the applicability of anoxic bioreactor processes for treatment of multiple contaminants.

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115 CHAPTER 7 CONCLUSIONS AND RECOMMENDATIONS CONCLUSIONS General Survey Biological treatment is of great interest to the drinking water industry based on the response to this survey. Utility professionals by far provided the greatest number of responses to the survey but regulators and consulting professionals were also well represented. Academic, vendor, and DoD professionals also provided input but to a lesser extent. s across the U.S. were obtained with 49 out of 50 states being represented. International responses were also received though to a lesser extent. Therefore the survey results are primarily representative of U.S. experiences with and perspectives on biological drinking water treatment. Conclusions based on these results are as follows: The perceived use and acceptance of biological drinking water treatment varied among different professional groups. About ten percent of utility and regulator professionals considered aerobic biological treatment to be used to a wide-tomoderate extent compared to about half of consultant and academic professionals. In general professionals considered anoxic biological drinking water to be used to a lesser extent than aerobic biological drinking water treatment which is the case currently there are no full-scale anoxic biological drinking water plants in operation in the U.S. The differences in perception among different professionals are attributable to varying degrees of awareness and/or appreciation of the process that is compounded by a lack of standard process definitions and terminology. Clearly there is a need for standardization of terminology and process definitions in the field of biological drinking water treatment. Also, the divergence of opinions and the high level of Don t responses suggest a lack of a shared knowledge base and a need for educational outreach efforts. People are drawing conclusions based on different understandings of the processes, which are shaped by a lack of information, rather than the processes themselves. With respect to acceptance of biological processes, utility and regulator professionals weighed public health protection very strongly compared to other concerns (e.g., environmental footprint). Consultant and academic professionals believed biological processes are safe and demonstrated a greater willingness to embrace their use. Nevertheless, most professionals in all groups considered acceptance of biological drinking water treatment to be low and not easy to increase when compared to conventional treatment. On the other hand, many professionals believe there is a strong-to-moderate likelihood that anoxic biological drinking water treatment for nitrate and perchlorate will be accepted in the next five to seven years. Varying opinions regarding the most significant barriers to acceptance were held by the different professional groups. In addition, a wide range of opinions existed within each professional group indicating a lack of consensus. With respect to 89

116 90 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America general biological drinking water treatment, utility professionals considered permitting and regulations, public perception, insufficient full-scale experience, potential public health risks, reliance on/use of microorganisms, and operator training/certification to be to most significant barriers. Of these potential barriers, insufficient full-scale experience was most consistently considered by all professions to be one of the most significant. Other barriers often elicited very different responses. For example, permitting and regulations were considered to be of high significance by utilities, moderate significance by consultants, and low significance by regulators. These differences of opinions among professions can indicate a difference in priorities but also can indicate a difference in technology understanding or awareness. Thus in addition to these specific acceptance barriers, a lack of unified understanding and definition of biological drinking water treatment can also be considered as a potential barrier to acceptance. Technology acceptance barriers for future acceptance of anoxic biological drinking water treatment for nitrate or perchlorate were considered to be greater when compared to biological treatment in general. Various methods are possible for overcoming these barriers. Most professionals considered more full-scale systems, regulatory acceptance documents, and industry research to be effective tools for overcoming acceptance barriers. The recommendation that more full-scale systems are needed to overcome acceptance barriers is in part attributable to a lack of awareness of the extent to which aerobic biological drinking water treatment is currently practiced. Thus case studies of fullscale systems can be an effective tool for education and outreach. Two full-scale anoxic biological drinking water systems for perchlorate or nitrate are currently being designed in California. The permitting and operation of these systems will greatly facilitate acceptance of anoxic biological drinking water treatment in the U.S. Regulatory acceptance documents are practical tools that can create a common basis for technology application, can be used by multiple professional groups, and can result in increased technology acceptance. Most professional groups listed research as having a high impact on technology acceptance and contaminant removal was most frequently cited as a research priority followed by safety. Research into contaminant removal will be particularly important in expanding the application of biological drinking water treatment especially with respect to high profile contaminants such as EDCs and PPCPs. Safety was listed as the second highest research priority and has been addressed historically by the Water Research Foundation. Safety concerns can additionally be addressed via full-scale case studies. For example, in the electronic case studies discussed below, safety was not expressed as a significant operational concern. Monitoring and control of biological treatment processes was also listed as a research need and is the focus of a new Water Research Foundation project. Aerobic biological treatment was considered most suitable for treatment of AOC/BDOC, TOC and DBP precursors, and taste and odor compounds. Anoxic biological drinking water treatment was considered most suitable for treatment of perchlorate, nitrate, and nitrite. Conventional drinking water treatment was considered most suitable for treatment of iron/manganese, turbidity/particle counts, and HPC bacteria/total coliforms, but also for TOC/EDC precursors, taste and odor

117 Chapter 7: Conclusions and Recommendations 91 compounds, and color. These results contrast with electronic case study results as described below. Finished water generated by biological processes was generally considered by professionals not to be equivalent (i.e., worse) to that generated by conventional processes. These results also contrast to those obtained in the case studies below. Significant uncertainty among utility professions existed with respect to design, operations and maintenance, training, staffing, and regulatory requirements for biological drinking water treatment. Consultant professionals on the other hand considered the level of effort for design and operation of aerobic biological drinking water treatment to be similar to that for conventional treatment. The opinion may be attributable to the typical design process for aerobic biological filtration being similar if not nearly identical to the process for conventional media filtration. The use of conventional process design tools for biological treatment processes stems from the lack of design, monitoring, and control guidance for biological drinking water treatment. Specific concerns associated with biological drinking water treatment included bacterial sloughing/breakthrough, pathogen or contaminant breakthrough, and unknown/changing regulatory conditions. These concerns were considered to be significant by all professional groups including regulatory professionals. Electronic Case Studies The electronic survey also offered drinking water professionals the option to provide case studies. Survey questions were designed to determine the general type of drinking water treatment process being used and then specific questions were asked about each process. Conclusions based on these cases studies were as follows: A process selection decision tree was a useful means of categorizing biological drinking water treatment processes. The biological process categories included ozone-enhanced biological filtration (OEBF), rapid biological filtration (RBF), granular activated carbon biological adsorption (GBA), slow biological filtration (SBF), and biological perchlorate/nitrate process (BPNP). About 60 percent of the case studies involved use of biological drinking water treatment processes. This value is much greater than the extent to which professionals perceive that biological drinking water treatment is used. Therefore, it is reasonable to conclude that biological drinking water treatment is actually used to a greater extent than currently thought. Of the biological drinking water treatment case studies, the majority that were based on full-scale treatment plants involved ozone enhanced biological filtration or rapid biological filtration. Many case studies involved biological perchlorate/nitrate processes but were mostly based on pilot studies since fullscale drinking water plants do not exist today in the U.S. The number of treatment plants involving GAC biological adsorption was relatively small. This last process was also considered to be incidental rather than managed. The other biological processes were all managed. Therefore, GAC biological adsorption case studies may be under represented since many utilities may not be aware that their post filtration GAC contactors are generally biologically active. Since GAC has been

118 92 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America demonstrated to support greater concentrations of heterotrophic bacteria, greater emphasis on the GBA process is warranted. The case studies indicated that biological drinking water treatment processes are capable of treating a broader group of contaminants and with better performance than is perceived by many professionals. TOC and DBP precursors, AOC/BDOC, taste and odor compounds, iron/manganese, turbidity/particle counts, and color removals were shown to be greater in the aerobic biological treatment case studies relative to the general survey perceptions. In addition, removals of many of these constituents were similar to or better than removals by conventional treatment processes. Perceptions and reality were more in line with each other for anoxic biological treatment processes. Perchlorate/nitrate/nitrite was considered most suitable for removal by this process both in the general survey and in the case studies. In general the case studies indicated that biological processes had positive or neutral effects on finished water quality. Very few negative effects were observed. These positive perspectives from the survey respondents who completed the case studies contrast to the less positive perspectives of the general drinking water industry observed in the general survey. The levels of operational concerns for biological drinking water treatment expressed in the case studies were generally no-to-low or moderate. The general survey responses indicated greater operational concerns further illustrating the gap between perceived and actual concerns of biological treatment the concerns are perceived to be greater than they are in reality. Operational strategies including backwashing varied widely among the case studies. This variability may be attributable to differences in source water quality nevertheless it indicates that generalizations regarding operations may not be possible based on the current understanding of the processes. A lack of direct monitoring of biological process parameters (e.g., bacterial concentrations or activity) complicates the development of operational guidelines because the necessary data are not being collected. While many questions exist, most case study respondents agreed that temperature and consistent operations were the most important factors affecting performance. Most case study respondents also indicated that a greater number of operators and higher operator classification were not required. Telephone Case Studies Based on the telephone case studies biological drinking water treatment is being used in numerous locations across North America and Europe. The manner in which it is implemented and used varies: Incidental approach (e.g., discontinuing chlorine upstream of a filter to reduce DBPs). Managed approach (e.g., design and operate the process with the intent of optimizing or promoting biological activity).

119 Chapter 7: Conclusions and Recommendations 93 Regulatory agencies (i.e., Ohio EPA, California Department of Public Health, Oregon Health Division, and Virginia Department of Public Health) were accepting of biological processes though the opinions were not uniform within some agencies (e.g., California Department of Public Health). Biological processes with the exception of anoxic BPNP have not been optimized within many if not most of the treatment plants. There is a significant opportunity for improving the removal of regulated and un-regulated substances. Nevertheless, performance of these biological processes was generally good and provided high quality finished water in the distribution system. Generally, problematic operational issues were not encountered. Therefore, these telephone case studies confirm and expand upon the positive attributes of biological drinking water treatment identified in the electronic case studies. RECOMMENDATIONS General recommendations based on these conclusions are as follows. 8 Additional specific recommendations for utilities are presented in Chapter 8. Additional case studies on aerobic full-scale drinking water treatment plants should be developed with a focus on dispelling many of the misconceptions of biological drinking water treatment. As full-scale anoxic biological perchlorate/nitrate processes are commissioned in the U.S. in the next few years, case studies should be conducted to establish confidence in the technology for drinking water treatment. These case studies will be very important since these processes function predominately via biological contaminant removal mechanisms whereas most of the aerobic biological drinking water treatment plants function via a combination of physical, chemical, and biological mechanisms. Development of regulatory acceptance documents for biological drinking water treatment is recommended. Possible venues for development and publication of such documents include the Water Research Foundation, the U.S. EPA, and the Interstate Technology & Regulatory Council (ITRC). Create clear and consistent terminology and process definitions for biological drinking water treatment. The terms used in this report (OEBF, RBF, GBA, SBF, and BPNP) can be used as an initial platform for development of such terminology. Continue and expand biological drinking water treatment research in the areas of contaminant removal, safety, and monitoring and control. Develop new on-line monitoring tools and laboratory methods to optimize biological treatment processes in full-scale operation. Expand education and outreach efforts to familiarize drinking water professionals with the benefits of biological drinking water treatment and to assuage perceived technology acceptance concerns. 8 These order in which the recommendations are presented does not reflect any prioritization.

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121 CHAPTER 8 RECOMMENDATIONS TO UTILITIES Biological treatment is defined as a process that is partly or wholly dependent on biological mechanisms to achieve treatment objectives. Biological drinking water treatment processes often improve the biological stability of water in distribution systems. Biological stability of drinking water is a concept that refers to the potential for biofilm and/or pathogen growth in the distribution system the more biologically stable the finished water, the less the potential for biofilm and pathogen growth in the distribution system. Other purposes of biological treatment include removal of contaminants such as disinfection byproduct precursors, taste and odor compounds, pharmaceuticals, iron, manganese, ammonia, nitrate, and perchlorate. The Water Research Foundation has sponsored extensive research in this area and a list of these projects is included in Appendix G. Drinking water treatment plants use a variety of physical and chemical treatment processes, and many of these plants also use biological processes. However awareness of these processes by drinking water industry stakeholders particularly water utilities and regulatory agencies, is often low. Utilities should consider re-assessing the role of biological processes for optimizing their treatment plants. A first step in the re-assessment can simply involve use of the process selection decision tree developed for this survey to categorize the drinking water treatment process. The decision tree can be used to quickly evaluate an existing treatment process train with respect to whether beneficial biological processes are present in the treatment process train or not. Additional evaluations can then be conducted to assess whether new biological treatment processes can be used to produce high quality water. A second step is to develop an applied understanding of biological treatment processes and microbiology among utility staff to increase awareness and facilitate optimization of those processes. A starting point may include reviewing on-line resources (e.g., Wikipedia searches on microbiology and bacteria ) and text books such as Brock Biology of Microorganisms. If practical, a more in-depth understanding may be developed by enrollment in applied microbiology courses and training. The focus of the selected course or training should have an environmental microbiology focus rather than a medical microbiology focus. Examples can include groundwater and wastewater microbiology. With this enhanced understanding utilities will be in a better position to monitor beneficial biological processes in their plants and assess biological the significance of these processes. In addition, utilities will be in a better position to monitor the environmental conditions or parameters that affect these processes. A third step is to determine what monitoring and control tools merit use for biological process optimization. Monitoring of the biological processes is an important prerequisite to optimizing performance. Even though limited guidance is currently available on how biological drinking water treatment processes should be monitored and controlled, initiation of efforts toward collection of biological process data (e.g., biomass concentration on filter or GAC media) will facilitate development of understanding and baselines for the processes. The Water Research Foundation has initiated a new research project that specifically addresses this topic. A fourth step is to consider completing case studies, papers, and presentations on process. Education and outreach is highly recommended with a particular focus on benefits, technology acceptance, design considerations, operational requirements, and performance. For those utilities that do not currently have a biological treatment process, consider the potential benefits of 95

122 96 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America biological treatment and identify retrofits or changes in operational procedures that would be required to initiate biological treatment. Compare the value of these benefits to the costs of identified changes. Pilot-scale testing may be needed to quantify the benefits and collect process data necessary to estimate costs. With this information an informed decision can be made as to whether conversion to biological treatment makes sense for each treatment plant.

123 APPENDIX A SURVEY QUESTIONS 1. (G1) Are you a resident inside the U.S.? 2. (G2-US) In which state do you live? 3. (G2-INT) In which country do you live? 4. (G5) Choose the one category that best describes your profession. 5. (U-TA-1) Do you believe that biological water treatment processes are generally accepted by the drinking water industry, i.e., the same as conventional treatment? 6. (U-TA-2) Characterize the extent to which biological water treatment processes are used. 7. (U-TA-3) How difficult is it to gain acceptance of biological treatment processes when compared to conventional treatment? 8. (U-TA-4) What do you think are the most significant barriers to acceptance of any type of biological treatment processes in drinking water treatment plants? 9. (U-TA-5) In your own opinion, how significant are the following operational concerns associated with any type of biological treatment processes? 10. (U-TA-6) For the following stakeholder groups, what methods do you think will be most successful to help them gain acceptance of biological treatment processes? (Check all that apply for each row.) 11. (U-TA-7) What do you think is the likelihood of acceptance for anoxic or anaerobic biological treatment processes for perchlorate/nitrate removal in drinking water treatment plants within the next 5 to 7 years? 12. (U-TA-8) What do you think are the most significant barriers to future acceptance of anoxic or anaerobic treatment processes (e.g., for treatment of perchlorate or nitrate) in drinking water treatment plants? 13. (U-TA-9) Characterize each process with respect to level of effort. 14. (U-TA-10) For each treatment process (i.e., for each column), choose up to three contaminants you believe are especially suitable for removal by that process. 15. (U-TA-11) With respect to finished water quality compare biological processes with conventional treatment processes using the criteria below. 16. (U-TA-12) How will additional research promote acceptance of biological processes for drinking water? 17. (U-TA-13) Should the following biological treatment processes be: 18. (U-TA-14) In your own opinion, list research priorities for biological treatment of drinking water. 19. (U-TA-15) Please list any additional technology acceptance issues that have not been addressed in this survey. 20. (U-TA-16) Do you have a water treatment plant or pilot plant that could serve as a case study? If so you will be asked additional questions about that plant. 21. (WTP-G-1a:1) Provide the following information for the water treatment plant. 22. (WTP-G-1b:1) Provide the following information for the water treatment plant. 23. (WTP-G-2:1) What is the capacity and population served for this water treatment plant? 24. (WTP-G-3:1) What type of water source(s) is used for this treatment plant? 25. (WTP-G-4a:1) Characterize the average source water quality for this water treatment plant for the following parameters. 97

124 98 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America 26. (WTP-G-4b:1) Characterize the average source water quality for this water treatment plant for the following parameters. 27. (WTP-G-5:1) Does this water treatment plant involve a biological treatment process for perchlorate/nitrate removal? 28. (RES-1:1) Is any disinfectant residual generally present in water exiting treatment train filters but before any supplemental disinfectant addition? 29. We have concluded that your process is a conventional and non-biological treatment process. Would you like to provide data for another case study? 30. (OZ-1:1) Does your treatment train include an ozone process? 31. (GAC-1:1) Does your treatment train include a post-filter granular activated carbon (GAC) contactor? 32. (SSF-1:1) Does your treatment train include a slow sand filtration process? 33. (OEBF-1:1) Was the biological water treatment process designed as a "managed" or "incidental" process? 34. (OEBF-2:1) Choose one or more contaminants removed by the biological process. 35. (OEBF-3:1) How significant are the following operational concerns for your biological treatment process? 36. (OEBF-4:1) Choose up to three source water quality parameters that most significantly impact performance of the biological process. 37. (OEBF-5:1) What plant operating conditions impact performance of the biological process? 38. (OEBF-6:1) How does the biological water treatment process impact the water quality in the distribution system? 39. (OEBF-7:1) Based on plant operations, what is the optimal ozone dose and/or ozone to TOC ratio for enhancing biological filtration performance? 40. (OEBF-8:1) What is your final disinfectant? 41. (OEBF-9:1) What is your target disinfectant residual leaving the plant? 42. (OEBF-10:1) What dose do you need to achieve your target disinfectant residual? 43. (OEBF-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? 44. (OEBF-12:1) Choose one or more approaches currently used to produce biologically stable water leaving the plant: 45. (OEBF-13:1) Choose one or more approaches currently used to maintain biologically stable water in the distribution system. 46. (OEBF-14:1) What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? 47. (OEBF-15:1) What percent of the time is the biological water treatment process in continuous operation? 48. (OEBF-16:1) How is performance of the biological water treatment process impacted by taking it off-line for an extended period (> 1 week)? 49. (OEBF-17:1) What type of washwater is used to backwash the biological water treatment process? 50. (OEBF-18:1) What is the average backwash frequency for the process? 51. (OEBF-19:1) Does having a biological process trigger the need for additional plant operators over a conventional process?

125 Appendix A: Survey Questions (OEBF-20:1) Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes? 53. (OEBF-21:1) Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? 54. (OEBF-22:1) Do you have another water treatment plant or pilot plant that could serve as a case study? If so you will be asked additional questions about that plant. 55. (RBF-1:1) Was the biological water treatment process designed as a "managed" or "incidental" process? 56. (RBF-2:1) Choose one or more contaminants removed by the biological process. 57. (RBF-3:1) How significant are the following operational concerns for your biological treatment process? 58. (RBF-4:1) Choose up to three source water quality parameters that most significantly impact performance of the biological process. 59. (RBF-5:1) What plant operating conditions impact performance of the biological process? 60. (RBF-6:1) How does the biological water treatment process impact the water quality in the distribution system? 61. (RBF-7:1) What is your final disinfectant? 62. (RBF-8:1) What is your target disinfectant residual leaving the plant? 63. (RBF-9:1) What dose do you need to achieve your target disinfectant residual? 64. (RBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? 65. (RBF-11:1) Choose one or more approaches currently used to produce biologically stable water leaving the plant. 66. (RBF-12:1) Choose one or more approaches currently used to maintain biologically stable water in the distribution system. 67. (RBF-13:1) What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? 68. (RBF-14:1) What percent of the time is the biological water treatment process in continuous operation? 69. (RBF-15:1) How is performance of the biological process impacted by taking it off-line for an extended period (> 1 week)? 70. (RBF-16:1) What type of washwater is used to backwash the biological water treatment process? 71. (RBF-17:1) What is the average backwash frequency for the process? 72. (RBF-18:1) Does having a biological process trigger the need for additional plant operators over a conventional process? 73. (RBF-19:1) Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes? 74. (RBF-20:1) How was the Rapid Biological Filtration (RBF) process introduced into the water treatment process train? 75. (RBF-21:1) Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? 76. (RBF-22:1) Do you have another water treatment plant or pilot plant that could serve as a case study? If so you will be asked additional questions about that plant.

126 100 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America 77. (BPNP-1:1) What treatment processes were considered for perchlorate and nitrate treatment for meeting water quality and treatment objectives? 78. (BPNP-2:1) What treatment process is being used for perchlorate and nitrate treatment for meeting water quality and treatment objectives? 79. (BPNP-3:1) Choose one or more contaminants removed by the biological process. 80. (BPNP-4:1) How significant are the following operational concerns for your biological treatment process? 81. (BPNP-5:1) Choose up to three source water quality parameters that most significantly impact performance of the biological process? 82. (BPNP-6:1) What plant operating conditions impact performance of the biological process? 83. (BPNP-7:1) How does the biological water treatment process impact the water quality in the distribution system? 84. (BPNP-8:1) What is your final disinfectant? 85. (BPNP-9:1) What is your target disinfectant residual leaving the plant? 86. (BPNP-10:1) What dose do you need to achieve your target disinfectant residual? 87. (BPNP-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? 88. (BPNP-12:1) Choose one or more approaches currently used to produce biologically stable water leaving the plant: 89. (BPNP-13:1) Choose one or more approaches currently used to maintain biologically stable water in the distribution system. 90. (BPNP-14:1) What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? 91. (BPNP-15:1) What percent of the time is the biological water treatment process in continuous operation? 92. (BPNP-16:1) How is performance of the biological water treatment process impacted by taking it off-line for an extended period (> 1 week)? 93. (BPNP-17:1) What type of washwater is used to backwash the biological water treatment process? 94. (BPNP-18:1) What is the average backwash frequency for the process? 95. (BPNP-19:1) Does having a biological process trigger the need for additional plant operators over a conventional process? 96. (BPNP-20:1) Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes? 97. (BPNP-21:1) Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? 98. (BPNP-22:1) Do you have another water treatment plant or pilot plant that could serve as a case study? If so you will be asked additional questions about that plant. 99. (GBA-1:1) Was the biological water treatment process designed as a "managed" or "incidental" process? 100. (GBA-2:1) Choose one or more contaminants removed by the biological process (GBA-3:1) How significant are the following operational concerns for your biological treatment process? 102. (GBA-4:1) Choose up to three source water quality parameters that most significantly impact performance of the biological process.

127 Appendix A: Survey Questions (GBA-5:1) What plant operating conditions impact performance of the biological process? 104. (GBA-6:1) How does the biological water treatment process impact the water quality in the distribution system? 105. (GBA-7:1) What is your final disinfectant? 106. (GBA-8:1) What is your target disinfectant residual leaving the plant? 107. (GBA-9:1) What dose do you need to achieve your target disinfectant residual? 108. (GBA-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? 109. (GBA-11:1) Choose one or more approaches currently used to produce biologically stable water leaving the plant (GBA-12:1) Choose one or more approaches currently used to maintain biologically stable water in the distribution system (GBA-13:1) What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? 112. (GBA-14:1) What percent of the time is the biological water treatment process in continuous operation? 113. (GBA-15:1) How is performance of the biological water treatment process impacted by taking it off-line for an extended period (> 1 week)? 114. (GBA-16:1) What type of washwater is used to backwash the biological water process? 115. (GBA-17:1) What is the average backwash frequency for the process? 116. (GBA-18:1) Does having a biological water treatment process trigger the need for additional plant operators over a conventional process? 117. (GBA-19:1) Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional water treatment processes? 118. (GBA-20:1) What is the empty-bed contact time for the process? 119. (GBA-21:1) Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? 120. (GBA-22:1) Do you have another water treatment plant or pilot plant that could serve as a case study? If so you will be asked additional questions about that plant (SBF-1:1) Was the biological water treatment process designed as a "managed" or "incidental" process? 122. (SBF-2:1) Choose one or more contaminants removed by the biological process (SBF-3:1) How significant are the following operational concerns for your biological treatment process? 124. (SBF-4:1) Choose up to three source water quality parameters that most significantly impact performance of the biological process (SBF-5:1) What plant operating conditions impact performance of the biological process? 126. (SBF-6:1) How does the biological water treatment process impact the water quality in the distribution system? 127. (SBF-7:1) What is your final disinfectant? 128. (SBF-8:1) What is your target disinfectant residual leaving the plant? 129. (SBF-9:1) What dose do you need to achieve your target disinfectant residual? 130. (SBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process?

128 102 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America 131. (SBF-11:1) Choose one or more approaches currently used to produce biologically stable water leaving the plant (SBF-12:1) Choose one or more approaches currently used to maintain biologically stable water in the distribution system (SBF-13:1) What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? 134. (SBF-14:1) What percent of the time is the biological water treatment process in continuous operation? 135. (SBF-15:1) How is performance of the biological water treatment process impacted by taking it off-line for an extended period (> 1 week)? 136. (SBF-16:1) Does having a biological process trigger the need for additional plant operators over a conventional process? 137. (SBF-17:1) Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes? 138. (SBF-18:1) What method is used to clean the slow sand filter? 139. (SBF-19:1) Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? 140. (SBA-20:1) Do you have another water treatment plant or pilot plant that could serve as a case study? If so you will be asked additional questions about that plant (R-TA-1) Do you believe that biological water treatment processes are generally accepted by the drinking water industry, i.e., the same as conventional treatment? 142. (R-TA-2) Characterize the extent to which biological water treatment processes are used: 143. (R-TA-3) How difficult is it to gain acceptance of biological treatment processes when compared to conventional treatment? 144. (R-TA-4) What do you think are the most significant barriers to acceptance of any type of biological treatment processes in drinking water treatment plants? 145. (R-TA-5) In your own opinion, how significant are the following operational concerns associated with any type of biological treatment processes? 146. (R-TA-6) For the following stakeholder groups, what methods do you think will be most successful to help them gain acceptance of biological treatment processes? (Check all that apply for each row.) 147. (R-TA-7) What do you think is the likelihood of acceptance for anoxic or anaerobic biological treatment processes for perchlorate/nitrate removal in drinking water treatment plants within the next 5 to 7 years? 148. (R-TA-8) What do you think are the most significant barriers to future acceptance of anoxic or anaerobic treatment processes (e.g., for treatment of perchlorate or nitrate) in drinking water treatment plants? 149. (R-TA-9) Characterize each process with respect to level of effort (R-TA-10) For each treatment process (i.e., for each column), choose up to three contaminants you believe are especially suitable for removal by that process (R-TA-11) With respect to finished water quality, compare biological processes with conventional treatment processes using the criteria below (R-TA-12) How will additional research promote acceptance of biological processes for drinking water? 154. (R-TA-14) In your own opinion, list the research priorities for biological treatment of drinking water.

129 Appendix A: Survey Questions (R-TA-15) Please list any additional technology acceptance issues that have not been addressed in this survey (REG-1) Does your agency prohibit biological treatment processes for drinking water? 157. (REG-2) Are there any special permits or approvals required for the following biological treatment processes? 158. (REG-3) How many drinking water treatment plants are currently permitted in your state that include the following processes (REG-4) What are the requirements for operation of the treatment process? 160. (REG-5) Does your agency require a higher plant operator classification for biological processes as compared to conventional treatment processes? 161. (REG-6) Does your agency have guidance documents for the design of biological processes? 162. (REG-7) Are you aware of any requirement for a disinfectant residual such as free chlorine or downstream of any biological process (C-TA-1) Do you believe that biological water treatment processes are generally accepted by the drinking water industry, i.e., the same as conventional treatment? 164. (C-TA-2) Characterize the extent to which biological water treatment processes are used: 165. (C-TA-3) How difficult is it to gain acceptance of biological treatment processes when compared to conventional treatment? 166. (C-TA-4) What do you think are the most significant barriers to acceptance of any type of biological treatment processes in drinking water treatment plants? 167. (C-TA-5) In your own opinion, how significant are the following operational concerns associated with any type of biological treatment processes? 168. (C-TA-6) For the following stakeholder groups, what methods do you think will be most successful to help them gain acceptance of biological treatment processes? (Check all that apply for each row.) 169. (C-TA-7) What do you think is the likelihood of acceptance for anoxic or anaerobic biological treatment processes for perchlorate/nitrate removal in drinking water treatment plants within the next 5 to 7 years? 170. (C-TA-8) What do you think are the most significant barriers to future acceptance of anoxic or anaerobic treatment processes (e.g., for treatment of perchlorate or nitrate) in drinking water treatment plants? 171. (C-TA-9) Characterize each process with respect to level of effort (C-TA-10) For each treatment process (i.e., for each column), choose up to three contaminants you believe are especially suitable for removal by that process (C-TA-11) With respect to finished water quality compare biological processes with conventional treatment processes using the criteria below (C-TA-12) How will additional research promote acceptance of biological processes for drinking water? 175. (C-TA-13) Should the following biological treatment processes be (C-TA-14) In your own opinion, list research priorities for biological treatment of drinking water (C-TA-15) Please list any additional technology acceptance issues that have not been addressed in this survey (CON-1) How many research projects have you conducted related to each listed biological treatment processes for drinking water?

130 104 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America 179. (CON-2) How many bench/pilot/full-scale testing projects have you conducted related to each listed biological treatment processes for drinking water? 180. (CON-3) How many design projects have you conducted related to each listed biological treatment processes for drinking water? 181. (CON-4) How many plants have you been involved in the construction related to each listed biological treatment processes for drinking water? 182. (CON-5) How many plants have you supplied equipment for related to each listed biological treatment processes for drinking water? 183. (CON-6) What pre-design studies do you typically perform on drinking water treatment projects? 184. (CON-7) What types of guidance documents do you use for designing the following drinking water treatment processes? 185. (CON-8) For each type of treatment process (i.e., each row), what do you consider to be a typical unit cost range (in $US/gallons per day, $/gpd) for estimating the normalized capital cost for the biological treatment process component? 186. (CON-9) For each type of treatment process (i.e., each row), what do you consider to be a typical or rule-of-thumb unit cost range (in $US/million gallons, $/mg) for estimating the normalized operating and maintenance costs for the biological treatment process component? 187. (CON-10) Do you have a water treatment plant or pilot plant that could serve as a case study? If so you will be asked additional questions about that plant Finally. How did you hear about this survey? 189. (G3) Please provide your contact information (G4) Please enter your address. To receive further information regarding the results from this survey an address must be supplied. We will not use your address for any purpose other than to send you notifications regarding this survey and will not be supplying it to anyone outside the survey team.

131 APPENDIX B COMPLETE SURVEY DATA LIST OF EXHIBITS Exhibit No. Exhibit Title 1 Survey Data 2 (G1) Are you a resident inside the U.S.? 3 (G2-US) In which state do you live? 4 (G2-INT) In which country do you live? 5 (G5) Choose the one category that best describes your profession. 6 (U-TA-2) Characterize the extent to which biological water treatment processes are used. (U-TA-1) Do you believe that biological water treatment processes are generally accepted by the 7 drinking water industry, i.e., the same as conventional treatment? (U-TA-13) Should the following biological treatment processes be: Implemented preferentially 8 since they represent a "green" technology or Implemented cautiously due to concerns over uncertain public health impacts. (U-TA-3) How difficult is it to gain acceptance of biological treatment processes when compared to 9 conventional treatment? (U-TA-7) What do you think is the likelihood of acceptance for anoxic or anaerobic biological 10 treatment processes for perchlorate/nitrate removal in drinking water treatment plants within the next 5 to 7 years? (U-TA-4) What do you think are the most significant barriers to acceptance of any type of 11 biological treatment processes in drinking water treatment plants? (U-TA-8) What do you think are the most significant barriers to future acceptance of anoxic or 12 anaerobic treatment processes (e.g., for treatment of perchlorate or nitrate) in drinking water treatment plants? (U-TA-15) Please list any additional technology acceptance issues that have not been addressed 13 in this survey. (U-TA-6) For the following stakeholder groups, what methods do you think will be most successful to 14 help them gain acceptance of biological treatment processes? (Check all that apply for each row.) (U-TA-12) How will additional research promote acceptance of biological processes for drinking 15 water? 16 (U-TA-14) In your own opinion, list research priorities for biological treatment of drinking water. (U-TA-10) For each treatment process (i.e., for each column), choose up to three contaminants 17 you believe are especially suitable for removal by that process. 18 (U-TA-9) Characterize each process with respect to level of effort. (U-TA-11) With respect to finished water quality compare biological processes with conventional 19 treatment processes using the criteria below. (U-TA-5) In your own opinion, how significant are the following operational concerns associated 20 with any type of biological treatment processes? 21 (REG-1) Does your agency prohibit biological treatment processes for drinking water? (REG-3) How many drinking water treatment plants are currently permitted in your state that 22 include the following processes? (REG-2) Are there any special permits or approvals required for the following biological treatment 23 processes? 24 (REG-4) What are the requirements for operation of the treatment process? 105

132 106 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit No. Exhibit Title 25 (REG-5) Does your agency require a higher plant operator classification for biological processes as compared to conventional treatment processes? 26 (REG-7) Are you aware of any requirement for a disinfectant residual such as free chlorine or downstream of any biological process? 27 (REG-6) Does your agency have guidance documents for the design of biological processes? 28 (CON-1) How many research projects have you conducted related to each listed biological treatment processes for drinking water? 29 (CON-2) How many bench/pilot/full-scale testing projects have you conducted related to each listed biological treatment processes for drinking water? 30 (CON-3) How many design projects have you conducted related to each listed biological treatment processes for drinking water? 31 (CON-4) How many plants have you been involved in the construction related to each listed biological treatment processes for drinking water? 32 (CON-5) How many plants have you supplied equipment for related to each listed biological treatment processes for drinking water? 33 (CON-6) What pre-design studies do you typically perform on drinking water treatment projects? 34 (CON-7) What types of guidance documents do you use for designing the following drinking water treatment processes? (CON-8) For each type of treatment process (i.e., each row), what do you consider to be a typical 35 unit cost range (in $US/gallons per day, $/gpd) for estimating the normalized capital cost for the biological treatment process component? (CON-9) For each type of treatment process (i.e., each row), what do you consider to be a typical 36 or rule-of-thumb unit cost range (in $US/million gallons, $/mg) for estimating the normalized operating and maintenance costs for the biological treatment process component? 37 (WTP-G-2:1) What is the capacity and population served for this water treatment plant? 38 (WTP-G-3:1) What type of water source(s) is used for this treatment plant? 39 (WTP-G-4a:1) Characterize the average source water quality for this water treatment plant for the following parameters. 40 Process Selection Decision Tree Results 41 Was the biological water treatment process designed as a "managed" or "incidental" process? 42 Choose one or more contaminants removed by the aerobic biological process. 43 How does the biological water treatment process impact the water quality in the distribution system? 44 What is your final disinfectant? 45 What dose do you need to achieve your target disinfectant residual? 46 What is your target disinfectant residual leaving the plant? 47 What type of washwater is used to backwash the biological water treatment process? 48 What is the average backwash frequency for the process? 49 Choose one or more approaches currently used to produce biologically stable water leaving the plant. 50 Choose one or more approaches currently used to maintain biologically stable water in the distribution system. 51 What tools or water quality parameters are used or should be used to monitor and control the biological process? 52 Does having a biological process trigger the need for additional plant operators over a conventional process? 53 Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes?

133 Appendix B: Complete Survey Data 107 Exhibit No. 54 Exhibit Title What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? 55 What percent of the time is the biological water treatment process in continuous operation? 56 How is performance of the biological water treatment process impacted by taking it off-line for an extended period (>1 week)? 57 Choose up to three source water quality parameters that most significantly impact performance of the biological process. 58 What plant operating conditions impact performance of the biological process? 59 How significant are the following operational concerns for your biological treatment process? 60 Have your observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? 61 Based on plant operations, what is the optimal ozone dose and/or ozone to TOC ratio for enhancing biological filtration performance? 62 What is the empty bed contact time for the GBA process? 63 How was the RBF process introduced into the water treatment process train? 64 What treatment processes were considered/are being used for perchlorate and nitrate treatment for meeting water quality and treatment objectives? 65 What treatment process is being used for perchlorate and nitrate treatment for meeting water quality and treatment objectives? 66 What method is used to clean the slow sand filter?

134 Exhibit 1 Survey Data TOTAL CONTACTS: Letter and/or sent to valid address Anyone who answered question about their profession % of Total Contacts Anyone who completed a response to initial Technology Acceptance Question (U-TA- 1 or R-TA-1 or C-TA-1) % of Total Contacts Anyone who competed a response to final Technology Acceptance Question (U- TA-16 or REG 7 or CON 10) % of Total Contacts Anyone who answered the final question in the survey (how did you hear about survey?) % of Total Contacts Water Utilities 3, % 357 9% 367 9% 279 7% DoD % 13 28% 13 28% 11 23% Regulatory % 31 34% 25 27% 22 24% Consultants % 42 59% 31 44% 29 41% Vendors % 7 58% 3 25% 2 17% Academics % 17 46% 11 30% 9 24% Total 4, % % % 352 8% Note: Utilities - US 3905 Utilities - Foreign 23 Exhibit 2 (G1) Are you a resident inside the U.S.? (* Indicates mandatory question) Percent Yes 95.1% 788 No 4.9% 41 answered question 829 skipped question Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

135 Appendix B: Complete Survey Data 109 Exhibit 3 (G2-US) In which state do you live? (* Indicates mandatory question) ANYONE WHO COMPLETED A RESPONSE TO U-TA-1 OR R-TA-1 OR All s C-TA-1 (UPDATE GRAPHIC AND SLIDE #1 WITH THIS DATA) (EO: 11/6/08) AL: ALABAMA 12 8 AK: ALASKA 1 1 AS: AMERICAN SAMOA 0 0 AZ: ARIZONA AR: ARKANSAS CA: CALIFORNIA CO: COLORADO CT: CONNECTICUT 7 3 DE: DELAWARE 7 4 DC: DISTRICT OF COLUMBIA 0 0 FM: FEDERATED STATES OF MICRONESIA 0 0 FL: FLORIDA GA: GEORGIA GU: GUAM 1 1 HI: HAWAII 1 1 ID: IDAHO 5 4 IL: ILLINOIS IN: INDIANA 13 8 IA: IOWA 11 7 KS: KANSAS 6 5 KY: KENTUCKY 13 8 LA: LOUISIANA 6 6 ME: MAINE 6 6 MH: MARSHALL ISLANDS 0 0 MD: MARYLAND 9 6 MA: MASSACHUSETTS MI: MICHIGAN MN: MINNESOTA MS: MISSISSIPPI 3 2 MO: MISSOURI 6 4 MT: MONTANA 2 0 NE: NEBRASKA 4 1 NV: NEVADA 3 2 NH: NEW HAMPSHIRE 7 4 NJ: NEW JERSEY 11 8 NM: NEW MEXICO 8 2 NY: NEW YORK NC: NORTH CAROLINA ND: NORTH DAKOTA 3 1 MP: NORTHERN MARIANA ISLANDS 0 0 OH: OHIO (continued)

136 110 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 3 (con t.) ANYONE WHO COMPLETED A RESPONSE TO U-TA-1 OR R-TA-1 OR All s C-TA-1 (UPDATE GRAPHIC AND SLIDE #1 WITH THIS DATA) (EO: 11/6/08) OK: OKLAHOMA 8 5 OR: OREGON 10 6 PW: PALAU 0 0 PA: PENNSYLVANIA PR: PUERTO RICO 0 0 RI: RHODE ISLAND 4 1 SC: SOUTH CAROLINA 13 6 SD: SOUTH DAKOTA 4 2 TN: TENNESSEE 19 4 TX: TEXAS UT: UTAH VT: VERMONT 2 1 VI: VIRGIN ISLANDS 0 0 VA: VIRGINIA WA: WASHINGTON WV: WEST VIRGINIA 2 2 WI: WISCONSIN 17 8 WY: WYOMING Exhibit 4 (G2-INT) In which country do you live? (* Indicates mandatory question) ANYONE WHO COMPLETED A RESPONSE TO U-TA-1 OR R-TA-1 OR All s C-TA-1 (UPDATE GRAPHIC AND SLIDE#2 WITH THIS DATA) Belgium 1 0 Canada 19 5 Italy 3 1 Germany 2 1 The Netherlands 6 3 Switzerland 1 1 Jordan 1 0 Other 1 0 Total 34 11

137 Appendix B: Complete Survey Data 111 Exhibit 5 (G5) Choose the one category that best describes your profession: (* Indicates mandatory question) ALL RESPONSES ANYONE WHO COMPLETED A RESPONSE TO U-TA-1 OR R-TA-1 OR C-TA-1 Percent Percent Water utility - manager/supervisor 66.4% % 311 Water utility - operator 4.5% % 18 Water utility - engineer/scientist 6.6% % 28 Department of Defense (DoD) or DoD Contractor - manager/supervisor 0.5% 4 0.0% 0 Department of Defense (DoD) or DoD Contractor - engineer/scientist 1.6% % 9 Department of Defense (DoD) or DoD Contractor - Remedial program manager 0.7% 5 0.9% 4 Regulatory agency - manager/supervisor 2.5% % 15 Regulatory agency - engineer/scientist 3.6% % 16 Engineering or Consulting firm - manager/supervisor 3.4% % 19 Engineering or Consulting firm - engineer/scientist 4.9% % 23 Equipment vendor - sales 0.5% 4 0.9% 4 Equipment vendor - engineer/scientist 0.4% 3 0.6% 3 Academic, professional or research institution - manager/supervisor 1.5% % 5 Academic, professional or research institution - engineer/scientist 2.7% % 12 answered question skipped question 99 0

138 Exhibit 6 (U-TA-2) Characterize the extent to which biological water treatment processes are used DoD No and Limited Use Moderate and Wide Use No Use Limited use Moderate use Wide Use Don t No use Limited Use Moderate Use Wide Use Don t Aerobic biological % 38.46% 15.38% 0.00% 46.15% 38% 15% Anaerobic/anoxic % 30.77% 15.38% 0.00% 46.15% 38% 15% UTILITIES answered question 13 skipped question 6 No and Limited Use Moderate and Wide Use No Use Limited Use Moderate Use Wide Use Don t No use Limited Use Moderate Use Wide Use Don t Aerobic biological % 31.92% 11.86% 2.54% 24.86% 61% 14% Anaerobic/anoxic % 33.33% 4.06% 0.87% 31.01% 64% 5% answered question 355 skipped question 210 REGULATORS No and Limited Use No Use Limited Use Moderate Use Wide Use Don t No use Limited Use Moderate Use Wide Use Don t Aerobic biological % 50.00% 3.57% 3.57% 17.86% 75% 7% Anaerobic/anoxic % 19.23% 0.00% 0.00% 23.08% 77% 0% answered question 28 skipped question 16 Moderate and Wide Use (continued) 112 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

139 Exhibit 6 (con t.) CONSULTANTS No Use Limited Use Moderate Use Wide Use Don t No use Limited Use Moderate Use Wide Use Don t No and Limited Use Aerobic biological % 41.86% 34.88% 13.95% 4.65% 47% 49% Anaerobic/anoxic % 54.76% 7.14% 7.14% 16.67% 69% 14% VENDORS answered question 43 skipped question 18 No and Limited Use Moderate and Wide Use Moderate and Wide Use Limited Moderate Wide Don t Limited Moderate Wide Don t No Use Use Use Use No use Use Use Use Aerobic biological % 57.14% 0.00% 14.29% 14.29% 71% 14% Anaerobic/anoxic % 71.43% 0.00% 14.29% 0.00% 86% 14% ACADEMICS answered question 7 skipped question 0 No and Limited Use Moderate and Wide Use Limited Moderate Wide Don t Limited Moderate Wide Don t No Use Use Use Use No use Use Use Use Aerobic biological % 27.27% 54.55% 9.09% 0.00% 36% 64% Anaerobic/anoxic % 72.73% 0.00% 0.00% 0.00% 100% 0% answered question 11 skipped question 11 Exhibit 7 (U-TA-1) Do you believe that biological water treatment processes are generally accepted by the drinking water industry, i.e., the same as conventional treatment? Vendors DoD Academics Regulators Consultants Utilities Yes 0.0% 0 7.7% 1 9.1% 1 9.7% % % 96 No 100.0% % % % % % 151 know 0.0% % 5 0.0% % % % 110 Appendix B: Complete Survey Data 113

140 Exhibit 8 (U-TA-13) Should the following biological treatment processes be DoD Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Aerobic biological processes % 44% Anaerobic/anoxic biological processes % 44% answered question 9 skipped question 10 UTILITIES Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Aerobic biological processes % 74% Anaerobic/anoxic biological processes % 85% answered question 297 skipped question 268 REGULATORS Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Aerobic biological processes % 86% Anaerobic/anoxic biological processes % 91% answered question 23 skipped question 21 (continued) 114 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

141 Exhibit 8 (con t.) CONSULTANTS Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Aerobic biological processes % 31% Anaerobic/anoxic biological processes % 47% VENDORS answered question 36 skipped question 25 Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Aerobic biological processes % 20% Anaerobic/anoxic biological processes % 20% ACADEMICS answered question 5 skipped question 2 Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Implemented preferentially since they represent a "green" technology Implemented cautiously due to concerns over uncertain public health impacts Aerobic biological processes % 22% Anaerobic/anoxic biological processes % 22% answered question 9 skipped question 13 Appendix B: Complete Survey Data 115

142 Exhibit 9 (U-TA-3) How difficult is it to gain acceptance of biological treatment processes when compared to conventional treatment? DoD Easy Moderate Difficult Easy Moderate Difficult Level of difficulty % 30.77% 23.08% 46.15% answered question 13 skipped question 6 UTILITIES Easy Moderate Difficult Easy Moderate Difficult Level of difficulty % 22.03% 31.64% 43.79% answered question 354 skipped question 211 REGULATORS Easy Moderate Difficult Easy Moderate Difficult Level of difficulty % 42.86% 39.29% 14.29% answered question 28 skipped question 16 CONSULTANTS Easy Moderate Difficult Easy Moderate Difficult Level of difficulty % 45.24% 40.48% 9.52% answered question 42 skipped question 19 (continued) 116 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

143 Exhibit 9 (con t.) VENDORS Easy Moderate Difficult Easy Moderate Difficult Level of difficulty % 14.29% 71.43% 14.29% answered question 7 skipped question 0 ACADEMICS Easy Moderate Difficult Easy Moderate Difficult Level of difficulty % 18.18% 72.73% 0.00% answered question 11 skipped question 11 Exhibit 10 (U-TA-7) What do you think is the likelihood of acceptance for anoxic or anaerobic biological treatment proceses for perchlorate/nitrate removal in drinking water treatment plants within the next 5 to 7 years? DOD UTILITIES REGULATORS CONSULTANTS VENDORS ACADEMICS Not likely 8% 1 25% 85 24% 6 7% 3 0% 0 18% 2 Moderate likelihood 31% 4 36% % 12 45% 19 43% 3 18% 2 Strong likelihood 39% 5 7% 24 8% 2 33% 14 57% 4 46% 5 know 23% 3 32% % 5 14% 6 0% 0 18% 2 Appendix B: Complete Survey Data 117

144 Exhibit 11 (U-TA-4) What do you think are the most significant barriers to acceptance of any type of biological treatment processes in drinking water treatment plants? DoD No Low Moderate High No or Low Moderate High Permitting and regulations % 46.15% 23.08% 23.08% Public perception % 15.38% 53.85% 23.08% Industry acceptance % 38.46% 7.69% 23.08% Design guidance or standards % 23.08% 7.69% 23.08% Not enough full-scale experience % 30.77% 30.77% 38.46% Reliability % 15.38% 30.77% 23.08% Reliance on/use of microorganisms % 15.38% 46.15% 30.77% Potential public health risks % 7.69% 38.46% 23.08% Maintenance % 23.08% 23.08% 30.77% Operator training/certification % 38.46% 15.38% 23.08% Cost % 23.08% 0.00% 46.15% Other barriers % 0.00% 0.00% % Please specify other barriers: 0 answered question 13 skipped question 6 UTILITIES No Low Moderate High No or Low Moderate High Permitting and regulations % 23.71% 40.29% 23.43% Public perception % 25.43% 39.14% 16.86% Industry acceptance % 41.09% 20.98% 16.95% Design guidance or standards % 35.90% 31.62% 21.65% Not enough full-scale experience % 28.16% 42.24% 21.55% Reliability % 25.57% 28.74% 31.32% Reliance on/use of microorganisms % 29.31% 32.18% 24.71% Potential public health risks % 22.41% 42.82% 22.13% Maintenance % 33.53% 22.54% 28.61% Operator training/certification % 29.48% 36.71% 20.81% Cost % 23.34% 26.80% 36.02% Other barriers % 5.58% 4.38% 84.86% Please specify other barriers: 19 answered question 351 skipped question 214 (continued) 118 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

145 Exhibit 11 (con t.) REGULATORS No Low Moderate High No or Low Moderate High Permitting and regulations % 28.00% 24.00% 16.00% Public perception % 25.93% 37.04% 22.22% Industry acceptance % 26.92% 23.08% 11.54% Design guidance or standards % 26.92% 30.77% 11.54% Not enough full-scale experience % 25.93% 44.44% 18.52% Reliability % 22.22% 25.93% 37.04% Reliance on/use of microorganisms % 46.15% 26.92% 15.38% Potential public health risks % 15.38% 42.31% 23.08% Maintenance % 46.15% 3.85% 19.23% Operator training/certification % 53.85% 23.08% 11.54% Cost % 30.77% 7.69% 30.77% Other barriers % 7.14% 0.00% 92.86% Please specify other barriers: 2 answered question 27 skipped question 17 CONSULTANTS No Low Moderate High No or Low Moderate High Permitting and regulations % 39.53% 30.23% 2.33% Public perception % 18.60% 39.53% 0.00% Industry acceptance % 46.51% 13.95% 0.00% Design guidance or standards % 41.86% 23.26% 2.33% Not enough full-scale experience % 34.88% 39.53% 2.33% Reliability % 34.88% 16.28% 4.65% Reliance on/use of microorganisms % 39.53% 16.28% 0.00% Potential public health risks % 11.63% 32.56% 0.00% Maintenance % 27.91% 13.95% 4.65% Operator training/certification % 34.88% 20.93% 4.65% Cost % 37.21% 6.98% 6.98% Other barriers % 12.50% 8.33% 54.17% Please specify other barriers: 6 answered question 43 skipped question 18 (continued) Appendix B: Complete Survey Data 119

146 Exhibit 11 (con t.) VENDORS No Low Moderate High No or Low Moderate High Permitting and regulations % 42.86% 42.86% 0.00% Public perception % 0.00% 57.14% 0.00% Industry acceptance % 14.29% 28.57% 14.29% Design guidance or standards % 42.86% 14.29% 0.00% Not enough full-scale experience % 42.86% 28.57% 0.00% Reliability % 57.14% 14.29% 14.29% Reliance on/use of microorganisms % 42.86% 28.57% 0.00% Potential public health risks % 14.29% 28.57% 0.00% Maintenance % 0.00% 0.00% 0.00% Operator training/certification % 14.29% 0.00% 0.00% Cost % 42.86% 0.00% 0.00% Other barriers % 0.00% 0.00% 83.33% Please specify other barriers: 1 answered question 7 skipped question 0 ACADEMICS No Low Moderate High No or Low Moderate High Permitting and regulations % 18.18% 54.55% 9.09% Public perception % 63.64% 27.27% 9.09% Industry acceptance % 36.36% 27.27% 9.09% Design guidance or standards % 45.45% 27.27% 0.00% Not enough full-scale experience % 36.36% 36.36% 0.00% Reliability % 27.27% 27.27% 0.00% Reliance on/use of microorganisms % 27.27% 36.36% 0.00% Potential public health risks % 27.27% 18.18% 0.00% Maintenance % 18.18% 9.09% 0.00% Operator training/certification % 45.45% 9.09% 0.00% Cost % 9.09% 18.18% 9.09% Other barriers % 0.00% 28.57% 42.86% Please specify other barriers: 3 answered question 11 skipped question 11 (continued) 120 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

147 Exhibit 11 (con t.) from U-TA-4 Number Date Please specify other barriers to acceptance 1 06/06/ :42:00 Post filtration should be required 2 06/09/ :14:00 Additional facilities 3 06/09/ :43:00 I am only familiar with the use of biological means for wastewater treatment 4 06/10/ :34:00 Analytical Monitoring and Process Control 5 06/13/ :57:00 Although common in the Netherlands, concern with HPCs in the US is a barrier to the acceptance of biological treatment in the US 6 06/13/ :49:00 Problems with sulfur reducing bacteria and H2S odors at times 7 06/19/ :16:00 Redundancy 8 06/20/ :59:00 Conflicting guidance and rules make it difficult to maintain biologically active filters 9 06/30/ :56:00 No one wants to be the first to try the technology 10 06/30/ :38:00 Understanding of the biological treatment process by treatment plant managers 11 07/08/ :00:00 Biofouling 12 07/08/ :55:00 Monitoring for unwanted biological agents in the biofilters 13 07/09/ :44:00 Reuse of Wastewater effluent 14 07/11/ :07:00 Lack of familiarity about the benefits of biological treatment processes 15 07/16/ :30:00 Certain methods needed to sustain bio-life forms can be problematic 16 07/22/ :17:00 Ability to find qualified staff 17 07/31/ :29:00 Lack of technical understanding 18 08/19/ :51:00 Regulator perceptions 19 09/10/ :31:00 Water industry is fairly resistant to anything new or different from C-TA-4 Number Date Please specify other barriers 1 06/04/ :18:00 The simple fact that putting bacteria in water is viewed as an action with an unknown outcome 2 06/16/ :52:00 Many places are practicing biological filtration without knowing it 3 06/30/ :18:00 NSF International and the blocking of these technologies from the marketplace by NSF International is the issue 4 07/29/ :46:00 uncertainty about microorganisms that enter water phase from biologically active media 5 08/06/ :57:00 Operator resistance to biological treatment is huge and more than just training. At all levels, plant staff are often afraid of any bacteria. It seems from the culture of associating all bacteria with coliforms, which must be zero leaving the plant 6 08/13/ :29:00 The U.S. mindset to not use a separate biological process. We tend to combine biological processes with another unit operation. This means the biological process is not generally optimized 7 08/20/ :22:00 The primary barrier is lack of understanding of utilities responsible for operating these systems 8 08/27/ :51:00 Regulator risk aversion 9 09/09/ :59:00 Conservatism 10 10/17/ :35:00 Other quality barriers like Mn removal or release if a MnO2 coating has developed. The most widely used biological process is biological filters or any GAC application, since they are automatically biological. Their use is widespread and especially common with ozone. from R-TA-4 Number Date Please specify other barriers 1 06/11/ :30:00 Unpredictable treatment. The conventional treatment trend becomes and mixture of art and science 2 06/20/ :46:00 Insufficient knowledge traditional engineering community Appendix B: Complete Survey Data 121

148 Exhibit 12 (U-TA-8) What do you think are the most significant barriers to future acceptance of anoxic or anaerobic treatment processes (e.g., for treatment of perchlorate or nitrate) in drinking water treatment plants? DoD No Low Moderate High know No or low Moderate High Permitting and regulations % 15% 62% 23% Public perception % 8% 62% 23% Industry acceptance % 46% 15% 23% Design guidance or standards % 31% 23% 23% Not enough full-scale experience % 31% 38% 23% Reliability % 23% 46% 23% Reliance on/use of microorganisms % 23% 38% 23% Potential public health risks % 31% 38% 23% Maintenance % 31% 15% 23% Operator training/certification % 46% 0% 23% Cost % 31% 15% 23% Other barriers % 0% 0% 100% Please specify other barriers: 0 answered question 13 skipped question 6 UTILITIES No Low Moderate High know No or low Moderate High Permitting and regulations % 19% 55% 20% Public perception % 27% 41% 18% Industry acceptance % 33% 37% 18% Design guidance or standards % 30% 44% 20% Not enough full-scale experience % 24% 51% 21% Reliability % 22% 48% 26% Reliance on/use of microorganisms % 25% 43% 23% Potential public health risks % 13% 59% 21% Maintenance % 35% 30% 26% Operator training/certification % 32% 37% 20% Cost % 21% 40% 34% Other barriers % 4% 3% 92% Please specify other barriers: 6 answered question 341 skipped question 224 (continued) 122 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

149 Exhibit 12 (con t.) REGULATORS No Low Moderate High know No or low Moderate High Permitting and regulations % 19% 46% 4% Public perception % 35% 35% 15% Industry acceptance % 36% 16% 12% Design guidance or standards % 12% 56% 12% Not enough full-scale experience % 24% 52% 8% Reliability % 20% 48% 16% Reliance on/use of microorganisms % 32% 32% 16% Potential public health risks % 24% 40% 20% Maintenance % 44% 24% 12% Operator training/certification % 44% 36% 4% Cost % 23% 31% 27% Other barriers % 7% 7% 80% CONSULTANTS Please specify other barriers: 1 answered question 26 skipped question 18 No Low Moderate High know No or low Moderate High Permitting and regulations % 34% 49% 5% Public perception % 25% 45% 0% Industry acceptance % 51% 32% 0% Design guidance or standards % 54% 24% 0% Not enough full-scale experience % 32% 61% 0% Reliability % 39% 37% 5% Reliance on/use of microorganisms % 39% 29% 5% Potential public health risks % 27% 39% 2% Maintenance % 34% 21% 5% Operator training/certification % 33% 30% 3% Cost % 23% 23% 13% Other barriers % 0% 0% 88% Please specify other barriers: 0 answered question 41 skipped question 20 (continued) Appendix B: Complete Survey Data 123

150 Exhibit 12 (con t.) VENDORS No Low Moderate High know No or low Moderate High Permitting and regulations % 14% 71% 0% Public perception % 14% 43% 0% Industry acceptance % 43% 29% 0% Design guidance or standards % 29% 43% 0% Not enough full-scale experience % 29% 57% 0% Reliability % 29% 43% 14% Reliance on/use of microorganisms % 17% 50% 0% Potential public health risks % 33% 33% 0% Maintenance % 50% 0% 0% Operator training/certification % 33% 0% 0% Cost % 43% 0% 0% Other barriers % 0% 0% 60% ACADEMICS Please specify other barriers: 1 answered question 7 skipped question 0 No Low Moderate High know No or low Moderate High Permitting and regulations % 27% 55% 18% Public perception % 45% 27% 18% Industry acceptance % 18% 55% 18% Design guidance or standards % 18% 55% 18% Not enough full-scale experience % 27% 45% 18% Reliability % 45% 9% 18% Reliance on/use of microorganisms % 9% 45% 18% Potential public health risks % 27% 18% 18% Maintenance % 55% 0% 18% Operator training/certification % 55% 9% 18% Cost % 36% 9% 27% Other barriers % 0% 0% 80% Please specify other barriers: 0 answered question 11 skipped question 11 (continued) 124 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

151 Exhibit 12 (con t.) U-TA-8 s Number Date Please specify other barriers 1 06/09/ :14:00 Re-oxidation and possible residues. 2 06/10/ :34:00 Training and process control/monitoring 3 06/13/ :49:00 High cost of pilot testing an unknown commodity. Difficult to get City Council approval for "R&D" type expenditures. Need financial incentives to take the risk. Cost of technology decreases over time as it is optimized so you get penalized twice financially for trying to advance a new treatment technique. 4 06/20/ :59:00 Anoxic or anaerobic treatment that produces taste and odor causing compounds will add to expensive treatment cost 5 06/23/ :38:00 Not all waters contain perchlorate. How does this affect acceptance? 6 07/08/ :55:00 Availability of quick turn-around (near real-time) microbial assay methods for desirable microbes and potential pathogens C-TA-8 Reponses Number Date Please specify other barriers 1 06/30/ :18:00 NSF International and the power afforded thereto by Congress in 1989 and then reinforced by all 50 states R-TA-8 s Number Date Please specify other barriers 1 06/11/ :30:00 Law suits associated with public health risk. Everybody will blame the water, esp with lost of disinfection Appendix B: Complete Survey Data 125

152 126 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 13 (U-TA-15) Please list any additional technology acceptance issues that have not been addressed in this survey Although I have lots of experience/knowledge of biological treatment processes for wastewater, I have heard/know very little about these processes for drinking water and could not answer many of the questions on this survey. Would like to know the effect of UV on biological treatment. Next gen DBPs (bromate...) know. This technology is not as accepted in Illinois as it is in California where we used BAF. Environmental impacts, especially nimby. N/A N/A Plant/Lab staff understanding of biofiltration. The primary problem I have with the survey is that it did not define conventional treatment. I consider I facility to use conventional treatment, even though we try to maintain biological activity in the top layer of our granular activated carbon. It is also unclear if you consider UV, or Ozone to be conventional treatment. We are all trying to produce the best possible water for the lowest possible cost to give our consumers the highest value for their investment in public infrastructure. Therefore, any future treatment scheme should be site and need specific. Microbial? Groundwater is our drinking water source. The only treatment we use is chlorination. We have absolutely no experience with any other treatment process. sms Again, I am not that familiar with the technologies currently being used. Working pilot units are better than test tube data for acceptance. Chronic affects of unknown by-product precursers. Have little knowledge of the processes sine we are a purchasing entity and are not exposed to treatment advances or controversial issues. Very little know about biological processes. Location of a plant, size of a plant. If it works and can be done safely, then it should be implemented to remove contaminants of high concern. Medical consequences if break through occurs. Reverse Osmosis, membrane filtration, ozonation w/ chlorine subsidized disinfection. I am not knowledgeable of this field of treatment. Unknown I don't know of any. Ultra-Violet Light/Membrane. I can't think of any. The issue of biological waste residuals disposal was not mentioned but will definitely be an issue of concerns. Membrane filters. It is going to frighten the consumer. know Unknown Public involvement and demonstrated success stories River Bank Filtration as a raw water treatment for Conventional Surface Water Treatment Plants (continued)

153 Appendix B: Complete Survey Data 127 Exhibit 13 (con t.) Pilot results in multiple state sites No opinion! Easy analytical methods for process control (e.g., AOC, BDOC) I don't know enough about the subject to list any issues. See U-TA-14 Education and outreach about the processes is extremely important. Getting the current and future research circulated and understood by Engineers and Water system Managers/Operators is essential. Disinfection concerns. Handling of treatment chemicals needed in the process. Reverse osmosis Massachusetts regulators tend to be conservative and cautious. Therefore, I think the greatest challenge will be regulatory acceptance of biological treatment for drinking water. Comparison of targeted anion exchange resins with biological systems in totally degrading perchlorate 1.Food: Microorganism Ratio ( F/M) in the feed water. 2. Elected surrogate organism or mix microbial population. 3. Compatibility of processing organisms with intestinal flora in event of the disinfection residual is lost in the distribution system. Public education of ongoing research Food: MicroOrganism Ratio(F/M) Obtain EPA approval as an Alternative Treatment Technology and potentially an NSF Environmental Technology Verification. Attacks on bio processes by the vendors of traditional processes. Question C-TA-12 is not well stated. The biological processes largely do not address the same water-quality challenges as do the conventional processes. So, they are a lot better at what they do already, but they do not address some things that conventional processes address. Examples in the first case are nitrate and perchlorate, while in the second case are turbidity and iron. this survey did not address source water quality, even though it is an important consideration for biological processes. some source waters are not appropriate for aerobic biological treatment such as slow sand filtration unless they receive appropriate pretreatment Again, the issue is NSF International Biotreatment acceptance and performance metrics compared to membrane and other separations- based technologies should have also been addressed. The survey is trying to simplify a complex topic - you can't compare biological and conventional processes in a general sense - each has their niche - we need to do both, not one or the other. Regulatory acceptance has been addressed, but it is a huge issue I also don't' know why you need to distinguish between aerobic and anoxic in terms of operator training, or public acceptance...???? Additionally, they are both "GREEN" compared to high-pressure membranes our advanced oxidation Lack of full-scale installations (for anaerobic/anoxic processes) and lack of universal or clearly defined regulations causes the most hesitancy in acceptance of these technologies None None The problem with anaerobic/anoxic ClO4- removal is consistency (365 days per year operations) and meeting the MCL, not consumer perception in my view. The survey failed to capture the most important deficiency

154 Exhibit 14 (U-TA-6) For the following stakeholder groups, what methods do you think will be most successful to help them gain acceptance of biological treatment processes? (Check all that apply for each row.) DoD More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs Industry Research Public Education Don t Industry Research Public Education Don t Water utility % 67% 33% 42% 25% 25% Department of Defense (DoD) % 58% 33% 25% 58% 25% Regulatory agency % 50% 17% 25% 50% 25% Engineering or consulting firm % 42% 8% 8% 50% 25% Equipment vendor % 42% 33% 0% 25% 25% Academic, professional, research % 25% 8% 0% 33% 25% Other stakeholder groups % 9% 9% 27% 27% 64% Please specify other: 0 answered question 12 skipped question 7 UTILITIES More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs Industry Research Public Education Don t Industry Research Public Education Don t Water utility % 62% 66% 42% 59% 9% Department of Defense (DoD) % 23% 11% 10% 24% 57% Regulatory agency % 46% 24% 25% 50% 20% Engineering or consulting firm % 49% 19% 12% 49% 22% Equipment vendor % 40% 18% 11% 26% 31% Academic, professional, research % 37% 15% 19% 32% 28% Other stakeholder groups % 13% 9% 17% 10% 74% Please specify other: 5 answered question 346 skipped question 219 (continued) 128 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

155 Exhibit 14 (con t.) REGULATORS More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs Industry Research Public Education Don t Industry Research Public Education Don t Water utility % 83% 75% 46% 67% 4% Department of Defense (DoD) % 22% 13% 9% 35% 57% Regulatory agency % 73% 46% 31% 81% 8% Engineering or consulting firm % 67% 33% 29% 58% 8% Equipment vendor % 46% 29% 17% 42% 29% Academic, professional, research % 48% 16% 36% 32% 20% Other stakeholder groups % 32% 23% 41% 41% 45% Please specify other: 5 answered question 26 skipped question 18 CONSULTANTS More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs Industry Research Public Education Don t Industry Research Public Education Don t Water utility % 73% 73% 41% 56% 2% Department of Defense (DoD) % 33% 15% 10% 40% 33% Engineering or consulting firm % 71% 20% 29% 66% 2% Equipment vendor % 49% 22% 16% 38% 16% Academic, professional, research % 27% 10% 20% 24% 12% Other stakeholder groups % 24% 17% 48% 28% 41% Please specify other: 5 answered question 41 skipped question 20 VENDORS More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs Industry Research Public Education Don t Industry Research Public Education Don t Water utility % 100% 29% 57% 43% 0% Department of Defense (DoD) % 71% 0% 29% 14% 14% Engineering or consulting firm % 86% 29% 14% 57% 0% Equipment vendor % 33% 33% 17% 83% 0% Academic, professional, research % 33% 0% 17% 33% 17% Other stakeholder groups % 17% 0% 0% 0% 83% Please specify other: 1 answered question 7 skipped question 0 (continued) Appendix B: Complete Survey Data 129

156 Exhibit 14 (con t.) ACADEMICS More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs More Fullscale Systems Operator Training Workshops/ Seminars Regulatory Guidance Docs Industry Research Public Education Don t Industry Research Public Education Don t Water utility % 82% 27% 55% 64% 0% Department of Defense (DoD) % 45% 18% 9% 45% 18% Engineering or consulting firm % 73% 0% 0% 55% 0% Equipment vendor % 64% 27% 18% 64% 9% Academic, professional, research % 27% 0% 18% 45% 0% Other stakeholder groups % 20% 0% 60% 0% 40% Please specify other: 2 answered question 11 skipped question 11 from U-TA-6 Number Date Please specify other 1 06/09/ :14:00 Public education will be a factor, but I don't think it will be a great factor. 2 06/20/ :59:00 Water Boards and water users 3 06/20/ :59:00 The problem will be with un-informed politicians. 4 06/25/ :44:00 Consumers 5 07/08/ :04:00 You are going to have to have research and some full scale operations to find out what the limitations are. We are currently using Ozone and biologicly active GAC, but I get the feeling you are looking at other and more extensive biological treatment. from R-TA-6 Number Date Please specify other 1 06/17/ :07:00 The public we serve; health advocacy organizations 2 06/20/ :46:00 Other water trade groups 3 06/23/ :25:00 Medical community 4 06/25/ :13:00 Community Activists 5 06/27/ :46:00 Environmental Watchdog Groups from C-TA-6 Number Date Please specify other 1 06/04/ :26:00 NGO's and public interest groups 2 06/13/ :16:00 Regulatory agencies 3 06/17/ :20:00 General public 4 06/27/ :09:00 The general public. 5 07/08/ :44:00 Consumers 6 07/08/ :44:00 Consumers 7 10/17/ :35:00 I don't understand these questions, becuase I think that biological filtration is well established, there are a number of plants using it, and plenty of research done by Puck et al. on these sort of things. 8 07/11/ :09:00 Constituents, Politicians. 130 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

157 Exhibit 15 (U-TA-12) How will additional research promote acceptance of biological processes for drinking water? DoD Low Impact Medium Impact High Impact Low Impact Medium Impact High Impact Aerobic biological processes % 33% 42% 25% Anaerobic/anoxic biological processes % 25% 50% 25% answered question 12 skipped question 7 UTILITIES Low Impact Medium Impact High Impact Low Impact Medium Impact High Impact Aerobic biological processes % 25% 46% 27% Anaerobic/anoxic biological processes % 19% 47% 32% answered question 333 skipped question 232 REGULATORS Low Impact Medium Impact High Impact Low Impact Medium Impact High Impact Aerobic biological processes % 36% 48% 12% Anaerobic/anoxic biological processes % 28% 52% 16% answered question 25 skipped question 19 CONSULTANTS Low Impact Medium Impact High Impact Low Impact Medium Impact High Impact Aerobic biological processes % 19% 49% 8% Anaerobic/anoxic biological processes % 24% 57% 11% answered question 37 skipped question 24 (continued) Appendix B: Complete Survey Data 131

158 Exhibit 15 (con t.) VENDORS Low Impact Medium Impact High Impact Low Impact Medium Impact High Impact Aerobic biological processes % 80% 20% 0% Anaerobic/anoxic biological processes % 40% 40% 0% answered question 5 skipped question 2 ACADEMICS Low Impact Medium Impact High Impact Low Impact Medium Impact High Impact Aerobic biological processes % 36% 55% 0% Anaerobic/anoxic biological processes % 9% 73% 9% answered question 11 skipped question Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

159 Appendix B: Complete Survey Data 133 Exhibit 16 (U-TA-14) In your own opinion, list research priorities for biological treatment of drinking water DOD AND UTILITIES How to get process started, water temperature effect on process, effective bacteria counts to show process is biological, going from conventional to biological - what could go wrong. Organics removal and potentially for biologica mitigation of Alage. Organic carbon removal. 1. Disinfection requirements following biological filtration. 2. Speciation of bacteria. 3. Comparison of filter performance between biologically active filters and chlorinated filters. 4. Impact of ozone prior to biofiltration. 5. Impact of algae on bio and nonbio filter performance. Must be proven safe, must address expected more stringent regulations. Maintain the same safety levels that are provided by conventional treatment. Taste and odor problems. TOC reduction. Possible EDC/PPCP applications. Cost effective process and analytical monitoring. Training criteria. Public Safety. Would prefer research on biological treatment to determine if it is effective in removing disinfection by product precursors. Safety. Reliability. Public acceptance. O&M. Operational costs. Anaerobic: While I know next to nothing about this technology, my major concern is T&O. Aerobic: Biggest need for research is fate of coliforms & pathogenic organisms in biologically active filters & efficacy of various post-filtration disinfection & relationship of shedding of HPC organisms & coliform (i.e. do HPC organisms reduce coliforms? Mask coliforms? No influence?) DON'T KNOW Have no experience except for slow sand filtration. Biologically active filters need to be researched using pilot studies. HPC measurements, coliform, and other bacteriological indicators need to be studied. As a pretreatment before finishing. Time, Cost & knowledge in the field. My understanding is that most require some type of polishing filter downstream of the biofilter. This significantly increases construction costs, and absent identified contaminants requiring biological treatment (and a regulatory mandate), is a barrier to its implementation. Impact of availability of nutrients on effectiveness of biological treatment and clogging of bio-filters Effectiveness of contaminant removal. Best practice for disposal of residuals from the process. Nitrate destruction. Does it work reliably, Cost effective, environmentally safe, safe to work with. know enough about what has been done or the process itself, especially for the Anaerobic/anoxic process. (continued)

160 134 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 16 (con t.) Biologically active filtration is widely used in ozonation plants. There seems to be plenty of research related to this aerobic process. Research on other biological processes should generate data that allows refinement of capital and O&M cost comparisons. If Anaerobic/anoxic process are significantly cheaper than other alternatives then the industry will begin to use the technology. Taste and odor issues, algal toxins and PPCP's (aerobic). Not too familiar with anaerobic processes except for perchlorate removal. Conventional treatment process. Aerobic biological. Anaerobic biological. Which contaminants can be treated more effectively than conventional treatment. Biomass Profiles. Biomass maintenance; filter backwash parameters. Post disinfection. Reliability and break-through prevention - i.e. 4-log removals of COC and only SDWA compliant water ever enters public water supply. Viability of bacteria through changing water conditions. Ability of bacteria to remove taste and odor compounds. Efficient filter washes with biological filters. Develop operational tool box to monitor types, concentrations and viability of micro-organisms I believe biological treatment is one tool in our tool chest. It should be studied in conjunction with conventional treatment, including the growing use of technologies, such as, UV, UF/MF. Treatment consistency. Residual bacteria. More bench scale testing, followed by pilot plant, and input on public perception. Engineering controls to safeguard against potential risk to public, including effective management/treatment of contaminants to side or waste streams. I am only mildly familiar with the actual technologies currently being used. If they work we should research them. How to best remove pharmaceutical drugs from water. Reliable safe drinking water treatment techniques should be considered first before they are chosen just because they are "green". Pathogen removal, Disinfection by-products removal, Taste and Odor. ' know Research,regulation,training and education. TOC Endocrine, Pharm and Personal care. Total organic carbon concentrations from biological filters and TTHM effects Whatever it takes to prove that aerobic,anaerobic/anoxic treatment can produce a safe potable water as conventional treatment. I need to read up on biological treatment of water vs wastewater. Long term effect on environment/health. Not familiar with current research relative to use of biological processes for removing contaminants. Identify parameters affecting process, e,g, temperature, substrate, chemicals present, flow rate, etc. Removal of NOM and endocrine disruptors. Pathogen removal, pharmaceutical challenges, 100% public health technology. Costs to implement and effectiveness as compared to conventional. (continued)

161 Appendix B: Complete Survey Data 135 Exhibit 16 (con t.) I am not knowledgeable of this field of treatment. Health effects. Endocrine disrupting compounds, pharmaceuticals, and personal care products, etc. The SOPs that ensure no public health threat. Cost comparison / other benefits compared to conventional treatment. Public Health, Maintenance of Equipment. Not familiar with it. Public health impact, cost of implementation and operation, ease of implementation and operation, and public acceptance. Public Education. Operational monitoring procedures and standards needed. Process reliability and safety. Endocrine disrupting Compounds. Operations personnel on average are not up to speed on the technology and must be exposed to it as research becomes available. AWWA webcast, ACE and local sections need to include biological treatment as part of the curriculum and technical programs. Fate of microconstituents and substances of concern, pharmaceuticals etc. Determine contaminant removal efficiencies, sizing of treatment components, residuals disposal. Documented history. Nitrate and Nitrite removal. Effectiveness, ease of use, cost, public acceptance. know. PPCP, Bacteriological and viral. Pilot plants with multiple raw water sources. TOC removal. Unsure of process, and where it is in development. Particle removal using bio processes also Taste and removal and TOC/dissolved Organic Carbon removal. Reuse as recycled or to Drinking water standards. Education and training are highly needed and recommended. Pilot scale demonstration. Flexibility, stability and reliability of the system. No opinion! Combination aerobic/anaerobic processes. Nitrate removal. I don't know enough about the subject to have an opinion. - We don't deal with biological treatment. Check the disinfection and die off of organisms after treatment. 1.Public Safety. 2.Potential byproducts. 3.Cost. 4.New concerns of pharmaceuticals. Costs, applicability, more systems online, dependability, downstream control of biological discharge in effluent stream. (continued)

162 136 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 16 (con t.) I have no knowledge of "Biological Treatment" methods. Full scale treatment testing. DBP rule eliminator bacteria. Safety - organism breakthrough. Adequate disinfection. Finished water quality determinations. Arsenic removal and maintenance cost. Disinfection,Disinfection By-Products. Organic removal. Research needs to address any possible health effects and control of biological breakthrough of the treatment process. Compare impacts of combinations of contaminant constituents, e.g. high perchlorate with high bacteria count. Do to the increase cost and health concerns with the use of chemicals to treat water, alternate methods of treatment that will have a green effect on the environment should be researched. Removal of PCP and emerging contaminants. Efficacy of biologically active filters for removal of AOC, etc. Operational parameters; fate of contaminants. More data needed on effects of chlorinated vs nonchlorinated backwash. Text: REGULATORS 1. Gravitational settling characteristics. 2. Floc carry-over ( fines). 3. Wide ranges in turbidity results. 4. Entrance velocity control. 5. Ph variations in feed water. 6. Chemical interferences. 7. Odor control. 8. Foam control (Aerobic process). Research must address public health concerns and some research into consumer acceptance is warranted. Cost, efficiency, efficacy, pathogens, impact on distribution system quality. iron, manganese, DOC, ammonia, MtBE. Data to achieve certification. 1. gravitational settling Characteristics. 2. Floc carry over. (No Suggestions) range in turbidity results. 4.Entrance velocity control. 5. ph variation in feed water. Sustained cold climates and remote locations such as commonly found throughout Alaska. Text: CONSULTANTS, ACADEMICS, VENDORS Process monitoring and control. Post-treatment for bacteria. Life cycle costs compared with conventional. Implementation of full scale nitrate and perchlorate treatment plants should be the focus, the research is over. Polishing for water reuse or recharge. Optimization of processes, expand beyond conventional ozone/gac. (continued)

163 Appendix B: Complete Survey Data 137 Exhibit 16 (con t.) Distribution system regrowth potential. More large-scale tests/demonstrations. More education of engineers, operators, and regulators. Modifications and pretreatment to extend range of raw water quality that can be treated by slow sand filtration. On-line Instrumentation and analysis for reliability, co-contaminant/multiple contaminant treatment in single process. Optimization of managed biological treatment including on-line monitoring procedures. I have never heard of biological treatment applications for potable water treatment. Need publications and seminars. Understanding the full breadth of what biological drinking water treatment processes can do from a contaminant removal perspective. Aerobic biological degradation of ozone-oxidized PPCP And EDCs. Anaerobic biological removal of bromate. Take control out of NSF International. Design guidelines, operational guidelines. research program aimed at gaining regulatory acceptance of biological treatment in water. 1. Trace organics contaminants, i.e. PPCPs, EDCs, tastes and odors, and algal toxins. 2. Pathogen inactivation/removal, i.e. viruses, parasites, and pathogenic bacteria. 3. Process optimization and enhancement for improved treatment and reduced cost. Degree of bacterial sloughing into effluent water. Process upset recovery. In the area I work, drinking water, it is more of an education process and gradual increase in use. There are many plants with old GAC which is relying on biological removal for much of its success, but many operators do not realize the importance of the biology. Biological treatment is a standard treatment process in the Netherlands. Therefore, most research have been done in the past. Current research interest are in the field of characterization of specific groups of microorganisms in biological treatment using molecular methods. 1. Role of biological processes for removal of organic micropollutants. 2. Removal of organic matter prior to desalination. 3. Monitoring tools for biofiltration. 4. Optimizing processes downstream of anoxic/anaerobic biological processes. Full scale studies to document existing designs. Development of monitoring and control "tool boxes". Development of an approach to link treatment objectives to operation and management of BAF. Question C-TA-11 makes no sense. Currently equivalent with respect to what??? Biological stability?? Dissolve iron and manganese?? Nitrate?? Demonstrate water quality is equivalent to conventional treatment. Demonstrate level of effort required for operations for reliable effluent quality. Aerobic processes are well established in the US, focus should be on anaerobic processes. Develop design standards for removal of multiple parameters. Aesthetics and stability. DIBs 1) Ability of biological treatment processes to produce safe drinking water. 2) Ability of biological treatment processes to treat emerging contaminants. Longer term pilots or demonstrations to evaluate seasonal swings in influent water quality.

164 Exhibit 17 (U-TA-10) For each treatment process (i.e., for each column), choose up to three contaminants you believe are especially suitable for removal by that process DoD Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Total organic carbon / disinfection by-product precursors % 27% 9% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) % 27% 0% Taste and odor compounds % 9% 55% Endocrine disrupting compounds, pharmaceuticals, and personal care products % 27% 18% Perchlorate/nitrate/nitrite % 82% 9% Iron/manganese % 9% 45% Turbidity/particle counts % 9% 73% HPC bacteria/total coliform % 0% 27% Bromate % 9% 9% Color % 0% 36% Other contaminants Total Please specify other contaminants: 0 answered question 11 skipped question 8 UTILITIES Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Total organic carbon / disinfection by-product precursors % 18% 48% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) % 27% 17% Taste and odor compounds % 14% 50% Endocrine disrupting compounds, pharmaceuticals, and personal care products % 26% 15% Perchlorate/nitrate/nitrite % 55% 14% Iron/manganese % 10% 56% Turbidity/particle counts % 9% 85% HPC bacteria/total coliform % 13% 64% Bromate % 10% 17% Color % 6% 48% Other contaminants % 4% 13% Total Please specify other contaminants: 14 answered question 294 skipped question 271 (continued) 138 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

165 Exhibit 17 (con t.) REGULATORS Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Total organic carbon / disinfection by-product precursors % 36% 56% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) % 16% 28% Taste and odor compounds % 12% 56% Endocrine disrupting compounds, pharmaceuticals, and personal care products % 20% 16% Perchlorate/nitrate/nitrite % 64% 28% Iron/manganese % 4% 48% Turbidity/particle counts % 0% 76% HPC bacteria/total coliform % 12% 52% Bromate % 8% 12% Color % 0% 24% Other contaminants % 4% 12% Total Please specify other contaminants: 1 answered question 25 skipped question 19 CONSULTANTS Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Total organic carbon / disinfection by-product precursors % 13% 61% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) % 34% 18% Taste and odor compounds % 11% 37% Endocrine disrupting compounds, pharmaceuticals, and personal care products % 16% 13% Perchlorate/nitrate/nitrite % 84% 3% Iron/manganese % 5% 66% Turbidity/particle counts % 5% 87% HPC bacteria/total coliform % 11% 53% Bromate % 18% 16% Color % 5% 34% Other contaminants % 8% 11% Total Please specify other contaminants: 5 answered question 38 skipped question 23 (continued) Appendix B: Complete Survey Data 139

166 Exhibit 17 (con t.) VENDORS Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Total organic carbon / disinfection by-product precursors % 40% 20% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) % 40% 0% Taste and odor compounds % 60% 60% Endocrine disrupting compounds, pharmaceuticals, and personal care products % 40% 0% Perchlorate/nitrate/nitrite % 80% 0% Iron/manganese % 0% 60% Turbidity/particle counts % 40% 80% HPC bacteria/total coliform % 20% 60% Bromate % 40% 20% Color % 40% 60% Other contaminants % 20% 0% Total Please specify other contaminants: 1 answered question 5 skipped question 2 ACADEMICS Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Aerobic Biological Processes Anaerobic/ Anoxic Biological Processes Conventional Treatment Processes Total organic carbon / disinfection by-product precursors % 27% 36% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) % 27% 9% Taste and odor compounds % 9% 18% Endocrine disrupting compounds, pharmaceuticals, and personal care products % 27% 9% Perchlorate/nitrate/nitrite % 91% 0% Iron/manganese % 0% 64% Turbidity/particle counts % 9% 82% HPC bacteria/total coliform % 9% 64% Bromate % 64% 0% Color % 9% 27% Other contaminants % 9% 0% Total Please specify other contaminants: 1 answered question 11 skipped question 11 (continued) 140 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

167 Exhibit 17 (con t.) from U-TA-10 only Number Date Please specify other contaminants 1 06/10/ :34:00 ozone byproducts, i.e., aldehydes and ketoacids; TOX. 2 06/11/ :31:00 High dissolved mineral groundwater. 3 06/20/ :43:00 know anything about any of these processes. 4 06/20/ :59:00 I consider conventional treatment to include activated carbon in some form. 5 06/23/ :40:00 Arsenic 6 06/24/ :03:00 No experience with biological treatment. 7 06/26/ :32:00 Not familiar with the other two treatments. 8 07/08/ :10:00 pathogen bacterium contamination removal. 9 07/08/ :00:00 VOCs 10 07/08/ :46:00 I have 33 years of experience in Conventional Treatment, 0 years in the other two processes. I have little or no basis for comment /15/ :45:00 know /17/ :30:00 Ozone byproducts /22/ :17:00 Heavy metals, salts, minerals /29/ :01:00 Certain anthropogenic contaminants such as chlorinated compounds and pesticides can be treated via biological treatment. from R-TA-10 only Number Date Please specify other contaminants 1 06/04/ :24:00 Arsenic from C-TA-10 only Number Date Please specify other contaminants 1 05/27/ :21:00 Chlorinated solvents. 2 06/05/ :04:00 Virus giardia. 3 06/05/ :49:00 Arsenic by Ion exchange. 4 06/13/ :47:00 TCE/PCE. 5 06/16/ :04:00 Chlorinated solvents. 6 06/17/ :23:00 Viruses, protozoa and pathogenic bacteria in slow sand filtration plants. 7 06/17/ :20:00 NDMA 8 07/11/ :09:00 Selenate, other reduced species. Appendix B: Complete Survey Data 141

168 Exhibit 18 (U-TA-9) Characterize each process with respect to level of effort DoD Aerobic biological processes High Moderate Low High Moderate Low Design requirements % 40% 10% 20% Operations and maintenance requirements % 40% 30% 20% Training requirements % 30% 20% 20% Operator certification requirements % 10% 40% 20% Staffing requirements % 70% 10% 20% Anaerobic/anoxic biological processes High Moderate Low High Moderate Low Design requirements % 36% 9% 18% Operations and maintenance requirements % 55% 9% 18% Training requirements % 36% 18% 18% Operator certification requirements % 9% 36% 27% Staffing requirements % 73% 9% 18% Conventional treatment processes High Moderate Low High Moderate Low Design requirements % 9% 27% 36% Operations and maintenance requirements % 18% 36% 18% Training requirements % 36% 27% 18% Operator certification requirements % 36% 36% 18% Staffing requirements % 36% 36% 18% Question Totals High Moderate Low answered question 11 skipped question 8 (continued) 142 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

169 Exhibit 18 (con t.) UTILITIES Aerobic biological processes High Moderate Low High Moderate Low Design requirements % 26% 5% 36% Operations and maintenance requirements % 28% 3% 36% Training requirements % 26% 4% 30% Operator certification requirements % 26% 6% 35% Staffing requirements % 29% 10% 41% Anaerobic/anoxic biological processes High Moderate Low High Moderate Low Design requirements % 17% 2% 41% Operations and maintenance requirements % 20% 2% 43% Training requirements % 19% 2% 36% Operator certification requirements % 21% 4% 40% Staffing requirements % 22% 6% 47% Conventional treatment processes High Moderate Low High Moderate Low Design requirements % 46% 24% 11% Operations and maintenance requirements % 54% 16% 11% Training requirements % 54% 15% 10% Operator certification requirements % 52% 15% 10% Staffing requirements % 51% 22% 15% answered question 328 skipped question 237 Question Totals High Moderate Low (continued) Appendix B: Complete Survey Data 143

170 Exhibit 18 (con t.) REGULATORS Aerobic biological processes High Moderate Low High Moderate Low Design requirements % 44% 12% 20% Operations and maintenance requirements % 38% 13% 29% Training requirements % 60% 0% 20% Operator certification requirements % 46% 17% 21% Staffing requirements % 44% 16% 32% Anaerobic/anoxic biological processes High Moderate Low High Moderate Low Design requirements % 32% 0% 24% Operations and maintenance requirements % 29% 4% 29% Training requirements % 24% 0% 28% Operator certification requirements % 33% 4% 29% Staffing requirements % 40% 12% 32% Conventional treatment processes High Moderate Low High Moderate Low Design requirements % 40% 44% 8% Operations and maintenance requirements % 67% 21% 8% Training requirements % 60% 20% 8% Operator certification requirements % 58% 21% 13% Staffing requirements % 52% 20% 24% answered question 25 skipped question 775 Question Totals High Moderate Low (continued) 144 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

171 Exhibit 18 (con t.) CONSULTANTS Aerobic biological processes High Moderate Low High Moderate Low Design requirements % 59% 10% 20% Operations and maintenance requirements % 45% 21% 16% Training requirements % 37% 21% 16% Operator certification requirements % 37% 18% 24% Staffing requirements % 29% 39% 26% Anaerobic/anoxic biological processes High Moderate Low High Moderate Low Design requirements % 29% 3% 24% Operations and maintenance requirements % 56% 6% 19% Training requirements % 28% 8% 19% Operator certification requirements % 31% 11% 36% Staffing requirements % 42% 19% 31% Conventional treatment processes High Moderate Low High Moderate Low Design requirements % 53% 30% 5% Operations and maintenance requirements % 63% 24% 3% Training requirements % 55% 32% 3% Operator certification requirements % 50% 21% 16% Staffing requirements % 50% 26% 18% answered question 41 skipped question 20 Question Totals High Moderate Low (continued) Appendix B: Complete Survey Data 145

172 Exhibit 18 (con t.) VENDORS Aerobic biological processes High Moderate Low High Moderate Low Design requirements % 40% 40% 0% Operations and maintenance requirements % 50% 25% 0% Training requirements % 50% 50% 0% Operator certification requirements % 20% 40% 0% Staffing requirements % 50% 50% 0% Anaerobic/anoxic biological processes High Moderate Low High Moderate Low Design requirements % 60% 0% 20% Operations and maintenance requirements % 25% 25% 25% Training requirements % 75% 0% 25% Operator certification requirements % 60% 20% 0% Staffing requirements % 25% 50% 25% Conventional treatment processes High Moderate Low High Moderate Low Design requirements % 40% 60% 0% Operations and maintenance requirements % 25% 75% 0% Training requirements % 50% 50% 0% Operator certification requirements % 60% 40% 0% Staffing requirements % 25% 75% 0% answered question 5 skipped question 2 Question Totals High Moderate Low (continued) 146 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

173 Exhibit 18 (con t.) ACADEMICS Aerobic biological processes High Moderate Low High Moderate Low Design requirements % 91% 9% 0% Operations and maintenance requirements % 55% 27% 0% Training requirements % 45% 18% 0% Operator certification requirements % 45% 18% 18% Staffing requirements % 36% 45% 9% Anaerobic/anoxic biological processes High Moderate Low High Moderate Low Design requirements % 27% 9% 9% Operations and maintenance requirements % 36% 9% 9% Training requirements % 45% 0% 9% Operator certification requirements % 45% 0% 27% Staffing requirements % 45% 18% 18% Conventional treatment processes High Moderate Low High Moderate Low Design requirements % 73% 27% 0% Operations and maintenance requirements % 73% 18% 0% Training requirements % 64% 27% 0% Operator certification requirements % 45% 36% 9% Staffing requirements % 55% 45% 0% answered question 11 skipped question 11 Question Totals High Moderate Low Appendix B: Complete Survey Data 147

174 Exhibit 19 (U-TA-11) With respect to finished water quality compare biological processes with conventional treatment processes using the criteria below DoD Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalent Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalen t Currently Equivalent Currently Equivalent Aerobic biological processes % 33% 0% 8% 50% Anaerobic/anoxic biological processes % 33% 0% 8% 50% answered question 12 skipped question 7 UTILITIES Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalent Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalen t Currently Equivalent Currently Equivalent Aerobic biological processes % 15% 11% 3% 61% Anaerobic/anoxic biological processes % 12% 13% 4% 70% answered question 331 skipped question 234 REGULATORS Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalent Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalen t Currently Equivalent Currently Equivalent Aerobic biological processes % 20% 8% 8% 48% Anaerobic/anoxic biological processes % 20% 16% 8% 52% answered question 25 skipped question 19 (continued) 148 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

175 Exhibit 19 (con t.) CONSULTANTS Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalent Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalen t Currently Equivalent Currently Equivalent Aerobic biological processes % 29% 9% 0% 20% Anaerobic/anoxic biological processes % 33% 17% 0% 42% answered question 36 skipped question 25 VENDORS Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalent Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalen t Currently Equivalent Currently Equivalent Aerobic biological processes % 40% 20% 0% 0% Anaerobic/anoxic biological processes % 20% 20% 0% 0% answered question 5 skipped question 2 ACADEMICS Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalent Expected to be Equivalent in 5-10 yrs Not Expected to be Equivalent in the Near Future Will never be Equivalen t Currently Equivalent Currently Equivalent Aerobic biological processes % 40% 0% 0% 20% Anaerobic/anoxic biological processes % 20% 20% 10% 40% answered question 10 skipped question 12 Appendix B: Complete Survey Data 149

176 Exhibit 20 (U-TA-5) In your own opinion, how significant are the following operational concerns associated with any type of biological treatment processes? DoD Process instability (i.e., resilience to varying environmental conditions) No Low Moderate High Low or No Moderate High % 23.08% 23.08% 30.77% Process inflexibility % 38.46% 7.69% 30.77% Source water quality changes % 23.08% 15.38% 23.08% Water temperature changes % 7.69% 15.38% 23.08% Bacterial sloughing/breakthrough % 23.08% 38.46% 23.08% Pathogen or contaminant breakthrough % 15.38% 46.15% 23.08% Process start-up and recovery time % 30.77% 15.38% 30.77% Post-treatment and disinfection % 30.77% 23.08% 23.08% Unknown or changing regulatory requirements % 30.77% 23.08% 30.77% Other operational concerns % 0.00% 0.00% % Please specify other operational concerns: 0 answered question 13 skipped question 6 UTILITIES No Low Moderate High Low or No Moderate High Process instability (i.e., resilience to varying environmental conditions) % 23.92% 45.82% 24.21% Process inflexibility % 31.59% 28.41% 29.28% Source water quality changes % 32.95% 36.71% 21.39% Water temperature changes % 34.29% 32.28% 24.50% Bacterial sloughing/breakthrough % 20.00% 52.46% 22.90% Pathogen or contaminant breakthrough % 13.83% 58.21% 21.61% Process start-up and recovery time % 33.04% 33.62% 27.25% Post-treatment and disinfection % 30.92% 31.21% 24.86% Unknown or changing regulatory requirements % 21.74% 41.16% 27.25% Other operational concerns % 7.23% 4.42% 83.53% Please specify other operational concerns: 16 answered question 347 skipped question 218 (continued) 150 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

177 Exhibit 20 (con t.) REGULATORS No Low Moderate High Low or No Moderate High Process instability (i.e., resilience to varying environmental conditions) % 34.62% 38.46% 15.38% Process inflexibility % 44.00% 16.00% 32.00% Source water quality changes % 38.46% 34.62% 15.38% Water temperature changes % 40.00% 32.00% 16.00% Bacterial sloughing/breakthrough % 34.62% 34.62% 19.23% Pathogen or contaminant breakthrough % 24.00% 40.00% 24.00% Process start-up and recovery time % 46.15% 15.38% 23.08% Post-treatment and disinfection % 16.00% 32.00% 20.00% Unknown or changing regulatory requirements % 32.00% 12.00% 36.00% Other operational concerns % 15.00% 10.00% 65.00% Please specify other operational concerns: 3 answered question 26 skipped question 18 CONSULTANTS No Low Moderate High Low or No Moderate High Process instability (i.e., resilience to varying environmental conditions) % 38.10% 33.33% 2.38% Process inflexibility % 40.48% 7.14% 2.38% Source water quality changes % 39.02% 26.83% 0.00% Water temperature changes % 42.86% 35.71% 2.38% Bacterial sloughing/breakthrough % 23.81% 45.24% 2.38% Pathogen or contaminant breakthrough % 16.67% 42.86% 2.38% Process start-up and recovery time % 50.00% 30.95% 4.76% Post-treatment and disinfection % 30.95% 21.43% 4.76% Unknown or changing regulatory requirements % 35.71% 26.19% 11.90% Other operational concerns % 13.04% 4.35% 60.87% Please specify other operational concerns: 4 answered question 42 skipped question 19 (continued) Appendix B: Complete Survey Data 151

178 Exhibit 20 (con t.) VENDORS No Low Moderate High Low or No Moderate High Process instability (i.e., resilience to varying environmental conditions) % 57.14% 14.29% 0.00% Process inflexibility % 28.57% 14.29% 0.00% Source water quality changes % 28.57% 14.29% 0.00% Water temperature changes % 57.14% 28.57% 0.00% Bacterial sloughing/breakthrough % 14.29% 57.14% 0.00% Pathogen or contaminant breakthrough % 14.29% 42.86% 0.00% Process start-up and recovery time % 57.14% 0.00% 0.00% Post-treatment and disinfection % 42.86% 14.29% 0.00% Unknown or changing regulatory requirements % 28.57% 14.29% 0.00% Other operational concerns % 0.00% 0.00% 60.00% Please specify other operational concerns: 0 answered question 7 skipped question 0 ACADEMICS No Low Moderate High Low or No Moderate High Process instability (i.e., resilience to varying environmental conditions) % 54.55% 27.27% 0.00% Process inflexibility % 36.36% 0.00% 0.00% Source water quality changes % 54.55% 27.27% 0.00% Water temperature changes % 54.55% 27.27% 0.00% Bacterial sloughing/breakthrough % 18.18% 54.55% 0.00% Pathogen or contaminant breakthrough % 45.45% 9.09% 0.00% Process start-up and recovery time % 72.73% 9.09% 0.00% Post-treatment and disinfection % 27.27% 9.09% 0.00% Unknown or changing regulatory requirements % 9.09% 54.55% 18.18% Other operational concerns % 0.00% 16.67% 66.67% Please specify other operational concerns: 1 answered question 11 skipped question 11 (continued) 152 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

179 Exhibit 20 (con t.) From U-TA-5 Number Date Please specify other operational concerns 1 06/09/ :14:00 Delving into a new area where little operational history exists. Lack of trained personnel. 2 06/10/ :34:00 Analytical Monitoring. 3 06/13/ :49:00 Fouling of membrane biofilms, ph excursions, incomplete destruction of nitrite. 4 06/17/ :46:00 Filter Sterilization. 5 06/18/ :31:00 Backwash procedures/parameters to maintain biomass not well defined. 6 06/20/ :43:00 We purchase all of our treated water from another agency. We have no experience with the processes. 7 06/20/ :59:00 Post biological treatment water quality is the true test of the use of active biological drinking water treatment. The ability to contain microbes in the filters or destroy them post filtrate must be maintained. 8 06/24/ :03:00 Have no experience with biological treatment. 9 06/30/ :37:00 Operational monitoring procedures and standards needed /30/ :11:00 Cost versus results is always a concern /30/ :38:00 Effect on distribution system /08/ :55:00 Ability to ensure no pathogens introduced or cultured in system /11/ :12:00 Quality control checks to insure proper operation. continuous monitoring of control checks with backup/redundant systems to insure continuous monitoring even when on monitor is down for maintenance /17/ :30:00 Design consideration is where are the biological filters located in relation to disinfection? 15 08/06/ :42:00 Preventive Mtce programs - take filters out of service to survey filter bed/media - cleaning & return to service. Lab tests- parameters needed to determine effectiveness of BAF /10/ :31:00 Can be difficult to retrofit an existing plant. from C-TA-5 Number Date Please specify other operational concerns 1 06/24/ :31:00 Algal growth in process units 2 06/27/ :09:00 Probably the major operational concern is providing either disinfection after the biological treatment to control heterotrophic bacteria and possibly pathogens and/or possibly including non-biologically active filtration to remove microorganisms from the biologically treated water. 3 07/11/ :09:00 Headloss variability, optimization of backwashing protocol. 4 08/06/ :57:00 Main issue here is to know what biological treatment does and does not do well. It can be upset, but for long-term concerns like DBP precursor removal, it can be very cost-effective. 5 09/09/ :59:00 Operator training and experience. from R-TA-5 Number Date Please specify other operational concerns 1 06/11/ :30:00 Gravitational settling and pin floc carry-over( fines). Turbidity requirements-meeting stringent future standards. 2 06/17/ :54:00 Operator training & familiarity with process. 3 06/23/ :25:00 Continuous monitoring of various microorganisms in the plant effluent. For example in case of pathogen breakthrough at the plant. Batch sampling currently being done at water plants may not be adequate. Particle counters may not be the answer because it cannot distinguish microorganisms vs other particles. Appendix B: Complete Survey Data 153

180 Exhibit 21 (REG-1) Does your agency prohibit biological treatment processes for drinking water? Percent Yes 12% 3 No 81% 21 know 8% 2 answered question 26 skipped question 803 Exhibit 22 (REG-3) How many drinking water treatment plants are currently permitted in your state that include the following processes Ranges None > 100 Conventional treatment process (CTP) CTP Ozone-enhanced biological filtration (OEBF) OEBF Rapid biological filtration (SBF) RBF Slow biological filtration (RBF) SBF GAC biological adsorption (GBA) GBA Biological perchlorate/nitrate removal (BPNP) BPNP answered question 24 skipped question 805 None > >50 0% 0% 4% 8% 8% 21% 42% 17% 4% 17% 63% 48% 26% 4% 0% 4% 0% 0% 17% 30% 4% 0% 65% 4% 0% 0% 0% 4% 0% 26% 4% 0% 4% 65% 9% 0% 4% 0% 4% 0% 17% 9% 4% 4% 46% 25% 4% 0% 0% 0% 4% 21% 29% 0% 4% 78% 0% 4% 0% 0% 0% 0% 17% 4% 0% 0% 154 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

181 Exhibit 23 (REG-2) Are there any special permits or approvals required for the following biological treatment processes? Yes No Yes No Ozone-enhanced biological filtration (OEBF) OEBF % 40% 20% Rapid biological filtration (RBF) RBF % 40% 20% Slow biological filtration (SBF) SBF % 44% 20% Granular activated carbon biological adsorption (GBA) GBA % 40% 20% Biological perchlorate/nitrate removal (BPNP) BPNP % 36% 28% answered question 25 skipped question 804 Exhibit 24 (REG-4) What are the requirements for operation of the treatment process? Aerobic biological process Yes No Yes No Standard monthly operating report % 0% 38% Bench-scale/laboratory testing % 7% 33% Pilot plant study % 6% 31% Full-scale demonstration % 21% 50% Operating data from other full-scale water treatment plants % 7% 40% Other requirements % 20% 80% Anaerobic/anoxic biological treatment process Yes No Yes No Standard monthly operating report % 0% 40% Bench-scale/laboratory testing % 7% 36% Pilot plant study % 6% 31% Full-scale demonstration % 21% 50% Operating data from other full-scale water treatment plants % 7% 40% Other requirements % 20% 80% (continued) Appendix B: Complete Survey Data 155

182 Exhibit 24 (con t.) Conventional treatment process Yes No Yes No Standard monthly operating report % 0% 9% Bench-scale/laboratory testing % 35% 10% Pilot plant study % 57% 10% Full-scale demonstration % 68% 11% Operating data from other full-scale water treatment plants % 50% 11% Other requirements % 46% 31% Question Totals Please specify other requirements: 4 answered question 23 skipped question 806 Number Date Please specify other requirements 1 06/04/ :34:00 Surface water rules. 2 06/23/ :34:00 Water Treatement Plant Operator certification licensce from the State and continuing education credits from accredited agecies. 3 06/25/ :32:00 these questions are too broad. For certain things, pilot plants may be required but not for all. Ect 4 07/10/ :01:00 12 months of "seasonal "water quality data. Exhibit 25 (REG-5) Does your agency require a higher plant operator classification for biological processes as compared to conventional treatment processes? Percent Yes 12.5% 3 No 58.3% 14 know 29.2% 7 answered question 24 skipped question Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

183 Exhibit 26 (REG-7) Are you aware of any requirement for a disinfectant residual such as free chlorine or downstream of any biological process? Percent Yes 40% 10 No 28% 7 know 32% 8 If yes, please comment on that requirement: 11 answered question 25 skipped question 804 Number Date If yes, please comment on that requirement 1 06/11/ :27:00 All water leaving a treatment facility must have a residual of 0.2 ppm of disinfection. 2 06/16/ :32:00 Residual required. 3 06/17/ :59:00 State regulation for maintaining chlorine residual in distribution system. 4 06/17/ :05:00 We would look at this requirement on a case-by-case basis to determine the need for continuous chlorination. 5 06/20/ :07:00 Detectable free chlorine in distribution system. 6 06/20/ :08:00 All water systems must maintain a free chlorine residual of at least 0.2 mg/l in the distribution system. 7 06/20/ :51:00 All surface waters require min 0.2 mg/l disinfectant residual at entry point to distribution independent of treatment type. 8 06/24/ :17:00 All public water distribution systems must maintain a chlorine residual at all times. 9 06/25/ :32:00 Any system that treats its water, must disinfect /26/ :15:00 We have not been asked to consider biologic filtration - hence take this into account when evaluating the above answers /27/ :54:00 State of MN requires. Exhibit 27 (REG-6) Does your agency have guidance documents for the design of biological processes? Percent Yes 8% 2 No 72% 18 know 20% 5 answered question 25 skipped question 804 Appendix B: Complete Survey Data 157

184 Exhibit 28 (CON-1) How many research projects have you conducted related to each listed biological treatment processes for drinking water? NOTE: CON1 THROUGH CON9 INCLUDE CONSULTANTS, VENDORS, OR ACADEMICS None 1 to 5 6 to 10 Greater than 10 Slow biological filtration (SBF) Rapid biological filtration (RBF) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Biological perchlorate/nitrate process (BPNP) Conventional treatment process (CTP) answered question 50 skipped question 779 None 1 to 5 6 to 10 Greater than 10 73% 27% 0% 0% 0% 65% 27% 6% 2% 0% 52% 36% 8% 2% 2% 52% 36% 10% 2% 0% 69% 19% 8% 4% 0% 46% 27% 13% 15% 0% Exhibit 29 (CON-2) How many bench/pilot/full-scale testing projects have you conducted related to each listed biological treatment processes for drinking water? None 1 to 5 6 to 10 Greater than 10 Slow biological filtration (SBF) Rapid biological filtration (RBF) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Biological perchlorate/nitrate process (BPNP) Conventional treatment process (CTP) answered question 49 skipped question 780 None 1 to 5 6 to 10 Greater than 10 73% 27% 0% 0% 0% 57% 34% 6% 2% 0% 43% 45% 9% 2% 2% 48% 38% 13% 2% 0% 64% 24% 7% 4% 0% 28% 45% 6% 21% 0% 158 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

185 Exhibit 30 (CON-3) How many design projects have you conducted related to each listed biological treatment processes for drinking water? None 1 to 5 6 to 10 Greater than 10 Slow biological filtration (SBF) Rapid biological filtration (RBF) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Biological perchlorate/nitrate process (BPNP) Conventional treatment process (CTP) answered question 49 skipped question 780 None 1 to 5 6 to 10 Greater than 10 91% 9% 0% 0% 0% 70% 28% 2% 0% 0% 57% 37% 4% 2% 0% 63% 29% 6% 2% 0% 76% 24% 0% 0% 0% 44% 29% 15% 13% 0% Exhibit 31 (CON-4) How many plants have you been involved in the construction related to each listed biological treatment processes for drinking water? None 1 to 5 6 to 10 Greater than 10 Slow biological filtration (SBF) Rapid biological filtration (RBF) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Biological perchlorate/nitrate process (BPNP) Conventional treatment process (CTP) answered question 49 skipped question 780 None 1 to 5 6 to 10 Greater than 10 know 94% 6% 0% 0% 0% 83% 15% 2% 0% 0% 70% 26% 4% 0% 0% 69% 31% 0% 0% 0% 85% 15% 0% 0% 0% 56% 29% 6% 8% 0% Appendix B: Complete Survey Data 159

186 Exhibit 32 (CON-5) How many plants have you supplied equipment for related to each listed biological treatment processes for drinking water? None 1 to 5 6 to 10 Greater than 10 Slow biological filtration (SBF) Rapid biological filtration (RBF) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Biological perchlorate/nitrate process (BPNP) Conventional treatment process (CTP) answered question 48 skipped question 781 None 1 to 5 6 to 10 Greater than 10 >1 96% 2% 0% 0% 2% 2% 96% 2% 0% 0% 2% 2% 96% 0% 2% 0% 2% 2% 96% 2% 0% 0% 2% 2% 94% 4% 0% 0% 2% 4% 89% 6% 0% 2% 2% 9% 160 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

187 Appendix B: Complete Survey Data 161 Exhibit 33 (CON-6) What pre-design studies do you typically perform on drinking water treatment projects? Biological Perchlorate/Nitrate Process (BPNP) Other Biological Processes (SBF/RBF/GBA/OEBF) Conventional Treatment Processes Laboratory study Pilot plant study Literature search Process alternatives desk-top evaluation Full-scale performance at facility Full-scale performance at other facility Not applicable Other studies Please specify other types of studies: 1 answered question 45 skipped question 784 Relative to total # of reponses to each question Biological Other biological perchlorate/nitrate processes process (BPNP) (SBF/RBF/GBA/OEBF) Conventional treatment processes 17% 15% 17% 19% 21% 20% 28% 25% 23% 12% 17% 18% 7% 11% 12% 5% 8% 10% 7% 2% 1% 4% 1% 0% Total Relative to total # of respondents to the question (n=45) Biological Other biological perchlorate/nitrate processes process (BPNP) (SBF/RBF/GBA/OEBF) Conventional treatment processes 31% 40% 51% 33% 58% 58% 51% 69% 67% 22% 47% 53% 13% 29% 36% 9% 22% 29% 13% 4% 2% 7% 2% 0% Number Date Please specify other types of studies 1 06/30/ :23:00 Full literature and biological toxicology evaluation, FMEA and NSF/ANSI Standard 61 Review.

188 162 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 34 (CON-7) What types of guidance documents do you use for designing the following drinking water treatment processes? Biological Perchlorate/Nitrate Process (BPNP) Other Biological Processes (SBF/RBF/GBA/OEBF) Conventional Treatment Processes None Water Research Foundation reports ESTCP cost and performance reports U.S. EPA guidance documents State guidance documents Industry textbooks Vendor design documents Consultant-developed design tools Academic research articles Not applicable Other types of documents Please specify other types of documents: 1 answered question 44 skipped question 785 Relative to total # of reponses to each question Biological Other Biological Perchlorate/Nitrate Processes Process (BPNP) (SBF/RBF/GBA/OEBF) ConventionalTreatment Processes 6% 6% 3% 17% 15% 13% 3% 2% 1% 10% 17% 14% 3% 8% 12% 14% 16% 16% 13% 7% 13% 8% 9% 14% 22% 18% 12% 6% 2% 1% 0% 1% 1% Total Relative to total # of respondents to the question (n=44) Biological Other biological perchlorate/nitrate processes process (BPNP) (SBF/RBF/GBA/OEBF) Conventional treatment processes 9% 16% 9% 27% 43% 45% 5% 5% 5% 16% 48% 52% 5% 23% 43% 23% 45% 59% 20% 20% 48% 14% 25% 50% 36% 50% 43% 9% 7% 5% 0% 2% 5% Number Date Please specify other types of documents 1 2/3/2009 Joint research program of Dutch water companies.

189 Exhibit 35 (CON-8) For each type of treatment process (i.e., each row), what do you consider to be a typical unit cost range (in $US/gallons per day, $/gpd) for estimating the normalized capital cost for the biological treatment process component? Less than 0.10 per gpd $ $0.20 per gpd $0.21 to $.50 per gpd $0.51 to $1.00 per gpd Greater than $1.00 per gpd Slow biological filtration (SBF) Rapid biological filtration (RBF) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Biological perchlorate/nitrate process (BPNP) Conventional treatment process (CTP) answered question 42 skipped question 787 Less than 0.10 per gpd $ $0.20 per gpd $0.21 to $.50 per gpd $0.51 to $1.00 per gpd Greater than $1.00 per gpd 7% 10% 12% 5% 2% 63% 2% 17% 7% 5% 0% 68% 0% 12% 12% 7% 2% 67% 0% 5% 12% 10% 10% 64% 3% 5% 13% 13% 5% 63% 5% 5% 10% 12% 17% 51% Appendix B: Complete Survey Data 163

190 Exhibit 36 (CON-9) For each type of treatment process (i.e., each row), what do you consider to be a typical or rule-of-thumb unit cost range for estimating the normalized operating and maintenance costs for the biological treatment process component? Less than $50/million gallons (mg) Greater than $350/mg $51 to $101 to $151 to $201 to $251 to $301 to 100/mg 150/mg 200/mg 250/mg 300/mg 350/mg Slow biological filtration (SBF) Rapid biological filtration (RBF) GAC biological adsorption (GBA) Ozone enhanced biological filtration (OEBF) Biological perchlorate/nitrate process (BPNP) Conventional treatment process (CTP) answered question 43 skipped question 786 Less than $50/million gallons (mg) Greater than $350/mg $51 to 100/mg $101 to 150/mg $151 to 200/mg $201 to 250/mg $251 to 300/mg $301 to 350/mg 10% 10% 0% 0% 2% 0% 0% 0% 79% 5% 5% 7% 2% 0% 0% 0% 0% 81% 2% 7% 12% 0% 2% 0% 0% 2% 74% 2% 5% 2% 9% 2% 2% 0% 2% 74% 7% 0% 7% 2% 2% 10% 2% 0% 69% 10% 5% 5% 2% 7% 2% 0% 2% 67% 164 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

191 Exhibit 37 (WTP-G-2:1) What is the capacity and population served for this water treatment plant? WATER TREATMENT PLANT #1 WATER TREATMENT PLANT #2 WATER TREATMENT PLANT #3 TOTALS Design Current Operation Design Current Operation Design Current Operation Design Current Operation <1 mgd % 5 8% 1-5 mgd % 6 10% 6-10 mgd % 16 26% mgd % 21 34% mgd % 7 11% mgd % 6 10% > 200 mgd % 0 0% know % 1 2% TOTAL Design Current Operation Design Current Operation Design Current Operation < % 2 3% % 1 2% % 19 33% % 7 12% > % 28 48% know % 1 2% TOTAL Appendix B: Complete Survey Data 165

192 166 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 38 (WTP-G-3:1) What type of water source(s) is used for this treatment plant? WATER TREATMENT PLANT #1 Current Water Treatment Plant Reservoir/lake River/stream Groundwater Groundwater under direct influence of surface water 1 1 answered question 51 skipped question 7 WATER TREATMENT PLANT #2 Current Water Treatment Plant Reservoir/lake 8 8 River/stream 5 5 Groundwater 3 3 Groundwater under direct influence of surface water 0 0 answered question 13 skipped question 45 WATER TREATMENT PLANT #3 Current Water Treatment Plant Reservoir/lake 0 0 River/stream 1 1 Groundwater 1 1 Groundwater under direct influence of surface water 0 0 answered question 2 skipped question 56

193 Appendix B: Complete Survey Data 167 Exhibit 39 (WTP-G-4a:1) Characterize the average source water quality for this water treatment plant for the following parameters: WTP-1 WTP-2 WTP-3 Total Percent Turbidity < 10 NTU % NTU % > 50 NTU % Unknown % Total % TOC < 2 mg/l % 2-4 mg/l % 4-6 mg/l % > 6 mg/l % Unknown % Total % Alkalinity < 50 mg/l % mg/l % > 100 mg/l % Unknown % Total % ph < % % > % Unknown % Total % Bromide <= 0.05 mg/l % > 0.05 and <= 0.1 mg/l % > 0.1 mg/l % Unknown % Total % Total Fe <= 0.15 mg/l % > 0.15 and <= 0.3 mg/l % > 0.3 and <= 1 mg/l % > 1 mg/l % Unknown % Total % Total Mn <= mg/l % > and <= 0.05 mg/l > % > 0.05 mg/l % Unknown % Total % (continued)

194 168 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 39 (con t.) WTP-1 WTP-2 WTP-3 Total Percent Total Nitrate/Nitrite < 1 mg-n/l % > 1 and < 10 mg-n/l % > 10 mg-n/l % Unknown % Total % Perchlorate <=4 ug/l % > 4 and <= 22 ug/l % > 22 ug/l % Unknown % Total % Threshold odor number < % % % > % Total % Minimum source water temperature < 40 Deg F % Deg F % Deg F % Deg F % Deg F % > 80 Deg F % Total % Maximum source water temperature < 40 Deg F % Deg F % Deg F % Deg F % Deg F % > 80 Deg F % Total %

195 Exhibit 40 Process Selection Decision Tree Results WATER TREATMENT PLANT #1 (WTP-G-5:1) Does this water treatment plant involve a biological treatment process for perchlorate/nitrate removal? (* Indicates mandatory question) Percent (RES-1:1) Is any disinfectant residual generally present in water exiting treatment train filters but before any supplemental disinfectant addition? (* Indicates mandatory question) Percent We have concluded that your process is a conventional and non-biological treatment process. Would you like to provide data for another case study? Percent Yes 13.5% 9 Yes 34.1% 15 Yes 44.4% 8 No 86.5% 44 No 56.8% 25 No 55.6% 10 answered question 53 know 9.1% 4 answered question 18 skipped question 5 answered question 44 skipped question 40 skipped question 14 WATER TREATMENT PLANT #2 (WTP-G-5:2) Does this water treatment plant involve a biological treatment process for perchlorate/nitrate removal? (* Indicates mandatory question) Percent (RES-1:2) Is any disinfectant residual generally present in water exiting treatment train filters but before any supplemental disinfectant addition? (* Indicates mandatory question) Percent We have concluded that your process is a conventional and non-biological treatment process. Would you like to provide data for another case study? Percent Yes 13.3% 2 Yes 50.0% 6 Yes 37.5% 3 No 86.7% 13 No 41.7% 5 No 62.5% 5 answered question 15 know 8.3% 1 answered question 8 skipped question 43 answered question 12 skipped question 50 skipped question 46 WATER TREATMENT PLANT #3 (WTP-G-5:3) Does this water treatment plant involve a biological treatment process for perchlorate/nitrate removal? (* Indicates mandatory question) Percent (RES-1:3) Is any disinfectant residual generally present in water exiting treatment train filters but before any supplemental disinfectant addition? (* Indicates mandatory question) Percent Yes 0.0% 0 Yes 100.0% 2 No 100.0% 2 No 0.0% 0 answered question 2 know 0.0% 0 skipped question 56 answered question 2 skipped question 56 (continued) Appendix B: Complete Survey Data 169

196 Exhibit 40 (con t.) WATER TREATMENT PLANT #1 (OZ-1:1) Does your treatment train include an ozone process? (* Indicates mandatory question) Percent (GAC-1:1) Does your treatment train include a post-filter granular activated carbon (GAC) contactor? (* Indicates mandatory question) Percent (SSF-1:1) Does your treatment train include a slow sand filtration process? (* Indicates mandatory question) Percent Yes 55.6% 15 Yes 25.0% 3 Yes 22.2% 2 No 44.4% 12 No 75.0% 9 No 77.8% 7 answered question 27 answered question 12 answered question 9 skipped question 31 skipped question 46 skipped question 49 WATER TREATMENT PLANT #2 (OZ-1:2) Does your treatment train include an ozone process? (* Indicates mandatory question) Percent (GAC-1:2) Does your treatment train include a post-filter granular activated carbon (GAC) contactor? (* Indicates mandatory question) Percent (SSF-1:2) Does your treatment train include a slow sand filtration process? (* Indicates mandatory question) Percent Yes 80.0% 4 Yes 0.0% 0 Yes 0.0% 0 No 20.0% 1 No 100.0% 1 No 100.0% 1 answered question 5 answered question 1 answered question 1 skipped question 53 skipped question 57 skipped question 57 WATER TREATMENT PLANT #3 (OZ-1:3) Does your treatment train include an ozone process? (* Indicates mandatory question) (GAC-1:3) Does your treatment train include a post-filter granular activated carbon (GAC) contactor? (* Indicates mandatory question) (SSF-1:3) Does your treatment train include a slow sand filtration process? (* Indicates mandatory question) Percent Percent Percent Yes 0.0% 0 Yes 0.0% 0 Yes 0.0% 0 No 0.0% 0 No 0.0% 0 No 0.0% 0 answered question 0 answered question 0 answered question 0 skipped question 58 skipped question 58 skipped question Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

197 Exhibit 41 (OEBF-1:1) Was the biological water treatment process designed as a "managed" or "incidental" process? WTP-1 WTP-2 WTP-3 Total Percent Managed process (focus on promoting biological treatment performance) % Incidental process (focus on optimizing non-biological treatment performance - e.g., turbidity and particle removal) % know % (RBF-1:1) Was the biological water treatment process designed as a "managed" or "incidental" process? Total Percent Managed process (focus on promoting biological treatment performance) % Incidental process (focus on optimizing non-biological treatment performance - e.g., turbidity and particle removal) % know % (GBA-1:1) Was the biological water treatment process designed as a "managed" or "incidental" process? Total Percent Managed process (focus on promoting biological treatment performance) % Incidental process (focus on optimizing non-biological treatment performance - e.g., turbidity and particle removal) % know % (SBF-1:1) Was the biological water treatment process designed as a "managed" or "incidental" process? Total Percent Managed process (focus on promoting biological treatment performance) % Incidental process (focus on optimizing non-biological treatment performance - e.g., turbidity and particle removal) % know % Appendix B: Complete Survey Data 171

198 Exhibit 42 (OEBF) Choose one or more contaminants removed by the biological process WTP-1 WTP-2 WTP-3 Total Percent Total organic carbon / Disinfection by-product precursors % Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) % Taste and odor compounds % Endocrine disrupting compounds, pharmaceuticals, and personal care products, etc. 4 25% Perchlorate/nitrate/nitrite % Iron/manganese % Turbidity/particle counts % HPC bacteria/total coliform % Bromate % Color % Other contaminants Please specify other contaminants: (RBF-2:1) Choose one or more contaminants removed by the biological process Percent Total Percent Total organic carbon /Disinfection by-product precursors 100.0% % Assimilable organic carbon/biodegradable dissolved organic carbon 100.0% (AOC/BDOC) 4 100% Taste and odor compounds 100.0% % Endocrine disrupting compounds, pharmaceuticals, and personal 33.3% care products, etc. 1 25% Perchlorate/nitrate/nitrite 0.0% % Iron/manganese 33.3% % Turbidity/particle counts 66.7% % HPC bacteria/total coliform 33.3% % Bromate 0.0% % Color 33.3% % Other contaminants 0.0% Please specify other contaminants: answered question skipped question (continued) 172 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

199 Exhibit 42 (con t.) (BPNP-3:1) Choose one or more contaminants removed by the biological process Percent Total Percent Total organic carbon /disinfection by-product precursors 16.7% % Assimilable organic carbon/biodegradable dissolved organic carbon 16.7% (AOC/BDOC) 2 22% Taste and odor compounds 0.0% % Endocrine disrupting compounds, pharmaceuticals, and personal 0.0% care products, etc. 0 0% Perchlorate/nitrate/nitrite 100.0% % Iron/manganese 0.0% % Turbidity/particle counts 16.7% % HPC bacteria/total coliform 0.0% % Bromate 0.0% % Color 0.0% % Other contaminants 0.0% % Please specify other contaminants: answered question skipped question (GBA-2:1) Choose one or more contaminants removed by the biological process Percent Total Percent Total organic carbon /disinfection by-product precursors 100.0% % Assimilable organic carbon/biodegradable dissolved organic carbon 0.0% (AOC/BDOC) 0 0% Taste and odor compounds 100.0% % Endocrine disrupting compounds, pharmaceuticals, and personal 33.3% care products, etc. 1 33% Perchlorate/nitrate/nitrite 0.0% % Iron/manganese 0.0% % Turbidity/particle counts 66.7% % HPC bacteria/total coliform 33.3% % Bromate 0.0% % Color 33.3% % Other contaminants 0.0% Please specify other contaminants: answered question skipped question (continued) Appendix B: Complete Survey Data 173

200 Exhibit 42 (con t.) (SBF-2:1) Choose one or more contaminants removed by the biological process Percent Total Percent Total organic carbon /disinfection by-product precursors 0.0% % Assimilable organic carbon/biodegradable dissolved organic carbon 0.0% (AOC/DOC) 0 0% Taste and odor compounds 0.0% % Endocrine disrupting compounds, pharmaceuticals, and personal 0.0% care products, etc. 0 0% Perchlorate/nitrate/nitrite 0.0% % Iron/manganese 100.0% % Turbidity/particle counts 0.0% % HPC bacteria/total coliform 0.0% % Bromate 0.0% % Color 0.0% % Other contaminants 0.0% Please specify other contaminants: answered question skipped question OEBF Number Date Please specify other contaminants 1 06/23/ :14:00 The system is not used BPNP Number Date Please specify other contaminants 1 06/24/ :24:00 DBCP 174 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

201 Exhibit 43 (OEBF-6:1) How does the biological water treatment process impact the water quality in the distribution system? WTP1 WTP 2 Positive Impact Negative Impact No Change Positive impact Negative Impact No Change Chlorine/chloramine disinfectant residuals Chlorine/chloramine demand and residual decay rates Total coliform positives HPC bacteria concentrations Biofilm levels Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Other water quality parameters Please specify other water quality parameters: 2 Please specify other water quality parameters: 1 answered question 14 answered question 1 skipped question 44 skipped question 57 WTP 3 TOTAL Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Chlorine/chloramine disinfectant residuals Chlorine/chloramine demand and residual decay rates Total coliform positives HPC bacteria concentrations Biofilm levels Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Other water quality parameters Please specify other water quality parameters: 0 answered question 0 15 skipped question 58 Positive Impact Negative Impact No Change Chlorine/chloramine disinfectant residuals 53% 0% 27% 20% Chlorine/chloramine demand and residual decay rates 50% 7% 21% 21% Total coliform positives 27% 0% 53% 20% HPC bacteria concentrations 20% 13% 40% 27% Biofilm levels 20% 0% 20% 60% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations 53% 0% 0% 47% Customer taste and odor complaints 60% 0% 13% 27% Customer colored water complaints 33% 0% 40% 27% Corrosion 0% 0% 27% 73% Dissolved oxygen (DO) concentration 0% 0% 33% 67% Other water quality parameters (continued) Appendix B: Complete Survey Data 175

202 Exhibit 43 (con t.) (RBF-6:1) How does the biological water treatment process impact the water quality in the distribution system? WTP1 WTP 2 Positive Impact Negative Impact No Change Positive impact Negative Impact No Change Chlorine/chloramine disinfectant residuals Chlorine/chroramine demand and residual decay rates Total coliform positives HPC bacteria concentrations Biofilm levels Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Other water quality parameters Please specify other water quality parameters: 0 Please specify other water quality parameters: 0 answered question 3 answered question 1 skipped question 55 skipped question 57 WTP 3 TOTAL Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Chlorine/chloramine disinfectant residuals Chlorine/chroramine demand and residual decay rates Total coliform positives HPC bacteria concentrations Biofilm levels Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Other water quality parameters Please specify other water quality parameters: 0 answered question 0 4 skipped question 58 Positive Impact Negative Impact No Change Chlorine/chloramine disinfectant residuals 75% 0% 25% 0% Chlorine/chroramine demand and residual decay rates 100% 0% 0% 0% Total coliform positives 50% 0% 50% 0% HPC bacteria concentrations 50% 0% 50% 0% Biofilm levels 75% 0% 0% 25% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations 75% 0% 0% 25% Customer taste and odor complaints 100% 0% 0% 0% Customer colored water complaints 100% 0% 0% 0% Corrosion 75% 0% 25% 0% Dissolved oxygen (DO) concentration 0% 0% 0% 100% Other water quality parameters (continued) 176 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

203 Exhibit 43 (con t.) (BPNP-7:1) How does the biological water treatment process impact the water quality in the distribution system? WTP1 WTP 2 Positive Impact Negative Impact No Change Positive impact Negative Impact No Change Chlorine/chloramine disinfectant residuals Chlorine/chloramine demand and residual decay rates Total coliform positives HPC bacteria concentrations Biofilm levels Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Other water quality parameters Please specify other water quality parameters: 1 Please specify other water quality parameters: 0 answered question 7 answered question 2 skipped question 51 skipped question 56 WTP 3 TOTAL Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Chlorine/chloramine disinfectant residuals Chlorine/chloramine demand and residual decay rates Total coliform positives HPC bacteria concentrations Biofilm levels Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Other water quality parameters Please specify other water quality parameters: 0 answered question 0 9 skipped question 58 Positive Impact Negative Impact No Change Chlorine/chloramine disinfectant residuals 0% 0% 56% 44% Chlorine/chloramine demand and residual decay rates 0% 33% 22% 44% Total coliform positives 13% 0% 38% 50% HPC bacteria concentrations 0% 0% 50% 50% Biofilm levels 0% 0% 50% 50% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations 0% 13% 50% 38% Customer taste and odor complaints 0% 11% 44% 44% Customer colored water complaints 0% 0% 50% 50% Corrosion 0% 0% 50% 50% Dissolved oxygen (DO) concentration 0% 0% 50% 50% Other water quality parameters (continued) Appendix B: Complete Survey Data 177

204 Exhibit 43 (con t.) (GBA-6:1) How does the biological water treatment process impact the water quality in the distribution system? WTP1 WTP 2 Positive Impact Negative Impact No Change Positive impact Negative Impact No Change Chlorine/chloramine disinfectant residuals Chlorine/chloramine demand and residual decay rates Total coliform positives HPC bacteria concentrations Biofilm levels Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Other water quality parameters Please specify other water quality parameters: 0 Please specify other water quality parameters: 0 answered question 3 answered question 0 skipped question 55 skipped question 58 WTP 3 TOTAL Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Chlorine/chloramine disinfectant residuals Chlorine/chloramine demand and residual decay rates Total coliform positives HPC bacteria concentrations Biofilm levels Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Other water quality parameters Please specify other water quality parameters: 0 answered question 0 3 skipped question 58 Positive Impact Negative Impact No Change Chlorine/chloramine disinfectant residuals 67% 0% 0% 33% Chlorine/chloramine demand and residual decay rates 33% 0% 0% 67% Total coliform positives 0% 0% 33% 67% HPC bacteria concentrations 0% 0% 33% 67% Biofilm levels 0% 0% 33% 67% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations 0% 0% 33% 67% Customer taste and odor complaints 33% 0% 33% 33% Customer colored water complaints 0% 0% 33% 67% Corrosion 0% 0% 33% 67% Dissolved oxygen (DO) concentration 0% 0% 0% 100% Other water quality parameters (continued) 178 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

205 Exhibit 43 (con t.) (SBF-6:1) How does the biological water treatment process impact the water quality in the distribution system? WTP1 WTP 2 Positive Impact Negative Impact No Change Positive impact Negative Impact No Change Chlorine/chloramine demand and residual decay rates Total coliform positives HPC bacteria concentrations Biofilm levels Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Other water quality parameters Please specify other water quality parameters: 0 Please specify other water quality parameters: 0 answered question 1 answered question 0 skipped question 57 skipped question 58 WTP 3 TOTAL Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Chlorine/chloramine demand and residual decay rates Total coliform positives HPC bacteria concentrations Biofilm levels Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Other water quality parameters Please specify other water quality parameters: 0 answered question 0 1 skipped question 58 Positive Impact Negative Impact No Change Chlorine/chloramine demand and residual decay rates 0% 0% 100% 0% Total coliform positives 0% 0% 100% 0% HPC bacteria concentrations 0% 0% 100% 0% Biofilm levels 0% 0% 100% 0% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) concentrations 0% 0% 100% 0% Customer taste and odor complaints 100% 0% 0% 0% Customer colored water complaints 100% 0% 0% 0% Corrosion 0% 0% 100% 0% Dissolved oxygen (DO) concentration 0% 0% 0% 100% Other water quality parameters (continued) Appendix B: Complete Survey Data 179

206 Exhibit 43 (con t.) Other water quality parameters OEBF 6.1 Number Date Please specify other water quality parameters 1 06/23/ :14:00 It was supposed to remove TOC 2 08/06/ :54:00 Need to study this Number Date Please specify other water quality parameters 1 06/18/ :59:00 Note: Same responses as Lanier Filter Plant BPNP 7.1 Number Date Please specify other water quality parameters No change because a surface water treatment plant polishes the biological treatment plant 1 06/17/ :51:00 effluent. Exhibit 44 (OEBF-8:1) What is your final disinfectant? WTP1 WTP 2 WTP 3 Percent Total Percent Chlorine 53.3% % Combined chlorine (e.g., chloramine) 46.7% % Other 0.0% % Please specify other disinfectant: answered question % skipped question (RBF-7:1) What is your final disinfectant? WTP1 WTP 2 WTP 3 Percent Total Percent Chlorine 66.7% % Combined chlorine (e.g., chloramine) 33.3% % Other 0.0% % Please specify other disinfectant: answered question % skipped question (BPNP-8:1) What is your final disinfectant? WTP1 WTP 2 WTP 3 Percent Total Percent Chlorine 83.3% % Combined chlorine (e.g., chloramine) 0.0% % Other 16.7% % Please specify other disinfectant: answered question % skipped question (continued) 180 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

207 Exhibit 44 (con t.) (GBA-7:1) What is your final disinfectant? WTP1 WTP 2 WTP 3 Percent Total Percent Chlorine 66.7% % Combined chlorine (e.g., chloramine) 33.3% % Other 0.0% % Please specify other disinfectant: answered question % skipped question (SBF-7:1) What is your final disinfectant? WTP1 WTP 2 WTP 3 Percent Total Percent Chlorine 100.0% % Combined chlorine (e.g., chloramine) 0.0% % Other 0.0% % Please specify other disinfectant: answered question % skipped question ALL Total Percent Chlorine 22 69% Combined chlorine (e.g., chloramine) 9 28% Other 1 3% Please specify other disinfectant: % Other water quality parameters OEBF Number Date Please specify other disinfectant 1 06/30/ :58:00 chloramines after clearwell (secondary disinfection) BPNP Number Date Please specify other disinfectant 1 06/17/ :51:00 UV and chlroine Appendix B: Complete Survey Data 181

208 182 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 45 (OEBF-10:1) What dose do you need to achieve your target disinfectant residual? WTP1 WTP2 WTP3 Percent Total Percent < 0.5 mg/l 0.0% % mg/l 0.0% % mg/l 20.0% % mg/l 6.7% % mg/l 0.0% % mg/l 20.0% % > 3.0 mg/l 53.3% % know 0.0% % answered question skipped question (RBF-9:1) What dose do you need to achieve your target disinfectant residual? WTP1 WTP2 WTP3 Percent Total Percent < 0.5 mg/l 0.0% % mg/l 33.3% % mg/l 33.3% % mg/l 0.0% % mg/l 0.0% % mg/l 0.0% % > 3.0 mg/l 33.3% % know 0.0% % answered question skipped question (BPNP-10:1) What dose do you need to achieve your target disinfectant residual? WTP1 WTP2 WTP3 Percent Total Percent < 0.5 mg/l 0.0% % mg/l 33.3% % mg/l 0.0% % mg/l 16.7% % mg/l 16.7% % mg/l 0.0% % > 3.0 mg/l 0.0% % know 33.3% % answered question skipped question (GBA-9:1) What dose do you need to achieve your target disinfectant residual? WTP1 WTP2 WTP3 Percent Total Percent < 0.5 mg/l 0.0% % mg/l 0.0% % mg/l 66.7% % mg/l 0.0% % mg/l 0.0% % mg/l 0.0% % > 3.0 mg/l 33.3% % know 0.0% % answered question skipped question (continued)

209 Appendix B: Complete Survey Data 183 Exhibit 45 (con t.) (SBF-9:1) What dose do you need to achieve your target disinfectant residual? WTP1 WTP2 WTP3 Percent Total Percent < 0.5 mg/l 0.0% % mg/l 0.0% % mg/l 100.0% % mg/l 0.0% % mg/l 0.0% % mg/l 0.0% % > 3.0 mg/l 0.0% % know 0.0% % answered question skipped question Exhibit 46 (OEBF-9:1) What is your target disinfectant residual leaving the plant? WTP1 WTP 2 WTP 3 Percent Total Percent < 0.5 mg/l 0.0% % mg/l 0.0% % mg/l 26.7% % mg/l 20.0% % mg/l 20.0% % > 2.5 mg/l 33.3% % know 0.0% % answered question % skipped question (RBF-8:1) What is your target disinfectant residual leaving the plant? WTP1 WTP 2 WTP 3 Percent Total Percent < 0.5 mg/l 33.3% % mg/l 0.0% % mg/l 33.3% % mg/l 0.0% % mg/l 0.0% % > 2.5 mg/l 33.3% % know 0.0% % answered question % skipped question (BPNP-9:1) What is your target disinfectant residual leaving the plant? WTP1 WTP 2 WTP 3 Percent Total Percent < 0.5 mg/l 0.0% % mg/l 66.7% % mg/l 0.0% % mg/l 0.0% % mg/l 0.0% % > 2.5 mg/l 0.0% % know 33.3% % answered question % skipped question (continued)

210 184 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 46 (con t.) (GBA-8:1) What is your target disinfectant residual leaving the plant? WTP1 WTP 2 WTP 3 Percent Total Percent < 0.5 mg/l 0.0% % mg/l 33.3% % mg/l 33.3% % mg/l 0.0% % mg/l 0.0% % > 2.5 mg/l 33.3% % know 0.0% % answered question % skipped question (SBF-8:1) What is your target disinfectant residual leaving the plant? WTP1 WTP 2 WTP 3 Percent Total Percent < 0.5 mg/l 0.0% % mg/l 100.0% % mg/l 0.0% % mg/l 0.0% % mg/l 0.0% % > 2.5 mg/l 0.0% % know 0.0% % answered question % skipped question

211 Appendix B: Complete Survey Data 185 Exhibit 47 (OEBF-17:1) What type of washwater is used to backwash the biological water treatment process? WTP1 WTP 2 WTP 3 Percent Total Percent Chlorinated 40.0% % Chloraminated 20.0% % Chlorinated intermittently 6.7% % Non-chlorinated 33.3% % know 0.0% % Not applicable 0.0% % answered question skipped question (RBF-16:1) What type of washwater is used to backwash the biological water treatment process? WTP1 WTP 2 WTP 3 Percent Total Percent Chlorinated 33.3% % Chloraminated 33.3% % Chlorinated intermittently 33.3% % Non-chlorinated 0.0% % know 0.0% % Not applicable 0.0% % answered question skipped question (BPNP-17:1) What type of washwater is used to backwash the biological water treatment process? WTP1 WTP 2 WTP 3 Percent Total Percent Chlorinated 0.0% % Chloraminated 0.0% % Chlorinated intermittently 0.0% % Non-chlorinated 42.9% % know 28.6% % Not applicable 28.6% % answered question skipped question (GBA-16:1) What type of washwater is used to backwash the biological water process? WTP1 WTP 2 WTP 3 Percent Total Percent Chlorinated 0.0% % Chloraminated 33.3% % Chlorinated intermittently 0.0% % Non-chlorinated 66.7% % know 0.0% % Not applicable 0.0% % answered question skipped question

212 186 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 48 (OEBF-18:1) What is the average backwash frequency for the process? WTP1 WTP 2 WTP 3 Percent Total Percent Less than once every 12 hours 0.0% % Once every hours 33.3% % Once every hours 26.7% % Once every hours 40.0% % Greater than every 168 hours 0.0% % know 0.0% % Not applicable 0.0% % answered question skipped question (RBF-17:1) What is the average backwash frequency for the process? WTP1 WTP 2 WTP 3 Percent Total Percent Less than once every 12 hours 0.0% % Once every hours 0.0% % Once every hours 66.7% % Once every hours 33.3% % Greater than every 168 hours 0.0% % know 0.0% % Not applicable 0.0% % answered question skipped question (BPNP-18:1) What is the average backwash frequency for the process? WTP1 WTP 2 WTP 3 Percent Total Percent Less than once every 12 hours 0.0% % Once every hours 14.3% % Once every hours 0.0% % Once every hours 14.3% % Greater than every 168 hours 14.3% % know 28.6% % Not applicable 28.6% % answered question skipped question (GBA-17:1) What is the average backwash frequency for the process? WTP1 WTP 2 WTP 3 Percent Total Percent Less than once every 12 hours 0.0% % Once every hours 66.7% % Once every hours 0.0% % Once every hours 0.0% % Greater than every 168 hours 33.3% % know 0.0% % Not applicable 0.0% % answered question skipped question

213 Exhibit 49 (OEBF-12:1) Choose one or more approaches currently used to produce biologically stable water leaving the plant WTP1 WTP 2 WTP 3 Percent Total Percent Optimize ozone dose (unique to OEBF) 33.3% % Optimize empty-bed contact time for biological filtration 13.3% % Increase chlorine/chloramine disinfectant dose 53.3% % Increase chlorine:ammonia ratio 13.3% % Provide advanced treatment (UV or membranes) downstream 0.0% % Monitor HPC levels downstream of filtration 46.7% % Monitor AOC/BDOC downstream of filtration 13.3% % Optimize corrosion control 53.3% % Minimize carbon-source residuals in finished water 26.7% % know 6.7% % Please specify other approaches: answered question skipped question (RBF-11:1) Choose one or more approaches currently used to produce biologically stable water leaving the plant WTP1 WTP 2 WTP 3 Percent Total Percent Optimize empty-bed contact time for biological filtration 66.7% % Increase chlorine/chloramine disinfectant dose 33.3% % Increase chlorine:ammonia ratio 0.0% % Provide advanced treatment (UV or membranes) downstream 0.0% % Monitor HPC levels downstream of filtration 33.3% % Monitor AOC/BDOC downstream of filtration 0.0% % Optimize corrosion control 66.7% % Minimize carbon-source residuals in finished water 33.3% % know 0.0% % Please specify other approaches: answered question skipped question (continued) Appendix B: Complete Survey Data 187

214 Exhibit 49 (con t.) (BPNP-12:1) Choose one or more approaches currently used to produce biologically stable water leaving the plant WTP1 WTP 2 WTP 3 Percent Total Percent Aerate to increase dissolved oxygen 42.9% % Aerate to promote aerobic biodegradation 28.6% % Optimize empty-bed contact time for biological filtration 0.0% % Increase chlorine/chloramine disinfectant dose 14.3% % Increase chlorine:ammonia ratio 0.0% % Provide multi-media filtration downstream 42.9% % Provide advanced treatment (UV or membranes) downstream 14.3% % Monitor HPC levels downstream of filtration 14.3% % Monitor AOC/BDOC downstream of filtration 14.3% % Optimize corrosion control 0.0% % Minimize electron donor residuals in finished water 42.9% % know 42.9% % Please specify other approaches: answered question skipped question (GBA-11:1) Choose one or more approaches currently used to produce biologically stable water leaving the plant WTP1 WTP 2 WTP 3 Percent Total Percent Optimize empty-bed contact time for biological filtration 33.3% % Increase chlorine/chloramine disinfectant dose 66.7% % Increase chlorine:ammonia ratio 33.3% % Provide advanced treatment (UV or membranes) downstream 33.3% % Monitor HPC levels downstream of filtration 0.0% % Monitor AOC/BDOC downstream of filtration 0.0% % Optimize corrosion control 100.0% % Minimize carbon-source residuals in finished water 66.7% % know 0.0% % Please specify other approaches: answered question skipped question (continued) 188 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

215 Exhibit 49 (con t.) (SBF-11:1) Choose one or more approaches currently used to produce biologically stable water leaving the plant WTP1 WTP 2 WTP 3 Percent Total Percent Optimize empty-bed contact time for biological filtration 0.0% % Increase chlorine/chloramine disinfectant dose 100.0% % Increase chlorine:ammonia ratio 0.0% % Provide advanced treatment (UV or membranes) downstream 100.0% % Monitor HPC levels downstream of filtration 0.0% % Monitor AOC/BDOC downstream of filtration 0.0% % Optimize corrosion control 0.0% % Minimize carbon-source residuals in finished water 0.0% % know 0.0% % Please specify other approaches: answered question skipped question Other water quality parameters OEBF 12.1 Number Date Please specify other approaches 06/18/2008 Same responses as Lanier Filter Plant 1 18:59:00 SBF 11.1 Number Date Please specify other approaches 1 06/23/ :40:00 Required minimum contact basin retention time Appendix B: Complete Survey Data 189

216 Exhibit 50 (OEBF-13:1) Choose one or more approaches currently used to maintain biologically stable water in the distribution system WTP1 WTP 2 WTP 3 Percent Total Percent Increase flushing frequency in filtration system 13.3% % Disinfect new or repaired pipelines prior to placing in service 80.0% % Implement strategic pipeline replacement program 46.7% % Increase distribution monitoring 40.0% % Increase disinfectant residual 26.7% % Change monitoring points 13.3% % Monitor HPC levels in distribution system 80.0% % Monitor AOC/BDOC in distribution system 26.7% % know 6.7% % Please specify other approaches: answered question % skipped question (RBF-12:1) Choose one or more approaches currently used to maintain biologically stable water in the distribution system WTP1 WTP 2 WTP 3 Percent Total Percent Increase flushing frequency in filtration system 33.3% % Disinfect new or repaired pipelines prior to placing in service 66.7% % Implement strategic pipeline replacement program 66.7% % Increase distribution monitoring 66.7% % Increase disinfectant residual 33.3% % Change monitoring points 33.3% % Monitor HPC levels in distribution system 66.7% % Monitor AOC/BDOC in distribution system 0.0% % know 0.0% % Please specify other approaches: answered question % skipped question (continued) 190 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

217 Exhibit 50 (con t.) (BPNP-13:1) Choose one or more approaches currently used to maintain biologically stable water in the distribution system WTP1 WTP 2 WTP 3 Percent Total Percent Increase flushing frequency in filtration system 0.0% % Disinfect new or repaired pipelines prior to placing in service 16.7% % Implement strategic pipeline replacement program 16.7% % Increase distribution monitoring 0.0% % Increase disinfectant residual 0.0% % Change monitoring points 0.0% % Monitor HPC levels in distribution system 16.7% % Monitor AOC/BDOC in distribution system 0.0% % know 83.3% % Please specify other approaches: answered question % skipped question (GBA-12:1) Choose one or more approaches currently used to maintain biologically stable water in the distribution system WTP1 WTP 2 WTP 3 Percent Total Percent Increase flushing frequency in filtration system 0.0% % Disinfect new or repaired pipelines prior to placing in service 66.7% % Implement strategic pipeline replacement program 33.3% % Increase distribution monitoring 66.7% % Increase disinfectant residual 0.0% % Change monitoring points 33.3% % Monitor HPC levels in distribution system 33.3% % Monitor AOC/BDOC in distribution system 0.0% % know 33.3% % Please specify other approaches: answered question % skipped question (continued) Appendix B: Complete Survey Data 191

218 Exhibit 50 (con t.) (SBF-12:1) Choose one or more approaches currently used to maintain biologically stable water in the distribution system WTP1 WTP 2 WTP 3 Percent Total Percent Increase flushing frequency in filtration system 0.0% % Disinfect new or repaired pipelines prior to placing in service 100.0% % Implement strategic pipeline replacement program 0.0% % Increase distribution monitoring 0.0% % Increase disinfectant residual 100.0% % Change monitoring points 0.0% % Monitor HPC levels in distribution system 0.0% % Monitor AOC/BDOC in distribution system 0.0% % know 0.0% % Please specify other approaches: answered question % skipped question Please specify other approaches 13.1 Number Date Please specify other approaches 1 06/18/ :59:00 Same responses as Lanier Filter Plant 192 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

219 Appendix B: Complete Survey Data 193 Exhibit 51 (OEBF-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP1 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Gas-phase ozone (on-line) (unique to OEBF) Residual ozone (on-line) (unique to OEBF) Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 2 answered question 13 skipped question 45 (OEBF-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP 2 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Gas-phase ozone (on-line) (unique to OEBF) Residual ozone (on-line) (unique to OEBF) Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 1 answered question 1 skipped question 57 (continued)

220 194 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 51 (con t.) (OEBF-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP 3 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Gas-phase ozone (on-line) (unique to OEBF) Residual ozone (on-line) (unique to OEBF) Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 0 skipped question 58 (OEBF-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? Total Could Be Used, But Not Required Are Used Should Be Used Not Applicable Gas-phase ozone (on-line) (unique to OEBF) Residual ozone (on-line) (unique to OEBF) Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 3 answered question 14 (continued)

221 Appendix B: Complete Survey Data 195 Exhibit 51 (con t.) (OEBF-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? Percent Could Be Used, But Are Used Should Be Used Not Required Not Applicable NA or Don t Gas-phase ozone (on-line) (unique to OEBF) 38% 0% 8% 0% 54% 54% Residual ozone (on-line) (unique to OEBF) 69% 0% 15% 0% 15% 15% Dissolved oxygen (on-line) 0% 23% 31% 8% 38% 46% Oxidation-reduction potential (on-line) 0% 8% 25% 0% 67% 67% ph 21% 0% 36% 7% 36% 43% Temperature 43% 7% 29% 0% 21% 21% Turbidity 64% 7% 7% 7% 14% 21% Particle counts 54% 8% 15% 8% 15% 23% Total organic carbon (TOC) 64% 0% 7% 0% 29% 29% Taste and odor threshold 0% 15% 23% 8% 54% 62% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) 8% 31% 23% 0% 38% 38% Coliforms 50% 14% 21% 0% 14% 14% Opportunistic bacterial pathogens 0% 31% 31% 0% 38% 38% HPC bacteria 62% 8% 15% 0% 15% 15% Biofilm formation rate (BFM) 0% 8% 31% 0% 62% 62% Biomass concentration 0% 38% 15% 0% 46% 46% ATP 0% 0% 15% 0% 85% 85% NADH Flourescence 0% 0% 15% 0% 85% 85% Oxalic acids/aldehydes 8% 15% 31% 0% 46% 46% Other water quality parameters (RBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP1 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 3 skipped question 55 (continued)

222 196 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 51 (con t.) (RBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP 2 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 1 skipped question 57 (RBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP 3 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 0 skipped question 58 (continued)

223 Appendix B: Complete Survey Data 197 Exhibit 51 (con t.) (RBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? Total Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 4 (RBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? Percent Could Be Used, But Are Used Should Be Used Not Required Not Applicable NA or Don t Dissolved oxygen (on-line) 0% 0% 100% 0% 0% 0% Oxidation-reduction potential (on-line) 0% 0% 75% 0% 25% 25% ph 100% 0% 0% 0% 0% 0% Temperature 100% 0% 0% 0% 0% 0% Turbidity 100% 0% 0% 0% 0% 0% Particle counts 100% 0% 0% 0% 0% 0% Total organic carbon (TOC) 75% 0% 25% 0% 0% 0% Taste and odor threshold 100% 0% 0% 0% 0% 0% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) 0% 50% 50% 0% 0% 0% Coliforms 100% 0% 0% 0% 0% 0% Opportunistic bacterial pathogens 50% 25% 0% 0% 25% 25% HPC bacteria 75% 25% 0% 0% 0% 0% Biofilm formation rate (BFM) 0% 75% 25% 0% 0% 0% Biomass concentration 0% 75% 25% 0% 0% 0% ATP 0% 25% 0% 0% 75% 75% NADH Flourescence 0% 25% 0% 0% 75% 75% Oxalic acids/aldehydes 0% 25% 0% 0% 75% 75% Other water quality parameters (continued)

224 198 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 51 (con t.) (BPNP-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP1 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) Nitrate concentration (on-line) Perchlorate concentration (on-line) Chemical oxygen demand (COD) Specific electron donor concentration Perchlorate or nitrate reducing bacteria concentration ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 2 answered question 7 skipped question 51 (continued)

225 Appendix B: Complete Survey Data 199 Exhibit 51 (con t.) (BPNP-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP 2 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) Nitrate concentration (on-line) Perchlorate concentration (on-line) Chemical oxygen demand (COD) Specific electron donor concentration Perchlorate or nitrate reducing bacteria concentration ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 2 skipped question 56 (continued)

226 200 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 51 (con t.) (BPNP-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP 3 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) Nitrate concentration (on-line) Perchlorate concentration (on-line) Chemical oxygen demand (COD) Specific electron donor concentration Perchlorate or nitrate reducing bacteria concentration ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 0 skipped question 58 (continued)

227 Appendix B: Complete Survey Data 201 Exhibit 51 (con t.) (BPNP-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? Total Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) Nitrate concentration (on-line) Perchlorate concentration (on-line) Chemical oxygen demand (COD) Specific electron donor concentration Perchlorate or nitrate reducing bacteria concentration ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters answered question 9 (continued)

228 202 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 51 (con t.) (BPNP-11:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? Percent Could Be Used, But Are Used Should Be Used Not Required Not applicable know NA or Don t Dissolved oxygen (on-line) 25% 25% 25% 0% 25% 25% Oxidation-reduction potential (on-line) 0% 38% 50% 0% 13% 13% Nitrate concentration (on-line) 56% 33% 0% 0% 11% 11% Perchlorate concentration (on-line) 25% 0% 50% 13% 13% 25% Chemical oxygen demand (COD) 0% 0% 50% 13% 38% 50% Specific electron donor concentration 13% 13% 50% 13% 13% 25% Perchlorate or nitrate reducing bacteria concentration 11% 0% 44% 22% 22% 44% ph 25% 25% 13% 25% 13% 38% Temperature 25% 25% 13% 25% 13% 38% Turbidity 50% 0% 25% 13% 13% 25% Particle counts 11% 11% 11% 56% 11% 67% Total organic carbon (TOC) 38% 0% 50% 0% 13% 13% Taste and odor threshold 11% 11% 22% 22% 33% 56% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) 25% 13% 13% 13% 38% 50% Coliforms 25% 25% 13% 25% 13% 38% Opportunistic bacterial pathogens 0% 13% 25% 25% 38% 63% HPC bacteria 38% 0% 13% 13% 38% 50% Biofilm formation rate (BFM) 0% 13% 38% 13% 38% 50% Biomass concentration 0% 13% 38% 13% 38% 50% ATP 0% 0% 38% 13% 50% 63% NADH Flourescence 0% 0% 25% 13% 63% 75% Oxalic acids/aldehydes 0% 0% 25% 13% 63% 75% Other water quality parameters 25% 0% 25% 0% 50% (GBA-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP1 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 1 answered question 3 skipped question 55 (continued)

229 Appendix B: Complete Survey Data 203 Exhibit 51 (con t.) (GBA-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP 2 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 0 skipped question 58 (GBA-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP 3 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 0 skipped question 58 (continued)

230 204 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 51 (con t.) (GBA-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? Total Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total organic carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 1 answered question 3 (GBA-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? Percent Could Be Used, But Are Used Should Be Used Not Required Not Applicable NA or Don t Dissolved oxygen (on-line) 0% 0% 67% 0% 33% 33% Oxidation-reduction potential (on-line) 0% 33% 33% 0% 33% 33% ph 100% 0% 0% 0% 0% 0% Temperature 100% 0% 0% 0% 0% 0% Turbidity 100% 0% 0% 0% 0% 0% Particle counts 33% 0% 33% 33% 0% 33% Total organic carbon (TOC) 100% 0% 0% 0% 0% 0% Taste and odor threshold 67% 33% 0% 0% 0% 0% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) 0% 0% 67% 0% 33% 33% Coliforms 33% 0% 33% 0% 33% 33% Opportunistic bacterial pathogens 33% 0% 33% 0% 33% 33% HPC bacteria 0% 0% 67% 0% 33% 33% Biofilm formation rate (BFM) 0% 33% 67% 0% 0% 0% Biomass concentration 0% 33% 67% 0% 0% 0% ATP 0% 33% 33% 0% 33% 33% NADH Flourescence 33% 33% 0% 0% 33% 33% Oxalic acids/aldehydes 0% 33% 0% 33% 33% 67% Other water quality parameters 50% 0% 0% 0% 50% (continued)

231 Appendix B: Complete Survey Data 205 Exhibit 51 (con t.) (SBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP1 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total Organic Carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 1 skipped question 57 (SBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP 2 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total Organic Carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 0 skipped question 58 (continued)

232 206 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 51 (con t.) (SBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? WTP 3 Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total Organic Carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 0 skipped question 58 (SBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? Total Could Be Used, But Not Required Are Used Should Be Used Not Applicable Dissolved oxygen (on-line) Oxidation-reduction potential (on-line) ph Temperature Turbidity Particle counts Total Organic Carbon (TOC) Taste and odor threshold Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Coliforms Opportunistic bacterial pathogens HPC bacteria Biofilm formation rate (BFM) Biomass concentration ATP NADH Flourescence Oxalic acids/aldehydes Other water quality parameters Please specify other water quality parameters: 0 answered question 1 (continued)

233 Appendix B: Complete Survey Data 207 Exhibit 51 (con t.) (SBF-10:1) What tools or water quality parameters are used or should be used to monitor and control the biological process? Percent Could Be Used, But Are Used Should Be Used Not Required Not Applicable NA or Don t Dissolved oxygen (on-line) 100% 0% 0% 0% 0% 0% Oxidation-reduction potential (on-line) 100% 0% 0% 0% 0% 0% ph 100% 0% 0% 0% 0% 0% Temperature 100% 0% 0% 0% 0% 0% Turbidity 100% 0% 0% 0% 0% 0% Particle counts 100% 0% 0% 0% 0% 0% Total Organic Carbon (TOC) 0% 0% 100% 0% 0% 0% Taste and odor threshold 0% 0% 100% 0% 0% 0% Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) 0% 0% 0% 0% 100% 100% Coliforms 0% 0% 0% 0% 100% 100% Opportunistic bacterial pathogens 0% 0% 0% 0% 100% 100% HPC bacteria 0% 0% 0% 0% 100% 100% Biofilm formation rate (BFM) 0% 0% 0% 0% 100% 100% Biomass concentration 0% 0% 0% 0% 100% 100% ATP 0% 0% 0% 0% 100% 100% NADH Flourescence 0% 0% 0% 0% 100% 100% Oxalic acids/aldehydes 0% 0% 0% 0% 100% 100% Other water quality parameters Please specify other water quality parameters OEBF 11.1 Number Date Please specify other water quality parameters 1 06/23/ :14:00 Do not use the process 2 08/06/ :54:00 We do not do enough monitoring of our BAF process Number Date Please specify other water quality parameters 1 06/18/ :59:00 Same responses as Lanier Filter Plant BPNP 11.1 Number Date Please specify other water quality parameters 1 06/04/ :30:00 HAAS 2 06/24/ :18:00 Head loss GBA 10.1 Number Date Please specify other water quality parameters 1 07/08/ :46:00 Monitor for TTHM and HA5's

234 208 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 52 (OEBF-19:1) Does having a biological process trigger the need for additional plant operators over a conventional process? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 86.7% % know 13.3% % answered question skipped question (RBF-18:1) Does having a biological process trigger the need for additional plant operators over a conventional process? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 100.0% % know 0.0% % answered question skipped question (BPNP-19:1) Does having a biological process trigger the need for additional plant operators over a conventional process? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 116.7% % know 116.6% % answered question skipped question (GBA-18:1) Does having a biological water treatment process trigger the need for additional plant operators over a conventional process? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 33.3% % No 66.7% % know 0.0% % answered question skipped question (SBF-16:1) Does having a biological process trigger the need for additional plant operators over a conventional process? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 0.0% % know 100.0% % answered question skipped question

235 Appendix B: Complete Survey Data 209 Exhibit 53 (OEBF-20:1) Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 86.7% % know 13.3% % answered question skipped question (RBF-19:1) Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 100.0% % know 0.0% % answered question skipped question (BPNP-20:1) Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 50.0% % know 50.0% % answered question skipped question (GBA-19:1) Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 100.0% % know 0.0% % answered question 3 3 skipped question 55 (SBF-17:1) Does having a biological process in your water treatment plant require a higher plant operator classification than for conventional treatment processes? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 100.0% % know 0.0% % answered question 1 1 skipped question 57

236 210 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 54 (OEBF-14:1) What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? WTP1 WTP 2 WTP 3 Percent Total Percent < 1 months 57.1% % 1-2 months 0.0% % 3-4 months 7.1% % 5-8 months 0.0% % 9-12 months 0.0% % > 12 months 0.0% % Unstable 0.0% % know 35.7% % answered question % skipped question (RBF-13:1) What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? WTP1 WTP 2 WTP 3 Percent Total Percent < 1 months 66.7% % 1-2 months 33.3% % 3-4 months 0.0% % 5-8 months 0.0% % 9-12 months 0.0% % > 12 months 0.0% % Stable performance hasn't been reached 0.0% % know 0.0% % answered question % skipped question (BPNP-14:1) What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? WTP1 WTP 2 WTP 3 Percent Total Percent < 1 months 71.4% % 1-2 months 14.3% % 3-4 months 0.0% % 5-8 months 0.0% % 9-12 months 0.0% % > 12 months 0.0% % Stable performance hasn't been reached 0.0% % know 14.3% % answered question % skipped question (GBA-13:1) What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? WTP1 WTP 2 WTP 3 Percent Total Percent < 1 months 33.3% % 1-2 months 0.0% % 3-4 months 33.3% % 5-8 months 0.0% % 9-12 months 0.0% % > 12 months 0.0% % Stable performance hasn't been reached 0.0% % know 33.3% % answered question % skipped question (continued)

237 Appendix B: Complete Survey Data 211 Exhibit 54 (con t.) (SBF-13:1) What is the minimum amount of time required to achieve stable biological performance upon startup or return to service of the process? WTP1 WTP 2 WTP 3 Percent Total Percent < 1 months 0.0% % 1-2 months 100.0% % 3-4 months 0.0% % 5-8 months 0.0% % 9-12 months 0.0% % > 12 months 0.0% % Stable performance hasn't been reached 0.0% % know 0.0% % answered question % skipped question Exhibit 55 (OEBF-15:1) What percent of the time is the biological water treatment process in continuous operation? WTP1 WTP 2 WTP 3 Percent Total Percent Operates 100% of the time 66.7% % Operates > 95% of the time 6.7% % Operates > 90% of the time 6.7% % Operates > 50% of the time 6.7% % Operates seasonally 0.0% % Varies 0.0% % know 13.3% % answered question skipped question (RBF-14:1) What percent of the time is the biological water treatment process in continuous operation? WTP1 WTP 2 WTP 3 Percent Total Percent Operates 100% of the time 66.7% % Operates > 95% of the time 33.3% % Operates > 90% of the time 0.0% % Operates > 50% of the time 0.0% % Operates seasonally 0.0% % Varies 0.0% % know 0.0% % answered question skipped question (continued)

238 212 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 55 (con t.) (BPNP-15:1) What percent of the time is the biological water treatment process in continuous operation? WTP1 WTP 2 WTP 3 Percent Total Percent Operates 100% of the time 14.3% % Operates > 95% of the time 0.0% % Operates > 90% of the time 28.6% % Operates > 50% of the time 0.0% % Operates seasonally 14.3% % Varies 0.0% % know 42.9% % answered question skipped question (GBA-14:1) What percent of the time is the biological water treatment process in continuous operation? WTP1 WTP 2 WTP 3 Percent Total Percent Operates 100% of the time 33.3% % Operates > 95% of the time 33.3% % Operates > 90% of the time 0.0% % Operates > 50% of the time 0.0% % Operates seasonally 33.3% % Varies 0.0% % know 0.0% % answered question skipped question (SBF-14:1) What percent of the time is the biological water treatment process in continuous operation? WTP1 WTP 2 WTP 3 Percent Total Percent Operates 100% of the time 100.0% % Operates > 95% of the time 0.0% % Operates > 90% of the time 0.0% % Operates > 50% of the time 0.0% % Operates seasonally 0.0% % Varies 0.0% % know 0.0% % answered question skipped question

239 Appendix B: Complete Survey Data 213 Exhibit 56 (OEBF-16:1) How is performance of the biological water treatment process impacted by taking it off-line for an extended period (> 1 week)? WTP1 WTP 2 WTP 3 Percent Total Percent Performance stabilizes immediately 6.7% % Performance stabilizes within 4 hours 0.0% % Performance stabilizes within 5 to 24 hours 6.7% % Performance stabilizes within 1 day to 1 week 0.0% % Performance stabilizes within 1 week to 1 month 20.0% % Performance does not stabilize for several months 0.0% % know 66.7% % answered question skipped question (RBF-15:1) How is performance of the biological process impacted by taking it off-line for an extended period (> 1 week)? WTP1 WTP 2 WTP 3 Percent Total Percent Performance stabilizes immediately 0.0% % Performance stabilizes within 4 hours 33.3% % Performance stabilizes within 5 to 24 hours 0.0% % Performance stabilizes within 1 day to 1 week 33.3% % Performance stabilizes within 1 week to 1 month 0.0% % Performance does not stabilize for several months 0.0% % know 33.3% % answered question skipped question (BPNP-16:1) How is performance of the biological water treatment process impacted by taking it off-line for an extended period (> 1 week)? WTP1 WTP 2 WTP 3 Percent Total Percent Performance stabilizes immediately 14.3% % Performance stabilizes within 4 hours 14.3% % Performance stabilizes within 5 to 24 hours 14.3% % Performance stabilizes within 1 day to 1 week 0.0% % Performance stabilizes within 1 week to 1 month 14.3% % Performance does not stabilize for several months 0.0% % know 42.9% % answered question skipped question (GBA-15:1) How is performance of the biological water treatment process impacted by taking it off-line for an extended period (> 1 week)? WTP1 WTP 2 WTP 3 Percent Total Percent Performance stabilizes immediately 0.0% % Performance stabilizes within 4 hours 0.0% % Performance stabilizes within 5 to 24 hours 33.3% % Performance stabilizes within 1 day to 1 week 0.0% % Performance stabilizes within 1 week to 1 month 0.0% % Performance does not stabilize for several months 33.3% % know 33.3% % answered question skipped question (continued)

240 214 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 56 (con t.) (SBF-15:1) How is performance of the biological water treatment process impacted by taking it off-line for an extended period (> 1 week)? WTP1 WTP 2 WTP 3 Percent Total Percent Performance stabilizes immediately 0.0% % Performance stabilizes within 4 hours 0.0% % Performance stabilizes within 5 to 24 hours 0.0% % Performance stabilizes within 1 day to 1 week 0.0% % Performance stabilizes within 1 week to 1 month 0.0% % Performance does not stabilize for several months 0.0% % know 100.0% % answered question skipped question

241 Appendix B: Complete Survey Data 215 Exhibit 57 (OEBF-4:1) Choose up to three source water quality parameters that most significantly impact performance of the biological process WTP-1 WTP 2 WTP 3 Percent Total Percent Temperature 60.0% % Total organic carbon (TOC) 40.0% % Dissolved organic carbon (DOC) 6.7% % Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) 20.0% % Algae 33.3% % Nutrient levels (nitrogen, phosphorus) 6.7% % Iron and manganese 20.0% % ph 0.0% % Dissolved oxygen 20.0% % Turbidity 13.3% % Other water quality parameters 13.3% Please specify other water quality parameters: answered question % skipped question (RBF-4:1) Choose up to three source water quality parameters that most significantly impact performance of the biological process WTP-1 WTP 2 WTP 3 Percent Total Percent Temperature 66.7% % Total organic carbon (TOC) 33.3% % Dissolved organic carbon (DOC) 33.3% % Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) 33.3% % Algae 33.3% % Nutrient levels (nitrogen, phosphorus) 0.0% % Iron and manganese 0.0% % ph 33.3% % Dissolved oxygen 0.0% % Turbidity 33.3% % Other water quality parameters 0.0% Please specify other water quality parameters: answered question % skipped question (BPNP-5:1) Choose up to three source water quality parameters that most significantly impact performance of the biological process WTP-1 WTP 2 WTP 3 Percent Total Percent Temperature 83.3% % Total organic carbon (TOC) 66.7% % Dissolved organic carbon (DOC) 0.0% % Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) 0.0% % Algae 0.0% % Nutrient levels (nitrogen, phosphorus) 16.7% % Iron and manganese 33.3% % ph 0.0% % Dissolved oxygen 16.7% % Turbidity 66.7% % Nitrate or perchlorate concentrations 0.0% (unique to BPNP) 7 88% Other water quality parameters 0.0% Please specify other water quality parameters: answered question % skipped question (continued)

242 216 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 57 (con t.) (GBA-4:1) Choose up to three source water quality parameters that most significantly impact performance of the biological process WTP-1 WTP 2 WTP 3 Percent Total Percent Temperature 66.7% % Total organic carbon (TOC) 66.7% % Dissolved organic carbon (DOC) 0.0% % Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) 0.0% % Algae 33.3% % Nutrient levels (nitrogen, phosphorus) 0.0% % Iron and manganese 0.0% % ph 0.0% % Dissolved oxygen 0.0% % Turbidity 0.0% % Other 33.3% Please specify other water quality parameters: answered question % skipped question (SBF-4:1) Choose up to three source water quality parameters that most significantly impact performance of the biological process WTP-1 WTP 2 WTP 3 Percent Total Percent Temperature 0.0% % Total Organic Carbon (TOC) 0.0% % Dissolved organic carbon (DOC) 0.0% % Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) 0.0% % Algae 0.0% % Nutrient levels (nitrogen, phosphorus) 0.0% % Iron and manganese 100.0% % ph 100.0% % Dissolved oxygen 100.0% % Turbidity 0.0% % Other 0.0% Please specify other water quality parameters: answered question % skipped question Other Water Quality Parameters OEBF 4.1 Number Date Please specify other water quality parameters 1 06/12/ :53:00 chlorinated filter backwash water 2 06/17/ :18:00 unkown Number Date Please specify other water quality parameters 1 06/18/ :59:00 Note: Same responses as Lanier Filter Plant GBA 4.1 Number Date Please specify other water quality parameters 1 07/08/ :46:00 Alkalinity,Total hardness,total Dissolved Solids, Sulfate's

243 Exhibit 58 (OEBF-5:1) What plant operating conditions impact performance of the biological process? WTP-1 WTP 2 Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Higher ozone dose (unique to OEBF) Lower ozone dose (unique to OEBF) Higher flow rate Lower flow rate Chlorinated/chloraminated filter backwashing Non-chlorinated/non-chloraminated filter backwashing Resting filters after backwashing Continuous operation Intermittent operation Plant shut down Media replacement Other plant operating conditions Please specify other plant operating conditions: 2 Please specify other plant operating conditions: 1 answered question 14 answered question 1 skipped question 44 skipped question 57 (OEBF-5:1) What plant operating conditions impact performance of the biological process? WTP 3 Total Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Higher ozone dose (unique to OEBF) Lower ozone dose (unique to OEBF) Higher flow rate Lower flow rate Chlorinated/chloraminated filter backwashing Non-chlorinated/non-chloraminated filter backwashing Resting filters after backwashing Continuous operation Intermittent operation Plant shut down Media replacement Other plant operating conditions Please specify other plant operating conditions: 0 Please specify other plant operating conditions: answered question 0 answered question 15 skipped question 58 skipped question (continued) Appendix B: Complete Survey Data 217

244 Exhibit 58 (con t.) (OEBF-5:1) What plant operating conditions impact performance of the biological process? Percent Positive Impact Negative Impact No Change Higher ozone dose (unique to OEBF) 27% 20% 33% 20% Lower ozone dose (unique to OEBF) 7% 20% 53% 20% Higher flow rate 0% 33% 40% 27% Lower flow rate 33% 0% 47% 20% Chlorinated/chloraminated filter backwashing 27% 53% 7% 13% Non-chlorinated/non-chloraminated filter backwashing 53% 0% 7% 40% Resting filters after backwashing 21% 0% 21% 57% Continuous operation 60% 0% 13% 27% Intermittent operation 0% 27% 13% 60% Plant shut down 0% 33% 13% 53% Media replacement 0% 33% 13% 53% Other plant operating conditions (RBF-5:1) What plant operating conditions impact performance of the biological process? WTP-1 WTP 2 Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Higher flow rate Lower flow rate Chlorinated/chloraminated filter backwashing Non-chlorinated/non-chloraminated filter backwashing Resting filters after backwashing Continuous operation Intermittent operation Plant shut down Media replacement Other plant operating conditions Please specify other plant operating conditions: 0 Please specify other plant operating conditions: 0 answered question 3 answered question 1 skipped question 55 skipped question 57 (continued) 218 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

245 Exhibit 58 (con t.) (RBF-5:1) What plant operating conditions impact performance of the biological process? WTP 3 Total Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Higher flow rate Lower flow rate Chlorinated/chloraminated filter backwashing Non-chlorinated/non-chloraminated filter backwashing Resting filters after backwashing Continuous operation Intermittent operation Plant shut down Media replacement Other plant operating conditions Please specify other plant operating conditions: 0 Please specify other plant operating conditions: answered question 0 answered question 4 skipped question 58 skipped question (RBF-5:1) What plant operating conditions impact performance of the biological process? Percent Positive Impact Negative Impact No Change Higher flow rate 50% 25% 25% 0% Lower flow rate 25% 0% 75% 0% Chlorinated/chloraminated filter backwashing 50% 25% 25% 0% Non-chlorinated/non-chloraminated filter backwashing 25% 25% 25% 25% Resting filters after backwashing 25% 50% 25% 0% Continuous operation 75% 0% 25% 0% Intermittent operation 0% 100% 0% 0% Plant shut down 0% 75% 25% 0% Media replacement 75% 0% 0% 25% Other plant operating conditions 0% 0% 0% 100% (continued) Appendix B: Complete Survey Data 219

246 Exhibit 58 (con t.) (BPNP-6:1) What plant operating conditions impact performance of the biological process? WTP-1 WTP 2 Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Higher flow rate Lower flow rate Increased electron donor concentration Decreased electron donor concentration Increased nutrient (N or P) concentration Decreased nutrient (N or P) concentration Filter backwashing Filter bumping with air Filter bumping with nitrogen Resting filters after backwashing Continuous operation Intermittent operation Plant shut down Media replacement Other plant operating conditions Please specify other plant operating conditions: 0 Please specify other plant operating conditions: 0 answered question 7 answered question 2 skipped question 51 skipped question 56 (BPNP-6:1) What plant operating conditions impact performance of the biological process? WTP 3 Total Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Higher flow rate Lower flow rate Increased electron donor concentration Decreased electron donor concentration Increased nutrient (N or P) concentration Decreased nutrient (N or P) concentration Filter backwashing Filter bumping with air Filter bumping with nitrogen Resting filters after backwashing Continuous operation Intermittent operation Plant shut down Media replacement Other plant operating conditions Please specify other plant operating conditions: 0 Please specify other plant operating conditions: answered question 0 answered question 9 skipped question 58 skipped question (continued) 220 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

247 Exhibit 58 (con t.) (BPNP-6:1) What plant operating conditions impact performance of the biological process? Percent Positive Impact Negative Impact No Change Higher flow rate 0% 67% 11% 22% Lower flow rate 38% 13% 25% 25% Increased electron donor concentration 50% 0% 25% 25% Decreased electron donor concentration 0% 75% 0% 25% Increased nutrient (N or P) concentration 11% 22% 44% 22% Decreased nutrient (N or P) concentration 13% 38% 25% 25% Filter backwashing 38% 0% 50% 13% Filter bumping with air 25% 0% 50% 25% Filter bumping with nitrogen 13% 0% 38% 50% Resting filters after backwashing 13% 0% 38% 50% Continuous operation 63% 0% 25% 13% Intermittent operation 0% 50% 25% 25% Plant shut down 0% 13% 50% 38% Media replacement 0% 38% 38% 25% Other plant operating conditions 0% 0% 50% 50% (GBA-5:1) What plant operating conditions impact performance of the biological process? WTP-1 WTP 2 Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Higher flow rate Lower flow rate Chlorinated filter backwashing Non-chlorinated filter backwashing Resting filters after backwashing Continuous operation Intermittent operation Plant shut down Media replacement Other plant operating conditions Please specify other plant operating conditions: 1 Please specify other plant operating conditions: 0 answered question 3 answered question 0 skipped question 55 skipped question 58 (continued) Appendix B: Complete Survey Data 221

248 Exhibit 58 (con t.) (GBA-5:1) What plant operating conditions impact performance of the biological process? WTP 3 Total Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Higher flow rate Lower flow rate Chlorinated filter backwashing Non-chlorinated filter backwashing Resting filters after backwashing Continuous operation Intermittent operation Plant shut down Media replacement Other plant operating conditions Please specify other plant operating conditions: 0 Please specify other plant operating conditions: answered question 0 answered question 3 skipped question 58 skipped question (GBA-5:1) What plant operating conditions impact performance of the biological process? Percent Positive Impact Negative Impact No Change Higher flow rate 0% 67% 33% 0% Lower flow rate 67% 0% 33% 0% Chlorinated filter backwashing 33% 67% 0% 0% Non-chlorinated filter backwashing 67% 0% 0% 33% Resting filters after backwashing 33% 0% 33% 33% Continuous operation 100% 0% 0% 0% Intermittent operation 0% 100% 0% 0% Plant shut down 0% 100% 0% 0% Media replacement 33% 67% 0% 0% Other plant operating conditions (SBF-5:1) What plant operating conditions impact performance of the biological process? WTP-1 WTP 2 Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Higher flow rate Lower flow rate Continuous operation Intermittent operation Plant shut down Media replacement Other plant operating conditions Please specify other plant operating conditions: 0 Please specify other plant operating conditions: 0 answered question 1 answered question 0 skipped question 57 skipped question Biological Drinking Water Treatment Perceptions and Actual Experiences in North America (continued)

249 Exhibit 58 (con t.) (SBF-5:1) What plant operating conditions impact performance of the biological process? WTP 3 Total Positive Impact Negative Impact No Change Positive Impact Negative Impact No Change Higher flow rate Lower flow rate Continuous operation Intermittent operation Plant shut down Media replacement Other plant operating conditions Please specify other plant operating conditions: 0 Please specify other plant operating conditions: answered question 0 answered question 1 skipped question 58 skipped question (SBF-5:1) What plant operating conditions impact performance of the biological process? Percent Positive Impact Negative Impact No Change Higher flow rate 0% 0% 100% 0% Lower flow rate 0% 0% 100% 0% Continuous operation 0% 0% 100% 0% Intermittent operation 0% 0% 100% 0% Plant shut down 0% 0% 100% 0% Media replacement 0% 0% 0% 100% Other plant operating conditions Other plant operating conditions OEBF 5.1 Number Date Please specify other plant operating conditions 1 06/23/ :14:00 we do not use the process 2 08/06/ :54:00 We need to do more research in this area of the plant - don't test for various parameters to highlight performance/optimize BAF Number Date Please specify other plant operating conditions 1 06/18/ :59:00 Note: Same responses as Lanier Filter Plant GBA 5.1 Number Date Please specify other plant operating conditions 1 07/08/ :46:00 Proper chemical dosing Appendix B: Complete Survey Data 223

250 Exhibit 59 (OEBF-3:1) How significant are the following operational concerns for your biological treatment process? WTP 1 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 2 answered question 15 skipped question 43 (OEBF-3:1) How significant are the following operational concerns for your biological treatment process? WTP 2 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 1 answered question 1 skipped question 57 (continued) 224 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

251 Exhibit 59 (con t.) (OEBF-3:1) How significant are the following operational concerns for your biological treatment process? WTP 3 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 0 answered question 0 skipped question 58 (OEBF-3:1) How significant are the following operational concerns for your biological treatment process? Total No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: answered question 16 skipped question (continued) Appendix B: Complete Survey Data 225

252 Exhibit 59 (con t.) (OEBF-3:1) How significant are the following operational concerns for your biological treatment process? Percent No Low Moderate High No to Low Process instability (i.e., resilience to varying environmental conditions) 19% 38% 31% 6% 6% 56% Process inflexibility 19% 38% 31% 6% 6% 56% Source water quality changes 13% 44% 31% 6% 6% 56% Water temperature changes 13% 40% 40% 0% 7% 53% Bacterial sloughing/breakthrough 13% 60% 7% 13% 7% 73% Pathogen or contaminant breakthrough 20% 27% 33% 13% 7% 47% Process start-up and recovery time 6% 44% 31% 13% 6% 50% Post-treatment and disinfection 7% 33% 20% 33% 7% 40% Unknown or changing regulatory requirments 7% 40% 33% 7% 13% 47% Other operational concerns 22% 22% 22% 0% 33% 44% (RBF-3:1) How significant are the following operational concerns for your biological treatment process? WTP 1 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 0 answered question 3 skipped question 55 (continued) 226 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

253 Exhibit 59 (con t.) (RBF-3:1) How significant are the following operational concerns for your biological treatment process? WTP 2 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 0 answered question 1 skipped question 57 (RBF-3:1) How significant are the following operational concerns for your biological treatment process? WTP 3 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 0 answered question 0 skipped question 58 (continued) Appendix B: Complete Survey Data 227

254 Exhibit 59 (con t.) (RBF-3:1) How significant are the following operational concerns for your biological treatment process? Total No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: answered question 4 skipped question (RBF-3:1) How significant are the following operational concerns for your biological treatment process? Percent No Low Moderate High No to Low Process instability (i.e., resilience to varying environmental conditions) 0% 75% 25% 0% 0% 75% Process inflexibility 0% 75% 25% 0% 0% 75% Source water quality changes 0% 0% 100% 0% 0% 0% Water temperature changes 0% 0% 100% 0% 0% 0% Bacterial sloughing/breakthrough 0% 75% 25% 0% 0% 75% Pathogen or contaminant breakthrough 0% 75% 25% 0% 0% 75% Process start-up and recovery time 0% 75% 25% 0% 0% 75% Post-treatment and disinfection 0% 25% 75% 0% 0% 25% Unknown or changing regulatory requirments 0% 25% 25% 0% 50% 25% Other operational concerns 0% 100% 0% 0% 0% 100% (continued) 228 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

255 Exhibit 59 (con t.) (BPNP-4:1) How significant are the following operational concerns for your biological treatment process? WTP 1 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirements Other operational concerns Please specify other operational concerns: 1 answered question 7 skipped question 51 (BPNP-4:1) How significant are the following operational concerns for your biological treatment process? WTP 2 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirements Other operational concerns Please specify other operational concerns: 0 answered question 2 skipped question 56 (continued) Appendix B: Complete Survey Data 229

256 Exhibit 59 (con t.) (BPNP-4:1) How significant are the following operational concerns for your biological treatment process? WTP 3 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirements Other operational concerns Please specify other operational concerns: 0 answered question 0 skipped question 58 (BPNP-4:1) How significant are the following operational concerns for your biological treatment process? Total No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirements Other operational concerns Please specify other operational concerns: answered question 9 skipped question (continued) 230 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

257 Exhibit 59 (con t.) (BPNP-4:1) How significant are the following operational concerns for your biological treatment process? Percent No Low Moderate High No to Low Process instability (i.e., resilience to varying environmental conditions) 0% 33% 33% 22% 11% 33% Process inflexibility 0% 67% 11% 11% 11% 67% Source water quality changes 0% 56% 22% 11% 11% 56% Water temperature changes 0% 56% 22% 11% 11% 56% Bacterial sloughing/breakthrough 11% 56% 0% 22% 11% 67% Pathogen or contaminant breakthrough 11% 44% 11% 0% 33% 56% Process start-up and recovery time 0% 44% 22% 22% 11% 44% Post-treatment and disinfection 22% 11% 44% 11% 11% 33% Unknown or changing regulatory requirements 11% 11% 56% 11% 11% 22% Other operational concerns 0% 67% 0% 33% 0% 67% (GBA-3:1) How significant are the following operational concerns for your biological treatment process? WTP 1 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 0 answered question 3 skipped question 55 (continued) Appendix B: Complete Survey Data 231

258 Exhibit 59 (con t.) (GBA-3:1) How significant are the following operational concerns for your biological treatment process? WTP 2 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 0 answered question 0 skipped question 58 (GBA-3:1) How significant are the following operational concerns for your biological treatment process? WTP 3 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 0 answered question 0 skipped question 58 (continued) 232 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

259 Exhibit 59 (con t.) (GBA-3:1) How significant are the following operational concerns for your biological treatment process? Total No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: answered question 3 skipped question (GBA-3:1) How significant are the following operational concerns for your biological treatment process? Percent No Low Moderate High No to Low Process instability (i.e., resilience to varying environmental conditions) 33% 33% 0% 33% 0% 67% Process inflexibility 33% 33% 0% 33% 0% 67% Source water quality changes 33% 0% 33% 33% 0% 33% Water temperature changes 0% 0% 100% 0% 0% 0% Bacterial sloughing/breakthrough 0% 33% 67% 0% 0% 33% Pathogen or contaminant breakthrough 0% 33% 67% 0% 0% 33% Process start-up and recovery time 0% 67% 33% 0% 0% 67% Post-treatment and disinfection 0% 67% 33% 0% 0% 67% Unknown or changing regulatory requirments 0% 50% 0% 50% 0% 50% Other operational concerns 0% 0% 0% 0% 100% (continued) Appendix B: Complete Survey Data 233

260 Exhibit 59 (con t.) (SBF-3:1) How significant are the following operational concerns for your biological treatment process? WTP 1 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 0 answered question 1 skipped question 57 (SBF-3:1) How significant are the following operational concerns for your biological treatment process? WTP 2 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 0 answered question 0 skipped question 58 (continued) 234 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

261 Exhibit 59 (con t.) (SBF-3:1) How significant are the following operational concerns for your biological treatment process? WTP 3 No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: 0 answered question 0 skipped question 58 (SBF-3:1) How significant are the following operational concerns for your biological treatment process? Total No Low Moderate High Process instability (i.e., resilience to varying environmental conditions) Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory requirments Other operational concerns Please specify other operational concerns: answered question 1 skipped question (continued) Appendix B: Complete Survey Data 235

262 Exhibit 59 (con t.) (SBF-3:1) How significant are the following operational concerns for your biological treatment process? Percent No Low Moderate High No to Low Process instability (i.e., resilience to varying environmental conditions) 0% 100% 0% 0% 0% 100% Process inflexibility 0% 100% 0% 0% 0% 100% Source water quality changes 0% 100% 0% 0% 0% 100% Water temperature changes 0% 100% 0% 0% 0% 100% Bacterial sloughing/breakthrough 0% 100% 0% 0% 0% 100% Pathogen or contaminant breakthrough 0% 100% 0% 0% 0% 100% Process start-up and recovery time 0% 0% 0% 100% 0% 0% Post-treatment and disinfection 0% 0% 100% 0% 0% 0% Unknown or changing regulatory requirments 0% 0% 0% 0% 100% 0% Other operational concerns Other Operationals Concerns OEBF 3.1 Number Date Please specify other operational concerns 1 06/13/ :13:00 Run time between backwash of bio-filters 2 06/23/ :14:00 The system required frequent backwashes and was not designed to backwash automatically Number Date Please specify other operational concerns 1 06/18/ :59:00 Note: Same responses as Lanier Filter Plant BPNP Number Date Please specify other operational concerns 1 Oct 10, :41 PM Optimizing nutrient dose and backwash requirements 236 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

263 Appendix B: Complete Survey Data 237 Exhibit 60 (OEBF-21:1) Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 6.7% % No 66.7% % know 26.7% % answered question skipped question (RBF-21:1) Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 66.7% % No 33.3% % know 0.0% % answered question skipped question (BPNP-21:1) Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 50.0% % know 50.0% % answered question skipped question (GBA-21:1) Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 66.7% % know 33.3% % answered question skipped question (SBF-19:1) Have you observed macro-organisms (e.g., nematodes) in the treatment process or in the distribution system? WTP1 WTP 2 WTP 3 Percent Total Percent Yes 0.0% % No 100.0% % know 0.0% % answered question skipped question

264 Exhibit 61 (OEBF-7:1) Based on plant operations, what is the optimal ozone dose and/or ozone to TOC ratio for enhancing biological filtration performance? Ozone Dose WTP1 WTP 2 < 1 mg/l 1-2 mg/l 3-4 mg/l 5-6 mg/l >6 mg/l < 1 mg/l 1-2 mg/l 3-4 mg/l 5-6 mg/l >6 mg/l Selections Ozone/TOC ratio WTP1 WTP 2 < >1.0 know < >1.0 know Selections Question Totals Question Totals answered question 13 answered question 2 skipped question 45 skipped question 56 Ozone Dose WTP 3 TOTAL < 1 mg/l 1-2 mg/l 3-4 mg/l 5-6 mg/l >6 mg/l < 1 mg/l 1-2 mg/l 3-4 mg/l 5-6 mg/l >6 mg/l Selections Ozone/TOC ratio WTP 3 TOTAL < >1.0 < >1.0 Selections Question Totals Question Totals answered question 0 answered question 15 skipped question 58 Ozone Dose Percent < 1 mg/l 1-2 mg/l 3-4 mg/l 5-6 mg/l >6 mg/l Selections 0% 57% 21% 7% 0% 14% Ozone/TOC ratio Percent < >1.0 Selections 0% 29% 43% 0% 29% 238 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

265 Appendix B: Complete Survey Data 239 Exhibit 62 (GBA-20:1) What is the empty-bed contact time for the process? WTP1 WTP 2 WTP 3 Answer Options Percent Total < 5 minutes 0.0% minutes 33.3% minutes 33.3% > 20 minutes 0.0% know 33.3% answered question skipped question Exhibit 63 (RBF-20:1) How was the Rapid Biological Filtration (RBF) process introduced into the water treatment process train? WTP1 WTP 2 WTP 3 Percent Total Percent Part of original design 0.0% % Stopped chlorination upstream of filter 66.7% % Retrofit filter (e.g. new media or deeper box) 66.7% % Other 0.0% % Please specify other: % answered question skipped question

266 240 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Exhibit 64 (BPNP-1:1) What treatment processes were considered for perchlorate and nitrate treatment for meeting water quality and treatment objectives? WTP-1 WTP-2 WTP-3 Percent Total Percent Fluidized bed bioreactor 28.6% % Packed bed bioreactor 42.9% % Membrane bioreactor 0.0% % Membrane biofilm reactor 14.3% % Ion exchange 42.9% % Tailored granular activated carbon 14.3% % Water supply blending 14.3% % know 14.3% % Other processes 0.0% 0 0 Please specify other processes: 1 1 answered question skipped question (BPNP-2:1) What treatment process is being used for perchlorate and nitrate treatment for meeting water quality and treatment objectives? WTP-1 WTP-2 WTP-3 Percent Total Percent Fluidized bed bioreactor 14.3% % Packed bed bioreactor 42.9% % Membrane bioreactor 0.0% % Membrane biofilm reactor 0.0% % Ion exchange 14.3% % Tailored granular activated carbon 0.0% % Water supply blending 14.3% % know 14.3% % Other processes 0.0% 0 0 Please specify other processes: 1 0 answered question skipped question BPNP-1 Other Number Date Please specify other processes 1 06/24/ :24:00 Pilot plant BPNP-2 Other Number Date Please specify other processes 1 08/12/ :42:00 Biological removal

267 Appendix B: Complete Survey Data 241 Exhibit 65 (BPNP-2:1) What treatment process is being used for perchlorate and nitrate treatment for meeting water quality and treatment objectives? WTP-1 WTP-2 WTP-3 Total Percent Fluidized bed bioreactor % Packed bed bioreactor % Membrane bioreactor % Membrane biofilm reactor % Ion exchange % Tailored granular activated carbon % Water supply blending % know % Other processes 0 0 Total Exhibit 66 (SBF-18:1) What method is used to clean the slow sand filter? Percent Scrape and clean upper sand layer 0.0% 0 Scrape and dispose upper sand layer 0.0% 0 Support fabric to clean upper layer 0.0% 0 Re-sanding 0.0% 0 Other methods 100.0% 1 Please specify other methods: 1 answered question 1 skipped question 57 Number Date Please specify other methods: 1 06/23/ :40:00 Backwashing

268

269 APPENDIX C CONTACTS LIST Contacts for Biofiltration Interviews Charlie Anderson Interim Assistant Director of Utilities/Treatment City of Arlington 1901 Lakewood Drive Arlington, Texas [email protected] Julie Hunt Director of Water Utilities Arlington Water Utilities 1901 Lakewood Drive Arlington, Texas [email protected] Russell Navratil Division Director, Water Treatment Facility Henrico y Three Chopt Road Henrico, VA Ext. 222 [email protected] Doug Meyer District Engineer Virginia Department of Health 8600 Dixon Powers Drive Henrico, Virginia Ext. 105 [email protected] Tim Sherman Operations Maintenance Supervisor, Geren Island Filtration Facility City of Salem, Public Works Department, Operations/Water Division th St. SE/Bldg #2 Salem, OR [email protected] 243

270 244 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America David E Leland Manager Drinking Water Program Oregon Health Division P.O. Box Portland, OR (503) [email protected] Johanna Castro Senior Engineer Water Quality Unit Santa Clara Valley Water District 5750 Almaden Expressway San Jose, CA x2590 [email protected] Gary Stolarik Manager Process Engineering Los Angeles Department of Water and Power 111 N. Hope Street Los Angeles, CA [email protected] Jess Brown Manager Research Group Carollo Engineers 401 N. Cattlemen Road, Suite 306 Sarasota, FL [email protected] Richard Haberman Supervising Sanitary Engineer California Department of Public Health Drinking Water Field Operations Branch 265 West Bullard Avenue Suite 101 Fresno, CA [email protected]

271 Appendix C: Contacts List 245 Catherine S. Ma Supervising Sanitary Engineer Chief, North Coastal Region Drinking Water Field Operations Branch California Department of Public Health 850 Marina Bay Parkway, Bldg P., 2nd Fl Richmond, CA (510) Jeffrey Vogt Senior Chemist Water Quality and Treatment Division Greater Cincinnati Water Works 5651 Kellogg Avenue Cincinnati, OH Jeff Swertfeger Assistant Superintendent, Water Quality Water Quality and Treatment Division Greater Cincinnati Water Works 5651 Kellogg Avenue Cincinnati, OH Jeff Davidson Manager Public Drinking Water Unit Ohio EPA South West District Office 401 E. Fifth St. Dayton, OH Johanna Léger Drinking Water Unit Technical Division of Veolia Eau Immeuble Giovanni Battista Pirelli B 1 rue Giovanni Battista Pirelli Saint Maurice France + 33 (0) [email protected]

272

273 APPENDIX D WORKSHOP AGENDA Biological Drinking Water Treatment Workshop Agenda January 20, :00 1:30 PM Welcome, introductions, and workshop objectives (John Albert & Phillippe Daniel) 1:30 2:00 PM Project 4129: Key Findings and Comments (Pat Evans) 2:00 2:15 PM Terminology Initial Feedback (Phillippe Daniel) 2:15 2:30 PM Charge to breakout groups (Phillippe Daniel) 2:30 4:00 PM Breakout group meetings 4:00 4:45 PM Presentations by breakout group chairs 4:45 5:20 PM Group discussion (Phillippe Daniel) 5:20 5:30 PM Terminology Further Feedback (Phillippe Daniel) 6:00 PM Dinner hosted by the Water Research Foundation January 21, :30 8:00 AM Continental Breakfast 8:00 8:10 AM Charge to breakout groups (Phillippe Daniel) 8:10 10:15 AM Breakout group meeting 10:15 11:15 AM Presentations by breakout group chairs 11:15 11:30 AM Break 11:30 AM 12:15 PM Group discussion (Phillippe Daniel) 12:15 12:30 PM Consensus Recommendations 12:30 12:45 PM Wrap-up and adjourn 247

274

275 APPENDIX E WORKSHOP ATTENDEES Biological Drinking Water Treatment Workshop Attendee List Name Organization Role John Albert WaterRF PM Eva Nieminski UDEQ PAC Ed Bouwer JHU PAC Mark LeChevallier AWC PAC Anne Camper MSU PAC Pat Evans CDM PI Phillippe Daniel CDM Facilitator Jeff Vogt GCWW, OH Utility Neal Spivey Buford, GA Utility Brad Coffey MWD, CA Utility Rick Sakaji EBMUD Utility Rod Nesmith PADEP Regulator Ying Ying McCauley UDEQ Regulator Sam Perry WA DOH Regulator Chris Schulz CDM Consultant Kerry Meyer CH2M Hill Consultant Jess Brown Carollo Consultant Michele Prevost Montreal Academic Scott Summers U Colorado Academic Monica Emelko U Waterloo Academic Lut Raskin U Mich Academic Herve Buisson Veolia Vendor Todd Webster Envirogen Vendor Hsiao wen Chen WaterRF Scribe Jonathan Cuppett WaterRF Scribe Ron LeBlanc WaterRF Scribe 249

276

277 APPENDIX F BIOLOGICAL DRINKING WATER TREATMENT EXPERT WORKSHOP PRESENTATION ON THE SURVEY RESULTS 251

278 252 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Biological Drinking Water Treatment Expert Workshop Water Research Foundation Project 4129 January 20-21, 2010

279 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 253 Agenda ½ Day One Workshop objectives Project 4129: Key Findings and Comments Terminology Initial Feedback Breakout meetings Presentations by breakout group chairs Group discussion Terminology Further Feedback Dinner ½ Day Two Review Breakout group meeting Presentations by breakout group chairs Group prioritization Consensus Recommendations Wrap-up and adjourn

280 Workshop Objectives Achieve consensus on biological drinking water treatment definitions and terminology to promote greater technology acceptance. Outcome: consensus article in OpFlow. Coordinated with the AWWA Committee on Biological Drinking Water Treatment. Develop a research roadmap for the Water Research Foundation Research Advisory Committee (RAC). Identify areas that have been sufficiently (not exhaustively!) studied for purposes of technology acceptance and adoption. Highlight areas which will yield significant additional insight/value to the field. 254 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

281 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 255 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Water Research Foundation Project 4129 January 20-21, 2010

282 256 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

283 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 257 Perceptions of Biological Drinking Water Treatment do not Reflect Reality

284 258 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Characterize the extent to which the following processes are used. ACADEMICS CONSULTANTS VENDORS DoD UTILITIES REGULATORS Aerobic 0% 20% 40% 60% 80%100% Moderate to Wide Use No to Limited Use VENDORS DoD CONSULTANTS UTILITIES REGULATORS ACADEMICS Anoxic 0% 20% 40% 60% 80% 100% Moderate to Wide Use No to Limited Use

285 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 259 State Regulators s Regarding Number of Permitted Plants Conventional treatment process (CTP) Ozone-enhanced biological filtration (OEBF) Rapid biological filtration (SBF) Slow biological filtration (RBF) GAC biological adsorption (GBA) Biological perchlorate/nitrate removal (BPNP) 0% 20% 40% 60% 80% know None >50

286 260 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Case Study Plant Distribution 60% Biological Non-Biological (Conventional) Ozone-enhanced biological filtration (OEBF) Rapid biological filtration (RBF) Biological perchlorate/nitrate process (BPNP) GAC biological adsorption (GBA) Slow biological filtration (SBF) 3 Plants 2 Plants 8 Plants 11 Plants 28 Plants 19 Plants 0% 10% 20% 30% 40%

287 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 261 Perceived Applicability of Aerobic Biological Treatment for Contaminant Removal TOC/DBP precursors AOC/BDOC Taste and odor EDC/PPCPs Perchlorate/nitrate/nitrite Iron/manganese Turbidity/particle counts HPC bacteria/total coliform Bromate Color 0% 20% 40% 60% 80% 100% UTILITIES REGULATORS CONSULTANTS ACADEMICS VENDORS

288 262 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Perceived Applicability of Conventional Treatment for Contaminant Removal TOC/DBP precursors AOC/BDOC Taste and odor EDC/PPCPs Perchlorate/nitrate/nitrite Iron/manganese Turbidity/particle counts HPC bacteria/total coliform Bromate Color 0% 20% 40% 60% 80% 100% UTILITIES REGULATORS CONSULTANTS ACADEMICS VENDORS

289 Actual Applicability of Aerobic Treatment TOC/DBP precursors AOC/BDOC Taste and odor EDC/PPCP Perchlorate/nitrate/nitrite Iron/manganese Turbidity/particle counts HPC/coliforms Bromate Color 0% 20% 40% 60% 80% 100% Aerobic biological processes - General Survey Conventional treatment processes - General Survey Ozone-enhanced biological filtration case studies Rapid biological filtration case studies GAC biological adsorption case studies Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 263

290 264 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Conventional vs. Biological Aerobic & Anoxic Treatment Conventional Treatment Process Cl 2 Cl 2 Aerobic Biological Treatment Process Electron Donor Cl 2 Anoxic Biological Treatment Process

291 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 265 Perceived Applicability of Anoxic Biological Treatment for Contaminant Removal TOC/DBP precursors AOC/BDOC Taste and odor EDC/PPCPs Perchlorate/nitrate/nitrite Iron/manganese Turbidity/particle counts HPC bacteria/total coliform Bromate Color 0% 20% 40% 60% 80% 100% UTILITIES REGULATORS CONSULTANTS ACADEMICS VENDORS

292 Actual Applicability of Anoxic Treatment Total organic carbon / disinfection by-product presursors Assimilable organic carbon/biodegradable dissolved organic carbon (AOC/BDOC) Taste and odor compounds Endocrine disrupting compounds, pharmaceuticals, and personal care products, etc. Anaerobic/anoxic biological processes - General Survey Conventional treatment processes - General Survey BPNP - Case Studies Perchlorate/nitrate/nitrite Iron/manganese Turbidity/particle counts HPC bacteria/total coliform Bromate Color 0% 20% 40% 60% 80% 100% 266 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

293 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 267 Perceived Impact on Finished Water Quality ACADEMICS VENDORS CONSULTANTS REGULATORS UTILITIES DoD 0% 20% 40% 60% 80% 100% Currently equivalent Expected to be equivalent in 5-10 yrs Not expected to be equivalent in the near future Will never be equivalent know

294 Actual Impact on Finished Water Quality Chlorine/chloramine disinfectant residuals Chlorine/chloramine demand and residual decay rates Total coliform positives HPC bacterial concentrations Biofilm levels AOC/BDOC concentrations Customer taste and odor complaints Customer colored water complaints Corrosion Dissolved oxygen (DO) concentration Degree of Consensus High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) OEBF Ozone-enhanced biological filtration RBF Rapid biological filtration GBA GAC biological adsorption Negative Impact OEBF RBF GBA Rating No Change Positive Impact Don t know 268 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

295 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 269 Perceived Operational Concerns DoD Utilities Regulators Consultants Vendors Academics Process instability Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory conditions Degree of Consensus High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) High Moderate Rating None to Low Don t know

296 Actual Operational Concerns Process instability Process inflexibility Source water quality changes Water temperature changes Bacterial sloughing/breakthrough Pathogen or contaminant breakthrough Process start-up and recovery time Post-treatment and disinfection Unknown or changing regulatory conditions Degree of Consensus High ( 10% difference between two most frequent ratings) Low (<10% difference between two most frequent ratings) OEBF High RBF GBA SBF Rating None to Moderate Low BPNP Don t know OEBF Ozone-enhanced biological filtration RBF Rapid biological filtration GBA GAC biological adsorption SBF Slow biological filtration BPNP Biological perchlorate/nitrate removal process 270 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

297 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 271 Do you believe that biological water treatment processes are generally accepted by the drinking water industry, i.e., the same as conventional treatment? Utilities Consultants Regulators Academics DoD Vendors 0% 20% 40% 60% 80% 100% Yes know No

298 272 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America How should biological processes be implemented? VENDORS ACADEMICS CONSULTANTS DoD UTILITIES REGULATORS Aerobic 0% 50% 100% Implemented preferentially since they represent a "green" technology Anoxic 0% 50% 100% Implemented cautiously due to concerns over uncertain public health impacts

299 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 273 How do we increase acceptance? Industry research More full-scale systems Operator training workshops/seminars Public education Regulatory guidance documents Don t know 0% 20% 40% 60% 80% 100% UTILITIES REGULATORS CONSULTANTS ACADEMICS VENDORS DoD

300 Research Priorities Contaminant removal Safety know Cost Monitoring and control Downstream treatment incl disinfection Training/education Reliability Pathogens O&M Water conditions Biological Activity Public acceptance Pilot studies Full-scale Residuals Finished water/ distribution system quality Clogging/backwash Potential problems Optimization Process configurations Design Water re-use Nutrients As pretreatment Bench tests Flexibility Startup Low temperatures Pretreatment Bacterial sloughing Anaerobic processes 0% 5% 10% 15% 20% 25% 274 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

301 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 275 Research Priorities Readable Version Contaminant removal Safety know Cost Monitoring and control Downstream treatment incl disinfection 0% 5% 10% 15% 20% 25%

302 276 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Contaminant Removal Research Priorities EDC/PPCP TOC/AOC/NOM DBP T&O General Nitrate/nitrite pathogens Algae, Algal toxins particle Arsenic perchlorate 0% 5% 10% 15% 20% 25% 30% Respondents

303 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 277 How Do We Monitor & Control Biological Filters Today? Differential Pressure Surface Loading Rate Turbidity Pre-Oxidant Concentration Pathogens Coagulant Concentration Backwash Duration Post-Backwash Rest Duration Backwash Disinfectant

304 278 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Multiple Mechanisms Are Involved Physical & Chemical Filtration Coagulation Adsorption Ion exchange Oxidation Biological Bio-Precipitation Bio-Absorption Bio-Adsorption Bio-Transformation Bio-Degradation

305 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 279 Permission granted by King Features, Corbis, and University of Georgia

306 280 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Workgroup Objectives Research Priorities Develop a research roadmap for the Water Research Foundation Research Advisory Committee (RAC). Highlight areas which will yield significant additional insight/value to the field. Identify areas that have been sufficiently (not exhaustively!) studied for purposes of technology acceptance and adoption.

307 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 281 Discussion Item #1 Expert Impressions

308 282 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Impressions of Survey Results on Research Priorities Contaminant removal Safety know Cost Monitoring and control Downstream treatment incl disinfection 0% 5% 10% 15% 20% 25%

309 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 283 Survey Contaminant Removal Research Priorities EDC/PPCP TOC/AOC/NOM DBP T&O General Nitrate/nitrite pathogens Algae, Algal toxins particle Arsenic perchlorate 0% 5% 10% 15% 20% 25% 30% Respondents

310 284 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Discussion Item #1 Expert Impressions

311 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 285 Workshop Objectives Lingo Achieve consensus on biological drinking water treatment definitions and terminology to promote greater technology acceptance. Outcome: consensus article in OpFlow. Coordinated with the AWWA Committee on Biological Drinking Water Treatment. Your task: speak up now or forever

312 286 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Discussion Item #2 Terminology Impressions

313 Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 287 Terminology: Process Categorization for Case Studies

314 288 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America Discussion Item #2 Terminology Impressions

315 Affiliation Chair in Bold A Aerobic Removal & Biological Stability Training Center B Anoxic Removal Eagle View C Monitoring, Control, & Optimization Lake View D Safety Considerations Spruce View PAC Eva Nieminski Ed Bouwer Mark LeChevallier Anne Camper Academia Monica Emelko Scott Summers Lut Raskin Michèle Prévost Utility Jeff Vogt Rick Sakaji Brad Coffey Neal Spivey Consultant / Vendor Pat Evans & Herve Buisson Jess Brown & Todd Webster Kerry Meyer Regulator Solitha Dharman Sam Perry Ying Ying McCauley Chris Schulz Rod Nesmith Scribe Jonathan Cuppett Hsiao-wen Chen Ron LeBlanc John Albert Appendix F: Biological Drinking Water Treatment Expert Workshop Presentation on the Survey Results 289

316 Workshop Objectives Achieve consensus on biological drinking water treatment definitions and terminology to promote greater technology acceptance. Outcome: consensus article in OpFlow. Coordinated with the AWWA Committee on Biological Drinking Water Treatment. Develop a research roadmap for the Water Research Foundation Research Advisory Committee (RAC). Identify areas that have been sufficiently (not exhaustively!) studied for purposes of technology acceptance and adoption. Highlight areas which will yield significant additional insight/value to the field. 290 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

317 APPENDIX G WATER RESEARCH FOUNDATION BIOLOGICAL TREATMENT PROJECTS 291

318 Project # / Publication Title (and E-link) Order Number Yr funded Objectives / Abstract 154 Investigation of the Biological Stability of Water in Treatment Plants and Distribution Systems Examines how treatment processes affect biological stability in the distribution system. Also determines how biodegradable organic matter (BOM) and components of BOM influence distribution system regrowth. 252 Optimizing Filtration in Biological Filters 263 Colonization of Biologically Active Filter Media With Pathogens 289 Advanced Oxidation and Biodegradation Processes for the Destruction of TOC and DBP Precursors 408 Microbial Activity on Filter-Adsorbers 409 Biologically Enhanced Slow Sand Filtration for Removal of Natural Organic Matter 504 Ozone and Biological Treatment for DBP Control and Biological Stability 509 Assimilable Organic Carbon Measurement Techniques 631 Removal of Natural Organic Matter in Biofilters Addresses key issues related to optimization of biological filters for multiple objectives, namely, simultaneous particle or floc removal and biodegradation of organic compounds, on a number of source waters and process designs (direct filtration, post-sedimentation, following ozone, etc.) Establishes whether opportunistic and frank pathogenic bacteria can colonize and persist on biologically active filter media. Also investigates Giardia and Cryptosporidium for their ability to persist in biological filters. Determines if these filters are an important source of pathogens entering the distribution system Establishes whether opportunistic and frank pathogenic bacteria can colonize and persist on biologically active filter media. Also investigates Giardia and Cryptosporidium for their ability to persist in biological filters. Determines if these filters are an important source of pathogens entering the distribution system. Published in Quantifies the magnitude and prevalence of water quality changes mediated by microorganisms associated with GAC filter-adsorbers in order to improve overall treatment plant performance by promoting or discouraging microbial - GAC interactions that affect finished water quality Investigates and helps define the potential for biologically enhanced slow-rate filtration for removal of organic matter, including the use of ozone in combination with slow-rate filtration Evaluates the use of ozone with biological treatment to control disinfection byproducts. Also examines the impact of this treatment scheme on biological regrowth and on the maintenance of a disinfectant residual in the distribution system. Provides useful information to utilities that are designing or retrofitting ozone into their plants Refines and field tests a simplified, routine bioassay technique that permits utilities to easily monitor nutrient fluctuations and adjust treatment processes to minimize bacterial regrowth in distributed and stored waters Investigates the ability of a biofilter to remove natural organic matter (NOM) and assesses the likely benefits of reducing NOM by biodegradation. Also investigates preozonation and NOM biodegradation to determine optimal ozone doses. Evaluates sand as a support medium for the microbiological population. Published in Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

319 Project # / Publication Title (and E-link) Order Number Yr funded Objectives / Abstract 712 Design of Biological Processes for Organics Control Evaluates whether biofilm process fundamentals and kinetics largely developed for wastewater treatment can be applied to the design and operation of biofilm processes for drinking water treatment. Optimizes the filtration performance of biologically active filters. Also evaluates possible negative impacts of biological treatment on effluent quality and assesses the impact of biological processes on taste and odor reduction. 816 Removal of DBP Precursors by GAC Adsorption 917 Microbial Impact of Biological Filtration 2535 Removal of Bromate and Perchlorate in Conventional Ozone/GAC Systems 2622 Evaluation of Riverbank Filtration As a Drinking Water Treatment Process Evaluates the use of GAC for disinfection by-product control at six representative utilities. Addresses optimized performance based on pretreatment (coagulation and ozonation plus biological treatment), empty bed contact time, and blending. Discusses the relationship between natural organic matter characteristics and DBP formation. Also provides optimization guidelines and cost estimates for GAC implementation. Research partner: USEPA Documents the positive and negative impacts of biological filtration on the microbial quality of drinking water. Examines the changes in microbial populations through conventional and biologically active treatment processes, evaluates the effects of microbial antagonism within biologically active filters, evaluates the release and impact of carbon fines on distribution biofilms, and evaluates the microbial populations in four full-scale treatment systems. Research partner: USEPA Determines whether conventional ozone/granular activated carbon systems can be modified to remove perchlorate and bromate without sacrificing system performance Provides information on the removal of DBP precursors, herbicides, and microbial contaminants as a function of bank filtration variables including raw water quality, filtration distance and velocity, temperature, and riverbed sediments. Reports on the mechanisms of DBP precursor removal in bank filtration process, and distinguishes the contribution of physical, physical-chemical, and biological processes to the removal. Tailored Collaboration partner: Louisville Water Company. Published in Appendix G: Water Research Foundation Biological Treatment Projects 293

320 Project # / Publication Title (and E-link) Order Number Yr funded Objectives / Abstract 2577 Biological Treatment and Downstream Processing of Pechlorate- Contaminated Water 91017F This report documents use of an anaerobic packed bed bioreactor for treatment of nitrate and perchlorate in drinking water plus downstream aeration and filtration processes to produce water suitable for potable uses Impact of UV Disinfection on Biological Stability 2775 Ozone-Enhanced Biofiltration for Geosmin and MIB Removal 2804 Membrane Biofilm Reactor Process for Nitrate and Perchlorate Removal 2824 Cometabolism of Trihalomethanes in Nitrifying Biofilters 2825 Haloacetic Acid Removal Using Granular Activated Carbon 2839 Treatability of Algal Toxins Using Oxidation, Adsorption, and Membrane Technologies 90999F 2000 Evaluates the impact of ultraviolet disinfection on biofilm accumulation in drinking water distribution systems. Compares the effectiveness of chlorine dioxide, free chlorine, and monochloramine as secondary disinfectants for reducing bacterial regrowth (bulk water and biofilm cells) in the presence and absence of UV disinfection Develops design criteria and operating guidelines for biofiltration, following ozone applications, to optimize the removal and control of geosmin and MIB F 2001 Evaluates the efficiency of a biological process to reduce perchlorate concentrations of up to 1,000 micrograms per liter to levels of 4-18 micrograms per liter. Also evaluates the impact of co-contaminants on process performance, characterizes process effluents, and defines post treatment requirements. Includes pilot-scale testing F 2001 Investigates a biological treatment process for the destruction of trihalomethanes (THMs) in drinking water treatment plants. Determines cometabolism kinetics and the significance of enzyme competition with ammonia for all four THMs with pure culture organism. Extends the kinetics and enzyme competition experiments to mixed-culture nitrifiers typically encountered in drinking water treatment. Also demonstrates THM cometabolism in continuous-flow biofilters and studies monochloramine destruction in GAC beds. Demonstrates THM cometabolism in continuous-flow GAC biofilters receiving ammonia, monochloramine, and THMs in the influent F 2001 Generates data and promotes better understanding of the mechanism of HAAs removal in GAC filter beds. Explores the effect of EBCT and temperature, as well as methods to enhance the HAA degradation Will develop chemical and engineering data and criteria necessary to assess algal toxin treatment for a variety of raw water qualities and locations. Will characterize various treatment technologies including ozone, advanced oxidation, powdered activated carbon, granular activated carbon, biological treatment, and membranes. Will also develop implementation and cost data for those technologies. Tailored Collaboration partner: City of Cocoa (Fla.). 294 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

321 Project # / Publication Title (and E-link) Order Number Yr funded Objectives / Abstract 2859 Innovative Alternatives to Minimize Arsenic, Perchlorate, and Nitrate Residuals 91054F 2002 Develops and validates innovative processes to minimize the production of water treatment residuals and yield benign residuals from treatment processes that are used to remove nitrate, perchlorate, and arsenic. Research partner: USEPA. Published in Development of a Simplified Biodegradable Organic Matter Technique 4021 Occurrence, Impacts, and Removal of Manganese in Biofiltration Processes 4022 Removal of Pesticides and Their Ionic Degradates by Granular Activated Carbon 4040 Control of Trace Organics by Ultraviolet - Hydrogen Peroxide Oxidation 4129 Potable Water Biological Treatment Project 4131 Optimizing the Sustainability of Treatment Processes for Nitrate Removal in Inland Communities (Tailored Collaboration) 2005 Will develop a rapid, simple, and reliable method for measuring biodegradable organic matter in drinking water. Research partner: EAWAG Will optimize biological filtration by improving understanding of the origin and fate of manganese during biological filtration treatment, and by identifying the impacts of manganese release and optimal conditions for removal Will determine the removal of pesticides and their ionic degradates by granular activated carbon treatment. Research partner: TZW (Germany) Will study the degradation of trace organic contaminants such as endocrine disruptors by UV/H2O2 technology followed by biologically active GAC. Research partner: Kiwa N.V Will expand and supplement existing biologically active filtration (BAF) research by documenting operating conditions of existing BAFs and critical success factors for implementation of new BAFs that can treat emerging contaminants including perchlorate and nitrate Will investigate the operational and performance-related features of GAC biofilters that operate without pre-ozone and develop practical guidance and tools that can be used by water utilities considering this treatment technology. Will build upon the existing body of work, many of which were Foundation-funded research projects, by conducting a demonstration-scale evaluation of GAC filter adsorbers. Tailored collaboration partner: Birmingham Water Works Board. Appendix G: Water Research Foundation Biological Treatment Projects 295

322 Project # / Publication Title (and E-link) Order Number 4135 Fate and Impact of Antibiotics in Slow- Rate Biofiltration Processes (Unsolicited) 4155 GAC Biofilters in Retrofit Applications: An Approach for Cost Effective Regulatory Compliance (Tailored Collaboration) 4162 Establishing Guidelines for the Use of Ozone-GAC for Control of Endocrine Disruptors and Related Compounds in Water (Tailored Collaboration) 4202 Biological Nitrate Removal Pre- Treatment System for a Drinking Water Application (Tailored Collaboration) 4215 Enhancing Biofiltration to Achieve Sustained Removal of Multiple Inorganic and Organic Contaminants (Tailored Collaboration) Yr funded Objectives / Abstract 2007 Will investigate the synergistic impact of multiple antibiotics on biofilm bacteria that are the heart of slow-rate biofiltration processes use worldwide for the production of drinking water. Will provide parameters necessary for predicting the fate and impact of antibiotics in drinking water treatment processes such as slow sand filtration and bank filtration Will investigate the operational and performance-related features of GAC biofilters that operate without pre-ozone and develop practical guidance and tools that can be used by water utilities considering this treatment technology. Will build upon the existing body of work, many of which were Foundation-funded research projects, by conducting a demonstration-scale evaluation of GAC filter adsorbers. Tailored collaboration partner: Birmingham Water Works Board Will investigate the effectiveness of ozone and biological filtration at removing selected endocrine disrupting compounds (EDCs), pharmaceutical and personal care products (PPCPs), their daughter products, and residual endocrine activity from municipal water supplies. Will provide utilities with information on likely removals of these compounds under a broad range of water qualities and treatment scenarios. Tailored Collaboration partner: Pawtucket Water Supply Board Will pilot-test three commercially available biological filtration processes for the removal of nitrate from a surface water supply. Will determine the impact of temperature and other design parameters on the overall operation and maintenance of each of the three systems. Tailored Collaboration partner: City of Thornton 2008 Reviews the status of understanding concerning distribution system water quality changes, and presents the results of an expert workshop held in 2007 to identify the highest priority research needs for this area. This information will be used by an Expert Panel to identify relevant goals for the Strategic Initiative, as well as to prepare a sequenced multi-year research plan to achieve those goals. 296 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America

323 Project # / Publication Title (and E-link) Order Number 4231 Assessing and Enhancing Biological Filtration 4312 An p[erationa Definitiaon of Biostability in Drinking Water Yr funded Objectives / Abstract 2009 The objective of this project is to develop a tool-box of strategies and protocols for monitoring, optimization, and control of BF treatment processes, as well as a summary of design parameters aimed at specific treatment objectives. This project will encourage drinking water utilities to fully understand the benefits of implementing this treatment technology, which is underutilized in North America. This project will also help define proper design and operation of biological treatment processes and help identify applications where BF is the right approach The objective of the project is to develop a practical operational definition of biologically stable drinking water and to develop guidance for water professionals on how to optimize treatment prior to water distribution to produce biologically stable water that will not promote the growth of pathogens. Appendix G: Water Research Foundation Biological Treatment Projects 297

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325 REFERENCES ASCE and Awwa Water Treatment Plant Design, 4th ed. McGraw-Hill, New York. Bouwer, E. J., and P. B. Crowe Biological Processes in Drinking Water Treatment. J Awwa. September. 82:93. Brown, J and J. Safely Efficient Biological Removal of Nitrate from Reverse Osmosis By-Pass Water at the Arlington Desalter WTP. Proceedings of Awwa Annual Conference. San Diego, California. Burr, M., A. K. Camper, R. DeLeon, and P. Hacker Colonization of Biologically Active Filter Media with Pathogens. Water Research Foundation, Denver, Colorado. Page, D., Wakelin, S., Van Leeuwen, J., Dillon, P Review of Biofiltration Processes Relevant to Water Reclamation via Aquifers. CSIRO Land and Water Science Report 47/06. Rittmann, B. E., and V. L. Snoeyink Achieving Biologically Stable Water. Journal Awwa. 76(10): Urfer, D., P. Huck, S. D. J. Booth, and B. M. Coffey Biological Filtration for BOM and Particle Removal: A Critical Review. Journal Awwa. 89(12): U.S. EPA Feasibility Study of Granular Activated Carbon Adsorption and On-Site Regeneration. EPA-600/S October U.S. EPA The History of Drinking Water Treatment. EPA-816-F February. Weiss, W. J., E. J. Bouwer, W. P. Ball, C. R. O Melia, R. Aboytes, and T. F. Speth Riverbank Filtration: Effect of Ground Passage on NOM Character. J. Water Supply: Research and Technology AQUA. 53: Westerhoff, P., R. S. Summers, Z. Chowdhury, and S. Kommineni Ozone-Enhanced Biofiltration for Geosmin and MIB Removal. Water Research Foundation, Denver, Colorado. Westerhoff, G. and R. Miller Design of the GAC Treatment Facility at Cincinnati. J. Awwa. April. pp

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327 ABBREVIATIONS AOC ASCE ATP Awwa BAF BDOC BPNP Assimilable organic carbon American Society for Civil Engineering Adenosine triphosphate American Water Works Association Biologically active filter Biodegradable dissolved organic carbon Biological perchlorate/nitrate process C Degrees Celsius CDPH California Department of Public Health CFU Colony forming units CTP Conventional treatment process DBP DNA DOC DoD EDC EPA ESTCP GAC GBA GCWW gpd gpm gpm/ft 2 h HAA5 HPC ITRC kg LAAFP m 3 m/h mgd Disinfection by-products Deoxyribonucleic acid Dissolved organic carbon Department of Defense Endocrine disrupting compounds Environmental Protection Agency Environmental Security Technology Certification Program Granular activated carbon Granular activated carbon biological adsorption Greater Cincinnati Water Works Gallons per day Gallons per minute Gallons per minute per square foot Hours Halo-acetic acids Heterotrophic plate counts Interstate Technology & Regulatory Council Kilogram Los Angeles Aqueduct Filtration Plant Cubic meter Meters per hour Million gallons per day 301

328 302 Biological Drinking Water Treatment Perceptions and Actual Experiences in North America mg/l MIB ml mm MTBE µg/l N NA NADH NOM NTU O&M OEBF PAC PPCP RBF SBF SCVWD SDWIS T&O TCR TOC TTHM U.S. UV WMWD Milligrams per liter Methyl isoborneol Milliliter Millimeter Methyl tertiary butyl ether Micrograms per liter Number Not applicable Nicotine adenine dinucleotide hydrogen Natural organic matter Nephalometric turbidity units Operations and maintenance Ozone-enhanced biological filtration Project Advisory Committee Pharmaceutical and personal care products Rapid biological filtration Slow biological filtration Santa Clara Valley Water District Safe Drinking Water Information System Taste and odor Total Coliform Rule Total organic carbon Total trihalomethanes United States Ultraviolet Western Municipal Water District

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330 WEB-ONLY /10-RF 6666 West Quincy Avenue, Denver, CO USA P F Biological Drinking Water Treatment Perceptions and Actual Experiences in North America 4129