Nova Scotia Treatment Standards for Municipal Drinking Water Systems

Transcription

1 Nova Scotia Treatment Standards for Municipal Drinking Water Systems Approval Date: March 12, 2012 Effective Date: March 12, 2012 Approved By: S. J. Snook, Deputy Minister Version Control: Replaces: Treatment Standard for Municipal Surface Source Water Treatment Facilities, December 2002 Protocol for Determining Groundwater Under the Direct Influence of Surface Water, December 2002 Treatment Standard for Municipal Groundwater Source Water Facilities, May 2003 Guidelines for the Determination of Natural Filtration Log Removal Credit for Giardia, January 20, 2006

2 TABLE OF CONTENTS PART I - INTRODUCTION 1.0 Preamble Purpose Authority Background Application Document Layout Treatment Standard Components System Assessment Report Protocol for Determining Groundwater Under the Direct Influence of Surface Water Compliance Timelines Existing Municipal Drinking Water Systems Drinking Water Systems Acquired by a Municipality Newly Constructed Municipal Drinking Water Systems PART II - SOURCE WATER PROTECTION 3.0 Overview Minimum Requirements PART III - ADEQUATE TREATMENT AND DISTRIBUTION 4.0 Overview Protection Against Pathogenic Organisms Minimum Treatment Requirements a) Surface Water b) Groundwater Under the Direct Influence of Surface Water (GUDI) c) Non-GUDI Treatment Credits for Filtration (Log Removal) Disinfection Credits (Log Inactivation) a) CT Concept for Chemical Disinfection b) IT Concept for UV Disinfection Protection Against Chemical Contaminants Disinfection By-Products Guidelines for Canadian Drinking Water Quality Guidelines for Monitoring Public Drinking Water Supplies i

3 4.3 Management of Waste Streams Filter Backwash Water a) Discharges into a Freshwater Watercourse b) Discharges into Municipal Wastewater System c) Discharges into a Marine or Brackish Environment d) Discharges into a Non-Aquatic Environment Filter Backwash and Clarifier Solids Water Distribution Systems Other Considerations Engineered Filtration for Pathogen Reduction Primary Disinfection for Pathogen Reduction Secondary Disinfection PART IV - OPERATIONS, MONITORING, REPORTING AND MANAGEMENT 5.0 Overview Operations Manual Monitoring and Recording Reporting Requirements Management PART V - GLOSSARY AND REFERENCES 6.0 Glossary References APPENDICES Appendix A - Protocol for Determining Groundwater Under the Direct Influence of Surface Water Appendix B - Guidelines for the Determination of Natural Attention Credit for Protozoa Appendix C - Technical Considerations for Filtration and Disinfection Processes Appendix D - Log Inactivation Information and Tables for Free Chlorine, Chlorine Dioxide, Ozone and Ultraviolet (UV) Light Appendix E - Baffling Factors for Sample Clearwell Designs Appendix F - Sample CT Calculations Appendix G - Technical Information on Reporting Requirements ii

4 LIST OF TABLES Table 1 Log Removal Credits for Various Treatment Technologies Meeting Prescribed Turbidity Limits Table 2 Baffling Factors Table 3 Disinfection By-Products Requiring Routine Monitoring by Municipal Water Utilities iii

5 PART I - INTRODUCTION 1.0 Preamble 1.1 Purpose The purpose of this document is to set out the minimum requirements that apply to municipal drinking water systems in Nova Scotia. It is considered unacceptable for systems capable of exceeding this standard to allow their water quality to degrade in quality to only meet the minimum requirements. 1.2 Authority (NSE) has been designated as the lead agency to take such measures as are reasonable to provide access to safe, adequate and reliable municipal drinking water supplies (Environment Act, Section 104(c)). To carry out this mandate, Section 105(3)(c) of the Environment Act states: (3) The Minister may (c) establish or adopt water-quality guidelines, objectives and standards; In addition, Section 35 of the Water and Wastewater Facilities and Public Drinking Water Supplies Regulations, made pursuant to the Environment Act, requires that an owner of a public drinking water supply provide safe drinking water that meets the latest version of the Guidelines for Canadian Drinking Water Quality (GCDWQ) as published by Health Canada. As the GCDWQ specify treatment goals for protection against pathogenic organisms, such as protozoa and viruses, these treatment standards specify minimum requirements for Nova Scotia. 1.3 Background The first Nova Scotia drinking water treatment standards were developed in the Fall of 2002 and finalized in early Since 2003, there have been a number of changes recommended by Health Canada. Health Canada recommends that treatment for surface water and groundwater under the direct influence of surface water (GUDI) be based on a minimum 3-log reduction of Cryptosporidium and Giardia and 4-log reduction for viruses unless source water quality requires a higher log reduction; for groundwater not under the direct influence of surface water (non- GUDI), Health Canada recommends that treatment be based on a minimum 4-log reduction for viruses. 1 of 100

6 Cryptosporidium cannot be inactivated with chlorine whereas a minimum of 0.5-log reduction can be achieved for Giardia. The first Nova Scotia treatment standards for surface water and GUDI sources only referenced Giardia. Minimum treatment requirements for both Cryptosporidium and Giardia for surface water and GUDI sources are now included in Nova Scotia s updated treatment standards. The treatment standards for non-gudi sources in Nova Scotia remains unchanged at 4-log reduction for viruses. Historically, municipal drinking water systems in Nova Scotia have used chlorine for primary and secondary disinfection. A number of alternate primary disinfectants, such as ultraviolet (UV) light, chlorine dioxide and ozone, and alternate secondary disinfectants, such as chloramines, are now included in Nova Scotia s updated treatment standards. Additionally, the use of membrane technology has become common in recent years. Nova Scotia s updated treatment standards set out minimum requirements for the use of membrane technology, as well as the management of waste streams for all filtration technologies. 1.4 Application These standards apply to municipal drinking water systems in Nova Scotia that utilize any of the following water sources: surface water - means water that is found in lakes, rivers, streams, ponds, surface water impoundments and other natural watercourses. groundwater under the direct influence of surface water or GUDI - means any water beneath the surface of the ground with: i) significant occurrence of insects or other macro-organisms, algae, organic debris, or large-diameter pathogens such as Giardia lamblia or Cryptosporidium; or ii) significant and relatively rapid shifts in water characteristics such as turbidity, temperature, conductivity, or ph which closely correlate to climatological or surface water conditions. non-gudi - means a well that has been classified as not under the direct influence of surface water (i.e. non-gudi) based on the Protocol for Determining Groundwater Under the Direct Influence of Surface Water and has been accepted as such in writing by the NSE regional hydrogeologist. Municipal water utilities that purchase treated water from an adjoining system shall obtain water from a municipal drinking water system that complies with Nova Scotia s Treatment Standards. 2 of 100

7 1.5 Document Layout These treatment standards are structured into five parts. Part I provides an overview and compliance timelines. Parts II, III and IV detail the minimum requirements of the treatment standard components that apply to municipal drinking water systems. Part V includes a glossary and references. Technical appendices are also attached where necessary. 2.0 Treatment Standard Components The components of these treatment standards are based on the universally accepted multiple-barrier approach to drinking water management, namely: Source Water Protection: Minimum requirements are described in Part II. Adequate Treatment and Distribution: Minimum requirements are described in Part III. Operations, Monitoring, Reporting and Management: Minimum requirements are described in Part IV. 2.1 System Assessment Report A system assessment report includes the following components to verify that the system meets current environmental standards for producing and distributing safe drinking water: a characterization of the water source; an evaluation of treatment processes, facilities and equipment; an evaluation of the distribution system; a review of operations, maintenance, monitoring and management of the municipal drinking water system. Environmental standards are frequently updated and enhanced. A municipal drinking water system shall be assessed at least every ten years, or sooner if required, to: evaluate the capability of the system to consistently and reliably deliver an adequate quantity of safe drinking water; to verify compliance with regulatory requirements, as amended from time to time; present options and costs to address deficiencies. A system assessment may be required sooner than every ten years if there are significant land use or environmental changes in the source water area or in response to a serious adverse water quality event. 3 of 100

8 The System Assessment Report shall be completed in accordance with Terms of Reference published by NSE, as amended from time to time. The System Assessment Report shall be acceptable to NSE. 2.2 Protocol for Determining Groundwater Under the Direct Influence of Surface Water Municipal water utilities with groundwater supplies shall ensure that all wells in their system have been classified in accordance with the Protocol for Determining Groundwater Under the Direct Influence of Surface Water as outlined in Appendix A (GUDI Protocol). The completion of the GUDI Protocol and classification of wells, shall be acceptable to the NSE regional hydrogeologist. Classification is required for all wells that were not classified under the previous treatment standards. Reclassification of wells may be required if there are changes to the well construction or well setting that could cause significant changes to groundwater and surface water interaction. Well setting changes that would trigger the need for reclassification are those that involve surface water bodies, such as the installation of a new ditch or dugout within 60 metres of the well. Wells that are classified GUDI - High Risk shall require engineered filtration and disinfection to meet Nova Scotia s Treatment Standards. Wells that are classified as GUDI - Medium Risk may be eligible to receive credit for natural in-situ attenuation provided the Guidelines for the Determination of Natural Filtration Log Removal Credit for Protozoa are followed as outlined in Appendix B and the NSE regional hydrogeologist accepts the determination in writing. In this case, natural attenuation plus UV disinfection may be utilized to address protozoan risks while chlorine is utilized to address viral risks as outlined in Part III. Minimum requirements for the use of UV disinfection are specified in Appendix C. Municipal drinking water supplies with wells that have been classified as GUDI - Medium Risk shall also: continuously monitor turbidity at each individual GUDI wellhead at a point prior to disinfection; conduct Microscopic Particulate Analysis (MPA) testing every two years for each individual GUDI well, in spring following a rainfall. Any MPA testing shall be completed in accordance with Step 3 of the Protocol for Determining Groundwater Under the Direct Influence of Surface Water as outlined in Appendix A (e.g. if there is a 15 day time-of-travel, then the well shall be sampled 15 days after a surface water event). 4 of 100

9 If the classification of any medium risk GUDI well increases to high, NSE shall be immediately notified and the municipal water utility shall take any necessary corrective action. If MPA results change from medium to low, the municipal water utility may request NSE reclassify the well. In evaluating this request, the NSE regional hydrogeologist will consider the site-specific hydrology, well construction and any changes that have occurred since the well was originally classified. The NSE regional hydrogeologist may require two or more additional MPA samples to confirm the new classification. Any MPA testing shall be completed in accordance with Step 3 of the Protocol for Determining Groundwater Under the Direct Influence of Surface Water as outlined in Appendix A. Wells that are classified as low risk are deemed to be non-gudi unless advised otherwise by the NSE regional hydrogeologist. 2.3 Compliance Timelines Existing Municipal Drinking Water Systems The timelines for meeting these treatment standards shall be as follows: On or before April 1, the municipal water utility shall submit three copies of the completed System Assessment Report to the local office of NSE. On or before October 1, the municipal water utility shall submit a corrective action plan to the local office of NSE to address deficiencies identified by the System Assessment Report. The purpose of the System Assessment Report is to verify that municipal drinking water systems meet current environmental standards, including the minimum requirements set out by these treatment standards. The purpose of the corrective action plan is to outline the implementation schedule that will be followed to address all deficiencies identified by the System Assessment Report. The corrective action plan shall be acceptable to NSE. It is the municipal water utility s responsibility to ensure that funding is in place to complete the System Assessment Report process and implement any required corrective action Drinking Water Systems Acquired by a Municipality Drinking water systems transferred to, or purchased by, a municipality shall be given site-specific time frames to meet the treatment standards based on the complexity of the transferred/purchased system. 5 of 100

10 Newly Constructed Municipal Drinking Water Systems All new municipal drinking water systems shall be designed and constructed to meet the minimum requirements set out by these treatment standards upon commissioning. NSE has also adopted the Atlantic Canada Guidelines for the Supply, Treatment, Storage, Distribution and Operation of Drinking Water Supply Systems. These treatment standards and the Atlantic Canada Guidelines establish the minimum requirements for all new municipal drinking water systems in Nova Scotia. If there is a discrepancy between the treatment standards and the Atlantic Canada Guidelines, the more stringent shall apply. For new groundwater wells, a minimum of one raw water bacteria sample shall be collected to assess the water quality screening criteria in Step 1 of the Protocol for Determining Groundwater Under the Direct Influence of Surface Water (see Appendix A); the sample shall be collected at the end of the 72-hour pumping test, as specified in the Guide to Groundwater Withdrawal Approvals. If a new well will fail Step 1 because bacteria was detected in a single sample, additional sampling shall be carried out to confirm whether or not bacteria is regularly present. A minimum of four additional samples shall be collected, one per month, as outlined in Section A.2.1 of Appendix A. If any of these additional samples contain bacteria the well shall fail Step 1, unless subsequent corrective action and sampling demonstrate the well does not regularly contain bacteria. For new groundwater wells that fail Step 1 of the Protocol for Determining Groundwater Under the Direct Influence of Surface Water as outlined in Appendix A, the following shall apply: The well may be connected to the distribution system to allow the completion of Steps 2 and 3 of the Protocol for Determining Groundwater Under the Direct Influence of Surface Water as outlined in Appendix A. Step 2 shall be completed under proposed normal operating conditions (e.g. proposed flow rate, well on/off cycling, etc.) for 52 weeks of operation in accordance with the Protocol for Determining Groundwater Under the Direct Influence of Surface Water as outlined in Appendix A. Step 3 shall be completed in accordance with the Protocol for Determining Groundwater Under the Direct Influence of Surface Water as outlined in Appendix A. During the completion of the GUDI Protocol, the well shall be equipped with a disinfection system capable of achieving 4-log reduction for viruses with the provisions outlined in Section of 100

11 NSE may require twice weekly bacteria sampling and the maintenance of a 0.4 mg/l free chlorine residual during the completion of the GUDI Protocol. NSE may require the installation of UV disinfection during the completion of the GUDI Protocol. Wells classified as GUDI shall be required to meet 3-log reduction for protozoa (e.g. Cryptosporidium oocysts and Giardia cysts) and a minimum of 4-log reduction for viruses as outlined in Section 4.1.1(b) of these treatment standards. Wells classified as non-gudi shall be required to meet a minimum of 4-log reduction for viruses as outlined in Section 4.1.1(c) of these treatment standards. 7 of 100

12 PART II - SOURCE WATER PROTECTION 3.0 Overview Choosing the highest quality source, whether surface water or groundwater, is an important part of delivering a sustainable supply of high quality drinking water. Effective water treatment begins with source water protection to minimize the input of fecal contamination from human and animal sources, and chemical contamination from human activities. Source water protection is the first barrier in the multiplebarrier approach used in Nova Scotia. 3.1 Minimum Requirements Municipal water utilities are responsible for taking reasonable steps to protect the source from contamination. Minimum requirements for source water protection include: A source water protection plan (SWPP) shall be developed by the municipal water utility responsible for the source. The SWPP should be developed using the five guidance documents published by NSE: Step 1 - Form a Source Water Protection Advisory Committee Step 2 - Delineation a Source Water Protection Area Boundary Step 3 - Identify Potential Contaminants and Assess Risk Step 4 - Develop a Source Water Protection Management Plan Step 5 - Develop a Monitoring Program to Evaluate the Effectiveness of a Source Water Protection Plan The municipal water utility should complete the risk identification process depending on the source type as follows: surface water - within the natural watershed boundary; groundwater under the direct influence of surface water (GUDI) - within the natural watershed boundary s and the 25-year time-oftravel; non-gudi - within the 25-year time-of-travel. Municipal water utilities with large natural watershed boundaries may focus their management strategies on high risk activities and activities close to the intake. They may also consider a graduated risk management approach based on distance from the intake. Examples of high risk activities include: wastewater discharges, agricultural uses, residential development, chemical plants, etc. 8 of 100

13 The municipal water utility shall submit the SWPP in written and electronic format to the local office of NSE. The SWPP shall be acceptable to NSE. The municipal water utility shall develop a schedule to implement the SWPP. The schedule shall outline the tasks (short-, medium-, and long-term) for implementing the recommended risk management strategies and monitoring program. The implementation plan shall be acceptable to NSE. The municipal water utility shall review the SWPP and implementation plan annually. The municipal water utility shall summarize the results of the annual review, using the checklist published by NSE, in the utility s annual report. Municipal water utilities shall have regard for source-specific issues that may warrant additional review when evaluating risks. Additional monitoring may be required to make science-based decisions. 9 of 100

14 4.0 Overview PART III - ADEQUATE TREATMENT AND DISTRIBUTION The second barrier in the multiple barrier approach used in Nova Scotia involves making water safe by having adequate treatment in place to remove natural or manmade contaminants and maintaining a high-quality distribution system. This is achieved by determining what contaminants are present in the water supply and installing adequate treatment methods to remove the contaminants, including disinfection to inactivate microorganisms. A high-quality distribution system is reliable, providing a continuous supply of potable water at adequate pressure. NSE has also adopted the Atlantic Canada Guidelines for the Supply, Treatment, Storage, Distribution and Operation of Drinking Water Supply Systems. These guidelines, and any additional technical details provided in Section 4.5 or Appendix C, shall be followed to standardize the design, approval, construction and operation of municipal drinking water systems in Nova Scotia. If there is a discrepancy between the treatment standards and the Atlantic Canada Guidelines, the more stringent shall apply. 4.1 Protection Against Pathogenic Organisms Protozoa and viruses can be responsible for severe, and in some cases, fatal gastro-intestinal illnesses. The goal of treatment is to reduce the presence of disease-causing organisms and associated health risks to an acceptable or safe level (Health Canada, 2004). Log reduction is a measure of the decrease of pathogenic organisms after treatment process. For example: 3-log reduction for protozoa means a 99.9% reduction in protozoa levels; 4-log reduction for viruses means a 99.99% reduction in virus levels. Log reduction may comprise two components: log removal by physical treatment - well operated filtration technology is assigned a removal credit towards reducing protozoa and virus levels as described in Section 4.1.2; log inactivation by disinfection - protozoa and virus inactivation levels are calculated using the disinfection concepts described in Section of 100

15 4.1.1 Minimum Treatment Requirements The municipal water utility shall ensure that the level of treatment provided to remove or inactivate pathogenic organisms is commensurate with the source type as outlined in the following sections. a) Surface Water For surface water sources, overall treatment requirements shall meet a minimum of 3-log reduction for protozoa (e.g. Cryptosporidium oocysts and Giardia cysts) and a minimum of 4-log reduction for viruses. Surface water treatment requirements shall be met by a combination of engineered filtration and disinfection. Filtration shall be assigned treatment credits as described in Section Disinfection shall provide a minimum of 0.5-log inactivation for Giardia. Where UV light is used for primary disinfection, chemical disinfection shall be required to meet log inactivation criteria for viruses as described in Section b) Groundwater Under the Direct Influence of Surface Water (GUDI) For GUDI sources, as classified by the Protocol for Determining Groundwater Under the Direct Influence of Surface Water (see Appendix A) and accepted as such in writing by the NSE regional hydrogeologist, overall treatment requirements shall meet a minimum of 3-log reduction for protozoa (e.g. Cryptosporidium oocysts and Giardia cysts) and 4-log reduction for viruses. High risk GUDI treatment requirements shall be met by a combination of engineered filtration and disinfection. Filtration shall be assigned treatment credits as described in Section Disinfection shall provide a minimum 0.5-log inactivation for Giardia. Where UV light is used for primary disinfection, chemical disinfection shall be required to meet log inactivation criteria for viruses as described in Section Medium risk GUDI treatment requirements shall be met by a combination of filtration and disinfection. Filtration may be via natural in-situ attenuation if the Guidelines for the Determination of Natural Filtration Log Removal Credit for Protozoa are followed (see Appendix B) and the NSE regional hydrogeologist accepts the determination in writing. In this case, UV disinfection shall be required to meet the remaining log reduction requirements for protozoa and chemical disinfection shall be required to meet log inactivation criteria for viruses as described in Section of 100

16 c) Non-GUDI For non-gudi sources, as classified by the Protocol for Determining Groundwater Under the Direct Influence of Surface Water (see Appendix A) and accepted as such in writing by the NSE regional hydrogeologist, overall treatment requirements shall meet a minimum of 4-log reduction for viruses; treatment requirements shall be met by disinfection. For water entering a distribution system from a non-gudi source, or the combined flow, turbidity levels shall not exceed 1.0 NTU: In at least 95% of the measurements by grab sampling for each calendar month (minimum frequency of one per day or more frequently if stated in the facility Approval to Operate); In at least 95% of the measurements made or 95% of the time each calendar month if continuous monitoring is the method of turbidity measurement. For systems experiencing elevated turbidity measurements related to well pump start-up, such as with air bubble formation, continuous monitoring recording may be delayed for up to 4 minutes, 59 seconds. However, it is recommended that all turbidity data be captured for trending purposes. For groundwater supplies that exceed 1.0 NTU for water entering a distribution system, a maximum of 5.0 NTU may be permitted if the owner demonstrates that the turbidity is non-health related and that the disinfection process is not compromised by the use of this less stringent value Treatment Credits for Filtration (Log Removal) Drinking water treatment technologies meeting the turbidity limits specified in Table 1 can apply the noted removal credits for Cryptosporidium, Giardia and viruses. Facilities that believe they can achieve a higher log credit than is automatically given, can be granted a log removal credit based on a demonstration of performance. For example, facilities with conventional or direct filtration that achieve 0.15 NTU 95% of the time each calendar month in combined filter effluent are eligible to receive an additional 0.5-log removal credit for protozoa. Facilities with conventional or direct filtration that achieve 0.15 NTU 95% of the time each calendar month in individual filter effluent are eligible to receive an additional 1.0-log removal credit for protozoa. 12 of 100

17 Table 1 - Log Removal Credits for Various Treatment Technologies Meeting Prescribed Turbidity Limits Treatment Technology Protozoa Credit Cryptosporidium Giardia 1 1 Virus Credit 1 Individual Filter Turbidity Limit (unless noted otherwise) 2 Conventional filtration - includes chemical mixing, coagulation, flocculation, clarification and rapid gravity filtration 2 Direct filtration - includes chemical mixing, coagulation, flocculation, and rapid gravity filtration 3.0-log 3.0-log 2.0-log Shall be less than or equal to 0.2 NTU in at least 95% of the measurements made or at least 95% of the time each calendar month. Shall not exceed 1.0 NTU at any time. 2.5-log 2.5-log 1.0-log Filter-to-waste until below 0.2 NTU - filters shall be capable of directing filtered water to waste im m ediately following a backwash for a period of time until the filtrate turbidity value is below NTU. Slow sand filtration 3.0-log 3.0-log 2.0-log Shall be less than or equal to 1.0 NTU in at least 95% of the measurements made or at least 95% of the time each calendar month. Shall not exceed 3.0 NTU at any time. Filter-to-waste - a filter-to-waste feature shall be provided so that the filtered water im mediately after filter cleaning is directed into a 3 waste stream. Diatomaceous earth filtration 3.0-log 3.0-log 1.0-log Shall be less than or equal to 1.0 NTU in at least 95% of the measurements made or at least 95% of the time each calendar month. Shall not exceed 3.0 NTU at any time. Filter-to-waste - a filter-to-waste feature shall be provided so that filtered water im m ediately after filter backwashing is directed into 3 a waste stream. Micro-filtration 4 Demonstration and challenge testing 5 No credit Shall be less than or equal to 0.1 NTU in at least 99% of the measurements made or at least 99% of the time each calendar month. If turbidity exceeds 0.1 NTU for more than 15 minutes, direct integrity testing shall be immediately conducted on the membrane treatment unit. 6 Shall not exceed 0.3 NTU at any time. Filter-to-waste - a filter-to-waste feature shall be provided for operational flexibility. 13 of 100

18 Treatment Technology Ultra-filtration 4 Reverse osmosis and nanofiltration Protozoa Credit Cryptosporidium Giardia 1 1 Demonstration and challenge testing 5 No credit until direct integrity testing is available Virus Credit 1 Removal efficiency dem onstrate d through challenge testing and verified by direct integrity testing No credit until direct integrity testing is available Individual Filter Turbidity Limit (unless noted otherwise) Shall be less than or equal to 0.1 NTU in at least 99% of the measurements made or at least 99% of the time each calendar month. If turbidity exceeds 0.1 NTU for more than 15 minutes, direct integrity testing shall be immediately conducted on the membrane treatment unit. 6 Shall not exceed 0.3 NTU at any time. Filter-to-waste - a filter-to-waste feature shall be provided for operational flexibility. Shall be less than or equal to 0.1 NTU in at least 99% of the measurements made or at least 99% of the time each calendar month. Shall not exceed 0.3 NTU at any time. Filter-to-waste - a filter-to-waste feature shall be provided for operational flexibility. Natural In-situ Attenuation for M edium Risk GUDI Sources log No credit Shall be less than or equal to 1.0 NTU in at least 95% of the measurements made or at least 95% of the time each calendar m onth at each individual GUDI wellhead. Continuous turbidity monitoring - required at each individual GUDI wellhead. M icroscopic Particulate Analysis - MPA testing is required every two years for each individual GUDI well, in spring following a rainfall. 8 Notes: 1. Disinfection shall provide a minimum 0.5-log inactivation for Giardia unless a higher log inactivation credit is required. Where disinfection is used to address any shortfall in the log reduction requirements for Cryptosporidium, an alternate disinfectant such as UV, chlorine dioxide or ozone shall be required. 2. Facilities with conventional or direct filtration that achieve 0.15 NTU 95% of the time each calendar month in combined or individual filter effluent are eligible to receive additional log removal credits for protozoa to meet minimum treatment requirements as follows: combined 0.5-log; individual 1.0-log. 3. Alternatives that demonstrate an equivalent benefit to filter-to-waste may be considered by NSE on a case-by-case basis for existing facilities. All new facilities shall include a filter-to-waste provision. 4. If membrane filtration is the sole treatment technology employed, disinfection shall follow the filtration process to meet virus inactivation requirements. 5. Membrane removal efficiency shall be demonstrated through challenge testing and verified by direct integrity testing. See Appendix C for additional information on membrane filtration. 6. If the unit passes direct integrity testing, it may continue to be used for water treatment; if not, the unit shall be taken out of service. 7. A natural in-situ attenuation log credit may be assigned if the Guidelines for the Determination of Natural Filtration Log Removal for Protozoa are followed (see Appendix B) and the NSE regional hydrogeologist accepts the determination in writing. 8. MPA testing shall be completed in accordance with Step 3 of the Protocol for Determining Groundwater Under the Direct Influence of Surface Water as outlined in Appendix A (e.g. if there is a 15 day time-of-travel, then the well shall be sampled 15 days after a surface water event). 14 of 100

19 For facilities that do not meet the individual filter effluent turbidity limits, the municipal water utility shall submit a corrective action plan outlining how they intend to meet the turbidity limits. The corrective plan shall be acceptable to NSE. Filtration processes shall be approved and meet industry accepted standards. In particular, filtration processes for pathogen reduction are required to be continuously monitored, and have a shut off feature and alarm when turbidity criteria are not achieved. Other considerations are outlined in Section Wells classified as non-gudi do not require treatment for protozoa because they are not under the direct influence of surface water; disinfection shall provide 4-log inactivation for viruses Disinfection Credits (Log Inactivation) Disinfection is responsible for inactivating any microbial pathogens that pass through previous unit processes. Disinfection shall provide any remaining log reduction credits necessary to meet the minimum treatment requirements specified in Section To determine the log inactivation portion that is necessary by disinfection involves a number of steps as follows: confirm the log reduction requirements (see Section 4.1.1); find the filtration log removal credits appropriate for the filtration system(s) employed (see Table 1 - for surface water and GUDI sources) and subtract this from the requirements specified in Section 4.1.1; determine if any additional filtration credits are available from enhanced performance (if applicable) and subtract this from the reminder above; the result is the log inactivation portion that shall be met by disinfection credits. Note: For surface water and high risk GUDI sources with engineered filtration, a minimum of 0.5-log inactivation for Giardia is to be provided by disinfection credits. Where disinfection is used to address any shortfall in the log reduction requirements for Cryptosporidium, an alternate disinfectant such as UV, chlorine dioxide or ozone shall be required. Where UV disinfection is used to inactivate protozoa, chemical disinfection shall be required to meet log inactivation requirements for viruses. 15 of 100

20 a) CT Concept for Chemical Disinfection Chemical disinfectants include free chlorine, chlorine dioxide and ozone. Due to the poor disinfecting capability of chloramines, they shall not be accepted as a primary disinfectant. In order to demonstrate that required disinfection credits are achieved, these treatment standards use the concept of the disinfection concentration (C) multiplied by the time that 10 percent of the water is in contact with the disinfectant (T 10). T10 is calculated by multiplying the theoretical hydraulic detention time (e.g. tank volume divided by flow rate) by the baffling factor of the contact chamber. T 10 may also be established by trace studies. This calculated value (i.e. CT achieved) is referenced to log inactivation tables for Cryptosporidium, Giardia and/or viruses first published by the US EPA (i.e. CT required). CT required can also be calculated from equation (for Giardia only) as outlined in Appendix D. CT tables for free chlorine, chlorine dioxide, and ozone are included in Appendix D. The science-based impacts of ph and temperature on the effectiveness of some disinfectants have been taken into account where applicable. To determine if a system meets the log inactivation requirements, the ratio of the calculated value (CT achieved) to the table value (CT required) must be equal to or greater than one. The CT calculation is based on the following equation: Formula: CT = Concentration (mg/l) x Time (minutes) x Baffling Factor Baffling factors are provided in Table 2. Examples of baffling factors to use for sample contact chamber designs are included in Appendix E. The baffling factor shall be acceptable to NSE. Typically, to ensure that different parameters and their effect on the disinfection process are addressed, design ranges are set for worst case scenarios that affect the primary disinfectant used for CT. For free chlorine, worst case design ranges typically include the following: Lowest temperature of the water to be disinfected. Highest ph value of the water to be disinfected with chlorine. Lowest chlorine residual found at the outlet of the designated chlorine contact volume. Minimum contact time (typically occurs under highest flow conditions). 16 of 100

21 For systems that include the volume in clearwell or on site storage tank for CT determination, the calculation shall be made based on the minimum operating level in the tank. The highest flow condition shall also be confirmed (e.g inflow or outflow). Note: Distribution system storage is not eligible for CT credits. Sample CT calculations are provided in Appendix F for various sources and treatment technologies. Where free chlorine is used, it is recommended that municipal water utilities minimize the formation of disinfection by-products. However, this should be done in consideration of operational requirements (e.g. water quality and quantity, distribution system residual, etc.) and without compromising the effectiveness of disinfection. Disinfection processes shall be approved and meet industry accepted standards. In particular, disinfection processes are required to be continuously monitored, and have a shut off feature and alarm when the equipment malfunctions as outlined in Section Other considerations are outlined in Section Table 2 - Baffling Factors Baffling Condition Baffling Factor T10/T Baffling Description Unbaffled (mixed flow) 0.1 Agitated basin Very low length-to-width ratio High inlet and outlet flow velocities High potential for stagnant zones and shortcircuiting Poor 0.3 Single or multiple unbaffled inlets and outlets No intra-basin baffles Potential for stagnant zones or short-circuiting Average 0.5 Baffled inlet or outlet Some intra-basin baffles Superior 0.7 Perforated inlet baffle Serpentine or perforated intra-basin baffles Outlet weir or perforated launders Most of tank volume is utilized Perfect (plug flow) 1 Length to width ratio greater than or equal to 10:1 Perforated inlet, outlet and intra-basin baffles 17 of 100

22 b) IT Concept for UV Disinfection In order to demonstrate that required disinfection credits are achieved, these treatment standards use the concept of the UV intensity (I) multiplied by the exposure time (T). The amount of UV light delivered to pathogens in a reactor is called UV dose and 2 is measured in millijoules per square centimetre (mj/cm ). The UV dose depends on: UV intensity, or magnitude of UV light, measured by UV intensity sensors in 2 2 Watts/cm or Watts/m. UV transmittance (UVT). Water flow rate and hydraulics in the reactor. Formula: 2 UV dose = UV intensity (Watts/cm ) x Time of exposure (seconds) 2 These treatment standards require a minimum UV dose (IT) of 40 mj/cm. The 2 minimum required UV dose of 40 mj/cm achieves greater than 4-log reduction for protozoa but only 0.5-log reduction for viruses (assuming adenovirus). Note: Where UV light is used for primary disinfection, chemical disinfection shall be required to meet log inactivation criteria for viruses. UV performance is highly dependent on water quality, flow rate, electrical power quality and other operational parameters. To receive inactivation credit, a UV reactor must operate within the validated limits (e.g. intensity is greater than the minimum specified, flow is below the maximum specified, UVT is above the minimum specified). UV systems are required to have a shut off feature and alarm when the equipment malfunctions, loses power or ceases to provide the appropriate level of disinfection as outlined in Section Other considerations are outlined in Section Protection Against Chemical Contaminants Disinfection By-Products Water that meets the maximum acceptable concentrations for the disinfection byproducts specified in Table 3 is considered safe for all domestic uses, including drinking, bathing, showering and food preparation. Municipal water utilities shall balance effective disinfection for microbial protection (see Section 4.1) against the creation of disinfection by-products. Municipal water utilities shall make every effort to maintain concentrations of disinfection by-products as low as reasonably achievable without compromising the effectiveness of primary disinfection. 18 of 100

23 Municipal water utilities are responsible for routinely determining disinfection byproduct levels. Trihalomethanes (THMs) and haloacetic acids (HAA5) shall be sampled on a quarterly basis at appropriate locations in the distribution system. It should be noted that sampling locations may differ for THMs and HAA5. This is because THMs continue to form from the chlorine injection point to the furthest location from the chlorine injection point; HAA5 on the other hand, may begin to decay at some point between the source and the furthest point from the source depending on the size of the distribution system. Once a compliance value is determined after a minimum of four quarterly samples have been analyzed at each sample location (i.e. locational running annual average), non-gudi groundwater supplies with THM and HAA5 concentrations less than 0.01 mg/l (10 µg/l) may request a reduction in sampling frequency to annual. Surface water and GUDI sources are not eligible for this reduction in sampling frequency; an increased sampling frequency may be required for facilities using surface water or GUDI sources during peak by-product formation periods. Other disinfection by-products shall be analyzed as appropriate based on the considerations noted in Table 3. Where results confirm that a maximum acceptable concentration has been exceeded, the municipal water utility shall notify NSE and develop a corrective action plan to remediate the situation. The corrective action plan shall be acceptable to NSE. Any municipal water utility changing coagulants or disinfectants to control disinfection by-product concentrations shall undertake a study, complete with a monitoring program, to confirm that no unintended consequences (e.g. release of heavy metals such as lead, antimony, etc.) will occur due to the process change. The study and monitoring program design shall be acceptable to NSE. If unintended consequences are found to occur, the municipal water utility shall take appropriate corrective action to remediate the situation. The corrective action shall be acceptable to NSE Guidelines for Canadian Drinking Water Quality Section 35 of the Water and Wastewater Facilities and Public Drinking Water Supplies Regulations, made pursuant to the Environment Act, requires that municipal water utilities meet the health-related Guidelines for Canadian Drinking Water Quality (GCDWQ). In their guidance to authorities responsible for providing drinking water on federal lands, Health Canada recommends that the full suite of health-related parameters be tested once every five years. As NSE follows Health Canada recommendations, municipal water utilities shall test for the full suite of health-related parameters at a minimum of once every five years for: untreated raw water from each source; and treated water. 19 of 100

24 The sampling frequency shall be enhanced for parameters that have detectable levels in raw water. Sampling frequency shall be acceptable to NSE. Where results confirm that a maximum acceptable concentration has been exceeded in treated water, the municipal water utility shall notify NSE and develop a corrective action plan to remediate the situation. The corrective action plan shall be acceptable to NSE. An exceedance of an aesthetic objective or operational guideline may also require a corrective action plan if found to compromise disinfection or other critical treatment processes Guidelines for Monitoring Public Drinking Water Supplies Section 33 of the Water and Wastewater Facilities and Public Drinking Water Supplies Regulations, made pursuant to the Environment Act, requires that municipal water utilities monitor water quality for the parameters listed in the Guidelines for Monitoring Public Drinking Water Supplies (GMPDWS). Surface water and GUDI supplies shall be monitored for these parameters once every year; non-gudi supplies shall be monitored, at a minimum, once every two years. Sampling locations shall include: untreated raw water from each source; and treated water. Where results confirm that a maximum acceptable concentration has been exceeded, the municipal water utility shall notify NSE and develop a corrective action plan to remediate the situation. The corrective action plan shall be acceptable to NSE. An exceedance of an aesthetic objective or operational guideline may also require a corrective action plan if found to compromise disinfection or other critical treatment processes. 20 of 100

25 Table 3 - Disinfection By-Products Requiring Monitoring by Municipal Water Utilities 7 Parameter M aximum Acceptable Concentration (mg/l) Considerations Sampling Frequency Sampling Location Bromate 0.01 Form s when ozone reacts with naturally-occurring brom ide Forms in sodium hypochlorite solutions that are not stored appropriately 1 Chlorate 1.0 By-product of chlorine dioxide Forms in sodium hypochlorite solutions that are not stored appropriately 1 Chlorite 1.0 By-product of chlorine dioxide Monthly m onitoring required by municipal water system s using ozone Monitoring required by m unicipal water system s that store solutions for more than three months A minimum of quarterly sampling is required by m unicipal water system s using chlorine dioxide as a disinfectant Monitoring required by m unicipal water system s that store solutions for more than three months A minimum of quarterly sampling is required by m unicipal water system s using chlorine dioxide as a disinfectant In treated water entering the distribution system In treated water entering the distribution system Mid-point and 2 far-point in the distribution system In treated water entering the distribution system Mid-point and 2 far-point in the distribution system Haloacetic Acids 0.08 (HAA5) 3 (80 µg/l) By-product of chlorine addition Running locational annual average based on a minimum of four quarterly samples 4 W here historical data show the highest HAA5 concentration 5 21 of 100

26 Parameter M aximum Acceptable Concentration (mg/l) Considerations Sampling Frequency Sampling Location N-Nitrosodimethylam ine (NDMA) (0.04 ìg/l) By-product of chloramination A minimum of quarterly sampling is required by m unicipal water system s using chloram ination In treated water entering the distribution system and farpoint in the 2 distribution system May be found in chlorinated system s with nitrogen or hum ic substances present in the source water Quarterly 6 In treated water entering the distribution system Trihalom ethanes 0.1 (THMs) 3 (100 µg/l) By-product of chlorine addition Running locational annual average based on a minimum of four quarterly samples 4 At the point in the distribution system with the highest potential 2 THM levels Notes: 1. Sodium hypochlorite solutions should be stored in a cool dry location away from sunlight where the temperature does not exceed 30Celsius. 2. Areas in the distribution system with the longest disinfectant retention time (e.g. typically farthest from chlorine injection site(s)). 3. Non-GUDI supplies with THM and HAA5 concentrations less than 0.01 m g/l (10 µg/l) m ay request a reduction in sam pling frequency to annual. 4. Increased frequency m ay be required for facilities using surface water or GUDI sources during peak by-product form ation periods. 5. W here historical data are not available, HAA5 concentrations shall be monitored in the middle and extremities of the distribution system. Areas where disinfectant residuals are significantly lower than the system average because of long residence tim e (e.g. dead end, low flow areas) shall be targeted. In system s with booster chlorination stations and water tanks/reservoirs, HAA5 concentrations shall be m onitored downstream of these com ponents. 6. Quarterly monitoring may be reduced to an annual frequency if the monitoring program consistently does not show the presence of NDMA in the treated water entering the distribution system. 7. Current to February 2012; other disinfection by-products to be added per updates to the Guidelines for Canadian Drinking W ater Quality. 22 of 100

27 4.3 Management of Waste Streams Waste streams from all treatment facilities shall be properly managed. Drinking water treatment processes produce the following waste streams: filter backwash water; filter backwash solids; clarifier solids. Membrane filtration technology produces other waste streams that shall be properly managed as outlined in Appendix C Filter Backwash Water Filter backwash water shall be discharged to an approved location. Filter backwash water shall not be discharged to the raw water inlet pumps or intake structures. If water from the filter backwash treatment system is discharged to the raw water reservoir/intake, it shall be at a location which is downstream of the raw water intake. When an existing facility already has a discharge upstream, the municipal water utility shall demonstrate no impact on raw water quality. Otherwise the municipal water utility shall develop a corrective action plan to remediate the situation. The corrective action plan shall be acceptable to NSE. a) Discharges into a Freshwater Watercourse Where filter backwash water discharges to a freshwater watercourse, the following discharge criteria shall apply: Maximum concentration of suspended solids shall not exceed 5 mg/l over naturally-occurring clear flow background watercourse concentrations. The naturally-occurring background concentrations in the watercourse shall be calculated as the 90th percentile value from a minimum of 12 monthly clear flow samples. Chlorine residual shall not exceed 0.02 mg/l. ph shall be in the range of 6.5 to 9.0. If it is not possible to achieve this ph range, the municipal water utility shall complete a study to determine background values and recommend end of pipe discharge criteria for ph. The study shall be acceptable to NSE. Discharge shall be non-acutely lethal with acute toxicity determined using Reference Method for Determining Acute Lethality to Rainbow Trout. 23 of 100

28 For metals, the following options for setting discharge criteria limits may be considered by the municipal water utility (listed in order of preference): i) Meet the limits set by the Canadian Council of Ministers of the Environment (CCME) Canadian Water Quality Guidelines for the Protection of Aquatic Life. ii) iii) iv) If naturally-occurring background concentrations of metals in the watercourse are higher than the values specified in the CCME Canadian Water Quality Guidelines for the Protection of Aquatic Life, NSE may allow discharge criteria limits to be set at the 90th percentile of the watercourse s background concentrations. A minimum of 12 monthly samples from the watercourse shall be required to establish background concentrations. If it is not possible to achieve the 90th percentile of background concentrations, NSE may allow a 10 percent increase above the 90th percentile. If it is not possible to achieve the 90th percentile plus 10 percent, the municipal water utility shall complete a study to recommend end of pipe discharge criteria limits. The study shall be acceptable to NSE. Discharge criteria limits shall be specified by NSE once the study has been reviewed. Consultation may be required with NSE, Environment Canada, and the federal Department of Fisheries and Oceans (DFO). Once discharge criteria limits have been set, the municipal water utility shall comply with the following: discharge criteria limits shall be met before discharging into the watercourse (i.e. end of pipe limits); discharge criteria shall be met in 95% of samples; sampling frequency shall be at least monthly or as required by NSE. It should be noted that membrane processes may concentrate naturally-occurring compounds such as metals, solids and radionuclides in the waste streams to levels above the CCME Water Quality Guidelines for the Protection of Aquatic Life. It is important that municipal water utilities with membrane facilities establish discharge criteria, particularly where aluminum is naturally-occurring in the source water. 24 of 100

29 b) Discharges into a Municipal Wastewater System Where backwash wastewater discharges into a municipal wastewater system, the municipal water utility shall: ensure capacity exists within the municipal wastewater system; contact NSE to determine if other requirements may apply. c) Discharges into a Marine or Brackish Environment Where backwash wastewater discharges into a marine or brackish environment, the municipal water utility shall contact NSE to determine what requirements shall apply. d) Discharges into a Non-Aquatic Environment Where backwash wastewater discharges into a non-aquatic environment, the municipal water utility shall contact NSE to determine what requirements shall apply Filter Backwash and Clarifier Solids Solids generated by the filter backwash and clarification processes (e.g. sedimentation or dissolved air flotation) shall be disposed in accordance with a solids disposal plan that has been prepared by the municipal water utility. The solids disposal plan shall be acceptable to NSE. 4.4 Water Distribution Systems The water distribution system is the final barrier before delivery to the consumer s tap. Even when the water leaving the treatment plant is of the highest quality, if precautions are not taken its quality can seriously deteriorate. In extreme cases, dangerous contamination can occur. A well-maintained distribution system is a critical component of a safe drinking water system. It is essential that municipal water utilities have adequate mechanisms in place so that their distribution systems can be properly maintained and renewed. Programs shall be in place to: monitor distribution system water quality (e.g. total coliforms and E. coli bacteria, chlorine residual, turbidity, ph, etc.); minimize corrosion and the release of lead; detect and deter cross-contamination from cross-connections, fire sprinkler systems, etc. 25 of 100

30 In addition, as part of the comprehensive distribution system program, municipal water utilities should have active programs to deal with threats to distribution system integrity, including but not limited to: pipe age, leaks, pressure transients, storage tanks, pumping stations. 4.5 Other Considerations Engineered Filtration for Pathogen Reduction In addition to the requirements outlined in Part III, the Atlantic Canada Guidelines for the Supply, Treatment, Storage, Distribution and Operation of Drinking Water Supply Systems and Appendix C, the following requirements apply in Nova Scotia: Engineered filtration for pathogen reduction is required for all surface water and high risk GUDI sources. A minimum of two filters (redundancy) is required. Where two filters are provided, each shall be capable of supplying the maximum day demand with the largest filter out of service. Where more than two filters are provided, the maximum day demand shall be met with the largest filter out of service. Conventional and direct filtration facilities shall filter-to-waste until turbidity is below 0.2 NTU. A filter-to-waste feature shall also be required for slow sand and diatomaceous earth filtration. Continuous on-line turbidity monitoring is required for individual filters with measurements taken at a minimum of once every five minutes. Filtration shall meet the turbidity limits set in Table 1 to receive the log removal credits noted in Table 1. Alarms shall be in place to alert staff when turbidity limits are not met. For membrane filtration, if turbidity exceeds 0.1 NTU for more than 15 minutes, direct integrity testing shall be immediately conducted on the membrane treatment unit. If the unit passes direct integrity testing, it may continue to be used for water treatment; if not, the unit shall be taken out of service. Standard operational procedures shall be developed for the filtration process. 26 of 100

31 4.5.2 Primary Disinfection for Pathogen Reduction In addition to the requirements outlined in Part III, the Atlantic Canada Guidelines for the Supply, Treatment, Storage, Distribution and Operation of Drinking Water Supply Systems and Appendix C, the following requirements apply in Nova Scotia: A minimum of two primary disinfection units (redundancy) is required at each treatment facility to ensure that inadequately disinfected water is not distributed. Where two disinfection units are provided, each shall be capable of meeting the maximum day demand flow. Where more than two disinfection units are provided, the maximum day demand flow shall be met with the largest unit out of service. Groundwater supplies with multiple wells may apply for system-wide redundancy. System wide redundancy means the disinfection unit at one well can act as the redundant unit for another well provided there is adequate system capacity to meet maximum day demand with the largest well out of service. Continuous on-line monitoring of the disinfection process is required at each treatment facility with measurements taken at a minimum of once every five minutes to ensure that inadequately disinfected water is not distributed. Disinfection equipment shall be operated in such a manner as to prevent inadequately disinfected water from being distributed. Water systems shall be equipped with alarm capabilities to notify operations staff if the disinfection process fails to operate properly. Acceptable primary disinfectants include: free chlorine, chlorine dioxide, ozone and UV. Chloramines shall not be accepted as a primary disinfectant. If sodium hypochlorite is used for primary disinfection, bromate and chlorate shall be monitored when solutions are stored for more than three months. If chlorine dioxide is used for primary disinfection, the process shall operate in such a manner as to ensure that the maximum chlorine dioxide dose is 1.2 mg/l. Chlorate and chlorite shall be monitored as disinfection by-products. If ozone is used for primary disinfection, bromate shall be monitored as a disinfection by-product. 27 of 100

32 If UV is used for primary disinfection, units shall provide a minimum dose of 2 40 mj/cm ; UV disinfection shall be followed by chemical disinfection to achieve log inactivation criteria for viruses. Additional requirements are described in Appendix C. Standard operational procedures shall be developed for the primary disinfection process. Municipal water utilities shall immediately notify NSE when operational conditions are outside the design ranges for the primary disinfection process. Municipal water utilities shall investigate the cause and take necessary corrective action. CT/IT shall be calculated during every such event Secondary Disinfection In addition to the requirements outlined in Part III, the Atlantic Canada Guidelines for the Supply, Treatment, Storage, Distribution and Operation of Drinking Water Supply Systems and Appendix C, the following requirements apply in Nova Scotia: Continuous on-line chlorine residual monitoring, with measurements taken at a minimal of once every five minutes, is required for the water entering the distribution system from the facility and leaving any water storage structure within the water distribution system. Grab sample monitoring of the distribution system chlorine residual is required on a weekly basis. Utilities shall use secondary disinfection to maintain an effective residual in the distribution system. Acceptable secondary disinfectants include free chlorine and chloramines. If free chlorine is used for secondary disinfection, the process shall be operated in such a manner as to ensure that a 0.20 mg/l minimum free chlorine residual is achieved throughout the water distribution system; the maximum free chlorine residual of water delivered to consumers is 4.0 mg/l. If chloramines are used for disinfection, the process shall be operated in such a manner as to ensure that a minimum of 1.0 mg/l combined chlorine residual is achieved throughout the water distribution system; the maximum combined chlorine residual of water delivered to consumers is 3.0 mg/l. 28 of 100

33 If chloramines are used for disinfection, free ammonia and nitrates/nitrites shall be monitored weekly. Municipal water utilities shall take necessary corrective action to address nitrification events. Corrective action shall be acceptable to NSE. If chloramines are used for disinfection, NDMA shall be monitored as a disinfection by-product. THMs and HAA5 shall be monitored as disinfection by-products. Any municipal water utility switching from free chlorine to chloramines to stabilize chlorine residual levels shall undertake a study, complete with a monitoring program, to confirm no unintended consequences will occur due to the switch in secondary disinfectant. The study and monitoring program design shall be acceptable to NSE. If unintended consequences are found to occur, the municipal water utility shall take appropriate corrective action to remediate the situation. The corrective action shall be acceptable to NSE. Municipal water utilities shall notify NSE whenever the distribution system chlorine residual is lower than the stipulated level and take corrective action as necessary to restore the chlorine residual to required levels. Corrective action shall be acceptable to NSE. 29 of 100

34 PART IV - OPERATIONS, MONITORING, REPORTING AND MANAGEMENT 5.0 Overview The final stage in the multi-barrier approach is proving that the drinking water is safe through effective operations, monitoring, reporting and management. All municipal water utilities are encouraged to publicly report their water quality results to their consumers. 5.1 Operations Manual Municipal water utilities shall prepare a comprehensive operations manual that includes: Standard Operational Procedures; Emergency Notification Procedures; Contingency Plans. The municipal water utility shall review and update the contingency plans and emergency notification procedures annually and ensure that the operations manual is kept up to date. A copy of the operations manual is to be kept on site at all times and is to be available for review immediately upon request by NSE. All employees shall be apprised of the operations manual. Municipal water utilities should refer to the guidance document published by NSE on developing a comprehensive operations manual for minimum requirements. 5.2 Monitoring and Recording Methods for monitoring and recording are to be carried out as per the requirements of the Water and Wastewater Facilities and Public Drinking Water Supplies Regulations, made pursuant to the Environment Act, and the Guidelines for Monitoring Public Drinking Water Supplies. Municipal water utilities shall monitor and sample in accordance with their annual monitoring program to demonstrate that Section 35 of the Water and Wastewater Facilities and Public Drinking Water Supplies Regulations is being met. The annual monitoring program shall include: compliance monitoring, including QA/QC requirements; process monitoring; response monitoring; special process characterization and optimization monitoring (if applicable); source water characterization monitoring. 30 of 100

35 The monitoring program shall be acceptable to NSE. Municipal water utilities should refer to the guidance document published by NSE on developing an annual sampling plan for minimum requirements. 5.3 Reporting Requirements Municipal water utilities are responsible for complying with all terms and conditions of their operating approval. This includes immediate, annual and ad hoc reporting functions as outlined in Appendix G. There are also requirements to provide information upon request or for inspection/review as outlined in Appendix G. 5.4 Management Classified water treatment and water distributions facilities shall be operated by certified operators in accordance with the Water and Wastewater Facilities and Public Drinking Water Supplies Regulations, made pursuant to the Environment Act. Municipal water utilities are responsible for meeting the terms and conditions of their Approval to Operate. A thorough, well-thought-out due diligence program for managing water-related risks and meeting public expectations can help meet these responsibilities. Municipal water utilities should refer to the guidance document entitled Safe Drinking Water Systems: A Diligent Approach, as published by NSE for more information. 31 of 100

36 PART V - GLOSSARY AND REFERENCES 6.0 Glossary Average day demand means the average amount of water necessary in a 24-hour timeframe to meet all needs of all customers. It is determined by dividing annual usage by the total number of days in the year. Contact time denoted as T 10 is an effective contact time for disinfection in minutes and represents the time when 10 percent of the water passes the contact unit; that is 90 percent of the water remains in the unit and will be exposed to longer disinfection within the unit. T 10 can be established by tracer studies or calculated using theoretical hydraulic detention times multiplied by an appropriate baffling factor. Conventional filtration means a treatment process that includes chemical mixing, coagulation, flocculation, clarification (sedimentation or dissolved air flotation) and rapid gravity filtration. All filters should be designed so that the filtered water immediately after filter backwashing is directed into a waste stream ( filter-to-waste provision). Cryptosporidium means a widespread intestinal coccidian protozoan parasite about 3.5 micrometres in diameter, causing diarrhea and capable of infecting humans, birds, fish and snakes. It is responsible for waterborne disease outbreaks. Diatomaceous earth means the microscopic remains of the discarded outer surface of diatoms. Diatomaceous earth filtration means a filtration method on which diatomaceous earth is used as the filtering medium. Direct filtration means a treatment process that includes chemical mixing, coagulation, flocculation and rapid gravity filtration (e.g. no clarification process). All filters should be designed so that the filtered water immediately after filter backwashing is directed into a waste stream ( filter-to-waste provision). Disinfectant means an agent that destroys or inactivates harmful microorganisms. Disinfection means the process of destroying or inactivating pathogenic organisms by either chemical or physical means. Disinfection by-products means the chemical by-products that are formed when a disinfectant reacts with organic matter in the water. 32 of 100

37 Filtrate means the liquid that has passed through a filter. Filtration means the removal of suspended materials in a fluid stream by passage of the fluid through a filter medium. Filter-to-waste means a practice of discharging filtered water directly to disposal immediately following backwashing until the filtered water is of acceptable quality. Giardia means the genus name for a group of single-celled, flagellated, pathogenic protozoans found in a variety of vertebrates, including mammals, birds and reptiles. These organisms exist either as trophozoiles or as cysts, depending on the stage of the life cycle. Giardia lamblia means the species of Giardia that is a common cause of human diarrheal disease. Log reduction means a negative of the base 10 logarithm of the fraction of pathogens remaining after the treatment process. Maximum day demand means the highest daily use rate during the year. Membrane filtration means a filtration process that uses pressure-driven semipermeable membranes to reject particles and produce a filtrate. The most appropriate type of membrane depends on a number of factors including targetted material to be removed, source water quality characteristics, treated water quality requirements, membrane pore size, molecular weight cut-off, membrane material and system configuration. A filter-to-waste feature should be provided for initial start-up and commissioning of the membrane system and for emergency diversions in the event of a membrane integrity breach. Municipal drinking water system means a public drinking water supply that holds a municipal water works approval issued under the Activities Designation Regulations, made pursuant to the Environment Act, for the collection, production, treatment, storage, supply or distribution of potable piped water to the public. Municipal wastewater system means a municipality owned or operated facility for the collection, treatment and release of wastewater. Municipal water utility means a utility owned, operated or managed by a municipality, village or service commission either directly or through a board or commission, for the purpose of producing, transmitting, delivering or furnishing water directly or indirectly to or for the public. Natural attenuation means the attenuation of particles through in-situ soil, filtration or adsorption prior to a location from which the water is withdrawn (e.g. through a well). 33 of 100

38 Natural watershed boundary means the area drained by or contributing to a stream, lake or other body of water. It is the area that topographically appears to contribute all the water that passes through a given cross-section of a stream. Topography is the change in height of land relative to sea level. Peak hourly demand means the highest hourly use rate during the year; it is typically two to four times the average day flow and is generally supplied from storage tanks. Redundancy means a minimum of two process units shall be provided (e.g. two filters, two primary disinfection units, two pumps, etc.). Where only two process units are provided, each shall be capable of meeting the maximum day demand at the unit s rated capacity. Where more than two process units are provided, the process shall be capable of meeting maximum day demand with the largest unit out of service. Slow sand filtration means filtration that depends on the formation of schmutzdecke, which is a layer of bacteria, algae and other microorganisms on a biopopulation within the sand bed. Raw water passes through the sand bed where physical, chemical and biological mechanisms remove contaminants. The most important removal mechanism has been attributed to the biological process. No chemicals are added nor is there a need to backwash. The filter is cleaned by scrapping off the clogged sand and eventually replacing the sand. A filter-to-waste feature should be provided so that the filtered waste immediately after filter cleaning is directed into a waste stream. Time-of-travel means the determination, usually by modeling, of the time in years for groundwater recharge to travel from a certain field point to the wellhead. In Nova Scotia, three time-of-travel zones are recommended, including a 2-year zone, 5-year zone, and 25-year zone. The 2-year zone is the smallest zone. This zone is used to protect against microbial contaminants such as bacteria and viruses. The 5-year zone is used to protect against chemical contaminants such as petroleum contaminants and persistent mobile contaminations. The 25-year zone is the largest zone. This zone is used to protect against chemical contaminants such as chlorinated solvents, nitrates and road salt. The three zones are also used to define the source water protection area. The outer boundary of the 25-year zone - the largest zone - sets the boundary for the source water protection planning process. 34 of 100

39 7.0 References Alberta Environment Standards and Guidelines for Municipal Waterworks, Wastewater and Storm Drainage Systems. Edmonton, AB. American Water Works Association Guidance Manual for Compliance with the Filtration and Disinfection Requirements for Public Water Systems Using Surface Water Sources. Denver, CO: AWWA. American Water Works Association The Drinking Water Dictionary. Denver, CO: AWWA. Andrews Hofmann and Associates Lecture notes from the ACWWA course entitled Optimizing Disinfection for the Control of Pathogens, Halifax, NS, May 14-15, AWWARF and U.S. Environmental Protection Agency Integrated Membrane Systems. Denver, CO and Washington, DC : AWWA. Bartram, J., Corrales, L., Davison, A., Deere, D., Drury, D., Gordon, B., Howard, G., Rinehold, A., Stevens, M Water Safety Plan Manual: Step-by-step risk management for drinking-water suppliers. Geneva : World Health Organization. Bolton, James R., and Christine A. Cotton The Ultraviolet Disinfection Handbook. Denver, CO: American Water Works Association. Canadian Council of Ministers of the Environment (CCME) Water Quality Guidelines for the Protection of Aquatic Life. Winnipeg, MB: CCME. Canadian Water Works Association Canadian Guidance Document for Managing Drinking Water Systems: A Risk Assessment/Risk Management Approach. Ottawa, ON: CWWA. CBCL Limited Atlantic Canada Guidelines for Supply, Treatment, Storage, Distribution, and Operation of Drinking Water Supply Systems. Coordinated by Atlantic Canada Water Works Association in association with the four Atlantic Provinces. Craun G.F., and Calderon R.L Observational epidemiologic studies for endemic waterborne risks: cohort, case-control, time-series, and ecologic studies. Journal of Water Health 4 (2): Ernst, Caryn Protecting the Source: Land Conservation and the Future of America s Drinking Water. San Francisco, CA: Trust for Public Land ; Denver, CO: American Water Works Association. 35 of 100

40 Great Lakes - Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers Recommended Standards for Water Works. Albany, NY: Health Education Services. Hartnett, E., McFadyen, S., Douglas, I., Robertson, W., and Paoli, G. Quantitative microbiological risk assessment: New tools to assess and manage risks from pathogens in drinking water. Proceedings from the Water Quality Technology Conference, AWWA. Charlotte, NC, November 4-8, Health Canada From Source to Tap: The multi-barrier approach to safe drinking water. Ottawa, ON Guideline for Canadian Drinking Water Quality: Supporting Documentation - Turbidity. Ottawa, ON Guideline for Canadian Drinking Water Quality: Supporting Documentation - Enteric Viruses. Ottawa, ON Guideline for Canadian Drinking Water Quality: Supporting Documentation - Protozoa: Giardia and Cryptosporidium. Ottawa, ON Guidance for Providing Safe Drinking Water in Areas of Federal Jurisdiction. Ottawa, ON Guideline for Canadian Drinking Water Quality - Enteric Protozoa: Giardia and Cryptosporidium (Document for Public Comment). Ottawa, ON Guideline for Canadian Drinking Water Quality - Enteric Viruses (Document for Public Comment). Ottawa, ON Guideline for Canadian Drinking Water Quality - Turbidity in Drinking Water (Document for Public Comment). Ottawa, ON. Hrudey, Steve E., and Hrudey, Elizabeth J Safe Drinking Water - Lessons from Recent Outbreaks in Affluent Nations. London, UK: IWA Publishing. Job, C. A Benefits and Costs of Protection. Groundwater Monitoring and Remediation 16(2): Laing, Robert D Report of the Commission of Inquiry into matters relating to the safely of the public drinking water in the City of North Battleford, Saskatchewan. Regina, SK: Queen s Printer. Manitoba Water Stewardship Drinking Water Quality Standards Regulations. Winnipeg, MB. 36 of 100

41 Martin, Peter Calculating C x T Compliance. Journal AWWA. 85(12):12. O Connor, Dennis R. 2002a. Part One: Report of the Walkerton Inquiry: The Events of May 2000 and Related Issues. Toronto, ON: Ontario Ministry of the Attorney General. O Connor, Dennis R. 2002b. Part Two: Report of the Walkerton Inquiry: A Strategy for Safe Drinking Water. Toronto: ON: Ontario Ministry of the Attorney General. Ontario Ministry of the Environment Drinking Water Systems Regulations. Public Safety Canada Canadian Disaster Database - Epidemic: Walkerton, O N, h t t p : / / w w 5. p s - s p. g c. c a / r e s / e m / c d d / d e t a i l s - en.asp?dis= &haz=ep&title=epidemic:%20walkerton%20on,% Quebec Department of Sustainable Development, Environment and Parks Design Guidelines for Drinking Water Production Facilities. Reynolds K.A., Mena K.D., and Gerba, C.P Risk of waterborne illness via drinking water in the United States. Reviews of Environmental Contamination and Toxicology 192: Saskatchewan Environment The Water Regulations. Scottish Government The Cryptosporidium (Scottish Water) Directions. United States Environmental Protection Agency Surface Water Treatment Rule. Washington, DC: Office of Water a. Why Do Wellhead Protection - Issues and Answers in Protecting Public Drinking Water Supply Systems. EPA 813-K Washington, DC: Office of Water b. Benefits and Costs of Prevention: Case Studies of Community Wellhead Protection. Volume 1: USEPA 813-B Washington, DC: Office of Water Disinfection Profiling and Benchmarking Guidance Manual. Washington, DC: Office of Water Alternative Disinfectants and Oxidants Guidance Manual. Washington, DC: Office of Water. 37 of 100

42 Guidance Manual for Sanitary Survey of Public Water Systems for Surface water and GWUDI. Washington, DC: Office of Water Interim Enhanced Surface Water Treatment Rule. Washington, DC: Office of Water National primary drinking water regulations: Long term 2 enhanced surface water treatment: proposed rule Membrane Filtration Guidance Manual. Washington, DC: Office of Water Long Term 2 Enhanced Surface Water Treatment Rule. Washington, DC: Office of Water UV Disinfection Guidance Manual: For the Final LT2ESWTR. Washington, D.C: Office of Water. 38 of 100

43 APPENDIX A - PROTOCOL FOR DETERMINING GROUNDWATER UNDER THE DIRECT INFLUENCE OF SURFACE WATER 39 of 100

44 SUMMARY OF GUDI ASSESSMENT PROCESS GUDI is an acronym for Groundwater Under the Direct Influence of surface water. It refers to situations where microbial pathogens can travel from surface water through an aquifer to a water well. The purpose of this document is to provide a process for determining whether a water well is GUDI or non-gudi. The Nova Scotia GUDI assessment process consists of three steps. The steps are shown on the flow chart in Figure A.1 and are summarized below. For wells that complete all three steps, the process can take up to two years because of the sampling and monitoring requirements under Steps 2 and 3. Step 1 is a screening step used to rapidly identify obvious non-gudi wells based on available information. Step 1 considers four evaluation criteria: 1) the sensitivity of the well and aquifer setting; 2) the distance from the well to the nearest surface water body; 3) the well construction; and 4) the raw well water quality. A well can be classified as non-gudi if it satisfies all of these four criteria (details on criteria evaluation are provided in Section A.2 of this appendix). If the well does not meet these criteria, it fails Step 1 and proceeds to Step 2. Step 2 is used to determine if there is a hydraulic connection through the aquifer that could allow rapid recharge of the well by surface water. Rapid recharge is defined as recharge that occurs between the well and surface water with a travel time of 90 days or less. Step 2 includes a review of available hydrogeologic information and one year of water quality monitoring at the wellhead and a nearby surface water body. At a minimum, the monitoring shall include weekly temperature and electrical conductivity measurements. If no hydraulic connection is identified between the well and surface water that could allow recharge within 90 days, the well can be classified as non-gudi. If a hydraulic connection is identified that could allow recharge from surface water within 90 days, the well fails Step 2 and proceeds to Step 3. Step 3 is used to determine if there are surface water particulates (e.g., insects, organic debris, etc.) present in the well that indicate it has been influenced by surface water. This is done using a laboratory test called the Microscopic Particulate Analysis (MPA). The results from Step 2 are needed to determine when the MPA samples should be collected. A minimum of two MPA samples are required. The MPA test results are used to determine if the well has a low, medium or high risk of being influenced by surface water. Wells that have low risk MPA results can be classified as non-gudi. Wells that have medium or high risk MPA results are classified as GUDI. 40 of 100

45 Figure A.1: GUDI Assessment Flow Chart 41 of 100

46 A.1 INTRODUCTION GUDI is an acronym for Groundwater Under the Direct Influence of surface water. It refers to groundwater sources (e.g., wells, springs, infiltration galleries, etc.) where microbial pathogens are able to travel from surface water to the groundwater source. The purpose of this document is to provide a process for determining whether or not a groundwater source is GUDI, where GUDI is defined as (U.S.EPA, 1991): any water beneath the surface of the ground with: i) significant occurrence of insects or other macro-organisms, algae, organic debris, or large-diameter pathogens such as Giardia lamblia or Cryptosporidium; or ii) significant and relatively rapid shifts in water characteristics such as turbidity, temperature, conductivity, or ph which closely correlate to climatological or surface water conditions. Part (i) of the definition is aimed at determining if there are particulates present in the well that are indicative of surface water. This may be determined using Microscopic Particulate Analysis (MPA) which analyzes for significant numbers of large macro-organisms, algae and surrogate indicators of surface water. Part (ii) of the definition is aimed at establishing whether there is a hydraulic connection between the groundwater source and surface water. This implies that if groundwater is rapidly recharged by surface water, then microbial pathogens can enter the groundwater source. The GUDI assessment process described in this document is based on guidance provided by U.S.EPA (1991), AWWA (1996), AWWA (2001) and the Ontario MOE (2001). The process consists of three steps, beginning with a screening step that provides a method to rapidly identify obvious, non-gudi sources (i.e., true groundwater) that do not require a detailed investigation. Sources that fail Step 1 shall proceed to Step 2 to determine if there is a hydraulic connection which allows rapid recharge between the groundwater source and surface water. If there is no hydraulic connection identified in Step 2, the source can be classified as non-gudi. If a hydraulic connection exists, Step 3 shall be completed to determine if there are particulates present in the groundwater source that are indicative of surface water. A flow chart showing the GUDI assessment process is presented in Figure 1 and explanation of each step is provided in Section A.2 of this appendix. GUDI assessments shall be carried out by, or under the supervision of, a qualified hydrogeologist which is defined here as a person with hydrogeology training and experience, and licenced to practice in Nova Scotia by APGNS or APENS. 42 of 100

47 A GUDI assessment shall be completed for each well in a wellfield and each well shall be classified as either GUDI or non-gudi. This also means that when water quality data is collected under Step 2 and Step 3 of the GUDI assessment (e.g., temperature, conductivity, MPA tests, etc.), the samples shall be collected from each individual well, not from a point in the distribution system where water has already been mixed with water from other sources. A.2 GUDI ASSESSMENT PROCESS A.2.1 Step 1 The objective of this step is to identify obvious non-gudi sources that do not need further investigation. The screening step will normally involve a file search, review of well construction details and a site visit. If the well passes Step 1 it can be classified as non-gudi; if it fails Step 1 it shall proceed to Step 2. For a groundwater source to be considered non-gudi it shall satisfy all of the four criteria listed below. If it does not meet these criteria, it fails Step 1 and proceeds to Step Sensitive settings - the well shall not fall into any of the following categories: spring, infiltration gallery, horizontal collection well, wells in karst aquifers, unconfined aquifers and wells that are part of an enhanced recharge/infiltration project. 2. Proximity to surface water - the well shall be greater than 60 metres from the nearest intermittent or permanent surface water body (i.e., a surface water body is defined as water open to the atmosphere and subject to surface runoff, such as ponds, lakes, wetlands, lagoons, reservoirs, estuaries, rivers, streams, brooks, ditches). 3. Well construction - the well shall meet the current Well Construction Regulations; the casing shall extend at least 12 metres below ground surface; and the well shall have a drive shoe, wellhead and annular seal that will prevent surface water from entering the well and prevent water from migrating within the annular space. 4. Water quality - there shall be no confirmed record of total coliforms or E. coli bacteria in untreated samples collected over three years. Confirmed means the result was verified by re-sampling. If a well fails Step 1 due to well construction issues, modifications can be made to the well so it meets the screening criteria. If after the modifications are made the well still fails the screening criteria, then Step 2 shall be completed. Note that if well construction improvements are planned, they shall be completed prior to proceeding to Step 2 because changes to the well may affect the results of Step of 100

48 If the well will fail Step 1 because bacteria was detected in a single sample, additional sampling shall be carried out to confirm whether or not bacteria is regularly present. A minimum of four additional bacteria samples shall be collected, one per month. If any of these additional samples contain bacteria the well shall fail Step 1, unless subsequent corrective action and sampling demonstrate the well does not regularly contain bacteria. A.2.2 Step 2 The objective of Step 2 is to determine if there is a hydraulic connection that could allow rapid recharge of the well by precipitation or surface water. Rapid recharge is defined as recharge that occurs between the well and surface water with a travel time of 90 days or less. Step 2 shall include the collection of one year of water quality data (temperature, electrical conductivity) and a review of available hydrogeologic information. Additional hydrogeologic data may also be collected if the review of available data indicates there is insufficient information to determine if a hydraulic connection is present. Raw water quality data shall be collected at the well and a nearby surface water body for a period of one year to determine if there is a close relationship between changes in the surface water quality and the well water quality. Patterns are best recognized from one-year hydrographs; however, a shorter time may be sufficient if a hydraulic connection is recognized early in the monitoring program. Water quality parameters shall include, but not necessarily be limited to, temperature and electrical conductivity. Temperature and conductivity measurements shall be measured on a weekly basis at a minimum, however, hourly or daily measurements collected with a datalogger are recommended. The water quality data shall be plotted and the graphs inspected for rapid changes and obvious similarities between surface water and groundwater. The time lag between peaks or inflection points of the surface water and groundwater temperature and conductivity graphs shall be used to estimate the time-of-travel. The well is considered rapidly recharged if the time-of-travel is less than 90 days. If there is no surface water body located within 500 metres of the wellhead, precipitation data shall be used for comparison to the groundwater temperature and conductivity data. A rainfall gauge shall be used at the well site to measure precipitation. The precipitation records from an Environment Canada climate station can be used in lieu of an on-site rainfall gauge if the climate station is located within 20 km of the wellhead. 44 of 100

49 The hydrogeologic information review shall be used to assess whether there is potential for a hydraulic connection and to estimate the time-of-travel between the well and surface water. The review shall include, but not be limited to, an evaluation of the following: well characteristics (well depth, casing depth, annular seal, etc.); aquifer characteristics (aquifer type, confining layers, unsaturated zone thickness, hydraulic conductivity, effective porosity, depth to water bearing zones, the degree of connection between the surface water and aquifer - does the surface water body penetrate the aquifer?); hydraulic gradient (vertical gradient under pumping conditions, horizontal gradient between the well and the surface water body under pumping conditions, variation of static water level and surface water level with time, variation of static water level with precipitation); surface water features; and groundwater quality and flow (time-of-travel between the surface water and well). At the end of Step 2 it shall be determined if there is a hydraulic connection that could allow rapid recharge of the well by surface water within 90 days. If there is no such hydraulic connection, the well passes Step 2 and can be classified as non- GUDI. If there is a hydraulic connection that could allow recharge within 90 days, then the well fails Step 2 and shall proceed to Step 3. A.2.3 Step 3 The objective of Step 3 is to determine if there are significant particulates present in the well that are indicative of surface water. This is determined using Microscopic Particulate Analysis (MPA) in accordance with the method described in U.S. EPA, 1992, or an alternative method approved in writing by NSE. A minimum of two MPA samples shall be collected. The samples are to be collected during periods when there is the greatest probability that surface water is impacting groundwater. The results from Step 2 shall be used to help select the most appropriate MPA sampling times (e.g., if there is a 15 day time-of-travel, then the well shall be sampled 15 days after a surface water event). It is recommended that one sample be collected in the spring after a heavy rainfall (25-50 mm) or snow melt and one be collected in the fall after a prolonged dry period. 45 of 100

50 The MPA scores shall be evaluated based on the risk factors specified by the U.S. EPA (1992) as follows: low risk = MPA score < 10 medium risk = MPA score 10 to 19 high risk = MPA score >20 Wells that have low risk MPA scores for both samples can be classified as non- GUDI. If any of the MPA samples fall into the medium or high risk categories the well shall be classified as GUDI unless remedial action and/or further sampling demonstrates otherwise. If remedial action is completed, the well may be reclassified if Step 3 is repeated and the results show the well is low risk. However, prior to proceeding with remedial action the utility shall obtain written approval of their approach from the NSE regional hydrogeologist. In evaluating this request, the NSE regional hydrogeologist will consider the likelihood that remedial action will be effective, as per the guidance on the modification of sources in US EPA (1991). MPA results shall be submitted to NSE complete with a qualified hydrogeologist s report that documents the timing of the MPA sample collection relative to weather events and confirms that it corresponds to a period in which there is the greatest probability that surface water is impacting groundwater in the sampled well as described above. A.3 GUDI CLASSIFICATION The final determination of whether a well is GUDI or non-gudi shall be based on all the evidence collected. Wells that have no evidence of existing or potential hydraulic connection with surface water shall be classified as non-gudi, and wells that have a hydraulic connection with a medium or high risk MPA score shall be classified as GUDI. If a water well is declared GUDI at any point in the process, the additional investigation steps are not required. 46 of 100

51 A.4 REFERENCES American Water Works Association (AWWA) Determining Groundwater Under the Direct Influence of Surface Water. American Water Works Association (AWWA) Investigation of Criteria for GWUDI Determination. Ontario Ministry of the Environment (MOE) Terms of Reference, Hydrogeological Study to Examine Groundwater Sources Potentially Under Direct Influence of Surface Water. October U.S. Environmental Protection Agency (U.S.EPA) Guidance Manual for Compliance with the Filtration and Disinfection Requirements for Public Water Systems Using Surface Waters. U.S. Environmental Protection Agency, Office of Drinking Water. March U.S. Environmental Protection Agency (U.S.EPA) Consensus Method for Determining Groundwater Under the Direct Influence of Surface Water Using Microscopic Particulate Analysis (MPA). U.S. Environmental Protection Agency. EPA 910/ October of 100

52 APPENDIX B - GUIDELINES FOR THE DETERMINATION OF NATURAL FILTRATION LOG REMOVAL CREDIT FOR PROTOZOA 48 of 100

53 B.1 Introduction Municipal groundwater systems that have been determined to be Groundwater Under the Direct Influence of surface water (GUDI) shall meet the following treatment requirements: protozoa: 3-log reduction; viruses: 4-log reduction. Depending on the level of surface water influence, the system may be eligible for a 1.0-log natural filtration credit towards the protozoa log reduction requirements. The combination of a natural filtration credit and UV disinfection may be used to meet the 3-log reduction requirements for protozoa. Natural filtration refers to the ability of an aquifer to remove microscopic particulates, such as Giardia and Crytosporidium, as groundwater migrates through the aquifer towards a water well. Natural filtration is most appropriately applied as one component of a treatment process and is best suited to systems with minimal influence of surface water. The purpose of this appendix is to outline the criteria for determining which groundwater systems in Nova Scotia are eligible for a natural filtration log removal credit for protozoa and describe how to apply for this credit. B.2 Eligible Groundwater Systems Municipal groundwater systems are eligible for a natural filtration log removal credit if they meet all of the following three conditions: 1. All three steps of the Protocol for Determining Groundwater Under the Direct Influence of Surface Water (GUDI Protocol - see Appendix A) have been completed; 2. The supply has been determined to be GUDI; 3. The supply has been determined to be medium risk based on the Microscopic Particulate Analysis (MPA) results from Step 3 of the GUDI Protocol (see Appendix A). Municipal groundwater systems are not eligible for a natural filtration credit if they are located in karst aquifers or have been determined to be high risk based on MPA testing. 49 of 100

54 B.3 Criteria for Awarding a Natural Filtration Credit Natural filtration log removal credits will be awarded by (NSE) to eligible systems on a case-by-case basis. To be considered for a natural filtration credit, medium risk GUDI systems are required to perform at least one additional MPA test to confirm the original MPA results collected during Step 3 of the GUDI study. The additional MPA test shall be collected when the well is most susceptible to surface water influence, such as in the spring after a heavy rainfall or snow melt. The results from Step 2 of the GUDI Protocol shall be used to help select the most appropriate MPA sampling times (i.e., if there is a 15 day time-oftravel from the surface water body to the well, then the well should be sampled 15 days after a surface water event). Although not mandatory, testing for Giardia and Cryptosporidium is also recommended to assess surface water influence. Check with your laboratory to see if Giardia and Cryptosporidium tests can be done during the MPA test. If the results of the additional MPA testing confirm the system is medium risk, the system is eligible for a natural filtration credit. If the results indicate that the system is high risk, the system is not eligible for a natural filtration credit. All medium risk GUDI systems will receive a 1.0 log removal credit for protozoa, unless there are site-specific reasons that indicate a natural filtration log removal credit should not be awarded. Site specific issues that will be considered when awarding a natural filtration credit include, but are not limited to: raw water turbidity data; the well head should not lie within the 100 year floodplain of a surface water body; and, the well should not be located within 60 metres of a stream that has the potential for stream channel erosion which could reduce the degree of natural filtration over time. B.4 How to Apply for a Natural Filtration Credit To be awarded a natural filtration credit, eligible groundwater systems shall apply in writing to the NSE district office where the water system is located. The written request shall include the following information for each well: G G G G Water supply name; Well name and map showing well location; Confirmation that the well has completed the GUDI Protocol and it has been classified as a medium risk GUDI well; Confirmation that the well is not located in a karst aquifer (based on geological maps and well log information); 50 of 100

55 G G G G Results from an additional MPA test, taken after the GUDI Protocol MPA samples, to confirm the well is medium risk; Raw water turbidity data (if turbidity data exceed 1.0 NTU, provide raw water bacteria data); Confirmation that the well is not located within a 100 year floodplain, this can be done using existing information such as flood maps, local historical knowledge and air photos; (information on how to obtain existing floodplain mapping for some areas of the province is available at the following website: and Confirmation that the well is not located within 60 metres of a surface water body that has the potential for stream channel erosion. Note that the potential for stream channel erosion can be evaluated by examining the history of high-flow and flood events at the site and by reviewing air photographs for evidence of stream channel meander. Information submitted shall be complete and acceptable to NSE. The applicant will receive a written response from NSE indicating whether or not a natural filtration credit shall be awarded. Systems that are awarded a natural filtration credit shall be required to complete a MPA test every two years to confirm the well is not high risk and submit results to NSE to maintain the credit. If ongoing MPA monitoring indicates the well has become high risk, systems shall be required to take corrective action, such as modifying the well construction or providing additional filtration treatment. 51 of 100

56 APPENDIX C - TECHNICAL CONSIDERATIONS FOR FILTRATION AND DISINFECTION PROCESSES 52 of 100

57 C.1 Ultraviolet (UV) Light Disinfection The use of UV disinfection systems for water treatment is becoming more common in Nova Scotia. UV dose delivery depends on a number of factors including reactor design (hydrodynamics), flow rate, UV transmittance of water, UV intensity, lamp output, lamp placement, aging, fouling and microbe inactivation kinetics. A safety factor is added to establish a design dose and is established through UV validation. UV validation testing is usually conducted by the UV manufacturer or a third party to pre-validate their reactors to determine the operating conditions under which a UV reactor would deliver the validated dose. The validation testing is conducted for the full-scale testing of the reactor that will actually be used in field and inactivation of a test micro-organism with dose-response characteristics quantified through bioassay tests. The operating conditions include flow rate, UV intensity, UV lamp status, an account for UV absorbance of the water, lamp fouling, aging inlet and outlet piping configuration of the UV reactor and measurement of uncertainty of online sensors, etc. UV lamps are sensitive to fluctuation in electrical power; voltage that varies more than 10 to 15 percent above or below the normal voltage for as little as two to five cycles (power blip of 0.03 to 0.08 seconds) may cause UV lamps to lose their arc (i.e. UV lamps would go out). The purpose of this appendix is to specify minimum requirements when UV is used for primary disinfection. UV systems should be designed taking into account: redundancy and reliability; minimum dose and performance requirements; UV transmittance (UVT); scaling and fouling. C.1.1 Redundancy and Reliability A minimum of two UV treatment units are required in parallel to provide redundancy regardless of the design of the system. Where two units are provided, each unit shall be capable of meeting the maximum day demand flow. Where more than two units are provided, the maximum day demand flow shall be met with the largest unit out of service. UV intensity and flow through the reactors, shall be monitored a minimum of once every five minutes to ensure the UV dose is greater than or equal to 2 40 mj/cm. 53 of 100

58 Provisions shall be in place to prevent the distribution of water if UV dose 2 drops below 40 mj/cm. Each UV unit shall be equipped with an alarm notification and shutdown in the event of: high temperature in the reactor, lamp, ballast or transformer; high flow rates that causes dose to fall below design specifications; low UV dose; low UV intensity; low UVT that causes dose to fall below design specifications; UV has shutdown; or any other emergency situation. Note: NSF 55, Class A units are acceptable for small systems with flow less than 25 Igpm (30 USgpm). In the case of a power outage or power quality problems, which cause one or more of the UV units to become inoperable, contingencies shall be in place that prevent inadequately disinfected water from being distributed, including during the lamp warm-up time. UV disinfection units shall be equipped with UV sensors reading calibrated UV intensity. UV sensors shall be calibrated on a monthly basis. Off-line reference sensors used for calibration shall be of equal quality to the on-line sensors. UVT analysers shall be calibrated weekly. UV equipment replacement components shall be equal to or better than components used during validation. The UV lamp shall be monitored in a manner that ensures bulb replacement is accomplished prior to the maximum lamp life expectancy. In the case of UV bulb breakage during operation, provisions shall be in place to contain the broken lamp, and contingencies shall be in place that prevent inadequately disinfected water from being distributed. 54 of 100

59 C.1.2 Minimum Dose and Performance Requirements 2 UV systems shall be certified to provide a minimum dose of 40 mj/cm at all points within the reactor at all times when water is passing through the treatment process. Acceptable certification includes: US EPA UV Guidance Manual DVGW-W294 (Germany) NSF Standard 55 Class A (for small systems with flow less than 25 Igpm (30 USgpm)) The municipal water utility shall provide to NSE an independent third party validation that demonstrates the manufacturer s system will meet 40 mj/cm 2 and sufficient log inactivation to meet treatment requirements. If the UV dose is inadequate to achieve the required virus reduction, UV shall be followed by another disinfectant such as chlorine with the appropriate CT to achieve log inactivation requirements for viruses. UV dose shall always be followed by a secondary disinfectant such as chlorine to maintain a residual in the water distribution system. The raw water characteristics shall be analysed for the following water quality parameters as per the Recommended Standards for Water Works (2007); pre-treatment shall be required for UV installations if the water quality exceeds any of the following limits: UV 254 nm Absorption cm-1 (equivalent to a minimum UVT of 70%) Dissolved Iron 0.3 mg/l Dissolved Manganese 0.05 mg/l Hardness 120 mg/l Hydrogen Sulfide Non-detectable Iron bacteria None ph 6.5 to 9.5 Suspended Solids 10 mg/l Turbidity 1.0 NTU Total Coliforms 1,000/100mL E. coli * Cryptosporidium * Giardia * * These organisms may indicate that the source is either surface water or groundwater under the direct influence of surface water and may require additional filtration pre-treatment. Consult with NSE for additional guidance. 55 of 100

60 C.1.3 UV Transmittance (UVT) UVT is an important water quality parameter for determining the efficacy of the UV unit. UVT is a measure of the UV light at 254 nm that transmits through the water column in the UV chamber. UVT is described by the following equation. UVT = 100 x 10 -A254 Knowledge of the UV 254 absorbance/transmittance of the water to be treated is critical when designing for good performance of UV systems. Low UVT is usually due to high levels of dissolved organic material (DOC) (Bolton and Cotton, 2008). Waters with UVT above 90% will usually work well with standard UV systems, 80-90% UVT will require more lamps and/or closer spacing, but waters with UVT less than 80% may require more design consideration and require appropriate validation of performance. It is more difficult to design with UVT less than 80%, since the power required to provide the required UV dose rises sharply as the %T decreases (Bolton and Cotton, 2008). Design of UV systems should ideally be based on the worst-case water transmittance of at least 12 months of UVT data for each facility (e.g. using the 5th percentile of monthly, bimonthly or weekly samples) (Bolton and Cotton, 2008). If the UVT needs to be improved, then pre-treatment ahead of UV should be considered. UVT measurements should be performed on water as it would enter the reactor (e.g. no lab filtration or ph adjustment). All UV units shall be installed with UV sensors so that %UVT shall be calculated at a minimum daily. Alarms shall be installed and configured in such a manner that alarms sound when UVT is below the manufacturer s specifications. C.1.4 Scaling and Fouling Scaling and fouling of the quartz sleeve can have a significant influence on disinfection efficacy. Over time, water quality parameters can form or deposit on the sleeve and interfere with the UV light penetrating the water column. Scaling and fouling results from the presence of metals, hardness, alkalinity, and particulate suspended in the water column. Scaling and fouling can be controlled if proper maintenance of the UV unit has been performed. Frequency of cleaning will vary depending on the water quality characteristics. Maintenance of the quartz sleeve shall be performed based on the manufacturer s recommendations. UV units shall have on-line mechanical sleeve cleaning devices or provision for physical-chemical cleaning. 56 of 100

61 C.2 On-site Generation of Sodium Hypochlorite C.2.1 Salt Quality The salt supplied shall be tested and certified as meeting the specifications of NSF 60. The salt shall contain no organic binders, flow control agents or resin cleaning material. C.2.2 Equipment Quality The electrolyzer and generator shall be certified as meeting the specifications of NSF 61 for use in drinking water systems. C.2.3 Redundancy A minimum of two electrolyzers are required to provide redundancy. Where two units are provided, each shall be capable of meeting the maximum day demand flow. Where more than two disinfection units are provided, the maximum day flow shall be met with the largest unit out of service. C.2.4 Other Requirements Appropriate precautions shall be in place to handle hydrogen gas. C.3 Membrane Treatment Technology Requirements The use of membranes for water treatment is becoming more common, especially in Nova Scotia. The purpose of this appendix is to state the requirements that membrane water treatment plants shall be required to meet in Nova Scotia with regard to: The number of membrane treatment units (e.g. trains, skids, racks, stages, etc.) Challenge Testing Direct Integrity Testing Continuous Indirect Integrity Testing Turbidity Filter-to-waste C.3.1 Number of Membrane Treatment Units Case studies of existing membrane plants have shown that having additional capacity has been extremely beneficial to deal with unexpected fouling rates and the corresponding decrease in flux to compensate for the higher fouling rates (AWWARF, 2004). The EPA Membrane Filtration Guidance Manual states that standard operational unit processes such as backwashing, chemical cleaning, and 57 of 100

62 integrity testing may be problematic if it becomes necessary to conduct these processes more frequently than was planned. The effect can be more pronounced for smaller systems with fewer membrane treatment units. As well, filter redundancy is an industry-wide practice that helps ensure that a safe and a consistent quality and quantity of water is provided. Similar requirements exist in Nova Scotia for rapid sand filters. a) Membrane Treatment Units Used for Pathogen Reduction Credits A minimum of two membrane treatment units are required in parallel to provide redundancy regardless of the design capacity of the system. Where only two units are provided, each shall be capable of meeting the maximum daily design flow at the approved flux rate. Where more than two membrane treatment units are provided, the maximum daily design flow shall be met with the largest unit out of service at the approved flux rate. Design parameters established by manufacturer shall not be exceeded. b) Integrated Membrane Systems An integrated membrane system is one that incorporates microfiltration/ ultrafiltration (MF/UF) for pathogen reduction credits followed by nanofiltration/reverse osmosis (NF/RO) for the reduction of organics to reduce the formation of disinfection by-products. Membrane treatment units used for pathogen reduction credits - shall meet the requirements outlined in a above. In addition, the municipality shall provide documentation that there will be no operational scenarios where the NF/RO system for organics reduction will be operated without pre-treatment by the MF/UF system for pathogen reduction unless stipulated in the Approval to Operate. Membrane treatment units used for the reduction of organics - shall meet the following requirements: 3 i) 0 to 1,000 m /d - one or two membrane treatment units may be provided. Where only one membrane treatment unit is provided, the following requirements shall apply: 58 of 100

63 a shelf spare shall be provided for the following equipment: pressure pump, pressure meter, transducer, pressure switches, conductivity meter, fuses and any other unique electrical device. the unit shall be sized to meet 100% of the maximum daily design flow at the approved flux rate. Where two membrane treatment units are provided: each unit may be sized to meet a minimum of 50% of the maximum daily design flow at the approved flux rate. ii) iii) 3 1,001 to 2,000 m /d - a minimum of two membrane treatment units shall be provided. Each unit may be sized to meet a minimum of 50% of the maximum daily design flow at the approved flux rate. 3 Greater than 2,000 m /d - a minimum of two membrane treatment units shall be provided. Where only two units are provided, each shall be capable of meeting the maximum daily design flow at the approved flux rate. Where more than two membrane treatment units are provided, the maximum daily design flow shall be met with the largest unit out of service at the approved flux rate. C.3.2 Challenge Testing Regardless of the capacity of the membrane units, the design parameters set by the manufacturer shall not be exceeded. The objective of challenge testing is to demonstrate pathogen removal efficiency. It is intended to be a one-time, product-specific test to establish the maximum log reduction credit that the product is eligible to receive. Challenge testing involves seeding the feed water with an acceptable challenge particulate and measuring the log reduction in the concentration of the challenge particulate between the feed and filtrate. Testing shall be conducted on a full-scale membrane module or small-scale module that is identical in material and similar in construction as that used at the treatment facility. The actual removal efficiency of a membrane shall be verified by third party challenge testing. This is a one-time product specific test and is not site-specific. Acceptable challenge testing shall follow that provided in the EPA Membrane Filtration Guidance Manual or an acceptable equivalent. This documentation shall be provided to upon request. 59 of 100

64 C.3.3 Direct Integrity Testing The purpose of direct integrity testing is to verify the removal efficiency of a membrane filtration system on an ongoing basis during operation. This will verify that the membrane has no integrity breaches of a magnitude that would compromise the ability of the membrane to achieve the pathogen reduction required. Direct integrity testing is a physical test applied directly to the pathogen barrier associated with a membrane treatment unit (e.g. an individual train, skid, rack, stage, etc.) in order to identify and isolate integrity breaches. Direct integrity testing is commonly accomplished using pressure-based tests or marker-based tests. As new types of direct integrity tests are developed in the future, they may be used provided the basic requirements for test resolution, sensitivity, and frequency can be satisfied. a) Membrane Treatment Units Used for Pathogen Reduction Credits The integrity of the membrane system and the actual removal efficiency of the membrane shall be demonstrated by direct integrity testing of the membrane under normal operating conditions. Direct integrity testing shall follow that outlined in the EPA Membrane Filtration Guidance Manual or an acceptable equivalent. Direct integrity testing shall be responsive to an integrity breach in the order of three micrometres or less. Direct integrity testing shall be conducted on each membrane treatment unit at a frequency of no less than once each day that the unit is in operation. Less frequent testing may be approved if supported by demonstrated process reliability, the use of multiple barriers effective for cysts (Giardia), oocysts (Cryptosporidium) or viruses or reliable process safeguards. C.3.4 Continuous Indirect Integrity Testing The objective of continuous indirect integrity monitoring is to monitor a membrane filtrate system for significant integrity problems between direct integrity test applications. Indirect methods do not assess the integrity of the membrane barrier directly, but instead utilize water quality parameters as a surrogate to infer information about membrane integrity based on the levels of the monitored parameters relative to the known baseline in a fully integral system. Although indirect integrity monitoring is generally not as sensitive for detecting integrity breaches as the various direct methods, the indirect methods do have the advantage of being able to be applied to continuously monitor membrane filtrate quality during production, thus providing some means of assessing integrity between direct integrity test applications. 60 of 100

65 In addition to continuous turbidity monitoring, other methods of indirect testing include particle counting, particle monitoring, conductivity monitoring (for NF/RO systems), or others as deemed acceptable by NSE. a) Membrane Treatment Units Used for Pathogen Reduction Credits All membranes shall have continuous indirect integrity testing. Indirect integrity testing shall follow that outlined in the EPA Membrane Filtration Guidance Manual or an acceptable equivalent. Continuous indirect integrity testing shall be conducted at a minimum frequency of once every 5 minutes. b) Integrated Membrane Systems C.3.5 Turbidity Membrane treatment units used for pathogen reduction credits - shall meet the requirements outlined in a above. Membrane treatment units used for the reduction of organics - the municipal water utility shall have a means of verifying the rejection rate and rectifying any performance issues. The treated water turbidity levels from individual membrane units shall be based on continuous measurements of turbidity, using an on-line turbidimeter, with results recorded at minimum frequency of once every five minutes. If turbidity exceeds 0.1 NTU for more than 15 minutes, direct integrity testing shall be immediately conducted on the membrane treatment unit. If the unit passes direct integrity testing, it may continue to be used for water treatment; if not, the unit shall be taken out of service. C.3.6 Filter-to-waste A filter-to-waste feature shall be provided for: initial start-up and commissioning of the membrane system; those systems that have to be tested on-line during production in the event of a membrane integrity breach; emergency diversion of water. The filter-to-waste feature for membranes is to provide operational flexibility and therefore shall not have any filter ripening conditions associated with it in an approval to operate. 61 of 100

66 C.3.7 Management of Waste Streams Waste streams that are generated from backwash and cleaning cycles shall be managed properly. The use of membrane technology produces the following waste streams: filter backwash wastewater; filter backwash solids; clean-in-place chemical waste; chemically enhanced backwash (CEB) wastewater and solids. The municipal water utility should provide an estimate of the waste stream composition and concentrations. It should be noted that membrane treatment processes may concentrate naturally-occurring compounds such as metals, solids and radionuclides in the waste streams. a) Filter Backwash Water The municipal water utility shall manage filter backwash water in accordance with Part III, Section b) Filter Backwash Solids The municipal water utility shall manage filter backwash solids in accordance with Part III, Section c) Clean-in-place (CIP) Chemical Waste Membranes require periodic chemical cleaning, which involves re-circulating cleaning chemicals and scouring the membrane surface, to reduce fouling. CIP chemical wastes shall be disposed in a manner that is acceptable to NSE. Neutralization of cleaning solutions shall be provided including dechlorination such that the chlorine residual concentration shall not exceed 0.02 mg/l and adjustment of ph such that the ph is within a range of 6.5 to 9.0 (unless background values are outside this range in which case ph shall be within 0.2 of background). The CIP chemical waste stream may be neutralized in the process tank where CIP has taken place or transferred to a holding tank until neutralization has occurred. d) Chemically Enhanced Backwash (CEB) Wastewater and Solids Membranes may require periodic enhanced backwash, which involves injecting chlorine, caustic, or acid during a filter backwash cycle to improve, and lengthen cycles before CIP is required. CEB wastewater shall meet the requirements outlined in a above. CEB solids shall meet the requirements outlined in c above. 62 of 100

67 APPENDIX D - LOG INACTIVATION INFORMATION AND TABLES FOR FREE CHLORINE, CHLORINE DIOXIDE, OZONE AND ULTRAVIOLET (UV) LIGHT 63 of 100

68 D.1 Introduction CT required can be determined by the following methods: from CT disinfection tables first published by USEPA; or calculated from equation (for Giardia only). D.2 Reading CT required from US EPA Disinfection Tables: CT values can be read from the tables, which follow in the appendix, using the following parameters: required log reduction; minimum temperature of the water; maximum ph of the water; free chlorine residual concentration before first consumer (when using free chlorine). Note that tables are specific to target organism (Giardia, Cryptosporidium, viruses) and type of disinfectant (free chlorine, chlorine dioxide, ozone, UV). Since water treatment facilities rarely operate at ph, temperature and chlorine concentrations that exactly match the values listed in the CT tables, CT required must be determined by one of the following methods: linear interpolation method; approximation method. Linear interpolation method may have to be used several times to find intermediate values for chlorine, temperature and ph (see example 2 in Appendix F). Because of the complexity of this process, the approximation method is frequently used to find CT. required D.2.1 The Approximation Method With the approximation method, conservative values for ph, temperature, and residual disinfectant concentration are used to select a CT value from the table. It is a conservative method that slightly underestimates the actual effectiveness of the disinfection process. However, it requires no mathematical calculations and therefore is simpler and reduces errors. 64 of 100

69 To find the CT required from the tables using the approximation method: Find the CT table for the temperature that is equal or (next) lower to the actual measured water temperature. For example, if the measured water 0 0 temperature is 7 C use a table for 5 C. Go to the section of the table for the ph which is equal to or (next) higher than the actual measured ph of the water. For example, if the measured ph is 6.3, use the ph 6.5 section. Use the free chlorine concentration that is equal or (next) higher than the actual concentration measured at the plant. For example if the measured free chlorine concentration is 1.5 mg/l, use the 1.6 mg/l row. For example, find the CT required for the 0.5 log inactivation credit for Giardia and the following water parameters: 0 temperature = 7 C; ph = 6.7; free chlorine = 1.7 mg/l. 0 Since there is no table for 7 C, we should select table with next lower temperature, 0 which in this case is a table for 5 C. This table contains ph values 6.5 and ph 7.0. Since our measured value is 6.7, we choose the next higher value, that is ph 7. Finally looking at free chlorine concentration, we see that table contains values for concentrations 1.6 mg/l and 1.8 mg/l. With a measured value of 1.7 mg/l, we use the next higher value, in this case 1.8 mg/l. Using this process, the CT required would be 27. CT log inactivation tables have been provided in this appendix to facilitate the calculation of CT via the linear interpolation or approximation method. required D.2 Calculating CT required from Equation (for Giardia Only) The following equation, developed by Martin (1993), is most often used in disinfection calculations for Giardia. 65 of 100

70 Where : CT: ph: Cl: required inactivation number measure of the acidity or basicity free chlorine concentration log reduction: required logarithmic reduction in Giardia cysts temp: water temperature Please note this equation does not apply to Cryptosporidium which is not inactivated by chlorine. See the log inactivation tables for alternate disinfectants for Cryptosporidium inactivation. The following table compares CT required as determined by the approximation method and the Martin equation for two scenarios. Log Reduction Required Temperature 0 ( C) ph Chlorine Residual (mg/l) Approximation Method 1 Martin Notes: 1. Values taken from the CT tables 66 of 100

71 CT Log Inactivation Values (in mg.min/l) for Giardia using free chlorine at 0.5 o C Free Cl 2 Residual ph < 6.0 ph = 6.5 ph = 7.0 ph = 7.5 Log Inactivation Log Inactivation Log Inactivation Log Inactivation Free Cl 2 Residual ph = 8.0 ph = 8.5 ph > 9.0 Log Inactivation Log Inactivation Log Inactivation of 100

72 Free Cl 2 Residual CT Log Inactivation Values (in mg.min/l) for Giardia using free chlorine at 5 o C ph < 6.0 ph = 6.5 ph = 7.0 ph = 7.5 Log Inactivation Log Inactivation Log Inactivation Log Inactivation Free Cl 2 Residual ph = 8.0 ph = 8.5 ph > 9.0 Log Inactivation Log Inactivation Log Inactivation of 100

73 Free Cl 2 Residual CT Log Inactivation Values (in mg.min/l) for Giardia using free chlorine at 10 o C ph < 6.0 ph = 6.5 ph = 7.0 ph = 7.5 Log Inactivation Log Inactivation Log Inactivation Log Inactivation Free Cl 2 Residual ph = 8.0 ph = 8.5 ph > 9.0 Log Inactivation Log Inactivation Log Inactivation of 100

74 CT Log Inactivation Values (in mg.min/l) for Giardia using free chlorine at 15 o C Free Cl 2 Residual ph < 6.0 ph = 6.5 ph = 7.0 ph = 7.5 Log Inactivation Log Inactivation Log Inactivation Log Inactivation Free Cl 2 Residual ph = 8.0 ph = 8.5 ph > 9.0 Log Inactivation Log Inactivation Log Inactivation of 100

75 CT Log Inactivation Values (in mg.min/l) for Giardia using free chlorine at 20 o C Free Cl 2 Residual ph < 6.0 ph = 6.5 ph = 7.0 ph = 7.5 Log Inactivation Log Inactivation Log Inactivation Log Inactivation Free Cl 2 Residual ph = 8.0 ph = 8.5 ph > 9.0 Log Inactivation Log Inactivation Log Inactivation of 100

76 Free Cl 2 Residual CT Log Inactivation Values (in mg.min/l) for Giardia using free chlorine at 25 o C ph < 6.0 ph = 6.5 ph = 7.0 ph = 7.5 Log Inactivation Log Inactivation Log Inactivation Log Inactivation Free Cl 2 Residual ph = 8.0 ph = 8.5 ph > 9.0 Log Inactivation Log Inactivation Log Inactivation of 100

77 CT Values (in mg. min/l) for 4-log inactivation of viruses free chlorine ph Temperature o ( C) of 100

78 CT Log Inactivation Values (in mg min/l) for Cryptosporidium using Chlorine Dioxide Log Inactivation Water Temperature ( C) CT Log Inactivation Values (in mg min/l) for Giardia using Chlorine Dioxide, ph Log inactivation Water temperature ( C) < CT values (in mg min/l) for 4 - log Virus Inactivation using Chlorine Dioxide ph o Temperature ( C) 6 9 < of 100

79 CT Log Inactivation Values (in mg min/l) for Cryptosporidium using Ozone Log Inactivation Water Temperature ( C) CT Log Inactivation Values (in mg min/l) for Giardia using Ozone, ph Log Inactivation Water temperature ( C) < CT values (in mg min/l) for 4 - log Virus Inactivation using Ozone ph o Temperature ( C) 6 9 < of 100

80 UV Dose Log Inactivation Values for Cryptosporidium, Giardia, and Viruses UV dose (mj/cm 2 ) Log Inactivation Cryptosporidium Giardia Viruses* *Based on adenovirus inactiviation. 76 of 100

81 APPENDIX E - BAFFLING FACTORS FOR SAMPLE CONTACT CHAMBER DESIGNS 77 of 100

82 Poor Baffling T 10/T 0 = 0.3 single or multiple unbaffled inlets and outlets no intra-basin baffles potential for stagnant zones and short-circuiting 78 of 100

83 Average Baffling T 10/T 0 = 0.5 baffled inlet or outlet some intra-basin baffles 79 of 100

84 Superior Baffling T 10/T 0 = 0.7 perforated inlet baffle serpentine or perforated intra-basin baffles outlet weir or perforated launders most of tank volume utilized 80 of 100

85 APPENDIX F - SAMPLE CT CALCULATIONS 81 of 100

86 EXAMPLE 1 Source Water - Surface Water The source water is surface water from a river. Treatment Requirements Based on source water conditions, the treatment requirements are set at: 3.0-log reduction for Cryptosporidium and Giardia; 4.0-log reduction for viruses. Filtration Credits (Log Removal) The treatment facility is a direct filtration plant. Individual filter effluent turbidity was reviewed and meets the limits of 0.2 NTU 95% of the time. Therefore, this facility receives the following filtration credits towards meeting the treatment requirements: 2.5-log reduction for Cryptosporidium; 2.5-log reduction for Giardia; 1.0-log reduction for viruses. Based on the above, log inactivation (disinfection) must provide the following log reduction: Cryptosporidium: 3.0-log reduction required Subtract 2.5-log filtration credit Equals 0.5-log inactivation credit needed Giardia 3.0-log reduction required Subtract 2.5-log filtration credit Equals 0.5-log inactivation credit needed Viruses 4.0-log reduction required Subtract 1.0-log filtration credit Equals 3.0-log inactivation credit needed Treatment Deficiency #1 Because this facility has a shortfall in log removal credits for Cryptosporidium, an alternate disinfectant such as UV, chlorine dioxide or ozone will be required to meet treatment requirements. 82 of 100

87 In this example, UV is selected. The UV unit must be able to provide a minimum dose of 2 40 mj/cm. This is sufficient to receive a 4-log inactivation credit for Cryptosporidium and Giardia (see IT tables in Appendix D) which meets the above shortfalls. UV is only assigned a 0.5-log inactivation credit for viruses. As such, 2.5-log inactivation is required by chlorine. Disinfection Credits (Log Inactivation) The contact chamber has the following configuration: Direction of flow Contact Chamber Specifications: Volume: 270 cubic metres Max. Flow: 4.1 MLD Dimensions: 9.1 m x 10 m x 3 m Baffling: Single Baffle Min. Temperature: 5 C Highest ph: 7.6 This facility uses free chlorine for primary disinfection. In the winter, the fac i lity has a minimum of 1.0 mg/l free chlorine residual leaving the contact chamber. Based on the configuration of the contact chamber the length to width ratio is 2:1, which is poor. A baffling factor of 0.3 can be used. Tank low level occurs when the tank is 70% full. CT Calculation Volume of chamber: 270 cubic metres = L = 0.27 ML x 0.7 (low level) = ML Contact time actual: Volume Max. Flow = ML 4.1 MLD = days x 24 hours per day x 60 minutes per hour = 66.4 minutes CT actual: Concentration of disinfectant x contact time x baffling factor = 1.0 mg/l x 66.4 minutes x 0.3 = 19.9 mg.min/l CT required (Giardia): UV disinfection is providing 4.0-log inactivation for Cryptosporidium and Giardia. 83 of 100

88 Adequate for 0.5-log Giardia? Yes CT required (Viruses): Referring to the CT tables in Appendix D, 8 mg.min/l provides o 4.0-log inactivation of viruses at 5 C, ph 6-9 Adequate for CT actual CT required = = 2.49 (greater than 1) viruses? Therefore adequate Conclusion This facility will require the installation of an alternate disinfectant, in this example UV, to provide sufficient disinfection for Cryptosporidium and Giardia inactivation. Chemical disinfection will also be required to provide adequate disinfection for virus inactivation. 84 of 100

89 EXAMPLE 2 Source Water - Surface Water The source water is surface water from a lake. Treatment Requirements Based on source water conditions, the treatment requirements are set at: 3.0-log reduction for Cryptosporidium and Giardia; 4.0-log reduction for viruses. Filtration Credits (Log Removal) The treatment facility is a conventional filtration plant. Individual filter effluent turbidity was reviewed and meets the limits of 0.2 NTU 95% of the time. Therefore, this facility receives the following filtration credits towards meeting the treatment requirements: 3.0-log reduction for Cryptosporidium; 3.0-log reduction for Giardia; 2.0-log reduction for viruses. Based on the above, log inactivation (disinfection) must provide the following log reduction: Cryptosporidium: 3.0-log reduction required Subtract 3.0-log filtration credit Equals 0.0-log inactivation credit needed Giardia 3.0-log reduction required Subtract 3.0-log filtration credit Equals 0.0-log inactivation credit needed Viruses 4.0-log reduction required Subtract 2.0-log filtration credit Equals 2.0-log inactivation credit needed There is no shortfall in log removal credits for Cryptosporidium in this example. 85 of 100

90 Disinfection Credits (Log Inactivation) The contact chamber has the following configuration: Direction of flow Contact Chamber Specifications: Volume: 303 cubic metres Max. Flow: 3.1 MLD Dimensions: 5.1 m x 20 m x 3 m Baffling: Five Baffles Min. Temperature: 7 C Highest ph: 7.3 This facility uses free chlorine for primary disinfection. In the winter, the fac i l ity has a minimum of 0.4 mg/l free chlorine residual leaving the contact chamber. Based on the configuration of the contact chamber the length to width ratio is 4:1, and multiple baffles, which is good. A baffling factor of 0.7 can be used. Tank low level occurs when the tank is 85% full. CT Calculation Volume of chamber: 303 cubic metres = L = ML x 0.85 (low level) = ML Contact time actual: Volume Max. Flow = ML 3.1 MLD = days x 24 hours per day x 60 minutes per hour = minutes CT actual: Concentration of disinfectant x contact time x baffling factor = 0.4 mg/l x minutes x 0.7 = of 100

91 Adequate for Referring to CT Tables in Appendix D: 0.5-log Giardia? o CT at 5 C and ph 7.0 = 23 o CT at 5 C and ph 7.5 = 28 o CT at 10 C and ph 7.0 = 18 o CT at 10 C and ph 7.5 = 21 Therefore: o CT at 7 C and ph 7.3 = 21.6 mg.min/l CT actual CT required = = 1.55 (greater than 1) Therefore adequate CT required (Viruses): Referring to CT tables in Appendix D, 7.2 mg.min/l provides 4.0- log inactivation of viruses Adequate for CT actual CT required = = 4.65 (greater than 1) viruses? Therefore adequate Conclusion This facility adequately removes and inactivates Cryptosporidium, Giardia and viruses and meets Nova Scotia s Drinking Water Treatment Standards. 87 of 100

92 EXAMPLE 3 Source Water - High Risk GUDI Source This example demonstrates the requirements for groundwater under the direct influence of surface water. The results from the GUDI protocol indicate that the drilled wells serving the facility have been classified as high risk GUDI. This classification has been accepted in writing by the NSE regional hydrogeologist. Treatment Requirements Since the facility has been classified as high risk GUDI, the facility requires engineered filtration for pathogen reduction. The treatment requirements for this facility are: 3 - Log reduction for Cryptosporidium and Giardia; 4 - Log reduction for viruses. Filtration Credits (Log Removal) The facility has a micro-filtration (MF) membrane system with pre-coagulation. Individual filter effluent turbidity was reviewed and meets the limits of 0.1 NTU 99% of the time. Direct integrity testing indicates that the membrane provides 3.14-log removal for protozoa (e.g. Cryptosporidium oocysts and Giardia cysts). The system receives no credits for the removal for viruses. Therefore, this facility receives the following filtration credits towards meeting the treatment requirements: 3.14-log reduction for Cryptosporidium; 3.14-log reduction for Giardia; 0.0-log reduction for viruses. Based on the above, log inactivation must provide the following log reduction: Cryptosporidium: 3.00-log reduction required Subtract 3.14-log filtration credit Equals 0.0-log inactivation credit needed Giardia 3.00-log reduction required Subtract 3.14-log filtration credit Equals 0.0-log inactivation credit needed Viruses 4.0-log reduction required Subtract 0.0-log filtration credit Equals 4.0-log inactivation credit needed There is no shortfall in log removal credits for Cryptosporidium in this example. 88 of 100

93 The contact chamber has the following configuration: Contact Chamber Specifications: Volume: 750 cubic metres Max. Flow: 12.5 MLD Dimensions: 5.1 m x 20 m x 3 m Baffling: no baffles, inlet at top of basin, outlet at bottom of basin Min. Temperature: 5 o C Highest ph: 7.5 The facility uses free chlorine. In the winter, the facility has a minimum of 1.2 mg/ L free chlorine leaving the contact chamber. Based on the configuration of the contact chamber, there is no baffling with poor mixing. A baffling factor of 0.1 can be used. Tank low level occurs when the tank is 85% full. CT Calculation Volume of chamber: 750 cubic metres = L = ML x 0.85 (low level) = ML Contact time actual: Volume Max. Flow = ML 12.5 MLD = days x 24 hours per day x 60 minutes per hour = 73.4 minutes CT actual: Concentration of disinfectant x contact time x baffling factor = 1.2 mg/l x 73.4 minutes x 0.1 = 8.81 mg.min/l CT required (Giardia): Referring to the CT tables in Appendix D, for 0.5-log inactivation o of Giardia at 5 C and ph 7.5, CT = 28 mg.min/l Adequate for CT actual CT required = = 0.31 (less than 1) 0.5-log Giardia? Therefore not adequate 89 of 100

94 CT required (Viruses): Referring to the CT tables in Appendix D, 8 mg.min/l provides o 4.0-log inactivation of viruses at 5 C, ph 6-9 Adequate for CT actual CT required = = 1.1 (greater than 1) viruses? Therefore adequate Conclusion The current configuration of the contact chamber is not sufficient to provide 0.5-log inactivation for Giardia. The contact chamber can be increased in size, the baffling improved, the chlorine residual increased to 4.0 mg/l or UV disinfection can be added. 90 of 100

95 EXAMPLE 4 Source Water - Medium Risk GUDI Source This example demonstrates the requirements for groundwater under the direct influence of surface water. The results from the GUDI protocol indicate that the drilled wells serving the facility have been classified as medium risk GUDI. This classification has been accepted in writing by the NSE regional hydrogeologist. Treatment Requirements Since the facility has been classified as a medium risk GUDI, the treatment requirements for this facility are: 3 - Log reduction for Cryptosporidium and Giardia; 4 - Log reduction for viruses. Filtration Credits (Log Removal) A medium risk GUDI facility is eligible for a 1.0-log natural filtration credit for protozoa if the Guidelines for the Determination of Natural Filtration Log Removal for Protozoa are followed (see Appendix B) and the NSE regional hydrogeologist accepts the determination in writing. This process has been completed and accepted by NSE. Therefore, this facility receives the following filtration credits towards meeting the treatment requirements: 1.0-log reduction for Cryptosporidium; 1.0-log reduction for Giardia; 0.0-log reduction for viruses. Based on the above, log inactivation must provide the following log reduction: Cryptosporidium: 3.0-log reduction required Subtract 1.0-log filtration credit Equals 2.0-log inactivation credit needed Giardia 3.0-log reduction required Subtract 1.0-log filtration credit Equals 2.0-log inactivation credit needed Viruses 4.0-log reduction required Subtract 0.0-log filtration credit Equals 4.0-log inactivation credit needed 91 of 100

96 Treatment Deficiency #1 Because this facility has a shortfall in log removal credits for Cryptosporidium, an alternate disinfectant such as UV, chlorine dioxide or ozone will be required to meet treatment requirements. In this example, UV is selected. The UV unit must be able to provide a minimum dose of 2 40 mj/cm. This is sufficient to receive a 4-log inactivation credit for Cryptosporidium and Giardia (see IT tables in Appendix D) which meets the above shortfalls. UV is only assigned a 0.5-log inactivation credit for viruses. As such, 3.5-log inactivation for viruses must be addressed. In this example, chlorine is selected to inactivate viruses. Disinfection Credits (Log Inactivation) The contact chamber has the following configuration: Direction of flow Contact Chamber Specifications: Volume: 450 cubic metres Max. Flow: 4.5 MLD Dimensions: 5 m x 30 m x 3 m Baffling: Five Baffles Min. Temperature: o 10 C Highest ph: 7.5 The facility uses free chlorine for virus disinfection. The facility has a minimum of 0.5 mg/l free chlorine residual leaving the contact chamber. Based on the configuration of the contact chamber the length to width ratio is 4:1, and multiple baffles, which is good. A baffling factor of 0.7 can be used. The tank is configured such that it is always full (e.g. outlet weir controls water level). 92 of 100

97 CT Calculation Volume of chamber: 450 cubic metres = L = ML x 1 (low level) = ML Contact time actual: Volume Max. Flow = ML 4.5 MLD = 0.1 days x 24 hours per day x 60 minutes per hour = 144 minutes CT actual: Concentration of disinfectant x contact time x baffling factor = 0.5 mg/l x 144 minutes x 0.7 = 50.4 CT required (Giardia): UV disinfection is providing 4.0-log inactivation for Cryptosporidium and Giardia. Adequate for 0.5-log Giardia? Yes CT required (Viruses): Referring to the CT tables in Appendix D, 6 mgmin/l provides 4.0- o log inactivation of viruses at 10 C, ph 6-9 Adequate for CT actual CT required = = 8.4 (greater than 1) viruses? Therefore adequate Conclusion This facility will require the installation of an alternate disinfectant, in this example UV, to provide sufficient disinfection for Cryptosporidium and Giardia inactivation. Chemical disinfection will also be required to provide adequate disinfection for virus inactivation. 93 of 100

98 EXAMPLE 5 Source Water - Non-GUDI This example demonstrates the requirements for a non-gudi source. The results from the GUDI protocol indicate that the drilled wells serving the facility have been classified as non- GUDI. This classification has been accepted in writing by the NSE regional hydrogeologist. Treatment Requirements Since the facility has been classified as non-gudi, the treatment requirements for this facility are: 4 - Log reduction for viruses. Treatment Adequacy A non-gudi facility does not require engineered filtration for pathogen reduction. Therefore, only disinfection is required for the 4-log inactivation of viruses. The utility has two choices for primary disinfection: chemical disinfection only or UV and chemical disinfection. The facility well field is located 2.1 km from the first customer with a 12 ductile iron water main, which provides plug flow. The baffling factor for the water main is 1. The maximum flow in the system is 3.8 MLD. 0 The minimum water temperature is 5 C. With chemical disinfection only the utility ensures that the minimum free chlorine concentration at the first customer is 0.4 mg/l. This facility is considering UV as an added barrier for disinfection, but wanted to compare the two choices before making the final selection. Option 1: Chemical disinfection only Volume of the chamber = Length of water main x cross-sectional area = 2100 m x sq. m = 153 cu. m = ML Contact time actual = Volume/Max. Flow = ML /4.5 MLD = days x 24 hours per day x 60 minutes per hour = 49.0 min CT actual = Concentration of disinfectant x contact time x baffling factor 94 of 100

99 CT actual = 0.4 mg / L x 49.0 min x 1.0 CT actual = 19.6 mg min/l CT required (viruses): Referring to CT Tables in Appendix D, 8 mgmin/l provides 4.0-log 0 inactivation at 5 C, ph 6-9 Adequate for CT= CT actual CT required = = 2.45 (greater than 1) viruses? Therefore adequate Option 2: UV with chemical disinfection UV will only provide 0.5-log inactivation for viruses so chemical disinfection will be required for 3.5-log inactivation of viruses. Given that the chemical disinfection would provide most of the inactivation the utility reduced the free chlorine concentration to 0.3 mg /L as a cost saving measure. CT actual = Concentration of disinfectant x contact time x baffling factor CT actual = 0.3 mg/l x 49.0 min x 1.0 CT actual = 14.7 mg-min/l CT = CT CT = = 1.84 (greater than 1) actual required Adequate for viruses? Therefore adequate. Conclusion Both options are sufficient for disinfection. Since the facility only obtains a 0.5-log reduction credit for viruses for the UV unit, the utility must evaluate the additional capital and operating costs of the UV unit, reduced cost of chlorine addition and risk benefit. 95 of 100

100 APPENDIX G - TECHNICAL INFORMATION ON REPORTING REQUIREMENTS 96 of 100

101 G.1 Immediate Reporting Requirements The municipal water utility shall immediately notify NSE when the following occurs: a) whenever the presence of total coliforms or E.coli bacteria is detected; b) upon receipt of results that indicate a maximum acceptable concentration or interim maximum acceptable concentration has been exceeded; c) lack of disinfection or failure of key water treatment process; d) use of emergency water supply from an untreated or inadequately treated source; e) a serious incident of raw water contamination; f) when it is necessary to use a by-pass; g) when it is necessary to use a back-up water supply; h) any incidents of non-compliance with the Approval to Operate; i) any other incident that may adversely affect the quality of water within the system (including line breakage); j) if the chlorine residual in the water distribution system is less than stipulated; k) if the GUDI status of a well changes (for groundwater only). G.2 Annual Reporting Requirements The municipal water utility shall comply with the following annual reporting requirements. G.2.1 Annual Report - By April 1 of each year The municipal water utility shall prepare and submit to NSE an annual performance report. The annual report shall contain, but not be limited to, the following information on the form provided by NSE: a) a summary and discussion of the quantity of water supplied during the reporting period on a per month basis showing design values, maximum daily flow and average daily flow for each month and any other parameters or conditions specified in the Water Withdrawal Approval; 97 of 100

102 b) a summary and interpretation of analytical results obtained in accordance with the monitoring and recording section of the Approval, including an explanation for any exceedance of the maximum acceptable concentration (MAC) or interim maximum acceptable concentration (IMAC) of healthrelated parameters listed in the Guidelines for Canadian Drinking Water Quality, latest edition and the actions taken to address the exceedance; c) annual trend graphs for parameters that are continuously monitored; d) date and description of any emergency or upset conditions which occurred during the period being reported upon and action taken to correct them; e) any modifications to the contingency plan or emergency notification procedures, including a description of how the information was communicated to staff; f) a list of the names of each laboratory utilized and the parameters analysed by each lab; g) an update on the status of the source water protection plan, including any modifications to the plan or implementation schedule, and a summary of activities taken to achieve the goals and objectives of the plan; h) all incidents of chlorine residual below the stipulated value with a description of actions taken; i) verification that the operational conditions remained within the design range for achieving CT or IT; if operational conditions went outside the design ranges, CT or IT calculations shall be provided with a summary of corrective actions taken; j) records of any violations of the conditions of the Approval and actions taken by the Approval Holder to correct those violations; k) any complaints received and the steps taken to determine the cause of complaint(s) and the corrective measures taken to alleviate the cause and prevent its recurrence; l) a review of the QA/QC program to validate the measurements obtained from continuous monitoring equipment and for all analysis conducted at the Facility or a non-certified laboratory; m) a list of each certified operator and their level of certification. 98 of 100

103 G.2.2 Annual Sampling Plan - By October 1 of each year The municipal water utility shall prepare and submit to NSE an annual sampling plan. The annual sampling plan shall recommend a monitoring program for the following year, highlighting any changes and the reason for the change. The annual monitoring program shall include: compliance monitoring, including QA/QC requirements; process monitoring; response monitoring; special process characterization and optimization monitoring (if applicable); source water characterization monitoring. G.3 Ad Hoc Reporting Requirements The municipal water utility shall notify NSE when the following occurs: a) when any extensions to or modifications of the Facility are proposed which are not granted under the existing approval to operate - this includes process changes or waste disposal practices; b) whenever the municipal water utility becomes aware of any new or relevant information respecting any adverse effect that actually results, or may potentially result, from any activity to which the Approval relates; c) if sampling is changed such that a sample is analysed by a lab that does not meet the Department's "Policy on Acceptable Certification of Laboratories" (excluding those parameters that are allowed by the Approval to be tested on-site or by a non-certified lab); d) if modifications to the sludge disposal plan are proposed; e) if a sampling location is proposed to be moved or re-located. 99 of 100

104 G.4 Information to be Provided Upon Request or For Inspection/Review G.4.1 Upon request by The municipal water utility shall provide the following information upon request by NSE: a) the name of each laboratory utilized, and the parameters analysed by that laboratory; b) verification that the UV system (if applicable) is capable of continually 2 meeting the 40 mj/cm requirement; c) any monitoring results or reports required by the Approval; d) verification that chemicals used in the treatment process and all materials contacting the water meet ANSI standard NSF/60 (for chemical additives) or NSF/61 (for materials); e) standard operational procedures for the filtration and disinfection processes; f) laboratory certificate of analysis. G.4.2 To be available for inspection or review upon request The municipal water utility shall ensure the following information is available for inspection or review upon request by NSE: a) operations manual; b) record drawings, incorporating any amendments made from time to time; c) process control on-site testing and sampling results; d) source water protection testing and sampling results; e) calibration logs for instrumentation, such as flow measuring devices and continuous water quality analysers and indicators. 100 of 100