Facilities Plan. Wastewater Treatment Facility. Detroit Lakes, Minnesota. January 23, SEH No. DLPUC

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Facilities Plan. Wastewater Treatment Facility. Detroit Lakes, Minnesota. January 23, 2015. SEH No. DLPUC 127205"

Transcription

1 Facilities Plan Wastewater Treatment Facility Detroit Lakes, Minnesota SEH No. DLPUC January 23, 2015

2 Table of Contents 1.0 Introduction Regulatory Requirements Facility Planning Flow and Load Projections Infiltration and Inflow Projected Flows and Loads Existing Conditions Year Flood Elevation Historical, Archaeological, Cultural, and Environmental Elements Liquid Treatment Alternative Evaluation Discharge Location Evaluation of Liquid Treatment Alternatives Preliminary Treatment Primary Treatment Secondary/Tertiary Treatment Disinfection Existing WWTF Site or New Site for Liquid Treatment Processes Seasonal Versus Year-Round Discharge Estimated Cost for Recommended Liquid Alternative Solids Treatment Alternative Evaluation Solids Treatment Biosolids Handling Existing WWTF Site or New Site for Solids Treatment and Biosolids Handling Processes Estimated Cost for Recommended Solids Alternative Expansion Summary of Recommendations and Proposed Project Schedule Wastewater User Rate Impact Evaluation Page List of Tables Table 1 Technical Memoranda Title and Scope... 2 Table WWTF Projected Flows and Loads... 3 Table 3 Preliminary Effluent Limits... 6 Table 4 Liquid Treatment Alternative Estimated Cost... 8 Table 5 Solids Treatment Alternative Estimated Cost Table 6 Anticipated Schedule Table 7 Loan Payment Table 8 Annual Payments SEH is a registered trademark of Short Elliott Hendrickson Inc. Facilities Plan DLPUC Detroit Lakes Public Utilities Commission Page i

3 Table of Contents (Continued) Figure Year Flood Elevation Figure 2 Potential Expansion Figure 3 Hydraulic Profiles List of Figures Appendix A Appendix B Appendix C Appendix D List of Appendices Technical Memoranda Environmental Information Worksheet (EAW) Liquid Treatment Alternatives Cost Breakdown Solids Treatment Alternative Cost Breakdown z:\ae\d\dlpuc\127205\4-prelim-dsgn-rprts\facility plan components\draft for city\draft facilities plan docx DLPUC Page ii Facilities Plan Detroit Lakes Public Utilities Commission

4 January 2015 Facilities Plan Wastewater Treatment Facility Prepared for Detroit Lakes Public Utilities Commission 1.0 Introduction The City of Detroit Lakes is located in northwestern Minnesota in Becker County. The 2010 U.S. Census Bureau population for Detroit Lakes was 8,569. The population of the City increases during the summer months due to tourism and lake homes and there are currently no significant industries in the City limits. The planning area encompasses the city limits as well as some of the surrounding lakes. 2.0 Regulatory Requirements The Detroit Lakes wastewater treatment facility (WWTF) discharges wastewater in accordance with Minnesota National Pollutant Discharge Elimination System (NPDES)/State Disposal System (SDS) permit no. MN A copy of the current permit is included in Appendix A in Technical Memorandum No. 3. This permit became effective February 6, 2014 and expires January 31, The permit requires the City to complete Phase III of a Toxicity Identification Evaluation (TIE) and the facility will have a chronic whole effluent toxicity (WET) limit of 1.0 toxic unit values (TUc). The permit also requires the facility to achieve an effluent quality of 198 kilogram per year (kg/yr) phosphorous by October 1, At the projected flows for the 20-year design year of 2038, the concentration equivalent for the phosphorous limit is 0.06 mg/l. 3.0 Facility Planning The City of Detroit Lakes authorized this facility planning study of its wastewater treatment facility (WWTF) to: Comply with a requirement in the City s current NPDES permit to prepare a facility plan. Address the phosphorous and toxicity limits in the current NPDES permit. Assess the existing WWTF structures for potential re-use or re-purposing. Estimate flows and loads to the WWTF for the 20-year design period (2038) including planned annexations. Evaluate alternate discharge locations, options for discharge (seasonal vs year round), and technologies for liquid and solids treatment improvements. Develop cost estimates for treatment alternatives and evaluate user rate impacts resulting from recommended improvements. These tasks were accomplished through the development of five technical memoranda included in Appendix A. The title and scope of each technical memorandum is included in Table 1. DLPUC Page 1

5 Each technical memorandum was written to include its respective conclusions and recommendations. This facility plan condenses the discussions of each technical memorandum for convenience. Technical Memoranda No. Table 1 Technical Memoranda Title and Scope Scope 1. Future Conditions Develop future flows and loads to the WWTF for a 20-year planning period including population growth and planned annexations. 2. Site and Capacity Assessment Provide a description of the existing facilities at the WWTF; identify structures that have potential for reuse and/or repurposing; capacity assessment for structures with potential reuse. 3. Liquid Treatment Alternative Evaluation Evaluate liquid treatment alternatives; evaluate alternate discharge locations, site locations, and seasonal versus year-round discharge; provide an estimate of capital and operation and maintenance (O&M) costs. 4. Solids Treatment Alternative Evaluation Evaluate solids treatment alternatives; provide an estimate of capital and operation and maintenance (O&M) costs. 5. Wastewater User Rate Impact Evaluation Evaluate the impacts of the wastewater treatment facility capital projects identified in technical memoranda No. 3 and No. 4 on the wastewater user rates. 4.0 Flow and Load Projections The facility plan uses a 20-year design year for assessing the future needs at the Detroit Lakes WWTF. Therefore, 2038 future flows and loads become the design criteria for the WWTF improvements. 4.1 Infiltration and Inflow Infiltration and inflow (I/I) is essentially clean water that enters the collection system as a result of rainfall or elevated groundwater levels. The MPCA has established guidelines to assist in evaluating the extent of I/I. A cursory review of the I/I was performed and the calculated I/I conditions of 181 gallons per capita per day (gpcd) are below the 275 gpcd threshold for a maximum month I/I condition. 4.2 Projected Flows and Loads The 2010 population in Detroit Lakes was 8,569 according to the U.S Census Bureau. The community is projected to grow to 12,066 by the year 2038, which is the 20-year design year. The addition of annexations for North Long Lake, Willow Springs & North Highway 59, West Long Lake, Highland Drive, Lake Floyd, and Lake Sallie will add an estimated 3,518 people to the population projection, making the total population projected to be 15,584 in DLPUC Page 2 Facilities Plan Detroit Lakes Public Utilities Commission

6 The projected flows and loads are based on the population projections and the historical flow and load data from the WWTF. The details for the projected flows and loads and the Flow and Load Determination Worksheets required by MPCA can be found in Technical Memorandum No. 1. Table WWTF Projected Flows and Loads Current 2038 Projections Population, Detroit Lakes 8,569 12,066 Population, Total (includes annexations) 15,584 1 Flow Condition TSS BOD Phos TKN Average Dry Weather Flow (ADW), mgd Average Wet Weather Flow (AWW) 3, mgd Annual Average Flow, mgd Peak Hourly Wet Weather Flow (PHWW) 4, mgd Peak Instantaneous Wet Weather Flow (PIWW) 5, mgd Average, lb/day 1,893 3,442 Peak, lb/day 5,671 10,314 Average, lb/day 1,597 2,905 Peak, lb/day 3,620 6,584 Average, lb/day Peak, lb/day Average, lb/day Peak, lb/day 1,131 2,057 1 : Includes 1,599 connections from annexations at 2.2 persons per household. The population increase due to annexation is 3, : Includes 120 gallons per capita per day for Detroit Lakes population growth. 3 : June 1-30, 2013 received 6.0 rain. 4 : Peaking factor from Ten State Standards used to calculate actual data not available. 5 : Assumed value actual data not available. Facilities Plan DLPUC Detroit Lakes Public Utilities Commission Page 3

7 5.0 Existing Conditions The City of Detroit Lakes WWTF currently discharges treated effluent from the secondary and tertiary treatment process to Lake St. Clair in the winter months and discharges effluent from the secondary treatment process to Rapid Infiltration Basins (RIBs) and spray irrigators in the summer months. The treatment components consist of: Preliminary Treatment (mechanical barscreen, raw wastewater pumping, flowmetering) Primary Treatment (primary clarifiers) Secondary Treatment (Trickling filters and final clarifiers) 1942 (rock media trickling filter) and 1962 (plastic media trickling filter and final clarifiers). Tertiary Treatment (Chemical precipitation facility) Disinfection (Chlorination) Effluent Disposal (RIBs and spray irrigators) 1976 (some RIBs and spray irrigators) and 1991 (some RIBs). Solids Treatment (Anaerobic digesters, sludge storage) 1962 (storage) and 1996 (Anaerobic digesters). A description and review of each of these components can be found in Technical Memorandum No. 2. The structures identified for reuse and/or repurposing include the Grit Removal Building, the effluent channel of the aerated grit chamber, the primary clarifiers, and the anaerobic digesters. The RIBs and land application effluent disposal systems do not currently meet the groundwater separation distances discussed in MPCA guidance documents and are located in an area with poor soils for filtration. Continued use or expansion of this effluent disposal system is not recommended due to the site conditions Year Flood Elevation The FEMA map in the area of the existing WWTF indicates that the property is Unmapped and no flood hazard information is available. The County Ditch #14 wetland that extends along the southeastern side of the Airport west of Hwy 59 was the subject of a Hydraulic and Water Quality Study initiated by the Pelican Rapids Watershed District (April 2006). This study identifies the existing 100-year floodplain elevation of the Ditch 14 - Airport wetland to be feet. This elevation is noted on Figure 1 and is not a concern for the existing WWTF site. If new sites are considered for treatment or biosolids storage, the flood plain elevation at those sites must be considered. There are several state agencies which govern activities in the flood plain: Under the Minnesota statewide floodplain management standards, local communities cannot allow development in the floodway that would cumulatively cause more than six inches increase in the height of the 100-year flood (MN DNR). Development is normally allowed in the flood fringe provided that the buildings are placed on fill so that the lowest floor, including the basement, is above the 100-year flood level. DLPUC Page 4 Facilities Plan Detroit Lakes Public Utilities Commission

8 Minnesota Building Code requires public utility facilities within the floodplain to be designed to minimize increases in flood elevations and be compatible with existing local comprehensive floodplain development plans. Where failure or interruption of the public facility results in danger to the public health or safety, protection to the flood protection elevation shall be provided. The flood protection elevation is defined as an elevation one foot above the 100-year flood. The elevation of the lowest floor of a dwelling must be at or above the flood protection level. Local regulations will also require the access road elevation to be within two feet of the flood protection elevation. MPCA design guidelines for wastewater treatment facilities require treatment plant structures and electrical and mechanical equipment to be protected from physical damage by the 100-year flood. Additionally, treatment plants should remain fully operational and accessible during the 25-year flood. These requirements apply to new construction and to existing facilities undergoing major modification. 5.2 Historical, Archaeological, Cultural, and Environmental Elements An Environmental Information Worksheet (EIW) is required by the MPCA as part of a facility plan. The completed EIW can be found in Appendix B. As part of the planning step, the State requires information related to the presence of rare, endangered, or historic resources and/or landmarks. The National Register for Historic Places was searched for the planning area. The results of the search can be found in Appendix B. There are no historical, archaeological, or cultural areas within the project boundaries. Adjacent properties are not anticipated to be adversely affected. The Minnesota Department of Natural Resources was also contacted to determine if rare plant or animal species or other significant natural features exist near the project area. The National Heritage and Non game Research Program databased was also searched and results can be found in Appendix B. Any potential project at the wastewater treatment facility should have no impact on any natural features. 6.0 Liquid Treatment Alternative Evaluation The following scenarios were evaluated in Technical Memorandum No. 3 for the liquid treatment alternatives: Alternate Discharge Location Multiple Treatment Technologies Seasonal vs. Year-Round Discharge Existing Site vs. New Site 6.1 Discharge Location The current WWTF discharges to Lake St. Clair. Two alternate discharge locations were identified as Becker County Ditch No. 5 and the Buffalo River. Both discharge locations are located within the Buffalo Red River Watershed District (BRRWD). The City requested preliminary effluent limits from the MPCA for the alternate discharge locations to determine whether they would have a less stringent phosphorous limit than Lake St. Clair. A copy of the preliminary effluent limits from the MPCA is included in Technical Memo No. 3 in Appendix C. Table 3 is a summary of the preliminary effluent limits for the alternate discharge location scenarios. Facilities Plan DLPUC Detroit Lakes Public Utilities Commission Page 5

9 Substance or Characteristic Table 3 Preliminary Effluent Limits Becker County Ditch No. 5 Continuous Discharge Seasonal Discharge Continuous Discharge Buffalo River Seasonal Discharge 5-Day Carbonaceous Biochemical Oxygen Demand, mg/l Total Suspended Solids, mg/l Fecal Coliform, organisms/ml (1) 200/ / / /100 Ammonia N, mg/l: Jun 1 Sep N/A 1.0 N/A Oct 1 Nov Dec 1 Mar Apr 1 May N/A 13.0 N/A ph Range Total Residual Chlorine, mg/l Total Chloride, mg/l (2) 229 (275) 229 (275) 231 (277) 233 (280) Chronic WET, TUc Total Phosphorus, mg/l (3) (3) (1) Applicable from April October. If chlorine is used to achieve the effluent limitation for fecal coliform group organisms, then dechlorination must be provided. (2) The values in parenthesis are maximum daily values. (3) A more restrictive total phosphorous limit of 0.5 mg/l is applicable if discharge occurs from June 1 September 30. The preliminary effluent limits from the MPCA also include the following comments which have been summarized here: The discharge location for Becker County Ditch No. 5 is upstream of Reep Lake and two years of in-lake monitoring would be required. If the monitoring showed further impairment with phosphorus, a more restrictive monthly average limit of 0.2 mg/l may be assigned in the future if necessary. Minnesota has adopted numeric river eutrophication standards in 2014 and are awaiting review and approval from the Environmental Protection Agency (EPA). If discharging to the Buffalo River, the permittee would be evaluated to determine reasonable potential to cause or contribute to downstream impaired waters. If found to have reasonable potential for Total Phosphorus impairment, the WWTF would be required to have a Total Phosphorus Water Quality Based Effluent Limit (WQBEL), resulting in a TP monthly average limit near 0.3 mg/l. The more restrictive limits included in these comments were used in the evaluation of treatment alternatives. DLPUC Page 6 Facilities Plan Detroit Lakes Public Utilities Commission

10 6.2 Evaluation of Liquid Treatment Alternatives Alternatives for liquid treatment that have been evaluated fall into the following categories: Preliminary Treatment Primary Treatment Secondary/Tertiary Treatment Disinfection The details of the evaluation of all categories can be found in Technical Memorandum No. 3. The recommendations for each category are as follows: Preliminary Treatment A new preliminary treatment building to house new mechanical screening, a wetwell, and new wastewater pumps. The aerated grit basin would be replaced with a vortex grit system. The new vortex grit chamber would be constructed such that the existing effluent channel for the aerated grit basin could be utilized for the vortex grit effluent. The equipment required for the vortex grit system would replace the equipment in the existing Grit Removal Building, including the grit pumps and grit classifier. The electrical system for the grit system and primary clarifiers is currently housed in a steel enclosure added on to the Grit Removal Building. The Grit Removal Building would be modified to add a room for the electrical equipment Primary Treatment A new primary clarifier would be built south of the existing primary clarifiers as the original design intended. New piping would be added from the splitter structure to the new clarifier. The two existing primary clarifiers would be rehabilitated with new drives, scrapers, skimmer arms, skirts, scum beaches, and launders Secondary/Tertiary Treatment A new activated sludge process would be constructed with enhanced biological phosphorous removal (EBPR) for secondary treatment. These processes would require new structures and equipment, including blowers, diffusers, and mixers. Two new final clarifiers would be constructed as part of the secondary treatment. The new clarifiers would require new structures and equipment and would be covered. Additional tertiary processes are required to polish effluent to reliably achieve low effluent phosphorus concentrations. A two-stage granular filtration process would be constructed in a new building. Two-stage granular media filtration processes involve either filters operated in series or special media which uses filtration and adsorption to remove phosphorus. Chemical feed systems would be needed for the tertiary treatment process Disinfection UV disinfection would be added for disinfection. The UV disinfection channel and equipment would be housed in the same building as the tertiary treatment process. The UV disinfection would be the last step prior to discharge of effluent. Facilities Plan DLPUC Detroit Lakes Public Utilities Commission Page 7

11 6.3 Existing WWTF Site or New Site for Liquid Treatment Processes The existing WWTF site has limited area for expansion and is surrounded by wetlands and bordered by Willow Street. The challenge of a site like this is to maintain treatment during construction. Considerations of phased construction, bypass pumping, and special construction methods were considered. A new site location was also considered. The location of the new site was not identified but was assumed to be within the City limits. Based on the cost evaluation, a new site was not recommended for the liquid treatment processes. 6.4 Seasonal Versus Year-Round Discharge The existing RIBs and spray irrigators do not have adequate capacity for the projected flows and are not in compliance with groundwater separation requirements. Therefore a seasonal discharge would require a new site with land disposal. A seasonal discharge was considered as well as year-round discharge for all discharge locations evaluated. A year round discharge to Lake St Clair was recommended based on the cost evaluation. 6.5 Estimated Cost for Recommended Liquid Alternative The estimated costs for the alternatives for the liquid treatment are presented in the Table 4. The recommended alternative is highlighted. The costs presented are capital costs and 20- year present values which take into account both the capital cost and the annual operations and maintenance (O&M) costs over a 20-year period. A more detailed breakdown of the liquid treatment alternative estimated cost can be found in Appendix C. Site Location Existing WWTF Site New WWTF Site Table 4 Liquid Treatment Alternative Estimated Cost (1) Discharge Location St Clair Lake Becker Co Ditch No. 5 Buffalo River Becker Co Ditch No. 5 Buffalo River Discharge Frequency Notes: (1) Recommended alternative is highlighted above. Total Estimated Liquid Treatment Capital Cost Estimated 20-Year Present Value Year Round $23,634,000 $30,350,000 Seasonal $36,437,000 $44,958,000 Year Round $25,738,000 $32,188,000 Seasonal $37,491,000 $44,656,000 Year Round $28,621,000 $35,038,000 Seasonal $42,574,000 $49,706,000 Year Round $28,105,000 $34,737,000 Seasonal $39,858,000 $47,205,000 Year Round $30,988,000 $37,587,000 Seasonal $44,941,000 $52,255, Solids Treatment Alternative Evaluation The following components were evaluated in Technical Memorandum No. 4 for the solids treatment alternatives: Solids Treatment Biosolids Handling DLPUC Page 8 Facilities Plan Detroit Lakes Public Utilities Commission

12 The evaluation of all categories can be found in Technical Memorandum No. 4. The recommendations for each category are as follows: 7.1 Solids Treatment Anaerobic digestion, aerobic digestion, autothermal aerobic digestion (ATAD), and sludge drying were evaluated. Detail on the evaluation of each alternative can be found in Technical Memorandum No. 4. Changes are recommended to improve the operation and replace aging components of the existing anaerobic digesters. It is assumed that both the primary digester and secondary digester would require new covers. Mixing and heating systems would be replaced and the existing building area is assumed sufficient for these replacements. The anaerobic treatment process can cause the release of biologically bound phosphorus, resulting in a return stream with high phosphorus concentrations as well a high ammonia concentrations. The presence of high concentrations of phosphorus or ammonia is a concern with low-level phosphorus permit limits and ammonia toxicity issues. These return streams can also upset the EBPR process and can produce conditions conducive to struvite formation. Sidestream handling processes, ranging from equalization to struvite harvesting, would be added to address these return streams. 7.2 Biosolids Handling Liquid biosolids handling/storage and dewatered cake handling/storage were evaluated. Biosolids dewatering is a process unit operation to reduce the moisture content of biosolids. One of the main benefits of biosolids dewatering is the reduction in volume of biosolids required for hauling or further processing. A new screw press would be housed in a new building along with the chemical feed system and other ancillary equipment for dewatering, a conveyance system, and the truck that would carry the cake biosolids to the cake storage facility. The new cake storage facility would consist of a pad upon which the cake would be placed and a cover to keep the dewatered solids as dry as possible. The cover would be similar to that used for protection of sand and salt piles at many municipal utilities, consisting of a membrane fabric with an arched shape and open ends. 7.3 Existing WWTF Site or New Site for Solids Treatment and Biosolids Handling Processes The existing WWTF site has limited area for expansion and is surrounded by wetlands and bordered by Willow Street. The challenge of a site like this is to maintain treatment during construction. Like the evaluation for the liquid treatment alternatives, considerations of phased construction, bypass pumping, and special construction methods were considered. A new site location was also considered. The location of the new site was not identified but was assumed to be within the City limits. Based on the cost evaluation, a new site was not recommended for the solids treatment and biosolids handling processes. Facilities Plan DLPUC Detroit Lakes Public Utilities Commission Page 9

13 7.4 Estimated Cost for Recommended Solids Alternative The estimated costs for the recommended alternatives for the solids treatment are presented in the Table 5. The costs presented are capital costs and 20-year present values which take into account both the capital cost and the annual operations and maintenance (O&M) costs over a 20-year period. A more detailed breakdown of the solids treatment alternative estimated cost can be found in Appendix D. Table 5 Solids Treatment Alternative Estimated Cost Site Location Solids Treatment Alternative Existing WWTF Site New WWTF Site Anaerobic Digestion Aerobic Digestion ATAD Dryer Anaerobic Digestion Aerobic Digestion ATAD Dryer Solids Handling Alternative Dewatering & Cake Storage Estimated Capital Cost Estimated 20-year present value $6,855,000 $10,270,000 Liquid Solids Storage $7,090,000 $11,412,000 Dewatering & Cake $7,412,000 $11,833,000 Storage Liquid Solids Storage $7,882,000 $13,536,000 Dewatering & Cake $9,877,000 $13,107,000 Storage Liquid Solids Storage $9,645,000 $13,695,000 Dewatering & Cake $10,985,000 $13,404,000 Storage Dewatering & Cake $9,150,000 $12,565,000 Storage Liquid Solids Storage $9,260,000 $13,582,000 Dewatering & Cake $9,553,000 $13,974,000 Storage Liquid Solids Storage $9,773,000 $15,427,000 Dewatering & Cake $11,847,000 $15,077,000 Storage Liquid Solids Storage $11,490,000 $15,540,000 Dewatering & Cake $11,110,000 $13,529,000 Storage 8.0 Expansion Because space at the existing WWTF site is very limited, adding capacity for an industry or future growth beyond the 20-year projection was considered. Each process could be modified or added to in order to gain additional capacity. The new preliminary treatment building would have three influent channels constructed. Only two mechanical barscreens will be supplied for the 20-year design projections, however a third could be added when needed. The raw wastewater pumps in the new preliminary treatment building would be sized for the 20-year flow projections. However, room to add an additional pump will be made and piping will be stubbed out to a future pump. The vortex grit removal system has the ability to operate for a range of flows. As the flows reach or exceed the capacity of the unit, the grit removal efficiency begins to decline. If DLPUC Page 10 Facilities Plan Detroit Lakes Public Utilities Commission

14 additional flow capacity is needed, the grit system could continue to be used with a lower grit removal efficiency. There are two existing primary clarifiers and it is recommended that a third clarifier of the same size as the existing be constructed. The additional capacity required for the 20-year projection did not require a clarifier of that size, therefore, the third clarifier will have additional capacity if needed in the future. The secondary treatment system would consist of an Integrated Fixed Film Activated Sludge (IFAS) system which integrates media into an activated sludge process. The media will comprise approximately 30% of the volume, but could go as high as 60% if additional treatment capacity is needed in the future. The tertiary treatment system would require additional building space and filters for additional capacity. Once the existing trickling filters are removed there would be space at existing WWTF site to expand the proposed tertiary treatment building. The UV disinfection system could be expanded by adding another bank of UV lights. The effluent channel could be designed for three banks but only two banks would be installed for the 20-year design projections. The third could be added when additional capacity is needed. The final clarifiers could be round or rectangular. Rectangular construction allows for shared wall construction and less space required. A third final clarifier could be constructed once the existing final clarifier structure is demolished. The existing anaerobic digesters have more capacity than what is needed for the 20-year design projections and could be used when needed. The proposed dewatering system is estimated to operate four days per week at the 20- year design projections. To increase the capacity of the unit, the hours and days of operation could increase to meet the needs of a potential increased sludge quantity. The cake biosolids storage facility is estimated to have one year of storage. If additional storage is required in the future, hauling the cake biosolids could occur twice per year rather than once per year. The placement of the cake biosolids could also be optimized by spreading it thin to allow more dewatering to occur during storage and allow for more cake to be stored. Figure 2 shows the proposed layout of the recommended WWTF processes at the existing WWTF site. The cake biosolids storage facility is currently proposed to be located at the WWTF site. The land where the cake storage is sited is not currently owned by the City, and would need to be purchased. The storage facility could be moved to a location across the street from the WWTF site and the space adjacent to the WWTF site could be reserved for future expansion of other unit treatment process, however this has not been included in the evaluation of project costs. This could be further evaluated during preliminary design. 9.0 Summary of Recommendations and Proposed Project Schedule The recommended alternative includes an improved wastewater treatment facility at the existing WWTF site discharging year-round to the existing discharge at Lake St Clair. Figure 3 shows a hydraulic profile that was developed using existing plans and proposed treatment alternatives. The total estimated project cost for the liquid treatment and solids treatment improvements is $30,489,000. The project costs do not include any improvements for the collection system (which includes lift stations) as those improvements will be addressed on an as needed basis rather than included in the WWTF improvements. Facilities Plan DLPUC Detroit Lakes Public Utilities Commission Page 11

15 Table 6 shows the proposed schedule for the project. Table 6 Anticipated Schedule Action Tentative Date Submit Facility Plan and PPL application to MPCA 2015 Submit Plans and Specifications to MPCA Complete Construction Wastewater User Rate Impact Evaluation Understanding the impact the new capital projects will have on the existing rates requires knowledge of the existing annual operations and maintenance costs and an understanding of how those annual costs will change with the capital projects in place. This evaluation provided an estimated impact to future wastewater user rates based on existing costs and projected future costs. The details of the evaluation can be found in Technical Memorandum No. 5. It is estimated that at design conditions the facility will cost approximately $345,000 more per year to operate and maintain than was budgeted in This cost is for operation and maintenance (O&M) only and does not include new debt service. Approximately 30 percent of this additional cost is comprised by each labor, chemical, and utilities, with the last 10 percent due to additional solids disposal. Recognizing that at design conditions there is more flow and load than the facility sees today and in the future the cost would be spread amongst more users, for the basis of estimating the impacts to the current user rates, the projected O&M costs were estimated to be $240,000 more per year than current costs. Based on assumptions that the City would be eligible for $4 million (Wastewater Infrastructure Fund) WIF grant and $3 million Point Source Implementation Grant (PSIG), the City would need to finance $23.5 million (assuming there are no City wastewater funds available). Table 7 summarizes the annual loan payment for the different loan terms based on the amount needed to finance. Table 7 Loan Payment Parameter Scenario 1 Scenario 2 Amount to Finance $23,489,000 $23,489,000 Loan Term 20 years 30 years Interest Rate 1.5% 1.5% Loan Payments, Semi Annual Semi Annual Payment $681,889 $508,351 Annual Payment $1,363,779 $975,186 Notes: a) Assumes a total project cost of $30,489,000 less $4,000,000 in WIF grant and less $3,000,000 in PSI grant. b) At a 2% interest rate the annual payment for scenario 1 (20 year loan term) increases by $66,964 and scenario 2 (30 year loan term) by $69,814. DLPUC Page 12 Facilities Plan Detroit Lakes Public Utilities Commission

16 The City s user rates should be set at level to cover the annual payments for the financing as well as the annual O&M costs (current costs of $1.7 million plus the added O&M of $240,000). The resulting annual payments are identified in Table 8. The project costs do not include any improvements for the collection system (which includes lift stations) as those improvements will be addressed on an as needed basis rather than included in the WWTF improvements. Table 8 Annual Payments Parameter Scenario 1 Scenario 2 Existing O&M a $1,709,630 Additional O&M b $241,253 Annual Financing Payment c $1,363,779 $1,016,703 Total Annual Cost $3,314,662 $2,967,586 Current Annual Revenue $1,697,815 Net Increase Cost $1,616,847 $1,269,771 % Increase 95% 75% Notes: a) Includes $540,000 for depreciation and existing $226,738 PFA Loan Payment. b) Excludes additional depreciation above that which is currently figured. c) Assumes loan terms as identified in Table X. Based on the existing wastewater user rate structure a typical residential family using 6,000 gallons of water per month pays approximately $36.31 per month. Assuming the same typical residential user, a 20-year loan term (Scenario 1) would result in the user paying approximately $70.89 per month. With a 30-year loan (Scenario 2), the user amount is $62.58 per month. The specific changes to the rates (i.e. the increases to the monthly fee versus the commodity charges) should be evaluated further with a detailed rate analysis following detailed design estimates and additional loan and grant information is available. Facilities Plan DLPUC Detroit Lakes Public Utilities Commission Page 13

17 Figures Figure Year Flood Elevation Figure 2 Potential Expansion Figure 3 Hydraulic Profiles

18 Figure No. 1

19 1. Preliminary Treatment 2. Vortex Grit Removal 3. Primary Clarifier 4. Biological P Removal 5. Activated Sludge 6. Final Clarifier 7. Filtration Alternatives 8. Blower/Pump House 9. Chemical Feed Equipment 10. Chemical Storage Building 11. Digesters 12. Sidestream Treatment or Aerobic Digester or Biofilter 13. Solids Handling Building 14. Sludge Cake Storage (add media) 4 3 Legend Structures planned for 2038 projects Expansion options for growth beyond 2038 Figure 2: Potential Expansion North

20

21 Appendix A Technical Memoranda A-1 Technical Memorandum No. 1 A-2 Technical Memorandum No. 2 A-3 Technical Memorandum No. 3 A-4 Technical Memorandum No. 4 A-5 Technical Memorandum No. 5

22 Technical Memorandum No. 1 Future Conditions Wastewater Treatment Facility Detroit Lakes, Minnesota SEH No. DLPUC December 23, 2014

23 Table of Contents Page 1.0 Introduction Population Growth Annexation Flow and Load Projections Load Determination Summary...4 List of Tables Table WWTF Projected Flows... 2 Table 2 Inflow and Infiltration Determination... 3 Table WWTF Projected Loads... 4 List of Appendices Appendix A MPCA Flow Determination Worksheet Appendix B MPCA Load Determination Worksheet Appendix C DMR Summary for 2011, 2012, and 2013 Z:\AE\D\Dlpuc\127205\4-prelim-dsgn-rprts\Flow and Load Calcs\Technical Memo #1\DRAFT SENT TO CITY\Second draft to City\Technical Memorandum No DRAFT.docx SEH is a registered trademark of Short Elliott Hendrickson Inc. Technical Memorandum No. 1 DLPUC Detroit Lakes Public Utilites Commission Page i

24 December 2014 Technical Memorandum No. 1 Future Conditions Wastewater Treatment Facility Prepared for Detroit Lakes Public Utilites Commission 1.0 Introduction The purpose of Technical Memorandum No. 1 is to address the future flows and loads to the Wastewater Treatment Facility (WWTF). There are several components to be considered when examining the 20-year growth projections for the community. Items which will be evaluated include: 2038 population estimates. Treatment of wastewater from annexations of area lakes and developments. Treatment of future commercial and/or industrial growth. 2.0 Population Growth The annual population growth used for the City of Detroit Lakes for the next 20 years is based on historical population data provided by the Minnesota State Demographic Center and data from the City of Detroit Lakes Housing Study dated August 2013 by Community Partners Research. The 2010 Census data indicated that the population was 8,569 in 2010, which was used to estimate the population in Based on a 22.6% growth over a 20-year period the anticipated 2038 projected population is 12, Annexation There are five planned annexation areas anticipated within the 20-year design period. The areas include the following: North Long Lake 78 parcels Willow Springs & North Highway parcels West Long Lake 108 parcels Highland Drive 91 parcels Lake Floyd 671 parcels A planned annexation for Lake Sallie has also been included as it is anticipated at the 20- year design year of Lake Sallie has 605 parcels. A planned annexation for Lake Melissa is not included as it is anticipated beyond the 20- year design year of Lake Melissa has 718 parcels. The total annexation includes 1,599 parcels with an estimated 2.2 people per parcel. This equates to a population of 3,518. This will be added to the 2038 projected population to get a total design population of 15,584. DLPUC Page 1

25 4.0 Flow and Load Projections The historical flow data from 2011 thru 2013 was used to help determine the 20-year projected flows and loads. The MPCA flow determination worksheet for the 20-year design period is included in Appendix A. A value of 120 gallons/capita/day (gpcd) was used to determine the projected flows. Although this value may be higher than the typical value of gpcd, this number takes into account the increased summer population. The projected average wet weather flow for 2038 is 2.21 MGD. The four projected flow conditions for 2038 are reported in Table 1 (2038 WWTF Projected Flows) and account for the projected 2038 population of 15,584. The City currently does not have a significant industrial user and no additional capacity has been included for an increase for a large commercial or industrial user in the 20-year planning period. Table WWTF Projected Flows Current 2038 Projections Population, Detroit Lakes 8,569 12,066 Population, Total 15,584 1 Flow Condition Average Dry Weather Flow (ADW) Average Wet Weather Flow (AWW) Annual Average Flow Peak Hourly Wet Weather Flow (PHWW) Peak Instantaneous Wet Weather Flow (PIWW) : Includes 1,599 connections from annexations at 2.2 persons per household. The population increase due to annexation is 3, : Includes 120 gallons per capita per day for Detroit Lakes population growth. 3 : June 1-30, 2013 received 6.0 rain. 4 : Peaking factor from Ten State Standards used to calculate actual data not available. 5 : Assumed value actual data not available. DLPUC Technical Memorandum No. 1 Page 2 Detroit Lakes Public Utilites Commission

26 Table 2 was used to establish the average day and peak month infiltration and inflow (I/I). The I/I flow contribution was used in determining the average wet weather flow. Table 2 Inflow and Infiltration Determination Average Annual Average Flow Dry Weather Flow Peak Month Flow Average Day I&I Peak Month I&I Average Flow = Average of all 12 months Dry Weather Flow = Average of Dec, Jan, and Feb Average Day I&I = Average Flow Dry Weather Flow Peak Month Flow = Highest Monthly Average Flow Value for Each Year Peak Month I&I = Peak Month Flow Dry Weather Flow The peak hour and peak instantaneous flows were difficult to establish because the data is not currently being collected at the treatment plant. Figure 1 in the Recommended Standards for Wastewater Facilities (also known as Ten State Standards) may be used for determining peak hour flows in the event that historic data is not readily available. While this approach may be conservative, it is the approach used to determine the peak hourly design flow here. The peaking factor for the projected peak hourly flow will be 2.9 based on the projected population. For the peak instantaneous flows the MPCA guidelines suggest using either actual data or a peaking factor of 2.5. Since actual data is not available and 2.5 is less than the peaking factor determined for the peak hourly flow, the peaking factor for the peak instantaneous flow will be the same as the peaking factor for the projected peak hourly flow of Load Determination The MPCA Determination of Design Loadings worksheet was used to establish the projections for 2038 at the Detroit Lakes WWTF. The worksheet was slightly modified to include TKN in place of NH3-N. TKN is comprised of both organic and ammonia nitrogen. Organic nitrogen contributions are important when considering biological nutrient removal. The following factors/assumptions were used when calculating the projected loads: CBOD5 contribution will be based on lb/capita/day. This is the current CBOD5 ratio based on data from 2011, 2012, and TSS contribution will be based on lb/capita/day. This is the current TSS ratio based on data from 2011, 2012, and TKN contribution will be based on lb/capita/day. This is the current TKN ratio based on data from 2011, 2012, and TP contribution will be based on lb/capita/day. This is the current TP ratio based on data from 2011, 2012, and The projected peak loads will be determined based on the current average/peak ratio. Technical Memorandum No. 1 DLPUC Detroit Lakes Public Utilites Commission Page 3

27 The MPCA load determination worksheet for the 20-year design period is included in Appendix B. The projected design and peak loadings for 2038 are shown in Table 3 (2038 WWTF Project Loads). Table WWTF Projected Loads ADW AWW Peak Flow, gpd 1,861,800 2,208,800 BOD5, mg/l BOD5, #/day 2,898 2,898 6,584 TSS, mg/l TSS, #/day 3,444 3,444 10,314 TP, mg/l TP, #/day TKN, mg/l TKN, #/day , Summary The determination of flows and loads is an important item in the planning of a new or expanded wastewater treatment facility. An analysis of existing flow and load conditions will help determine the hydraulic and pollutant removal capacity needed to properly treat wastewater and comply with permit conditions. A summary of the 2011, 2012, and 2013 DMR data provided by the City is included in Appendix C. This data was used to determine current flows and loads and in determining the future flows and loads for the design year of DLPUC Technical Memorandum No. 1 Page 4 Detroit Lakes Public Utilites Commission

28 Appendix A MPCA Flow Determination Worksheet

29 Appendix A MPCA Flow Determination Worksheet (A) For determination of peak hourly wet weather design flows (PHWW): Gallons Per Day 1 Present peak hourly dry weather flow 2 Present peak hourly flow during high ground water period (no runoff) 3 Present peak hourly dry weather flow [same as (1)] - 4 Present peak hourly infiltration = 5 Present hourly flow during high ground water period and runoff at point of greatest distance between Curves Y and Z 6 Present hourly flow during high ground water (no runoff) at same time of day as (5) - measurement 7 Present peak hourly inflow = 8 Present peak hourly inflow adjusted for a 5-year 1-hour rainfall event 9 Present peak hourly infiltration [same as (4)] 10 Peak hourly infiltration cost effective to eliminate - 11 Peak hourly infiltration after rehabilitation (where rehabilitation is cost effective) = 12 Present peak hourly adjusted inflow [same as (8)] 13 Peak hourly inflow cost effective to eliminate - 14 Peak hourly inflow after rehabilitation (where rehabilitation is cost effective) = 15 Population gpcd times 2.5 (peaking factor) 16 Peak hourly flow from planned industrial increase 17 Estimated peak hourly flow from future unidentified industries 18 Peak hourly flow from other future increases 19 Peak hourly wet weather design flow [(1)+(11)+(14)+(15)+(16)+(17)+(18)] = 6,405,520 (1) (B) For determination of peak instantaneous wet weather design flow (PIWW): Gallons Per Day 20 Peak hourly wet weather design flow [same as (19)] 21 Present peak hourly inflow adjusted for a 5-year 1-hour rainfall event [same as (8)] - 22 Present peak inflow adjusted for a 25-year 1-hour rainfall event + 23 Peak instantaneous wet weather design flow = 6,405,520 (2) (C) For determination of average dry weather design flow (ADW): Gallons Per Day 24 Present average dry weather flow 1,020, Population increase gpcd 419,640 (3) 26 Average flow from planned industrial increase + 27 Estimated average flow from other future unidentified industries + 28 Average flow from other future increases Annexations 120 gpcd , Average dry weather design flow [(24)+(25)+(26)+(27)+(28)] = 1,861,800 (D) For determination of average wet weather design flow (30-day average for mechanical plants and 180-day average for controlled discharge ponds) (AWW): Gallons Per Day 30 Present average dry weather flow 1,020, Average infiltration after rehabilitation (where rehabilitation is cost effective) + 173, Average inflow after rehabilitation (where rehabilitation is cost effective) + 173, Population increase 120 gpcd + 419, Average flow from planned industrial increase + 35 Estimated average flow from other future unidentified industries + 36 Average flow from other future increases Annexations 120 gpcd + 422, Average wet weather design flow [(30)+(31)+(32)+(33)+(34)+(35)+(36)] = 2,208,800 (1) Peaking factor is 2.9 based on Ten State Standards (2) Peaking factor is an assumed value of 2.9 (3) A value of 120 gallons/capita/day (gpcd) was used to determine the projected flows. Although this value may be higher than the typical value of gpcd, this number takes into account the increased summer population.

30 Appendix B MPCA Load Determination Worksheet

31 Appendix B MPCA Load Determination Worksheet Unit Basis ADW AWW Residential Waste Population 12,066 Flow, GPD 1,439,640 1,439,640 BOD5, #/day ,242 2,242 TSS, #/day ,667 2,667 TKN, #/day P, #/day Out-of-Town Students and Workers Seasonal Residents Industrial Number Flow, GPD BOD5, #/day TSS, #/day NH3-N, #/day P, #/day Number Flow, GPD BOD5, #/day TSS, #/day NH3-N, #/day P, #/day Flow, GPD Rated Flow, GPD BOD5, #/day TSS, #/day TKN, #/day P, #/day Other (Specify) Population 3,518 Lake Floyd Rated Flow, GPD 422, ,160 BOD5, #/day TSS, #/day TKN, #/day P, #/day Infiltration GPD 173,500 Inflow GPD 173,500 Total Flow, GPD Rated Flow, GPD 1,861,800 2,208,800 BOD5, mg/l BOD5, #/day 2,898 2,898 TSS, mg/l TSS, #/day 3,444 3,444 TKN, mg/l TKN, #/day P, mg/l P, #/day

32 Appendix C DMR Summary for 2011, 2012, and 2013

33 2011 DMR Summary Flow BOD TSS Phos TKN Month Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max January February March April May June July August September October November December Yearly Avg Peak Month Yearly Min Day Yearly Max Day

34 2012 DMR Summary Flow BOD TSS Phos TKN Month Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max January February March April May June July August September October November December Yearly Avg Peak Month Yearly Min Day Yearly Max Day

35 2013 DMR Summary Flow BOD TSS Phos TKN Month Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max Daily Min Mo Avg Daily Max January February March April May June July August September October November December Yearly Avg Peak Month Yearly Min Day Yearly Max Day

36 Technical Memorandum No. 2 Site and Capacity Assessment Wastewater Treatment Facility Detroit Lakes, Minnesota SEH No. DLPUC August 7, 2014

37 Table of Contents Page 1.0 Description EXISTING FACILITY DESCRIPTION TREATMENT COMPONENT REVIEW MAIN WASTEWATER PUMPING STATION Description: Condition: Capacity: Recommendations: AERATION AND GRIT REMOVAL BUILDING AND AERATED GRIT BASIN Description: Condition: Capacity: Recommendations: PRIMARY CLARIFIER SPLITTER STRUCTURE AND PRIMARY CLARIFIERS Description: Condition: Capacity: Recommendations: TRICKLING FILTERS Description: Condition: Recommendations: FINAL CLARIFIERS Description: Condition: Recommendations: ANAEROBIC DIGESTERS Description: Condition: Capacity: Recommendations: SLUDGE STORAGE Description: Condition: Capacity: Recommendations: CHEMICAL PRECIPITATION AND DISINFECTION Description: Condition: Recommendations: AERATED AND STABILIZATION PONDS Description:... 9 SEH is a registered trademark of Short Elliott Hendrickson Inc. Technical Memorandum No. 2 DLPUC Detroit Lakes Public Utilities Commission Page i

38 Table of Contents (Continued) Condition: Capacity: Recommendations: EFFLUENT DISPOSAL Description: Condition: Capacity: Recommendations: CONCLUSION...12 List of Tables Table 1 Unit Process Construction and Improvement Dates... 2 Table 2 Condition / Capacity Assessment Summary List of Figures Figure 1 Detroit Lakes WWTF Location... 1 Figure 2 Detroit Lakes Process Flow Diagram... 3 Figure 3 Groundwater Monitoring Well Readings and Stabilization Pond Separation Elevation a Figure 4 Groundwater Monitoring Well Readings and RIB Separation Elevations a Z:\AE\D\Dlpuc\127205\4-prelim-dsgn-rprts\Site and Capacity Assessment\Technical Memorandum No docx

39 August 2014 Technical Memorandum No. 2 Site and Capacity Assessment Wastewater Treatment Facility Prepared for Detroit Lakes Public Utilities Commission 1.0 Description The purpose of this memo is to provide a description of the existing facilities at the wastewater treatment facility and to identify structures that have potential for reuse and/or repurposing and evaluate whether those structures identified have adequate capacity for the projected future flows and loads. 2.0 EXISTING FACILITY DESCRIPTION The existing wastewater treatment facility (WWTF) is located in the southwestern region of the city of Detroit Lakes, MN. The WWTF consists of the following treatment elements as illustrated in Figure 1: Figure 1 Detroit Lakes WWTF Location DLPUC Page 1

40 Mechanical Trickling Filtration Facility, which includes preliminary treatment, primary clarifiers, trickling filters, final clarification, and solids treatment, is located along Willow Street West approximately three miles south of Highway 10 and one mile east of Highway 59 South. Chemical precipitation facilities for phosphorus removal as well as chlorination for disinfection is located one mile northwest of the Mechanical Trickling Filtration Facility along Highway 59 South. Aeration pond located at the intersection of Highway 59 South and Willow Street West. Stabilization pond located one half mile west of the aeration pond. Spray irrigation and rapid infiltration basin systems located in three main plots around the Detroit Lakes Airport which is approximately one mile north of the facility's stabilization pond. The facility was originally constructed in 1929 as an Imhoff settling tank. In 1942 the facility was converted to a trickling filter facility. During 1962 major renovations of the facility were conducted. The process train was expanded to include the aerated and stabilization ponds. Land application processes and the chemical precipitation facility were added in 1975 and Improvements were made on preliminary treatment, primary clarification and sludge digestion in Table 1 summarizes the construction and improvements dates for major process components at the Detroit Lakes WWTF. Table 1 Unit Process Construction and Improvement Dates Unit Process Date Constructed Improvement Date Description Preliminary Treatment Influent flow measurements, solids screening, grit removal, lift pumps. (2) Primary Clarifiers Settlable solids removal. (2) Trickling Filters Secondary biological treatment. Final Clarifier 1962 Settling of treated trickling filter effluent. Sludge Treatment and Storage Effluent Pump to Trickling Filters , 1995 Treatment and storage of solids Pump trickling filter facility effluent to aerated pond. Aerated Pond 1962 BOD reduction. Stabilization Pond 1962 Additional BOD reduction and storage. Chemical Precipitation Facility Rapid Infiltration Basins Spray Irrigation Facilities 1976 Tertiary treatment for phosphorus removal prior to surface discharge (Nov. Apr.) Effluent discharge (May-Oct.) 1976 Effluent discharge (May-Sept.) DLPUC Technical Memorandum No. 2 Page 2 Detroit Lakes Public Utilities Commission

41 According to the NPDES permit, the Detroit Lakes WWTF is designed to treat an average annual influent flow of 1.64 MGD and an average wet weather flow of 2.02 MGD with a 5-Day Carbonaceous Biochemical Oxygen Demand (CBOD5) strength of 320 mg/l. The Detroit Lakes WWTF is considered a Class A facility. This classification comes from Minnesota Administrative Rule , which defines a scoring system assigning facilities to Classes A, B, C, or D. With this classification, the facility must be operated by an operator who is certified to operate a Class A facility. Figure 2 represents a process flow diagram of the Detroit Lakes WWTF. Figure 2 Detroit Lakes Process Flow Diagram 3.0 TREATMENT COMPONENT REVIEW The facilities were toured with City Staff and a general assessment on the condition of each unit process was made. The assessment included a review of the structural and mechanical features of each unit by visual inspection and City staff providing input on the operations of each unit process. The following structures/unit processes were determined to have potential for reuse and/or repurposing: The main wastewater pumping station building which houses the mechanical screening, wetwell, and raw wastewater pumps. The aeration and grit removal building which houses the blower for the aerated grit chamber, the grit pump, and the grit classifier. The aerated grit basin. The primary clarifier splitter structure that was designed to add a third primary clarifier. The two primary clarifier tanks with aluminum domes. Technical Memorandum No. 2 DLPUC Detroit Lakes Public Utilities Commission Page 3

42 The two anaerobic digester tanks. The digester building that houses the boiler, heat exchanger, sludge pumps, and biogas safety equipment. Each of the structures/unit processes identified for potential reuse and/or repurposing is described in more detail and evaluated for available capacity at the 2038 projected flows. If the condition of a process or unit did not warrant reuse, the capacity of the process/unit was not evaluated. Capacities of treatment units determined to be reused/repurposed were evaluated using accepted design standards from the Recommended Standards for Wastewater Facilities (2004, often referred to as Ten States Standards ), the Fourth Edition of the Wastewater Engineering Treatment and Reuse text by Metcalf and Eddy (2003), and the Fifth Edition of the Water Environment Federation Manual of Practice No. 8 (WEF MOP-8) Design and Treatment of Municipal Wastewater Treatment Plants (2010). 3.1 MAIN WASTEWATER PUMPING STATION Description: The wastewater influent from the collection system enters the facility at the Waste Pumping Station which houses the facility s mechanical bar screen and two influent pumps. The pumps transport wastewater from the pumping station to the Grit Removal Building. The Main Wastewater Pumping Station consists of coarse screening mechanical bar screen with a manual bar screen bypass and raw sewage pumping. The lower level of the Main Wastewater Pumping Station houses both a mechanical bar screen as well as a manual bypass bar screen which is hand raked. Additionally there is a wetwell followed by two parallel influent wastewater pumps (one redundant). The channels to both screens are 24 inches wide and slope away from the influent pipe. After exiting the bar screen channel, wastewater enters a 10 foot x 12 foot wetwell. Two pipes feed wastewater through two parallel influent pumps (one redundant) prior to leaving the pump station. A magnetic flow meter is located after the two pumps. The upper level of the Main Wastewater Pumping Station has the mechanical bar screen which extends through an opening in the floor to the lower level. Screened debris is deposited into a dumpster via a connecting chute for disposal Condition: The building for the main wastewater pumping station appears to be in good condition. The space was designed specifically for the equipment that it houses with no room for expansion within the existing walls. The screening equipment and pumps are nearly 20 years old and appear to be reaching the end of their useful life Capacity: The wetwell is undersized as it should be sized for two minutes of flow entering the wastewater treatment facility. Its current volume is nearly 2,800 gallons and current Peak Instantaneous Wet Weather (PIWW) flow for two minutes is 5,500 gallons with 2038 PIWW for two minutes being 8,000 gallons DLPUC Technical Memorandum No. 2 Page 4 Detroit Lakes Public Utilities Commission

43 The channel flow velocity for the mechanical bar screen is dictated by the influent level in the wetwell. Pump start is set at a channel depth of 1.3 feet and would represent minimum channel velocity. With an Average Wet Weather (AWW) flow of 1.37 million gallons per day (MGD), bar screen channel velocity of wastewater would be 0.46 feet per second. Ten States Standard for wastewater bar screening recommends a minimum channel velocity of 1.25 feet per second to prevent settling of debris in the flow channel. For the projected 2038 flows it is estimated that a wider channel will be needed as well as a channel with adequate slope. It is also estimated that a larger wetwell is needed for storage of influent prior to pumping Recommendations: Because there is no room for expansion of the channel width or wetwell volume and the equipment needs to be replaced due to age, the reuse of this building is not practical, however, it could be considered for repurposing as a process return lift station during design. 3.2 AERATION AND GRIT REMOVAL BUILDING AND AERATED GRIT BASIN Description: Screened influent flows in a channel to the aeration grit basin located at the Aeration Grit Removal Building. The basin contains an airline with diffuser head. An air blower in the upper level of the Grit Removal Building supplies compressed air to the air diffuser. The grit feeds into a 4 foot square sump and feeds a grit pump which lifts the suspension to a grit separator and hydrogritter located in the building. The separated grit is collected in a bin in the lower level. At the top of the aeration grit basin, effluent water passes under an underflow weir before spilling into an effluent channel. Effluent water then leaves the Grit Removal Building and enters a concrete splitter box prior to flowing into either of the two primary clarifiers. There is the option of bypassing the grit removal process. Influent water would feed into the bypass effluent channel and enter the concrete splitter box Condition: The blower, grit pump, and grit classifier are nearly 20 years old and appear to be reaching the end of their useful life. Because the Grit Removal Building appears to be in good condition, the building could be reused for replacement of similar type equipment. There is no visible chipping or pitting of concrete in the aerated grit chamber. The electrical room is currently enclosed in a steel enclosure outside the Grit Building. Building modifications may be needed to better enclose the electrical room Capacity: Per the manufacturer s design capacity, a 14 foot square aerated grit basin is sufficient to treat a PIWW flow of approximately 5.0 MGD. The 2038 projections estimate a PIWW flow of 6.33 MGD, which exceeds the design volume of the existing unit. Visually the aerated grit chamber is not producing a substantial amount of turbulence in the treated wastewater. This could be caused by unsteady or uncontrolled air supply, improper diffuser location, or less than ideal tank geometry. Technical Memorandum No. 2 DLPUC Detroit Lakes Public Utilities Commission Page 5

44 3.2.4 Recommendations: Replacement of the equipment should be considered due to age and type of grit system selected. The existing Grit Building could house similar type equipment (pumps, grit classifiers, etc.) and could be reused to house equipment for a grit removal system. While the aerated grit basin is lacking capacity and should not be considered for reuse or repurposing, the effluent channel could be reused with merging a similar or different type of technology (i.e. vortex grit removal). 3.3 PRIMARY CLARIFIER SPLITTER STRUCTURE AND PRIMARY CLARIFIERS Description: Wastewater from the aerated grit basin flows to a concrete splitter box. The splitter box is equipped with three 24 inch sluice gates to control wastewater distribution to the primary clarifiers. Currently the facility has two primary clarifiers. The third is for future construction. Each 40 foot diameter clarifier is fed from the splitter box. Wastewater enters each clarifier from a central influent column and feed well. The clarifiers are equipped with skimmer blades tipped with squeegees and rake arms with stainless steel squeegees to assist in the collection of sludge. Each clarifier is covered with an aluminum dome Condition: The condition of the tanks appears to be good. There is no visible chipping or pitting of the concrete structures. The aluminum domes on the tanks appear to be in good condition. There is no visible deterioration of the dome material. One of the aluminum domes appears to have been hit by something at the point where the cover meets the tank. The damage appears to be minimal and repairable. The clarifier equipment is 20 years old and corrosion and wear is evident on the clarifier mechanisms. The condition of the handrails and walkways is good and shows minimal signs of corrosion Capacity: The clarifiers are 40 foot diameter concrete tanks with feet of water depth at the sidewall. Total volume per clarifier is approximately 115,000 gallons with an AWW detention time of 2.55 hours and a Peak Hourly Wet Weather (PHWW) detention time of 0.88 hours at the projected 2038 flow rates. The clarifiers have a combined average surface loading of 867 gallons per day per square foot (gpd/sf) with 2038 projected flows. The recommended surface loading is between 600 and 800 gpd/sf to prevent floc from spilling into the launder weirs which will cause increased turbidity in process water. Peak surface loading for the clarifiers is 2,519 gpd/sf which also exceeds the recommended 1,200 to 1,700 gpd/sf. The weir loading is 26,865 gpd/ft which is within the Metcalf and Eddy recommended 10,000 to 40,000 gallons per day per foot (gpd/ft) at PHWW flow. The two existing primary clarifiers are not adequate for the projected 2038 flows Recommendations: The design of the primary clarifiers in 1995 included the future construction of a third clarifier. The splitter box should be reused for three clarifiers. Due to the age and condition of the clarifier equipment, replacement for the existing clarifier equipment should be considered. The two existing primary clarifiers and domes could be reused if a third primary clarifier is constructed. DLPUC Technical Memorandum No. 2 Page 6 Detroit Lakes Public Utilities Commission

45 3.4 TRICKLING FILTERS Description: The primary clarifier effluent flows to the trickling filter inlet collection box where the flow is split between the small trickling filter and the large trickling filter. The small trickling filter has plastic media and the large trickling filter has rock media. The trickling filters have rotary distributors which supply a flow of water across the filtration media. Effluent from the trickling filters feed to the final clarifiers Condition: The condition of the large trickling filter is poor. There is significant deterioration of the concrete above the rock media. Reinforcement bars are exposed inside the tank and large cracks in the concrete surrounding the tank are present. Large sections of the top of the tank wall have fallen away from the structure due to deterioration. The condition of the small trickling filter was evaluated by a structural engineer. The structure was found to be structurally sound. However, the configuration, size, and location make it difficult to reuse or repurpose the tank. While the mechanical distribution arm appears to be good, the Staff reports the underdrain is starting to fail. There is also a concern about the adequacy of the existing ventilation system Recommendations: Due to the condition of the large trickling filter, continued use of this structure for any purpose should not be considered. Because the large trickling filter should not continue to be used and trickling filter technology will not likely be considered due to the advanced treatment needs of the Facility, the small trickling filter should not be considered for reuse. Additionally, the location and configuration of the tank will make it difficult to repurpose the tank if it is not used as a trickling filter. 3.5 FINAL CLARIFIERS Description: Influent wastewater to the final clarifiers pass through two manholes, the first of which provides a bypass of final clarification and the second distributes flow through the final clarifiers. Sludge is collected and transported to the head of the facility. The effluent passes through the existing control buildings which houses an effluent pump. The pump delivers water to the aerated pond located west of the treatment facility Condition: The condition of the final clarifiers is poor. While the tank had minimal chipping or pitting of the concrete, the walkways were deteriorated significantly. The tank would require modifications if repurposed. The tanks would not be reused as final clarifiers as more process control will be needed with advanced treatment or final clarifiers may not be needed at all. The final clarifier equipment is over 20 years old and should be considered at the end of its useful life Recommendations: Because there is evidence of deterioration of the walkways and significant repairs would be needed, the final clarifier structure should not be considered for reuse. Technical Memorandum No. 2 DLPUC Detroit Lakes Public Utilities Commission Page 7

46 3.6 ANAEROBIC DIGESTERS Description: Primary sludge from the two primary clarifiers is pumped to the anaerobic digestion system. The anaerobic digestion system was constructed in The primary sludge is transferred with three sludge pumps to the primary digester. The primary digester is 45 feet in diameter with a sidewater depth of 22 feet. Accounting for the cone, the tank has a volume of approximately 293,000 gallons. The existing digester is mixed with a gas mixing system and is heated through a tube-in-tube heat exchanger. The digested sludge transfers by gravity to a secondary digester which is 50 foot diameter and has a volume of approximately 360,000 gallons. The secondary digester also has the ability to be heated, but no mixing system is installed Condition: The condition of the building and tanks appears to be good. The existing mixing and heating systems are 20 years old and other mixing systems, such as draft tubes, linear motion mixers, or pumped mixing should be considered. The boiler, heat exchanger, and recirculation pumps should all be considered for replacement Capacity: To produce Class B biosolids and to comply with the design recommendations from the Minnesota Pollution Control Agency (MPCA), the digester should be sized for a solids retention time (detention time) of at least 15 days. Based on projected sludge volumes for 2038 flow and loading conditions with treatment from an activated sludge treatment system employing enhanced biological treatment with tertiary filtration, the existing primary digester has adequate capacity with a retention time of 18 days. Also to comply with the Ten State Standards recommendations, the volatile solids loading rate should not exceed 0.08 pounds of volatile solids per cubic foot of digester volume (lb VS/cf). However, this volatile solids loading rate is conservative and the Water Environment Federation Manual of Practice No. 8 (MOP-8), a standard reference for wastewater design and operation, suggests a typical design volatile solids loading rate of 0.12 to 0.16 lb VS/cf. Based on projected sludge volumes for 2038 flow and loading conditions with treatment from an activated sludge treatment system employing enhanced biological treatment with tertiary filtration, the existing primary digester has adequate capacity with a volatile solids loading rate is lb VS/cf-d Recommendations: Due to the age of the equipment and technology available replacement of the equipment should be considered, including the digester mixing and heating system. With proper coatings, the digester covers could continue to be used. An internal inspection of the tanks would be required to determine the condition of the steel covers. For the basis of this facility plan, it is assumed new covers would be required. 3.7 SLUDGE STORAGE Description: Digested sludge from the primary digesters overflows to the secondary digester. The secondary digester is 50 feet in diameter with a sidewater depth of 22 feet. Accounting for the cone, the tank has a volume of 362,262 gallons. The sludge storage tank has a volume of 137,332 gallons, for a combined sludge storage volume of 499,610 gallons. DLPUC Technical Memorandum No. 2 Page 8 Detroit Lakes Public Utilities Commission

47 3.7.2 Condition: The condition of the secondary digester appears to be good. The condition of the sludge storage tank is unknown as a visual inspection was not feasible Capacity: Ten States Standards requires solids storage for 120 to 180 days. Based on estimates of future solids production, the existing sludge storage volume provides only 60 days of storage (assuming the solids are decanted to achieve 4.5% solids) Recommendations: Because the tank was built in 1962, the condition could not be verified visually, and the capacity does not meet storage requirements for both current and future conditions, the sludge storage tank should not be considered for reuse or repurposing. 3.8 CHEMICAL PRECIPITATION AND DISINFECTION Description: The Chemical Precipitation Facility is located north of the stabilization pond and is designed to work from November until April to treat effluent waste water to meet permit requirements prior to surface discharge into Saint Clair Lake, and has a design capacity of 1.44 MGD. The facility utilizes ferric sulfate for the removal of phosphorus in facility wastewater. The Chemical Precipitation Facility consists of two solids contact clarifiers, two dual media gravity filters, and a chlorination unit for disinfection of the facility effluent Condition: The chemical precipitation plant is nearly 40 years old. While it still continues to work well, the chemical precipitation process becomes a bottleneck at flows over 1.2 MGD, which is well below the projected average wet weather flow of 2.18 MGD. The equipment, including the pumps, chemical feed, clarifiers, filters, and chlorination system, have outlived their useful life and would need to be considered for replacement. The hydraulic capacity of the chemical precipitation plant would also need to increase to meet the 2038 projections Recommendations: Attempting to replace all aging equipment and installing larger capacity equipment in the existing chemical precipitation plant building is not practical and would likely cost as much as constructing new facilities for phosphorous removal at the existing mechanical WWTF site or a new site. The reuse or repurposing of the chemical precipitation plant should not be considered. 3.9 AERATED AND STABILIZATION PONDS Description: The aerated pond is a three-acre water body which was equipped with floating aerators. Although the facility was originally designed to have an aerated pond, the aerators are no longer operational. Effluent is piped across Highway 59 South to a 25-acre stabilization pond adjacent to the chemical precipitation facility. The pond acts as both a stabilization pond and as storage for the Chemical Precipitation Facility, Rapid Infiltration Basins, and Spray Irrigation Facilities. Technical Memorandum No. 2 DLPUC Detroit Lakes Public Utilities Commission Page 9

48 3.9.2 Condition: The stabilization pond does not meet recommended pond design criteria for both seepage and groundwater separation. According to the NPDES permit the 25-acre stabilization pond is leaking beyond the allowable 3,500 gallons per acre per day limit. While the pond is grandfathered in under the current permit, any improvements to the pond would require it meet current a seepage rate of 500 gallons per acre per day according to the MPCA Recommended Pond Design Criteria. The groundwater monitoring well readings would indicate that the groundwater is higher than the 4 foot of separation needed between the pond bottom and groundwater according to the MPCA Recommended Pond Design Criteria. Figure 3 below shows the groundwater level readings reported in the monthly DMR reports and the 4 foot separation elevation from the floor of the stabilization pond. Figure 3 Groundwater Monitoring Well Readings and Stabilization Pond Separation Elevation a Groundwater Elevation (ft) Recorded Groundwater Elevation 4' Separation Elevation For Stabilization Pond Groundwater Monitoring Well Notes: (a) The Groundwater Monitoring Well Readings were calculated based on the well elevations and the depth to water readings from the DMR reports. The stabilization pond bottom elevation is from the 1991 plans for the Infiltration Basins Capacity: At the projected wet weather flow of 2.18 MGD the stabilization pond has approximately 11.2 days of detention time Recommendations: Continued use of the stabilization pond should not be considered as it cannot reliably meet the required separation distance or seepage rates without significant modifications. According to the National Resource Conservation Service (NRCS) maps for the Detroit Lakes area, the depth to groundwater generally ranges from 0-12 inches, with some small areas of greater than 36 inches for land around the stabilization pond. Expansion or modification of the stabilization pond is not practical due to groundwater depths in the area. DLPUC Technical Memorandum No. 2 Page 10 Detroit Lakes Public Utilities Commission

49 3.10 EFFLUENT DISPOSAL Description: As an alternative to the chemical precipitation facility, the city operates 19 Rapid Infiltration Basins covering acres as well as 4 Spray Irrigators in three major sites located around the Detroit Lakes Airport. The irrigation sites cover a total of 54 acres which are supported by two irrigation pumps and fixed nozzle distributors. The operation of spray irrigation is based on a flow limit of 130 million gallons of annual application. The Rapid Infiltration Basin s application volume is determined by filling the basin to three inches of water depth and monitoring how long it takes for the effluent water to infiltrate. The Rapid Infiltration Basins and Spray Irrigation are utilized from May until October. It is not possible to operate the Chemical Precipitation Facility and some of the Rapid Infiltration Basins and Spray Irrigation simultaneously since they share inlet structures Condition: Visual observation by staff of the RIBs indicate that some beds are dry within 24 hours of application, whereas other beds are never dry. Some beds remain wet on one end and dry on the other end. The water is slow to drain and inconsistent from bed to bed. According to the Guidance and Submittal Requirements for Rapid Infiltration Basin Wastewater Treatment Systems from MPCA the groundwater separation distance from the bottom of a RIB must be at least 3 feet. Review of the groundwater monitoring wells around the spray irrigation sites and RIBs show that the groundwater elevation in the majority of the wells is higher than the required 3 foot separation elevation from the floor of the RIBs. This would explain the slow or lack of infiltration in some RIBs. Figure 4 below shows the groundwater level readings reported in the monthly DMR reports and the required 3 foot separation elevation for the RIBs (the 3 foot separation elevation for the 1974 RIBs is 1349 ft and for the 1991 RIBs is 1346 ft). Technical Memorandum No. 2 DLPUC Detroit Lakes Public Utilities Commission Page 11

50 Figure 4 Groundwater Monitoring Well Readings and RIB Separation Elevations a 1365 Groundwater Elevation (ft) Recorded Groundwater Elevation 3' Separation Elevation for 1991 RIBs 3' Separation Elevation for 1974 RIBs Groundwater Monitoring Well Notes: (a) The Groundwater Monitoring Well Readings were calculated based on the well elevations and the depth to water readings from the DMR reports. The elevation of the bottom of all RIBs is from the 1991 plans for the Infiltration Basins Capacity: According to the NPDES permit, the RIBs are to be filled to a maximum of 3 inches one day and allowed to dry for the next 3-5 days. The capacity of the spray irrigation sites is also limited in the NPDES permit. The quantity of effluent to be applied on Sites #1 and #2 annually is 75 million gallons and on Sites #3 and #4 annually is 55 million gallons. If the number of days of land disposal is 165 days, the spray irrigation system and RIBs provide an average estimated 953,000 gallons per day of capacity. This falls short of the projected average wet weather flow for 2038 of 2.18 MGD. While the sites have operated above the estimated capacity, the flows to the RIBs and spray irrigation is still less than the projected 2038 average wet weather flow Recommendations: The lands available around the current spray irrigation and RIB sites are considered somewhat limited and very limited for infiltration according to the National Resource Conservation Service (NRCS) maps for the Detroit Lakes area. The depth to groundwater generally ranges from 0-12 inches, with some small areas of greater than 36 inches. The RIBs do not meet the 3 feet of separation required by MPCA and expansion of and/or continued use of the RIBs should not be considered as they cannot reliably provide adequate infiltration or meet the separation requirements. 4.0 CONCLUSION The Detroit Lakes WWTF structures/unit processes were reviewed for condition, potential for reuse or repurposing, and capacity if considered for reuse. Table 2 is a summary of the review. DLPUC Technical Memorandum No. 2 Page 12 Detroit Lakes Public Utilities Commission

51 Table 2 Condition / Capacity Assessment Summary Treatment Process Capacity Sufficient? Reuse Repurpose Comments Main Wastewater Pump Station Screening No No No Pumping/Wetwell No No Yes Wetwell could be used as process return lift station; pumps need replacement Grit Removal Building And Aerated Grit Chamber Grit Removal Building N/A Yes No Building could be used with similar type grit equipment Aerated Grit Chamber No Yes No The effluent channel of the aerated grit chamber could be reused Equipment (blower, pumps, hydrogritter) Primary Clarifiers No No No Equipment needs replacement Splitter Box Yes Yes No Designed with a future third clarifier Tanks No Yes No Existing tanks in good condition; additional tankage needed Domes N/A Yes No Domes in good condition Trickling Filters Large trickling filter N/A No No Condition of structure is poor Small trickling filter N/A No No Trickling filter technology not appropriate; difficult location and configuration for repurposing Final Clarifiers Tanks N/A No No Condition of walkways poor; major modifications needed if repurposed Equipment N/A No No Equipment needs replacement Anaerobic Digesters Primary Digester Yes Yes Yes Tank in good condition Covers N/A No No With proper coatings covers could be reused, inspection needed Equipment Yes No No Equipment needs replacement, including mixing, pumping, heating systems Building N/A Yes Yes Building in good condition Sludge Storage Secondary Digester Yes Yes Yes Tank in good condition Sludge Storage Tank No No No Condition cannot be verified; built in 1962 Chemical Precipitation Facility Structures and Equipment N/A No No Built in 1962; hydraulic bottleneck; equipment and tanks need replacement Ponds Stabilization Pond No No No Does not meet seepage or groundwater separation guidelines; Effluent Disposal Spray Irrigation and RIBs No No No RIBs do not meet groundwater separation guidelines, cannot reliably provide adequate infiltration Technical Memorandum No. 2 DLPUC Detroit Lakes Public Utilities Commission Page 13

52 Technical Memorandum No. 3 Liquid Treatment Alternative Evaluation Detroit Lakes, Minnesota SEH No. DLPUC January 9, 2015

53 Table of Contents Page 1.0 Effluent Standards Future Limits Toxicity Reduction Evaluation Total Phosphorus Alternative Discharge Locations Liquid Treatment Alternative Evaluation Cost Development Preliminary Treatment New Building for Screening and Pumping New Vortex Grit Chamber with Existing Grit Removal Building Primary Treatment Disinfection Secondary And Tertiary Treatment Conventional Activated Sludge (CAS) Integrated Fixed-Film Activated Sludge (IFAS) Enhanced Biological Phosphorus Removal (EBPR) Filtration Enhanced Filtration Tertiary/High-Rate Clarification Two-Stage Granular Media Filtration Membrane Biological Reactor (MBR) Secondary & Tertiary Treatment Summary of Alternatives Discharge Location Phosphorous Concentration Secondary and Tertiary Treatment Costs Additional Costs for each Location Consideration of Chlorides Existing WWTF Site Vs New WWTF Site Seasonal Discharge vs. Year Round Discharge Summary...15 SEH is a registered trademark of Short Elliott Hendrickson Inc. Technical Memorandum No. 3 DLPUC Detroit Lakes Public Utilites Commission Page i

54 Table of Contents (Continued) List of Tables Table 1 Average Phosphorus Concentration... 1 Table 2 Preliminary Effluent Limits... 2 Table 3 Preliminary Treatment, Primary Treatment, and UV Disinfection... 5 Table 4 Secondary and Tertiary Treatment System Costs Table 5 Phosphorus Limits Table 6 Secondary and Tertiary Treatment Table 7 Discharge Location Cost Considerations Table 8 WWTF Site Location Cost Considerations Table 9 Seasonal Vs. Year Round Discharge Cost Considerations Table 10 Summary of Alternatives List of Figures Figure 1 Secondary and Tertiary Treatment Alternatives... 6 Figure 2 Cost Diagram for Secondary and Tertiary Treatment Systems List of Appendices Appendix A Appendix B Appendix C Appendix D Appendix E NPDES Permit Alternate Discharge Location Map MPCA Preliminary Effluent Limits Site Layout Liquid Treatment Cost Breakdown S:\AE\D\Dlpuc\127205\4-prelim-dsgn-rprts\Liquid Memo\DRAFT Technical Memorandum No. 3 - rev2_ docx

55 January 2015 Technical Memorandum No. 3 Liquid Treatment Alternative Evaluation Prepared for Detroit Lakes Public Utilites Commission 1.0 Effluent Standards The Detroit Lakes WWTF discharges wastewater in accordance with Minnesota National Pollutant Discharge Elimination System (NPDES)/State Disposal System (SDS) permit no. MN A copy of the current permit is included in Appendix A. This permit became effective February 6, 2014 and expires January 31, Future Limits The current NPDES/SDS permit has identified future limits for the Detroit Lakes WWTF and provided compliance schedules for achieving the limits. 2.1 Toxicity Reduction Evaluation The City has completed Phases I and II of a Toxicity Identification Evaluation (TIE) due to failed Chronic Whole Effluent Toxicity (WET) tests. The first two phases indicated that the toxicity is primarily ammonia, but has also identified high specific conductance as a potential source as well. The City will be required to complete Phase III of a TIE and the facility will have a chronic WET limit of 1.0 TUc. 2.2 Total Phosphorus The Detroit Lakes WWTF currently discharges effluent to St Clair Lake in the winter months and must achieve a 12-month moving average limit of 1.0 mg/l phosphorus. The permit will require 198 kilogram per year (kg/yr) limit for the Facility s discharge and the Facility must attain compliance no later than October 1, The future limit of 198 kg/yr will significantly reduce the concentration of phosphorus that can be discharged to St Clair Lake. See Table 1 for the average phosphorus concentration the Facility would have to meet if seasonally discharged to St Clair Lake (at current and future AWW flows) and if discharged to St Clair Lake year round to achieve the future limit of 198 kg/yr. Discharge Table 1 Average Phosphorus Concentration Seasonal Discharge at current AWW flow of 1.37 MGD (1) Seasonal Discharge at projected AWW flow of 2.20 MGD (1) Year Round Discharge at current AWW flow of 1.37 MGD Year Round Discharge at projected AWW flow of 2.20 MGD (1) Seasonal discharge assumes 200 days/year to St. Clair Lake. Average Daily Phosphorus Concentration to Achieve Mass Limit of 198 kg/yr 0.20 mg/l 0.12 mg/l 0.10 mg/l 0.06 mg/l DLPUC Page 1

56 3.0 Alternative Discharge Locations The City explored the option of alternative discharge locations and the impact on the phosphorus limit the WWTF must achieve. The two alternative discharge locations identified are Becker County Ditch No. 5 and the Buffalo River. Both discharge locations are located within the Buffalo Red River Watershed District (BRRWD). The City met with BRRWD to discuss the impacts of the WWTF effluent discharge on flow within the watershed. Both locations are considered viable options for discharge, although Becker County Ditch No. 5 is only 3.2 miles from the existing WWTF location whereas the Buffalo River is 11.2 miles. The location for the discharge to the Buffalo River was selected where there would be no lakes downstream to influence the phosphorous limit. A map showing the two alternate discharge locations is included in Appendix B. A preliminary effluent limit request was submitted to the MPCA for the two identified discharge locations. The request included flows for both seasonal and year-round discharge scenarios. A copy of the preliminary effluent limits from the MPCA is included in Appendix C. Table 2 is a summary of the preliminary effluent limits for the different scenarios. Substance or Characteristic 5-Day Carbonaceous Biochemical Oxygen Demand, mg/l Table 2 Preliminary Effluent Limits Becker County Ditch No. 5 Continuous Discharge Seasonal Discharge Continuous Discharge Buffalo River Seasonal Discharge Total Suspended Solids, mg/l Fecal Coliform, organisms/ml (1) 200/ / / /100 Ammonia N, mg/l: Jun 1 Sep N/A 1.0 N/A Oct 1 Nov Dec 1 Mar Apr 1 May N/A 13.0 N/A ph Range Total Residual Chlorine, mg/l Total Chloride, mg/l (2) 229 (275) 229 (275) 231 (277) 233 (280) Chronic WET, TUc Total Phosphorus, mg/l (3) (3) (1) Applicable from April October. If chlorine is used to achieve the effluent limitation for fecal coliform group organisms, then dechlorination must be provided. (2) The values in parenthesis are maximum daily values. (3) A more restrictive total phosphorous limit of 0.5 mg/l is applicable if discharge occurs from June 1 September 30. The preliminary effluent limits from the MPCA also include the following comments which have been summarized here: The discharge location for Becker County Ditch No. 5 is upstream of Reep Lake and two years of in-lake monitoring would be required. If the monitoring showed further impairment with phosphorus, a more restrictive monthly average limit of 0.2 mg/l may be assigned in the future if necessary. DLPUC Technical Memorandum No. 3 Page 2 Detroit Lakes Public Utilites Commission

57 Minnesota has adopted numeric river eutrophication standards in 2014 and are awaiting review and approval from the Environmental Protection Agency (EPA). If discharging to the Buffalo River, the permittee would be evaluated to determine reasonable potential to cause or contribute to downstream impaired waters. If found to have reasonable potential for Total Phosphorus impairment, the WWTF would be required to have a Total Phosphorus Water Quality Based Effluent Limit (WQBEL), resulting in a TP monthly average limit near 0.3 mg/l. If the City choses to pursue a new discharge location, the following considerations must be made: Discharge to Becker County Ditch No. 5 will require further survey of the ditch system and evaluation of Reep Lake would need to be completed. It is possible that Becker County Ditch No. 5 will require some improvements to handle the additional flow from the Detroit Lakes WWTF. As mentioned above, two years of in-lake monitoring of Reep Lake would be required to determine the final phosphorous discharge limit. Discharge to Becker County Ditch No. 5 and the Buffalo River will require the City to acquire right-of-way along the route of the forcemain from the WWTF. The location of discharge to the Buffalo River where there are no lakes downstream is approximately 11.2 miles from the WWTF, whereas the location of discharge to Becker County Ditch No. 5 is 3.2 miles. Discharge to either Becker County Ditch No. 5 or the Buffalo River will require a nondegradation analysis. Minn R requires an agency nondegradation review for all waters of the state for significant new or expanded discharges. The lake monitoring, the acquisition of right-of-way, and/or the non-degradation review will require multiple years before a NPDES discharge permit for either location can be obtained. 4.0 Liquid Treatment Alternative Evaluation Alternatives for liquid treatment that have been evaluated fall into the following categories: Preliminary Treatment Primary Treatment Secondary/Tertiary Treatment Disinfection For the purpose of this planning-level report, the costs presented represent the alternative of using the existing WWTF site. Additional costs for a new WWTF site are identified later in the report. In order to use the existing site for the improvements, the existing control building is proposed to be demolished and removed completely before construction of the secondary treatment system can begin. There are currently two sets of pumps in the control house that are used: the effluent pumps and the sludge pumps to pump WAS from the final clarifiers to the head of the WWTF. These pumps will have to be temporarily relocated during the first phase of construction. Construction must be phased to keep the existing plant in operation until new treatment systems are online. Technical Memorandum No. 3 DLPUC Detroit Lakes Public Utilites Commission Page 3

58 4.1 Cost Development Engineer s estimates of probable cost are presented throughout the following sections. Capital costs are the total costs to construct the upgrades to the wastewater facility. The capital cost includes design engineering costs, the construction costs, and the legal and construction administration costs incurred during construction. Assumptions about equipment and materials take-offs were done to prepare the construction cost estimates for facility planning purposes. Cost data from recent construction projects were utilized where appropriate. Other budgetary prices were obtained from equipment representatives. Standard percentages or lump sums were used for piping, electrical, site work, contractor s overhead and profit, bonds, engineering, and City administrative expenses related to the project. The engineer s estimates of construction cost are based on a 2014 time frame. The Engineering News Record Construction Cost Index during this time period was The estimates do not account for inflation and the reader is cautioned to keep this in mind when reviewing the cost estimates. Since this report is a planning tool, these estimates, by their nature must be considered approximate and will need refinement as more detailed design develops. The construction cost estimates include an allowance for contingencies. Contingency allowances are important in planning studies, when the focus is on developing conceptual solutions and the time and budget limitations require the details to be generalized. This report uses a 20-percent contingency applied to all capital cost estimates. As further details are developed, the costs for each improvement/alternative could decrease. The operation and maintenance costs include labor, routine maintenance/repair, and energy required to operate the equipment. 5.0 Preliminary Treatment Preliminary treatment is currently accomplished with a single coarse screening mechanical barscreen, wastewater pumps, and an aerated grit basin system. The screening channel does not promote adequate velocity and is not wide enough for the projected flows. The wetwell is undersized and does not provide enough detention time for pumping during high flow events. Attempting to install larger capacity screening and a larger wetwell in the existing structure is not practical as the building layout does not provide space for expansion. The aerated grit basin does not meet the capacity needs of the 2038 projected flows and is not producing the turbulence needed to remove grit from the system. 5.1 New Building for Screening and Pumping The City owns land east of the existing wastewater pumping building. A new preliminary treatment building to house new mechanical screening, a wetwell, and new wastewater pumps would be built on that land. The main wastewater interceptor is located in that area and would connect easily the new preliminary treatment building. Other raw wastewater piping would need to be extended to connect. DLPUC Technical Memorandum No. 3 Page 4 Detroit Lakes Public Utilites Commission

59 5.2 New Vortex Grit Chamber with Existing Grit Removal Building The existing aerated grit system is located near the primary clarifiers. The aerated grit basin would be replaced with a vortex grit system. The new vortex grit chamber would be constructed such that the existing effluent channel for the aerated grit basin could be utilized for the vortex grit effluent. This also means the existing effluent piping to the primary clarifier splitter box could also be used. The equipment required for the vortex grit system would replace the equipment in the existing Grit Removal Building, including the grit pumps and grit classifier. The electrical system for the grit system and primary clarifiers is currently housed in a steel enclosure added on to the Grit Removal Building. The Grit Removal Building would be modified to add a room for the electrical equipment. The estimated capital and operation and maintenance (O&M) costs for a new preliminary treatment building with screening and pumping, a new vortex grit chamber and grit equipment, and modifications for the Grit Removal Building is shown below in Table Primary Treatment Primary treatment is currently accomplished in two 40- foot diameter center-feed primary clarifiers. The clarifiers are covered with aluminum domes. The flow is split in a structure prior to the clarifiers and the structure is designed for a third clarifier. A new 40-foot diameter primary clarifier would be built south of the existing primary clarifiers as the original design intended. The new primary clarifier would also be center fed and have an aluminum dome. New piping would be added from the splitter structure to the new clarifier. The two existing primary clarifiers would be rehabilitated with new drives, scrapers, skimmer arms, skirts, scum beaches, and launders. The estimated capital and O&M costs for a new primary clarifier with aluminum dome and rehabilitation of existing primary clarifiers is shown below in Table Disinfection Disinfection is currently accomplished at the Chemical Precipitation Plant with chlorination. In order to remove chlorine gas from the site and bring the disinfection process back to the mechanical WWTF site, UV disinfection should be added for disinfection. Space in any of the secondary treatment alternatives can be made for the UV disinfection channel and equipment. The UV disinfection would be the last step prior to discharge of effluent. Because there is a t-shirt manufacturer in town that discharges to the WWTF, samples of the effluent should be taken to determine whether transmissivity of the wastewater due to dyes will affect the UV disinfection system. The estimated capital and O&M costs for a new UV disinfection system and building is shown below in Table 3. Table 3 Preliminary Treatment, Primary Treatment, and UV Disinfection Process Capital Cost O&M Cost Preliminary Treatment $2,653,000 $35,500 Primary Treatment $2,508,000 $26,900 Disinfection $1,397,000 $13,500 Technical Memorandum No. 3 DLPUC Detroit Lakes Public Utilites Commission Page 5

60 8.0 Secondary And Tertiary Treatment Secondary treatment is currently accomplished with two trickling filters followed by final clarifiers. The trickling filter process does not have the capability or operational flexibility to achieve the low phosphorous levels required by the NPDES/SDS permit. The WWTF currently does not have tertiary treatment. With the variability in the effluent phosphorus limit depending upon the type of discharge (seasonal or year round) and the location of the discharge (as presented in Section 3.0), a suite of secondary and tertiary alternatives were considered to achieve varying effluent phosphorus concentrations. Figure 1 outlines the alternatives considered for secondary and tertiary treatment and the corresponding estimated effluent phosphorus concentrations the alternative can achieve. Generally, chemical and biological phosphorus removal processes have been used to meet effluent phosphorus limits typically ranging between 0.5 and 1.0 mg/l. Additional tertiary processes are required to polish effluent to reliably achieve effluent phosphorus concentrations below mg/l. This polishing involves improved TSS removal (filtration/settling). The following sections discuss these treatment alternatives. Each of these alternatives are assumed to provide ammonia treatment (to avoid toxicity issues) and are expandable to provide total nitrogen removal, if required in the future. Estimated capital and O&M costs are presented at the end of the section. Figure 1 Secondary and Tertiary Treatment Alternatives Effluent Phosphorus Concentration (mg/l) 3.4 Conventional Activated Sludge EBPR Filters Filters w/coagulation Zones Tertiary Clarifiers with Filters IFAS 2-Stage Granular Media MBR 8.1 Conventional Activated Sludge (CAS) CAS systems can generally achieve 20% phosphorus removal as a result of settling insoluble phosphorus and cell growth. Based on this, a CAS system could remove phosphorus from the influent concentration of 4.25 mg/l to approximately 3.4 mg/l. A conventional activated sludge system includes aeration basins with fine-bubble diffusers, return activated sludge (RAS) pumps, waste activated sludge (WAS) pumps, blowers for aeration, and a final clarification. For the basis of this planning-level study, it is assumed that the aeration basin will be sized for a loading of 15 lb BOD/d/1000 cf to achieve BOD removal and nitrification (per Ten States Standards for a single-stage nitrification system). It is assumed that the primary clarifiers will remove 30% of the influent BOD. Further it is assumed that two final clarifiers would be required to treat the influent flow as well as an assumed RAS rate of 150%. Figure 1 in Appendix D presents an example site arrangement for a CAS system. DLPUC Technical Memorandum No. 3 Page 6 Detroit Lakes Public Utilites Commission

61 Operations and maintenance costs for all alternatives presented include labor and routine maintenance/repair costs. Operations costs for a CAS system also include electricity to operate pumps and blowers. The CAS system results in a waste sludge that requires stabilization and disposal. For the basis of comparing the liquid-treatment processes, it is assumed that stabilization and disposal costs $180 per dry ton produced. 8.2 Integrated Fixed-Film Activated Sludge (IFAS) IFAS systems are hybrid systems that rely on both suspended and fixed-film growth to achieve treatment. They offer a smaller footprint than a conventional activated sludge system. The system contains some form of media that allows for fixed biofilm growth. Often these systems are retrofits for existing activated sludge systems, where adding the media allows for increased treatment capacity with no change in footprint. However, due to limited space at the existing WWTF, an IFAS system was considered. An IFAS system would require a 40% smaller footprint than a conventional activated sludge system. This means less cost for the tankage, however, the IFAS system requires media and media retention screens, which are not required for a CAS system. The IFAS system would still require final clarifiers, blowers, and RAS/WAS pumps, just as the CAS system alternative. Due to the media, an IFAS system does require a 3-6 millimeter (mm) fine screen for preliminary treatment; however, this is a commonly used range for screens and is not considered a cost factor. The operations and maintenance costs for an IFAS are nearly identical to the CAS system. Figure 2 in Appendix D presents an example site arrangement for an IFAS system. 8.3 Enhanced Biological Phosphorus Removal (EBPR) A conventional activated sludge or IFAS system alone would not be adequate to meet the phosphorus effluent limits anticipated for year-round discharge at the three discharge locations. Biological phosphorus removal is an option to further reduce the effluent phosphorus concentration. Biological phosphorus removal is achieved by conditioning the microorganisms within the treatment plant for enhanced phosphorus uptake. This is accomplished by subjecting the microorganisms to aerobic, anoxic, and anaerobic stages. An activated sludge system (either CAS or IFAS) provides the aerobic environment, so an EBPR system adds anaerobic and anoxic reactors. In addition to this additional tankage, the MPCA also requires chemical phosphorus removal facilities for backup. Figures 1 and 2 in Appendix D present process additions that would be required for EBPR. Many treatment plants, when operated to optimize biological phosphorus removal, can consistently achieve effluent TP concentrations of less than 0.5 mg/l with only secondary clarification for suspended solids removal (Randall et al, 1992). For the Detroit Lakes facility, it has been assumed that an EBPR system can remove 85% of the influent TP, or down to a concentration of 0.7 mg/l. The performance of the EBPR system is dependent upon the presence of volatile fatty acids (VFAs) and the VFA to P ratio. Another relationship that has been used to determine the effectiveness of EBPR is the BOD to P ratio. A BOD:P ratio of approximately 20 to 25 is ideal. Currently the raw influent BOD:P ratio is approximately 23 (assuming 30% BOD removal in the primary clarifiers), which is within this ideal range. Technical Memorandum No. 3 DLPUC Detroit Lakes Public Utilites Commission Page 7

62 Understanding the phosphorus speciation is important to determining the effectiveness of various forms of phosphorus removal, biological or physical/chemical. The following information should be collected to determine whether biological phosphorus removal can be successfully implemented at the facility: Influent orthophosphorus, soluble phosphorus, non-soluble orthophosphorus,tkn, ammonia nitrogen, and COD Primary effluent parameters, including BOD, TSS, total phosphorus, orthophosphorus, soluble phosphorus, non-soluble orthophosphorus, and TKN Costs for EBPR assume an Anaerobic/Oxic (A/O) process, where there is an anoxic chamber and a series of anaerobic zones located upstream of an aerobic zone. There are other options for EBPR besides A/O, the advantages and disadvantages of which should be considered during design. In addition to the operations and maintenance costs of a CAS/IFAS system, operations and maintenance costs for an EBPR system includes polishing chemical costs and electricity to operate chemical feed pumps and anaerobic/anoxic zone mixers. 8.4 Filtration To achieve effluent phosphorus limits below 0.7 mg/l, suspended solids in the clarified effluent need to be removed. This can be achieved through filtration. Filtration coupled with an EBPR system is likely to achieve an effluent phosphorus concentration of approximately 0.3 mg/l. There are a number of filtration options available with different flow configurations (upflow/downflow) and media types (sand, anthracite, cloth, compressible synthetic). The costs and evaluation provided herein represent the filtration level of treatment. The specific type of filter to be used should be evaluated during design, when an understanding of the hydraulics can be incorporated. For the basis of this evaluation, a disc cloth filter system has been assumed. Disc cloth filters have been installed in facilities required to meet effluent phosphorus limits as low as 0.1 mg/l. The disc cloth filter system would consist of two filters housed in a building to treat the peak hourly flow of 6.33 MGD. The filter system would also include backwash pumping system. Figures 1 and 2 in Appendix D show a location for filtration systems, and Figure 3 shows the footprint requirement for a disc cloth filter system. In addition to the operations and maintenance costs of a CAS/IFAS system with EBPR, operations and maintenance costs for a filtration system includes additional electricity for backwash pumping and additional chemical costs. 8.5 Enhanced Filtration Due to the low phosphorus limits imposed in Wisconsin, there has been pilot testing to optimize performance of filtration systems for phosphorus removal. Kruger, a manufacturer of disc cloth filters, has optimized filter performance to consistently achieve effluent phosphorus concentrations of mg/l at multiple facilities in Wisconsin. Kruger believes 0.06 mg/l may be achievable, but pilot testing would be required to confirm this. To optimize the filtration process, coagulation and flocculation tanks are added upstream of the filters to allow chemicals (ferric chloride or alum) and polymer to adequately mix with the waste stream. For a relatively small increase in the cost, increased treatment for phosphorus can be accomplished. DLPUC Technical Memorandum No. 3 Page 8 Detroit Lakes Public Utilites Commission

63 This enhanced filtration process involves multipoint coagulation addition. Coagulant (ferric chloride/alum) would be added just prior to the secondary clarifiers. After the secondary clarifiers, three short stages rapid mix, coagulation, and flocculation are recommended prior to the filters. Coagulant would be added to the rapid mix and coagulation basins and polymer would be added to the flocculation stage. This system requires additional chemical use and a slightly larger footprint. Figures 1 and 2 in Appendix D show a location for filtration systems, and Figure 3 shows the footprint requirement for an enhanced filtration system. 8.6 Tertiary/High-Rate Clarification Tertiary or high-rate clarification is a process to further settle solids prior discharge. The clarification process follows the final clarifiers of the activated sludge/ifas process. Similar to enhanced filtration, high-rate clarification involves effective mixing of the effluent with coagulant and polymer to enhance settling. There are a number of processes that fall into this tertiary clarification category (DensaDeg, Actiflo, CoMag, Trident HS, etc). Each of these systems has a different approach to improve settling. One system recycled solids back, another uses a microsand media as a seed for floc formation, and another uses magnetic ballast to bind precipitated phosphorus. Figures 1 and 2 in Appendix D show a location for filtration systems, and Figure 3 shows the footprint requirement for a high-rate clarification system. Generally, these systems claim to achieve effluent phosphorus concentrations between 0.01 and 0.05 mg/l. The ability to achieve these low effluent phosphorus levels is dependent on the phosphorus speciation. A facility that operates tertiary clarifiers in Breckenridge, CO meets an average phosphorus concentration of mg/l, with a range of 0.01 mg/l to 0.15 mg/l prior to final filtration. These tertiary/high-rate clarification systems have been installed in Colorado, California, and Massachusetts, among other states. The costs for a tertiary clarification system were based on a DensaDeg system. This system assumes two high-rate clarifiers. The presented cost includes filtration following the tertiary clarifier, as this will increase the reliability of the system. The DensaDeg manufacturer has indicated that an average effluent limit of 0.06 mg/l is achievable without tertiary filters, depending upon the phosphorus speciation. However, other facilities that have used tertiary clarifiers to meet low-level phosphorus limits have followed the tertiary clarifiers with filters. Depending on phosphorus speciation and upon completion of pilot testing, it may be determined that filters are not necessary, which would result in a $3.6 million decrease in the capital cost for this option. The O&M costs for a high-rate clarifier system beyond that required for an EBPR system include electricity for the clarifier system and chemicals. 8.7 Two-Stage Granular Media Filtration Two-stage granular media filtration processes involve either filters operated in series or special media which uses filtration and adsorption to remove phosphorus. These two-stage systems can achieve effluent phosphorus in the range of to mg/l, depending on speciation. There are a number of systems that fall into this category of two-stage granular media filtration (Parkson Dynasand D2, BluePro, Memcor, etc). These systems should be evaluated further during design if two-stage granular media filtration is used, but costs are provided for a Blue Pro system. Blue Pro s system has been installed at facilities with effluent limits as low as 0.05 mg/l in Idaho. Similar to tertiary clarifiers, the ability to achieve ultra-low effluent phosphorus levels is dependent upon the phosphorus speciation, as physical/chemical methods cannot remove soluble non-ortho phosphorus. Technical Memorandum No. 3 DLPUC Detroit Lakes Public Utilites Commission Page 9

64 The BluePro system consists of 17 filters (7 required for future average wet weather flow conditions, and 10 more for peak hour conditions). Figures 1 and 2 in Appendix D show a location for filtration systems, and Figure 3 shows the footprint requirement for the BluePro system. The system requires the use of ferric chloride. The O&M costs for a two-stage filtration system beyond that required for an EBPR system include electricity for the filtration system and chemicals. 8.8 Membrane Biological Reactor (MBR) A MBR couples a membrane filtration system with a suspended-growth biological reactor to provide a high-quality effluent. The membrane filters take the place of secondary clarifiers and filters. A MBR system would consist of additional screening to removal particles greater than 2 mm, activated sludge tankage, membrane tankage, aeration systems, pumps, membrane cleaning system, and a building to house equipment and membranes. Chemicals (ferric/alum) are still required to bind the phosphorus to solids; additional chemicals are also required for membrane cleaning. MBR systems have achieved effluent phosphorus concentrations as low as mg/l. One facility operating an MBR in Utah reported an annual average effluent phosphorus concentration of 0.07 mg/l with a maximum month concentration of 0.17 mg/l and another facility in Colorado reported an annual average concentration of with a maximum month concentration of mg/l. Figure 4 in Appendix D shows a site layout for an MBR system. While MBR systems provide high-quality effluent, there are some challenges. MBR systems are known to have high O&M costs, although equipment manufacturers have made progress in lowering the energy costs for membrane systems over the past few years. An additional O&M cost is replacement of the membranes. Membrane life is highly dependent upon the background water quality and is negatively affected by the presence of calcium carbonate, iron, and manganese. 8.9 Secondary & Tertiary Treatment Summary of Alternatives Several options were evaluated for varying degrees of phosphorus removal. Figure 2 presents the incremental capital costs for the different stages of secondary/tertiary treatment. Figure 2 Cost Diagram for Secondary and Tertiary Treatment Systems Effluent Phosphorus Concentration (mg/l) CAS: $6.4M Filters: $3.4M Filters w/coagulation Zones: $0.5M EBPR: $1.0M Tertiary Clarifiers with Filters (1) : $7.5M IFAS: $6.7M 2-Stage Granular Media: $5.5M MBR (2) : $16.9M (1) Cost assumes filtration following tertiary clarifiers for increased reliability. The added capital cost for the filters is approximately $3.4 million. (2) MBR costs include 2 mm fine screens. DLPUC Technical Memorandum No. 3 Page 10 Detroit Lakes Public Utilites Commission

65 As presented in Figure 2, the estimated capital costs for the CAS and IFAS systems were similar. For the basis of this planning-level study and for ease of presenting cost alternatives, it is assumed the two systems have the same capital cost of $6,790,000. Table 4 provides an overview of these options and the estimated capital, O&M, and present value costs. Table 4 Secondary and Tertiary Treatment System Costs Alternative Capital Cost (2) O&M Cost (3) 20-Year Present Value (1) 1. CAS/IFAS $6,790,000 $235,000 $9,984, CAS/IFAS with EBPR $7,790,000 $278,700 $11,578, CAS/IFAS with EBPR with Filters $11,140,000 $373,200 $16,212,000 4a. CAS/IFAS with EBPR with Enhanced Filters $11,680,000 $405,900 $17,196,000 4b. CAS/IFAS with Tertiary Clarifiers and Filters (4) $15,250,000 $477,700 $21,741,000 4c. CAS/IFAS with Two-Stage Filtration $13,280,000 $486,100 $19,886,000 4d. MBR (5) $16,926,000 $436,000 $22,857,000 Notes: (1) Present Value assumes 4% escalation. (2) Capital costs DO NOT include solids treatment system improvements. (3) O&M costs are presented to compare alternatives. O&M costs may vary by 25% based on a number of factors, but variations are considered equal across the alternatives. (4) Pilot testing may reveal that an effluent phosphorus concentration of mg/l can be reliably achieved without the need for filters following the tertiary clarifiers. (5) Capital cost for the MBR system includes fine screens. While solids treatment costs were incorporated into the O&M costs, the estimated solids production from the various systems was not the largest contributor to the varying O&M costs. The labor to operate the increasingly involved processes was the biggest factor contributing to the variation in the O&M costs, followed by chemical use. Generally, to meet the effluent limits required at the existing site for year-round discharge (0.06 mg/l), either alternatives 4b, 4c, or 4d should be considered for secondary/tertiary treatment. The capital costs for these systems range from $13.3M to $16.9M. If other discharge locations are available, Alternatives 2, 3, or 4a should be considered. 9.0 Discharge Location 9.1 Phosphorous Concentration Each discharge location considered has an equivalent phosphorus concentration limit based on either the mass loading limit of 198 kg/yr at AWW flow or the preliminary effluent limit provided by MPCA. Because the existing discharge location of St Clair Lake has a mass loading limit, whether the discharge is seasonal or year round has an impact on the phosphorus concentration limit. The phosphorous limits for both alternate discharge locations also vary depending on whether the discharge is seasonal or year round. Table 5 summarizes the phosphorous concentration limits for all considered discharge locations. Technical Memorandum No. 3 DLPUC Detroit Lakes Public Utilites Commission Page 11

66 Discharge Location Table 5 Phosphorus Limits Phosphorus Limit, mg/l St Clair Lake (seasonal) 0.12 St Clair Lake (year round) Becker County Ditch No. 5 (seasonal) 1.0 (1) Becker County Ditch No. 5 (year round) 1.0 (Oct-May); 0.5 (Jun-Sep) (1) Buffalo River (seasonal) 1.0 (1) Buffalo River (year round) 1.0 (Oct-May); 0.5 (Jun-Sep) (1) (1) Regardless of seasonal or year round discharge, the discharge limits for Becker County Ditch No. 5 and Buffalo River may change to 0.2 mg/l and 0.3 mg/l, respectively, because of in-lake monitoring and adoption of the eutrophication standards. These lower values were assumed in the evaluation of liquids treatment alternatives. 9.2 Secondary and Tertiary Treatment Costs In order to achieve the phosphorus limits for each discharge location both secondary and tertiary treatment will be required. All discharge locations will require secondary treatment and the level of tertiary treatment required will vary. Table 6 below summarizes the secondary and tertiary treatment required for each location and the costs associated with those. Discharge Location St Clair Lake (seasonal) St Clair Lake (year round) Becker County Ditch No. 5 (seasonal) Becker County Ditch No. 5 (year round) Buffalo River (seasonal) Buffalo River (year round) Table 6 Secondary and Tertiary Treatment Secondary Treatment Type AS with EBPR AS with EBPR AS with EBPR AS with EBPR AS with EBPR AS with EBPR Capital Cost Tertiary Treatment $7,790,000 Filters with Coagulation Zones $7,790,000 Two-stage Filtration (2) Type Capital Cost Capital Cost Total $4,040,000 $11,830,000 $5,640,000 $13,430,000 $7,790,000 Filters (1) $3,500,000 $11,290,000 $7,790,000 Filters (1) $3,500,000 $11,290,000 $7,790,000 Filters (1) $3,500,000 $11,290,000 $7,790,000 Filters (1) $3,500,000 $11,290,000 AS = Activated Sludge EBPR = Enhanced Biological Phosphorus Removal (1) Because 0.5 mg/l is at the extreme low end for the phosphorus limit achievable with EBPR it assumed that tertiary treatment will be required to meet 0.5 mg/l consistently. Additionally, regardless of seasonal or year round discharge, the phosphorous discharge limits for Becker County Ditch No. 5 and Buffalo River may change to 0.2 mg/l and 0.3 mg/l, respectively, because of in-lake monitoring and adoption of the eutrophication standards and filters will be necessary to achieve those levels. (2) While the two-stage filtration alternative is shown, the tertiary clarifier option could potentially have a lower capital cost if the filters are not needed for reliability. Pilot testing of both tertiary clarifiers and two-stage filtration systems during design should be considered to evaluate further the O&M costs and the reliability of the technology. DLPUC Technical Memorandum No. 3 Page 12 Detroit Lakes Public Utilites Commission

67 9.3 Additional Costs for each Location When considering any of the discharge locations the additional costs in Table 7 must also be included. Table 7 Discharge Location Cost Considerations Costs St Clair Lake Becker County Ditch No. 5 (3)(4)(5) Buffalo River (4) New storage pond N/A $2,200,000 (1) N/A Pumping and Forcemain $697,000 (2) $2,721,000 (2) $7,824,000 (2) to discharge location (1) The BRRWD has indicated that roughly two weeks of storage would be required for times of extreme high flows. It is estimated that this will only be used maybe once every 10 years on average. This assumes new construction as the existing pond does not meet guidelines for allowable seepage or separation to groundwater. (2) This cost includes a pump station and forcemain to divert the wastewater effluent to the new discharge location. It is assumed that discharge location at Becker County Ditch No. 5 is 3.2 miles from the existing WWTF site and the discharge location at the Buffalo River is 11.2 miles from the existing WWTF. The pumping and forcemain cost to St Clair Lake is a replacement of existing effluent pumps and piping for 0.5 mile. (3) Cost for ditch improvements for Becker County Ditch No. 5 are not included. (4) Cost for acquiring right-of-way for new forcemain is not included. (5) The BRRWD would also require an annual maintenance fee for use of a ditch system within the Buffalo Red River Watershed. This fee has been included as an operation and maintenance (O&M) cost. 9.4 Consideration of Chlorides Chloride limits will be considered for the WWTF discharge in the future. The current NPDES permit is for discharge to a wetland which then flows to St Clair Lake. The MPCA has indicated that because the discharge first enters a wetland, a chloride limit that matches the background levels of the wetland may be considered; however, a variance to this limit may be appropriate. With any discharge location, a chloride limit is likely in the future, however the timing of the requirement is uncertain. Current standards indicate the limit may be 230 mg/l. To reach this concentration limit, treatment of clean water source rather than the wastewater stream is most feasible. There will be costs associated with the source water treatment required for all options. This is not included in this cost analysis and will be based on the outcome of future monitoring and permit requirements Existing WWTF Site Vs New WWTF Site The existing WWTF site has limited area with little room for expansion. The City owns some additional land east of the site, however the rest is surrounded by wetlands and bordered by Willow Street. The challenge of a site like this is to maintain treatment during construction. Considerations of phased construction, bypass pumping, and special construction methods must be considered. A new site location can also be considered, however there are costs associated with building a new facility at a new location that need to be included. Table 8 summarizes cost considerations for expanding the WWTF on the existing site or moving to a new site. Technical Memorandum No. 3 DLPUC Detroit Lakes Public Utilites Commission Page 13

68 Table 8 WWTF Site Location Cost Considerations Costs Existing WWTF site New WWTF site Structure protection for close proximity excavation Pumping and Forcemain to new WWTF site $615,000 (1) N/A N/A $1,017,000 (2) Preliminary Treatment Adder N/A $705,000 (3) Primary Clarifier Adder N/A $670,000 (4) Land N/A $100,000 (5) Dewatering (6) /Demolition $787,600 (7) $1,082,600 (8) Utilities to Site (water, electricity, etc.) (9) $65,000 $485,000 Lab/Office (10) $225,000 N/A (1) When excavating in close proximity to existing structures, methods must be used to protect the existing structures. Sheeting and shoring is typically used and in extreme cases a special vertical shoring system can be used. (2) Because the existing collection system directs the wastewater to the existing WWTF site a pump station and forcemain are needed to direct the wastewater to the new WWTF. This cost includes a pump station and one mile of forcemain. Because the new WWTF site location has not been identified, an additional cost must be added for each mile beyond one mile from the existing WWTF for forcemain. (3) The alternative considered for the preliminary treatment at the existing site included reuse of the existing Grit Removal Building. At a new site the preliminary treatment building would have to be larger to accommodate the grit system equipment and tankage. (4) The alternative considered for the primary clarifiers at the existing site included reuse of two primary clarifier structures (in addition to construction of a third primary clarifier) and domes and the primary clarifier splitter box. At the new site the primary clarifiers and splitter box will be new. (5) It is assumed the City will have to purchase the land needed for the new WWTF site. It is assumed that a minimum of 10 acres is needed. (6) Because of the high groundwater conditions throughout Detroit Lakes, dewatering costs need to be included. Because there will be more new construction with a new site, the dewatering costs will be higher. (7) Structures assumed to be demolished are the small trickling filter, large trickling filter, control building, and barscreen building. It is assumed the identified structures will be removed to make room for the new unit processes. (8) Structures assumed to be demolished are the small trickling filter, large trickling filter, control building barscreen building, primary clarifiers, Grit Removal Building, digesters and digester building. It is assumed that all structures will be removed as they are no longer needed. (9) The new WWTF will require new utilities, including water service and electricity to site. It assumed that the utilities must be run ¼ mile from a main existing utility. The existing WWTF electrical service capacity will have to be increased. (10) The new lab/office space will be located at the existing WWTF. This could be a new building or a modification of an existing building Seasonal Discharge vs. Year Round Discharge The WWTF currently has a seasonal discharge to St Clair Lake. Discharge to the Rapid Infiltration Basins (RIBs) and spray irrigators typically starts in late spring and goes into the fall. As discussed in previous sections the existing RIBs and spray irrigators do not have adequate capacity for the projected flows and are not in compliance with groundwater DLPUC Technical Memorandum No. 3 Page 14 Detroit Lakes Public Utilites Commission

69 separation requirements. The costs in Table 9 should be considered when deciding to keep a seasonal discharge or change to a year round discharge. Table 9 Seasonal Vs. Year Round Discharge Cost Considerations Seasonal Discharge Year Round Discharge Storage Pond $3,941,000 (1) N/A Irrigation system $7,850,000 (2)(3) N/A Pumping and Forcemain $3,869,000 (4) N/A (1) A storage pond is required prior to effluent disposal by irrigation. The existing pond is leaking and is not meeting separation requirements. A new pond is proposed to meet the MPCA Recommended Pond Design Criteria and provides 30 days of storage at the projected AWW flow. (2) It is assumed that if seasonal discharge is desired a new spray irrigation system would be needed. The current system used in conjunction with the existing RIBs does not meet current standards. (3) A cost is presented in this table for spray irrigation but the cost is more appropriately presented as a range of $5,000,000-$10,000,000 since location and site conditions can significant impacts on the costs. (4) This cost includes a pump station and forcemain to divert the wastewater effluent to the new spray irrigation location. It is assumed the spray irrigation location is 5.0 miles from either the existing or new WWTF Summary There are many factors to consider when evaluating the liquid treatment alternatives for the Detroit Lakes WWTF including site location, discharge location, and seasonal or year round discharge. Table 10 provides a summary of the liquid treatment alternatives estimated capital costs. This information provides a liquid treatment construction cost summary and does not include review of solids treatment costs or other non-monetary impacts such as stormwater impacts as they will play a role in the recommended alternative. A more detailed breakdown of the estimated liquid treatment capital costs can be found in Appendix E. Table 10 Summary of Alternatives Site Location Discharge Location Discharge Frequency Total Estimated Liquid Treatment Cost Existing WWTF Site New WWTF Site St Clair Lake Becker Co Ditch No. 5 Buffalo River Becker Co Ditch No. 5 Buffalo River Year Round $23,634,000 Seasonal $36,437,000 Year Round $25,738,000 Seasonal $37,491,000 Year Round $28,621,000 Seasonal $42,574,000 Year Round $28,105,000 Seasonal $39,858,000 Year Round $30,988,000 Seasonal $44,491,000 Additional considerations/costs not included in the table above that will need to be considered when making a final decision include: Technical Memorandum No. 3 DLPUC Detroit Lakes Public Utilites Commission Page 15

70 Costs for solids treatment improvements are not included. The results of the evaluation for solids treatment will have an impact on the liquid treatment scenarios and should be considered together. Water treatment technologies required for a possible future chloride limit. Ditch improvements required for discharge to Becker County Ditch No. 5. Right-of-way acquisitions required for the forcemain to discharge to Becker County Ditch No. 5, Buffalo River, or a new spray irrigation site. Time required and cost associated with non-degradation review required for a new discharge to Becker County Ditch No. 5 or Buffalo River. DLPUC Technical Memorandum No. 3 Page 16 Detroit Lakes Public Utilites Commission

71 Appendix A NPDES Permit

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117 Appendix B Alternate Discharge Location Map

118 Detroit Lakes WWTF

Minnesota Pollution Control Agency

Minnesota Pollution Control Agency Minnesota Pollution Control Agency STATE OF MINNESOTA Minnesota Pollution Control Agency MUNICIPAL DIVISION PUBLIC NOTICE OF INTENT TO REISSUE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)/ STATE

More information

Minnesota. BMI Project No. M21.037315

Minnesota. BMI Project No. M21.037315 Wastewater Treatment Facility Plan City of Paynesville Minnesota BMI Project No. M21.037315 March 2009 TABLE OF CONTENTS EXECUTIVE SUMMARY... 1 A. GENERAL... 1 B. DESIGN PARAMETERS... 1 C. COST ESTIMATES...

More information

EXISTING WASTEWATER TREATMENT FACILITIES

EXISTING WASTEWATER TREATMENT FACILITIES Chapter 5 EXISTING WASTEWATER TREATMENT FACILITIES 5.1 THERESA STREET WWTF 5.1.1 Overview The Theresa Street WWTF is the larger of the two wastewater treatment facilities owned and operated by the City.

More information

Cambridge Wastewater Treatment Facility

Cambridge Wastewater Treatment Facility Cambridge Wastewater Treatment Facility Emergency Situations If you have a water or sewer emergency that relates to the City s utility system call the Public Works office at 763-689-1800 on normal working

More information

Waste Water Treatment Process

Waste Water Treatment Process Waste Water Treatment Process INCLINED SCREW PUMPS The raw influent flows into a wet well where it is carried up nearly thirty feet by one of two inclined screw pumps. The 78-inch diameter screw pumps

More information

EXISTING WASTEWATER TREATMENT FACILITIES

EXISTING WASTEWATER TREATMENT FACILITIES Chapter 5 EXISTING WASTEWATER TREATMENT FACILITIES 5.1 THERESA STREET WWTF 5.1.1 Overview The Theresa Street WWTF is the larger of the two wastewater treatment facilities owned and operated by the City

More information

Fort Wayne Water Pollution Control Plant

Fort Wayne Water Pollution Control Plant Fort Wayne Water Pollution Control Plant The Water Pollution Control Plant located on Dwenger Avenue -- provides wastewater treatment for the City of Fort Wayne and surrounding areas. Following the treatment

More information

WASTEWATER TREATMENT OBJECTIVES

WASTEWATER TREATMENT OBJECTIVES WASTEWATER TREATMENT OBJECTIVES The student will do the following: 1. Define wastewater and list components of wastewater. 2. Describe the function of a wastewater treatment plant. 3. Create a wastewater

More information

Description of the Water Conserv II Facility

Description of the Water Conserv II Facility Description of the Water Conserv II Facility Introduction The Water Conserv II (WCII) Water Reclamation Facility provides service to a majority of the southwest section of Orlando. The WCII facility has

More information

NPDES Permit No. IL0020737. Notice No. SKT:13120601.bah. Public Notice Beginning Date: April 9, 2014. Public Notice Ending Date: May 9, 2014

NPDES Permit No. IL0020737. Notice No. SKT:13120601.bah. Public Notice Beginning Date: April 9, 2014. Public Notice Ending Date: May 9, 2014 Public Notice/Fact Sheet Issued By: Notice No. SKT:13120601.bah Public Notice Beginning Date: April 9, 2014 Public Notice Ending Date: May 9, 2014 National Pollutant Discharge Elimination System (NPDES)

More information

Energy Efficiency and Recovery Opportunities Analysis for Municipal Wastewater Treatment Plant Operations

Energy Efficiency and Recovery Opportunities Analysis for Municipal Wastewater Treatment Plant Operations Utah State University DigitalCommons@USU All Graduate Plan B and other Reports Graduate Studies 4-28-2015 Energy Efficiency and Recovery Opportunities Analysis for Municipal Wastewater Treatment Plant

More information

Wastewater Treatment

Wastewater Treatment BOD Bio Chemical Oxygen Demand TSS Total Suspended Solids Wastewater Treatment Fecal Coliform ph NH3 Nitrogen Ammonia What is Sewage Pathogens or disease-causing organisms are present in sewage. Sewage

More information

WINERY WASTEWATER TREATMENT***

WINERY WASTEWATER TREATMENT*** WINERY WASTEWATER TREATMENT*** by Edwin Haynes*, George Stevens*, and Paul Russell, Jr.** INTRODUCTION In 1969 experience with treatment of winery wastewaters in this Country was limited to one winery

More information

Phosphorus Removal. Wastewater Treatment

Phosphorus Removal. Wastewater Treatment Phosphorus Removal In Wastewater Treatment by Derek Shires (512) 940-2393 Derek.Shires@ett-inc.com Why do we care? Eutrophication of surface water - Especially reservoirs Maximum agronomic uptake - Limiting

More information

Iowa DNR Wastewater Treatment Technology Assessment No. 09-01

Iowa DNR Wastewater Treatment Technology Assessment No. 09-01 Iowa DNR Wastewater Treatment Technology Assessment No. 09-01 Evaluation of Full-Scale LemTec Biological Treatment Facilities for Wastewater Design Review Considerations by the Iowa Department of Natural

More information

William E. Dunn Water Reclamation Facility. Facility Overview & Information

William E. Dunn Water Reclamation Facility. Facility Overview & Information William E. Dunn Water Reclamation Facility Facility Overview & Information General Area Served: Plant History Facility Highlights Northern Pinellas County St. Joseph Sound to East Lake Road (E/W) Tampa

More information

An Algae Based Treatment System Provides A Truly Sustainable Treatment Solution For Small & Seasonal Wastewater Treatment Plants

An Algae Based Treatment System Provides A Truly Sustainable Treatment Solution For Small & Seasonal Wastewater Treatment Plants An Algae Based Treatment System Provides A Truly Sustainable Treatment Solution For Small & Seasonal Wastewater Treatment Plants Agenda Small and Seasonal Plant Issues Algae and Bacteria in Symbiosis Cincinnati

More information

NPDES Permit No. IL0052639. Notice No. IL0052639-12.TTL. Public Notice Beginning Date: June 15, 2012. Public Notice Ending Date: July 16, 2012

NPDES Permit No. IL0052639. Notice No. IL0052639-12.TTL. Public Notice Beginning Date: June 15, 2012. Public Notice Ending Date: July 16, 2012 NPDES Permit No. IL0052639 Notice No. IL0052639-12.TTL Public Notice/Fact Sheet Issued By: Public Notice Beginning Date: June 15, 2012 Public Notice Ending Date: July 16, 2012 National Pollutant Discharge

More information

Texas Commission on Environmental Quality Page 1 Chapter 217 - Design Criteria for Domestic Wastewater Systems

Texas Commission on Environmental Quality Page 1 Chapter 217 - Design Criteria for Domestic Wastewater Systems Texas Commission on Environmental Quality Page 1 217.31. Applicability. SUBCHAPTER B: TREATMENT FACILITY DESIGN REQUIREMENTS 217.31-217.39 Effective August 28, 2008 This subchapter details the design values

More information

Wastewater Facility Plan

Wastewater Facility Plan Village of Poplar Douglas County, Wisconsin Project No. 7752000 April 2009 Village of Poplar Douglas County, Wisconsin Project No. 7752000 Prepared by: MSA Professional Services, Inc. 301 West First Street,

More information

Bay Park Sewage Treatment Plant Super Storm Sandy Recovery

Bay Park Sewage Treatment Plant Super Storm Sandy Recovery County of Nassau Department of Public Works Bay Park Sewage Treatment Plant Super Storm Sandy Recovery Edward P. Mangano County Executive Shila Shah-Gavnoudias, P.E. Commissioner of Public Works Bay Park

More information

TABLE OF CONTENTS EXECUTIVE SUMMARY...1 1.0 DESCRIPTION OF EXISTING CONDITIONS... 1-1. 1.1 Population... 1-1. 1.2 Wastewater Flows...

TABLE OF CONTENTS EXECUTIVE SUMMARY...1 1.0 DESCRIPTION OF EXISTING CONDITIONS... 1-1. 1.1 Population... 1-1. 1.2 Wastewater Flows... TABLE OF CONTENTS EXECUTIVE SUMMARY...1 1.0 DESCRIPTION OF EXISTING CONDITIONS... 1-1 1.1 Population... 1-1 1.2 Wastewater Flows... 1-1 1.3 Existing Wastewater Facilities... 1-2 1.3.1 City of Celina...

More information

ADVANCED LAGOON TREATMENT TECHNOLOGIES FOR WASTEWATER TREATMENT

ADVANCED LAGOON TREATMENT TECHNOLOGIES FOR WASTEWATER TREATMENT ADVANCED LAGOON TREATMENT TECHNOLOGIES FOR WASTEWATER TREATMENT ABSTRACT by Vikram M Pattarkine*, Randall C Chann**, Charles E Tharp** *Brinjac Engineering Inc, 114 North 2 nd Street, Harrisburg, PA 1711

More information

THE MARSHALL STREET ADVANCED POLLUTION CONTROL FACILITY (CLEARWATER, FLORIDA) CONVERSION TO 4-STAGE BARDENPHO TO IMPROVE BIOLOGICAL NITROGEN REMOVAL

THE MARSHALL STREET ADVANCED POLLUTION CONTROL FACILITY (CLEARWATER, FLORIDA) CONVERSION TO 4-STAGE BARDENPHO TO IMPROVE BIOLOGICAL NITROGEN REMOVAL THE MARSHALL STREET ADVANCED POLLUTION CONTROL FACILITY (CLEARWATER, FLORIDA) CONVERSION TO 4-STAGE BARDENPHO TO IMPROVE BIOLOGICAL NITROGEN REMOVAL ABSTRACT Timur Deniz, Ph.D., Thomas W. Friedrich, P.E.

More information

-O^ DEQ. National Pollutant Discharge Elimination System PERMIT EVALUATION AND FACT SHEET November 12,2003

-O^ DEQ. National Pollutant Discharge Elimination System PERMIT EVALUATION AND FACT SHEET November 12,2003 \ I -O^ DEQ State of Oregon Department of Environmental Quality National Pollutant Discharge Elimination System PERMIT EVALUATION AND FACT SHEET November 12,2003 Oregon Department of Environmental Quality

More information

An effective equivalent to screening and

An effective equivalent to screening and FWRJ Continuous Rotating Belt Filtration for Primary Treatment and Combined Sewer Overflows Miguel Gutierrez An effective equivalent to screening and primary settling, rotating belt filters enable a design

More information

2015 YEAR END REPORT WATER/WASTEWATER TREATMENT PLANTS

2015 YEAR END REPORT WATER/WASTEWATER TREATMENT PLANTS 2015 YEAR END REPORT WATER/WASTEWATER TREATMENT PLANTS Madison s water and wastewater treatment operations specialists are highly trained professionals who strive to give the citizens of Madison the best

More information

WATER TREATMENT PROCESSES. Primary treatment. runoff

WATER TREATMENT PROCESSES. Primary treatment. runoff WATER TREATMENT PROCESSES Effluent Primary treatment Secondary Treatment runoff Tertiary treatment Water Treatment Processes PRIMARY TREATMENT to prepare the wastewater for biological treatment Purpose

More information

Questionnaire: Operation of Wastewater Treatment Plants

Questionnaire: Operation of Wastewater Treatment Plants This questionnaire has been designed by a work team of the Technological Center CARTIF to obtain information about the wastewater treatment plant in the field of the project - Development of tools and

More information

Canada-wide Strategy for the Management of Municipal Wastewater Effluent

Canada-wide Strategy for the Management of Municipal Wastewater Effluent Canada-wide Strategy for the Management of Municipal Wastewater Effluent Endorsed by CCME Council of Ministers, February 17, 2009, Whitehorse Executive Summary Wastewater from households, industrial, commercial

More information

WISCONSIN WASTEWATER OPERATORS ASSOCIATION

WISCONSIN WASTEWATER OPERATORS ASSOCIATION Integrity. People. Knowledge. WISCONSIN WASTEWATER OPERATORS ASSOCIATION ANNUAL CONFERENCE GREEN BAY Resources. MEETING LOW LEVEL PHOSPHORUS LIMITS BY CHEMICAL ADDITION WHAT IS PHOSPHORUS Atomic # 15 Electron

More information

City of Rutland Wastewater Treatment Facility Phosphorus Removal Planning Study

City of Rutland Wastewater Treatment Facility Phosphorus Removal Planning Study City of Rutland Wastewater Treatment Facility Phosphorus Removal Planning Study October 2014 Table of Contents 1. EXECUTIVE SUMMARY... 1 1.1. Regulatory Update... 1 1.2. Operating Data... 1 1.3. WWTF

More information

Wastewater: The Basics. February 2016

Wastewater: The Basics. February 2016 Wastewater: The Basics February 2016 1 Introduction The Clean Water Program is a comprehensive, 10-year plan to upgrade San Mateo s sanitary sewer collection system and the San Mateo Wastewater Treatment

More information

Report prepared by: Kelly Hagan and Mark Anderson Grand River Conservation Authority 400 Clyde Road Cambridge ON N1R 5W6

Report prepared by: Kelly Hagan and Mark Anderson Grand River Conservation Authority 400 Clyde Road Cambridge ON N1R 5W6 2013 Watershed Overview of Wastewater Treatment Plant Performance Report prepared by: Kelly Hagan and Mark Anderson Grand River Conservation Authority 400 Clyde Road Cambridge ON N1R 5W6 Table of Contents

More information

ADDENDUM TO THE FACT SHEET FOR NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) PERMIT NO. WA-002264-1 June 25, 2010

ADDENDUM TO THE FACT SHEET FOR NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) PERMIT NO. WA-002264-1 June 25, 2010 ADDENDUM TO THE FACT SHEET FOR NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) PERMIT NO. WA-002264-1 June 25, 2010 I. GENERAL INFORMATION Facility: City of Blaine Wastewater Treatment Plants 9235

More information

REQUIRED MAINTENANCE FOR AT GRADE OR MOUND SEPTIC SYSTEMS. 1. Check sludge level in septic tank, pump tank and clean effluent filter.

REQUIRED MAINTENANCE FOR AT GRADE OR MOUND SEPTIC SYSTEMS. 1. Check sludge level in septic tank, pump tank and clean effluent filter. Appendix A: Service Required for Maintenance REQUIRED MAINTENANCE FOR AT GRADE OR MOUND SEPTIC SYSTEMS 1. Check sludge level in septic tank, pump tank and clean effluent 2. Check pumping station to assure

More information

Nutrient Removal at Wastewater Treatment Facilities. Nitrogen and Phosphorus. Gary M. Grey HydroQual, Inc. ggrey@hydroqual.com 201 529 5151 X 7167

Nutrient Removal at Wastewater Treatment Facilities. Nitrogen and Phosphorus. Gary M. Grey HydroQual, Inc. ggrey@hydroqual.com 201 529 5151 X 7167 Nutrient Removal at Wastewater Treatment Facilities Nitrogen and Phosphorus Gary M. Grey HydroQual, Inc. ggrey@hydroqual.com 201 529 5151 X 7167 1 Agenda Nitrification and Denitrification Fundamentals

More information

Bio-P Removal- Principles and examples in MI and elsewhere S. Joh Kang, Ph.D., P.E. Tetra Tech, Inc. Ann Arbor, MI 2010 Presentation Outline Optimization of Chemicals and Energy Bio-P Removal - Review

More information

CHAPTER 14 WASTEWATER TREATMENT PONDS

CHAPTER 14 WASTEWATER TREATMENT PONDS CHAPTER 14 WASTEWATER TREATMENT PONDS 14-1, Background. A wastewater stabilization pond is a relatively shallow body of wastewater contained in an earthen basin which is designed to treat wastewater. (

More information

Sewerage Management System for Reduction of River Pollution

Sewerage Management System for Reduction of River Pollution Sewerage Management System for Reduction of River Pollution Peter Hartwig Germany Content page: 1 Introduction 1 2 Total emissions 3 3 Discharge from the wastewater treatment plants 4 4 Discharge from

More information

TOBERMORY SEWAGE LAGOON

TOBERMORY SEWAGE LAGOON TOBERMORY SEWAGE LAGOON Annual Report January 1 to December 31, 2013 Prepared by: David Trombley Process & Compliance Technician Ontario Clean Water Agency West Highlands Hub March 31, 2014 Ministry of

More information

OPTIMIZING BIOLOGICAL PHOSPHORUS REMOVAL FROM AN SBR SYSTEM MIDDLEBURY, VT. Paul Klebs, Senior Applications Engineer Aqua-Aerobic Systems, Inc.

OPTIMIZING BIOLOGICAL PHOSPHORUS REMOVAL FROM AN SBR SYSTEM MIDDLEBURY, VT. Paul Klebs, Senior Applications Engineer Aqua-Aerobic Systems, Inc. OPTIMIZING BIOLOGICAL PHOSPHORUS REMOVAL FROM AN SBR SYSTEM ABSTRACT MIDDLEBURY, VT Paul Klebs, Senior Applications Engineer Aqua-Aerobic Systems, Inc. The Middlebury Wastwater Treatment Plant, located

More information

PERMITTEE/FACILITY NAME: City of Detroit Water and Sewerage Department / Detroit Wastewater Treatment Plant

PERMITTEE/FACILITY NAME: City of Detroit Water and Sewerage Department / Detroit Wastewater Treatment Plant Permit No. MI0022802 FACT SHEET PERMITTEE/FACILITY NAME: City of Detroit / Detroit Wastewater Treatment Plant COUNTY: Wayne DESCRIPTION OF EXISTING WASTEWATER TREATMENT FACILITIES: The Detroit (DWSD) owns

More information

Water Reuse for Agricultural Processing: A Community Case Study

Water Reuse for Agricultural Processing: A Community Case Study Water Reuse for Agricultural Processing: A Community Case Study August 2012 By: Prepared by: Short Elliott Hendrickson Inc. 3535 Vadnais Center Drive Saint Paul, MN 55110-5196 651.490.2000 SEH is a registered

More information

Provided below is a description of the processes generating wastewater in a poultry plant and a typical pretreatment and full treatment system.

Provided below is a description of the processes generating wastewater in a poultry plant and a typical pretreatment and full treatment system. II. PROCESS OVERVIEW Provided below is a description of the processes generating wastewater in a poultry plant and a typical pretreatment and full treatment system. II.1. Wastewater Generation A typical

More information

The City of Boulder 75 th Street Wastewater Treatment Facility

The City of Boulder 75 th Street Wastewater Treatment Facility The City of Boulder 75 th Street Wastewater Treatment Facility Wastewater Collection and Treatment The Foundation of Public Health Wastewater Collection Boulder s wastewater collection system, also known

More information

SECTION 6 EXISTING WASTEWATER MANAGEMENT SYSTEMS

SECTION 6 EXISTING WASTEWATER MANAGEMENT SYSTEMS SECTION 6 EXISTING WASTEWATER MANAGEMENT SYSTEMS This section will describe the Town s existing wastewater management systems. This includes on-site disposal systems and private collection systems. The

More information

Options for Handling Feedlot Runoff at Large CAFOs

Options for Handling Feedlot Runoff at Large CAFOs Options for Handling Feedlot Runoff at Large CAFOs Water Quality/Feedlots #6.57 Updated November 2007 Contents General permit options... page 2 Individual permit options... page 3 MPCA Area Offices Brainerd:

More information

INTEGRATED POND AND BNR ACTIVATED SLUDGE TREATMENT PROCESS TO ACHIEVE RELIABLE NITROGEN AND PHOSPHORUS REMOVAL

INTEGRATED POND AND BNR ACTIVATED SLUDGE TREATMENT PROCESS TO ACHIEVE RELIABLE NITROGEN AND PHOSPHORUS REMOVAL INTEGRATED POND AND BNR ACTIVATED SLUDGE TREATMENT PROCESS TO ACHIEVE RELIABLE NITROGEN AND PHOSPHORUS REMOVAL Annalien Toerien Golder Associates Africa, PO Box 6001, Halfway House, 1685. E-mail: atoerien@golder.co.za

More information

Alberta Environment Standards for Advanced Waste Systems

Alberta Environment Standards for Advanced Waste Systems Alberta Environment Standards for Advanced Waste Systems + Alberta Rural Organic Waste to Resources Network + George Neurohr Regional Municipal Engineer Grande Prairie, Alberta May 1, 2012 Contents: Introduction

More information

Ann Arbor Wastewater Treatment Plant Facilities Renovations Project September 2015

Ann Arbor Wastewater Treatment Plant Facilities Renovations Project September 2015 Ann Arbor Wastewater Treatment Plant Facilities Renovations Project September 2015 The Facilities Master Plan was completed in 2004 and identified the need for improvements to the City of Ann Arbor s Wastewater

More information

Source Water Protection Practices Bulletin Managing Sanitary Sewer Overflows and Combined Sewer Overflows to Prevent Contamination of Drinking Water

Source Water Protection Practices Bulletin Managing Sanitary Sewer Overflows and Combined Sewer Overflows to Prevent Contamination of Drinking Water United States Office of Water EPA 916-F-01-032 Environmental Protection (4606) July 2001 Agency Source Water Protection Practices Bulletin Managing Sanitary Sewer Overflows and Combined Sewer Overflows

More information

Maricopa Association of Governments. Technical Memorandum No. 1 INFRASTRUCTURE DEVELOPMENT COSTS. August 2001

Maricopa Association of Governments. Technical Memorandum No. 1 INFRASTRUCTURE DEVELOPMENT COSTS. August 2001 Maricopa Association of Governments Technical Memorandum No. 1 INFRASTRUCTURE DEVELOPMENT COSTS August 2001 3033 NORTH 44TH STREET, SUITE 101 PHOENIX, ARIZONA 85018 (602) 263-9500 FAX (602) 265-1422 Technical

More information

Town of New Castle Utility Department Introduction

Town of New Castle Utility Department Introduction Town of New Castle Utility Department Introduction Town of New Castle Utility Department Mission Statement Our commitment is to ensure that our customers receive high quality water and wastewater treatment

More information

CHAPTER 5 - WASTEWATER TREATMENT FACILITIES

CHAPTER 5 - WASTEWATER TREATMENT FACILITIES CHAPTER 5 - WASTEWATER TREATMENT FACILITIES 5.1 Introduction The purpose of this chapter is to summarize the evaluation of the existing wastewater facilities infrastructure and performance. The results

More information

SMALL COMMUNITY TREATMENT PLANT EXPANSION WHILE IN OPERATION USING ADVANCED TECHNOLOGY

SMALL COMMUNITY TREATMENT PLANT EXPANSION WHILE IN OPERATION USING ADVANCED TECHNOLOGY SMALL COMMUNITY TREATMENT PLANT EXPANSION WHILE IN OPERATION USING ADVANCED TECHNOLOGY Adel Bassyouni, HDR Engineering, Guillermo Garcia, HDR Engineering, Don Mc Dermott, Viejas Public Works Department

More information

Wastewater: The Basics

Wastewater: The Basics Wastewater: The Basics Basic information about wastewater, the San Mateo Wastewater Plant, and the Clean Water Program March 2016 1 Introduction? Wastewater means water that has been used or contains dissolved

More information

Experts Review of Aerobic Treatment Unit Operation and Maintenance. Bruce Lesikar Texas AgriLife Extension Service

Experts Review of Aerobic Treatment Unit Operation and Maintenance. Bruce Lesikar Texas AgriLife Extension Service Experts Review of Aerobic Treatment Unit Operation and Maintenance Bruce Lesikar Texas AgriLife Extension Service Overview Overview of Aerobic Treatment Units Installing for accessibility to system components

More information

City of Patterson Waste Water Treatment Plant.

City of Patterson Waste Water Treatment Plant. City of Patterson Waste Water Treatment Plant www.ci.patterson.ca.us Our Mission: To manage and operate safe, cost-efficient, and environmentally sound services for the benefit of the citizens of Patterson.

More information

City of Charlottetown Wastewater Treatment Expansion & Upgrading

City of Charlottetown Wastewater Treatment Expansion & Upgrading City of Charlottetown Wastewater Treatment Expansion & Upgrading Background As Canada s smallest provincial capital, the City of the Charlottetown has a population of approximately 34,000 residents and

More information

NEVADA CITY WASTEWATER TREATMENT INQUIRY

NEVADA CITY WASTEWATER TREATMENT INQUIRY NEVADA CITY WASTEWATER TREATMENT INQUIRY REASON FOR INVESTIGATION The 2003-2004 Grand Jury investigated the status of wastewater treatment in unincorporated Nevada County. This year, the Grand Jury investigated

More information

5. TREATMENT FACILITIES

5. TREATMENT FACILITIES 5. TREATMENT FACILITIES 5.1. Background... 1 5.2. Nine Springs Wastewater Treatment Plant... 1 5.2.1. Liquid Treatment Facilities... 3 5.2.2. Biosolids Disposal Facilities... 6 5.2.3. Operation and Maintenance

More information

CHAPTER 10-2. Section 1 Inventory of Existing Sanitary Sewer Collection and Treatment Facilities

CHAPTER 10-2. Section 1 Inventory of Existing Sanitary Sewer Collection and Treatment Facilities CHAPTER 10-2 SEWAGE COLLECTION AND TREATMENT FACILITIES Section 1 Inventory of Existing Sanitary Sewer Collection and Treatment Facilities 1.1 SANITARY SEWER COLLECTION SYSTEM The City of Washougal operates

More information

SEWAGE TREATMENT PLANT AT BRAMPTON FARMS, ST. CATHERINE FCS # 0853/76/C ENGINEERING REPORT

SEWAGE TREATMENT PLANT AT BRAMPTON FARMS, ST. CATHERINE FCS # 0853/76/C ENGINEERING REPORT CIVIL & STRUCTURAL ENGINEERING CONSULTANTS 7A Barbados Avenue, Kingston 5, Jamaica, Tele: (876) 754-2154/5 Fax: (876) 754-2156 E-mail: mail@fcsconsultants.com SEWAGE TREATMENT PLANT AT BRAMPTON FARMS,

More information

CHAPTER 8 UPGRADING EXISTING TREATMENT FACILITIES

CHAPTER 8 UPGRADING EXISTING TREATMENT FACILITIES CHAPTER 8 UPGRADING EXISTING TREATMENT FACILITIES 8-1. General. Upgrading of wastewater treatment plants may be required to handle increased hydraulic and organic loadings to meet existing effluent quality

More information

Holistic Aeration and Chemical Optimization Saves Big Money from 1 MGD to 600 MGD. Trevor Ghylin, PE PhD

Holistic Aeration and Chemical Optimization Saves Big Money from 1 MGD to 600 MGD. Trevor Ghylin, PE PhD Holistic Aeration and Chemical Optimization Saves Big Money from 1 MGD to 600 MGD Trevor Ghylin, PE PhD Outline Background Case Study: Sterno, Sweden (~1.8 MGD) 65% Aeration Energy Reduction Case Study:

More information

NPDES Permit No. IL0021695. Notice No. JCH:12012302.bah. Public Notice Beginning Date: November 27, 2012. Public Notice Ending Date: December 27, 2012

NPDES Permit No. IL0021695. Notice No. JCH:12012302.bah. Public Notice Beginning Date: November 27, 2012. Public Notice Ending Date: December 27, 2012 Notice No. JCH:12012302.bah Public Notice/Fact Sheet Issued By: Public Notice Beginning Date: November 27, 2012 Public Notice Ending Date: December 27, 2012 National Pollutant Discharge Elimination System

More information

Microscopic Examination of Activated Sludge

Microscopic Examination of Activated Sludge Microscopic Examination of Activated Sludge Educational Objectives Upon completion of this course, the operator should be able to use the microscope to view microorganisms present in activated sludge,

More information

Northport/Leelanau Township Wastewater Treatment Facility

Northport/Leelanau Township Wastewater Treatment Facility 21 st Century Biofilm Reactors High Quality Yet Simple Operations Northport/Leelanau Township Wastewater Treatment Facility Presented by: Rich Grant, PE Carey Bond, PE Date Presented by: Rich Grant, PE

More information

MUNICIPAL WASTEWATER TREATMENT PLANT ENERGY EVALUATION FOR ITHACA AREA WASTEWATER TREATMENT FACILITY

MUNICIPAL WASTEWATER TREATMENT PLANT ENERGY EVALUATION FOR ITHACA AREA WASTEWATER TREATMENT FACILITY MUNICIPAL WASTEWATER TREATMENT PLANT ENERGY EVALUATION FOR ITHACA AREA WASTEWATER TREATMENT FACILITY Agreement No. 7185 Prepared for THE NEW YORK STATE ENERGY RESEARCH AND DEVELOPMENT AUTHORITY Albany,

More information

Treatment and Biosolids Technologies. City of Morro Bay New Water Reclamation Facility

Treatment and Biosolids Technologies. City of Morro Bay New Water Reclamation Facility Treatment and Biosolids Technologies City of Morro Bay New Water Reclamation Facility Engineering Component of Siting Study Project engineering team will look at the following parameters related to each

More information

San Luis Obispo County Los Osos Wastewater Project Development TECHNICAL MEMORANDUM SEPTAGE RECEIVING STATION OPTION TABLE OF CONTENTS

San Luis Obispo County Los Osos Wastewater Project Development TECHNICAL MEMORANDUM SEPTAGE RECEIVING STATION OPTION TABLE OF CONTENTS San Luis Obispo County Los Osos Wastewater Project Development TECHNICAL MEMORANDUM SEPTAGE RECEIVING STATION OPTION TABLE OF CONTENTS Page No. 1.0 BACKGROUND...1 2.0 INTRODUCTION - SEPTAGE RECEIVING STATION...1

More information

The Corporation of the Municipality of Wawa

The Corporation of the Municipality of Wawa The Corporation of the Municipality of Wawa Prepared by: Water & Sewer Department Infrastructure Services February 2016 2015 Annual Sewage Performance Report Table of Contents Signature Page... (i) Table

More information

CASE STUDY: BRISBANE WATER FAIRFIELD WASTE WATER TREATMENT PLANT

CASE STUDY: BRISBANE WATER FAIRFIELD WASTE WATER TREATMENT PLANT 2006 Virotec International plc All rights reserved. A COMMERCIAL APPLICATION OF VIROSEWAGE CASE STUDY: BRISBANE WATER FAIRFIELD WASTE WATER TREATMENT PLANT Significant reductions in and are noticed. The

More information

Orange County Sanitation District

Orange County Sanitation District Orange County Sanitation District The Orange County Sanitation District operates large wastewater treatment plants in Fountain Valley and Huntington Beach, CA. These plants treat about 230 million gallons

More information

During the past decade, the city of

During the past decade, the city of An Advanced Pollution Control Facility s Conversion to Four-Stage Bardenpho to Improve Biological Nitrogen Removal Timur Deniz, Thomas W. Friedrich, and John Milligan During the past decade, the city of

More information

Technical Feasibility of a Wet Weather Flow Treatment Facility

Technical Feasibility of a Wet Weather Flow Treatment Facility Wastewater Master Plan DWSD Project No. CS-1314 Technical Feasibility of a Wet Weather Flow Treatment Facility Technical Memorandum Original Date: August 9, 2001 Revision Date: September 2003 Author: Tetra

More information

GUIDELINES FOR LEACHATE CONTROL

GUIDELINES FOR LEACHATE CONTROL GUIDELINES FOR LEACHATE CONTROL The term leachate refers to liquids that migrate from the waste carrying dissolved or suspended contaminants. Leachate results from precipitation entering the landfill and

More information

Advanced Wastewater Treatment and Disposal Systems. Water and Wastewater Utility Operation and

Advanced Wastewater Treatment and Disposal Systems. Water and Wastewater Utility Operation and Advanced Wastewater Treatment and Disposal Systems Water and Wastewater Utility Operation and Management for Tribes Preliminary Treatment Primary Treatment Secondary Treatment Tertiary Treatment Disinfection

More information

5. Environmental Analysis

5. Environmental Analysis 5.11 The potential for adverse impacts on utilities and service systems was evaluated based on information concerning current service levels and the ability of the service providers to accommodate the

More information

St. John s Harbour Clean-Up Phase 2. Project Description

St. John s Harbour Clean-Up Phase 2. Project Description St. John s Harbour Clean-Up Phase 2 Project Description February 2003 NEWFOUNDLAND DESIGN ASSOCIATES LIMITED 1 Introduction The City of St. John s, the adjoining City of Mount Pearl and the Town of Paradise

More information

Fusion Series Treatment Systems Small Scale Residential & Commercial Treatment Units

Fusion Series Treatment Systems Small Scale Residential & Commercial Treatment Units SECTION: C3.10.120 CL0052 0911 Supersedes New Fusion Series Treatment Systems Small Scale Residential & Commercial Treatment Units Clarus Environmental 3649 Cane Run Rd. Louisville, KY 40211 877-244-9340

More information

Components of a Basement Flooding Protection Plan: Sewer System Improvements. November 2000

Components of a Basement Flooding Protection Plan: Sewer System Improvements. November 2000 Components of a Basement Flooding Protection Plan: Sewer System Improvements November 2000 Components of a Basement Flooding Protection Plan: Sewer System Improvements November 2000 SEMCOG 2000 Prepared

More information

POTW PHOSPHORUS REMOVAL PROCESSES

POTW PHOSPHORUS REMOVAL PROCESSES POTW PHOSPHORUS REMOVAL PROCESSES Ohio Lake Erie Phosphorus Task Force - December 20, 2007 ROBERT M. BONNETT, PE Northeast Ohio Regional Sewer District OUTLINE SOURCES AND FORMS IN WASTEWATER TYPICAL POTW

More information

Executive Summary. Purpose and Need for Project. Background Work

Executive Summary. Purpose and Need for Project. Background Work Executive Summary Purpose and Need for Project The City of St. John s, and the adjoining City of Mount Pearl and the Town of Paradise now encompass a development of approximately 12,000 hectares, with

More information

IEPA Log No.: C-0679-14 CoE appl. #: CEMVR-OD-P-2014-1343. Public Notice Beginning Date: June 10, 2015 Public Notice Ending Date: July 10, 2015

IEPA Log No.: C-0679-14 CoE appl. #: CEMVR-OD-P-2014-1343. Public Notice Beginning Date: June 10, 2015 Public Notice Ending Date: July 10, 2015 IEPA Log No.: C-0679-14 CoE appl. #: CEMVR-OD-P-2014-1343 Public Notice Beginning Date: June 10, 2015 Public Notice Ending Date: July 10, 2015 Section 401 of the Federal Water Pollution Control Act Amendments

More information

Small Wastewater Treatment Systems

Small Wastewater Treatment Systems Small Wastewater Treatment Systems By Michael Albanese, P.Eng. H2FLOW EQUIPMENT INC. www.h2flow.com Why do you need one? Typical Reasons Enviromental Regulations New Development Failing Septic Systems

More information

Phosphorus Removal in Wastewater Treatment

Phosphorus Removal in Wastewater Treatment RESEARCH & DEVELOPMENT REPORT NO. Phosphorus Removal in Wastewater Treatment (Final Report) Research and Development Section Electrical & Mechanical Projects Division Nov 2013 Final Report endorsed by

More information

After the Flush. Safe disposal of our wastewater is a valued and complex, not-for-profit municipal service.

After the Flush. Safe disposal of our wastewater is a valued and complex, not-for-profit municipal service. After the Flush Published: July 14, 2011 Sewage or wastewater is something we rarely think or talk about. The wastewater from our toilets, showers, washing machines and dishwashers quickly departs our

More information

Upper Occoquan Service Authority Centreville, Virginia A Case Study

Upper Occoquan Service Authority Centreville, Virginia A Case Study Upper Occoquan Service Authority Centreville, Virginia A Case Study Dennis Clough, Managing Director Energy Systems Group Upper Occoquan Service Authority About the Upper Occoquan Service Authority 54

More information

Treatment Mound Design Considerations & Details

Treatment Mound Design Considerations & Details Design Considerations & Details 10001 84th Avenue, Clairmont, AB T0H 0W0 Phone: 780.513.3950 Fax: 780.539.7686 www.countygp.ab.ca Permit Number: PRPSW The following information is to accompany the Private

More information

PRELIMINARY ENGINEERING REPORT AND UTILITY PLAN NEW WASTEWATER TREATMENT FACILITY TOWN OF MEAD FOR A FOR THE

PRELIMINARY ENGINEERING REPORT AND UTILITY PLAN NEW WASTEWATER TREATMENT FACILITY TOWN OF MEAD FOR A FOR THE PRELIMINARY ENGINEERING REPORT AND UTILITY PLAN FOR A NEW WASTEWATER TREATMENT FACILITY FOR THE TOWN OF MEAD REVISED NOVEMBER 6, 2006 PRELIMINARY ENGINEERING REPORT AND UTILITY PLAN FOR A NEW WASTEWATER

More information

Water Resources Analysis and Plan

Water Resources Analysis and Plan This chapter of the Waconia Comprehensive Plan addresses the local and regional wastewater system, the water supply system, and surface water management. Wastewater and Comprehensive Sewer Plan Introduction

More information

Retrofitting an Aeration Basin with Anoxic Zone to Reduce Operations Cost and Improve Performance

Retrofitting an Aeration Basin with Anoxic Zone to Reduce Operations Cost and Improve Performance Retrofitting an Aeration Basin with Anoxic Zone to Reduce Operations Cost and Improve Performance Ed Griffenberg, Operations Specialist HDR Engineering, Edmonds, WA 2012 PNCWA Conference, Boise, Idaho Case

More information

New and Innovative Rare Earth Technology for Low-Level Phosphorus Removal Presented to: By: Date:

New and Innovative Rare Earth Technology for Low-Level Phosphorus Removal Presented to: By: Date: New and Innovative Rare Earth Technology for Low-Level Phosphorus Removal Presented to: By: Date: Conference on the Environment Pam Cornish Business Development Manager Nov 19, 2014 1 Discussion Outline

More information

Odor Control A Successful Case Study of an Evaluation and Assessment at a Wastewater Treatment Plant in Gallup, New Mexico

Odor Control A Successful Case Study of an Evaluation and Assessment at a Wastewater Treatment Plant in Gallup, New Mexico Odor Control A Successful Case Study of an Evaluation and Assessment at a Wastewater Treatment Plant in Gallup, New Mexico PNCWA 2012 Annual Conference and Exposition October 24, 2012 Presented by Fred

More information

Facility Classification Standards

Facility Classification Standards Facility Classification Standards Approval Date: April 3, 2009 Effective Date: April 3, 2009 Approved By: Nancy Vanstone, Deputy Minister Version Control: Replaces Facility Classification Standards dated

More information

Pursuant to Department of Environmental Protection Rules Chapter 555, effective March 9, 2009

Pursuant to Department of Environmental Protection Rules Chapter 555, effective March 9, 2009 APPLICATION FOR ADDITION OF TRANSPORTED WASTES IN WASTEWATER TREATMENT FACILITIES Pursuant to Department of Environmental Protection Rules Chapter 555, effective March 9, 2009 This application is to be

More information

RECOMMENDED STANDARDS for WASTEWATER FACILITIES

RECOMMENDED STANDARDS for WASTEWATER FACILITIES RECOMMENDED STANDARDS for WASTEWATER FACILITIES POLICIES FOR THE DESIGN, REVIEW, AND APPROVAL OF PLANS AND SPECIFICATIONS FOR WASTEWATER COLLECTION AND TREATMENT FACILITIES 2014 EDITION A REPORT OF THE

More information

Example: 2. Solution. Provide depth D = 1.5 m. Sewage flow = 10000 x 170 x 0.80 x 10-3 = 1360 m 3 /d. Now, 0.182(1+. = 1.562. Q L = 2.

Example: 2. Solution. Provide depth D = 1.5 m. Sewage flow = 10000 x 170 x 0.80 x 10-3 = 1360 m 3 /d. Now, 0.182(1+. = 1.562. Q L = 2. Example: 2 Design low rate trickling filter for secondary treatment of sewage generated from 10000 persons with rate of water supply 170 LPCD. The BOD 5 after primary treatment is 110 mg/l and BOD 5 of

More information