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Resolution 2022-12 FDEP State Revolving Fund (SRF)/Clean Water State Revolving Fund Wastewater Facilities Plan
RESOLUTION NUMBER 2422-12 A RESOLUTION OF THE CITY COMMISSION OF THE CITY OF WINTER SPRINGS, FLORIDA, RELATING TO THE FLORIDA DEPARTMENT OF ENVIRONMENTAL PROTECTION (FDEP) STATE REVOLVING FUND (SRF), ADOPTING THE CLEAN WATER STATE REVOLVING FUND WASTEWATER FACILITIES PLAN FOR THE IMPLEMENTATION OF THE EAST AND WEST WATER RECLAMATION FACILITY IMPROVEMENTS; PROVIDING FOR THE REPEAL OF PRIOR INCONSISTENT RESOLUTIONS, SEVERABILITY,AND AN EFFECTIVE DATE. WHEREAS, Florida Statutes provide for loans to local government agencies to finance the design, and construction of wastewater facilities; and the Florida Administrative Code requires the City Commission to formally adopt a facilities plan outlining necessary wastewater facility improvements to comply with State of Florida funding requirements; and WHEREAS, the City Commission of the City of Winter Springs, Florida previously approved Resolutions 2022-08, 2022-09, and 2022-10, adopting the Winter Springs Wastewater Master Plan and the Conceptual Design Reports for the East and West Water Reclamation Facilities, which were intended to guide the creation and preparation of the more specific Clean Water State Revolving Fund Wastewater Facilities Plan (hereinafter the "Wastewater Facilities Plan") adopted in this Resolution and form the conceptual basis for the design and construction of the facilities; and WHEREAS, the City Commission of the City of Winter Springs, Florida agrees with the findings and summary of necessary improvements as outlined in the Wastewater Facilities Plan for the purpose of designing and constructing Water Reclamation Facilities to replace the existing East and West Water Reclamation Facilities; and NOW, THEREFORE, BE IT RESOLVED by the City Commission of the City of Winter Springs, Florida as follows: SECTION 1. FINDINGS The foregoing findings are incorporated herein by reference and made a part hereof. SECTION 2. ADOPTION OF WASTEWATER FACILITIES PLAN. The City of Winter Springs Florida, is authorized to and does hereby adopt the proposed Wastewater Facilities Plan, attached hereto as Exhibit A. The City Manager is hereby designated as the authorized representative to provide the assurances and commitments that will be required by the Wastewater Facilities Plan. The City Manager is hereby designated as the authorized representative to execute the Wastewater Facilities Plan which will become the foundation of all activities related to the wastewater facility improvements. The City Manager is further authorized to represent the City in carrying out the Wastewater Facilities Plan. The City Manager is authorized to delegate responsibility to appropriate City Staff to carry out technical, financial, and administrative activities associated with the Wastewater Facilities Plan. The legal authority for adoption of this Wastewater Facilities Plan is pursuant to the City Charter, City Code of Ordinances, and the Laws of the State of Florida. SECTION 3. REPEAL OF PRIOR INCONSISTENT RESOLUTIONS. All Resolutions or part of Resolutions in conflict with any of the provisions of this Resolution are hereby repealed. SECTION 4. SEVERABILITY. If any section or portion of a section of this Resolution proves to be invalid, unlawful, or unconstitutional, it shall not be held to invalidate or impair the validity, force, or effect or any other section or part of this Resolution. SECTION 5. EFFECTIVE DATE This Resolution shall take effect upon its approval and adoption by the City Commission. APPROVED AND ADOPTION THIS 13TH DAY OF.TUNE,2022. CITY COMMISSION Q"r. CITY OF WINTER SPRINGS,FLORIDA �..• ;� A-1 o,t � L Ch KEVIN MCCANN,MAYOR (SEAL) ATTEST: APPROVED AS TO FORM: CHRISTIAN GOWAN,CITY CLERK ANTHONY A.GARGANESE,CITY ATTORNEY Clean Water State Revolving Fund Facilities Plan for City of Winter Springs May 2022 Incorporated 1959 Certification I certify that the information contained in this report is true and correct to the best of my knowledge and that this report has been prepared using sound engineering principles. Florida Registration No. Signature of Engineer&Date Name Scott Richards, P.E. Carollo Engineers,Inc. 200 E. Robinson Street, Suite 91400 Orlando, FL 32801 (407) 377-4312 on behalf of Jason Norberg,Director of Public Works and Utilities City of Winter Springs Public Works Office 400 Old Sanford Oviedo Road Winter Springs, FL 32708 (407) 327-5989 Company, Address, Phone Number, Email Acknowledgement The City of Winter Springs would like to acknowledge the professional work performed by the Consultants below: • Carollo Engineers, Inc., for the "East Water Reclamation Facility (WRF) Conceptual Design Report (CDR)", dated April 2022 (see Appendix A) and the "West Water Reclamation Facility (WRF) Conceptual Design Report (CDR)", dated April 2022 (see Appendix B). • Kimley-Horn for the "2022 Wastewater and Reclaimed Water Master Plan", dated April 2022 (see Appendix Q. Table of Contents Chapter 1.0 Summary of Findings and Recommendations......................................................... 1 Chapter2.0 Introduction ............................................................................................................. 2 2.1 Background....................................................................................................................................................2 2.2 Project Descriptions and Need.......................................................................................................................2 Chapter 3.0 Environmental Impacts............................................................................................ 6 3.1 Environmental Review—Project#1 East WRF Improvements.....................................................................6 3.2 Environmental Review—Project#2 West WRF Improvements....................................................................8 Chapter 4.0 Development of Alternatives................................................................................. 11 4.1 General.........................................................................................................................................................11 4.2 Cost-Effectiveness.......................................................................................................................................11 4.3 East WRF Improvements.............................................................................................................................11 4.3.1 No Action............................................................................................................................................11 4.3.2 Construct a New BNR Facility............................................................................................................11 4.3.3 Construct a New MBR Facility............................................................................................................12 4.4 West WRF hnprovements...........................................................................................................................12 4.4.1 No Action............................................................................................................................................12 4.4.2 Construct a New BNR Facility............................................................................................................12 4.4.3 Construct a New MBR Facility............................................................................................................13 Chapter 5.0 Selected Alternatives............................................................................................. 14 5.1 Description of Proposed Facilities...............................................................................................................14 5.2 East WRF Improvements.............................................................................................................................14 5.3 West WRF Improvements...........................................................................................................................14 5.4 Cost to Construct Facilities..........................................................................................................................15 Chapter 6.0 Implementation and Compliance........................................................................... 16 6.1 Public Hearing/Dedicated Revenue Hearing...............................................................................................16 6.1.1 Financial Planning...............................................................................................................................16 6.1.2 Implementation....................................................................................................................................16 6.1.3 Implementation Schedule....................................................................................................................16 6.1.4 Compliance..........................................................................................................................................16 Figures Figure 1 Wastewater Utility Service Area'....................................................................................................................5 Figure 2 East WRF Environmental Survey Area(Project#1).......................................................................................8 Figure 3 West WRF Envirorunental Survey Area(Project#2)....................................................................................10 Appendix Appendix A City of Winter Springs East WRF Conceptual Design Report Appendix B City of Winter Springs West WRF Conceptual Design Report Appendix C 2022 Wastewater and Reclaimed Water Master Plan Appendix D ESA Environmental Constraints Review and the Florida Natural Area Inventory(FNAI)Tracking List—East WRF Appendix E ESA Environmental Constraints Review and the Florida Natural Area Inventory (FNAI)Tracking List—West WRF Appendix F Present Worth Cost Analysis Appendix G Advertisement of Public Meeting Appendix H Summary of Public/Dedicated Revenue Hearing Appendix I Capital Financing Plan Appendix J Current User Rate System Chapter 1.0 Summary of Findings and Recommendations This Facilities Plan was prepared by the City of Winter Springs (City)to meet the requirements of the Florida Department of Environmental Protection (FDEP) State Revolving Fund(SRF) program for the funding of wastewater improvement projects. The project areas included in this Facilities Plan are all within City limits. This Facilities Plan includes two wastewater treatment plant improvement projects. Project 1 provides improvements to the East Water Reclamation Facility (WRF) and Project 2 provides improvements to the West Water Reclamation Facility (WRF). These two projects are part of the City's 2022 Wastewater and Reclaimed Water Master Plan (Appendix Q. Please note that it is the City's intent to fund these projects with a combination of SRF and potential federal funding (ARPA or similar), as well as direct available City funds. The City is currently estimating to request$50,000,000 in loans for the construction of the two projects. Negative environmental impacts are not anticipated from the construction of these projects other than temporary disturbances associated with construction. These projects are not anticipated to have adverse effects on flora, fauna, threatened or endangered plant or animal species, surface water bodies, groundwater, prime agricultural lands, archaeological or historical sites, floodplains, or air quality. In order to complete construction of the new proposed facilities, limited impacts on wetlands and undisturbed natural areas are expected to occur, as further noted in the attached documents. These projects do not have any anticipated adverse human health or environmental effects on minority or low-income communities. Project descriptions and costs are provided below: 1. East WRF Improvements: Construction of new replacement of a 1.5 million gallon per day (MGD)BNR facility to improve effluent quality and build redundancy/resiliency to the plant. The estimated cost for the selected alternative (in 2022 dollars)is $34,792,000. This cost estimate includes engineering and construction. 2. West WRF Improvements: Construction of new replacement of a 1.5 million gallon per day (MGD)BNR facility to improve effluent quality and build redundancy/resiliency to the plant. The estimated cost for the selected alternative (in 2022 dollars)is $34,792,000. This cost estimate includes engineering and construction. 1 Chapter 2.0 Introduction 2.1 Background The City of Winter Springs (City)is located within Seminole County in Central Florida. The City is bordered by the Cities of Oviedo, Maitland, Casselberry, and Longwood. The City of Winter Springs Public Works Department is responsible for the planning and implementation of the service area infrastructure needs. The City owns and operates the East Water Reclamation Facility (WRF) located in the east portion of the City with a current design capacity of 2.012 million gallons per day (mgd), the West Water Reclamation Facility (WRF) located in the west portion of the City with a current design capacity of 2.07 mgd, fifty-one (5 1)lift stations, and approximately 136,000 linear feet (LF) of force mains. The total City area is approximately 15 square miles, and an estimated 37,291 customers are provided City wastewater services. Figure 1 shows the service area boundary. This Facilities Plan was prepared by the City of Winter Springs to meet the requirements of the Florida Department of Environmental Protection (FDEP) State Revolving Fund (SRF)program for funding wastewater improvement projects. The project areas included in this Facilities Plan are all within City limits. The planning period for this Facilities Plan extends through the year 2027. The recommendations of this Facilities Plan are consistent with the City's 2022 Wastewater and Reclaimed Master Plan. The City is also currently updating its Comprehensive Plan to include the plan for these facilities. 2.2 Project Descriptions and Need This Facilities Plan includes the wastewater treatment facility improvement projects listed below. Project 1 provides improvements to the existing East WRF, and Project 2 provides improvements to the existing West WRF. 1. East WRF Improvements: Constructed in the mid-1970's,the existing East WRF is comprised of two separate package treatment plants (circular field erected steel tanks) originally designed to use an activated sludge process, known as contact stabilization. The facility is permitted for a flow of 2.012 mgd average annual daily flow (AADF) but currently experiences flows at approximately half this capacity. The City is consequently paying to operate and maintain an oversized and outdated facility, which has no built-in reliability/redundancy (i.e., a single treatment process cannot be taken offline without taking the whole basin/package plant out of service). Furthermore, the package plants at the East WRF have experienced numerous challenges and failures, and are currently under consent order issued by the FDEP (OGC Case 921-0790). 2 The City recently contracted with Carollo Engineers, Inc. to complete the conceptual design for the proposed East WRF as part of the East WRF Conceptual Design Report (CDR), dated April 2022 (see Appendix A). Carollo Engineers, Inc. and Wekiva Engineering conducted assessments of the existing East WRF as part of the project and concluded that no major component has permanent value worth restoring. Based on the condition of the current facility, the East WRF CDR focuses on the construction of new replacement of the East WRF. The goal is to conceptualize a new facility which can meet current and future water quality requirements while planning for growth over decades to come. This facility should also be built for resiliency and reliability, such that the City does not experience the current facility challenges again. The City plans to "right-size"the proposed facility and replace the existing East WRF with a 1.5 mgd BNR facility. The proposed East WRF will also include new headworks screening and grit removal, a new odor control facility, new secondary clarifiers, a chlorine contact basin, new disk filters,pump stations, and electrical, chemical, and administrative buildings. The estimated conceptual construction cost for this project is $34,792,000. This cost estimate includes engineering and construction. 2. West WRF Improvements: Constructed in the late-1980's, the existing West WRF is comprised of two separate package treatment plants (circular field erected steel tanks) originally designed to use an activated sludge process, known as contact stabilization. The facility is permitted for a flow of 2.07 mgd AADF but currently experiences flows at approximately half this capacity. The City is consequently paying to operate and maintain an oversized and outdated facility, which has no built-in reliability/redundancy (i.e., a single treatment process cannot be taken offline without taking the whole basin/package plant out of service). Furthermore, the package plants at the East WRF have experienced numerous challenges and failures, and are currently under consent order issued by the FDEP (OGC Case #21-1055). The City recently contracted with Carollo Engineers, Inc. to complete the conceptual design for the proposed West WRF as part of the West WRF Conceptual Design Report (CDR), dated April 2022 (see Appendix B). Carollo Engineers, Inc. and Wekiva Engineering conducted assessments of the existing West WRF as part of the project and concluded that no major component has permanent value worth restoring. 3 Based on the condition of the current facility,the West WRF CDR focuses on the construction of new replacement of the West WRF. The goal is to conceptualize a new facility which can meet current and future water quality requirements while planning for growth over decades to come. This facility should also be built for resiliency and reliability, such that the City does not experience the current facility challenges again. The City plans to "right-size"the proposed facility and replace the existing West WRF with a 1.5 mgd BNR facility. The proposed West WRF will also include new headworks screening and grit removal, a new odor control facility, new secondary clarifiers, a chlorine contact basin, new disk filters,pump stations, and electrical, chemical and administrative buildings. The estimated conceptual construction cost for this project is $34,792,000. This cost estimate includes engineering and construction. 4 J L CTI Y L Y O � x — R p 3 N N b w ro ro 3 ro 3 N o a o Am $ S t7 CL. zi Lu w" Chapter 3.0 Environmental Impacts 3.1 Environmental Review—Project 91 East WRF Improvements An environmental review of the site was completed based on the planned facilities concept. Environmental Science Associates (ESA)reviewed the environmental constraints associated with the concept for the area shown in Figure 2. Appendix D includes the ESA environmental constraints review and the Florida Natural Area Inventory (FNAI)tracking list. Minor site constraints, including wetland impacts in some areas of construction, will need to be addressed during design. The following items are addressed to meet state, federal and potential funding requirements: • List threatened, endangered,proposed, and candidate species and designated critical habitats that may be present in the project area (may be obtained from U.S. Fish and Wildlife Service). A list of potential threatened, endangered, proposed, and candidate species and designated critical habitats that may be present within the general area of the proposed Project is attached as Appendix D, Florida Natural Areas Inventory. Habitat for many of these species, does not exist within the Project review area, except for the Bald eagle (Haliaeetus leucocephalus) and gopher tortoise (Gopherus polyphemus), as identified in the General Environmental Constraints Review (Appendix D). The Audubon Florida EagleWatch Nest Locator database identified no nest trees within 600-feet(protective nest buffer zone) of the Project review area, therefore impacts to the bald eagle are not anticipated. Additionally, during the environmental review, no gopher tortoise burrows were observed within or directly adjacent to the Project area. However, a 100-percent gopher tortoise burrow survey will need to be performed within the upland limits of proposed Project footprint, at least 90 days from construction initiation, in accordance with the Florida Fish and Wildlife Conservation Commission gopher tortoise survey and permitting guidelines (reference in Rule 68A-27.003, Florida Administrative Code). No other listed species, or critical habitat was observed or identified within the property limits. • Discuss any significant adverse effects upon flora,fauna,threatened or endangered plant or animal species, surface waterbodies,prime agricultural lands,wetlands, or undisturbed natural areas. No listed flora or faunal species were identified within the attached Environmental Constraints Review(Appendix D). The proposed Project is anticipated to impact approximately up to 2 acres of forested wetlands that were identified as medium quality and jurisdictional to the state and federal agencies. Other areas that may be impacted from the Project activities include highly disturbed, maintained upland areas that are inclusive of the treatment facility.No other undisturbed natural areas exist within the footprint of the proposed Project. The facility is located within the City of Winter Springs Planned Unit Development(PUD)Zone; therefore,no prime or unique agricultural lands exist within the proposed Project footprint. 6 • List any significant adverse environmental effects and what project features will mitigate such effects. It is anticipated that the Project activities will impact approximately up to 2 acres of medium quality forested wetlands. During the final design phase of the Project, all impacts will be minimized, where feasible,to further reduce the footprint and the Project impacts. Additionally,preliminary project corridor analysis indicates that on-site mitigation will be possible. All construction activities will obtain and comply with National Pollutant Discharge Elimination Systems (NPDES)permits and employ Best Management Practices to assure no impacts to water resources during construction. The site development associated with the Project will follow state water quality and quantity regulations to avoid alteration in drainage patterns, soil erosion or runoff. The Project will obtain construction and operation phase permits from the required state and federal agencies and will operate in accordance with all relevant regulations. In addition, appropriate state and federal permits will be obtained and mitigation will occur to off-set those impacts. Mitigation options for this area include the following: o Utilizing an approved mitigation site within the Lake Jesup Basin. o Constructing a wetland mitigation site within the Lake Jesup Basin. o Either enhance and/or preserve City-owned wetlands. o Utilize land owned or purchased by the City of Winter Springs, or Investigations with FDEP to utilize an out-of-basin,regionally significant mitigation bank (within the same watershed—St. Johns River Watershed)with a Cumulative Impact Analysis. • Discuss any significant adverse human health or environmental effects on minority or low-income communities. The East WRF is located in the eastern area of Winter Springs, primarily surrounded by residential community. Recent data from the EJSCREEN Census Summary Report(Accessed April 2022) indicated an overall City population demographic index of 26 percent with 19 percent reported as low-income. For the immediate area around the East WRF,the demographic index is 16 percent, with 3 percent reported as low-income. All values are under the state and national averages. Furthermore,this project considers the replacement of an existing WRF with a new facility. An improved and modernized WRF will benefit the entire community with improved reliability in wastewater treatment and effluent water quality which meets or exceeds regulatory requirements. Therefore, disproportionate high or adverse environmental effects to a minority population are not anticipated. 7 -4 e Rev wA- 0 GPSLOoano,, WM" —ONlneated WellandlOSW Umks �-' "' Wetland Feature, OSW Featarted xL*' vAa Ylgc W _ ©Ea.WRF Property Boundary 77 —;�_� ._ yie +fir ,� ,*1,•'` .` r , Feet Figure 2 East WRF Environmental Survey Area (Project#1) 3.2 Environmental Review—Project 92 West WRF Improvements An environmental review of the site was completed based on the planned facilities concept. Environmental Science Associates (ESA)reviewed the environmental constraints associated with the concept for the area shown in Figure 3. Appendix E includes the ESA environmental constraints review and the Florida Natural Area Inventory (FNAI)tracking list. Minor site constraints, including wetland impacts in some areas of construction, will need to be addressed during design. The following items are addressed to meet state, federal and potential funding requirements: • List threatened, endangered,proposed, and candidate species and designated critical habitats that may be present in the project area (may be obtained from U.S. Fish and Wildlife Service). A list of potential threatened, endangered, proposed, and candidate species and designated critical habitats that may be present within the general area of the proposed Project is attached as Appendix E, Florida Natural Areas Inventory. Habitat for many of these species does not exist within the Project review area, except for the Bald eagle (Haliaeetus leucocephalus) and gopher tortoise (Gopherus polyphemus), as identified in the General Environmental Constraints Review (Appendix E). The Audubon Florida EagleWatch Nest Locator database identified no nest trees within 600-feet(protective nest buffer zone) of the Project review area, therefore impacts to the bald eagle are not anticipated. Additionally, during the environmental review,no gopher tortoise burrows were observed within or directly adjacent to the Project area. However, a 100-percent gopher tortoise burrow survey will need to be performed within the upland limits of proposed Project footprint, at least 90 days from construction initiation in accordance with the Florida Fish and Wildlife Conservation Commission gopher tortoise survey and permitting guidelines (reference in 8 Rule 68A-27.003, Florida Administrative Code).No other listed species, or critical habitat was observed or identified within the property limits. • Discuss any significant adverse effects upon flora,fauna,threatened or endangered plant or animal species, surface waterbodies,prime agricultural lands,wetlands, or undisturbed natural areas. No listed flora or faunal species were identified within the attached Environmental Constraints Review(Appendix E). The proposed Protect is anticipated to impact existing parcel area which generally includes primarily disturbed, maintained upland areas that are inclusive of the treatment facility. No other undisturbed natural areas exist within the footprint of the proposed Project. The facility is located within the City of Winter Springs Planned Unit Development(PUD)Zone; therefore, no prime or unique agricultural lands exist within the proposed Project footprint. • List any significant adverse environmental effects and what project features will mitigate such effects. It is anticipated that the Project activities will be located on primarily existing disturbed, maintained uplands. The parcel is primarily surrounded by uplands area which consist of residential areas, power easements and previous golf- course parcel. During the final design phase of the Project, all potential impacts will be minimized with a site layout which considers use of existing disturbed, maintained parcel area and minimization to any natural upland areas. All construction activities will obtain and comply with National Pollutant Discharge Elimination Systems (NPDES)permits and employ Best Management Practices to assure no impacts to water resources during construction. The site development associated with the Project will follow state water quality and quantity regulations to avoid alteration in drainage patterns or soil erosion or runoff. The Project will obtain construction and operation phase permits from the required state and federal agencies and will operate in accordance with all relevant regulations. In addition, appropriate state and federal permits will be obtained where required. • Discuss any significant adverse human health or environmental effects on minority or low-income communities. The West WRF is located in the Western area of Winter Springs, surrounded by residential community to the North/West and power easement/vacated golf course property to the South/East. Recent data from the EJSCREEN Census Summary Report (Accessed April 2022) indicates an overall City population demographic index of 26 percent with 19 percentreported as low-income. For the immediate area around the West WRF,the demographic index is 39 percent,with 19 percent reported as low-income. The demographic index is near the state and national averages,with low income being below average. Furthermore, this project considers the replacement of an existing WRF with a new facility. An improved and modernized WRF will benefit the entire community with improved reliability in wastewater treatment and effluent water quality which meets or exceeds regulatory requirements. Therefore, disproportionate high or adverse environmental effects to a minority population is not anticipated. 9 "=GE Wetland Features - QSW Features - Q West WRF Property BoundarylReview Area ACL. s, a k . - _ F�u��r. ., _':.'r1e UVi .�'`�• r- 0 ~450 'd a Feet IK Figure 3 West WRF Environmental Survey Area (Project#2) 10 Chapter 4.0 Development of Alternatives 4.1 General An alternatives analysis and cost comparison were performed for each project. The various factors that affected the decision-making process, which led to each selected alternative and the rationale for that selection, are discussed in this section. The options for the East WRF Improvements are: 1. No action. 2. Construct a new BNR facility. 3. Construct a new MBR facility. The options for West WRF Improvements are: 1. No action. 2. Construct a new BNR facility. 3. Construct a new MBR facility. 4.2 Cost-Effectiveness Present worth was used to compare the various alternatives developed in this facilities plan. The capital and O&M costs along with the present worth of all alternatives are presented in Appendix F. 4.3 East WRF Improvements 4.3.1 No Action Under this alternative, the City would take no action to replace or address the condition of the East WRF. In this scenario, the existing ring-steel package plants will continue to deteriorate until further mechanical, structural and electrical related failures occur, ultimately leading to the facility's inability to treat wastewater. This would result in negative impacts to the environment and community. This alternative is, therefore, unviable and was rejected. 4.3.2 Construct a New BNR Facility Under this alternative, a new BNR facility would be constructed, and the existing treatment facility will be replaced. The new facility will allow for reliable and effective treatment of wastewater for the City into the distant future, beyond the 20-year planning horizon. This alternative also allows for future expansion to meet potential growth and considers future regulatory changes which may require stricter effluent criteria. 11 Furthermore, and as detailed in the attached CDR(Appendix A), the BNR process provides a proven reliable treatment process which is both common and consistent with the knowledge of City operational staff. Additionally, this option provides a treatment process which is resilient and redundant in its ability to meet effluent water quality, and is expected to be lower in both capital and operational costs compared to the MBR alternative. This alternative was selected as it aligns with the City's values to provide long-term performance and reliability. 4.3.3 Construct a New MBR Facility A new MBR facility would be constructed to replace the existing treatment facility under this alternative, which will allow for reliable and effective treatment of the City's wastewater beyond the 20-year planning horizon. This alternative also allows for future expansion to meet potential growth and considers future regulatory changes which may require stricter effluent criteria. As detailed in the attached CDR(Appendix A), the MBR process provides more advance technology with a smaller footprint. However, this technology is less popular, as it requires specialized equipment and training for the City's operational staff. This option is expected to provide long-term performance and reliability at higher capital and operational costs compared to the BNR alternative. While this option meets treatment goals, it does not best align with the City's values and was therefore rejected. 4.4 West WRF Improvements 4.4.1 No Action Under this alternative,the City would take no action to replace or address the condition of the West WRF. In this scenario, the existing ring-steel package plants will continue to deteriorate until further mechanical, structural and electrical related failures occur,ultimately leading to the facility's inability to treat wastewater. This would result in negative impacts to the environment and community. This alternative is, therefore, unviable and was rejected. 4.4.2 Construct a New BNR Facility Under this alternative, a new BNR facility would be constructed, and the existing treatment facility will be replaced. The new facility will allow for reliable and effective treatment of wastewater for the City into the distant future, beyond the 20-year planning horizon. This alternative also allows for future expansion to meet potential growth and considers future regulatory changes which may require stricter effluent criteria. Furthermore, and as detailed in the attached CDR(Appendix B), the BNR process provides a proven reliable treatment process which is both common and consistent with the knowledge of City operational staff. Additionally,this option provides a treatment process which is resilient and redundant in its ability to meet effluent water quality, and is expected to be lower in both capital and operational costs compared to the MBR alternative. This alternative was selected as it aligns with the City's values to provide long-term performance and reliability. 12 4.4.3 Construct a New MBR Facility A new MBR facility would be constructed to replace the existing treatment facility under this alternative, which will allow for reliable and effective treatment of the City's wastewater beyond the 20-year planning horizon. This alternative also allows for future expansion to meet potential growth and considers future regulatory changes which may require stricter effluent criteria. As detailed in the attached CDR(Appendix B), the MBR process provides more advance technology with a smaller footprint. However, this technology is less popular, as it requires specialized equipment and training for the City's operational staff. This option is expected to provide long-term performance and reliability at higher capital and operational costs compared to the BNR alternative. While this option meets treatment goals, it does not best align with the City's values, and was therefore rejected. 13 Chapter 5.0 Selected Alternatives 5.1 Description of Proposed Facilities This section includes a description of the recommended facilities, estimated costs and estimated operation and maintenance costs. No repair or replacement costs are associated with the recommended facilities. 5.2 East WRF Improvements The new East WRF will provide capacity to reliably treat the City's wastewater flows to meet regulatory requirements through the next 20 years, with the ability to expand to accommodate future growth. This alternative includes: • Construction of a new 1.5-mgd BNR facility. • Construction of new headworks screening and grit removal, odor control facility, primary treatment basins, secondary clarifiers, a chlorine contact basin,new disk filters,pump stations, and electrical, chemical, and administrative buildings. • All ancillary equipment including backup generator, electrical, and SCADA equipment. • Site, civil and yard piping modifications. • Demolition and abandonment of existing facilities. The total estimated combined engineering and construction cost is $34,792,000. 5.3 West WRF Improvements The new West WRF will provide a facility which is capable of reliably treating the City's wastewater to meet regulatory requirement. The new facility will provide capacity to treat anticipated flows through the next 20 years, with the ability to expand the facility where growth occurs. This alternative includes: • Construction of new 1.5 mgd BNR facility. • Construction of new headworks screening and grit removal, a new odor control facility, primary treatment basins,new secondary clarifiers, a chlorine contact basin, new disk filters,pump stations, and electrical, chemical, and administrative buildings • All ancillary equipment including backup generator, electrical, and SCADA equipment. • Site, civil and yard piping modifications. • Demolition and abandonment of existing facilities. The total estimated combined engineering and construction cost is $34,792,000. 14 5.4 Cost to Construct Facilities. The details of construction and the O&M costs for the projects are presented in Appendix F. The following tabulation presents the total project cost inclusive of the non-construction items. Please note that it is the City's intent to fund these projects with a combination of SRF and potential federal funding (ARPA or similar), as well as direct available City funds. The City is currently estimating to request$50,000,000 in loans for the construction of the two new wastewater facilities. 15 Chapter 6.0 Implementation and Compliance 6.1 Public Hearing/Dedicated Revenue Hearing A public hearing was held on June 13, 2022,to explain the projects and enable public participation in the final evaluation of project alternatives and costs. Notice of the meeting was provided in The Orlando Sentinel (Appendix G). 6.1.1 Financial Planning The Department of Environmental Protection's State Revolving Fund is expected to be the financing source for these projects. A Capital Financing Plan (CFP)has been prepared to explain to the public and to the State Agency what the financial impact on the users of the water system will be. The CFP is shown in Appendix I. 6.1.2 Implementation The City of Winter Springs has the sole responsibility and authority to implement the recommended facilities. There are no inter-local agreements necessary for the City to provide wastewater collection services to the planning area. 6.1.3 Implementation Schedule The project schedules are listed below: ACTIVITY ESTIMATED DATE Complete design documents July 2023 Obtain permits for construction October 2023 Start construction November 2023 Complete construction November 2026 6.1.4 Compliance 1. Treated wastewater will comply with FDEP standards. 2. The environmental aspects of the proposed facilities are satisfactory. 3. The recommendations of this Facilities Plan are consistent with the City's 2022 Wastewater and Reclaimed Master Plan. The City is also currently updating its Comprehensive Plan to include the plan for these facilities. 16 Appendix A City of Winter Springs East WRF Conceptual Design Report .6f •` ;'� SSR �' 114 City of Winter Springs 'AEast Water Reclamation incorporated 1959 U to CONCEPTUAL DESIGN REPORT Ap i 1:! ted 59 City of Winter Springs East Water Reclamation Facility CONCEPTUAL DESIGN REPORT April 2022 This document is released for the purpose of information exchange review and planning only underthe authority of Brian J. Graham,April 2022, State of FL PE No.44683. EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Contents 1.0 Introduction, Summary of Existing Facilities, and Wastewater Flow and Load Projections 1 1.1 Introduction 1 1.2 Basis for Conceptual Design 1 1.3 Summary of Existing Facility 3 1.3.1 Existing Treatment Process and Effluent Disposal 3 1.3.2 Condition Assessment 5 1.3.3 Site Boundary and Contour Survey 5 1.3.4 Environmental Review 6 1.3.5 Odor Survey 8 1.3.6 Geotechnical Investigation 10 1.3.7 Wastewater Characterization and Population Flow Projections 10 1.3.8 Wastewater Flow and Loading Characterization 10 1.3.9 Population Projections 13 1.3.10 Proposed East WRF Design Capacity 14 2.0 Liquid Stream Alternatives Evaluation 2.1 Evaluation Overview 15 2.2 Selection of Liquid Stream Treatment Alternatives 15 2.2.1 Preliminary List of Potential Process Alternatives 16 2.2.2 Biological Nutrient Removal to Achieve AWT 18 2.2.3 Potential AWT Treatment Alternatives 19 2.3 Descriptions of Proposed AWT-Capable Treatment Alternatives 21 2.3.1 Five-Stage Activated Sludge BNR(5-Stage BNR) 21 2.3.2 Membrane Bioreactor 22 2.3.3 Sequencing Batch Reactor(SBR) 25 2.3.4 Aerobic Granular Sludge—AquaNereda® 27 2.3.5 Ballasted Activated Sludge—NuvodaTM 29 2.3.6 Integrated Fixed-Film Activated Sludge 31 2.4 Structured Decision Analysis 33 2.4.1 Process Evaluation Criteria and Sub-Criteria 33 2.4.2 Paired Comparison Results 35 APRIL2022 i EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 3.0 Shortlisted Alternatives Evaluation 37 3.1 Objectives 37 3.2 Conceptual Design Criteria 37 3.2.1 Influent Flows and Loads 37 3.2.2 Regulatory Requirements 40 3.3 5-Stage BNR Alternative("Buildout"Scenario:2.1 mgd with AWT) 40 3.3.1 Process Design 40 3.3.2 Conceptual Site Layout 45 3.3.3 Hydraulic Considerations 47 3.4 MBR Alternative("Buildout"Scenario:2.1 mgd with AWT) 49 3.4.1 Process Design 49 3.4.2 Site Layout 54 3.4.3 Hydraulic Considerations 56 3.5 Common Processes and Shared Facilities 56 3.5.1 Odor Control Technology 56 3.5.2 Chemical Systems 56 3.5.3 Reclaimed Water Storage and Reject Storage 59 3.5.4 Solids Handling 60 3.5.5 Potential Industrial Load Influences 61 3.6 Conceptual Level Cost Estimates("Buildout"Scenario) 61 3.6.1 Cost Estimating Accuracy 61 3.6.2 No Action Alternative 61 3.6.3 BNR and MBR Capital Conceptual Cost Estimates 62 3.6.4 Annual O&M Conceptual Cost Estimates 62 4.0 Final Recommendation 4.1 Recommended Alternative 66 4.2 Recommended Plant Capacity and Treatment Standard 66 4.3 Recommended Conceptual Site Layout and Cost Estimate 67 4.4 Funding Considerations 70 4.4.1 SRF Funding 70 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Appendices AppendixA Existing WRF PFD Appendix B East WRF Survey Appendix C Ecological Assessment and FNAI Tracking List Appendix D Odor Control Assessment Appendix E CWSRF Planning Document Requirements Checklist Tables Table 1 East Permit Renewal Effluent Disposal Site/Water Quality Requirements Request 4 Table 2 East WRF Hydrogen Sulfide Monitoring Summary 9 Table 3 East WRF Historical Monthly and Annual Average Daily Flows 10 Table 4 East WRF Influent cBOD5 and TSS Concentrations and Loads 12 Table 5 Winter Springs Population and Flow Growth Factors 13 Table 6 5-Stage BNR Fact Sheet 22 Table 7 Membrane Bioreactor(MBR)Fact Sheet 23 Table 8 Sequencing Batch Reactor(SBR) Fact Sheet 26 Table 9 Aerobic Granular Sludge(AGS)Fact Sheet 28 Table 10 Ballasted Activated Sludge(BAS) Fact Sheet 30 Table 11 Integrated Fixed-Film Activated Sludge(IFAS) Fact Sheet 32 Table 12 Major Evaluation Criteria and Corresponding Sub-Criteria 34 Table 13 Major Evaluation Criteria and their Relative Importance 35 Table 14 East WRF Influent Design Flow and Mass Load Peaking Factors 38 Table 15 Conceptual Influent Design Wastewater Flows and Loads 39 Table 16 Headworks Design Criteria for 5-Stage BNR 41 Table 17 Secondary Treatment Design Criteria for 5-Stage BNR 42 Table 18 Filter Design Criteria for 5-Stage BNR 43 Table 19 Chlorine Contact Chamber Design Criteria for 5-Stage BNR 44 Table 20 Headworks Design Criteria for MBR 49 Table 21 Secondary Treatment Design Criteria for MBR 50 Table 22 Chlorine Contact Chamber Design Criteria for MBR 52 Table 23 MBR Chemical Cleaning System 53 Table 24 Supplemental Carbon Storage and Feed Design Criteria 58 APRIL2022 I iii EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Table 25 Alum System Design Criteria 58 Table 26 Solids Handling Design Criteria 60 Table 27 AACE International Guidelines for Cost Estimating Accuracy 61 Table 28 5-Stage BNR Conceptual Capital Cost 63 Table 29 MBR Conceptual Capital Cost 64 Table 30 Conceptual Annual O&M Cost Comparison 65 Table 31 1.5 mgd BNR Conceptual Capital Cost 69 Figures Figure 1 Existing East WRF Process Flow Diagram 3 Figure 2 East WRF Site and Contour Survey 6 Figure 3 East WRF Environmental Survey Area 8 Figure 4 OdaLog Installation Locations at East WRF 9 Figure 5 East WRF Annual Average Daily Flows 11 Figure 6 East WRF Historic Monthly cBOD5 and TSS Loading 12 Figure 7 East WRF Flow Projections 14 Figure 8 Overview of Biological Treatment Technologies for Nitrogen and Phosphorus Removal from Municipal Wastewater 17 Figure 9 Biological Treatment Technologies for Achieving AWT in Municipal Wastewater 20 Figure 10 5-Stage BNR Process Flow Diagram 21 Figure 11 Membrane Bioreactor(MBR)Flow Diagram 23 Figure 12 Sequencing Batch Reactor(SBR) Process Flow Diagram 25 Figure 13 Aerobic Granular Sludge(AGS)Process Flow Diagram 27 Figure 14 Ballasted Activated Sludge(BAS) Flow Diagram 29 Figure 15 Integrated Fixed-Film Activated Sludge(IFAS) Flow Diagram 31 Figure 16 Process Alternative Ranking Using Weighted Criteria 36 Figure 17 5-Stage BNR Conceptual Site Layout(2.1 mgd with AWT) 46 Figure 18 Hydraulic Profile forthe 5-Stage BNR Alternative 48 Figure 19 MBR Conceptual Site Layout(2.1 mgd with AWT) 55 Figure 20 1.5 mgd Conceptual BNR Site Layout(1.5 mgd) 68 APRIL 2022 1 iv EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Abbreviations AADF annual average daily flow AC acre AGS aerobic granular sludge alum aluminum sulfate AWT advanced wastewater treatment BAS ballasted activated sludge BNR biological nutrient-removal BOD biochemical oxygen demand Carollo Carollo Engineers, Inc. CAS conventional activated sludge CBOD5 5 day carbonaceous biochemical oxygen demand City City of Winter Springs cf cubic feet cfm cubic feet per minute cfs cubic feet per second EBPR enhanced biological phosphorus removal EPA Environmental Protection Agency EQ equalization F.A.0 Florida Administrative Code FDEP Florida Department of Environmental Protection FOG fats, oils, and grease ft feet gpm/ft' gallons per minute per square foot HLD high level disinfection HRT hydraulic retention time IBC intermediate bulk container IFAS integrated fixed-film activated sludge IMLR internal mixed liquor recycle Ib/d pounds per day MBR membrane bioreactor MDF maximum daily flow MG million gallons mg/L milligrams per liter mgd million gallons per day MLSS mixed liquor suspended solids MMADF maximum month average daily flow APRIL 2022 v EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS O&M operations and maintenance PHF peak hourflow psig pounds per square inch, gauge RAS return activated sludge RFI request for inclusion rbCOD readily biodegradable chemical oxygen demand SBR sequencing batch reactor SCADA supervisory control and data acquisition scfm standard cubic feet per minute SFAS step feed activated sludge SHT sludge holding tank SRT sludge retention time SWD side water depth TDH total dynamic head TMP transmembrane pressure TN total nitrogen TP total phosphorus TRC total residual chlorine TS total solids TSS total suspended solids WAS waste activated sludge WRF water reclamation facility APRIL 2022 vi EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS EXECUTIVE SUMMARY The City of Winter Springs owns and operates the East Water Reclamation Facility(WRF).The facility is permitted for 2.012 mgd AADF by the Florida Department of Environmental Protection but currently experiences flows at approximately half this capacity.The East WRF was originally constructed in the mid-1970s and has consequently reached the end of its useful life, requiring both replacement and modernization. Carollo and Wekiva Engineering conducted assessments of the East WRF as part of this project and the priority repairs projects over the past year and concluded that no major component has permanent value worth restoring.While some existing infrastructure and minor components may be rehabilitated and reused,they generally only serve temporary purposes and have no permanent value. Based on the condition of the current facility,this CDR focuses on the construction of new replacement of the East WRF. Specifically,the goal is to conceptualize a new facility which can meet current and future water quality requirements while planning for growth over decades to come.This facility should also be built for resiliency and reliability, such that the City does not experience the current facility challenges again. To conceptualize the future facility, a boundary survey, ecological assessment, and odor study were completed as part of this CDR. Carollo then performed an analysis of all liquid treatment technologies to determine which treatment alternative best suits the City.As part of this evaluation, Carollo performed the following: • Prepared a working list of liquid-stream technologies proven to meet Advanced Wastewater Treatment(AWT)standards, • Performed a conceptual-level review of the selected liquid-stream process alternatives, • Developed evaluation criteria to rank each of the process alternatives in terms of their abilityto meet the City's values, • Hosted a paired comparison exercise with a City-appointed selection committee for City to apply a value(or weight)to each evaluation criterion, and • Shortlisted two alternatives from the working list for further development and in-depth analysis(i.e., conceptual site layout and capital/operational cost estimate). The working list of liquid-stream technologies proven to meet AWT included: • Five-stage activated sludge BNR(5-stage BNR). • Membrane bioreactor(MBR). • Ballasted activated sludge(BAS). • Aerobic granular sludge(AGS). • Sequencing batch reactor(SBR). • Integrated fixed-film activated sludge(IFAS). APRIL 2022 1 ES-i EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS The paired comparison exercise with the City-appointed selection committee, as well as the decision analysis, resulted in the list of treatment alternatives below.The alternatives are ranked from highest to lowest based on the City's applied values: 1. Five-stage activated sludge BNR(5-stage BNR). 2. Membrane bioreactor(MBR). 3. Sequencing batch reactor(SBR). 4. Ballasted activated sludge(BAS). 5. Integrated fixed-film activated sludge(IFAS). 6. Aerobic granular sludge(AGS). Conceptual designs, site layouts, and capital/O&M cost estimates were developed forthe top two scoring technologies:5-stage BNR and MBR.The design flows and loads used to compare the BNR and MBR conceptual designs and costs to provide a final recommendation correspond to a true"buildout"scenario.This scenario represents what the City may require in the far-term future, i.e., post-2045, in terms of quantity and quality.These far-term future needs include a flow of 2.1 mgd AADF, and a production of AWT-quality effluent. However, a final recommendation for a conceptual East WRF, sized fortoday's needs, is later provided. The conceptual capital cost estimates forthe 5-stage BNR and MBR alternatives at"buildout" (2.1 mgd with AWT)are approximately$48,082,000 and $53,922,000, respectively.The MBR alternative proved slightly more costly than the BNR(as the MBR alternative requires additional fine screening,flow equalization, increased chemical storage, etc.).An annual O&M comparison shows that the MBR alternative is also more costly to operate and maintain, costing approximately$150,000 more than the 5-stage BNR alternative on an annual basis. Class 5 accuracies were used to determine the conceptual cost estimates and have a 20 percent contingency applied due to the conceptual level of design. Both BNR and MBR are established technologies in the United States,with a track record of successfully meeting stringent nutrient discharge limits. However,5-stage BNR is known as the "Gold Standard"of CAS technologies and is more highly implemented in Florida, creating a large, local resource pool for operators to turn to when in-need of support.Additionally,the 5-stage BNR process is similarto current operations and does not require a high degree of additional operator training. On the other hand,while MBR has a smaller footprint in comparison to the 5-stage BNR, it requires a higher pumping/energy and chemical use, and more mechanical equipment, which ultimately creates more required maintenance. Based on these non-economic factors, as well as the conceptual capital cost estimates, it is recommended that the City select the 5-stage BNR alternative as the proposed treatment process forthe East WRF. Limited growth is expected within the City of Winter Springs over the next 20 years. Results from the population analysis indicated that 2045 flows may range anywhere from 1.04 to 1.43 mgd AADF.Additionally,the"City of Winter Springs 2022 Wastewater and Reclaimed Water Master Plan"prepared by Kimley-Horn projects that population growth within available parcels and potential septic to sewer conversions may result in flows up to 1.49 mgd overthe next 20 years. Both projections are far less than the current permitted capacity of 2.012 mgd. APRIL2022 I ES-ii EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Rather than designing, constructing, and paying for an oversized faci I ity today, and consequently having to operate and maintain the oversized facility, Carollo recommends that the City`build for today but plan for tomorrow"(i.e., right-size the WRF for near-term growth). To elaborate, since flows are not expected to surpass 1.49 mgd AADF in the next 20 years, Carollo recommends that the proposed East WRF be designed for a capacity 1.5 mgd AADF, while also allocating space onsite such that the capacity can be readily expanded to meet future needs.Additionally, because AWT is not required today, it is recommended to phase the construction process to ensure current treatment standards are being met but allow AWT build-out to meet future requirements. A proposed conceptual site layout for this 1.5 mgd scenario(to meet today's treatment standards)was developed. It is recommended that the City initially construct a facility based off of this conceptual design and modify as needed to meet future quantity and quality needs, ultimately to the full buildout scenario of 2.1 mgd with AWT(if required). The conceptual capital cost estimate for the recommended 1.5 mgd East WRF is approximately $34,792,000. By right sizing the East WRF for today's needs,the City would save approximately $13 million dollars,today, on capital costs,with additional savings on annual O&M costs.The City would also have the flexibility, reliability, and redundancy to take basins offline,while still operating efficiently and meeting effluent requirements. APRIL2022 I ES-iii EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 1.0 Introduction, Summary of Existing Facilities, and Wastewater Flow and Load Projections 1.1 Introduction The City of Winter Springs(City)owns and operates two Water Reclamation Facilities(WRF):the East(FLA011068)and West(FLA011067)WRF.The East WRF consists of two separate package wastewater treatment plants(WWTPs), known as WWTP No.1 and No.2.These plants were constructed in the mid-1970s and early 1990s, respectively, and have a total combined capacity slightly above 2 mgd.These plants, and the entire east facility, have reached the end of their useful life and require replacement. Carollo Engineers, Inc. (Carollo)has been tasked with assessing and summarizing the current facility, and further recommending two treatment process alternatives forthe Cityto incorporate in the design of their new WRF. Ratherthan replacing the East WRF in-kind,the proposed plant process will be planned forthe future ability to meet more stringent treatment requirements and effluent criteria,which will inevitably be required with future environmental regulations.The purpose of this Conceptual Design Report(CDR)is to provide the City with two proposed treatment process alternatives for the new East WRF, and a final recommendation with an associated conceptual design, site layout, and cost estimate.This CDR will form the basis for the subsequent detailed design, permitting, bidding, and construction phases of the new facility construction. Overall goals of this project are to provide a new wastewater facility that is reliable, meets current regulations with the ability to achieve future regulations, aligns with the City's growth and associated treatment needs, and emphasizes City values. 1.2 Basis for Conceptual Design The East WRF currently operates as a secondary wastewater treatment facility underthe Florida Department of Environmental Protection's(FDEP)domestic wastewater facility permit No. FLA011068.The facility is permitted to treat annual average daily flows(AADF)of up to 2.012 mgd but experiences flows at approximately half of this capacity. The existing treatment processes at the East facility provide the level of treatment required for its effluent to meet the following water quality requirements under the current permit: • A 5-day carbonaceous biochemical oxygen demand(cBOD5)concentration of less than or equal to 20 milligrams per liter(mg/L),when calculated as an annual average. • A total suspended solids(TSS)concentration of less than or equal to 5 mg/L for any single sample. A total residual chlorine(TRC)concentration of 1 mg/L, minimum, for any single sample. A total nitrate,as nitrogen(NO3-—N)concentration of less than or equal to 12 mg/L for any single sample. APRIL 2022 1 1 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS The FDEP sets forth the regulatory requirements for effluent discharges from wastewater treatment facilities and addresses end-use effluent water quality standards. Effluent disposed via public access reuse(PAR) has higher disinfection requirements compared to non-beneficially discharged effluent. Furthermore, effluent that is discharged for groundwater recharge and surface water discharges in protected watersheds typically require the achievement of the highest level of wastewater treatment, known as Advanced Wastewater Treatment(AWT).AWT is defined in F.S.403.086(4)(a)and requires that wastewater be treated beyond the secondary state, providing an effluent that has annual average values, including: • A 5-day cBOD5 concentration of less than or equal to 5 mg/L, • A TSS concentration of less than or equal to 5 mg/L, • A total nitrogen(TN)concentration, expressed as nitrogen, of less than or equal to 3 mg/L, • A total phosphorus(TP)concentration, expressed as phosphorus, of less than or equal to 1 mg/L, and • Received high-level disinfection(HLD)as stated in 62-600.440 Florida Administrative Code(F.A.C.). HLD requires an effluent which meets the following criteria: - Any single sample shall not exceed 5 mg/L TSS priorto application of a disinfectant. Any single sample shall not exceed 25 fecal coliform values per 100 mL of sample. - On a monthly basis,75 percent of the fecal coliform values shall be below the detection limits. - When chlorine is used for disinfection,a TRC of at least 1 mg/L shall be maintained at all times and the minimum acceptable contact time shall be 15 minutes at the peak hourly flow(PHF). The current East WRF operations do not include disposal of treated effluent via any methods that require AWT. However,there are strong indications that state regulatory agencies will enact future regulations that will require the City to treat its effluent to achieve AWT standards. For example,the City of Winter Springs is surrounded by protected watersheds defined by the St.John's River Water Management District(SJRWMD).Any treated effluent applied to these protected watersheds must be treated to a higher standard,with stricter nutrient limits.Over time as these protected watershed basins are expanded, it is logical to assume that in the future,the City may be located within a protected watershed and will be required to treat any site-applied effluent to the higher standard.Additionally, more stringent treatment standards are required for Surface Water and Backup Discharges,which are application methods not currently used by the City but may be in the future. To summarize,while AWT is not required today,there are strong indications that it will be in the future. It is recommended that when designing the new East WRF,the City plan for a facility that does not necessarily meet AWT today, but has the foundation in-place to al low for future modifications to do so. Consequently,the proposed conceptual designs outlined in this report are intended to meet current effluent requirements with the ability to be readily modified to achieve AWT, if required in the future. APRIL 2022 12 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 1.3 Summary of Existing Facility A condition assessment, as well as various surveys and studies,were conducted to gather an overall understanding of the facility and the condition of the existing components.The following subsections summarizes the findings of these assessments and the current condition of the East WRF. 1.3.1 Existing Treatment Process and Effluent Disposal The East WRF is comprised of two separate package treatment plants(circular field-erected steel tanks)originally designed to use an activated sludge process, known as contact stabilization, and a third concrete tank dedicated to sludge thickening and holding(Digester No.3).The treatment units consist of a surge tank, influent screening, concentric aeration basins(made up of reaeration and contact tanks), and a clarifier in the center. RAS is also part of the aeration process and is provided using air lifts.The clarified effluent then flows from the treatment tanks to the tertiary moving-bed filters(Dyna Sand®filters), and finally to the chlorine contact chamber.A 0.18 million-gallon(MG)concrete sludge digester/holding tank,3 MG covered reclaimed water(RW)storage tank and combined 5.61 MG combined wet weather and reject storage pond are all onsite components of the East WRF, as well. Solid residuals are stored in a sludge holding tank(SHT)that is aerated for mixing and preventing septic conditions priorto dewatering. Stored solids are dewatered using a mobile belt filter press and then hauled offsite for processing.A process flow diagram(PFD)of the existing East WRF is included in Appendix A, with a snapshot shown in Figure 1. [(n6 r.ixacnmx rx,e,n.se �s I 0 0 0 0 Attachment Na.2 PROCESS FLOW DIAGRAM CITY OF WINTER SPRINGS EAST WRF Figure 1 Existing East WRF Process Flow Diagram APRIL 2022 3 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS The East WRF supplies PAR-quality effluent to the City's reuse service area for irrigation purposes.To be considered PAR-quality, reclaimed water must have experienced secondary treatment,contain no more than 5 mg/L total suspended solids(TSS), and achieve HLD. Effluent that meets PAR quality but is generated in excess of customer demand(e.g., during heavy rain events)is stored onsite at the facility in the GST, and combined wet weather/reject storage pond.The City also has alternate disposal sites, including the Oak Forest Spray Field land application site and Owasco rapid infiltration basin(RIB)which can accept 0.201 mgd and 0.61 mgd AADF, respectively. However,these alternate disposal sites are permitted under the same reuse system, ultimately requiring the same effluent requirements as their primary PAR disposal method (R-001).Therefore,any effluent that does not meet PAR quality is diverted to the onsite reject pond—of which 2 MG of the total 5.61 MG is dedicated reject storage. The current East WRF permit(No. FLA011068)expires in March 2022,and Carollo recently supported the City on the completion and submission of the facility permit renewal.With the renewal,the City requested the State to designate the Owasco RIB as a R-003 discharge location and change the water quality/effluent requirements for discharge to this location. In doing so, this site(R-003)would be permitted under a separate reuse system and used for disposal of non-spec effluent which does not meet PAR standards.The East Permit would then match the permit conditions for non-PAR discharges in the City's West WRF Permit(FLA011067).These non-par discharge quality requirements are shown below in Table 1. Table 1 East Permit Renewal Effluent Disposal Site/Water Quality Requirements Request Site ID Location Effluent Quality Requirement [cBOD5]<30 mg/L(1) [TSS]<5 mg/L(z) R-001 PAR System [TN]—Report [TP]—Report Fecal Coliform<25#/100 mL(3) [cBOD5]<30 mg/L(1) R-002 N/A(5) [TSS]<5 mg/L(z) Fecal Coliform<200#/100 mL(4) [cBOD5]<30 mg/L(1) R-003 Owasco RIBS [TSS]<30 mg/L(2) [NO3--N]<12 mg/L(z) Fecal Coliform<200#/100 mL(4) Notes: (1) Monthly Average. (2) Single Sample Maximum. (3) Single Sample Maximum(Samples Collected 7 days/week). (4) Monthly Geometric Mean(Samples Collected Weekly). (5) The Oak Forest Spray Field has potable wells located within a 500-foot buffer surrounding the site,and consequently, cannot accept non-PAR quality effluent(FDEP Rule 62-610.421 F.A.C.). APRIL 2022 14 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 1.3.2 Condition Assessment Overthe past year, Carollo has visited the East WRF numerous times,through which a condition assessment of the existing unit processes was completed. Part of this assessment has also included priority repairs to the current facility in orderto maintain operation until the facilities are permanently replaced. Since the facility was originally constructed in the mid-1970s(with an expansion in the early-1990s),a majority of its components have reached the end of their useful life and are visibly degraded/corroded.As a subconsultant to Carollo,Wekiva Engineering also performed a structural assessment of the primary assets at the East WRF in December 2021 and concluded that no major component at this facility has permanent value worth restoring.While some existing infrastructure and minor components may be rehabilitated and reused,they may only serve temporary purposes and have no permanent value. One exception to this is the existing chlorine contact chamber. Structurally,the chlorine contact chamber is in acceptable condition and could be rehabilitated to lower construction costs, including new repumping equipment costs. Some components still require replacement, such as the effluent gates. However,the existing chlorine contact chamber may not fit into the hydraulic profile of the new East WRF.This must be further analyzed during subsequent design stages. The existing electrical equipment is also outdated and does not meet current National Electric Code(NEC).As such,for conceptual design purposes, no unit process equipment (e.g., mechanical, structural, or electrical assets)will be preserved forthe new East WRF. There are, however, some non-unit process items which have the possibility of being maintained for storage purposes, including the reuse GST, onsite storage/reject pond, and one of the three circular steel structures.The GST and storage/reject pond are in good condition overall and can continue to store treated effluent forthe new WRF. One of the three steel structures may also be repaired or rehabilitated and temporarily used to store solid residuals from the new treatment scheme, allowing the City time to plan and design for a permanent solids handling facility. Like the chlorine contact chamber,the feasibility of reusing these existing assets must be further assessed during later design stages. 1.3.3 Site Boundary and Contour Survey L&S Diversified(L&S)completed a conceptual-level boundary and topographic survey to facilitate the planning stages of the project.The established boundary of the East WRF totals approximately 50.6 acres, although this includes a number of trees and wetlands which have been preliminarily identified. Figure 2 shows the limits of the site boundary and contour survey. In addition to displaying boundary lines, easement information, and contour lines,the attached survey(included in Appendix B), also displays existing buried mains, as well as the elevations of key hydraulic infrastructure. APRIL 2022 5 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS M r �. \ �- ..,..:-;��-��.��,' - �--^� f .pax''� ���✓ �= ,J. a, Figure 2 East WRF Site and Contour Survey 1.3.4 Environmental Review An environmental review was completed ofthe site based on the planned concept facilities. Environmental Science Associates(ESA)completed an environmental constraints review within the review area shown in Figure 3.Appendix C includes the ESA environmental constraints review and the Florida Natural Area Inventory(FNAI)tracking list. In general, and as further described below,there are minor site constraints which will need to be addressed in design, primarily including wetland impacts in some areas of construction. The following items are addressed to meet state,federal and potential funding requirements: • List threatened, endangered, proposed, and candidate species and designated critical habitats that may be present in the project area(may be obtained from U.S. Fish and Wildlife Service).A list of potential threatened, endangered, proposed, and candidate species and designated critical habitats that may be present within the general area of the proposed Project is attached as Appendix C, Florida Natural Areas Inventory. Habitat does not exist within the Project review area for a majority of these species,with the exception ofthe Bald eagle(Haliaeetus leucocephalus)and gopher tortoise(Gopherus polyphemus), as identified in the General Environmental Constraints Review(Appendix Q.The Audubon Florida EagleWatch Nest Locator database was reviewed,and no nest trees were identified within 600-feet(protective nest buffer zone) ofthe Project review area,therefore impacts to the bald eagle are not anticipated. Additionally, during the environmental review, no gopher tortoise burrows were observed within or directly adjacent to the Project area. However,a 100-percent gopher tortoise burrow survey will need to be performed within the upland limits of proposed Project footprint, at least 90 days from construction initiation in accordance with the APRIL 2022 1 6 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Florida Fish and Wildlife Conservation Commission gophertortoise survey and permitting guidelines(reference in Rule 68A-27.003, Florida Administrative Code). No other listed species, or critical habitat was observed or identified within the property limits. • Discuss any significant adverse effects upon flora,fauna,threatened or endangered plant or animal species, surface waterbodies, prime agricultural lands,wetlands,or undisturbed natural areas. No listed flora or faunal species were identified within the attached Environmental Constraints Review(Appendix Q.The proposed Protect is anticipated to impact approximately up to 2 acres of forested wetlands that were identified as medium quality and jurisdictional to the state and federal agencies. Other areas that may be impacted from the Project activities include highly disturbed, maintained upland areas that are inclusive of the treatment facility. No other undisturbed natural areas exist within the footprint of the proposed Project.The facility is located within the City of Winter Springs Planned Unit Development(PUD)Zone,- therefore, one;therefore, no prime or unique agricultural lands exist within the proposed Project footprint. • List any significant adverse environmental effects and what project features will mitigate such effects. It is anticipated that the Project activities will impact approximately up to 2 acres of medium quality forested wetlands. During the final design phase of the Project, all impacts will be minimized,where feasible,to further reduce the footprint and the Project impacts.All construction activities will obtain and comply with National Pollutant Discharge Elimination Systems(NPDES)permits and employ Best Management Practices to assure no impacts to water resources during construction.The site development associated with the Project will follow state water quality and quantity regulations to avoid alteration in drainage patterns or soil erosion or runoff.The Project will obtain construction and operation phase permits from the required state and federal agencies and will operate in accordance with all relevant regulations. In addition, appropriate state and federal permits will be obtained and mitigation will occurto off-set those impacts. Mitigation options for this area include: - Utilization of an approved mitigation site within the Lake Jesup Basin, - Construction of a wetland mitigation site within the Lake Jesup Basin, either utilizing land owned or purchased bythe City of Winter Springs, or - Investigations with FDEP to utilize an out-of-basin, regionally significant mitigation bank(within the same watershed-St.Johns River Watershed)with a Cumulative Impact Analysis. • Discuss any significant adverse human health or environmental effects on minority or low-income communities.The East WRF is located in the eastern area of Winter Springs, primarily surrounding by residential community. Recent data from the EJSCREEN Census Summary Report(Accessed April 2022)indicates an overall City population demographic index of 26 percent with low income being 19 percent. Forthe immediate area around the East WRF,the demographic index is 16 percent,with low income being 3 percent.All values are underthe state and national averages. Furthermore,this project considers the replacement of an existing WRF with a new facility.An improved and modernized WRF will benefit the entire community with improved reliability in wastewater treatment and effluent water quality which meets or APRIL 2022 17 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS exceeds regulatory requirements.Therefore, disproportionate high or adverse environmental effects to a minority population is not anticipated. LEGEND - Review Area ,do - "--- !- • - , GPS Locations -Delineated WetlandlOSW Limits Wetland Features IL.. OSW Features East WRF Property Boundary r� in L fy cul J� ,++* .d1, Ott i• x •aYlfs .:.••a �ahtfr. ......c W. ;• .;._...?�r..ii-i:''tiJtt.:r.`.�lle..r:i:•: ii_c "-atre:.:•'vlr:w•..:bac::. ••v,_U..al.•.,:-.attr'.':' Figure 3 East WRF Environmental Survey Area 1.3.5 Odor Survey Webster Environmental Associates, Inc.(Webster)completed an odor survey at the East WRF in November 2021.This study was done to assess the Hydrogen sulfide(H2S)gas odor impact on the local area,for consideration with the design and construction of a new treatment facility. Hydrogen sulfide occurs naturally in sewers, manure pits, well water, oil and gas wells, and volcanoes.The health effects of hydrogen sulfide depend on how much H2S a worker breathes and for how long.The odorthreshold for hydrogen sulfide gas falls in the 0.01 to 1.5 ppm range and some will begin to notice the`rotten egg smell"at these concentrations.The odor becomes more offensive at 3 to 5 ppm. Prolonged exposure in confined areas at these concentrations may cause nausea,tearing of the eyes, headaches, or loss of sleep. However, because wastewater facilities are mainly open to the atmosphere, operators and visitors are generally not at risk for negative health effects from H2S during routine operation. Six OdaLogT"' units were installed around the facility and recorded Hydrogen sulfide(H2S)gas concentrations for nine days.These OdaLogT"' units measure H2S in the range of+/-300 ppb and were installed at the following locations:flow splitter box/headworks, surge tanks, SHT, digester, and belt filter press.The sixth 0daLogT1 unit was installed on a tree outside of the WRF property, nearthe public park entrance,to understand how odors may disperse from the treatment site and migrate to the park area.The locations of each logger are shown graphically in Figure 4. APRIL 2022 18 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS - -------- — ---------------- — = East WRF ©dor Logger Locations --�— --� ------------ Z r oa g ISE II III �Idwd9 � , rc, a IIIA i .,• I f I Figure 4 OdaLog Installation Locations at East WRF The OdaLogT"' data from the nine-day monitoring period is included in Table 2.All locations were found to have low to moderate concentrations of H2S(with an average of 0 to 3 ppm), apart from the surge tank which had very high, brief spikes each day.These spikes then quickly dispersed,only lasting approximately 5 minutes.They would occur daily between 11am and 2pm and range from 100 to 1,200 ppm.While it is not confirmed, one potential cause ofthese brief spikes could be attributed to the master lift stations experiencing peak flows.A number of wastewater lift stations discharge directly into the surge tank at the East WRF and because they likely turn on at the same time during peak flows, high loads will be discharged into the surge tank at these times.Webster noted that these concentrations are likely to also cause offsite odor detections. The park entrance instrument surprisingly recorded two brief spikes of 0.1 ppm, also lasting approximately 5 minutes,which may be the result ofthe high H2S coming from the surge tank.A full copy ofthe Odor Study report can be found in Appendix D. Table 2 East WRF Hydrogen Sulfide Monitoring Summary Instrument LocationInstrument Logging Duration Range .. .. •• Influent Splitter Box 0-1,000 11/10/21 to 11/19/21 0.12 2 Surge Tank 0-1,000 11/10/21 to 11/19/21 3 1201 Thickener Tank 0-1,000 11/10/21 to 11/19/21 0 0 Aerobic Digester Tank 0-1,000 11/10/21 to 11/19/21 0 1 Belt Press 0-200 11/10/21 to 11/19/21 0 7 Park Entrance 0-50 11/10/21 to 11/19/21 0 0.1 APRIL 2022 1 9 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 1.3.6 Geotechnical Investigation At the time of this report, no geotechnical investigation has been conducted at the East WRF. This information will be needed priorto the design stages but is not necessary within conceptual design.A complete geotechnical survey and determination of structure locations should therefore be performed as part of the final design. 1.3.7 Wastewater Characterization and Population Flow Projections Based on the identified service area, population growth, and historical facility flows, a projected flow was developed for the East WRF to use when sizing the new facility.The following subsections summarize the existing historical water quality and quantity data, as well as population projections,to develop design criteria forthe future facility, including flows, loads, and peaking factors. 1.3.8 Wastewater Flow and Loading Characterization Historical flow data was gathered and analyzed as part of the recently completed East WRF permit renewal.Table 3 provides historical monthly flows observed at the facility overthe past 10 years, as well as minimum, maximum and annual average flows.All data was obtained from Discharge Monitoring Reports(DMR)submitted by the City to FDEP. Table 3 East WRF Historical Monthly and Annual Average Daily Flows(1) Month/Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 January 0.99 0.80 1.03 1.10 1.03 0.99 1.02 1.00 1.04 0.97 1.03 February 0.95 0.85 1.00 0.98 0.98 1.03 0.95 0.96 1.10 1.00 1.00 March 0.95 1.03 1.07 1.01 1.05 1.01 0.91 0.96 1.05 1.04 0.97 April 0.91 1.02 1.04 1.00 1.02 1.11 0.98 0.96 1.10 1.05 1.04 May 0.84 0.99 1.08 1.00 1.01 1.05 0.96 0.96 0.99 1.02 0.95 June 0.83 1.05 1.05 0.98 0.92 1.07 0.95 1.06 1.04 0.96 0.94 July 0.90 1.12 1.21 1.01 0.98 0.96 1.10 1.07 1.07 0.90 0.97 August 0.91 1.08 1.17 1.03 1.04 0.96 1.07 1.07 1.05 0.98 1.11 September 0.84 1.17 1.06 1.07 1.13 1.05 1.35 1.04 0.97 1.09 1.13 October 0.96 1.21 1.03 1.12 1.02 1.13 1.16 0.88 1.00 1.03 1.01 November 0.88 1.06 1.10 1.03 1.08 0.99 0.94 1.03 1.00 1.06 - December 0.88 1.13 0.98 1.06 1.02 0.99 1.16 1.07 1.00 1.01 - Minimum 0.83 0.80 0.98 0.98 0.92 0.96 0.91 0.88 0.97 0.90 0.94 Maximum 0.99 1.21 1.21 1.12 1.13 1.13 1.35 1.07 1.10 1.09 1.13 AADF(2) 0.90 1.04 1.07 1.03 1.02 1.03 1.05 1.01 1.03 1.01 1.01 Notes: (1) All units of flow are in mgd. (2) AADFfor 2021 is the average from January to October. APRIL 2022 110 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Figure 5 is a plot of AADF, long-term average flow, and the permitted capacity at the East WRF. This figure shows that the yearly AADF never exceeded the permitted capacity of 2.012 mgd between 2011 and 2021.Additionally,the long-term average flow was 1.02 mgd AADF and the maximum monthly flow observed was 1.35 mgd over this 10-year period, indicating that East WRF has operated at roughly half of its permitted capacity. East WRF -*-AADF ---Long-Term Average - - Permitted Capacity 2.2 2.0 - - - - - - - - - - - - - - - - - - - - - - - - - � - - 1.8 Permitted Capacity=2.012 mgd 1.4 E 1.2 1.0 --- ---- --- -- 0.8 - 0.6 Long-Term Average Flow=1.02 mgd 0.4 - 0.2 - 0.0 Figure 5 East WRF Annual Average Daily Flows In addition to flows, historical loading information over the past year was compiled for the East WRF.Table 4 and Figure 6 present average monthly influent cBOD5 and TSS concentrations and loadings observed at East WRF between October 2020 and October 2021. No influent TN and TP data was available as these parameters are not required to be monitored in the facility's influent under its current permit. Consequently, industry standard ratios of 1:5 and 1:11 were used for TKN:cBOD5 and TP:cBOD5, respectively. It should be emphasized that these factors should be refined during later design stages following a detailed influent sampling campaign. Influent TSS and cBOD5 both exhibited similartrends,with maximum loads observed in February 2021 and average annual loads of 1,970 and 1,980 Ib/d, respectively. Minimum loads were observed in October 2020 and May 2021.Additionally, a statistical analysis was performed to remove data outliers prior to calculating the relevant design peaking factors-results of this analysis are presented in Section 3.2.1 Influent Wastewater Flows and Loads. APRIL 2022 111 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Table 4 East WRF Influent cBOD5 and TSS Concentrations and Loads Influent :ODcBC)D5 Influent TSS Influent TSS Month/Year Concentration Loading Concentration Loading lb/day • lb/day Oct-20 122 1,043 130 1,111 Nov-20 126 1,110 180 1,585 Dec-20 182 1,538 296 2,501 Jan-21 212 1,821 292 2,508 Feb-21 341 2,838 452 3,762 Mar-21 341 2,753 254 2,051 Apr-21 275 2,374 220 1,899 May-21 213 1,682 125 987 Jun-21 322 2,522 260 2,036 Jul-21 276 2,224 266 2,143 Aug-21 228 2,118 266 2,471 Sep-21 188 1,693 61 549 Oct-21 201 1,695 135 1,138 Average 230 1,960 230 1,900 Minimum 122 1,043 61 573 Maximum 341 2,838 452 3,762 East WRF flnf oBOD5 Load flnf TSS Load 4,000 3,500 03,000 :;'2,500 0 2,000 m 1,500 1,000 500 0 CP Figure 6 East WRF Historic Monthly cBOD5 and TSS Loading APRIL 2022 112 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 1.3.9 Population Projections Population data and projections for Winter Springs were obtained from a combination of reports prepared by the U.S. Census Bureau and the Bureau of Economic and Business Research(BEBR). Because the U.S. Census reports current populations on a city-basis,while the BEBR report lists population projections on a county-basis, a number of assumptions were applied forthis analysis to draw meaningful conclusions from the data available. However,these assumptions were verified with the analyzed data made by Kimley-Horn in the`City of Winter Springs 2022 Wastewater and Reclaimed Water Master Plan"for consistency and accuracy.Additionally, internal meetings were held with the City Plannerto gain an understanding of future potential growth or other wastewater contributors that may impact the East WRF's future wastewater flows. One assumption made is that the City of Winter Springs will experience the same growth projected for Seminole county through 2045, and that wastewater flows would increase proportional to this population growth.Another assumption was that all of the citizens reported by the U.S. Census were connected to the City's sewer system, and that the City's wastewater service area exhibits an even split between East and West WRFs.This even-split assumption is consistent with the analyzed data within the"City of Winter Springs 2022 Wastewater and Reclaimed Water Master Plan"prepared by Kimley-Horn. Based on these assumptions,the growth factors listed in Table 5 were developed and used to project wastewater flows through 2045. Discussions with the City Planner revealed that generally limited growth is expected in the near future since no large, new developments within the City's wastewater service area are currently planned.Additionally, a majority of City property has been developed and the City does not plan to acquire any considerable portion of additional land. Table 5 Winter Springs Population and Flow Growth Factors Projection Type(1)(2) 2025 2030 2035 2040 2045 Low Series -1.2% 0.8% 2.3% 3.1% 3.2% Medium Series 6.0% 10.9% 15.0% 18.5% 21.5% High Series 12.8% 21.3% 28.9% 35.9% 42.3% Notes: (1) All factors shown in the table above correspond to population growth relative to the current Winter Springs population. (2) Sources:U.S.Census Bureau(2020),Winter5prings population estimates base and BEBR(2020),Projections of Florida Population by County,2025-2045. In addition to the factors provided above,an average 2020 wastewater generation rate of 65 gallons per capita per day(gpcd)was calculated for Winter Springs, based on the`even split' assumption between the East and West WRF.The 65 gpcd is also consistent with the per capita rates used within the"City of Winter Springs 2022 Wastewater and Reclaimed Water Master Plan"prepared by Kimley-Horn.The calculated per capita wastewater generation rate is slightly less than the typical industry standard range of 70 to 80 gpcd for residential communities but aligns with the City's development projections. APRIL 2022 113 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 1.3.10 Proposed East WRF Design Capacity Figure 7 displays the resulting flow projections for East WRF after synthesizing population data for Winter Springs from the 2020 BEBR and U.S. Census reports(i.e.,Table 5). Results from this analysis indicate that 2045 flows may range anywhere from 1.04 to 1.43 mgd AADF,which are less than the current permitted capacity of 2.012 mgd.Additionally,the"City of Winter Springs 2022 Wastewater and Reclaimed Water Master Plan"prepared by Kimley-Horn projects that if growth were to occur with available parcels, along with potential septic to sewer conversions, flow may reach 1.49 mgd over the next 20 years.This CDR considers replacement of the facility at its current capacity,evaluating a WRF at 2.1 mgd AADF. However, right-sizing the facility to account for near-term growth will be evaluated in Section 4,the Final Recommendation section. 0 Low Medium High 0 CurrentAADF 1.5 1.4 1.3 1.2 � 1.1 1.0 3 0 0.9 LL 0.8 - 0.7 I - 0.5 0.5 — 2025 2030 2035 2040 2045 Figure 7 East WRF Flow Projections APRIL 2022 114 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 2.0 Liquid Stream Alternatives Evaluation 2.1 Evaluation Overview The conversion of the East WRF to an AWT-capable facility requires modernization all of its existing liquid treatment processes.To determine which treatment alternative best suits the City, an analysis of all available liquid treatment technologies was completed by the project team, as well as a thorough and well-vetted selection process based on City values.As part of this evaluation, Carollo performed the following: • Prepared a working list of liquid-stream technologies proven to meet AWT standards, • Performed a conceptual-level review of the selected liquid-stream process alternatives, • Developed evaluation criteria to rank each of the process alternatives in terms of their ability to meet the City's values, • Hosted a paired comparison exercise with a City-appointed selection committee for City to apply a value(or weight)to each evaluation criterion, and • Shortlisted two alternatives from the working list for further development and in-depth analysis(i.e., conceptual site layout and capital/operational cost estimate). It is important to note that the removal of key constituents from domestic wastewater (i.e., BOD,TSS, TN, and TP)is achieved primarily during a wastewater treatment facility's secondary treatment process.While an overall, conceptual-level recommendation is provided within this CDR forthe entire East WRF,the paired comparison exercise focused only on the alternatives for secondary treatment processes and did not compare alternatives for preliminary treatment, secondary clarification, biosolids handling, odor control, and pumping requirements. These processes have been analyzed by Carollo and subconsultants,with recommendations provided in Sections 3 and 4. 2.2 Selection of Liquid Stream Treatment Alternatives Municipal wastewater treatment plants in Florida rely on a relatively low number of treatment processes to remove nutrients(e.g., nitrogen and phosphorus). Most of these processes are variations of the conventional activated sludge(CAS)process, often incorporating different sequencing and configurations of process tanks with anaerobic, anoxic, and aerobic zones. However,from a global perspective, a larger number of process configurations for nutrient removal have been developed and many of these configurations are currently in-service at municipal wastewater treatment facilities abroad. When compared to physical or chemical processes, biological processes have generally been proven to be more economically efficient in removing nitrogen and phosphorus from municipal wastewater.Additionally, land-based technologies, such as natural or constructed wetlands and algae scrubbers, are not typically used to remove nutrients from municipal wastewater due to theirvery large land requirements and limited operating capacity. Consequently, only biological treatment-based technologies have been considered in these evaluations. APRIL 2022 115 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Biological treatment uses either suspended-or attached-growth processes to maintain biological activity.These are defined as: • Suspended-growth: Processes that use biomass suspended in wastewater(activated sludge)to perform the required biochemical transformations. Examples are sequencing batch reactors using in-basin clarification and continuous-flow reactors using separate clarifiers or membranes for solids separation. • Attached-growth: Processes that use biomass that attaches to, and forms a film on, media(i.e., biofilm). Examples are trickling filters, rotating biological contactors, and packed bed reactors. Biological processes typically operate in a continuous-flow mode of operation but can also be operated in a batch-process mode.A recycle stream is typically used to maintain the microorganism population within the treatment process.The solids retention time(SRT)and hydraulic retention time(HRT)of the biological processes are critical to achieving the required secondary treatment. It should be highlighted that not all biological treatment processes can remove nutrients from domestic wastewater.To do so, a biological treatment process must foster the growth of certain microorganism communities.These microorganisms help remove nitrogen through the two-step process of nitrification and subsequent denitrification: 1. Nitrification: Oxidation of ammonia(NH3)to nitrite(NO2)and then to nitrate(NO3). 2. Denitrification: Reduction of nitrate to nitrite and then to nitrogen gas(N2). Biological phosphorus removal, on the other hand, is accomplished through an enhanced biological process that encourages certain microorganisms to uptake phosphorus in greater (stoichiometric)quantities than required for their normal growth.When these microorganisms are wasted from the system, phosphorus removal is achieved, and the overall process is termed enhanced biological phosphorus removal(EBPR). 2.2.1 Preliminary List of Potential Process Alternatives To begin, Carollo created an extensive list of biological wastewater treatment technologies capable of achieving some degree of nutrient removal.This list is referred to as`The Universe of Alternatives", and includes a broad spectrum of proven technologies that can be grouped according to the following physical characteristics: • The use of microorganism communities(i.e., suspended growth or attached growth), • The physical configurations of the treatment processes(i.e., land-based, aquatic, or mechanical facilities), • The location of the solids-separation/clarification unit process,which further categorizes suspended-growth processes into single-sludge and multiple-sludge systems, • The physical configuration of single-sludge systems distinguished as processes with multiple stages or phases, and Concentrations of nutrients in sidestreams with separate sidestream treatment processes required for facilities with significantly elevated concentrations of nitrogen and phosphorus in their sidestreams. Figure 8 shows a graphical representation of these groupings. APRIL 2022 116 z `o n LL p u 6 K O �' O O a --x ea Q LLd L C N M r g 0 x u° a } ❑ O V O d w a d O d�Nw � H C C ❑ V C] c.Qm t _ rym= � Ln o y ¢wc� �° _'Z roc�'�r�„ �aro � Baa �W E C0❑ ';z �i pa � ° � Ln Lu W m V Z @ r6 O C � V N V s+ � O c u�„ � o �p •Y.� 7 E „ v ow 14 O u O a m �? 45v in Ln Q a0 'n ro O 7 _a q Q v L —� uH OOL LLC and � N p L 7 O yyLn > op x Q �. C �IZ62f O O g a s V L�---;Jaw` ¢pExx¢d 11, (�6 o � yusgy � V „ �a�s� m mem " �`y�Na°V�w56 rn Q.T•� y r."3 7 W w of m y N Z O 8 V G 0 m[z1 7 m M C � vii a' ° o � 41 m t 0 m m m D d a uai 2 n x �/`j QC OUd¢ u^r� C OK p� m4 W(L. mrv. W b g LL EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 2.2.2 Biological Nutrient Removal to Achieve AWT To achieve an AWT-quality effluent, a biological nutrient removal(BNR)process must be configured with different sequencing and configurations of process tanks with anaerobic(no free oxygen or nitrate), anoxic(no free oxygen), and aerobic(oxygen rich)zones.These zones create various degrees of oxidation and reduction potential which favorthe growth of specific bacteria with different capabilities of metabolizing cBOD5, nitrogen, and phosphorus.The primary purpose of each zone is briefly summarized below: • Anaerobic Zone:Wastewater enters this zone and is depleted of oxygen or oxidized nitrogen(i.e., nitrate), which allows both the uptake of readily biodegradable organic material and the release of soluble orthophosphate from by certain microorganisms into the wastewater.This zone significantly reduces cBOD5 and, in terms of nutrient removal, mainly serves the purpose of increasing enhanced biological phosphorus removal (EBPR)efficiency in 02. • Pre-Anoxic Zone:This zone consists of internal mixing to maintain anoxic conditions and not introduce dissolved oxygen. Mixed liquorfrom the anaerobic reactor and recycle flows from the aerobic zone enter this zone while heterotrophic bacteria use the cBOD5 in the wastewaterto reduce nitrates recycled back from the aerobic zone to nitrogen gas.The lack of dissolved oxygen in this zone encourages the biomass to use chemically-bound oxygen in nitrate for growth,thus removing nitrogen from the system (i.e., denitrification). • Aerobic Zone: Following the pre-anoxic zone,the mixed liquor enters the third zone, which uses supplemental aeration to provide dissolved oxygen to organisms that oxidize nitrogen in the wastewater from ammonia to nitrites and nitrates(i.e., nitrification).An internal recycle pump sends a portion of the flow, rich in nitrates and nitrites,to the pre-anoxic zone for denitrification.This zone also oxidizes any remaining cBOD5 and removes phosphorus by absorbing orthophosphate in the biomass in excess which is later wasted as sludge. • Post-Anoxic Zone:This zone further reduces nitrogen in the effluent.Any unreduced nitrate that was not recycled to the pre-anoxic zone is reduced to nitrogen gas here. Compared to the first anoxic zone,the denitrification reaction rate within this second anoxic zone is generally endogenous and slower because of a lower`driving force'due to the reduced cBOD5 concentration compared to pre-anoxic zones(most cBOD5 is removed in the aeration zone). However,the size of the second anoxic zone can be reduced by adding an external carbon source such as glycerol orotherforms of supplemental carbon. • Reaeration Zone:This final zone is a small aeration step that strips nitrogen gas and inhibits phosphorus release.To remove phosphorus, sludge must be wasted from the process,typically from the clarifier underflow(i.e., from the RAS)or in the membrane tank when membranes are used for solids separation. As discussed above,the process basins for a BNR configuration have anaerobic zones to facilitate phosphorus removal, anoxic zones to achieve denitrification, and aerobic zones to achieve nitrification, phosphorus,and cBOD5 removal.The effluent from the process basins consists of treated wastewater and suspended solids,which are composed of microorganisms, biodegradable, and non-biodegradable(inert)matter.These microorganisms consume organics in the wastewater during their growth process and need to be periodically wasted from the APRIL 2022 118 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS system to maintain a stable biological community in the BNR process.To accomplish this wasting, effluent is transferred to a subsequent solids separation system(e.g., secondary clarifiers or membrane bioreactors)to separate the suspended material from the treated wastewater. Most of the separated suspended solids are then recycled back to the BNR process to maintain the desired concentration of microorganisms in the treatment process,while the remaining suspended solids are wasted from the system via a sludge stream for subsequent treatment. There are many process variations to achieve an AWT-quality effluent, each with slight changes to the arrangement of the process basin zones and the type of solids-liquid separation employed. However, not all variations can meet the strict effluent limits required for AWT.The following subsections detail a number of technologies that have proven success with consistently achieving AWT. 2.2.3 Potential AWT Treatment Alternatives To prepare a working list of technologies for further evaluations, Carollo refined the initial list of all available nutrient removal processes shown in Figure 8.As noted in this figure, not all processes shown are capable of achieving both nitrogen and phosphorus removal. Hence,this extensive list was shortened to Figure 9 to produce a refined list of technologies that can consistently meet AWT standards using BNR. The 5-stage BNR process configuration is the most commonly used technology for achieving AWT, and was thus selected as the first, baseline alternative for further review.The remaining alternatives were then selected on the following basis: • National experience and use of the process. • Record of performance for full scale installations. • Representation of viable forms of emerging treatment processes ortechnologies. In addition to the 5-stage activated sludge BNR process, Carollo selected viable candidate processes from Figure 9 that represented processes from the following categories: • Single Sludge: Multiple Stages. • Single Sludge: Multiple Phases. • Ballasted Activated Sludge:Aerobic Granular Sludge. • Ballasted Activated Sludge: Ballasted Activated Sludge. • Attached Growth: Moving Bed. According to this selection process, Carollo chose the following technologies for further analysis: • Five-stage activated sludge BNR(5-stage BNR). • Membrane bioreactor(MBR). • Ballasted activated sludge(BAS). • Aerobic granular sludge(AGS). • Sequencing batch reactor(SBR). • Integrated fixed-film activated sludge(IFAS). APRIL 2022 119 ) cD cD $ \ ( o m ; � § / E § Lu \ ) ` L $ Lu ` J / a _ { vol ] \ ■ ro Ln /o k \ $ � > � k � p k � % - £ \ < \ � Z o � ; \ ik ■ ® /\ : ] d �7 © ) ! � E EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 2.3 Descriptions of Proposed AWT-Capable Treatment Alternatives This section presents technology fact sheets for each of the six process configurations on Carollo's working list. Each fact sheet includes the following information: • A brief description of the process. • A simplified process flow schematic that shows the general arrangement of various secondary-and tertiary-treatment unit processes including recycle streams. • A table of basic facts about the technology, i.e., perceived process reliability, major advantages and disadvantages, operational considerations, relative energy usage, footprint, sludge production, chemicals used, and impact on neighbors. Because it is the most common process for achieving AWT effluent quality and because of the large number of installations of the 5-stage BNR process, it will be used as a baseline process that the other process configurations will be compared against. 2.3.1 Five-Stage Activated Sludge BNR(5-Stage BNR) The 5-stage BNR process is a conventional activated sludge BNR process which is configured with the five zones as described in Section 2.2.2 and has proven to achieve the strict AWT effluent requirements. Figure 10 shows the 5-stage BNR process flow configuration while Table 6 outlines additional considerations and information concerning this technology. IMLR(2Q-4Q) Secondary Clarifier Screened, Degritted,and Equalized - Influent(Q) Anaerobic Pre-Anoxic Aerobic Zone Post-Anoxic Re-air Zone Zone Zone Zone WAS to Biosolids Handling Processes RAS(Q) Effluent(Q)to Disinfection Deep-bed Filter Figure 10 5-Stage BNR Process Flow Diagram APRIL 2022 121 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Table 6 5-Stage BNR Fact Sheet Parameters Description Proprietary Process/Equipment None known. No sole-sourced or proprietary equipment required. National Experience/Success Successfully used at many plants in Florida and elsewhere. Process Reliability Reliable and well-proven in the U.S. • Consistently meets AWT effluent quality. • Operational familiarity that does not require additional Major Advantages training. • Large local and national peer communities available for operations to reach out to for troubleshooting. Major Drawbacks Requires a larger footprint than the other alternatives. Pre-Treatment Requirements Single-stage screening and grit-removal. Operational Considerations Similarto current operations. • Possible use of alum or ferric chloride for phosphorus Chemical Requirements removal during process upsets. • Possible use of supplemental carbon depending on carbon to nitrogen ratio in the influent wastewater. Footprint Larger footprint than those of other alternative configurations. Increased WAS production due to nitrogen and phosphorus Residuals Management removal.This increase is comparable to other treatment configurations. Energy Use Moderate energy use compared to other technologies. Ease of Expansion/Upgrade Expansion requires additional parallel trains. Impact on Neighbors Noise and odor comparable to those of other configurations. 2.3.2 Membrane Bioreactor Membrane Bioreactor(MBR)is a variation of BNR in which MBR tanks and equipment replace secondary clarifiers and tertiary filters. Compared to what is achieved in conventional clarification processes,an MBR provides a high degree of solids separation and can operate with much higher MLSS concentrations while also producing effluent with low suspended solids(TSS <1 mg/L). Unlike activated sludge processes which rely on secondary clarifiers for suspended solids separation, MBR process basins can operate at significantly higher MLSS concentrations (6,500 to 7,500 mg/L compared to 2,000 to 4,000 mg/L for CAS systems)and are therefore much smaller. Plants operating MBR processes require two-stage screening typically using coarse screens followed by 2 mm perforated secondary screens to protect the membranes.The membrane causes a significant head-loss on the forward flows, which requires an additional set of permeate pumps to convey flows from the membrane tank to the downstream disinfection process. Figure 11 shows the MBR process flow configuration. APRIL 2022 122 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS IMLR(1Q-2Q) Alum or Iron Salt (As Needed) Clean in IMLR(2Q—4Q) Place Chemicals Backpulse and Screened, V CIP Pumps Degritted,and wii °r~' Equalized ;,'u p Effluent(Q)to Influent(Q) Disinfection an O Secondary-Stage Anaerobic Pre-Anoxic Aerobic Zone Post-Anoxic MBR Screen Zone Zone Zone (2 mm perforated screen) WAS to Bicsolids Handling Processes RAS(30—50) Figure 11 Membrane Bioreactor(MBR)Flow Diagram Table 7 outlines additional considerations and information concerning MBR. Table 7 Membrane Bioreactor(MBR)Fact Sheet Parameters I Description • Each membrane system is unique and proprietary.Over recent years,competition has increased with multiple manufacturers entering the field,which has driven innovation, Proprietary changed perceptions,and closed gaps in costs with conventional technologies. Process/Equipment Hollow-fiber and flat-plate configurations available. • Early selection and procurement are recommended. National • Well-established and largely successful technology with approximately 500 Experience/Success installations nationally and thousands of installations worldwide. Process Reliability • Very reliable. • Consistently produces effluent of very high quality meeting AWT requirements. • Smallest footprint of all the alternatives. • Volume of the process basins is relatively small since they can be operated at higher MLSS concentrations. • Eliminates secondary clarifiers and filtration processes. Major Advantages • Highly automated process. • Helps pre-position future potable reuse options. - Membrane systems have a positive public perception since they are state-of-the-art technologies. • Improves disinfection efficiency, because of the very low TSS and turbidity in the effluent. APRIL 2022 123 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Description More mechanical equipment and maintenance than required for five-stage BNR. • Higher energy use than what's required the five-stage BNR process since the aeration basins operate with higher MLSS concentrations and have a higher aeration demand. • Chemical and scouring equipment required to maintain membranes increases energy costs. • Higher chemical usage to keep membranes clean. Major Drawbacks • Higher pumping than required for five-stage BNR process. • Flow equalization required to attenuate flow and minimize membrane cost. • Physical-hydraulic barrier at the membranes can cause hydraulic bottlenecks during wet weather flows, making flow equalization or membrane redundancy critical. • Shifts in operational strategies(e.g.,towards automation,analyzers,sensors)can challenge operations staff. • Fine screenings may result in cBOD5 loss in primary treatment while also requiring additional screenings-material handling. Pre-Treatment Two-staged screenings with perforated fine screens(<_2 mm)to remove fine solids such as Requirements hair and fibers. • More mechanical equipmentto maintain. Operational • Automated membrane process. Considerations • Periodic membrane cleaning required. • Reliable access to the membranes is key. • Higher chemical use than five-stage BNR process since sodium hypochlorite and citric Chemical acid are needed to chemically clean membranes. Requirements . As-needed use of alum or ferric chloride to trim phosphorus. Footprint Smallest footprint of the configurations or any other proven full-scale biological treatment technology. Residuals • WAS produced comparable to that of five-stage BNR process. Management • Total quantity of solids produced is moderately higher than that of BNR since additional screenings material is produced from fine screenings. Energy Use Higher energy consumption than the five-stage BNR process. • Expansion requires constructing additional process trains and membrane units. Ease of • Depending on the initial design of process trains, upgrade, and expansion of the MBRs Expansion/Upgrade can be modular and may only consist of adding additional membrane units or cassettes. Impact on • Noise and odor comparable to those of the five-stage BNR process. Neighbors Smaller footprint can allow MBRs to be enclosed. APRIL 2022 124 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 2.3.3 Sequencing Batch Reactor(SBR) SBR is another variation of BNR that accomplishes the 5-stage BNR process through a series of time steps in a single reactor.Typically, a single cycle for each SBR reactor consists of five steps: • Step 1, Fill: Influent raw wastewater is added to the reactor, and anoxic and anaerobic conditions are created. • Step 2, React: Influent flow is continuous with aeration applied continuously or intermittently. • Step 3, Settle:Aeration is stopped, and solids/liquids separation occurs. • Step 4, Draw/Decant: Clarified effluent is withdrawn from the top of the reactor via a decanting mechanism. • Step 5, Idle: Sludge is wasted. Figure 12 shows SBR's process flow configuration.Activated sludge aeration and liquid solids separation occur in the same tank,thus RAS or secondary clarifiers and their associated pumps are not required. Under SBR, flexibility is allowed in the duration of aerobic and anaerobic phases to encourage optimum nitrogen and phosphorus removal rates. Alum or Iron Salt (As Needed) Screened, Degritted,and Equalized o Influent(Q) = Effluent(Q)to Disinfection SBR Equalization Deep-bed Filter Tank WAS to Biosolids 10 Handling Processes Surplus Sludge Figure 12 Sequencing Batch Reactor(SBR) Process Flow Diagram Table 8 outlines additional considerations and information concerning SBR. APRIL 2022 125 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Table 8 Sequencing Batch Reactor(SBR) Fact Sheet Parameters Description Proprietary Several SBR equipment manufacturers exist.Process tanks are customizable, Process/Equipment although some configurations are proprietary. National More than 1,300 facilities in the U.S.,Canada,and Europe employ SBRs. Experience/Success Process Reliability Handful of plants in Florida use SBRs and successfully produce effluent meeting AWT quality. • Biological treatment and secondary clarification can be achieved in a single reactor vessel. Major Advantages • SBR processes can handle large seasonal variations in flow and loads. • Process modification is flexible. • No internal MLSS or RAS recycle required so less pumping energy required than what BNR uses. • SBR processes are more commonly used atfacilities with flowrates of 5 mgd or less in the U.S. • Requires larger-sized blowers than what's used for the five-stage BNR process. • Requires flow equalization downstream of the process tanks and upstream of filters.Without equalization before tertiary filtration,the filters must be"oversized"to accommodate extremely high peak flows. Major Drawbacks • Sludge settleability can create adverse process conditions. • Greater operator involvement than what's required for the five-stage BNR process. • Some SBR equipment and control systems are proprietary making repair, replacement,and troubleshooting of control systems difficult without involving the equipment manufacturer. • Equipment failure(e.g., decanter, mixer,aeration systems,etc.)requires taking the entire SBR process-train offline,affecting redundancy and available capacity. Pre-Treatment Requirements Traditional screening and grit-removal. Operational Requires a sophisticated system of units and controls,as well as a higher level Considerations of maintenance for controls,switches,and valves,compared to what's required for BNR. Chemical Similar to BNR with as-needed use of alum or ferric chloride for phosphorus Requirements removal. Footprint Slightly smaller compared to the five-stage BNR process.Secondary clarifiers can be removed but footprint is still required for multiple SBR basins. Residuals WAS produced similar to that of five-stage BNR process. Management Energy Use Low to moderate energy use compared to five-stage BNR process. Ease of Fairly modular construction is possible. Expansion/Upgrade Impact on Neighbors Noise and odor comparable to those of five-stage BNR process. APRIL 2022 1 26 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 2.3.4 Aerobic Granular Sludge—AquaNereda® Aerobic Granular Sludge(AGS)is a novel method to remove carbon, nitrogen, and phosphorus in a single bioreactor.Aerobic granular sludge itself consists of dense granules of mixed microbial communities that do not coagulate and,therefore, settle much fasterthan activated sludge flocs. The AGS treatment process is similarto that of SBR but operates in three steps:1)fill and draw, 2)react,and 3)settle. Similar to SBR, separate secondary clarifiers or recycling of RAS is not required. Compared to the 5-stage BNR process activated sludge,AGS granules settle very rapidly so process basins can be much smaller.The granules'high settling velocities allow bioreactor operation at very high MLSS concentrations(8,000 to 12,000 mg/L),thereby reducing the overall footprint of the process tanks. The outer layers of the granule are aerobic and support nitrifier growth,while anoxic and anaerobic zones occur in the center orthe granule.As such,AGS can perform carbon removal, nitrification, denitrification, and phosphorus removal all in one bioreactor.There is currently only one operating AGS facility in the United States, but there are several operating throughout the world. Figure 13 shows the AGS process flow configuration. Alum or Iron Salt (As Needed) Screened, Degritted,and v Equalized v Influent(Q) Effluent(Q)to c� Disinfection m c m C- AGS Reactor Equalization Deep-bed Filter co Tank v WAS to Biosolids Handling Processes Buffer Tank Figure 13 Aerobic Granular Sludge(AGS)Process Flow Diagram APRIL 2022 27 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Table 9 outlines additional considerations and information concerning AGS. Table 9 Aerobic Granular Sludge(AGS)Fact Sheet Parameters Description Proprietary Process/Equipment Limited providers of AGS systems for municipal wastewater treatment in North America. National Experience/Success In the U.S,one full-scale AGS facility is in in operation.As of January 2020,there were over 75 installations worldwide. Largely unknown.At the time this report was written,there Process Reliability were no full-scale operating plants in the U.S.that were treating to AWT standards. • AGS granules settle faster than five-stage BNR process sludge,thus requires less reactor volume. • Process train can be operated at a higher MLSS Major Advantages concentration than what can be done with five-stage BNR process without affecting performance. • Requires no internal MLSS or RAS recycle so demands less pumping energy than what five-stage BNR process uses. • Local and national peer communities not available for operations to reach out to for troubleshooting. • Proprietary dependence to operate and troubleshoot equipment. • Limited national presence. Major Drawbacks • Largely unknown process. • Multiple means for a single point of failure with higher consequences of failure. • Process failure requires taking the entire AGS process- train offline,affecting redundancy and available capacity. Pre-Treatment Requirements Single-stage screening and grit-removal. Operational Considerations Largely unknown process.Operational requirements were unknown when this report was written. Chemical Requirements Similarto those of BNR with as-needed use of alum or ferric chloride for phosphorus removal. Footprint Slightly smaller compared to that of five-stage BNR Modified BardenphOT""process. Residuals Management WAS produced similar to that of five-stage BNR process. Energy Use Slightly less energy use compared to what five-stage BNR process uses due to reduced pumping requirements. Ease of Expansion/Upgrade Fairly modular construction is possible. Impact on Neighbors Similar to those of five-stage BNR process. APRIL 2022 128 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 2.3.5 Ballasted Activated Sludge—NuvodaTM Ballasted Activated Sludge(BAS)is based on BNR with one variation:the addition of ballasting material to the process tanks.The ballast material supplements BNR by significantly improving the settleability of MLSS in the secondary clarifiers,which allows for higher operational MLSS concentrations in the process tanks without stressing the secondary clarifiers. There are several types of ballast material, ranging from the traditional material Magnetite to more novel organic media like Kenaf. Magnetite is an inert,fully-oxidized, and very fine magnetic iron material that requires intense mechanical equipment to separate the ballast media from the waste stream. Kenaf, on the other hand, is a naturally occurring lignocellulosic material harvested from the rapid-growing Kenaf plant(Hibiscus Cannabinus)that is recycled with less energy-intensive equipment from the waste stream compared to Magnetite. New ballast is introduced to the system via a ballast-mixing tank and is recovered from the WAS streams using recovery drums,which then feed the recovered material back into the ballast-mixing tank. New ballast is reintroduced to the process stream with the RAS flow to compensate for any ballast lost through the wasting process since the ballast recovery is not 100 percent efficient. Because BAS can improve the capacity of existing process tanks without modifying its footprint, it is highly suited as a retrofit process. Figure 14 shows BAS'S process flow configuration. MOBT11 Media WAS Screens (as needed) _4t Ultimate MLR(2Q 4Q) WAS Disposal Screened, Degritted,and Clarifier Equalized Effluent(Q)to Influent(Q) Filtration Anaerobic Pre-Anoxic Post-Anoxic Re-air Zone Zone Aerobic Zone Zone Zone RAS WAS Figure 14 Ballasted Activated Sludge(BAS)Flow Diagram APRIL 2022 1 29 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Table 10 outlines additional considerations and information concerning BAS. Table 10 Ballasted Activated Sludge(BAS) Fact Sheet Parameters Description Proprietary BAS sidestream includes the ballast-mixing tank,dispersion mills, and recovery Process/Equipment drums,which are proprietary equipment.Some examples of ballast material are magnetite and kenaf. National Experience/Success No BAS plants in Florida but there are several successful BAS plants across the US. Process Reliability Comparable to the five-stage BNR process. • BAS process can meet AWT effluent water quality goals. Major Advantages • Volume of the process basins is reduced when compared to that of BNR since the basins can be operated at higher MLSS concentrations. • Local and national peer communities not available for operations to reach out to for troubleshooting. • Shift in operational strategies and additional operations training required to operate the ballast-recovery equipment. • Proprietary dependence to operate and troubleshoot equipment. • Limited national presence. Major Drawbacks • Ballast recovery rates are not 100 percent,so new ballasts are required on an on-going basis to replenish the wasted amounts. Depending on recovery rates, sizing of the system,and shipment availability, ballast replenishment can be an expensive O&M item. 0 More mechanical equipment and maintenance needed than what's required for BNR. • More pumping than what's required for the five-stage BNR process. Single-stage screening and grit-removal.Second stage(fine screening)is Pre Treatment Requirements preferred.In the absence of fine screening upstream of the WAS,dedicated WAS screening may be required. • Proprietary dependence to operate and troubleshoot equipment. Operational Considerations • Ballast and MLSS concentrations must be monitored to schedule ballast shipments. Chemical Requirements Similartothe five-stage BNR process. Comparable to BNR.Process basins are smallerthan what's used for BNR, but the Footprint reduced footprint is offset by the space needed for ballast-recovery equipment and ballast-storage areas. Residuals Management WAS contains irrecoverable ballasts,which may help with thickening. However, total solids produced will be higher compared to what's produced in BNR. Energy Use Higher energy consumption than what's consumed for the five-stage BNR process due to the ballast-recovery equipment. • Expansion requires additional parallel trains. • Compared to the five-stage BNR process,additional considerations are Ease of Expansion/Upgrade required due to the use of ballast-recovery equipment(shear mills, larger and additional magnetic drums, larger and additional ballast tanks,and additional pumps). • Noise and odor comparable to those of the five-stage BNR process. Impact on Neighbors • Ballast system equipment can be contained in a building but will result in additional truck traffic to the facility. APRIL 2022 130 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 2.3.6 Integrated Fixed-Film Activated Sludge Attached-growth processes, when coupled with suspended-growth processes, provide enhanced nutrient removal. Integrated fixed-film activated sludge(IFAS)is one such process in which attached-and suspended-growth biomass is combined within the same reactor. In IFAS,floating orfixed media is introduced inside the aeration tanks.The combination of suspended and attached biomass results in a concentration of biomass that is significantly higher than what can be expected in a suspended-growth process alone.This provides two important benefits. First,the required volume of the aeration tank is substantially reduced. Second,the attached biomass places no additional load on the final clarifiers, so the solids loading to the clarifiers is substantially reduced when compared to what's imposed by a suspended-growth process with the same SRT. Figure 15 shows the IFAS process flow configuration. Screen Wall to Retain Media in Aerobic Zone IMLR(2Q—4Q) Alum or Iron Salt (As Needed) Aerobic Reactor with IFAS Media Screened, Degritted,and Equalized Influent(Q) Anaerobic Pre-Anoxic Aerobic Zone Post-Anoxic Re-air Zone Zone Zone Zone V Effluent(Q)to Secondary Disinfection Clarifier Deep-bed Filter WAS to Biosolids Handling Processes RAS(Q) Figure 15 Integrated Fixed-Film Activated Sludge(IFAS)Flow Diagram APRIL 2022 131 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Table 11 outlines additional considerations and information concerning IFAS. Table 11 Integrated Fixed-Film Activated Sludge(IFAS) Fact Sheet Parameters Description Proprietary There are several IFAS media and equipment manufacturers, but most are Process/Equipment unique and proprietary.Available types of media include rope, sponge carriers, hard plastic carriers,trickling filter media, kenaf, and flat sheets. National Experience/Success Many installations in the US with more widespread use in Europe. Process Reliability Comparable to that of five-stage BNR process. • Reduced solids loading to clarifiers due to retained biomass in aeration Major Advantages basins. • Volume of process basins is reduced compared to that of five-stage BNR process since the basins can be operated at higher MLSS concentrations. • Higher dissolved-oxygen concentrations are required in the aerobic tanks resulting in higher energy usage than what five-stage BNR uses. • Additional screens are required in the process tanks to retain media in the tanks.Additional pumping within the process tanks may be required to move any media clogged on the screens. Major Drawbacks • Forward flow velocity through the process tanks is critical to prevent unequal distribution of media within the tanks. • Proprietary dependence to replace the media and troubleshoot. • Taking basins offline for maintenance is problematic since media must be removed. Pre-Treatment Single-stage screening and grit-removal is adequate.Screening size depends on Requirements the type of media used. Fine screening may be necessary to prevent blinding of media-retaining screens. • Normal life-expectancy of the media is 10 to 30 years depending on the media. • Proprietary dependence to replace the media and troubleshoot. Operational Considerations Media retaining screens affect additional hydraulic losses. • Potential for plugging and media-clogging in the media-retaining screens thus requiring more maintenance. • Maintaining the aeration system requires media to be removed and displaced. Chemical Requirements Similar to those of five-stage BNR process. Footprint Smallerthan that of the five-stage BNR process but largerthan that of MBR. Residuals Management Similarto that of five-stage BNR process. Higher energy consumption than that of the five-stage BNR process.The Energy Use attached biomass requires higher dissolved-oxygen concentrations,thus lowering the field-oxygen transfer efficiency.Additional pumping inside the process basins may result in higher energy demand. Ease of Expansion/Upgrade Expansion requires additional parallel trains.The capacity of the existing tankage could be increased to a certain point by introducing additional media. Impact on Neighbors Similar to those of five-stage BNR process. APRIL 2022 132 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 2.4 Structured Decision Analysis A structured decision analysis was used to characterize the AWT-capable treatment process alternatives and rank them according to their ability to meet a prioritized set of evaluation criteria established by the City and Carollo.These five evaluation criteria include: 1. Established Technology, 2. Treatment Effectiveness, 3. Operability, 4. Constructability and Sequencing(Implementability), and 5. Footprint and Flexibility for Future Upgrade. The City selected a committee to participate in a paired comparison exercise where values(or weights)were applied to each of the evaluation criterion.These weights ultimately established the relative importance of each criterion to use in evaluating and comparing the liquid stream process alternatives.The weighted scores developed by the selection committee were combined with technical criteria developed by Carollo(representing each alternative's ability to satisfy the criteria/sub-criteria)in a decision model.The decision model calculated a unitless`decision score"and the alternative that best satisfies the most valued criteria(according to the City's selection committee)received the highest score.The top two alternatives are further evaluated in Section 3 of this CDR and include conceptual site layouts and cost estimates(including present worth). The evaluation criteria set did not include any economic factors such as capital and operating costs.Although these costs will be evaluated forthe two shortlisted technologies(in Section 3 of the report), it was intentional to exclude these from the evaluation criteria. Doing so eliminated any financial bias or appeal for the City to select the`cheapest"alternative. 2.4.1 Process Evaluation Criteria and Sub-Criteria To effectively measure the performance of each alternative againstthe five established criteria, additional sub-criteria were developed to provide a further breakdown for evaluation.The importance of each sub-criterion was assigned a numerical value by a team of senior wastewater process specialists within Carollo according to understanding of key project drivers and industry standards.The sub-criteria were presented to the City's appointed scoring committee and given as a rubric to follow when the committee completed the paired comparison exercise in January 2022.Table 12 lists the five major evaluation criteria, along with their corresponding sub-criteria. APRIL 2022 133 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Table 12 Major Evaluation Criteria and Corresponding Sub-Criteria Major Criteria Sub-Criteria 1. Established a. Number of installations in the U.S.of similar capacity. Technology b. Number of installations in Florida of similar capacity. c. Maturity of process technology. a. Proven processes and technologies for meeting Florida's AWT limits. 2. Treatment b. Robustness of treatment(e.g.,ability to handle a range of influent Effectiveness conditions;ease of recovery from upset). c. Redundancy and reliability. a. Safe work environment,operational flexibility,complexity of operation,staffing requirements(e.g.,special skills ortraining), residuals/process additives production. b. Process monitoring and control effectiveness(including industry-recognized process control methods,accessible peers to 3. Operability discuss process control options,and effective troubleshooting methods established). c. Chemical requirements. d. Maintenance requirements(number and complexity of process equipment components and required frequency of maintenance, storage requirements(e.g.,for media),special maintenance equipment). a. Safe construction. b. Maintained plant operations,minimize shutdowns 4. Constructability and (phasing/sequencing). Sequencing C. Potential schedule impacts(e.g.,equipment manufacturing and (Implementability) delivery timeframes). d. Space requirements for construction. e. Permitting. f. OSHA/NFPA requirements. a. Footprint required. 5. Footprint and b. Expandability. Flexibility for Future c. Adaptability for potential future regulations or effluent uses. Upgrades d. Truck traffic impacts. e. Sustainability(energy use,solids handling). APRIL 2022 34 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 2.4.2 Paired Comparison Results The City formed a selection committee(made up of four City employees of various departments) to participate in a paired comparison exercise in January 2022. During this exercise,the criteria were weighted against one another using a paired comparison method. Members of the selection committee individually and privately scored each of the five criteria against each other in terms of highest value/prioritization.This ultimately developed the average weight for each criterion. Results of this exercise are presented in Table 13. Table 13 Major Evaluation Criteria and their Relative Importance Major Criteria Average Weight(Percent) 1: Established Technology 18 2:Treatment Effectiveness 23 3:Operability 30 4:Constructability&Sequencing(Implementability) 17 5: Footprint&Flexibility for Future Upgrades 12 The City placed the highest value on Operability,followed by Treatment Effectiveness, Established Technology, Constructability and Sequencing(Implementability), and lastly Footprint and Flexibility for Future Upgrade. Footprint and size of the plant is not a concern for the City since the new WRF will be built on the existing plant site and sufficient area is available, explaining why that criterion has a lower average weight. By placing the highest average weight on Operability,the City is emphasizing their value in constructing a WRF that is easy and safe for operators to operate with minimal additional training. The unweighted scores from Carollo's alternative scoring matrix were then combined with the weights established by the selection committee and inputted into a decision model.The decision model calculated a unitless`decision score"and the alternative that best met the most valued criteria(according to the City's selection committee)received the highest score. Figure 16 shows the results of the structured decision analysis. Based on the City's applied values established by the selection committee, 5-stage BNR and MBR were the top two scoring technologies. Both of these processes are mature,with a track record of successfully meeting stringent nutrient discharge limits. BNR was considered to be preferable to MBR in terms of Operability, which is the most important criterion to the City(average weight of 30 percent). This is partly attributed to the number and complexity of process equipment components associated with MBR. On the other hand, MBR scored better than BNR in terms of Footprint and Flexibility for Future Upgrades.AGS(Nereda)and BAS(Nuvoda)were ranked lowerthan the other processes, largely because they did not score well relative to Treatment Effectiveness and Established Technology. APRIL 2022 135 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Technology Ranking 5.00 4.50 _ 4.00 ■ - 3.50 ■ 3.00 0 2.50 ■ U 2.00 1.50 1.00 0.50 0.00 BNR MBR SBR Nuvoda IFAS Nereda Technology ■S.FOOTPRINT AND FLEXIBILITY FOR FUTURE UPGRADES ■4.CONSTRUCTABILIFY&SEQUENCING(IMPLEMENTABILITY) ■3.OPERABILITY ■2.TREATMENT EFFECTIVENESS ■1.ESTABLISHED TECHNOLOGY Figure 16 Process Alternative Ranking Using Weighted Criteria These results were discussed and agreed upon with the City at a Process Selection Scoring workshop held in January 2022.These top two alternatives are further evaluated in Section 3 of this CDR and include conceptual site layouts and life-cycle cost estimates. EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS 3.0 Shortlisted Alternatives Evaluation 3.1 Objectives The decision analysis discussed in Section 2 resulted in the list of treatment alternatives below, which are ranked from highest to lowest based on the City's applied values: 1. 5-stage activated sludge BNR(5-stage BNR). 2. Membrane bioreactor(MBR). 3. Sequencing batch reactor(SBR). 4. Ballasted activated sludge(BAS). 5. Integrated fixed-film activated sludge(IFAS). 6. Aerobic granular sludge(AGS). This section of the CDR evaluatesthe conceptual process modeling, sizing, site layouts, and life cycle cost estimates forthe East WRF's top two scoring treatment process alternatives:5-stage BNR and MBR.A final treatment alternative recommendation will be provided in Section 4 to support the City in making the informed decision of which AWT-capable process to select forthe upgraded East WRF.An associated conceptual site layout and cost estimate are also provided for the final recommendation within Section 4. The design criteria presented in this report are conceptual level and must be further refined during the Project's subsequent design stages. 3.2 Conceptual Design Criteria The following subsection evaluates the design criteria used to conceptually size, layout, and cost the 5-stage BNR and MBR alternatives. It should be noted that the criteria used to compare the conceptual designs of the two shortlisted treatment alternatives within this section are not the final design recommendation for the East WRF at this time.As is explained further below,the design flows and loads used to compare the BNR and MBR conceptual designs and costs correspond to a true`buildout"scenario.This scenario represents what the City may require in the far-term future, i.e., post-2045, in terms of quantity(population growth)and quality(AWT requirements).The conceptual designs and costs included within this section are used to compare/evaluate the two shortlisted treatment alternatives to later make an ultimate design recommendation.The conceptual design and cost estimate forthe final recommended treatment process—sized for current quantity/quality requirements—is included within Section 4 of this report. 3.2.1 Influent Flows and Loads The East WRF's historic wastewater flow and loads were previously analyzed in Section 1.5.To further characterize the facility's influent wastewater, Carollo relied on historical monthly data obtained from DMRs over the past three years to identify representative flow and loading peaking factors, which are key in the design and operation of a WRF. Factors were determined for a range of conditions including annual average, maximum month, maximum day, and peak hour. APRIL 2022 1 37 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS Although it is common practice forth e capacity of a WRF to bed escri bed in terms of the annual average daily flow(AADF),this value is not used to directly size any unit process or operation. Rather, sizing is based on the parameters which directly impact the performance of each unit process or operation. For example, aeration MDL and process volume requirements for BNR systems are designed around a maximum month average daily mass load(MMADL),while hydraulic elements such as pipes, pumps,and filters are designed around maximum day(MDF) or peak hourly flows(PHF), depending on if flow equalization(EQ)is provided. Appropriate peaking factors for the proposed East WRF were determined based on a combination of historic data and Carollo's experience in designing facilities of similar capacity here in Florida. Maximum month peaking factors and annual average flows and loads were calculated from historic East WRF influent data over the past three years.Accurate daily and hourly influent data was unavailable during the conceptual phase of the Project, and thus standard industry estimating methods were used where applicable for max day and peak hour factors. References used include the Recommended Standards for Wastewater Facilities(2014) prepared by the Great Lakes—Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers(also referred to as the 10-State Standards), and Munksgaard and Young's Flow and Load Variations at Wastewater Treatment Plants(1980). Table 14 lists the East WRF's proposed design flow and loading peaking factors forthe CDR, determined from the methods described above. Table 14 East WRF Influent Design Flow and Mass Load Peaking Factors Peaking Factor(l) Value Hydraulic Peaking Factors Maximum Month Average Day Flow(MMADF)(z) 1.1 Maximum Day Flow(MDF)(') 2.0 Peak Hour Flow(PHF)(4) 3.0 Loading Peaking Factors Maximum Month Average Day(MMAD)—TSS(z) 1.9 Maximum Month Average Day(MMAD)—cBOD5(2) 1.5 Maximum Day(MD)—TSS(') 3.5 Maximum Day(MD)—cBOD5(3) 2.4 Notes: (1) All peaking factors are relative to the long-term annual average day conditions experienced between Jan 2018 and Oct 2021. (2) Calculated using East WRF historic influent data from Jan 2018 through Sep 2021. (3) D.G.Munksgaard and J.C.Young,"Flow and Load Variations at Wastewater Treatment Plants,"JWPCF.52(8)1980: 2131-2144. (4) Fair,G.M.and Geyer,J.C."Water Supply and Wastewater Disposal"1'Ed.,John Wiley&Sons,Inc.,New York(1954), p.136. Carollo recommends that the City perform a detailed influent load and flow analysis during the subsequent design phase to refine the factors provided in Table 14 to provide the most accurate design for the East WRF.As they stand,these factors—primarily MMAD TSS and cBOD5—are greater than those of typical medium-strength domestic wastewater facilities, which may result in the oversizing of process basins or mechanical equipment. For example,the historic organic (i.e.,cBOD5)maximum month loading factor was calculated to be 1.5,which is greater than the typical range of 1.2 to 1.3.A higher loading factor correlates to a greater process volume APRIL 2022 38 EAST WRF CONCEPTUAL DESIGN REPORT I CITY OF WINTER SPRINGS requiring larger basins and greater calculated air demand and consequently, more blowers or larger blowers to provide the required process air. Due tot he costa nd process efficiency implications associated with under or oversizing unit processes,these factors require verification via a detailed influent sampling campaign. Table 15 provides the resulting design flows and loads used within the conceptual design forthe two shortlisted technologies based on the factors in Table 14. Forthe comparison of the conceptual designs forthe BNR and MBR alternatives,a design AAD of 2.1 mgd and PHF of 6.3 mgd was used.A 2.1 mgd design flow evaluates replacement of the East WRF to meet its existing capacity and avoids de-rating the plant's capacity.The conceptual design for 2.1 mgd ultimately represents a true`buildout"scenario, demonstrating what the City may require in the far-term future, i.e., post-2045, in terms of quantity(population growth)and quality(AWT).A conceptual design and cost estimate forthe final recommended treatment alternative—sized for today's needs—is included within Section 4 of this report. Table 15 Conceptual Influent Design Wastewater Flows and Loads Parameter Unit Minimum Day AADM MMAD Influent Flow mgd 1.9 2.1 2.3 4.2 6.3 Concentrations cBOD5 mg/L 150 220 300 260 - TSS mg/L 120 260 450 450 - TKNO) mg/L 30 44 60 50 - TP(4) mg/L 13 20 28 24 - Loads cBOD5 Ib/d 2,300 3,800 5,700 9,100 - TSS Ib/d 1,840 4,600 8,700 15,600 - TKN Ib/d 460 770 1,200 1,800 - TP Ib/d 210 350 530 840 - Notes: (1) Based on historic East WRF influent from Jan 2018 through Sep 2021. (2) PHF provided only for the design of hydraulic elements. (3) Influent TKN:cBODs assumed to be 1:5 due to lack of absence of influent nutrient monitoring. (4) Influent TP:cBODs assumed to be 1:11 due to lack of absence of influent nutrient monitoring. Unit processes forthe new East WRF will be sized to handle the targeted design flows and loads afterthe applicable peaking factors are applied.The process and hydraulic design of unit processes will include multiple treatment units,which builds reliability and ensures each treatment process can be maintained with any one parallel unit removed from service for inspection or maintenance.The upgraded East WRF will not only meet the minimum Class 1 reliability and redundancy criteria established by the EPA and enforced by FDEP [U.S. Environmental Protection Agency, Design Criteria for Mechanical, Electric, and Fluid Systems and Component Reliability(1974, EPA 430-99-74-001)], but also provide operators with unit processes that can be readily taken offline for maintenance or repair without disrupting the overall treatment process. It should be noted that although no low-flow or low-load analysis was performed as part of this CDR effort,they will be required during the later design phase to ensure mechanical equipment is properly sized for such scenarios. APRIL 2022 139