WASTEWATER SYSTEM MASTER PLAN

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2 ` WASTEWATER SYSTEM MASTER PLAN (Reuse and Effluent Disposal Alternatives and Siting Alternative Analysis) FOR CITY OF GREEN COVE SPRINGS, FLORIDA Prepared by: MITTAUER & ASSOCIATES, INC. Consulting Engineers Orange Park, Florida Project No March 2015

3 WASTEWATER SYSTEM MASTER PLAN (Reuse and Effluent Disposal Alternatives and Siting Alternative Analysis) FOR CITY OF GREEN COVE SPRINGS, FLORIDA Prepared by: MITTAUER & ASSOCIATES, INC. Consulting Engineers Orange Park, Florida Project No March 2015

4 Executive Summary The City s last wastewater master plan was completed in 2008, and numerous items have changed through the years that have affected the previous plan s scope and objectives. The City has encountered issues including but not limited to: (a) an economic recession; (b) wastewater treatment operational adjustments to meet nutrient reduction requirements; (c) new Total Maximum Daily Loading ( TMDL ) regulations/nutrient loading restrictions to the St. Johns River; (d) a Future Land Use Amendment related to a 2,000+ acre parcel of land (i.e., Reynolds Parcel ) that will be a major factor in the City s long-term growth; and (e) future wastewater treatment plant siting considerations. These activities have sharpened the City s focus and provided additional clarity on its wastewater collection and treatment needs as well as requirements to expand the City s reclaimed water delivery systems. Accordingly, the City desires to appropriately plan for its infrastructure needs in order to identify the most logical and practical means of accommodating the growth and demands placed on the City s wastewater and reclaimed water systems. This translates into developing an implementable capital improvement plan based on projected demands that will take into account the following: 1. Wastewater Service Areas; 2. The Planning Period which will be through the Year 2040; 3. Wastewater Projections for the Service Area; 4. Wastewater Treatment Alternatives and Requirements through the Planning Period; 5. Wastewater Reuse and Disposal Alternatives through the Planning Period; 6. The capabilities and capacities of the existing infrastructure; 7. Regional options related to infrastructure connections; and 8. The influence of current and pending regulatory requirements for the design, permitting, construction, operation and maintenance of infrastructure improvements. As a result of the above, the City tasked Mittauer & Associates, Inc. to update and develop a ( Plan ) in light of the new realities facing the City. The enclosed Plan reviewed the City s wastewater and reclaimed water delivery needs in the Mittauer & Associates, Inc. Project No Page ES-1

5 following sequence: Existing Wastewater and Reclaimed Water System Capabilities (Section II); Population Growth Review and Projections (Section III); Regulatory and Policy Considerations (Section IV); Projected Wastewater Demands (Section V); and Wastewater Infrastructure Expansion Analysis (Section VI). A general summary of findings for each section is provided herein. Section II. Existing Wastewater and Reuse System Review included consideration of the City s existing: (a) sewer and reclaimed water demands; (b) treatment system; (c) collection system; (d) lift stations and associated transmission mains (i.e., force mains); (e) wastewater treatment system; (f) reclaimed water delivery system; and (g) capacities for each component. An analysis was completed identifying limiting capacities for each system and their components. Critical components of the review and analysis are summarized as follows: The City owns and operates two (2) permitted Wastewater Treatment Plants ( WWTP ) within the Service Area. The Harbor Road Wastewater Treatment Plant ( HRWWTP ) is located on the north end of the City and currently serves the majority of the community, while the South Wastewater Treatment Plant ( SWWTP ) is located toward the south end of the City. Items associated with the HRWWTP include the following: - The HRWWTP is not anticipated to provide sufficient biological nutrient removal ( BNR ) capabilities once flows begin to exceed 0.60 to 0.65 million gallons per day ( MGD ). Total Nitrogen ( TN ) levels are anticipated to be difficult to control as flows exceed these values. Without expansion of the City s reclaimed water system and/or advanced treatment capabilities, the City would likely have difficulty meeting their St. Johns River TMDL obligations. - The annual average daily flow to the HRWWTP in 2013 and 2014 was MGD and MGD, respectively. These flows are approximately 84% and 71% of the current nutrient removal capacity estimated at 0.65 MGD AADF. Mittauer & Associates, Inc. Project No Page ES-2

6 - The existing HRWWTP has components that were built in 1971 (44 years old), 1986 (29 years old), and 2001 (14 years old). Typical life expectancy for these facilities is between 30 to 40 years. Notwithstanding the biological nutrient removal upgrades that are needed, the HRWWTP needs facility improvements including but not limited to: (a) back-up bar screen; (b) redundant clarifier; (c) back-up filter; (d) updated/expanded laboratory and office areas; (e) piping improvements (liquid and air); (f) effluent piping integrity testing/evaluation; and (g) permanent biosolids dewatering capabilities. - As noted elsewhere, infiltration/inflow into the City s collection system impacts peak flows into the HRWWTP which impacts mechanical and biological performance. - As the City contemplates long-term objectives, the existing permitted capacities for each WWTP should be underscored. Notwithstanding the TMDL limitations, the HRWWTP river outfall has a peak flow capacity of 2.78 MGD PHF and permitted capacity of 1.25 MGD AADF. Increasing the permitted capacities may be difficult. Using a 3.0 peaking factor, the HRWWTP outfall would likely begin to reach its service potential at a flow around 0.90 MGD AADF. Items associated with the SWWTP include the following: - The SWWTP is not anticipated to provide sufficient BNR capabilities once flows begin to exceed 0.30 to 0.35 MGD. TN levels are anticipated to be difficult to control as flows exceed these values. Without expansion of the City s reclaimed water system and/or advanced treatment capabilities, the City would likely have difficulty meeting their St. Johns River TMDL obligations. - The annual average daily flow to the SWWTP in 2013 and 2014 was MGD and MGD, respectively. These flows are approximately 60% and 66% of the current nutrient removal capacity estimated at 0.35 MGD AADF. - The existing SWWTP was built in 1991 (24 years old). Typical life expectancy for these facilities is between 30 to 40 years. Notwithstanding the biological nutrient removal upgrades that are needed, the SWWTP needs facility improvements including but not limited to: (a) new influent screening; (b) ensure all steel or aluminum components are structurally sound; (c) effluent piping integrity testing/evaluation; and (d) permanent biosolids dewatering capabilities. Mittauer & Associates, Inc. Project No Page ES-3

7 - As noted elsewhere, infiltration/inflow into the City s collection system impacts peak flows into the HRWWTP which impacts mechanical and biological performance. - As the City contemplates long-term objectives, the existing permitted capacities for each WWTP should be underscored. Notwithstanding the TMDL limitations, the SWWTP river outfall has a peak capacity of 2.52 MGD PHF and a permitted capacity of 0.50 MGD AADF. Increasing the permitted capacities may be difficult. Items associated with the North and South Service Area collection systems are summarized as follows: - The City s collection system (i.e., gravity sewer system) includes 31 pump stations, tens of thousands of feet of gravity sewer piping, and hundreds of gravity sewer manholes. - The North Service Area population is anticipated to be 5,500 persons which is served by the HRWWTP. The South Service Area is anticipated to serve 1,400 persons. Both service areas have infiltration and inflow that affect peak flows into the each wastewater treatment plant, dilute the wastewater strength, and contribute grit into the wastewater system. The City continues to monitor and provide annual capital improvements to address the most problematic areas of the collection system. The City should be aware that peak flows from the collection transmission system impact clarifier performance as well as BNR capabilities. - The most significant North Service Area pump stations are Pump Station Nos. 3, 4, and 26. Pump Station No. 4 will have significant importance related to future expansion alternatives. Pump Station ( P.S. ) No. 2 is the largest South Service Area station. Actual pump run times indicate P.S. No. 2 is delivering 85 to 90% of the South Service Area s flow to the SWWTP. This station will also have a significant influence on future expansion alternatives. - Some limited areas within the City s Service Area are currently served via onsite means. Many of these areas are rural in nature or they are located at a sufficient distance where connection to the City s central sewer system is not economically feasible. The approximate units that are currently served by Mittauer & Associates, Inc. Project No Page ES-4

8 OSTDS are summarized as follows: North Upper Service Area (River Front Lots) = 70 units North Upper Service Area (Occupied Large Lots) = 45 units North Upper Service Area (Occupied Small Lots) = 135 units North Core Service Area (Occupied Large Lots) = 75 units South Core Service Area (Occupied Large Lots) = 40 units Total = 365 units If these areas were connected to a central sewer system with advanced treatment capabilities, then a 93% TN loading reduction would be anticipated. Items associated with the existing reclaimed water system is summarized as follows: - The North Service Area currently has Magnolia Point as its only reclaimed water customer while the South Service Area currently has no viable reuse customer base. - The Magnolia Point reuse system is a critical component of the City s wastewater/reclaimed water infrastructure. The current reuse demand of 0.20 MGD (AADF) allows the City to remain in compliance with the current TMDL restrictions. Without this reuse demand, the City would have difficulty meeting their Total Phosphorus loading requirements and Total Nitrogen would be near the compliance limit. Section III. Growth Review and Projections Section III develops population projections that are utilized in Section V to estimate future wastewater and reuse demands. In addition, this section focused on various dynamics that will affect population growth within and around the City. In particular, the following resources were reviewed, discussed, and analyzed regarding population growth potential and projections within the City s 2040 Urban Boundary: Reynolds Future Land Use Map ( FLUM ) Amendment Clay County 2025 Comprehensive Plan City of Green Cove Springs 2025 Comprehensive Plan Florida Department of Transportation ( FDOT ) Outer Beltway City of Green Cove Springs 2040 Urban Boundary City of Green Cove Springs Build-Out Study Mittauer & Associates, Inc. Project No Page ES-5

9 University of Florida Bureau of Economic and Business Research ( BEBR ) Population Projections Medium-Growth population projections were developed based on the 2013 BEBR population projections for Clay County. The result of that population projection analysis and conversion of those values into single-family dwelling units using an estimated density of 2.2 capita per unit is summarized in Table ES-1. TABLE ES THROUGH 2040 DWELLING UNIT PROJECTIONS Year North Service Area Projection South Service Area Projection (capita) (ERU) a (capita) (ERU) a a: ERU = 2.2 capita/unit ,500 2,500 1, ,130 2,790 1, ,720 3,050 1, ,260 3,300 1, ,740 3,520 1, ,170 3,710 2, The South Service Area growth will be the most dynamic area for the City to monitor and manage. It is also the area that could be significantly influenced by regional growth and new highway extensions. It is anticipated industrial and residential demands within this area could significantly exceed population projections due to the First Coast Expressway and Reynolds redevelopment. Section IV. Regulatory and Policy Considerations The most dynamic regulatory areas which could impact the City s infrastructure planning are related to nutrient loading, alternative water supply needs/demands (non-potable irrigation), public-access reclaimed water quality requirements, wastewater effluent disposal, WWTP siting, and biosolids management. Each of these topics were discussed and reviewed in further detail in relation to the following areas: St. Johns River TMDL; St. Johns River Water Management District ( SJRWMD ) Regional Review and Mittauer & Associates, Inc. Project No Page ES-6

10 City s Consumptive Use Permit ( CUP ); Water Conservation; Reclaimed Water Use; Effluent Disposal Restrictions; Regional Interconnects; and Biosolids Management. Based on current TMDL restrictions, the City s maximum river outfall capacity is anticipated to be 1.87 MGD (AADF) based on advanced wastewater treatment capabilities providing a reliable TN effluent concentration of 3 mg/l. Section V. Projected Wastewater Demands Utilizing the population projections developed in Section III, wastewater demand projections were reviewed utilizing the following metrics: Low-Demand Projection 190 gpd/eru Medium-Demand Projection 240 gpd/eru High-Demand Projection 300 gpd/eru (City Ordinance) Reviewing the City s Build-Out Study, Reynolds FLUM Amendment projections, and other data, the City s Service Area Wastewater Build-Out Demand projection is summarized in Table ES-2. TABLE ES-2 SUMMARY OF SERVICE AREA WASTEWATER FLOW PROJECTIONS Area Exist. WW Flow (gpd) Growth Potential (gpd) Build-Out Demand (gpd) a North-Upper Service Area 43, , ,200 a North-Magnolia Service Area 96, , ,200 a North-Core Service Area 361, , ,400 Total North Service Area 500,000 1,024,800 1,524,800 Total South Service Area 212,000 1,827,000 2,039,000 a: Anticipated split of flows based on approximate ERU counts per sub-area. Total - 3,563,800 Mittauer & Associates, Inc. Project No Page ES-7

11 The Planning Period defined within the Plan was through Using the population growth projection summarized in Section III, the North Service Area projections are summarized in Table ES-3. TABLE ES THROUGH 2040 NORTH SERVICE AREA WASTEWATER PROJECTIONS Year M edium Growth Population (capita ERUs) Low-Demand WW Projection (gpd AADF) M edium-demand WW Projection (gpd AADF) High-Demand WW Projection (gpd AADF) ,500 2, , , , ,130 2, , , , ,720 3, , , , ,260 3, , , , ,740 3, , ,800 1,056, ,170 3, , ,400 1,113,000 The South Service Area projections are summarized in Table ES-4. TABLE ES THROUGH 2040 SOUTH SERVICE AREA WASTEWATER PROJECTIONS Year M edium Growth Population (capita ERUs) Low-Demand WW Projection (gpd AADF) M edium-demand WW Projection (gpd AADF) High-Demand WW Projection (gpd AADF) , , , , , , , , , , , , , , , , , , , , , , , ,500 As discussed within the Plan, the South WWTP current flows are averaging between 200,000 to 250,000 gpd (AADF), which exceeds the population based projections. This is based on infiltration/inflow and industrial demands. Mittauer & Associates, Inc. Project No Page ES-8

12 The total service area projection is provided in Table ES-5. The flow projection was based on a combined review of the City s population projections, per capita demands, historical wastewater flows, etc. that are discussed and reviewed within Section V. TABLE ES THROUGH 2040 TOTAL SERVICE AREA WASTEWATER PROJECTIONS Year M edium Growth Population (capita ERUs) M edium-demand WW Projection (gpd-aadf) ,900 3, , ,690 3, , ,430 3, , ,110 4, , ,710 4,420 1,050, ,250 4,655 1,130,000 Reclaimed water demands were reviewed based on current Magnolia Point irrigation characteristics as well as typical planning values. Based on this review, it is anticipated each reclaimed water Equivalent Residential Unit ( ERU ) connection would have an irrigation system with an instantaneous demand of approximately 10 to 15 gpm (10 gpm will be used for projections) and average day demand of approximately 500 gpd (AADF). The City should anticipate peak hourly flows that are 6 to 12 times the average daily demands. Section VI. Wastewater Infrastructure Expansion Analysis Based on the projected wastewater demands within the Service Area and the anticipated time horizon of when those demands may influence the system, a review of the City s future expansion needs was completed with consideration of the City s TMDL compliance requirements. The analysis included a review of the following items: Wastewater Treatment Objectives; Wastewater Treatment Technology; Future Infrastructure Expansion Scenarios & Estimated Costs; and Reclaimed Water Service. Mittauer & Associates, Inc. Project No Page ES-9

13 Due to the river restrictions and potential for future regulations that will require enhanced nutrient removal within reclaimed water, all future expansion alternatives included advanced wastewater treatment ( AWWT ) components with public-access reclaimed water treatment capabilities. AWWT is defined as a treatment system that can produce wastewater effluent having: Biochemical Oxygen Demand (CBOD 5) 5 mg/l; Total Suspended Solids (TSS) 5 mg/l; Total Nitrogen (TN) 3 mg/l; and Total Phosphorus (TP) 1 mg/l. Broadly, the three (3) expansion/improvement alternatives considered for the City included: Expansion alternatives associated with existing WWTP sites; A new regional facility capable of treating the City s entire Service Area; or Regional interconnect(s) with Clay County Utility Authority (CCUA). In total, five (5) alternatives were reviewed which are summarized as follows: Alternative No. 1 Existing Facility Expansion Summary In order to develop baseline expansion costs to compare against other alternatives, options were reviewed to modify and expand each of the City s existing WWTPs. Infrastructure needs were evaluated to expand the HRWWTP to meet the North Service Area build-out demand of 1.5 MGD AADF and South Service Area build-out demand of 2.0 MGD AADF. Both WWTPs would meet Advanced Wastewater Treatment ( AWWT ) requirements after completion. Alternative No. 2 North Service Area Reuse Expansion Summary This alternative included expansion of the North Service Area reclaimed water delivery system to maximize service to the Magnolia Point development (i.e., residential and golf course) and/or expansion into other development areas within the North Service Area. Alternative No. 3 Regional Expansion at New Site Summary This scenario reviewed the needs to decommission the HRWWTP and SWWTP and develop a new regional AWWTP. The City s existing transmission system would be modified to divert all flows to a new regional site developed to meet the City s Build-Out flow of 3.50 to 3.75 MGD AADF. The regional facility was first reviewed for potential siting options in the South Service Area, and then the North Service Area. Detailed siting options were reviewed for over 15 large parcels relative to suitability for a regional AWWTP and associated near-term effluent disposal options. Development of this option included modification to the City s existing transmission Mittauer & Associates, Inc. Project No Page ES-10

14 system including but not limited to: (1) new master pump stations at the HRWWTP and SWWTP; (2) re-routing existing force mains to the new Regional AWWTP; and (3) existing pump station upgrades. Effluent disposal options include consideration of near-term and long-term options. In the near-term, restricted-access alternatives are required since the City does not have any existing reuse customers outside of the Magnolia Point golf course. In the long-term, effluent disposal is anticipated to be addressed via public-access reclaimed water delivery systems within new developments. Alternative No. 4 CCUA Regional Interconnect Summary Within this alternative, options were reviewed to develop bulk service reuse mains to deliver public-access reclaimed water to CCUA for subsequent service to their customers. Alternative No. 5 Regional Consolidation at HRWWTP Summary As a result of the analysis that was completed for Alternatives No. 1 through No. 4, it was determined that a regional consolidation option at the City s HRWWTP should be reviewed. This was determined as a prudent option since the City already had a large reclaimed water user being served from the HRWWTP, and the City has existing infrastructure opportunities (i.e., pump stations and force mains) that could be leveraged in an efficient manner to reduce the regional consolidation capital needs. As part of this process, the SWWTP would be decommissioned, but the permitted connection would remain in case the site was needed in the future for treatment and/or other wastewater purposes (i.e., reclaimed water storage and pumping station to Reynolds and/or other development in the South Service Area). The City s existing transmission system would be modified to divert all flows to the HRWWTP, and the HRWWTP treatment system design would include capabilities to meet the City s Build-Out flow of 3.5 MGD AADF. Development of this option includes modification to the City s existing transmission system including, but not limited to: (1) modifications to the City s existing Pump Station No. 2 and No. 4 to meet Planning Period flows; (2) extension of new force main from Pump Station No. 2 to the Harbor Road WWTP; and (3) modification and expansion of the HRWWTP to meet advanced wastewater treatment standards. With consolidation and construction of an advanced wastewater treatment plant, the City s near-term pressure to expand reclaimed water systems would be mitigated. However, policy considerations may dictate a desire to move away from a river outfall in which case one of the reclaimed water expansion alternatives defined in Alternative No. 2 could be utilized. Mittauer & Associates, Inc. Project No Page ES-11

15 Within the Plan, a present-worth ( PW ) value is calculated for each alternative and added to the comparative operation and maintenance ( O&M ) costs. This was done to provide an apples-to-apples comparison between each alternative. The PW value was calculated using a 30-year period with a 3% interest rate to create an annualized value that could be added to each alternative s O&M costs. The O&M costs are based on each alternative running at capacity and are not intended to represent the overall utility needs. They are only intended to define costs particular to each alternative on a comparative basis. Once the PW plus O&M costs were calculated for each alternative, a normalized value was created by dividing these costs over each alternative s treatment capacity. This was done to provide a cost-benefit value that could be compared against each alternative. The resulting conceptual opinion of construction costs and associated present-worth costs for each alternative are summarized in Table ES-6. Alternative Description Existing Facility Expansion 1 a. HRW W TP AW W T Modification b. SW W TP AW W T Modification North Service Area Reuse Expansion a. Mag Pt Reuse Expan. Alt. No. 1 2 b. Mag Pt Reuse Expan. Alt. No. 2 c. Mag Pt Reuse Expan. Alt. No. 3 d. North SA Expan. Alt. No. 1 TABLE ES-6 SUMMARY OF PRELIMINARY COST ESTIMATES FOR EACH OPTION Phasing Capacity (AADF) a MGD b MGD a MGD b MGD c MGD d MGD Present-Worth Summary a. $1,390,000 PW ($14.0 M Const. + $0.68 M O&M) b. $1,280,000 PW ($16.5 M Const. + $0.44 M O&M) a. $443,000 PW ($7.9 M Const. + $40 k O&M) b. $345,000 PW ($6.1 M Const. + $35 k O&M) c. $38,100 PW ($600 k Const. + $7.5 k O&M) d. $303,000 PW ($5.3 M Const. + $33 k O&M) 3 Regional Expansion at New Site 1.25 MGD $2,250,000 PW ($30.5 M Const. + $0.69 M O&M) 4 CCUA Regional Interconnect N/A N/A 5 Regional Consolidation at HRW W TP 1.25 MGD $1,400,000 PW ($17.1 M Const. + $0.53 M O&M) A cost-benefit evaluation of each alternative is summarized as follows: Alternative No. 1 = $1.19/gpd ($2,670,000 PW/2.25 MGD) [Effluent disposal expansion not included. Mag Pt Golf Course Reuse and River Outfalls are maintained] Mittauer & Associates, Inc. Project No Page ES-12

16 Alternative No. 3 = $1.80/gpd ($2,250,000 PW/1.25 MGD) [Onsite 1.0 MGD wetland capacity and Mag Pt Golf Course Reuse Included] Alternative No. 5 = $1.12/gpd ($1,400,000 PW/1.25 MGD) [Effluent disposal expansion not included. Mag Pt Golf Course Reuse and River Outfalls included] While Alternative No. 1 has a relatively close PW/treatment capacity value when compared against Alternative No. 5, the near-term capital needs are almost 1.8 times greater ($30.5 million versus $17.1 million). In addition, the subsequent expansion costs at the SWWTP site would be more costly in comparison to the Harbor Road WWTP expansion due to the support piling requirements. It is anticipated that expansion to the Alternative No. 5 treatment system to 2.50 MGD (AADF) would cost approximately $6 to $8 million, which would still result in a total capital cost less than $25 million versus a $30 million total for Alternative 1. As a result of the near-term and long-term needs and costs, Alternative No. 5 was selected as the recommended alternative. In sum, Alternative No. 5 is selected due to the following benefits: Cost effective solution in the near-term and long-term to address advanced wastewater treatment requirements in comparison to alternatives reviewed herein; Provides flexibility in available treatment capacity to address growth that could exceed projections reviewed within the Plan (i.e., South Service Area growth resulting from First Coast Expressway and/or Reynolds Redevelopment); Consolidates wastewater treatment to one (1) facility, thus reducing operational redundancies and inefficiencies; Addresses near-term issues related to toxicity concerns at the South WWTP; Provides a reclaimed water supply base that can be leveraged into near-term reuse expansion within Magnolia Point or other areas within the North Service Area; thus, decreasing potable water demands, decreasing water withdrawals Mittauer & Associates, Inc. Project No Page ES-13

17 from the aquifer, and decreasing wastewater effluent flows to the St. Johns River; Moves wastewater treatment systems away from wildlife attraction buffer areas adjacent to the Reynolds airfield as defined by the Federal Aviation Administration (FAA); Maximizes and leverages the City s existing infrastructure by utilizing existing Pump Stations No. 2 and No. 4 to address near-term and Planning Period demands; Eliminates the need for new land acquisition and costly collection system modifications; and Subsequent expansion of the treatment system will be cost effective in comparison to options related to expansion at the existing South WWTP site. Mittauer & Associates, Inc. Project No Page ES-14

18 TABLE OF CONTENTS I. INTRODUCTION A. OBJECTIVE B. GENERAL APPROACH II. EXISTING WASTEWATER AND REUSE SYSTEM A. TOTAL MAXIMUM DAILY LOAD (TMDL) B. TREATMENT FACILITIES Harbor Road WWTP a. Treatment Capacity b. Treatment Process Overview ) Hydraulic Capacity ) Biological Treatment Efficiency ) Mechanical Reliability ) Facility Needs c. Effluent Disposal Capacity ) Current FDEP and TMDL Limitations ) St. Johns River Outfall Capacity (Hydraulic) ) Magnolia Point Capacity d. Residuals Disposal Capacity South WWTP a. Treatment Capacity b. Treatment Process Overview ) Hydraulic Capacity ) Biological Treatment Efficiency ) Mechanical Reliability c. Effluent Disposal Capacity d. Residuals Disposal Capacity C. COLLECTION AND TRANSMISSION SYSTEMS North Service Area a. Transmission System ) Existing Capacity Per Pump Station ) Hydraulic Capacity of P.S. Nos. 3 and No ) Hydraulic Capacity of P.S. No. 4 Collection System ) General Operation and Maintenance Mittauer & Associates, Inc. Project No Page i

19 2. South Service Area a. Gravity System b. Transmission System ) Overall Characterization of the South Service Area ) Hydraulic Capacity of P.S. Nos. 2, 19, and ) Hydraulic Capacity of P.S. Nos. 2 and 19 Collection System ) General Operation and Maintenance D. ONSITE SEWAGE DISPOSAL SYSTEMS E. RECLAIMED WATER DISTRIBUTION AND WET-WEATHER OUTFALLS III. GROWTH REVIEW AND PROJECTIONS A. OVERVIEW B. REYNOLDS FLUM AMENDMENT C. CLAY COUNTY 2025 COMPREHENSIVE PLAN Future Land Use Element Community Facilities Element Intergovernmental Coordination Element Capital Improvements Element Transportation Element Economic Development Element D. GREEN COVE SPRINGS 2025 COMPREHENSIVE PLAN Future Land Use Element Sanitary Sewer, Solid Waste, Drainage, Potable Water, and Aquifer Recharge Element E. FDOT OUTER BELTWAY F. GREEN COVE SPRINGS 2040 URBAN BOUNDARY G. GREEN COVE SPRINGS BUILD-OUT STUDY H. BEBR POPULATION PROJECTIONS IV. REGULATORY AND POLICY CONSIDERATIONS A. OVERVIEW B. ST. JOHNS RIVER TMDL C. NUMERIC NUTRIENT CRITERIA D. SJRWMD REGIONAL STUDIES AND CITY S CUP / WATER CONSERVATION Regional Studies Mittauer & Associates, Inc. Project No Page ii

20 2. City s Consumptive Use Permit (CUP) / Water Conservation E. RECLAIMED WATER USE CONSIDERATIONS Reclaimed Water Availability Reclaimed Water Treatment Requirements F. BIOSOLIDS MANAGEMENT G. SUMMARY V. PROJECTED WASTEWATER DEMANDS A. OVERVIEW B. BUILD-OUT STUDY: MAXIMUM WASTEWATER DEMAND / RECLAIMED WATER SUPPLY C. WASTEWATER DEMANDS THROUGH THE PLANNING PERIOD North Service Area / HRWWTP Demands South Service Area / SWWTP Demands D. PLANNING PERIOD FLOW SUMMARY E. RECLAIMED WATER DEMANDS VI. WASTEWATER INFRASTRUCTURE EXPANSION ANALYSIS A. OVERVIEW B. WASTEWATER TREATMENT OBJECTIVES C. CURRENT OPERATING BUDGET D. WASTEWATER TREATMENT TECHNOLOGY Oxidation Ditch Process Stage BNR Process Integrated Fixed Film Activated Sludge Process (IFAS) / Moving Bed Biological Reactor (MBBR) Phosphorus Removal Approach E. FUTURE INFRASTRUCTURE EXPANSION ANALYSIS Alternative No. 1 Summary Alternative No. 2 Summary a. Mag Pt Reuse Expansion Alt. No b. Mag Pt Reuse Expansion Alt. No c. Mag Pt Reuse Expansion Alt. No d. North Service Area Expansion Alt. No Alternative No. 3 Summary a. Restricted-Access Sprayfield Disposal b. Constructed Wetland Disposal c. Rapid Infiltration Basins d. Selected Alternative Alternative No. 4 Summary Mittauer & Associates, Inc. Project No Page iii

21 5. Alternative No. 5 Summary F. SUMMARY OF ALTERNATIVE REVIEW VII. CAPITAL IMPROVEMENT PLAN A. OVERVIEW B. IMPLEMENTATION SCHEDULE TABLES II-1 Facility Recommendations Highlighted in 2008 Plan II vs TN and TP Annual Loading Comparison II-3 HRWWTP Hydraulic Process Train Overview II Through 2014 HRWWTP Annual Average Daily Flows II Through 2013 Existing HRWWTP BNR Results II Through 2013 HRWWTP Calibration Results II-7 Projected HRWWTP Theoretical Wastewater Treatment Levels - Low Loading II-8 Projected HRWWTP Theoretical Wastewater Treatment Levels - High Loading II-9 Projected HRWWTP Recommended Wastewater Treatment Levels - Low Loading II-10 Projected HRWWTP Recommended Wastewater Treatment Levels - High Loading II-11 HRWWTP Class III Reliability Review II-12 HRWWTP Effluent Limitations II Through 2013 HRWWTP River and Reuse Monthly Average Daily Flows II-14 SWTTP Hydraulic Process Train Overview II Through 2013 SWWTP Monthly Average Daily Flows II Through 2013 Existing SWWTP BNR Results II Through 2013 SWWTP Calibration Results II-18 Projected SWWTP Theoretical Wastewater Treatment Levels - Low Loading II-19 Projected SWWTP Theoretical Wastewater Treatment Levels - High Loading II-20 Projected SWWTP Recommended Wastewater Treatment Levels - Low Loading II-21 Projected SWWTP Recommended Wastewater Treatment Levels - High Loading II-22 SWWTP Class III Reliability Review II-23 SWWTP Effluent Limitations Mittauer & Associates, Inc. Project No Page iv

22 II-24 Wastewater Collection & Transmission Basin Summary II-25 North Service Area P.S. Capacity Overview II-26 Pump Station Nos. 3 & 4 Existing Wetwell Review II-27 South Service Area P.S. Capacity Overview II-28 Pump Station Nos. 2 & 19 Existing Wetwell Review II-29 Comparison of Central Treatment vs. OSTDS Effluent Concentrations III-1 Summary of Service Area Development Potential III-2 Reynolds Development Potential Comparison III Through 2040 Clay County Population Projections III Through 2040 North Service Area Population Projections III Through 2040 South Service Area Population Projections III Through 2040 Dwelling Unit Projections V-1 Summary of Anticipated Wastewater Build-Out Demand V-2 Comparison of Reynold s Build-Out Demand Potentials V-3 North Service Area Development Potential V-4 South Service Area Development Potential V-5 Summary of Service Area Wastewater Flow Projections V Through 2040 North Service Area Wastewater Projections V Through 2014 HRWWTP Flows With Annual Rainfall V HRWWTP Flow Projections V Through 2040 South Service Area Wastewater Projections V Through 2013 SWWTP Flows With Annual Rainfall V SWWTP Flow Projections V Service Area Flow Projections V Through 2040 Summary of Service Area Wastewater Projections V Through 2014 HRWWTP Reuse & River Average Flows (AADF) VI-1 Fiscal Year 2009 Through 2013 Wastewater Expenditures VI-2 SWWTP and HRWWTP River Outfall Capacity Limits VI-3 HRWWTP AWWT Expansion Alternative - IFAS MBBR Improvements / Advantages & Disadvantages VI-4 SWWTP AWWT Expansion Alternative - Oxidation Ditch Improvements / Advantages & Disadvantages VI-5 Magnolia Point Reuse Expansion Alternative No. 1 / Advantages & Disadvantages VI-6 Magnolia Point Reuse Expansion Alternative No. 2 / Advantages & Disadvantages Mittauer & Associates, Inc. Project No Page v

23 VI-7 Magnolia Point Reuse Expansion Alternative No. 3 / Advantages & Disadvantages VI-8 North Service Area Reuse Expansion Alternative No. 4 / Advantages & Disadvantages VI-9 Regional Expansion Alternative - Oxidation Ditch Improvements / Advantages & Disadvantages VI-10 Regional Consolidation at HRWWTP / Advantages & Disadvantages VI-11 Summary of Preliminary Cost Estimates for Each Option VII-1 Capital Improvement Schedule FIGURES II-1 Overall Service Area Map II-2 HRWWTP - Existing Site Plan II-3 HRWWTP Flow Schematic II-4 HRWWTP Outfall Locations II-5 MLE Process Schematic II-6 Bardenpho Process Schematic II-7 Harbor Road BTU 5-Stage Treatment Layout II-8 January 2010 Through December 2013 HRWWTP River and Reuse Monthly Average Daily Flow II-9 SWWTP - Existing Site Plan II-10 SWWTP Flow Schematic II-11(A) North - Upper Service Area Map/Collection System II-11(B) North - Upper Service Area Map/Collection System II-12 North - Magnolia Service Area Map/Collection System II-13(A) North - Core Service Area Map/Collection System II-13(B) North - Core Service Area Map/Collection System II-14 North Service Area P.S. Flow Schematic II-15 P.S. No. 4 Gravity Sewer FM Discharge Locations II-16(A) South Service Area Map/Collection System II-16(B) South Service Area Map/Collection System II-17 South Service Area P.S. Flow Schematic II-18 Existing OSTDS Areas III Urban Services Boundary III-2 Reynolds Parcel Limits III-3 First Coast Outer Beltway Mittauer & Associates, Inc. Project No Page vi

24 V-1 HRWWTP Historical Annual Average Daily Flow Trend V-2 HRWWTP Annualized Regression Trend Projected to V-3 HRWWTP Projected Flow Variation (Population Based vs. Trendline) V-4 June 1, 2012 through September 30, 2012 SWWTP Influent Daily Flow and Daily Rainfall V-5 June 1, 2012 through September 30, 2012 SWWTP Excessive I/I Review V-6 SWWTP Historical Annual Average Daily Flow Trend V-7 SWWTP Projected Population-Based Flow V-8 Flow Projection Summary VI-1 Oxidation Ditch Process Flow Schematic VI-2 5-Stage Bardenpho Process Schematic VI-3 Sample Biofilm Carrier VI-4 IFAS and MBBR Process Schematic VI-5 North and South Service Area Demand Projection Summary With Existing BNR Treatment Capabilities VI-6(A) HRWWTP - Existing Facility Expansion Alternative VI-6(B) HRWWTP - Existing Facility Expansion Alternative VI-7 HRWWTP BTU No. 1 IFAS MBBR Modifications VI-8 SWWTP - Existing Facility Expansion Alternative VI-9 Wildlife Attraction Buffers VI-10 Conceptual Magnolia Point Reuse Piping VI-10A HRWWTP - Conceptual Public Access Reuse System Expansion VI-11 Conceptual Remote Residential Reuse Pump Station VI-12 Conceptual Magnolia Point Bulk Reuse Expansion VI-13 Magnolia Point Lake Augmentation Candidates VI-14 North Service Area Reuse Main Extension VI-15 Regional WWTP & Sprayfield Disposal Candidate Sites (Parcel Map) VI-16 Regional WWTP & Constructed Wetland Disposal Candidate Sites VI-17 South Service Area Regional WWTP with Onsite Disposal VI-18 Oxidation Ditch Site Plan at Regional Site VI-19 Future CCUA Reuse Water Treatment Plant Locations VI-20 Alternative No. 4 Regional AWWTP at Harbor Road VI-21 Alternative No. 4 Collection System Improvements Mittauer & Associates, Inc. Project No Page vii

25 ATTACHMENTS A Green Cove Springs - Aggregate Permit for Total Nitrogen and Total Phosphorus (February 20, 2014) B Green Cove Springs - Administrative Order 116 NE - Final Quarterly Progress Report (June 20, 2013) C Harbor Road WWTP FDEP Operating Permit (February 21, 2014) D South WWTP FDEP Operating Permit (February 20, 2014) E Existing Wastewater Collection and Transmission System Data F CCUA Service Area Maps G Fleet & Associates Architects/Planners, Inc. - Green Cove Springs Utility Service Area Build-out Study (May 26, 2006) H Basin Management Action Plan (BMAP) for the Implementation of Total Maximum Daily Loads (TMDL) for Nutrients Adopted by the FDEP for the Lower St. Johns River Basin Main Stem (October 2008) I 2013 Five-Year Assessment Report for the Lower St. Johns River Main Stem BMAP (February 2014) J St. Johns River Water Management District (SJRWMD) Consumptive Use Permit (CUP) and Technical Staff Report (TSR) (January 10, 2012) K Green Cove Springs Water Conservation Plan (Public Supply) (September 28, 2011) L Reynolds Park Future Land Use Map (FLUM) Amendment - Maximum Impact Analysis for Infrastructure (May 2009) M Fiscal Year 2009 through 2013 Wastewater Fund Expenditures and Revenues N Alternative No. 1 Analysis Details O Alternative No. 2 Analysis Details P Alternative No. 3 Analysis Details Q Alternative No. 5 Analysis Details Mittauer & Associates, Inc. Project No Page viii

26 I. INTRODUCTION A. OBJECTIVE The City of Green Cove Springs ( City ) authorized the preparation of this report to: 1. Update the previous completed in 2008 ( 2008 Plan ); 2. Address a number of environmental and growth related issues that developed since completion of the 2008 Plan that affected the City s wastewater and reuse infrastructure; and 3. Provide direction related to the City s expansion needs to serve the City s residents while also meeting the environmental stewardship requirements in an efficient and economical manner. Since completion of the 2008 Plan, the City addressed an economic recession, wastewater treatment operational adjustments to address Total Maximum Daily Loading ( TMDL ) regulations/nutrient loading restrictions to the St. Johns River, a Future Land Use Amendment related to a 2,000+ acre parcel of land (i.e., Reynolds Parcel ) that will be a major factor in the City s long-term growth, and initial future wastewater treatment plant siting considerations. These activities have sharpened the City s focus and provided additional clarity on its needs. Accordingly, the City desires to appropriately plan for its infrastructure needs in order to identify the most logical and practical means of accommodating the growth and demands placed on the City s wastewater and reclaimed water systems. This translates into developing an implementable capital improvement plan based on projected demands that will take into account the following: 1. Wastewater Service Areas; 2. The Planning Period which will be through the Year 2040; 3. Wastewater projections for the Service Area; 4. Wastewater treatment alternatives and requirements through the Planning Period; Mittauer & Associates, Inc. Project No Page 1

27 5. Wastewater disposal and reclaimed water delivery alternatives through the Planning Period; 6. The capabilities and capacities of the existing infrastructure; 7. Regional options related to infrastructure connections; and 8. The influence of current and pending regulatory requirements for the design, permitting, construction, operation and maintenance of infrastructure improvements. The objective of this 2015 ( Plan ) is to develop a capital improvement approach that will accommodate the above elements. The Plan will identify proposed projects, an implementation schedule, and review necessary capital needs to implement the proposed alternative(s). B. GENERAL APPROACH This Plan will utilize a number of documents that have been previously published and reviewed by the City including, but not limited to: Comprehensive Plan 2. Reynolds FLUM Amendment materials 3. FDOT Outer Beltway Plans Magnolia Point Executive Committee Study 6. Utility & Service Area Build-out Study (Fleet & Assoc. 2006) These documents will be referenced and applicable portions included herein as Attachments. In concert, these materials, along with other traditional planning references, will be utilized to determine wastewater flows and develop avenues to utilize and maximize use of the existing wastewater collection, transmission, treatment ( Wastewater System ) and reclaimed water facilities ( Reuse System ) which are reviewed and discussed in Section II. Section III provides an aggregate growth review from various sources to be utilized in developing future wastewater demands. Section IV reviews the regulatory implications on the future design and operation of the Wastewater System while Section V will expand upon the previous sections and determine timelines on proposed growth with associated wastewater Mittauer & Associates, Inc. Project No Page 2

28 and reuse demand projections. Implications of the proposed demands on future Wastewater System expansion is reviewed in Section VI. Section VI includes budgetary cost estimates for designing, permitting, and constructing various Wastewater System Alternatives along with a present-worth analysis of the alternatives. The selected alternative is further addressed with an implementation schedule and presented as a capital improvement plan in Section VII. Mittauer & Associates, Inc. Project No Page 3

29 II. EXISTING WASTEWATER AND REUSE SYSTEM The City of Green Cove Springs is located on the St. Johns River in Clay County, Florida, and lies at the crossroads of State Road 16 and U.S. Highway 17, approximately 30 miles south of the City of Jacksonville, Florida. The U.S Census listed the City s population at 5,378 persons, the 2010 Census counted 6,908 persons, and the University of Florida Bureau of Economic and Business Research s ( BEBR ) Year 2012 estimate is 6,977 persons. From 2000 to 2010, the population growth was approximately 2.8% per year. In the last few years, growth has been flat to approximately 0.5% per year. Electric, water, and wastewater services are provided by the City and the electric service area varies from the water and sewer service area limits. The electrical and water system are not reviewed as part of this report, but the Build-Out Study and previous reports completed by Mittauer & Associates, Inc. (e.g., 2005 Potable Water Capacity Analysis Report with general update in October 2007, January 2007 Water Facilities Plan, etc.) include more detailed discussions on future demands for those utilities. The wastewater service area ( Service Area ) encompasses approximately 6.77 square miles. The City limits and Service Area boundaries differ from one another, and the respective limits are shown in Figure II-1. The sub-areas within the North Service Area and the overall South Service Area boundaries are presented in this figure; however, a more in-depth discussion for these sub-areas is provided in Section II.C. The City s owns and operates a wastewater collection system that contains miles of gravity sewer piping, force main piping, manholes, service laterals, and pump stations. The majority of the City is served by central sewer that pumps the largely domestic wastewater to one (1) of the City s two (2) wastewater treatment plants ( WWTP ). The Harbor Road WWTP ( HRWWTP ) generally serves the core city and northern reaches of the City, while the South WWTP ( SWWTP ) serves a southerly portion of the core city, as well as commercial and industrial customers located in the southern end of the City s service area. Both WWTPs have capabilities to produce public-access reclaimed water ( reuse ), but only the HRWWTP has a bulk-use customer located at the Magnolia Point Golf Course. Both WWTPs have permitted outfalls within the St. Johns River that are currently restricted based on nutrient loading regulated by the TMDL enacted by Florida Department of Environmental Protection ( FDEP ) in The City s existing wastewater and reuse systems are more particularly reviewed herein. Mittauer & Associates, Inc. Project No Page 4

30 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-1 Overall Service Area Map.dwg, 2/25/ :23:19 AM LS1/LS2 LS1/LS2 LS1/LS2 LS1/LS2 LS1/LS2 LS1/LS2 LS1/LS2 LS1/LS2 > FM PLE > FM PLE LS1/LS2 > FM PLE LS3/LS4 LS3/LS4 LS3/LS4 > FM PLE LS6/LS4 LS6/LS4 LS6/LS4 LS2/LS3 LS2/LS3 LS2/LS3 LS6/LS4 LS5/LS4 LS3/LS4 LS3/LS4 LS3/LS4 LS5/LS4 LS6/LS4 LS3/LS4 LS3/LS4 LS27/LS4 LS15/LS14 CREEK LS15/LS14 LS15/LS14 TELLGRASS CT. LS18/LS16 LS1/LS2 LS1/LS2 LS15/LS16 LS16/LS17 LS1/LS2 LS15/LS14 LS15/LS14 LS15/LS14 LS16/LS17 LS13/LS14 LS13/LS14 LS13/LS14 LS13/LS14 LS13/LS14 LS13/LS14 LS13/LS14 LS15/LS14 LS13/LS14 LS13/LS14 LS13/LS14 LS15/LS14 LS13/LS14 LS13/LS14 LS2/LS4 LS5/LS27 LS5/LS27 LS2/LS4 LS2/LS4 LS2/LS4 LS27/LS4 LS27/LS4 LS27/LS4 LS3/LS4 LS3/LS4

31 The 2008 Plan and/or subsequent review documents have identified various needs and/or recommendations related to various facility improvements. These items are also redressed herein but are summarized in Table II-1. TABLE II-1 FACILITY RECOMMENDATIONS HIGHLIGHTED IN 2008 PLAN Facility Improvement Comments HRWWTP Construct by-pass manual bar rack to meet Class III reliability requirem ents. Construct redundant clarifier to meet Class III reliability requirem ents. Replacem ent of aeration piping. Modification of filter overflow piping and filter by-pass piping. Construct waste activated sludge (W AS) and Digester No. 2 piping m odification. Aeration delivery m odifications to increase biological nutrient rem oval capabilities and consider internal recycle pum ping. Construct Biosolids Dewatering Im provem ents. Investigate the discharge outfall for the St. Johns River since its installation was constructed over 20 years ago and may need some maintenance or m odifications depending on silt levels within this area of the river. Pending funding availability and long-term W W TP needs. Pending funding availability and long-term W W TP needs. Most problem atic areas have been replaced. Completed. Completed. Aeration delivery m odifications com pleted, and recycle pumping pending funding and ultim ate W W TP needs. City is currently utilizing a contract arrangem ent to dewater biosolids, which allows the existing drying beds to be taken out of service. Longterm solution still needed. Services to be included in future capital improvement budget. SWWTP All corrosion-related impacts to the W W TP influent components should be repaired as soon as possible. Construct new fine screen to replace existing bar rack that allows rags and other debris to pass into the W W TP. Significant areas have been repaired and/or replaced. Existing bar rack would remain as a backup. Improvements pending funding availability. Mittauer & Associates, Inc. Project No Page 6

32 TABLE II-1 (cont.) FACILITY RECOMMENDATIONS HIGHLIGHTED IN 2008 PLAN Facility Improvement Comments SWWTP Aeration delivery m odifications to increase biological nutrient rem oval capabilities. Install autom ated blower operation based on DO and/or ORP levels would increase effluent reliability and consistency. Convert the RAS pumping from an airlift to a centrifugal pum p system would also enhance treatment efficiency. Include consideration of Recycle Pumping system. Electrical surges im pact the Filter s program mable logic controller (PLC) from time to time. Investigate the discharge outfall for the St. Johns River since its installation was constructed over 20 years ago and may need some maintenance or m odifications depending on silt levels within this area of the river. Completed. Current screening deficiencies affecting ability to install these sensitive m onitoring components Improvements pending funding availability. The City has investigated the cause of the surge and related issues, but has not been to able to isolate the cause. The City continues to monitor the situation and repair the filter controls as needed Services to be included in future capital improvement budget. COLLECTION AND TRANSM ISSION SYSTEM Sewer lining and/or m anhole rehabilitation to reduce Infiltration and Inflow City has completed some sewer lining improvements. Im provem ents within South Service Area are delayed due to unknown timing related to Reynolds redevelopm ent. City m ay consider system evaluation (i.e. insitu study) to determine most problematic areas and further define capital im provem ent needs. A. TOTAL MAXIMUM DAILY LOAD (TMDL) In March 2007, FDEP, along with the various public and private stakeholders, began to finalize the nutrient limits for various reaches of the St. Johns River. Based on the modeling that was completed, FDEP established the Lower St. Johns River Mittauer & Associates, Inc. Project No Page 7

33 Basin Management Action Plan ( BMAP ) that was adopted on October 10, As a result of the BMAP, the City was allotted an annual nutrient allocation from the City s two (2) wastewater treatment plants of: 46.7 pounds per day ( ppd ) or 17,055.5 pounds per year ( ppy ) for Total Nitrogen ( TN ); and 11.6 pounds per day ( ppd ) or 4,244.2 pounds per year ( ppy ) for Total Phosphorus ( TP ). In March 2009, FDEP issued Administrative Order ( AO ) 116NE that required the City to meet their TMDL requirements by October 1, An aggregate permit was also issued to track/regulate the City s nutrient loading to the river. A copy of the City s current aggregate permit is provided as Attachment A. In September 2011, the City of Green Cove Springs ( City ) submitted a minor permit modification request to redefine portions of the City s AO 116NE. The City had completed various operational modifications to the SWWTP and HRWWTP that resulted in significant reductions to their TN and TP loadings. The performance of each WWTP is discussed and reviewed further herein. However, since the operational modifications were implemented, the City greatly reduced their TN and TP loading when comparing against the loading that was occurring prior to the operational changes. On March 19, 2012, FDEP issued the revised AO approving the requested modifications limiting the capital improvement needs. The Revised AO had the following two (2) major requirements: Quarterly reporting of the City s ongoing treatment results/efficacy including updates to the rolling 12-month St. Johns River TN and TP loading; and Final reporting related to reasonable assurances of the City s capabilities to meet the AO TN and TP loading requirements if both the SWWTP and HRWWP were operating at 100% capacity. The Revised AO did not change the permit limits for annual TN and TP loading. Pursuant to the Revised AO, the City s final quarterly summary was submitted to FDEP on June 21, 2013 and is enclosed herein as Attachment B. The final quarterly summary highlighted the 12-month loading characteristics from May 2012 Mittauer & Associates, Inc. Project No Page 8

34 through April 2013 as follows: HRWWTP Delivered: 4,781 lb/yr of TN (28.0% of City s Total TN load) 811 lb/yr of TP (19.1% of City s Total TP load) SWWTP Delivered: 2,548 lb/yr of TN (14.9% of City s Total TN load) 2,074 lb/yr of TP (48.9% of City s Total TP load) City s Total Load: 7,329 lb/yr of TN (43.0% of TMDL Maximum) 2,885 lb/yr of TP (68.0% of TMDL Maximum) In comparison, the nutrient loading levels from the first 12-month reporting period (i.e., May 2009 through April 2010, pre-operational changes) compared to the last reporting period (i.e., May 2012 through April 2013, post-operational changes) illustrate the significant, positive impact. A summary of each is provided in Table II-2. TABLE II VS TN AND TP ANNUAL LOADING COMPARISON 12-month Reporting Period TN Loading (lb/yr) TP Loading (lb/yr) May 09 - April 10 30,245 7,198 May 12 - April 13 7,329 2,885 Difference 22,916 4,313 These operational changes resulted in TN and TP loading reductions of 76% (22,916 lb/yr / 30,245 lb/yr) and 60% (4,313 lb/yr / 7,198 lb/yr), respectively. Accordingly, the City did not have to complete various capital improvements that were contemplated when the AO was originally drafted and approved. As shown in Attachment B and detailed further herein, the above loading (i.e., biological nutrient removal performance) has been maintained around these levels (i.e., TN < 8,000 lb/yr and TP < 3,000 lb/yr) since October 2012 and February 2012, respectively. The TMDL restrictions are an integral boundary condition for the City to manage going forward. As growth occurs and wastewater flows increase, the City will have to manage their nutrient loading levels below these requirements. Mittauer & Associates, Inc. Project No Page 9

35 This dynamic is discussed further herein in subsequent sections of the Plan. B. TREATMENT FACILITIES The City owns and operates two (2) permitted WWTPs within the Service Area. The HRWWTP is located on the north end of the City and currently serves the majority of the community, while the SWWTP is located toward the south end of the City. Both wastewater treatment facilities are shown in Figure II Harbor Road WWTP The HRWWTP was originally designed to treat 500,000 gallons per day ( gpd ), or 0.5 million gallons per day ( MGD ), of domestic wastewater. The plant was constructed in 1971 as a Contact Stabilization Plant ( 1971 WWTP ) using activated sludge. The 1971 WWTP construction included the following components: Influent Communitor; Circular-Concrete Contact Tank; Circular-Concrete Final Clarifier; Circular-Concrete Stabilization Tank; Concrete Chlorine Contact Tank; Outfall to the St. Johns River; Circular-Concrete Aerobic Digester; and Sludge Drying Beds. The HRWWTP was expanded in 1986 to provide an additional capacity of 750,000 gpd (0.75 MGD) to bring the total WWTP capacity to 1.25 MGD. The 1986 expansion included adding an influent Structure/Splitter Box with manual bar screen and a circular-concrete Package WWTP configured in the contact stabilization process with a central clarifier as a separate hydraulic train. In addition to this separate hydraulic train, the 1971 WWTP communitor was replaced with a manual bar rack for screening. In 1996, the original 1971 WWTP was taken out of service and converted to other process units as follows: Manual Bar Rack (taken out of service); Circular-Concrete Contact Tank (occasional surge tank); Circular-Concrete Final Clarifier (occasional surge tank); Mittauer & Associates, Inc. Project No Page 10

36 Circular-Concrete Stabilization Tank (converted to another aerobic digester); Concrete Chlorine Contact Tank (currently in service); Outfall to the St. Johns River (currently in service); Circular-Concrete Aerobic Digester (currently in service); and Sludge Drying Beds (currently in service). A subsequent modification to the HRWWTP occurred in 2002 which included the following: Modification of the influent structure via installation of a mechanical fine screen and abandonment of the manual bar screen; Modifying the existing contact stabilization process to a single-stage nitrification activated-sludge system with the AccuWeb System; Installation of a filtration system with high-level disinfection capabilities; and Installation of reuse pumps and pipeline for delivery of bulk public-access reclaimed water to the Magnolia Point Golf and Country Club ( Magnolia Point ). The 2002 modification allowed the HRWWTP to treat domestic wastewater to public-access reclaimed water criteria with the main end user being Magnolia Point. The most recent modification to the HRWWTP occurred in 2005 when the chlorination technology was changed from a gas to a liquid, sodium hypochlorite feed system. A copy of the current HRWWTP operating permit is provided in Attachment C, and the current site plan for the HRWWTP is provided as Figure II-2. As a result of the TMDL nutrient removal requirements discussed in Section II.A., the City began operational changes at the HRWWTP around January 2010 to reduce TN and TP loading to the River via biological means. The HRWWTP modifications were related to modifying air delivery within the existing aeration basin to produce additional anoxic/anaerobic zones to Mittauer & Associates, Inc. Project No Page 11

37 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-2 HRWWTP Exist Site Plan.dwg, 2/25/ :39:27 AM

38 assist/enhance/create conditions for biological nutrient removal ( BNR ) of TN and TP. The HRWWTP process flow schematic is provided as Figure II-3. Since initiating these operational modifications, the City has been enhancing their efficiency through use of hand-held instruments that measure dissolved oxygen ( DO ) and oxidation-reduction potential ( ORP ) that provide two (2) key parameters/variables to manage appropriate conditions for biological TN and TP removal. At the HRWWTP, the operators have also created a detailed database of monitoring parameters to assist their efforts in managing the activated-sludge system and increasing the treatment system s efficiency. It is important to note that neither the SWWTP nor the HRWWTP were designed with BNR capabilities. Both systems were designed to meet standard secondary treatment without consideration of TN and TP levels within the effluent. The HRWWTP has two (2) main effluent disposal points. The initial effluent disposal location for the facility is located within the banks of the St. Johns River near Governor s Creek and was constructed with the 1971 WWTP improvements. The second disposal location was constructed as part of the 2002 improvements and is located at Magnolia Point. The second disposal location was permitted and constructed as part of the public-access reclaimed water improvements and is located within the Magnolia Point stormwater management system. The location of each outfall is provided as Figure II-4. The specific St. Johns River outfall location is not currently known. The City has previously attempted to locate the end of the pipe, but it was not found due to the siltation and muck within this area of the river. The location shown in Figure II-4 is based on the design drawings for the outfall. The City should attempt to locate the pipe end in the future to determine the structural integrity of the outfall in addition to the severity of siltation over the outfall. a. Treatment Capacity As discussed previously, the HRWWTP was designed and permitted to treat a total flow of 0.75 MGD on a three-month average daily flow basis ( TMADF ) which did not include any BNR capabilities. Through the operational modifications discussed further herein, it is anticipated the maximum treatment capacity of the HRWWTP will be limited to approximately 0.65 MGD if no facility improvements are made to the biological treatment unit and/or no reuse system expansion occurs. Mittauer & Associates, Inc. Project No Page 13

39 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-3 HRWWTP Flow Schematic.DWG, 2/25/ :40:13 AM

40 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-4 HRWWTP Outfall Locations.dwg, 2/25/ :46:45 AM

41 The annual average daily flow to the HRWWTP in 2013 was MGD (AADF) which is approximately 84% of the current nutrient removal capacity estimated to be 0.65 MGD (AADF). b. Treatment Process Overview The raw wastewater delivered from the pump stations within the North Service Area is first screened via a mechanical fine screen and then flows to the biological treatment units ( BTU ) for oxidation, nitrification, and denitrification. The City is also having some success in removing Total Phosphorus via biological means. Following the biological treatment, the wastewater is conveyed to a settling basin or clarifier which separates the solids (or sludge) from the clear liquid (or effluent). Most of the settled sludge is recirculated into the BTU as return activated sludge ( RAS ). A portion of the settled sludge is wasted to the digesters for further stabilization. The clarified effluent is then routed to the filter basins for further removal of suspended solids, bacteria, and viruses prior to disinfection in order to meet the FDEP requirements for public-access reuse water. The water discharged from the filter is called filtrate which then travels to the chlorine contact chamber where a disinfectant (hypochlorite) is injected into the process stream. The baffled chlorine contact chamber ( CCC ) provides the necessary contact time and mixing in accordance with FDEP requirements. Also located at the CCC is sampling equipment which continually tests the filtrate to ensure it meets public-access reuse standards. If the treated wastewater meets public-access reuse requirements and the Magnolia Point stormwater management system has storage capacity, the HRWWTP effluent is discharged to Magnolia Point for use in their irrigation system. If the effluent does not meet reuse requirements or the stormwater system is at capacity, the wastewater is dechlorinated and discharged to the St. Johns River. The HRWWTP has the following components that comprise the City s reclaimed water treatment system components: Disk Filter High-Level Disinfection Equipment Effluent Monitoring Equipment Reclaimed Water Delivery ( Reuse ) Pumps Mittauer & Associates, Inc. Project No Page 16

42 The following components of the HRWWTP current operations will be reviewed: Hydraulic Capacity; Biological Treatment Capacity; Mechanical Reliability; and Facility Needs. 1) Hydraulic Capacity Typically, a WWTP is designed with components capable of accepting a hydraulic flow between two (2) to four (4) times the average day design capacity of the facility. This is referred to as the peaking factor and is commonly used to review the WWTP s capacity to treat wastewater at peak times during the day. Wastewater systems are typically characterized as having a diurnal flow which means that there are two (2) times during the day in which flow is greater than the average for the day. These times typically coincide with morning (5 a.m. to 10 a.m.) and afternoon (4 p.m. to 9 p.m.) hours when large blocks of residents are cooking, showering, etc. Another factor which will impact peak flows into a WWTP is infiltration and inflow or I/I. I/I is created by stormwater or elevated groundwater levels which flow into the gravity wastewater collection system via cracks, holes, crushed pipes, failed gaskets, etc. Typically, older cities with dated infrastructure, such as vitrified clay pipe ( VCP ), have issues with I/I due to pipe failure which allows groundwater to enter the collection system. Thus, during rain events, the WWTP can experience large peaks due to elevated groundwater levels and stormwater runoff. Further I/I discussion is provided in Section II.B. For purposes of the HRWWTP evaluation, the WWTP components were reviewed to determine the limiting peak factor for the facility. Based on an analysis of the facility infrastructure it was determined that the HRWWTP could handle a peak hour flow of approximately 2.6 times the average daily flow. The original design capacity was 0.75 MGD, which means it should be able to handle a peak flow of up to 1.95 MGD (i.e., 2.6 x 0.75 MGD) without significantly impacting the biological treatment efficiency of the WWTP or hydraulically overloading the system. The major components within the HRWWTP treatment process train are listed within Table II-3 and include the hydraulic design capacity of each unit. Mittauer & Associates, Inc. Project No Page 17

43 The peak capacity is either based on manufacturer information or hydraulic process review. TABLE II-3 HRWWTP HYDRAULIC PROCESS TRAIN OVERVIEW Process Unit Mechanical Fine Screen Clarifier Disk Filter Chlorine Contact Chamber Reuse Pumps Peak Design Capacity, M GD 1.94 MGD 1,350 gpm (PF = 2.6) 1.95 MGD 1,350 gpm (PF = 2.6) 1.95 MGD 1,350 gpm (PF = 2.6) 2.25 MGD 1,560 gpm (PF = 3.0) b 1.87 MGD 1,300 gpm (PF = 2.5) a Comments Hydraulic overloading has not been noted during current operation when flows have been elevated. The clarifier is lim ited by peak overflow rate. Typical upper range 2 is 1,200 gal/ft -day which is met at a peak flow of 1.95 MGD. The City will also need to monitor MLSS levels to ensure solids loading rates of the clarifier are not exceeded. Pending backwashing scenarios, the peak factor m ay be less than 2.6 due to hydraulic constraint created by the filter elevation. Peak factor provided with CT equal to 40 as long as chlorine feed concentration equal to 3.0 mg/l or greater Firm capacity with one (1) pump out of service River Outfall c 1.25 MGD 870 gpm The only outfall inform ation (PF = 1.67) b currently available is the original 1971 design docum ents. Further analysis is needed to determ ine the current structural integrity of the outfall. a: Due to the river outfall, the capacity of the reuse pumps are not considered limiting on the hydraulic capacity of the HRWWTP. b: 1.25 MGD represents the FDEP permitted capacity. Based on review of the design drawings, it is anticipated this outfall can handle a peak flow of 2.78 MGD (1,930 gpm) or peaking factor of 3.7; however, the current status of the outfall needs to be investigated for confirmation. As noted in Table II-3, the HRWWTP currently has a peak flow capacity of approximately 1.95 MGD (1,350 gpm) which equates to a peaking factor of 2.6. In order to control some of the larger peak flows that the Mittauer & Associates, Inc. Project No Page 18

44 WWTP experiences, the operators have been using the surge tanks to capture a portion of the flow for subsequent treatment after the peak flow has passed. The total capacity of the surge tanks is 137,600 gallons at maximum storage elevation which represents 7% (137,600 gallons/1,950,000 gallons) of the total volume needed to capture a peak daily flow of 1.95 MGD. Therefore, if peak flows become a more frequent event and the HRWWTP treatment configuration is maintained, the City will need to consider expansion of the flow-equalization capacity at the HRWWTP and improvements to the existing tanks which currently do not have mixing and/or aeration capabilities. The City has modified the piping around the disk filter to provide a true bypass during peak flows. The filter did not include this capability when originally constructed. As a result, the filter became a significant hydraulic constriction during peak flows that resulted in frequent backwashing that also overloaded the WWTP s in-plant pump station. The filter capacity was limited based upon its internal weir configuration. The filter can treat near the rated capacity of the filter as long as backwashing or other operational items do not increase the elevation within the filter basin above feet which is approximately 3 inches above the current influent, filter-weir elevation. If the elevation begins to exceed this value, the operators will need to bypass the filter and/or make use of the flow equalization tanks to maintain the flow at or below 2.00 MGD. Due to this dynamic, the City modified the overflow piping so it discharged to the chlorine contact chamber in lieu of the original configuration which routed the flow to the in-plant pump station. The original configuration compounded the hydraulic problems since the flow recycled back to the head of the BTU and then back to the filter and did not provide a hydraulic relief. In addition to the previously listed items, further review of the existing filter s backwash operation and influent weir elevation should be considered to further decrease upstream hydraulic elevations during peak hour flows. A review of the average daily flows (ADF) over the past seven (7) years is provided in Table II-4. In 2008, the City modified portions of the stormwater management system that were not completed when the reuse Mittauer & Associates, Inc. Project No Page 19

45 system was originally placed on-line. This allowed the existing control structure to be in compliance with the permit, but resulted in less reclaimed water being utilized at Magnolia Point. In addition, Magnolia Point stopped irrigating nine (9) holes within the development around 2011/2012 that also resulted in a demand reduction. Aggregate rainfall also affected demands in 2012 and However, in 2014 the City fine-tuned the reuse pump controls so that delivery capacities could be maximized. Accordingly, reclaimed water use increased from this improvement. TABLE II THROUGH 2014 HRWWTP ANNUAL AVERAGE DAILY FLOWS Total Flow River Flow River Flow Reuse Flow Reuse Flow (% of Total (MGD- (MGD- (MGD- (% of Total Year AADF) AADF) Flow) AADF) Flow) % % % % % % % % % % % % % % Average % % 2) Biological Treatment Efficiency The 1971 WWTP and 1986 improvements included a design which utilized a contact-stabilization treatment approach for biological treatment. In 2002 this approach was changed through inclusion of the AccuWEB system and modification of the 1986 Package WWTP so that a larger aeration tank was available. The AccuWEB system provides for a fixed-film system where biological masses can be concentrated in the treatment tank without increasing the overall solids within the aeration basin, in theory, creating a higher treatment efficiency. The HRWWTP is currently operating in this mode which will be discussed further in this Mittauer & Associates, Inc. Project No Page 20

46 subsection. The 2002 improvements included capabilities for the City to begin conversion of their operation into a BNR configuration called the Modified Ludzack Ettinger ( MLE ) process. The MLE process schematic is provided as Figure II-5. The MLE process creates an anoxic zone as the first compartment within the process train where denitrification can occur thus completing the conversion of influent ammonia to nitrogen gas. Standard components of the MLE process are an internal recycle stream of aerated mixed liquor which brings the nitrified liquid in contact with the influent carbon sources within an oxygen-depressed environment. Within the anoxic basin, nitrate is used as an electron donor to metabolize the influent carbon sources and is reduced to nitrogen gas which results in removal of nitrogen from the wastewater. The internal recycle is combined with RAS flow from the clarifier. Anoxic tanks are typically designed with a mixer or jet system which will keep the tank mixed without the use of air. The HRWWTP currently has a baffled basin which could be used as an anoxic basin for the MLE process, but there are no recycle pumps or capabilities to mix the anoxic tank if the diffusers were shut off. Therefore, some additional facility components would be required in order to allow the HRWWTP to further reduce total nitrogen concentrations in the effluent. As noted herein, the City began a process of limiting air (i.e., decreasing DO levels) within various areas of the BTU beginning in 2009 and more stringently in The approach was to create additional anoxic/anaerobic basins to provide biological nutrient removal capabilities for TN and TP. While the City does not currently have a recycle pumping component, the HRWWTP is now operating in a quasi 5-stage Bardenpho process without a recycle component. Figure II-6 depicts the traditional 4-stage and 5-stage Bardenpho process flow schematics while Figure II-7 depicts the City s current operational configuration at the HRWWTP. Actual anoxic, anaerobic, and/or aeration basin volumes are a function of dissolved oxygen and nitrate levels and change from time to time. In some basins, the City delivers a small amount of air to the basin to keep some mixing capabilities but not enough for the biological demand which keeps a depressed DO level. This low DO level allows the microbiology to denitrify while also creating conditions for TP removal Mittauer & Associates, Inc. Project No Page 21

47 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-5 MLE Process Schematic.dwg, 2/25/ :58:24 AM

48 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-6 Bardenpho Process Schematic.dwg, 2/25/ :20:06 AM

49 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-7.dwg, 2/25/ :21:47 AM

50 through the changing DO concentrations. The following review will consider the HRWWTP BTU operating as: (i) a single-stage nitrification system without BNR requirements; and (ii) a 5-Stage Bardenpho BNR system. (i) Single-Stage Nitrification System Based on a design influent flow of 0.75 MGD, a peak factor of 2.0, an MLSS concentration of 4,000 mg/l (note - HRWWTP is currently operating around this MLSS concentration), and influent CBOD 5 and TKN concentrations of 220 and 60 mg/l respectively, an analysis of the oxidation and nitrifying potential of the current HRWWTP BTU was performed. For a single-stage nitrification system, an aeration detention time (hydraulic residence time HRT ) of 6 to 15 hours is recommended. The detention time provided is 12.8 hours (i.e., (365,000 gallons + 33,500 gallons (anoxic basin being used as an aeration basin)) 750,000 gpd x 24 hrs/day) which is in line with the recommended range. Oxygen requirements are typically 1.4 lb O 2 /lb CBOD5 and 4.6 lb O 2 /lb NH 3. For a 0.75 MGD plant treating 220 mg/l CBOD 5 and 60 mg/l TKN with an effluent limitation of 20 mg/l CBOD 5 and 10 mg/l TN, this corresponds to an oxygen demand of 3,190 ppd or 135 lbs/hr. Assuming each coarse bubble diffuser has a 5.7% transfer efficiency at 15-foot side water depth, the required air feed rate is 2,270 cfm into the aeration tank. The existing centrifugal blowers were designed to deliver 2,300 cfm which should provide sufficient capacity to treat an average daily flow of 0.75 MGD at the aforementioned loading with stated effluent requirements. The typical RAS pump flow rate is adequate for the single-stage nitrification system at the HRWWTP design flow rate. The typical value is 0.5 to 1.5, so the 0.79 MGD RAS pump rate at 100% motor speed is within the acceptable range. (ii) 5-Stage Bardenpho System Since the City is currently operating the BTU in a quasi 5-stage Mittauer & Associates, Inc. Project No Page 25

51 arrangement (no nitrified recycle flow), a review of the oxidation/nitrification and denitrification capabilities was completed with a 0.75 MGD AADF of flow and previously noted influent and effluent characteristics. However, it was determined the HRWWTP BTU would be unable to provide denitrification capabilities since the entire treatment volume would be required for oxidation and nitrification of the raw wastewater. In order to review the BNR capabilities based on available treatment volumes, a numerical biological treatment model was developed to determine potential effluent characteristics. In particular, TN removal was evaluated based on biological nutrient removal capabilities alone while it was assumed TP removal could be accomplished through chemical feed capabilities, if needed, to achieve at least a 1.0 mg/l level. To summarize, Table II-5 lists the HRWWTP annual average effluent values with noted minimum and maximums per year since 2010 with associated AADF flow and CBOD 5 and TSS concentrations. The influent TKN is estimated based on the Total Ammonia values provided by the HRWWTP operators. TABLE II THROUGH 2013 EXISTING HRWWTP BNR RESULTS Year Flow (M GD-AADF) Influent Conc. a (CBOD5 TKN ) Effluent Conc. (TN TP) ppm 62 ppm 6.8 ppm 0.9 ppm ppm 50 ppm 5.0 ppm 0.7 ppm ppm 54 ppm 4.4 ppm 0.7 ppm ppm 70 ppm 5.2 ppm 1.0 ppm a: Influent TKN estimated from Total Ammonia testing provided by WWTP Operators. The numeric model assessed oxidation, nitrification, and denitrification capabilities only. Based upon a HRWWTP aeration treatment volume of 205,000 gallons and anoxic/anaerobic volume of 194,000 gallons Table II-6 summarizes the calibration results. Mittauer & Associates, Inc. Project No Page 26

52 TABLE II THROUGH 2013 HRWWTP CALIBRATION RESULTS Year Flow (M GD-AADF) Actual Annual Avg Effluent Conc. (TN) Modeled Effluent Conc. (TN) ppm 3.0 ppm a A ppm 4.7 ppm a: Average values through March As shown above, the theoretical versus actual TN limits have a variance where actual concentrations are greater than the theoretical. Review of the weekly HRWWTP data from 2012 indicated TN concentrations varied between a low of 0.7 mg/l to a maximum of 7.9 mg/l with an annual average of 4.4 mg/l. These fluctuations are a result of a number of factors including changing temperatures, mixed liquor levels, mixing capabilities, influent loading, dissolved oxygen levels, blower performance, air piping leaks, etc. Grit levels in existing tankage will also affect available treatment volumes. Since the HRWWTP was designed for secondary treatment capabilities, the current operational controls are anticipated to have fluctuations since they do not have recommended biological nutrient removal capabilities and associated treatment volumes. Components such as recycle pumps and mixers are not currently on-line which results in a reduction in treatment efficiency. In addition, as treatment levels become more stringent, most WWTPs also employ more real-time data feedback to assist the operator s control of the activated sludge system. A combination of these improvements would likely assist in producing a more stable effluent, but the BTU will be limited based on its existing structural configuration (i.e., available treatment volume). Based on the modeled evaluation, the HRWWTP s anticipated maximum theoretical treatment level is summarized for a lowloading (i.e., CBOD 5 = 220 mg/l and TKN = 60 mg/l) and highloading (i.e., CBOD 5 = 300 mg/l and TKN = 60 mg/l) within Tables II-7 and II-8, respectively. These values utilize a winter o o wastewater temperature of 18 C and a summer temperature of 25 C mimicking what has been recorded at the HRWWTP over the past Mittauer & Associates, Inc. Project No Page 27

53 three (3) years. Projections of future performance would require significant operational oversight as well as completion of the system improvements mentioned previously. TABLE II-7 PROJECTED HRWWTP THEORETICAL WASTEWATER TREATMENT LEVELS - LOW LOADING HRWWTP Flow (MGD) Loading (BOD 5 TKN) HRWWTP Effluent (BOD 5 TN) Low Loading Projected Treatment Limitations 0.50 MGD 220 mg/l 60 mg/l 10 mg/l 4 mg/l 0.55 MGD 220 mg/l 60 mg/l 10 mg/l 4 mg/l 0.60 MGD 220 mg/l 60 mg/l 10 mg/l 5 mg/l 0.65 MGD 220 mg/l 60 mg/l 10 mg/l 8 mg/l 0.70 MGD 220 mg/l 60 mg/l 10 mg/l 10 mg/l TABLE II-8 PROJECTED HRWWTP THEORETICAL WASTEWATER TREATMENT LEVELS - HIGH LOADING HRWWTP Flow (MGD) Loading (BOD 5 TKN) HRWWTP Effluent (BOD 5 TN) High Loading Projected Treatment Limitations 0.50 MGD 300 mg/l 60 mg/l 10 mg/l 5 mg/l 0.55 MGD 300 mg/l 60 mg/l 10 mg/l 8 mg/l 0.60 MGD 300 mg/l 60 mg/l 10 mg/l 12 mg/l 0.65 MGD 300 mg/l 60 mg/l 10 mg/l 26 mg/l 0.70 MGD TN Reduction Not Feasible N/A As noted within the projections and dependent on influent loading, the HRWWTP is not anticipated to provide sufficient BNR capabilities once flows begin to exceed 0.60 to 0.65 MGD. TN levels are anticipated to be difficult to control as flows exceed these values. Mittauer & Associates, Inc. Project No Page 28

54 Since the HRWWTP average TN levels from 2010 through 2013 have varied between 4.4 to 6.8 mg/l (5.3 mg/l average) with flows between and MGD and CBOD 5 loading between 176 and 220 mg/l, we are recommending the City utilize the loading shown in Tables II-9 and II-10 until such time that performance data from the WWTP is in line with theoretical estimates. The values were derived based on the current operational differences from the theoretical values and utilize an approximate 1.6 safety factor (i.e., theoretical value * 1.6 = recommended value). TABLE II-9 PROJECTED HRWWTP RECOMMENDED WASTEWATER TREATMENT LEVELS - LOW LOADING HRWWTP Flow (MGD) Loading (BOD 5 TKN) HRWWTP Effluent (BOD 5 TN) Low Loading Projected Treatment Limitations 0.50 MGD 220 mg/l 60 mg/l 10 mg/l 6.4 mg/l 0.55 MGD 220 mg/l 60 mg/l 10 mg/l 6.4 mg/l 0.60 MGD 220 mg/l 60 mg/l 10 mg/l 8.0 mg/l 0.65 MGD 220 mg/l 60 mg/l 10mg/l 12.8 mg/l 0.70 MGD 220 mg/l 60 mg/l 10 mg/l 16.0 mg/l TABLE II-10 PROJECTED HRWWTP RECOMMENDED WASTEWATER TREATMENT LEVELS - HIGH LOADING HRWWTP Flow (MGD) Loading (BOD 5 TKN) HRWWTP Effluent (BOD 5 TN) High Loading Projected Treatment Limitations 0.50 MGD 300 mg/l 60 mg/l 10 mg/l 8.0 mg/l 0.55 MGD 300 mg/l 60 mg/l 10 mg/l 12.8 mg/l 0.60 MGD 300 mg/l 60 mg/l 10 mg/l 19.2 mg/l 0.65 MGD 300 mg/l 60 mg/l 10 mg/l 41.6 mg/l Mittauer & Associates, Inc. Project No Page 29

55 3) Mechanical Reliability Lastly, a review of the mechanical reliability requirements for the HRWWTP was conducted to determine future expansion requirements. Due to the current outfall to the St. Johns River, the HRWWTP has to meet Class III Reliability Requirements in accordance with FDEP Rule (1)(a), Florida Administrative Code ( FAC ). If the St. Johns River Outfall were not available and the reuse system was the only means of discharging effluent, the reliability requirement would be a Class I status in accordance with FDEP Rule , FAC. In the context of the current FDEP Permit and operation, only Class III Reliability was reviewed and is summarized in Table II-11. TABLE II-11 HRWWTP CLASS III RELIABILITY REVIEW Process Unit Class III Requirement HRWWTP Screening Pumping Blowers RAS/W AS Pumps Scum Pumps In-Plant Pum p Station Reuse Pumps Metering Pum ps Clarification Manual Back-up Bar Screen Required Back-up pump(s) (one pump shall meet peak daily flow) Two Basins (secondary basin m ay have 50% design capacity) Mechanical Fine Screen, No m anual back-up currently provided Two pumps provided for all system s capable of handling a peak daily flow of 2.6 or greater. One Clarifier Provided Aeration One Basin Permissible One Basin Provided Filtration No back-up Required One Filter provided Digester No back-up Required Two Digesters Provided Disinfectant Basin (CCC) Two Basins (secondary basin m ay have 50% design capacity) Two Cham bers Provided (one cham ber in the Package W W TP) Emergency Generator C a p a c i t y t o O p e r a t e : Screening, Main W astewater Pumps, Clarifier, Blowers, Disinfectant Facilities, and Critical Operation Building Needs Provided Mittauer & Associates, Inc. Project No Page 30

56 Expansion requirements for each WWTP are further discussed in Section VI; however, the City should note that the back-up bar screen and redundant clarifier are currently reliability issues that need to be addressed even if the HRWWTP is not expanded in the future. While the existing filter does not require a backup unit, the City should consider installing an additional unit for increased treatment capacity and to resolve hydraulic issues with the current installation. It was determined that the existing filter elevation creates a hydraulic constraint on the HRWWTP as noted previously. 4) Facility Needs The current HRWWTP laboratory and office areas are dated and do not include sufficient room to store manuals, perform laboratory tests, and generally provide enough working room for the operators. Restroom and shower facilities are also minimal and not adequate for current operations. Installation of a new operations/laboratory building should be considered by the City during future capital improvements at the HRWWTP site. Specific facility needs per treatment process or equipment requirement are summarized in Table II-1. c. Effluent Disposal Capacity The HRWWTP effluent disposal capacity is affected by a number of factors including Magnolia Point storage capacity, Magnolia Point irrigation needs, effluent quality, reuse pumping capacity, and St. Johns River TMDL limits. More broadly, the aforementioned factors are categorized as hydraulic and biological constraints. Discussion related to the TMDLs is provided in Sections II.A. and II.B.2. The HRWWTP disposal capacity items will be reviewed as follows: Current FDEP Permit and TMDL Limitations; Existing St. Johns River Outfall; and Magnolia Point Reuse Capacity. Mittauer & Associates, Inc. Project No Page 31

57 1) Current FDEP Permit and TMDL Limitations The current FDEP permitted effluent limitations for the HRWWTP are listed in Table II-12. TABLE II-12 HRWWTP EFFLUENT LIMITATIONS Parameter/Units Effluent Limits Sampling Interval CBOD 5 (max.) TSS (m g/l) ph (Std. Units) Cl2 Residual for Disinfection (m g/l) Cl2 Residual for Dechlorination (m g/l) Maxim um Fecal Coliform (#/100 ml) (River) 20/25/40/60 (Reuse) 20/30/45/60 (River) 20/30/45/60 (Reuse) 5 in any 1 Sample (River) 6.0 to 8.5 (Reuse) 6.0 to 8.5 (River) 0.50 (Reuse) 1.00 (River) 0.01 (Reuse) n/a (River) 200/400/800 (Reuse) 25 Ann/Mon/W k/single Ann/Mon/W k/single Ann/Mon/W k/single Ann/Mon/W k/single Daily Sam ple, Report Monthly Daily Sam ple, Report Monthly Daily Sam ple, Report Monthly a b c Mon /Mon /Single Single c d Total Nitrogen (ppy) 17, m onth rolling sum d Total Phosphorus (ppy) 4, m onth rolling sum a: Monthly Mean Reported b: No More than 10% in the Monthly Sampling can be Greater than 400 c: Any Single Sample Can Not Exceed 800 (River) or 25 (Reuse) d: Combined effluent disposal quantity from SWWTP and HRWWTP. Based upon current review of the HRWWTP effluent sampling records, the facility is currently in compliance with permit requirements. 2) St. Johns River Outfall Capacity (Hydraulic) The HRWWTP outfall capacity is limited based on hydraulic constraints as well as TMDL loading. The following discussion is only related to hydraulic aspects of the outfall since the nutrient loading review is provided elsewhere. The St. Johns River outfall was constructed with the 1971 WWTP, and the design was based on a 16" ductile iron plain-end, pipe discharge Mittauer & Associates, Inc. Project No Page 32

58 similar to a roadway culvert at invert elevation (-) 2.80 feet (NGVD). The 16" outfall is located near Governors Creek as shown within Figure II-4. Currently, the outfall is completely submerged. Treated effluent which does not meet reclaimed water standards is dechlorinated and disposed of at the 16" outfall. Reclaimed water is also disposed of at this location when the Magnolia Point stormwater system does not have capacity for additional reclaimed water. In both scenarios, the treated effluent/reclaimed water gravity flows from the HRWWTP beneath U.S. 17 to the outfall location within the banks of the St. Johns River. Based on the pipe slopes provided within the gravity system, the outfall should have a capacity of approximately 1,950 gpm or 2,776,000 gpd (2.78 MGD-PHF) on a peak hour flow ( PHF ) basis. However, the City should attempt to locate the pipe end in the future and perform some in-situ video testing to determine the structural integrity of the outfall in addition to the severity of siltation over and around the outfall. Overall, the limiting factor related to the HRWWTP river outfall capacity will be the TMDL restrictions. If no additional reuse customers are added to the City s system and the existing treatment systems remain in their current configurations, then the HRWWTP river outfall capacity is anticipated to have a limiting capacity of 0.65 MGD AADF. 3) Magnolia Point Capacity Reclaimed water from the HRWWTP is typically directed to the Magnolia Point stormwater system unless the reclaimed water does not meet public-access criteria or the receiving stormwater management facility does not have capacity to accept the water. The FDEP permit lists the Magnolia Point irrigation capacity as 0.75 MGD on an annual average daily flow ( AADF ) basis over an irrigated area of 151 acres. This represents an application rate of approximately 1.28 inches per week or a supplemental irrigation application of 67 inches per year. These values are much greater than typically seen for a golf course irrigation system. Generally, a supplemental (irrigation water needed beyond that received by rainfall) application rate of 32 to 36 inches per year is used for golf Mittauer & Associates, Inc. Project No Page 33

59 course irrigation depending upon the type of turf which is being grown, groundwater levels, slope of course, regional rainfall amounts, etc. Using the 32 inches per year value as the annual application rate, the City should anticipate that Magnolia Point would be limited to an effluent capacity of 0.36 MGD AADF. In 2011, Magnolia Point began to only irrigate 18 holes in lieu of the 27 holes available. In addition, modifications were made in 2009 to ensure reclaimed water was not delivered when lake elevations were above the stormwater management control weir elevation. As a result, the annual average reclaimed water demand between 2011 and 2013 was MGD in lieu of flows over MGD in years preceding Generally, monthly and daily reclaimed water demands will fluctuate in response to prevailing weather patterns; however, the annual average demand is expected to remain between 0.20 and 0.25 MGD while only 18 holes are irrigated. The historic monthly flows during 2010 through 2013 to the St. Johns River and to Magnolia Point are shown in Table II-13. TABLE II THROUGH 2013 HRWWTP RIVER AND REUSE MONTHLY AVERAGE DAILY FLOWS River Reuse River Reuse River Reuse River Reuse Month (MGD) (MGD) (MGD) (MGD) (MGD) (MGD) (MGD) (MGD) January February March April May June July August September October November December AADF Mittauer & Associates, Inc. Project No Page 34

60 The Reuse trends for 2010 through 2013 are illustrated in Figure II-8. Based on this information and to ensure prudent nutrient loading projections to the river, the City should plan on an average flow of 0.20 MGD AADF being delivered to Magnolia Point for public-access reuse with the rest of the effluent being discharged to the St. Johns River. Until new public-access reclaimed water users are secured, the reuse disposal capacity of the HRWWTP will be considered maximized. d. Residuals Disposal Capacity The following discussion summarizes the current operation at the HRWWTP while a more detailed discussion related to 2010 FDEP biosolids disposal rule changes and Class AA implications is provided in Section III. The HRWWTP was originally configured to provide aerobic digestion to achieve Class B biosolids stabilization. The City modified the approach to incorporate the ENNIX process which introduces a custom blend of growth enhancing proteins, minerals, organic acids, and target enzymes as well as substrate-specific aerobic and facultative anaerobes which breakdown the sludge without process air while still meeting the Class B requirements. In addition to the cost savings gained through minimized blower operation and subsequent electrical consumption, the ENNIX process offers the following benefits: Reduced sludge disposal cost through higher treatment efficiency; Increased solids handling capacity; Reduced maintenance due to fewer mechanical components; Alkalinity and ph control; Assured compliance; Greater reliability; and Absence of noxious odors. The current operation includes pumping waste sludge from the BTU to the existing digester tank which can transfer sludge to a parallel open-top tank digester. The main digester ( Digester #1") has a side water depth of 12 feet, and an internal diameter of 45 feet, resulting in a total volume of 142,750 gallons. A floating surface aerator can provide air to the tank but is currently only used on a limited basis for occasional mixing in accordance Mittauer & Associates, Inc. Project No Page 35

61 City of Green Cove Springs M&A Project Figure II-8: January 2010 through December 2013 HRWWTP River and Reuse Monthly Average Daily Flow River Monthly Average Daily Flow (MGD) Reuse Average Monthly Flow (MGD) Linear (River Monthly Average Daily Flow (MGD)) Linear (Reuse Average Monthly Flow (MGD)) Flow (MGD) Date

62 with the ENNIX process requirements. The second digester ( Digester #2"), currently uses the tankage available in the original stabilization tank constructed with the 1972 WWTP. The second digester also has a side water depth of 12 feet and a 40-foot internal diameter, resulting in a total volume of 112,800 gallons. The City is currently reviewing and budgeting means to optimize the sludge influent piping to either digester as well as the means to more effectively decant Digester #2. 3 The two digesters when combined in parallel provide 5.7 ft per capita (i.e., 3 34,150ft /6,000 capita) which is greater than the recommended range 3 of 2 to 4 ft /capita. The sludge stabilization requirements of CFR 503 are met by having greater than 40 days of sludge retention time ( SRT ) for pathogen reduction. The current SRT is calculated as follows: Traditionally, the City transferred digested sludge from Digesters #1 and #2 to onsite drying beds for dewatering prior to eventual transport and disposal in a permitted landfill. Sludge was transferred from the digesters to the drying beds by gravity via manual control valves and piping. The City has recently moved away from the sludge drying beds and is pursuing other interim on-site dewatering options until a final approach is selected. Dewatered materials are still transferred to the landfill for ultimate disposal. Ultimately, the City would like to construct permanent dewatering capabilities to address the biosolids dewatering needs. When in use, the combined drying beds provide 15,000 square feet of drying 2 bed surface. Based on a 1.25 ft per capita design value, the existing drying beds provide adequate area for sludge dewatering (i.e., 15,000 SF > 7,500 SF (6,000 capita * 1.25 SF/capita). The existing beds also provide a greater surface area than required when reviewed using the solids loading 2 rate criteria of dry pounds/ft -yr. The current solids loading rate is dry pounds/ft -yr, i.e., [(325 lb/day (WAS from HRWWTP)* 365 days/yr) /15,000 SF]. While the drying beds have greater capacity than required when reviewing typical engineering criteria, their use is heavily dependent on rainfall patterns Mittauer & Associates, Inc. Project No Page 37

63 since the drying beds are open to the atmosphere. The City s existing digester capacity can become limited based on prevailing weather patterns which can impact the activated sludge system by limiting WAS flows and increasing solids within the BTU/Clarifier. In addition, the removal of sludge from the drying beds is an operator intensive activity. Other dewatering applications are reviewed and discussed in Section IV and Class AA biosolids requirements are reviewed in Section III. 2. South WWTP The SWWTP provides secondary treatment of domestic wastewater. The southerly service area characteristics include industrial customers, but no pretreatment is required at this time. The biological treatment unit within the SWWTP was designed to operate as an extended air activated sludge system. Treatment consists of aeration, clarification, chlorination, and dechlorination. The original design capacity was 0.50 MGD (AADF) with chlorinateddechlorinated effluent being discharged to the St. Johns River via a 16-inch pressurized outfall. The permitted capacity has been modified through the operational changes that have been enacted at the WWTP in order to provide biological nutrient removal of TN. Until reuse customers are developed within the Southern Service Area and/or HRWWTP increases reuse capacity, the permitted capacity is currently limited to 0.35 MGD (AADF) based on nutrient loading projections as discussed further herein. The initial construction of the SWWTP occurred in 1992 and included the following components: Influent Manual Bar Rack; Circular-Steel Package WWTP (aeration basin, aerobic digester, and clarifier); Redundant Circular-Steel Clarifier; Concrete Chlorine Contact Tank; St. Johns River Outfall piping; and Sludge Drying Beds. Mittauer & Associates, Inc. Project No Page 38

64 A subsequent modification to the SWWTP occurred in 2005 which included: Installation of a filtration system with high-level disinfection capabilities; and Installation of reuse pumps and pipeline stubbed to southeast corner of the site for future delivery of bulk public-access reclaimed water. The 2005 modification allowed the SWWTP to treat domestic wastewater to public-access reuse water criteria. At that time, a potential golf course near the SWWTP was being reviewed as a potential reclaimed water user. Due to economic constraints on that potential end user, reclaimed water delivery has not come to fruition at the SWWTP. Thus, treated effluent disposal is still limited to the St. Johns River. In 2008/2009, the City installed two (2) new 1,800 cubic feet per minute (cfm) centrifugal blowers to replace two (2) existing 875 cfm units. The 875 cfm blower was unable to carry the oxygen demand for the WWTP and resulted in ammonia violations. The new blowers were designed in anticipation of additional growth and loading from a dairy pre-treatment facility that was going to pump its effluent to the SWWTP. As a result of the housing market declines and the dairy addressing its treatment needs onsite, the flows and loading to the SWWTP did not occur. Review of the modified BTU configuration and its treatment efficacy is discussed further herein. Beginning in 2010, the City began a process of cycling blowers on and off to create anoxic/anaerobic conditions to provide BNR capabilities for TN. Due to the tank configurations and cycling approach, BNR of TP is not available. While the blowers are cycled off, the RAS pumping through the airlift is also discontinued since it requires air flow, which is not a recommended condition but a result of the blower cycling operations. The blower cycling has significantly reduced the TN effluent concentrations. TN levels dropped from over 30 mg/l to below 15 mg/l during Then, as the SWWTP operators began to utilize the handheld DO and ORP probes and further modulate aeration timing, the TN levels continued to drop in 2012 where the average was around 4.0 mg/l. The TN levels in 2013 continue to average around 3.5 mg/l which is meeting the treatment limitations of the system (i.e., maximizing the treatment efficiency). Mittauer & Associates, Inc. Project No Page 39

65 The current site plan for the SWWTP is provided as Figure II-9 while the process flow schematic is provided as Figure II-10. All of the biological treatment components are provided within the one (1) WWTP package unit. The SWWTP is currently permitted under FDEP Permit No. FL The permit was renewed in 2013 and a copy of the permit is provided in Attachment D. a. Treatment Capacity As discussed previously, the SWWTP was designed and initially permitted to treat a total flow of 0.50 MGD. The WWTP is currently treating approximately 210,000 gpd or operating at 42% of its original design capacity. Through the BNR operational modifications, it is anticipated the maximum treatment capacity of the SWWTP will be limited to approximately 0.35 MGD if no facility improvements are made to the biological treatment unit and/or no reuse system expansion occurs. Currently, the annual average daily flow to the SWWTP is approximately 0.21 MGD AADF which is approximately 60% of the current nutrient removal capacity. b. Treatment Process Overview Treatment through the SWWTP consists of a manual bar screen which screens the influent wastewater. Screened effluent is then discharged into the aeration basins for oxidation and nitrification. Following the aeration basin, the wastewater travels to the secondary clarifier to settle and concentrate the solids within the mixed liquor. The clarified effluent discharges over peripheral V-notch weirs into a discharge pipe which flows to the filter. After filtration, the filtrate then flows to the CCC for subsequent disinfection. Discharge flow from the chlorine contact chamber flows over a V-notch weir to the effluent wetwell where sulfur dioxide is currently injected for dechlorination prior to being discharged into the St. Johns River. The current pre-treatment mechanisms at the WWTP are not adequate and allow rags and other debris to enter the process train. These components eventually find their way into the influent piping to the clarifier and create clogs. Eventually, the obstruction becomes significant enough to impact hydraulic flow through the plant and requires use of the redundant clarifier in order to clean the debris from the piping. Mittauer & Associates, Inc. Project No Page 40

66 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-9 SWWTP Existing Site Plan.dwg, 2/25/ :39:46 AM

67 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-10 SSWTF Flow Schematic.dwg, 2/25/ :41:39 AM

68 The solids process train consists of the aeration basin, aerobic digester, and sludge handling facilities. The RAS is airlifted into the aeration basin from the secondary clarifiers. The stabilized RAS is either mixed with the influent wastewater in the aeration basin or wasted to the aerobic digester. The waste activated sludge ( WAS ) can be diverted from the RAS flow entering the aeration basin to the aerobic digester. The digested sludge is pumped to the sludge drying beds. After the sludge is dewatered, it is removed and transferred to the Rosemary Hill Landfill transfer station for ultimate disposal at a landfill in exchange for the treatment plant handling leachate generated by the closed Rosemary Hill Landfill. The following components of the SWWTP current operation will be reviewed: Hydraulic Capacity; Biological Treatment Efficiency; and Mechanical Reliability. 1) Hydraulic Capacity The original SWWTP permitted average daily flow capacity was 0.50 MGD and was designed to treat up to 1.25 MGD (i.e., 2.5 * 0.50 MGD) without impacting the hydraulic capacity or biological treatment efficiency of the WWTP. The major components within the SWWTP treatment process train are listed within Table II-14 and include the design capacity, either hydraulic or biological, of each unit. Peak capacity is either based on manufacturer information or hydraulic process review. TABLE II-14 SWWTP HYDRAULIC PROCESS TRAIN OVERVIEW Process Unit Peak Design Capacity, MGD Comments Manual Bar Rack 1.5 MGD (PF = 3.0) Clarifier 1.25 MGD (PF = 2.5) No hydraulic issues, but the screen performs poorly. Lim ited by peak overflow rate. Pending MLSS concentration, flows could exceed the clarifier s peak solids loading rate. Mittauer & Associates, Inc. Project No Page 43

69 TABLE II-14 (cont.) SWWTP HYDRAULIC PROCESS TRAIN OVERVIEW Process Unit Disk Filter Chlorine Contact Chamber Reuse Pumps River Outfall Peak Design Capacity, MGD 2.0 MGD (PF = 4) 1.5 MGD (PF = 3.0) 1.5 MGD a (PF = 3.0) a 2.52 MGD (PF = 5.0) Comments Based on design drawings. Detailed hydraulic profile calculations were not reviewed. Meets CT = 40 (public access requirements) at noted flow and chlorine feed rate of 1.6 mg/.l Firm capacity with one (1) pump out of service. Firm capacity with one (1) pum p out of service. a: Due to the river outfall, the capacity of the reuse pumps are not considered limiting on the hydraulic capacity of the HRWWTP. As noted in Table II-14, the SWWTP is limited based on the clarifier size. The current peak flow capacity is approximately 1.25 MGD which equates to a peaking factor of 2.5. Generally, the hydraulic surge into the SWWTP is controlled by Pump Station No. 2 (P.S. 2 capacity is 640 gpm (0.92 MGD)) which collects the majority of the Southerly Service Area and transmits the raw wastewater to the SWWTP for treatment and disposal. In order to control some of the peak flows that the WWTP experiences, the City should review options to use the existing SCADA system to control Pump Station No. 2 to buffer flows coming into the WWTP. For example, the pump control system could be modified so the lag pump comes on at an elevation above the influent invert thus allowing the Pump Station No. 2 collection system to act as a surge tank. The City could also review the potential for adding variable frequency drives on the motors so the speed of the pumps could be controlled to allow the operator flexibility in delivery wastewater flows to the WWTP. Either option would require a high level override which would require both pumps to operate at a pre-determined level. This would ensure any surcharge within the collection system was maintained within a margin of safety so as to not impact other areas of the system. P.S. No. 2 capacity along with any other stations (e.g., P.S. No. 2 + P.S. No. 9 capacity = 1,100 gpm (1.58 MGD)) that pump at concurrent times can overload the SWWTP clarifier as well as short-circuit the BNR process in the current blower-cycling configuration. Mittauer & Associates, Inc. Project No Page 44

70 A summary of recent flows through the SWWTP are summarized in Table II-15. TABLE II THROUGH 2013 SWWTP MONTHLY AVERAGE DAILY FLOWS Month 2010 (M GD-ADF) 2011 (M GD-ADF) 2012 (MGD-ADF 2013 (M GD-ADF) January February March April May June July August Septem ber October November Decem ber AADF ) Biological Treatment Efficiency The following review will consider the SWWTP BTU operating as: (i) a single-stage nitrification system without BNR requirements; and (ii) an activated-sludge system with blower cycling similar to a sequencing batch reactor ( SBR ) design. (i) Single-Stage Nitrification System (Pre-BNR Modifications) Based on a design influent flow of 0.50 MGD, a peak factor of 3.0, an MLSS concentration of 3,000 mg/l, and influent CBOD 5 and TKN concentrations of 220 and 60 mg/l, respectively, an analysis of the oxidation and nitrifying potential of the current SWWTP BTU was performed. Mittauer & Associates, Inc. Project No Page 45

71 For a single-stage nitrification system, an aeration detention time (hydraulic residence time HRT ) of 6 to 15 hours is recommended. The detention time provided is 12.6 hours (i.e., 262,700 gallons 500,000 gpd x 24 hrs/day) which is in line with the recommended range. Oxygen requirements are typically 1.4 lb O 2 / lb CBOD5 and 4.6 lb O 2 / lb NH 3. For a 0.50 MGD plant treating 220 mg/l CBOD5 and 60 mg/l TKN with an effluent limitation of 20 mg/l CBOD 5 and 10 mg/l TN, this corresponds to an oxygen demand of 2,130 ppd or 90 lbs/hr. Assuming each coarse bubble diffuser has a 5.7% transfer efficiency at a 15-foot side water depth, the required air feed rate is 1,500 cfm into the aeration tank. The existing centrifugal blowers were designed to deliver 1,800 cfm which should provide sufficient capacity to treat an average daily flow of 0.50 MGD and provide aeration to the digester and air lifts at the aforementioned loading with stated effluent requirements. The typical RAS pump flow rate is adequate for the single-stage nitrification system at the SWWTP design flow rate. The recommended RAS pumping flow rate is typically between 0.5 to 1.5 times the influent flow. A 1.5 factor at 0.50 MGD of influent flow would result in a recommended RAS flow rate of 0.75 MGD (1,050 gpm), which is achievable with an 8-inch air lift pump. (ii) Activated Sludge System with Blower Cycling (Quasi SBR Operations) Since the City is currently operating the BTU with blower cycling, a review of the oxidation/nitrification and denitrification capabilities was completed with a 0.50 MGD (AADF) of flow and previously noted influent and effluent characteristics. However, it was determined the SWWTP BTU would be unable to provide denitrification capabilities at design flows since the entire treatment volume would be required for oxidation and nitrification of the raw wastewater. In order to review the BNR capabilities based on available treatment volumes, a numerical biological treatment model was developed to determine potential effluent characteristics. In particular, TN removal was evaluated based on biological nutrient removal capabilities alone while it was assumed TP removal could be accomplished through chemical feed capabilities, if needed, to achieve at least a 1.0 mg/l Mittauer & Associates, Inc. Project No Page 46

72 level. To summarize, Table II-16 lists the SWWTP annual average effluent values with noted minimum and maximums per year since 2010 with associated AADF flow and CBOD 5 and TSS. The Influent TKN is estimated based on typical domestic wastewater levels and those seen at the City s HRWWTP. TABLE II THROUGH 2013 EXISTING SWWTP BNR RESULTS Year Flow (M GD-AADF) Influent Conc. (CBOD5 TKN) Effluent Conc. (TN TP) ppm 40 ppm (est.) 30.8 ppm 4.7 ppm ppm 40 ppm (est.) 12.5 ppm 5.0 ppm ppm 40 ppm (est.) 3.8 ppm 3.1 ppm ppm 40 ppm (est.) 4.3 ppm 2.5 ppm The numeric model assessed oxidation, nitrification, and denitrification capabilities only. Based upon the SWWTP available treatment volumes, Table II-17 summarizes the calibration results. TABLE II THROUGH 2013 SWWTP CALIBRATION RESULTS Year Flow (M GD-AADF) Actual Annual Avg Effluent Conc. (TN) M odeled Effluent Conc. (TN) ppm 3.0 ppm ppm 3.0 ppm As shown above, the theoretical versus actual TN limits can vary significantly. The SWWTP values have varied based upon aeration cycle timing and the City s more recent control of the blowers based on hand-held DO and ORP meter readings. As the City has utilized the meter readings, the differential between theoretical and actual has diminished. We do anticipate fluctuations based on other factors including, but not limited to, changing temperatures, mixed liquor levels, mixing capabilities, influent loading/peak flows, dissolved oxygen levels, blower performance, air piping leaks, etc. Grit levels Mittauer & Associates, Inc. Project No Page 47

73 in existing tankage will also affect available treatment volumes. Since the SWWTP was designed for secondary treatment capabilities, the current operational controls are anticipated to have fluctuations since they do not have recommended biological nutrient removal capabilities and associated treatment volumes. Components such as recycle pumps and mixers are not currently on-line, and the RAS flow is discontinued when the blowers are off which results in a reduction in treatment efficiency. In addition, as treatment levels become more stringent, most WWTPs also employ more real-time data feedback to assist the operator s control of the activated sludge system. A combination of these improvements would likely assist in producing a more stable effluent. However, the BTU s ability to provide nutrient removal will be limited overall based on its existing structural configuration (i.e., available treatment volume). As noted with the pump station capacities that deliver raw wastewater to the SWWTP, peak flows from P.S. 2 and P.S. 19 can lead to large instantaneous flows into the SWWTP BTU. If these flows coincide with the blower off cycle, then the City can anticipate marginal treatment and could have elevated ammonia levels. We believe this has occurred from time to time at the SWWTP and resulted in ammonia violations within the effluent. Based on the modeled evaluation, the SWWTP s anticipated maximum theoretical treatment level is summarized for a lowloading (i.e., CBOD 5 = 200 mg/l and TKN = 50 mg/l) and highloading (i.e., CBOD 5 = 250 mg/l and TKN = 50 mg/l) within Tables II-18 and II-19, respectively. These values utilize a winter o o wastewater temperature of 18 C and a summer temperature of 25 C mimicking what has been recorded at the City s HRWWTP over the past three (3) years. Projections of future performance would require significant operational oversight as well as completion of the system improvements mentioned previously. Mittauer & Associates, Inc. Project No Page 48

74 TABLE II-18 PROJECTED SWWTP THEORETICAL WASTEWATER TREATMENT LEVELS - LOW LOADING SWWTP Flow (MGD) Loading (BOD 5 TKN) SWWTP Effluent (BOD 5 TN) Low Loading Projected Treatment Limitations 0.20 MGD 200 mg/l 50 mg/l 10 mg/l 4 mg/l 0.25 MGD 200 mg/l 50 mg/l 10 mg/l 4 mg/l 0.30 MGD 200 mg/l 50 mg/l 10 mg/l 6 mg/l 0.35 MGD 200 mg/l 50 mg/l 10 mg/l 9 mg/l 0.40 MGD 200 mg/l 50 mg/l 10 mg/l 13 mg/l > 0.40 MGD BNR Capabilities Lim ited (Only Secondary Treatment Available) TABLE II-19 PROJECTED SWWTP THEORETICAL WASTEWATER TREATMENT LEVELS - HIGH LOADING HRWWTP Flow (MGD) Loading (BOD 5 TKN) HRWWTP Effluent (BOD 5 TN) High Loading Projected Treatment Limitations 0.20 MGD 250 mg/l 50 mg/l 10 mg/l 4 mg/l 0.25 MGD 250 mg/l 50 mg/l 10 mg/l 4 mg/l 0.30 MGD 250 mg/l 50 mg/l 10 mg/l 6 mg/l 0.35 MGD 250 mg/l 50 mg/l 10 mg/l 10 mg/l 0.40 MGD 300 mg/l 50 mg/l 10 mg/l 28 mg/l > 0.40 MGD BNR Capabilities Lim ited (Only Secondary Treatment Available) As noted within the projections and depending on influent loading, the SWWTP is not anticipated to provide sufficient BNR capabilities once flows begin to exceed 0.35 MGD. TN levels are anticipated to be difficult to control as flows exceed these values. TMDL limitations may also impact available treatment volumes dependent on other Mittauer & Associates, Inc. Project No Page 49

75 influencing factors such as HRWWTP loading and available reuse flow as discussed in Section II.B. Due to current field fluctuations and limited BNR treatment components (i.e. RAS pumps, recycle pumps, real-time blower controls, etc.), we are recommending the City utilize the loading shown in Tables II-20 and II-21 until such time that performance data from the WWTP is inline with theoretical estimates. TABLE II-20 PROJECTED SWWTP RECOMMENDED WASTEWATER TREATMENT LEVELS - LOW LOADING SWWTP Flow (MGD) Loading (BOD 5 TKN) SWWTP Effluent (BOD 5 TN) Low Loading Projected Treatment Limitations 0.20 MGD 200 mg/l 50 mg/l 10 mg/l 4 mg/l 0.25 MGD 200 mg/l 50 mg/l 10 mg/l 4 mg/l 0.30 MGD 200 mg/l 50 mg/l 10 mg/l 6 mg/l 0.35 MGD 200 mg/l 50 mg/l 10 mg/l 9 mg/l 0.40 MGD 200 mg/l 50 mg/l 10 mg/l 13 mg/l TABLE II-21 PROJECTED SWWTP RECOMMENDED WASTEWATER TREATMENT LEVELS - HIGH LOADING HRWWTP Flow (MGD) Loading (BOD 5 TKN) HRWWTP Effluent (BOD 5 TN) High Loading Projected Treatment Limitations 0.20 MGD 250 mg/l 50 mg/l 10 mg/l 4 mg/l 0.25 MGD 250 mg/l 50 mg/l 10 mg/l 4 mg/l 0.30 MGD 250 mg/l 50 mg/l 10 mg/l 6 mg/l 0.35 MGD 250 mg/l 50 mg/l 10 mg/l 10 mg/l 0.40 MGD 300 mg/l 50 mg/l 10 mg/l 28 mg/l Mittauer & Associates, Inc. Project No Page 50

76 3) Mechanical Reliability Lastly, a review of the mechanical reliability requirements for the SWWTP was conducted to determine future expansion requirements. The SWWTP has to meet Class III Reliability Requirements in accordance with FDEP Rule (1)(a), FAC. Table II-22 summarizes the reliability review for the SWWTP. TABLE II-22 SWWTP CLASS III RELIABILITY REVIEW Process Unit Class III Requirement SWWTP Screening No back-up screen required. No back-up provided. Pumping Blowers In-Plant Pum p Station Effluent Pum ps Reuse Pumps Metering Pum ps Back-up pump(s) (one pump shall meet peak daily flow) Two (2) pum ps provided for all system s capable of providing peak daily flow of 1.5 MGD or greater Clarification Two Basins (secondary basin may have 50% design capacity) T w o (2 ) C la rifie rs provided Aeration One Basin Perm issible Two (2) basins provided. Filtration No back-up required One (1) Filter provided Digester No back-up required O n e ( 1 ) D i g e s t e r provided Disinfectant Basin (CCC) T w o B a s in s ( s e c o n d a r y basin may have 50% design capacity) Two (2) Cham bers provided via gates Emergency Generator C a p a c i t y t o o p e r a t e : Screening, Blowers, Main W a s t e w a t e r P u m p s, C la r if ie r, D i s i n f e c t a n t Facilities, and C ritical Operation Bldg Needs Provided Expansion alternatives related to the SWWTP are limited as further discussed in Section VI. However, the aforementioned review has summarized limiting components as well as anticipated treatment limitations. Mittauer & Associates, Inc. Project No Page 51

77 c. Effluent Disposal Capacity The SWWTP effluent disposal capacity is only limited by the existing St. Johns River outfall and the St. Johns River TMDL limits. The TMDL implications were discussed in Section II.A. and II.B. This subsection reviews other potential limiting factors on current effluent disposal capacity such as: Current FDEP Permit Limitations; and Current TMDL Implications. The current FDEP permitted effluent limitations for the SWWTP are listed in Table II-23. TABLE II-23 SWWTP EFFLUENT LIMITATIONS Parameter Effluent Limits Units CBOD 5 (max.) TSS (m g/l) ph (Std. Units) Cl2 Residual for Disinfection (m g/l) Cl2 Residual for Dechlorination (m g/l) Maxim um Fecal Coliform (#/100 ml) (River) 20/25/40/60 (Reuse) 20/30/45/60 (River) 20/30/45/60 (Reuse) 5 in any 1 Sample (River) 6.0 to 8.5 (Reuse) 6.0 to 8.5 (River) 0.50 (Reuse) 1.00 (River) 0.01 (Reuse) n/a (River) 200/400/800 (Reuse) 25 Ann/Mon/W k/single Ann/Mon/W k/single Ann/Mon/W k/single Ann/Mon/W k/single Daily Sam ple, Report Monthly Daily Sam ple, Report Monthly Daily Sam ple, Report Monthly a b c Mon /Mon /Single Single c d Total Nitrogen (ppy) 17, m onth rolling sum d Total Phosphorus (ppy) 4, m onth rolling sum a Monthly Mean Reported b No More than 10% in the Monthly Sampling can be Greater than 400 c Any Single Sample Can Not Exceed 800 (River) or 25 (Reuse) d: Combined effluent disposal quantity from SWWTP and HRWWTP. Mittauer & Associates, Inc. Project No Page 52

78 d. Residuals Disposal Capacity The SWWTP contains only one digester which is a compartment of the ringsteel package WWTP. The digester has a side water depth of 16 feet and a total volume of 102,500 gallons. Centrifugal blowers with coarse bubble diffusers deliver oxygen to the digester compartment. 3 3 The digester provides 6.9 ft per capita (i.e., 13,705 ft /2,000 capita) which 3 is greater than the recommended range of 2 to 4 ft /capita. Digested sludge from the digester is transferred via gravity to onsite drying beds for further dewatering prior to eventual transport and disposal in a permitted landfill. The combined drying beds provide 10,000 square feet of drying bed surface. 2 Based on a 1.25 ft per capita design value, the existing drying beds provide adequate area for sludge dewatering (i.e., 10,000 SF > 2,500 SF (2,000 capita * 1.25 SF/capita). As discussed within the HRWWTP review, the City has traditionally transferred digested sludge to onsite drying beds for dewatering prior to eventual transport and disposal in a permitted landfill. The City has recently moved away from the sludge drying beds and is pursuing other interim onsite dewatering options until a final approach is selected. Dewatered materials are still transferred to the landfill for ultimate disposal. Ultimately, the City would like to construct permanent dewatering capabilities to address the biosolids dewatering needs since sludge drying bed operations are heavily dependent upon rainfall patterns, and cleaning the beds are operator intensive. Consideration of available dewatering technologies is provided in Section VI. Recent FDEP rule changes related to biosolids disposal and Class AA residual requirements are discussed further in Section III. C. COLLECTION AND TRANSMISSION SYSTEMS For purposes of this report, the City s wastewater system is being broken into two (2) main sub-service areas within the overall Service Area that was illustrated in Figure II-1. The northerly half of the service area which collects and transmits wastewater to the HRWWTP is called the North Service Area while the area which delivers wastewater to the SWWTP is entitled the South Service Area. The North Service Area generally includes the following components: Mittauer & Associates, Inc. Project No Page 53

79 North-Core Service Area which includes the oldest areas of the City; North-Magnolia Service Area which consists of existing and future phases of Magnolia Point; and North-Upper Service Area which includes all other areas within the northern extremes of the North Service Area. The South Service Area includes a much smaller portion of the Core City and the commercial/industrial areas within the Reynolds Industrial Park. The North Service Area is currently the most populated area of the City. In contrast, the South Service Area is least populated but has the highest potential for future development and growth. Each sub-service area is delineated in Figure II-1. Wastewater is collected and transmitted to both WWTPs via gravity collection piping, pump stations, and force mains. A list of the current pump stations and their respective collection areas are summarized in Table II-24 which will be referenced throughout the following subsections of this report. TABLE II-24 WASTEWATER COLLECTION & TRANSMISSION BASIN SUMMARY Basi n I.D. P.S. I.D. P.S. Location WWTP Service Area P.S. Discharge Location Current Treatment Location 1 1 SR 16 W est Near Cem etery North-Core P.S. #4 Collection System HRW W TP 2 2 Palmetto Ave. & Golfair St. South SW W TP SW W TP 3 3 Gum St. & St. Johns Ave. North-Core P.S. #4 Collection System HRW W TP 4 4 Lam ont St. North-Core HRW W TP HRW W TP 5 5 Verm ont Ave. & East St. North-Core 6 6 Middleburg Ave. North-Core P.S. #4 Collection System P.S. #4 Collection System HRW W TP HRW W TP Mittauer & Associates, Inc. Project No Page 54

80 TABLE II-24 (cont.) WASTEWATER COLLECTION & TRANSMISSION BASIN SUMMARY Basin I.D. P.S. I.D. P.S. Location WWTP Service Area P.S. Discharge Location Current Treatment Location 7 7 Governor Cir. North-Core 8 8 Gum Public W orks North-Core 9 9 City Hall at W alnut St. North-Core P.S. #4 Collection System P.S. #4 Collection System P.S. #4 Collection System HRW W TP HRW W TP HRW W TP Electric Dept at Harbor Rd. North-Magnolia HRW W TP HRW W TP Magnolia Shopping Center North-Magnolia HRW W TP HRW W TP North End of Enterprise W ay North-Magnolia HRW W TP HRW W TP Constancia Drive (Magnolia) North-Magnolia HRW W TP HRW W TP Muirfield opposite Inverness North-Magnolia HRW W TP HRW W TP Colonial Dr. & Stonebriar North-Magnolia HRW W TP HRW W TP Cherry Hill Ct. (Colonial Dr.) North-Magnolia Preston Trail (Shoal Creek) North-Magnolia Shinnecock North-Magnolia P.S. #15 Collection System P.S. #16 Collection System P.S. #14 Collection System HRW W TP HRW W TP HRW W TP North of SR 16 E (Reynolds) South-Reynolds SW W TP SW W TP JP Hall Ind. Park South-Reynolds Food Lion W arehouse South-Reynolds P.S. #2 Collection System P.S. #2 Collection System SW W TP SW W TP HRW W TP North-Magnolia HRW W TP HRW W TP SW W TP South-Reynolds SW W TP SW W TP Mittauer & Associates, Inc. Project No Page 55

81 TABLE II-24 (cont.) WASTEWATER COLLECTION & TRANSMISSION BASIN SUMMARY Basi n I.D. P.S. I.D. P.S. Location WWTP Service Area P.S. Discharge Location Current Treatment Location Pegasus (Reynolds) South-Reynolds P.S. #19 Collection System SW W TP SW W TP Lab Bldg. South-Reynolds SW W TP SW W TP W inn Dixie U.S. 17 North North-Upper HRW W TP HRW W TP Calico Jack (The Cove) North-Core Olym pic Drive North-Magnolia P.S. #4 Collection System P.S. #13 Collection System HRW W TP HRW W TP Hickory Knolls North-Upper HRW W TP HRW W TP Five Oaks North-Upper HRW W TP HRW W TP The components listed in Table II-24 are further discussed and reviewed in the context of each service area within the following subsections of the report. Section VI will also review options related to modifying these stations and/or their force mains to facilitate future infrastructure expansion alternatives. 1. North Service Area A review of the existing gravity collection ( Gravity System ) and force main ( FM System ) systems was conducted, and the results of these findings are discussed herein. Existing infrastructure capacity, as it relates to future expansion needs, is discussed in Section VI of the report. As shown in Figure II-1, the North Service Area is comprised of the Core City Area, Magnolia Point, and older areas located within the northern reaches of the North Service Area. The overall North Service Area Gravity System is illustrated within Figures II-11 through II-13. Mittauer & Associates, Inc. Project No Page 56

82 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-11A-B North - Upper Service Area.dwg, 2/25/ :50:26 AM

83 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-11A-B North - Upper Service Area.dwg, 2/25/ :50:58 AM > 4 FM > 4 FM > 4 FM

84 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-12 North - Magnolia Service Area.dwg, 2/25/ :56:23 AM CR EE K > 4 FM > 4 FM >4 FM TELLGRASS CT.

85 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-13A-B North - Core Service Area.dwg, 2/25/ :59:37 AM > 4 FM >4 FM > 4 FM

86 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-13A-B North - Core Service Area.dwg, 2/25/2015 2:41:22 PM > > 4 FM 4 FM > 4 FM > 4 FM

87 The majority of the Gravity System within the Core City Areas, and the northern reaches of the North Service Area were constructed during an era when vitrified clay piping ( VCP ) was the predominate gravity sewer material. In contrast, the newer subdivisions and commercial developments, such as those constructed or being constructed within the Magnolia Point area, utilized polyvinyl chloride ( PVC ) piping which is the current industry standard. As the older VCP collection systems have aged, they have tended to fracture, settle, or have other similar failures. Since the natural groundwater elevation within Florida is very near the ground surface, the relatively deep portions of the gravity collection systems (typically 10 to 25 feet below grade) are submerged. This condition in combination with the dated infrastructure often allows groundwater and sand particles ( grit ) to infiltrate into the collection system. In more extreme cases, the faulty piping and/or poor connections to manholes can create potential roadway failures due to the materials beneath the roadway eroding away due to the influence of the piping being open to the surrounding conditions. The collection system matrix allows the City to identify and target areas of the wastewater system which are likely experiencing infiltration. This additional groundwater leads to over sizing of treatment facilities necessitating extra capacity within the WWTP, creating hydraulic surges within the wastewater systems, and potentially leading to ineffective wastewater treatment. The data collection and the resulting database will effectively allow the City to target areas in which I/I maybe an issue. Mittauer & Associates, Inc. recommends that the City take the following steps to further determine the status of their Gravity System, categorize the needs, and lead the City to a point of creating capital improvement budgets to remedy the deficient areas. The City should continue to review and plan for improvements to those areas which contain VCP systems which will only become a more significant issue as the Gravity System ages. As those areas are rehabilitated, the City may be able to gain capacity within the existing WWTP. This can be used to more effectively serve the community since capacity which could be available for new developments is not lost to treatment of groundwater inflow. The available capacity can then be used for reservation of new or redeveloped growth which will generate impact fees which can more effectively fund necessary improvements. Mittauer & Associates, Inc. Project No Page 62

88 a. Transmission System As shown within Table II-24, the Gravity System within the North Service Area is much larger than the South Service Area, and it contains the bulk of the City s pump stations. The pump stations which are reviewed and discussed in detail within this section of the report are limited to P.S. Nos. 3, 4, and 26. These stations are reviewed in detail since they are either the larger, more critical stations within the network or present a potential for future repumping scenarios discussed in Section VI. Further, P.S. No. 4 is currently a significant repump station for the City which will also be reviewed, within Section VI, for potential modification to transmit wastewater to a new southerly WWTP. Figures II-11 through II-13 illustrate the limits of the transmission system in relation to the City s existing roadway infrastructure while Figure II-14 provides an overall schematic of how each pump station repumps or manifolds together to deliver wastewater to the HRWWTP. Figure II-14 shows the extent of repumping and the amount of pump stations flowing into P.S. No. 4 which is further discussed in this subsection of the report. This subsection will review the following characteristics of the City s existing North Service Area FM System: Existing Capacity per Pump Station; Hydraulic Capacity of P.S. Nos. 3 and 4; Hydraulic Capacity of P.S. No. 4 Collection System; and General Operation and Maintenance Considerations. In order to determine the potential hydraulic constraints to pump wastewater under future infrastructure modification scenarios, force main hydraulics were reviewed based on a maximum allowable pipe velocity of approximately 5 feet per second. This velocity is in the upper-end of economical pumping range and allows for economical pump selection as well as lower operational costs due to smaller motor sizing. The analysis was limited to those stations which are currently manifolded (i.e., pump stations with their force mains connected to one another which are hydraulically interactive) to calculate current system capacity. Mittauer & Associates, Inc. Project No Page 63

89 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-14 North Service Area PS Flow Schematic.dwg, 2/25/2015 3:00:41 PM

90 The future infrastructure modifications are discussed in Section VI, while the results of the existing infrastructure constraints are discussed within this section. It should be noted that the results are preliminary and require final design considerations, however they are considered applicable to this study and valid for use in the planning level cost estimates. 1) Existing Capacity per Pump Station The City s Comprehensive Plan 2020, adopted on November 21, 2006, within the Sanitary Sewer, Solid Waste, Drainage, Potable Water, and Natural Groundwater, and Aquifer Recharge Element lists the required wastewater level of service to be 120 gallons per resident ( capita ) per day (Policy 4.1.1). The current population estimated to reside within the City is approximately 7,035 persons and the total accounted for lots currently being served by the City s wastewater system is approximately 3,870. When dividing the total population per lot count, the per capita household density is approximately 1.8 capita per household (7,035 persons/3,870 lots). A typical planning household density is between 2 and 3.5 persons, thus for planning purposes a value of 2.2 capita is used with flow projections reviewing impacts of densities varying between 2.2 and 2.4 capita. Table II-25 summarizes the pump stations within the North Service Area and the associated average day demand pursuant to an ERU density of 2.2 capita and a planning flow demand of 100 gpcd. The table also includes a calculation for peak hourly flow ( PHF ) which is typically calculated at a factor of four (4) times the average daily flow values. Pumps within each pump station are typically sized to meet the peak hour flow value, and at a minimum have to provide enough flow to meet the self-cleansing velocity of the force main piping. Mittauer & Associates, Inc. Project No Page 65

91 TABLE II-25 NORTH SERVICE AREA P.S. CAPACITY OVERVIEW P.S. I.D. P.S. Location FM Delivery Location a (FM Size) b ERUs b Current ADF (GPD) Current c PHF GPM (Design d GPM ) 1 SR 16 W est Near Cem etery P.S. #4 (6") , (180) 3 Gum St. & St. Johns Ave. P.S. #4 (8") , (320) 4 Lamont St. HRW W TP (12") , (1,050) 5 Vermont Ave. & East St. P.S. #4 (4") 33 7, (100) 6 Middleburg Ave. 7 Governor Cir. P.S. #4 (6") P.S. #4 (4") ,000 7 (180) (100) 8 Gum Public W orks P.S. #4 (4") (100) 9 City Hall at W alnut St. P.S. #4 (4") (100) 10 Electric Dept at Harbor Rd. HRW W TP (4") (100) 11 Magnolia Shopping Center HRW W TP (4") (100) 12 North End of Enterprise W ay HRW W TP (4") 11 2,400 7 (100) 13 Constancia Drive (Magnolia) HRW W TP (4") 62 13, (100) 14 Muirfield opposite Inverness HRW W TP (6") , (130) 15 Colonial Dr. & Stonebriar HRW W TP (6") , (250) 16 Cherry Hill Ct. (Colonial Dr.) P.S. #15 (6") , (180) 17 Preston Trail (Shoal Creek) P.S. #16 (4") 7 1,600 4 (100) Mittauer & Associates, Inc. Project No Page 66

92 TABLE II-25 (cont.) NORTH SERVICE AREA P.S. CAPACITY OVERVIEW P.S. I.D. P.S. Location FM Delivery Location a (FM Size) b ERUs b Current ADF (GPD) Current c PHF GPM (Design d GPM ) 18 Shinnecock 22 HRW W TP 26 W inn Dixie 27 Calico Jack - The Cove 29 Olym pic Drive 30 Hickory Knolls 31 Five Oaks P.S. #14 (6") HRW W TP (4") HRW W TP (8") P.S. #4 (4") P.S. #13 (4") HRW W TP (4") HRW W TP (4") , (180) (100) (320) (100) , (100) 99 21, (100) 54 11, (100) Total 2, ,400 n/a a: If Pump Station is listed, then the actual discharge is into the collection system of that pump station. b: FM size and ERU counts are estimated from the City s current records and parcel maps. c: PHF is based on a peaking factor of four (4) d: GPM values are recommended minimum firm capacity required at each pump station. The majority of the pump stations are low-flow (i.e., 100 gpm ±) stations which pump into a gravity collection system for repumping via another pump station to the HRWWTP. The most critical pump stations within the system are P.S. Nos. 3, 4, 15, 16, and 18. These pump stations are responsible with delivering a combined average daily flow of 397,500 gpd or approximately 70% of the North Service Area s total demand. P.S. No. 4 repumps flow from seven (7) pump stations which have a combined average daily flow of 318,000 gpd or 56% of the total demand. P.S. No. 15 repumps flow from fewer stations (three); however, the total average daily flow is approximately 142,800 gpd or 25% of the North Service Area s total demand. In combination, these two stations pump over 80% of the North Service Area s wastewater to the HRWWTP. Therefore, mechanical reliability and redundancy measures for these two stations Mittauer & Associates, Inc. Project No Page 67

93 are critical for the overall viability of the North Service Area s wastewater collection and transmission system. 2) Hydraulic Capacity of P.S. Nos. 3 and 4 The existing capacity for P.S. Nos. 3 and 4 are further evaluated in context of their existing wetwell dimensions and capacity of each existing gravity collection system. The dimensions of each station s wetwell determine potential storage capacity as well as potential pump sizing if the pump stations have to be upgraded in the future. This item will be reviewed in particular within Section IV. Typically, a pump station wetwell is designed to minimize the number of starts during any given hour as well as ensure the minimum pump run times to avoid short-cycling of the motor. Typically a run time of two (2) minutes or greater is provided to minimize mechanical failures and lengthen the life of the motor. The equation for sizing a typical pump station wetwell is as follows: V = Q T/4 where: V = Wetwell Volume (gal) Q = Pump Flow (gpm) T = Time between Run Times (min) The pump flow rate should equal or exceed the influent flow rate from the collection system (repump flows + gravity flows) and the typical time between run times is six (6) to ten (10) minutes. For purposes of this report a ten (10) minute time was used. A further check is provided to ensure the pump run time is greater than two (2) minutes which is calculated as follows: V = Q * 2 min A summary of the wetwell characteristics for the noted pump stations is provided in Table II-26. Mittauer & Associates, Inc. Project No Page 68

94 TABLE II-26 PUMP STATION NOS. 3 & 4 EXISTING WETWELL REVIEW Pump Station Exist. Pump Flowrate (gpm) Current Peak Influent Flowrate a (gpm) Wetwell Diameter (ft) Exist. Wetwell Volume (gal) Min. Reqd. Wetwell Volume (gal) P.S. # , a P.S. #4 1, ,975 3,825 a: Value does not match Table II-25 since it includes influent flows from other pump stations which pump into the P.S. #4 collection system. The minimum wetwell volume shown within the table is the calculated minimum. The existing wetwell volume available indicates that the pump station could be modified with installation of larger pumps. A summary of the total (two pumps running if triplex system) pump sizing that could be provided in each wetwell is shown as follows: P.S. No. 3 = 450 gpm P.S. No. 4 = 1,590 gpm P.S. No. 3 currently has an 8-inch FM with capacity to pump approximately 785 gpm (V = 5.0 fps) while P.S. No. 4 has a 12-inch FM capable of pumping approximately 1,760 gpm (V = 5.0 fps). Based on the minimum wetwell volumes shown within the table and the existing force main capacities, a summary of the total (two pumps running if triplex system) pump sizing that could be provided at P.S. No. 4 is 1,590 gpm (PHF). This corresponds to an average daily flow of 572,400 gpd (AADF) when assuming a 4.0 peak factor. 3) Hydraulic Capacity of P.S. No. 4 Collection System The receiving gravity collection system for P.S. No. 4 was reviewed to determine if any additional capacity was available for future repumping scenarios from P.S. No. 2 in the South Service Area or future development to the north or northwest. Mittauer & Associates, Inc. Project No Page 69

95 The various influent discharge locations for P.S. No. 4 are shown within Figure II-15 along with the pipe diameters of the existing collection system. In parentheses are the assumed pipe capacities based on gravity piping laid at minimum slopes to provide a 2.0 fps velocity. Based on this assumption, the various pipe diameters have the following pipe capacities at the noted slope: 8" Pipe = 345 gpm (0.40 %) 10" Pipe = 490 gpm (0.25%) 12" Pipe = 720 gpm (0.20%) 15" Pipe = 1,125 gpm (0.15%) 18" Pipe = 1,560 gpm (0.11%) The current system provides adequate capacity. However, piping modifications may be required depending upon where additional flows are added to the system. These items will be reviewed in Section IV. Based on the 18-inch influent piping, P.S. No. 4's maximum capacity is limited to 1,560 gpm (PHF) or approximately 561,600 gpd (AADF). 4) General Operation and Maintenance As with the gravity collection system data collection, the City is beginning to build a database incorporating data for all of the pump stations within the City. The information includes electrical service information, generator components, pump sizing, wetwell dimensions, etc. A copy of the current matrix along with the current field summary review reports per select pump station is provided as Attachment E. The City should be aware of peak flows from the collection transmission system that could impact clarifier performance as well as BNR capabilities. Mittauer & Associates, Inc. Project No Page 70

96 > 4 FM >4 FM >4 FM M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-15 PS 4 Discharge Locations.dwg, 2/25/2015 3:04:32 PM

97 2. South Service Area Similar to the North Service Area analysis, a general review and analysis of the existing Gravity System and FM System were completed. The results of these findings are discussed further herein and will be applied to future wastewater demands and infrastructure modifications within Section VI. a. Gravity System This subsection will review the following characteristics of the City s existing Gravity System within the South Service Area: Existing Gravity System Characterization; and I/I Review. As shown in Figure II-1, the South Service Area is mostly comprised of the industrial park and some developments on the south end of the Core City. The overall South Service Area Gravity System is illustrated within Figure II-16. The majority of the Gravity System within the industrial park and the Pump Station No. 2 collection system were constructed using VCP. As discussed in Section II.C., this will likely lead to potential I/I as well as maintenance issues as the system ages. In the past, Pump Station No. 19's collection system has been found to be completely plugged with dirt when one of the upstream pump stations was having difficulty pumping into the system. This provides some confirmation of the status of the piping and potential concern for future maintenance issues which need to be addressed prior to, or during, redevelopment of this and other areas of concern. As discussed previously, Mittauer & Associates, Inc. recommends the City maintain and update its master spreadsheet delineating pipe slopes, piping materials, manhole labels, manhole depths, etc., and should begin to map areas where more in-situ television studies are completed. The matrix included in Attachment E includes data entry points for TV inspection results which the City can use in its analysis of the existing infrastructure. Mittauer & Associates, Inc. Project No Page 72

98 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-16A South Service Area.dwg, 2/25/2015 3:11:22 PM > 4 FM > 4 FM > 4 FM > 4 FM

99 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-16B South Service Area.dwg, 2/25/2015 3:12:13 PM

100 As a recap to the discussion provided within the North Service Area section, Mittauer & Associates, Inc. recommends that the City take the noted steps to further determine the status of their Gravity System, categorize its needs, and develop capital improvement budgets to remedy the deficient areas. b. Transmission System This subsection will review the following characteristics of the City s existing Transmission System within the South Service Area: Overall Characterization of the South Service Area; Hydraulic Capacity of P.S. Nos. 2, 19, and 21; Hydraulic Capacity of P.S. Nos. 2 and 19 Collection System (P.S. No. 21 not reviewed since it is not likely to have a repump need through its collection system); and General Operation and Maintenance Considerations. 1) Overall Characterization of the South Service Area As discussed in the Gravity Sewer Section review, the South Service Area is mostly comprised of industrial and commercial lands excluding those portions of the system which are served by P.S. No. 2. The existing residential areas which comprise P.S. No. 2's service area are located just south of the North Core Service Area, and they can be defined as having the same characteristics. In contrast, the largest land masses within the South Service Area are comprised of the industrial/commercial parks or vacant lands which are either candidates for potential redevelopment or will become new, large-scale developments. The growth within the area will be reviewed in Section V while this discussion primarily focuses on the two large pump stations (P.S. Nos. 2 and 19) and the three (3) large transmission mains which convey the South Service Area wastewater into the SWWTP. Figure II-16 illustrates the limits of the transmission system in relation to the City s existing roadway infrastructure while Figure II-17 provides an overall schematic of how each pump station repumps or manifolds together to deliver wastewater to the SWWTP. Mittauer & Associates, Inc. Project No Page 75

101 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure II-17 South Service Area Flow Schematic.dwg, 2/25/2015 3:12:57 PM

102 Table II-27 summarizes the pump stations within the South Service Area and the associated flows which were computed as discussed in Section II.B. TABLE II-27 SOUTH SERVICE AREA P.S. CAPACITY OVERVIEW P.S. I.D. P.S. Location FM Delivery Location a (FM Size) b ERUs b Current ADF (gpd) Current c PHF gpm d (gpm ) 2 Palmetto Avenue and Golfair Street SW W TP (12") , ,432 (640) 19 E. Rey. Ind. Pk. SW W TP (12") e 1 30, (530) 20 J.P.Hall Ind.Pk. Near Tamko SW W TP (4"/6"/12") e 1 5, (80) 21 U.S. 17 Food Lion W arehouse SW W TP (6"/12") e 1 30, (160) 23 South GCS W astewater Plant SW W TP (4") f (100) 24 Pegasus P.S. #19 (6") e 1 5, (240) e Total ,910 n/a a: If Pump Station is listed, then the actual discharge is into the collection system of that pump station. b: FM size and ERU counts are based the City s current records and parcel maps. c: PHF GPD value is based on a peaking factor of four (4) d: GPM values are recommended firm capacity values for each Pump Station e: Commercial/Industrial Park Flows are estimated. As shown in the table, the South Service Area is primarily serviced from P.S. Nos. 2, 19, and 21. P.S. No. 2 accounts for 63% of the entire service area flow based on planning values. Actual pump run times indicate P.S. No. 2 is delivering 85 to 90% of the flow. Therefore, P.S. No. 2 is the main contributor to feeding the SWWTP. The total flow at the SWWTP is currently averaging around 250,000 gpd which is approximately 60,000 gpd (250, ,000 gpd) greater than that anticipated from an ERU basis in Table II-27. The difference is likely a result of infiltration/inflow and industrial users within the South Service Area. Mittauer & Associates, Inc. Project No Page 77

103 2) Hydraulic Capacity of P.S. Nos. 2, 19, and 21 The existing capacity for P.S. Nos. 2, 19, and 21 will be evaluated in context of the existing wetwell dimensions and force main hydraulics. P.S. No. 21's wetwell sizing will not be reviewed since it is unlikely that a repump scenario would occur. However, the 6" force main which serves this location extends approximately 18,000 feet south of SR 16 and could be used to service future developments in the southern extents of the South Service Area. The wetwell characteristics for P.S. Nos. 2 and 19 were reviewed since there is a chance that they could be used in a repump scenario. A summary of the wetwell characteristics for the noted pump stations is provided in Table II-28. TABLE II-28 PUMP STATION NOS. 2 & 19 EXISTING WETWELL REVIEW P.S. Exist. Pump Flowrate (gpm) Current Influent Flowrate (gpm) P.S. Dia (ft) Available Wetwell Volume (gal) Min. Reqd. Wetwell Volume (gal) ,400 1, ,500 1,325 The minimum required wetwell volume shown within the table is the calculated minimum. The available wetwell volume indicates that the pump station could be upgraded with installation of larger pumps. A summary of the maximum pump sizing that could be provided in each wetwell is shown as follows: P.S. No. 2 = 1,325 gpm P.S. No. 19 = 3,000 gpm Similar to the North Service Area review, FM capacities were reviewed based on a maximum pipe velocity of 5.0 feet per second. For the existing manifold scenario, Pump Stations Nos. 2, 19, and 21 are assumed to be operating simultaneously and flowing into the existing 12-inch FM. The capacity of each pump station is summarized as follows: Mittauer & Associates, Inc. Project No Page 78

104 P.S. No. 2 = 640 gpm (running alone) P.S. No. 19 = 530 gpm (running alone) P.S. No. 21 = 160 gpm (running alone) Sum = 1,300 gpm The 12-inch FM capacity is 1,760 gpm and thus has additional capacity for future flows. All future FM capacities should consider the WWTP s clarifier capacities as well as BNR arrangements. 3) Hydraulic Capacity of P.S. Nos. 2 and 19 Collection System The receiving gravity collection systems for P.S. Nos. 2 and 19 were reviewed to determine if any additional capacity was available for future repumping scenarios. Currently, P.S. No. 2 only receives force main flow from the Cove Apartments. In the past, Gustafson s considered development of a pre-treatment system that would deliver wastewater from their property into the P.S. No. 2 collection system. The Gustafson flow would have brought the existing 8" and 10" collection system to capacity. The Gustafson connection did not materialize and does not appear to be an option going forward. The P.S. No. 19 collection system appears to be greatly oversized for its current needs. Most of the gravity piping located north of S.R. 16 is 12 inches while the flows expected within the system are only a fraction of the pipe s capacity at peak hourly flow. Therefore, there is significant capacity within this collection system for future use if the piping still has structural integrity and/or does not have excessive I/I issues. The following summarizes the potential limiting factors for flow expansion in each pump station: P.S. No. 2 Limiting Infrastructure: The pump station could potentially be increased to a capacity of 1,360 gpm pending future manifold scenarios and clarifier capacity. P.S. No. 19 Limiting Infrastructure: The large diameter collection system piping would allow for repump scenarios if needed; however, the integrity and status of the piping would need to be Mittauer & Associates, Inc. Project No Page 79

105 researched prior to making any final recommendations. The upper capacity of the 12" collection system piping is approximately 750 gpm, and the overall pump station could be increased to a capacity of 750 gpm pending future manifold scenarios. 4) General Operation and Maintenance As discussed within the North Service Area section of this report, a copy of the current pump station matrix along with the current field summary review reports per select pump station is provided as Attachment E. This information should be kept in a central location and updated during any upgrades or modifications to the system. The City should be aware of peak flows from the collection transmission system that could impact clarifier performance as well as BNR capabilities. D. ONSITE SEWAGE TREATMENT & DISPOSAL SYSTEMS Some limited areas within the City s Service Area are currently served via onsite means. Many of these areas are rural in nature or they are located at a sufficient distance where connection to the City s central sewer system is not economically feasible. This subsection is intended to identify these areas and generally quantify their capacities and respective demands on nutrient loading. The FDEP provides the following summary related to Onsite Sewage Treatment and Disposal Systems (OSTDS): The septic tank is only one component of a properly designed OSTDS. By definition, an OSTDS can contain any one or more of the following components: septic tank; subsurface drainfield; aerobic treatment unit (ATU); graywater tank; laundry wastewater tank; grease interceptor; pump tank; waterless, incinerating or organic waste-composing toilet; and sanitary pit privy. An OSTDS is not a package plant. The system must provide for subsurface effluent disposal and must not have any open tanks or open treatment units. Mittauer & Associates, Inc. Project No Page 80

106 The Bureau of Onsite Sewage Programs in the Florida Department of Health ( FDOH ) and the environmental health section of the County Health Departments regulate the use of OSTDS. However, FDOH does not permit the use of an OSTDS where the estimated domestic sewage flow (as calculated in Table 1 of 64E-6.008, F.A.C.) from the establishment is over 10,000 gpd or the commercial sewage flow is over 5,000 gpd; or where there is a likelihood that the system will receive toxic, hazardous, or industrial wastes; or where a sewer system is available; or if any system or flow from the establishment is currently regulated by FDEP, unless a variance from these prohibitions has been granted by FDOH. While septic tanks can provide an economical and beneficial mechanism to treat domestic wastewater, the use of these systems in more densely developed areas and/or areas with high groundwater can be problematic. Table II-29 compares nutrient removal parameters and capabilities between an OSTDS and central treatment systems such as MLE or AWWT. TABLE II-29 COMPARISON OF CENTRAL TREATMENT VS. OSTDS EFFLUENT CONCENTRATIONS Parameter Raw Wastewater AWWT Treatment System MLE Treatment System a Septic Tank Effluent b 1-ft below Drainfield b 3-ft below Drainfield b BOD 5 (m g/l) TSS (m g/l) Total Nitrogen (m g/l) Amm onia (m g/l) Nitrate (m g/l) Total Phosphorus (m g/l) Fecal Coliform (MPN/100 m L) < 5 < C (RIB) c (Reuse) < 5 < < 40 < < 20 0 < 1 < 2 < 12 < 1 < 40 < < 1 < < 10 < < (Reuse) c < 200 (RIB) < (Reuse) c a: FDEP Permit Limit or Anticipated Treatment Level using AWWT or MLE Treatment Process rd b: Values from Table 14-7 of Wastewater Engineering - Treatment, Disposal, and Reuse, 3 Edition, Metcalf & Eddy, Inc., c: Filtration is provided by the City to achieve this requirement Mittauer & Associates, Inc. Project No Page 81

107 As noted above, the treatment levels within the OSTDS are greatly dependent upon an effective drainfield. If groundwater is elevated or a drainfield is substandard, then treatment levels from an OSTDS system are greatly compromised. Figure II-18 identifies a number of isolated areas within the City that remain on septic tanks. It is anticipated that central sewer service to these areas would be extended as a result of either: (1) new development adjacent to existing homesteads; (2) redevelopment; or (3) future compliance requirements. However, near-term extensions into these areas is not anticipated by the City. The largest aggregated existing OSTDS area by comparison is the river front area east of U.S. 17 identified as the North Upper Service Area River Front Lots, Occupied Large Lots, and Occupied Small Lots. In total, it is anticipated that approximately 250 units are currently served by an OSTDS within this region of the City s Service Area. The approximate units that are currently served by OSTDS are illustrated within Figure II-18 and are summarized as follows: North Upper Service Area (River Front Lots) = 70 units North Upper Service Area (Occupied Large Lots) = 45 units North Upper Service Area (Occupied Small Lots) = 135 units North Core Service Area (Occupied Large Lots) = 75 units South Core Service Area (Occupied Large Lots) = 40 units Total = 365 units Using a planning value of 240 gpd per unit results in average daily demand of approximately 87,600 gpd AADF. If the majority of these areas have sufficient separation from the groundwater, the TN loading is calculated as follows: MGD * 40 mg/l * 8.34 lb/mg-mg/l = 29 pounds of TN/day = 10,715 pounds per year If these areas were connected to the central sewer system with advanced treatment capabilities, then the anticipated benefit of TN reduction is summarized as follows: MGD * 3 mg/l * 8.34 lb/mg-mg/l = 2 pounds of TN/day = 730 pounds per year The ability to treat the wastewater within a designed nitrogen removal system results in a 93% loading reduction ((10, ppy)/10,715 ppy). Total Phosphorus removal would also be enhanced through a central treatment system. Mittauer & Associates, Inc. Project No Page 82

108

109 E. RECLAIMED WATER DISTRIBUTION AND WET-WEATHER OUTFALLS The North Service Area currently has Magnolia Point as its only reclaimed water customer while the South Service Area currently has no viable reclaimed water customer base. The near-term issues related to reclaimed water use and the St. Johns River TMDL limitations were discussed in this section and will be explored on a long-term basis in Section VI. Future reclaimed water use will be evaluated in Sections IV and V. It is anticipated that the City s existing St. Johns River outfalls will eventually be limited to wet-weather discharges as the City expands its reclaimed water delivery capabilities or be completely eliminated pending final direction by the City. As the City contemplates long-term objectives, the existing permitted capacities for each WWTP should be underscored. Notwithstanding the TMDL limitations, the HRWWTP river outfall has a peak flow capacity of 2.78 MGD (PHF) and permitted capacity of 1.25 MGD (AADF). The SWWTP river outfall has a peak capacity of 2.52 MGD (PHF) and a permitted capacity of 0.50 MGD (AADF). Increasing these permitted capacities may be difficult; with a 3.0 peaking factor, the HRWWTP outfall would likely begin to reach its service potential at a flow around 0.90 MGD (AADF). Mittauer & Associates, Inc. Project No Page 84

110 III. GROWTH REVIEW AND PROJECTIONS A. OVERVIEW The City s overall Service Area is mostly developed with scattered vacant parcels, including some large tracts of land, throughout the Service Area that could be developed. With the exception of Reynolds Park property in the southern portion of the City and Magnolia Point/Magnolia West in the northern portion of the City, the majority of the land in the City Limits is platted into small parcels ( ½ Ac), and the majority of these platted parcels are proposed for in-fill residential development. Larger platted parcels exist in the area north of the City Limits to Black Creek and are anticipated to be future residential developments. The City recently discussed a 2040 Urban Boundary Plan that delineated a potential future service area. The current City limits and existing Water and Sewer Service Area are shown within the 2040 Urban Boundary on Figure III-1. As the City considers wastewater needs into 2040, the anticipated build-out of the City s service area needs to be considered including potential expansion of the current service area. Therefore, the limits of the future wastewater and reuse service will consider the 2040 Urban Boundary limits shown in Figure III-1. Section V will develop potential wastewater and reuse demands based upon population projections, and this section will focus on various dynamics that will affect population growth within and around the City. In particular, the following resources will be reviewed, discussed, and analyzed regarding population growth potential and projections within the City s 2040 Urban Boundary: Reynolds Future Land Use Map (FLUM) Amendment Clay County 2025 Comprehensive Plan City of Green Cove Springs 2025 Comprehensive Plan Florida Department of Transportation (FDOT) Outer Beltway City of Green Cove Springs 2040 Urban Boundary City of Green Cove Springs Build-Out Study University of Florida Bureau of Economic and Business Research (BEBR) Population Projections Mittauer & Associates, Inc. Project No Page 85

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112 B. REYNOLDS FLUM AMENDMENT In 2009, Clay Port, Inc. submitted an application to amend the City s Comprehensive Plan and associated future land use map to promote the redevelopment of Reynolds Park ( Reynolds ). Clay Port submitted the text and map amendment to the City for review and approval, and subsequently to the Department of Community Affairs (DCA) [now the Department of Economic Opportunity (DEO)] and other reviewing agencies. The Reynolds Property is located on U.S. 17 and State Road 16 in the City of Green Cove Springs and contains five (5) City parcels within the larger boundary of the Reynolds Property. Figure III-2 depicts the limits of Clay Port s ownership and defines the land that is called Reynolds throughout the remainder of the Plan. The purpose of the Amendment was to revise the Future Land Use designation of the Reynold s parcel through amendment of the future Land Use Element to allow redevelopment under a mixed-use land use designation. The amendment also changed the land use category for five (5) parcels of land owned by the City of Green Cove Springs. The Amendment changed the Reynold s land use categories from Residential Medium Density, Commercial Medium Intensity, Commercial High Intensity, Conservation, and Industrial to land use categories of Reynolds Park Mixed Use Redevelopment District (MU-RP) and Conservation. In sum, the proposed changes: Added a new land use category to the City s Future Land Use Element; Amended the Future Land Use Map to change the land use on 1,600 acres owned by Clay Port to MU-RP category and retain the Conservation designation on 142 acres; Amended the adopted Future Land Use Map to change the land use on 1.5 acres of land owned by the City to the MU-RP category; Amended the Future Transportation Map to reflect the alignment of the First Coast Outer Beltway; Added a policy to the Future Land Use Element that addresses the location of existing wellheads within the City; and Amended the adopted Existing and Future Recreation map to delete the Reynolds Golf Course. Mittauer & Associates, Inc. Project No Page 87

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114 The MU-RP land use category provided flexibility to redevelop the land under several scenarios via the establishment of minimum and maximum development entitlements. The maximum percentage of developable land in the residential, commercial, or industrial/offices uses sets up the potential for the following three (3) different development scenarios under the MU-RP category: 1. Maximum Residential 65% Residential (834 acres/3,920 ERUs) 18% Commercial (231 acres/4.0 million SF) 12% Industrial (154 acres/3.3 million SF) 3% Office (38 acres/0.8 million SF) 2% Institutional (26 acres/0.2 million SF) 2. Maximum Commercial 50% Residential (641 acres/3,014 ERUs) 33% Commercial (423 acres/7.3 million SF) 12% Industrial (154 acres/3.3 million SF) 3% Office (38 acres/0.8 million SF) 2% Institutional (26 acres/0.2 million SF) 3. Maximum Industrial 30% Residential (385 acres/1,809 ERUs) 23% Commercial (295 acres/5.1 million SF) 36% Industrial (462 acres/10.0 million SF) 9% Office (115 acres/2.5 million SF) 2% Institutional (26 acres/0.2 million SF) As discussed further in the Plan, the redevelopment of the Reynolds area is the most dynamic variable in the City s long-term wastewater and reclaimed water service needs. The timing associated with the redevelopment is difficult to estimate, but the City will need to make long-term provisions to service this corridor. Some near-term objectives are discussed in Section III and long-term flow projections are reviewed in Section V. C. CLAY COUNTY 2025 COMPREHENSIVE PLAN Within Clay County s 2025 Comprehensive Plan, a number of elements are reviewed with the following being the most applicable to the City s future planning: 1. Future Land Use Element 2. Community Facilities Element Mittauer & Associates, Inc. Project No Page 89

115 3. Intergovernmental Coordination Element 4. Capital Improvements Element 5. Transportation Element 6. Economic Development Element 1. Future Land Use Element The purpose of the County s Future Land Use Element is stated to...examine the existing land uses and to determine present and future land use needs such as the amount of land needed to accommodate future growth and development. The following policies and objectives are highlighted as they apply to the City s Wastewater and Reuse planning. Policy Centralized Water and Sewer Service Area Map is identified on the future land use map series. The Centralized Water and Sewer Service Area are designed to accommodate and encourage compact and contiguous urban development. A copy of the map, which is the CCUA Service Area Map, is provided as Attachment F. The land included within the Centralized Water and Sewer Service Area Map is served, or is planned to be served, with adequate water and sewer services which are guaranteed through development agreements or by agreements to serve by the Clay County Utility Authority, based on the County s adopted level-of-service standards. The Centralized Water and Sewer Service Area Map shall be updated annually. Existing development within the Centralized Water and Sewer Service Area that is served by individual potable water and sewer systems may continue to be served by said individual systems. However, whenever feasible, it is recommended to consider connection to central services as specified in this Plan. In case wells or septic tanks are malfunctioning and need to be replaced, it is subject to connection to appropriate central services pursuant to Chapter 64E F.A.C. Policy Centralized Water and Sewer Service Areas may be expanded to include undeveloped land in or near existing urban areas. Services and facilities must be guaranteed through 'agreements to serve' by the Clay County Utility Authority or any appropriate service providers. Mittauer & Associates, Inc. Project No Page 90

116 Policy All development, excluding development or redevelopment of vacant residential lots with densities less than three (3) dwelling units per acre, within the Centralized Water and Sewer Service Areas shall be served by central water and wastewater services, if available. Onsite sewage treatment and disposal systems will be allowed within the Centralized Water and Sewer Service Area if central sewer is not available. Objective 1.9. The County shall ensure the availability of suitable land for water, wastewater, stormwater, and solid waste facilities sufficient to support proposed development. Policy Clay County shall work diligently with the Clay County Utility Authority and other utility providers to efficiently deliver services to meet future demand by identifying the need for additional land for expansion to meet the projected demand in the Plan. 2. Community Facilities Element The purpose of the County s Community Facilities Element is stated to...provide for necessary public facilities and services based on existing and future land use and population projections. The following goals, policies, and objectives are highlighted as they apply to the City s Wastewater and Reuse planning. Goal. Develop water, wastewater, drainage, and solid waste systems that provide and maintain adequate community facilities in a timely and coordinated manner. Coordinate the implementation of a comprehensive water management program in conjunction with SJRWMD to guide the development of the water supply, preserve water quality, promote efficient water use, maintain the aquifer, and protect groundwater recharge. Objective 1. Clay County shall only allow development permits to be issued concurrent with adequate sanitary sewer, potable water, solid waste, and drainage facility capacity based on adopted levels of service. Mittauer & Associates, Inc. Project No Page 91

117 Policy 1.1. Clay County hereby adopts the following as the level of service standards to be maintained for sanitary sewer, potable water, solid waste, and drainage facilities in Clay County: a. Sanitary Sewer: Average Flow gpd ERC Policy 1.5. The County shall not permit any additional development that would cause the particular facility type(s) to fall below the threshold LOS identified: a. Sanitary sewer and potable water: volume of existing use plus volume of committed use is 90 percent or greater. Policy 1.6. The County shall coordinate with potable water and sanitary sewer service providers to prepare annual summaries of water and sewer system demand and capacity information for each facility. This data will be used to make a determination of adequate capacity availability which will be required prior to issuance of building permits. Policy The County shall coordinate with the Clay County Utility Authority to determine plant expansion needs as they are identified. Objective 3. The County shall ensure sufficient service of solid waste, potable water, and wastewater to meet the future needs of the County and the municipalities within the County. The County shall coordinate with the Clay County Utility Authority, municipalities within the County, and private service providers to plan the efficient delivery of services to meet future demand. Policy 3.1. Clay County shall develop, in conjunction with the Clay County Utility Authority, private utility providers, state, and local governments, a Potable Water, Wastewater and Reuse Master Plan to coordinate the efficient delivery of these services to the urban areas of the County. Policy 3.2. The County shall coordinate with the Clay County Utility Authority to establish urban service areas for the unincorporated portion of Clay County. Policy 3.3. The County shall coordinate with the Clay County Utility Authority and private potable water and sanitary sewer service providers to prioritize extension of distribution and collection lines to areas planned for growth as Mittauer & Associates, Inc. Project No Page 92

118 identified on the Future Land Use Map (urban service areas) and in order to promote infill development. Objective 4: The County shall maximize the use of existing public facilities through mandatory hookups for any new developments within Centralized Water and Sewer Areas and prioritization of stormwater discharge alternatives. The County shall also encourage the use of public facilities for existing developments through active deliberation of Centralized Water and Sewer System. Policy 4.3. The County shall permit individual wastewater disposal systems (septic tanks) outside the Centralized Water and Sewer Area, provided that site and soil conditions are suitable for onsite sewage treatment plant (septic tank) use as determined by the requirements of Chapter 62, F.A.C.. Minimum design flows for septic systems shall be based on the estimated daily sewage flow as defined by Chapter 64E-6.008, F.A.C., System Size Determination, as it may be amended from time to time. Policy 4.4. The County shall prohibit the establishment of Type III wastewater treatment facilities as defined by Chapter (89) F.A.C. The FDEP and/or the County Health Department may waive the requirement of mandatory onsite sewage disposal connection if it determines that such connection is not required in the public interest due to public health considerations. Policy 4.6. Centralized Water and Sewer Areas may be expanded to include undeveloped land in or near existing urban areas provided that services and facilities are guaranteed through development agreements or by agreements to serve by the Clay County Utility Authority, when individual development agreements are impractical due to overriding public concerns or the involvement of multiple property owners. An enforceable development agreement shall include development agreements pursuant to County land development regulations and/or local utility regulations; an agreement pursuant to Chapter 163, F.S. and Concurrency Management System (Rule 9J , F.A.C.) or an agreement or development order issued in accordance with Chapter 380, F.S. Mittauer & Associates, Inc. Project No Page 93

119 3. Intergovernmental Coordination Element The County s Intergovernmental Coordination Element is stated to...identify and resolve incompatible goals, objectives, policies, and development proposed in local government comprehensive plans and to determine and respond to the needs for coordination processes and procedures with adjacent local governments and regional and state agencies. The following policies and objectives are highlighted as they apply to the City s Wastewater and Reuse planning. Policy 1.1. The County shall coordinate with its municipalities, the School Board, military installations, regional, state, federal agencies, and other local service providers to identify and discuss issues related to plan implementation, development, and funding which affect one or more of these jurisdictions in such areas as land use, transportation, sewer and water service areas, drainage, recreational facilities, public school facilities, and capital improvement programming, and include, but are not limited to, addressing the actions called for in the policies of the Clay County Comprehensive Plan. Policy 1.5. The County shall coordinate and share data annually with local governments, special districts, utility companies, and other agencies to prepare a capacity availability statement for water, sewer, and solid waste. a. The County shall cooperate with other local governments, public and private utilities, regional water supply authorities, special districts, and water management districts with regard to potable and reuse water service delivery. Objective 2. The County shall establish a means by which Level-of-Service (LOS) standards are coordinated and used consistently throughout the unincorporated and incorporated portions of the County and by other service providers. Policy The County shall work with its municipalities and adjacent local governments as appropriate to identify potential areas of annexation and to identify and implement joint planning areas. Mittauer & Associates, Inc. Project No Page 94

120 4. Capital Improvements Element The County s Capital Improvements Element is designed to ensure...facilities and services [are] available at their adopted service standard concurrent with the impacts of development. This guidance applies to the City s Wastewater and Reuse planning as follows: Goal. To provide necessary public facilities and services to the County's residents, businesses and industries in a timely manner that maximizes the use of the existing infrastructure and promotes orderly growth. Objective 3. All land use decisions shall be coordinated with the availability of fiscal resources and the schedule of capital improvements and subsequent years capital improvements programs to maintain adopted LOS and to provide existing and future facility needs. Policy 3.1. The County shall use the following LOS standards in reviewing the impacts of new development and redevelopment upon public facility provision: b. Sanitary Sewer: Average Flow GPD/ERC or as approved by FDEP 5. Transportation Element The County s Transportation Element is stated to provide...the framework for the provision of an efficient and safe transportation system that meets the travel needs of all present and future residents of Clay County. The element is coordinated with regional, state, and federal transportation agencies and helps to maintain the quality of the environment in the County. The First Coast Outer Beltway is a critical growth factor for the City and the County. Discussions related to this component and associated timing is provided in Section III. 6. Economic Development Element The County s Economic Development Element is stated to...guide policy to attract economic prosperity; build a strong business environment, achieve long-term structural change and communicate the Clay County opportunity to targeted businesses and primary industries to support a viable local economy. This guidance applies to the City s Wastewater and Reuse planning as follows Mittauer & Associates, Inc. Project No Page 95

121 Objective 2: Clay County shall ensure an adequate supply of land uses that support a viable economy and allow for employment generation such as office and industrial uses on the Future Land Use Map (FLUM). Objective 4: Clay County shall enhance business development opportunities by ensuring that Clay County develops and maintains a comprehensive, long-range infrastructure program as a key critical component of sustaining current economic growth as well as attracting future economic growth. Policy 4.3: Clay County shall coordinate future growth areas with the Clay County Utility Authority and/or municipal government expansion areas to encourage the expansion of existing and/or development of new businesses and industries. Policy 4.4: Clay County shall encourage the location of businesses and industries in areas with adequate infrastructure; in areas scheduled for future infrastructure improvements to expand existing capacity as identified in the Capital Improvement Element; or in areas to be provided with the required infrastructure as identified in binding development agreements. Policy 4.7: Clay County shall encourage utility providers to expand and extend public water and sewer facilities in a timely manner to support county wide economic development objectives and to facilitate the expedient processing of requests for service in projected growth areas. D. GREEN COVE SPRINGS 2025 COMPREHENSIVE PLAN Like Clay County, the City also completes and maintains a comprehensive plan that is reviewed by the regional planning council, Department of Economic Opportunity, and others. This document provides overall guidance related to a wide range of factors as reviewed for the County in Section III.C. The City s 2025 Comprehensive Plan also included a review of various long-term planning elements. Those that are most applicable to this Plan include the following: 1. Future Land Use Element 2. Transportation Element 3. Sanitary Sewer, Solid Waste, Drainage, Potable Water, and Aquifer Recharge Element; 4. Intergovernmental Coordination Element Mittauer & Associates, Inc. Project No Page 96

122 The future land use and sanitary sewer elements are further explored in detail in the following subsections.. 1. Future Land Use Element The following excerpts from the City s Comp Plan are provided in this section, and discussion is provided in various areas as it relates to this Plan s focus. Objective 1.11 Reynolds Park Mixed Use Category. (b) Minimum Development by In order to ensure that a mix of uses is developed in the MURP category over the planning period (2025), development within the MURP category must contain the following components and provide for the minimum development identified below in an approved PUD(s) no later than 2025, unless such period is extended by the City. The minimums identified may be accomplished under multiple PUD development approvals. The PUD approvals required no later than 2025 include at a minimum the following 3 components and corresponding development. Component Town Center Neighborhood Employment Center Minimum Development Minimum 40 dwelling units and Minimum 100,000 square feet commercial/office use Minimum 5 acres, if located north of SR 16; or Minimum 100 acres, if located south of SR 16 Minimum 10 acres, if located north of SR 16, of which 5 acres shall be Commercial/Office use; or Minimum 40 acres, if located south of SR 16, minimum of 20 acres shall be Commercial/Office use The Village Center, Resort, and Pier Components are permitted but are not required by The aforementioned provision begins to provide some basis for a development time horizon. As noted within the provision, the 2025 deadline can be extended if approved by the City. Within Section V, development time horizons are discussed including implications of the First Coast Outer Beltway. Mittauer & Associates, Inc. Project No Page 97

123 As it relates to wastewater and reclaimed water infrastructure, Clay Port, or its successors, would be required to meet the following provisions: Infrastructure Planning. Redevelopment of Reynolds Park shall maximize the existing infrastructure and as necessary, expand existing services to meet demand. (a) Monitoring for Short Term Infrastructure Impacts. Beginning March 1, 2011 and every other year thereafter, each fee simple landowner within the MURP category shall submit to the City a summary of the projected demand for water, electrical, and wastewater infrastructure associated with anticipated development for the periods ending three years and five years after the year in which the report is filed. This requirement shall not apply to any parcel for which the proposed development is the subject of a Development or Utility Service Agreements with the City for the provision of water, electrical, or wastewater utilities entered into in 2011 or later. Reservations of capacity issued under concurrency management shall not be affected by infrastructure report results. Provision of the information shall not be construed to establish any right or reservation and shall not obligate the City to provide the capacity to meet the projected demand unless the obligation is the subject of an enforceable Development Agreement or Utility Service Agreement entered into in 2011 or later. (d) Wastewater Treatment Facilities. To accommodate future growth an additional 17.5 acres of land will be needed for sewer plant expansion, a reuse facility, and buffers adjacent to the existing South Wastewater Treatment Plant. The landowner shall donate, at no cost to the City, 5.6 acres of land adjacent to the existing South Wastewater Treatment Plant for plant expansion and the City shall purchase from the landowner an additional 11.9 acres. The location and dimension of the property for expansion of South Wastewater Treatment Plant shall be mutually agreed upon by the City and the landowner. As compensation for the purchase of the 11.9 acre parcel, the City shall grant the landowner credits for wastewater impact fees. The value of the property to be purchased shall be determined by an appraisal prepared by a licensed appraiser mutually agreed on by the City and the landowner, based on the value of the property on May 15, 2010, using the land use and zoning Mittauer & Associates, Inc. Project No Page 98

124 designation existing on such date. The parties shall equally split the cost of the real estate transaction, including any appraisal expense. The value of the property shall be divided by $3,000 to determine the number of wastewater impact fee credits to be granted to the landowners. The credits shall be transferable to future landowners of property within the MURP category for development within Reynolds Park and may be used at anytime prior to December 31, The City shall receive title of the 17.5 acre parcel prior to October 1, Capital costs of new facilities will be addressed in the Capital Improvements Element and adopted Capital Improvements Plan, as required by Chapter 163, Florida Statutes. Costs associated with capital expenditures for the facilities and that provides capacity necessary to meet the adopted level of service standard must be the subject of an enforceable Development Agreement between the City and any developer within the MURP category and shall be included in the City s Capital Improvement Element. (e) Water Reuse. Development within the MURP category shall utilize reuse for irrigation purposes where available, economically feasible, and consistent with State regulations. 2. Sanitary Sewer, Solid Waste, Drainage, Potable Water, and Aquifer Recharge Element Goal 4. The City of Green Cove Springs shall provide sanitary sewer, solid waste, drainage and potable water facilities and services to meet the needs of existing and future populations. Objective 4.1. The City shall assure implementation of the Concurrency Management System, which will include procedures to ensure that when a development permit is issued, adequate facility capacity is available or will be available when needed to serve the development. All system improvements for replacement, expansion, or increase in capacity of facilities shall comply with the adopted level of service standards for the facilities. Policy The City shall use the following level of service standard as the basis for determining the availability of facility capacity and the demand generated by development. Facility Sanitary Sewer Level of Service Standard 120 gallons per capita per day Mittauer & Associates, Inc. Project No Page 99

125 Policy All improvements for replacement, expansion, or increase in capacity shall be compatible with the adopted level of service standards for facilities. Policy The City shall review facility demands and capacity information when building permits are issued. Policy Prior to approval of a building permit or its functional equivalent, the City shall consult with its water suppliers to determine whether adequate water supplies are available to serve the new development no later than the anticipated date of issuance of a certificate of occupancy or its functional equivalent. The City shall ensure with its water suppliers that adequate water supply and potable water facilities shall be in place and available to serve the new development no later than the issuance of a certificate of occupancy or its functional equivalent. Objective 4.2. The City shall continue to provide safe and adequate sanitary sewer service to all existing and future developments located within the City limits. Existing Sanitary Sewer deficiencies shall be scheduled for correction in the Capital Improvements Element. Policy All future development shall continue to be required to connect to the City's Sanitary Sewer Collection system. Policy The City shall continue to ensure proper maintenance of its sanitary sewer facilities and ensure wastewater effluent meets all state and federal requirements. Policy All sanitary sewer improvements and replacements shall be corrected in accordance with the priorities set forth in the Capital Improvements Element. Objective 4.6. Future development shall be required to connect with central sewer and water systems and provide drainage facilities which maximize the use of existing facilities and discourage urban sprawl. Policy The City shall annually monitor the condition of level of service standards for solid waste, potable water, sanitary sewer, and drainage facilities. Mittauer & Associates, Inc. Project No Page 100

126 The Planning and Zoning Department shall be assigned the task of reviewing all development orders to determine their current and future impacts on the capacities of existing public facilities. Policy No permit shall be issued for new development which will result in an increase in demand on deficient capacities or if adequate facility capacities for solid waste, potable water, sanitary sewer and drainage facilities is not available prior to or concurrent with the development's impact. Policy The City shall continue to maintain existing public facilities in such a manner so as to encourage in-fill development on vacant parcels of land that are within a close proximity to existing public facilities Extension of public utilities outside of the City limits shall be in the areas designated in the Green Cove Springs Water and Sewer Service Area in the Interlocal Agreement with Clay County Utility Authority (CCUA). Objective 8.3. The City shall use Level of Service (LOS) Standards to measure the adequacy of existing public facilities and to ensure that future development will be served with adequate public facilities. Policy The City shall require that public facilities shall meet or exceed the following Level of Service Standards: Sanitary Sewer 120 gallons per person per day. E. FDOT OUTER BELTWAY The North Florida Transportation Planning Organization ( TPO ) is the independent regional transportation planning agency for Clay, Duval, Nassau, and St. Johns Counties. It leads the region s efforts in planning, funding, and mobilizing resources to develop and maintain the transportation system. It s mission is to provide a regional forum for developing an effective transportation system that moves people and goods safety, economically, and efficiently, maintaining a high quality of life in North Florida. The Transportation Improvement Program ( TIP ) is a staged multi-year program of transportation project improvements to be implemented during the next five-year period in the North Florida TPO area which will be funded by Title 23 U.S.C. and the Mittauer & Associates, Inc. Project No Page 101

127 Federal Transit Act, prepared in accordance with 23 CFR Part 450 and 49 CFR Part 613. Projects listed in the TIP include recommended improvements consistent with the approved 2035 Long Range Transportation Plan and the adopted comprehensive plans of member local governments within the North Florida TPO area. In accordance with the Federal requirements in 23 CFR (b), the North Florida TPO TIP was compiled by staff of the North Florida TPO. Annually, staff requests five year transportation improvement programs from the following public agencies: Florida Department of Transportation, the City of Jacksonville Public Works Department, Jacksonville Transportation Authority, Jacksonville Airport Authority, St. Johns County, City of St. Augustine, City of St. Augustine Beach, Clay County, City of Green Cove Springs, Town of Orange Park, Nassau County, City of Fernandina Beach, City of Callahan, City of Jacksonville Beach, City of Atlantic Beach, City of Neptune Beach, and the Town of Baldwin. The projects are then reviewed by the North Florida TPO staff for consistency and coordination, to the maximum extent possible, with the adopted long range transportation plan, the adopted comprehensive plans of member local governments, the Jacksonville Airport Authority's Aviation Master Plans, and the Jacksonville Transportation Authority's Transit Development Plan. TIP revisions, amendments, additions, or other modifications can be made during the year if approved by the North Florida TPO. The current TIP includes projections related to the First Coast Outer Beltway (a.k.a. First Coast Expressway). Figure III-3 outlines the current alignment of the highway. It is anticipated completion of this work will result in significant growth potential within Clay County and the City by decreasing commute times from these areas to regional employment centers. At this time, the TIP projects various First Coast Outer Beltway improvements as follows: FY 13/14 I-95 to U.S. 17 ROW Review and ROW Acquisition (TIP Work Item ) FY 13/14 U.S. 17 to Blanding Blvd (SR 21) ROW Review and ROW Acquisition (TIP Work Item ) First Coast Expressway Current Funding Summary (TIP ) 2014/15 - $50, /16 - $0 2016/17 - $184, /18 - $17,524, /19 - $0 Mittauer & Associates, Inc. Project No Page 102

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129 First Coast Expressway Current Funding Summary (TIP ) 2014/15 - $50, /16 - $0 2016/17 - $856, /18 - $5,535, /19 - $247,020 The various project limits are depicted within Figure III-3. The expansion project includes the following legs: First Coast Outer Beltway (ID - 61) Corridor From I-10 to Blanding Blvd (SR 21) New Six (6) Lane Expressway Year of Completion 2020 First Coast Outer Beltway (ID - 62) Corridor From Blanding Blvd (SR 21) to U.S. 17 New Four (4) Lane Expressway Year of Completion 2020 First Coast Outer Beltway (ID - 63) Corridor From U.S. 17 to I-95 New Six (6) Lane Expressway Year of Completion 2020 First Coast Outer Beltway (ID - 64) New Interchange at CR 209 (St. Johns County) Year of Completion 2025 Based on these projections, the new expressway would be completed by Pending overall economic conditions, the completion of this work could represent a significant shift in growth projections within the City. Therefore, the City should continue to monitor the progress of this roadway network and prepare infrastructure to address growth demands by Mittauer & Associates, Inc. Project No Page 104

130 F. GREEN COVE SPRINGS 2040 URBAN BOUNDARY On April 3, 2012, the City Council adopted a policy for annexation and established an Urban Boundary that was depicted within Figure III-1. The boundary was established to identify potential annexation areas where enclaves, service delivery, and development patterns/land-use controls would be important to the City due to their proximity to existing City/Service Area limits. The boundaries are based on logical expansion of the current city limits, and urban services provided by the City's Utilities and other departments. The modifications do not result in changes to the City s existing service area. Due to CCUA s regional service area, the locations within the 2040 Urban Boundary are currently planned to be served by CCUA. However, if developments occur before CCUA is ready to serve, then an interlocal agreement may be required for the City to provide sewer and/or reuse service into these areas. G. GREEN COVE SPRINGS BUILD-OUT STUDY The Build-Out Study prepared by Fleet & Associates in 2006 (see Attachment G) noted that many parcels in the Service Area are underdeveloped and can be developed with higher densities and intensities than currently exist. This work preceded the Reynolds FLUM Amendment but is still applicable since the FLUM Amendment kept the intensities and densities less than, or equal to, what was available under the previous land use categories. The City s 2008 Plan included an in-depth review of the document and included discussion of: Build-Out Study Assumptions; Build-Out Wastewater Demand Calculations per Service Area; Wastewater Demands through the Planning Period; - Historic Service Area Growth; - North Service Area Wastewater Projections; - South Service Area Wastewater Projections; and - Basis of WWTF Expansion Analysis. For purposes of this Plan, the summary findings will be presented and discussed. Mittauer & Associates, Inc. Project No Page 105

131 The Build-Out Study conclusions related to maximum build-out potential is summarized in Table III-1. TABLE III-1 SUMMARY OF SERVICE AREA DEVELOPMENT POTENTIAL Area/Project Dwelling Units (Ea) Office Space (SF) Commercial Space (SF) Hotel Rooms (Ea) Restaurants (seats) Vacant Parcels over 2 Acres Vacant Parcels under 2 Acres Underdeveloped Parcels over 2 Acres Magnolia Point Phase 7 & 8 1, , a Reynolds 3,600 50, ,000 1,200 - JM/Huntley , Governor s Point PUD Pyram id Property St. Johns Landing Total 8, , , a: Since publication of the Build-out Study, the Reynolds FLUM Amendment was completed and reviewed maximum entitlements per land use designations that differed from this projection. The Reynolds FLUM Amendment discussed in Section III.B. reviewed the existing land use designations along with the proposed mixed-use options at their maximum intensities and densities. Those values are provided in comparison to the Build-Out Study in Table III-2. Mittauer & Associates, Inc. Project No Page 106

132 TABLE III-2 REYNOLDS DEVELOPMENT POTENTIAL COMPARISON Reynolds Review Basis Dwelling Units (Ea) Office Space (SF) Commercial Space (SF) Hotel Rooms a (Ea) Institutional (SF) Industrial (SF) Build-out Study 3,600 50, ,000 1, FLUM Amendment Max Residential FLUM Amendment Max Commercial FLUM Amendment Max Industrial 3, ,000 4,000,000 1, ,000 3,300,000 3, ,000 7,300,000 1, ,000 3,300,000 1,809 2,500,000 5,100,000 1, ,000 10,000,000 a: Within the Reynolds FLUM Amendment, the materials reference time-share units. This data, along with the different development potentials for Reynolds, is further summarized and expanded in the context of potential impacts to the City s existing and proposed wastewater infrastructure within Section V. H. BEBR POPULATION PROJECTIONS The year 2000 census counts for Clay County and Green Cove Springs were 140,814 and 5,378 persons, respectively. The year 2010 census counts for each were 190,865 (+35.5% change or 3.55% per year) and 6,908 (+28.5% change or 2.85% per year), respectively. The 2013 University of Florida s Bureau of Economic and Business Research (BEBR) population projections for Clay County are provided in Table III-3. The percentage growth between each 5-year period is shown for a low-growth, medium-growth, and high-growth projection as well as an annualized value for average growth per year. Mittauer & Associates, Inc. Project No Page 107

133 TABLE III THROUGH 2040 CLAY COUNTY POPULATION PROJECTIONS b Low Growth Medium Growth High Growth Year (Pop) 5-yr Avg/yr (% ) (Pop) 5-yr Avg/yr (% ) (Pop) 5-yr Avg/yr (% ) , , , a a a , % -0.1% 203, % 2.0% 215, % 4.1% , % 2.2% 226, % 3.8% 249, % 5.2% , % 1.6% 248, % 3.2% 283, % 4.5% , % 1.0% 268, % 2.7% 317, % 4.0% , % 0.5% 286, % 2.2% 349, % 3.4% , % 0.0% 302, % 1.8% 380, % 3.0% a: Percentages are for 3-year span between 2012 and 2015 b: 2013 BEBR Projections by County for (Bulletin 165) As shown in the Table III-3, the percentage growth decreases for each of the three options as one approaches the out years, but sustains some larger growth through the near-term periods. For purposes of this analysis, the medium-growth projections will be utilized for the City. However, the City should note the Low- Growth projections that indicate relatively flat numbers. The HRWWTP is estimated to serve approximately 5,500 persons and the City s estimated service population is 6,900 persons leaving approximately 1,400 persons being served by the SWWTP. For purposes of this analysis, the estimated population being served by the HRWWTP will be maintained at 5,500 persons in Applying the Medium-Growth and High-Growth criteria, the following population estimates are calculated for the North Service Area as shown in Table III-4. Mittauer & Associates, Inc. Project No Page 108

134 TABLE III THROUGH 2040 NORTH SERVICE AREA POPULATION PROJECTIONS Year Medium Growth (% Ä) a Medium Growth Population (capita) High Growth (% Ä) a High Growth Population (capita) 2015 n/a 5,500 n/a 5, % 6, % 6, % 6, % 7, % 7, % 8, % 7, % 8, % 8, % 9,710 a: Noted percentage changes are over a five-year period and are not annualized values. As noted previously, the highest-growth potential within the City resides in the South Service Area due to the redevelopment potential of the Reynolds Parcel. To maintain consistency between the analyses of the different sub-service areas, the previous population projections (medium- and high-growth projections) will be maintained to determine wastewater flow demands per year within Section V. However, the analysis will also review possible development scenarios which could modify and increase timelines for infrastructure construction. Applying the previously reviewed population projection estimates for the Service Area, Table III-5 presents the estimated population growth for the South Service Area assuming the 2015 population being served by the SWWTP is approximately 1,400 persons. Mittauer & Associates, Inc. Project No Page 109

135 TABLE III THROUGH 2040 SOUTH SERVICE AREA POPULATION PROJECTIONS Year Medium Growth (% Ä) M edium Growth Population (capita) High Growth (% Ä) High Growth Population (capita) 2015 n/a 1,400 n/a 1, % 1, % 1, % 1, % 1, % 1, % 2, % 1, % 2, % 2, % 2,470 For comparison purposes, the Medium-Growth North and South Service Area population projections are converted to single-family dwelling unit counts based on an estimated density of 2.2 capita per unit. The result of this calculation is provided in Table III-6. TABLE III THROUGH 2040 DWELLING UNIT PROJECTIONS Year North Service Area Projection South Service Area Projection (capita) (ERU) a (capita) (ERU) a ,500 2,500 1, ,130 2,790 1, ,720 3,050 1, ,260 3,300 1, ,740 3,520 1, ,170 3,710 2, a: ERU = 2.2 capita/unit As noted in Table III-1, the Build-Out Study anticipates that the development and redevelopment potential of the entire Service Area results in approximately 8,200 units of which 4,650 units are anticipated within the South Service Area. The development potential within the South Service Area is underscored based on the Mittauer & Associates, Inc. Project No Page 110

136 current and projected ERU density (640 ERUs in 2015 and 945 ERUs in 2040) in comparison to the anticipated build-out density of 4,650 ERUs. Current density is estimated to be 13% (640/4,650) of the build-out potential and is only anticipated to increase to 20% (945/4,650) in These projections will be further expanded upon in Section V. Mittauer & Associates, Inc. Project No Page 111

137 IV. REGULATORY AND POLICY CONSIDERATIONS A. OVERVIEW The most dynamic regulatory areas which could impact the City s infrastructure planning are related to nutrient loading, alternative water supply needs/demands (non-potable irrigation), public-access reuse water quality requirements, effluent disposal, WWTP siting, and biosolids management. Each of these topics are discussed in further detail in relation to the following areas: St. Johns River TMDL; SJRWMD Regional Review and City s CUP; Water Conservation; Reclaimed Water Use; Effluent Disposal Restrictions; Regional Interconnects; and Biosolids Management. B. ST. JOHNS RIVER TMDL In September 2006, CH2MHILL completed its report for the St. Johns River Water Management District ( SJRWMD ) which was entitled Total Maximum Daily Load (TMDL) Compliance Optimization Analysis for the Lower St. Johns River (LSJR) Basin, and FDEP issued their final report on July 8, 2008 entitled Total Maximum Daily Load for Nutrients for the Lower St. Johns River. Section II addressed the City s operational modifications resulting from these requirements and the associated regulations that followed. A copy of the final FDEP TMDL reports are included herein as Attachment H. The net result of the reports and the regulations discussed in Section II, was limits to the amounts of nutrients that could discharge to the river. At this time, the City is limited as follows: 17,055.5 pounds per year ( ppy ) for Total Nitrogen ( TN ); and 4,244.2 pounds per year ( ppy ) for Total Phosphorus ( TP ). Specific wastewater demands within the Service Area will be explored in Section V. However, the aforementioned values will be reviewed in the context of applicable wastewater treatment technology and effluent concentrations the City could expect Mittauer & Associates, Inc. Project No Page 112

138 to reliably meet. These maximum concentrations within the effluent will allow a means of calculating maximum discharge flowrates to the St. Johns River from each respective WWTP. Typical, conventional, wastewater treatment technology can reliably remove 60 to 80% of total nitrogen and typically removes marginal amounts of total phosphorus. To meet the proposed total nitrogen limits listed within the TMDL documents, the City could be required to implement advanced wastewater treatment ( AWWT ) technologies where total nitrogen and total phosphorus removal efficiencies will approach 90 to 95%. For purposes of this analysis, TN concentrations of 10 mg/l, 5mg/L, and 3 mg/l, and TP concentrations of 5 mg/l, 3 mg/l, and 1 mg/l are used to determine the maximum amount of wastewater which could be discharged to the St. Johns River while meeting the TMDL requirements. The following equations will review the mass loading on a City level: Q MAX (MGD-AADF) = TMDL Limit (ppy) / (TN (mg/l) x 8.34 lb/mg-mg/l x days-yr ) where: Q MAX = Max. Allowable Discharge (MGD-AADF) TMDL = TMDL Limit (ppy) TN or TP = Effluent TN or TP Concentration (mg/l) Conv. Factor = 8.34 lb/mg-mg/l The maximum allowable discharge allocations based on respective TN and TP effluent levels for each plant are calculated as follows: River Q MAX-TN = mg/l (AADF) = mg/l (AADF) = mg/l (AADF) River Q MAX-TP = mg/l (AADF) = mg/l (AADF) = mg/l (AADF) Mittauer & Associates, Inc. Project No Page 113

139 The City s existing WWTPs, with operational modifications, are currently treating wastewater to average TN and TP levels of: Existing Effluent TN Levels = 5.4 mg/l 0.50 MGD) and 3.7 mg/l 0.20 MGD) Existing Effluent TP Levels = 0.8 mg/l 0.50 MGD) and 4.0 mg/l 0.20 MGD) As noted within Section II, the above treatment levels cannot be maintained at the existing WWTPs once flows and loading increase since neither the HRWWTP nor the SWWTP were designed for biological nutrient removal capabilities. The current levels are being achieved through operational modifications to the systems. With an AWWT system, the anticipated effluent quality would be 5 mg/l (BOD 5) 5 mg/l (TSS) 3 mg/l (TN) 1 mg/l (TP). Additional improvements can ensure lower TN levels, but they can be costly to construct and to operate. The other part of the equation is the amount of reuse water that is pumped from the WWTP to reuse customers which results in a reduction of flow to the river. At AWWT levels, the City s effluent disposal capacity to the river would be limited by Total Phosphorus with an annual average daily flow of 1.39 MGD AADF. However, it is anticipated lower TP levels could be realized through a combination of biological nutrient removal and additional chemical feed, if needed, to maintain levels below 1.0 mg/l. Therefore, TN levels would be the limiting basis of overall effluent disposal levels to the river. Within Section VI, various infrastructure expansion alternatives are reviewed. Assuming current TMDL levels are remained constant, the maximum river capacity will be considered as follows: River Maximum Outfall Capacity = 1.87 MGD AADF limited by TN = 3 mg/l Additional alternatives within Section VI may include lower TN levels, but those will be reviewed on a case-by-case basis. Lastly, as the City reduces TN and TP loading to the river, the City could also evaluate sale of TN and TP loading credits with other utilities and/or cities that may require options to reduce their loading footprint into the river. Mittauer & Associates, Inc. Project No Page 114

140 C. NUMERIC NUTRIENT CRITERIA As stated on FDEP s website, numeric nutrient criteria ( NNC ) are: Water quality standards...established in state rules as the goals for the protection of aquatic ecosystems, safe recreation and fishing, and provision of water supplies the essential designated uses of surface waters. The standards contain water quality criteria (specific numeric values) that, when achieved, protect these goals. Numeric nutrient criteria are measurable levels of nitrogen and phosphorus (nutrients) set at values that will protect the designated uses of a waterbody from the harmful effects of nutrient pollution. Measurable levels of aquatic health related to the effects of excess nitrogen or phosphorus, such as the amount of algae or the water clarity, also constitute numeric nutrient criteria. The Environmental Protection Agency ( EPA ) was in litigation with FDEP related to NNC and how to apply standards to various water bodies through the state of Florida. At one time during this process there was concern the NNC may reverse, modify, and/or further restrict the Lower St. Johns TMDL evaluation process and associated basin management action plan ( BMAP ). One of the concerning topics was potential movement away from an annual loading model, related to TN and TP, to a maximum effluent concentration that would further restrict utilities. In the end, FDEP s St. Johns River TMDL was accepted by the EPA on June 27, 2013, and is the governing limitation for the City to monitor which maintained an annual mass loading metric in lieu of specific effluent concentration. FDEP s 2013 Five-Year Assessment Report, see Attachment I, stated the following as it relates to numeric nutrient criteria: On November 30, 2012, the U.S. Environmental Protection Agency (EPA) approved the Department s numeric nutrient criteria (NNC) for rivers, streams, lakes, and some estuaries. In January 2014, a federal judge granted EPA s motion to discontinue federal rulemaking and allow the Department to implement its NNC. As part of the Department s NNC, established restoration goals in the form of TMDLs continue to apply. Therefore, the LSJR TMDLs remain the applicable nutrient standards for the main stem of the river, and will remain in effect once all of Department s nutrient standards are in effect because the standards establish nutrient TMDLs as site-specific interpretations of the narrative nutrient criteria. Given the unknowns associated with future regulatory actions. The City may consider options to further limit their river outfalls allowing them the most flexibility in managing their City. Future evaluations of the river s health could result in Mittauer & Associates, Inc. Project No Page 115

141 additional restrictions requiring elevated treatment levels and/or elimination of WWTP outfalls altogether. Therefore, it is in the City s best interest to further reduce and/or eliminate WWTP outfalls to the river. D. SJRWMD REGIONAL STUDIES AND CITY S CUP WATER CONSERVATION Within this subsection, a brief discussion of some larger regional work within Northeast Florida will be reviewed and summarized as it applies to the City s longterm planning as well as the City s requirements within their Consumptive Use Permit ( CUP ). 1. Regional Studies The City is currently part of the North Florida Regional Water Supply Partnership. This partnership is a result a joint agreement between the St. Johns River Water Management District ( SJRWMD ), Suwannee River Water Management District ( SRWMD ), and FDEP. Collectively these entities have created a water supply planning area that extends west to Suwannee and Gilchrist Counties; south to Alachua, Putnam, and Flagler Counties; north to the state line; and east to the Atlantic Ocean. Work is primarily focused on water supply planning which includes, but is not limited to, groundwater modeling, springs protection, minimum flows and levels, water quality in surface water bodies, wetland protection, water conservation opportunities, water supply development, etc. This work is currently ongoing, but it is anticipated the City will hear more about water conservation and maximizing reclaimed water opportunities as much as possible to offset groundwater withdrawals. This is further discussed in the following subsection. 2. City s Consumptive Use Permit (CUP) Water Conservation The City s CUP primarily defines how much water the City can pump from the aquifer to supply the needs of the City s Service Area. A number of technical aspects go into the review and approval of a CUP application that are beyond the scope of this Study. However, one (1) relevant issue is related to reclaimed water use and how it relates to decreasing potable water use for irrigation purposes. The City completed a five-year compliance review with the SJRWMD in January This review included a number of items associated with the City s water system but also included discussion related to water conservation Mittauer & Associates, Inc. Project No Page 116

142 and reuse projections. A copy of the City s current CUP and associated technical staff report are provided in Attachment J. The items to note, as they relate to the sewer/reuse system, include the following: Permit Expiration Date is July 13, The permittee must continue implementation of the water conservation program measures and schedule as referenced in the Water Conservation Plan submitted to the District on September 28, 2011, for permit duration. A copy of this plan is provided as Attachment K. If at any time within permit duration it becomes practical, economically feasible, and permissible under applicable state and federal statutes or regulations promulgated thereunder, the District may require the permittee to become a reclaimed water purveyor or increase the availability of reclaimed water for use at a permissible application site. The permittee must conduct a detailed water audit every 3 years and submit it to the District by January 31 of 2015, 2018, and All water uses given in the audit must be for the previous calendar year and documentation provided on how the amounts were metered or determined. If the water audit shows that the system losses and unaccounted for water utility uses exceed 10%, a leak detection and repair program must be implemented. This review will include considerations of potable irrigation use that may lead to reclaimed water supply considerations. The lowest quality water sources, such as reclaimed water and surface/storm water, must be used as an irrigation source when available pursuant to District rules and applicable state law and deemed feasible by the District. By March 31, 2016, the permittee must submit a report to the District evaluating the effectiveness of the permittee's water rate structure on water use consumption patterns within the service area. The report must be based on the most recent year's water use and must include the following: (a) the number of residential accounts; (b) the distribution of customers water use consumption (broken down into 2,000 Mittauer & Associates, Inc. Project No Page 117

143 gallons/month increments); (c) the number of customers using irrigation meters, if any; (d) the breakdown, in 2,000 gallon/month increments, of all irrigation meter customer water use, and; (e) the annual residential water use purchased (in million gallons) by year. This evaluation must include a comparison of water use patterns within each 2,000 gallon/month breakdown. Within the City s last five-year compliance report, the actual irrigation use that was metered separately accounted for approximately MGD AADF of the City s total water demand. The majority of the potable irrigation demand is located within Magnolia Point, which may be a future reclaimed water expansion project option as explored within Section VI. E. RECLAIMED WATER USE CONSIDERATIONS As the City explores expanding their reclaimed water infrastructure, this section reviews some items that are background considerations going forward. More specific work related to the reclaimed water expansion alternatives will be explored in Section VI. In the interim, the following reuse aspects are considered: Reclaimed Water Availability Reclaimed Water Treatment Requirements 1. Reclaimed Water Availability In concert with the water conservation measures, increasing reclaimed water use within the City could assist in reducing water demands by offsetting the irrigation component of the demand. While reclaimed water use is critical, it is not the panacea to overall water demand reduction. In addition, reclaimed water use is often hampered through: Reclaimed water availability. Available supplies of reclaimed water can be hampered by the following items: 1) If reclaimed water rates are not defined properly, then overuse can occur, wasting the commodity; Mittauer & Associates, Inc. Project No Page 118

144 2) Even with proper reclaimed water rates, the overall reclaimed water demand within a given area typically exceeds the amount of wastewater supplied to the WWTP for reclaimed water production. For example, a 0.25 acre lot with an 1,800 square foot residence with a driveway would have an average irrigation demand of approximately 575 gpd based on an irrigation rate of 0.75 inches per week. The same residence would likely only supply approximately 200 to 300 gpd of wastewater to the system. Thus, the reclaimed water demand for this single unit would exceed the supply it produced by a factor of two (2) to three (3) or worst-case ratio of three (3) to one (1); and/or 3) Capital investment costs are often prohibitive to construct new reclaimed water service infrastructure to existing neighborhoods along with proper cross-connection control. More specific analysis of current reclaimed water use and associated discussion related to demands is provided in Section V of the Plan. 2. Reclaimed Water Treatment Requirements This section will review nutrient loading, pathogen removal, and emerging substances of concern. Each of these items could affect future reclaimed water treatment requirements. Nutrient Loading At this time, the reclaimed water treatment requirements are relatively straightforward to meet. The two (2) primary components include filtration and high-level disinfection. Additional nutrient removal requirements has not been a specific requirement as it relates to public-access systems. However, nutrient loading is becoming more expansive and a component of reviews related to public-access reclaimed water storage and use. The City should be aware that additional nutrient reductions may be required for public-access reclaimed water in the future. Therefore, as facility improvements are contemplated, AWWT levels should be utilized as the design standard. Historically, systems that had rapid infiltration basins, sprayfields, etc. have had to meet a 12 mg/l for TN, and then had groundwater compliance requirements Mittauer & Associates, Inc. Project No Page 119

145 at monitoring wells that could not exceed 10 mg/l. The City currently has this requirement at Magnolia Point. However, in the recent past facilities which have new reclaimed water storage in stormwater ponds have required a mass loading analysis related to the co-mingled water being discharged through the stormwater outfall. This has typically required lower TN and TP levels than provided via conventional treatment. Pathogen Removal In addition to nutrient levels, FDEP continues to monitor pathogens within the reclaimed water. As stated in FDEP s Monitoring for Protozoan Pathogens in Reclaimed Water: Florida s Requirements and Experience: In 1999, revisions to Chapter , Florida Administrative Code (F.A.C.) added requirements for pathogen monitoring to Florida s reuse rules. The protozoan pathogens that required monitoring included Giardia lamblia and Cryptosporidium parvum. Cryptosporidium was not known to be a human pathogen until This gastrointestinal infection results in a watery diarrhea which may be accompanied by abdominal pain, nausea, anorexia, dehydration, and weight loss. The organism is spread by a fecal/oral route. Infection by Cryptosporidium is regarded as being self-limiting in immunocompetent individuals. Most individuals become asymptomatic within two weeks. It is a more serious infection in immunocompromised individuals. Patients with AIDS typically are unable to clear the infection, and the infection is frequently fatal. Giardia lamblia is a protozoan pathogen that is found worldwide. It infects the intestinal tract and can result in a variety of symptoms such as chronic diarrhea, bloating, abdominal cramps, frequent greasy malodorous stools, fatigue, and weight loss. Giardia is transmitted by a fecal/oral route. Infections by Giardia are regarded as being self-limiting and frequently are asymptomatic. When symptoms occur, they typically last two to six weeks. Both Cryptosporidium and Giardia have low infective doses. A 1995 study established the median infectious dose (ID 50) for humans at 132 oocysts. The median infectious dose for Giardia is between 50 and 100 cysts. Filtration and passage through soils are effective in removing cysts and oocysts from water. Mittauer & Associates, Inc. Project No Page 120

146 In 1999, requirements for pathogen monitoring were added to Chapter , F.A.C. in an effort to learn more about the presence of these organisms in reclaimed water. Depending on what this monitoring shows, the DEP may or may not move toward additional rulemaking that could involve placing controls or limits on these organisms. Not all cysts or oocysts in a disinfected reclaimed water will be viable (capable of causing infection). The DEP has implemented follow-up procedures for contacting facilities that report relatively high concentrations of the protozoan pathogens. Although pathogen standards have not been established in Florida, the DEP writes to facilities that report concentrations of Giardia greater than 5 cysts per 100 L or of Cryptosporidium greater than 5 oocysts per 100 L. The 5 per 100 L threshold used by DEP generally reflects the work of York and Walker- Coleman. Contacts are made to alert the facilities to the significance of these pathogens and to encourage refinement of their filtration processes. Staff in DEP s district offices evaluate facilities reporting concentrations of 5 per 100 L or greater and conduct follow-up inspections of the facilities. These inspections provide opportunities to discuss the significance of these pathogens and ascertain whether the facilities have implemented corrective actions to reduce pathogen concentrations. Facilities reporting relatively high concentrations are encouraged, but not required, to resample upon implementation of operational refinements. The DEP also sends follow-up letters to facilities reporting relatively high pathogen concentrations to augment the district offices efforts. The City has not had any pathogen monitoring issues, but if issues were encountered, the City may be required to modify their filtration method from disc filters to a mixed-media or sand filters in order to achieve the required removal of the pathogens. At this time, the disc filter manufacturers cannot certify removal of these organisms due to their size in comparison to the filter fabric s pore size. Emerging Substances of Concern (ESOC) The FDEP formed a workgroup to evaluate strategies to effectively address a wide variety of potential contaminants commonly referred to as Emerging Mittauer & Associates, Inc. Project No Page 121

147 Substances of Concern ( ESOC ). In December 2008, the FDEP issued a report entitled Emerging Substances of Concern. Highlights from that report are provided as follows: These include global organic contaminants such as flame retardants (PBDEs), pharmaceuticals and personal care products (PPCPs), endocrinemodulating chemicals (EMCs), nanoparticles, and biological metabolites. It is almost inevitable that small amounts of these compounds which are manufactured to protect human health, improve consumer goods, or optimize agricultural production are unintentionally released into the environment. Relatively recent improvement in laboratory analytical methods have enabled the identification of these substances which likely have been present in waters for decades. ESOC are particularly challenging for regulatory agencies because of their sheer numbers (there are approximately 14 million commercially available compounds in the United States) and because the majority of them (98%) are unregulated substances with a high degree of uncertainty associated with their environmental fate, transport, and toxicological effects. Because environmental risk cannot be meaningfully assessed for the vast majority of ESOC, traditional management practices such as regulating specific analytes must be modified to include other approaches including prevention and effects-based environmental assessment methods. The ESOC workgroup believes that it is more efficient and effective for the EPA to proceed with a comprehensive, holistic national effort for addressing ESOC rather than having individual states pursue a more limited, piecemeal approach. The workgroup strongly agreed that it is imperative that a more effective pre-release strategy for ESOC also be implemented nationally by the federal agencies charged with regulating chemicals. The workgroup concluded that preventing ESOC from entering the environment is the most effective control strategy. Therefore, DEP s initial efforts to address ESOC have focused on pollution prevention, including the development of a brochure by the Division of Waste Management on the proper disposal of unused pharmaceuticals and the establishment of an ESOC clearinghouse website by the Center for Environmental and Human Toxicology, University of Florida. Mittauer & Associates, Inc. Project No Page 122

148 This is not a present issue, but one that could affect wastewater treatment technology in the future. F. BIOSOLIDS MANAGEMENT The treatment and disposal of domestic wastewater biosolids is governed by 40 Code of Federal Regulations (CFR) 503. In order to land apply the biosolids from a domestic wastewater treatment facility, the biosolids must undergo some form of treatment to achieve pathogen reduction and vector attraction reduction. Depending on the level of pathogen and vector attraction reduction achieved, the biosolids are classified as Class AA, Class A, or Class B. Class AA biosolids are the highest classification and can be sold as a commercial fertilizer without any restrictions. Class A represents a higher level of treatment than Class B, but both Class A and Class B biosolids have a number of land application site restrictions. Class A and Class B designations are based on both pathogen reduction and vector attraction reduction ( VAR ) levels. Class AA requires that pathogen reduction process requirements are met and that the biosolids not exceed specific metal concentrations. Compliance with the Class AA requirement is dependent upon both the pathogen reduction process and an effective industrial pretreatment program for metal concentrations enforced through the local municipality. Class AA products currently generated in Florida include composted materials, lime stabilized/pasteurized product, heat treated and pelletized products, and digested product meeting requirements established by both EPA and FDEP. Class AA product can be applied to land for agricultural purposes; used internally by the City for backfill, fertilizer, or other applications; distributed and marketed; or used for land reclamation. The City currently treats all of its wastewater biosolids to Class B requirements and hauls them to the Clay County landfill. The most problematic item associated with the City s biosolids management is related to the dewatering of the material. Historically, sludge drying beds were utilized, which are not efficient at the City s biosolids production levels. Options are currently being reviewed to transition to a different dewatering technology, and this component will also be reviewed as part of expansion alternatives within Section VI. The City is also contemplating a modification to the arrangement with Clay County to dispose of the biosolids via a different route and eliminate the landfill leachate treatment requirements. As the City considers this option, the alternative disposal options must be evaluated. Mittauer & Associates, Inc. Project No Page 123

149 In 2010, FDEP revised Rule , F.A.C., applying additional restrictions and requirements related to biosolids management. One of the main additions was related to those facilities that have a land application disposal site. For these locations, a more in-depth Nutrient Management Plan ( NMP ) is required before biosolids can be applied to a site and may further restrict the amount of biosolids that can be applied to a given parcel. The City does not currently have to address these requirements due to their agreement with Clay County. If the City were to modify their biosolids disposal location and required a land application site for Class B biosolids, then an in-depth review of the potential site(s) would be required to ensure it met the current rule requirements and/or the City should contract with a regional facility to manage the biosolids disposal requirements. A number of utilities are currently reviewing options to expand their onsite biosolids treatment systems to provide Class AA treatment. A number of utilities and regional biosolids managers have utilized solar drying technology for this purpose. The premise of solar drying technology is to harness energy from the sun in order to remove moisture from the biosolids. Solar drying can reduce sludge volume, but the extent of volume reduction is dependent upon the incoming sludge solids content as well as local weather conditions. Dewatering prior to the solar drying process is a requirement of the system. Solar drying has an intrinsic low energy cost and can produce up to a 90% dry solids content. The solar drying process meets 503 Rule pathogen reduction requirements under the equivalent process to a PFRP alternative (Alternative 6). The 503 Rule VAR requirements are met when the percent solids are greater than or equal to 75% (Option 7). While the solar drying process meets 503 Rule Class A pathogen reduction and VAR requirements, the process does not provide for treatment of the source of potential odors within the product. Depending on the type or lack of an upstream biosolids treatment process, solar drying has the potential to produce odors from the odor-causing compounds present in the sludge. Odor control systems are available but do not provide any treatment of the biosolids. An odor control system only works in an enclosed building. The system is sized in order to treat the air within the building while the odor-causing components remain in the material. If the problem is not addressed pre- or post-solar drying processing, the biosolids have the potential to produce an odor offsite when land applied. At the City s current flows and anticipated growth through the planning period, we do not anticipate this approach being cost effective for the City. Mittauer & Associates, Inc. Project No Page 124

150 G. SUMMARY When the City begins to expand their treatment infrastructure, a more detailed review or analysis of the most applicable biosolids treatment mechanisms should be performed. Implications of the TMDL requirements and required reuse are reviewed further in Sections V and VI. However, the general assessment gained from this section indicates advanced wastewater treatment capabilities in addition to further reuse will be required as the City grows. Mittauer & Associates, Inc. Project No Page 125

151 V. PROJECTED WASTEWATER DEMANDS A. OVERVIEW Section III developed various background information related to potential growth variables that are anticipated to affect the City s planning within the current Planning Period. Redevelopment of Reynolds, the construction of the First Coast Outer Beltway, and associated regional growth within the County are major variables that will impact the City s infrastructure needs. This information should be compared against population projections that anticipate likely demand curves based on historical information and potential population growth based on these growth variables. The Reynolds Redevelopment, for example, presents a significant supply of housing, industrial uses, commercial uses, etc., but these components will not develop until demand for the products are anticipated. Accordingly, Section III concluded with a review of the UF BEBR estimates for population growth utilizing the Medium-Growth curves as the basis of estimates going forward. The information presented in Section III will be developed into flow demands herein that will provide a basis for subsequent infrastructure planning reviewed in Section VI. B. BUILD-OUT STUDY: MAXIMUM WASTEWATER DEMAND RECLAIMED WATER SUPPLY The dwelling unit flow basis is a planning value and will likely project a larger demand than will be realized as development occurs. The industry continues to move into a water conservation mindset where more low-flow fixtures are used in homes which results in lower wastewater flows but higher concentrated loadings. In Section III, the level of service for wastewater based on Clay County s and the City s Comprehensive Plan were respectively 279 gpd/eru and 120 gpcd. The City s Ordinance defines an ERU as 300 gpd resulting in a household density of 2.5 persons (300 gpd/120 gpcd). The HRWWTP is estimated to serve approximately 5,500 persons, and Section II tabulated the HRWWTP flow from 2008 through The average flow during this five-year period was approximately MGD (AADF). Based on these values, the resultant per capita contribution to the HRWWTP is estimated as 90 (0.500 MGD/5,500 persons) gallons per capita day (gpcd). In comparison, the SWWTP is estimated to serve approximately 1,400 persons and the average Mittauer & Associates, Inc. Project No Page 126

152 five-year flow has been MGD (AADF) resulting an estimated per capita flow of 150 gpcd (0.212 MGD/1,400 persons). Both values/systems are influenced by groundwater infiltration within the City s old collection piping as discussed in Section II with the South Service Area being more severe. The South Service Area large gallon-per-capita-day value is also influenced by industrial users. FDEP recommends a planning value of 100 gpcd for wastewater systems, but a number of communities that have newer collection system piping and/or are located in areas where there is not high groundwater levels are experiencing values as low as 50 to 80 gpcd. A traditional household density is 2.4 capita per household. In order to provide a review of potential demand variations, the following projections will be utilized within the Plan: Low-Demand Projection 190 gpd/eru (80 gpcd * 2.4 capita/unit) Medium-Demand Projection 240 gpd/eru (100 gpcd * 2.4 capita/unit) High-Demand Projection 300 gpd/eru (City Ordinance) Using the 2.2 capita/unit value that was reviewed in Section II, the flow projections potentially vary between 85 gpcd (190 gpd-eru/2.2 capita-eru) to 140 gpcd (300 gpd-eru/2.2 capita-eru). For projection purposes, the 190, 240, and 300 gpd/eru values will be utilized in the Plan s analyses. Table III-1 summarized the Build-Out Study s projection for maximum development within the City s Service Area. Those values will now be converted into wastewater flow projections. The flow projections will be based on the following planning values for wastewater production per type of development: Dwelling Unit (ERU) = see above for low, medium, and high basis; Office Space = 0.15 gpd/sf (Rule 64E-6.008, F.A.C.); Commercial Space = 0.15 gpd/sf (Rule 64E-6.008, F.A.C.); Industrial Space = 0.14 gpd/sf (Rule 64E-6.008, F.A.C.); Hotel = 100 gpd/room (Rule 64E-6.008, F.A.C.); and Restaurant = 20 gpd/seat (Rule 64E-6.008, F.A.C.). Utilizing the above and the build-out summary provided in Table III-1, the build-out wastewater demand calculations are summarized in Table V-1. Mittauer & Associates, Inc. Project No Page 127

153 TABLE V-1 SUMMARY OF ANTICIPATED WASTEWATER BUILD-OUT DEMANDS Wastewater Demand (gpd) Item Units Quantity Low M edium High Residential Units Ea 8,930 1,696,700 2,143,200 2,679,000 Office Space SF 410,000 61,500 61,500 61,500 Com m ercial Space SF 250,000 37,500 37,500 37,500 Hotel Rm 1, , , ,000 Restaurant Seat 50 1,000 1,000 1,000 Exist. North Service , , ,000 Area Demand a Exist. South Service , , ,000 Area Demand a Total - 2,634,700 3,081,200 3,617,000 a: It is anticipated that existing services would be redeveloped, thus there is some inherent overlap in the wastewater values. However, given the status of the proposed developments and the time horizon for potential developments, the overlap is not considered significant in the context of this study. As noted in Section III.B., the Reynolds build-out variables differ when comparing the Build-Out Study and the FLUM Amendment Materials. Attachment L summarizes the various wastewater production calculations for each of the Reynolds Parcel development options delineated within Table III-2. A summary of the total wastewater demand for each is summarized in Table V-2. TABLE V-2 COMPARISON OF REYNOLDS BUILD-OUT DEMAND POTENTIALS Wastewater Demand (gpd) Scenario Low M edium High Build-Out Study 849,000 1,029,000 1,245,000 FLUM Amendment Max Residential FLUM Amendment Max Commercial FLUM Amendment Max Industrial 2,116,800 2,312,800 2,548,000 2,439,660 2,590,360 2,771,200 3,073,710 3,164,160 3,272,700 Mittauer & Associates, Inc. Project No Page 128

154 When the Medium Wastewater Demand values are averaged, the resulting Reynolds projection is approximately 2.3 MGD (AADF) which is 1.3 MGD (AADF) greater than the Build-Out Study projection. However, the FLUM Amendment assumes 100% utilization of available densities and intensities which is unlikely. For purposes of this Plan, a 70% effective value will be utilized based on the average Medium Wastewater Demand projection. Therefore, the Reynolds build-out demand will be capped at 1.61 MGD-AADF (2.3 MGD * 0.70). Table V-1 identified a potential wastewater build-out demand ranges between 2.6 and 3.6 MGD (AADF) with 3.1 MGD (AADF) being the medium projection. The 3.1 MGD demand included a less dense/intense Reynolds build-out. As shown in Attachment L, the difference between the Reynolds Projection is 0.58 MGD-AADF (1.610 MGD MGD). As a result, the build-out demand could approach a maximum of approximately 3,750,000 gpd-aadf (3.1 MGD MGD). However, other considerations related to the potential build-out demand are discussed herein. To further summarize this data in the context of potential impacts to the City s existing and proposed wastewater infrastructure, the overall build-out demand needs to be split into the anticipated sub-service areas in order to review potential force main routing options as well as potential repump scenarios which may be required. Within this review the Medium-Demand Projection will be utilized for residential projections. Based on a review of the Build-Out Study and discussions with the City, it is anticipated that the North Service Area contains the subset of values listed in Table V-3. Mittauer & Associates, Inc. Project No Page 129

155 TABLE V-3 NORTH SERVICE AREA DEVELOPMENT POTENTIAL Area/Project Dwelling Units (Ea) Flow (gpd) North-Core Area Vacant Parcels over 2 Acres ,000 Vacant Parcels under 2 Acres ,800 Underdeveloped Parcels over 2 Acres 1, ,400 Governor s Point PUD 50 12,000 Subtotal - 1, ,200 North-Magnolia Area Vacant Parcels over 2 Acres 60 14,400 Vacant Parcels under 2 Acres 70 16,800 Underdeveloped Parcels over 2 Acres 80 19,200 Magnolia Point Phases ,000 Magnolia Point Phase 7 & ,800 Subtotal ,200 North - Upper Service Area a Vacant Parcels over 2 Acres ,200 Vacant Parcels under 2 Acres 70 16,800 Underdeveloped Parcels over 2 Acres 1, ,600 CCUA Agreem ent 70 16,800 Subtotal - 1, ,400 Total - 4,270 1,024,800 a: As noted in Section II.C., existing OSTDS Areas likely comprise a potential wastewater demand of approximately 60,000 gpd Mittauer & Associates believes there is some potential for further commercial and office growth within the North Service Area, however the approach was to only use the dwelling unit counts from the Build-Out Study. In comparison to the North Service Area, the same analysis was completed for the South Service Area based on the Build-Out Study and known developments currently being tracked by the City. The summary of this analysis is shown in Table V-4. Mittauer & Associates, Inc. Project No Page 130

156 TABLE V-4 SOUTH SERVICE AREA DEVELOPMENT POTENTIAL Area/Project Dwelling Units (Ea) Office Space (SF) Commercial Space (SF) Hotel Rooms (Ea) Restaurant (seats) Flow (gpd) Vacant Parcels over 2 Acres Vacant Parcels under 2 Acres Underdeveloped Parcels over 2 Acres , ,400 Reynolds See Discussion in Section V.B. 1,610,000 JM/Huntley , ,000 Pyramid Property ,600 Total - 1,827,000 Tables V-3 and V-4 collectively provide information on the proposed and potential development within the Service Area; however, they do not include the current, base flow which is on-line. Those values are provided and the complete subservice area demand picture is clarified in Table V-5. TABLE V-5 SUMMARY OF SERVICE AREA WASTEWATER FLOW PROJECTIONS Area Exist. WW Flow (gpd) Growth Potential (gpd) Build-Out Demand (gpd) a North-Upper Service Area 43, , ,200 a North-Magnolia Service Area 96, , ,200 a North-Core Service Area 361, , ,400 Total North Service Area 500,000 1,024,800 1,524,800 Total South Service Area 212,000 1,827,000 2,039,000 a: Anticipated split of flows based on approximate ERU counts per sub-area. Total - 3,563,800 Mittauer & Associates, Inc. Project No Page 131

157 Based on Table V-5 projections and no WWTP consolidation, the contemplated build-out flow for the HRWWTP and SWWTP is estimated at 1,525,000 gpd (1.53 MGD-AADF) and 2,039,000 gpd (2.04 MGD-AADF), respectively. The City should consider that these values are based on complete build-out (development and re-development) of all available land within the City and will likely not come to full fruition due to issues such as lower than expected densities due to site constraints (setbacks, environmental issues, stormwater management, etc.); development of 100% of the available lots may not occur; some parcels may have land which cannot be developed; etc. However, for purposes of this report, these values will be used to analyze future infrastructure impacts and potential development scenarios. Since treatment trains are typically designed and constructed in rounded increments. If the City continued to utilize two (2) separate WWTPs to serve the community, then an anticipated build-out maximum for HRWWTP would be 1.75 MGD (AADF) and the SWWTP would be 2.25 MGD (AADF). If flows/treatment are combined to one regional WWTP, then the overall treatment plant capacity would likely need to consider a capacity of 3.50 to 3.75 MGD AADF. C. WASTEWATER DEMANDS THROUGH THE PLANNING PERIOD The Build-Out Study and the aforementioned analysis allows the City to determine the ultimate build-out of the Service Area. However, the study did not place a time line on the anticipated demand/flow per year. In order to review the potential pace of development within the Service Area and associated needs for infrastructure construction, previous growth projections along with known development timetables will be reviewed to determine flow rates through the Year The ultimate wastewater demand will be a direct function of the development rate (which is a function of the prevailing market for commercial, office, and recreational developments) along with potential migration of persons to the City from other areas. Therefore, the actual demand timelines could vary drastically if the market conditions were to significantly change. Growth will first be considered on an aggregate level within the entire Service Area and then applied to the North Service Area and the South Service Area as appropriate. Projections are based on historic trend lines and census data, as well as known development timelines which have been permitted or are in construction. Mittauer & Associates, Inc. Project No Page 132

158 Within the enclosed flow projections, specifically within the South Service Area, some consideration was given to actual timelines the City should expect before one of the larger developments is in a position to begin construction. The total entitlement process would likely take two (2) to four (4) years before the necessary approvals (re-zoning approval, site planning, engineering design, and permits) are in-hand for construction of these projects. Actual construction of the required infrastructure to serve the development(s) would likely take a minimum of two (2) years before the first unit was on-line for service. Therefore, the total time frame would extend over three (3) to five (5) years if no issues are encountered during the process. The following analysis takes the above discussion into further consideration and applies these concepts to each Service Area. The flow projections are based on the Medium and High-Demand values with the Medium-Growth Projections presented in Section III. 1. North Service Area HRWWTP Demands Utilizing the population growth projection summarized in Table III-3, the North Service Area projections are projected below. TABLE V THROUGH 2040 NORTH SERVICE AREA WASTEWATER PROJECTIONS Year M edium Growth Population (capita ERUs) Low-Demand WW Projection (gpd-aadf) M edium-demand WW Projection (gpd-aadf) High-Demand WW Projection (gpd-aadf) ,500 2, , , , ,130 2, , , , ,720 3, , , , ,260 3, , , , ,740 3, , ,700 1,055, ,170 3, , ,000 1,113,800 Mittauer & Associates, Inc. Project No Page 133

159 The estimated build-out for the North Service Area is 1.5 MGD based on the assumptions presented in the Build-Out Study and assuming some of the necessary redevelopment, septic-tank phase-outs, and core city in-fill occurs. Based on the medium-growth trend line projection with the medium-demand value of 240 gpd/eru, the North Service Area will be flowing around 59% of the build-out capacity in However, as discussed in Section II, the projected demands are anticipated to exceed the Biological Nutrient Removal capabilities of 0.65 MGD between 2015 and To provide another check on the proposed growth projections, the HRWWTP more recent flow trends were reviewed and compared against the proposed population projections. The HRWWTP AADF for 2008 through 2013 are tabulated in Table V-7 with annual rainfall amounts. As illustrated in the table, the flows into the HRWWTP are being influenced by rainfall amounts, not growth per se. The average rainfall in 2008 through 2011 was 50 inches per year while the 2012 and 2013 average rainfall was 70 inches. Average WWTP flow during the same time periods were MGD and MGD, respectively. The aggregate average during this time period is 0.50 MGD, which appears to be more appropriate and discounts flow from infiltration and inflow from elevated rainfall amounts. TABLE V THROUGH 2014 HRWWTP FLOWS WITH ANNUAL RAINFALL Year HRWWTP Flow (MGD AADF) Annual Rainfall (in) Estimated per Capita Demand (gpcd) In comparison, the HRWWTP AADF records since 1998 were reviewed and a regression analysis was completed to determine the current flow trends. Due Mittauer & Associates, Inc. Project No Page 134

160 to the flow variations from year to year, the correlation for the trend line was not 2 high (i.e., R value = 0.13), but it did produce a positive slope. The linear trendline was projected to 2040 and anticipated the HRWWTP demand would be approximately 0.60 MGD-AADF in Figure V-1 and Figure V-2 graphically depict this information. For projection purposes, the population and flow trend projections are started at the 2013 Average HRWWTP Flow of MGD, which is anticipated to include influence from infiltration and inflow. These projections would assume no modifications to the collection system to decrease those contributions, thus projecting a higher flow value than would be expected if I/I was not an influencing factor. A summary of the flow projection methods are summarized in Table V-8 and depicted in Figure V-3. TABLE V HRWWTP FLOW PROJECTIONS Year Population Based M edium-growth (MGD-AADF) AADF Trend Line (MGD) As shown above, the values calculated from each analysis differ in the rate and amount of growth within the North Service Area. Depending on the amount of redevelopment that occurs and the intensity of those developments, the actual population that will exist in the next 15 to 20 years is debatable. However, the City is beginning to see more activity within the Magnolia Point development with Phase 8 under construction and other development prospects discussing projects with the City which are located toward the northern extents of the Service Area. Therefore, the City must prepare for the population-based projections but prudently address infrastructure improvements to address lower growth potentials. Mittauer & Associates, Inc. Project No Page 135

161 City of Green Cove Springs M&A Project Figure V-1 : HRWWTP Historical Annual Average Daily Flow Trend 0.80 Original Harbor Road WWTP Capacity = 0.75 MGD 0.70 Biological Nutrient Removal Treatment Capacity = 0.65 MGD (Assuming no additional reuse & Mag Pt = 0.20 MGD (AADF)) Flow (MGD-AADF) HRWWTP Annual Flow (MGD-AADF) Original WWTP Permit Capacity (MGD) Current BNR Max. Treatment Capacity (MGD) Linear (HRWWTP Annual Flow (MGD-AADF)) Year

162 City of Green Cove Springs M&A Project Figure V-2: HRWWTP Annual ized Regression Trend Projected to Original WWTP Capacity = 0.75 MGD Biological Nutrient Removal Treatment Capacity = 0.65 MGD (Assuming no additional reuse & Mag Pt = 0.20 MGD (AADF)) 0.50 Flow (MGD-AADF) HRWWTP Annual Flow (MGD-AADF) Original WWTP Permit Capacity (MGD) Current BNR Max. Treatment Capacity (MGD) Linear (HRWWTP Annual Flow (MGD-AADF)) Year

163 City of Green Cove Springs M&A Project Figure V-3: HRWWTP Projected Flow Variation (Population Based vs. Trendline) Original WWTP Capacity = 0.75 MGD BNR Treatment Capacity = 0.65 MGD (Assuming no additional reuse & Mag Pt = 0.20 MGD (AADF)) Flow (MGD-AADF) Original WWTP Permit Capacity (MGD) 0.20 Current BNR Max. Treatment Capacity (MGD) Population Based Medium-Growth Flow Projection (MGD-AADF) 0.10 Linear Trend Line Flow Projection (MGD-AADF) Year

164 Pending actual wastewater demands and future reclaimed water demands within the City s Service Area, the City may be required to make capital decisions related to the HRWWTP and/or SWWTP before 2020 due to the TMDL restrictions. As noted in Section II, if reclaimed water demands remain around 0.20 MGD, then the 0.65 MGD capacity limitation is a restriction that must be addressed by the City. I/I reduction may reduce near-term flows and provide a relief related to larger capital expenditures. For purposes of this Plan, the Medium-Growth Population Projections presented in Table V-8 will be utilized going forward and utilized to determine capital expenditures associated with the HRWWTP, reclaimed water availability, and the North Service Area collection system improvements/modifications. 2. South Service Area SWWTP Demands As shown in Table V-5, the Build-Out Study, along with the wastewater calculations, anticipate a build-out wastewater demand of 2.0 MGD (AADF) within the South Service Area. As noted previously, the highest-growth potential for the City resides in the South Service Area due to the redevelopment potential of the large land tracts (i.e., Reynolds) which could be potentially constructed with significant densities and intensities. To maintain consistency between the analyses of the different sub-service areas, the previous population projections will be maintained to determine wastewater flow demands per year. However, the City should be aware of possible development scenarios which could modify and increase timelines for infrastructure construction. Applying the previously reviewed population projection estimates for the Service Area, Table V-9 presents the estimated population growth for the South Service Area. Mittauer & Associates, Inc. Project No Page 139

165 TABLE V THROUGH 2040 SOUTH SERVICE AREA WASTEWATER PROJECTIONS Year M edium Growth Population (capita ERUs) Low-Demand WW Projection (gpd-aadf) M edium-demand WW Projection (gpd-aadf) High-Demand WW Projection (gpd-aadf) , , , , , , , , , , , , , , , , , , , , , , , ,500 As noted in Section III, the Reynolds FLUM Amendment and the First Coast Outer Beltway represent two (2) significant variables that could impact development within the City s South Service Area. The new expressway is anticipated to complete construction on or before 2020, so the current population projections could shift as the City approaches and moves past this time horizon. As noted in Table V-9, the current medium-growth population projections estimate a unit (i.e., ERU) increase of approximately 10 to 15 units per year for each five-year period after This value could easily double or quadruple if the economy is strong, and the expressway facilitates growth into the City. Therefore, the City should be prepared to address larger demands associated with development and/or redevelopment as 2020 approaches. The estimated build-out for the South Service Area is 2.0 MGD based on the assumptions presented in the Build-Out Study and assuming some of the necessary redevelopment and in-fill occurs. Based upon the medium-growth trend line projection with the medium-demand value of 240 gpd/eru, the South Service Area will be flowing around 11% of the build-out capacity in If these projections were to hold, the current SWWTP biological nutrient removal capacity would be sufficient with 0.20 MGD (AADF) of reuse at the Magnolia Point golf course and no further nutrient loading reductions by the state. However, the variables associated with the Reynold s redevelopment, First Coast Outer Beltway and likely reductions to nutrient loading, point the City in a direction to reduce flows to the river to ensure the City has flexibility to meet Mittauer & Associates, Inc. Project No Page 140

166 future regulatory compliance requirements and serve future City customers. Further, if I/I issues remain in the Reynolds parcel, then regional rainfall will also affect wastewater flows that could impact TMDL requirements. To provide another review on the proposed growth projections, the more recent SWWTP flow trends were reviewed and compared against the proposed population projections. The SWWTP AADF for 2008 through 2013 are tabulated in Table V-10 with annual rainfall amounts. As illustrated in the table and discussed within Section II, the flows into the SWWTP are influenced by infiltration and inflow. However, during this review period, the South Service Area also suffered from the recession and slow recovery. As such, the flow reduction and general inconsistency between the various years is related to both variables. However, in the more near-term, the information does indicate a 40,000 gpd AADF increase from 2011 flows to 2012 and 2013 which consisted of more than 15 inches of additional rainfall. This period did not consist of any large increase of customers underscoring the high per capita flow rates indicating infiltration issues. TABLE V THROUGH 2014 SWWTP FLOWS WITH ANNUAL RAINFALL Year SWWTP Flow (MGD AADF) Annual Rainfall (in) Estimated per Capita Demand (gpcd) A more detailed analysis of actual rain events versus daily flows into the WWTP were reviewed to determine any contribution of infiltration and inflow into the system. A review of rain events during the aforementioned September 2012 Mittauer & Associates, Inc. Project No Page 141

167 TMADF (Jul-Aug-Sept) report period were reviewed, and the following was noted: Rainfall totals were taken from closest available monitoring station, which was the Harbor Road WWTP; From June 5, 2012 through June 17, 2012, approximately 9.56 inches of rainfall occurred; Prior to the rain events, the average daily flow from June 1 to June 4, 2012 was MGD (ADF); Following the rain events, the average daily flow from June 5 to June 17, 2012 was MGD (ADF); The influent flow peaked at MGD (ADF) on June 7, 2012 when over 5 inches of rainfall occurred; Similar response windows were noted for various days during June, July, and August 2012; and As more frequent rain events occurred, the baseline flow (i.e., flow during dry periods) took longer and longer to achieve illustrating the likely infiltration of groundwater into the collection system. A summary of the rain events and flow responses from June 1, 2012 through September 30, 2012 are provided in Figure V-4. The figure illustrates the different WWTP influent flow responses and durations as a function of the various rain events. The curves also provide further indication of the direct correlation between rainfall and SWWTP flows. The FDEP categorizes a system as having excessive I/I if the aggregated flow is greater than or equal to 275 gpcd. It is estimated that the SWWTP serves approximately1,400 persons. Using the 275 gpcd value, the amount of flow to the SWWTP that would be considered excessive I/I by FDEP is any influent flow greater than 385,000 gpd (275 gpcd * 1,400 persons). Figure V-5 adds this data point in comparison to the flows and rainfall shown in Figure V-4. As shown within the figure, a number of rain events resulted in influent flows exceeding MGD. Mittauer & Associates, Inc. Project No Page 142

168 City of Green Cove Springs M&A Project Figure V-4: June 1, 2012 through September 30, 2012 SWWTP Influent Daily Flow and Daily Rainfall Daily Flow (MGD) Monthly Rainfall (in) Flow (MGD) Rainfall (in) /19/12 6/2/12 6/16/12 6/30/12 7/14/12 7/28/12 8/11/12 8/25/12 9/8/12 9/22/12 10/6/12 10/20/12 Date

169 City of Green Cove Springs M&A Project Figure V-5 : June 1, 2012 through September 30, 2012 SWWTP Excessive I/I Review Daily Flow (MGD) Excessive I/I Influent Flow Threshold (275 gpcd) Monthly Rainfall (in) 8 Flow (MGD) Rainfall (in) /19/12 06/02/12 06/16/12 06/30/12 07/14/12 07/28/12 08/11/12 08/25/12 09/08/12 09/22/12 10/06/12 10/20/12 Date

170 The City is aware of the South Service Area collection system issues, but the majority of the areas that are anticipated to have the greatest depth and most likely potential for I/I are also located in the Reynolds parcel that is slated for major redevelopment. However, this is an issue that must be managed appropriately going forward due to the TMDL implications for the City. To provide a comparison for flow projections, the SWWTP AADF records since 2005 were reviewed and a regression analysis was completed to determine the current flow trends as illustrated within Figure V-6. The correlation was higher 2 than the HRWWTP review with an R value of 0.71, but the trend produced a negative slope. At worst, the City would project flat or slow growth but not negative. Therefore, the flow projection is not utilized for future comparisons within this Plan. For projection purposes, the population projection was calibrated to the 2013 Average SWWTP Flow of MGD. This flow value is anticipated to include influence from infiltration and inflow so real demands may be as low as 180,000 to 190,000 gpd. These projections would assume no modifications to the collection system limiting those contributions so the City may have seasonal spikes in flow due to wetter years in comparison to drier years. Further, the Reynolds redevelopment and the First Coast Outer Beltway are two (2) significant factors that could result in higher wastewater demands following Utilizing the BEBR population projection guidance, the flow projection for the SWWTP is summarized in Table V-11 and depicted in Figure V-7. TABLE V SWWTP FLOW PROJECTIONS Year Population Based Medium-Growth (MGD AADF) Mittauer & Associates, Inc. Project No Page 145

171 City of Green Cove Springs M&A Project Figure V-6 : SWWTP Historical Annual Average Daily Flow Trend Original South WWTP Capacity = 0.50 MGD Flow (MGD-AADF) Biological Nutrient Removal Treatment Capacity = 0.35 MGD (Assuming no additional reuse & Mag Pt = 0.20 MGD (AADF)) SWWTP Annual Flow (MGD-AADF) Original WWTP Permit Capacity (MGD) Current BNR Max. Treatment Capacity (MGD) Linear (SWWTP Annual Flow (MGD-AADF)) Year

172 City of Green Cove Springs M&A Project Figure V-7: SWWTP Projected Population Based Flow Original WWTP Capacity = 0.50 MGD Flow (MGD-AADF) BNR Treatment Capacity = 0.35 MGD (Assuming no additional reuse & Mag Pt = 0.20 MGD (AADF)) Anticipated Completion of First Coast Outer Beltway Demand Projections could Shift Original WWTP Permit Capacity (MGD) Current BNR Max. Treatment Capacity (MGD) Population Based Medium-Growth Flow Projection (MGD- AADF) Year

173 D. PLANNING PERIOD FLOW SUMMARY For purposes of analyzing the efficiency of future infrastructure expansion scenarios, it is important to frame the anticipated 2040 flows in context of the North Service Sub-Areas. Table V-12 summarizes the projected flow increase from the service areas. TABLE V SERVICE AREA FLOW PROJECTIONS AREA Exist. WW Flow (gpd) Projected 2040 Flow (gpd) % Increase North-Upper Service Area 43, , % North-Magnolia Service Area 96, ,200 33% North-Core Service Area 361, ,400 20% North Service Area Subtotal 500, ,000 68% South Service Area Subtotal 212, ,000 37% Total 712,000 1,130,000 59% The projections within the South Service Area are anticipated to fluctuate widely as the First Coast Expressway and Reynolds redevelopment are both anticipated to affect growth patterns and associated flow projections. In the aggregate, the 1.1 to 1.5 MGD total flow projection for the City may be accurate, but determining exactly where those flows will come from is difficult. For example, a 647% increase of flows within the North-Upper Service Area is unlikely, unless septic-phase out does occur, while a growth percentage greater than 37% in the South Service Area is likely pending expressway timing. Within Section VI, options are reviewed including rerouting P.S. No. 2 to the North Service Area (i.e., HRWWTP). P.S. No. 2 largely pumps the South Core Service Area. Re-routing of this station will allow for consolidation of the City s WWTPs and would have a significant near-term impact on wastewater flows at the HRWWTP. Expanding further on the above summary, Table V-13 is provided to summarize anticipated demands within the North Sub-Service Areas for the near-term Planning Period. This information will be used to determine potential flow impacts to the Mittauer & Associates, Inc. Project No Page 148

174 HRWWTP and SWWTP and associated expansion requirements when the various FM reroutings are reviewed in Section VI. TABLE V THROUGH 2040 SUMMARY OF SERVICE AREA WASTEWATER PROJECTIONS Year N.-Upper Service Area (MGD) N.-M agnolia Service Area (MGD) N.-Core Service Area (MGD) Total N. Service Area (MGD) S. Service Area (MGD) Total Service Area (MGD) The proposed flow projections are illustrated in Figure V-8. E. RECLAIMED WATER DEMANDS Presently, the City s only reuse customer is the Magnolia Point Golf Course as described in Section II. A review of the average daily flows (ADF) over the past six (6) years to Magnolia Point and the associated effluent river outfall is provided in Table V-14. Mittauer & Associates, Inc. Project No Page 149

175 City of Green Cove Springs M&A Project Figure V-8: Flow Projection Summary HRWWTP BNR Max. Treatment Capacity (MGD) SWWTP BNR Max. Treatment Capacity (MGD) North Service Area Demand Projection (MGD-AADF) South Service Area Demand Projection (MGD-AADF) Total Service Area Demand Projection (MGD-AADF) Flow (MGD-AADF) HRWWTP BNR Treatment Capacity = 0.65 MGD (Assuming no additional reuse & Mag Pt = 0.20 MGD (AADF)) SWWTP BNR Treatment Capacity = 0.35 MGD (Assuming no additional reuse & Mag Pt = 0.20 MGD (AADF)) Year

176 TABLE V THROUGH 2014 HRWWTP REUSE AND RIVER AVERAGE FLOWS (AADF) Year Total Flow (MGD- AADF) River Flow (MGD- AADF) River Flow (% of Total Flow) Reuse Flow (MGD- AADF) Reuse Flow (% of Total Flow) % % % % % % % % % % % % Average % % As illustrated within the table, the overall reuse flows fluctuate from year to year. This is due to rainfall, a decrease in the number of holes the golf course is playing/maintaining, and modifications to the stormwater/reuse holding ponds to ensure compliance with the Reuse Operating Protocol. The net effect of these three (3) items results in differing demand responses. For long-term planning, a 0.20 MGD (AADF) flow to Magnolia Point has been utilized and will be utilized in this Plan as expansion scenarios are reviewed in Section VI. As the City considers reuse expansion into potential residential areas, the demands associated with such a system should be considered since there is not a one-to-one relationship between wastewater supply and reclaimed water demand. Typically, a supplemental irrigation demand (i.e., water supplied above that received by rainfall) is recommended at rate of 0.75" per week which amounts to 39 inches of supplemental watering a year. Upon a general review of the Magnolia Point residential development, the City s largest residential irrigation demand was approximated based on the largest lots within the development which have lot dimensions of approximately 120 feet by 240 feet, or 0.70 acres. Assuming approximately 3,500 square feet of the lot is non-irrigable (i.e., house, driveway, sidewalk, etc.) that leaves 25,300 square feet of irrigable area. Utilizing the SJRWMD watering recommendation of 0.75" per week, the anticipated irrigation demand would be as follows: Mittauer & Associates, Inc. Project No Page 151

177 Residential Irrigation Demand = 2 25,300 ft *0.75 in/week*(4.33 weeks/month) 3 * (1 ft/ 12 in) * (7.48 Gal/ ft ) = 51,200 gallons/month (1,700 gpd-adf) Reviewing the same metrics for a 1/4 acre lot and approximately 1,200 square feet of non-irrigable area results in the following irrigation demand: Residential Irrigation Demand = 2 9,690 ft *0.75 in/week*(4.33 weeks/month) 3 * (1 ft/ 12 in) * (7.48 Gal/ ft ) = 19,600 gallons/month (650 gpd-adf) Many of these connections currently have separate potable irrigation meters. From September 2012 to August 2014, an average of 345 connections that have a separate irrigation meter were active (i.e., irrigated). During this time period and for these active meters, the average irrigation demand was 12,200 gallons per month or 400 gpd ADF. This value is less than anticipated from the planning metrics outlined above, and the differential is likely due to less irrigable acreage per connection as well as a general trend toward more water conservation as it relates to irrigation practices. In total, the current irrigation practices represent approximately MGD (ADF) of potential reuse demand with a total reuse population of 345 homes. Based on the same September 2012 to August 2014 time period, the monthly irrigation demand varied between a low of 47,500 gallons per month to a high of 211,000 gallons per month. Between the monthly high and monthly low, the differential is 440%. As another review, the irrigation demand is reviewed as it relates to irrigation limitations of two (2) days per week during daylight savings (mid-march to November) and one (1) day per week during all other times. While this restriction does not apply to reclaimed water irrigation, it is provided as guidance related to what is considered a reasonable amount of irrigation. At the Harbor Road WTP, the peak flow from the high service pumps during irrigation cycles can be as high as 1,400 gpm and includes some potable demands such as showering, bathing, and other in-house demands. The average monthly demands have been 100 gpm resulting in a peaking factor of 12 to 14 when compared to the Harbor Road WTP peaks between 1,200 to 1,400 gpm. Mittauer & Associates, Inc. Project No Page 152

178 It is anticipated each of the ERU connections would have an irrigation system that would have an instantaneous demand of approximately 10 to 15 gpm (10 gpm will be used for projections). In addition, if watering occurred as prescribed by the SJRWMD, then odd-numbered homes would have two (2) days available for watering, even-numbered homes a separate two-day grouping, and non-residential on another two-day period. Watering times are also restricted to approximately 15 hours of the day from times after 4 p.m. and before 10 a.m. For each development, we could conservatively assume 25% of the homes would be irrigating on the same day during their designated watering day, and a large percentage would be irrigating around the same time. Thus, the City should anticipate peak hourly flows that are 6 to 12 times the average daily demands. It is anticipated that newer development would have greater densities than Magnolia Point resulting in a net reduction of irrigable area. However, the City should plan for a reasonable average reuse ERU demand value that provides some flexibility to address seasonal, daily, and hourly peaks. A value between 400 to 500 gpd (AADF) per ERU may be a prudent value to assess reclaimed water demand. For purposes of this plan, a 500 gpd/eru value will be utilized. In comparison, the average wastewater supply will likely average between 150 to 250 gpd (AADF) per ERU creating an overall deficit. Therefore, the City must limit the reclaimed water service area to reasonable limits where appropriate storage and supply volumes can ensure a reasonable expectation of service capabilities to reuse customers. The appropriate storage volumes for the reclaimed water expansion alternatives will be reviewed in Section VI along with considerations related to pump station sizing and associated piping based on the aforementioned considerations. Mittauer & Associates, Inc. Project No Page 153

179 VI. WASTEWATER INFRASTRUCTURE EXPANSION ANALYSIS A. OVERVIEW Based on the projected Build-Out wastewater demands within the Service Area and the anticipated time horizon of when those demands may influence the system, a review of the City s future expansion needs is required comparing the proposed demands with the existing infrastructure capabilities. The results of this analysis will be incorporated into a capital improvement budget for the City s consideration to address the wastewater system needs to serve the public through The analysis will include a review of the following items: Wastewater Treatment Objectives; Wastewater Treatment Technology; Future Infrastructure Expansion Scenarios & Estimated Costs; and Reclaimed Water Service. B. WASTEWATER TREATMENT OBJECTIVES The objective of this analysis is to review potential treatment technologies which could be applied to the City s existing WWTP sites or a potential new site which has not yet been defined. For the existing sites, the constraints which are reviewed include treatment capabilities and efficiencies to meet effluent requirements; operation and maintenance considerations; available site area for expansion; capability for future expansion to meet Build-Out Demands; capability for incorporation of a Class AA bio-solids treatment process; and conceptual costs. The new site included review of all the aforementioned factors except site constraints. It is assumed that any new site would be procured with enough land area to meet the City s existing and future needs. As discussed in Section II of the report, the City s effluent capacity is currently limited as a result of the Lower St. Johns River TMDL. The current regulations allow for an annual mass loading ceiling (i.e., pound per year) related to TN and TP in lieu of an instantaneous, or maximum, discharge concentration (i.e., mg/l). Thus, the City has some ability to manage loading to the river via increased reuse quantities and/or employing treatment modifications during the year to reduced TN and/or TP concentrations. Mittauer & Associates, Inc. Project No Page 154

180 As denoted in Section II, the City s existing WWTPs are limited in their abilities to reduce nutrients as capacity/flows/loading to each WWTP increases. Section IV discussed the potential for further nutrient limitations that could result in additional limitations in TN and TP concentrations or outright restrictions of outfalls to the river. Section V reviewed growth potential and provided flow projections denoting that the HRWWTP biological removal capacity may be close to reaching its maximum efficiency. As a result, TN and TP effluent concentrations could begin to rise which would require an offsetting increase in reuse quantities to ensure the City remains below their TMDL annual limits. In the long run, the City should begin to plan for and implement systems that eliminate river outfalls or limit them to large wet-weather events and/or emergency needs. In concert, the City will need to expand their reuse system to serve additional customers and/or explore other effluent disposal options to reduce or eliminate the risk associated with maintaining a river outfall. Section IV also discussed the potential nutrient limitations that could become part of reclaimed water quality requirements. Due to the river restrictions and potential for future regulations that will require enhanced nutrient removal within reclaimed water, all future expansion alternatives reviewed herein will include treatment components required to meet advanced wastewater treatment ( AWWT ) with public-access reuse standards. Thus, each future treatment technology reviewed is required to produce an effluent which will meet the following requirements: CBOD 5 5 mg/l; TSS 5 mg/l; TN 3 mg/l; and TP 1 mg/l. C. CURRENT OPERATING BUDGET An important component related to the various alternatives is related to operating expenses and those differentials between current and future options. Attachment M summarizes the City s current expenses and revenues for the past five (5) fiscal years. Table VI-1 summarizes the aggregate expenditure categories. Mittauer & Associates, Inc. Project No Page 155

181 TABLE VI-1 FISCAL YEAR 2009 THROUGH 2013 WASTEWATER EXPENDITURES Aggregate Category FY 09 FY 10 FY 11 FY 12 FY 13 Personnel (Salary, OT, Retirem ent, Insurance) Operating Expenses $ 338,000 $ 319,740 $ 377,240 $ 403,130 $ 375,700 $ 481,450 $ 543,050 $ 996,440 $ 511,610 $ 564,270 Debt Service $ 0 $ 0 $ 0 $ 0 $ 0 Transfers $ 224,520 $ 195,510 $ 171,220 $ 188,440 $ 232,800 Sum $1,043,979 $1,058,310 $1,544,911 $ 1,103,192 $ 1,172,783 The FY 11 Operating Expenses category was higher due to a $484,000 Depreciation Expense that was not accounted for in the preceding or following fiscal years. The Operating Expenses are an area that will be discussed for each alternative evaluated herein. D. WASTEWATER TREATMENT TECHNOLOGY In order to meet the treatment objectives discussed in Section VI.B., the selection of the type of treatment technology is critical to ensure a reliable system is installed to meet the effluent requirements. For purposes of this report, the following treatment technologies are reviewed: Oxidation Ditch Process utilized for expansion options; 5-Stage Bardenpho BNR Process utilized for retrofit alternatives and expansion at existing sites; and Moving Bed Biological Reactor ( MBBR ) with 5-Stage BNR utilized for retrofit alternatives and expansion at existing sites. For all options, TP removal will be approached through biological means. However, cost estimates will also include provisions for removing this nutrient via chemical addition. Mittauer & Associates, Inc. Project No Page 156

182 The general advantages and disadvantages of each approach are discussed further in this subsection. The application of each technology to the City s existing or proposed WWTP sites is reviewed in Section VI.D. One of the issues that each proposed treatment technology must address is related to removal of nitrogen and phosphorus to relatively low levels. In Section II, the MLE and/or Bardenpho processes were discussed in relation to the City s existing WWTP operations. However, it was noted that each WWTP does not purely meet the requirements to run these activated sludge processes due to existing facility limitations. For example, the HRWWTP does not currently have recycle pumping, and the discharge location for the RAS piping is not in accordance with the process flow requirements. At the SWWTP, the process does not have a recycle flow and the system s RAS is disabled when blowers are cycled off. From a planning perspective, the MLE process can typically provide treatment where effluent TN levels are reduced to 10 mg/l or less, but can not be a reliable activated sludge process to meet the future effluent requirements (TN 3 mg/l). MLE is also not a process that can reduce TP. The most reliable biological treatment approach to reach the required levels is through the 5-Stage Bardenpho BNR ( 5-Stage Process ) system, which is more specifically reviewed herein. The treatment technologies that will be reviewed each offer a different approach to achieving the TN and TP effluent goals, but they all tend to provide a sequence of treatment similar to the 5-Stage Process. 1. Oxidation Ditch Process An Oxidation Ditch process is an activated sludge technology that runs in a complete-mix mode. The configuration of an oxidation ditch can be a single channel or multiple interconnected channels which are typically shaped like an oval. Unlike typical package plant designs, the configuration of the basin along with the placement of the aerators creates separate zones where dissolved oxygen levels transition from high to depressed levels. These zones are created in one tank, without the separate walls or compartments which are typically part of an activated sludge facility. Aeration is provided via mechanical aerators in lieu of separate blowers and submerged diffusers. The aerators also provide mixing power to keep the mixed liquor suspended and prevent settling. Following the oxidation ditch process, a secondary clarifier is required to settle and concentrate solids. Mittauer & Associates, Inc. Project No Page 157

183 Advantages of the Oxidation Ditch process include: Capable of consistently achieving high levels of BOD, TSS, and TN removals with minimum operator attention; Capable of removing TP with the inclusion of an anaerobic selector compartment; Long history of reliable service and performance; Produces minimal sludge due to long solids retention time; Aeration system alleviates need for separate blowers and is accessible for maintenance (i.e., not submerged); and Operation is relatively simple and straightforward. Disadvantages of the Oxidation Ditch process include: Requires large amount of tankage; Requires separate clarifiers; and Requires large land area. A process flow schematic for a typical facility is provided as Figure VI Stage BNR Process The process flow schematic for this approach is provided as Figure VI-2 and generally includes one (1) anaerobic tank for TP removal, two (2) anoxic tanks which create an environment for denitrification and two (2) aeration tanks which create an environment for nitrification and oxidation. The combined system reduces the influent ammonia to gaseous nitrogen and captures TP within the biomass. Advantages of the 5-stage BNR process are generally listed as follows: Smaller footprint required in comparison to the oxidation ditch process; Can reliably remove TN to levels between 3 to 5 mg/l; Provides a biological TP removal mechanism; Similar to conventional activated sludge processes; Lower sludge production due to larger SRTs; and Sludge settling characteristics is typically good. Mittauer & Associates, Inc. Project No Page 158

184 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure VI-1 Oxidation Ditch Flow Schematic.dwg, 2/25/2015 3:39:47 PM

185 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure VI-2 BARDENPHO PROCESS SCHEMATIC.dwg, 2/25/2015 3:41:09 PM

186 Disadvantages of 5-stage BNR process include: Requires large amount of tankage; Requires separate clarifiers; and Requires multiple tanks in series which can increase construction costs and limits future operational flexibility. 3. Integrated Fixed Film Activated Sludge Process (IFAS) Moving Bed Biological Reactor (MBBR) The Integrated Fixed Film Activated Sludge Process ( IFAS ) includes any wastewater system that incorporates some type of fixed film media within a suspended growth activated sludge process and continues to provide a RAS flow stream. The media systems that can be used vary greatly and can include rope media, looped strand media, sponge cuboids, plastic wheels, or packing material of various types. The media can be free floating in the mixed liquor or fixed within the aeration basin on cages or frames. The HRWWTP currently has this component as part of its activated sludge process. The basic principle behind the IFAS Process is to expand the treatment capacity or upgrade the level of treatment by supplementing the suspended growth biomass by growing additional biomass on fixed film media contained within the mixed liquor. The additional biomass allows a higher effective rate of treatment within smaller process tanks, thus making volume available to incorporate denitrification and/or biological phosphorus removal within the same tanks. The additional biomass provided by placing media directly into the suspended growth reactor creates additional biological activity within the same basin without increasing clarifier solids loading which often limits the treatment capacity of existing activated sludge treatment systems. The result of this combination is an increased overall active biomass which increases the wastewater treatment capabilities of the system. For purposes of this evaluation, the activated sludge system that includes a RAS flow stream will be called an IFAS WWTP while the other will be an MBBR WWTP. Several types of media are used to fix the biomass in an MBBR reactor. Ropetype, sponge, and plastic media are typical product components. More commonly, plastic media is used for municipal applications and generally takes the form of free floating plastic wheels, also referred to as biomass carriers. Mittauer & Associates, Inc. Project No Page 161

187 This media requires the installation of screens to keep the media within the appropriate basins. A typical biofilm carrier is shown in Figure VI-3. The MBBR Process offers a very simple operating treatment system while having no return sludge from the clarifiers and the ability to handle large flow and load changes while maintaining its treatment efficiency. The process allows the retention of slow growing nitrification bacteria within the aerobic reactor while not being washed out during cold temperatures or hydraulic events since they are housed within specially designed biomedia. Figure VI-3: Sample Biofilm Carrier Advantages of the IFAS MBBR process are generally listed as follows: Additional biomass for treatment without increasing solids loading on clarifiers; Additional treatment capacity without increasing process tank volume; Improves solids settling; Greater resistance to organic and hydraulic shock loads; Reduced operational costs; Stable sludge production; and As loadings increase, additional media can be added to compensate. Disadvantages of the IFAS MBBR process are generally listed as follows: Biological phosphorus removal requires additional stages; Requires extensive screening and grit removal for proper operation; Requires additional screens within the treatment process for media retention; and Requires external blowers and diffused aeration delivery systems. Full flow schematic is provided as Figure VI-4. Mittauer & Associates, Inc. Project No Page 162

188 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure VI-4.dwg, 3/30/ :19:57 AM

189 4. Phosphorus Removal Approach For all future WWTP alternatives, TP removal will be conceptually designed through biological nutrient removal means. However, construction cost estimates will include an alum feed system to ensure TP concentrations will remain below the target limit of 1 mg/l. E. FUTURE INFRASTRUCTURE EXPANSION ANALYSIS In order to efficiently and effectively treat existing and future wastewater demands within the community, the City is reviewing a number of options to economically meet the regulatory requirements outlined in Sections II and IV while providing appropriate levels of service to their customers. Evaluation of alternatives are included within this section to compare and contrast various options. While cost (construction, operation & maintenance ( O&M ), and financing) is a critical factor, other non-cost factors will also be evaluated within each alternative. For example, the poor soils located within and near the SWWTP increase capital costs and the SWWTP s proximity to an airfield elevates siting concern related to potential Reynolds redevelopment options. Some alternatives contain sub-alternatives related to effluent disposal options, but all alternatives considered the Build-Out Demand determined in Section V. Broadly, the three (3) alternatives considered for the City included: Expansion alternatives associated with existing WWTP sites; A new regional facility capable of treating the City s entire Service Area; or Regional interconnect(s) with Clay County Utility Authority (CCUA). Separately, but related to the expansion alternatives above, options were analyzed related to expansion of the City s reclaimed water delivery options. Options included: Public-Access Reuse Expansion (i.e., Magnolia Point Expansion and North Service Area Expansion); and Restricted-Access Reuse Expansion (i.e., sprayfields, constructed wetlands, rapid-infiltration basins, etc.). Mittauer & Associates, Inc. Project No Page 164

190 As noted in Section IV.B., advanced wastewater treatment levels alone will not provide sufficient reductions in Total Nitrogen ( TN ) or Total Phosphorus ( TP ) loading to meet the City s Build-out Demands of 3.50 to 3.75 MGD while maintaining a St. Johns River outfall. If 100% of the City effluent went to the St. Johns River, the maximum estimated flow, with current TMDL restrictions, would cap effluent disposal levels at 1.87 MGD (AADF) for TN and 1.39 MGD (AADF) for TP. TP levels should remain below 1.0 mg/l such that TN loading is limiting, thus the current TMDL is anticipated to limit the City s river discharge to 1.87 MGD (AADF) with advanced treatment. In addition, the City s existing permitted outfall capacities at the HRWWTP and SWWTP are 1.25 MGD (AADF) and 0.50 MGD (AADF), respectively. Based on the infrastructure s peak flow design capacity, each outfall has respective capacities of 2.78 MGD (PHF) and 2.52 MGD (PHF). Table VI-2 summarizes these various limiting factors for each WWTP. TABLE VI-2 SWWTP AND HRWWTP RIVER OUTFALL CAPACITY LIMITS Location TMDL w/ AWWT (MGD-AADF) a Current FDEP Permit (M GD-AADF) Hydraulic Design Capacity b (MGD-PHF) (M GD-AADF) HRW W TP Aggregate SW W TP Sum a: 1.87 MGD AADF limitation based on TN being limited factor for TMDL compliance. b: PHF values based on hydraulic analysis, see Section II for discussion. AADF values calculated based on a 3.0 peaking factor (i.e., PHF/3.0) Therefore, based on the summary above, the HRWWTP could reach it s outfall capacity when average daily flows approach 0.90 MGD (AADF) based on hydraulic limitations only. This is also based on a 3.0 peaking factor. The SWWTP would be limited first by the permitted capacity of 0.50 MGD (AADF). On a physical facility basis, the SWWTP would reach its effluent hydraulic limitations as flows approach 0.80 MGD with a 3.0 peaking factor. Appropriate wet-weather storage with expanded reclaimed water delivery options is one way to address these limitations and is reviewed within the reuse expansion review options. As the City contemplates these measures, the current outfall Mittauer & Associates, Inc. Project No Page 165

191 capacities must be considered due to regulatory restrictions that will likely complicate any future expansion and/or alteration of these river connections. In light of these outfall limitations as well as future risk associated with potential tightening of nutrient limitations, the City is also considering policy directives that would continue to limit, if not eliminate, river outfalls. Based on the aforementioned guidelines and expansion directives, a detailed analysis of various infrastructure expansion options was completed. The details of Alternative No. 1 through No. 5 are provided in separate attachments as listed herein. Each enclosure outlines the analysis results and associated recommendations. The selected alternative s features and near-term expansion requirements within the Planning Period will be discussed herein. The alternative analyses that were completed for the City s future expansion requirements are defined as follows: Alternative No. 1 Existing Facility Expansion Summary As reviewed in Section II, the two (2) existing WWTPs are currently located miles apart which can lead to inefficient operation of the system and increased O&M costs. However, in order to develop baseline expansion costs to compare against other alternatives, options were reviewed to modify and expand each of the City s existing WWTPs. Within the Alternative No. 1 scenario, infrastructure needs were evaluated to expand the HRWWTP to meet the North Service Area build-out demand of 1.5 MGD (AADF) and meet the South Service Area build-out demand of 2.0 MGD (AADF) via phased construction. Both WWTPs would meet Advanced Wastewater Treatment ( AWWT ) requirements after completion. The detailed review is provided within Attachment N. Within this scenario, elements associated with modifying the City s collection and transmission system are not considered. Any expansion to those facilities are anticipated to include proceeds from development through separate development agreements and/or impact fee revenue. This may not, and likely will not, cover all capital costs, but defining future force main needs is currently problematic as redevelopment locations with associated densities and intensities are not known. With consolidation and construction of an advanced wastewater treatment plant, the City s near-term pressure to expand reclaimed water systems would be mitigated. However, policy considerations may dictate a desire to move away from a river Mittauer & Associates, Inc. Project No Page 166

192 outfall in which case one of the reclaimed water expansion alternatives defined in Alternative No. 2 could be utilized. In addition, growth within the South Service Area is anticipated to include public-access reuse systems. Alternative No. 2 North Service Area Reuse Expansion Summary This alternative includes expansion of the North Service Area reclaimed water delivery system to maximize service to the Magnolia Point development (i.e., residential and golf course) and/or expansion into other development areas within the North Service Area. The South Service Area public-access reclaimed water delivery alternatives are currently unavailable and predicated on future development. Given the unknown timing of future development and the unknown characteristics of the development location, layout, demands, etc., a conceptual reclaimed water delivery system could not be developed at this time. However, restricted-access reuse opportunities in the South Service Area were evaluated as part of Alternative No. 3. Details related to the Alternative No. 2 review are provided in Attachment O. Alternative No. 3 Regional Expansion at New Site Summary This scenario reviews the needs to decommission the HRWWTP and SWWTP and develop a new regional facility. The City s existing transmission system would be modified to divert all flows to a new regional site developed to meet the City s Build Out flow of 3.50 to 3.75 MGD (AADF) via phased WWTP construction. Due to the land availability in the South Service Area and anticipated development potential in this area of the City, the regional facility was first reviewed for potential siting options in the South Service Area. Several siting options were reviewed relative to suitability for a regional WWTP and associated near-term effluent disposal options. Development of this option includes modification to the City s existing transmission system including but not limited to: (1) new master pump stations at the HRWWTP and SWWTP; (2) re-routing existing force mains to the new Regional WWTP; and (3) existing pump station upgrades. Effluent disposal options include consideration of near-term and long-term options. In the near-term, restricted-access alternatives are required since the City does not have any existing reuse customers outside of the Magnolia Point golf course. In the long-term, effluent disposal is anticipated to be addressed via public-access reclaimed water delivery systems within new developments. Details related to this review are provided in Attachment P. Mittauer & Associates, Inc. Project No Page 167

193 Within this alternative, siting options within the North Service Area were also explored at a cursory level. Suitable options for a new regional site located within the North Service Area were not available due to limited parcel sizes, competing uses (i.e., residential and commercial uses next to wastewater site), and environmental concerns (i.e., wetlands and floodplains). Alternative No. 4 CCUA Regional Interconnect Summary Within this alternative, options were reviewed to develop bulk service reuse mains to deliver public-access reclaimed water to CCUA for subsequent service to their customers. This concept is not fully developed as it would also need detailed discussions with CCUA related to bulk charges, maintenance requirements, capacity fees, etc. Preliminary conversations with CCUA indicated they have not paid bulk reclaimed water fees from other municipalities, so the City would need to consider the lack of any offsetting revenue from this alternative. The approach within this alternative was to construct a new reclaimed water delivery pipeline from the Harbor Road WWTP to an existing or future CCUA Water Reclamation Facility (WRF). At each CCUA WRF, a ground storage tank would be the point of delivery for the City s reclaimed water. A bulk meter would be installed and reclaimed water would flow to CCUA as long as storage volume was available. Within this approach, the distance to the current and/or future WRFs is a significant capital investment. For purposes of this review, the capital outlay and City s ongoing maintenance costs are reviewed and compared against other alternatives. However, given CCUA s current demands and available infrastructure, this option is not a near-term solution since CCUA does not have the demand for additional reclaimed water supplies. Alternative No. 5 Regional Consolidation at HRWWTP Summary As a result of the analysis that was completed for Alternatives No. 1 through No. 4 it was determined that a regional consolidation option at the City s HRWWTP should be reviewed. This was determined as a prudent option since the City already had a large reclaimed water user being served from the HRWWTP, and the City has existing infrastructure opportunities (i.e., pump stations and force mains) that could be leveraged in an efficient manner to reduce the regional consolidation capital needs. As part of this process, the SWWTP would be decommissioned, but the permitted connection would remain in case the site was needed in the future for Mittauer & Associates, Inc. Project No Page 168

194 treatment and/or other wastewater purposes (i.e., reclaimed water storage and pumping station to Reynolds and/or other development in the South Service Area). The City s existing transmission system would be modified to divert all flows to the HRWWTP, and the HRWWTP treatment system design would include capabilities to meet the City s Build Out flow of 3.50 to 3.75 MGD (AADF) via phased construction. Development of this option includes modification to the City s existing transmission system including, but not limited to: (1) modifications to the City s existing Pump Station No. 2 and No. 4 to meet Planning Period flows/demands; (2) extension of new force main from Pump Station No. 2 to the Harbor Road WWTP; and (3) modification and expansion of the HRWWTP to meet advanced wastewater treatment standards. With consolidation and construction of an advanced wastewater treatment plant, the City s near-term pressure to expand reclaimed water systems would be mitigated. However, policy considerations may dictate a desire to move away from a river outfall in which case one of the reclaimed water expansion alternatives defined in Alternative No. 2 could be utilized. Details related to this review are provided in Attachment Q. The aforementioned options and the detailed review which is provided in this section considers the long-term wastewater collection, transmission and treatment needs of the City. In the interim and as discussed in Sections II and IV, the current St. Johns River TMDL regulations and future concern related to more stringent river outfall restrictions require the City to begin review of alternatives to greatly reduce or eliminate this connection through other effluent disposal means. 1. Alternative No. 1 Analysis In order to review this scenario, the Service Area s existing infrastructure and the associated expansion needs will be reviewed as follows: HRWWTP Required Improvements to Serve the North Service Area through the Planning Period and Build-Out; and SWWTP Required Improvements to Serve the South Service Area through the Planning Period and Build-Out. As shown in Table V-5, the North and South Service Area Build-Out Demands are respectively 1.5 MGD (AADF) and 2.0 MGD (AADF). These values will be utilized within each facility review to determine total site and facility needs. In Mittauer & Associates, Inc. Project No Page 169

195 the interim, the Planning Period demand projections shown in Table V-12 are respectively 0.61 MGD (AADF) and 0.29 MGD (AADF). The South Service Area demand has the greatest potential to change and significantly exceed these population-based flow projections as discussed in Section IV and V. However, this scenario is developed to compare and contrast subsequent modifications explored within the Plan. HRWWTP Improvements As explored in Section II, the City has completed operational modifications to each WWTP to allow for biological nutrient removal of TN. The HRWWTP is also providing TP removal through biological means. As flows and loading increase, the current effluent quality is anticipated to decline with elevated nutrient levels. Once the HRWWTP flow begins to reach 0.60 to 0.65 MGD (ADF), TN and TP levels are anticipated to increase beyond the current effluent quality of 8 mg/l (TN) and 1 mg/l (TP). At the SWWTP, flows approaching 0.30 to 0.35 MGD (ADF) are anticipated to elevate TN concentrations above the current 3 mg/l (TN) values. Figure VI-5 illustrates the demand projections for each WWTP along with the current BNR capacity limitations. Due to the current reuse system limitations (i.e., only one (1) reuse customer, Magnolia Point Golf Course) and TMDL restrictions, the City must consider these facility limitations in the near-term. In order to meet the near-term nutrient removal criteria as well as provide capacity for the North Service Area build-out demands, the aforementioned improvements are addressed through future facility expansion. Due to the site limitations, the approach to meet the City s near-term and long-term needs includes modifications to the biological treatment units to maximize available volume in the existing activated sludge system (i.e.. BTU No. 1). Utilizing the IFAS MBBR treatment approach outlined in Section VI.B., the proposed improvements to the HRWWTP include: New influent structure with fine screening, grit removal systems, and flow splitter to meet IFAS MBBR system requirements and provide required redundancy; New flow equalization system to address elevated peaks from I/I contributions and manage peak flows related to existing clarifier size; Retrofit of BTU No. 1 with IFAS MBBR system components; New parallel BTU No. 2 with IFAS MBBR system components and central clarifier; Mittauer & Associates, Inc. Project No Page 170

196 City of Green Cove Springs M&A Project Figure VI-5: North and South Service Area Demand Projection Summary with Existing BNR Treatment Capabilities HRWWTP BNR Treatment Capacity = 0.65 MGD (Assuming no additional reuse & Mag Pt = 0.20 MGD (AADF)) HRWWTP BNR Max. Treatment Capacity (MGD) Flow (MGD-AADF) SWWTP BNR Treatment Capacity = 0.35 MGD (Assuming no additional reuse & Mag Pt = 0.20 MGD (AADF)) SWWTP BNR Max. Treatment Capacity (MGD) North Service Area Demand Projection (MGD-AADF) South Service Area Demand Projection (MGD-AADF) Total Service Area Demand Projection (MGD-AADF) Year

197 New parallel filtration system; Chlorine Contact Chamber expansion; Digester Expansion; and New Biosolids Dewatering System. Figure VI-6 gives a general site plan layout of the proposed improvements while Figure VI-7 provides a plan view of the BTU modifications required to complete the conversion to an MBBR facility. The HRWWTP would have a rated AWWT capacity of 1.50 MGD (AADF) following construction of these items. Capital costs include both construction and non-construction costs associated with the Alternative. Construction costs are based on budget pricing from equipment vendors, recent bid pricing for similar work, and engineering judgment. Non-construction costs include engineering, administration, legal, and finance-related costs and will be represented as 15% of the total estimated construction cost. Detailed cost estimates are provided in Attachment N. A summary of the IFAS MBBR WWTP opinion of probable capital cost is as follows: Construction Cost = $12,200,000 (includes 15% Contingency) Non-Construction Cost = $1,830,000 Total Cost = $14,030,000 For purposes of a comparative review between options, O&M costs for each alternative are limited to power, chemicals, and equipment maintenance/repair for each specific alternative. Labor costs are assumed to be the same for all alternatives as all required labor will be accomplished by existing operations staff. Therefore, labor costs will not be included in the O&M cost analysis. The opinion of probable O&M costs when the WWTP is flowing at capacity (i.e., 1.5 MGD AADF) is $675,000 per year with details presented in Attachment N. For each alternative, an annualized cost for the option is developed for comparison purposes. The construction costs are annualized assuming financing for the improvements will occur through a funding agency, and no grant proceeds are included at this time. A 30-year term and a discount rate of 3.0% will be utilized to annualize the capital cost. The annualized capital costs will be added to the Total Annual O&M Cost to provide a total annualized cost for the alternative. The summary for this alternative is provided as follows: Mittauer & Associates, Inc. Project No Page 172

198 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure VI-6A.dwg, 3/30/ :01:24 PM

199 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure VI-6B.dwg, 2/25/2015 3:58:55 PM

200 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure VI-7 HRWWTP BTU No1 MBBR MODS.dwg, 2/25/2015 4:00:01 PM

201 Total Est. Const. Cost = 3.0% for 30 yrs = $12,200,000 x = $622,000/yr Total Est. Annual O&M Cost = $675,000/yr TOTAL ANNUAL COST $1,297,000/yr (estimated) The advantages and disadvantages of the alternative are presented in Table VI-3. TABLE VI-3 HRWWTP AWWT EXPANSION ALTERNATIVE - IFAS MBBR IMPROVEMENTS ADVANTAGES & DISADVANTAGES Advantages Disadvantages 1. Maxim izes use of existing BTU. 1. Clarifier sizing requires flow equalization system. 2. Limits collection system m odifications associated with regional alternatives. 3. Maxim izes reclaim ed water supply for reuse expansion into Magnolia Point. 2. Requires work within the existing BTU. 3. Increased chem ical costs to assist settling characteristics of the MLSS and BNR capabilities. 4. Maintenance concerns related to biofilm m edia m aintenance and control. Increased sludge production and handling. 5. Retains a two (2) W W TP system for City s on-going operations and maintenance. 6. Maintains existing site with W TP and adjacent to railroad system. Reclaimed water delivery expansion alternatives are reviewed in Alternative No. 2, which include facility improvements to the HRWWTP (see Figure VI-10A). SWWTP Improvements In order to meet the near-term nutrient removal criteria as well as provide capacity for the South Service Area build-out demands, the initial approach includes consideration of current nutrient removal needs while also developing the site to accommodate future treatment units for Build-out Demands. Since the long-term potential for the site/service area is 2.0 MGD and the near-term demands are 0.20 to 0.25 MGD with weak influent wastewater strength, the first phase must consider both extremes. For this alternative, the proposed Mittauer & Associates, Inc. Project No Page 176

202 improvements to the SWWTP include: New influent structure with fine screening, grit removal systems, and flow splitter; New 0.75 MGD (AADF) AWWT Oxidation Ditch ( Treatment Train No. 1"); Two (2) new 55-foot diameter central clarifiers; New parallel filtration system installation timing is discussed in Section VI.E.; Chlorine Contact Chamber expansion; Conversion of existing BTU and clarifiers to two (2) new Aerobic Digesters; and New Biosolids Dewatering System. Figure VI-8 gives a general site plan layout of the proposed improvements. Due to the known poor soils, all water bearing structures, expect the chlorine contact chamber, are designed with 12-inch precast support pilings spaced at one (1) piling per 12 square feet. The Oxidation Ditch Improvements opinion of probable capital cost is detailed within Attachment N, and is summarized as follows: Construction Cost = $14,200,000 (includes 15% Contingency) Non-Construction Cost = $2,100,000 Total Cost = $16,300,000 The opinion of probable O&M costs are $440,000 and are presented in Attachment N. The cost summary for this alternative is provided as follows: Total Est. Const. Cost = 3.0% for 30 yrs = $14,200,000 x = $724,000/yr Total Est. Annual O&M Cost = $440,000/yr TOTAL ANNUAL COST $1,164,000/yr (estimated) The advantages and disadvantages of the alternative are presented in Table VI-4. Mittauer & Associates, Inc. Project No Page 177

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204 TABLE VI-4 SWWTP AWWT EXPANSION ALTERNATIVE OXIDATION DITCH IMPROVEMENTS ADVANTAGES & DISADVANTAGES Advantages 1. No modifications to the City s transm ission system required. Disadvantages 1. Maintains existing site with poor soils and noncom pliant with FAA recom m endations related to airfield proxim ity. Retains a two (2) W W TP system for City s on-going operations and m aintenance. Subsequent phases will be expensive due to piling requirem ents. 2. New site acquisition is not required. 2. Located adjacent to Reynolds redevelopment area that may result in the W W TP being located adjacent to a residential and/or commercial land use. 3. Maintain ability to keep a permitted river outfall for wet-weather events or near-term use until reuse dem and materializes. 3. Interim effluent disposal needs may be required offsite in order to m aintain TMDL requirements until such time that reuse customers were available. As noted above, a non-cost construction factor related to this site is its proximity to an airfield and the recommendations related to wastewater system buffers. Figure VI-9 provides an aerial denoting the Wildlife Attraction Buffers from the Florida Aviation Administration (FAA) Advisory Circular related to this item. 2. Alternative No. 2 Analysis For this alternative, four (4) options are presented related to expanding the HRWWTP Reclaimed Water Delivery ( Reuse ) System. These alternatives include: 1) Residential Reuse Expansion to Magnolia Point residences with storage and high service pumping capabilities at the HRWWTP ( Mag Pt Reuse Expansion Alt. No. 1"); 2) Residential Reuse Expansion to Magnolia Point residences with storage and high service pumping within Magnolia Point ( Mag Pt Reuse Expansion Alt. No. 2"); Mittauer & Associates, Inc. Project No Page 179

205 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure VI-9 Wildlife Buffers.dwg, 2/25/2015 4:17:07 PM

206 3) Magnolia Point Stormwater Treatment Lake Augmentation ( Mag Pt Reuse Expansion Alt. No. 3"); 4) Residential Reuse Expansion to North Service Area with storage and high service pumping capabilities at the HRWWTP ( North Service Area Reuse Expansion Alt. No. 1"). Each of these alternatives are based on expansion from the existing Harbor Road WWTP, but any of the options and associated components could be utilized as part of other expansion scenarios including the Recommended Alternative outlined herein and within Attachment Q. In essence, the components and requirements defined herein are mutually exclusive alternatives to increase reclaimed water consumption. It is important to note that each of the scenarios outlined herein do not include any reject storage, since each approach anticipates the river outfall would be available for any off-spec water that does not meet the publicaccess reclaimed water requirements. a. Mag Pt Reuse Expansion Alt. No. 1 For this alternative, the HRWWTP components would be expanded to provide residential retail reclaimed water service ( retail reuse ) to Magnolia Point homes. The current HRWWTP reuse pumps were designed to provide bulk service to the Magnolia Point golf course and are not capable of meeting the necessary delivery pressures for residential irrigation. The bulk approach also relies on the Magnolia Point stormwater ponds as a storage vehicle which would not benefit the residential expansion. Separate storage would be required to service this project. In order to provide retail reuse service from the HRWWTP, the following improvements are required: Transfer Pumps; Ground Storage Tanks; Reclaimed Water ( Reuse ) Pumping System with Controls; and Reclaimed Water Piping Extensions and Connections to Magnolia Point Customers. Mittauer & Associates, Inc. Project No Page 181

207 As noted in Section II.B.1., the HRWWTP is currently treating 0.50 MGD (AADF) of raw wastewater and providing 0.20 MGD (AADF) of reclaimed water supply to the Magnolia Point golf course. Section V.E. developed some reuse demand metrics for Magnolia Point which included a review of historical irrigation records for those homes that presently have separate irrigation meters. Based on irrigation planning values derived from an application rate of 0.75 inches per week, estimated irrigation areas, and historical records, the recommended irrigation demand planning value was estimated to be 500 gpd-aadf/eru. This provides some measure of annual withdrawals but does not provide daily demand needs and/or peakhour pumping requirements. Within Magnolia Point, approximately 715 parcels have been platted, and the near-term construction of Phase 8 will add another 121 parcels. In total, the potential build-out demand would encompass approximately 835 parcels/connections. Utilizing the aforementioned planning values, the reuse demands are summarized as follows: Average Build-Out Demand = 835 ERUs * 500 gpd/eru = 417,500 gpd (AADF) At current HRWWTP flows of approximately 0.50 to 0.55 MGD and a Magnolia Point Golf Course Demand of 0.20 MGD, the available near-term supply from the HRWWTP is approximately 0.30 to 0.35 MGD resulting in an anticipated daily deficit between 67,500 to 117,500 gpd (AADF). The Alternative No. 5 option would address this potential deficit by consolidating service at the HRWWTP and providing more reclaimed water supplies. In addition, long-term projections anticipate it would be addressed through growth and/or redevelopment within the North Service Area. Peaking factors within irrigation systems can be quite large as discussed in Section V.E. Since the Harbor Road WTP currently meets this irrigation demand along with the essential use demands within the development, flow records from the water plant were reviewed and it was determined that peak flows into Magnolia Point can exceed 1,400 gpm (2.0 MGD). This demand includes irrigation and essential use but underscores peaks that occur within the system. The following review will apply peaking factors of 4.0, 6.0, and 10.0 to determine potential ranges of instantaneous irrigation demands. Mittauer & Associates, Inc. Project No Page 182

208 Maximum Day Demand Peak Hour Demand Peak Hour Demand = AADF * 4.0 Peaking Factor = 417,500 gpd * (day/24 hr) * (hr/60 min) * 4 = 1,160 gpm (1.67 MGD) = AADF * 6.0 Peaking Factor = 417,500 gpd * (day/24 hr) * (hr/60 min) * 6 = 1,700 gpm (2.45 MGD) = AADF * 10.0 Peaking Factor = 417,500 gpd *(day/24 hr)*(hr/60 min)*10 = 2,900 gpm (4.18 MGD) Given the Harbor Road WTP records and the assumption that homes will be irrigating on different blocks, the peak flow demand utilized for pipeline estimates is 1,700 gpm (2.45 MGD). For storage purposes, three (3) days of storage is estimated at the build-out AADF demand. Therefore, the estimated minimum storage required for the system is calculated as follows: Reclaimed Water Storage = 3 days * 417,500 gpd (AADF) = 1,252,500 gallons (1.25 MG) For this scenario, it is assumed the existing river outfall would remain as a wet-weather and/or reject water connection. This would allow flexibility in the ultimate storage capacity required for the reuse system. However, we would recommend a minimum storage volume of 1.5 MG to provide sufficient operational flexibility during maximum water demand periods where consecutive daily demands would exceed supply. For this option, the storage would occur at the HRWWTP site and would utilize two (2) 0.75 MG prestressed ground storage tanks ( GST ) to store the reclaimed water for delivery to the reuse customers. Figure VI-10 outlines the general reuse piping extensions and Figure VI-10A illustrates the conceptual reclaimed water system improvements to the HRWWTP. Mittauer & Associates, Inc. Project No Page 183

209 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure VI-10 Conceptual Reuse Piping.dwg, 2/25/2015 4:17:52 PM

210 M:\CAD Files\Green Cove Springs\ \Exhibits\Figure O-1.dwg, 3/30/2015 1:47:18 PM

211 The opinion of probable capital cost is presented in Attachment O and is summarized as follows: Construction Cost = $7,900,000 (includes 15% Contingency) Non-Construction Cost = $1,200,000 Total Cost = $9,100,000 The opinion of probable O&M costs are $40,000 and are also presented in Attachment O. The cost summary for this alternative is provided as follows: Total Est. Capital Cost = 3.0% for 30 yrs = $7,900,000 x = $404,000/yr Total Est. Annual O&M Cost = $40,000/yr TOTAL ANNUAL COST $444,000/yr (estimated) The advantages and disadvantages of the alternative are presented in Table VI-5. TABLE VI-5 MAGNOLIA POINT REUSE EXPANSION ALTERNATIVE NO. 1 ADVANTAGES & DISADVANTAGES Advantages 1. Magnolia Point is a development that has irrigation systems and is accustom ed to separate m eters. 2. Close proximity to HRW W TP, and will assist with TMDL reduction to river. 3. W ill have larger irrigation demands in com parison to non-planned residential neighborhoods. Disadvantages 1. Replum bing Magnolia Point with reclaim ed distribution system would present an inconvenience to residents & capital intensive. 2. FDEP requirements must be met for retrofitting existing irrigation system s that do not meet reuse requirements. 3. City will have to bolster their crossconnection policies and review m aintenance requirem ents related to backflow prevention devices. Mittauer & Associates, Inc. Project No Page 186

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213 b. Mag Pt Reuse Expansion Alt. No. 2 For this alternative, the existing HRWWTP reclaimed water delivery components would remain largely unchanged. The approach would include extending the existing 12-inch reuse main to another lake within the Magnolia Point development where the reclaimed water could be stored and repumped into the residential development. A packaged irrigation pump station similar to the golf course irrigation pumping system would be constructed and connected to the City s SCADA system for monitoring and remote control. Figure VI-11 depicts a typical vertical turbine irrigation system that would be utilized in this approach. Similar to the current golf course bulk feed, the design for this alternative would include lake elevation monitoring with a control valve that would open when the lake was below the normal water level and close when the water level was above this mark. The pump station controls would be based on local delivery pressure and turn on and off based on pressure, which would also include VFD control of the pumps. The overall demands are the same as outlined in Alternative No. 1, but the piping extensions within the development would be modified to accommodate the revised pump station location. FDEP and the SJRWMD review these types of storage systems (i.e., comingled stormwater with reclaimed water) in greater detail as it relates to the lake s outfall and associated nutrient loading to receiving water bodies. If this option were to be developed, pre-application meetings and further analysis would be required to determine if a nutrient loading analysis to the Governor s Creek and/or its tributaries would be required. If required, the analysis may result in determination that the alternative is not feasible. Water quality will become more of a concern with this option when compared to Alternative No. 1. The combined storage of the reclaimed water with the surface water within an open water body will lead to algae growth and growth of other microorganisms. Appropriate filtration of the water coming into the suction piping will be required to ensure residential irrigation systems do not clog on a regular basis. Given the bulk delivery approach, modifications to the existing reuse pumps at the HRWWTP are not considered. It is anticipated the new connection will allow the pumps to run over longer durations. Control aspects related to the suction piping at the plant will need to be reviewed to ensure pumps do not exceed the available flow causing short-cycling. Mittauer & Associates, Inc. Project No Page 188

214 Figure VI-12 gives a general site plan layout of the proposed improvements including a general reuse piping extension map. The opinion of probable capital cost is details in Attachment O, and is summarized as follows: Construction Cost = $6,200,000 (includes 15% Contingency) Non-Construction Cost = $930,000 Total Cost = $7,130,000 The opinion of probable O&M costs are $35,000 and are presented in details within Attachment O. The cost summary for this alternative is provided as follows: Total Est. Const. Cost = 3.0% for 30 yrs = $6,200,000 x = $316,000/yr Total Est. Annual O&M Cost = $35,000/yr TOTAL ANNUAL COST $351,000/yr (estimated) The advantages and disadvantages of the alternative are presented in Table VI-6. TABLE VI-6 MAGNOLIA POINT REUSE EXPANSION ALTERNATIVE NO. 2 ADVANTAGES & DISADVANTAGES Advantages 1. Magnolia Point is a developm ent that has irrigation system s and is accustom ed to separate m eters. 2. Close proximity to HRW W TP, and will assist with TMDL reduction to river. 3. W ill have larger irrigation dem ands in com parison to non-planned residential neighborhoods. Disadvantages 1. Requires offsite pum ping station and additional telem etry connections. 2. Replum bing Magnolia Point with reuse distribution system would present an inconvenience to residents & capital intensive. 3. FDEP requirem ents must be m et for retrofitting existing irrigation systems that do not m eet reuse requirem ents. Nutrient loading requirem ents will require review with the FDEP and SJRW MD and may result in a system that could not be permitted. 4. City will have to bolster their cross-connection policies and review m aintenance requirem ents related to backflow prevention devices. Mittauer & Associates, Inc. Project No Page 189

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216 c. Mag Pt Reuse Expansion Alt. No. 3 This alternative is not considered a mutually exclusive option when compared to Alternatives No. 1 and/or No. 2 since the capacity of the alternative is not specifically known. In addition, this option would require further coordination with the Magnolia Point Golf Course as well as operational support from its maintenance staff. This approach attempts to maximize reclaimed water use through augmentation of various Magnolia Point stormwater lakes that were designed as wet detention systems but are typically dry and/or have normal water levels that are well below the design elevations. The SJRWMD and FDEP do not consider lake augmentation as a beneficial use, and the co-mingled reclaimed water and stormwater approach may require a nutrient loading analysis for the receiving water bodies. Within this concept, existing drain lines from the irrigation system into the stormwater lakes would be modified with float valves near the lake s edge. The float valves would be set in a stilling well and would be open when water level is below the design normal water level and closed when above. If the valve is open, then irrigation water would flow into the lakes when the irrigation system is on providing additional demand as the lakes fill up during each irrigation cycle. If a drain line were not available, then a new 2-inch to 4-inch connection would be made to the irrigation system with a new float valve. The lakes conceptually identified for use in this concept are shown in Figure VI-13. Seventeen (17) potential lakes were identified for use in this approach. Pending actual irrigation system run times, the anticipated increase reuse demand from this alternative is calculated as follows: Alt No. 3 Reuse Demand = Irrigation Cycle Time (min) * 4" drain line capacity (gpm) * No. of Drain Lines = 45 minutes * 195 gpm * 17 = 8,775 gallons * 17 = 149,175 gallons/irrigation cycle If an average month had eight (8) irrigation cycles, the approach would result in an average monthly demand of 1,193,400 gallons per month (149,175 gallons * 8) or 39,780 gpd AADF. These estimates assume each lake would have available volume to accept the reclaimed water during each irrigation cycle. Mittauer & Associates, Inc. Project No Page 191

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218 The opinion of probable capital cost is detailed within Attachment O and summarized as follows: Construction Cost = $596,000 (includes 15% Contingency) Non-Construction Cost = $89,000 Total Cost = $685,000 The opinion of probable O&M costs are $7,500 and are summarized in Attachment O. The cost summary for this alternative is provided as follows: Total Est. Const. Cost = 3.0% for 30 yrs = $596,000 x = $30,400/yr Total Est. Annual O&M Cost = $7,500/yr TOTAL ANNUAL COST $37,900/yr (estimated) The advantages and disadvantages of the alternative are presented in Table VI-7. TABLE VI-7 MAGNOLIA POINT REUSE EXPANSION ALTERNATIVE NO. 3 ADVANTAGES & DISADVANTAGES Advantages 1. Maxim izes existing infrastructure to increase reuse demands. 2. W ill aesthetically im prove the Magnolia Point lake system. 3. No new pumping systems and/or complex controls. Disadvantages 1. Coordination with Golf Course is required. 2. Control valves will need interm ittent maintenance. 3. FDEP and SJRW MD coordination will be required related to mass balance reviews and potential impacts to localized receiving water bodies. d. North Service Area Expansion Alt. No. 1 For this alternative, the HRWWTP components would be expanded to provide residential retail service to existing customers within the North Mittauer & Associates, Inc. Project No Page 193

219 Service Area, initially limited to the Upper Limits portion as defined in Section II. This alternative is defined as a mutually exclusive option when compared to the Magnolia Point Alternative No. 1. However, the HRWWTP improvements as shown in Figure VI-10A and defined herein overlap those defined for the Magnolia Point Alternative No.1 option (i.e., transfer pumps, high service pumping, and storage). Therefore, the HRWWTP improvement components defined for this alternative could be removed if implemented in another phase since they would already be online. The City is currently reviewing and approving development of a project entitled Edgewater Landing. This residential development is the first new construction within the North Service Area with significant densities. The 171 detached-single-family homes will be developed with reuse infrastructure, but will be fed potable water until such time as reclaimed water is available for delivery. Similar to the Magnolia Point Alternative No. 1 scenario, the same infrastructure would be required at the HRWWTP to provide residential service to this area. In order to provide retail reuse service from the HRWWTP, the following improvements are included within this scenario: Transfer Pumps; Ground Storage Tanks; Reclaimed Water ( Reuse ) Pumping System with Controls; and Reclaimed Water Piping Extensions and Connections to Customers. Utilizing the same metrics as the Magnolia Point review, the Edgewater Landing development would provide potential near-term demands as follows: Average Daily Demand = 85,500 gpd (171 ERUs * 500 gpd) = 60 gpm Maximum Day Demand = 240 gpm (60 gpm * 4) Peak Hourly Flow = 360 gpm (60 gpm * 6) = 600 gpm (60 gpm * 10) Mittauer & Associates, Inc. Project No Page 194

220 Figure VI-14 outlines the general reuse piping extensions, and Figure VI- 10A illustrates the HRWWTP improvements. The opinion of probable capital cost is presented in Attachment O, and is summarized as follows: Construction Cost = $5,300,000 (includes 15% Contingency) Non-Construction Cost = $800,000 Total Cost = $6,100,000 If the Magnolia Point Reuse Expansion Alternative No. 1 were completed ahead of this expansion, then the Construction Costs would be limited to the reuse main extension which would modify the construction costs to approximately $1,200,000. The opinion of probable O&M costs are $33,000 and are presented in Attachment O. The cost summary for this alternative is provided as follows: Total Est. Const. Cost = 3.0% for 30 yrs = $5,300,000 x = $270,000/yr Total Est. Annual O&M Cost = $33,000/yr TOTAL ANNUAL COST $303,000/yr (estimated) The advantages and disadvantages of the alternative are presented in Table VI-8. Mittauer & Associates, Inc. Project No Page 195

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222 TABLE VI-8 NORTH SERVICE AREA REUSE EXPANSION ALTERNATIVE NO. 4 ADVANTAGES & DISADVANTAGES Advantages 1. Edgewater Landing is a developm ent that will have a separate reuse irrigation system in place and ready for use. Disadvantages 1. Relatively large near-term costs with lower benefit. Build-out of development is also unknown. 2. W ill assist with TMDL reduction to river. 2. City will have to bolster their crossconnection policies and review m aintenance requirem ents related to backflow prevention devices. 3. Reuse Main extension along U.S. 17 could also be utilized for other connections. 3. Alternative No. 3 Analysis For this scenario the entire Service Area s needs are proposed to be addressed through a regional WWTP that would consolidate treatment of the City s North and South Service Area. Through discussions related to the Reynolds FLUM Amendment and other regional reviews such as the 2008 Wastewater System Master Plan, the City s intention was to consolidate wastewater treatment service in the South Service Area. The main driver for this approach was the anticipated shift in wastewater service needs caused by the Reynolds redevelopment (i.e., demand center shift from the north and north core-city service areas to the southern limits of the City). In the near-term, a consolidated facility away from the existing sites causes one (1) significant complication related to effluent disposal requirements. Without the river outfall(s) and no near-term reclaimed water delivery location, the City would be required to treat all of the effluent via restricted-access means that are typically land intensive. Therefore, the effluent disposal requirements become a significant factor in siting a WWTP. As a result of the near-term effluent disposal needs without a river outfall, three (3) options were evaluated to address this item for the consolidated site. They Mittauer & Associates, Inc. Project No Page 197

223 are summarized as follows: Restricted-Access Sprayfield Disposal; Constructed Wetland Disposal; and Rapid Infiltration Basins. a. Restricted-Access Sprayfield Disposal For this option, the WWTP effluent would be pumped to a location where a fixed-head or center-pivot style irrigation system is available to deliver the reclaimed water in accordance with FDEP requirements. Since each WWTP alternative has included AWWT requirements, meeting the rule restrictions for restricted-access effluent disposal is not an issue. The main driver related to this disposal option is the underlying hydraulic conductivity of the soils since it defines how much area is required to irrigate the WWTP flows. FDEP typically defines an initial maximum sprayfield capacity of two (2) inches per week. As discussed further herein, the soils within this region are not highly conductive, and could result in hydraulic capacity being limited to values less than two (2) inches per week. Until additional site-specific geotechnical work is completed with associated hydraulic modeling, an application rate varying between 1.0 inches per week and 2.0 inches per week was utilized to determine land area requirements. Potentially, lands within the South Service Area could have application rates below 1.0 inches per week. Confirmation of a reasonable application rate via a geotechnical exploration would be prudent if a sprayfield system were selected as an effluent disposal solution. A consolidated treatment system would likely be sized for a capacity of 1.25 MGD AADF resulting in a land area requirement as follows: Conceptual Sprayfield Area Needs = 1.25 MGD/1.0 inch/week 3 = [1,250,000 gpd * (1 ft /7.48 gal) * (7 days/week) * (12 in/ft)] / [1.0 inch/wk] 2 2 = 14,050,000 ft * (AC/43,560 ft ) = inch/week = inch/week As seen from these calculations, the land area requirements become Mittauer & Associates, Inc. Project No Page 198

224 excessive at these higher flow rates. It is anticipated the sprayfield option would be an interim step until a public-access reclaimed water customer(s) become available. Pending costs and growth expectations due to the Outer Beltway Construction and/or Reynolds redevelopment, the City may consider a lesser sprayfield capacity between 0.80 to 1.00 MGD (AADF) pending Magnolia Point reclaimed water demands. Current combined flows from the HRWWTP and SWWTP are approximately 0.75 MGD AADF, and flow projections provided in Section V do not anticipate exceeding 1.00 MGD until after At a 0.80 MGD effluent disposal capacity, the sprayfield needs are reduced as follows: 0.80 MGD Sprayfield = 0.8 MGD/1.0-inches/week = [800,000 gpd * (1 ft3/7.48 gal) * (7 days/week) * (12 in/ft)] / [ 1.0 in/wk] 2 2 = 9,000,000 ft * (AC/43,560 ft ) = inch/week = inch/week Given the flow and permitted application rate uncertainties, a land area of 150 acres was utilized as the land-area basis within the Regional WWTP and sprayfield acquisition screening process. However, actual grading, setback, etc. requirements could result in a larger parcel size. For this review, it is assumed the Regional WWTP would be sited with the sprayfield. The sprayfield system would provide effluent disposal capabilities until such time as reclaimed water demands were present in the South Service Area. Within Attachment P, the detailed screening analysis for these sites was completed including a review of nine (9) large parcels inside and outside of the City s Service Area. A location map of the parcels is provided as Figure VI-15. As a result of the screening analysis, Parcel E or Parcel G were selected as the recommended locations to site the regional WWTP and interim effluent disposal system. See additional details within Attachment P. Mittauer & Associates, Inc. Project No Page 199

225 b. Constructed Wetland Disposal As noted in the aforementioned review, many of the lands near the SWWTP and within the South Service Area are within low lying areas that have wetlands or are adjacent to wetland areas. While these areas are unsuitable for sprayfield development, the option of constructing a wetland and discharging to a natural wetland system was reviewed to determine if it would be a cost effective alternative. A detailed analysis of the requirements is provided within Attachment P and included a review of eight (8) potential parcels as shown within Figure VI-16. Through the analysis provided in Attachment P, it was determined that the required land area would be limited based on hydraulic loading and Total Nitrogen ( TN ) loading (at a concentration of 3.0 mg/l). At 1.00 MGD AADF of permitted capacity, it is anticipated 50 acres of land would be needed just for effluent disposal needs without the WWTP site, buffers, construction tieins, etc. The wetland system would be developed with 40% of the land area as lined wetland cells and 60% as unlined. Additional site specific, water balance, nutrient loading, etc. analysis would need to be done to determine final treatment aspects, but the aforementioned review provides an overall land area basis. In total, a land area of 100 to 150 acres was utilized to review the various parcel options. c. Rapid Infiltration Basins (Percolation Ponds) Due to the site limitations (i.e., general poor soils) determined during the sprayfield and wetland disposal options, alternatives related to rapid infiltration basins (RIBs) were not completed. This effluent disposal option can reduce land area needs since application rates can be permitted as high as 3 inches per day (21 inches per week) or higher, but require site specific geotechnical testing and modeling/analysis. Given the parcel findings outlined herein, the RIB disposal option was not considered feasible at this time. The only parcels that may provide some capabilities for RIB disposal are located outside of the City s Service Area along SR 16 heading west toward Penney Farms. Along this location, the topographic elevations climb and soils improve. Mittauer & Associates, Inc. Project No Page 200

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228 d. Selected Alternative The constructed wetland option was the most cost effective effluent disposal alternative when compared to the sprayfield costs as well as the siting limitations within the South Service Area. Due to the Outer Beltway construction interface with Parcels N or J, the conceptual location for the regional facility was slated as either Parcel E or G. For purposes of the Plan, Parcel G is utilized. Regional Consolidation The conceptual approach to consolidate includes developing a site that would provide the capacity to meet the nutrient removal criteria as well as provide capacity for the total Build-Out Demands. Current combined flows from the HRWWTP and SWWTP are approximately 0.70 to 0.75 MGD (AADF) and the Build-Out Potential is 3.5 MGD (AADF). To accommodate the first phase, provide a logical expansion sequence, and provide some contingency for buildout, the first phase will include construction of a 1.25 MGD (AADF) treatment train and the overall facility will have provisions for three (3) 1.25 MGD (AADF) trains bringing the total capacity to 3.75 MGD (AADF). The HRWWTP and SWWTP systems would be decommissioned and replaced with pump stations. Each master pump station would have a new bulk force main to deliver the wastewater to the new regional site. In total, the City has eleven (11) pump stations within the North Service Area and three (3) pump stations within the South Service Area that respectively manifold together and deliver wastewater to the HRWWTP and SWWTP. Due to the elevation changes from the existing WWTP sites to the new location, the existing pump stations would have to be modified to the new head conditions or a repump station would need to be constructed at each WWTP to deliver the raw wastewater to the new WWTP. In order to develop an order-of-magnitude level of construction costs to compare against other alternatives, Parcel G was developed as the South Service Area Regional Site. Notwithstanding the location and required coordinate with Clay County and CCUA, Parcel G was selected due to its benefits in comparison to other locations and the limitations available to the City along U.S. 17 due to parcel geometry and the Outer Beltway construction limits. For this location, the bulk force main from the SWWTP would be constructed using a 16-inch main that would extend approximately 21,500 feet to Parcel G (12,500 feet of this Mittauer & Associates, Inc. Project No Page 203

229 pipeline would be an 18-inch force main that would manifold with the HRWWTP pump station). The 16-inch force main from the HRWWTP pump station to Parcel G would be approximately 17,500 feet to the manifold point. The last complication associated with this alternative is maintaining service to the Magnolia Point Golf Course. At this time, it is assumed bulk service to this location would need to be maintained. Therefore, costs are also included herein to develop a new bulk reclaimed water main that would extend from the Regional WWTP back to the Magnolia Point bulk reuse delivery system. A conceptual bulk main routing for the force main and reclaimed water mains is provided in Figure VI-17. The Phase 1 improvements include: HRWWTP and SWWTP decommissioning; HRWWTP and SWWTP Master Pump Stations; Bulk force main extensions from Master Pump Stations to Regional WWTP; Influent structure with fine screening, grit removal systems, and future flow splitter considerations; 1.25 MGD (AADF) AWWT Oxidation Ditch ( Treatment Train No. 1"); Two (2) new 75-foot diameter central clarifiers with RAS/WAS pump station; Filtration system; Chlorine Contact Chamber with disinfection facilities; Reclaimed water transfer pump station; Reclaimed water (i.e., wet-weather and/or reject) storage ponds; Reuse pumping station and reclaimed water main to Magnolia Point; Constructed wetland effluent disposal system; Two (2) new Aerobic Digesters; Biosolids dewatering system; and Control building with emergency generator. Figure VI-18 gives a general site plan layout of the proposed improvements In the near-term, the only public-access reuse option is located at Magnolia Point. Mittauer & Associates, Inc. Project No Page 204

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