North Fulton Wastewater Capacity Analysis and Economic Assessment

Transcription

1 North Fulton Wastewater Capacity Analysis and Economic Assessment Fulton County Department of Water Resources Project No /27/2015

2 North Fulton Wastewater Capacity Analysis and Economic Assessment prepared for Fulton County Department of Water Resources Fulton County, Georgia Project No /27/2015 prepared by Burns & McDonnell Engineering Company, Inc. Alpharetta, GA Engineered Horizons, LLC Duluth, GA COPYRIGHT 2015 BURNS & McDONNELL ENGINEERING COMPANY, INC.

3 North Fulton Wastewater Capacity Analysis Table of Contents TABLE OF CONTENTS EXECUTIVE SUMMARY... i 1.0 INTRODUCTION AND OBJECTIVES Objectives COMPLIANCE WITH DISTRICT PLANS POPULATION PROJECTIONS Historic Population Trends Future Population Projections Sewershed Population Projections WASTEWATER FLOW FORECASTS North Fulton Sewersheds Historic Trends and Metrics Intergovernmental Agreements Methodology Wastewater Flow Forecasts through TREATMENT CAPACITY NEEDS Treatment Capacity Needs ALTERNATIVES EVALUATION Big Creek Sewershed Alternatives Long-term Alternatives for Big Creek WRF Short-Term Management Options for Big Creek WRF Big Creek Sewershed Alternatives Cost Summary JCEC Sewershed Alternatives Option A: JCEC Expansion to 20 MGD (Long-Term) Option B-1: Cauley Creek WRF Purchase Option B-2: Cauley Creek WRF Restart (Private Operator) JCEC Sewershed Alternatives Cost Summary Little River / Etowah Sewershed Strategy - Expansion to 2.6 MGD RECOMMENDATIONS Big Creek Sewershed Recommendations Johns Creek Sewershed Little River Sewershed Reuse Water Recommendations APPENDIX A - OUTREACH TO CITIES IN NORTH FULTON APPENDIX B FOLLOW UP MEETINGS WITH CITIES APPENDIX C - COST ESTIMATE CALCULATIONS Fulton County Department of Water Resources TOC-1 Burns & McDonnell

4 North Fulton Wastewater Capacity Analysis Table of Contents LIST OF TABLES Page No. Table 2-1: Irrigation Customers Rate Implementation Schedule Table 4-1: Total Flow to North Fulton Wastewater Treatment Facilities Table 4-2: Wastewater Generation Rate Table 4-3: Wastewater Transfers between Counties Table 6-1: Big Creek Sewershed Alternatives Cost Summary 2015 Dollars Table 6-2: JCEC Sewershed Alternatives Cost Summary 2015 Dollars Table 6-3: JCEC Sewershed Alternatives Cost Summary 2015 Dollars Fulton County Department of Water Resources TOC-2 Burns & McDonnell

5 North Fulton Wastewater Capacity Analysis Table of Contents LIST OF FIGURES Page No. Figure 1-1: North Fulton Study Area and Sewersheds Figure 3-1: North Fulton Cities Figure 3-2: Historic City Populations in North Fulton Figure 3-3: City of Alpharetta Population Projections Figure 3-4: City of Johns Creek Population Projections Figure 3-5: City of Milton Population Projections Figure 3-6: City of Mountain Park Population Projections Figure 3-7: City of Roswell Population Projections Figure 3-8: North Fulton Cities and Sewersheds Figure 3-9: Big Creek Sewershed Population within Chattahoochee Basin Figure 3-10: Big Creek Sewershed Population within Etowah Basin Figure 3-11: JCEC Sewershed Population Figure 3-12: Little River Sewershed Population Figure 3-13: Etowah Sewershed Population Figure 4-1: Historic Population and Wastewater Flow Trends Figure 4-2: Big Creek Sewershed Projected Flows Figure 4-3: JCEC Sewershed Projected Flows Figure 4-4: Little River Sewershed Projected Flows Figure 4-5: Etowah Sewershed Projected Flows Figure 5-1: Treatment Capacity Needs: Big Creek Sewershed Figure 5-2: Treatment Capacity Needs: Little River Sewershed Figure 5-3: Treatment Capacity Needs: JCEC Sewershed Fulton County Department of Water Resources TOC-3 Burns & McDonnell

6 North Fulton Wastewater Capacity Analysis Executive Summary EXECUTIVE SUMMARY Fulton County Department of Water Resources (DWR) completed its last round of master planning in 2008, with a Water and Wastewater Master Plan Update. Since that time the County has survived the drought of record, the 500-year flood, and an economic recession that continues to challenge the view of normal. With development and growth returning in earnest to the North Fulton area, DWR is taking a careful look at how much wastewater capacity is needed at each of its facilities and assessing strategies to provide additional capacity. To plan for this need, DWR commissioned this evaluation. Purpose This evaluation accomplishes the following objectives: Figure ES-1. North Fulton Sewersheds Etowah Sewershed Develop wastewater flow forecasts based on the most recent population forecasts for the North Fulton sewersheds Assess wastewater treatment capacity needs for each sewershed Little River WRF Little River Sewershed Big Creek WRF Big Creek Etowah Sewershed Big Creek Chattahoochee Sewershed JCEC Johns Creek Environmental Campus (JCEC) Evaluate and recommend the most cost effective solution for wastewater treatment capacity in each sewershed, including the evaluation of proposals regarding the Cauley Creek Water Reclamation Facility (WRF). Results and Recommendations Study area is limited to the North Fulton area that is served by Big Creek WRF, JCEC or Little River WRF, and the Etowah Basin that is currently unsewered. The planning period is 20 years; through year Fulton County Department of Water Resources i Burns & McDonnell

7 North Fulton Wastewater Capacity Analysis Executive Summary Population projections provided by each city s planning or community development department indicated the area will grow by 27% over 20 years. Wastewater flow forecasts developed for each sewershed; total flow for North Fulton is forecast to be 50.9 MGD in Treatment capacity assessment and recommendations: o JCEC, a 15-MGD state-of-the-art facility, has adequate wastewater treatment capacity through If additional capacity is required, expanding JCEC by 5 MGD to 20 MGD is the least cost option for additional capacity. The capital cost of the expansion is estimated to be $3.2M. o Under current conditions, Big Creek WRF periodically experiences flows nearing the permitted maximum month average day limit of 24 MGD, generally during wet months. The least cost option is to fully utilize the MGD of treatment capacity Fulton County DWR owns in Cobb County Water System s (CCWS) R.L. Sutton WRF. DWR plans to continue coordination with CCWS on any collection system modifications to transfer flow to the R.L. Sutton WRF. This approach provides treatment capacity through the planning period for an estimated cost of collection system improvements of $30M. Alternatively, DWR can preserve the owned capacity at R.L. Sutton WRF by moving ahead with the Big Creek expansion during planning period. o Little River WRF is currently operating at its permitted capacity. The sewershed is currently under a development and sewer connection moratorium. This project should soon be clear from a regulatory perspective to move ahead with an expansion in capacity to 2.6 MGD, more than sufficient to meet the projected flow of 1.4 MGD by Reuse water recommendations: o The reasons to implement a water reuse system have changed due to a changing regulatory landscape. In the early 2000s, the North Fulton reuse system provided a way for wastewater to be discharged when it a river discharge was not allowed. Now, discharges to rivers are preferred and encouraged. o Once a benefit to reuse customers, irrigation with reuse water is no longer allowed during drought conditions. o A business case evaluation is recommended for any and all reuse proposals to assess whether a reuse water system is a viable and cost effective service for Fulton County to provide. Fulton County Department of Water Resources ii Burns & McDonnell

8 North Fulton Wastewater Capacity Analysis Introduction and Objectives 1.0 INTRODUCTION AND OBJECTIVES Fulton County Department of Water Resources (DWR) provides wastewater collection and treatment services to three primary basins, or sewersheds, in North Fulton County: Big Creek, JCEC and Little River. Figure 1-1 presents the Study Area and sewersheds in North Fulton. The small black lines represent sewer lines in the Big Creek (Chattahoochee and Etowah), JCEC and Little River Sewersheds. The Etowah Sewershed currently has no collection system or treatment facilities. The wastewater generated in this sewershed is treated by on-site systems, such as septic tanks. Figure 1-1: North Fulton Study Area and Sewersheds Etowah Sewershed Little River Sewershed Big Creek Etowah Sewershed Big Creek - Chattahoochee Sewershed JCEC Sewershed The sewersheds are generally aligned with the watershed basins and include the Johns Creek, Big Creek Chattahoochee, Big Creek Etowah, Little River and Etowah sewershed. The Big Creek-Etowah sewershed is located in the Etowah River watershed; the wastewater generated in this area is pumped to Fulton County Department of Water Resources 1-1 Burns & McDonnell

9 North Fulton Wastewater Capacity Analysis Introduction and Objectives the Big Creek Water Reclamation Facility (WRF) for treatment and was separated from the rest of the Etowah River basin to account for this flow. Wastewater generated within the sewersheds, except for the Etowah Sewershed, flows to treatment plants owned and operated by the County including Johns Creek Environmental Campus (JCEC), Big Creek WRF and the Little River WRF. A brief snapshot of current North Fulton wastewater treatment assets follows: The JCEC is a state-of-the-art facility that discharges highly treated effluent into the Chattahoochee River and has a treatment capacity of 15 MGD on a maximum month average day (MMAD) basis. This facility replaced the original Johns Creek Water Pollution Control Plant (WPCP). In 2009, with the capacity and efficiency of the newly commissioned JCEC facility, the Cauley Creek WRF, which was owned and operated by an private owner, was no longer needed. The contract for use of the Cauley Creek WRF was terminated early and the owner compensated as contractually obligated. The Big Creek WRF has a permitted capacity of 24 MGD-MMAD and also discharges to the Chattahoochee River. DWR currently diverts 3.5 MGD to Cobb County Water System (CCWS) from Big Creek WRF for treatment. An additional 2 to 2.5 MGD of wastewater is pumped to CCWS from Big Creek at three other pump stations, for a total of 5 to 6 MGD of flow. DWR owns 25.8% reserve capacity, which is currently MGD, at the CCWS s R.L. Sutton WRF. The 3.5 MGD diversion does not count against that capacity as it is in exchange for treatment of flow from Cobb County. The Little River WRF, located in adjacent Cherokee County provides tertiary filtration and discharges to the Little River within the Etowah River basin. A planned expansion and upgrade of the facility described in the August 2012 Design Development Report will improve treatment technology via membranes and expand the treatment from 1.0 MGD-MMAD capacity to 2.6 MGD-MMAD. The Little River basin is currently under a moratorium until the plant expansion completed. Little River WRF also provides reuse water to the Settindown Creek Golf Course. 1.1 Objectives DWR s goal is to provide wastewater collection and treatment at the least cost to its customers. To adequately plan for the next 20 years (through 2035), DWR requested a thorough, independent assessment of wastewater flow forecasts in the North Fulton sewersheds and the required treatment capacity needs. Based on treatment needs over the planning horizon, alternatives were developed along Fulton County Department of Water Resources 1-2 Burns & McDonnell

10 North Fulton Wastewater Capacity Analysis Introduction and Objectives with a present-worth analysis, including operations and maintenance. The most cost effective option for each sewershed was identified and recommended. A related objective that is documented in Section 2.0 of this document is the approach that will be implemented for Fulton County to be in compliance with the Metropolitan North Georgia Water Planning District s (District) Action Item 5.1 conservation pricing for irrigation customers. With compliance achieved on this action item, progress can be made on the upgrade and expansion of the Little River WRF. Fulton County Department of Water Resources 1-3 Burns & McDonnell

11 North Fulton Wastewater Capacity Analysis Compliance with District plans 2.0 COMPLIANCE WITH DISTRICT PLANS The Georgia General Assembly created The Metropolitan North Georgia Water Planning District (District) in The District prepares stormwater, water supply and wastewater management plans, which are approved by the Georgia Environmental Protection Division (EPD). The statute creating the District provides that EPD may not issue a water related permit to any local government in the District area not in compliance with the Plans. EPD conducts audits of local governments to determine plan compliance. Therefore, in order to receive EPD permits for future wastewater treatment facilities in north Fulton County, Fulton County must receive certification from EPD that Fulton County is in compliance with the District plans. One of the requirements of the District s water supply plan is a fee structure for irrigation water supply. The rate (cost to the customer) of this irrigation water must be greater than or equal to 200% of the first tier residential water rate. In December 2013, EPD informed Fulton County that the County cannot be certified as compliant with the Metro District plan since the County did not employ the District required irrigation rate structure and that nine customers in north Fulton County were paying irrigation rates less than the District-required irrigation rate. In order to comply with the District plan, Fulton County adopted the District irrigation rate structure and developed a schedule to apply the newly adopted irrigation rate for the nine facilities. The timeline is presented in Table 2-1. Table 2-1: Irrigation Customers Rate Implementation Schedule Customer New Rate Implementation Date Johns Creek United Methodist Church November 2017 Country Club of the South December 2017 Atlanta Athletic Club January 2018 City of Johns Creek November 2021 River Farm Subdivision November 2021 Perimeter Church April 2022 Standard Club May 2022 River Pine Golf Club May 2022 St. Ives Golf Club January 2023 Fulton County Department of Water Resources 2-1 Burns & McDonnell

12 North Fulton Wastewater Capacity Analysis Compliance with District plans In November 2014, Fulton County informed EPD of its new compliant irrigation rate ordinance and committed to move the nine customers onto this rate according to the above schedule. Fulton County formally requested EPD s certification of compliance with the District s plans and the District irrigation rate. However, in April 2015, EPD denied the certification saying the nine facilities must have the 200% irrigation rate immediately. EPD did state that there were no other issues to be resolved to achieve compliance with the District plans. Subsequently, Fulton County has cooperated with EPD to identify options to quickly and fully implement its new irrigation rate. Of the several options presented and discussed, EPD and Fulton have agreed upon the following course of action. Fulton County will terminate or amend the existing irrigation water contracts for the nine customers. New or amended contracts will be executed based upon a water rate equal to the established Fulton County irrigation rate, which is equivalent to the 200% rate adopted by the District. Fulton County will establish water credits to these customers for payment for easements previously granted to these customers and/or the outstanding portion of the contract. The credits will be used for future irrigation water payments and the cost of the irrigation water shall be the 200% irrigation rate. EPD has tentatively concurred with this proposal, and Fulton County is now implementing this option. Upon completion, Fulton County will provide the new or amended contracts to EPD who will then issue a certification that Fulton County is in full compliance with District plans. Fulton County Department of Water Resources 2-2 Burns & McDonnell

13 North Fulton Wastewater Capacity Analysis Population Projections 3.0 POPULATION PROJECTIONS The first step to forecast future wastewater flows is to identify population forecasts for the Study Area. This section documents historic population trends and the population forecasts used for this Study. 3.1 Historic Population Trends North Fulton County is comprised of five cities, as shown on the map in Figure 3-1. With the incorporation of the cities of Johns Creek and Milton in 2006, there is no unincorporated land in North Fulton County. Figure 3-1: North Fulton Cities As seen in Figure 3-2, the cities within North Fulton have experienced significant growth since 1990 (city population estimates for years prior to incorporation were developed by the Georgia Office of Planning and Budget or OPB). The annual growth rate in recent years has been between two percent and six percent. Fulton County Department of Water Resources 3-1 Burns & McDonnell

14 North Fulton Wastewater Capacity Analysis Population Projections Figure 3-2: Historic City Populations in North Fulton Population 3.2 Future Population Projections Local, state and federal entities develop future population projections to plan for future services, such as transportation, water, wastewater, parks, etc. Population projection data was obtained from a number of sources for evaluation, including the following: Atlanta Regional Commission (ARC): traffic analysis zones (TAZ) data published in 2012 with projections through The TAZ provide small area breakdown of population; typically smaller than census tracts. The Georgia Office of Planning and Budget (OPB): county-level population projections through United States Census Bureau: 2010 census population counts and 2012 population estimates for each city City of Alpharetta Community and Economic Development Departments, City of Johns Creek Community Development Department, City of Milton Community Development Department, City of Mountain Park, City of Roswell Community Development Department: each City Fulton County Department of Water Resources 3-2 Burns & McDonnell

15 North Fulton Wastewater Capacity Analysis Population Projections provided most current population projections based on land use development vision and rigorous projection methods The Burns & McDonnell team met (in person or on the phone) with each City s development director to discuss population projections provided, current development patterns and vision for development through Documentation of this outreach effort and discussion notes are included in Appendix A. In general, each City conducted a detailed analysis of their available developable land coupled with future land use plan, and calculated the population that would result from those future developments. Comparison to previous Comprehensive Plans and/or ARC data showed that the current population projections are not significantly different. Future population projections for each of the cities are shown in Figures 3-3 through 3-7. The City of Alpharetta uses the slogan A Technology & Employment Hub to describe the community. Alpharetta contains 20 million square feet of office space (nearly equal to Buckhead s 22 million) plus four exits along Georgia 400. They do not anticipate significant single-family residential development in the future, but see most of their development being commercial or mixed-use. Redevelopment is occurring on a few large parcels that were formerly commercial space. Figure 3-3: City of Alpharetta Population Projections Population 110, ,000 90,000 80,000 70,000 60,000 50,000 40,000 30,000 20,000 10, The City of Johns Creek anticipates continued single family residential as the preferred style of development, with commercial development along the major corridors. The City Center initiative is planned to attract more businesses and mixed use to the downtown area. Most growth is anticipated by Fulton County Department of Water Resources 3-3 Burns & McDonnell

16 North Fulton Wastewater Capacity Analysis Population Projections 2025 as large tracts of land for development begin to taper. The opportunity for redevelopment is anticipated to be limited due to the number of single-family home subdivisions, which make it a challenge to purchase enough homes to convert to new types of development. Figure 3-4: City of Johns Creek Population Projections Population 110, ,000 90,000 80,000 70,000 60,000 50,000 40,000 30,000 20,000 10, The City of Milton has a strong desire to maintain the rural character of pre-developed Fulton County. Thus, future development is anticipated to be predominately residential at a minimum density of one unit per acre, which is the Fulton County minimum requirement for septic service. All commercial development will be focused on three areas, called development nodes, including Crabapple, Deerfield and the Arnold Mill Corridor. Currently, the first two have sewer service available; however, the Arnold Mill Corridor does not. The City desires sewer service extensions to this area to allow for this to be a commercial development node within the City. Fulton County Department of Water Resources 3-4 Burns & McDonnell

17 North Fulton Wastewater Capacity Analysis Population Projections Figure 3-5: City of Milton Population Projections Population 110, ,000 90,000 80,000 70,000 60,000 50,000 40,000 30,000 20,000 10, As seen in Figure 3-6, the City of Mountain Park expects to remain very similar to the way they are today with very little growth over the planning period. Figure 3-6: City of Mountain Park Population Projections Population 1, The City of Roswell is currently well developed, and therefore does not anticipate significant growth over the planning period. The growth that is currently happening and expected to continue is higher density redevelopment near the downtown area, and mixed-use developments in other similar areas. Fulton County Department of Water Resources 3-5 Burns & McDonnell

18 North Fulton Wastewater Capacity Analysis Population Projections Figure 3-7: City of Roswell Population Projections 110, ,000 90,000 80,000 Population 70,000 60,000 50,000 40,000 30,000 20,000 10, Sewershed Population Projections North Fulton lies within two major river basins, the Chattahoochee, which serves as the eastern and southern county boundary in North Fulton, and the Etowah, which bisects the northern portion of North Fulton. The Chattahoochee River basin contains several tributary creeks, the two largest being Big Creek and Johns Creek, both of which originate in Forsyth County. The collection system in North Fulton is comprised primarily of gravity sewers, which generally follow streams and rivers within a watershed. This is the most economical way to collect wastewater. Pump stations and force mains are employed to pump wastewater from a topographically low area to a higher area. Based on the topography, Fulton County developed three facilities to treat wastewater in North Fulton County: The Big Creek Water Reclamation Facility (WRF) is located just west of the confluence of Big Creek with the Chattahoochee River. In addition, as development moved northward, limited sewer was constructed in the Etowah basin and is collected and pumped to the Big Creek basin via pumping stations. The Johns Creek Environmental Campus (JCEC) is located adjacent to the Holcomb Bridge Road crossing of the Chattahoochee River, south of the confluence of Johns Creek. The Little River WRF is located outside of Fulton County and serves the Little River basin. Little River is a tributary to the Etowah River. Fulton County Department of Water Resources 3-6 Burns & McDonnell

19 North Fulton Wastewater Capacity Analysis Population Projections The area served by a wastewater treatment facility is commonly referred to as a sewershed, since it may not conform exactly to hydrologic watersheds. Each sewershed associated with each treatment facility is presented in Figure 3-8. Figure 3-8: North Fulton Cities and Sewersheds Municipal boundaries rarely follow watershed or sewershed boundaries. So the next step in developing wastewater flows is to use data analysis tools to translate the City population projections to sewershed populations. Figure 3-8 shows the city boundaries relative to the sewershed boundaries. There is overlap between portions of the cities between the sewershed boundaries. A small portion of the City of Sandy Springs (shown in yellow on the Figure 3-8) contributes flow to the Big Creek WRF and to JCEC. The majority of flow generated in Sandy Springs is treated by the City of Fulton County Department of Water Resources 3-7 Burns & McDonnell

20 North Fulton Wastewater Capacity Analysis Population Projections Atlanta. Using the TAZ data, the portion of the Sandy Springs population located within the JCEC and Big Creek Sewersheds were assigned to those sewersheds. The ARC-obtained Traffic Analysis Zone GIS data includes residential and employment populations for 5-year increments through TAZ boundaries are small areas located with county boundaries that are generally smaller than census tracts. Using GIS, the city boundaries and TAZ boundaries, the sewersheds were overlain and data joined to create sewershed populations based on TAZ data. However, the most recent ARC regional TAZ data was published in 2012, and was lower than the local projections for each City. The resulting sewershed populations were adjusted upward based on the percent difference between the two data sets. The resulting populations for each sewershed are shown in Figures 3-9 through Figure 3-9: Big Creek Sewershed Population within Chattahoochee Basin 240, , ,000 Population 120,000 80,000 40, Fulton County Department of Water Resources 3-8 Burns & McDonnell

21 North Fulton Wastewater Capacity Analysis Population Projections Figure 3-10: Big Creek Sewershed Population within Etowah Basin 30,000 25,000 20,000 15,000 10,000 5, Figure 3-11: JCEC Sewershed Population 100,000 80,000 Population 60,000 40,000 20, Fulton County Department of Water Resources 3-9 Burns & McDonnell

22 North Fulton Wastewater Capacity Analysis Population Projections Figure 3-12: Little River Sewershed Population 12,000 10,000 8,000 Population 6,000 4,000 2, Figure 3-13: Etowah Sewershed Population 50,000 40,000 Population 30,000 20,000 10, Fulton County Department of Water Resources 3-10 Burns & McDonnell

23 North Fulton Wastewater Capacity Analysis Wastewater Flow Forecasts 4.0 WASTEWATER FLOW FORECASTS The population of North Fulton is expected grow by 27% by As discussed in Section 3, each sewershed has its own vision for future growth, ranging from Little River s 13% growth to Etowah s 47% growth over the planning period. The increase in population is projected to produce 50.9 million gallons per day (MGD) of wastewater in North Fulton that will need to be managed in North Fulton Sewersheds Historic Trends and Metrics Daily wastewater influent flow rates for each facility located in each sewershed (Big Creek, JCEC/Johns Creek WRF/Cauley Creek WRF, and Little River) for the period 2006 to 2014 were reviewed. From this data, two important statistical numbers were calculated. Annual average day flow (AAD) rates and maximum month average day flow (MMAD). The AAD flow is the amount of flow a facility receives on average over the entire year; the MMAD flow is the average daily flow for the month with the highest volume of flow. The MMAD flow is of particular importance as it is used to permit wastewater treatment facilities and this is the capacity for which recommendations for additional capacity are made. Table 4-1 presents the AAD and MMAD combined flow to all North Fulton facilities for years 2006 through An important ratio is the MMAD to AAD factor. This factor is applied to AAD flows to estimate the MMAD. The geometric mean of the ratios is There were significant weather events during this period the drought of record from 2007 to 2009 followed by the 500-year flood event in late 2009 both of which influence the ratio. Reviewing studies in North Fulton from years prior to 2007, the average MMAD to AAD ratio used historically is 1.24 and was used for this study. Table 4-1: Total Flow to North Fulton Wastewater Treatment Facilities Year AAD MMAD MMAD to AAD Ratio Fulton County Department of Water Resources 4-1 Burns & McDonnell

24 North Fulton Wastewater Capacity Analysis Wastewater Flow Forecasts When the average daily flow received at each facility in North Fulton is summed and plotted over time, an interesting trend becomes apparent. As shown in Figure 4-1, the population increased by 20% and the wastewater flows decreased by 20% over the period from 2006 to Figure 4-1: Historic Population and Wastewater Flow Trends , % Increase in Population 250,000 Wastewater Flow (MGD) % Decrease in Flow 200, , ,000 Population Day Average Flow All Plants Total Population 50,000 Linear (30-Day Average Flow All Plants) Jan-06 Jan-07 Jan-08 Jan-09 Jan-10 Jan-11 Jan-12 Jan-13 Jan-14 - Water efficient fixtures and changes in water usage behaviors are having an impact on both the regional and national level. This net 40% reduction in water use and wastewater generation is a success story for the conservation and stewardship initiatives promoted by the State, Metro Water District and Fulton County. Similar trends are also being seen as the update-in-progress 2016 Metro Water District Plans reviews water consumption and population for the 15-County region. To develop wastewater generation rates, the base year of 2010 was selected, as it was a census year with actual counts of the population, rather than estimates or projections of the population in each city. The 2010 AAD wastewater flow in each sewershed was divided by the number of people in 2010 in each sewershed. The AAD wastewater generation rate for the base year is shown in Table 4-1. Fulton County Department of Water Resources 4-2 Burns & McDonnell

25 North Fulton Wastewater Capacity Analysis Wastewater Flow Forecasts Table 4-2: Wastewater Generation Rate Sewershed Wastewater Generation Rate (gallons per person per day) AAD MMAD Big Creek JCEC Little River As seen on Table 4-1, the different development patterns for the sewersheds influence the wastewater generation rate. The Big Creek and JCEC sewersheds have a mix of residential and employment while the Little River sewershed is primarily residential. The wastewater generation rate includes all components of flow including inflow and infiltration (groundwater and stormwater that enters the collection system), and thus represents the flow received at the treatment facility. Compared to the current Metro District-wide generation rate of 104 gallons per person per day on an AAD basis, these rates are significantly higher. 4.2 Intergovernmental Agreements An important element of wastewater flows in Fulton County is the receipt and transfer of wastewater from surrounding counties. Table 4-3 provides a summary of contracted flow allocations and reserved capacity. Flows into the County are included in the projections for each sewershed. Table 4-3: Wastewater Transfers between Counties Reserve Annual Allocation Average flow Average Capacity Average in Big to Big Creek Flow to at R.L. Flow to Creek WRF Allocation JCEC Sutton Cobb s County WRF (MGD) (12/14-5/15) (MGD) in JCEC (MGD) (12/14-5/15) (MGD) WRF (MGD) WRF (MGD) Forsyth DeKalb Cobb DWR has an agreement with Cobb County that the Big Creek WRF can divert up to 3.5 MGD for treatment at R.L. Sutton WRF in exchange for treatment of Cobb County flows at Big Creek. This exchange does not count as part of the total Reserve Capacity that Fulton County owns in CCWS s R.L. Fulton County Department of Water Resources 4-3 Burns & McDonnell

26 North Fulton Wastewater Capacity Analysis Wastewater Flow Forecasts Sutton WRF. In addition to the 3.5 MGD diversion to CCWS, DWR transfers flow from the Big Creek sewershed to CCWS via three pump stations. With the diversion and pump stations combined, the average flow transferred to CCWS for the past 12 months was 5.4 MGD. 4.3 Methodology To project wastewater flows for each sewershed in North Fulton the 2010, the wastewater generation rates presented in Table 4-1 were applied to the population projections for each sewershed over the planning period. The generation rates for each sewershed were held constant over the planning period, despite the downward trend in wastewater flows presented in Figure 4-1. This decision essentially builds in a safety factor for additional development or other unforeseen factors over the planning period. 4.2 Wastewater Flow Forecasts through 2035 The wastewater flow forecasts through 2035 are presented in the following figures. Please note that for the Big Creek Sewershed, the 3.5 MGD that is currently conveyed to Cobb County Water System s R.L. Sutton WRF was subtracted from the flow forecasts at the Big Creek WRF through the planning period Figure 4-2: Big Creek Sewershed Projected Flows 30.0 Wastewatr Flow (MGD) Big Creek AAD Total Big Creek MMAD Fulton County Department of Water Resources 4-4 Burns & McDonnell

27 North Fulton Wastewater Capacity Analysis Wastewater Flow Forecasts Figure 4-3: JCEC Sewershed Projected Flows Wastewater Flow (MGD) JCEC AAD JCEC MMAD Figure 4-4: Little River Sewershed Projected Flows Wastewater Flow (MGD) Little River AAD Little River MMAD Fulton County Department of Water Resources 4-5 Burns & McDonnell

28 North Fulton Wastewater Capacity Analysis Wastewater Flow Forecasts Figure 4-5: Etowah Sewershed Projected Flows Wastewater Flows (MGD) Etowah AAD Etowah MMAD Fulton County Department of Water Resources 4-6 Burns & McDonnell

29 North Fulton Wastewater Capacity Analysis Treatment Capacity Needs 5.0 TREATMENT CAPACITY NEEDS This section presents a comparison of the flow forecasts to the permitted treatment capacity in each sewershed to identify long-term treatment needs in North Fulton. The Big Creek Sewershed has an urgent need for additional treatment capacity. The Little River Sewershed has a need for additional treatment capacity. JCEC Sewershed has ample capacity through the planning period. 5.1 Treatment Capacity Needs The wastewater flow forecast for each sewershed presented in Section 4.0 was compared to the permitted treatment capacity to identify if and where additional capacity may be required. The annual average day (AAD) flow is the amount of wastewater the treatment facility routinely needs to treat. However, due primarily to rain events treatment facilities need to be sized to treat flows higher than the average flow. Treatment capacity is designed and permitted to treat the maximum month average day (MMAD) flow, which is flow average daily flow for the month with the highest volume of flow. Treatment capacity is permitted on a MMAD basis. Figures 5-1 through 5-3 provide an overview of treatment capacity needs for the Big Creek, JCEC and Little River sewershed. The Big Creek WRF has a permitted treatment capacity of 24 MGD. As noted in Section 4.0, the Big Creek AAD and MMAD projected wastewater flows were reduced by 3.5 MGD, which is the amount of flow that Fulton County diverts to CCWS s R.L. Sutton WRF for treatment. The amount of flow that Big Creek pumps to CCWS (approximately another 2 MGD on average for the past 12 months) via other pump stations was not removed. This difference in approach is due to the diversion being taken just prior to the Big Creek WRF while the other pump stations are located at other points in the sewershed. This approach provides a level of conservatism in the assessment and provides a complete picture of flows generated in the basin. As seen in Figure 5-1, the Big Creek WRF has an urgent need for additional capacity by Fulton County Department of Water Resources 5-1 Burns & McDonnell

30 North Fulton Wastewater Capacity Analysis Treatment Capacity Needs Figure 5-1: Treatment Capacity Needs: Big Creek Sewershed Wastewatr Flow (MGD) Big Creek AAD Total Big Creek MMAD Permitted Treatment Capacity The Etowah sewershed does not currently have wastewater collection or treatment, except for the southeastern portion that is pumped to Big Creek. The portion of the Etowah that is pumped to Big Creek WRF is included in the flows presented in Figure 5-1. For the remaining Etowah sewershed, it is assumed that the flows generated at commercial nodes described in Section 3.0 would be treated at the Little River WRF. Collection system infrastructure would need to be funded and constructed to convey the wastewater to the WRF. With the uncertainty over whether these projects will come to fruition, the Etowah sewershed flows were not included in the Little River WRF projections at this time. As seen in Figure 5-2, the Little River WRF is also in need of additional capacity. The Little River WRF has a permitted treatment capacity of 1.0 MGD on a MMAD basis. The sewershed is under a moratorium for development and connections to the collection system. Approximately 0.2 MGD of treated effluent is pumped from the effluent discharge to the adjacent Settindown Golf Course. Fulton County Department of Water Resources 5-2 Burns & McDonnell

31 North Fulton Wastewater Capacity Analysis Treatment Capacity Needs Figure 5-2: Treatment Capacity Needs: Little River Sewershed Wastewater Flow (MGD) Little River AAD Little River MMAD Permitted Treatment Capacity Figure 5-3 presents the treatment capacity needs at the JCEC facility. The facility is permitted to treat 15 MGD on a MMAD basis. As seen on Figure 5-3, JCEC has adequate capacity through the planning period. Fulton County Department of Water Resources 5-3 Burns & McDonnell

32 North Fulton Wastewater Capacity Analysis Treatment Capacity Needs Figure 5-3: Treatment Capacity Needs: JCEC Sewershed Wastewater Flow (MGD) JCEC AAD JCEC MMAD Permitted Treatment Capacity Fulton County Department of Water Resources 5-4 Burns & McDonnell

33 North Fulton Wastewater Capacity Analysis Alternatives Evaluation 6.0 ALTERNATIVES EVALUATION To meet the needs forecast in Section 5.0, a number of alternatives were identified and assessed based on economics, technical feasibility and ability to meet the need within the timeframe required. Alternatives for short- (5-year), medium- (5-10-year) and long-term (beyond 10 years) time frames are presented below for each sewershed along with cost comparisons of present worth. 6.1 Big Creek Sewershed Alternatives The Big Creek sewershed is projected to experience flows of 24.3 MGD-MMAD in With current permitted treatment capacity of 24 MGD, this will leave a small deficit of 0.3 MGD, as presented in Figure 5-1. By 2020, the Big Creek WRF is projected to have flows of Big Creek WRF 25.8 MGD-MMAD, which represents a growing deficit. Over the short-term, the Big Creek WRF will be managed to operate within its permit. Several options exist for short-term and long-term; these alternatives are discussed in the following sub-sections Long-term Alternatives for Big Creek WRF There are two viable opportunities for the long-term capacity needs at the Big Creek WRF. One is the 14 MGD expansion of the facility and the other is to take advantage of capacity Fulton County owns in CCWS s R.L. Sutton WRF. Each of these options is discussed in more detail below Diversion to CCWS Fulton County owns 25.8% reserve capacity, which is currently MGD, in CCWS s R.L. Sutton WRF. As the facility expands, the capacity that Fulton County owns increases. Big Creek WRF currently diverts up to 3.5 MGD of flow to Cobb County Water System (CCWS) and has conveyed up to 6 MGD through existing infrastructure without incident. The 2035 deficit in treatment capacity is projected to be approximately 8 MGD for the Big Creek sewershed. The capacity available at R.L. Sutton Fulton County Department of Water Resources 6-1 Burns & McDonnell

34 North Fulton Wastewater Capacity Analysis Alternatives Evaluation is more than adequate to provide treatment capacity to the sewershed through 2035 and beyond. Modifications to the collection and transmission system may be necessary to utilize the full capacity owned by Fulton County. The potential cost for these transmission system improvements is $30M, although a detailed study has not yet been completed Big Creek WRF Expansion to 38 MGD Expansion of the Big Creek WRF s treatment capacity by 14 MGD is a long planned and viable alternative. With construction costs ranging from $173 to $288 Million, depending on the treatment technology selected, this expansion in capacity would address the long-term basin needs through year 2035 and beyond. It is conceivable that the CCWS diversion might defer the Big Creek expansion some years while funding is secured Short-Term Management Options for Big Creek WRF The best short-term management option should segue into the selected long-term option with the least amount of operational change and money spent. The options considered include additional diversion to CCWS, Forsyth County flow reduction plan, and flow diversion to JCEC. Each of these options is described below. Big Creek WRF currently conveys up to 3.5 MGD of flow to Cobb County Water System (CCWS) through an intergovernmental agreement and has conveyed up to 6 MGD through existing infrastructure. The 3.5 MGD of flow diverted to CCWS is already included in the flow forecasts, but there is additional flow that can be sent to CCWS with relatively minimal changes to the downstream collection system in Cobb County Diversion of additional flows to Cobb County Water System In 2015, DWR diverted from 3.0 to 3.5 MGD of flow from the Big Creek WRF into the Cobb County Water System (CCWS) under intergovernmental agreement. In addition, there are several pump stations that convey wastewater to CCWS at other points before it reaches the Big Creek WRF. Records indicate that Fulton has pumped a total of 5 to 6 MGD to CCWS in previous years. One tool DWR can use to manage flows into Big Creek WRF during the next 5 years is to increase pumping during peak flows as needed to meet demands at Big Creek WRF until the additional collection system capacity is available or Big Creek WRF expansion is on-line by Fulton County Department of Water Resources 6-2 Burns & McDonnell

35 North Fulton Wastewater Capacity Analysis Alternatives Evaluation Decrease flows from Forsyth County DWR is receiving a monthly average of 1.80 MGD from Forsyth County in the Big Creek basin for the first half of A reduction in the flow from Forsyth County to no more than 1.25 MGD is scheduled to occur by Meetings with Forsyth County during the research on this analysis found that Forsyth is moving in this direction and will certainly not increase flows to Fulton County Diversion of flows from Big Creek WRF to JCEC (Short Term) As a contingency alternative, DWR completed a feasibility study in 2009 investigating the possible diversion of flows from Big Creek WRF to JCEC to provide relief capacity during peak flows for the Big Creek sewershed. This option, while technically feasible may well be practically impossible. The option requires extensive land acquisition for the pumping and transmission facilities to complete the diversion. The diversion project, including planning, permitting, engineering, land acquisition and construction, would run parallel with the time line for other long-term alternatives. With an estimated completion year of 2019 to 2020 for the diversion, the project would essentially become unnecessary with long-term options, such as Big Creek WRF expansion or conveyance to CCWS facilities, also operational by The Big Creek to Johns Creek feasibility study is approximately 6-years old and needs to be updated, including more robust hydraulic modeling of the sewer transmission and collection system, before it can be acted upon. The option, with an estimated construction cost of $16.8 Million, which does not include all easement acquisition, is less attractive as it would divert needed funding away from the primary objective of increasing capacity inside the Big Creek sewershed. Combined with the projected O&M costs for the diversion transmission system, the total cost for comparison is $21 Million over the 20-year planning period of operation, respectively. Existing Fulton County water and sewer ratepayers have and continue to pay for the existing capacity at both Big Creek and Johns Creek treatment facilities. The diversion project would effectively cause ratepayers to pay again to utilize capacity they have previously financed both inside and outside Fulton County (i.e., Cobb County). Diverting flow from Big Creek WRF to JCEC would tend to drive an earlier expansion of JCEC to treat the increase in flow. It is projected that the expansion at JCEC would need to begin in 2020 and certainly be in place by As discussed below, the estimated cost this expansion is $3.2 Million, with a present worth of $5.0 Million including O&M for the 10-year window. The total expenditure for this intra-fulton County diversion would be approximately $19 Million plus $5.0 Million, or $24 Million for the 10-year Fulton County Department of Water Resources 6-3 Burns & McDonnell

36 North Fulton Wastewater Capacity Analysis Alternatives Evaluation window to year The difficulty in implementing this solution combined with its costs has eliminated it from further consideration Big Creek Sewershed Alternatives Cost Summary Table 6-1 provides a summary of the Big Creek Sewershed Alternatives in 2015 dollars. Both estimated capital cost and O&M are presented. Appendix C provides the basis for the cost estimates. Table 6-1: Big Creek Sewershed Alternatives Cost Summary 2015 Dollars Alternatives Long-Term Options Diversion to CCWS RL Sutton WRF (10 MGD) Expand Big Creek to 38 MGD Short-term Options Additional Diversion to CCWS RL Sutton WRF (5-6 MGD) Forsyth County Flow Reduction Capacity Added Estimated Capital Cost Estimated O&M Costs Total Project Cost (Capital + O&M) Over 20-years 10 MGD $30M $5M $35M 14 MGD $173M - $288M $13M $186M - $300M 1.5 to 2.0 MGD Diversion to JCEC 3.0 to 8.0 MGD Minimal costs; coordination with CCWS Minimally different than current 0.55 MGD No cost No change $16.8M+upgrade JCEC $5M $2.2M over 10 years $24M 6.2 JCEC Sewershed Alternatives The JCEC sewershed is projected to receive flows of 11.0 MGD by JCEC is currently permitted to treat up to 15 MGD. By 2035, JCEC is projected to have 2.1 MGD surplus capacity when flows are projected to be 12.9 MGD-MMAD. DWR is projected to have sufficient capacity at JCEC for the entire 20- year planning period. Included in these flow projections are flows into the basin from Forsyth County which comprise approximately 0.76 MGD for the first half of Under the intergovernmental agreement with Forsyth County, DWR has agreed to receive up to 1.37 MGD from Forsyth County. Based on this analysis, JCEC is forecast to have sufficient capacity to JCEC Fulton County Department of Water Resources 6-4 Burns & McDonnell

37 North Fulton Wastewater Capacity Analysis Alternatives Evaluation serve the growth predicted in the basin, which includes the projected growth in the City of Johns Creek, for the 20-year planning period. For additional capacity to be needed in JCEC sewershed, one would have to believe the sewershed s population would increase by 75% to nearly double the current population (130,000 people). With 130,0000 people in the sewershed, the population density would be similar to Buckhead in Atlanta, where approximately 7.5 people reside per acre. The Buckhead density compares with current Johns Creek projections of 17% growth over 20 years which would yield 3.88 people per acre. To manage that increased flow during or beyond the 20-year window, there are two options: Option A: Expand JCEC by 5 MGD to capacity of 20 MGD with a Capital Cost = $3.2M, or Option B: Purchase Cauley Creek WRF for additional 5 MGD with a Capital Cost = $15M + upgrades and operating costs The options are described in detail below Option A: JCEC Expansion to 20 MGD (Long-Term) When constructed, certain design and redundancy features were incorporated into the plant that would provide an easy and cost effective expansion in treatment capacity when the future need arises. It is estimated that an increase in treatment capacity to 20 MGD can be achieved for approximately $3.2 Million. This added capacity is the most cost effective solution for additional treatment capacity in the entire North Fulton system. Appendix C provides documentation on the cost estimate for JCEC expansion. For the long term, JCEC is projected to experience flows of 12.9 MGD by 2035, which still remains under the permitted capacity of 15 MGD Option B-1: Cauley Creek WRF Purchase The Owners of the Cauley Creek WRF propose to sell the dormant facility to Fulton County for an immediate purchase price of $15 Million. As the facility has been effectively out-of-service since December 2012, the outright purchase of the facility by Fulton County would require due diligence (onsite condition assessment) to determine what additional improvements would be needed to restore the facility to Class I reliability status. Also, with an outright purchase of the facility, Fulton County would incur the annual operation and maintenance costs for the facility. For comparison with other options for new treatment capacity in the Fulton County Department of Water Resources 6-5 Burns & McDonnell

38 North Fulton Wastewater Capacity Analysis Alternatives Evaluation Johns Creek Basin, the present value of the purchase price plus long term operation and maintenance of the facility over the 20-year planning period is estimated at $27.9 Million. Appendix C provides the basis for this estimate Option B-2: Cauley Creek WRF Restart (Private Operator) As a comparison with the outright purchase, if Fulton County opted to pay for additional treatment only, the Owners of the Cauley Creek WRF propose to treat up to 5 MGD for $3.25 per thousand gallons treated. For comparison with other options for treatment in the Johns Creek basin, the present value for the annual treatment expenditure over the 5, 10, and 20 year planning periods is estimated at approximately $28, $52, and $100 Million, respectively. Appendix C provides the basis for this estimate JCEC Sewershed Alternatives Cost Summary Table 6-2 provides a summary of the JCEC Sewershed Alternatives in 2015 dollars. As noted in Section 6.2, there is adequate wastewater treatment capacity at JCEC through the planning horizon; however, if additional capacity were needed, the options and associated costs to meet those needs are provided below. Appendix C provides the basis for the cost estimates. Table 6-2: JCEC Sewershed Alternatives Cost Summary 2015 Dollars Alternatives Capacity Added Estimated Capital Cost Estimated O&M Costs (over 20 years) Total Project Cost (Capital + O&M) Upgrade JCEC to 20 MGD 5 MGD $3.2M $3.3M $6.5 Purchase Cauley Creek WRF Cauley Creek WRF Private Operator 5 MGD $15M + upgrades $12.9M $27.9M + upgrades 5 MGD None None $100M 6.3 Little River / Etowah Sewershed Strategy - Expansion to 2.6 MGD The basin is projected to receive flows of 1.2 MGD in Little River WRF, located in Cherokee County, is currently permitted to treat up to 1.0 MGD with approximately 0.2 MGD of treated effluent pumped from the effluent discharge to the Settindown Golf Course, also in Cherokee County. By 2035, Little River WRF is projected to receive flows in the Little River WRF Fulton County Department of Water Resources 6-6 Burns & McDonnell