draft - st. johns county, florida...integrated water resources plan prepared for st. johns county...

SJCUD Integrated Water Resources Plan Technical Report

St. Johns County Utility Department | March 2015

DRAFT

ST. JOHNS COUNTY UTILITY DEPARTMENT

INTEGRATED WATER RESOURCES PLAN

Prepared for

St. Johns County Utility Department

1205 State Road 16

St. Augustine, Florida 32084-8646

Prepared by

Jones Edmunds & Associates, Inc.

730 NE Waldo Road

Gainesville, Florida 32641

PE Certificate of Authorization #1841

PG Certificate of Authorization #133

and

CDMSmith

8381 Dix Ellis Trail

Suite 400

Jacksonville, Florida 32256

March 2015

DRAFT

TABLE OF CONTENTS GLOSSARY .................................................................................................................................................. v

EXECUTIVE SUMMARY ........................................................................................................................ ES-1

1 INTRODUCTION ............................................................................................................................ 1-1

2 CONSTRAINTS AND DRIVERS ................................................................................................... 2-1

3 CURRENT CONDITIONS .............................................................................................................. 3-1

3.1 Utility Services ............................................................................................................................ 3-1

3.2 Potable Water System ............................................................................................................... 3-4

3.2.1 Mainland and Anastasia Island Service Area .................................................................... 3-4

3.2.2 Northwest Service Area ..................................................................................................... 3-4

3.2.3 Northeast Service Area ...................................................................................................... 3-4

3.2.4 SR 16 Service Area ............................................................................................................ 3-5

3.2.5 South Service Area ............................................................................................................ 3-5

3.2.6 Ponte Vedra System Service Area .................................................................................... 3-5

3.2.7 Interconnects ...................................................................................................................... 3-5

3.3 Wastewater System ................................................................................................................... 3-6




3.3.4 SR 16 Service Area ............................................................................................................ 3-6



3.3.7 Interconnects ...................................................................................................................... 3-7

3.4 Reclaimed Water System ........................................................................................................... 3-8




3.4.4 SR 16 Service Area ............................................................................................................ 3-8



3.5 Stormwater System .................................................................................................................... 3-9

3.5.1 Regional Stormwater Facilities .......................................................................................... 3-9

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc i March 2015 Table of Contents

DRAFT

4 NEEDS ASSESSMENT ................................................................................................................. 4-1

4.1 Population .................................................................................................................................. 4-1

4.2 Water Demands ......................................................................................................................... 4-2

4.3 Gap Analysis .............................................................................................................................. 4-6

5 WATER SUPPLY OPTIONS ......................................................................................................... 5-1

5.1 Groundwater............................................................................................................................... 5-1

5.2 Interconnects .............................................................................................................................. 5-1

5.3 Reclaimed Water ........................................................................................................................ 5-1

5.4 Conservation .............................................................................................................................. 5-1

5.5 Surface Water ............................................................................................................................ 5-1

5.6 Regional Partnership Projects .................................................................................................... 5-3

5.7 Wastewater ................................................................................................................................ 5-3

6 IWRP EVALUATION FRAMEWORK ............................................................................................ 6-1

6.1 IWRP Process and Terms .......................................................................................................... 6-1

6.2 Objectives and Performance Measures ..................................................................................... 6-2

6.3 Integrated Systems Model ......................................................................................................... 6-3

6.3.1 Systems Model Software Selection ................................................................................... 6-4

6.3.2 Ranking Methodology ........................................................................................................ 6-6

7 ALTERNATIVE EVALUATIONS ................................................................................................... 7-1

7.1 Alternatives Development Process ............................................................................................ 7-1

7.2 Original Alternatives ................................................................................................................... 7-3

7.2.1 Original Alternative Development ...................................................................................... 7-3

7.2.2 Original Alternative Results ................................................................................................ 7-3

7.3 Hybrid Alternatives ..................................................................................................................... 7-5

7.3.1 Hybrid Alternative Development ........................................................................................ 7-5

7.3.2 Hybrid Alternative Results .................................................................................................. 7-6

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc ii March 2015 Table of Contents

DRAFT

LIST OF FIGURES Figure 3-1 Service Areas and Major Facilities ................................................................................... 3-2 Figure 3-2 Regional Stormwater Facilities ...................................................................................... 3-10 Figure 4-1 Projected Served Population (BEBR Medium Growth) .................................................... 4-2 Figure 4-2 Main System Raw Water Demands ................................................................................. 4-5 Figure 4-3 Ponte Vedra System Raw Water Demands ..................................................................... 4-6 Figure 4-4 Main System Gap Analysis .............................................................................................. 4-7 Figure 4-5 Ponte Vedra Gap Analysis ............................................................................................... 4-8 Figure 5-1 Groundwater Options ....................................................................................................... 5-4 Figure 5-2 Interconnection Options ................................................................................................... 5-5 Figure 5-3 Reclaimed Water Options ................................................................................................ 5-6 Figure 5-4 Surface Water Options ..................................................................................................... 5-7 Figure 5-5 Regional Partnerships ...................................................................................................... 5-8 Figure 5-6 Wastewater Options ......................................................................................................... 5-9 Figure 6-1 IWRP Process .................................................................................................................. 6-2 Figure 6-2 IWRP-SIM Model Conceptualization ................................................................................ 6-5 Figure 6-3 Multi-Attribute Rating Method .......................................................................................... 6-6 Figure 7-1 Normalized and Weighted Scores for Original Alternatives ............................................. 7-5 Figure 7-2 Normalized and Weighted Scores for All Alternatives ..................................................... 7-7 Figure 8-1 Percent CUP used on annual basis for Low Cost Plus Alternative ................................. 8-2 Figure 8-2 Water Demand Projection Sensitivity Scenarios ............................................................. 8-3 Figure 8-3 Residential Outdoor Demand Multipliers for Varying Climate Conditions ....................... 8-6 Figure 8-4 Nonresidential Demand Multipliers for Varying Climate Conditions ................................ 8-7 Figure 9-1 Base Integrated Water Resources Plan........................................................................... 9-3 Figure 9-2 Additional Integrated Water Resources Options .............................................................. 9-4 Figure 9-3 SJCUD Water Supply Portfolio by 2020 .......................................................................... 9-5 Figure 9-4 SJCUD Water Supply Portfolio by 2040 .......................................................................... 9-5

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc iii March 2015 Table of Contents

DRAFT

LIST OF TABLES Table 2-1 Constraints That Will Likely Limit Water Supply .............................................................. 2-2 Table 2-2 Summary of Drivers That Will Influence SJCUD’s Water Supply Needs ......................... 2-3 Table 3-1 SJCUD Major Water and Wastewater Facilities .............................................................. 3-3 Table 4-1 Single-Family Unit Average Monthly Use (gallons per day) ............................................ 4-3 Table 4-2 Water Use Summary Statistics (gpd) ............................................................................... 4-4 Table 4-3 Delivery System and Treatment Plant Loss Factors ........................................................ 4-4 Table 4-4 Weather-Related AADF Peaking Factors ........................................................................ 4-5 Table 4-5 System Component Limitations ....................................................................................... 4-8 Table 5-1 Water Supply Options ...................................................................................................... 5-2 Table 6-1 Objectives and Performance Measures ........................................................................... 6-3 Table 7-1 Options-Alternatives Matrix .............................................................................................. 7-2 Table 7-2 Raw Scorecard for Original Alternatives .......................................................................... 7-4 Table 7-3 Raw Scorecard for Hybrid Alternatives ............................................................................ 7-8 Table 7-4 Original Weighting Scheme ........................................................................................... 7-10 Table 7-5 Alternative Ranking Under Various Weighting Scenarios.............................................. 7-11 Table 8-1 Alternative Reliability Results for Different Allowable Groundwater Withdrawals ........... 8-2 Table 8-2 Reliability of the Low Cost Plus Alternative Under Different High-Demand

Projections ....................................................................................................................... 8-4 Table 8-3 Project Options to Improve Reliability of Low Cost Plus Alternative Under High-

Demand Scenarios........................................................................................................... 8-5 Table 8-4 Reliability of Low Cost Plus Alternative with Climate Variability ...................................... 8-9 Table 8-5 Project Options Eligible for Cost Share with SJRWMD ................................................... 8-9 Table 8-6 Life Cycle Costs With and Without Water Management District Cost Sharing .............. 8-10 Table 9-1 IWRP Recommended Options ......................................................................................... 9-1

APPENDICES Appendix A Existing Conditions

Appendix B Population and Water Demands

Appendix C Gap Analysis

Appendix D Option Fact Sheets

Appendix E IWRP-SIM

Appendix F Stakeholder Meetings

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc iv March 2015 Table of Contents

DRAFT

GLOSSARY Term Definition Alternative Combinations of options designed to best meet the stated objectives and

will be evaluated against the criteria (objectives and metrics).

Aquifer Storage and Recharge (ASR)

A water supply strategy that stores excess water in an aquifer to be removed at a later time.

Annual Average Daily Flow (AADF)

The annual average daily flow.

Capital Cost The fixed expense incurred to construct or install utility infrastructure including land, equipment, materials, and labor.

Constraints A limitation or restriction to a potential water resource.

Consumptive Use Permit (CUP)

A permit issued by the St. Johns River Water Management District that authorizes the use of water in a manner that does not interfere with other existing legal users and protects water resources from harm.

Design Capacity The size or limit that a facility, process, or structure is designed to handle.

Drivers A factor that can change the amount, location, and timing of water supply needs.

Effluent Discharge from wastewater treatment facilities.

Firm Capacity The size or limit of capacity that accounts for the reliability of the process or equipment. For water systems, the firm capacity is typically the delivery capacity with the largest unit out of service.

Fixed Operations and Maintenance Cost

The cost associated with routine maintenance and repair of utility facilities including labor; typically given annual amounts.

Florida Department of Environmental Protection (FDEP)

State agency that regulates and issues permits for operating and maintaining water, wastewater, and reclaimed water facilities.

Gap Analysis Analysis performed to identify where and when existing and future capacities are not sufficient to meet future demands.

Integrated Water Resources Plan (IWRP)

Comprehensive plan that evaluates and recommends long-term water resources strategies.

Land Development Requirements (LDRs)

Local ordinances that dictate the rules and policies for developing land within the County.

Life Cycle Cost The total of nominal annual costs discounted by a discount rate for the life of the project/alternative.

Limited Wet-Weather Discharge System

A facility that is permitted to discharge to receiving waters during wet weather events.

Long-Term After 2020.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc v March 2015 Glossary

DRAFT

Term Definition

Low-Pressure Reverse Osmosis (LPRO)

A water treatment technology that uses the principle of reverse osmosis to remove dissolved solids from water by passing water through a membrane.

Main System A part of the utility that serves the following service areas: Northwest, Northeast, SR 16, Mainland and Anastasia Island, and South.

Membrane Concentrate The concentrated solids and water that is a by-product of the reverse osmosis treatment process that uses membranes.

Membrane Permeate The clean water that is produced from the reverse osmosis treatment process that uses membranes.

Million Gallons per Day (MGD)

Common flow rate measurement of water and wastewater facility processes and capacities.

Minimum Flows and Levels (MFLs)

Regulatory criteria that is established by FDEP and the Water Management Districts that define the sustainable limits of water use while protecting water resources from significant harm.

National Pollutant Discharge Elimination System (NPDES)

A federal regulatory program that controls the amount of pollutants that can be discharged to receiving waters.

Objectives The major goals of the plan that are typically defined in broad understandable terms (e.g., ensure water reliability).

Option Individual projects or demand management measures.

Performance Measures Qualitative or quantitative metrics that indicate how well an objective is being achieved (e.g., frequency and magnitude of water shortages). Objectives combined with their corresponding metrics represent the criteria by which alternatives are compared against.

Permitted Design Capacity The permitted size or limit that a facility, process, or structure is designed to handle.

Ponte Vedra System A part of the utility that serves the Ponte Vedra area of the County.

Rapid Infiltration Basins (RIBs)

Facilities that are designed to recharge treated water to the aquifer.

Reclaimed Water (Reuse) Highly treated wastewater effluent that meets the state and federal requirements to be provided for beneficial purposes.

Regional Stormwater Treatment (RST) Facility

A facility that treats stormwater at a regional scale. Typically a large pond (>10 acres) or wetland designed to capture and treat water from watersheds with high nutrient loading.

Resiliency A measure of how much a change in a driver has on the water supply plan. Resiliency helps with understanding how flexible an alternative is in meeting the water supply needs when one or more drivers change.

Reverse-Osmosis Treatment

A treatment technology that uses the principles of reverse osmosis to remove dissolved solids from the water.

Sensitivity A measure of how much a change in an input parameter has on the results. Sensitivity analysis helps with understanding the variability in the results caused by changing the input parameters.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc vi March 2015 Glossary

DRAFT

Term Definition

Short-Term Prior to 2020.

St. Johns County Utility Department (SJCUD)

A department within St. Johns County administration that provides water, wastewater, and reclaimed water to customers.

St. Johns River Water Management District (SJRWMD)

A state agency that is responsible for managing groundwater and surface water resources in 18 counties including St. Johns County. This agency issues consumptive and environmental resources permits to the county.

Stormwater Harvesting A water supply strategy that captures excess stormwater for distribution and use as a water supply source.

Total Maximum Daily Load (TMDL)

The maximum amount of pollutant loading that a water body can receive without violating a water quality standard criteria.

Tri-County Agriculture Area (TCAA)

An area that includes Putnam, Flagler, and St. Johns Counties where there is significant agricultural land use.

Variable Operations and Maintenance Cost

The cost of operating utility facilities that vary based on utilization or flow such as chemicals and energy; typically given on a per unit or volume basis.

Wastewater Treatment Facility (WWTF)

A facility that treats wastewater to meet regulatory standards and discharges back to the environment.

Water Treatment Plant (WTP)

A facility that treats and supplies drinking water.

Zero Liquid Discharge A treatment process that recycles close to 100% of the water for beneficial use; typically achieved through crystallization or evaporation.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc vii March 2015 Glossary

DRAFT

1 INTRODUCTION Water is a critical resource in St. Johns County. The County recognizes that long-term economic prosperity will depend on effectively managing its water resources. To meet its existing and future water supply needs, the St. Johns County Utilities Department (SJCUD) has invested significantly in conservation, reclaimed water, and alternative water supply. However, based on state regulatory and regional planning efforts, how the County will meet future potable water demands remains uncertain. To reduce this uncertainty, SJCUD will need to continue to build its portfolio of water supply options. Past utility and water management district efforts indicate that the most sustainable and cost-effective solutions will likely involve integrating traditional sources of water supply with non-traditional solutions such as enhanced recharge, regional partnerships with agriculture, and stormwater harvesting. Additionally, the County has water management responsibilities for flood control and compliance with water quality standards. Rather than dealing with each of these water issues in isolation, the County realizes that a comprehensive, integrated approach will result in a less expensive and more sustainable water supply solution.

This Integrated Water Resources Plan (IWRP) identifies the combination of alternatives that best meets SJCUD’s objectives and provides a roadmap for SJCUD to implement short-term and long-term water supply solutions through 2040. The objectives of the IWRP are as follows:

Define the Future Water Needs of the Community: The IWRP’s main purpose is to authenticate the most economical water source for the County by identifying alternatives and establishing the criteria for when alternatives need to be initiated.

Develop an Integrated Water Resource Systems Computer Model: This project will provide SJCUD with a computer model that can be actively modified as conditions change. The model will be an interactive tool that allows SJCUD staff to modify the variables in the decision matrix.

Produce an Integrated Plan that Includes Stakeholder and Public Involvement: The IWRP process will provide a plan for the County’s water source with tangible projects and a timeline for implementation based on necessity. The IWRP will combine SJCUD customers’ water needs with the most appropriate water source to help secure water supply through the 2040 planning horizon.

This report presents the Final IWRP and supporting analyses:

Section 2 identifies the constraints that will likely limit traditional groundwater supplies and presents drivers that could influence the timing and need for future water supplies.

Section 3 summarizes the current status of water resources and utility services.

Section 4 presents the future water supply needs.

Section 5 presents the potential options evaluated and modeled in the system model (IWRP-SIM).

Section 6 presents the evaluation framework.

Section 7 evaluates the combination of options (alternatives) tested.

Section 8 presents the sensitivity of the preferred alternatives to changes in drivers.

Section 9 presents the recommended plan.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc 1-1 March 2015 Introduction

DRAFT

2 CONSTRAINTS AND DRIVERS Water resource constraints will limit or restrict existing and potential water supply resources for SJCUD. For example, the MFLs established by the St. Johns River Water Management District (SJRWMD) may limit the amount of groundwater available in the County. Additionally, factors can change the amount, location, and timing of water supply needs within the County. These factors are defined as drivers. Tables 2-1 and 2-2 identify the constraints and drivers considered in developing the IWRP. Developing the preferred plan requires relating the constraints to SJCUD’s utility system and County water resources to evaluate and develop integrated water supply alternatives using an integrated systems model (IWRP-SIM) and evaluation framework. The IWRP identifies the best short- and long-term water supply solutions that overcome the constraints and are the most resilient to the drivers that will impact water supply needs within the County. Appendix A provides a detailed discussion of each constraint and driver.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc 2-1 March 2015 Constraints and Drivers

DRAFT

Table 2-1 Constraints That Will Likely Limit Water Supply

Constraint How Will It Constrain Water Supply in St. Johns County

Service Areas Most Likely to Constrained

Cost Funding projects is limited by County budgets and rates. All.

Infrastructure and Operations

The existing capacity asset age and operations will limit how SJCUD develops water supply strategies.

Mainland, Northwest, and Ponte Vedra (Marsh Landing) potential capacity limits, and system interconnects between Mainland and Northwest are limiting transfers.

Customer Acceptance and Public Opinion

Development of water supplies has potential to affect many stakeholders. Therefore, new projects could be limited by stakeholder buy-in.

All.

Consumptive Use Permit Limits

Current permits valid through 2032 (for the Ponte Vedra System) and 2024 (for the other service areas) limit the amount of groundwater supplies.

All except Ponte Vedra (population and therefore demand is not expected to increase significantly in Ponte Vedra).

MFLs

Additional groundwater withdrawals will only be permitted if they do not impact existing MFLs. Existing groundwater withdrawals may be affected by prevention and recovery plans.

Northwest is closest to the MFL water bodies that are most likely to constrain future withdrawals.

Non-MFL Water Resources

Additional groundwater withdrawals will only be permitted if they do not impact non-MFL water resources such as wetlands and springs.

Northwest is closest to the non-MFL water resources that are most likely to constrain future withdrawals.

Other Legal Users

Additional groundwater withdrawals will only be permitted if they do not impact existing legal users. A significant number of legal users are within the County. Public supply, agriculture, and recreational use are the top water users.

All.

Raw Water Quality (e.g. Salt Water Intrusion)

A decrease in a raw water quality can increase the cost of operating a WWTF. If reverse-osmosis effluent is sent to a WWTF, this could also affect WWTF operations.

Mainland and Ponte Vedra are closest to potential sources of saltwater intrusion.

Finished Water Quality

Alternative water sources and interconnecting service areas could affect finished water quality.

All except Ponte Vedra (population and therefore demand is not expected to increase significantly in Ponte Vedra).

Various Regulations Related to Surface Water Discharge of Wastewater

Surface water quality regulations for Total Maximum Daily Loads, Numeric Nutrient Criteria, and Human Health Criteria could affect WWTF effluent disposal options. These regulations will also impact stormwater services provided by the County’s Public Works Department.

All. Mainland and Anastasia Island have the largest surface water discharges.


DRAFT

Table 2-2 Summary of Drivers That Will Influence SJCUD’s Water Supply Needs Driver Importance to IWRP How It is Incorporated into the IWRP

Population Growth

The rate of population growth will influence the timing and capacity of solutions.

SJCUD has prepared service-area level population projections for the planning horizon. The project team categorized this usage and developed three different growth scenarios. Total demand estimates (based on population growth) were created for each planning interval. In IWRP-SIM, the total demand can be distributed across service areas in the model to simulate different growth scenarios.

Economic Influences on Land Use

Economic influences could significantly change the balance of residential, commercial, and agricultural land uses in St. Johns County. These changes could affect the distribution of future population growth and the alternative water supply options available to SJCUD.

IWRP-SIM allows for shifting demands between service areas that can account for changes in economic patterns within the County.

Changes in Climate

Water supply sources and needs are driven by changes in climate, which impacts the potential yield of supplies and peaking needs of customers.

Within the planning horizon defined for this project, the component of climate most likely to change is precipitation. Changes in precipitation could affect potable water demand, particularly outdoor demand. Model scenarios have been developed to simulate the expected range of changes in precipitation. Changes in demand will be estimated and used to bracket results from other scenarios.

Regional Partnerships

SJRWMD is moving forward with strategies that could relieve the water resources constraints for additional groundwater supplies. These strategies will likely change the amount of available groundwater.

Collaborative partnerships identified in the plan could significantly affect the priorities associated with projects identified in the IWRP. These projects and cost share opportunities will be incorporated into IWRP-SIM.

Regulatory Change

Regulatory thresholds set the boundaries for determining the potential yield of water supply strategies.

The set of regulations with the largest impact on future water supply options for SJCUD are related to Consumptive Use Permitting and the associated environmental impacts (e.g., MFLs). Model scenarios and project options have been developed to evaluate various regulatory changes such as offsets and substitution of existing environmental impacts and more restrictive groundwater allocations.


DRAFT

3 CURRENT CONDITIONS The following summarizes the existing conditions that will serve as the starting point for the IWRP. Appendix A provides a detailed summary of the current status of water resources and utility services.

3.1 UTILITY SERVICES

SJCUD owns and operates the Main System and Ponte Vedra System that provide water, wastewater, and reclaimed water services. As Figure 3-1 shows, the Main System has five service areas that cover a majority of the County and is isolated from the Ponte Vedra System in the northeast. Existing and near-term treatment and conveyance facilities are represented in the IWRP integrated model. Potable water, wastewater, and reclaimed water facilities are summarized by service areas. SJCUD owns three additional utility systems – Moultrie Woods, Fruit Cove Oaks and Bartram Oaks – that are small and not included in the analyses. Although SJCUD does not use stormwater as a water supply source, it may be an important alternative to meet water supply needs in the future. Therefore, existing stormwater facilities are discussed in this section. Table 3-1 summarizes the major water and wastewater treatment works owned and operated by the County. The existing condition is assumed to reflect SJCUD’s facilities and operations as of December 2012. In some cases, facilities under construction but not yet operational will be considered in the existing conditions.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc 3-1 March 2015 Current Conditions

DRAFT

Figure 3-1Service Areas and Major Facilities

0 3 6

Miles1:380,160

")̈

")̈

")̈

")̈

")̈

")̈

!j

!j

!j

!j

!j

!j

!j

!j

Mainland and Anastasia Island

Northeast

Northwest

Ponte Vedra System

South

SR16

D U V A LD U V A L

S T J O H N SS T J O H N S

C L A YC L A Y

P U T N A MP U T N A M

F L A G L E RF L A G L E R

£¤90£¤1

£¤1

£¤17

£¤17

£¤17

£¤1£¤17 £¤90£¤17

£¤1

£¤1

£¤1

£¤1

¬«208

¬«202¬«109

¬«5A

¬«16

¬«207

¬«100

¬«16

¬«20

¬«224

¬«13

¬«103

¬«A1A

¬«312

¬«128

¬«A1A

¬«16¬«16

¬«100

¬«152

¬«19

¬«21

¬«134

¬«115A

¬«9B

¬«9A

¬«A1A¬«A1A

¬«206

¬«13

¬«3

§̈¦295

§̈¦95

§̈¦95

§̈¦95

SR-207WWTF

Players ClubSouth WWTF

SR-16WWTF

MarshLanding WWTF

AnastasiaIsland WWTF

NORTHWESTWWTF

Innlet Beach WWTFSawgrass WWTF

SAWGRASS WTPPLANTATIONWTP

MARSHLANDING WTP

INNLETBEACH WTP

CR 214WTP

NORTHWESTWTP

St. Johns County IWRP

Legend")̈ Water Treatment Plants!j WW Treatment Facilities

Service AreasMainland and Anastasia IslandNortheastNorthwestPonte Vedra SystemSR16South

®For Informational Purposes Only Q:\ (GNVGISPROJECTS)\19270_st_johns_co\086_IWRP\mxd\3_1_IWRP_Service_Areas_and_Major_Facilities.mxd SAN 10/23/2014

DRAFT

Table 3-1 SJCUD Major Water and Wastewater Facilities Potable Water Wastewater and Reclaimed Water

Utility Services Area

Potable Water Source Treatment Capacity

2012 Average Flow (MGD)

Comments Facility Name Permit No.

Permitted Treatment Capacity (MGD)

Effluent Disposal Method(s) 2012 Average WWTF Flow (MGD)

2012 Average Reuse Flow (MGD)


CR 214 WTP and Tillman Ridge Wellfield

CR 214 WTP = 8.0 MGD 4.31

12-inch inter connect with SR 16 service area can provide ~1 MGD to CR 214 WTP

Anastasia Island (AI) & SR 207

AI = FL0038831; SR 207 = FLA011747

AI = 4.95; SR 207 = 0.25

AI = Marsh Creek Golf Course (0.8 MGD). Remainder sent to surface water (Matanzas River); SR 207 = Public Access Reuse (St. Johns Co. Golf Course).

AI = 2.5; SR 207 = 0.12

AI = 0.441; SR 207 = 0.12

Northeast Interlocal Agreement with JEA

Agreement for 1.5 MGD AADF 0.49

Interlocal Agreement with JEA N/A N/A N/A N/A N/A

Northwest NW WTP 6.0 MGD 1.18

NW WWTF FL0670651 3.0

3.0 MGD of Public Access Reuse to World Golf Village and 0.9 MGD of surface water discharge to Mill Creek (tributary of St. Johns River)

N/A N/A

SR 16 NW NW WTP = 6.0 MGD NA 20-inch interconnect

with Northwest WTP.

SR 16 and NW WWTF through a 12-inch PVC interconnect

SR-16 = FL0043109 SR-16 = 1.32

SR 16 = Public Access Reuse (World Golf Village and Slammer and Squire Golf Course) and Wetland Treatment System

1.057 MGD 0.675

South N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A

Ponte Vedra

Marsh Landing WTP, Innlet Beach WTP, Plantation WTP, Sawgrass WTP

Marsh Landing WTP = 2.4 MGD; Innlet Beach WTP = 3.6 MGD, Plantation WTP = 6.0 MGD, Sawgrass WTP = 3.0 MGD

3.81

Innlet Beach WWTF, Marsh Landing WWTF, Players Club WWTF, Sawgrass WWTF

Innlet Beach WWTF = FL0044237, Marsh Landing WWTF = FL0044253, Players Club WWTF, Sawgrass WWTF = FL0117897

3.5 Public Access and Surface Water Discharge (Wet Weather) 2.148 1.032


DRAFT

3.2 POTABLE WATER SYSTEM

The IWRP incorporates the capacity and viability of future water supply from six water treatment plants (WTPs):

Main System

CR 214 WTP, Mainland Service Area.

Northwest (NW) WTP, NW and SR 16 Service Areas.

Ponte Vedra System

Marsh Landing WTP, Ponte Vedra Service Area (formerly St. Johns Service Company).

Innlet Beach WTP, Ponte Vedra Service Area (formerly St. Johns Service Company).

Sawgrass WTP, Ponte Vedra Service Area (formerly Intracoastal Utilities).

Plantation WTP, Ponte Vedra Service Area (formerly Intracoastal Utilities).

The Upper Floridan Aquifer (UFA) is the single water supply source for SJCUD. SJRWMD has issued the County two Consumptive Use Permits (CUPs) that authorize the use of groundwater by SJCUD:

Main System CUP – governs the withdrawals at the Northwest and Tillman Ridge (CR 214) Wellfields, has a total authorized use of 16.12 MGD, and expires in 2024.

Ponte Vedra System CUP – authorizes withdrawals from the North and South Wellfields up to 7.0 MGD and expires in 2032.

3.2.1 MAINLAND AND ANASTASIA ISLAND SERVICE AREA

The CR 214 (Tillman Ridge) Wellfield supplies the CR 214 WTP. The CR 214 low-pressure reverse-osmosis (LPRO) WTP has a permitted and design capacity of 8.0 MGD. The treatment facility provides 4.0 MGD of LPRO membrane permeate treatment capacity and 4.0 MGD of pretreated raw water blend to achieve the 8.0 MGD finished water capacity.

The CR 214 Wellfield consists of eight UFA wells with a firm capacity of 13.25 MGD with the largest well out of service and a total capacity of approximately 15.62 MGD.

3.2.2 NORTHWEST SERVICE AREA

The NW WTP was recently expanded and has a permitted design capacity of 6.0 MGD. The NW Wellfield consists of three UFA wells with a fourth well coming online in 2015. Three additional UFA wells are planned for the long-term water demands for the NW WTP Service Area. Preliminary considerations were made for a future expansion of the NW WTP of 9.0 MGD during the last plant expansion.

3.2.3 NORTHEAST SERVICE AREA

The Northeast Service Area is served by an interlocal agreement with JEA that can provide up to 1.5 MGD on an annual average daily flow (AADF) basis through 2021. The interlocal agreement can be renewed annually based on mutual agreement between SJCUD and JEA


DRAFT

3.2.4 SR 16 SERVICE AREA

The SR 16 Service Area is served by the CR 214 Mainland WTP. SJCUD is planning to serve SR 16 from the northwest through an interconnect that became operational in October 2014.

3.2.5 SOUTH SERVICE AREA

SJCUD does not provide potable water services in the South Service Area. Construction of a South potable water system is contingent on development in the South Service Area.

3.2.6 PONTE VEDRA SYSTEM SERVICE AREA

3.2.6.1 Marsh Landing WTP and Wellfield

The Marsh Landing WTP has a design capacity of 2.4 MGD and is supplied by the Marsh Landing Wellfield. The distribution system from this plant is connected with the Innlet Beach WTP, providing system redundancy and reducing dead-end pipes. The WTP is supplied by two wells drawing from the UFA that provide a firm capacity of 1.44 MGD and a total capacity of 3.6 MGD.

3.2.6.2 Innlet Beach WTP and Wellfield

The Innlet Beach WTP has a design capacity of 3.6 MGD and is supplied by the Innlet Beach Wellfield. The Innlet Beach Wellfield consists of four wells drawing from the UFA that provide a firm capacity of 5.33 MGD and a total capacity of 7.78 MGD.

3.2.6.3 Plantation WTP and Wellfield

The Plantation WTP has a permitted design capacity of 6.0 MGD. The Plantation WTP has four wells to draw water from the UFA that provide a firm capacity of 6.48 MGD and a total capacity of 8.64 MGD.

3.2.6.4 Sawgrass WTP and Wellfield

The Sawgrass WTP has a permitted design capacity of 3.0 MGD. The distribution system from this WTP is connected to the Plantation WTP, providing system redundancy and reducing dead-end pipes. The Sawgrass WTP operates only during peak demand periods, usually between 4 AM and 10 AM during the dry months. The WTP is typically on stand-by during winter. During non-peak periods, the Plantation WTP provides adequate flow to the combined distribution system.

The Sawgrass WTP is fed by two wells withdrawing from the UFA that provide a firm capacity of 1.44 MGD and a total capacity of 3.6 MGD. The two wells provide a total withdrawal capacity of approximately 3.6 MGD.

3.2.7 INTERCONNECTS

The SR 16 Service Area was served by the CR 214 WTP through an interconnect. In October 2014, a 20-inch main was constructed between the NW and SR 16 Service Areas. The goal of the interconnect is to reduce demand on the CR 214 WTP by supplying the SR 16 Service Area with 0.5 MGD from the Northwest WTP. This interconnect will eventually allow water to be sent to the CR 214 WTP through a 12-inch main. The CR 214 WTP no longer serves the SR 16 Service Area. Based on preliminary hydraulics, SJCUD could send 1.0 MGD from the NW WTP to the CR 214 WTP. The system will not have enough pressure to serve customers directly. Rather, water from the NW WTP will fill storage tanks at the CR 214 WTP.


DRAFT

3.3 WASTEWATER SYSTEM

SJCUD owns and operates several wastewater treatment facilities (WWTFs) and collection systems. Although the IWRP focuses on water supply, in many cases the wastewater conveyance and treatment capacities in the SJCUD Service Area will play an important role in constraining or enabling water supply growth. For example, the Anastasia Island (AI) WWTF receives concentrate from CR 214 WTP LPRO facility. Total dissolved concentrations at the AI WWTF could limit the ability to serve reclaimed water customers. Also, each WWTF is capable of generating reclaimed water that can meet public-access reuse standards. Therefore, increases in WWTF flows can offset future potable water demands.


3.3.1.1 SR 207 WWTF

The SR 207 WWTF is permitted by the Florida Department of Environmental Protection (FDEP) for 0.25-MGD AADF. Based on the 2012 Annual Reuse Report, the average daily flows are approximately 0.12 MGD (50% capacity).

The SR 207 WWTF Service Area has historically been able to divert flow to the AI WWTF Service Area during times of high flow, high waste strength, or system upgrades. Recent service area changes, coinciding with the conveyance of membrane concentrate to the AI WWTF, have significantly reduced the ability to convey wastewater generated east of I-95 to the SR 207 WWTF, although some SR 207 wastewater can be conveyed to the AI WWTF.

3.3.1.2 Anastasia Island (AI) WWTF

The AI WWTF is permitted by FDEP for 4.95-MGD AADF. The permitted amount includes up to 0.8 MGD of effluent reuse. The remainder of WWTF flows is sent to the Matanzas River. Based on the 2012 Annual Reuse Report, the average daily flows are approximately 2.5 MGD (50% capacity). The AI WWTF receives reverse-osmosis concentrate effluent from the CR 214 WTP.


SJCUD is commissioning the NW WWTF. Its permitted capacity is 3.0-MGD AADF. After construction of the WWTF, the NW and SR 16 Service Areas will be interconnected and capable of sending flow in either direction.


Wastewater generated in the US 1 North Corridor will be conveyed to JEA for treatment until 2021 under a wholesale service agreement with SJCUD.


The SR 16 WWTF is permitted by FDEP for 1.32-MGD AADF. The facility is capable of treating 1.5 MGD, but effluent disposal is limited to 1.32 MGD. The capacity of the facility is not limited by the treatment ability of the process units but by the amount of treated effluent that can be used for public-access reuse for irrigation of the World Golf Village golf course and landscape areas. As stated in the operating permit, this reuse capacity is based on irrigating 209 acres at World Golf Village.

The SR 16 WWTF is also permitted to discharge 0.5-MGD AADF of reclaimed water to a hydrologically altered and man-made treatment wetland system adjacent to the WWTF. This discharge is considered to be a permitted beneficial reuse system in accordance with Chapter 62-610.810(2)(g), FAC. The wetland


DRAFT

treatment system provides additional treatment of the reclaimed water to meet surface discharge water quality criteria on the outfall from the wetland system to Cowan Swamp, a Class III freshwater system.

According to the 2012 Reuse Report, the SR 16 WWTF processed approximately 1.057 MGD, with 0.675 MGD sent to reuse and 0.382 MGD sent to surface water discharge.


SJCUD does not operate a WWTF in the South Service Area. The location for a future WWTF has been identified, and construction is contingent on development in the South Service Area.


SJCUD operates four WWTFs in the Ponte Vedra System Service Area: Innlet Beach, Marsh Landing, Players Club, and Sawgrass.

3.3.6.1 Innlet Beach WWTF

The Innlet Beach WWTF is permitted to treat 0.5-MGD AADF. The WWTF is permitted to discharge up to 0.5 MGD to a slow-rate public-access reuse system to nearby golf courses or up to 0.5 MGD to a surface water discharge through the Sawgrass stormwater pond system. The surface water discharge system is a limited wet-weather discharge. Based on the 2012 Annual Reuse Report, the Innlet Beach WWTF treated 0.369 MGD, with most of the effluent (0.337 MGD) discharged to the reuse system.

3.3.6.2 Marsh Landing WWTF

The Marsh Landing WWTF is permitted to treat 0.80-MGD AADF. The facility is permitted to discharge up to 1.1 MGD to a slow-rate public-access reuse water system or send 0.8 MGD through the Marsh Landing stormwater system to the Intracoastal Waterway. This is a limited wet-weather discharge system. Based on the 2012 Annual Reuse Report, total flow through the plant is approximately 0.492 MGD. Approximately 0.192 MGD is sent to reuse and 0.3 MGD is sent to surface water discharge.

3.3.6.3 Players Club WWTF

The Players Club WWTF is permitted to treat 0.70-MGD AADF. The WWTF is permitted to discharge up to 0.7 MGD to a slow-rate public-access reuse water system or send 0.7 MGD through the stormwater system of the Sawgrass Stadium Course Stormwater lake system to the Intracoastal Waterway. This is a limited wet-weather discharge system. Based on the 2012 Annual Reuse Report, total flow through the plant is approximately 0.4 MGD. Approximately half this flow is sent to reuse and half is sent to surface water discharge.

3.3.6.4 Sawgrass WWTF

The Sawgrass WWTF is permitted to treat 1.5-MGD AADF under FDEP Facility Permit No. FL0117897. The WWTF is permitted to discharge up to 1.5 MGD to a slow-rate public-access reuse water system or send 1.2 MGD to the Intracoastal Waterway. Based on the 2012 Annual Reuse Report, total flow through the plant is approximately 0.877 MGD. Approximately 0.303 MGD is sent to reuse, and 0.574 MGD is sent to surface water discharge.

3.3.7 INTERCONNECTS

After the NW WWTF is completed, the NW and SR 16 Service Areas will be interconnected and capable of sending flow in either direction. One potential future interconnect project might be the Shores Master Lift Station (MLS) on the site of a former WWTF, which now only pumps to the AI WWTF. This master


DRAFT

pump station could be redesigned to pump to a future WWTF in the southwest area of the County while still maintaining the ability to divert some wastewater flow to the AI WWTF.

3.4 RECLAIMED WATER SYSTEM

The NW and SR 16 reclaimed water service areas will be interconnected once the NW WWTF is constructed. Once construction is complete, reclaimed water can be delivered to and from either treatment plants or service areas.


The permitted capacity of the AI WWTF is 4.95-MGD AADF. The facility has a surface water discharge permit that allows up to a 4.95-MGD (full effluent flow) discharge to the Matanzas River. The permit also allows the WWTF to reuse up to 0.8 MGD of reclaimed water at the Marsh Creek Golf Course, which is included in the permit under the Part III slow-rate public-access land-application reuse system. The effluent water quality at the AI WWTF has significantly higher sodium and total dissolved solids (TDS) levels compared to SR 16 and SR 207 WWTF. The AI WWTF receives wastewater that is blended with concentrate from the CR 214 WTP. Historical TDS data collected monthly from January 2010 through July 2010 show the effluent TDS at AI WWTF ranged from 1,750 mg/L to 2,190 mg/L during that period. The landscape and turf at the Marsh Creek Golf Course have a higher tolerance for salinity than average residential landscape.

Public-access reuse is the primary means of effluent disposal for the SR 207 WWTF. The permitted capacity of the slow-rate public-access land-application reuse system is 0.25-MGD AADF. Almost all the treated effluent is used to irrigate the adjacent St. Johns County Golf Course. A supplemental groundwater well was permitted and installed at the golf course to provide an adequate supply of irrigation water for the golf course. The effluent water quality at SR 207 is adequate for public-access reuse.


SJCUD is commissioning the NW WWTF. Its permitted capacity is 3.0-MGD AADF. When the NW WWTF is completed, the NW and SR 16 Service Areas will be interconnected and capable of sending flow in either direction. The NW WWTF will be permitted to discharge 3.0 MGD to public-access reuse at the World Golf Village and 0.9 MGD of surface water discharge to Mill Creek (a tributary of the St. Johns River). SJCUD is expanding their residential reuse water system in this area and continues to identify suitable neighborhoods for future inclusion of reuse water systems for residential irrigation.


Wastewater generated in the US 1 North Corridor will be conveyed to JEA for treatment until 2030 under a wholesale service agreement with SJCUD.


The permitted reuse capacity of the SR 16 WWTF is limited to 1.32-MGD AADF, which is based on irrigating 209 acres at World Golf Village. SJCUD is expanding their residential reuse water system in this area and continues to identify suitable neighborhoods for future inclusion of reuse water systems for residential irrigation.The SR 16 WWTF is also permitted to discharge 0.5-MGD AADF of reclaimed water to a hydrologically altered and manmade treatment wetland system adjacent to the WWTF. Historical TDS data collected monthly from November 2008 through February 2009 show the TDS at SR 16 WWTF ranged from 1,060 mg/L to 1,230 mg/L during that period. The TDS and chloride levels could have negative impacts on ornamental landscape vegetation, especially in areas with poor drainage. The


DRAFT

effluent quality at SR 16 should continue to be monitored, and potential effects on vegetation should be identified.


SJCUD does not operate a WWTF in the South Service Area. Construction of the South WWTF is contingent on development in the South Service Area. In general, reclaimed water was assumed to be a significant component of the effluent disposal capacity of the new WWTF.


Reclaimed water is a significant component of the effluent disposal capacity at the four SJCUD WWTFs in the Ponte Vedra System Service Area. The WWTF are permitted to provide public-access reuse to several golf courses in Ponte Vedra. At this time, SJCUD has no plans to expand or significantly alter the reclaimed water system in the Ponte Vedra System Service Area.

3.5 STORMWATER SYSTEM The County’s Public Works Department maintains the Municipal Separate Storm Sewer System (MS4) system. SJCUD does not operate any surface water facilities, but the County Public Works Department maintains the MS4.

3.5.1 REGIONAL STORMWATER FACILITIES

The County owns and operates several regional stormwater treatment (RST) facilities as shown in Figure 3-2 that could benefit the County’s water supply. The following RST facilities store and treat stormwater as part of the County’s NPDES and TMDL responsibilities.

The Fox Creek Regional Stormwater Facility was constructed in 2012 and permitted as part of the West King Street Drainage Improvements. The West King Street collection system has not been constructed, so the majority of stormwater flow entering the pond is runoff generated from natural land uses, such as wetlands. Water quality is not measured at the pond, but the pollutant presence is expected to be limited given the contributing watershed. The pond is permitted to serve over 1,100 acres. The treatment-volume capacity of the pond is over 90 acre-feet, and the total pond volume is over 650 acre-feet.

The Masters Tract RST facility became a standalone project as part of the Lower St. Johns River Algal Initiative. The RST facility will cover 160 acres of land, with three agricultural canals conveying stormwater runoff from a 1,400-acre contributing basin. The majority of the contributing area is planted row crops, so the project was designed with a treatment train for Total Nitrogen removal. The RST facility will hold 288 acre-feet of stormwater. The project is under construction.

The Deep Creek West RST facility is owned by SJRWMD but operated by the County. The County is investigating additional treatment opportunities at the site. The RST facility holds 150 acre-feet of stormwater.

The County is investigating the feasibility of a new RST facility in the southwest part of the County. The location of this facility is being identified through the County’s ongoing stormwater modeling project and the County-wide pollutant load assessment.


DRAFT

Figure 3-2Regional Stormwater Facilities

0 3 6

Miles1:380,160

_̂_̂

_̂


Northeast

Northwest

Ponte Vedra System

South

SR16

D U V A LD U V A L


C L A YC L A Y



£¤90£¤1

£¤1

£¤17

£¤17

£¤17

£¤1£¤17 £¤90£¤17

£¤1

£¤1

£¤1

£¤1

¬«208

¬«202¬«109

¬«5A

¬«16

¬«207

¬«100

¬«16

¬«20

¬«224

¬«13

¬«103

¬«A1A

¬«312

¬«202

¬«128

¬«A1A

¬«16¬«16

¬«100

¬«152

¬«19

¬«21

¬«134

¬«115A

¬«9B

¬«9A

¬«A1A¬«A1A

¬«206

¬«13

¬«3

§̈¦295

§̈¦95

§̈¦95

§̈¦95

Deep CreekWest RST

MastersTract RST

Fox Creek RegionalStormwater Facility


Legend_̂ Regional Stormwater FacilitiesService Areas

Mainland and Anastasia IslandNortheastNorthwestPonte Vedra SystemSR16South

®For Informational Purposes Only Q:\ (GNVGISPROJECTS)\19270_st_johns_co\086_IWRP\mxd\3_2_IWRP_Regional_Facilities.mxd SAN 10/23/2014

DRAFT

4 NEEDS ASSESSMENT

4.1 POPULATION

The basis of County population estimates is derived from the University of Florida Bureau of Economic and Business Research (BEBR). The population and water demands were developed at the parcel and planned development (major subdivision or neighborhood) spatial scale and aggregated up to the service areas. Before the population was estimated, each parcel or planned development was assigned one of the following categories:

Existing – development has infrastructure and services already in place.

Planned Approved – development has been approved but does not have service.

Planned Not Approved – development is likely but it has not been approved for construction.

Future – unknown development in the service area that is likely to be served by SJCUD.

Unserved – properties that are existing without service or lands that are undevelopable or not projected to be served within the planning horizon.

The extent of areas to be served by SJCUD in 2040 is based on the information provided by SJCUD. In some cases, planned developments and neighborhoods are partially complete and the undeveloped part of the development was assigned to the Planned Approved category. After categorizing the parcels and planned developments (properties to be served), population was estimated using SJCUD growth projections and the GIS and Associates, Inc. (GISA)-parcel-based estimates. SJCUD provided the amount of population growth in 5-year increments for each service area; these data are used to constrain the total number of people that can be served in each service area within a given period. The GISA-parcel-based-estimates were used to spatially distribute the population within each parcel and planned development to be served. Population estimates for three growth conditions (Low, Medium, High) were developed. Appendix B summarizes the population and water demands incorporated into the IWRP. Figure 4-1 displays the projected population in each service area for the medium-growth conditions. The population served by SJCUD is expected to grow by 88,000 people by 2040.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc 4-1 March 2015 Needs Assessment

DRAFT

Figure 4-1 Projected Served Population (BEBR Medium Growth)

0 0 152

778

2,20

6

8,79

6

4,83

6

5,60

3

6,56

9

7,73

6

8,96

1

10,9

93

6,58

3

7,35

0

8,31

6

9,48

3

10,7

08

12,7

40

14,2

07

17,5

57

23,2

07

29,1

12

35,2

70 47,6

33

52,9

74

56,1

29

61,3

79

67,0

49

72,9

63 83,7

60

24,0

87

24,3

99

24,9

35

25,5

65

26,1

65

26,7

26

102,687

111,038124,558

139,723

156,273

190,648

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

200,000

2012 2015 2020 2025 2030 2040

Serv

ed P

opul

atio

n

South SR16 NortheastNorthwest Mainland and Anastasia Island Ponte Vedra SystemGrand Total

4.2 WATER DEMANDS

The IWRP water demand analysis has five end uses:

Single-Family (SF) Indoor

SF Outdoor

Multi-Family (MF) Indoor

MF Outdoor

Non Residential (NR)

The first step in estimating water demands is to estimate the number of SF, MF, and NR units that will be developed within each planned development. The water demand in each planned development is then calculated by assigning a per-unit water use metric for each use type (i.e., indoor use/SF unit) and multiplying by the number of units being served estimated in the population projections (i.e., indoor use/SF unit x SF unit served in 2040 = 2040 SF indoor water use). The water use metrics calculations are based on analysis of the monthly consumption data contained in SJCUD’s Accountmaster geodatabase. The monthly consumption data from January 2007 to October 2012 were used in the analysis. The separation of indoor and outdoor water was accomplished by analyzing water use patterns, developing a


DRAFT

procedure to estimate indoor water use, and subtracting it from the total water use to obtain outdoor water use. This process is necessary because customers typically do not have separate water meters measuring indoor and outdoor consumption. The separation technique is only applicable to residential uses. No attempt was made to separate NR uses into indoor and outdoor water use due to the highly variable water use behavior of NR customers. Table 4-1 summarizes the average water per-connection use for each service area and planning category for the SF water use. Appendix B provides per-connection water use for MF and NR water use.

Table 4-1 Single-Family Unit Average Monthly Use (gallons per day) Service Area Per Connection Water Use Per Capita Water Use Planning Category Indoor Outdoor Total Indoor Outdoor Total Mainland and Anastasia Island

Existing 109 30 139 49 14 63 Planned Approved 118 41 159 53 18 72 Planned Not-Approved 113 36 149 51 16 67 Future 113 36 149 51 16 67 Northwest

Existing 183 79 262 63 27 90 Planned Approved 184 87 271 64 30 93 Planned Not-Approved 186 87 273 64 30 94 Future 188 88 275 65 30 95 Northeast

Existing 163 84 247 59 30 89 Planned Approved 195 107 302 70 38 109 Planned Not-Approved 195 107 302 70 38 109 Future 195 107 302 70 38 109 SR 16

Existing 137 37 174 58 16 74 Planned Approved 111 31 142 47 13 60 Planned Not-Approved 126 35 161 54 15 69 Future 126 35 161 54 15 69 South

Existing 157 68 225 63 27 90 Planned Approved 158 74 233 64 30 93 Planned Not-Approved 160 75 235 64 30 94 Future 161 75 236 65 30 95 Ponte Vedra System

Existing 219 143 362 88 57 145 Planned Approved 219 485 704 88 195 283 Planned Not-Approved 219 168 387 88 68 156 Future 219 168 387 88 68 156 Table 4-2 summarizes water use metrics for each service area. The primary observation from reviewing the water use metrics is that the Ponte Vedra System customers use more water than customers in the Main System (Mainland and AI, Northeast, Northwest, and SR 16). In the Main System, the typical SF


DRAFT

home is consuming 71 gallons per capita per day (gpcpd), with 53 gpcpd being used indoors and 18 gpcpd being used outdoors. In the Ponte Vedra System, a typical SF home is estimated aas using 145 gpcpd with 88 gpcpd being used indoors and 57 gpcpd being used outdoors. The indoor SF water use compares well with previous estimates (Jones Edmunds; 2010, 2011) and with the national end use study (Mayer et al., 1999).

Table 4-2 Water Use Summary Statistics (gpd)

Service Area Per Equivalent Connection (gpd) Per Capita

Gross Residential Gross Residential Mainland and Anastasia Island 175 130 79 59 Northeast 240 224 86 81 Northwest 250 208 86 72 SR 16 212 127 90 54 Ponte Vedra System 386 287 170 127 Main System Weighted Average 196 152 81 63 Utility Weighted Average 240 184 102 78

The total raw water demand is calculated by adjusting the daily customer demands to account for treatment and delivery system losses (Table 4-3).

Table 4-3 Delivery System and Treatment Plant Loss Factors

Service Area Delivery System Loss Factors1

Treatment System Loss

Factor2

Customer to Well Loss

Factor Mainland and Anastasia Island 1.05 1.07 1.12 Northeast 1.10 1.00 1.10 Northwest 1.07 1.05 1.12 Ponte Vedra 1.10 1.00 1.10 1Delivery system loss factors are derived from dividing the metered WTP flows by the metered customer use from 2007 to 2012. 2Treatment plant loss factors are derived from dividing the metered well withdrawals by the metered WTP flows from 2007 to 2012.

The AADF demands for each growth scenario are adjusted to account for the increased demands during drier-than-normal and hotter-than-normal conditions experienced over the past 5 years. The most extreme demand conditions experience over the past 5 years occurred in 2011. Table 4-4 shows the AADF peaking factors for weather conditions based on the 2011 conditions.


DRAFT

Table 4-4 Weather-Related AADF Peaking Factors Service Area 2011 AADF/5-Year AADF Mainland and Anastasia Island 1.04 Northeast 1.07 Northwest 1.08 Ponte Vedra 1.16

Figures 4-2 and 4-3 show the low-, medium-, and high-growth raw water AADF demands adjusted for peak demand weather conditions for the Main System (Mainland, Northeast, Northwest, SR 16, and South) and the Ponte Vedra System, respectively.

Figure 4-2 Main System Raw Water Demands

7.6

10.7

12.6

15.2

18.2

25.4

7.6

10.011.4

13.1

15.1

19.0

7.6

9.410.1 10.6 11.1 11.3

0.0

5.0

10.0

15.0

20.0

25.0

30.0

2010 2015 2020 2025 2030 2035 2040

AADF

Dem

and

(MG

D)

High Growth Medium Growth Low Growth


DRAFT

Figure 4-3 Ponte Vedra System Raw Water Demands

5.25.4

5.65.9

6.26.5

5.2 5.3 5.55.7

5.9 6.0

5.2 5.2 5.2 5.3 5.3 5.4

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

2010 2015 2020 2025 2030 2035 2040

AADF

Dem

and

(MG

D)High Growth Medium Growth Low Growth

4.3 GAP ANALYSIS

A gap analysis was performed before developing the IWRP-SIM model to establish where the existing system capacities and configurations fail to meet future water supply service needs. The gap analysis helps identify where and when future projects are needed. The gap analysis results also serve as a cross check with the results of the IWRP-SIM model. Figures 4-4 and 4-5 show potential shortfalls in infrastructure capacity and traditional groundwater allocations under medium- and high-growth demand scenarios. SJCUD has a 16.1-MGD CUP for the Main System that expires in 2024. Whether SJCUD will be allocated the same groundwater in the future is uncertain. The Ponte Vedra System does not have any system-wide limits under the medium-growth scenario. Table 4-5 summarizes the most limiting future water supply and infrastructure components.

SJCUD has near-term (by 2020) water supply infrastructure needs in the Mainland and AI System (treatment upgrades) and Northwest System (wellfield upgrades). Long-term water supply limitations start to occur in 2030. The most constrained system is the Northwest. The wellfield at the Northwest WTP needs more capacity to serve the combined demands in the Northwest, SR 16, and Mainland Systems. To address this need, SJCUD is drilling a new well at the Northwest WTP. Additionally, the interconnection between the Northwest and Mainland Systems will help defer the near-term treatment upgrades in the Mainland System. The gap analysis is showing high-service pumping limitations in the Northeast System starting in 2020. The County will need to monitor the distribution system capacity to confirm that the high-service pumping is a limiting factor.


DRAFT

Appendix C summarizes the gap analysis. Once the project needs were identified, the project team worked with SJCUD and other stakeholders to develop over 40 project options to be incorporated into IWRP-SIM and evaluated as a potential water supply solution. Appendix D contains a summary of the project options incorporated into the integrated model. Once the IWRP-SIM model was developed, an analysis was performed to confirm the gap analysis results and identify additional gaps in the reuse and wastewater systems. The IWRP-SIM analysis is provided in Appendix E.

Figure 4-4 Main System Gap Analysis


DRAFT

Figure 4-5 Ponte Vedra Gap Analysis

Table 4-5 System Component Limitations Planning Year

Mainland and Anastasia Island System Northeast System Northwest System Ponte

Vedra 2012 None None Wellfield None 2015 None None Wellfield None

2020 None High Service Pumping Wellfield, Treatment None

2025 Treatment, High Service Pumping

High Service Pumping

Wellfield, Treatment, Storage None

2030 CUP, Treatment, High Service Pumping


CUP, Wellfield, Treatment, Storage, High Service Pumping

None

2040

CUP, Wellfield Treatment, High Service Pumping, Transmission to South Service Area


CUP, Wellfield, Treatment, Storage, High Service Pumping

None


DRAFT

5 WATER SUPPLY OPTIONS This section briefly describes the potential options considered in developing the IWRP. Table 5-1 summarizes the options that were considered to help close infrastructure and water supply gaps for each service area. Figures 5-1 through 5-6 show the conceptualized locations of project options. No options are shown for the Ponte Vedra System since no water supply or capacity limitations occur within the planning horizon under medium-growth conditions. The SR 16 Service Area is being interconnected with the Northwest Service Area and is considered a part of the Northwest System. In many cases, the investment in water supply options will also impact the infrastructure limitations. For example, investment in reclaimed water infrastructure as an alternative water supply will reduce the need for infrastructure upgrades to high-service pumping and system storage. Appendix D provides more detailed fact sheets with project costs and yields for each project option.

5.1 GROUNDWATER

The County’s primary water supply is from fresh and brackish groundwater sources. Groundwater will continue to be a significant component of SJCUD’s water supply. The IWRP includes options for expanding existing groundwater facilities as well as developing new fresh and brackish groundwater sources. Land use transitions where existing land use with permitted groundwater withdrawals are retired or transferred to SJCUD are also considered.

5.2 INTERCONNECTS

Interconnecting facilities between service areas to provide more reliability and gain additional flexibility without major capital improvements to treatment and storage systems is often advantageous. Several options are to connect water, wastewater, and reclaimed water service areas to better serve customers.

5.3 RECLAIMED WATER

SJCUD continues to expand the use of highly treated wastewater to offset recreational and landscape irrigation. The IWRP includes options for expanding reuse to existing and future developments within the County. The expansion of reuse is typically limited by the amount of storage or the ability to supplement with an additional water source when not enough wastewater is being treated at the WWTF. The IWRP includes several options for storage and supplementation including aquifer storage and recovery, stormwater harvesting, and temporary groundwater sources.

5.4 CONSERVATION

Saving water by reducing consumption or making use more efficient is a key component of the IWRP. The conservation options include evaluating the impacts of changing land development requirements, implementing conservation programs, and incentivizing more efficient use by other legal users within the County.

5.5 SURFACE WATER The integration of surface water into the County’s water supply could be an important option to offset future groundwater withdrawals. Surface water options include stormwater harvesting for offsetting agricultural demands and supplementing reclaimed water systems during peak demands and developing the St. Johns River or its tributary for offsetting future groundwater demands.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc 5-1 March 2015 Water Supply Options

DRAFT

Table 5-1 Water Supply Options

Options Mainland and Anastasia Island System

Northeast System

Northwest System/SR 16

South System

Groundwater (Figure 5-1) Expand CR 214 WTP and Wellfield (GW1) √ New WTP and Wellfield in Northeast (GW2) √ Expand Northwest WTP and Wellfield (GW3) √ Ground Storage Improvements (GW4) √ √ √ √ New WTP and Wellfield in South (GW5) √ Land Use Transitions (GW6) √ √ √ Interconnects (Figure 5-2) Connect Northeast to Northwest\SR 16 Reuse

System (IRW1) √

Connect South to Mainland\AI Reuse System (IRW2) √

Connect Ponte Vedra to Northeast (IW1) √ Connect Northwest and Northeast Potable

Water Systems (IW2) √ √

Connect Northwest and South Potable Water Systems (IW3) √

Connect Northwest and South Potable Water Systems via Mainland\AI (IW4) √

Connect Northeast and Northwest Wastewater Systems (IWW1) √ √

Reclaimed Water (Figure 5-3) Expand Mainland\AI Reuse System (RW1) √ Expand Northwest/SR 16 Reuse System

(RW2) √

Expand South Reuse System (RW3) √ Reuse Supplementation Using Groundwater

(RW4) √ √ √

Reuse Supplementation Using Aquifer Storage and Recovery (RW5) √ √ √

Reuse Supplementation Using Stormwater Harvesting from Fox Creek (RW6) √ √

Reuse Supplementation Using Stormwater Harvesting from Tri-County Agricultural Area (TCAA) (RW7)

√ √

Reuse Supplementation Using Stormwater Harvesting from County Roadways (RW8) √ √

Reuse Supplementation Using Stormwater Harvesting from I-95 Corridor (RW9) √


DRAFT

Options Mainland and Anastasia Island System

Northeast System

Northwest System/SR 16

South System

Conservation Implement Conservation Land Development

Requirements (SAV1) √ √ √ √

Promote Cost-Effective Conservation Programs (SAV2, SAV3) √ √ √ √

Implement Maximum Conservation Programs (SAV4, SAV5) √ √ √ √

Passive Implementation of Increased Efficiency Standard Plumbing Fixtures (SAV6) √ √ √ √

Partner with Agricultural Users to Implement Water-Saving Equipment (SAV7) √ √ √

Surface Water (Figure 5-4) Stormwater Harvesting to Offset Agricultural

Demands (SW1 and SW2) √ √

St. Johns River (SW3) √ √ √ Regional Partnerships (Figure 5-5) Participate in Lower Floridan Recovery and

Prevention Project near Clay-Putnam MFL Lakes (GW7)

√ √ √ √

Participate in Regional Recharge (Rapid Infiltration Basins) Recovery and Prevention Project near Clay-Putnam MFL lakes (GW8)

√ √ √ √

Participation in Regional Desalination Plant (SW4) √ √

Wastewater (Figure 5-6) New South WWTF (WW1) √ CR 214 WTP Concentrate Disposal (WW2) √ South WTP Concentrate Disposal (WW3) √ Expand AI WWTF (WW4) √ Expand NW WWTF (WW5) √

5.6 REGIONAL PARTNERSHIP PROJECTS

SJCUD may have opportunities to participate in regional projects to offset groundwater impacts to lakes in Clay and Putnam Counties. Participating in a regional desalination facility is also included as an option.

5.7 WASTEWATER

Collecting, treating, and recycling wastewater is an integral part of SJCUD’s service to the County. The IWRP includes several wastewater options that will impact SJCUD’s operations and the preferred water supply plan.


DRAFT

Figure 5-1Groundwater Options

0 3 6

Miles1:384,661

")̈

")̈

")̈

")̈

")̈

")̈

!j

!j

!j

!j

!j

!j

!j

!j


Northeast

Northwest

Ponte Vedra System

South

SR16

D U V A LD U V A L

S T J O H N SS T J O H N SC L A YC L A Y



£¤1

£¤17

£¤17

£¤17

£¤1

£¤1

£¤1

¬«202¬«109

¬«5A

¬«16

¬«207

¬«100

¬«16

¬«20

¬«224

¬«13

¬«A1A

¬«312

¬«202

¬«A1A

¬«21

¬«16¬«16

¬«100

¬«152

¬«19

¬«134

¬«115A

¬«9B

¬«9A

¬«A1A

¬«A1A

¬«206

¬«13

¬«3

§̈¦295

§̈¦95

§̈¦95

§̈¦95

GW1

GW2

GW3

GW5


Legend

(( Groundwater Options

")̈ Water Treatment Plants!j WW Treatment Facilities

Land Use Transition (GW6)Opportunities

®For Informational Purposes Only Q:\ (GNVGISPROJECTS)\19270_st_johns_co\086_IWRP\mxd\5_1_IWRP_Groundwater_Options.mxd SAN 10/23/2014

Note:GW4 Ground Storage in Ponte Vedra and Main System are not shown. These facilities would be located as needed in the respectivedistribution sytems.

DRAFT

Figure 5-2Interconnection Options

0 3 6

Miles1:384,661

")̈

")̈

")̈

")̈

")̈

")̈

!j

!j

!j

!j

!j

!j

!j

!j


Northeast

Northwest

Ponte Vedra System

South

SR16

D U V A LD U V A L


C L A YC L A Y



£¤1

£¤17

£¤17

£¤17

£¤90

£¤1

£¤1

£¤1

¬«202¬«109

¬«5A

¬«16

¬«207

¬«100

¬«16

¬«103

¬«20

¬«224

¬«13

¬«A1A

¬«312

¬«202

¬«A1A

¬«16¬«16

¬«100

¬«152

¬«19

¬«21

¬«134

¬«115A

¬«9B

¬«9A

¬«A1A

¬«A1A

¬«206

¬«13

¬«3

§̈¦295

§̈¦95

§̈¦95

§̈¦95


Legend")̈ Water Treatment Plants!j WW Treatment Facilities

Interconnection OptionsWater SystemReuse SystemWastewater System

®For Informational Purposes Only Q:\ (GNVGISPROJECTS)\19270_st_johns_co\086_IWRP\mxd\5_2_IWRP_Interconnection_Options.mxd SAN 10/23/2014

IWW1

IRW1

IW2

IW3

IRW2IW4, IW3

IW1

DRAFT

Figure 5-3Reclaimed Water Options

0 3 6

Miles1:380,160

")̈

")̈

")̈

")̈

")̈

")̈

!j

!j

!j

!j

!j

!j

!j

!j


Northeast

Northwest

Ponte Vedra System

South

SR16

D U V A LD U V A L


C L A YC L A Y


£¤17

£¤17

£¤17

£¤90£¤1

£¤1

£¤1

£¤17

£¤17 £¤90£¤1

£¤1

£¤1

£¤1£¤17

¬«208

¬«202

¬«109

¬«5A

¬«16

¬«207

¬«16

¬«20

¬«224

¬«13

¬«A1A

¬«103

¬«202

¬«128

¬«A1A

¬«16¬«16

¬«100

¬«152

¬«19

¬«21

¬«134

¬«115A

¬«111

¬«9B

¬«9A

¬«A1A¬«A1A

¬«206

¬«13

¬«3

§̈¦295

§̈¦95

§̈¦95

§̈¦95

RW4

RW4

RW4

RW6

RW7

RW8

RW1

RW5

RW5

RW3

RW9

RW2

RW5


LegendReclaimed Water Options

(( Reuse SystemExpansion

((Groundwater ReuseSupplementation

(( Aquifer StorageRecovery

(( Stormwater ReuseSupplementation

((Stormwater ReuseSupplementation(Roadway)


Reclaimed WaterExpansion (RW1, RW2,RW3)

®For Informational Purposes Only Q:\ (GNVGISPROJECTS)\19270_st_johns_co\086_IWRP\mxd\5_3_IWRP_Reclaimed_Water.mxd SAN 10/23/2014

Note:1. The shaded areas that indicate reuse expansion are general areas where reclaimed water could be served to offset potable water use. They are not intended to designate where reuse will be served in the future. Reuse service areas will be evaluated on a case by case basis.2. The location of groundwater supplementation (RW4) and ASR (RW5) are conceptual.

DRAFT

Figure 5-4Surface Water Options

0 3 6

Miles1:384,661

")̈

")̈

")̈

")̈

")̈

")̈

!j

!j

!j

!j

!j

!j

!j

!j


Northeast

Northwest

Ponte Vedra System

South

SR16

D U V A LD U V A L




£¤1

£¤17

£¤17

£¤17

£¤1

£¤1

£¤1

¬«202¬«109

¬«5A

¬«16

¬«207

¬«100

¬«16

¬«20

¬«224

¬«13

¬«A1A

¬«312

¬«202

¬«A1A

¬«21

¬«16¬«16

¬«100

¬«152

¬«19

¬«134

¬«115A

¬«9B

¬«9A

¬«A1A

¬«206

¬«13

¬«3

§̈¦295

§̈¦95

§̈¦95

§̈¦95SW1

SW2

SW3

SW4


LegendSurface Water Options

(( Stormwater Harvesting

(( St. Johns River

(( Desalination


Land Use TransitionOpportunities

®For Informational Purposes Only Q:\ (GNVGISPROJECTS)\19270_st_johns_co\086_IWRP\mxd\5_4_IWRP_Surface_Water_Options.mxd SAN 10/23/2014

DRAFT

Figure 5-5Regional Partnerships

0 4 8

Miles1:506,880

")̈

")̈

")̈

")̈

")̈

")̈

!j

!j

!j

!j

!j

!j

!j

!j


Northeast

Northwest

Ponte Vedra System

South

SR16

N A S S A UN A S S A U

D U V A LD U V A L

B A K E RB A K E R


C L A YC L A Y

B R A D F O R DB R A D F O R D

A L A C H U AA L A C H U A P U T N A MP U T N A M


M A R I O NM A R I O N

£¤1£¤90

£¤17

£¤17

£¤17

£¤17

£¤17£¤90£¤17

£¤301

£¤301

£¤1

£¤1

£¤1

£¤1£¤17

£¤90

£¤1

£¤1

£¤1

£¤1£¤90

£¤90

£¤301

£¤1

£¤17

¬«103

¬«A1A

¬«208

¬«202

¬«26

¬«109

¬«5A

¬«10A

¬«114

¬«207

¬«111

¬«16

¬«129

¬«16

¬«20

¬«224

¬«13

¬«115A

¬«A1A

¬«312

¬«228

¬«13

¬«128

¬«100

¬«A1A

¬«100

¬«16¬«16

¬«26

¬«117

¬«21

¬«152¬«228

¬«19

¬«134

¬«11

¬«109

¬«115A

¬«230

¬«116¬«113

¬«9B

¬«9A

¬«A1A

¬«100

¬«206

¬«116

¬«13

¬«3

GW7

GW8

LAKEBROOKLYN

LAKEGENEVA

SW4


Legend

(( Regional Recovery andPrevention Project

(( Desalination


®For Informational Purposes Only Q:\ (GNVGISPROJECTS)\19270_st_johns_co\086_IWRP\mxd\IWRP\5_5_IWRP_RegionalPartnerships.mxd SAN 10/23/2014

DRAFT

Figure 5-6Wastewater Options

0 3 6

Miles1:380,160

")̈

")̈

")̈

")̈

")̈

")̈

!j

!j

!j

!j

!j

!j

!j

!j


Northeast

Northwest

Ponte Vedra System

South

SR16

D U V A LD U V A L


C L A YC L A Y



£¤1

£¤17 £¤90

£¤1

£¤1

£¤1

£¤17

£¤17

£¤17

£¤1

¬«202¬«109

¬«5A

¬«16

¬«207

¬«100

¬«16

¬«20

¬«224

¬«13

¬«103

¬«A1A

¬«202

¬«A1A

¬«16¬«16

¬«100

¬«152

¬«19

¬«21

¬«134

¬«115A

¬«111

¬«9B

¬«9A

¬«A1A

¬«A1A

¬«206

¬«13

¬«3

§̈¦295

§̈¦95

§̈¦95

§̈¦95

WW1

WW2

WW3

WW4

WW5


LegendWastewater Options

((WWTF

(( Concentrate Disposal


Land Use TransitionOpportunities

®For Informational Purposes Only Q:\ (GNVGISPROJECTS)\19270_st_johns_co\086_IWRP\mxd\5_6_IWRP_Wastewater_Options.mxd SAN 10/23/2014

DRAFT

6 IWRP EVALUATION FRAMEWORK

6.1 IWRP PROCESS AND TERMS

The project options described in the previous section were evaluated within the framework of this IWRP. This evaluation provides SJCUD with information to support decisions about future investments to meet water resources needs. The framework described in this section connects the integrated model results with the overall objectives of the planning process.

Terms commonly used within this IWRP process include:

Objectives: Represent major goals of plan, defined in broad, understandable terms (e.g., ensure water reliability).

Metrics/Performance Measures: Indicate how well an objective is being achieved (e.g., frequency and magnitude of water shortages). Objectives combined with their corresponding metrics represent the criteria by which alternatives are compared against.

Options: Represent individual projects or demand management measures.

Alternatives: Represent combinations of options designed to best meet the stated objectives and will be evaluated against the criteria (objectives and metrics).

The IWRP process starts by defining planning objectives and performance measures that are important to SJCUD, customers, regulators, and other stakeholders. Then the process continues with the identification and characterization of various supply and demand-side options. Because no single option is likely able to meet all specified planning objectives, options are combined in various ways to develop alternatives. The alternatives are then evaluated using the integrated systems model that simulates system constraints, supply reliability, lifecycle costs, water quality, and other metrics. The output from the systems model, along with some qualitative metrics, is summarized in a decision tool to facilitate ranking of alternatives. Figure 6-1 presents the overall IWRP process for St. Johns County.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc 6-1 March 2015 IWRP Evaluation Framework

DRAFT

Figure 6-1 IWRP Process

Define Planning Objectives & Metrics

AnalyzeAlternatives

(Systems Model)

Raw PerformanceScore Card

Rank Alternatives

(Decision Tool)

Identify Options(building blocks)

Build Integrated Alternatives

High LevelRecommendations

Foundational Modelfor Refinement/

Analysis

6.2 OBJECTIVES AND PERFORMANCE MEASURES

The first workshop with SJCUD identified the guiding objectives for the IWRP. Each objective has associated performance measures, which were reviewed and modified by the broader group of St. Johns County staff and leadership at the kickoff meeting. One of the expectations of the integrated model is that it will provide numerical output in the form of the performance measures that are deemed to be quantitative as opposed to qualitative. These will then be used in a scorecard along with any qualitative scores to provide balanced, broad-based comparisons of alternatives. The objectives and performance measures are listed in Table 6-1, and more detail on their use is provided in Section 7.


DRAFT

Table 6-1 Objectives and Performance Measures Objective Performance Metric Units

Provide reliable water supply solution

Frequency Percent of months meeting demand

Volume Percent of total volume demand met through the planning period

Develop cost-effective solutions with rate payers in mind

Life cycle cost of projects and policies Million dollars present value

Provide solutions that are easy to operate and maintain

Qualitative operational complexity Qualitative scale 1–5

Provide solutions that are permittable

Degree of new/unpermitted solutions Qualitative scale 1–5

Maximize customer acceptance of water supply solution

Qualitative impact on customers including cost, irrigation restrictions or changes, sustainability of solutions

Qualitative scale 1–5

Reduce potential impacts to regional water supply constraints

Total CUP offsets allowed by regional projects

MGD of CUP offsets in final simulation year

Maximize beneficial wastewater reuse

Treated wastewater reuse and aquifer replenishment

Total percent of wastewater that is reused

Minimize impact on ecosystems

Qualitative impact of projects and policies on ecosystem Qualitative scale 1–5

Maintain groundwater quality throughout the County

Severity of salinity in the Northwest wells Estimated average salinity mg/L

Severity of salinity in CR 214 and South wells Estimated average salinity mg/L

Reduce County's TMDL obligations

Average annual reduction in phosphorus load Average kg/year

Average annual reduction in nitrogen load Average kg/year

6.3 INTEGRATED SYSTEMS MODEL

An important aspect of any IWRP study is the ability to analyze alternatives in an integrated, interconnected manner. This is especially important when water, wastewater, and reclaimed water intersect in decision making. While numerous models and tools can be used to evaluate IWRP alternatives, “systems models” have several advantages including the following:

Extremely customizable and integrated, allowing for all of the most pertinent systems or parts of systems to be accounted for.

Ability to simulate demands, supplies, major system constraints, costs, and other metrics in a comprehensive manner.

Highly visual, with built-in graphics, and performance indicators for on-the-fly simulations.

Quick run time, facilitating systems learning and exploration of “what-if” analyses.


DRAFT

6.3.1 SYSTEMS MODEL SOFTWARE SELECTION

At the beginning of the IWRP Project, various systems models and customized spreadsheet tools were thoroughly evaluated for St. Johns County. Based on the needs of the project, software cost, and flexibility, the systems model STELLA (Systems Thinking Experimental Learning Laboratory with Animation), developed by ISEE Systems, was selected for this project. STELLA is a dynamic and graphical systems model that uses object-oriented programming to develop virtually any type of system (e.g., physical, biological, financial, facilities) or multiple systems. It is frequently used in environmental engineering studies to better understand the implications of decisions across a broad array of physical, social, and environmental sectors that are essential for integrated water resource planning.

STELLA allows users to model physical flow systems with operations or planning-level resolution. An on-screen control interface is then developed that facilitates rapid adjustments of system variables for alternatives and sensitivity analysis. STELLA does not make decisions but is used to generate information and promote more informed and balanced decisions via rapid comparison of the performance of alternatives using physical, environmental, and economic metrics. Its ability to include multi-sectoral interests in an analytical framework distinguishes it from more traditional hydraulic or numeric groundwater models, which evaluate systems in a purely one-dimensional physical setting. While systems models are not typically used to model detailed hydraulics or complex water allocations and surface hydrology, they excel at quickly simulating multiple systems in a very comprehensive manner.

Figure 6-2 displays the conceptualization of IWRP-SIM and Appendix E contains the methodology used to develop the St. Johns County integrated water resources systems model. The model runs for 30 years on a monthly time step, simulating a future period starting from any user-defined year between 2014 and 2020. The user inputs existing conditions and future options input parameters such as treatment plant capacities and global parameters such as economic rates, climate schemes, and high/medium/low-demand projections. Future options can be turned on and off to create different alternative management programs. The model outputs a wide variety of results, including time series of supply and demand and the values of quantifiable performance measures.


DRAFT

Figure 6-2 IWRP-SIM Model Conceptualization


DRAFT

6.3.2 RANKING METHODOLOGY

The systems model produces raw output of various quantitative metrics. In addition, qualitative metrics are important to consider in the overall ranking of alternatives. Both types of metrics are rolled up to the primary objectives shown in Table 6-1. Tying these metrics and objectives together are weightings of relative importance. To facilitate the ranking of alternatives, a decision software tool called Criterium Decision Plus (CDP), developed by InfoHarvest, was used. CDP uses a method called multi-attribute rating to convert raw performance metrics (both quantitative and qualitative) into standardized scores (removing units such as dollars for cost or MGD for water supply) and applies relative weights to compare and rank alternatives. Figure 6-3 displays the multi-attribute rating approach used by CDP, which is summarized below:

Step 1 compares the raw performance metric of a given objective for all alternatives being evaluated. In this example, Alternative 6 has a raw cost (or performance) of $10 million.

Step 2 standardizes the raw performance metric for each objective into comparable numeric scores (the higher the score the better the performance). In this example, Alternative 6 has relatively high costs when compared to the other alternatives, so the standardized score for this objective (between 0 and 10) is 3.4, a fairly low performance.

Steps 3 and 4 calculate the partial score for the alternative based on the standardized score and the relative weight for the objective being calculated. In this example, the cost objective was given a weight of 9% (out of a possible 100%). The partial score for this objective represents the standardized score (3.4) multiplied by the objective weight (0.09), which equals 0.306.

Step 5 plots the partial score of 0.306 for Alternative 6, and this procedure repeats for all other objectives for Alternative 6 until a total score for the project is calculated (see Step 6). The process is repeated for all alternatives so they can be compared and ranked.

Figure 6-3 Multi-Attribute Rating Method


DRAFT

7 ALTERNATIVE EVALUATIONS

7.1 ALTERNATIVES DEVELOPMENT PROCESS

The integrated model was used to simulate a variety of alternative management plans aimed at meeting the St. Johns County Service Area needs and satisfying the IWRP objectives outlined in Section 6. While water supply shortages are a focus of this planning exercise, the integrated model allows for analysis of trade-offs between the water, wastewater, and reuse water systems (e.g., indoor water conservation will decrease wastewater demands, and increased reuse infrastructure will decrease outdoor water demands). Each alternative was evaluated using the 13 performance measures explained in Section 6.

At the outset of the alternatives development process, the project team designed three distinct alternatives by narrowly focusing on three objectives:

Minimize costs.

Maximize reliability.

Maximize sustainable use of water resources.

Each alternative comprised several options chosen to narrow the predicted service gaps and target one of the three objectives. For this first round of alternative development, the goal was not to satisfy all service area demands, but rather to understand system trade-offs in broad terms.

The next step of alternatives development was to combine successful aspects of the original three groups of options to create hybrid alternatives. For example, the High Reliability Alternative provided robust solutions to meeting future demands, but at a very high cost. The project team sought less-costly options to replace some of the most expensive options to create a High Reliability/Lower Cost Alternative. The goal of the hybrid alternatives was to improve metrics where the original alternatives fell short, without losing the original focus.

All alternatives were scored based on the scoring methodology described in Section 6. Table 7-1 shows which options have been included in each of the original and hybrid alternatives. The following sections discuss how these options were chosen and the results of the scoring analysis for each alternative.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc 7-1 March 2015 Alternative Evaluations

DRAFT

Table 7-1 Options-Alternatives Matrix

ID Name Low Cost Low Cost Plus High Reliability with Desalination

High Reliability + Lower Cost

Variation HR + LC (NW to South water instead of South WTP

High Sustainability High Reliability with St. Johns River

GW1 CR 214 WTP Expansion 2MGD, 2020 2MGD, 2020

3MGD, 2020 3MGD, 2020

GW2 New Northeast WTP

2MGD, 2035

2MGD, 2035

GW3 Northwest WTP Expansion 9 MGD upgraded capacity, 2022

9 MGD upgraded capacity, 2022





GW5 New South WTP

2 MGD, 2020 2 MGD, 2020

2 MGD, 2020

GW7 Regional Recovery and Prevention Project (Lower Floridan)

Realized at NE

Realized at NE

IW3 Northwest and South Water System Interconnect

1 MGD, 2020

IW4 Northwest and South Water Systems Interconnect via MAI 1 MGD, 2020 1 MGD, 2020

RW1 MAI Reuse Expansion

5 MGD, 2020

5 MGD, 2020

RW2 Northwest/SR 16 Reuse System Expansion

1 MGD, 2020

3 MGD, 2020

RW3 South Reuse System Expansion

2 MGD, 2020

2 MGD, 2020

RW6 Fox Creek Pond Reuse Supplementation

2 MGD, 2020

5 MGD, 2020

RW7 TCAA Reuse Supplementation

1 MGD, 2020

RW8 Stormwater Harvesting for Reuse Supplementation (I-95 Corridor)

1 MGD + no additional storage

RW9 Stormwater Harvesting for Reuse Supplementation (SJC Roadways)

2 MGD + 50 MG additional storage

SAV1 Land Development Code Requirements included in future demands

included in future demands






SAV2 Cost Effective Conservation Programs for Main System 2020 2020

SAV3 Maximum Conservation for Main System

Included in demands

SAV4 Cost Effective Conservation Programs for Ponte Vedra 2020 2020

SAV5 Maximum Conservation for Ponte Vedra System

Included in demands

SAV6 Increased Efficiency Indoor Standards included in future demands







SAV7 Agricultural Conservation Partnerships

Group 4, realize at CR214

Group 4, realize at CR214 Group 4, realize at NW

SW1 Masters Regional Stormwater Treatment Facility Stormwater Harvesting (Agriculture Demands)

Realize at NW

SW2 Tri-County Agriculture Area Stormwater Harvesting (Agriculture Demands)

Realize at South Realize at NW Realize at NW

SW3 St. Johns River

3 MGD yield SW4 Regional Desalination Project

4 MGD yield for SJC

WW1 New South WWTF 1 MGD, 2020 1 MGD, 2020 1 MGD, 2020 1 MGD, 2020 1 MGD, 2020 1 MGD 1 MGD, 2020 WW2 CR 214 WTP Expansion Concentrate Disposal

included Included

WW3 New South WTP Concentrate Disposal included


DRAFT

7.2 ORIGINAL ALTERNATIVES

This section describes the development and scoring results of the original three alternatives and a baseline (no action) alternative, which were centered around three distinct objectives: 1) minimize costs, called Low Cost; 2) maximize reliability, called High Reliability; and 3) maximize sustainable use of water resources, called High Sustainability.

7.2.1 ORIGINAL ALTERNATIVE DEVELOPMENT

1. Low Cost – The goal when choosing projects for the Low Cost Alternative was to develop a portfolio that would increase the County’s level of service commensurate with projected growth, but not to implement new and different water supply strategies. For example, transferring water and upgrading existing facilities were prioritized over seeking new sources and building new facilities. Modest water conservation was included, which is generally predicted to reduce water supply costs in the long term. Reclaimed water project options were not included. The only new facility project option in the Low Cost alternative is the New South WWTF, which was included in all alternatives because it is the only option for treating wastewater generated in the South Service Area.

2. High Reliability – The goal of the High Reliability Alternative was to include projects that would provide 100% reliability in meeting water and wastewater demands. The cost of providing services was not considered a constraint, resulting in an expensive alternative. New facilities and sources were prioritized over efficient use of existing facilities. For example, the alternative includes building a new South WTP rather than transferring water from CR 214 WTP or the Northwest Service Area. The alternative also includes obtaining water from a new desalination plant to meet Mainland Service Area demands. This is the only alternative that includes desalination. Reclaimed water services were not considered a priority in the High Reliability Alternative.

3. High Sustainability – Projects chosen for the High Sustainability Alternative focused on making efficient use of water resources. Cost and reliability were not considered a priority. For example, the alternative includes high levels of potable water conservation, large increases in reclaimed water infrastructure, and several stormwater reuse agreements.

4. Baseline or No Action – The Baseline Alternative represents what the performance measures would score if no actions were taken to increase water resources services. No options were simulated – only the current capacities, constraints, and supplies.

7.2.2 ORIGINAL ALTERNATIVE RESULTS

The scorecard shown in Table 7-2 provides the raw scores for each of the original alternatives and the baseline. The raw scores clearly reflect the singular objectives of the original alternatives. Quantitative scores were calculated by the integrated model (e.g. reliability, cost, percent wastewater reused). Qualitative scores were determined by the project team based on professional judgment. The Low Cost Alternative scores best in the life-cycle cost, operational complexity, and permittability performance measures. Although not the worst, it does not score well in reliability, meeting demands only 79.6% of months. The High Reliability Alternative scores best in the reliability metrics and in groundwater quality. Groundwater salinity is a function of Floridan Aquifer pumping. The introduction of desalination reduces the amount of groundwater pumping required. The trade-off for High Reliability Alternative scores is an expensive alternative. The High Sustainability Alternative scores well in the environmental and water quality performance measures due to the large increases in wastewater and stormwater reuse.


DRAFT

Table 7-2 Raw Scorecard for Original Alternatives

Criteria Objective Performance Metric Units Best score Baseline Low

Cost High Reliability

High Sustainability

Rel

iabi

lity


Frequency Percent of months meeting demand high 20.2 79.6 100 20.2

Volume Percent of total volume demand met through the planning period high 90.8 99.2 100 96.1

Cos

t Develop cost effective solutions with rate payers in mind

Life-cycle cost of projects and policies Million dollars present value low $571.6 $625.6 $771.45 $777.5

Impl

emen

tatio

n

Provide solutions that are easy to operate and maintain

Qualitative operational complexity Qualitative scale 1–5 high 3 5 3.5 3.25

Provide solutions that are permittable

Degree of new/unpermitted solutions Qualitative scale 1–5 high 3 4.5 3.5 3.75



Qualitative scale 1–5 high 3 4.5 3.5 5

Env

ironm

enta

l



MGD of CUP offsets in final simulation year high 0 0 1.1 2.4



Total percent of wastewater that is reused high 25.5 26.3 26.0 66.1

Minimize impact on ecosystems

Qualitative impact of projects and policies on ecosystem

Qualitative scale 1–5 high 3 3.5 2 5

Wat

er Q

ualit

y


Severity of salinity in North wells Estimated average salinity mg/L low 38 41 40 37

Severity of salinity in South wells Estimated average salinity mg/L low 359 356 291 347


Average annual reduction in phosphorus load Average kg/year high 2,800 2,800 2,800 7,400

Average annual reduction in nitrogen load Average kg/year high 8,400 8,400 8,400 24,700

Note: Bold values indicate the highest score for each performance measure.


DRAFT

Figure 7-1 shows the normalized, weighted scores for the original alternatives and baseline. The Low Cost Alternative scored the best, whereas the High Reliability Alternative scored the worst, based on the scoring system explained in Section 6. The Low Cost Alternative scored better than the other two alternatives in two of the five objectives: cost and implementation. The High Sustainability Alternative scored best in the environmental and water quality objectives, and the High Reliability Alternative had the best score in the reliability objective category. These results were predictable, reinforcing the original purpose behind each alternative. The next step was to attempt to improve the original alternatives by incorporating projects to boost scores in categories where they may have been lacking. For example, the Low Cost Alternative needed projects to improve reliability, and the High Reliability Alternative needed lower-cost options. The next steps also involved answering “either-or” questions such as, “Which is the more attractive non-groundwater source: desalination or the St. Johns River?”

Figure 7-1 Normalized and Weighted Scores for Original Alternatives

Note: Bold values indicate highest score for each objective.

7.3 HYBRID ALTERNATIVES

Using the scoring results of the original alternatives, the project team developed hybrid alternatives in an attempt to improve the scores and address the shortcomings of alternatives aimed at only a single objective. This section explains the development of the hybrid alternatives and their resulting scores.

7.3.1 HYBRID ALTERNATIVE DEVELOPMENT

The hybrid alternative development process involved rearranging the original alternatives in an attempt to answer the following guiding questions:

Is it possible to increase the reliability of the Low Cost Alternative while maintaining the lowest life cycle cost?

Can sustainability options be added to the Low Cost Alternative to improve environmental and water quality performance?


DRAFT

Is it possible to achieve the 100% reliability with the High Reliability Alternative while reducing the life-cycle cost?

Which is the better non-groundwater supply source for the Mainland Service Area: desalination or St. Johns River?

How do options that supply water to the South Service Area impact the results?

Four hybrid alternatives were developed:

1. Low Cost Plus – Reuse system expansions were added to the Low Cost portfolio. The expansion capacities aimed to allow all wastewater to be reused. Two stormwater reuse supplementation projects were also included – Fox Creek and TCAA.

2. High Reliability + Lower Cost – A large expansion of the CR 214 WTP replaced the desalination plant and Northeast water service would come from JEA instead of building a new plant. The high groundwater withdrawals would be offset by agricultural conservation partnerships and TCAA stormwater harvesting. The high groundwater withdrawals would necessitate concentrate disposal upgrades at the CR 214 and South WTPs.

3. High Reliability + Lower Cost, with South Transfer – This hybrid was a variation on the previous alternative. The difference was the source of water to the South Service Area. This alternative includes building a pipeline to transfer water from the Northwest to the South Service Area rather than constructing a new South WTP.

4. High Reliability with St. Johns River – This alternative is identical to the original High Reliability Alternative, with one substitution: The St. Johns River is used to supply growing demands in the Mainland Service Area rather than desalination.

7.3.2 HYBRID ALTERNATIVE RESULTS

The raw scorecard results are presented in Table 7-3 for the hybrid alternatives.

Scores improved over the original alternatives in many of the target performance measures. The Low Cost Plus Alternative improved in reliability, environmental, and water quality metrics. The trade-off was cost – the Low Cost Plus Alternative life-cycle cost rose by $45.1 million. These are life-cycle costs, which means total present-value costs including capital and operations and maintenance for the entire 30-year planning period. The other three hybrid alternatives focused on improving or changing the High Reliability Alternative. Costs were improved for all three while the excellent reliability remained unchanged.

The least expensive of the High Reliability variations was the High Reliability + Lower Cost Alternative with a Northwest to South Service Area transfer. The life-cycle cost was reduced by $19.7 million, with a trade-off of 5% reduction in the frequency of meeting demands. The deficits were very small, however, as the volume reliability rounded to 100%. These results show that transferring water to the South Service Area may be a less expensive option than constructing a new plant in that service area.

The St. Johns River appears to be less expensive than desalination as an alternative supply source to groundwater pumping for the Mainland Service Area. Overall, the High Reliability with St. Johns River Alternative was as reliable as using desalination

Figure 7-2 shows the normalized, weighted scoring results for the original and hybrid alternatives. The hybrid Low Cost Plus Alternative scored best, whereas the original High Reliability Alternative scored worst. The Low Cost Plus Alternative scored best in only one objective – water quality – but had good performance across all five objectives. Adding reuse options to the original Low Cost Alternative proved


DRAFT

to be an effective way to boost reliability and improve scores for water quality and environmental objectives. The cost of the alternative increased with these additions but remains one of the top three least expensive alternatives (discounting the baseline).

Figure 7-2 Normalized and Weighted Scores for All Alternatives

Note: Bold values indicate highest score for each objective


DRAFT

Table 7-3 Raw Scorecard for Hybrid Alternatives

Criteria Objective Performance Metric Units Best score is Low Cost Plus* High Reliability + Lower Cost**

Variation HR + LC (NW to South water instead of South WTP)**

High Reliability with St. Johns River**

Rel

iabi

lity


Frequency Percent of months meeting demand high 91.4 100 95 100

Volume Percent of total volume demand met through the planning period high 99.8 100 100 100

Cos

t Develop cost effective solutions with rate payers in mind Life cycle cost of projects and policies Million dollars present value low $670.7 $686.8 $667.1 $706.2

Impl

emen

tatio

n

Provide solutions that are easy to operate and maintain Qualitative operational complexity Qualitative scale 1–5 high 4 3.75 3.75 3.5

Provide solutions that are permittable Degree of new/ unpermitted solutions Qualitative scale 1–5 high 4.5 3.5 3.5 3.5



Qualitative scale 1–5 high 4.5 4 4 4

Envi

ronm

enta

l Reduce potential impacts to regional water supply constraints


MGD of CUP offsets in final simulation year high 0 3.8 2.5 1.1



Total percent of wastewater that is reused high 59.9 25.0 25.0 25.7

Minimize impact on ecosystems Qualitative impact of projects and policies on ecosystem Qualitative scale 1–5 high 4 3.5 3.25 2

Wat

er Q

ualit

y Maintain groundwater quality throughout the County

Severity of salinity in North wells Estimated average salinity mg/L low 40 40 42 40

Severity of salinity in South wells Estimated average salinity mg/L low 353 359 366 308


Average annual reduction in phosphorus load Average kg/year high 6,400 3,400 3,400 2,800

Average annual reduction in nitrogen load Average kg/year high 19,000 11,700 11,700 8,400

* Bold (italics) values indicate a better (worse) score than the original Low-Cost Alternative.

** Bold (italics) values indicate a better (worse) score than the original High-Reliability Alternative.


DRAFT

7.4 STAKEHOLDER PROCESS

SJCUD hosted two stakeholder meetings to share the progress and gather feedback from the public and key agencies. A copy of the stakeholder presentations is included in Appendix F. The first stakeholder meeting held on February 13, 2014, presented the results of the gap analysis and outlined the evaluation process. The potential water resources projects and strategies were also discussed. The second stakeholder meeting was held on June 12, 2014. The performance measures and preliminary model results were presented and discussed. The feedback gained during these meetings was used to guide the selection of options within the various hybrid alternatives and arrive at a preferred plan. In addition the public stakeholder meetings, SJCUD met with several agencies and stakeholder groups to discuss potential strategies and partnership opportunities. Many of these discussions were used in selecting options to include in the integrated systems model and in the development of hybrid alternatives.

7.5 PREFERRED ALTERNATIVE

The preferred alternative, based on the integrated modeling results and scoring methodology described in Section 6, is the Low Cost Plus Alternative. While it does not score highest in the majority of objective categories, it contains project options that balance trade-offs, such as reliability and cost, and incorporate more sustainable options that will help the County with meeting future water quality challenges.

The role of weighting in the scoring process must be understood and evaluated. Initially, each of the five objective categories was weighted equally (20% each). This means that the reliability performance metrics carried the same importance as the environmental, cost, water quality, and implementation metrics. The performance measures within each objective were also weighted, generally evenly with some variation. Table 7-4 shows the original weighting scheme using in the scoring process.


DRAFT

Table 7-4 Original Weighting Scheme Criteria Weight Objective Subweight Performance Metric

Reliability 20 Provide reliable water supply solution

40 Frequency 60 Volume

Cost 20 Develop cost-effective solutions with rate payers in mind 100 Life cycle cost of projects

and policies

Implementation 20

Provide solutions that are easy to operate and maintain 40 Qualitative operational

complexity Provide solutions that are permittable 40 Degree of new/unpermitted

solutions

Maximize customer acceptance of water supply solution 20


Environmental 20


40 Total CUP offsets allowed by regional projects

Maximize beneficial wastewater reuse 30 Treated wastewater reuse

and aquifer replenishment

Minimize impact on ecosystems 30 Qualitative impact of projects and policies on ecosystem

Water Quality 20


25 Severity of salinity in North wells

25 Severity of salinity in South wells


25 Average annual reduction in phosphorus load

25 Average annual reduction in nitrogen load

Sum of Weights 100 100

A sensitivity analysis on the five objective weights tests the resiliency of the scoring methodology. In a robust decision support model, the top alternative will remain unchanged under a variety of weighting schemes. Table 7-5 shows the ranks of the alternative scores using four different weighting scenarios:

Equal weights (baseline)

Cost weighted 40%, other objectives split remaining 60% evenly

Reliability weighted 40%, other objectives split remaining 60% evenly

Water quality and environmental weighted 35% each, other objectives split remaining 30% evenly


DRAFT

Table 7-5 Alternative Ranking Under Various Weighting Scenarios

Alternative Base Weights (All Equal)

Cost Weight Higher

Reliability Weight Higher

WQ and Env. Weights Higher

Low Cost Plus 1 2 1 2 Low Cost 2 1 2 4 High Rel + Lower Cost 3 5 3 3 High Rel + Lower Cost, with NW Transfer 4 4 4 5

High Sustainability 5 7 7 1 High Rel with St Johns River 6 6 5 6 High Reliability with Desalination 7 8 6 7

No Options 8 3 8 8

The results of the weighting sensitivity analysis show that the Low Cost Plus Alternative scores first or second for all scenarios. Only one scenario produces a ranking where neither Low Cost Plus nor Low Cost is the top alternative. When the water quality and environmental objectives are given 70% of the weighting importance, the High Sustainability Alternative scores best. This result is to be expected considering the portfolio of high reuse and low reliance on groundwater. However, the Low Cost Plus Alternative still receives the second-best score. This is a testament to the robustness of the overall scoring methodology and reflects the balanced portfolio of the Low Cost Plus Alternative.


DRAFT

8 PLAN RESILIENCY As described in Section 6, the model was developed based on several assumptions about future conditions in the St. Johns County Service Area. The results depend on estimates of permit conditions, demand projections, and costs – which are difficult to predict and can vary substantially. A sensitivity analysis was done to test the resiliency of the highest-scoring alternatives. The following section describes the system’s response to changes in permit allocations, demand projections, and cost-share agreements. The following general conclusions can be made based on the results of the sensitivity scenarios:

Traditional water supplies are likely not adequate to meet 2040 demands.

Conservation alone will likely not defer the need to develop alternative water supply strategies.

The plan is sensitive to growth in the South Service Area.

Desalination and St. Johns River are not preferred strategies at this time, but partnerships are required to avoid these alternatives.

8.1 PERMIT ALLOCATION

For future scenarios, St. Johns County was assumed to be able to use 90% of the Northwest and Tillman Ridge CUP allocations. To pump more than 90% of the allocation, St. Johns County would need to implement offset projects, such as stormwater harvesting or regional partnerships. The CUPs are issued by SJRWMD, so St. Johns County does not have full control over future allocation decisions. The integrated model was used to test the 90% assumption, comparing total annual projected groundwater pumping to CUP allocations and varying the percent-allowable allocation usage from 90% to 85%.

Figure 8-1 shows the percent of the Northwest and Tillman Ridge CUPs used through the simulation period for the Low Cost Plus Alternative. The model assumes that the CUP allocation is spread evenly throughout the year, thereby limiting the usage during peak demand months and producing more conservative groundwater pumping constraints. Between 2014 and 2043, based on the existing CUP allocation not increasing after 2024, the maximum percent-used on an annual basis is 85% for the Tillman Ridge CUP and 80% for the Northwest CUP. The drop in percent used in 2020 reflects the implementation of conservation.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc 8-1 March 2015 Plan Resiliency

DRAFT

Figure 8-1 Percent CUP used on annual basis for Low Cost Plus Alternative

The reliability of the top-scoring alternatives declines when groundwater withdrawals are further restricted to 85% of the monthly averaged CUP allocation. Table 8-1 shows the original alternative reliabilities and the results using 85% allowable withdrawal.

Table 8-1 Alternative Reliability Results for Different Allowable Groundwater Withdrawals

Alternative 10% Restriction Reliability 15% Restriction Reliability Frequency % Volume % Frequency % Volume %

Low Cost Plus 91.4 99.8 85.4 99.5 Low Cost 79.6 99.2 70.4 98.5 High Reliability 100 100 96.7 100

Frequency %: Percent of months in simulation that supplies are within 5% of demands.

Volume %: Percent of total demand volume met over entire simulation period.

The High Reliability Alternative, which relies less on groundwater withdrawals, is less susceptible to changes in allowable CUP usage. Both the Low Cost and Low Cost Plus Alternatives experience a 6 to 10% reduction in reliability frequency. Additional CUP offset options were turned on in the Low Cost Plus Alternative simulation to determine what measures might be required to boost reliability if groundwater withdrawals were to be restricted in the future. Any one of the following options would increase reliability to the original alternative levels if the groundwater withdrawals were to be restricted to 85% of the monthly average allocation. All offset benefits were realized at the CR 214 WTP to boost the Tillman Ridge CUP.

Agricultural Conservation Partnerships, Group 1. Impact on life-cycle cost: $1.1 million.

TCAA Stormwater Harvesting for Agriculture. Impact on life-cycle cost: $8.7 million.

Masters Tract Regional Stormwater Facility for Agriculture. Impact on life-cycle cost: $3 million.


DRAFT

Lower Floridan Regional Recovery and Prevention Projects. Impact on life-cycle cost: $2.3 million.

Keystone Heights Regional Recovery and Prevention Projects. Impact on life-cycle cost: $12.5 million.

8.2 DEMAND PROJECTIONS

Three demand projections were developed at the outset of the IWRP process: low, medium, and high. The demand projections are explained in Section 3. The medium projections were used to develop and score the IWRP alternatives. The sensitivity of the top three alternatives was tested using higher demands.

The sensitivity analysis included three additional high-demand forecasts:

Original high demand forecast (BEBR high).

High demands with an expansion of the St. Johns County Service Area.

High demands with more growth distributed in the South Service Area.

Figure 8-2 shows the total annual service area demand for the three sensitivity scenarios compared with the medium-demand forecast. The third scenario has the same total demand as the high projection, but with more growth in the South Service Area and less growth in other service areas. The South demands are also shown to illustrate this difference.

Figure 8-2 Water Demand Projection Sensitivity Scenarios

The integrated model simulated the demand projection sensitivity scenarios for the highest scoring alternative: Low Cost Plus. Table 8-2 shows the reliability results for the four demand projections: medium, high, larger service area, and more growth in the South.


DRAFT

Table 8-2 Reliability of the Low Cost Plus Alternative Under Different High-Demand Projections

Scenario Frequency % Volume % Medium Projection 91.4 99.8 High Projection 54.1 94.1 Growth of Service Area 14.6 92.3 More Growth in South 18.0 94.1 Frequency %: Percent of months in simulation that supplies are within 5% of demands.

Volume %: Percent of total demand volume met over entire simulation period.

While the frequency that water demands can be met drops drastically with higher demand projections, the volume reliability is not as impacted. This is because most demands are being met, particularly in the non-peak, non-summer months. However, the date for which the first deficits are realized is sooner with increased demand projections, thereby increasing the months that demands are not met (even by a small margin) and decreasing the frequency metric. Also, the two metrics have different denominators. Frequency reliability uses total months in the simulation, which is unchanging. Volume reliability uses the total volume of water demanded, which changes depending on the demand scenario. Thus, these two metrics will not always track together.

The integrated model was used to test options that would restore acceptable levels of reliability to the Low Cost Plus Alternative under the higher-demand scenarios. Table 8-3 summarizes the options that could be used to bring the frequency reliability metric to above 90%.

In addition to the cost of providing services to more customers (which would presumably be offset by more rate-paying customers), the impact of higher-than-anticipated growth in water demands would be approximately $30 million over the planning period. These cost estimates are life-cycle costs from 2014 through 2043 shown in 2014 dollars. This additional cost is approximately 5% of the total life-cycle cost of the Low Cost Plus Alternative and approximately 10% of the water supply life-cycle cost of the Low Cost Plus Alternative.

The model sensitivity results show that if more growth is centered in the South Service Area, the planned upgrades to the Northwest and CR 214 that are part of the Low Cost Plus Alternative portfolio would be adequate. This is because the demand projections distribute the growth away from the Northwest and CR 214 Service Areas, thereby allowing that water to be used to serve the South Service Area. The remaining increase in demand for that scenario is in the Northeast Service Area, which is why the purchase agreement with JEA would need to be increased. If the agreement with JEA cannot be increased, additional water can be provided from the Northwest or an interconnect with Ponte Vedra.

The worst-case demand scenario – a high projection with an increased service area size – would likely result in the need for regional projects that offset groundwater withdrawals so that St. Johns County can realize greater CUP allocations for both the Tillman Ridge and Northwest permits. An alternative to increased groundwater withdrawals would be developing the St. Johns River or contributing to a regional desalination plant that would serve the Mainland and South Service Areas. If St. Johns County paid into a regional desalination plant, starting in 2035 at a yield of 4 MGD, Mainland and South demands would be met through the planning period. This project would have a life-cycle cost of approximately $45 million and would replace the $8.7 million TCAA stormwater project and the $7.7 million CR 214 WTP upgrade.


DRAFT

Table 8-3 Project Options to Improve Reliability of Low Cost Plus Alternative Under High-Demand Scenarios

Service Area Option Estimated Impact

on Life-Cycle Cost

Hig

h D

eman

d Pr

ojec

tion

All service areas

Assume land use transitions from agriculture to development allows St. Johns County to realize additional CUP permit allocations

Not applicable

Northeast Increase booster pump station capacities and increase purchase agreement with JEA (no option evaluated) To be Determined

Northwest/ SR 16

Agriculture conservation partnerships group 2 (CUP increase) $4.4 million Lower Floridan Regional Recovery and Prevention Project (CUP increase) $2.3 million

Additional capacity at Northwest WTP and wellfields $5.3 million

Mainland/South

TCAA stormwater harvesting for agriculture (CUP increase) $8.7 million Additional capacity at CR 214 WTP $7.7 million

Incr

ease

d Se

rvic

e Ar

ea

Same options as High Demand Projection above $28.4 million + unknown costs

Mor

e G

row

th in

Sou

th

Serv

ice

Area

All service areas

Assume land use transitions from agriculture to development allows St. Johns County to realize additional CUP permit allocations

Not applicable

Northwest/ SR 16

Agriculture conservation partnerships group 3 $3.4 million

Mainland/South

Lower Floridan Regional Recovery and Prevention Project (CUP increase) $2.3 million

Masters regional stormwater facility for agriculture $3.0 million

8.3 CLIMATE VARIABILITY

The annual demand projections are multiplied in the integrated model by monthly factors to account for seasonal variability in water use. Residential outdoor demands and nonresidential demands (which include indoor and outdoor uses) are subject to seasonal variation. Indoor demands are considered constant throughout the year.

Climate trends may present long periods of drier or wetter than average conditions in St. Johns County. The monthly factors were developed based on historically dry and wet 30-year periods. The historically dry and wet factors are applied to the monthly demands to reflect the potential impacts of climate on the IWRP. Figures 8-3 and 8-4 show the variations in monthly multipliers reflecting average, wet, and dry climate periods.


DRAFT

Figure 8-3 Residential Outdoor Demand Multipliers for Varying Climate Conditions


DRAFT

Figure 8-4 Nonresidential Demand Multipliers for Varying Climate Conditions


DRAFT

Figure 8-4 Nonresidential Demand Multipliers for Varying Climate Conditions (Continued)

The Low Cost Plus Alternative was simulated using a combination of the high-demand forecast and the dry climate conditions to understand the supply shortfalls under a potential high-stress scenario. Table 8-4 shows the results of the climate variability sensitivity.


DRAFT

Table 8-4 Reliability of Low Cost Plus Alternative with Climate Variability Scenario Frequency % Volume % Medium demand projection, average climate 91.4 99.8 Medium projection, dry climate 89.8 99.7 High projection, dry climate 53.6 93.8

The dry climate scenario causes the reliability of the Low Cost Plus Alternative to drop slightly. However, the same additional options that help to increase the reliability under average climate conditions and the high demand projection, shown in Table 8-3, also achieve good reliability (over 90% frequency) for dry climate conditions.

8.4 WATER MANAGEMENT DISTRICT COST SHARE

Some of the projects options available to St. Johns County to meet water resources needs may be eligible for cost sharing with SJRWMD. The project options listed in Table 8-5 were assumed to be eligible for cost share.

Table 8-5 Project Options Eligible for Cost Share with SJRWMD ID Name

GW8 Regional Recovery and Prevention Project (RIBS near Keystone Heights) IRW1 Northeast and Northwest/SR 16 Reuse System Interconnect IRW2 South and MAI Reuse System Interconnect RW1 MAI Reuse Expansion RW2 Northwest/SR 16 Reuse System Expansion RW3 South Reuse System Expansion RW5 Aquifer Storage and Recovery Reuse Supplementation RW6 Fox Creek Pond Reuse Supplementation RW7 TCAA Reuse Supplementation RW8 Stormwater Harvesting for Reuse Supplementation (I-95 Corridor) RW9 Stormwater Harvesting for Reuse Supplementation (SJC Roadways) SAV2 Cost Effective Conservation Programs for Main System SAV3 Maximum Conservation for Main System SAV4 Cost Effective Conservation Programs for Ponte Vedra SAV5 Maximum Conservation for Ponte Vedra System SAV7 Agricultural Conservation Partnerships

SW1 Masters Regional Stormwater Treatment Facility Stormwater Harvesting (Agriculture Demands)

SW2 TCAA Drainage District Stormwater Harvesting (Agriculture Demands) SW4 Regional Desalination Project WW2 CR 214 WTP Expansion Concentrate Disposal WW3 New South WTP Concentrate Disposal


DRAFT

The cost-share amount was assumed to be the lesser of $5 million or 33% of the construction cost. Construction costs were assumed to be 75% of the total estimated capital cost of the option.

The cost-share scenario was applied to the Low Cost Plus and High Reliability Alternatives to explore the impact on life-cycle cost. Table 8-6 shows the resulting life-cycle costs of these two alternatives if the full potential cost share is realized for all eligible projects.

Table 8-6 Life Cycle Costs With and Without Water Management District Cost Sharing

Life Cycle Costs (Million $)

Low Cost Plus High Reliability* Original With Cost Share Original With Cost Share

Water Cost 291.79 291.79 444.74 438.42 Wastewater Cost 316.30 316.30 317.58 317.58 Reclaim Water Cost 54.34 45.74 9.13 9.13 Conservation Cost 8.24 4.12 0.00 0.00 Total 670.67 657.95 771.45 765.13 Total Savings 12.72 (1.9%) 6.32 (0.8%) *Implement TCAA stormwater harvesting instead of Lower Floridan Regional Recovery and Prevention Plan Project to gain additional CUP allocation, because stormwater harvesting is eligible for cost sharing.

Bold values were reduced from original cost calculations.

Reclaimed water and conservation projects included in the Low Cost Plus Alternative are eligible for cost sharing, resulting in the $12.72-million reduction in total life-cycle cost for the alternative – a 1.9% saving to the County. The High Reliability Alternative, however, does not contain as many cost-share-eligible projects. Stormwater reuse projects that allow St. Johns County to realize a higher CUP allocation are eligible for cost share, resulting in a $6.32-million (0.8%) reduction in total life-cycle cost for the High Reliability Alternative. By comparing these two alternatives, the Low Cost Plus Alternative remains the less-expensive plan based on life-cycle cost and offers more savings opportunities if SJRWMD cost shares are offered.


DRAFT

9 RECOMMENDED PLAN The recommended integrated water resources plan is summarized in Table 9-1 and shown in Figures 9-1 and 9-2 for medium-growth conditions. The base plan is developed from the Low Cost Plus Alternative. It contains project options that best meet the County’s objectives by balancing the trade-offs between higher reliability and lower cost as well as higher sustainability and lower reliability. As Figures 9-3 and 9-4 show, SJCUD water supply will need to become more diversified. Traditional groundwater supplies will continue to make up a majority of the potable water supply; however, it will likely not meet the future water supply needs due to water resources constraints that will limit additional withdrawals and potential drivers that could increase water demands. Several near-term (by 2020) components are required to implement the preferred water supply strategy:

Continued emphasis on water conservation.

Expanding mixed-use reclaimed water.

Expanding the wellfield in the Northwest Service Area.

Preparing for interconnecting the Northwest Service Area to the South Service Area until growth supports a new WTP.

The expansion of reclaimed water service will present challenges. Additional supplemental sources or significant amounts of storage will be required when wastewater supplies are not sufficient to meet peak irrigation demands. SJCUD will need to develop a strategy for meeting peak irrigation demands. The following options are recommended to secure supplemental supplies:

I-95 FDOT Expansion (Northwest/SR 16).

Fox Creek (Mainland/Northwest).

Stormwater harvesting in the TCAA area (South/Mainland).

Aquifer storage and recovery (Mainland/Northwest).

The most favorable options are to harvest stormwater through partnerships with other entities within the County. However, the reuse demands in the Mainland and Northwest Systems will likely require more quantities than stormwater can provide. Therefore, ASR is recommended in these service areas. An additional technique that other utilities have employed to reduce the need for supplemental supplies is to develop a rate structure for reclaimed water that promotes efficiency and tends to reduce the peak demands. The base plan includes providing supplemental sources for near-term demands, but does not include ASR or rate strategies that might be needed in the long-term to expand the reuse system.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc 9-1 March 2015 Recommended Plan

DRAFT

Table 9-1 IWRP Recommended Options

Service Area

Option AADF Capacity

(MGD)

Life Cycle Cost ($Millions)

Complete By

Base

pla

n

All service areas

Maintain existing land development requirements (SAV1) 0.14 not

applicable ongoing

Promote cost-effective conservation (SAV2 and SAV4) 1.14 $3.8 2020

Mainland

Expand CR 214 WTP to 10 MGD max day (GW1) 1.3 $8.8 2020

Expand reuse to serve new mixed use development (RW1)

5.0 0.39 potable offset $10.9 as needed

Develop supplemental reclaimed water source from Fox Creek Regional Stormwater Facility (RW6)

2.0 $14.1 2020

Develop supplemental reclaimed water source with Aquifer Storage and Recovery (RW5)

3.0 $69.8 2030

Northeast None

Northwest/ SR16

Expand Northwest Wellfield and WTP to 9 MGD max day (GW3) 2.2 $5.9 2022

Expand reuse to serve new mixed use developments (RW2)

3.0 0.29 potable offset

$9.9 as needed

Develop supplemental reclaimed water source from stormwater harvesting (I-95 corridor – RW-8)

2.0 with 40 MG of storage $14.5 2025

South

Interconnect with Northwest via Mainland Service Area (IW4) 2.0 $18.5 2020

New wastewater treatment plant (WW1) 1.0 $19.4 2020

Expand reuse system in South (RW3) 2.0 0.21 potable offset

$6.4 2020

Develop supplemental reclaimed water source from Agricultural Stormwater Treatment Facilities (RW7)

1.0 $7.4 2020

Ponte Vedra None

Hig

h D

eman

ds a

nd/o

r Inc

reas

ed P

opul

atio

n S

erve

d

All Service Areas

Develop framework for land use transition CUP transfers (GW6) 1.1 not

applicable ongoing

Participate in Lower Floridan regional recovery and prevention project (GW7) 1.0 $2.3 2030

Northeast

Increase booster pump station and increase purchase agreement with JEA (to be evaluated)

to match demand in NE

to be determined 2030

Northwest/ SR16

Expand Northwest Wellfield and WTP from 9 to 12 MGD max day (GW3) 3.2 $5.3 2030

Develop conservation partnerships with Agricultural users (SAV7) 0.5 $4.4 2030

Mainland/ South

Expand CR 214 WTP to 12 MGD Max Day (GW1) 2.0 $7.7 2030


DRAFT

Service Area

Option AADF Capacity

(MGD)

Life Cycle Cost ($Millions)

Complete By In

crea

sed

Gro

wth

in S

outh

All Service Areas

Develop framework for land use transition CUP transfers (GW6) 0.2 not

applicable ongoing

Participate in Lower Floridan regional recovery and prevention project (GW7) 1.4 $2.3 2036

Northwest/ SR16

Develop conservation partnerships with Agricultural users (SAV7) 0.5 $4.4 2036

Mainland/ South

Transfer Masters Regional Stormwater Facility CUP offsets (SW1) 0.32 $3.0 2038

Build new WTP in South (GW5) 3.0 $56.8 2040

Chl

orid

e In

crea

ses

Mainland/ South

Implement Zero Liquid Discharge at CR 214 and South WTPs (WW2 and WW3)

not applicable $19.1 dependent on chloride concentrations


DRAFT

Figure 9-1Base Integrated Water Resources Plan

0 3 6

Miles1:384,661

")̈

")̈

")̈

")̈

")̈

")̈

!j

!j

!j

!j

!j

!j

!j

!j


Northeast

Northwest

Ponte Vedra System

South

SR16

D U V A LD U V A L


C L A YC L A Y



£¤1

£¤17

£¤17

£¤17

£¤1

£¤1

£¤1

¬«202¬«109

¬«5A

¬«16

¬«207

¬«100

¬«16

¬«20

¬«224

¬«13

¬«A1A

¬«202

¬«A1A

¬«21

¬«16¬«16

¬«100

¬«152

¬«19

¬«134

¬«115A

¬«9B

¬«9A

¬«A1A

¬«A1A

¬«206

¬«13

¬«3

§̈¦295

§̈¦95

§̈¦95

§̈¦95

WW1

GW1RW6

RW7

RW8

RW1

RW5

RW5

RW3

RW2

RW5


Legend


((WWTF

Reclaimed Water Options

(( Reuse SystemExpansion

(( Aquifer StorageRecovery

(( Stormwater ReuseSupplementation

((Stormwater ReuseSupplementation(Roadway)

((Water

Water System")̈ Water Treatment Plants!j

WW TreatmentFacilities

®For Informational Purposes Only Q:\(\\Gnvgisprojects)\19270_st_johns_co\086_IWRP\mxd\IWRP\9_1_IWRP_BasePlan.mxd SAN 11/21/2014

IW4

All Service AreasMaintain Existing Land Development Requirements(SAV1)

Cost Effective Conservation(SAV2 & SAV4)

Interconnect

DRAFT

Figure 9-2Additional Integrated Water Resources Options

0 3 6

Miles1:380,160


Northeast

Northwest

Ponte Vedra System

South

SR16

D U V A LD U V A L




£¤1

£¤1

£¤1

£¤1£¤17

£¤17

£¤17

¬«202¬«109

¬«5A

¬«16

¬«207

¬«100

¬«16

¬«20

¬«224

¬«13¬«21

¬«A1A

¬«312

¬«202

¬«A1A

¬«16¬«16

¬«100

¬«152

¬«19

¬«134

¬«115A

¬«9B

¬«9A

¬«A1A

¬«A1A

¬«206

¬«13

¬«3

§̈¦295

§̈¦95

§̈¦95

§̈¦95

WW2

WW3

GW1

GW3

GW5

SW1

SAV7

NorthwestWholesaleAgreement


Legend

(( Regional Partnerships


(( Concentrate Disposal

(( Stormwater Harvesting

(( Agricultural Conservation


®For Informational Purposes Only Q:\(\\Gnvgisprojects)\19270_st_johns_co\086_IWRP\mxd\IWRP\9_2_IWRP_AdditionalOptions.mxd SAN 11/21/2014

All Service Areas

Regional Partnerships -Lower Floridan (GW7)

Landuse Transition(GW6)

DRAFT

Figure 9-3 SJCUD Water Supply Portfolio by 2020

Figure 9-4 SJCUD Water Supply Portfolio by 2040


DRAFT

The base plan will meet the future water supply needs for the assumed medium-growth conditions and service area population distribution. As Section 8 discusses, additional options must be added to the based plan to make the strategy resilient to changes in growth, population distribution, climate, regulatory change, and funding sources. Table 9-1 includes the additional long-term (by 2030) water supply options that will provide SJCUD with additional supplies if needed to adapt to future water supply constraints and drivers. SJCUD should continue to be an active stakeholder in local and regional water supply issues and take the following actions to help implement the long-term options if needed in the future:

Develop framework for incorporating land use transitions into CUPs.

Explore groundwater offset credits.

Promote investigating ASR for reclaimed water storage in the Mainland and Northwest Service Areas.

Promote low-cost local options near Minimum Flows and Levels (MFL) lakes in Keystone Heights.

Continue to look for conservation partnerships with other legal users.

Monitor groundwater quality at CR 214 wellfield.

Evaluate long-term purchase agreement with JEA.

The need for additional water supplies is very sensitive to the growth in the South Service Area. The base plan options do not meet the long-term (after 2035) demands in the South Service Area. To hedge against this long uncertainty, continuing to interconnect from Northwest water supplies to serve new demands in the SR16, Mainland, and South Service Areas is recommended. This will provide SJCUD with more control over when a South WTP is constructed and provide additional operation flexibility if groundwater quality degrades at the CR 214 WTP.

Another key finding of the analysis is that using the St. Johns River or participating in a regional desalination project are not preferred strategies, but partnerships are required to avoid these alternatives.

Table 9-1 summarizes the life-cycle costs (in 2014 dollars) for the recommended plan. The base plan will satisfy the estimated demands over the planning horizon under medium-growth conditions and is estimated to cost $189 over the planning horizon. Additional options are required if population growth, climate variability, or raw water quality trends lead to increased demands from alternative water supply sources. The additional life-cycle cost to implement the base plan are estimated to be $99 million.


DRAFT

10 REFERENCES Jones Edmunds & Associates, Inc. 2011. SJCUD Main System Demand-Side Management Study.

Technical Memorandum. St. Johns County Utility Department. March 2011.

Jones Edmunds & Associates, Inc. 2011. Ponte Vedra Demand-Side Management. St. Johns County Utility Department. February 2011.

Jones Edmunds & Associates, Inc. 2010. St. Johns County Demand-Side Management. St. Johns County Utility Department. April 2010.

Mayer, Peter, and DeOreo, William B. (eds.). 1999. Residential End Uses of Water. U.S.A.: AWWA Research Foundation and American Water Works Association.

W:\19270\086019000\IWRP_Final_Report 2015-03-10.doc 10-1 March 2015 References

DRAFT

draft - st. johns county, florida...integrated water resources plan prepared for st. johns county...

Documents