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HomeMy WebLinkAbout; Lower San Luis Rey River Valley; Groundwater Storage and Recovery Feasibility Study; 2000-02-01San Diego County Wafer Autfiorify GROUNDWATER STORAGE AND RECOV LOWER SAN L RIVER VALLEY Final Draft —^ Prepared by: ASL Consulting Engineers rebruary 2000 San Diego County Water Authority Groundwater Storage and Recovery Project: Lower San Luis Rey River Valley Technical Report - Phase I Project Study Team San Diego County Water Authority Bob Yamada, P.E., Senior Civil Engineer - Project Manager Dan Diehr, Senior Water Resources Specialist - Project Engineer Ken Weinberg, Director of Water Resources F. Cesar Lopez Jr., Senior Water Resources Specialist ASL Consulting Engineers Howard Arnold, P.E., Project Manager Steve Tedesco, P.E., Vice President Robert Weber, P.E., Project Engineer Stephen Johnson, P.E., Vice President - Stetson Engineers Quang Nguyen, P.E., Project Engineer - Stetson Engineers David Gardner, R.G., C.H.G., C.E.G., Senior Vice President - Fugro West, Inc. Andrea Corrao, P.E., President - The Corrao Group Shannon Cobum, Project Engineer - The Corrao Group Nicole Frichette - The Recycling Group Lois Humphreys - The Recycling Group Project Advisory Committee Carlsbad Municipal Water District Robert Greaney, P.E. - General Manager William Plummer, P.E. - District Engineer City of Oceanside Water Utilities Department Greg Blakely - Project Manager Barry Martin - Acting Water Utilities Director Mike McGrath - Water Operations Supervisor ^ Rainbow Municipal Water District QO Mike Metts, P.E. - Acting District Engineer (Q ^ Eric Oltmann - General Manager \' February, 2000 ASL Consulting Engineers 10815 Rancho Bernardo Road Suite 200 San Diego, CA 92127 J\3B92\0005\(itledoc Table of Contents EXECUTIVE SUMMARY ES-1 CHAPTER 1 - INTRODUCTION 1.1 Authority Background 1-1 1.2 Project Background 1-2 1.3 Purpose ofFeasibility Study 1-2 1.4 Phase 1 Study Approach 1-2 1.5 Study Area 1-3 1.6 Data Compilation 1 -4 1.6.a Existing / Plarmed Projects 1-4 1.6.b Potential Sources for Recharge Water 1-5 1.6.C Storage Needs / Demands 1-6 1.6.d Data from Other Agencies 1-6 CHAPTER 2 - HYDROGEOLOGIC INFORMATION 2.1 Overview 2-1 2.2 Summary of Hydrogeologic Information 2-1 2.2.a Mission Basin 2-1 2.2. b Bonsall Basin 2-4 2.3 Recharge and Extraction Alternatives 2-6 2.3. a Basin Conjunctive Use (BCU) 2-5 2.3 .b Feasibility of Aquifer Storage and Recovery (ASR) 2-6 2.4 Adequacy of Existing Hydrogeologic Data 2-7 2.5 Existing Groundwater Models 2-8 2.5.a Mission Basin Model 2-8 2.5.b Bonsall Basin Model 2-9 2.5.C Other Models 2-9 2.5.d Applicability of Existing Models for Future Use 2-10 CHAPTER 3 - EXISTING AND PLANNED WATER SYSTEMS: SUPPLY, DEMAND, TREATMENT, AND STORAGE 3.1 Overview 3-1 3.2 City of Oceanside 3-3 3.2.1 Water Supply 3-3 3.2.2 Demand 3-3 3.2.3 Existing and Planned Treatment Facilities 3-5 3.2.4 Distribution System 3-5 3.2.5 Storage 3-6 3.2.6 Potential for Use of Groundwater Storage 3-6 SAN DIEGO COUNTT WATER AUTHORITT GroundwaterStora^e & Recovery Project ]:\3892\ooo5\Repori\toc.doc TOC-i Lowcr San Luis Rey River Valley Table of Contents (continued) 3.3 Carlsbad Municipal Water District 3-7 3.3.1 Water Supply 3-7 3.3.2 Demand 3-8 3.3.3 Treatment Facilities 3-10 3.3.4 Distribution System 3-10 3.3.5 Storage 3-10 3.3.6 Potential for Use of Groundwater Storage 3-11 3.4 Rainbow Municipal Water District 3-11 3.4.1 Water Supply 3-11 3.4.2 Demand 3-11 3.4.3 Treatment Facilities 3-13 3.4.4 Distribution System 3-13 3.4.5 Storage 3-13 3.4.6 Potential for Use of Groundwater Storage 3-13 CHAPTER 4 - PROJECT CONCEPTS 4.1 Overview and Background 4-1 4.2 Water System Requirements for Project Implementation 4-3 4.3 Groundwater Storage Issues and Limitations 4-3 4.4 Groundwater Storage and Recovery Operations 4-5 4.5 Treatment and Disinfection Issues 4-6 4.6 Recharge Water Availability 4-6 4.7 Concept Descriptions 4-7 4.7.a Mission Basin 1.63 MGD Desalter Project 4-8 4.7.b Mission Basin 6.70 MGD Desalter Project with Provisions to Supply Carlsbad MWD and Seasonal and/or Carry-over Storage Operations 4-10 4.7.C Mission Basin 6.70 MGD Desalter with Regional Use ofthe Weese Water Filtration Plant 4-15 4.7.d Bonsall Basin 3.60 MGD Desalter with Groundwater Storage and Recovery Operations 4-17 4.8 Higher Yield Project Alternatives 4-19 4.8.1 Introduction 4-19 4.8.2 Review of Hydrolgeologic and Environmental Issues Associated with Higher Yields 4-19 4.8.3 Mission Basin Higher Yield 4-21 4.8.4 Bonsall Basin Higher Yield 4-24 CHAPTER 5 - ENVIRONMENTAL AND REGULATORY ISSUES AND REQUIREMENTS 5.1 Overview of Applicable Regulations 5-1 5.2 Public Health Regulations 5-1 5.2.a Cahfomia Department of Health Services (DHS) 5-1 5.2.b -County of San Diego Department of Environmental Health (SDEHS) 5-3 SAN DIEGO COUNTT WATER AuTHORirr GroundwaterStorage & Recovery Project j:\3892\ooo5\Rcport\toc.doc TOC-ii Lower Sau Luis Rey RiveT Valley Table of Contents (continued) 5.3 Environmental Regulations 5-4 5.3.a USACOE 5-4 5.3.b USFWS 5-4 5.3.C DFG 5-5 5.3.d EPA 5-5 5.3.e RWQCB 5-5 5.3.f SWRCB 5-6 5.3. g Cahfomia Coastal Commission (CCC) 5-6 5.4 Local Regulations 5-7 5.4. a City of Oceanside Water Utilities Department 5-7 5.4.b City of Oceanside Parks and Recreation Department 5-7 5.4.c Rainbow Municipal Water District 5-7 5.4.d Local Engineering Department 5-7 5.4.e County of San Diego, Real Property Division 5-8 5.4.f County of San Diego Pubhc Works or Flood Control Division 5-8 5.4. g County of San Diego, Air Pollution Control District (APCD) 5-8 5.5 Regulatory/Environmental Issues and Permit Requirements Related to Recharge of Reclaimed Water 5-8 5.5. a Injection 5-9 5.5. b Surface Spreading of Reclaimed Water 5-11 5.6 Regulatory/Environmental Issues and Permit Requirements Related to Groundwater Extraction 5-13 5.6. a Riparian Vegetation 5-13 5.6.b Land Subsidence or Water-Logging 5-17 5.6.C Seawater Intrusion 5-17 5.6.d Environmentally-Significant Impacts on Surface Water Flows 5-18 5.7 Regulatory/Environmental Issues and Permit Requirements Related to Recharge of Imported Water 5-19 5.8 Regulatory Requirements Governing the Quality and Treatment of Potable Water Supplies 5-19 CHAPTER 6 - COST / BENEFIT ASSESSMENT 6.1 Project Costs 6-1 6.2 Discussion of Project Costs 6-14 6.3 Project Benefits 6-19 6.4 Cost/Benefit Comparison and Discussion 6-22 CHAPTER 7 - PHASE 2 HYDROGEOLOGIC FIELD INVESTIGATION PROGRAM 7.1 Overview 7-1 7.2 Approach 7-1 7.3 Program for Each Concept 7-3 7.3.a Mission Basin 1.63 Concept 7-4 7.3.b Mission Basin 6.70/iO.O MGD Concept 7-5 SAN DIEGO COUNTT WATERAUTHORirr GroundwaterStoraje & Recovery Project j:\3892\ooo5\Report\toc.doc TOC-iii Lowcr San Luis Rey River Valley Table of Contents (continued) 7.3.C Mission Basin 6.70/10.0 MGD Concept with Regional Use of City of Oceanside's Weese Filtration Plant 7-16 7.3.d Bonsall Basin 3.60/4.60 MGD Local Yield Project with GSR Operation 7-16 7.4 Phase 2 Cost Estimate 7-19 CHAPTER 8 - CONCLUSIONS AND RECOMMENDATIONS 8.1 Introduction 8-1 8.2 Findings and Conclusions 8-1 8.3 Recommendations 8-6 LIST OF TABLES 3-1 Monthly ADD - All Agencies 3-2 3-2 Departure from Average Monthly ADD - All Agencies 3-2 3-3 ADD and Storage - City of Oceanside 3-4 3-4 ADD and Storage - Carlsbad MWD 3-9 3- 5 ADD and Storage - Rainbow MWD 3-12 4- 1 Mission Basin 1.63 MGD Project Concept 4-9 4-2 Mission Basin 6.70 MGD Project Concept 4-12 4-3 Mission Basin 6.70 MGD - Weese Water 4-16 4- 4 Bonsall Basin 3.60 MGD Project Concept - Proposed Facilities 4-18 5- 1 Basin Plan Water Quality Objectives and San Luis Rey WWTP Reclaimed Water Quality 5-22 6- 1 Mission Basin 1.63 MGD Desalter 6-4 6-2 Mission Basin 6.70 MGD Desalter 6-5 6-2A Mission Basin 10.0 MGD Desalter 6-7 6-3 Mission Basin 6.70 MGD Desalter - Weese Filtration Plant 6-9 6-3 A Mission Basin 10.0 MGD Desalter - Weese Filtration Plant 6-11 6-4 Bonsall Basin 3.6 MGD Desalter 6-13 6-4A Bonsall Basin 4.6 MGD Desalter 6-14 6-5 Cost Summary 6-18 6- 6 Project Concept Benefit Summary 6-24 7- 1 Phase 2 Cost Estimate - General Task Item 7-19 7-2 Phase 2 Field Investigations - Project-Specific Tasks 7-19 LIST OF FIGURES 1- l Project Study Area 2- 1 Mission and Bonsall Basins Location Map 2-2 Cross Section 2-3 Mission and Bonsall Basins - Thickness of Alluvial Fill 2-4 Mission and Bonsall Basins - Total Dissolved Solids (Spring 83- Spring 84) 2-5 Mission and Bonsall Basins - Sulfate (Spring 83- Spring 84) 2-6 Injection Simulation No. 1 SAN DIEGO COUNTT WATERAuTHORrrr GroundwaterStorage & Recovery Project I:\3892\ooo5\Rcport\roc.doc TOC-iv I^wcr San Luis Rey RivcT Valley Table of Contents (continued) LIST OF FIGURES (CONTINUED) 2- 7 Injection Simulation No. 2 3- 1 Pressure Zone Boundaries 4- 1 Mission Basin 1.63 MGD Concept 4-2 Mission Basin 6.70 MGD Concept 4-3 Regional Use of Weese Filtration Plant Concept 4-4 Bonsall Basin 3.60 MGD Concept 4-5 Operational Schematic - Mission Basin 1.63 MGD 4-6 Operational Schematic - Mission Basin 6.73 MGD 4-7 Operational Schematic - Mission Basin 6.70 MGD 4-8 Operational Schematic - Mission Basin 6.70 Operation) 4-9 Operational Schematic - Bonsall Basin 3.60 MGD 4-10 Operational Schematic - Bonsall Basin 3.60 MGD 4-11 Operational Schematic - Bonsall Basin 3.60 Operation) Concept (Seasonal Operation) Concept (Seasonal Operation) Concept (Carryover Operation) MGD Concept (Replenishment Concept (Seasonal Operation) Concept (Carryover Operation) MGD Concept (Replenishment APPENDICES A Project Advisory Committee Meeting Minutes B Water Resources Data Compilation Database C La Jolla/Eocene Formation Information D Detailed List of Facilities E Project Cost Information DIEGO COUNTT WAITER AUTHORITT J :\3892\0005\Report\toc, doc TOC-v GroundwaterStorage & Recovery Project Lower San Luis Rey River Valley EXECUTIVE SUMMARY Lower San Luis Rey River Valley GROUNDWATER STORAGE AND RECOVERY FEASmiLITT STUDY: PHASE 1 1.0 PURPOSE OF STUDY This report summarizes the first phase of a planned three-phase study to evaluate the feasibility of Groundwater Storage and Recovery (GSR) projects in the Lower San Luis Rey River Valley in Northern San Diego County. The San Diego County Water Authority (Authority) is conducting this three-phase study as part of the 2030 Regional Water Facilities Master Plan. The purpose of Phase 1 is to evaluate the feasibility of storing surface-water supplies in the Mission and Bonsall Groundwater Basins for subsequent recovery and use. Conjunctive-use (i.e. groundwater storage and recovery projects) could enhance groundwater yields in the study area by providing artificial replenishment to the groundwater basins. The Authority is performing this study in conjunction with a similar effort in the southwest portion of its service area (San Diego Formation Aquifer Storage and Recovery Feasibility Study). Groundwater storage and recovery project alternatives may include, but are not limited to, the recharge, storage, and recovery of imported water, local-rainfall runoff, and/or recycled-municipal wastewater (reclaimed water). a. Study Approach The Phase 1 scope of work includes the following general work tasks; • Compilation of available water resources data and information regarding the study area; • Development of Geographical Information System (GlS)-based mapping and data for the study area; • Evaluation of hydrogeology and existing and planned groundwater use • Evaluation of existing water systems engineering constraints to the implementation of groundwater storage and recovery projects; • Conceptual design of alternative groundwater storage and recovery projects; • Preliminary evaluation of permitting and environmental issues related to groundwater storage and recovery project concepts; • Development of costs and benefits, and ranking criteria for groundwater storage and recovery project concepts; and • Development of recommended Phase 2 work activities; and Phase 1 is a "desktop" study, which is primarily based on existing data and information previously developed by others. The primary goal of Phase 1 was to develop candidate project concepts that warrant further study based on a preliminary estimate of costs and benefits. SANDIEGO COUNTY WATERAUTHORTTT ] :\3892\0005\Rcporc\c\ccsiim-doc ES-1 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Based upon the results of Phase 1 study and subsequent discussions with its member agencies, the Authority may elect to study selected project concepts fiirther during Phases 2 and 3 of the study. Phase 2 will likely include additional refinement of Phase 1 project concepts, discussions with regulatory agencies regarding the Phase 1 project concepts, field investigations to obtain additional hydrogeologic data, and further analysis of the technical and political feasibility of selected project concepts. Phase 2 field investigations could include subsurface explorations and groundwater modeling. The purpose of these activities would be to further evaluate specific assumptions regarding aquifer characteristics and behavior to enhance the study team's understanding of how groundwater storage and recovery projects might perform. Phase 3 would likely include additional engineering analysis to further refine project concept design, operational scenarios, and costs and benefits based on Phase 2 data. Existing hydrogeologic information about the groundwater recharge and extraction potential of the Mission and Bonsall Basins in the Lower San Luis Rey River Valley was reviewed by the study team. In addition, information regarding existing and planned local water systems was gathered from both the Authority and its member agencies. This information was subsequently used to identify potential project concepts and possible recharge and extraction sites. b. Study Area The study area is located in Northern San Diego County and within the Authority's service area. It includes the alluvial aquifers identified as the Mission and Bonsall Groundwater Basins and hydrologic units within Lower San Luis Rey River Valley (LSLRRV). The Mission Groundwater Basin (Mission Basin) lies almost entirely within the City of Oceanside. The Mission Basin extends upstream from the Pacific Ocean past the eastern boundary of City of Oceanside just west of the Bonsall Bridge (near the intersection of Highway 76 and SI3) (Figure 1). The Bonsall Groundwater Basin (Bonsall Basin) is located east of the Mission Basin generally within unincorporated areas of San Diego County. The Bonsall Basin extends to a point about one mile west of the intersection of Rice Canyon Road and Highway 76. Local retail water agencies, including Authority member agencies, that have an interest in the development of groundwater resources within these basins. Authority member agencies include Carlsbad Municipal Water District (CMWD), City of Oceanside, and Rainbow Municipal Water District (RMWD). Representatives of these agencies formed a Project Advisory Committee (PAC) for this project. The role of the PAC during the Phase 1 study was to review study findings and provide input to the study team on groundwater storage and recovery project alternatives. During the Phase 1 study, three meetings were held with the PAC. The initial PAC meeting was held on October 27, 1998. At the meeting, study plans were introduced, data gathering and some preliminary project concepts developed by the study team (Authority and consultant staff) were discussed. Following this initial meeting between the PAC members and the study team, individual meetings were held with each PAC member to further discuss the study SAN DIEGO COUNTY WATERAuTHORrrr J:\3892\0005\Report\cxecsum.doc ES-2 Groundwater Storage &" Recovery Project Lower San Luis Rey River Valley and data needs, and possible project concepts. The second PAC meeting was held on March 10, 1999 to introduce and discuss preliminary project concepts developed by the study team. Following this meeting, the study team refined the project concept operational scenarios, esfimated capital and operating costs, and developed a list of potential project benefits and institutional issues. These items were presented to the PAC at the third PAC meeting held on July 15, 1999. c. Previous Studies The Mission and Bonsall groundwater basins have been the subject of numerous water resources management studies and project studies conducted by local agencies, the Authority, and other federal and state agencies. Many of these studies date back nearly 40 years and were performed to examine the water resources associated with the basins or implement specific potable and reclaimed water transmission, supply or storage programs, or drainage and flood control projects. Others that have studied water resources within the basins include the U.S. Geological Survey (USGS), Califomia Department of Water Resources (DWR), Califomia State or Regional Water Quality Control Board (State or Regional Board), Califomia Department of Health Services (DHS), U.S. Army Corps of Engineers (COE), and the County of San Diego. 2.0 HYDROGEOLOGY Hydrogeology of the Mission and Bonsall Groundwater Basins has been described by various federal, state, regional, and local agencies. The study team has used resuhs from previous studies and investigations for its preliminary evaluation of the potential for groundwater storage and recovery in the study area. a. Description of the Mission Basin The Mission Basin is a shallow, alluvium- filled valley located at the western tenninus of the San Luis Rey River. The river alluvium extends about nine miles from the narrow canyon at the western, or downstream end (adjacent to the Pacific Ocean), to the Bonsall (bedrock) Narrows near the Bonsall Bridge at the upstream or eastem end. Due to the generally coarse- grain character of river alluvium, it will readily yield water to wells. The alluvium is unconsolidated and exceeds 200 feet in thickness in some places, (USGS, December 1985). The ground-surface elevation/ surface of the alluvium ranges from approximately 120- feet above mean sea level (amsl) at the east end of the Bonsall Basin (at Bonsall Narrows) to approximately 10-feet amsl in the canyon at the westem end of the basin. The maximum or "gross" groundwater storage capacity of the Mission Basin is estimated to be approximately 90,000 acre-feet. The usable storage of the Mission Basin is estimated to be roughly 30,000 acre-ft. Usable storage has been estimated based on records of historical low groundwater elevations, estimates of the total volume of alluvial materials, and the specific yield of those materials. According to USGS investigations, groundwater in the Mission Basin is generally unconfmed in the eastem part but generally semi-confined or confined in the westem part. However, the horizontal extent, depth, and thickness of the confining layers have not been well defined throughout the basin. SAN DIEGO COUNTY WATERAUTHORITT I:\3892\0005\Report\cxccsiim.doc ES-3 Groundwater Storage & Recovery Project L/Ower San Luis Rey River Valley Groundwater in the Mission Basin generally contains moderately high concentrafions of Total Dissolved Solids (TDS), Chloride, and Sulfate. Analytical results of water quality samples collected by the USGS in Spring 1983 indicate the TDS concentrations ranged from 1,220 to 1,540 milligrams per liter (mg/1), Chloride concentrations ranged from 320 to 630 mg/1, and Sulfate concentrations ranged from 150 to 360 mg/1 (USGS, December 1985). Analytical results of water quality samples collected from three pumping wells in 1991 and 1996 are consistent with these ranges (Oceanside, September 1991 and February 7, 1997(a)). The TDS, Chloride, and Sulfate concentrations have exceeded the recommended secondary standards for drinking water set by the State of Califomia (500 mg/1 for TDS and 250 mg/l for Chloride and Sulfate). High TDS concentrations in the westem portion of the Mission Basin are thought to be the result of seawater intmsion that was reported to have occurred as early as the mid-l940's following a period of low rainfall and extensive groundwater pumping. b. Description of the Bonsall Basin The Bonsall Basin is located northeast and immediately upstream of the Mission Basin. It is a relatively shallow and narrow alluvium-filled river basin underlain by crystalline bedrock. The Bonsall Basin alluvium extends from the Bonsall (bedrock) Narrows (Bonsall Bridge) to Monserate (bedrock) Narrows, located east of 1-15. The Bonsall Basin is approximately nine miles long with an average width of about one-half mile and a maximum width of approximately one- mile. Its thickness ranges from approximately 50 feet in the Bonsall Narrows area to 75 feet or more in the Monserate Narrows area (USGS, 1974). The ground surface elevation ranges from approximately 280-feet amsl in the Monserate Narrows area to approximately 120-feet amsl in the Bonsall Narrows area. The maximum or "gross" groundwater storage capacity of the Bonsall Basin is reported to range from approximately 18,000 acre-feet (USGS, 19745) to 40,000 acre-feet (SDCWA Groundwater Feasibility Study, September, 1995). The usable storage of the Bonsall Basin is estimated to be about 9,000 acre-ft. Usable storage has been estimated based on historical records of low groundwater elevations, an estimate of the volume of alluvial materials in the basin, and the specific yield of those materials. Groundwater in the Bonsall Basin has experienced similar water quality problems of the Mission Basin. Analytical results of water samples collected in Spring 1984 (Earthlnfo Inc., 1996) indicate the TDS concentrations ranged from 694 to 2,330 mg/1, Chloride concentrations ranged from 120 to 580 mg/1, and Sulfate concentrations ranged from 210 to 760 mg/L The best groundwater quality is found in the eastem portion of the basin. The poorest quality groundwater is found in the central part of the Bonsall Basin (USGS, December 1985). Analyfical results of water quality samples collected from two production wells in 1995 are consistent with these ranges (RMWD, January 1996). 3.0 ENVIRONMENTAL REGULATIONS Implementation of Groundwater Storage and Recovery project concepts in the Mission and Bonsall Basins will require careful consideration of SAN DIEGO CO UNTY WATER A UTHORUY ]:\3892\0005\Report\c>:ecsuni.d(x: ES-4 Groundwater Storage <& Recovery Project Lower San Luis Rey River Valley potential environmental issues and permitting requirements related to sensitive habitats and the use of reclaimed water. Projects could result in impacts to local wetland or riparian habitats. California and federal environmental laws require project impact analysis and someUmes mitigation to protect listed threatened and endangered species. The Califomia Department of Fish and Game (DFG) and the US Fish and Wildlife Service (USFWS) are the primary agencies responsible for the enforcement of laws that are intended to protect endangered and sensitive species and their habitats. The U.S Army Corps of Engineers (USACOE) is responsible for regulating activifies that may affect flood control. Aspects of a GSR program that these agencies might be interested in • reviewing include; • the constmction of facilities; • potential project impacts to surface water flow or quality; • potential project impacts to the salinity of the San Luis Rey River estuary; • potential project impacts on depths to groundwater; and • potential project impacts to terrestrial and aquatic habitats. An environmental impact report (EIR) will likely be required before implementation of groundwater projects in the Lower San Luis Rey River Valley. The EIR would detail potential impacts to environmentally sensitive areas. Implementation of groundwater project components may potentially impact wetlands, waters of the U.S. or critical habitat/species. If potential impacts to endangered species are identified, the regulatory agencies may require mitigation habitat to be developed and maintained as a condifion of project approval. Other agencies that may require permits/approvals include: • USEPA • California Regional Water Quality Control Board - San Diego Region Permit Requirements for the Protection of Human Health The California Department of Health Services (DHS) and the County of San Diego Environmental Health Services Department (SDEHS) regulate activities that could potentially impact the public health. These activities include water well constmcfion, use of reclaimed water, and drinking water treatment. In addition to the constmction of the recharge/extraction component of a groundwater project, appurtenant facilities include conveyance pipelines, electrical services, protective fencing, and treatment facilifies. Constmction management aspects are regulated by several local entities such as the City of Oceanside Engineering Department and County Department of Public Works and Real Property Division. Local Construction and Zoning Permit Requirements In addition to local ordinances, an applicable federal regulation is Govemment Code 53091, which states that building, and "zoning ordinances of a county or city shall not apply to the locafion or constmction of facilifies for the production, generation, storage, or transmission of water." Under this regulation, groundwater wells are typically exempt from local jurisdictional zoning and building permit requirements. This code, however, does not apply to the engineering permit requirements within a SAN DIEGO COUNTY WATERAuTHORmr ):\3892\0005\Rqxirt\execsiim.doc ES-5 Groundwater Storage Recovery Project Lower San Luis Rey River Valley local jurisdiction. Local engineering department permit requirements typically concem public right-of-way encroachments and connections to existing public facilities. 4.0 PROJECT CONCEPTS Groundwater Storage and Recovery project concepts developed in this Phase 1 feasibility study could provide a constant yield that will be sustained with artificial replenishment provided on a seasonal basis. The need for constant yield projects is driven by the andcipated need to demineralize stored groundwater upon extraction. It is assumed that water used to replenish either the Mission or Bonsall Basin will mix with poor quality groundwater currently stored in these basins and be degraded to the point that it will require demineralization. For both economic and operational reasons, it is assumed that the demineralization treatment facilifies will need to be operated constantly (as opposed to facilifies that could be available on a standby basis). It should be noted that proposed facilities referred to in this report are in addition to those currently required for the planned Oceanside's 6.37-MGD expansion of the Mission Basin Desalter. In addition, it is important to note that the use of Oceanside facilities has been assumed. Besides the existing Mission Basin Desalter facility site, those facilifies include existing wells, recharge sites, and conveyance facilities owned by the City of Oceanside, as well as some of the City's other planned facilities. As such, implementafion agreements with the City of Oceanside would be an integral component of any Groundwater Storage and Recovery Project in the Mission Basin. Project concepts have been sized based upon each basin's estimated usable storage potential, or in the case of concept 1, the amount of reclaimed- water recharge that is projected to be available. The project concepts developed by the study team are briefly identified as follows; 1. Mission Basin 1.63-MGD Desalter with seasonal recharge of reclaimed water, 2. Mission Basin 6.70-MGD Desalter with provisions to supply Carlsbad MWD, and facilities for groundwater storage and recovery of both reclaimed and discounted-imported water. 2A. Mission Basin 10.0-MGD Desalter with provisions to supply Carlsbad MWD, and facilities for groundwater storage and recovery of both reclaimed and discounted-imported water. 3. Mission Basin 6.70-MGD Desalter with facilities for groundwater storage and recovery of reclaimed and discounted-imported water, plus expansion and regional use of City of Oceanside's Weese Filtration Plant (WFP). 3A. Mission Basin 10.0-MGD Desalter with facilities for groundwater storage and recovery of reclaimed and discounted-imported water, plus expansion and regional use of City of Oceanside's Weese Filtrafion Plant (WFP). 4. Bonsall Basin 3.60-MGD Desalter with facilities for groundwater SAN DIEGO COUNTY WATERAUTHORUY J:\3892\0005\Report\cxecsum.doc ES-6 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley storage and recovery of discounted- imported water. 4A. Bonsall Basin 4.60-MGD Desalter with facilities for groundwater storage and recovery of discounted- imported water. 1. Mission Basin 1.63 MGD Desalter Project The project would supply an additional 1.63 MGD (1825 acre-ft/year) to the City of Oceanside. This concept would operate as a constant yield /seasonal storage project to supply a portion of the City of Oceanside's local demands in its 320-pressure zone. It is thought to be a feasible next step expansion in the City's groundwater program, if the City's reclaimed water facilifies are expanded. Project capacity is based upon the artificial recharge that could be provided by Title 22 reclaimed water from the City's San Luis Rey WWTP. 2/2A. Mission Basin 6,70/10.0 MGD Desalter proiect with provisions to supply Carlsbad MWD and Seasonal and/or Carryover Storage Operations The project would supply an additional 6.70 /lO.O MGD (7504 /11,200 acre- ft/year) of potable water to City of Oceanside, Carlsbad MWD, and other member agencies connected to the Authority's North County Distribution Pipeline. Project concept No. 2 is based on a continuous extraction and a three-year outage of imported-water replenishment, while Project Concept 2A is based on a two-year outage for imported water replenishment. This project concept(s) could provide a constant yield and use both carryover and seasonal storage groundwater. Oceanside would use the water to supply either its 320 or 511-pressure zones and Carlsbad MWD could supply either its 255 or 490- pressure zones. Other agencies that are connected to the NCDP at the Oceanside 6/VID 11/Rainbow 12 FCF could also receive Mission Basin groundwater through a new connection and pump station at that location. Artificial recharge could be provided by Title 22-reclaimed water from the City's San Luis Rey WWTP and unfiltered imported water from the Authority's Second Aqueduct. However, if the imported water recharge supply is curtailed, such as after an earthquake or during a prolonged drought, it is assumed that water in carryover storage in the Mission Basin could be extracted to maintain producfion of the groundwater demineralization facility. The extent to which the Basin can be drafted and how much storage in the basin can be utilized by the project are unknown. The availability of storage needs to be evaluated fiirther during subsequent field invesfigations and modeling studies and ultimately addressed by a groundwater management plan. However, for the purposes of this conceptual description, it is assumed that all usable storage in Basin could be extracted. It is assumed that groundwater in (carryover) storage could extracted and then replenished following restoration of imported water service. A seawater-intmsion barrier is also assumed in this concept since it is assumed that he Basin would be overdrafted during when replenishment water was unavailable. Advanced Tertiary reclaimed water from the San Luis Rey WWTP, a more reliable source of replenishment water, would be used for the seawater-intmsion barrier. When the SAN DIEGO COUNTY WATERAUTHORITT J:\3892\0005\Rci.iort\cxecsum.doc ES-7 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley basin is nearly fiill, the reclaimed water could be directed away from the seawater-intmsion barrier and into a recharge pond further inland. The reclaimed water for the seawater barrier could be injected at the Mission Basin narrows near Interstate 5. It is assumed nanofiltration would be performed on the reclaimed water before injection, although the need for this will be fiirther evaluated in subsequent phases of the study. 3/3A. Mission Basin 6.70/10,0 MGD Desalter with Regional use of the Weese Water Filtration Plant This project would supply an additional 6.70 /lO.O MGD (7504 /11,200 acre- ft/year) of potable water to City of Oceanside and Carlsbad MWD, and an equal amount of treated water to other Authority member agencies located south of the Weese Filtration Plant. This project concept proposes to expand Mission Basin groundwater producfion by either 6.70-MGD (Project Concept 3) or 10.0-MGD (Project Concept 3A) and construct a corresponding increment of addifional treatment capacity at the City of Oceanside's Weese Filtration Plant. The expanded Weese Plant capacity could be used by the Authority to serve member agencies south of the plant's locafion in Northern San Diego County. During periods when imported-water replenishment is not available, the basin could be overdrafted, as discussed under Concept No. 2, until such fime as the replenishment supply again becomes available. 4/4A. Bonsall Basin 3.60/4.60-MGD Desalter with Groundwater Storage and Recovery Operations This project could supply an addifional 3.60 /4.60 MGD (4032 /5152 acre-ft/year) of potable water to Rainbow MWD and offset filtered-water aqueduct deliveries. This project concept could supply a constant yield and use both the carryover and seasonal storage capacity of the Bonsall Basin. Project capacity of 3.40- MGD is based on a three-year extraction period without replenishment, and the 4.6-MGD is based upon a two-year extraction period without replenishment. Artificial recharge could be provided by imported water from the Authority's Second Aqueduct. However, if the imported-water recharge supply is curtailed, such as after an earthquake or during an extended drought, it is assumed that water in carryover storage in the Bonsall Basin would be ufilized to supply the District. The extent to which the Basin can be drafted is unknown and needs to be further evaluated during subsequent phases of the study. Available data indicates historic-low groundwater levels equate to a usable storage of approximately 9,000 acre-ft. As the case with the Mission Basin concepts, it is assumed this volume could be extracted from storage over either a two or three-year period, and then replenished over a corresponding period following restoration of imported-water service. 5.0 PROJECT COSTS AND BENEFITS Proiect Costs Proj ect costs were calculated and converted to unit costs in dollars per acre- ft of potable water a project could produce. The total unit costs consist of three primary elements; • Unit cost for amortized capital for facilifies constmcfion SAN DIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Report\i;xccsum.dcK-ES'8 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley • Unit cost for amorfized Operation & Maintenance costs • Unit cost for amortized recharge water costs These were organized into subcategories including Replenishment and Extraction Costs, Treatment Costs, Distribufion Costs, and Replenishment Water Costs for both seasonal/carryover and seasonal- only operations. Costs were calculated for the following operating scenarios; • Mission Basin 1.63-MGD desalter expansion project concept. This includes seasonal recharge with reclaimed water from the City of Oceanside's San Luis Rey WWTP over a six-month period every year and does not include carryover storage extraction or replenishment. • Mission Basin 6.70 /10.0-MGD desalter expansion project concepts. Both concepts include seasonal recharge with seasonally-discounted water over a six-month period every year and do not include carryover extraction or replenishment. • Mission Basin 6.70 /10.0-MGD desalter expansion project concepts. Replenishment could typically be performed on a seasonal basis (as in the previous concept), however; replenishment could be perfomied using long-term-storage imported water. During periods when the long- term-storage water is unavailable, the project would maintain production by extracting groundwater from carryover storage. • Mission Basin 6.70 /10.0-MGD desalter expansion with Regional use of WFP. These concepts would operate very similar to the concept described above in terms of the schedule for groundwater recharge and extraction. It has been assumed that the WFP would operate continuously without regard to the groundwater recharge schedule. • Bonsall Basin 3.60/ 4.60-MGD desalter project concepts. Again, replenishment could be performed on a seasonal basis, however; recharge would be performed using long-term- storage imported water. During periods when the long-term-storage water is unavailable, the project would maintain production by extracting groundwater from carryover storage. • Bonsall Basin 3.60 /4.60 MGD desalter project concepts with replenishment using seasonally- discounted imported water only. Unit costs for the various project concepts range from $715 to $l,283/acre-ft of potable water produced. It should be noted that for completeness these costs include distribution costs, which are typically not included in the evaluafion of new water supply alternatives. Without distribution costs, the unit costs to produce water range from $589 to $l,047/acre-ft. A cost summary for each project is shown in Table ES-1. SAN DIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Report\exccsiim.doc ES-9 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Table ES'l Cost Summary Mission Basin 1.63 MGD Desalter Mission Basin 6.70 MGD Desalter w/Provisions to Supply Carlsbad MWD Mission Basin 10.0 MGD Desalter w/Provisions to Supply Carlsbad MWD Mission Basin 6.70 MGD Desalter w/Regional use of Weese Filtration Plant Mission Basin 10.0 MGD Desalter w/Regional use of Weese Filtration Plant Bonsall Basin 3.60 MGD Desalter Bonsall Basin 4.60 MGD Desalter CATEGORY Unit Cost ($/acre-m Unit Cost (S/acre-ft) Unit Cost ($/acre-m Unit Cost t$/acre-ft^ Unit Cost f$/acre-ft) Unit Cost ($/acre-ft> Unit Cost (S/acre-ft> REPLENISHMENT AND EXTRACTION COSTS $141 $217 $162 $109 $81 $92 $88 TREA TMENT COSTS $277 $381 $319 $258 $227 $272 $273 DISTRIBUTION COSTS $95 $236 $213 $129 $120 $340 $319 REPLENISHMENT HEATER COSTS (Reclaimed (Mission Basin only) and ITS Discount Imported Water) (SEASONAL/CARRYOVER) $377 $392 $406 $419 S225 $279 REPLENISHMENT WATER COSTS (Reclaimed (Mission Basin only) and Seasonal Discount Imported Water) (SEASONAL ONLY) $202 $449 $476 $442 $455 $292 $343 TOTAL (Seasonal Only): S7/5 $1,047 $1,170 $938 $883 $995 $1,023 TOTAL (Seasonal Only): (w/o distribution costs) S620 $1,047 $957 $808 $763 S656 $704 TOTAL (Seasonal/Carryover): $1,211 $1,086 $902 $847 $928 $959 TOTAL (Seasonal/Carryover): (w/o distribution costs) $975 $873 $772 $727 $589 $640 SAN DIEGO COUNTY WATERAUTHORUY I:\3892\0005\Repon\exccsum.doc ES-10 Groundwater Storage Recovery Project Lower San Luis Rey River Valley Proiect Benefits Direct economic measurement of a regional storage benefit is difficult at best given the current level of understanding of how future costs may be allocated. It is apparent, however, that any measure of additional storage or treated-water capability is a benefit to the region given the fiiture uncertainty regarding reliability of imported water supplies and the region's projected growth. The Phase 1 study has not allocated costs for the project concepts, rather, has identified the total cost a given concept would incur to produce water. In general, the availability of local water supplies provides increased system-wide reliability and may allow deferral of future projects to expand treated-water delivery and local treatment capacity. The Phase 1 study has developed a benefit ranking and scoring procedure that was applied to each project concept. Benefits that have been identified considered by the Phase 1 study include; and • Additional increment of regional treated water supply • Increased supply reliability during a shortage • Beneficial use of reclaimed water • Increased capture of local mnoff • Basin management • Public acceptance • Regulatory, environmental and legal issues • Interagency agreement compatibility Each project concept was evaluated and ranked according to the above criteria and a corresponding ranking scale as discussed in Chapter 6 ofthe study report. The ranking system consists of assigning a numerical scope to each concept for each benefit/ranking criterion. A summary of project rankings is provided as Table ES-2. Table ES-2 Project Concept Benefit Summary Benefit 1 2 2A 3 3A 4 4A 1 Additional increment of regional treated supply 2 3 4 4 4 2 3 2 Increased supply rcUabihty during a shortage 4 3 2 4 4 3 2 3 Beneficial use of reclaimed water 2 2 2 2 2 1 1 4 Increased capture of rainfall runoff and San Luis Rey Bjver return flow 1 2 3 2 3 2 3 5 Basin management 2 3 4 3 4 3 4 6 Public acceptance 1 3 3 3 3 2 2 7 Regulatory^ environmental and legal issues 2 3 3 3 3 2 2 8 Interagency agreement compatibility 4 3 3 2 2 4 4 Totals 18 22 24 23 25 19 21 Project Concept SAN DIEGO COUNTY WATERAUTHORITT J:\3892\0005\Reporc\execsiim.doc ES-U Groundwater Storage & Recovery Project Lower San Luis Rey River Valley 6.0 ANALYSIS OF COSTS & BENEFITS All of the groundwater project concepts developed during the Phase 1 study offer benefits to the region. As mentioned previously, the cuirent understanding of the issues associated with project implementation does not allow for a direct economic comparison of how costs and benefits are realized. At this fime, the study team believes that a non-economic water management benefits framework is more appropriate to determine priorities for pursuing various projects. Each project concept provides for some measure of groundwater storage, and an opportunity to replenish the groundwater basins using discounted imported water or reclaimed water. In addifion, several project concepts have been configured to supply several member agencies. In the case of the project concepts that propose Authority construction and use of additional capacity at the Weese Filtration Plant, a substantial portion of the Authority's service area can be provided with an additional increment of treated water due to expanded groundwater producfion in the Mission Basin. The Phase 1 study's benefit ranking process gave Project Concept 3A - Mission Basin 10.0-MGD Desalter with Regional use ofthe Weese Water Filtrafion Plant the highest score (25). This project produces the most potable water and makes more potable water available to more agencies than any of the other concepts. It also had the second lowest total unit cost of producing water ($727/acre- ft for seasonal/carryover operation, and S763/acre-ft for seasonal-only operation). Project Concepts 2A (Mission Basin 10.0- MGD Desalter with provisions to supply Carlsbad MWD) and 3 (Mission Basin 6.70- MGD Desalter with Regional use of the Weese Water Filtration Plant) scored next highest each with scores of 24 and 23, respectively. Both projects make, treated water available to multiple agencies with total unit costs to produce water ranging from $772 per acre-ft (for seasonal/carryover operation of concept 3) to $957 per acre-ft (for seasonal-only operation of concept 2A). Both projects can continue to produce during an imported water shortage or emergency. Project Concept 2 (Mission Basin 6.70-MGD Desalter with provisions to supply Carlsbad MWD) scored next highest at 22. This project had a total unit cost of producing water of $975 per acre-ft for seasonal/carryover replenishment operation, and $ 1,047/acre-ft for seasonal-only replenishment operation. The project will supply 3.47-MGD to City of Oceanside and 3.23-MGD to Carlsbad and can confinue to produce during an imported water shortage or emergency. The project is also configured to alternatively supply 3.23-MGD to the NCDP agencies. Project Concept 4A (Bonsall Basin 4.60- MGD Desalter) scored next highest at 21. This project had a total unit cost of producing water of $640 per acre-ft for seasonal/carryover replenishment operation, and $704 per acre-ft for seasonal-only replenishment operation. The project will offset 4.60-MGD (5,152 acre-ft/year) of treated water aqueduct deliveries to Rainbow MWD and can continue to produce during an imported water shortage or emergency. Project Concept'4 (Bonsall Basin 3.60-MGD Desalter) scored next highest with a score of 19. Project Concept 1 (Mission Basin 1.63- MGD Desalter) rounded out the projects with a score of 18. These projects would supply one agency each with total unit costs to produce water ranging from $589/acre-ft (for SAN DIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Report\execsum.doc ES-12 (yroundwater Storage & Recovery Project Lower San Luis Rey River Valley seasonal/carryover replenishment operation of concept 4) to $656/acre-ft (for seasonal-only replenishment operation of concept 4). Both projects can confinue to produce during an imported water shortage or emergency. 7.0 CONCLUSIONS AND RECOMMENDATIONS Conclusions • There is potential for an estimated 39,000 acre-ft of storage to be developed in the Lower San Luis Rey River Valley (Mission and Bonsall Basins) if a groundwater replenishment program is implemented. • Groundwater storage and recovery projects in the Mission and Bonsall Basins provide the opportunity to purchase imported water at a discount. • Mission and Bonsall Basins can provide an additional increment of treated water within the Authority's service area. • If groundwater in the Lower San Luis Rey River Valley is replenished during the wet winter seasons and when seasonally- discounted or long-term-storage water is available, a porfion of the region's treated water demand can be supplied during peak-demand periods or during prolonged droughts and relief some ofthe burden on the region's imported water system and surface water resources. • Implementation of groundwater storage and recovery projects in the Mission and Bonsall Basins could also provide the opportunity to capture additional local mnoff in the basins and thereby reduce the need to purchase discounted imported water for artificial replenishment. The extent to which addifional local runoff could be captured by the Phase 1 project concepts has not been quantified. • With the modification of existing water supply systems and construction of additional pipelines and pump stations, it is possible to supply Mission Basin groundwater to City of Oceanside, Carlsbad MWD and several of the NCDP agencies (Vallecitos WD and Vista Irrigation District). • Expansion of Mission Basin groundwater production, coupled with a replenishment program, creates a potential for an in-lieu arrangement with the City of Oceanside. Such an agreement would allow the Authority to use of a portion of the Weese Filtration Plant to provide addifional treated water to the majority of the Authority's service area. • Additional groundwater production from the Bonsall Basin (used by Rainbow MWD) coupled with groundwater replenishment would offset aqueduct deliveries during periods of peak demands and extended droughts. • Direct economic measurement of a regional storage benefit is difficult at best given the current level of understanding of how future costs may be allocated among the Authority and its member agencies. However, it apparent that any measure of storage or additional local treated water capability is a benefit to the region given the future uncertainty regarding imported water supplies and the region's projected population growth. Recommendations It is recommended that the Authority proceed with Phase 2 of the Lower San Luis Rey River Valley Groundwater Storage and Recovery Feasibility Study. SAN DIEGO COUNTY WATERAUTHORTTT ]:\3892\0005\Report\cxccsuiii.iioc ES-13 (groundwater Storage & Recovery Project Lower San Luis Rey River Valley The study team recommends the following project concept priorities: 1. 2. MGD MGD Project Concept No.3A- 10.0 Mission Basin Desalter with 10.0 expansion to Weese WFP Project Concept No. 2A - 10.0 MGD Mission Basin Desalter 3. Project Concept No. 3 - 6.70 Mission Basin Desalter with 6.70 expansion to Weese WFP 4. Project Concept No. 2 Mission Basin Desalter MGD MGD 6.70 5. Project Concept No. 4A - 4.6 Bonsall Basin Desalter 6. Project Concept No 4 Bonsall Basin Desalter 7. Project Concept No. 1 Mission Basin Desalter MGD MGD - 3.60 MGD - 1.63 MGD Project concepts with higher yields are preferred over those with lower yields in light of the potential benefit to the region's water supply system. It is recommended that additional discussions be conducted with the City of Oceanside, Cadsbad MWD, and Rainbow MWD before developing a detailed scope of work for Phase 2. Phase 2 studies may include some additional project concept development as well as field invesfigafions. Field investigafions may include such activities as a water well survey, aquifer-performance tesfing, infiltration tests, groundwater and geochemical modeling, and geophysical surveys to further evaluate aquifer characterisfics and geology. The regulatory agencies identified in Chapter 5 should be contacted following further evaluation and screening of concepts idenfified in this study. Early consultation and planning with all the permitting agencies will be useful in idenfifying addifional study tasks and can ulfimately expedite the permit process. The detailed requirements and constraints identified during these initial consultafions can reduce the level of potential environmental impact of a given project by understanding what design elements need to be adjusted. SAN DIEGO COUNTY WATERAUTHORTTT J;\3892\0005\Report\cxecsum.doc ES-14 (jroundwater Storage &'Recovery Project Lower San Luis Rey River Valley REFERENCES; 1. USGS, December 1985. Evaluafion of the Mission, Santee, and Tijuana Hydrologic Subareas for Reclaimed-Water Use, San Diego County, Califomia; U.S. Geological Survey Water-Resources Investigations Report 85-4032. Prepared by John A. Izbicki. Sacramento, California. 2. City of Oceanside, September 1991. Draft Report on the Aquifer Performance Test. Prepared by NBS Lowry and Stetson Engineers Inc. Oceanside, Califomia. 3. City of Oceanside, February 7, 1997(a). Mission Basin Ground-Water Flow Model, Aquifer Performance Test Results for Model Calibrafion. Prepared by Stetson Engineers Inc. Oceanside, Califomia. 4. Earth Info., 1996. USGS Quality of Water, West 1 Ground. Boulder, Colorado. 5. USGS, October 1984. Hydrologic on Salt Balance Investigafions Using Digital Models, Lower San Luis Rey River Area, San Diego County, Califomia. Water Resources Invesfigafions 24-74. SAN DIEGO COUNTY WATERAUTHORITT Groundwater Storage & Recovery Project j:\3892\ooo5\Rcport\execsiim.doc ES-15 Lowcr San Luts Rey Rivcr Valley Chapter 1 - Introduction 1.1 Authority Background The Authority is a public agency, formed in 1944 under the County Water Authority Act. The Authority was established to import water and supplement exisfing local supplies the San Diego region. Its mission is to provide a safe and reliable water supply to its member agencies. The Authority currently has 24-member agencies. They include 6 cifies, 16 special districts, and the Pendleton Military Reservation. The County of San Diego is a non-voting, ex-officio member of the Authority. The member agencies include special water districts and municipal water departments. The agencies purchase both treated and untreated water from the Authority and distribute it to individual customers. The member agencies are considered Authority's customers. A 34-member Board of Directors governs the Authority. Each member agency is represented on the Authority Board of Directors. The General Manager and supporting Authority staff implement the policies approved by the Board of Directors and handle the day-to-day operations. The estimated population in San Diego County is 2.6 million people. Ninety-seven percent of the population lives within the Authority's service area. The Authority's service area lies within the foothills and coastal areas of the westerly third of San Diego County and encompasses approximately 907,000 acres. The Authority currently purchases all of its water from the Metropolitan Water District of Southern Califomia (MWD). MWD can provide the Authority a mix of water from Northem California^ via the State Water Project and the Colorado River via the Colorado River Aqueduct. However, the Authority's imported water supply is primarily obtained from the Colorado River. Depending upon local annual rainfall, imported water supplies about 70-90 percent of demand in the region. The remainder is obtained primarily from captured rainfall runoff, groundwater, and recycled municipal wastewater. The Authority has recently focused more attention on developing alternative or supplementary imported and local water supplies and storage. This in direct response to; increasing water demands, decreasing reliability of imported water, projected and real increases in costs of imported water, and a need for addifional storage. Local groundwater may be used to supplement existing imported water supplies and offset seasonal and peak-day water demands. A portion ofthe region's groundwater supply could also be reserved for prolonged droughts and emergencies if programs are implemented that would provide artificial replenishment and barriers to seawater intmsion in coastal groundwater basins. In addition, the development of replenishment programs within the region could provide an opportunity to purchase imported water at a discount cither through MWD's Seasonal Storage Service Program or from transfer supplies. A portions of the groundwater basins may also be replenished with recycled or reclaimed water usually available during periods of low water demand. SAN DIEGO COUNTY WATERAUTHORTTT Groundwater Storage & Recovery Project ]:\3892\ooo5\Report\chapti,doc 1-1 Lowcr San Luis Rey Rivcr Valley 1.2 Project Background The Authority's 1995 Emergency Water Storage Groundwater Feasibility Study identified an opportunity for development of the groundwater storage in the Mission Basin located in the Lower San Luis Rey River Valley. The 1996 San Diego Formation Task Force Report of Investigation identified a potential for the development of groundwater storage in the San Diego Formation, located near the San Diego Bay. In 1999, the Authority Board of Directors authorized a total budget of $2.64 million in the FY 1999-2000 Capital Improvement Project (CIP) to explore the hydrogeology and further evaluate the potential for groundwater storage and recovery projects in the San Diego Formafion and the Mission Basin. The Authority is conducting the two feasibility studies in coordination with the development of the Authority's 2030 Regional Water Facilities Master Plan. As part of the master planning effort, the Authority expects that future regional storage requirements will be better defined and groundwater storage potenfial better understood. 1.3 Purpose of the Feasibility Study The Authority is conducting a three-phase study in the Lower San Luis Rey River Valley to assess the feasibility of storing and recovering surface water supplies. The purpose of Phase 1 study is to review; existing local water supply systems, water supplies and demand, hydrogeologic informafion and information requirements; and to develop groundwater storage and recovery concepts that might be appropriate for the Lower San Luis Rey River Valley. It addition to conceptual design, Phase 1 tasks include a preliminary evaluation of costs and benefits for ahernative project concepts. Altemafive sources of recharge (groundwater replenishment) in the Lower San Luis Rey River Valley include discounted imported water, local rainfall mnoff, and excess recycled municipal wastewater. 1.4 Phase I Study Approach The Phase 1 scope of work includes the following general work tasks: • Compilation of available water resources data and information regarding the study area, • Development of Geographical Infomiation System (GlS)-based mapping and data for the study area, • Evaluation of study area hydrogeology and exisfing and planned groundwater use, • Evaluation of existing water systems engineering constraints to the implementation of groundwater storage and recovery projects, • Conceptual design of groundwater storage and recovery projects, • Evaluation of permitting and environmental issues regarding potenfial groundwater storage and recovery project concepts, SAN DIEGO COUNTY WATERAUTHORITT (Groundwater Storage & Recovery Project j:\3892\ooo5\Report\chapd.doc 1-2 Lowcr San Luis Rey River Valley • Development of costs and benefits and ranking criteria for groundwater storage and recovery project concepts, • Development of recommended Phase 2 work activities, and • Development of recommendations for potenfial public outreach activifies to be considered for Phase 2 work activities. Phase 1 is intended to be a "desktop" study. It is primarily based on existing information documented in numerous study reports. The goal of Phase 1 is to develop candidate project concepts that might warrant further study. Following the completion of the Phase 1 report, the Authority intends to conduct follow-up discussions with its member agencies and other interested agencies. After these discussions, the Authority will decide whether to conduct Phase 2 studies of selected project concepts. Phase 2 will likely include field investigations to obtain addifional data and informafion regarding both the technical and economical feasibility of selected project concepts. Phase 2 may include field explorations to test specific assumptions regarding aquifer performance and behavior. The addifional field explorations and office studies would be used to enhance the understanding of how groundwater storage and recovery projects might operate and perform. If conducted. Phase 3 would likely include additional engineering analysis to further refine project concept design, operational scenarios, and costs and benefits. 1.5 Study Area The Authority's feasibility study focuses on the alluvial deposits found within the Lower San Luis Rey River Valley. These alluvial deposits are commonly referred to as the Mission and Bonsall Groundwater Basins. The alluvium is the principal water-bearing unit in the Lower San Luis Hydrologic Area (HA). The Mission Groundwater Basin is located within the Mission Hydrologic Subarea (HSA 903.11) and the Bonsall Groundwater Basin is located within the Bonsall HSA (903.12). The Mission Basin lies almost entirely within the City of Oceanside. The basin extends upstream from the Pacific Ocean to just past the eastem boundary of City of Oceanside and west of the Bonsall Bridge. The Bonsall Bridge is located near the intersecfion of Highway 76 and S13 (Figure 1-1). The Bonsall groundwater basin is located east and upstream of the Mission Basin. It is generally located within unincorporated areas of San Diego County. The Bonsall Groundwater Basin extends eastward to a point about one mile west of the intersecfion of Rice Canyon Road and Highway 76 (Figure 1-1). Authority member agencies that have an interest in the development of groundwater resources within these basins include the City of Oceanside, Carisbad Municipal Water District (CMWD), and Rainbow Municipal Water District (RMWD). The agencies are represented on a Project Advisory Committee (PAC) formed for this project. The role ofthe PAC during the Phase 1 study was to review study findings and provide input to the study process. SAN DIEGO COUNTY WATER A UTHORITT Groundwater Storage & Recovery Project j:\3892\0005\Reporc\chapci.doc 1-3 Lowcr Sau Luts Rey Rivcr Valley Water District Boundaries Fallbrool< Public Utility District Rainbow MWD Vallecitos County WD Vista ID Valley Center MWD San Luis Rey MWD Carlsbad MWD Rincon Del Diablo MWD j Vista ID & Vallecitos County WD Rincon Del Diablo & Vallecitos County WD Pendleton Military Reservation City of Escondido Second Sar Diego Aqueduct City of Oceanside Unserved SDCWA Facilities Creeks Major Roads Freeways Lagoons Lakes Alluvial Aquifer First San Diego' Aqueduct Rey River (Cfty.^f/bceanslde) Deten^ Basin & Ppten^al Riparian abnat(Typ) proxirpatexocation dfCA/lWD Wells Pacific Ocean Buena Vist< Lagoon Aqua Hedionda Lagoon Water Filtration Plant (ftfty of Oceanside) Figure 1-1 Project Study Area 5 Miles During the Phase 1 study, three meetings were held with the PAC. The initial PAC meefing was held on October 27, 1998. At the meefing, the study team and the Phase 1 study were introduced. In addition, discussions regarding work tasks and preliminary project concepts were initiated. Following this initial meeting, individual meefings were conducted with each PAC member to collect and review available informafion and to discuss possible project concepts. The second PAC meefing was held on March 10, 1999 to introduce and discuss preliminary project concepts developed by the Phase 1 study team. Following this meeting, the study team refined the project concepts including operafional scenarios, estimated capital and operafing costs, and potenfial benefits and institufional issues. These items were presented and discussed with the PAC at a third meefing. Documentation of PAC meetings is contained in Appendix A. The Mission and Bonsall groundwater basins have been the subject of numerous water resources management studies conducted by local agencies, the Authority, and other federal and state agencies. Many of these studies date back nearly 40 years. They were performed to: evaluate water resources, implement specific potable and reclaimed water transmission, supply or storage programs, or develop drainage and flood control projects. Other governmental agencies have also studied water resources within the basins. Those agencies include the U.S. Geological Survey (USGS), California Department of Water Resources (DWR), Califomia State or Regional Water Quality Control Board (State or Regional Board), Califomia Department of Health Services (DHS), U.S. Army Corps of Engineers (COE), and the County of San Diego. /. 6 Data Compilation Exisfing water resources data and informafion was compiled as part ofthe first work task. Document information was entered into a database program and numbered for subsequent identification. The exisfing information used in the Phase 1 study is briefly summarized below. A complete copy of the database is provided in Appendix B. 1.6.a Existing / Planned Proiects Existing or planned groundwater projects within the Mission and Bonsall basins are generally those developed by the individual Authority/PAC members. A brief summary of known facilifies and programs is as follows: Project DcscriDHon Status Atiencv Document ID Former Carlsbad Mutual Water Company extraction wells Wells (6) loeated in the Mission Basin near the intersection of Mission Avenue and Foussat Street. Wells are unequipped and currently non-operational and may soon be abandoned. Reportedly were operational approximately 30 years ago CMWD 3,35 SAN DIEGO COUNTY WATERAUTHORITT J :\3 892\0005\Rcport\chapr 1 ,doc 1-4 (groundwater Storage Recovery Project Lower San Ltiis Rey River Valley Proiect Descrintion Status Aaencv Document ID Mission Basin Desalting Facility R.O. Plant and associated wells (5) located on Fireside Drive north of Mission Avenue. Currently operating at 2 MGD, with expansion lo 6.37 MGD under final design. Ultimate 20 MGD capacity being considered by the City. City of Oceanside 2, 8, 47, 53 Mission Basin AB 3030 Plan Develop and implement an AB 3030 groundwater management plan for the Mission Basin Under consideration by the City. City of Oceanside 2,8 Bonsall Basin Desalter R.O. Plant and associated pumping wells Phase I and 11 evaluation feasibility studies have been performed completed. The District is reportedly considering a 2.68 MGD.68- MGD project. RMWD 9. 10, 11,52, 61, 70 The information contained within the above referenced water resources documents was deemed adequate for the purposes of the Phase 1 study. For the Mission Basin, design reports and documents for City of Oceanside projects were available for the study team's use. For potential projects within the Bonsall Basin, informafion was less developed and assumptions had to be made regarding the proposed facilities in order to develop storage concepts. 1.6.b Potential Sources for Recharge Water The following potenfial sources of water for Mission and Bonsall basin replenishment were identified during data review acfivifies and discussions with PAC members. Source Busin Flow fMGD) Oiialitv Document ID Reclaimed Water from San Luis Rey WWTP Mission Improvements currently under design, (approx. 3-4 MGD could be available during winter months) Tertiary Treatment at SLR WWTP. Consistency with Basin Plan TDS goals may limit feasibility. 2, 14, 18 Reclaimed Water from CMWD Mission T.B.D. Tertiary Treatment at Mcadowlark or Encina WWTPs. See Note 1 Seasonal Imported Water from Second Aqueduct Mission T.B.D. (approx. 5 to 10 MGD possible based on capacity) Unllltered imported water. 2,8, 47,53 Seasonal Imported Water from Second Aqueduct Bonsall T.B.D. Unfiltered imported water. N/A Notes: 1. Per discussions with CMWD N/A = Not Available SAN DIEGO COUNTY WATERAUTHORTTT ] :\3892\0005\Rcix)rtVhapr] .doc 1-5 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley In general, the above data was sufficient for the development and preliminary evaluation of storage concepts. However, assumpfions had to be made concerning the quality of reclaimed water from the City of Oceanside's planned San Luis Rey WWTP. The City of Oceanside anticipates that potential nitrate levels in reclaimed water may limit the feasibility of direct injecfion of reclaimed water (based on DHS guidehnes) without some advanced level of treatment. This is discussed in subsequent chapters of this report. 1.6.C Storage Needs/Demands Existing and projected demand and storage requirements were determined using water master plans available from the PAC members. The information was used to determine what demands could be met by potenfial Groundwater Storage and Recovery (GSR) programs within the Mission and Bonsall basins. The research presents a general summary of demands with operational and emergency storage requirements and available storage volumes for existing and projected ultimate conditions. Data is organized by individual pressure zones for each agency system and can be found in the corresponding Master Plans. Monthly demand data (Chapter 3) was used to assess how GSR programs may be able to meet increases in demand during the dry summer months. The informafion enabled idenfificafion of potential opportunities for seasonal or carryover storage that could be met by GSR programs. 1.6.d Data from Other Agencies As noted earlier, the Mission and Bonsall basins have also been studied by various Federal, State, and regional agencies. These agencies include USGS, DWR, DHS, State and Regional Boards, and the County of San Diego. Available hydrologic and hydrogeologic information was obtained from: the San Diego Region Water Quality Control Plan (Basin Plan), hydrologic maps and studies prepared by USGS and DWR, and well infonnation available from the State DWR and a USGS well database. Information in the USGS database included water level and quality data for the Mission and Bonsall basins from the period of 1930 to 1980. A majority of this information is contained within the USGS and DWR reports (Document ID's 30, 31, 32, 33, 62) and those prepared as part of the City of Oceanside's projects (Document ID'S 1, 5, 51, 52). The existing hydrologic and hydrogeologic information as listed herein is further evaluated and summarized in Chapter 2. SAN DIEGO COUNTY WATER A UTHORTTT Groundwater Storage & Recovery Project I:\3892\ooo5\Rcport\chaprLdoc 1-6 Lowcr San Luis Rey River Valley Chapter 2 - Hydrogeologic Information 2.1 Overview The purpose of this chapter is to report the currently available information regarding the Mission and Bonsall Groundwater Basins located in the Lower San Luis Rey River Valley (Mission and Bonsall HSAs). Infomiation reported in this chapter includes descriptions of geology, aquifer characteristics, groundwater quality, groundwater use and basin-storage capacity, descripfions of exisfing groundwater models, the feasibility of storage and recovery methods, and an evaluation of the adequacy of information for development ofthe project concepts. Available infonnafion is used to help identify potentially suitable groundwater recharge and extraction methods and potential facility locations. The information is also used to identify "fatal flaws" and data or informafion gaps that may need to be addressed in subsequent phases of this project to better determine project feasibility. This chapter contains a summary of hydrogeologic information pertinent to the study of groundwater storage and recovery projects also referred to as "aquifer storage and recovery" or "conjunctive-use" projects. 2.2 Summary of Hydrogeologic Information The Lower San Luis Rey River Valley includes the Mission and Bonsall Groundwater Basins. These groundwater basins have been studied or investigated by various Federal, State, regional, and local agencies for over 50 years as documented in Chapter 1. Some ofthe more important findings of these studies are summarized below. 2.2.a Mission Basin Geohsv and Hydrogeolosv: The Mission Basin is a shallow, alluvium- filled basin located in the lower portion of the San Luis Rey River Valley. The basin extends approximately nine miles from a narrow canyon adjacent to the Pacific Ocean to the Bonsall Narrows, as shown on Figure 2-1. The Mission Basin is approximately one to two miles wide. The thickness of alluvium exceeds 200 feet in some places, as shown in the cross section on Figure 2-2 (U.S. Geological Survey (USGS), December 1985). The ground surface elevation in the basin ranges from approximately 120 feet above mean sea level (msl) at the Bonsall Narrows to approximately 10 feet above msl at the narrow canyon near the Pacific Ocean. The Mission Basin alluvium is bounded mostly by marine sedimentary deposits of Tertiary age including the San Onofre Breccia and the La Jolla Group. These deposits consist primarily of cemented sand, sandy shale, and SAN DIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Report\chapt2.doc 2-1 GrouTuiwater Storage & Recovery Project Lower San Luis Rey River Valley RGURE2-1 LEGEND GROUNDWATER BASIN BOUNDARY STREAM CHANNEL APPROXIMATE UNCONFINED-CONFINED BOUNDARY •o3co2 PRODUCTION WELL APPROXIMATE SCALE r = 6.000' O:\J0eS\l78AneURE 2_1.DWC O:\J0eS\1 78AFK;URE 2_1.PC2 >>> 3ICM EASr OARVtY AVENUE *EST COVINA. CAUFORHIA 91791 TEb (828) 987-8202 FAX: («2«) S31-706S 2171 E Franeteeo Blvd., SuH* K Son Rofofl C<riHomla 94*01 STETSON 2851 W Ouadalup* Rd., Sutt* A209 pyrail^prqg^ U«M Arizona BS202 SAN DIEGO COUNTY WATER AUTHORITY MISSION AND BONSALL BASINS LOCATION MAP shale. These deposits are saline and of low permeability and not considered to be good aquifer material. The younger alluvium and river-channel deposits consist of clay, silt, sand, and gravel. In the east, alluvial fill is less than 1,000 feet wide and 100 feet thick. In the west, where the San Luis Rey River enters a narrow canyon before discharging to the Pacific Ocean, the alluvial fill again narrows to less than 1,000 feet but retains its thickness of more than 200 feet (USGS, December 1985). Near the middle of the basin, the basal part of the aquifer consists of coarse, clean sand and gravel. Overlying this very permeable zone is a thick sequence of fine sand, silt, and clay that locally confines the groundwater in the underlying aquifer (USGS, October 1974). According to the USGS, groundwater is unconfined in the eastem part of the Mission Basin but may be confined in the westem part (USGS, December 1985). To verify this conclusion, available drillers well logs and results from Aquifer Performance Tests (APTs) were reviewed. Based on available drillers' logs (DWR, May 1971), it appears that the approximate unconfined-confined boundary in the east of the Mission Basin is located between Douglas Drive and College Boulevard. In the west, the unconfined-confined boundary is esfimated to be located approximately one mile upstream of the narrow canyon at Interstate 5 as shown on Figure 2-1. A geologic cross-section of the Mission Basin along the San Luis Rey River from Guajome Lake to Interstate 5 is shown on Figure 2-2. Also presented on Figure 2-1 is a geologic cross section ofthe Mission Basin prepared from limited available well driller's logs and USGS maps. The cross section consistently shows the unconfined sand-gravel formation about 100 feet below ground surface. In addifion, the confining clay formations can be seen between approximately Douglas Drive westerly to about the Highway 76 By-Pass. Aquifer Characteristics and Storage Capacity: . The aquifer transmissivity has been esfimated by the U.S.G.S to be from 50,000 to 300,000 gallons per day per foot (gpd/ft). Hydraulic conductivity was estimated to range from 500 to 2,000 gallons per day per square foot (gpd/ft^) Coefficient of storage was esfimated to range from 0.12 to 0.16 (USGS, October 1974). Results from aquifer performance tests (APTs) conducted by the City of Oceanside in August 1991 and October 1996 indicate the aquifer west of Douglas Drive is semi-confined with a transmissivity ranging from 60,000 to 140,000 gpd/ft, hydraulic conductivity ranging from 1,500 to 2,300 gpd/ft^, and coefficient of storage ranging from 0.0005 to 0.001. The aquifer in the vicinity of the City of Oceanside's Well No. 4, i.e., east of Douglas Drive, acts as an unconfined aquifer with a transmissivity of 374,000 gpd/ft, a hydraulic conducfivity of 3,400 gpd/ft , and a coefficient of storage of 0.28 (Oceanside, September 1991 and February 7, 1997(a)). SAN DIEGO COUNTY WATERAUTHORTTT Groundwater Storage & Recovery Project j:\3892\0005\RcportVhapt2.doc 2-2 Lowcr San Luis Rey River Valley FIGURE 2-2 16000 ISOOO 20000 22000 DISTANCE (FEET) LEGEND 24000 36000 Joe BOULDERS SILT BED ROCK •J CLAY SEE FIGURE 2-1 FOR LOCATION OF CROSS SECTION A-A' SAND PERFORATIONS STETSON ENGINEERS INC. 3104 EAST GARVEY AVENUE WEST COVINA, CAUFORNIA 91791 TEL: (626) 967-6202 FAX: [626) 331-7065 2171 E Francisco Slvd.. Suite K Son Rafael California 94901 2651 W Guadalupe Rd., Suite A209 Mesa Arizona B5202 SAN DIEGO COUNTY WATER AUTHORITY CROSS SECTION A-A' Di\J0BS\t7t7\ei0Ultt l-i.01K Dl\JOBSM7SAFI0'JRE 2-2.K2 These field tests, performed by the City of Oceanside, tend to confirm the prior esfimate of aquifer characteristics by the USGS. However, it is noted that some fairly significant variations were found in the field testing. This suggests potential significant variations in aquifer characteristics and supports the need for addifional field investigation. In Spring 1983, the groundwater elevations ranged from approximately 100 feet above msl in the Bonsall Narrows area to approximately 10 feet above msl in the narrow canyon, as shown Figure 2-3. As a result, the average hydraulic gradient in Spring 1983 was approximately 0.2 percent (USGS, December 1985). The maximum groundwater storage ofthe Mission Basin is estimated at approximately 92,000 acre-feet. The safe yield of the Mission basin was estimated at approximately 7,500 acre-feet per year (acre-ft/yr) (Stetson Engineers Inc. (SEI), September 1996). This esfimate was based upon available USGS derived aquifer characterisfics and historic groundwater production records. Water Quality: Groundwater in the Mission Basin has experienced water quality problems, especially Total Dissolved Solids (TDS), Chloride, and Sulfate. Analytical results of water quality samples collected in Spring 1983 indicate the concentrafions ranged from 1,220 to 1,540 milligrams per liter (mg/l) for TDS, from 320 to 630 mg/1 for Chloride, and from 150 to 360 mg/l for Sulfate, as shown on Figures 2-4 and 2-5 (USGS, December 1985). Analyfical results of water quality samples collected from three pumping wells during the APTs in 1991 and 1996 are consistent with these ranges (Oceanside, September 1991 and Febmary 7, 1997(a)). The TDS, Chloride, and Sulfate concentrations have exceeded the recommended secondary standards for drinking water set by the State of Califomia (500 mg/l for TDS and 250 mg/l for Chloride and Sulfate). Seawater intrusion was observed in the westem part of the Mission Basin as early as the mid-1940's. Based upon the data available, the groundwater in the Mission Basin should be considered high to very highly mineralized. Use of Mission Basin groundwater will likely require demineralization treatment. Groundwater Use: Groundwater from the Mission Basin has been used primarily for irrigafion and for water supply to the cities of Oceanside and Carlsbad; however, historic groundwater production data for irrigation is not available. Between 1940 and 1962, groundwater producfion by the City of Oceanside ranged from approximately 978 to 2,886 acre-ft/yr. It reduced drasfically to an average of approximately 90 acre-ft/yr since 1963 and from 1974 to 1993 all municipal producfion stopped (Oceanside, August 1991). In 1993, groundwater production by the City of Oceanside resumed at an average rate of approximately 2,800 acre-ft/yr with the constmction of the San Luis Rey Desalfing Facility. The City of Oceanside is planning to increase groundwater producfion by the year 2001 to about 8,800 acre-ft/yr, SAN DIEGO COUNTY WATERAUTHORTTT Groundwater Storage & Recovery Project ]:\3892\ooo5\Rcport\chapt2.doc 2-3 Lowcr Sau Luis Rey River Valley FIGURE 2-4 14.50 A2 1180 LEGEND GROUNDWATER BASIN BOUNDARY STREAM CHANNEL WELL NUMBER / TOTAL DISSOLVED SOLIDS CONCENTRATION IN MILUGRAMS PER LITER BASED ON ANALYSIS WELL NUMBER / TOTAL DISSOLVED SOLTOS CONCENTRATION IN MILUGRAMS PER LITER ESTIMATED FROM SPECIFIC CONDUCTANCE APPROXIMATE SCALE r = 6000' D:\J0BS\l7BAnCURE 2-4.DWC 0!\J0eS\1'8AnCLIRE 2-4.PC2 !S!l/'''^:^d All' tt^;i^ J 3104 EASr OAltVCY AVENUE ftST COVIHA. CttjroRWA 917B1 TEU {626) M7-W02 FAX: {«e> S31-70B 2171 E FranoiMO BM., SuH* K San ffafofl Celtfomtq 94901 STETSON 28»1 W Ouadalup* M.. SutI* A20* SAN DIEGO COUNTY WATER AUTHORITY MISSION AND BONSALL BASINS TOTAL DISSOLVED SOLIDS (SPRING 83-SPRING 84) including an expansion to their exisfing desalting facility (Oceanside, June 1998). Field surveys were conducted in the Mission Basin as part of the Authority's 1995 Emergency Storage Project Groundwater Feasibility Study. The surveys were conducted to "verity and update previous published information pertaining to the local geology, locate active groundwater wells, estimated local groundwater use, and identify current land uses within the basin. Topographic maps and aerial photos were analyzed and several published reports were consulted to assist the field surveys. In addition, interviews with local residents and workers were conducted in order to more accurately assess current amounts and types of groundwater use." Appendix contains the results of the well survey conducted as part of the Authority's 1995 study. The survey idenfified twenty-seven (27) operafing wells in the basin. Locafions of all observed active wells (1995) are presented on Figure (4-7 from 1995 report). According to the Authority's 1995 report, early in the 20'*^ century, groundwater in the Mission Basin had a TDS content of less then 500 mg/l. The basin was the sole source of water for agriculture as well as providing water to the City of Oceanside. Continued farming and livestock activifies resulted in groundwater quality declining to the point where the City of Oceanside abandoned its well field and for a fime was 100 percent dependent upon imported water to supply its needs. Currently, the City of Oceanside extracts and treats brackish groundwater for potable use. As of 1995, some local farms and the San Luis Rey Mission confinued to use groundwater. Available informafion indicates that between 1915 and 1963, groundwater production from the Mission Basin by the City of Carlsbad ranged from 125 to 3,737 acre-ft/yr (Dibble, February 1964). After 1963, the City of Carlsbad ceased groundwater producfion from the Mission Basin. Currently, total groundwater producfion (municipal and irrigation) from the Mission Basin is estimated at approximately 7,000 acre-ft/yr (SDCWA, September 1995). 2.2.b Bonsall Basin Geolosv and Hydrogeolosy: The Bonsall Basin is located upstream of the Mission Basin. It is a shallow, narrow, alluvium-filled valley along the San Luis Rey River extending from the Bonsall Narrows to Monserate Narrows, as shown on Figure 2-1. The Bonsall Basin is approximately nine miles long with a maximum width of about one mile. The thickness ofthe alluvial fill ranges from approximately 50 feet in the Bonsall Narrows area to 75 feet or more in the Monserate Narrows area, as shown on Figure 2-3 (USGS, 1985). The ground surface elevation ranges from approximately 280 feet above msl in the Monserate Narrows area to approximately 120 feet above msl in the Bonsall Narrows area. SAN DIEGO COUNTY WATERAZTTHORTTT (rroundwater Storage & Recovery Project j:\38y2\ooo5\Reporc\chapt2.doc 2-4 Lowcr San Luis Rey River Valley The alluvial aquifer in the Bonsall Basin is primarily well-sorted fine sand with small amounts of silt and clay. It is bounded and underlain by colluvium and weathered crystalline rocks in some areas. The coUuvium and weathered crystalline rocks are water bearing and contribute additional groundwater storage capacity to the system (USGS, 1985). Aquifer Characteristics and Storage Capacity: The maximum groundwater storage of the Bonsall Basin is estimated at approximately 18,000 acre-feet (USGS, 1985). Groundwater in the Bonsall Basin is reported to be unconfined by the USGS. The aquifer characterisfics were estimated from 1,000 to 2,000 gpd/ft^ for hydraulic conductivity, and from 0.12 to 0.16 for coefficient of storage (USGS, October 1974). In November 1983, the groundwater elevations ranged from approximately 280 feet above msl in the Monserate Narrows area to approximately 120 feet above msl in the Bonsall Narrows area, as shown. As a result, the average hydraulic gradient in November 1983 was approximately 0.3 percent (USGS, 1985). The safe yield of the Bonsall Basin was esfimated at approximately 2,800 acre-fVyr (Rainbow Municipal Water District (RMWD), January 1996). No APTs have been reported in the Bonsall Basin. At this time, very litfie recent or qualitafive data is available on the Bonsall Basin. Any new groundwater programs should include a field investigation program for the Bonsall Basin during Phase 2. Water Quality: Groundwater in the Bonsall Basin has experienced similar water quality problems of the Mission Basin. Analytical results of water quality samples collected in the Spring of 1984 (Earthlnfo Inc., 1996) indicate the concentrations ranged from 694 to 2,330 mg/l for TDS, from 120 to 580 mg/l for Chloride, and from 210 to 760 mg/l for Sulfate, as shown on Figures 2-4 and 2-5. Groundwater with lowest concentrations was found in the eastem part, while groundwater with highest concentrations was found in the central part of the Bonsall Basin (USGS, December 1985). Analytical results of water quality samples collected from two production wells in 1995 are consistent with these ranges (RMWD, January 1996). Based on these results, it may be concluded that any new groundwater programs should include demineralization prior to use. Groundwater Use: Groundwater from the Bonsall Basin was used primarily for irrigation of citrus and avocado groves in the Fallbrook area prior to the availability of imported water to Fallbrook in 1948. Local truck farms, citrus groves, and golf courses are currently the main users of groundwater in the Bonsall Basin. Historic groundwater production from the Bonsall Basin is not available. Groundwater well surveys were conducted in the Bonsall Basin during the Emergency Storage Project Groundwater Feasibility Study (SDCWA, 1995). The survey identified seventy-eight (78) wells in the basin. Currently, total groundwater production (municipal and irrigafion) SAN DIEGO COUNTY WATERAUTHORITT (^oundwater Storage & Recovery Project j:\3S92\ooo5\Report\diapt2.doc 2-5 Lowcr San Luts Rey River Valley RGURE2-5 El 400 LEGEND GROUNDWATER BASIN BOUNDARY STREAM CHANNEL WELL NUMBER / SULFATE CONCENTRATION IN MILUGRAMS PER LITER APPROXIMATE SCALE r = 6000' 9104 UST OAKVCr AVENUE WEST COVIHA, CAUFORMA 91TS1 TEL <S2S) 967-0202 fAXs (S2«) U1-T06S 2171 E Fran«l*«o Blvd., Sulta K Sqn RatiNl CoDfomki 94901 STETSON 3SS1 W Ouadalup* ltd., SuS* A309 SAN DIEGO COUNTY WATER AUTHORITY MISSION AND BONSALL BASINS SULFATE (SPRING 83-SPRING 84) O:\J0BS\t78AnCURE 2-S.DWO D:\JOBSV178AnCURE 2-S.PC2 FIGURE 2^ LEGEND GROUND-WATER BASIN BOUNDARY STREAM CHANNEL UNE OF EQUAL TfflCKNESS ,25 THICKNESS IN FEET BELOW GROUND SURFACE DASHED WHERE APPROXIMATE DATA SOURCE : U.S. GEOLOGICAL SURVEY WATER-RESOURCES INVESnGATIONS REPORT 85-4032 APPROXIMATE SCALE r = 6000' 0;\J(3eS\na7\T¥iWZ 2-3.DWC 0i\JOB3\178AnG«BE 2-3.PC2 3104 EAST OARVCr AVIKUE tItSt COVIHA, CAUFOttHIA 91781 TEL: <628) 9S7-8202 FAX: (62«> 331-7065 2t7| E FroneiMO Btvd., Sufl* K Son Rafo*! Cofflomta 04901 STETSON 3SSl W Ouatfalup* M., Suit* A2(I9 SAN DIEGO COUNTY WATER AUTHORITY MISSION AND BONSALL BASINS THICKNESS OF ALLUVIAL FILL ft-om the Bonsall Basin is estimated at approximately 2,500 acre-ft/yr (SDCWA, September 1995). 2.3 Recharge and Extraction Alternatives 23.3. Basin Conjunctive Use ("BCU) The term "basin conjunctive use" refers to a broad concept involving percolafion and/or injection of surface water (storm runoff, stream flow, imported water, recycled water) into a groundwater basin during periods of abundant supply to preserve and enhance the quantity and quality of the groundwater basin for beneficial uses, especially during periods of high demands. More specifically, conjuncfive use is "the planned use of surface and groundwater to improve the reliability of a region's total water resource. Conjunctive use can include the use of reclaimed water and imported water for artificial groundwater recharge and water banking. Water banking has tradifionally referred to the water that is stored in groundwater basins, normally during wet years, for future use during droughts and/or emergencies. Conjunctive use relies on the principle that by using surface water when it is plenfiful, recharging aquifers and conserving groundwater supplies in wet years, water will then be available for future pumping in dry years when surface supplies may be short. A BCU project or series of projects may include a combination of recharge projects, recharge and recovery projects, and groundwater protection projects. Several important factors were considered in developing BCU concepts for this study. The most important factor is the characteristics of the groundwater basin such as geology, hydrology, hydrogeology, and water quality conditions. These characteristics help determine what BCU projects may be appropriate. For example, a recharge and recovery project should not be developed in the westem portion of the Mission Basin, where seawater intrusion was observed, without a barrier project to prevent seawater intrusion. Other important factors affecting the feasibility of the BCU projects include availability of recharge water (rate, delivery schedule, and water quality) and applicable Federal, State, regional, and local rules and regulations. 2.3.b Feasibilitv of Aquifer Storage and Recovery (ASR) The term Aquifer Storage and Recovery (ASR) may be defined as the storage of water in a suitable aquifer through a well during times when water is available, and recovery of the water from the same well during fimes when it is needed (Pyne, 1995). ASR is a dual-purpose approach in which recharge is accomplished using one or more wells, with the same wells being used for recovery of the stored water. A key element of this concept is that 5^ DIEGO COUNTY WATERAUTHORTTT Groundwater Storage & Recovery Project I:\3892\ooo5\Report\chapt2.doc 2-6 Lowcr San Luis Rey Rivcr Valley January 1999 Project No. 98-71-0421 'BASE MAP: USGS 7.5' San Luis Rey, California quadrangle map, photorevised INJECTION SIMULATION NO. 2 San Diego Water Authority Proposed Groundwater Injection/Extraction Project FIGURE 2-6 the storage zone may contain native water of poor or brackish quality, as is the case with these basins. The most important factor affecting ASR feasibility is the characteristics of the storage zone including geology, hydrogeology, and water quality conditions. Suitable storage zones for ASR may be confined, semi-confined, or unconfined aquifers; however, most experience to date is with semi- . confined. Storage in unconfined aquifers appears to be feasible where the water table is deep and relatively flat, and overlying land use is not likely to affect the stored water. Other factors include well yield, availability of recharge water (rate, delivery schedule, and water quality) and applicable federal, state, regional, and local rules and regulations. In order to assess the feasibility of a true ASR-type project approach, two injection simulations were performed in an area in the central Mission Basin during this study. The simulations, which are presented as Figures 2-6 and 2-7, indicated 3-year injection flow paths beyond the potential zone of capture of a theoretical ASR well. Aquifer parameters used for the simulations are shown on the figures. 2.4 A dequacy of Existing Hydrogeologic Data Hydrogeologic data and information for the Mission and Bonsall Basins are generally found in the reports from numerous studies and investigafions discussed in this Chapter and Chapter 1. The most recent and comprehensive studies were conducted by the USGS in 1985 (USGS, 1985 and December 1985). In the Mission Basin, limited recent field data are available; however, additional field data would be needed to accurately characterize its hydrogeologic conditions. In the Bonsall Basin there is very limited information available and accordingly, addifion field data would be needed to characterize its hydrogeologic conditions in the vicinity of a proposed project The above described limitafions for the Mission and Bonsall Basin necessitate assumptions to be made for the purposes of this study. A number of assumptions that were made in order to estimate number of wells needed for extraction and recharge, locate recharge and extracfion facilifies, detennine treatment requirements, and assess infrastructure needs. Some of these assumptions are listed below: 1. Certain project concepts will require that a hydraulic seawater-intrusion barrier be established at the Mission Basin narrows. 2. Recharge water quality will degrade as a result of mixing poorer quality groundwater currently in both basins. 3. Existing ponds along the San Luis Rey River in the City of Oceanside can be used for spreading of recharge water. DIEGO COUNTY WATERAUTHORTTT (xroujuiwater Storage & Recovery Project j:\3892\ooo5\Retx3rt\chapt2.doc 2-7 Lowcr San Luis Rey River Valley 0,s "*tBASE MAP: USGS 7.5' San Luis Rey, California quadrangle map, photorevised 1975.jt^:^'^^ V \ , NORTH INJECTION SIMULATION NO. 1 San Diego Water Authority Proposed Groundwater Injection/Extraction Project FIGURE 2-7 4. Transmissivity of the aquifers in the areas proposed for injecfion and extracfion wells will be favorable for the proposed conditions. 5. Both Mission and Bonsall Basins are presenfiy in a "fiall basin" condifion. 6. No additional natural recharge will be captured as a result of proposed storage and recovery operafions. 2.5 Existing Groundwater Models 2.5.a Mission Basin Model The Mission Basin Model, which is owned by the City of Oceanside, is a finite-difference groundwater flow model using a modifled version of the Prickett-Lonnquist Aquifer Simulafion Model (PLASM) code to solve the partial differential equation for the two-dimensional groundwater flow. The Mission Basin Model was developed by Stetson Engineers in 1997 and is described in detail in its documentation and user's manual (Oceanside, February 7, 1997(b)). The model covers the entire Mission Basin from the Pacific Ocean to the Bonsall Narrows. The model grid consists of 100 columns in the northeast- southwest direcfion and 250 rows in the northwest-southeast direction with a uniform grid spacing of 200 feet. The grid has 25,000 nodes with 6,535 nodes represenfing the Mission Basin. Sources (lakes, recharge basins, unlined channels,) and sinks (wells) are represented by individual model nodes. The model was calibrated under steady-state conditions for July 1996 (high conditions) and February 1966 (low conditions) to demonstrate its capability to simulate groundwater elevations on a basinwide basis. The model was also calibrated using APT data under transient conditions to demonstrate its capability to simulate drawdowns at pumping wells. The model was developed to evaluate, on a basinwide basis, cumulative effects of multiple actions of the City of Oceanside's Desalting Facility expansion on the basin hydrogeology. It may also be used to help develop components for a groundwater management plan such as seawater intrusion, wellhead protection and recharge areas, mitigation of conditions of overdraft, replenishment of groundwater extracted by water producers, conjunctive use investigation and evaluation, operation of groundwater contamination cleanup, recharge, storage, conservation, water recycling, and extraction projects. The model possesses both the "generic" limitations of the PLASM code and its "site-specific" limitafions, as described in detail in the model documentation and user's manual (Oceanside, February 7,1997(b)). The most significant limitations involve limited field data for the model development and calibration. These limitations may affect the model simulation results in areas where field data are not available for calibrations. DIEGO COUNTY WATERAUTHORITT (Groundwater Storage & Recovery Project j:\3892\ooo5\Rcport\diapc2.doc 2-8 Lowcr San Luts Rey River Valley The model was used to evaluate five potential scenarios for the City of Oceanside's Desalting Facility expansion. These potential scenarios include extractions from existing and proposed new wells (up to 28,000 acre-ft/yr) and groundwater recharges (up to 22,000 acre-ft/yr) at the North Riverside Pond and the Upper Pond spreading basins. Simulation results for these scenarios are described in detail in separate technical memoranda (SEI, February 7, 1997) and presented in Chapter 4. 2.5.b Bonsall Basin Model The Bonsall Basin Model, which was developed for the RMWD by Camp Dresser & McKee Inc., is a finite-difference groundwater flow model using the FLOWPATH code to solve the partial differential equation for the two- dimensional groundwater flow. The model can calculate steady-state head (i.e., water level) variafions as well as velocity, pathline, travel fimes, and capture zones for single-layer confined or unconfined aquifers. Model development is grid-based and considers standard components of recharge and discharge for the system. Background data for model development relied on reports prepared by Albert A. Webb Associates (RMWD, August 13, 1992). Details of model development, input parameters, the calibration process, boundary condifion definitions, etc., are provided in the report (RMWD, January 26, 1996). The purpose of the model was to evaluate various groundwater pumping scenarios in the basin for purposes of source water for a demineralization (desalter) facility. The model, as developed, is considered a straight- forward, logical, and appropriate tool to assess superimposed pumping stress of various magnitudes at different locations in the basin affect water levels. Upon calibration, approximately 25 different simulations of extraction were performed. The model had considerable ufility for the intended purposes and offers additional utility in assessing GSR altemafives in the Bonsall Basin, particularly through applicafion of the relative groundwater flow direction and velocity package implicit in the model. The model can be used to assess how; for example, direct injection via well(s) or spreading basins would affect water levels as well as travel paths of injected water. 2.5.C Other Models Several other usefijl numerical or semianalyfical models could be developed to assess groundwater injection, storage, and recovery alternatives in the study area. The U.S. Environmental Protection Agency's Wellhead Protection Area (WHPA) model (Blandford and Huyakom, 1992) can be readily used to assess injectatc travel paths and flow rates under a variety of aquifer numerical values, well spacing, recharge basin layouts, and injecfion SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage &• Recovery Project j:\3892\ooo5\Rcport\chapt2.cioc 2-9 Lowcr San Luis Rey River Valley rates. The model also has utility in assessing recovery effectiveness and residency time in the subsurface. The results of this model can be analyzed using the standard These equafion to establish distance-drawup relafionships under assumed aquifer values and injection volumes. The predicted head variations can then be contoured. Examples are provided as Plates VII and VIII. Hydrogeochemical models can be used to perform injection water/groundwater equilibrium analyses to assess the potential for adverse geochemical reactions during injection operations. Chemical precipitation as a result of chemical interactions at the well screen/aquifer interface could plug interstitial pores between aquifer materials, effectively clogging the aquifer in the area of injecfion. Two hydrogeochemical model codes can be ufilized; PHREEQC (Parkhurst, 1998) and MINTEQA2 3.1 (Allison et al, 1993). PHREEQC can be utilized to calculate ranges of redox potentials (PE) and saturation indices for the various waters as well as to calculate final solutions of mixed native and source waters of varying porfions. The resulting solution are then input into MINTEQA2 which is utilized to calculate saturafion indices and predict chemical precipitation/dissolufion of the various solutions over a reasonable range of temperature, pH, and PE. 2.5d Applicabilitv of Existing Models for Future Use Despite their limitafions (as discussed previously), the existing groundwater models for the Mission and Bonsall basins can assist in further evaluation of project concept feasibility. This is discussed in further detail in Chapter 7 - Phase 2 Hydrogeologic Field Investigation Program. This will mainly include the use of actual field data within the models in order to provide a better understanding of how the proposed groundwater extraction and recharge projects would operate. SAN DIEGO COUNTY WATER A UTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\Report\ch;ipc2.doc 2-10 Lower San Luis Rey Rivcr Valley Chapter 3 - Existing and Planned Water Systems: Supply^ Demandy Treatment, and Storage 3.1 Overview An important issue that needs to be considered during project concept development is the availability of existing water systems in place. This includes the existing facilities that would move groundwater out of extracfion areas and bring in recharge water where needed. We reviewed existing water system facilities in the vicinity of the study area that would be potenfially suitable for the locafion of groundwater recharge or extracfion facilities. An overall study area map that indicates applicable member agency service areas and pressure zones is provided as Figure 3-1. This figure also presents the areas that can be served by the various Mission Basin project concepts that are discussed in Chapter 4. City of Oceanside pressure zones that are served by its current project are identified, and additional pressure zones in Oceanside and Carlsbad that can be served by expanded Mission Basin production are also indicated. As identified in the Phase 1 scope of work, the following issues were reviewed: • Estimates of the demand on the water system (i.e. seasonal and daily demands, total annual, carryover, and emergency storage requirements) that could be served by a groundwater storage and recovery project. • Determinafion of treatment needs for extracted groundwater in order to meet requirements of the receiving water system. • Capacity and alignment of conveyance facilities, and pumping requirements, to transport recharge water or extracted groundwater to and from existing facilities. For the purposes of this chapter, the above analysis consisted of a review of the City of Oceanside and Carlsbad Municipal Water District water facilifies for potenfial Mission Basin groundwater project locations and a review of Rainbow MWD's facilifies for Bonsall Basin project locafions. Monthly average daily water demand (ADD) for these agencies is presented in Table 3-1. However, when evaluafing possible opportunifies for seasonal groundwater storage and recovery projects, it is important to look at increases in demand during the dry summer months. These increases in demand, presented as a departure from the average, are presented in Table 3-2. SAN DIEGO COUNTY WATERAUTHORTTT I:\3892\0005\Rcport\c!iapt3,doc 3-1 (Grouruiwater Storage & Recovery Project Lower San Luis Rey River Valley Current 2MGD Oceanside Project Planned 6.37 MGD Oceanside Project Potential 6.70 MGD Authority Project Alluvial Aquifer County Lagoons Lakes Weese Water Filtration Plant Pressure Zones SDCWA Facilities Creeks Major Roads Freeways Figure 3-1 Pressure Zone Boundaries 6 Miles Tahle 3-1 San Diego County Water Authority Lower San Luis Rey Groundwater Storage and Recovery Feasibility Study Summary of Monthly Average Daily Water Demands Notes JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Carisbiid 1 10.26 8.22 6.71 11.25 18.70 20.29 19.05 19.46 16.76 15.41 9.97 7.31 Oceanside 2 16.95 12.72 16.78 26.38 29.88 32.18 3L17 35.18 30.97 27.66 22.10 17,49 Rainbow 3 24.51 17.40 8.75 18.88 17.52 35.51 27,23 45.81 45.48 46.59 38.91 34.35 TOTALS 51.72 38.34 32.24 56.51 66.10 87.98 77.45 100.45 93.21 89.66 70.98 59,15 Notes: L Data is in MGD for rhe year of 1996 2, Data is in MGD, July - December is 1995; January - June is 1996 3, Data is in MGD for the year of 1990 Table 3-2 San Diego County Water Authority Lower San Luis Rey Groundwater Storage and Recovery Feasibility Study Increase In Demand For Dry Summer Months notes JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Avg. Carlsbad 1 10,26 8.22 6.71 11.25 18.70 20,29 19.05 19.46 16.76 15.41 9.97 7.31 13.62 Departure from Avg. ------5.08 6,67 5.43 5.84 3.14 1.79 ---- Oceanside 2 16.95 12.73 16.78 26.38 29.88 32,18 31.17 35.18 30.97 27.66 22.10 17.49 24.96 Departure from Avg. "" " — 1.42 4,92 7,22 6.21 10.22 6.01 2.70 •" Rainbow 3 24.51 17.40 8,75 18.88 17,52 35.51 27.23 45.81 45.48 46.59 38.91 34.35 30.08 Departure from Avg. ---~ " 5,43 --15.73 15.4 16.51 8.83 4,27 TOTALS 5L72 38.34 32.24 57.93 76,10 101.87 89.09 116.51 102.36 94.15 70.98 59.15 Notes: 1. Data is in MGD for the year of 1996 (latest available data) 2. Data is in MGD, July - December is 1995; January - June is 1996 (latest available data) 3, Data is in MGD for the year of 1990 (latest available data) SAN DIEGO COUNTY WATERAUTHOIUTT J;\3892\0005\ReportVhapi3.doc 3-2 (Grouttdwater Storage & Recovery Project Lower San Luis Rey River Valley 3.2 City of Oceanside 3.2.1. Water Supply The City currently purchases approximately 95% of its demand from the Authority as either raw or treated water. Raw water is treated by the City at the Weese Water Filtration Plant (WFP) located along the Authority's Second Aqueduct. The City also meets a portion of its treated water demand in its San Francisco Peak 511 pressure zone by obtaining treated water directly from the Authority's Tri-Agencies Pipeline (TAP). The City's current local water source is the Mission Basin Groundwater Purificafion Facility, which is currently producing 2 MGD, with expansion to a production capacity of 6.37 MGD underway. Reclaimed water is available locally at the San Luis Rey Wastewater Treatment Plant (WWTP). Currently, 0.7 MGD of reclaimed water is produced and used for in'igafion at the golf course. 3.2.2 Demand ADD for the City of Oceanside in calendar year 1995 was 24.3 million gallons per day (MGD), with the maximum day demand (MDD) at 40.6 MGD (ASL, 1998). A table summarizing ADD, storage requirements by pressure zone at exisfing and ulfimate conditions, and 10 day emergency storage needs for the City of Oceanside is provided in Table 3-3. SAN DIEGO COUNTY WATERAUTHORITY Groundwater Storage & Recovery Project j:\3892\ooo5\Report\chapr3.doc 3-3 Lowcr Sau Luis Rey RivcT Valley Table 3-3 San Diego County WaterAuthority Lower San Luts Rey Groundwater Storage and Recovery Feasibility Study cur OF OCEANSIDE EXISTING CONDITIONS ULTIMATE CONDITIONS cur OF OCEANSIDE EXIST STORAGE MG AVG DAY GPM EXIST AVG DAY MGD EXIST TOTAL STORAGE MG(1) 10 DAY STORAGE MG (2) SURPLUS DEFICIT MG AVG DAY GPM ULT AVG DAY MGD ULT 10 DAY STORAGE MG SURPLUS DEFICIT MG ZONE HGL ZONE NAME EXIST STORAGE MG AVG DAY GPM EXIST AVG DAY MGD EXIST TOTAL STORAGE MG(1) 10 DAY STORAGE MG (2) SURPLUS DEFICIT MG AVG DAY GPM ULT AVG DAY MGD ULT 10 DAY STORAGE MG SURPLUS DEFICIT MG 739 MORRO HILLS 10 1664 2.40 5.49 23.96 -13.96 4665 6.72 67.18 -57.18 320 TALONE 13 3567 5.14 10.66 51.36 -38.36 5293 7.62 76.22 -63.22 511 GUAJOME 10 5009 7.21 14.59 72.13 -63,13 6588 9.49 94.87 -84.87 322 FIRE MOUNTAIN 5 4650 6.70 13.61 66.96 -61.96 6148 8.85 88.53 -83.53 320 WIRE MOUNTAIN (3) 3 286 0.41 1.74 4.12 -1.12 373 0.54 5.37 -2.37 409 HENIE HILLS 3 582 0.84 2.54 8.38 -5.38 812 1.17 11.69 -8.69 589 SAN FRANCISCO PEAK 6.5 1038 1.49 3.78 14.95 -8.45 1465 2.11 21.10 -14.60 50.5 16796 24.19 52.41 241.S6 -191.36 25344 36.50 364.95 -314.45 (1) operational + Fire + Reserre Storage = Total Storage (City of Oceanside Master Water Plan) (2) 10 day storage (lOxADD) (3) Includes the "Dovmtmvn"service area SAN DIEGO COUNTY WATERAUTHORTTT ]:\3892\0005\Repon:\chapc3.doc 3-4 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley 3.2.3 Existing and Planned Treatment Facilifies Existing potable water treatment facilities include the 2 MGD Mission Basin Groundwater Purificafion Facility and the 25 MGD Weese Filtration Plant. The Mission Basin Groundwater Purificafion Facility delivers reverse osmosis treated groundwater to the City's downtown service area. As part of the planned expansion program, treated Mission Basin water will also be pumped to the City's 320 pressure zone via the Wire Mountain Reservoir. The City's Water Master Plan also discusses the possibility of even further expansion of the Mission Basin Groundwater Purificafion program. This expanded program would include an interim expansion to 10 MGD production and an eventual expansion to 20 MGD. The Water Master Plan contained a program to construct the facilities required to move the expanded RO water throughout the City's 320 and 511 pressure zones to meet demands in these areas. Expanded RO producfion envisioned moving approximately 10 MGD into the 320 pressure zone, and then another 10 MGD into the 511 pressure zone. WFP treated water is at a hydraulic grade line (HGL) of 973.5 ft. Treated water from the WFP is delivered to the City's 739, 511, and 320 pressure zones through the Authority's North County Distribution Pipeline (NCDP). The WFP is expandable to 50 MGD, however, there are no current known plans to do so. The City is also considering future expansion of their tertiary wastewater treatment capacity at the San Luis Rey WWTP. The City's Preliminary Design Report (PDR) for the expansion has recommended that tertiary treatment facilifies be master planned for an average groundwater recharge component of 2 MGD, based on expected regulatory constraints (CaroUo, 1998) with respect to reclaimed water recharge of groundwater. The actual amount of reclaimed water available for groundwater recharge will vary seasonally, with more reclaimed water (up to 4.61 MGD) available during winter months (Carollo, 1998). The timetable for additional tertiary treatment to be on line is unknown at this fime. 3.2.4 Distribution System The City's existing conveyance system consists of mosfiy asbestos cement pipe (ACP), cement mortar lined and coated (CML&C) steel, ductile iron pipe (DIP), and PVC pipe. New distribution pipelines are typically DIP or PVC. Supply mains typically move westward from either WFP or the NCDP. The City's San Francisco Peak 511 pressure zone is fed directly from the TAP. Planned conveyance projects designated in the City's Water Master Plan are for improved fire flow, circulation of treated Mission Basin water, conveyance to the San Francisco Peak 511 pressure zone, and ultimate demand improvements. SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage i!^ Recovery Project j:\3893\ooo5\Report\chapc3.doc 3-5 Lowcr San Luis Rey Rivcr Valley The City's distribufion system includes the 739, 511, and 320 pressure zones and several pressure sub-zones within each. There are nine existing water pump stafions that serve the various pressure zones or sub-zones either as a primary means of service or in standby mode. Planned pump station upgrades or new stations designated in the City's Water Master Plan are also associated with circulation of Mission Basin water. 3.2.5 Storage The City of Oceanside's total existing system storage capacity is 50.5 MG, which is provided by twelve reservoirs. For the exisfing ADD, each pressure zone has a surplus of storage (operational, plus fire and reserve) except for the Guajome (511) and Wire Mountain (320) pressure zones, which have deficits of 4.59 and 8.61 MG, respecfively. The total system deficit for all pressure zones is 1.92 MG. At ulfimate conditions, all pressure zones, except for Fire Mountain (322) and San Francisco Peak (569), will experience storage deficits, for a total system deficit of 25.19 MG. For 10 average day emergency storage requirements (as recommended by the Authority), there is an exisfing storage shortfall of 171.5 MG, and an ultimate 10 day emergency storage shortfall of 294.5 MG. 3.2.6 Potential for Use of Groundwater Storage Based on the above discussion, a groundwater project could be ufilized to meet some of the City's average daily demand and offset storage deficiencies and requirements when Authority 10 day emergency storage requirements are considered. A groundwater project would operate on a constant yield basis (see below discussion) and would normally meet potable water demand. However, when imported water for recharge or direct potable use became unavailable, the groundwater project could continue to produce by drawing from carryover storage in the groundwater basin. The specific storage deficits by pressure zone that a groundwater project(s) could help meet are presented on Table 3-3. The City's Water Master Plan has factored in expanded groundwater producfion into their assessment of 10 day emergency storage opfions. Phased expansion to 6.37 MGD (which is currently in the bid process), and potential future 10 and 20 MGD production rates were evaluated in the Water Master Plan. The expanded Mission Basin groundwater purification operafions would meet demand and offset emergency storage deficiencies in the City's 320 pressure zone. This includes the Talone, Wire Mountain, and Fire Mountain pressure zones as indicated on Table 3-3. An expanded groundwater program operated by the Authority could be utilized to meet demand in both the 320 and 511 pressure zones or possibly supply other member agencies such as Carlsbad MWD through an existing connecfion or NCDP agencies through a new connection. SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage Recovery Project j:\3892\ooo5\Rcport\chapc3.doc 3-6 Lowcr San Luis Rey River Valley Based on documented Mission Basin water quality, demineralization treatment will be required prior to pumping groundwater into the distribufion system. The demineralization process operations would typically be required to operate on a constant basis, therefore the construcfion of standby or peaking demineralizafion treatment capacity to meet specific demand constraints may not be feasible. Therefore, it is assumed that demineralization facilities would produce water on a constant, year round basis without specific seasonal variation in the production rate. Recharge, however, could be performed seasonally on a regular and planned schedule. 3.3 Carlsbad Municipal Water District 3.3.1 Water Supplv The District currently purchases 100% of its demand from the Authority as treated water through four aqueduct connections (Connections 1 and 2 off the Second Aqueduct, and Connecfions 3 and 4 off the Tri-Agencies Pipeline). The District does not currently have a local water source; however, it does have 5 cfs of documented water rights to groundwater in the Mission Basin (ASL, 1997). The District owns six unequipped groundwater extraction wells in the Mission Basin; however, these wells have not been operated for approximately thirty years. A limited portion of the District can be served through an emergency connecfion with the City of Oceanside. This consists of an existing 12-inch diameter pipeline located in El Camino Real at Vista Way. The pipeline is fed from Oceanside's 3.0 MG Henie Hills reservoir at an HGL of 409 and can serve the District's 255 pressure zone (Downtown area). The District is also considering adding another connection with Oceanside at College Boulevard. It is also possible to move water from Oceanside to Carisbad MWD using a planned pump back scheme from Oceanside's San Francisco Peak pressure zone to the District's Maerkle reservoir/dam area. Reclaimed water is available in the District from the 2.0 MGD Meadowlark Water Reclamation Plant and the 0.75 MGD Gafner Water Reclamafion Plant. Vallecitos Water District and Leucadia County Water District own these facilities, respectively. The District, through inter-agency agreements with Vallecitos and Leucadia, purveys the reclaimed water. Potential future sources of addifional reclaimed water idenfified in the District's Water Reclamation Master Plan (Carollo, 1997) include expansion of Meadowlark to 4 MGD, construction of a new Encina Water Reclamation Plant adjacent to the Encina Water Pollution Control Facility, and implementation of a seasonal storage program. SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage ^ Recovery Project I:\3892\ooos\Repart\thapt3.doc 3-7 Lowcr San LatsRey Rivcr Valley 3.3.2 Demand ADD for the District for the period of January 1996 to December 1996 was 13.84 MGD, with the maximum daily demand during the same period at 19.9 MGD (ASL, 1997). A table summarizing ADD, storage requirements by pressure zone at existing and ultimate conditions, and 10 day emergency storage needs is provided in Table 3-4. SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\Rcport\chapt3.doc 3-8 Lowcr San Luis Rey River Valley Table 3-4 San Diego County WaterAuthority Lower San Luis Rey Groundwater Storage and Recovery Feasibility Study ADD and Storage Requirements CARLSBAD MWD EXISTING CONDITIONS ULTLVIATE CONDITIONS EXIST AVG DAY AVG DAY TOTAL 10 DAY SURPLUS AVG DAY AVG DAY 10 DAY SURPLUS ZONE ZONE STORAGE GPM MGD STORAGE STORAGE DEFICIT GPM MGD STORAGE DEFICIT HGL NAME MG EXIST EXIST MG(1) MG (2) MG ULT ULT MG MG 446 TAP 6 845 1.22 3.28 12.17 -6.17 800.9 1.15 11.53 -5.53 330 EUcry 5 570.8 0.82 2.53 8.22 -3.22 556.5 0.80 8.01 -3.01 392 Cannon "C" 1 35,3 0.05 1.05 0.51 0.49 150.1 0.22 2.16 -1.16 255 Sk>line & Elm (1.5 MG each) 3 2110.6 3.04 6.76 30.39 -27.39 2078.4 2.99 29.93 -26.93 490 Maerkle Reservoir 10 154.4 0.22 1.38 2.22 7.78 682.7 0.98 9.83 0.17 264 "E" 1.5 803.7 1.16 3.17 11.57 -10.07 1751.6 2.52 25.22 -23.72 375 Twin "D" 8.5 653.3 0.94 3.71 9.41 -0.91 2546.3 3.67 36.67 -28.17 700 Santa Fe 11 9 84 0.12 1.19 1.21 7.79 352.3 0.51 5.07 3.93 700 La Costa-Hi 6 100.4 0.14 1.23 1.45 4.55 594.1 0.86 8.56 -2.56 318 La Costa-Lo 1.5 1505 2.17 5.08 21.67 -20.17 3281.8 4.73 47.26 -45.76 580 580 0 366.9 0.53 1.97 5.28 -5.28 552 0.79 7.95 -7.95 285 285 0 37 0.05 1.06 0.53 -0,53 37 0.05 0.53 -0.53 325 325 0 8.4 0.01 0.98 0.12 -0.12 8.4 0.01 0.12 -0.12 318 318- Rancho Carlsbad 0 739.5 1.06 2.99 10.65 -10.65 1454.2 2.09 20.94 -20,94 680/580 680/580 LaCosta 0 196 0.28 1.5 2.82 -2.82 158.9 0.23 2.29 -2.29 550 550 0 478.6 0.69 2.27 6.89 -6.89 814 1.17 11.72 -11.72 510 510 0 45,2 0.07 1.09 0.65 -0.65 45.2 0.07 0.65 -0.65 430 430 0 0.00 0.00 0.00 511.2 0.74 7.36 -7.36 51.5 7266.4 10.46 32.41 104.64 -53.14 13383.7 19.27 192.73 -141.23 (1) operational -i- Fire + Reserve Storage = Total Storage Emcr^eficy Storage: 100% of the amount of water used (2) 10 day stort^e (JOxADD) (City of Carlsbad Master during the nmximum day Water Plan) of the peak month SANDIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Rctx)rt\chapt3.doc 3-9 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley 3.3.3 Treatment Facilifies There are no existing or planned potable water treatment facilities in the District. 3.3.4 Distribufion System The District's distribufion system is mostly ACP, with lesser portions consisting of DIP, steel, and PVC. Supply mains begin at each of the Authority connections and move westward through the District. Planned pipeline improvements include fire flow improvements, pipe replacements, or new pipelines to meet future demands. The District's water system is organized into pressure zones according to the grade line served. These include the 255, 318- Rancho Carlsbad, 318-La Costa/South Coastal, 325, 330, 349, 375, 446, 490, 510, 550, 680/580-La Costa and 700-Santa Fe II pressure zones. There are four water pump stations in the District's system. Three are used for emergency purposes and one is currently inactive. Planned pump station upgrades to correct storage deficiencies include the Calavera pump station and a new pump stafion to supply the 700 pressure zone. 3.3.5 Storage The District's total exisfing system storage capacity is 51.5 MG, excluding the 195.5 MG Maerkle Dam, which is out of service while it is being lined and covered. At exisfing ADD, the 580, 349, 285, 325, 318-Rancho Carisbad, 255, 700-Santa Fe II, 680/580-La Costa, 550, 510, and 318-La Costa/South Coastal pressure zones experience storage deficits (operational, plus fire and reserve). However, there is a total system surplus of storage of 10.23 MG. The only pressure zone without storage is the 580 pressure zone, which is fed directly from the TAP, and could be fed in an emergency from the Calavera Pump Station. At ulfimate conditions, all pressure zones, except for the 446, 490, 330, 700- Santa Fe II, and 700-La Costa Hi, experience storage deficits, for a total system deficit of 10.76 MG. For 10 day average emergency storage requirements (as recommended by the Authority), there is an existing storage shortfall of 115.5 MG, and an ultimate 10 day emergency storage shortfall of 246.6 MG. The District is planning to help offset this shortfall with the 195.5 MG Maerkle Dam. SAN DIEGO COUNTY WATERAUTHORITT (Groundwater Storage & Recovery Project j;\3892\0005\Repoi:t\chapt3.doc 3-10 Lowcr San Luis Rey River Valley 3.3.6 Potential for Use of Groundwater Storage Based on the above discussion, a groundwater program in the Mission Basin could meet some of the District's demand or offset emergency storage requirements/deficiencies; however, there would be a limited area that could be served from Oceanside's system through existing facilities. The specific storage deficits by pressure zone that a groundwater project(s) could help meet are presented on Table 3-4. Areas that can be served through existing facilities would generally consist of the 255 pressure zone served through the existing 12-inch diameter emergency connecfion at El Camino Real and Vista Way. This cormection would probably be limited to a flow of approximately 2 MGD, or 3.1 cfs, and could potentially be upsized to accommodate greater flows (perhaps the 5 cfs of Carlsbad's Mission Basin water rights). It is also possible to transfer water to Carlsbad through the Oceanside San Francisco Peak 511 pressure zone. The ability to move this water would only be limited by the ability of Oceanside's Lake Boulevard Pump Stafion to move water to the 511 HGL San Francisco Peak No. 2 reservoir. From this locafion a new pipeline could be constructed to connect to Carlsbad's Maerkle Dam and its 490 pressure zone. This could allow for a greater area within Carlsbad to be served. It is also possible to transfer treated water from Oceanside's WFP to the District via the Second Aqueduct and TAP if pumping facilities were constructed at the WFP. Since the Mission Basin groundwater treatment would operate on a constant, year round basis, specific seasonal variafion in production is not anticipated. 3.4 Rainbow Municipal Water District 3.4.1 Water Supply The District currently purchases 100% of its demand from the Authority as treated water through eight aqueduct connections. There are no current local water resources, however, the District has at various fimes studied the possibility of utilizing groundwater resources to supply a portion of its demands. 3.4.2 Demand ADD for the District for the highest recorded water use year (calendar year 1990) was 31.2 MGD (Webb, 1994). The calculated maximum day demand was 84.4 MGD. A table summarizing ADD and storage requirements by pressure zone for the District at existing and ultimate conditions is provided in Table 3-5. SANDIEGO COUNTT WATERAUTHORITT Groundwater Storage <&Recovery Project j:\3892\ooo5\Report\ciiapr3.doc 3-11 Lowcr San Luis Rey River Valley Table 3-5 San Diego County WaterAuthority Lower San Luis Rey Groundwater Storage and Recovery Feasibility Study ADD and Storage Requirements RAINBOW MWD EXISTING CONDTTIONS ULTLMATE CONDITIONS RAINBOW MWD EXIST STORAGE MG AVG DAY GPM EXIST AVG DAY MGD EXIST TOTAL STORAGE MG (1) 10 DAY STORAGE MG (2) SURPLUS DEFicrr MG AVG DAY GPM ULT AVG DAY MGD ULT 10 DAY STORAGE MG SURPLUS DEEICTT MG ZONE HGL ZONE NAME EXIST STORAGE MG AVG DAY GPM EXIST AVG DAY MGD EXIST TOTAL STORAGE MG (1) 10 DAY STORAGE MG (2) SURPLUS DEFicrr MG AVG DAY GPM ULT AVG DAY MGD ULT 10 DAY STORAGE MG SURPLUS DEEICTT MG 820 MORRO RESERVOIR 151.5 5555 8.00 32.32 79.99 71.51 5847 8.42 84.20 67.30 865 MORRO TANK 4 519 0.75 3.07 7.47 -3.47 550 0.79 7.92 -3.92 900 BECK 203.7 2446 3.52 18.83 35.22 168.48 3331 4.80 47.97 155.73 1010 GOPHER CANYON 12 4444 6.40 26.09 63.99 -51.99 4684 6.74 67.45 -55.45 1020 CANONITA 6 2886 4.16 20.12 41.56 -35.56 3571 5.14 51.42 -45.42 1200 NORTH RESERVOIR 11.8 2663 3.83 15.42 38.35 -26.55 2696 3.88 38.82 -27.02 1280 NORTHSIDE RESERVOIR 22.8 1303 1.88 8.05 18.76 4.04 1323 1.91 19.05 3,75 1338 VALLECITOS 0.4 267 0.38 2.45 3.84 -3,44 277 0.40 3.99 -3.59 1579 U-I 2.1 360 0.52 2.09 5.18 -3.08 367 0.53 5.28 -3.18 1710 HUNTLEY-GOMEZ 3.5 607 0.87 3.43 8.74 -5.24 618 0.89 S.90 -5.40 1970 RAINBOW HEIGHTS 4.9 624 0.90 3.54 8.99 -4.09 638 0.92 9.19 -4.29 2160 MAGEE 3 37 0.05 0.34 0.53 2.47 41 0.06 0.59 2.41 425.7 21711 31.26 135.75 312.64 113.06 23943 34.48 344.78 80.92 (1) operational -t- Fire -f Reserve Storage = Total Storage (Rainbow MWD Master Water Plan) Emergenc)' Storage: 100% ofthe amount of water used during the maximum day of the peak month (2) 10 day storage (lOxADD) SANDIEGO COUNTY WATERAUTHORTTT ):\3892\0005\Reixjrt\chapt3.doc 3-12 (Groutidwater Storage & Recovery Project Lower San Luis Rey River Valley 3.4.3 Treatment Facilities There are no existing or planned potable water treatment facilifies in the District. 3.4.4 Distribution System The District's transmission and distribufion system pipelines are mostly welded steel, with small amounts of DIP, ACP, and PVC. Planned pipeline projects include replacements, addifional pipelines to loop certain portions of the distribution system, and new pipeline improvements. The District's existing water system consists of eight active filtered water aqueduct connecfions and twelve primary pressure zones, which range in HGL from 820 to 2160 ft. The District also uses forty-six pressure stations, consisting of pressure sustaining, pressure reducing, and pressure sustaining/pressure reducing valves. 3.4.5 Storage Seventeen reservoirs provide a total system storage capacity of 425.7 MG, For the existing ADD, each pressure zone has a surplus of storage (operafional, plus fire and emergency calculated as 100% of the maximum day, peak month) except for the Gopher Canyon, Canonita, North Reservoir, and Vallecitos pressure zones, which have deficits of 12.81, 10.46, 3.44, and 1.99 MG, respecfively. Since the Canonita and North Reservoir pressure zones can be provided with additional storage from adjacent pressure zones via interconnecfions, the total system deficit is 14.8 MG (Webb, 1994). At ultimate conditions, the above pressure zones, except for the Canonita pressure zone, experience storage deficits, for a total system deficit of 17.8 MG (Webb, 1994). If 10 day storage requirements at ADD (as reconmiended by the Authority) are considered, there would be an existing system wide surplus of storage, however, eight pressure zones would experience deficits totaling 133.4 MG. A similar circumstance would exist at ulfimate condifions, with the same eight pressure zones experiencing a total storage deficit of 148.27 MG. 3.4.6 Potential for Use of Groundwater Storage Based on the above discussion, a groundwater project in the Bonsall Basin could be utilized to meet some of the District's demand or offset storage requirements/deficiencies when Authority 10 day emergency storage requirements are considered. A groundwater project would operate on a constant yield basis (see below discussion) and would normally meet potable SANDIEGO COUNTY WATERAUTHORTTT Groundwater Storage & Recovery Project j:\3892\ooo5\Rcpori\diapt3.dot 3-13 LowcT San Luis Rey River Valley water demand. However, when imported water for recharge or direct potable use became unavailable, the groundwater project could continue to produce by drawing from carryover storage in the groundwater basin. The specific storage deficits by pressure zone that a groundwater project(s) could help meet are presented on Table 3-5. The District's feasibility analysis of the Bonsall Basin groundwater use (CDM, 1996) assessed the potential to implement an approximate 2 MGD ground water program to serve the District's 865 Morro Tank pressure zone. This pressure zone would, under the 10-day emergency storage scenario, experience an ultimate storage deficit of approximately 4 MG. Potable water delivery to the District's 865 pressure zone would also result in less pumping costs than pumping to other District pressure zones that although also with emergency storage deficits, are located at substanfially higher grade lines. Based on documented Bonsall Basin water quality, demineralizafion treatment would be anticipated for use of groundwater in the District's distribution system. The demineralization process operations would typically be required to operate on a constant basis, therefore the construction of standby or peaking demineralizafion treatment capacity to meet specific demand constraints may not be possible. Therefore, it is assumed that demineralization facilities would produce on a constant, year round basis without seasonal variation in the production rates. Recharge, however, could be performed seasonally on a regular and planned schedule. SANDIEGO COUNTY WATERAUTHORITT (Groundwater Storage & Recovery Project j:\3892\ooo5\Rcporr\ciiapr3.doc 3-14 Lowcr San Luis Rey River Valley Chapter 4 - Project Concepts 4.1 Overview and Background During the initial tasks of the Phase 1 study, the study team evaluated groundwater basin hydrogeology and identified potential locations for groundwater recharge and extraction facilities. The team also evaluated existing water systems and identified engineering constraints to implementing groundwater storage or recovery projects in the study area. Following the evaluafion of hydrogeology, and exisfing and planned water supply systems, the study team turned its attenfion to the development of groundwater recharge and storage project concepts. These groundwater recharge and storage project concepts were introduced to the PAC at the Phase 1 study's second PAC meeting held on March 10, 1999. Further details of the project concepts, including preliminary costs, benefits, and institufional issues, were subsequently discussed with the PAC at the third PAC meeting held on July 15, 1999. The primary objective of this chapter is to define the four groundwater storage and recovery project concepts developed by the project team in sufficient detail to permit further feasibility analysis in subsequent chapters and study phases. Chapter 5 addresses environmental and Regulatory Issues. Chapter 6 will present costs and benefits as well as a project ranking based upon costs and benefits. A primary goal of the Phase 1 study is to develop concepts that are technically viable, consistent with current basin acfivities, economically sound and of benefit to the region. Several guiding principles and assumpfions direcfiy influenced project concept development in Phase 1. They are as follows: • It is assumed that by 2002 the City of Oceanside will expand its desalter to a potable water producfion rate of 6.37 MGD as planned. • The City of Oceanside plans to extract the remaining "safe yield" of the Mission Basin (6.37 MGD Project). Additional extracfion from the basin will require artificial replenishment. • For project concepts developed by the Authority, it has been assumed that all groundwater extracted from the Mission and Bonsall basin will be replenished artificially using discounted imported or reclaimed water. However, it should noted that if groundwater levels are lower than normal at the beginning of the rainy season, due to increased groundwater production, some additional natural recharge will be induced. As a result, the natural or safe yield of the basin will have been increased. It should also be noted that the right to this naturally replenished water could become a point of legal dispute if the matter is not addressed beforehand in a formal groundwater management plan or an equivalent agreement. The extent that this natural recharge may be available has not been quantified by the Phase 1 study. SAN DIEGO COUNTY WATER AUTHORITY GroundwaterStorage & Recovery Project j:\3892\ooo.s\Repon:\chapt4.doc 4-1 Lowcr San Luis Rey River Valley • It is assumed that "usable" groundwater storage is limited by historic low groundwater levels. • Groundwater storage and recovery projects will likely require the adoption of a groundwater basin management plan and the periodic lowering of groundwater levels in portions ofthe basin.overdrafted • Groundwater storage and recovery projects will be constrained by legal, environmental, polifical, or institufional constraints to the planned management of groundwater levels. • By providing a source of recharge, the average-annual yield for both the Mission and Bonsall Basins can be increased above the "safe yield." Groundwater can be replenished when water demand is low and replenishment water is available at a discount. Groundwater can be developed from "seasonal" and "carryover" storage when replenishment water may be unavailable (i.e. during times of peak seasonal demand, or drought, or other emergencies). • Due to current high dissolved solids content of groundwater presently stored in the Mission and Bonsall Basins and the potential for the movement of stored water away from recharge sites, it has been assumed that demineralization treatment will be required before recovered groundwater can be used for potable purposes. However, the concept of using an Aquifer Storage and Recovery (ASR) well field aligned along the regional groundwater flow direcfion to store and recover potable water (on an annual basis) may merit further evaluafion in Phase 2 (see Pyne, R.D.G., 1994). • Economic and operational considerations require that demineralizafion facilifies operate year round. Therefore, concepts have been designed as constant-yield projects. • It is assumed that the City of Oceanside will construct additional reclaimed water facilities at the San Luis Rey WWTP. • It is assumed that the City of Oceanside will complete the planned 36" diameter expansion of the land out fall from San Luis Rey WWTP to the ocean outfall. • Current MWD programs (Local Resources, Seasonal, and Long-Term Storage) will be available. • Metropolitan's Water District of Southern Califomia (Metropolitan) Local Resources Program requires that projects that recover groundwater for municipal and domestic use must be able to sustain groundwater production during a three- year shortage period without receiving replenishment service from Metropolitan. • Rights to extract and store water in the Mission and Bonsall Basin can be obtained and protected by a replenishment agency. • Existing facilifies and infrastructure owned, operated and maintained by Authority member agencies will be available to supply, treat, convey, and temporarily store project water (i.e. replenishment, product, and brine concentrate). SAN DIEGO COUNTY WATERAUTHORTTT Groundwater Storage & Recovery Project j;\3892\ooo.s\Report\chapt4.doc 4-2 Lowcr San Luis Rey River Valley • Portions of member agency potable water demands and storage requirements can be met by water developed from proposed storage and recovery projects. 4.2 Water System Requirements for Project Implementation Based upon an assessment of the existing water systems and proposed project configurafions, the following facility requirements for groundwater storage and recovery projects in the study area were identified: Facilities to move imported replenishment water to recharge areas in the Mission and Bonsall Basins. Spreading basins and/or injection well fields in both the Mission and Bonsall Basins. Additional extracfion facilities to enhance the Mission Basin and Bonsall Basin yields Facilities to convey extracted groundwater to treatment facilities Additional RO treatment capacity at the Oceanside desalter and a new RO treatment facility in the Bonsall Basin project Facilities to convey treated water groundwater to areas of demand. In the City of Oceanside, conveyance facilities will be required to move stored groundwater to the 320 and 511 pressure zones. For Carlsbad MWD, a limited area in its 255 downtown pressure zone could be served by a groundwater storage project through an exisfing connection with Oceanside. For Rainbow MWD, piping to its lowest pressure zone, 865 Morro, would be necessary to deliver recovered groundwater. • Additional conveyance to move Mission Basin stored groundwater to either the NCDP or Carlsbad MWD. • A pump station at the Weese Filtration Plant (WFP) to move treated water into Pipeline 4 ofthe Authority's Second Aqueduct. 4.3 Groundwater Storage Issues and Limitations Other than potential impacts to riparian habitat and endangered species, there are at least five basic concerns that may impact the design of a groundwater storage and recovery project. These concerns could potentially impact project yield, storage capacity, and feasibility. They include: 1. Potential for land subsidence 2. Potential for sea-water intrusion 3. Ability to recover stored water. 4. Potential impact to existing water wells 5. Potential impact to existing groundwater and surface-water rights. SANDIEGO COUNTY WATERAUTHORITY J;\3 892\0005\Rcport\chapt4.doc 4-3 Groufuiwater Storage Recovery Project Lower San Luis Rey River Valley Land Subsidence For the purposes ofthe Phase 1 feasibility study and project concept development, it is assumed that if groundwater levels are not lowered below historical low levels the potential for land subsidence will be minimized. It is likely that compressible (clay) soils are "pre-consolidated" (by previous lowering of the groundwater levels) and sediments will not compress further as long as they are not subjected to stresses greater than they have previously experienced (during historic low groundwater levels). Water levels in the Mission Basin were at a record low during the period between 1948-1960. During that period approximately 30,000 acre-ft of storage was utilized in the Mission Basin,. The 30,000 acre-ft volume was calculated based on the reported difference in basin-wide groundwater levels during the 1948-1960 period.. Similarly, it is estimated that approximately 9,000 acre-feet of groundwater storage was utilized in the Bonsall Basin between 1948-1960 (about 750 acre-ft/year). The 9,000 acre-ft volume was calculated based on the reported difference in basin-wide groundwater levels during the 1948-1960 period. Potenfial for Seawater Intrusion The Mission Basin is hydraulically connected with the Pacific Ocean at its western terminus. If groundwater levels decline significantly near the westem end of the groundwater basin, sea water may be induced to move inland. This is what occurred in the Mission Basin during the period of 1948-1960 when the basin experienced historically low groundwater levels. It is likely that groundwater levels (hydraulic head in the confined aquifer) will need to be maintained above sea level near the westem end of the Mission Basin to prevent seawater intrusion. The potenfial impact of temporarily lowering groundwater levels either seasonally or for longer periods will have to be studied in subsequent phases to develop management options to prevent seawater intmsion. Ability to Recover Stored Water The ability to recover groundwater stored in either the Mission or Bonsall Basins is a principal concem. There is a potenfial that higher quality replenishment water will migrate down gradient or be intercepted by private wells. Developing a proper well field design and adopting a groundwater management plan will help to address these two concems. For the purpose of the Phase I study, it is assumed that for all project concepts that a significant amount of loss of stored water will not occur. However, proposed concept designs, operations, and management will need to be evaluated more closely in subsequent phases of the feasibility study in order to confirm these assumpfions. SANDIEGO COUNTY WATERAUTHORTTT Groundwater Storage & Recovery Project ] ;\3892\0005\Etcport\chapt4.doc 4-4 Lowcr San Luis Rey River Valley Potential Impacts to Exisfing Water Wells Management of groundwater levels within either the Mission or Bonsall Basins will likely have impacts on other wells. Water levels may drop in other wells when basin extraction exceeds replenishment for a significant period of time. Impacts could range from increasing pumping costs to a temporary loss of supply. An updated survey of existing wells will be required to determine potential impacts and possible mitigation. Mitigafion has not been anticipated for this phase of the study and possible impact to other wells has not altered project concept design or costs. Potenfial Impacts to Existing Groundwater and Surface-Water Rights Adverse impacts to groundwater or surface water rights are not anticipated. However, water rights issues are likely to arise if a groundwater storage and recovery program is implemented. Rights to induced-recharge and replenishment water may be disputed once a replenishment project is constructed. Therefore, it likely that a formal groundwater management plan will be required prior to implementation of a large scale groundwater replenishment/storage program. This issue has not impacted project design and costs in this phase of the study. 4.4 Groundwater Storage and Recovery Operations Groundwater project concepts in the Mission and Bonsall Basins have been developed to operate as "constant yield" projects. Constant yield that exceeds the assumed safe yield of the Basin(s) need to be supported by artificial groundwater recharge operations. Artificial recharge using combinations of reclaimed and imported water have been considered. Constant-yield projects will draw on carryover storage when replenishment water is unavailable. The groundwater basin(s) will be refilled when replenishment supply again becomes available and/or by natural precipitation mnoff and groundwater inflow to the basin. It is assumed that replenishment can be accomplished by either land spreading and/or by directly injecting water into the Basin(s). It is also assumed that stored water will be degraded by storing it in the basin (see discussion in next section). By assuming "constant yield or extracfion", brackish groundwater desalting facilities used to treat extracted groundwater will operate more efficiently. It is assumed that replenishment is conducted on a seasonal basis and when available at a discounted rate. As is the case now, it is assumed that long-term- storage water may be used to replenish the basins. When replenishment supply is unavailable, groundwater levels will be lowered further and carryover storage water will be used to supply the desalter. Groundwater will then be replenished once the replenishment water becomes available again. SANDIEGO COUNTT WATERAUTHORTTT (Groundwater Storage &• Recovery Project j:\3892\ooo5\Rcport\chapt4,doc 4-5 Lowcr San Luis Rey River Valley 4.5 Treatment and Disinfection Issues Based on the water quality observed in both Basins as discussed in previous chapters, demineralization treatment of extracted groundwater will likely be necessary if the extracted water is to be used as a potable water supply. It is possible that if the basins are fully exercised, groundwater levels fluctuate over a wide range, and extracted groundwater is replenished with higher quality water, basin-wide water quality may improve. However, additional study and project operafion will be required before the degree of impact can be accurately determined or predicted. For the purposes of this study it is assumed that any incidental improvements in water quality are likely to be local (i.e., near recharge facilities) and not basin-wide. The City of Oceanside facility currently uses membrane treatment (Reverse Osmosis) to reduce TDS, iron, manganese, and sulfate. A portion of the untreated groundwater is bypassed around the RO process and re-blended with the RO permeate to produce a final blended treated water which is compliant with drinking water regulafions. This type of bypass is typical for brackish groundwater treatment facilities in order to opfimize the treatment process. The amount of groundwater that can be bypassed is related to the concentrations of TDS, iron and manganese. Pretreatment consists of addition of anti-scalant prior to the RO process. The operafion of RO facilities will result in the generation of a high-TDS (on the order of 8000 to 10,000 ppm TDS) concentrate that must be disposed of. Quantity estimates for the concentrate are based on the flow rate into the demineralization process and efficiency of the plant. It is assumed in the development of the project concepts that a treatment process similar to the City of Oceanside plant will be necessary to produce potable water. Pursuant to DHS regulafions, a measurable chlorine residual is required to be maintained in a potable water supply. Therefore, disinfecfion of the treated groundwater will be performed prior to blending with other potable water. This will be performed by the addition of chlorine and ammonia to form a chloramine residual. Chlorine and ammonia will be added at a 5:1 rafio, with the dosage depending on flow rate and distribution residual requirements. Dosages on the order of I to 2 ppm are typical. 4.6 Recharge Water Availability For the purposes of the feasibility study, two potential sources of replenishment water are assumed to be available I) imported water, and 2) reclaimed water from the City of Oceanside's planned San Luis Rey Wastewater Treatment Plant (WWTP). The City of Oceanside is planning its San Luis Rey WWTP Title 22 facilities based upon a assumed demand for about 2 MGD (yearly average). This demand also assumes a groundwater recharge limit of the same. Therefore, the project concepts SAN DIEGO COUNTY WATERAUTHORITT Groundwater Storage & Recovery Project ): \3892\ooo5\Rcport\ciiapt4.doc 4-6 Lowcr San Luis Rey River Valley described herein are based on a yearly average of 2 MGD and a maximum capacity of 4 MGD from the planned San Luis Rey WWTP (reclamation facility). The availability reclaimed water from the San Luis Rey WWTP however is anficipated to vary seasonally, with approximately 4 MGD available during the winter months. It has been assumed that construcfion of advanced reclaimed water facilities will be necessary to treat reclaimed water that will be injected. It is assumed that these facilities will be operated intermittently. However, from a process operafion standpoint (for example, the need to constanfiy run a microfiltration, or nanofiltration plant), it is appropriate to consider possible alternative uses of advanced treated reclaimed water to maximize the benefit of construcfing the advanced treatment facilities. 4.7 Concept Descriptions The project concepts developed by the study team are generally listed as follows: 1. Expand the Mission Basin Desalter by 1.63 MGD and recharge Mission Basin seasonally with reclaimed water. 2. Expand Mission Basin Desalter by 6.70 MGD, supply Oceanside and Carlsbad MWD with potable water, construct new groundwater storage and recovery facilifies to meet a seasonal and/or carryover storage demand. 3. Expand Mission Basin by 6.70 MGD, constmct facilities for groundwater storage and recovery to meet seasonal and/or carryover demands, and arrange for Authority use of City of Oceanside's Weese Filtration Plant (WFP) for in lieu deliveries of filtered water to other agencies. 4. Construct a Bonsall Basin 3.60-MGD Desalter and other facilities for groundwater storage and recovery to meet seasonal and/or carryover demand. 5. Develop storage and recovery projects using in the La Jolla /Eocene formations adjacent to the Mission Basin for groundwater storage. With the excepfion of the La Jolla/Eocene fomiational materials project concept, an overview of the conceptual design elements for each concept is provided below. Higher yield alternatives for project concepts 2, 3 and 4 were also developed and are discussed separately in Secfion 4-8. Based on the project team's current understanding of available data, the La Jolla/Eocene formations are not believed capable of developing yield or storage potenfial that warrants additional study during this project. Refer to Appendix C that contains a draft letter from Fugro West to ASL Consulting Engineers, Inc. The letter discusses a well pump test conducted for the City of Oceanside in a well located on the Swift/Eubank properties and the reliability of the information SAN DIEGO COUNTY WATERAUTHORITY GroundwaterStorage & Recovery Project j;\3892\ooo5\Reportvhapt4.da: 4-7 Lowcr San Luis Rey River Valley reported. The letter also provides recommendations to the Authority regarding a groundwater storage and recovery program in fractured granitic (bedrock) reservoir. All Mission Basin projects have been conceptualized assuming that the City of Oceanside's planned desalter expansion to a potable water production capacity of 6.37 MGD has been implemented. Project concepts are illustrated on Figures 4-1 through 4-4, and project concept operational schematics are illustrated on Figures 4-5 through 4-11. 4.7.a Mission Basin 1.63 MGD Desalter Proiect This concept would be anticipated to increase the yield of the Mission Groundwater Basin by replenishing the basin seasonally with reclaimed water. The addifional potable water production would be used to supply a portion of the City of Oceanside's local demands in its 320-pressure zone. It is thought to be a next feasible step in the expansion of the City's current groundwater program (beyond the City of Oceanside's planned 6.37-MGD Desalter expansion). Project components are illustrated in Figure 4-1. CONCEPTUAL BASIS OF DESIGN This proposed seasonal storage project concept could provide an addifional 1.63 MGD (1825 acre-ft/year) potable water production at the City of Oceanside's Mission Basin desalter. The concept requires increasing capacity of the existing desalter facility and performing seasonal recharge of the Mission Basin with an annual average of 2460 acre-ft/year of reclaimed water during the wetter, cooler months when projected reclaimed water demand at an expanded San Luis Rey WWTP would be lower. This project concept has been sized and configured to be consistent with the City's estimate of reclaimed water that is projected to be available for groundwater recharge. DESCRIPTION OF CONCEPT FACILITIES AND PROPOSED OPERATIONS Groundwater extraction from the basin will be increased using two of the City of Oceanside's wells, currenfiy designated as standby wells. Table 4-1 summarizes the project elements for this concept. A detailed list of proposed facilities can be found in Appendix D. An operational schematic for this project concept is shown on Figure 4-5. Since proposed groundwater extraction facilities are located in the eastem half of the Mission Basin and the extracted groundwater will be replenished seasonally, it is assumed that a seawater intrusion barrier will not be necessary as part of this concept. This assumption, however, would need to be tested with additional investigation. It has been assumed that during normal, or wet water years, groundwater levels would not be lowered in the SANDIEGO COUNTY WATERAUTHORITT Groundwater Storage &'Recovery Project i:\3892\ooo5\Report\chapt4.doc 4-8 Lowcr San Luis Rey River Valley westem portion basin where it might result in seawater intmsion. However, if a drought occurs locally, the basin would not receive normal amounts of recharge and could be overdrafted to a level where seawater intrusion may be possible. Under these circumstances, pumping may need to be curtailed, or the need for a seawater barrier considered. It is expected that currently planned groundwater monitoring would be performed to assess groundwater levels and the potential for seawater intrusion. Table 4-1 Project Elements Mission Basin 1,63 MGD Project Concept Project Element GROUNDWATER EXTRACTION • Use two existing standby wells located at the desalter site and North River Road well field. • GROUNDWATER TREATMENT • Expand existing Oceanside desalter from 6.37 MGD 8.0 MGD (1.63 MGD expansion). CONVEYANCE AND PUMPING • Construct addition to high hfl pump station at desalter site • Construct reclaimed water transmission pipeline from San Luis Rey WWTP to North Riverside Pond recharge area. • Upgrade the existing brine disposal outfall • Upgrade concentrate booster pumps at desalter RECHARGE FACiLmes • Construct outlet/flow control structure at the North Riverside Pond recharge area for surface spreading of reclaimed water. • Construct alternate spreading basin if needed. KEY ASSUMPTIONS AND CONSTRAINTS It is assumed that extraction wells for this project concept have already been constructed or will be constructed during 2000 as part of the City's planned 6.37-MGD expansion project. Two out of the eight wells for that project are designated for standby service, and it is assumed they can be utilized for producfion as part of this project concept. It is also assumed that the City's existing 16-inch cement mortar lined cast iron raw water transmission main which runs from the North River Road wellfield, to the Douglas wellfield, and to the desalter site could confinue to be utilized, although it would operate near its expected capacity. This project concept assumes that the City of Oceanside has implemented its plans to develop Title 22 reclaimed water treatment facilities at its San Luis Rey WWTP. It is assumed that the plant will have a capacity of 4.2 MGD. However, reclaimed water will likely only be available for groundwater replenishment in the winter months when irrigation demand for reclaimed water would be expected to decrease. SANDIEGO COUNTY WATERAUTHORTTT ]:\3892\()(J()5\Rcp()rr\chap[4.d<x 4-9 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Reclaimed water recharge would be performed seasonally over a six-month period at a rate of 4.2 MGD. According to anticipated requirements of the Department of Health Services (DHS), the reclaimed water used for groundwater recharge in the Upper Pond would not exceed 20% of the water withdrawn in any one extraction well. These limitations are further discussed in Chapter 5. The introduction of reclaimed water to the Mission Basin may also be constrained by the City of Oceanside's current practice of by-passing a portion of the recovered groundwater around the RO process. This is further discussed in Chapter 5. It is assumed that the North Riverside Pond can be utilized as a spreading basin for the reclaimed water. However this could potentially be constrained by seasonal operation of the North Riverside Pond as a flood control detention basin along the San Luis Rey River or by requirements that vegetafion be allowed to be estabhshed in the basin. For these reasons, the study team has identified several alternative spreading basin sites near the Upper and North Riverside Ponds. Costs for altemafive spreading basins have been included in cost esfimates as contingency items. During the Aquifer Performance Tests (APTs) conducted by the City in October 1996, field observations suggested that the infiltration capacity of the North Riverside Pond exceeded 1500 gpm, or 2.16 MGD. The exisfing pond configuration may be adequate to support higher capacities on a short-term seasonal basis consistent with the seasonal availability of the reclaimed water. However, addifional spreading basins may be needed. Constmction of an altemate site and extension of infrastructure to serve the site has been included in cost esfimates. It is assumed that the City of Oceanside has expanded the San Luis Rey WWTP land outfall. This would permit the upgraded brine line to be constmcted. 4-7.b Mission Basin 6.70 MGD Desalter Proiect with Provisions to Supply Carlsbad MWD and Seasonal and/or Carryover Storage Operafions This project concept could increase the yield of the Mission Groundwater Basin by a constant rate of 6.70 MGD by taking groundwater from both carryover and seasonal storage. Oceanside and Carlsbad MWD could both benefit from the addifional yield of an expanded Mission Basin Desalter. Other agencies that are connected to the NCDP at the Oceanside 6/VID 11/Rainbow 12 FCF could also benefit if stored water is pumped to their service areas that are connected to the FCF. Of the proposed increased yield of 6.70, 3.23 MGD could be pumped to Carlsbad MWD, and the remaining 3.47 MGD could be ufilized in the City of Oceanside's 320 and 511 pressure zones, or possibly moved to other NCDP agencies. Project components are illustrated in Figure 4-2. SAN DIEGO COUNTY WATER A UTHORTTT Groutidwater Storage & Recovery Project ] :\38y2\ooo5\Rcixirt\chapt4.dcK 4-10 Lower Sau Luis Rey River Valley CONCEPTUAL BASIS OF DESIGN This proposed seasonal and/or carryover storage project could result in an additional 6.70 MGD (7504 acre-ft/year) potable water production at the City of Oceanside's Mission Basin desalter. The concept requires increasing capacity of the existing desalter facility and performing seasonal recharge of the Mission Basin with a total annual average of 10,000 acre-ft/year. Proposed groundwater replenishment would consist of a combinafion of imported and reclaimed water during the wetter, cooler months. DESCRIPTION OF CONCEPT FACILITIES AND PROPOSED OPERATIONS Groundwater extraction from the basin will be increased using two of the City of Oceanside's wells (as with the proposed 1.63 MGD project concept), plus two additional wells at the new Douglas Drive wellfield and two additional wells at the North River Road wellfield. The majority of groundwater replenishment would be imported water. It is assumed that imported water can be conveyed to the recharge sites using exisfing City of Oceanside transmission pipelines and a new proposed imported water pipeline. Table 4-2 summarizes the project elements for this concept. A detailed list of proposed facilifies can be found in Appendix D. This project concept could operate seasonally like first concept introduced, however, the basin could also be overdrafted during drought or emergency when imported recharge water is not available. For the purpose of configuring the concept, it is assumed that a hydraulic barrier will be necessary to prevent seawater intrusion. Overdrafting the basin to historical low water levels is also assumedd. For cost-esfimafing purposes, it is assumed that the basin will be overdrafted to historical low water levels once every seven years and over a three-year period. As before, it is expected that a monitoring program would be performed to assess groundwater levels. SANDIEGO COUNTY WATERAUTHORITT (Groundwater Storage & Recovery Project j:\3S92\ooos\Report\i:hapt4,d<x 4-11 Lowcr San Luis Rey River Valley Table 4-2 Project Elements Mission Basin 6,70 MGD Project Concept Project Element GROUNDWATER EXTRACTION Existing standby wells at desalter site and North River Road. Two new wells at Douglas Drive Two new wells at North River Road GROUNDWATER/RECLAIMED WATER TREATMENT Expand existing Oceanside desalter from 6.37 MGD to potable water production capacity of 13.07 MGD Construct 2.0 MGD advanced reclaimed water treatment facilities al San Luis Rey WWTP (for intrusion barrier water). CONVEYANCE AND PUMPING Upgrade raw water collection line Construct addition to high lift pump station at desalter site. Construct pump station at NCDP/FCF site. Construct reclaimed water transmission pipeline from San Luis Rey WWTP to Upper Pond recharge area. Construct reclaimed water transmission pipeline from San Luis Rey WWTP to narrows intrusion barrier injection site. Extend the City's existing 24-inch aqueduct supply lines from the Weese WFP. Construct miscellaneous pipeline improvements between Oceanside and Carlsbad. Upgrade existing brine disposal outfall. Upgrade concentrate booster pumps at desalter, RECHARGE/INTRUSION BARRIER FACILITIES Construct outlet/flow control structure at the North Riverside Pond recharge area. Construct outlet/flow control structure at the Upper Pond recharge area. Construct imported water injection wellfield/flow control facility along the San Luis Rey River north of Mission Avenue. Construct seawater barrier wellfield at the narrows. This project would normally operate as a constant yield project with artificial recharge performed on a seasonal basis. Arfificial recharge would be provided by disinfected tertiary reclaimed water from the City's San Luis Rey WWTP and unfiltered imported water from the Authority's Second Aqueduct. However, if the imported water recharge supply is curtailed, such as after an earthquake or during a drought, it is assumed that water in carryover storage in the Mission Basin would be extracted in order to maintain supply to the City of Oceanside's desalter. SANDIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Rcpon\chapt4.doc 4-12 (Groundwater Storage Recovery Project Lower San Luis Rey River Valley The extent to which the Mission Basin can be overdrafted without adverse environmental effects is unknown and would need to be evaluated further during subsequent field invesfigafions and modeling studies. However, for the purposes of this conceptual descripfion, it is assumed that the Basin could be overdrafted to historic low groundwater levels (equal to the assumed usable storage in the Mission Basin of 30,000 acre-ft). It is assumed this volume would be extracted from storage over a three-year period and then replenished over a three-year period following restorafion of imported water service. KEY ASSUMPTIONS AND CONSTRAINTS This concept assumes that the City of Oceanside has constructed it planned 6.37-MGD desalter and associated extracfion wells. Additional wells would be added by this project at Douglas and North River Road. However, the rapid rate of land development in this area of Oceanside could possibly constrain the locations of project facilities. This project concept assumes that reclaimed water used for groundwater recharge in the North Riverside Pond will not comprise more than 20% of the water withdrawn in any one extracfion well. Site specific tesfing and groundwater modeling would be required for fijrther evaluation of this assumpfion. It is assumed that the City of Oceanside's Upper and North Riverside Ponds can be utilized as spreading basins for reclaimed and imported water, respecfively. This could potenfially be constrained by seasonal operation as flood control detention basins along the San Luis Rey River or by regulatory requirements that vegetation be established in the basin. For these reasons, the study team has identified several alternative spreading basin sites near the Upper and North Riverside Ponds. Costs for construction of these altemative recharge basins have been included in project cost estimates as contingency items. A seawater intrusion barrier at the narrows would provide protection against potenfial seawater intrusion if the Mission Basin were over-drafted to near historic low water levels. It is assumed that injecfion wells will be necessary to construct a seawater intmsion barrier and that advanced tertiary reclaimed water will be required for the injecfion barrier. Currently, the intmsion barrier is only envisioned to be needed when the carryover storage capacity ofthe Mission Basin is exercised such as during an outage of imported water. However, it may not be practical to operate these advanced teritary facilities on an as-needed basis. Altemate uses of this water may need to be considered to maximize the use of the advanced tertiary treatment facilifies. Altemate uses could include live-stream SANDIEGO COUNTY WATERAU'THORTTT (Groundwater Storage & Recovery Project I:\3892\ooo5\Rcport\chapi4.doc 4-13 Lowcr San Luis Rey River Valley discharge or other potenfially beneficial uses. Subsequent phases of the study will examine potential uses ofthe advanced tertiary water. It may be appropriate to consider larger advanced treatment facilities and injection recharge of groundwater in lieu of land spreading. It is assumed that the majority of the transmission and intrusion barrier facilifies could be located within the Caltrans Highway 76 right of way. It is assumed that the best locafion for the advanced treatment facilities, necessary to produce water for injection, would be at the San Luis Rey WWTP. The City of Oceanside is planning to construct 16.0 MG of surface storage to serve their 511-pressure zone near the FCF locafion at Osborne Street/East Vista Way. This concept assumes that facility is operafional and connected to the remainder ofthe 511-pressure zone via one ofthe two 24-inch City aqueduct lines which mn between Gopher Canyon and the Guajome 511 reservoirs. Water would be pumped from the 320-pressure zone to the 511- pressure zone by a new pump stafion at the existing Heritage reservoir site. It is also assumed that the planned San Luis Rey WWTP land outfall expansion to 36-inch has been completed. This would permit the upgraded brine line to be constmcted. The new 36-inch effluent land outfall will connect to the exisfing ocean outfall, which has been determined in the City's Wastewater Master Plan to have capacity surplus at ultimate flow conditions. It has been assumed that sufficient space exists within existing paved streets for a new 36-inch imported water recharge extension pipeline to be constmcted. Two alignments (Figure 4-2) may be possible for this new pipeline: • A 33,000 linear ft alignment parallel to the City's 42-inch 5^"^ aqueduct supply line (Mission Avenue/N. Santa Fe Avenue via E. Vista Way, Barsby St., and Camino Largo) which then continues west on Mission Avenue to Frazee Road. It would then tum north on Frazee Road to Old Grove Road, and then tum north on Old Grove Road to the Upper Pond. • A 34,200 linear ft alignment which mns north on E. Vista Way to Mission Avenue, and then west on Mission Avenue to Frazee Road. It would then tum north on Frazee Road to Old Grove Road, and then tum north on Old Grove Road to the Upper Pond. An alignment altemafive analysis would be performed as part of the design process to select the most appropriate alignment. The imported water recharge pipeline would be fed from an existing 39 cfs (25 MGD) capacity FCF that was formerly used to feed unfiltered water to the WFP (Oceanside FCF No. 3). This FCF is connected to Pipeline 3 and is not currenfiy in use since the City draws feed water for the Weese WFP from FCF No. 5, which is connected to Pipeline 5. The imported water would be delivered to the new importer water extension via the existing 2-24-inch City aqueduct lines which are currently inactive. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\Reporc\chapt4,doc 4-14 Lowcr Sau Luis Rey River Valley 4.7.C Mission Basin 6.70 MGD Desalter with Regional Use of the Weese Water Filtration Plant CONCEPTUAL BASIS OF DESIGN This proposed seasonal and/or carryover storage project could result in an addifional constant yield of 6.70 MGD (7504 acre-ft/year) of potable water from the Mission Basin. Expansion of facilities at the City of Oceanside's Mission Basin desalter would be required as in the previous concept. This concept would require the same amount of groundwater replenishment and would operate the same as the second concept in terms of groundwater extraction, recharge, and replenishment. This project concept also proposes to reserve a portion of ftiture capacity at the City of Oceanside's Weese Filtration Plant (WFP) equal to the Mission Basin expansion. This is an "in lieu" project concept that could provide expanded Mission Basin groundwater production while also providing an increase in the increment of treated water available to other Authority member agencies. The project would operate as a constant yield program with the Authority constmcfing Mission Basin groundwater facilities to enable the City of Oceanside to meet a greater portion of their daily demands with a local groundwater resource. It is proposed that the Authority construct and utilize excess Weese WFP plant capacity to meet filtered water demands in other parts of the County. It would also be possible for Oceanside and the Authority to realize carryover storage benefits if the imported water recharge delivery is interrupted. The basin could be overdrafted, as discussed under previous concepts, until imported water recharge supply again became available. Project components at the Weese WFP are illustrated in Figure 4- 3; project components associated with the Mission Basin groundwater portion of this concept are illustrated in Figure 4-2. DESCRIPTION OF CONCEPT FACILITIES AND PROPOSED OPERATIONS The Weese WFP is currently owned and operated by the City, and has a capacity of 25 MGD. However, the site has been master-planned for expansion and a potential ultimate capacity of 50 MGD. The Weese WFP's close proximity to the Authority's Second Aqueduct and its relafively high HGL make it a good location to move additional treated water into Pipeline 4 of the Second Aqueduct. The Second Aqueduct is used to deliver treated water to member agencies downstream of this location. This includes most Authority member agencies. Table 4-3 summarizes the project elements for this concept, which are above and beyond those presented earlier for the second concept. However, there are several conveyance and pumping facilifies idenfified in the second concept not required in this project. SANDIEGO COUNTY WATERAUTHORTTT (Groutuiwater Storage & Recovery Project j:\3892\D00s\RcportVhapc4,d<K 4-15 Lowcr Sau Luis Rey Rivcr Valley Table 4-3 Project Elements Mission Basin 6.70 MGD with Regional Use of the Weese Water Filtration Plant Project Concept Project Elements IMPORTED WATER TREATMENT • Expand existing City of Oceanside's Weese WFP by an increment equal to expanded Mission Basin production CONVEYANCE AND PUMPING • Construct treated water pump station at Weese WFP to pump treated water back into Pipeline 4 of the Second Aqueduct RECLAIMED WATER TREATMENT • Construct 2.0 MGD advanced tertiary reclaimed water treatment facilities at San Luis Rey WWTP (for intrusion barrier water). CONVEYANCE AND PUMPING • Upgrade raw water collection line. • Construct addition to high lift pump station at desalter site. • Construct reclaimed water transmission pipeline from San Luis Rey WWTP to Upper Pond recharge area. • Construct reclaimed water transmission pipeline from San Luis Rey WWTP to narrows intrusion barrier injection site. • Extend the City's existing 24-inch aqueduct supply lines from the Weese WFP. • Upgrade existing brine disposal outfall. • Upgrade concentrate booster pumps at desalter. RECHARGE/INTRUSION BARRIER FACILITIES • Construct outlet/flow control structure at the North Riverside Pond recharge area. • Construct outlet/flow control structure at the Upper Pond recharge area. • Construct imported water injection wellfield/flow control facility along the San Luis Rey north of Mission Avenue. • Construct seawater barrier wellfield at the narrows. KEV ASSUMPTIONS AND CONSTRAINTS The facilifies required to implement this project concept are generally as described in the previous Mission Basin 6.70-MGD Desalter concept, with the excepfion of facilifies or insfitutional arrangements associated with moving Mission Basin groundwater to agencies other than Oceanside. This project concept can accomplish that objecfive via in-lieu deliveries from the Weese WFP by gravity as opposed to pumping this water from the Mission Basin. Such facilifies as the pump station at the NCDP and numerous pipeline improvements necessary to move water to Carlsbad would be required. However, a pump station would be needed at the Weese WFP in SANDIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Rc-port\thapt4.doc 4-16 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley order to feed filtered water back into Pipeline 4 of the Second Aqueduct and deliver it to other agencies. For the purposes of evaluafing this altemafive, it is assumed this will be a 6.70-MGD pump station, an amount equal to the Authority's proposed Weese WFP capacity allotment. This pump station would pump treated water from the Weese WFP Regulatory Structure constmcted as part of the NCDP project. Based on the floor elevation of the Regulatory Structure (963 ft) and maximum Pipeline 4 HGL (1116 ft), total pump stafion lift will be on the order of 150 to 200 ft. The pump station could be located on Authority property adjacent to the Regulatory Structure, NCDP 1/RMWD 11 FCF, and Second Aqueduct. It should be noted that this altemative assumes that the City of Oceanside would perform the future expansion of the Weese WFP enabling them to meet future demands. We assume that Oceanside would expand Weese WFP up to its full capacity of 50 MGD. If the Authority were to carve out its 6.70 MGD of capacity, this would leave Oceanside with 43.3 MGD of capacity. At the projected ulfimate peak demand for Oceanside of 62.0 MGD, the Mission Basin would provide 13.07 MGD, the Tri-Agencies Pipeline would provide 6 MGD to serve the San Francisco Peak pressure zone, and the WFP would need to provide the remaining 42.9 MGD. 4.7.d Bonsall Basin 3.60 MGD Desalter with Groundwater Storage and Recovery Operations This project concept could provide an additional average annual yield of 3.60 MGD of potable water from the Bonsall Basin to the Rainbow MWD. Increased yield could be accomplished by providing seasonal artificial replenishment of groundwater. The water could be used to meet demand or offset storage requirements in the District's Morro 865 pressure zone. Project components are illustrated in Figure 4-4. CONCEPTUAL BASIS OF DESIGN This proposed project concept could increase the yield of the Bonsall Basin and provide an additional 3.60 MGD (4032 acre-ft/year) of potable water production. The concept proposes a new brackish groundwater desalter near the vicinity of Interstate 15 and Highway 76, near the existing Rainbow MWD offices and their former wastewater treatment plant. The desalter yield was based on the amount of groundwater that might be safely extracted over a 3-year period. The concept proposes artificial replenishment of the Bonsall Basin using imported water from the Authority's Second Aqueduct. Table 4-4 summarizes the project elements for this concept. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage &• Recovery Project j:\3892\0005\Rcport\chapi4.doc 4-17 LowcT San Luis Rey River Valley Table 4-4 Project Elements Bonsall Basin 3.60 MGD Project Concept Project Elements GROUNDWATER EXTRACTION • Develop and equip three wells north of the San Luis Rey River and west of Sage Road. GROUNDWATER TREATMENT • Construct desalter on Rainbow MWD property. CONVEYANCE AND PUMPING • Construct raw water collection line from Sage wellfield to the desalter. • Construct pipeline from new turnout (see below) lo recharge wellfield. • Construct pump station to feed the District's 865 pressure zone. • Construct brine disposal pipeline to connect to existing Oceanside land outfall. RECHARGE FACILITIES • Construct unfdtered water turnout along Second Aqueduct south of Highway 76. • Construct recharge wellfield on District property. This project could produce a constant yield project in conjuncfion with seasonal groundwater replenishment. Artificial recharge could be provided by imported water from the Authority's Second Aqueduct. However, if the imported replenishment supply is curtailed, such as during a prolonged statewide drought, it is assumed that water in carryover storage in the Bonsall Basin would be utilized to maintain supply to the brackish groundwater desalter. The extent to which the Basin can be drafted without adverse environmental effects is unknown and would need to be evaluated during subsequent field invesfigafions and modeling studies. Available data indicates historic low groundwater levels equate to an approximate 9,000 acre-ft storage volume. It is assumed this volume could be extracted from storage over a three-year period and then replenished over a three-year period following restoration of imported water service. The operational schematics for this concept are shown in Figures 4-9, 4-10 and 4-11. KEY ASSUMPTIONS AND CONSTRAINTS It is assumed that the rate of extracfion of groundwater from the Bonsall Basin will be envirorunentally and hydrogeologically feasible. It is assumed that a new brine land outfall can be constructed parallel to the District's planned sewage land outfall. SANDIEGO COUNTY WATERAUTHORITT J:\3892\0005\Rcport\cliapt4.doc 4-18 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley 4.8 Higher Yield Project Alternatives 4.8.1 Introduction The intent of this secfion is to introduce and discuss potential project alternatives that include greater desalter yields than those presented in the prior discussions. As discussed previously in this chapter, the calculation of project yields was based on the esfimated usable groundwater storage and an assumpfion regarding the length of fime carryover storage would be drawn upon in the absence of imported replenishment supplies (3 years). This secfion evaluates higher yields for the following project concepts; 1. Mission Basin 6.70 MGD Desalter Project with Provisions to Supply Carisbad MWD, 2. Mission Basin 6.70 MGD Desalter Project with Regional Use of the Weese Water Filtration Plant, and 3. Bonsall Basin 3.60 MGD Desalter Project. Since the assumption of the length of a potential outage of replenishment supply is key to sizing of project facilities, it deserves careful consideration. Historically, imported water outages or curtailment of replenishment supplies have been of brief duration. For example, in 1991, replenishment deliveries were curtailed for 15 days during the winter. The historical record suggests that it may be appropriate to consider shorter outage periods when sizing groundwater facilities, given the large initial investments required. If the length ofthe potential outage is shortened from a three-year period to a two-year period, the desalter yield can increase accordingly. Calculafions were performed for both the Mission and Bonsall Basins under this management scenario. For the Mission Basin, the desalter yield was increased to 10.0 MGD (versus 6.70 MGD under the three-year scenario), and for the Bonsall Basin, the desalter yield was increased to 4.6 MGD (versus 3.60 MGD under the three-year scenario). 4.8.2 Review of Hydrogeologic and Environmental Issues Associated with Higher Yields Hydrogeology of the Mission and Bonsall Basins was reviewed in Chapter 2, and a full discussion of potenfial environmental issues associated with the project concepts is discussed in Chapter 5. However, the following paragraphs provide a general discussion of potential hydrogeologic and environmental considerations associated with the higher yield project alternatives that are discussed in this subsection. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project I:\3892\ooo5\Repoit\chapr4,dot 4-19 Lowcr San Luis Rey River Valley Hydrogeologic Issues Increasing desalter yields will necessitate additional extraction of groundwater beyond that discussed previously. For the Mission Basin, a groundwater extraction of 9,300 gpm will be required for a desalter yield of 10.0 MGD. When compared with the 6.70 MGD project concept, this would be performed with two additional wells at the Douglas Drive site and one addifional well at the North River Road site. For the Bonsall Basin, groundwater extracfion of 4,300 gpm will be required for a desalter yield of 4.6 MGD. When compared with the 3.60 MGD project concept, this would be performed with one addifional well at a site near the San Luis Rey River and Sage Road. The potential impact of constmcfing addifional wells at the North River Road, Douglas Drive well fields, and in the Bonsall Basin will need to be evaluated as part of Phase 2 invesfigafions. Conceptually, the two-year replenishment water outage and increased groundwater yield proposed as part of the 10-MGD concepts do not appear to significantly alter the hydrogeologic impacts associated with the three- year replenishment water outage on a basinwide basis. Impacts similar to those previously discussed in Chapter 2 are anticipated. However, it is possible that these potential impacts could be more pronounced in the vicinity of the extraction and/or recharge wells or near spreading basins under the two-year replenishment due to increased rates of extraction and recharge. The local impacts, however, could be minimized if the extraction and recharge facilities are planned, designed, and operated properly. Environmental Issues When compared to a three-year outage, a two-year replenishment water outage may actually be more favorable to the environmental condition of the basins because the duration of basin stress would be shorter. Although the two-year replenishment water outage appears to be more favorable than the three-year replenishment water outage, possible environmental issues may still remain, many of which are similar to those associated with the prior concepts. Since more imported water of higher quality is used for replenishment, the potential for improvements in groundwater quality under this scenario should be greater. More importantly, since the higher yield concepts do not propose a proportional increase in the use of reclaimed water for groundwater recharge, the percentage of reclaimed water contributed to the Mission Basin would be reduced from 22 percent to approximately 15 percent of the managed basin yield. This is below the Califomia Department of Health Services' proposed regulafion of 20 percent. Again, the potenfial SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\RefX)rt\chapt4-doc 4-20 Lower San Luis Rey River Valley environmental impacts of the two-year replenishment water outage scenario may be more pronounced locally in the vicinity of the extraction and/or recharge facilities; however, these local impacts could be minimized through proper planning, design, and operation. 4.8,3 Mission Basin Higher Yield As discussed above, extraction of carryover storage over a two-year period in the Mission Basin translates into a constant desalter yield of 10.0 MGD. During years when replenishment supply is available, recharge would be performed on a seasonal basis or whenever discounted imported water was available for recharge, as discussed previously. Mission Basin Higher Yield 10.0 MGD Desalter Project with Provisions to Supply Carisbad MWD CONCEPTUAL BASIS OF DESIGN This proposed seasonal and/or carryover storage project could result in an additional 10.0 MGD (11,200 acre-ft/year) potable water producfion at the City of Oceanside's Mission Basin desalter. The concept requires increasing capacity of the existing desalter facility and performing recharge of the Mission Basin with a total annual average of 15,000 acre-ft/year. Proposed groundwater replenishment would consist of a combination of imported and reclaimed water during the wetter, cooler months and/or when discounted imported water was available as in the 6.70-MGD concept. It is assumed that at least 5 cfs, or 3.23 MGD of the yield, would be provided to Carlsbad MWD, and the remainder used by Oceanside or transferred to other agencies during periods of carryover storage extraction. DESCRIPTION OF CONCEPT FACILITIES AND PROPOSED OPERATIONS Many of the facilities required for this concept are the same as those proposed for the Mission Basin 6.70 MGD project concept. A detailed list of proposed facilities can be found in Appendix D. The following highlight the major differences: • An additional 4.4 MGD of groundwater is required to be extracted. This would be performed with one addifional well at North River Road and two addifional wells at Douglas Drive. • Raw water collection lines are required to be upsized. • The imported-water recharge pipeline and recharge wellfield would both require upsizing. • The Mission Basin desalter would need to be upgraded to a potable water production capacity of 10 MGD (assuming the same blending rafio can be utilized). SANDIEGO COUNTY WATERAUTHORITY (Groundwater Storage & Recovery Project j:\3892\ooo5\Reporc\ciiapc4.doc 4-21 Lower San Luis Rey River Valley • The treated water pump station at the desalter would need to be upgraded to 10 MGD. • The proposed pump stations at Oceanside's Heritage and future Osbome Reservoir sites would need to be upgraded to 6.53 MGD versus 3.23 MGD. • During normal operation, the Oceanside 511-pressure zone could be provided with an additional 3.3 MGD of treated Mission Basin groundwater. • Additional miscellaneous pipeline improvements within the Oceanside 320 and 511 pressure zones and interconnecfions with Carlsbad to accompany the above. As with the 6.7-MGD concept, this project scenario would allow the basin to be drafted during drought or emergency when imported water is not available for groundwater recharge. For the purpose of configuring this concept, it is assumed that a hydraulic barrier will be necessary to prevent seawater intmsion. Drafting the basin to historical low water levels is assumed. For cost-esfimating purposes, it is assumed that the basin will be drafted to historical low water levels once every seven years and over a two- year period. As with the 6.7 MGD concept, it is expected that a monitoring program would be performed to assess groundwater levels, however, costs for constructing and implementing a groundwater monitoring program have not been included. This project would operate in a similar manner as the Mission Basin 6.70- MGD project concept, however, the groundwater and replenishment water volumes would be proportionally higher to reflect the higher yield for this altemative. KEY ASSUMPTIONS AND CONSTRAINTS The major differences in assumpfions between this altemative an its 6.70 MGD counterpart can be summarized as follows: • Land for additional future groundwater extraction and recharge wells, and for wellhead facilities will be available in the areas of interest. • Both of the City of Oceanside's 24-inch aqueduct supply lines can be used for unfiltered water for groundwater recharge operations, as opposed to one for the 6.70 MGD project concept. • The entire capacity of exisfing Oceanside FCF No. 3 that formerly fed unfiltered water to WFP can be used for unfiltered water for groundwater recharge. Mission Basin Higher Yield 10.0-MGD Desalter Project with Regional Use of the Weese Water Filtrafion Plant SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\Report\thapt4.doc 4-22 LowcT San Luis Rey River Valley CONCEPTUAL BASIS OF DESIGN This proposed storage project could result in an addifional constant yield of 10.0 MGD (11,200 acre-ft/year) of potable water from the Mission Basin. Expansion of facilifies at the City of Oceanside's Mission Basin desalter would be required as in the previous concept. This concept would require the same amount of groundwater replenishment and would operate the same as the 10-MGD Higher Yield concept (previously discussed) in terms of groundwater extraction, recharge, and replenishment. However, this project concept proposes to reserve 10 MGD of future capacity at the City of Oceanside's Weese Filtration Plant (WFP). The 10.0 MGD of treated water from the WFP could be used by the Authority to serve other member agencies downstream of the WFP. 10 MGD of addifional Mission Basin Desalter production would be ufilized by Oceanside (in-lieu of 10 MGD of WFP capacity) to serve its 320 and 511 pressure zones. It is assumed the Authority would serve Carlsbad MWD with 5 cfs, or 3.23 MGD, from the WFP in-lieu of 5 MGD from the Mission Basin. This eliminates the need to constmct addifional pipeline improvements and interconnections between Oceanside and Carlsbad to provide Carisbad with treated Mission Basin groundwater. As with the 6.70 MGD Desalter Project (with Regional Use of Weese Water Filtrafion Plant), this "in lieu" project concept could provide expanded Mission Basin groundwater producfion while also providing an increase in the increment of treated water available to other Authority member agencies. Many of the facilifies required for this concept are identical to those required for its 6.70-MGD lower yield counterpart. A detailed list of proposed facilifies can be found in Appendix D. The following highlight the major differences: • WFP would need to be expanded by 10.0 MGD, as opposed to 6.70 MGD under the lowcr yield project. • The proposed treated-water pump station at WFP and its corresponding discharge pipeline to the Authority's Pipeline 4 would be sized for 10.0 MGD as opposed to 6.70 MGD. • The proposed Heritage Reservoir pump station would be sized for 5 MGD as opposed to 3.23 MGD for the lower yield altemafive. • An additional 4.4 MGD of groundwater is required to be extracted. This would be performed with one addifional well at North River Road and two addifional wells at Douglas Drive. • Raw water collection lines are required to be upsized. • The imported-water recharge pipeline and recharge wellfield would both require upsizing. SAN DIEGO COUNTY WATERAUTHORTTT Groundwater Storage & Recovery Project j:\3892\ooo5\Repon\chapt4.doc 4-23 Lower Sau Luts Rey River Valley • The Mission Basin desalter would need to be upgraded to a potable water producfion capacity of 10 MGD (assuming the same blending ratio can be ufilized). • The treated water pump stafion at the desalter would need to be upgraded to 10 MGD. KEY ASSUMPTIONS AND CONSTRAINTS The major differences in assumptions between this altemative an its 6.70 MGD counterpart can be summarized as follows: • Assuming Oceanside expands the exisfing 25-MGD Weese WFP by 15 MGD, Oceanside would have a total of 40 MGD of capacity at the Weese WFP to meet its projected ultimate peak demand of 62.0 MGD. The remainder of Oceanside's projected ultimate peak demand could be met using the proposed 16.37-MGD (Oceanside's proposed 6.37 MGD + Authority's proposed 10 MGD) producfion from the Mission Basin Desalter and 6 MGD from the Authority's Tri-Agencies Pipeline. • The Weese WFP site would be buih to maximum capacity (assuming the constmction of an addifional 25 MGD of direct-filtrafion facilities by the Authority and the City of Oceanside). • Land for additional proposed groundwater extraction and recharge wells and wellhead facilities will be available in the areas of interest. • Both of the City of Oceanside's 24-inch aqueduct supply lines can be used for unfiltered water for groundwater recharge operafions, as opposed to one for the 6.70 MGD project concept. • The entire capacity of existing Oceanside FCF No. 3 that formerly fed unfiltered water to WFP can be used for unfiltered water for groundwater recharge. 4.8.4 Bonsall Basin Higher Yield A two-year replenishment supply outage in the Bonsall Basin translates into a desalter yield of 4.6 MGD. During years when replenishment supply was available, the basin would be recharged on a seasonal basis or when discounted-imported water was available for recharge, as discussed previously. Bonsall Basin Higher Yield 4.60 MGD Desalter with Groundwater Storage and Recovery Operations CONCEPTUAL BASIS OF DESIGN This project concept could provide an additional average annual yield of 4.60 MGD (5,152 acre-ft/year) of potable water from the Bonsall Basin to the Rainbow MWD. Increased yield from the Bonsall Basin could be SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j;\3892\ooo5\Report\chapt4.doc 4-24 Lowcr Sau Luis Rey River Valley accomplished by providing artificial replenishment of groundwater. The addifional groundwater yield could be used to meet demand and offset storage requirements in the District's Morro 865 pressure zone. The concept proposes a new brackish groundwater desalter near the vicinity of Interstate 15 and Highway 76, near the existing Rainbow MWD offices and their former wastewater treatment plant. The concept proposes artificial replenishment of the Bonsall Basin using imported water from the Authority's Second Aqueduct. Many of the facilities required for this concept are identical to those required for its 3.60-MGD lower yield counterpart. A detailed list of proposed facilities can be found in Appendix D. The following highlight the major differences: • The proposed desalter and treated-water pump station and pipeline would have a capacity of 4.60 MGD versus 3.60 MGD for the lower yield project • One additional groundwater extraction well would be required. • One additional groundwater injecfion well would be required. • The proposed new unfiltered water turnout, flow control facility, and associated piping would need to be upsized for the new maximum replenishment water rate of 8 MGD. • A brine-disposal pipeline (to Oceanside) would be necessary for the estimated concentrate flow of 1.6 MGD. This project could produce a constant yield in conjunction with groundwater replenishment. Artificial recharge could be provided seasonally and when discounted- imported water fi:om the Authority's Second Aqueduct is available. However, if the imported replenishment supply is curtailed, such as during a prolonged statewide drought, it is assumed that water in storage in the Bonsall Basin would be utilized to maintain supply to the brackish- groundwater desalter. KEY ASSUMPTIONS AND CONSTRAINTS Other than the key assumptions that Rainbow MWD can utilize the desalter output on a constant yield basis and that the Oceanside land and ocean outfalls can handle the increase in concentrate flow, there are no known differences in the assumptions or constraints to the this higher yield project than those already discussed for its lower yield counterpart. SANDIEGO COUNTY WATERAUTHORTTT Groundwater Storage & Recovery Project I;\3S92\fl005\RcpoLt\ciiapt4.doc 4-25 Lowcr San Luis Rey River Valley Water District Boundaries Faiibrooic Public Utility District l^inbow MWD Vallecitos County WD Vista ID Carlsbad i^WD Vista ID & Vallecitos County WD Pendleton Military Reservation City of Oceanside Unserved Pipelines SDCWA Facilities Creoles Major Roads Freeways Lagoons La Ices Alluvial Aquifer Figure 4-1 Mission Basin 1.63 MGD Constant Yield Desalter with Seasonal Recharge 4 Miles Water District Boundaries Rainbow MWD Vallecitos County WD Vista ID Carlsbad MWD Pendleton Military Reservation City of Oceanside Unserved y%y Pipelines SDCWA Facilities Creeks Major Roads Freeways Lagoons Lakes Alluvial Aquifer Figure 4-2 Mission Basin 6.70 MGD Constant Yield Desalter with Seasonal and Carryover Storage Operations 3 Miles Water District Boundaries Rainbow MWD Vallecitos County WD Roads SDCWA Facilities Creeks Existing RMWD Gopher Canyon Reservoir Existing Regulatory Structure Existing Flow Control Facility Proposed Pump station Weese Water Filtration Plant (City of Oceanside) 25 MGD Current Capacity 50 MGD Potential Capacity Figure 4-3 Regional Use of Weese Filtration Plant 0.4 0.4 Miles Water District Boundaries Fallbrook Public Utility District Rainbow MWD Valley Center MWD San Luis Rey MWD Unserved SDCWA Facilities Creeks Major Roads Freeways Lagoons Lakes Alluvial Aquifer Figure 4-4 Bonsall Basin 3.6 MGD Constant Yield Desalter with Seasonal and Carryover Storage Operations 2 Miles FIGURE 4-5 10,000 ACRE-FtET/YEAR (NATURAL RECHARGE) 2.352 ACRE-FEETAEAR (RECLAIMED WATER RECHARGE) 1 10,000 ACRE-FEET/YEAR (8.9 MGD) '(CITY OF OCEANSIDE & PRIVATE USERS) DESALTER 6.37 MGD PRODUCTION (CITY OF OCEANSIDE ONLY) 2,352 ACRE-FE:ETAEAR (2.1 WGD) "(SDCWA) D(PANDEd 3ESALTER 1.63 MGD PRODUCTiON y/////////^//y MISSION GROUNDWATER BASIN 30.000 ACRE-FECT OPERATING STORAGE (FULL)' 0.5 MGD CONCENTRATE CONSTANT YELD / SEASONAL OPERATIONS CALCULATIONS: RECHARGE NATURM. 10,000 AC RE-FEET/YEAR RECLAIMED WATER 2,352 ACRE-FEETAEAR TOTAL 12.352 ACRE-FEETAEAR EXTRACTION CITY OF OCEANSIDE ic PRIVATE USERS 10.000 ACRE-FEETAEAR SDCWA 2,352 ACRE-FEETAEA^ TOTAL 12.352 ACRE-FEETAE^ NOTE; RECLAIMED WATER RECHARGE WILL BE PERFORMED ON A SIX MONTH SCHEDULE. ANNUAL AVERAGE IS INDICATED- EXISTING O ASL Consulting Engineers 10SI5 Rancho BemnnJo Road. Suits 200 Son Diego, California 92127 (856) 673-5505 MISSION BASIN 1.63 MGD PROJECT CONCEPT 4 So/? Diego County Woter Authority FIGURE 4-6 lO.OOO ACRE-FEETAEAR (NATURAL RECHARGE) 2.352 ACRE-FEETAEAR (RECLAMED WATER RECHARGE) 10,000 ACRE-FEETAEAR (8.9 MGD) "(CITY OF OCEANSIDE & PRIVATE USERS) 7,648 ACRE-FEETAEAR (IMPORTED WATER RECHARGE) DESW.TER ,6.37 MGD PRODUCTION (CITY OF OCEANSIDE ONLY) 10,000 ACRE-FEETAEAR (8.9 UGD) "(SDCWA) LXPANDEC DESALTER 6.70 MGD "PRODUCTION //////////////y///W//////y // MISSION GROUNDWATER BASIN //,30.000 ACRE-FEET OPERATING STORAGE (FULL) 2.2 MGD CONCENTRATE CONSTANT YIELD / SEASONAL OPERATIONS CALCULATIONS: RECHARGE NATUR>y. RECLAIMED WATER IMPORTED WATER 10,000 ACRE-FEET/rtAR 2.352 ACRE-FEETAEAR 7.648 ACRE-FEETAEAR ENACTION CITY OF OCEANSIDE & PRIVATE USERS 10,000 ACRE-FEETAEAR SDCWA 10.000 ACRE-FEETAEAR TOTAL 20,000 ACRE-FEETAEAR TOTAL 20,000 ACRE-FEETAEAR NOTE: RECLAIMED AND IMPORTED WATER RECHARGE WILL BE PERFORMED ON A SIX MONTH SCHEDULE. ANNUAL AVERAGE IS INDICATED. EXISTING ASL Consulting Engineers 10815 Rancho Bemordo Rood, Suits 200 Son Disgo. Californio 92127 (858) 673-5505 MISSION BASIN 6.70 MGD PROJECT CONCEPT 4 Son Diego County Woter Auttiorify FIGURE 4-7 2.352 ACRE-FEETAEAR (RECLAIMED WATER TO BARRIER WELLS) ^ SEAWATER INTRUSION BARRIER 10.000 ACRE-FECTAEAR (8.9 MGD) '(CITY OF OCEANSIDE <t PRIVATE USERS) 10,000 ACRE-FEETAEAR (NATURAL RECHARGE) DESALTER 6.37 MGD PRODUCTION (CnY OF OCEANSIDE OSLY) 10,000 ACRE-FEETAEAR (8.9 MGD) -(SDCWA) EXPANDED DESALTER 6.70 MGD PRODUCTION / 2.2 MGD ' CONCENTRATE ///>/////////// MISSION GROUNDWATER BASIN 30,000 ACRE-FEET OPERATING STORAGE (FULL AT YEAR 1) i-u. t I. c c c i. c £— CARRYOVER EXTRACTION OPERATION (3 YEAR OUTAGE OF IMPORTED WATER) CAI CUI ATIONS: RECHARGE NATURAL 3 X 10,000= 30.000 ACRE-FEET STORAGE = 30,000 ACRE-FEET TOTAL = 60.000 ACRE-FEET EXTRACTION CITY OF OCEANSIDE <fe PRIVATE USERS 3 X 10.000 = 30,000 ACRE-FEET SDCWA (3 YEAR OPERATION) = 30.000 ACRE-FEET TOTAL = 60,000 ACRE-FEET EXISTING CP "O CN o x: ASL Consulting Engineers 10915 Rancho Bernardo Rood. Suite 200 Son Diego. California 92127 (858) 673-5505 MISSION BASIN 6.70 MGD PROJECT CONCEPT 4 Son Diego County Woter Autiiority FIGURE 4-8 10,000 ACRE-FEETAEAR (NATURAL RECHARGE) 2.352 ACRE-FEETAEAR (RECLAIMED WATER RECHARGE) 17.548 ACRE-FEETAEAR (IMPORTED WATER RECHARGE) 1 r 10,000 ACRE-FECTAEAR (8.9 MG:) "(CITT OF OCEANSIDE & PRIVATE USESS) XL DESALTER 6.37 MGD PR0DUrT:ON (CITY OF 0CEAN5i:€ ONLY) 10,000 ACRE-FECTAEAR (8.9 M'O) '(SDCWA) DtPANOEO DESALTER 6.70 MGD PRODUCTION MISSION GROUNDWATER BASIN 30,000 ACRE-FECT OPERATING STORAGE (EMPTT) 2.2 MGD CONCENTRATE REPLENISHMENT OPERATION (FOLLOWING A 3 YEAR OUTAGE OF IMPORTED WATER) CALCULATIONS: RECHARGE NATURAL • 3 X 10.000 RECLAIMED WATER 3 X 2.352 IMPORTED WATER DIFFERENTIAL = 30.000 ACRE-FECT = 7.056 ACRE-FECT = 52,944 ACRE-FEET EXTRACTION CRY OF OCEANStOE & PRIVATE USERS 3 X 10,000 SDCWA 3 X 10,000 RECH/y^GE TO STORAGE TOTAL = 90,000 ACRE-FECT = 30.000 ACRE-FEE^ = 30.000 ACRE-FECT =. 30.000 ACRE-FEET TOTAL = 90.000 ACRE-FEET EXISTING ASL Consulting Engineers 10B1S Rancho Bemordo Rood. Suite 200 San Diego. Coiifomlo 92127 (858) 673-5505 MISSION BASIN 6.70 MGD PROJECT CONCEPT 4 Son Diego County Woter Autrionty FIGURE 4-9 2,800 ACRE-FECTAEW? (NATURAL RECHARGE) 400 ACRE-FECTAEAR -(PRIVATE USERS) 3,000 ACRE-FECTAEAR (IMPORTED WATER RECHARGE) 5,400 ACRE-FEETAEAR •(SDCWA) DESALTER 3.60 MGD PRODUCTION V////////f///////y BONSALL GROUNDWATER BASIN ,9,000 ACRE-FECT OPERATING STORAGE (FULL) 1.2 MGD CONCENTRATE CONSTANT YIELD / SEASONAL OPERATIONS CAL.CULATiONS-. RECHARGE NATURAL IMPORTED WATER 2,800 ACRE-FECTAEAR 3,000 ACRE-FECTAEAR EXTRACTION PRIVATE USERS SDCWA 400 ACRE-FECTAEAR 5.400 ACRE-FECTAEAR TOTAL 5.800 ACRE-FECTAEAR TOTAL 5,800 ACRE-FECTAEAR NOTE: IMPORTED WATER RECHARGE WILL BE PERFORMED ON A SIX MONTH SCHEDULE. ANNUAL AVERAGE IS INDICATED. EXISTING C7^ O SI a o Q < ASL Consulting Engineers 10B15 Rancho Semardo Road. Suite 200 Sof( Diego. California 92127 (858) 673-5505 BONSALL BASIN 3.60 MGD PROJECT CONCEPT Son Diego County Woter Authority FIGURE 4-10 400 ACRE-FECTAEAR "(PRIVATE USERS) 2,800 ACRE-FECTAEAR (NATURAL RECHARGE) 5,400 ACRE-FECTAEAR "(SDCWA) DESALTER 3.60 MGD PRODUCTION vr ////////////// BONSAa GROUNDWATER BASIN .000 ACRE-FECT OPERATING STORAGE (FUa AT YEAR 1) 1.2 MGD CONCENTRATE CARRYOVER EXTRACTION OPERATION (3 YEAR OUTAGE OF IMPORTED WATER) CALCULATIONS: RECHARGE NATURAL 3 X 2.800 STORAGE 8,400 ACRE-FECT 9.000 ACRE-FECT EXTRACTION PRIVATE USERS 3 X 400 SDCWA (3 YEAR OPERATION) = 1.200 ACRE-FECT 16.200 ACRE-FICT TOTAL 17.400 ACRE-FECT TOTAL 17,400 ACRE-FEEi EXISTING CT. T: O "D sz CD ASL Consulting Engineers 10S15 Rancho Berrwrdo Rood, Suito 200 San Diego, California 92127 (856) 673-5505 BONSALL BASIN 3.60 MGD PROJECT CONCEPT Son Diego County Woter Authority FIGURE 4-11 2,800 ACRE-FECTAEAR (NATURAL RECHARGE) r 400 ACRE-FECTAEAR "(PRIVATE USERS) 6,000 ACRE-FECTAEW? (IMPORTED WATER RECHARGE) ^ 5,400 ACRE-FECTAEAR "(SDCWA) DESALTER 3.60 MGD PROiXICTlON BONSALL GROUNDWATER BASIN 9.000 ACRE-FECT OPERATING STORAGE (EMPTY) 1.2 MGD CONCENTRATE REPLENISHMENT OPERATION (FOLLOWING A 3 YEAR OUTAGE OF IMPORTED WATER) CALCULATIONS: RECHARGE NATURAL 3 X 2,800 = 8,400 ACRE-FECTAEAR IMPORTED WATER 18,000 ACRE-FECTAEW^ TOTAL 26.400 ACRE-FECTAEAR PRIVATE USERS 3 X 400 = 1,200 ACRE-FECTAEAR SDCWA 3 X 5.400 = 16,200 ACRE-FECTAEAR RECHARGE TO STORAGE 9,000 ACRE-FECTA^ifl TOTAL 26.400 ACRE-FECTAEAR EXISTING "O CO o SI o / o Q < ^ in o o o ASL Consulting Engineers 10S1S Rancho Qemonla Road. Suite 200 Son Diego, California 92127 (858) 673-5505 BONSALL BASIN 3.60 MGD PROJECT CONCEPT 4 Son Diego County Woter Authority Chapter 6 - Cost / Benefit Assessment 6.1 Project Costs Based on the project concept descriptions and operating scenarios described in Chapter 4, project costs were calculated and converted to unit costs in dollars per acre-ft potable water production. The total unit cost consists of three primary elements: • Unit cost for amortized capital for facilities construction • Unit cost for amortized Operation & Maintenance • Unit cost for amortized replenishment water Unit costs per acre-ft of water produced can then be further broken down into the following major categories: • Replenishment/Extraction Costs • Treatment Costs • Distribution Costs • Replenishment Water Costs Costs were calculated for the following operating scenarios; 1. Mission Basin 1.63 MGD Desalter Continuous operation of the Mission Basin 1.63 MGD desalter expansion project concept with seasonal recharge. This includes recharge with reclaimed water from the City of Oceanside's proposed reclamation facility at the San Luis Rey Wastewater Treatment Plant. Recharge is assumed over a six-month period every year. Because the reclaimed water is assumed to be available every year there is no need to assume carryover extraction or replenishment. 2. Mission Basin 6.70 MGD Desalter • Continuous operation of the Mission Basin 6.70 MGD desalter expansion project concept with seasonal recharge. This includes recharge with reclaimed water and seasonally discounted imported water over a six-month period every year and does not include carryover extraction or replenishment. • Continuous operation of the Mission Basin 6.70 MGD desalter expansion project concept with seasonal recharge and carryover extraction. For this project concept it is assumed that recharge will be performed on a seasonal basis, however, recharge would be performed using imported long-term SANDIEGO COUNTY WATERAUTHORTTT f: \3892\0005\ReportVhapt6, doc 6-1 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley storage discounted water from MWD in addition to the reclaimed water recharge. During periods when the long-term-storage water is unavailable from MWD, the project would continue to extract groundwater and will draw from carryover storage. The rate of extraction is based upon estimated usable basin storage capacity and a three-year extraction period, which is consistent with the requirements of MWD's Local Resource Program. Continuous operation of this project concept using a two-year extraction period has also been examined and the costs presented. The continuous yield assuming only a two-year extraction period is 10.0 MGD. 3. Mission Basin 6.70 MGD and 10.0 MGD Desalter w/ Regional Use of Weese WFP • Continuous operation of the the Mission Basin 6.70 MGD (and altemative 10.0 MGD project concept) desalter expansion with seasonal recharge of reclaimed water and carryover storage/extraction of seasonally-discounted imported water, combined with regional use of Weese WFP. This concept would operate the same as. the Mission Basin 6.70 MGD concept in terms of the schedule for groundwater recharge and extraction. It has also been assumed that the Weese WFP would operate continuously without regard to the groundwater recharge schedule. 4. Bonsall Basin 3.60 MGD and 4.60 MGD Desalter w/ Imported Water Replenishment • Continuous operation of the Bonsall Basin 3.60 MGD desalter project concept with recharge of discounted-imported water and carryover storage extraction. Groundwater recharge would be performed using long-term storage discount water when available. During periods when the long-term storage water from MWD 'is unavailable, the project would continue to extract groundwater and will draw from the Bonsall Basin's carryover storage capacity. Project yield has been calculated based upon usable basin storage capacity estimates and a three-year extraction period, which is consistent with MWD's Local Resource Program. Continuous operation of this project concept assuming a two-year extraction period has also been examined and the costs presented. The continuous yield under the two-year extraction scenario is 4.6 MGD. The following general assumptions and procedures were utilized during cost development. These general assumptions are based on a combination of published cost data, general engineering judgment, and the study team's experience with local water systems projects: • July 1999 (ENR 6850) costs. • 30-year project life and an interest rate of 6% for present value and amortization schedules. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage &• Recovery Project j:\3892\ooo5\Report\chapc6-doc 6-2 Lowcr San Luis Rey River Valley • 3% per year escalation on O&M costs. • 2% per year escalation on imported-water recharge costs. • No escalation on MWD's seasonal or long-term storage discounts. • Reclaimed water will be available from the City of Oceanside's proposed reclamation facility at the San Luis Rey WWTP at $139/ acre-ft. (amortized cost over the life of the project). • O&M costs for pipelines: 0.5% of the total capital cost per year • Electric power costs: $0.10/kwh. • O&M costs for pump stations: 5% of the total capital cost per year. • 100-ft. hydraulic lift, 80% hydraulic efficiency, and 90% motor efficiency for calculating power costs for extraction wells. • O&M costs for extraction and injection wells: 2% of the total capital cost per year. These costs will include regular inspection and routine maintenance of the wellhead facilities. • Amortized costs computed by amortizing the present value of annual capital and O&M over the 30-year project life using an interest rate of 6% . • Costs related to basin-wide monitoring and ongoing evaluations are not included in the project costs. The extent of a basin monitoring well network or monitoring plan that may be required for these projects is unknown at this time. The extent to which the City of Oceanside's monitoring wells can be used is also unknown. • Costs related to the potential need for alternate replenishment water spreading basins in the Mission Basin have been included in certain project concepts. These costs include land acquisition and construction allowances should these facilities be needed. Project cost breakdowns for each concept are provided in Tables 6-1 to 6-4, and a summary of costs for all concepts is provided in Table 6-5. Detailed cost breakdowns and 30-year operating scenarios are provided as Appendix E. When reviewing the project costs presented in the tables below, the reader is cautioned against comparing unit costs directly with other water costs (i.e. imported, desalinated sea-water, etc.) without consideration of distribution system improvements and project benefits associated with these groundwater storage projects. Benefits including increased system reliability, storage, and treatment are discussed in more detail in Section 6.3. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project ];\3892\0005\Rcport\chapt6.doc 6-3 Lowcr San Luis Rey River Valley Table 6-1 Project Concept Mission Basin 1.63 MGD Desalter Item Description Capital O&M Amortized Amortized Unit Cost Cost Capital Cost O&M Cost Cost ($) ($/yr) ($/yr) ($/yr) ($/acre-ft) REPLENISHMENT AND EXTRACTION COSTS: 18-inch reclaimed water pipeline from desalter to North Riverside Pond $1,125,000 $5,600 Construct recharge water outlet structure at m North Riverside Pond $15,000 $1,500 Operate 2 existing wells (one at Desalter, one at North River Road well field) $34,400 Contingency for additional spreading basin (2.6AC) $750,000 $5,000 Contingency at 25% $472,000 Enginecring/admin/legai at 15% $283,500 Total: $2,646,000 $46,500 $192,300 $65,100 $141 TREA TMENT COSTS: Construct 1.63 MGD addition to existing Mission Basin Groundwater Purification Facility $850,000 $300,000 Contingency at 25% $212,500 Engineering/admin/legal at 15% $127,500 Total $1,190,000 $300,000 $86,500 $419,500 $277 DISTRIBUTION COSTS: Construct 1.63 MGD addition to existing Mission Basin Groundwater Purification Facility High Lift Pump Station $460,000 $73,000 Expand brine pumping facilities $120,000 $8,600 Contingency at 25% $145,000 Engineering/admin/legal at 15% $87,000 Total: $812,000 $81,600 $59,000 $114,100 $95 REPLENISHMENT WATER COSTS: Reclaimed Water from San Luis Rey WWTP $0 $369,000 Total: $0 $369,000 $0 $369,000 $202 Notes: • Costs for capital and O&M are in July 1999 dollars. • Amortized cost were computed by amortizing the present value of annual capital and O&M over the 30- year project life using an interest rate of 6%. SANDIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Repori\chapt6.doc 6-4 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Table 6-2 Project Concept Mission Basin 6.70 MGD Desalter wiProvisions to Supply Carlsbad MWD Item Description Capital O&M Amortized Amortized Unit Cost Cost Capital Cost O&M Cost Cost ($) ($/yr) ($/yr) ($/yr) ($/acre-ft) REPLENISHMENT AND EXTRA CTION COSTS: Construct recharge water outlet structure at North Riverside Pond $15,000 $1,500 Construct recharge water outlet stmcture at Upper Pond $25,000 $1,500 18-inch reclaimed water pipeline from Desalter to North Riverside Pond $1,125,000 $5,600 Extend aqueduct supply lines for imported water recharge $6,930,000 $34,700 Imported water injection wellfield (4 ea. 12" DIA, 200'D) $360,000 $7,200 Seawater intrusion injection wellfield (4 ea. 12"DIA, lOO'D) $320,000 $6,400 Reclaimed water pipeline to narrows injection well site $1,710,000 $8,600 Constmct 2 new wells at North River Road wellfield (12"DlA/200'D)/operate all plus desalter well $320,000 $102,400 Constmct 2 new wells at Douglas wellfield (12"DIA/200'D) $320,000 $39,800 Contingency for additional spreading basins (lOAC) $2,000,000 $15,000 Contingency at 25%i $3,241,300 Engineering/admin/legal at 15% $1,944,800 Total: $18,151,100 $222,700 $1,318,700 $432,800 $217 TREA TMENT COSTS: Construct 6.70 MGD addition to existing Mission Basin Groundwater Purification Facility $2,980,000 $1,200,000 Constmct 2 MGD Advance Reclaimed Water Treatment Facilities $2,300,000 $460,000 Contingency at 25% $1,320,000 Engineering/admin/legal at 15%) $792,000 Total $7,392,000 $1,660,000 $537,100 $2,321,100 $381 DISTRIBUTION COSTS: Upgrade brine pipeline $172,500 $900 Abandon existing brine pipeline $2,000 $0 Upgrade raw water collection lines $3,011,000 $15,000 Miscellaneous pipeline improvements to move water through 320 and 511 pressure zones $2,476,000 $12,400 Pipeline to Carlsbad's Maerkle Reservoir through SF Peak $1,018,500 $5,100 Construct 6.70 MGD addition to existing Mission Basin Groundwater Purification Facilities High Lift Pump Station $1,358,000 $300,000 Expand brine pumping facilities $347,000 $35,500 Construct 3.23 MGD pump station at Heritage Reservoir $608,800 $124,000 Construct 3.23 MGD pump station at NCDP FCF $931,000 $50,000 Contingency at 25% $2,481,200 Enginccring/admin/legal at 15% $1,488,800 Total: $13,894,800 $542,900 $1,009,500 $759,100 $236 SANDIEGO COUNTY WATERAUTHORTTT J;\3892\000.=i\Report\chapc6.doi; 6-5 (GroundwaterStorage ^ Recovery Project Lower San Luis Rey River Valley Item Description Capital Cost {$) O&M Cost ($/yr) Amortized Capital Cost ($/yr) Amortized O&M Cost ($/yr) Unit Cost ($/acre-ft) REPLENISHMENT WA TER COSTS (Seasonal/Carryover): Reclaimed Water from San Luis Rey WWTP Imported Water from MWD Total: $0 $0 $0 $369,000 $2,461,100 $2,830,100 $0 $2,830,100 $377 REPLENISHMENT WATER COSTS (Seasonal Only): Reclaimed Water from San Luis Rey WWTP Imported Water from MWD Total: $0 $0 $0 $369,000 $3,001,200 $3,370,200 $0 $3,370,200 $449 Notes: • Costs for capital and O&M are in July 1999 dollars. • Amortized costs were computed by amortizing the present value of annual capital and O&M over the 30- year project life using an interest rate of 6%. SANDIEGO COUNTY WATERAUTHORTTT I:\3892\0005\Reportyhapt6.doc 6-6 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Table 6-2A Project Concept Mission Basin 10.0 MGD Desalter Item Description Capital O&M Amortized Amortized Unit Cost Cost Capital Cost O&M Cost Cost ($) (S/yr) ($/yr) ($/yr) ($/acre-ft) REPLENISHMENT AND EXTRA CTION COSTS: Constmct recharge water outlet stmcture at North Riverside Pond $15,000 $1,500 Constmct recharge water outlet stmcture at Upper Pond $25,000 $1,500 18-inch reclaimed water pipeline from Desalter to North Riverside Pond $1,125,000 $5,600 Extend aqueduct supply lines for imported water recharge $7,260,000 $34,700 Imported water injection wellfield (5 ea. 12" DIA, 200'D) $540,000 $9,200 Seawater intmsion injection wellfield (4 ca. I2"DIA, lOO'D) $320,000 $6,400 Reclaimed water pipeline to narrows injection well site $1,710,000 $8,600 Constmct 3 new wells at North River Road wellfield (12"DlA/200'D)/operate all plus desalter well $360,000 $118,300 Constmct 4 new wells at Douglas wellfield {12"DIA/200'D) $480,000 $94,000 Contingency for additional spreading basins (lOAC) $2,000,000 $15,000 Contingency at 25%) $3,458,800 Engineering/admiii/legal at \ 5% $2,075,300 Total: $19,369,100 $294,800 $1,407,200 $412,200 $162 TREA TMENT COSTS: Constmct 10.0 MGD addition to existing Mission Basin Groundwater Purification Facility $3,800,000 $1,650,000 Constmct 2 MGD Advance Reclaimed Water Treatment Facilities $2,300,000 $460,000 Contingency at 25% $1,525,000 Engineering/admin/legal at 15% $915,000 Total $8,540,000 $2,110,000 $620,500 $2,950,300 $319 DISTRIBUTION COSTS: Upgrade brine pipeline $240,000 $1,200 Abandon existing brine pipeline $2,000 $0 Upgrade raw water coUecdon lines $3,011,000 $15,000 Miscellaneous pipeline improvements to move water through 320 and 511 pressure zones $2,700,000 $12,400 Pipeline to Carlsbad's Maerkle Reservoir through SF Peak $1,018,500 $5,100 Constmct 10.0 MGD addition to existing Mission Basin Groundwater Purification Facilities High Lift Pump Stadon $1,750,000 $445,000 Expand brine pumping facilities $375,000 $53,000 Construct6.53 MGD pump station at Heritage Reservoir $1,200,000 $250,000 Constmct 6.53 MGD pump station at NCDP FCF $1,200,000 $87,300 ConUngency at 25% $2,874,200 Enginecring/admin/legal at 15% $1,724,500 Total: $16,095,200 $869,000 $1,169,300 $1,215,100 $213 SANDIEGO COUNTY WATERAUTHORTTT ] :\3892\0005\Report\chap[6.doc 6-7 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Item Description Capital Cost ($) O&M Cost ($/yr) Amortized Capital Cost ($/yr) Amortized O&M Cost ($/yr) Unit Cost ($/acre-ft) REPLENISHMENT WATER COSTS (Season al/Carryover): Reclaimed Water from San Luis Rey WWTP Imported Water from MWD Total: $0 $0 $0 $369,000 $4,018,100 $4,387,100 $0 $4,387,100 $392 REPLENISHMENT WATER COSTS (Seasonal Only): Reclaimed Water from San Luis Rey WWTP Imported Water from MWD Total: $0 $0 $0 $369,000 $4,964,100 $5,333,100 $0 $5,333,100 $476 Notes: Costs for capital and O&M are in July 1999 dollars. Amortized costs were computed by amortizing the present value of annual capital and O&M over the 30- year project life using an interest rate of 6%. SANDIEGO COUNTY WATERAUTHORITY J:\3892\0005\Report\chapf6.doc 6-8 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Table 6-3 Project Concept Mission Basin 6.70 MGD DesalteriRegional Use of the Weese Filtration Plant Item Description Capital O&M Amortized Amortized Unit Cost Cost Capital Cost O&M Cost Cost ($) ($/yr) ($/yr) ($/yr) ($/acre-ft) REPLENISHMENT AND EXTRACTION COSTS: Constmct recharge water outlet stmcture at North Riverside Pond $15,000 $1,500 Construct recharge water outlet stmcture at Upper Pond $25,000 $1,500 18-inch reclaimed water pipeline from Desalter to North Riverside Pond $1,125,000 $5,600 Extend aqueduct supply lines for imported water recharge $6,930,000 $34,700 Imported water injection wellfield (4 ea/12"DIA/200'D) $360,000 $7,200 Seawater intmsion injection wellfield (4 ea/12"DIA/I00'D) $320,000 $6,400 Reclaimed water pipeline to narrows injection well site $1,710,000 $8,600 Construct 2 new wells at North River Road wellfield (12"DIA/200'D)/operate all plus desalter well $320,000 $102,400 Construct 2 new wells at Douglas wellfield (I2"DIA/200'D) $320,000 $39,800 Contingency for additional spreading basins (lOAC) $2,000,000 $15,000 Condngency at 25%i $3,261,300 Engineering/admin/legal at 15% $1,956,800 Total: $18,263,100 $222,700 $1,326,800 $311,400 $109 TREA TMENT COSTS: Construct 6.70 MGD addition to existing Mission Basin Groundwater Purification Facility $2,980,000 $1,200,000 Construct 6.70 MGD addition to existing Weese Filtration Plant $4,400,000 $400,000 Construct 2 MGD Advanced Reclaimed Water Treatment Facilities $2,300,000 $460,000 Contingency at 25% $2,420,000 Engineering/admin/legal at \5% $1,452,000 Total $13,552,000 $2,060,000 $984,600 $2,880,400 $258 DISTRIBUTION COSTS: Upgrade brine pipeline $172,500 $900 Abandon existing brine pipeline $2,000 $0 Upgrade raw water collection lines • $3,011,000 $15,000 Miscellaneous pipeline improvements to move water through 320 and 511 pressure zones Construct 6.70 MGD addition to exisdng $2,476,000 $12,400 Mission Basin Groundwater Purificafion Facility High Lift Pump Station $1,358,000 Expand brine pumping facilities $347,000 $300,000 Constmct 3.23 MGD pump station at Heritage $35,500 Reservoir $608,800 Construct 6.70 MGD pump station at WFP $1,200,000 $124,000 Constmct pipeline from pump stadon to $215,000 pipeline 4 $150,000 $10,000 Contingency at 25% $2,293,900 Engineering/admin/legal at \5% $1,376,300 Total: $12,995,500 $712,800 $944,200 $996,700 S129 SANDIEGO COUNTY WATERAUTHORITY J:\3892\0005\Rcport\ch3pt6.doc 6-9 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Item Description Capital Cost ($) O&M Cost ($/yr) Amortized Capital Cost ($/yr) Amortized O&M Cost ($/yr) Unit Cost (S/acre-ft) REPLENISHMENT WA TER COSTS (Seasonal/Carryover): Reclaimed Water from San Luis Rey WWTP Imported Water from MWD (Mission Basin) Imported Water from MWD (to WFP) Total: $0 $0 $0 $0 $369,000 $2,461,200 $3,256,400 $6,086,600 so $6,086,600 $406 REPLENISHMENT WATER COSTS (Seasonal Only): Reclaimed Water from San Luis Rey WWTP Imported Raw Water from MWD (Mission Basin) Imported Raw Water from MWD (to WFP) Total: $0 $0 $0 so $369,000 $3,002,500 $3,256,400 $6,627,900 $0 $6,627,900 $442 Notes: • Costs for capital and O&M are in July 1999 dollars, • Amortized costs were computed by amortizing the present value of annual capital and O&M over the 30- year project life using an interest rate of 6%. SANDIEGO COUNTY WATERAUTHORTTT J;\3892\0005\Report\chapi:6.doc 6-10 (Groundwater Storage Recovery Project Lower San Luis Rey River Valley Table 6-3A Project Concept Weese Filtration Plant Item Description Capital O&M Amortized Amortized Unit Cost Cost Capital Cost O&M Cost Cost ($) ($/yr) ($/yr) ($/yr) (S/acre-ft) REPLENISHMENT AND EXTRACTION COSTS: Constmct recharge water outlet stmcture at North Riverside Pond $15,000 $1,500 Constmct recharge water outlet stmcture at Upper Pond $25,000 $1,500 18-inch reclaimed water pipeline from Desalter to North Riverside Pond $1,125,000 $5,600 Extend aqueduct supply lines for imported water recharge $7,260,000 $34,700 Imported water injection wellfield (5 ea/12"DIA/200'D) $540,000 $9,200 Seawater intmsion injection wellfield (4 ea/12"DlA/IOO'D) $320,000 $6,400 Reclaimed water pipeline to narrows injection well site $1,710,000 $8,600 Constmct 3 new wells at North River Road wellfield (12"DIA/200'D)/operaCe all plus desalter well $360,000 $118,300 Constmct 4 new wells at Douglas wellfield (12"DIA/200'D) $480,000 $94,000 Contingency for additional spreading basins (lOAC) $2,000,000 $15,000 Contingency at 25% $3,458,800 Engineering/admin/legal at 15%i $2,075,300 Total: $19,369,100 $294,800 $1,407,200 $412,200 $81 TREA TMENT COSTS: Constmct 10.0 MGD addition to exisdng Mission Basin Groundwater Purification Facility $3,800,000 $1,750,000 Constmct 10.0 MGD addifion to exisfing Weese Filtration Plant $6,600,000 $600,000 Constmct 2 MGD Advanced Reclaimed Water Treatment Facilifies $2,300,000 $460,000 Contingency at 25%o $3,175,000 Engineering/admin/legal at 15%i $1,905,000 Total $17,780,000 $2,710,000 $1,291,700 S3,789,200 $227 DISTRIBUTION COSTS: Upgrade brine pipeline $240,000 $1,200 Abandon existing brine pipeline $2,000 $0 Upgrade raw water collection lines $3,011,000 $15,000 Miscellaneous pipeline improvements to move water through 320 and 511 pressure zones $2,700,000 Constmct 10.0 MGD addition to existing $12,400 Mission Basin Groundwater Purification Facility High Lift Pump Stafion $1,750,000 $445,000 Expand brine pumping facilities $375,000 $53,000 Constmct 6.53 MGD pump station at Heritage Reservoir $1,200,000 $250,000 Constmct 10.0 MGD pump stadon at WFP $1,800,000 $320,000 Constmct pipeline from pump station to pipeline 4 $180,000 $12,000 Contingency at 25% $2,814,500 Engineering/admin/legal at \5% $1,688,700 Total: $15,761,200 $1,108,600 $1,145,100 $1,550,100 $120 SANDIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Report\chapt6.doc 6-11 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Item Description Capital Cost ($) O&M Cost ($/yr) Amortized Capital Cost ($/yr) Amortized O&M Cost (S/yr) Unit Cost (S/acre-ft) REPLENISHMENT WATER COSTS (Seasonal/Carryover): Reclaimed Water from San Luis Rey WWTP Imported Water from MWD (Mission Basin) Imported Water from MWD (to WFP) Total: $0 $0 $0 $0 $369,000 $4,158,500 $4,860,300 $9,387,800 $0 $9,387,800 $419 REPLENISHMENT WATER COSTS (Seasonal Only): Reclaimed Water from San Luis Rey WWTP Imported Water from MWD (Mission Basin) Imported Water from MWD (to WFP) Total: $0 $0 $0 $0 $369,000 $4,964,100 $4,860,300 $10,193,400 $0 $10,193,400 $455 Notes: • Costs for capital and O&M are in July 1999 dollars. • Amortized costs were computed by amortizing the present value of annual capital and O&M over the 30- year project life using an interest rate of 6%. SANDIEGO COUNTY WATERAUTHORITY );\3892\0005\Rcpc)nyhapt6.doc 6-12 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Table 6-4 Project Concept Bonsall Basin 3.6 MGD Desalter Item Description Capital Cost ($) O&M Cost ($/yr) Amortized Capital Cost ($/yr) Amortized O&M Cost (S/yr) Unit Cost (S/acre-ft) REPLENISHMENT AND EXTRA CTION COSTS: Raw water pipeline from new unfiltered water turnout to injecfion wellfield Unfiltered water turnout Imported water injection wellfield (4 ea/12"DIA/200'D) Construct 3 new wells near Rainbow offices (3 ea/12"DIA/200'D) Contingency at 25%. Engineering/admin/Iegal at 15%) Total: $312,500 $300,000 $500,000 $360,000 $368,125 $220,875 $2,061,500 $700 $30,000 550,000 $76,400 $157,100 $149,800 $219,700 $92 TREA TMENT COSTS: Constmct 3.60 MGD Bonsall Basin Groundwater Purification Facility Contingency at 25% Engineering/admin/legal at I5%i Total $1,840,000 $460,000 $276,000 $2,576,000 $650,000 $650,000 $187,200 $908,900 $272 DISTRIBUTION COSTS: Raw water collection line Pipeline to connect into 865 pressure zone Brine pipeline to connect to Oceanside Constmct 3,60 MGD Pump Station to serve 865 zone Contingency at 25% Engineering/admin/legal at 15% Total: 51,062,500 $1,018,500 $5,700,000 $1,100,000 $2,220,300 $1,332,200 $12,433,500 $2,200 $5,100 $11,400 $315,000 $333,700 $903,300 $466,600 $340 REPLENISHMENT WATER COSTS (Seasonal/Carryover): Imported Water from MWD (Bonsall Basin) Total: $0 $0 $908,100 $908,100 $0 $908,100 $225 REPLENISHMENT WATER COSTS (Seasonal Only): Imported Water from MWD (Bonsall Basin) Total: so $0 $1,177,800 $1,177,800 $0 $1,177,800 $292 Notes: • Costs for capital and O&M are in July 1999 dollars. • Amortized costs were computed by amortizing the present value of annual capital and O&M over the 30- year project life using an interest rate of 6%. SANDIEGO COUNTY WATERAUTHORTTT J:\3892\0fl05\Rcport\chapc6-doc 6-13 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Table 6-4A Project Concept Bonsall Basin 4.6 MGD Desalter Item Description Capital Cost ($) O&M Cost ($/yr) Amortized Capital Cost ($/yr) Amortized O&M Cost ($/yr) Unit Cost ($/acre-ft) REPLENISHMENT AND EXTRA CTION COSTS: Raw water pipeline from new unfiltered water turnout to injecfion wellfield Unfiltered water turnout Imported water injection wellfield (5 ea/l2"DIA/200'D) Constmct 4 new wells near Rainbow offices (3 ea/i2"DIA/200'D) Contingency at 25% Engineering/admin/Iegal at 15% Total: $475,000 $350,000 $640,000 $480,000 $486,300 $291,800 $2,723,100 $800 $35,000 $50,000 $97,600 $183,400 $197,900 $256,500 $88 TREA TMENT COSTS: Constmct 4.60 MGD Bonsall Basin ' Groundwater Purification Facility Contingency at 25% Engineering/admin/Iegal at 15% Total $2,400,000 $600,000 $360,000 $3,360,000 $830,000 $830,000 $244,100 $1,160,600 $273 DISTRIBUTION COSTS: Raw water collection line Pipeline to connect into 865 pressure zone Brine pipeline to connect to Oceanside Construct 4.60 MGD Pump Stafion to serve 865 zone Contingency at 25% Engineering/admin/Iegal at 15%, Total: $1,400,000 $1,300,000 $6,000,000 $1,410,000 $2,527,500 $1,516,500 $14,154,000 $2,500 $5,500 $12,000 $420,000 $440,000 $1,028,300 $615,300 $319 REPLENISHMENT WATER COSTS (Seasonal/Carryover): Imported Water from MWD (Bonsall Basin) Total: $0 $0 $1,437,700 $1,437,700 SO $1,437,700 $279 REPLENISHMENT WATER COSTS (Seasonal Only): Imported Water from MWD (Bonsall Basin) Total: $0 $0 $1,766,600 $1,766,600 $0 $1,766,600 $343 6.2 Discussion of Project Costs Unit Costs Table 6-5 at the end of this section summarizes the unit costs for each concept. Overall, replenishment and extraction unit costs range from $81 to $217/acre-ft. Treatment unit costs range from $227 to $381/acre-ft, distribution unit costs range from $95 to 340/acre-ft, and replenishment water unit costs range from $202 to $476/acre-ft for seasonal operation and $225 to $419/acre-ft for seasonal and carryover operation. A general discussion of the project costs is presented below. SANDIEGO COUNTY WATERAUTHORTTT J;\3892\0005\Rcport\chapc6.doc 6-14 (Groundwater Storage & Recovery Project Lower San Lais Rey River Valley Replenishment and Extraction Costs Replenishment and Extraction costs are dependent upon the design and capacity of facilities required to recharge and extract groundwater from the basins. Total costs for facilities are based on the amount and required rate of replenishment and extraction. Replenishment unit costs will also vary according to replenishment method (i.e., the cost for spreading basins versus injection wells). Unit costs for extraction are dependent upon the required hydraulic lift, well efficiently, and motor efficiency of extraction facilities. A 100-ft lift has been assumed for the purposes of the cost estimates. Replenishment costs for the Mission Basin 1.63 MGD project will tend to be lower than other project concepts since this project is replenishing less water (the cost of the replenishment water itself is considered elsewhere) and the concept proposes use of an existing flood control detention basin for spreading reclaimed water and existing City of Oceanside standby wells for extraction. The Mission Basin 6.70 and 10.0 MGD project concepts have higher replenishment and extraction costs since these project concepts will utilize significant quantities of imported water for basin replenishment. Construction of new conveyance pipelines is necessary to bring the imported water into the basin to the recharge areas and construction of additional extraction wells is necessary. Replenishment will be performed using an existing flood control detention basin and an injection wellfield. The Bonsall Basin 3.60 and 4.60 MGD project concepts propose all new facilities for replenishment and extraction. These include a new unfiltered water turnout from the Authority's aqueduct, pipelines, and injection and extraction wells. Treatment Costs The Phase 1 study has assumed that all groundwater extracted from the Mission and Bonsall Basins will require treatment. A reverse osmosis process similar to the City of Oceanside's current process has been assumed. Treatment costs also include the construction of advanced tertiary reclaimed water treatment facilities, where such facilities are assumed necessary for injection of reclaimed water. Provisions for treatment of imported (raw) replenishment water are not included in the project costs. Treatment costs will vary by concept due to facility size or capacity. For example, for the Mission Basin 6.70 MGD concept, the treatment cost is $381/acre-ft. This includes expansion of the existing desalter and construction of advanced tertiary reclaimed water treatment facilities. However, for the Mission Basin 6.70 MGD/Regional use of WFP concept, the treatment cost is $258/acre-ft. A lower treatment cost is evident for this concept due to the concept's increased yield. Although the WFP concept has a higher total due to the need to also expand WFP's filtration capacity by an increment equal to Mission Basin production, this cost is SANDIEGO COUNTY WATERAUTHORTTT Groundwater Storage & Recovery Project j:\3892\ooo5\Report\ciiapt6.doc 6-15 IMWCT San Luis Rey River Valley divided by double the project yield, since the WFP output is included in the project cost calculations. Distribution Costs The main differences in distribution costs are the pumping requirements and pipeline improvements for the various concepts. Both Mission Basin concepts that propose to supply Carlsbad MWD have higher distribution costs due to the need for pipeline improvements between Oceanside and Carlsbad and the need to pump treated Mission Basin groundwater to the Oceanside 511 pressure zone. The Bonsall Basin project concepts have higher distribution costs due to the need to pump the treated Bonsall Basin groundwater to the Rainbow 865 pressure zone from an estimated desalter elevation on the order of 280 ft MSL. The Phase 1 study has included retail system distribution costs for completeness. However, when typically evaluating water supply options in a planning phase of a project, these distribution costs would not normally be included. As the detailed discussion in Chapters 3 and 4 indicate, distribution costs are related to pipeline and conveyance improvements needed to move groundwater through the member agencies' systems. Distribution costs become important when the ability to serve groundwater is considered. Member agencies within the project study area supply their systems from east to west by gravity from the Authority aqueduct, which operates at a much higher HGL than their systems. Moving stored water into the retailer's system from the groundwater basin (located at low elevations) will require pumping. Replenishment Water Costs Replenishment water costs for seasonal operation are higher than seasonal/carryover operation due to the difference in the MWD imported water seasonal and LTS discounts ($85 treated versus 141/acre-ft treated respectively). Replenishment water costs for some project concepts also include reclaimed water produced from the City of Oceanside's proposed San Luis Rey Reclamation Facility. This reclaimed water cost is based on the potential future cost of water from the plant once the plant becomes operational. The per acre-ft cost includes the estimated cost of tertiary filtration, UV disinfection, miscellaneous mechanical equipment, and contingencies based on an annual-average reclaimed water production of 2 MGD. Costs for a reclaimed water reservoir and pump station are not included in these figures. This cost estimate will need to be reexamined once the City of Oceanside expands its reclamation program. Differences in costs of replenishment water for the various project concepts are driven by the amount of water that is purchased and the MWD program it is purchased under. Projects that are operated seasonally will purchase seasonally- discounted water and it is assumed that the quantity of water purchased annually will not change over the life of the project. Projects expected to provide water from SAN DIEGO COUNTY WATERAUTHORITT (Groundwater Storage & Recovery Project ] :\3892\0005\Rcport\chapt6.doc 6-16 Lowcr San Luis Rey River Valley carryover storage will purchase long-term storage water, at a greater discount than seasonal storage water. Greater quantities of replenishment water may be needed for certain years over the life of the project after carryover storage is drawn upon (at this stage of the study it is assumed that all water extracted from the basins will be replenished artificially). Both seasonal and seasonal/carryover replenishment water costs were calculated for each concept in Tables 6-1, 6-2, 6-2A, 6-3, 6-3A, 6-4, and 6-4 A. Each mode of operation is summarized in Table 6-5. It is possible that actual total replenishment-water costs for a particular project concept could vary due to capture of natural recharge that can be credited to the project, or as in the case of Mission Basin concepts, the possible loss of replenishment water at the seawater intrusion barrier. Some loss of replenishment water may also be attributed to the degradation of recharge water and subsequent RO treatment loss. There has not been an attempt to quantify the potential gain or loss of recharge water from the groundwater basin in Phase 1. This will be attempted in later phases of the study. SANDIEGO COUNTY WATERAUTHORTTT Groundwater Storage Recovery Project ):\3892\0005\RcportViiapt6.dcx: 6-17 Lowcr San Luis Rey Rivcr Valley Table 6-5 Cost Summary Mission Basin 1.63 MGD Desalter Mission Basin 6.70 MGD Desalter w/Provisions to Supply Carlsbad MWD Mission Basin 10.0 MGD Desalter w/Provisions to Supply Carlsbad MWD Mission Basin 6.70 MGD Desalter w/Regional use of Weese Filtration Plant Mission Basin 10.0 MGD Desalter w/Regional use of Weese Filtration Plant Bonsall Basin 3.60 MGD Desalter Bonsall Basin 4.60 MGD Desalter CATEGORY Unit Cost ($/acre-ft) Unit Cost (S/acre-ft) Unit Cost (S/acre-ft) Unit Cost (S/acre-ft) Unit Cost t$/acre-ft) Unit Cost (S/acre-ft) Unit Cost ($/acre-ft) REPLENISHMENT AND EXTRACTION COSTS $141 $217 $162 $109 $81 $92 $88 TREA TMENT COSTS $277 $381 $319 $258 $227 $272 $273 DISTRIBUTION COSTS $95 $236 $213 $129 $120 $340 $319 REPLENISHMENT WATER COSTS (Reclaimed (Mission Basin only) and LTS Discount Imported Water) (SEASONAL/CARR YO VER) $377 $392 $406 $419 $225 $279 REPLENISHMENT WATER COSTS (Reclaimed (Mission Basin only) and Seasonal Discount Imported Water) (SEASONAL ONLY) $202 $449 $476 $442 $455 $292 $343 TOTAL (Seasonal/Carryover): $1,211 $1,086 $902 $847 $928 $959 TOTAL (Seasonal Only): $715 $1,283 $1,170 $938 $883 $995 $1,023 SANDIEGO COUNTY WATERAUTHORITT J:\3S92\0005\Reporc\chapt6.doc 6-18 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley 6.3 Project Benefits Several benefits have been identified by the study team for the proposed project concepts. These benefits are either direct benefits, indirect, or non-quantifiable. Examples of direct benefits are: credits, discounts, grants, and loans received from outside agencies. These are easy to quantify and can reflected in the unit costs. However, indirect and non-quantifiable benefits are difficult to assign a dollar value to and must be evaluated differently. For this Phase 1 study, each benefit (described below) was ranked on a scale of 1 to 4 (4 being the highest, or most desirable score) for each proposed project concept. The potential range of scores is based on a defined scale for each benefit, as described in each subsection below. The scores for the indirect and non-quantifiable benefits where then totaled for each project concept to determined how the projects compared to each other in terms of indirect or non-quanlifiable benefits. The summary of the benefit ranking for each concept is provided in Table 6-6. Benefits for project concepts that are capable of operating in both seasonal and seasonal/carryover mode were assessed for the seasonal/carryover mode of operation. Benefits and corresponding ranking methodology are as follows: Additional Increment of Regional Treated Supply This benefit ranking reflects the amount of additional treated-water made available to the region (i.e. multiple agencies). Most of the project concepts offer the opportunity for treated-water service to multiple agencies. A project concept received a higher ranking if it results in either a new increment of treated water (put into the Authority's system) or offsets treated-water demand. The higher the ranking of a particular project concept, the greater its ability to provide treated water to the region; thereby reducing or deferring the need for treatment plant expansions to meet average daily demands. Projects are ranked higher for this benefit if they produce more water versus other projects. A project would receive a score of 4 for this benefit if it provided 7 MGD or greater additional regional treated supply, a 3 for 4-7 MGD, 2 for 2-4 MGD and a 1 for less than 2 MGD. The Phase 1 study selected these threshold quantities based on the typical magnitude of groundwater projects in the region (i.e., Oceanside's 6.37 MGD expansion, Sweetwater Authority's 4 MGD expansion, etc.). Treated Water Availability During a Shortage This benefit relates to the ability of each concept to produce treated water during a water shortage (i.e. state-wide drought impacting the imported water supply). This carryover storage benefit is based on the ability of a project concept to continue to produce even when replenishment supplies are not available. A higher score indicates the project concept with the greatest potential to provide carryover storage SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3S92\ooo5\Report\cii.tpt6.doc 6-19 Lowcr San Luis Rey Rivcr Valley and offset the region's overall imported demand during a shortage. An imported- water shortage that lasts beyond the projected period when carryover storage can be extracted will constrain those project concepts that are mostly dependent on imported water for replenishment. Project concepts that propose to use reclaimed water only for replenishment would be unaffected by such a shortage and could continue to produce as long as the reclaimed water is available (theoretically this could be indefinite). The scale for evaluating this benefit can be established based on the historical record of imported water shortages, which have historically been of rather brief duration as discussed in Chapter 4. A project would receive a score of 4 for this benefit if produced indefinitely during a shortage. A score of 3 would be given for projects that can produce for a three-year period, and a 2 given for projects that can produce for a two-year period, and a 1 for projects that produce for one year or less. Beneficial Use of Reclaimed Water Benefits associated with the ability to make use of reclaimed water for basin replenishment or a seawater intrusion barrier have also been assessed for each concept. The benefits include wastewater disposal offsets and aquifer performance and quality improvements derived from seawater intrusion protection. In addition, groundwater recharge can provide a market for reclaimed water that might otherwise not be available during winter months. However, the amount of reclaimed water that can be used may be constrained by regulatory guidelines concerning the use of reclaimed water for groundwater recharge. A project concept that proposes to use 4 MGD or greater of reclaimed water would receive a 4 for this benefit, a project that proposes 2-4 MGD of reclaimed water use would receive a 3, a score of 2 would be for 1-2 MGD, and a 1 for 0-2 MGD. Increased Capture of Local Runoff All of the project concepts offer some level of basin recharge opportunities from local run-off. As the basin levels are lowered, the potential to capture local run-off increases. This is a potential significant benefit when considering the current "basin full" condition. Runoff that would otherwise flow to the ocean when the basin is fill! could potentially be captured and used to replenish previously extracted groundwater. Higher yielding projects, and projects that propose to draw on carryover storage will receive a higher ranking for this benefit since they will lower groundwater levels more than other concepts and thereby provide an opportunity to capture increasingly greater amounts of local runoff The range of possible scores for this benefit is intended to reflect a given project concepts' ability to capture more local runoff over a shorter period of time. A project will score 4 for this benefit when it proposes to draw down the basin to its historical low water levels over a one-year period. A project would score 3 for drawing the basin down to the low water level over a two-year period, a 2 would be given for drawing the basin down over a three-year period, and 1 for greater than three-years, or a project that operates on a seasonal basis only. SANDIEGO COUNTY WATERAUTHORITT (Groundwater Storage ^Recovery Project j:\3892\0005\Report\chapt6.doc 6-20 Lowcr Sun Luis Rey River Valley Basin Management Implementation of the project concepts described herein may trigger implementation of a formal basin management plan. Participants in the development of such a plan would likely include: the Authority, the City of Oceanside, Carlsbad MWD, resource agencies, and private groundwater users. A formal groundwater management plan would be a benefit to the basin and might address: control of seawater intrusion, replenishment of groundwater, monitoring of groundwater levels and storage, the permitting of new water wells, land use, overdraft conditions, fee and assessments for groundwater management plan implementation and /or groundwater replenishment, plan implementation, agreements with other agencies, etc. The need for formal basin management as related to the implementation of particular project concepts is as of yet unknown and would need to be determined based on consultation between the Authority, its member agencies involved with the project, and the regulatory agencies. However, the Phase 1 study proposes to assign a score of 4 for a project if it is anticipated that it would trigger a "high" level of basin management, a 3 for projects that result in a "moderate" level of basin management, a 2 for "low" basin management, and a 1 for no basin management. A "high" level of basin management may be needed for projects that propose to draw on a basin's entire allotment of carryover storage over short period of time whereby other users may be impacted, or by a project that may have possible impacts to sensitive habitats. A "low" level of basin management may be evident for projects that may not impact or be impacted by other activities in the basin. Public Acceptance Public acceptance of any public works project is a major concem that warrants evaluation during project planning. Projects need to be sensitive to their potential impacts to the local communities and groundwater users in the basin(s). Projects that produce additional, reliable sources of treated water may produce a positive public impact. The use of reclaimed water for basin recharge, however, is likely to be a sensitive public issue. The Phase 1 study proposes to assign a score of 4 for a project if it is anticipated that it would result in a "high" level of public acceptance, a 3 for projects that result in a "moderate" level of public acceptance, a 2 for "low" public acceptance, and a 1 for potential public opposition. Regulatory, Environmental and Legal Issues This criterion weights potential regulatory and environmental issues, such as permitting with the resource agencies, consistency with established environmental regulations, and potential impacts to sensitive habitat. Legal issues would include potential impacts to water rights for implementation of project concepts. To the extent available information permits, many potential regulatory, environmental, and legal issues that may seem to present insurmountable constraints to project development have been considered and addressed by the Phase 1 study project SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\Rcport\diapt6,doc 6-21 Lowcr San Luis Rey River Valley concepts (i.e., we are not proposing project concepts that we know at this stage are infeasible). A project that would be anticipated to have no potential regulatory, environmental, or legal issues that would adversely impact project development was scored a 4. A project that would have minor regulatory, environmental, or legal issues would score a 3. A project that would have major, but not insurmountable minor regulatory, environmental, or legal issues would score a 2, and a project that may have insurmountable issues would score a 1. Interagency Agreement Compatibility Interagency agreements for implementation of project concepts are an important consideration. The benefit of these agreements is cooperation and potential cost sharing among agencies. Agreements between the Authority and Oceanside would be needed for the Authority to participate in a desalter expansion and management of the increased basin yield during continuous/seasonal operations, and carryover extraction operations during imported water interruptions. Agreements between Carlsbad and Oceanside would be needed for concepts that propose to supply Carlsbad with treated Mission Basin groundwater. Agreements would also be needed if the Authority were to expand WFP. The Phase 1 study has ranked projects for this benefit according the possible complexity and difficulty in establishing interagency agreements to implement the project concepts. A project scored a 4 if it would need agreements that in the opinion of the study team should be straightforward to implement. A project would score 3 if the agreements would be of minor complexity, and a 2 if having difficult or complex, but resolvable issues. A project that in the opinion of the study team could potentially have irresolvable issues scored a 1. 6.4 Cost/Benefit Comparison and Discussion Project costs have been presented in Tables 6-1, 6-2, 6-3, 6-4, and 6-5. As shown in Table 6-6, the benefits of each project concept has been ranked according to the proceeding criteria. The benefit ranking and the costs for each concept is summarized below: The Phase 1 study's benefit ranking process gave Project Concept 3A - Mission Basin 10.0 MGD Desalter with Regional use of the Weese Water Filtration Plant the highest score (25). This project produces the most potable water, and makes more potable water available to more agencies than any of the others. It also had the second lowest total unit cost of producing water ($856/acre-ft for seasonal/carryover operation, and $892/acre-ft for seasonal-only operation). This concept scored well due to the new in-region treated water supply that it would create and its supply reliability during dry periods. This project concept would provide the most treated water to the region at the lowest unit cost. This project concept also offers the most operational flexibility in terms of being able to serve more agencies from WFP (including Carlsbad). SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\0005\Report\ciiapt6.doc 6-22 Lowcr San Luis Rey River Valley Project Concepts 2A (Mission Basin 10.0 MGD Desalter with provisions to supply Carlsbad MWD) and 3 (Mission Basin 6.70 MGD Desalter with Regional use of the Weese Water Filtration Plant) scored next highest each with scores of 24 and 23, respectively. Both projects make treated water available to multiple agencies with total unit costs to produce water ranging from $910/acre-ft (for seasonal/carryover operation of concept 3) to $l,188/acre-ft (for seasonal-only operafion of concept 2A). Both projects can continue to produce during an imported water shortage or emergency. Project concept 2A generally scored well for increased supply reliability during a shortage and its ability to serve multiple agencies. Project concept 3 also scored well for these same reasons. Project concept 2A scored 1 point higher than project concept 3 in the basin management category due to the potenfial additional basin management that may be needed due to the project's higher yield. Project Concept 2 (Mission Basin 6.70 MGD Desalter with provisions to supply Carlsbad MWD) scored next highest at 22. This project had a total unit cost of producing water of $l,227/acre-ft for seasonal/carryover operation, and $l,299/acre- ft for seasonal-only operafion. The project will supply 3.47 MGD to City of Oceanside and 3.23 MGD to Carlsbad and can continue to produce during an imported water shortage or emergency. The project is also configured to supply 3.47 MGD to the NCDP agencies. Significant conveyance and pumping improvements are required, however, to serve these agencies with Mission Basin groundwater. Project Concept 4A (Bonsall Basin 4.60 MGD Desalter) scored next highest at 21. This project had a total unit cost of producing water of $976/acre-ft for seasonal/carryover operafion, and $l,040/acre-ft for seasonal-only operation. The project will offset 4.60 MGD (5,152 acre-ft/year) of treated water aqueduct deliveries to Rainbow MWD and can continue to produce during an imported water shortage or emergency. The project does not propose to ufilize reclaimed water; therefore, it scored low for this benefit. Project Concept 4 (Bonsall Basin 3.60 MGD Desalter) scored next highest with a score of 19. Project Concept 1 (Mission Basin 1.63 MGD Desalter) rounded out the projects with a score of 18. These projects would supply one agency each with total unit costs to produce water ranging from $731/acre-ft (for seasonal-only operation of concept 1) to $l,012/acre-ft (for seasonal-only operafion of concept 4). Both projects can confinue to produce during an imported water shortage or emergency. Project concept 4 does not propose to utilize reclaimed water; therefore, it scored low for this benefit. Project concept 1 scored low in the public acceptance category since it proposes to use only reclaimed water for recharge versus a mixture of imported and reclaimed water. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage &• Recovery Project j:\3892\ooo5\Rcporr\chapt6,doc 6-23 Lower San Luis Rey River Valley Table 6-6 Project Concept Benefit Summary Project Concept Benefit 1 2 2A 3 3A 4 4A 1 Addifional increment of region treated supply 2 3 4 4 4 2 3 2 Increased supply reUability during a shortage 4 3 2 4 4 3 2 3 Beneficial use of reclaimed water 2 2 2 2 2 1 1 4 Increased capture of rainfall runoff and San Luis Rey River return flow 1 2 3 2 3 2 3 5 Basin management 2 3 4 3 4 3 4 6 Public acceptance 1 3 3 3 3 2 2 7 Regulatory, environmental and legal issues 2 3 3 3 3 2 2 8 Interagency agreement compatibility 4 3 3 2 2 4 4 Totals 18 22 24 23 25 19 21 SANDIEGO COUNTY WATERAUTHORITT J: \3 892\0005\Rcport\chapt6.doc 6-24 (Groutidwater Storage & Recovery Project Lower San Luis Rey River Valley Chapter 7 - Phase 2 Hydrogeologic Field Investigation Program 7.1 Overview The primary objective of this chapter is to outline in sufficient detail the types of field investigations required in Phase 2. These investigations will determine whether the hydrogeology of each specific project site can sustain the volumes and durations of groundwater extracfion, storage, recovery, and preservafion of water quality is consistent with the project concept assumptions. The project concepts developed by the study team are generally listed as follows: 1. Mission Basin Desalter (1.63 MGD expansion) with seasonal recharge. 2. Mission Basin Desalter (6.70/10.0 MGD expansion) with provisions to supply Carlsbad Municipal Water District with an allotment of potable water approximately equal to their Mission Basin water rights, and facilities for groundwater storage and recovery for seasonal and/or carryover use. 3. Mission Basin Desalter (6.70/10.0 MGD expansion) with use of City of Oceanside's Weese Filtrafion Plant (WFP) for in lieu deliveries of filtered water to other agencies. 4. Bonsall Basin 3.60/4.60 MGD Desalter with facilities for groundwater storage and recovery for seasonal and/or carryover use. 7.2 Approach From a hydrogeologic perspective, each project concept, whether located in the Mission or Bonsall basin, involves facilifies which will increase local basin groundwater production offset, in part, through the artificial recharge of either imported or reclaimed water. Artificial recharge will involve use of injecfion wells or by surface spreading. In some cases, exisfing and/or addifional extraction wells would be constructed and used to recover the recharged water or to maintain certain levels of basin extracfion. Carryover storage benefits would result from several of the project concepts. To verify the feasibility of each project concept, additional hydrogeologic data will be required in key areas of each alluvial groundwater basin. The following generalizafions regarding the hydrogeologic field investigations that will be performed during Phase 2 for each project area are briefly discussed below. • Areas that will involve increased levels of groundwater production or long-term GSR will require monitoring wells and test borings to verify the aquifer properties and hydraulic gradients of the alluvial aquifers. Monitoring well SANDIEGO COUNTY WATERAUTHORTTT ] :\3S92\0005\Report\chapt7.doc 7-1 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley arrays will provide knowledge of groundwater flow rates/direction under differing basin storage conditions and aquifer numerical parameters for evaluating injection/spreading rates and extraction well locations, spacing, and yields. Knowledge of aquifer geometry (thickness, lateral continuity) indicate most monitoring wells will be less than 200 feet in depth. Existing wells in selected project areas (with known design/construcfion data) may be used in conjunction with the wells to be drilled. Cone penetrometer soundings (CFTs) will be used in areas proposed for surface recharge (spreading basins) to assess near-surface (to depths of 50 feet) aquifer/soil properties. Micro wells will also be concurrenfiy installed in the CPT holes to obtain water level data, collect groundwater samples for chemical analyses, etc. The CPT data will assist in determining infiltration (recharge rates) in near-surface sediments. Surface geophysical techniques will be employed prior to drilling test borings and construcfion of monitoring wells in certain areas to better define aquifer geometry and hydrogeologic conditions. Geophysical explorafion techniques may also be used in critical areas where aquifer geometry needs to be refined. Given the relatively shallow depth to bedrock in the Lower San Luis Rey River Valley, pulse EKKO geophysical surveys (similar to 2-D seismic reflection) will likely be the geophysical technique of choice. This technique will provide a relatively low cost and non-invasive, environmentally acceptable manner to select proposed test hole sites (ground truth) and refine aquifer geometry (depth to bedrock). Small-diameter (6-inch) exploratory borings with core sampling devices will be drilled at sites to assess aquifer properties. Geophysical electrical log surveys will be performed in the completed boreholes prior to complefion to 2-inch- diameter monitoring wells. Undisturbed sediment samples will be collected for analysis of aquifer mineralogy using scanning electron microscopy (SEM), x-ray diffracfion, pore space measurements, permeability, geochemistry, and cation exchange capacity. Test wells using 6-inch-diameter (screen secfion) to 12-inch-diameter (pump housing secfion) casing will be constructed to perform aquifer tests. The acquired data (aquifer hydraulic conducfivity and storativity, etc.) will be used to refine existing aquifer models, assess well spacing criteria, interference effects, injection capacities, etc. Discrete aquifer zone sampling may be performed to assess aquifer water quality at selected groundwater extracfion and GSR sites. The acquired information will be used to evaluate the potential for aquifer clogging by mineral precipitafion when the different injectate source water qualifies (imported and reclaimed water) mix with native groundwater. SAN DIEGO COUNTY WATERAUTHORTTT (GroundwaterStorage & Recovery Project j:\3892\ooo5\Rcporr\chapt7.doc 7-2 Lowcr San Luis Rey Rivcr Valley • Various GSR pilot demonstration tests will be conducted at select locations to assess longer-term (up to 30 days) well performance, efficiency, water quality interactions, and recovery potential. It is anficipated that 6-inch-diameter test wells will be used for this purpose. • Areas where known subsurface contamination could be affected by GSR projects in the basin will be evaluated using certain assumptions. An inventory of known contaminated sites identified by the County Department of Environmental Health will be performed. • For each project concept and site, the potential project yield (injection, storage, recovery) based on the subsurface hydrogeology will be evaluated. The goals identified for the Phase 2 program include obtaining the necessary field data to maximize the potential for increased groundwater production and GSR while optimizing the benefits to the region. GSR recoverability will be evaluated by performing pilot tests that will expand the understanding of the hydrogeology throughout the Lower San Luis Rey River Valley. Prior to implementing the field invesfigation programs, several basin-wide field activities should be performed as follows: • An updated inventory of existing water wells and groundwater use in both basins (Mission and Bonsall) needs to be conducted together with the preparation of updated water level maps. Where possible, active wells should be sampled for analysis of general mineral constituents and other water quality parameters. Locate wells using GPS, and update the project GIS database accordingly. • Idenfify the interest, equipment types, and availability of drilling and geophysical logging contractors. • Obtain NPDES Permits to allow the discharge of extracted groundwater to surface waters during test well construction and for pump tests. A NPDES permit is required to discharge groundwater to storm drains when flow rates exceed 100,000 gallons per day or 69 gallons per minute. • Further evaluate environmental contamination impacts in project concept areas. • Evaluate compatibility of reclaimed and imported water with native groundwater. 7.3 Program for Each Concept Details of the recommended Phase 2 hydrogeologic field exploration programs for each concept are provided as follows: SANDIEGO COUNTY WATERAUTHORTTT Groufuiwater Storage &• Recovery Project j:\3892\ooo5\Reporc\ciiapt7.doc 7-3 Lower San Luis Rey River Valley 7.3.a Mission Basin 1.63 MGD constant yield/seasonal storage proiect As described in Chapter 4, this project concept would operate on a constant yield basis with groundwater extraction from three wells producing about 2,500 acre-feet/year of native groundwater. This project is not anticipated to provide significant carryover or seasonal storage benefits. City of Oceanside wells (existing or planned) will supply the additional project yield. It is assumed that adequate studies/reports exist related to the location, spacing, production capability, and environmental impacts for the planned addifional extraction wells (Douglas Wellfield and North River Road Wellfield). The project concept also assumes that 2 MGD of Title 22 reclaimed water can be artificially recharged by surface spreading at the Norths Riverside Pond Recharge Area and that no more than 20 percent of this reclaimed water will be withdrawn from proximate wells. The following provides details of the limited hydrogeologic field investigafions that would be required to evaluate this project concept. 1. Field Preparation • Site CPT soundings (8) and monitoring wells (3). • Obtain access. • Obtain permits. • San Diego County, Department of Planning and Land Use will require monitoring well permits. Well permits are ministerial. • Encroachment Permit may be required to drill monitoring wells depending on location from City of Oceanside or San Diego County Flood Control District. • Clear ufilifies. 2. Cone Penetrometer (CPT) soundings • Perform CPT soundings (8) to depths of 30 to 50 feet in North Riverside Pond Recharge Area and convert four (4) to micro wells (piezometers). • Evaluate CPT and micro well data (Go/No Go decision). • Assess presence of impermeable layers, depth to groundwater, gradient, infiltrafion capacity, presence of organics, etc. • Go: Confirm/modify monitoring well locafions. • No Go: Move to next project concept. 3. Drill small-diameter (6-inch) exploratory borings to bedrock and convert to 2-inch-diameter monitoring wells. • Direct rotary drill three boreholes to depths of approximately 200 feet (bedrock). Collect undisturbed samples at 10-foot intervals. • Log boreholes during drilling. • Perform geophysical surveys of each borehole (long/short normal, 6- foot lateral, SP) • Evaluate geophysical survey data (Go/No Go decision) SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project ) i\3892\0005\Reporc\chapt7.doc 7-4 Lowcr Sun Luis Rey River Valley • Go; Design 2-inch-diameter monitoring well. • No Go: Abandon/grout borehole to surface. • Complete borehole with 2-inch-diameter PVC casing with appropriately located screened secfions, gravel pack, surface cement seal, and mechanically develop. • Install small submersible pump, develop monitoring well(s), and purge until purge parameters (temp, pH, EC) stabilize. • Sample monitoring well(s) for inorganic and select organic constituents for assessment of environmental contaminants to provide baseline water quality data and assess geochemical compatibility of native groundwater with injected water. • Assess aquifer properties. Perform slug test(s), measure static/dynamic water levels, water level data, and instrument well(s) for collection of long-term water level data. • Survey well using GPS and establish elevation control to 0.01-foot accuracy. • Secure monitoring wells with protective vaults. 4. Assess aquifer mineralogy and material properties. • Perform x-ray diffraction, cation exchange capacity, and SEM analysis of select undisturbed samples (vadose and saturated zone). • Perform classificafion, grain size, and permeability of select samples, 5. Analyze data • Assess site recharge potenfial, infiltration rates, check between injected flows and native groundwater. • Assess direcfion, gradient, and rates of groundwater flow. • Perform numerical modeling of recharge scenarios using exisfing models. • Evaluate use of recharged water (reclaimed water mixing/dilution). • Assess recharge pond engineering requirements (berms, freeboard, intake, overflow, existing flood control seasonal restrictions, etc.). 6. Prepare technical memorandum of field investigation findings. 7.3.b Mission Basin 6.70/10.0 MGD constant vield/seasonal/carryover storage proiect (with provisions to supplv Carlsbad MWD) This project concept would operate both as a constant yield and carryover/seasonal storage program. The local, constant yield component of the project would involve up to 13.3 MGD of groundwater extraction. Basin recharge would occur using imported water from the SDCWA second aqueduct and Tifie 22 reclaimed water from the City of Oceanside's San Luis Rey Wastewater Treatment Plant. This project concept will include addifional groundwater extraction wells at the North River Road Wellfield SANDIEGO COUNTY WATERAUTHORITY (Groundwater Storage & Recovery Project j:\3892\ooo5\Rcixjrc\chapr7.doc 7-5 Lowcr Sau Luis Rey River Valley site and the Douglas Drive Wellfield site. Reclaimed water surface spreading will be performed at the North Riverside Pond Recharge Area, and imported water surface spreading will be performed at the Upper Pond Recharge Area site. To prevent adverse environmental effects associated with short-term basin overdraft, a seawater intrusion barrier will be included at the basin narrows near the coast using 2 MGD of reclaimed water injected in a series of wells. Field invesfigations to assess the hydrogeologic feasibility of this project concept are described below. Infrastructure required for this project concept is described in Chapter 4. The following provides details of hydrogeologic field invesfigations that would be performed for this project concept. Hydrogeologic investigations at the North Riverside Pond Recharge Area (Title 22 reclaimed water surface spreading) has been described previously and will not be repeated. Field explorafion will consist of CPT soundings, construcfion of monitoring wells in the Upper Pond Recharge Area, and the construction of test wells for aquifer analysis. Ut)per Pond Recharge Area 1. Field preparation • Site CPT soundings (8) and monitoring wells (3). • Obtain access. • Obtain permits. • San Diego County, Department of Planning and Land Use will require monitoring well permits. Well permits are ministerial. • Encroachment Permit may be required to drill monitoring wells depending on location from City of Oceanside or San Diego County Flood Control District. • Clear utilifies. 2. CPT soundings • Perform CPT soundings (8) to depths of 30 to 50 feet in Upper Pond Recharge Area and convert four (4) micro wells (piezometers). • Evaluate CPT and micro well data (Go/No Go decision). • Assess presence of impermeable layers, depth to groundwater, gradient, infiltration capacity, presence of organics etc. • Go: Confirm/modify monitoring well locations. • No Go: Move to next project concept. SAN DIEGO COUNTY WATERAUTHORITT (Groundwater Storage & Recovery, Project j:\3892\ooo5\Report\chapt7,dQc 7-6 Lowcr San Luts Rey River Valley 3. Drill small-diameter (6-inch) exploratory borings to bedrock and convert to 2-inch-diameter monitoring wells. • Direct rotary drill three boreholes to depths of approximately 200 feet (bedrock). Collect undisturbed samples for classification, aquifer mineralogy, and strength properties. • Log borehole during drilling. • Perform geophysical surveys of each borehole (long/short normal, 6- foot lateral, SP) • Evaluate geophysical surveys (Go/No Go decision) • Go: Design 2-inch-diameter monitoring well. • No Go: Abandon/grout borehole to surface. • Complete borehole with 2-inch-diameter PVC casing with appropriately located screened sections, gravel pack, surface cement seal, and mechanically develop. • Install small submersible pump, develop monitoring well(s) and purge until purge parameters (temp, pH, EC) stabilize. • Sample monitoring well(s) for inorganic and select organic constituents for assessment of environmental contaminants, to provide baseline water quality data, and assess geochemical compatibility of native groundwater with injected water. • Assess aquifer properties. Perform slug test(s), measure stafic/dynamic water levels, and instrument well(s) for collecfion of long-term water level data. • Survey well using GPS and establish elevafion control to 0.01 foot accuracy. • Secure monitoring wells with protecfive vaults. 4. Assess aquifer mineralogy and material projects. • Perform x-ray diffracfion, cation exchange capacity, and SEM analysis of select undisturbed samples (vadose and saturated zone). • Perform classification, grain size, and permeability of select samples. 5. Analyze data. • Assess site recharge potential, infiltration rates, injectate/nafive groundwater compatibility. • Assess direction, gradient, and rates of groundwater flow. • Perform numerical modeling of recharge scenarios using existing models. • Evaluate fate of recharged water (reclaimed water mixing/dilution). • Assess recharge pond engineering requirements (berms, freeboard, intake, overflow, existing flood control seasonal restrictions, etc.). SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j;\3892\ooo5\Rcporr\ch3pr7,doc 7-7 Lowcr San Luis Rey River Valley 6. Provide technical memorandum of field investigafion findings. Douglas Drive Wellfield Site 1. Assess existing wellfield data. • Compile/evaluate existing data regarding aquifer pump tests and well spacing criteria. • Inspect existing wells (if present) regarding ability to instrument for aquifer testing (pressure transducer installation). • Evaluate quality/reliability of data to determine well spacing criteria and distance/drawdown impacts of up to five (5) 1,100 gpm wells. • Evaluate expanded wellfield constraints (Go/No Go decision) • Go: Supplemental aquifer testing required. • No Go: Data adequate for expanded wellfield. • Design aquifer test program. 2. Drill two, small-diameter monitoring/observafion wells. • Direct rotary drill two, 2-inch-diameter monitoring wells to collect water level data during aquifer testing. Prepare lithologic logs and construction detail report. • Perform geophysical surveys. • Install casing, gravel pack, cement seal, and mechanically develop. • Provide submersible pump to purge and collect water quality samples. • Perform slug tests, collect water level data, and instrument monitoring wells for baseline water level data. • Survey wells for location, elevation, and secure well head. 3. Construct test well. • A test well will be constructed to perform pump tests to obtain aquifer data for the expanded wellfield including well spacing criteria, interference analysis, and to refine aquifer modeling. • Drill pilot boring to 200 feet and ream to 20-inch diameter, install 6- inch-diameter wire wrap well screen (0.090-inch slots) with select gravel pack, and cement seal. Provide 12-inch-diameter pump housing upper casing. • Develop test well by mechanical swab and air jet. 4. Well testing • Install variable speed pump and meters/valves for flows up to 1,000 gpm and pump and surge until stable water quality purge parameters are obtained. Perform step-drawdown test. • Analyze discharge water for select inorganic and organic constituents. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\Rcport\chapt7.dcK: 7-8 Lowcr Sau Luis Bey River Valley • Instrument test well to collect water level data using a pressure transducer and Hermit. • Perform constraint rate aquifer test for minimum 24 hours and evaluate aquifer response in all wells. • Analyze acquired data and revise aquifer models and expanded wellfield configuration/feasibility. Assess capture zone of wellfield and fate and transport of North Riverside Pond Recharge Area Title 22 reclaimed water. 5. Prepare technical memorandum of field investigations and aquifer modeling findings. North River Road Wellfield Site 1. Assess exisfing wellfield data. • Compile/evaluate existing data regarding aquifer pump tests and well spacing criteria. • Inspect exisfing wells (if present) regarding ability to instrument for aquifer tesfing (pressure transducer installation). • Evaluate quality/reliability of data to determine well spacing criteria and distance/drawdown impacts of up to five (5) 1,100 gpm wells. • Evaluate expanded wellfield constraints (Go/No Go decision) • Go: Supplemental aquifer testing required. • No Go: Data adequate for expanded wellfield. • Design aquifer test program. 2. Drill two, small-diameter monitoring/observation wells. • Direct rotary drill two, 2-inch-diameter monitoring wells to collect water level data during aquifer tesfing. Prepare lithologic logs. • Perform geophysical surveys. • Install casing, gravel pack, cement seal, and mechanically develop. • Provide submersible pump to purge and collect water quality samples. • Perform slug tests and collect water level data. • Survey wells for location, elevation, and secure well heads. 3. Construct test well. • A test well will be constructed to perform pump tests for aquifer data for the expanded wellfield including well spacing criteria, interference analysis, and to refine aquifer modeling. • Drill pilot boring to 250 feet and ream to 20-inch diameter, install 6- inch-diameter wire wrap well screen (0.090-inch slots) with select gravel pack, and cement seal. Provide 12-inch-diameter pump housing upper casing. • Develop test well by mechanical swab and air jet. SAN DIEGO COUNTY WATERAUTHORITT (Groundwater Storage & Recovery Project j;\3892\ooo5\Report\chapt7.doc 7-9 lAJWcr San Luis Rey River Valley 4. Well testing • Install variable speed pump and meters/valves for flows up to 1,000 gpm and pump and surge until stable water quality purge parameters are obtained. Perform step-drawdown test. • Analyze discharge water for select inorganic and organic constituents. • Instrument test well to collect water level data using a pressure transducer and Hermit. • Perform constant rate aquifer test for minimum 24 hours and evaluate aquifer response in all wells. • Analyze acquired data and revise aquifer models and expanded wellfield configuration/feasibility. 5. Prepare technical memorandum of field investigation and aquifer modeling findings. College Wellfield Site 1. Field preparation. • Site pulse EKKO seismic line locafions to assess aquifer geometry and locations for monitoring wells and test wells. • Obtain access. • Obtain permits. • Obtain San Diego County monitoring well and test well permits. • Obtain encroachment permits from landowners. • Clear utilities. 2. Perform pulse EKKO geophysical surveys. • Analyze acquired data (Go/No Go decision) • Assess aquifer storage and potential well yields. • Go: Confirm modify monitoring and test well locations. • No Go: Abandon project concept. 3. Drill small-diameter (6-inch) exploratory borings to bedrock (three total) and convert to 2-inch-diameter monitoring wells. • Direct rotary drill three boreholes to depths of approximately 200 feet (bedrock). Collect undisturbed samples. • Log boreholes during drilling. • Perform geophysical surveys of each borehole (long/short/normal, 6- foot lateral, SP). • Evaluate geophysical and cuttings data (Go/No Go decision). • Go: Design 2-inch-diameter monitoring wells. • No Go: Abandon/grout borehole to surface; restore sites. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project I:\3892\ooo5\Repoi:t\ciiapt7.doc 7-10 Lowcr San Luis Rey River Valley • Complete boreholes with 2-inch-diameter PVC casing with appropriately located screened section, gravel pack, surface cement seal, and mechanically develop. • Install submersible pump, develop monitoring wells and purge until purge parameter (temp, pH, EC) stabilize. • Sample monitoring wells for inorganic and select organic constituents for assessment of environmental contaminants to provide baseline water quality data, and to assess geochemical compatibility of native groundwater with injected water. • Assess aquifer properties. Perform slug tests and instrument wells for baseline water level data. • Survey wells using GPS and establish elevation control to 0.01 foot away. • Secure monitoring wells with protective vaults. 4. Assess aquifer numerology and material properties. • Perform classificafion, grain size, and permeability tests. • Perform x-ray defraction, CAC, and SEM analyses. 5. Analyze data (Go/No Go decision). • Assess storage potenfial, aquifer properties, well yields, geochemical compatibility, and rates/direction of groundwater movement. • Go: Design test well. • No Go: Abandon project concept. 6. Construct test well. • A test well will be constructed to perform pump tests for aquifer data for the proposed wellfield including well spacing criteria, interference analysis, and to refine aquifer modeling. • Drill pilot boring to 200 feet and ream to 20-inch diameter, install 6- inch-diameter wire wrap well screen (0.090-inch slots) with select gravel pack, and cement seal. Provide 12-inch-diameter pump housing upper casing. • Develop test well by mechanical swab and air jet. 7. Well testing • Install variable speed pump and meters/valves for flows up to 1,000 gpm and pump and surge until stable water quality purge parameters are obtained. Perform step-drawdown test. • Analyze discharge water for select inorganic and organic constituents. • Instrument test well to collect water level data using a pressure transducer and Hermit. • Perform constant rate aquifer test for minimum 24 hours and evaluate aquifer response in all wells. SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project I:\3892\ooo5\RqxDrt\chapt7.doc 7-11 Lowcr San Luts Rey River Valley • Analyze acquired data and revise aquifer models and wellfield configuration/feasibility. Assess capture zone of wellfield and fate and transport of North Riverside Pond Recharge Area Title 22 reclaimed water. Mission Avenue Imported Water Injection Site 1. Field preparation. • Site pulse EKKO seismic line locations to assess aquifer geometry and locations for monitoring wells and test wells. • Obtain access. • Obtain permits. • Obtain San Diego County monitoring well and test well permits. • Obtain encroachment permits from landowners. • Clear utilities. 2. Perform pulse EKKO geophysical surveys. • Analyze acquired data (Go/No Go decision) • Assess aquifer storage and potential well yields. • Go: Confirm modify monitoring and test well locafion. • No Go: Abandon project concept. 3. Drill small-diameter (6-inch) exploratory borings to bedrock (three total) and convert to 2-inch-diameter monitoring wells, • Direct rotary drill three boreholes to depths of approximately 200 feet (bedrock). Collect undisturbed samples. • Log boreholes during drilling. • Perform geophysical surveys of each borehole (long/shorl/normaJ, 6- foot lateral, SP). • Evaluate geophysical and cutfings data (Go/No Go decision). • Go: Design 2-inch-diameter monitoring wells. • No Go: Abandon/grout borehole to surface; restore sites. • Complete boreholes with 2-inch-diameter PVC casing with appropriately located screened section, gravel pack, surface cement seal, and mechanically develop. • Install submersible pump, develop monitoring wells and purge until purge parameter (temp, pH, EC) stabilize. • Sample monitoring wells for inorganic and select organic constituents for assessment of environmental contaminants to provide baseline water quality data, and to assess geochemical compatibility of native groundwater with injected water. • Assess aquifer properties. Perform slug tests and instrument wells for baseline water level data. • Survey wells using GPS and establish elevation control to 0.01 foot away. SANDIEGO COUNTY WATERAUTHORITY (GroundwaterStorage & Recovery Project j;\3892\0005\aeport\chapt7.doc 7-12 Lower San Luis Rey River Valley • Secure monitoring wells with protective enclosures/vaults. 4. Assess aquifer numerology and material properties. • Perform classification, grain size, and permeability tests. • Perform x-ray defraction, CAC, and SEM analyses. 5. Analyze data (Go/No Go decision). • Assess storage potenfial, aquifer properties, well yields, geochemical compatibility, and rates/direction of groundwater movement. • Go: Design test well. • No Go: Abandon project concept. 6. Construct test well. • A test well will be constructed to perform pump tests for aquifer data for the GSR wellfield including well spacing criteria, interference analysis, and to refine aquifer modeling. • Drill pilot boring to 200 feet and ream to 20-inch diameter, install 6- inch-diameter wire wrap well screen (0.090-inch slots) with select gravel pack, and cement seal. Provide 12-inch-diameter pump housing upper casing. • Develop test well by mechanical swab and air jet. 7. Well testing • Install variable speed pump and meters/valves for flows up to 1,000 gpm and pump and surge until stable water quality purge parameters are obtained. Perform step-drawdown test. • Analyze discharge water for select inorganic and organic constituents. • Instrument test well to collect water level data using a pressure transducer and Hermit. • Perform constant rate aquifer test for minimum 24 hours and evaluate aquifer response in all wells. • Analyze acquired data and revise aquifer models and wellfield configuration/feasibility. Assess capture zone of wellfield and fate and transport of North Riverside Pond Recharge Area Title 22 reclaimed water. 8. GSR pilot test (Go/No Go decision) • Evaluate data. • No Go: Do not perform GSR pilot test. • Go: Perform GSR pilot test. 9. Perform GSR pilot test. • Identify water source and construct conveyance pipelines. SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\m2\0D05\ncpon\chapt7.do^ 7-13 Lowcr San Luis Rey River Valley • Install/modify variable speed well pump used in aquifer test (Task 7 above). • Modify well to accept injection water including drop tubes, metering devices, pressure transducer, sampling ports. • Perform 7-day constant or variable rate injection tests with attendant performance monitoring. • Monitor adjacent monitoring wells for hydraulic response and water quality variafions. • Assess storage period and recovery schedule. • Perform extraction test with attendant monitoring of water quality and recovery efficiency. 10. Analyze acquired data. • Assess extraction, GSR feasibility. • Evaluate recovery efficiency. • Perform appropriate numerical modeling of aquifer system for scaled wellfield. Seawater Intrusion Barrier 1. Field preparation. • Site pulse EKKO seismic line locations to assess aquifer geometry and locations for monitoring wells and test wells. • Obtain access. • Obtain permits. • Obtain San Diego County monitoring well and test well permits. • Obtain encroachment permits from landowners. • Clear ufilifies. 2. Perform pulse EKKO geophysical surveys. • Analyze acquired data (Go/No Go decision) • Assess aquifer storage and potential well yields. • Go; Confirm modify monitoring and test well location. • No Go; Abandon project concept. 3. Drill small-diameter (6-inch) exploratory borings to bedrock (three total) and convert to 2-inch-diameter monitoring wells. • Direct rotary drill three boreholes to depths of approximately 200 feet (bedrock). Collect undisturbed samples. • Log boreholes during drilling. • Perform geophysical surveys of each borehole (long/short/normal, 6- foot lateral, SP). • Evaluate geophysical and cuttings data (Go/No Go decision). • Go: Design 2-inch-diameter monitoring wells. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\Rcixji-t\diapt7.doc 7-14 Lower San Luis Rey River Valley • No Go: Abandon/grout borehole to surface; restore sites. • Complete boreholes with 2-inch-diameter PVC casing with appropriately located screened section, gravel pack, surface cement seal, and mechanically develop. • Install submersible pump, develop monitoring wells and purge until purge parameter (temp, pH, EC) stabilize. • Sample monitoring wells for inorganic and select organic constituents for assessment of environmental contaminants to provide baseline water quality data, and to assess geochemical compafibility of native groundwater with injected water. • Assess aquifer properties. Perform slug tests and instrument wells for baseline water level data. • Survey wells using GPS and establish elevafion control to 0.01 foot away. • Secure monitoring wells with protecfive vaults. 4. Assess aquifer numerology and material properties. • Perform classificafion, grain size, and permeabilify tests. • Perform x-ray defracfion, CAC, and SEM analyses. 5. Analyze data (Go/No Go decision). • Assess storage potenfial, aquifer properties, well yields, geochemical compatibilify, and rates/direction of groundwater movement. • Go; Design test well. • No Go; Abandon project concept. 6. Construct test well. • A test well will be constructed to perform pump tests for aquifer data for the seawater intrusion barrier including well spacing criteria, interference analysis, and to refine aquifer modeling. • Drill pilot boring to 200 feet and ream to 20-inch diameter, install 6- inch-diameter wire wrap well screen (0.090-inch slots) with select gravel pack, and cement seal. Provide 12-inch-diameter pump housing upper casing. • Develop test well by mechanical swab and air jet. 7. Well testing • Install variable speed pump and meters/valves for flows up to 500 gpm and pump and surge until stable water quality purge parameters are obtained. Perform step-drawdown test. • Analyze discharge water for select inorganic and organic constituents. • Instrument test well to collect water level data using a pressure transducer and Hermit. SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j;\3892\ooo5\RqxDrc\chapt7,doc 7-15 Lowcr San Luis Rey River Valley • Perform constraint rate aquifer test for minimum 24 hours and evaluate aquifer response in all wells. • Analyze acquired data and revise aquifer models and seawater intrusion barrier wellfield configuration/feasibility. Assess fate/transport of reclaimed water. 8. Prepare Technical Memorandum of field investigafions and aquifer modeling and GSR pilot test findings and feasibility. 7.3.C Mission Basin 6.70/10.0 MGD expansion with Regional use of City of Oceanside's Weese Filtration Plant This project concept involves engineering improvements (infrastructure and exisfing treatment facilifies) to allow the distribution of additional filtered water supply to other parts of the Counfy. Some carryover storage benefit of imported water could resuh to the City of Oceanside. No additional hydrogeologic field investigafions would be performed for project Concept No. 3, which would not otherwise have been invesfigated as part of project Concept No. 2. 7.3.d Bonsall Basin 3.60/4.60 MGD constant vield/seasonal/carryover storage proiect This project would operate in the easteriy, upper portion of the Bonsall Basin as a constant yield project with carryover and seasonal storage, including GSR. Hydrogeologic studies would be conducted to verify the feasibility and magnitude of a constant yield project (i.e., groundwater extraction) in the area and how and what volumes of imported water could be recharged for basin conjuncfive use. Groundwater extraction wells (four wells producing from about 700 to 1,000 gpm each) and GSR wells (two wells injecting about 250 gpm each of imported water) would be constructed. Details of the proposed hydrogeologic field investigations for the project concept are described below. 1. Field preparation. • Site pulse EKKO seismic line locafions to assess aquifer geometry and locations for monitoring wells and test wells. • Obtain access. • Obtain permits. • Obtain San Diego County monitoring well and test well permits. • Obtain encroachment permits from landowners. • Clear ufilifies. 2. Perform pulse EKKO geophysical surveys. • Analyze acquired data (Go/No Go decision) • Assess aquifer storage and potenfial well yields. SAN DIEGO COUNTY WATERAUTHORTTT (GroundwaterStorage & Recovery Project ):\3892\0005\Rcport\chapt7.doc 7-16 Lower San Luis Rey River Valley • Go; Confirm modify monitoring and test well locations. • No Go; Abandon project concept. 3. Drill small-diameter (6-inch) exploratory borings to bedrock (three total) and convert to 2-inch-diameter monitoring wells. • Direct rotary drill three boreholes to depths of approximately 200 feet (bedrock). Collect undisturbed sami3les. • Log boreholes during drilling. • Perform geophysical surveys of each borehole (long/short/normal, 6- foot lateral, SP). • Evaluate geophysical and cutfings data (Go/No Go decision). • Go; Design 2-inch-diameter monitoring wells. • No Go; Abandon/grout borehole to surface; restore sites. • Complete boreholes with 2-inch-diameter PVC casing wifii appropriately located screened section, gravel pack, surface cement seal, and mechanically develop. • Install submersible pump, develop monitoring wells and purge until purge parameter (temp, pH, EC) stabilize. • Sample monitoring wells for inorganic and select organic constituents for assessment of environmental contaminants to provide baseline water quality data, and to assess geochemical compatibility of native groundwater with injected water. • Assess aquifer properties. Perform slug tests and instrument wells for baseline water level data. • Survey wells using GPS and establish elevation control to 0.01 foot away. • Secure monitoring wells with protecfive vauhs. 4. Assess aquifer numerology and material properties. • Perform classificafion, grain size, and permeability tests. • Perform x-ray defraction, CAC, and SEM analyses. 5. Analyze data (Go/No Go decision). • Assess storage potenfial, aquifer properties, well yields, geochemical compatibility, and rates/direction of groundwater movement. • Go: Design test well. • No Go: Abandon project concept. 6. Construct test well. • A test well will be constructed to perform pump tests for aquifer data for the proposed wellfield including well spacing criteria, interference analysis, and to refine aquifer modeling. • Drill pilot boring to 200 feet and ream to 20-inch diameter, install 6- inch-diameter wire wrap well screen (0.090-inch slots) with select SAN DIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\0005\Report\ciiapc7.doc 7-17 Lowcr San Luis Rey River Valley gravel pack, and cement seal. Provide 12-inch-diameter pump housing upper casing. • Develop test well by mechanical swab and air jet. 7. Well tesfing • Install variable speed pump and meters/valves for flows up to 1,000 gpm and pump and surge until stable water quality purge parameters are obtained. Perform step-drawdown test. • Analyze discharge water for select inorganic and organic constituents. • Instrument test well to collect water level data using a pressure transducer and Hermit. • Perform constant rate aquifer test for minimum 24 hours and evaluate aquifer response in all wells. • Analyze acquired data and revise aquifer models and wellfield configuration/feasibilify. 8. GSR pilot test (Go/No Go decision) • Evaluate data. • No Go; Do not perform GSR pilot test. • Go: Perform GSR pilot test. 9. Perform GSR pilot test. • Idenfify water source and construct conveyance pipelines. • Install variable speed well pump. • Modify well to accept injection water including drop tubes, metering devices, pressure transducer, sampling ports. • Perform 7-day constant or variable rate injection tests with attendant performance monitoring. • Monitor adjacent wells for hydraulic response and water quality variations. • Assess storage period and recovery schedule. • Perform extracfion test with attendant monitoring. 10. Analyze acquired data. • Assess extraction, GSR feasibihty. • Evaluate recovery efficiency. • Perform appropriate numerical modeling of aquifer system for scaled wellfield. 11. Prepare Technical Memorandum of field investigation and aquifer modeling and GSR pilot test findings. SANDIEGO COUNTY WATERAUTHORITT (Groundwater Storage & Recovery Project j:\3892\ooo5\ReportVhapc7.doc: 7-18 LowcT San Luis Rey Rivcr Valley 7.4 Ph ase 2 Cost Estim ate The cost estimates by major task for the Phase 2 Field Invesfigafion are provided in Tables 1 and 2. General, basin-wide tasks are listed in Table 7-1 while project concept-specific tasks are listed in Table 7-2. The estimated time frame for completion of the Phase 2 field investigations is 12 to 14 months. Table 7-1 Phase 2 Cost Estimate - General Task Item General Tasks Estimated Cost Basin Surveys, Water Level Map, Water Quality Sampling $60,000 Contractor Solicitation/Procurement 5,000 NPDES Permit Issues 5,000 Evaluation of Environmental Contamination 10,000 Evaluation of Water Quality Compatibility 10,000 Report Preparation 30,000 Project Management 20,000 Subtotal $140,000.00 Table 7-2 Phase 2 Field Investigation, Project-Specific Tasks (costs in thousands of dollars) Project Concept Field Prep CPT Soundings Pulse EKKO Seismic Exploratory Borings Monitoring Weils Test Well Construction Well Testing Assen Aquifer Properties Perform GSR Pilot Test Analyze Data Perform Aquifer Modeling Prepare Technical Memorandum Total Project Concept Cost Mission Basin, 1,63 MGD Desalter 5 20 ~ 35 --8 ~ 6 5 5 84 Mission Basin, 6.70/10.0 MGD Desalter (w/provisions to supply Carlsbad MWD), and GSR Operations 20 20 50 120 220 100 50 50 45 40 30 745 Mission Basin, 6,70/iO.O MGD Desaller w/Regional use of Weese Filtration Plant Bonsall Basin, 3,60/4.60 MGD Desalter w/GSR Operations 5 -20 35 50 20 10 50 15 15 10 230 Total 30 40 70 190 270 120 6S 100 66 60 45 1059 SANDIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Reporc\chapt7.doc 7-19 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Chapter 8 - Conclusions and Recommendations 8.1 Introduction Findings and conclusions of the Phase 1 feasibility study and recommendafions for fiiture work phases are presented herein. Findings and conclusions are organized according to general subjects or topics developed in Chapters 2, 3, 4, 5, 6, and 7. The materials either presented or referenced in the previous chapters support findings and conclusions presented in Section 8.2, and form the basis for recommendafions presented in Secfion 8.3. 8.2 Findings and Conclusions Hydrogeology • Total gross storage capacity in the Mission and Bonsall Basin alluvial aquifers have been esfimated to be 92,000 acre-feet and from 25,000 to 40,000 acre-feet (USGS 1974) respectively (SDCWA 1995). • The estimated "usable" volume of groundwater storage is approximately 30,000 acre-ft in the Mission Basin and 9,000 acre-ft in the Bonsall Basin. These volumes equate to the historical reported low groundwater levels in the basins. • The current safe yield in the Mission and Bonsall Basin have been estimated to be 6,700 and 5,400 acre-feet per [average] year respectively (SDCWA 1995). • The "safe yield of the Mission Basin will be fully utilized when the City of Oceanside's planned 6.37 MGD desalter expansion becomes operational. • Addifional groundwater production in the Mission Basin will require arfificial recharge (groundwater replenishment). • USGS has concluded that the groundwater in the Mission Basin is unconfined in the eastem portion and confined in the westem portion of the Basin. It appears that the approximate boundary between the confined and unconfined portions of the basin is generally located between Douglas Drive and College Boulevard. • Groundwater in the Mission and Bonsall Basin is high in Total Dissolved Solids (TDS) and generally exceeds drinking water standards. • It has been concluded by the study team that even with using water lower in TDS content to replenish the basins, water stored in either the Mission or Bonsall basins will require desalinafion following extracfion from storage. SANDIEGO COUNTY WATERAUTHORTTT J:\3892\0005\Repi)rt\chapt8.doc {-1 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley • It is possible fiiture water quality in the Mission and Bonsall Basins could improve due to the introduction of better quality recharge water, however, any improvements are likely to be localized and not basin-wide. • The potential to use Aquifer Storage and Recovery (ASR) (i.e. recharging and extracting groundwater using the same well) may be limited due to the steep hydraulic gradient that exists in the Mission and Bonsall Basins. • Groundwater can be replenished in the Mission Basin by using percolation basins (surface spreading) located in unconfined portions of the alluvial aquifer and/or injection wells in confined portions of the basin. • Establishment of seasonal and carryover storage projects in the Mission and Bonsall Basins will also create the opportunity to capture addifional local sources of water such as stomi runoff and stream flow. Although the potential extent of this contribution has not been quanfified in this study, it could represent a significant cost savings versus the need to purchase imported recharge water. • Extraction of groundwater from carryover storage in the Mission Basin will likely require implementation of a seawater-intrusion barrier at the westem end of the basin to prevent fiirther degradafion of groundwater quality. Water Supply Systems Issues Mission Basin • The City of Oceanside currently purchases approximately 95% of its water supply from the SDCWA as either raw or treated water. • Oceanside's average daily water demand (ADD), water use averaged over an entire year, is about 24-MG for a year ('95-'96 water use). However, the ADD varies from month to month and dramafically from winter to summer, throughout the year. ADD can be as low as 12-MG in spring months and as high as 35-MG in the summer months. Maximum Daily Demand (MDD) can exceed 40-MG for a particular day in the summer. • At the present, up to 25-MGD of raw imported water from the Authority Second Aqueduct (Pipeline 3) can be treated by the City of Oceanside at its Wesse Water Filtrafion Plant (WFP). • Currently 2-MGD of brackish groundwater is recovered and treated for potable use at its Mission Basin Groundwater Purification Facility (GPF). Therefore, using both the WFP and the GPF, Oceanside can produce 27- MGD of treated water for its own use. • Typically for about six months (April to October) out of the year, Oceanside's Average Daily Demand (ADD) exceeds its total 27-MGD treated water capacity. • Treated water is delivered to Oceanside from the Authority's Tri-Agencies Pipeline (TAP) and the North County Distribufion Pipeline (NCDP). SANDIEGO COUNTY WATERAUTHORITY (Groundwater Storage & Recovery Project j:\3892\0005\Report\chapc8.doc 8-2 Lowcr San Luts Rey River Valley The Authority's TAP and the NCDP also serve treated water to Vista ID, Carlsbad MWD, Vallecitos WD, Valley Center, and Rainbow MWD. Oceanside has no other storage than its 50.5-MG of service or distribution storage. Usable storage (essenfially raw water due to demineralizafion requirement) in the Mission Basin is currently limited due to the potenfial for seawater intmsion and the lack of reliable replenishment. The City of Oceanside could use additional groundwater producfion from the Mission Basin to meet demand and offset storage deficiencies in its 320 and 511 pressure zones. To increase groundwater production, the Mission Basin will require artificial recharge. Addifional pipelines and pump stations will be needed to move the groundwater through the system Additional potable water supply can be developed from the Mission Basin by drawing on the available useable storage of the basin, providing artificial recharge to replace water developed from storage, and expanding the Mission Basin Water Purificafion Facility (Desalter). Potable water supply developed from the Mission Basin can offset treated water demands on the Authority's Pipeline 4, and its North County Distribufion Pipeline (NCDP) and the Tri-Agencies Pipeline (TAP). Treated water produced from the Mission Basin could also be provided to agencies that are connected to theAuthority's North County Distribufion Pipeline (NCDP). A new pump station at the westem end of the NCDP, near the site of Oceanside's future Osborne reservoirs, would be needed to move groundwater to higher elevations. Authority member agencies with aqueduct connections downstream of the City of Oceanside's Weese Filtration Plant (WFP) could be served with treated water from WFP if the WFP were expanded from its current 25- MGD capacity. Through a potential in-lieu arrangement, the Authority could constmct an increment of capacity at WFP and provide a corresponding increment of groundwater production to Oceanside. Carlsbad MWD has rights to 5-cubic feet per second (cfs) or about 3.2 MGD of water from the Mission Basin. These water rights are pre-1914 appropriafive rights and are not subject to loss from non-use. Carlsbad MWD could be provided with treated water produced from the Mission Basin through an existing connection with the Oceanside system located at East Vista Way and El Camino Real. However, only a limited area within Carlsbad could be served through this connecfion. A greater portion of Carlsbad could be served with Mission Basin groundwater by constructing a new connection between the Carlsbad system and the Oceanside San Francisco Peak pressure zone. City of Oceanside flow control facilifies and pipelines could be used to a certain extent to bring imported water into the Mission Basin for groundwater recharge, however, extension of the exisfing aqueduct supply lines will be necessary. Imported water supplies stored in the Mission Basin SANDIEGO COUNTY WATERAUTHORTTT J :\3892\0005\Rcporc\chapi8.doc 8-3 (Groundwater Storage & Recovery Project Lower San Luis Rey River Valley could be used to supplement (raw) imported water supplies that are subject to cutback during prolonged statewide and regional drought, during times of emergency, or during routine aqueduct maintenance shutdown periods when imported water supplies may be cutoff. • A groundwater replenishment program will provide additional reliability to groundwater supplies in the Mission Basin that are dependent upon local rainfall and subject to prolonged local droughts. Bonsall Basin • Rainbow currently purchases 100% of its demand from the Authority as treated water. Currently, Rainbow does not use any local water resources, but has considered extracting and treating brackish groundwater from the Bonsall Basin. • Rainbow has previously made an application to the State to secure rights to irrigation return flows that recharge the groundwater in the Bonsall Basin. The application is currenfiy inactive pending environmental documentation. • ADD for the Rainbow (1990 - highest recorded water use year) was 31.2 MG. The calculated MDD was 84.4 MG. ADD demand varied from 8.75 MG in April 1990 to 45 MG in August, September, and October 1990. • Rainbow MWD does not have any water treatment facilities nor are any planned in the immediate future. • Hydraulic Grade Line (HGL) for Rainbow MWD distribution system ranges from 820 to 2160 feet. • Seventeen service or distribution reservoirs provide a total storage capacity of 425.7 MG. For the exisfing ADD, each pressure zone (except for four with HGLs > iOOO) has a surplus of operational, plus fire and emergency storage (calculated as 100%i of the MDD peak month). • If 10-day storage requirements (at ADD) were considered, there would be a surplus for Rainbow MWD's entire (existing) system. However, eight pressure zones would have a storage deficit of from 3 to 52 MG. However, only one of the pressure zones with a HGL < 1000 would have a storage deficit. The 865 pressure zone would have a deficit of about 3.5 MG. • Imported water supplies stored in the Bonsall Basin could be used to supplement (raw) imported water supplies that are subject to cutback during prolonged statewide and regional drought, during times of emergency, or during routine aqueduct maintenance shutdown periods when imported water supplies may be cut off. • A groundwater replenishment program will provide additional reliability to groundwater supplies in the Bonsall Basin that are dependent upon local rainfall and subject to prolonged local droughts. • Rainbow MWD could use treated water produced from the Bonsall Basin to meet demand in its 820 or 865 pressure zones. A treated water pump station and pipeline will be required to move the water to these zones. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\Rci5ort\chapc8.doc 8-4 Lower San Luis Rey River Valley • Facilities required to replenish the Bonsall Basin with imported water include an unfiltered-water turnout, a flow-control facility and associated piping, and groundwater injecfion wells. Environmental Issues Regulatory concems with groundwater storage and recovery projects in the Mission and Bonsall Basins include drinking water quality, potential impacts to riparian habitat, and local construction management • The use of reclaimed water for groundwater recharge and subsequent use of the groundwater for drinking water will be limited by existing Department of Health groundwater recharge policy and public concems. • The use of existing storm water retention basins for groundwater recharge in the Mission Basin could be constrained by their proposed use as revegetation basins for the San Luis Rey River. Project Costs and Benefits • Costs for groundwater storage and recovery projects in the Mission and Bonsall Basins will range from $715 to $1283/acre-ft of potable water produced. Carryover storage operations offer the best value as compared to seasonal only operations, as these projects have lower unit costs to produce water and provide more storage. • Distribution costs are typically not included in the evaluation of new water supply alternatives. However, the distribution requirements and costs have been included in this study for completeness. If distribufion costs are not considered, costs for groundwater storage and recovery projects in the Mission and Bonsall Basins will range from $589 to $ 1,047/acre-ft of potable water produced. • Project benefit rankings generally indicate that projects with the lowest overall unit cost result in the greatest overall benefit. • Implementation of groundwater storage and recovery projects in the Mission Basin will offer the opportunity for supplemental treated-water service to multiple agencies. • Groundwater storage and recovery projects in the Mission and Bonsall Basins provide the opportunity to store imported water at a discount. This essenfially converts an intermptible supply into a firm water supply. • Water stored in the Mission Basin can be made available to other member agencies for use during imported water shortages or emergencies. • Water stored in the Bonsall Basin could be used by Rainbow MWD to offset its peak demand on aqueduct deliveries allowing more imported water to be used by member agencies to the south. • Expanded Mission Basin groundwater production could also allow the Authority to use potenfial capacity at Oceanside's WFP to provide an added SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\Report\chapt8.doc 8-5 Lowcr San Luis Rey River Vall&y increment of regional treated water that could be served to other member agencies to the south. • Direct economic measurement of a regional storage benefit created by groundwater projects in the Mission and Bonsall Basins is difficult at best given the current level of understanding of how future costs may be allocated. It is apparent, however, that any measure of addifional storage or treated water capability is a benefit to the region given the fiiture uncertainty regarding reliability of imported water supplies and the region's projected growth. 8.3 Recommendations The following project concepts are recommended for further evaluation. They are in the following order of priority: 1. Project Concept No.3A - lO.O MGD Mission Basin Desalter with 10.0 MGD expansion to Weese WFP 2. Project Concept No. 2A - 10.0 MGD Mission Basin Desalter 3. Project Concept No.3 - 6.70 MGD Mission Basin Desalter with 6.70 MGD expansion to Weese WFP 4. Project Concept No.2 - 6.70 MGD Mission Basin Desalter 5. Project Concept No. 4A ~ 4.6 MGD Bonsall Basin Desalter 6. Project Concept No 4 - 3.60 MGD Bonsall Basin Desalter 7. Project Concept No. 1-1.63 MGD Mission Basin Desalter Project concepts with higher yield are preferred over those with lower yield when considering potential benefit to the region's water supply. While some project concept unit costs exceed the cost of imported water, project benefits including (but not limited to) the development of local groundwater carryover storage capacity and reducing the region's peak demand for treated imported water offer sufficient jusfification to proceed further with the planned three-phase feasibility study. It is also recommended that additional discussions with the City of Oceanside, Carlsbad MWD, and Rainbow MWD first be conducted before developing a scope of work for Phase 2 and proceeding with the feasibility study. Phase 2 studies may include some additional project concept development as well as field investigations to support preferred concepts. Field invesfigafions may include a water-well survey, aquifer-perfonnance tests (pumping tests), infiltrafion tests, groundwater and geochemical modeling, and perhaps some geophysical surveys to further evaluate aquifer strafigraphy. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project I:\3892\ooo5\Rcporc\chapt8.doc 8-6 Lowcr San Luis Rey River Valley The regulatory agencies identified in Chapter 5 should be contacted following further evaluation and screening of concepts idenfified in this study. Early consultafion and planning with all the permitfing agencies will be useful in idenfifying additional study tasks and can ultimately expedite the permit process. The detailed requirements and constraints identified during these initial consultations can reduce the level of potenfial environmental impact of a given project by understanding what design elements need to be adjusted. SANDIEGO COUNTY WATERAUTHORTTT (Groundwater Storage & Recovery Project j:\3892\ooo5\Rcporc\chapt8.doc 8-7 Lowcr San Luis Rey River Valley APPENDLX A Project Advisory Committee Meeting Minutes SAN DIEGO COUNTY WATER AUTHORITY Lower San Luis Rey River Valley Groundwater Storage and Recovery Feasibility Study Meeting Minutes Subject: Locafion: Date & Time: Prepared By: Attendees: First PAC Meefing San Diego Country Water Authority 3211 Fifth Avenue San Diego. CA 92103-5718 Tuesday October 27, 1998 2:30 p.m. to 4:00 p.m. Robert S. Weber, ASL Bob Yamada, San Diego County Water Authority Dan Diehr, San Diego County Water Authority Cesar Lopez, San Diego County Water Authority Jim Tumer, City of Oceanside Barry Martin, City of Oceanside Greg Blakely, City of Oceanside Howard Amold, ASL David Gardner, Fugro West Robert Weber, ASL Stephen Johnson, Stetson Engineers jhe Items discussed during the meeting are generally summarized as follows. Phase I Proiect Purpose. Scope, and Schedule 1. The project team was introduced and the scope reviewed. The project is the first of a three-phased approach conducted by the Authority to examine the potential for groundwater storage and recovery (GSR) projects in the Mission and Bonsall basins. The ASL team is under contract for Phase I at this time. The project is being conducted along with a similar project for the area referred to as the San Diego Formation. The San Diego Fonmation project is proceeding along ahead of this project, and Its methodology has been incorporated into the San Luis Rey project as appropriate, 2. Phase I is a "desktop" study to compile existing information, identify possible data gaps, and identify GSR project alternatives. 3. Local and regional benefits will fomi part of the Phase I evaluation criteria. This J:\3892\0005\mi-002rsw.wpd Page 1 ^ may include regional treatment or distribution capability, emergency storage, and in-lieu of deliveries which would be created as a result of GSR programs. The Authority may review the potential for participation in future GSR projects as an owner/operator. 4. Recommended project concepts from Phase 1 could be carried over to a Phase 11 field study which would include modeling and hydrogeologic field investigations. Recommendations for a Phase II public outreach program will be prepared during Phase I. 5. Phase III of the project would refine costs of potential GSR projects based on data obtained during Phase II. 6. The overall Phase I project schedule calls for a draft project report to be available for Authority review in eariy April 1999, and finalized in early May 1999. Authority staff anticipate submitting recommendations for Phase II activities to the Board of Directors in May or June of 1999. Initial Data Gathering (Task 1) Discussion 1. Individual meetings with the City of Oceanside, RMWD, and CMWD will be arranged by the ASL team to discuss and retrieve available water resources information. The Authority will be invited to participate in all individual meetings with PAC members. 2. Contacts for RMWD and CMWD are needed. ASL will contact Mike Metts of Dudek & Associates (RMWD's interim engineer) and Robert Greany or William Plummer of CMWD. 3. ASL recently prepared an updated Water Master Plan for the City Oceanside and CMWD. Pertinent information for the GSR study relative to Oceanside's and CMWD's water systems should be readily available within the Master Plans, Additional data needs will be discussed with the City and CMWD during individual meetings to be arranged as noted above. 4. Oceanside is in the process of expanding their San Luis Rey Wastewater Treatment Plant (WWTP) for tertiary treatment. A TM which discusses nitrate issues will be provided by the City. It is anticipated 5 MGD will be available. 5. A study conducted for the City by Montgomery in approximately 1970 considered utilizing imported water to recharge the basin in connection with channels to direct agricultural runoff away from spreading basins. The City will attempt to locate a copy of the study in the archives or obtain a copy from Montgomery. 6. The extent to which Camp Pendleton representatives may be Interested in this project is unknown. They currently have a 2 MGD emergency connection to J:\3892\0005\mi-002rsw.wpd Page 2 of 4 Oceanside's system at Morro Hills. Authority staff will coordinate with appropriate Camp Pendleton individuals to determine interest. 7. The City is considering an AB3030 plan for the Mission Basin; however, the fiming of implementing such a plan in conjunction with the planned desalter expansion projects is uncertain. 8. A preliminary bibliography of available water resources documents may be circulated by the ASL team for PAC comment by 11/6/98 or 11/9/98. Initial GSR Proiect Concepts City of Oceanside: 1. Oceanside has implemented a 2 MGD desalter project Design plans and CEQA documentation to expand production to 6.37 MGD are nearly complete, and the City's long terni goal is to extract 20 MGD from the Mission Basin. Oceanside's Water Master Plan describes the 20 MGD Mission Basin concept. 2. The current recharge rate of the Mission basin is estimated to be on the order of 8 MGD. Reclaimed water and imported seasonal water are envisioned as future recharge sources through percolation areas and direct injection/GSR wells. Reclaimed water may be ufilized on the west side of the basin and imported water on the east side. Seawater barrier issues will need to be considered. 3. There are currently three production wells on the desalter property, and two additional production wells to the east on Douglas Drive. The current expansion will include three additional production wells at the North River Road wellfield site and nine additional monitoring wells. 4. Environmental considerafions, mainly in the San Luis Rey River channel areas, are being looked at as part of the current expansion project, and will need further consideration in connection with the 20 MGD withdrawal concept. 5. The Authority recently put the 72-inch diameter North County Distribution Pipeline (NCDP) into service. With the NCDP and the City's associated 42-inch diameter supply line from the Oceanside 6 Flow Control Facility (FCF) in service, one of the City's exisfing twin 24-inch diameter lines from the Weese Filtration Plant (WFP) could be made available to instead supply seasonal imported recharge water from the Authority's Second Aqueduct to the San Luis Rey River. A new pipeline would be required; however, from the intersection of Osbome Street/East Vista Way to the San Luis Rey River Recharge area. 6. Potential inter-agency connections for nomial filtered water and emergency supply scenarios utilizing the WFP, NCDP, and the Osbome Street/East Vista Way FCF location could be explored in connection with the 20 MGD desalter J:\3892\0005\mi-002rsw.wpd Page 3 of 4 withdrawal concept. The City is also planning to construct additional storage near the Osborne Street/East Vista Way location. 7. The City may consider additional desalinization points in the future. 8. Brine disposal is through the City's exisfing ocean outfall. Capacity is believed to be sufficient for the potential improvements. J:\3892\0005\mi-002rsw.wpd Page 4 of 4 SAN DIEGO COUNTY WATER AUTHORITY Lower San Luis Rey River Valley Groundwater Storage and Recovery Feasibility Study Meeting Minutes Subject: Locafion: Date & Time: Prepared By: Attendees: Meeting with Carisbad Municipal Water District Carisbad Municipal Water District 5950 El Camino Real Carisbad, CA 92008 Wednesday November 4, 1998 1:30 p.m. to 3:00 p.m. Robert S. Weber, ASL Bob Yamada, San Diego County Water Authority Dan Diehr, San Diego County Water Authority William Plummer, Carisbad Municipal Water District Howard Amold, ASL Robert Weber, ASL The items discussed during the meeting are generally summarized as follows. 1. Authority staff reviewed the overall project phasing and scope/schedule for Phase 1. The role of the PAC and a general summary of the PAC kickoff meeting were discussed. 2. The District has recently updated its Water Resources Master Plan. It will have much of the infonnafion needed for the GSR Feasibility Study. Copies were provided to the Authority and ASL. 3. The District has pre-1914 water rights in the Mission basin, and also has 1935 rights that may expire by January 2000 unless plans for their use are submitted to the State. The Authority noted that there was always the right to recover water which has been purchased and placed in the basin, such as the case with a GSR project concept. 4. The District owns six groundwater pumping wells in the Mission basin and has associated easements through areas of Oceanside for transmission lines. The J:\3892\0005\nii-003rsw.wpd Page 1 of 2 wells were reportedly used from approximately 1915 to the late 1950s or eariy 1960s and will likely soon be abandoned by the District. 5. The District has considered initiating discussions with Oceanside concerning potential joint water supply projects involving the Mission basin, the Weese Filtrafion Plant, or both. 6. One emergency connection currently exists between the District and Oceanside. This is a 12-inch diameter connection at El Camino Real and Vista Way. 7. The District has also evaluated joint water supply projects with Olivenhain Municipal Water District or the ufilizafion of seawater desalinization. 8. The District is in the process of expanding its reclaimed water program. Reclaimed water could possibly be available for recharge of the Mission basin; however, the water would need to be transported a distance of approximately 3 to 5 miles. J:\3892\0005\mi-003rew.wpd Page 2 ol 2 SAN DIEGO COUNTY WATER AUTHORITY Lower San Luis Rey River Valley Groundwater Storage and Recovery Feasibility Study Meeting Minutes Subject: Location: Date & Time: Prepared By: Attendees: Meefing with Rainbow Municipal Water District Rainbow Municipal Water District 3707 Old Highway 395 Fallbrook, CA 92028 Tuesday November 24, 1998 10:00 a.m. to 11:00 a.m. Robert S. Weber, ASL Bob Yamada, San Diego County Water Authority Dan Diehr, San Diego County WaterAuthority Eric Oitmann, Rainbow Municipal Water District (General Manager) Mike Metts, Rainbow Municipal Water District (Acting District Eng.) Howard Arnold, ASL Robert Weber, ASL The items discussed during the meeting are generally summarized as follows. 1. Authority staff reviewed the overall project phasing and scope/schedule for Phase I. The role of the Project Advisory Committee (PAC) and a general summary of the PAC kickoff meeting were discussed. 2. Phase I will consist of a "desktop" analysis to develop potential Groundwater Storage and Recovery (GSR) project concepts. Project concept recommendations will be presented to the Authority's Board. 3. Selected project concepts may be further evaluated in subsequent phases of the project. Phase II activities would consist of field investigations and groundwater modeling, and Phase III would include refinement of the project concepts based on data generated in Phase 11. Subsequent to Phase 111, selected project concepts may proceed to an implementafion phase. 4. The potential for the Authority to participate In GSR projects as an J:\3892\0005\mi-005rsw.wpd Page 1 of 2 owner/operator will be considered during various phases of the project. 5. Member agency involvement with this project will be through the PAC. The PAC for the Lower San Luis Rey GSR Study consists of Carisbad MWD, City of Oceanside, and Rainbow MWD. 6. Currently, the District's Sewage (approximately 0.7 MGD) is treated at Oceanside's San Luis Rey WWTP. 7. There are currently no plans to re-activate the District's own WWTP. The District will participate in the Oceanside WWTP expansion. A capacity of 1.5 MGD is being negotiated with the City. 8. ASL will schedule a fime with Mike Metts to review relevant documentafion. Addifional individuals from the District's operations staff may also participate. J;\3892\0005\mi-005rsw.wpd Page 2 of 2 SAN DIEGO COUNTY WATER AUTHORITY Lower San Luis Rey River Valley Groundwater Storage and Recovery Feasibility Study Subject: Activifies with the City of Oceanside Prepared By: Robert S. Weber, ASL Activities with the City of Oceanside during Task 1 consisted of retrieving additional documentation related to the water resources of the Mission Basin. These documents are contained within the lisfing in Attachment A. J:\3892\0005\nii-004rsw.wpd ^^9® ^ °* ^ Subject: Locafion: San Diego County WaterAuthority Lower San Luis Rey River Valley Groundwater Storage and Recovery Feasibility Study MEETING MINUTES Project Advisory Committee (PAC) Meeting City of Oceanside Mission Basin Groundwater Purification Facility 215 Fireside Street Oceanside, CA 92054 Date & Time: Attendees: Prepared By: Wednesday, March 10,1999 09:00-11:00 A.M. PAC Members: Robert Greaney, Carisbad Municipal Water District William Plummer, Carisbad Municipal Water District Greg Blakely, City of Oceanside Barry Martin. City of Oceanside Mike McGrath. City of Oceanside Mike Metts, Rainbow Municipal Water District Eric Oltmann. Rainbow Municipal Water District Study Team Members: Bob Yamada, SDCWA Dan Diehr, SDCWA Howard Amold, ASL Consulting Engineers Steve Tedesco, ASL Consulting Engineers David Gardner. Fugro West, Inc. Tom Stetson, Stetson Engineers, Inc. Rob Weber, ASL Consulting Engineers Bill Moser, Montgomery Watson, Regional Facilifies Master Plan Coordinator for SDCWA Rob Weber, ASL Consulting Engineers These minutes are intended to summarize the suttstantive items or issues discussed at the meeting as recorded by the writer. If any of the attendees understand differently, please notify the writer as soon as possible. I. INTRODUCTIONS The project study team and PAC members were introduced and an overview of the Phase 1 scope and schedule was provided by Howard Amold and Bob J:\3e9ZV0005\5econdpacme6ting.doc Yamada. This is the second of three planned PAC meefings to be held during the Phase 1 Groundwater Storage and Recovery (GSR) feasibility study. The purpose of the meeting was to present the project concepts which have been developed by the study team and to solicit input from the PAC with regard to the concepts developed, or other projects which the PAC may be aware of. The study team has completed the following work tasks and project concept development associated with Phase 1: • Task 1 - Water Resources Data Compilafion • Task 2 - Development of Relafional (GIS) Database • Task 3 - Evaluation of Existing Hydrogeological Infonnation and Groundwater Use • Task 4 - Water Systems Engineering Constraints Analysis Project concepts have been developed in sufficient detail to permit evaluation in subsequent work tasks: • Task 5 - Conceptual Design of GSR Attematives • Task 6 - Detennine Pennitting Requirements and Environmental Constraints for Potential Recharge and Extraction Project Concepts • Task 7 - Economic Analyses: Detemnination of Costs and Benefits of GSR Project Alternatives • Task 8 - Phase 1 Ranking of Project Concepts • TThird PAC Meetincjl • Task 9 - Development of Recommendations for Field Investigation Program • Task 10 - Development of Recommendations for Public Outreach Program • Task 11 - Preparation of Phase I Report Based on the remaining project tasks, the study team anticipates approximate completion of Phase I by the end of June 1999. Following Phase 1, the Authority may consider recommendations for Phase 2 field studies for selected project concepts. Project concepts may be further refined in a Phase 3 study. 11. GROUNDWATER STORAGE AND RECOVERY (GSR) AND BASIN CONJUNCTIVE USE (BCU) CONCEPTS David Gardner provided an oven/iew of Mission and Bonsall Basin hydrogeology and general Aquifer Storage and Recovery concepts. Tme ASR. where water is injected Into an aquifer through a well, and that same water is later recovered through the sartie well may not lend itself directly to the Mission and Bonsall Basins due to Basin dynamics. However, spreading or Injection and later downgradient recovery through different facilities may be applicable. The project J:\3892\0005\secondpacnieQting.doc team has performed preliminary computer modeling to assess how recharge water may move through the Basin under certain scenarios. Total groundwater storage capacity in the Mission Basin is esfimated at 92,000 acre-ft. Total groundwater storage capacity in the Bonsall Basin is estimated at 18,000 acre-ft. Due to the availability of imported water, groundwater pumping in both basins has decreased over the past thirty years. During many years, the Basins are believed to have remained full. Tom Stetson provided an overview of Basin Conjunctive Use (BCU). Several BCU programs are ongoing in Los Angeles and Orange Counfies. and recharge, or spreading basins, are generally under the control of the local flood control districts. They are managed such that recharge operations may be temporarily suspended if the flood control districts need storage space due to impending storms. BCU would be feasible in the Mission and Bonsall Basins as indicated above. III. PROJECT CONCEPTS Howard Amold presented the study team's project concepts developed to date. Handouts illustrating the concepts, along with preliminary draft description sheets, were provided to the attendees. The project concepts are as follows: 1. Oceanside - Desalter expansion to 8 MGD-1OMGD. 2. Oceanside - Desalter expansion to 15 MGD with provisions to supply Carisbad MWD. 3. Desalter expansion to 15 MGD with Authority facilifies for groundwater storage and recovery for seasonal and/or carryover use. 4. Desalter expansion to 15 MGD with use of Oceanside's Weese Filtration Plant for in lieu of deliveries of filtered water to other agencies. 5. Off-Basin storage in the La Jolla/Eocene fonnation. 6. Rainbow - Desalter operafion at minimum 2 MGD with Authority facilities for groundwater storage and recovery for seasonal and/or carryover use. Each concept was presented and discussed. The concepts involve a variety of system configurations and institutional issues, many of which are related. The Oceanside - 8 MGD concept is perceived by the study team as possibly the next logical step in the expansion of the City's Mission Basin program, as reclaimed water capacity at the City*s San Luis Rey WWTP would be available for recharge. However, California DHS groundwater recharge guidelines for the percent of reclaimed water which can be used for recharge may limit the amount of reclaimed water which could initially be used for recharge. Recharge sites in the area of the Mission Basin which is semi-confined or unconfined (generally JA3892\0005\secondpacmeeting.doc East of Douglas Drive) were identified. These are currently used as 100 year event flood control overflow ponds along the San Luis Rey River. Bill Plummer of Carisbad MWD noted that the District is planning another interconnection with the City of Oceanside at College Boulevard for later this summer. The potential use of this connecfion can be listed in the Oceanside - 15 MGD/Carisbad concept, in addifion to the existing connection at El Camino Real/Vista Way and potenfial connecfion to Maeri<le at San Francisco Peak. Eric Oltmann of Rainbow MWD asked about the potenfial for imported recharge water to be introduced to the Mission Basin through the San Luis Rey River, similar to a management scenario used by United Water Conservation District on the Santa Clara River in Ventura County. This could have a positive impact on extracted water quality, depending on the extent of mixing that would occur. David Gardner will follow up with United Water Consen/ation District to obtain information on this approach so the team can assess its potential applicability to concepts that include Mission Basin recharge with imported water. Greg Blakely of the City of Oceanside noted that a private group has perfonned pump testing on wells located on private property near the eastem boundary of the City of Oceanside in Morro Hills. The City has copies of the test reports, and will provide a copy to the study team for analysis to detennine applicability to the project concepts. No other concepts, or variations, were discussed. IV. NEXT PAC MEETING Based on the remaining project tasks and schedule as indicated above, the next PAC meeting will be held after Task 8 - Phase 1 Ranking of Project Concepts. The purpose of the meeting will be to present and discuss the economic analysis developed in Task 7 and the proposed decisional framewori< developed in Task 8. The Phase 1 project concepts will be evaluated and ranked after the Third PAC meeting. An agenda will be circulated to the PAC once a proposed date has been identified. A late-April 1999 meefing date is anticipated based on the current schedule. J:\3892\0005\secondpacmeeting.doc San Diego County Water Authonty Lower San Luis Rey River Valley Groundwater Storage and Recovery Feasibility Study MEETING MINUTES Subject: Locafion: Project Advisory Committee,(PAC) Meefing City of Oceanside Mission Basin Groundwater Purificafion Facility 215 Fireside Street Oceanside, CA 92054 Date & Time: Attendees: Prepared By: Thursday, July 15, 1999 10:00 A.M.-12:00 P.M. PAC Members: Robert Greaney, Carisbad Municipal Water District Greg Blakely, City of Oceanside Mike McGrath, City of Oceanside Mike Metts, Rainbow Municipal Water District Eric Oltmann, Rainbow Municipal Water District Study Team Members: Bob Yamada, SDCWA Dan Diehr. SDCWA Howard Amold, ASL Consulting Engineers Steve Tedesco, ASL Consulting Engineers Steve Johnson, Stetson Engineers, Inc. Robert Weber, ASL Consulting Engineers Bill Moser, Montgomery Watson, Regional Facilities Master Plan Coordinator for SDCWA Robert Weber, ASL Consulting Engineers These minutes are intended to summarize the substantive items or issues discussed at the meeting as recorded by the writer. If any of the attendees understand differently, please notify the writer as soon as possible. I. INTRODUCTIONS The project study team and PAC members were introduced and an overview of the Phase 1 scope and schedule was provided by Howard Amold and Bob Yamada. This is the last of three planned PAC meefings to be held during the Phase 1 Groundwater Storage and Recovery (GSR) feasibility study. The purpose of the meeting was to present further informafion regarding operations, JA3892\0005\tfilrdpacmeeting.doc Page 1of4 San Diego County WaterAuthority Lower San Luis Rey River Valley Groundwater Storage and Recovery Feasibility Study MEETING MINUTES costs, benefits, and institutional issues for the project concepts which have been developed by the study team and to solicit input from the PAC with regard to concepts, costs and benefits, and institutional arrangements II. PROJECT CONCEPT AND INSTITUTIONAL OVERVIEW A PowerPoint show of the project concepts was presented to the PAC. A black and white copy of the slide show is provided as Attachment A. The PowerPoint show provided informafion on the following: • Conceptual design overview (hydrogeologic issues, environmental constraints, groundwater replenishment operations). • A review of project concepts and operational scenarios (i.e., constant yield/seasonal operation, carryover storage operation, and replenishment operation) was presented, • Project concepts consist of Mission Basin 1.63 MGD desalter. Mission Basin 6.70 MGD desalter. Mission Basin 6.70 MGD desalter with Regional use of the Weese Filtration Plant, and Bonsall Basin 3.60 MGD desalter. • Mission Basin project concepts have all been treated as increases from the existing Oceanside project and its planned expansion to a potable water production capacity of 6.37 MGD. All concepts have assumed that site would be further expandable by the capacities indicated. The Bonsall Basin project is stand-alone, as there is currently no municipal desalter project operating in the basin. • Operational scenarios and desalter yields were detennined based on theoretical carryover storage drawdown during a three year period which discounted replenishment water would not be available from MWD's Long Term Storage (LTS) Program. • Identified institufional issues for each concept were presented in a matrix fonnat by project concept. 111. ECONOMIC ANALYSIS A summary of the preliminary economic analysis for the above project concepts was presented to the PAC. Unit costs were calculated based on dollars per acre- ft of potable water produced. This is based on the constant yield of each project's desalter. However, in the case of the altemative for regional use of the Weese Filtrafion Plant, the total amount of potable water the project would produce (i.e., from the groundwater basin and also the additional potable water which would be available regionally at Weese) was ufilized. J:\3892\0005\thirdpacm6eting.doc Page 2 Of 4 San Diego County WaterAuthority Lower San Luis Rey River Valley Groundwater Storage and Recovery Feasibility Study MEETING MINUTES General discussion items regarding the economic analysis were: • Future costs for reclaimed water which might be available at Oceanside's San Luis Rey WWTP are not known, however, the $139/acre-ft figure used in this round of cost estimates will be revised. Action Item: ASL to discuss basis of reclaimed water costs with Authority/Oceanside and revise accordingly. • Project operations beyond safe yield will likely create the opportunity for the basins to capture increased natural njnoff, thereby reducing the amount of imported water that would need to be used for replenishment. Since it is difficult to quantify at this stage of the project, project costs assume basin replenishment will be with imported or reclaimed water sources. Action Item: Stetson/ASL to consider what, if any, amount of additional runoff may be appropriate to include at this stage of the study and include placeholder in cost estimates as appropriate. • 15% contingency and 10% engineering, administration, and legal may be low at this stage unfil additional information is known. Action Item: Contingencies to be discussed among Project Team and revised in cost estimates accordingly. iV. PROJECT CONCEPT EVALUATION CRITERIA Project evaluation criteria will include: • Ability of the project to serve more than one member agency (region). • Opportunity to store discounted water. • Service during dry periods or emergencies. • Ability to convert an interruptible supply (i.e. LTS water) into a finn supply (i.e.. constant yield from desalter). • Cost • Beneficial re-use of wastewater if reclaimed water is utilized for recharge or an intrusion barrier. • Potential for increased capture of rainfall and runoff that would otherwise flow into the ocean. • Public acceptance. V. PHASE 1 REPORT COMPLETION, MEMBER AGENCY FOLLOW-UP AND SCHEDULE The Phase 1 project technical report will be prepared and a draft distributed to the PAC members for review and comment. The Phase 1 technical report will contain the Technical Memoranda prepared for the project. Following J:\3892N0005Mhirdpacmeeting.doc Page 3 of 4 San Diego County Water Authority Lower San Luis Rey River Valley Groundwater Storage and Recovery Feasibility Study MEETING MINUTES incorporation of PAC member comments and fiaalization of the Phase 1 technical report (esfimated September 1999), individual follow-up meetings between PAC members and Authority staff will be requested to discuss project recommendafions for subsequent phases of the project. Action Item: Authority staff to schedule individual member agency meetings following completion of Phase 1. VI. PHASE 2 FIELD INVESTIGATION PROGRAM A general overview of the Phase 2 investigafion program was provided. This will include field exploration to obtain addifional data to further assess the technical feasibility and environmental issues associated with selected project concepts. VII. PUBLIC OUTREACH FOR PHASE 2 Phase 2 project elements were reviewed. Visibility of the project would be expected to increase with Phase 2, as there would be field exploration wori< such as drilling and pump tesfing occurring. Some level of effort will be made to identify key stakeholders, property owners, etc., and periiaps preparation of a communications management plan, and implementation of focus groups if necessary. VIII. OPEN AGENDA The following open agenda items were discussed: • Oceanside will conduct pilot testing of membrane filtration (Hydronautics) at the San Luis Rey WWTP. It may produce 500 ppm TDS water. This may replace the current 0.75 MGD tertiary filters, • Additional tertiary treatment at San Luis Rey WWTP may be looked at by the City. 2.5 MGD without a groundwater recharge component and 5.0 MGD with a groundwater recharge component are being considered. Timetable is on the order of 3 to 5 years. Distribution: PAC Members Study Team Members J:\3892\0O0S\thirdpacmeeting.doc Page 4 Of 4 APPENDIX B Water Resources Data Compilation Database Water Resources Data Compilation - Lower San Luis Rey River Valley - By Document Date Date DocumentlD Title AuthorName 5/1/61 58 Review and /Vnafysis of the Water System of City of Carisbad Boyle Engineering 1/1/66 59 Water System Engineering Study, City of Carlsbad Kubota. Jack Y. and Lill, Wayne P. 1/1/68 28 7.5 Minute Topographical Quadrangle Maps (Bonsall/Morro Hill/Oceanside/San Luis Rey/San Marcos) USGS Department of Water Resources 10/1/68 66 City of Oceanside Water Treatment Study James M. Montgomery Consulting Engineers 5/1/71 29 Water Welis in the San Luis Rey River V^ley Area, San Diego County, Califomia, Bulletin No, 91-18 Califomia Department of Water Resources 9/1/71 30 Maps of the Watersheds of the Santa Margarita and San Luis Rey Rivers USGS Department of Water Resources 1/1/72 67 City of OcearKide Updated Water Treatment Study James M. Montgomery Consulting Engineers 1/1/74 33 San Diego County Cooperative Groundwater Studies, Reclaimed Water Use. Phase 2 USGS Department of Water Resources 10/1/74 31 Hydrologic and Salt-Balance Investigations Using Digital Models. Lower San Luis Rey River Areas USGS Department of Water Resources 10/1/76 32 Predicted Effects of a Proposed Water Resources Management Plan in the Lower San Luis Rey River Valley USGS Department of Water Resources 11/30/79 44 O'ty of Oceanside Master Plan for the Downtown Water Distribution System and Sewerage Hirsch & Company 1/1/83 42 City of Oceanside Water Master Plan Update Phase III Interim Report ASL Consulting Engineers 6/1/83 21 City of Oceanside. Water System Study Update. June, 1983 ASL Consulting Engineers 11/1/84 55 Final Report on Surface and Groundwater Resources of the Upper San Luis Rey River System Stetson Engineers, Inc. 1/1/85 62 Maps of the Bonsall Area of the San Luis Rey River Valley (Geology/Hydrogeology/GW Quality) USGS Department of Water Resources 3/1/86 68 City of Oceanside Addendum to the Feasibility Report for Emergency Storage James M. Montgomery Consulting Engineers 11/1/87 40 Water Distribution Study San Diego County Water Autfiority 11/6/89 24 City of Oceanside, Wastewater Master Plan MacDonald-Stephens Engineers, Inc. 5/1/90 20 Draft Preliminary Design Report Robert A, Weese nitration Plant Expansion Engineering-Science. Inc. 6/1/90 18 San Luis Rey Wastewater Treatment Plant Master Plan MacDonald-Stephens Engineers. Inc. 7/a«l 16 City of Oceanside Master Plan of Dranage Districts 1 & 5 Camp Dresser & McKee/Cooper Engineering 10/1/91 14 City of Oceanside Water Reclamation Master Plan Dudek & /Associates 6/19/92 53 Phase 1 Report, Balanced Water Management Project, City of Oceanside, Supplemental Information Volume NBS Lowry Engineers and Planners; Stetson Engineers, Inc. 6/19/92 8 Final Draft Phase 1 Report, Balanced Water Management Project. City of Oceanside, Volume 1 NBS Lowry Engineers and Planners; Stetson Engineers. Inc. 8/1/92 70 Preliminary Feasibility of Develc^ing San Luis Rey River Surface and Groundwater Resources Alfred A. Webb Associates 1/1/93 41 Robert A. Weese RItration Plant Preliminary Chlorine Disinfection Study MacDonald-Stephens Engineers, Inc. 2/1/93 47 GrouTKlwater Recfiarge and Water Quality Issues, 2 MGD San Luis Rey Desalting FaaTrty NBS Lowry Engineers and Planners 4/19^^3 19 San Luis Rey Wastewater Treatment Plant Influent Conveyance System Evaluation MacDonald-Stephens Engineers, Irx;. 7/1/93 36 Prefiminary [}esiQn Report - San Diego County Water Authority North County Distribution Pipeline ASL Consulting Engineers Notes Proposed system improvements Proposed system improvements Topographical quadrangle maps, including welt locations Water filtration study, including groundwater Update to 1968 study Downtown vrater/sewer Master Plan Interim Master Plan update Water system update Related to La JoIla/RirKon/San Pasqual/Pauma/Pala Reservations Groundwater mappng Addendum to previous 1984 study Water Distribution Study 1987-2010 Wastewater Master Plan update Design Report (or filtration plan expansion pfojecl(s) Master Plan for WWTP expansion Drainage Master Plan Reclaimed Water Master Plan Balanced Water Management assessment supplemental data Balanced Water Mariagement assessment Report prepared for Rainbow Municipal Water District Chkirine Disinfection study Hydraulic and odor evaluation of WWTP influent Design Report for the NCDP Monday, November IS, 1999 Page I of 3 Date DocumentlD Title AuthorName Notes 1/1/94 48 Emergency Storage Project - Groundwater Feasibility Study NBS Lowry Engineers and Planners 4/20/94 45 City of Carisbad General Plan City o( Carisbad City of Carisbad General Plan 6/1/94 13 City of Oceanside Water Permit No. 04-14-94P-009, System No. 3710014, San Diego County State of Califomia Dept ot Health Services City of Oceanside water system permit 9/1/94 69 Water Master Plan - Rainbow Municipal Water District Alfred A. Webb /^sodates 11/1/94 37 Design Plans - San Diego County Water Authority North County Distribution Pipeline ASL Consulting Engineers Design Plans for the NCDP 1/1/95 56 Urban Water Management for the Rainbow Municipal Water District Rainbow Municipal Water District Urban management plan for RMWD 2/8/95 39 Design Plans - San Diego County Water Authority Regulatory Structure/CCT/NCDP 1/RMWD II ASL Consulting Engineers Design Plans for the NCDP 1/RMWD 1 FCFs/CCT and RS 5/10/95 43 City of Oceanside Final Draft Water Master Plan Camp Dresser & McKee Water Master Plan update 5/11/95 38 Design Plans - San Diego County Water Authority Oceanside 6/VlD 11/Rainbow 12 Flow Control Facility ASL Consulting Engineers Design Plans for the OC6/V1D11/RMWD12 FCF 5/15/95 25 City of Oceanside. Final Draft Wastewater Master Plan Camp Dresser & McKee Wastewater Master Plan update 6/19/95 5 Results of Pump Tests. Well Nos. 3,4. & 5, RO Plant and North River Road, Oceanside. CA Geopacifica Geotechnical Corisultants Desalter well pump test results 7/20/95 17 City of Oceanside Master Plan of Drainage Districts 2, 3 & 4 Willdan Associates Drainage Master Plan 9/1/95 6 Evaluation of Groundwater Pumping, Oty of Oceanside 5 MGD Expansion of Mission Basin Desalting Facility Michael R. Welch, Ph.D.. P.E. Desalter well pumping evaluation 11/6/95 12 Installation Operation and Maintenance Manual, City of Oceanside RO Well Pumps Afton Pumps, Inc. Desalter well pump data 1/1/96 49 Water Quality Control Plan for the San Diego Region Regional Water Quality Control Board 1/26/96 10 Deminer^ization of Groundwater within the Rainbow Munidpal Water District - Phase 1 - Quantity and Quality Analysis Camp Dresser & McKee 2/1/96 7 Supplemental Groundwater Pumping /^alysis. Expansion of Oceanside Mission Basin Desalting Facility to 6.37 MGD Michael R. Welch, Ph.D.. P.E. Supplemental dessdter well pumping analysis 3/1/96 11 Demineralization of Groundwater wittiin the Rainbow Municipal Water District - Phase II - Feasitxiity /Vialysis Camp Dresser & McKee 4/6/96 54 Aerial Photographs of the City of Oceanside Aerial Foto Bank Misc. aerials 4/12/96 46 Draft Endna Basin Demonstration Project Water Reclamation Master Plan Camp Dresser & McKee Water Reclamation Master Plan 5/1/96 57 Report on Potential Development of Water Resources for the Rainbow Munidpal Water District Stetson Engineers, Inc. Water resources evaluation for RMWD 1/1/97 15 City of Carisbad, Califomia Capital improvement Program Technical Appendix 1997-98 to Buildout aty of Carisbad City of Carlsbad CIP Technical /Appendix 2/7/97 51 Mission Basin Groundwater Row Model Aquifer Performance Test Results for Model Calibration Stetson Engineers, Inc. APT results 2/7/97 1 Mission Basin Groundwater Row Model Documentation and Users lulanual Stetson Engineers, Inc. Model documentation/users manual 2/7/97 52 Mission Basin Groundwater Row Model Simulation Results (Scenarios No. 1 through 5) Stetson Engineers, Inc. Model simulation results 5/29/97 9 Staff Report, Bonsall Groundwater Basin Update Rainbow Municipal Water District Chronology of RMWD's Bonsall Basin activities 6/1/97 4 Groundwater Resource Development Report San Diego County Water Authority Review of County-Wide Groundwater Resources 6/27/97 61 Staff Report, Bonsall Groundwater Basin Update Rainbow Municipal Water District Chronology of Bonsall Basin activities 10/1/97 3 Carisbad Munidpal Water District Volume III Water Master Plan Update ASL Consulting Engineers CMWD Water Master Plan 12/1/97 35 Carisbad Munidpal Water District Volume ll Water Resources Master Plan Carollo Engineers CMWD Water Resource Master Plan 1/13/98 26 Oty of Oceanskle Draft Wastewater Master Plan HYA Consulting Engineers City of Oceanside Wastewater Master Plan 5/1/98 64 Groundwater Monitoring Program Mission Basin Desalter Fadlity Exparision City of Oceanside Monitoring program and procedures 6/1/98 63 Initial Study Expansion of Mission Basin Desalting Fadlity to a Production Capacity of 6.37 MGD City of Oceanside EnviroTunental Document Monday, November IS, 1999 Page 2 of 3 Date DocumentlD Title AutliorName Notes 7/7/98 65 Negative Dedaration and Groundwater Monitoring Program Report City of Oceanside Negative'dec for desalter expansion 8/1/98 2 City of Oceanside Draft Water Master Plan ASL Consulting Engineers City of Oceanside Water Master Plan 10/29/98 34 Mission Basin Desalter Wells Water Level Data (1994 through 1998) City of Oceanside Desalter well levels for 1994 through 1998 11/1/98 71 Draft Preliminary Design Report - San Luis Rey Wastewater Treatment Plant Expansion Carollo Engineers WWTP expansion report (including reclaimed water expansion) 11/9/98 50 Groundwater Elevation/Water Quality Data (Raw Data from approximately 1930 to 1980) USGS Department of Water Resources Water level/quality raw data by state well number Monday, November IS, 1999 Page 3 of 3 Date DocumentlD Title AuthorName Notes 1/1/74 33 San Diego County Cooperative Groundwater Studies, Reclaimed Water Use, Phase 2 USGS Department of Water Resources 10/29/98 34 Mission Basin Desalter Wells Water Level Data (1994 through 1998) City of Oceanside Desalter well levels for 1994 through 1998 12/1/97 35 Carisbad Municipal Water District Volume 11 Water Resources Master Plan Carollo Engineers CMWD Water Resource Master Plan 7/1/93 36 Preliminary Design Report - San Diego County Water Authority North County Distribution Pipeline ASL Consulting Engineers Design Report for ttie NCDP 11/1/94 37 Design Plans - San Diego County Water Authority North County Distribution Pipeline /VSL Consulting Engineers Design Plans for the NCDP 5/11/95 38 Design Plans - San Diego County Water Authority Oceanside 6/VID 11/Rarnbow 12 Row Control Facility ASL Consulting Engineers Design Plans for the OC6/VID11/RMWD12 FCF 2/8/95 39 Design Plans - San Diego County Water Authority Regulatory Stmcture/CCT/NCDP 1/RMWD 11 ASL Consulting Engineers Design Plans for the NCDP 1/RMWD 1 FCFs/CCT and RS 11/1/87 40 Water Distribution Study San Diego County Water Authority Water Distribution Study 1987-2010 1/1/93 41 Robert A. Weese RItration Plant Preliminary Cfxlorine Disinfection Study MacDonald-Stephens Engineers, Inc. Chlorine Disinfection study 1/1/83 42 City of Oceanside Water Master Plan Update Ptiase 111 Interim Report ASL Consulting Engineers Interim Master Plan iqxiate 5/10/95 43 City of Oceanside Rnal Draft Water Master Plan Camp Dresser & McKee Water Master Pl^ update 11/30/79 44 City of Oceanside Master Plan for Vne Dovmtown Water Distribution System and Sewerage Hirsch & Company Downtown water/sewer Master Plan 4/20/94 45 City of Carisbad General Plan City of Carlsbad City of Carisbad Gener^ Plan 4/12/96 46 Draft Endna Basin Demonstration Project Water Reclamation Master Plan Camp Dresser & McKee Water Reclamation Master Plan 2/1/93 47 Groundwater Recharge and Water Quality Issues, 2 MGD San Luis Rey Desalting Facility NBS Lowry Engineers and Planners 1/1/94 48 Emergency Storage Project - Groundvrater Feasibility Study NBS Lowry Engineers and Planners 1/1/96 49 Water Quality Control Plan for the San Diego Region Regional Water Quality Control Board 11/9/98 50 Groundwater Elevation/Water Quality Data (Raw Data from approximately 1930 to 1980) USGS Department of Water Resources Water levet/quality raw data by state well numt>er 2/7/97 51 Mission Basin Groundwater Row Model Aquifer Perfonmance Test Results for Model Calibration Stetson Engineers, Inc. APT results 2/7/97 52 Mission Basin Groundwater Row Model Simulation Results (Scenarios No. 1 through 5) Stetson Engineers. Inc. Model simulation results 6/19/92 53 Phase 1 Report, Balanced Water Management Project, City of Oceanside, Supplemental Information Volume NBS Lowry Engineers and Planners; Stetson Engineers, Inc. Balanced Water Management assessment supplemental data 4/6/96 54 Aerial Photographs of the City of Oceanside Aerial Foto Bank Misc. aerials 11/1/84 55 Rnal Report on Surface and Groundwater Resources of the Upper San Luis Rey River System Stetson Engineers, Inc. Related io La Jolla/RirKxxi/San Pasqual/Pauma/Pala Reservations 1/1/95 56 Urtian Water Management for the Raintxiw Munidpal Water District Raintww Municipal Water District Urtian management plan for RMWD 5/1/96 57 Report on Potential Developrnent of Water Resources for ^e Rainbow Munidpal Water District Stetson Engineers, Inc. Water resources evaluation for RMWD 5/1/61 58 Review and Analysis of the Water System of Oty of Carisbad Boyle Engineering Proposed system improvements 1/1/66 59 Water System Engineering Study, City of Carlstjad Kubota, Jack Y. and Lill, Wayne P. Proposed system improvements 6/27/97 61 Staff Report. Bonsall Groundvrater Basin Update Rainbow Munidpal Water District Chronokigy of Bonsall Basin activities 1/1/85 62 Maps of the Bonsall Area of the San Luis Rey River Valley (Geology/Hydrogeology/GW Quality) USGS Department of Water Resources Groundwater mapping 6/1/98 63 Initial Study Expansion of Mission Basin Desalting Facility to a Production Capswaty of 6.37 MGD City of Oceanside Environmental Document 5/1/98 64 Groundwater Monitoring Program Mission Basin Desalter Fadlity Expansion City of Oceanside Monitoring program and procedures 7/7/98 65 Negative Dedaration STKJ Groundwater Monitoring Program Report Gty of Oceanside Negative dec for desalter expansion 10/1/68 66 City of Oceariside Water Treatment Study James M. Montgomery Consulting Er^ineers Water filtraUon study, bidudtng grourtdwater Monday, November 15,1999 Page 2 of 3 Date DocumentlD Title 1/1/72 67 City of Oceanside Updated Water Treatment Study 3/1/86 68 City of Oceanside Addendum to the Feasibility Report for Emergency Storage 9/1/94 69 Water Master Plan - Rainbow Municipal Water District 8/1/92 70 Preliminary Feasibility of Developing San Luis Rey River Surface and Groundwater Resources 11/1/98 71 Draft Preliminary Design Report - San Luis Rey Wastewater Treatment Plant Expansion AuthorName Notes James M. Montgomery Consulting Engineers James M. Montgomery Consulting Engineers Alfred A. Webb Assodates /Alfred A- Webb Associates Carollo Engineers Update to 1968 study Addendum to previous 1984 study Report prepared for Raintww Munidpal Water District WWTP expansion report (induding reclaimed water e^qiansion) Monday, November 15,1999 Page 3 of 3 APPENDIX C La Jolla / Eocene Formation Information April?, 1999 Project No. 98-71-0421 ASL Consulting Engineers, Inc. 10815 Rancho Bernardo Road San Diego, Califomia 92127 Attention: Mr. Howard Amold Subject: San Diego County Water Authofity^: Oceanside \. ^'-^ 72-Hour Well Pumping Test, Sw^i/Eufenk^opertiesjy Dear Howard: y- At our last PAC meefingv^e were infotrned of Various studies being conducted by a private entity on severaUargijbloclcs of land (Swifted Eubank properties) located adjacent and north of the lower Sairbuis ]^ey^oun3w''ater*.ykin. These properties historically have used groundwater from several we|ls complctedjn/ractured granite rocks. The quantity of ground- water available-ffonTffi^se wells appareijtJy greatly exceeds the existing and anticipated water needs (contatn^rizeS^knt and related auf^ery operations) of the properties. We understand that the prope'rty owners haA'e h^ cedairTwell performance tests conducted by the firm of L.R. Burzell'^hsultmg Servi^s who also have prepared a report for the City of Oceanside {Final Report to the'^ity\j)ceanside on the Results of a 72-Hour Well Pumping Test, January 17, 1999), presumably as aM^asis for possible sale of the surplus water to the City of Oceanside. The purpose of this letteKis^tobriefly comment on the information contained, in the Burzell report We note that the objectives of the test pumping of the various wells on the Swift and Eubank properties was to develop reliable data regarding: • Sustainable flow of the wells. • Extent of drawdown. • Affect of pumping on nearby wells. • Storage capacity in "the groundwater basin." • Hydraulic gradient in "the groundwater basin." • Transmissivity values of the aquifers. • Water quality data. ASL Consulting Engineers, Inc. April 7, 1999 (98-71-0421) We have the following concems regarding the testing program and the validity of the conclusions developed. • One of the objectives of the program was to assess the impact of ihe'^proposed project on proximate wells. The report should include a map showing'the^Ocation of such wells throughout the study area. • Well log information for the test and observation wells^buid be provided, including lithologic and well perforation information. " \ \^ • The report states that "steady state" pumping^leyels were achieved. The^data plotted on a semi-log time scale would demonstra'te that>steady\State was nof'lachieved. In fact, the time coordinates on the hydrographs Of.pump:tesf'data were not shown. %• X • Recovery to higher than static Dumping levels foUowingjhe 72-hour penod were observed. This was presumed to^^e due^o cessation of pumping of other wells in the basin during the test period. Proximate well'?ictivity sKpuld be documented, and pre- test background water levels in the^esf^d obsertation wells should be monitored prior to the test. -prior • Testing included/coUectiom of drawdown and recovery data from pumping and observation --^elfe;-. yet' inventional/^ethodologies for the estimation of transmissivities^'andstoragec^ftoent^werenot used. • Useprtfieaverage'derived>lransmissivity for the entire basin is likely not appropriate. • y?(^miing^ao a^rage thickness of 2,500 feet for aquifer samration is likely not .^^appropriate. "Vrac^res ^ilcely diminish with depth. Additionally, the feasibility of accessing groundwater at this depth is questionable. • The\nalysis^.aiid Conclusions includes a statement of average annual recharge of 0.3 acre-feet\per>cre. It is unclear how this estimate was derived. • The convulsions state that project extractions would have an insignificant effect on static water levels throughout the basin. The data presented do not support this statement. • The report states potential recharge from upgradient areas of two to three million gallons per day. The origin and mechanism of this recharge source is not advanced. Nevertheless, the specific capacity data indicate that a viable groundwater system within the fractured granite rock on the properties and within adjacent areas may exist, and the testing program has generated some credible data regarding a preliminary approximation of sustainable yield. -2- ASL Consulting Engineers, Inc. April 7. 1999 (98-71-0421) Of somewhat more interest to us is the discussion in the report on gross "basin" storage capacity and the inferred source of groundwater recharge reflected in the Ground Water Potentiometric Surface Map (Map No. 2). Table V\ in the report (Esfimated Water Storage Capacity of the Bonsall Tonalite Formation) provides some very broad*ajid far-reaching assumptions regarding the estimated storage volume of an approximate'-64-square-mile area. The estimation of the storage volume is totally driven by the surfade'''area considered, and we cannot conclude from the available data that a 64-square-mile5.esen^ir is available as recharge to the specific properties. What is more likely is that, with^usUined pumpage,"Agroundwater recharge will be induced from the lower San Luis Rey»<River, as underflow to the^'ractured granite. We note the rather immediate and pronounced drawdow^of the varimis monitonng wells as a result of pumping of the production wells, wtiith woulisuggest this conclusion. The groundwater elevation contours^shown on Map ^v^re siabject to different interpre- tations. We assume that the static waterVevels..shown reflect some'degree of confinement (artesian conditions). Given the fractured rikture of thengraniticj^^s, any assertion regarding water level gradients are viewed as speculative "and^possiljy^ misleading. We believe that considerable additional work wpuld be needed \a.c6nvincingly establish gradient and presumed sources of recharge to the^-^granitic aquifers onSthe properties. A more plausible gradient (regionally) would be fr9m east to west/ \ Water quality data'^(TablerIV.)^ppear/to us to reflect a source influenced by man's activities (i.e., discharge occurring within the"§an Luis Rey River). Swift Well No. 1 reflects the poorest groimdwafervquality (TDS ^f^around 1,500 mg/l), containing MB AS (detergent byproducts)^and notice^le nifrate ion concentrations that exceed the state standard. It should be noted thatHhe re^latory stancfard for nitrate-nitrogen is 10 mg/l, rather than the 45 mg/l shown on Table IV^'oX theVeport.Nitrate ion concentrations, and relatively high chloride and sulfate ions all seem t6N:eflect^.«oijrce other than a calcium bicarbonate type groundwater one would expect in a granitic^ource'(oxidizing) environment. In general, the groundwater quality appears to be little different-^rom that found in the lower San Luis Rey (Mission) basin (refer to Technical Memo No. 3). In summary, the well testing and water quality data suggest that perhaps several thousand acre-feet of marginal quality groundwater could be supplied by the subject wells to the City of Oceanside. The reliability of this source and environmental pennitting and engineering feasibility (conveyance, treatment, and costs) would require considerable further study. Should future long-term pumping tests be conducted, we would suggest: • Collection of the well performance data using microprocessor data loggers. • Collection of key water quality data at regular intervals throughout the testing. • Performance of tests for several months with attendant monitoring of flow (and underflow using piezometers) within the immediately proximate San Luis Rey River. JA3«92«O00StL-40riX3C -3- ASL Consulting Engineers, Inc. April 7, 1999 (98-71-0421) Benefits to the San Diego County Water Authority regarding the data contained in the report and use of fractured granitic reservoirs either for constant yield or groundwater storage are unclear. We believe that the San Diego County Water Authority and the project team should review the results of the subject well tests and possible water transfer with/autwn. The project team should remain informed regarding any discussions, reports, and foUow-up hydrogeologic or engineering studies conducted on the properties related to groundwate^r^sources. We tmst that this letter is helpful and will remain,availableip,review,any'additional data that may become available regarding bedrock aquifers in the^stu'dy-area. Sincerely/ FUGRO WEST, Da\idj\. GardnecJ^Hg 122 Senior^ice-President JA3S92MX»atL-4CI7£KX; -4- APPENDIX D Detailed List of Facilities Table D-l Project Elements Mission Basin 1.63 MGD Project Concept Category Proposed Facilities GROUNDWATER EXTRACTION Existing standby well no. 3 at desalter site - 1000 gpm Existing standby well no. 6 at North River road - 500 gpm GROUNDWATER TREATMENT Expand existing Oceanside desalter from 6.37 MGD to potable water production capacity of 8.0 MGD (1.63 MGD expansion). CONVEYANCE AND PUMPING Constmct 1.63 MGD addition to high lift pump station at desalter site to pump treated RO water to City's 320 pressure zone (total pump station capacity of 3 MGD). Water will be delivered to the 320 pressure zone through a new portion of a 24-inch pipeline being constmcted in Mission Avenue. A 30-inch pipeline which is being installed as part of the 6.37 MGD expansion will connect the high lift pump station to the new 24-inch line. Construct 4.2 MGD reclaimed water transmission pipeline from San Luis Rey WWTP to North Riverside Pond recharge area. This would be an 16-inch diameter, 9000 linear ft transmission line which would mn from the WWTP site east along North River Road to the North Riverside Pond recharge area. Upgrade approximately 1,500 linear ft of the existing 10-inch brine disposal outfall to 16-inch and connect this new pipeline to the planned 36-inch upgraded San Luis Rey WWTP land outfall. The remainder of the 10-inch brine disposal outfall which mns to the La Salina WWTP can be abandoned. Upgrade concentrate booster pumps at desalter to 2.1 MGD, with pumping head to be determined based on pressure in expanded 36-inch San Luis Rey WWTP land outfall. SANDIEGO COUNTY WATERAuTHORnr I :\3892\0005\Rcport\Appcndix-D.doc D-l Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Category Proposed Facilities CONVEYANCE AND PUMPING Construct 1.63 MGD addition to high lift pump station at desalter site to pump treated RO water to City's 320 pressure zone (total pump station capacity of 3 MGD). Water will be delivered to the 320 pressure zone through a new portion of a 24-inch pipeline being constructed in Mission Avenue. A 30-inch pipeline which is being installed as part of the 6.37 MGD expansion will connect the high lift pump station to the new 24-inch line. Constmct 4.2 MGD reclaimed water transmission pipeline from San Luis Rey WWTP to North Riverside Pond recharge area. This would be an 16-inch diameter, 9000 linear ft transmission line which would mn from the WWTP site east along North River Road to the North Riverside Pond recharge area. Upgrade approximately 1,500 linear ft of the existing 10-inch brine disposal outfall to 16-inch and connect this new pipeline to the planned 36-inch upgraded San Luis Rey WWTP land outfall. The remainder of the 10-inch brine disposal outfall which mns to the La Salina WWTP can be abandoned. Upgrade concentrate booster pumps at desalter to 2.1 MGD, with pumping head to be determined based on pressure in expanded 36-inch San Luis Rey WWTP land outfall. RECHARGE FACILITIES Construct outlet/flow control stmcture at the North Riverside Pond recharge area for surface spreading of reclaimed water. SANDIEGO COUNTT WATERAuTHORnr I:\3892\0005\Rqx)rt\Appcndi)t-D.doe D-2 (froundwftter Storage &" Recovery Project Lower San Luis Rey River Valley Table D-2 Proposed Facilities Mission Basin 6.70 MGD Project Concept Category Proposed Facilities GROUNDWATER EXTRACTION Existing standby well no. 3 at desalter site - 1000 gpm Existing standby well no. 6 at North River Road - 500 gpm Two new wells at Douglas Drive - 2066 gpm Two new wells at North River road - 3099 gpm GROUNDWATER/RECLAIMED WATER TREATMENT Expand existing Oceanside desalter from 6.37 MGD to potable water production capacity of 13.07 MGD (6.37 MGD existing capacity plus 6.70 MGD additional). Construct 2.0 MGD advanced reclaimed water treatment facilities at San Luis Rey WWTP (for intrusion barrier water). CONVEYANCE AND PUMPING Upgrade raw water collection line from North River Road wellfield to the desalter to 30-inch, 19,000 linear ft. Construct 6.70 MGD addition to high lift pump station at desalter site to pump treated RO water to City's 320 pressure zone. Water will be delivered to the 320 pressure zone through a new portion of a 24-inch pipeline being constructed in Mission Avenue by Caltrans. A 30-inch pipeline which is being installed as part of the 6.37 MGD expansion will connect the high lift pump station to the new 24-inch line. Construct 3.47 MGD pump station at NCDP/FCF site to feed water to NCDP agencies from the City's planned 511 reservoir(s) at that location. Construct 4.2 MGD reclaimed water transmission pipeline from San Luis Rey WWTP to Upper Pond recharge area. This would be a 16-inch diameter, 9000 linear ft transmission line which would run from the WWTP site east along North River Road into the North Riverside Pond recharge area. Construct 12-inch, 18,000 linear ft reclaimed water transmission pipeline from San Luis Rey WWTP to narrows intrusion barrier injection site. This pipeline could follow the San Luis Rey WWTP effluent land outfall alignment and then tum west along the Highway 76 alignment to the narrows. Extend the City's existing 24-inch aqueduct supply lines from the Weese WFP to serve as a portion of an imported water recharge pipeline. This would be a single 36-inch extension to both of the existing aqueduct supply lines and would SANDIEGO COUNTT WATERAuTHORnr J:\3892\0005\Rcport\Appcndix-D.doc D-3 Groundwater Storage &'Recovery Project Lower San Luis Rey River Valley Category Proposed Facilities run from the intersection of East Vista Way and the easterly prolongation of Osbome Street to Upper Pond via Mission Avenue and College Boulevard. Construct miscellaneous pipeline improvements between Oceanside and Carlsbad. Construct 30-inch, 3500 linear ft pipeline from the Henie Hills reservoir to serve additional 511 pressure zone areas. Construct 24-inch, 3450 linear ft pipeline along Lake Boulevard to serve additional 511 pressure zone areas. Construct 3.6 MGD pump station at Heritage Reservoir to move water from the 320 to the 511 pressure zone. Upgrade existing 12-inch connection between Carlsbad and Oceanside at El Camino Real and Vista Way to 14-inch pipeline and metering/flow control facility. Construct 14-inch, 9700 linear ft pipeline from Oceanside's San Francisco Peak No. 2 511 HGL reservoir to coimect to Carlsbad MWD Maerkle Dam and reservoir. This pipeline could be located in the existing easement for the Tri- Agencies Pipeline and associated lines that feed Carlsbad MWD. Upgrade approximately 1,500 linear ft of the existing 10-inch brine disposal outfall to 18-inch and connect this new pipeline to the planned 36- inch upgraded San Luis Rey WWTP land outfall. The remainder of the 10-inch brine disposal outfall that runs to the La Salina WWTP can be abandoned. Upgrade concentrate booster pumps at desalter to 5.0 MGD, with pumping head to be determined based on pressure in expanded 36- inch San Luis Rey WWTP land outfall. SANDIEGO COUNTT WATERAuTHORirr J:\3892\0005\Report\Appcndix-D.cloc D-4 Groundwater Storage & Recovery Project iMwer San Luis Rxy River Valley Category Proposed Facilities RECHARG E/INTRUS ION FACILITIES BARRIER Construct outlet/flow control structure at the North Riverside Pond recharge area for surface spreading of reclaimed water. Construct outlet/flow control structure at the Upper Pond recharge area for surface spreading of the imported water. Construct imported water injection wellfield/flow control facility along the San Luis Rey River north of Mission Avenue. This would consist of a group of four injection wells, each spaced 1000 ft apart in a square with target injection rates of 500 gpm/well, for a total of 2000 gpm, or 2.9 MGD. Construct seawater barrier wellfield at the narrows consisting of four injection wells, each spaced 1000 ft apart in a square with target injection rates of 350 gpm/weil, for a total of 1400 gpm, or 2.0 MGD. SANDIEGO COUNTT WATERAUTHORTTT J:\3892\000S\Rq>on\Appcndix-D.doc D-5 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Table D-2 A Project Elements Mission Basin 10.0 MGD Project Concept Category Proposed Facilities GROUNDWATER EXTRACTION Existing standby welis at desalter site and North River Road. Two new wells at Douglas Drive. Two new wells at North River Road. GROUNDWATER/RECLAIMED WATER TREATMENT Expand existing Oceanside desalter from 6.37 MGD to potable water production capacity of 16.37 MGD. Construct 2.0 MGD advanced reclaimed water treatment facilities at San Luis Rey WWTP (for intrusion barrier water). CONVEYANCE AND PUMPING Upgrade raw water collection line. Construct addition to high lift pump station at desalter site. Construct pump station at NCDP/FCF site. Construct reclaimed water transmission pipeline from San Luis Rey WWTP to Upper Pond recharge area. Construct reclaimed water transmission pipeline from San Luis Rey WWTP to narrows intrusion barrier injection site. Extend the City's existing 24-inch aqueduct supply lines from the Weese WFP. Construct miscellaneous pipeline improvements between Oceanside and Carlsbad. Upgrade existing brine disposal outfall. Upgrade concentrate booster pumps at desalter. RECHARGE/INTRUSION BARRIER FACILITIES Construct outlet'flow confrol structure at the North Riverside Pond recharge area. Construct outlet/flow control strucmre at the Upper Pond recharge area. Construct imported water injection well field/flow control facility along the San Luis Rey River north of Mission Avenue. Construct seawater barrier well field at the narrows. SANDIEGO COUNTT WATERAuTHORirr I:\3892\0005\Report\Appcndut-D.doc D-6 Groundwater Storage <& Rxcovery Project Lower San Luis Rsy River Valley Table D-3 Proposed Additional Facilities Mission Basin 6.70 MGD with Regional Use ofthe Weese Water Filtration Plant Protect Elements IMPORTED WATER TREATMENT • Expand existing City of Oceanside WFP by an increment equal to expanded Mission Basin production CONVEYANCE AND PUMPING • Construct freated water pump station at WFP to pump treated water back into Pipeline 4 of the Second Aqueduct RECLAIMED WATER TREATMENT • Construct 2.0 MGD advanced reclaimed water treatment facilities at San Luis Rey WWTP (for intrusion barrier water). CONVEYANCE AND PUMPING • Upgrade raw water collection line. • Construct addition to high lift pump station at desalter site. • Construct reclaimed water transmission pipeline from San Luis Rey WWTP to Upper Pond recharge area. • Construct reclaimed water transmission pipeline from San Luis Rey WWTP to narrows intrusion barrier injection site. • Extend the City's existing 24-inch aqueduct supply lines from the Weese WFP. • Upgrade existing brine disposal outfall. • Upgrade concentrate booster pumps at desalter. RECHARGE/INTRUSION BARRIER FACILITIES • Construct outlet/flow control structure at the North Riverside Pond recharge area. • Construct outlet/flow control structure at the Upper Pond recharge area. • Construct imported water injection wellfield/flow control facility along the San Luis Rey north of Mission Avenue. • Construct seawater barrier wellfield at the narrows. SANDIEGO COUNTT WATERAUTHORTTT J:\3892\0005\Rcport\Appcnd«-D.doc D-7 Groufuiwater Storage & Recovery Projea Lower San Luis Rey River Valley TableD'3A Project Elements Mission Basin 10.0 MGD with Regional Use ofthe Weese Water Filtration Plant Project Concept Category Proposed Facilities IMPORTED WATER TREATMENT • Expand existing City of Oceanside's Weese WFP by an increment equal to expanded Mission Basin production. CONVEYANCE AND PUMPING • Construct freated water pump station at Weese WFP to pump freated water back into Pipeline 4 ofthe Second Aqueduct. RECLAIMED WATER TREATMENT • Construct 2.0 MGD advanced tertiary reclaimed water treatment facilities at San Luis Rey WWTP (for intrusion barrier water). CONVEYANCE AND PUMPING • Upgrade raw water collection line. • Construct addition to high lift pump station at desalter site. • Construct reclaimed water transmission pipeline from San Luis Rey WWTP to Upper Pond recharge area. • Construct reclaimed water transmission pipeline from San Luis Rey WWTP to narrows intrusion barrier injecfion site. • Extend the City's existing 24-inch aqueduct supply lines from the Weese WFP. • Upgrade existing brine disposal outfall. • Upgrade concenfrate booster pumps at desalter. RECHARGE FACILITIES • Construct outlet/flow confrol structure at the North Riverside Pond recharge area. • Construct outlet/flow control structure at the Upper Pond recharge area. • Construct imported water injecfion well field/flow confrol facility along the San Luis Rey north of Mission Avenue. • Construct seawater barrier well field at the narrows. SANDIEGO COUNTT WATERAuTHORnr J;\3892\0{)05\Rcport\Appmdix-D.doc D-8 Groundwater Startle & Recovery Projea Lower San Luis Rey River Valley Table D-4 Proposed Facilities Bonsall Basin 3.60 MGD Project Concept Category Proposed Facilities GROUNDWATER EXTRACTION • Develop and equip three wells on open land north of the San Luis Rey River and 0.8 miles west of Sage Road (Sage wellfield site), each well would operate at 1,100 gpm. GROUNDWATER TREATMENT • Construct a 3.62 MGD desalter on District property consisting of RO and associated pre- and post-freatment components including iron and manganese treatment and chloramination facilifies. Blending would be performed to meet a target TDS level of 700 ppm. CONVEYANCE AND PUMPING • Construct 18-inch, 8500 linear ft raw water collection line from Sage wellfield to the desalter. • Construct 18-inch transmission pipeline from new turnout (see below) to recharge wellfield. • Construct 3.62 MGD high lift pump station to feed the District's 865 pressure zone and Pipeline 4 of the Second Aqueduct. • Construct 10-inch brine disposal pipeline to connect to existing Oceanside land outfall. RECHARGE FACILITIES • Construct 10 cfs unfiltered water turnout along Second Aqueduct south of Highway 76. • Construct recharge wellfield on District property consisting of eight injecfion wells, spaced 500 ft apart with target injection rates of approximately 500 gpm/well, for a total of 3722 gpm, or 5.36 MGD. SANDIEGO COUNTY WATERAUTHORTTT J :\3892\0005\Rqxjrt\Appcndb(-D.doc D-9 Groundwater Storage & Recovery Project Lower San Luis Rey River Valley Table D-4 A Proposed Facilities Bonsall Basin 3.60 MGD Project Concept Category Proposed Facilities GROUNDWATER EXTRACTION • Develop and equip four wells north of the San Luis Rey River and west of Sage Road. GROimowATER TREATMENT • Construct desalter on Rainbow MWD property. CONVEYANCE AND PUMPING • Construct raw water collection line from Sage well field to the desalter. • Construct pipeline from new turnout {see below) to recharge well field. • Construct pump station to feed the District's 865 pressure zone. • Construct brine disposal pipeline to connect to existing Oceanside land outfall. RECHARGE FACILITIES • Construct unfiltered water turnout along Second Aqueduct south of Highway 76. • Construct recharge well field on District property. SANDIEGO COUNTT WATERAUTHORITT J :\3892\0005\Rcpon:\Appcndi3(-D.doc D-10 Groundwater Storage &'Recovery Project Lower San Luis Rey River Valley APPENDDC E Project Cost Information TABLE D'1 Af/SS/OW BASIN 1.63 MGD CONSTANT YIELD/SEASONAL STORAGE: Year Total Low High Estimated Required Reclaimed Imported Reclaimed Reclaimed Reclaimed Low High Total Natural Artificial Water Water Low High Water Water Water Recharge Recharge Extraction Recharge Recharge Recharge Recharge Loss Loss Recharge Recharge Cost Cost Cost acre-ft/vear acre-(t/vear acre-ft/vear acre-ft/vear acre-ft/vear % % acre-ft/vear acre-ft/vear S/acre-ft 1 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 2 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 3 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 4 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 5 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 6 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 7 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 8 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 9 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 10 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 11 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 12 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 13 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 14 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 15 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 16 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 17 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 18 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 19 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 20 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 21 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 22 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 23 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 24 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 25 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 26 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 27 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 28 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 29 12352 10000 2352 2352 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 30 12352 10000 300000 2352 70560 2352 70560 0 0 5% 20% 2469.6 2822.4 $139 $344,410 $393,612 370560 PRESENT VALUE: AMORTIZED COST, $/YEAR: COST PER ACRE-FT: 370560 $4,740,750 $344,410 $210 $5,418,000 $393,612 $240 $225 File: N:\3892\0005\data\costmodel.xls Tab: MB1.63MGD 1 of 1 1/5/00 2:19 PM TABLE D-2 Total Low High Total Estimated Required Reclaimed Imported Imported Imported Total Natural Artificial Water Water Low High Water Water Extraction Recharge Recharge Recharge Recharge Loss Loss Recharge Recharge Year acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear % % acre-ft/vear acre-ft/vear 1 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 3 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 4 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 5 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 6 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 7 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 8 20000 10000 10000 0 0 5% 20% 0 0 9 20000 10000 10000 0 0 5% 20% 0 0 10 20000 10000 10000 0 0 5% 20% 0 0 11 20000 10000 10000 2352 17648 5% 20% 18530.4 21177.6 12 20000 10000 10000 2352 17648 5% 20% 18530.4 21177.6 13 20000 10000 10000 2352 17648 5% 20% 18530.4 21177.6 14 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 15 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 16 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 17 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 18 20000 10000 10000 0 0 5% 20% 0 0 19 20000 10000 10000 0 0 5% 20% 0 0 20 20000 10000 10000 0 0 5% 20% 0 0 21 20000 10000 10000 2352 17648 5% 20% 18530.4 21177.6 22 20000 10000 10000 2352 17648 5% 20% 18530.4 21177.6 23 20000 10000 10000 2352 17648 5% 20% 18530.4 21177.6 24 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 25 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 26 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 27 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 28 20000 10000 10000 0 0 5% 20% 0 0 29 20000 10000 10000 0 0 5% 20% 0 0 30 20000 600000 10000 300000 10000 300000 0 49392 0 220608 570000 5% 20% 0 0 Low Reclaimed Water Recharge acre-ft/vear High Reclaimed Water Recharge acre-ft/vear Untreated MWD Rate $/acre-ft LTS Discount $/acre-ft Imported Water Cost S/acre-ft Reclaimed Water Cost S/acre-ft 2469.6 2822.4 $349 $141 $208 $139 2469.6 2822.4 $356 $141 $215 $139 2469.6 2822.4 $363 $141 $222 $139 2469.6 2822.4 $370 $141 $229 $139 2469.6 2822.4 $378 $141 $237 $139 2469.6 2822.4 $385 $141 $244 $139 2469.6 2822.4 $393 $141 $252 $139 2469.6 2822.4 $401 $141 $260 $139 2469.6 2822.4 $409 $141 $268 $139 2469.6 2822.4 $417 $141 $276 $139 2469.6 2822.4 $425 $141 S284 $139 2469.6 2822.4 $434 $141 $293 $139 2469.6 2822.4 $443 $141 $302 $139 2469.6 2822.4 $451 $141 $310 $139 2469.6 2822.4 $460 $141 $319 $139 2469.6 2822.4 $470 $141 $329 $139 2469.6 2822.4 $479 $141 $338 $139 2469.6 2822.4 $489 $141 $348 $139 2469.6 2822.4 $498 $141 $357 $139 2469.6 2822.4 $508 $141 $367 $139 2469.6 2822.4 $519 $141 $378 $139 2469.6 2822.4 $529 $141 S388 $139 2469.6 2822.4 $540 $141 $399 $139 2469.6 2822.4 $550 $141 $409 $139 2469.6 2822.4 $561 $141 $420 $139 2469.6 2822.4 $573 $141 $432 $139 2469.6 2822.4 $584 $141 $443 $139 2469.6 2822.4 $596 $141 $455 $139 2469.6 2822.4 $608 $141 $467 $139 2469.6 2822.4 $620 $141 S479 $139 PRESENT VALUE: AMORTIZED COSTS, $/YEAR: COST PER ACRE-FT: Low Recharge Cost $2,014,734 $2,070,786 $2,127,959 $2,186,276 $2,245,759 $2,306,431 $2,368,318 $344,410 $344,410 $344,410 $5,614,994 $5,772,662 $5,933,483 $2,837,598 $2,910,108 $2,984,067 $3,059,506 $344,410 $344,410 $344,410 $7,341.409 $7,533,604 $7,729,644 $3.631,557 $3,719,946 $3,810,102 $3,902,062 $344,410 $344,410 $344,410 $36,359,173 $2,641,454 $391 High • Recharge Cost $2,302,553 $2,366,612 $2,431,953 $2,498,601 $2,566,581 $2,635,922 $2,706,649 $393,612 $393,612 $393,612 $6,417,137 $6,597,328 $6,781,123 $3,242,969 $3,325,837 $3,410,363 $3,496,579 $393,612 $393,612 $393,612 $8,390,181 $8,609,833 $8,833,879 $4,150,351 $4,251,366 $4,354,402 $4,459,499 $393,612 $393,612 $393,612 $41,553,341 $3,018,805 $447 $419 File: N:\3892\0005\data\costmodel.xls Tab: MB6.70MGD 1 of 1 1/5/00 2:19 PM TABLE D-2A PROJECT CONCEPT- MISSION BASIN 6.70 MGD CONSTANT YIELD/SEASONAL STORAGE Total Estimated Required Reclaimed Imported Total Natural Artificial Water Water Extraction Recharge Recharge Recharge Recharge Year acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear 1 20000 10000 10000 2352 7648 2 20000 10000 10000 . 2352 7648 3 20000 10000 10000: 2352 7648 4 20000 10000 10000 2352 7648 5 20000 10000 10000 2352 7648 6 20000 10000 10000 , 2352 7648 7 20000 10000 10000 • 2352 7648 8 20000 10000 10000 2352 7648 9 20000 10000 10000 2352 7648 10 20000 10000 10000 : 2352 7648 11 20000 10000 10000 2352 7648 12 20000 10000 10000 . 2352 7648 13 20000 10000 10000 2352 7648 14 20000 10000 10000 . 2352 7648 15 20000 10000 10000 2352 7648 16 20000 10000 10000 . 2352 7648 17 20000 10000 10000 . 2352 7648 18 20000 10000 10000 . 2352 7648 19 20000 10000 10000 ' 2352 7648 20 20000 10000 10000 . 2352 7648 21 20000 10000 10000 2352 7648 22 20000 10000 10000 . 2352 7648 23 20000 10000 10000; 2352 7648 24 20000 10000 10000 7 2352 7648 25 20000 10000 10000 • 2352 7648 26 20000 10000 10000 " 2352 7648 27 20000 10000 10000 2352 7648 28 20000 10000 10000 2352 7648 29 20000 10000 10000 • 2352 7648 30 20000 10000 10000 2352 7648 300000 300000 70560 229440 600000 600000 Low High Low High Imported Imported Reclaimed Reclaimed Untreated Seasonal Imported Reclaimed Low High Low High Water Water Water Water MWD Storage Water Water Recharge Recharge Loss Loss Recharge Recharge Recharge Recharge Rate Discount Cost Cost Cost Cost % % acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear $/acre-ft $/acre-ft $/acre-ft S/acre-ft m. 5% 20% 8030.4 9177.6 2469.6 2822.4 $349 $85 $264 $139 $2,463,300 $2,815,200 5% 20% 8030.4 9177.6 2469.6 2822.4 $356 $85 $271 $139 $2,519,352 $2,879,260 5% 20% 8030.4 9177.6 2469.6 2822.4 $363 $85 $278 $139 $2,576,525 $2,944,600 5% 20% 8030.4 9177.6 2469.6 2822.4 $370 $85 $285 $139 $2,634,842 $3.011,248 5% 20% 8030.4 9177.6 2469.6 2822.4 $378 $85 $293 $139 $2,694,325 $3,079,229 5% 20% 8030.4 9177.6 2469.6 2822.4 $385 $85 $300 $139 $2,754,998 $3,148,569 5% 20% 8030.4 9177.6 2469.6 2822.4 $393 $85 $308 $139 $2,816,884 $3,219,296 5% 20% 8030.4 9177.6 2469.6 2822.4 $401 $85 $316 $139 $2,880,008 $3,291,438 5% 20% 8030.4 9177.6 2469.6 2822.4 $409 $85 $324 $139 $2,944,394 $3,365,022 5% 20% 8030.4 9177.6 2469.6 2822.4 $417 $85 $332 $139 $3,010,068 $3,440,078 5% 20% 8030.4 9177.6 2469.6 2822.4 $425 $85 $340 $139 $3,077,056 $3,516,635 5% 20% 8030.4 9177.6 2469.6 2822.4 $434 $85 $349 $139 $3,145,383 $3,594,724 5% 20% 8030.4 9177.6 2469.6 2822.4 $443 $85 $358 $139 $3,215,077 $3,674,374 5% 20% 8030.4 9177.6 2469.6 2822.4 $451 $85 $366 $139 $3,286,165 $3,755,617 5% 20% 8030.4 9177.6 2469.6 2822.4 $460 $85 $375 $139 $3,358,674 $3,838,485 5% 20% 8030.4 9177.6 2469.6 2822.4 $470 $85 $385 $139 $3,432,634 $3,923,010 5% 20% 8030.4 9177.6 2469.6 2822.4 $479 $85 $394 $139 $3,508,073 $4,009,226 5% 20% 8030.4 9177.6 2469.6 2822.4 $489 $85 $404 $139 $3,585,020 $4,097,166 5% 20% 8030.4 9177.6 2469.6 2822.4 $498 $85 $413 $139 $3,663,507 $4,186,865 5% 20% 8030.4 9177.6 2469.6 2822.4 $508 $85 $423 $139 $3,743,563 $4,278,358 5% 20% 8030.4 9177.6 2469.6 2822.4 $519 $85 $434 $139 $3,825,221 $4,371,681 5% 20% 8030.4 9177.6 2469.6 2822.4 $529 $85 $444 $139 $3,908,511 $4,466,870 5% 20% 8030.4 9177.6 2469.6 2822.4 $540 $85 $455 $139 $3,993,468 $4,563,963 5% 20% 8030.4 9177.6 2469.6 2822.4 $550 $85 $465 $139 $4,080,123 $4,662,998 5% 20% 8030.4 9177.6 2469.6 2822.4 $561 $85 $476 $139 $4,168,512 $4,764,014 5% 20% 8030.4 9177.6 2469.6 2822.4 $573 $85 $488 $139 $4,258,669 $4,867,050 5% 20% 8030.4 9177.6 2469.6 2822.4 $584 $85 $499 $139 $4,350,628 $4,972,146 5% 20% 8030.4 9177.6 2469.6 2822.4 $596 $85 $511 $139 $4,444,427 $5,079,345 5% 20% 8030.4 9177.6 2469.6 2822.4 $608 $85 $523 $139 $4,540,102 $5,188,687 5% 20% 8030.4 9177.6 2469.6 2822.4 $620 $85 $535 $139 $4,637,690 $5,300,217 PRESENT VALUE: AMORTIZED COSTS, $/YEAR: COST PER ACRE-FOOT: $43,297,777 $49,483,174 $3,145,536 $3,594,899 $466 $532 File: N:\3892\0005\data\costmodeI01.xlsTab: MB6.70MGD 1 of 1 1/6/00 3:13 PM TABLE D-3 PROJECT CONCEPT-MISSION BASIN 6.70 MGD CONSTANT YIELD/SEASONAUCARRYOVER STORAGE/REGIONAL USE OF WEESE Total Low High Low High Estimated Required Reclaimed Imported Imported Imported Reclaimed Reclaimed Untreated Imported Reclaimed Low High WFP Total Natural Artificial Water Water Low High Water Water Water Water MWD LTS Water Water Recharge Recharge Water Extraction Recharge Recharge Recharge Recharge Loss Loss Recharge Recharge Recharge Recharge Rate Discount Cost Cost Cost Cost Cost Year acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear % % acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear $/acre-ft S/acre-ft $/acre-ft S/acre-ft - m m 1 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $349 $141 $208 $139 $2,014,734 $2,302,553 $2,618,896 2 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $356 $141 $215 $139 $2,070,786 $2,366,612 $2,671,274 3 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $363 $141 $222 $139 $2,127,959 $2,431,953 $2,724,699 4 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $370 $141 $229 $139 $2,186,276 $2,498,601 $2,779,193 5 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $378 $141 $237 $139 $2,245,759 $2,566,581 $2,834,777 6 20000 10000 10000 • 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $385 . $141 $244 $139 $2,306,431 $2,635,922 $2,891,473 7 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $393 $141 $252 $139 $2,368,318 $2,706,649 $2,949,302 8 20000 10000 10000 0 0 5% 20% 0 0 2469.6 2822.4 $401 $141 $260 $139 $344,410 $393,612 $3,008,288 9 20000 10000 10000 0 0 5% 20% 0 0 2469.6 2822.4 $409 $141 $268 $139 $344,410 $393,612 $3,068,454 10 20000 10000 10000 0 0 5% 20% 0 0 2469.6 2822.4 $417 $141 $276 $139 $344,410 $393,612 $3,129,823 11 20000 10000 10000 ^ 2352 17648 5% 20% 18530.4 21177.6 2469.6 2822.4 $425 $141 $284 $139 $5,614,994 $6,417,137 $3,192,420 12 20000 10000 10000 2352 17648 5% 20% 18530.4 21177.6 2469.6 2822.4 $434 $141 $293 $139 $5;772,662 $6,597,328 $3,256,268 13 20000 10000 10000 2352 17648 5% 20% 18530.4 21177.6 2469.6 2822.4 $443 $141 $302 $139 $5,933,483 $6,781,123 $3,321,393 14 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $451 $141 $310 $139 $2,837,598 $3,242,969 $3,387,821 15 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $460 $141 $319 $139 $2,910,108 $3,325,837 $3,455,578 16 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $470 $141 $329 $139 $2,984,067 $3,410,363 $3,524,689 17 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $479 $141 $338 $139 $3,059,506 $3,496,579 $3,595,183 18 20000 10000 10000 0 0 5% 20% 0 0 2469.6 2822.4 $489 $141 $348 $139 $344,410 $393,612 $3,667,087 19 20000 10000 10000 0 0 5% 20% 0 0 2469.6 2822.4 $498 $141 $357 $139 $344,410 $393,612 $3,740,428 20 20000 10000 10000 0 0 5% 20% 0 0 2469.6 2822.4 $508 $141 $367 $139 $344,410 $393,612 $3,815,237 21 20000 10000 10000 , 2352 17648 5% 20% 18530.4 21177.6 2469.6 2822.4 $519 $141 $378 $139 $7,341,409 $8,390,181 $3,891,542 22 20000 10000 10000 2352 17648 5% 20% 18530.4 21177.6 2469.6 2822.4 $529 $141 $388 $139 $7,533,604 $8,609,833 $3,969,373 23 20000 10000 10000 2352 17648 5% 20% 18530.4 21177.6 2469.6 2822.4 $540 $141 $399 $139 $7,729,644 $8,833,879 $4,048,760 24 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $550 $141 $409 $139 $3,631,557 $4,150,351 $4,129,735 25 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $561 $141 $420 $139 $3,719,946 $4,251,366 $4,212,330 26 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $573 $141 $432 $139 $3,810,102 $4,354,402 $4,296,576 27 20000 10000 10000 2352 7648 5% 20% 8030.4 9177.6 2469.6 2822.4 $584 $141 $443 $139 $3,902,062 $4,459,499 $4,382,508 28 20000 10000 10000 0 0 5% 20% 0 0 2469.6 2822.4 $596 $141 $455 $139 $344,410 $393,612 $4,470,158 29 20000 10000 10000 0 0 5% 20% 0 0 2469.6 2822.4 $608 $141 $467 $139 $344,410 $393,612 $4,559,561 30 20000 10000 300000 10000 300000 0 49392 0 220608 5% 20% 0 0 2469.6 2822.4 $620 $141 $479 $139 $344,410 $393,612 $4,650,753 600000 570000 PRESENT VALUE: AMORTIZED COSTS, $/YEAR: COST PER ACRE-FT: $36,359,173 $2,641,454 $185 $41,553,341 $3,018,805 $212 $198 $44,823,950 $3,256,411 $228 File: N:\3892\0005\data\costmodel.xls Tab: MB6.70WFP 1 of 1 1/6/00 2:48 PM TABLE D-4 PROJECT CONCEPT - BONSALL BASIN 3.6 MGD CONSTANT YIELD/SEASONAUCARRYOVER STORAGE: Year Total Low High Estimated Required Reclaimed Imported imported imported Untreated imported Low High Total Natural Artificial Water Water Low High Water Water MWD LTS Water Recharge Recharge Extraction Recharge Recharge Recfiarge Recharge Loss Loss Recharge Recharge Rate Discount Cost Cost Cost r acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear % %. acre-ft/vear acre-ft/vear $/acre-tt S/acre-ft $/acre-ft 1 5800 2800 3000 0 3000 5% 20% 3150 3600 $349 $141 $208 $655,200 $748,800 2 5800 2800 3000 0 3000 5% 20% 3150 3600 $356 $141 $215 $677,187 $773,928 3 5800 2800 3000 0 3000 5% 20% 3150 3600 $363 $141 $222 $699,614 $799,559 4 5800 2800 3000 0 3000 5% 20% 3150 3600 $370 $141 $229 $722,489 $825,702 5 5800 2800 3000 0 3000 5% 20% 3150 3600 $378 $141 $237 $745,822 $852,368 6 5800 2800 3000 0 3000 5% 20% 3150 3600 $385 $141 $244 $769,621 $879,567 7 5800 2800 3000 0 3000 5% 20% 3150 3600 $393 $141 $252 $793,897 $907,310 8 5800 2800 3000 0 0 5% 20% 0 0 $401 $141 $260 $0 $0 9 5800 2800 3000 0 0 5% 20% 0 0 $409 $141 $268 $0 SO 10 5800 2800 3000 0 0 5% 20% 0 0 $417 $141 $276 $0 $0 11 5800 2800 3000 0 6000 5% 20% 6300 7200 $425 S141 $284 $1,791,903 $2,047,889 12 5800 2800 3000 0 6000 5% 20% 6300 7200 $434 $141 $293 $1,845,507 $2,109,151 13 5800 2800 3000 0 6000 5% 20% 6300 7200 $443 $141 $302 $1,900,183 $2,171,638 14 5800 2800 3000 0 3000 5% 20% 3150 3600 $451 $141 $310 $977,976 $1,117,687 15 5800 2800 3000 0 3000 5% 20% 3150 3600 $460 $141 $319 $1,006,419 $1,150,193 16 5800 2800 3000 0 3000 5% 20% 3150 3600 $470 $141 $329 $1,035,430 $1,183,349 17 5800 2800 3000 0 3000 5% 20% 3150 3600 $479 $141 $338 $1,065,022 $1,217,168 18 5800 2800 3000 0 0 5% 20% 0 0 $489 $141 $348 SO $0 19 5800 2800 3000 0 0 5% 20% 0 0 $498 $141 $357 $0 $0 20 5800 2800 3000 0 0 5% 20% 0 0 $508 $141 $367 $0 $0 21 5800 2800 3000 0 6000 5% 20% 6300 7200 $519 $141 $378 $2,378,853 $2,718,689 22 5800 2800 3000 0 6000 5% 20% 6300 7200 $529 $141 $388 $2,444,196 $2,793,366 23 5800 2800 3000 0 6000 5% 20% 6300 7200 $540 $141 $399 $2,510,846 $2,869,538 24 5800 2800 3000 0 3000 5% 20% 3150 3600 $550 $141 $409 $1,289,414 $1,473,616 25 5800 2800 3000 0 3000 5% 20% 3150 3600 $561 $141 $420 $1,324,085 $1,513,241 26 5800 2800 3000 0 3000 5% 20% 3150 3600 $573 $141 $432 $1,359,450 $1,553,657 27 5800 2800 3000 0 3000 5% 20% 3150 3600 $584 $141 $443 $1,395,522 Si ,594,883 28 5800 2800 3000 0 0 5% 20% 0 0 $596 $141 $455 SO $0 29 5800-2800 3000 0 0 5% 20% 0 0 $608 $141 $467 $0 $0 30 5800 174000 2800 84000 3000 90000 0 0 0 81000 165000 5% 20% 0 0 $620 $141 $479 SO $0 PRESENT VALUE: AMORTIZED COSTS, S/YEAR: COST PER ACRE-FT: $11,666,493 $847,558 $234 $13,333,135 $968,638 $267 $250 Fllo: N;\3092\OOO5\clnln\coslniodol.xlsTnb; DD3.60UQD 1 ol 1 1/5/00 2:19 PM TABLE D-4A BONSALL BASIN 3.6 MGD Total Low High Estimated Required Reclaimed Imported imported Imported Seasonal Imported Low High Total Natural Artificial Water Water Low High Water Water IViWD Storage Water Low High Extraction Recharge Recharge Recharge Recharge Loss Loss Recharge Recharge Rate Discount Cost. Cost Cost Year acre-ft/vear acre-ft/vear acre-ft/vear , acre-ft/vear acre-ft/vear % % acre-ft/vear acre-ft/vear $/acre-ft $/acre-fl $/acre-ft m. $831,600 1 5800 2800 3000 0 3000 5% 20% 3150 3600 $349 $85 $264 m. $831,600 $950,400 2 5800 2800 3000 0 3000 5% 20% 3150 3600 S356 $85 $271 $853,587 $975,528 3 5800 2800 3000 0 3000 5% 20% 3150 3600 $363 $85 $278 $876,014 $1,001,159 4 5800 2800 3000 0 3000 5% 20% 3150 3600 $370 $85 $285 $898,889 $1,027,302 5 5800 2800 3000 0 3000 5% 20% 3150 3600 $378 $85 $293 $922,222 $1,053,968 6 5800 2800 3000 0 3000 5% 20% 3150 3600 $385 $85 $300 $946,021 $1,081,167 7 5800 2800 3000 0 3000 5% 20% 3150 3600 $393 $85 $308 $970,297 SI.108,910 8 5800 2800 3000 0 3000 5% 20% 3150 3600 $401 $85 $316 $995,058 $1,137,209 9 5800 2800 3000 0 3000 5% 20% 3150 3600 $409 $85 $324 $1,020,314 $1,166,073 10 5800 2800 3000 0 3000 5% 20% 3150 3600 $417 $85 $332 $1,046,075 $1,195,514 11 5800 2800 3000 0 3000 5% 20% 3150 3600 $425 $85 $340 $1.072,352 $1,225,545 12 5800 2800 3000 0 3000 5% 20% 3150 3600 $434 $85 $349 $1,099,154 $1,256,175 13 5800 2800 3000 0 3000 5% 20% 3150 3600 $443 $85 $358 $1,126,492 $1,287,419 14 5800 2800 3000 0 3000 5% 20% 3150 3600 S451 $85 $366 $1,154,376 $1,319,287 15 5800 2800 3000 0 3000 5% 20% 3150 3600 $460 $85 $375 $1,182,819 $1,351,793 16 5800 2800 3000 0 3000 5% 20% 3150 3600 $470 $85 $385 $1,211,830 $1,384,949 17 5800 2800 3000 0 3000 5% 20% 3150 3600 $479 $85 $394 $1,241,422 $1,418,768 18 5800 2800 3000 0 3000 5% 20% 3150 3600 $489 $85 $404 $1,271,605 $1,453,263 19 5800 2800 3000 0 3000 5% 20% 3150 3600 $498 $85 $413 $1,302,393 $1,488,449 20 5800 2800 3000 0 3000 5% 20% 3150 3600 $508 $85 $423 $1,333,795 $1,524,338 21 5800 2800 3000 0 3000 5% 20% 3150 3600 $519 $85 $434 $1,365,826 $1,560,944 22 5800 2800 3000 0 3000 5% 20% 3150 3600 $529 $85 $444 $1,398,498 $1,598,283 23 5800 2800 3000 0 3000 5% 20% 3150 3600 $540 $85 $455 $1,431,823 $1,636,369 24 5800 2800 3000 0 3000 5% 20% 3150 3600 $550 $85 $465 $1,465,814 $1,675,216 25 5800 2800 3000 0 3000 5% 20% 3150 3600 $561 $85 $476 $1,500,485 $1,714,841 26 5800 2800 3000 0 3000 5% 20% 3150 3600 $573 $85 $488 $1,535,850 $1,755,257 27 5800 2800 3000 0 3000 5% 20% 3150 3600 S584 $85 $499 $1,571,922 $1,796,483 28 5800 2800 3000 0 3000 5% 20% 3150 3600 $596 $85 $511 $1,608,716 $1,838,532 29 5800 2800 3000 0 3000 5% 20% 3150 3600 $608 $85 $523 $1,646,245 $1,881,423 30 5800 174000 2800 84000 3000 90000 0 0 3000 90000 174000 5% 20% 3150 3600 $620 $85 $535 $1,684,525 $1,925,171 PRESENT VALUE: AMORTIZED COSTS, $/YEAR: COST PER ACRE-FOOT: $15,130,490 $1,099,214 $303 $17,291,989 $1,256,244 $346 $325 File: N:\3892\0005\daln\costniodGl01.xls Tnb; DB3.60MGD 1 o( 1 1/5/00 2:20 PM TABLE D-5 PROJECT CONCEPT - MISSION BASIN 10.0 MGD CONSTANT YIELD/SEASONAUCARRYOVER STORAGE Total Low High Low High Estimated Required Reclaimed Imported Imported Imported Reclaimed Reclaimed Untreated Imported Reclaimed Low High Total Natural Artificial Water Water Low High Water Water Water Water MWD LTS Water Water Recharge Recharge Extraction Recharge Recharge Recharge Recharge Loss Loss Recharge Recharge Recharge Recharge Rate Discount Cost Cost Cost Cost Year acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear % % acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear $/acre-ft $/acre-ft $/acre-ft S/acre-ft m. 1 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $349 $141 $208 $139 $3,106,734 $3,550,553 2 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $356 $141 $215 $139 $3,199,431 $3,656,492 3 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $363 $141 $222 $139 $3,293,982 $3,764,551 4 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $370 $141 $229 $139 $3,390,424 $3,874,770 5 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $378 $141 $237 $139 $3,488,795 $3,987,194 6 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $385 $141 $244 $139 $3,589,133 $4,101,867 7 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $393 $141 $252 $139 $3,691,479 $4,218,833 8 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $401 $141 $260 $139 $344,410 $393,612 9 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $409 $141 $268 $139 $344,410 $393,612 10 25000 10000 15000 2352 27648 5% 20% 29030.4 33177.6 2469.6 2822.4 $417 $141 $276 $139 $8,359,335 $9,553,526 11 25000 10000 15000 2352 27648 5% 20% 29030.4 33177.6 2469.6 2822.4 $425 $141 $284 $139 $8,601,499 $9,830,285 12 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $434 $141 $293 $139 $4,234,739 $4,839,702 13 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $443 $141 $302 $139 $4,349,997 $4,971,425 14 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $451 $141 $310 $139 $4,467,559 $5,105,782 15 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $460 $141 $319 $139 $4,587,473 $5,242,826 16 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $470 $141 $329 $139 $4,709,785 $5,382,611 17 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $479 $141 $338 $139 $4,834,543 $5,525,192 18 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $489 $141 $348 $139 $344,410 $393,612 19 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $498 $141 $357 $139 $344,410 $393,612 20 25000 10000 15000 2352 27648 5% 20% 13280.4 15177.6 2469.6 2822.4 $508 $141 $367 $139 $5,223,989 $5,970,273 21 25000 10000 15000 2352 27648 5% 20% 29030.4 33177.6 2469.6 2822.4 $519 $141 $378 $139 ' $11,306,163 $12,921,329 22 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $529 $141 $388 $139 $5,496,775 $6,282,028 23 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $540 $141 $399 $139 $5,637,273 $6,442,597 24 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $550 $141 $409 $139 $5,780,581 $6,606,378 25 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $561 $141 $420 $139 $5,926,755 $6,773,434 26 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $573 $141 $432 $139 , $6,075,852 $6,943,831 27 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $584 $141 $443 $139 $6,227,932 $7,117,637 28 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $596 $141 $455 $139 $344,410 $393,612 29 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $608 $141 $467 $139 $344,410 $393,612 30 25000 10000 300000 15000 450000 2352 56448 27648 378552 5% 20% 29030.4 33177.6 2469.6 2822.4 $620 $141 $479 $139 $14,243,289 $16,278,045 750000 735000 PRESENT VALUE: AMORTIZED COSTS, $/YEAR: COST PER ACRE-FT: $56,361,108 $4,094,573 $606 $64,412,695 $4,679,512 $693 $650 File: N:\3892\0005\data\costmodel.xIsTab: MB10MGD 1 of 1 1/6/00 3:35 PM TABLE D-5A PROJECT CONCEPT- MISSION BASIN 10.0 MGD CONSTANT YIELD/SEASONAL STORAGE Total Low High Low High Total Estimated Required Reclaimed Imported Imported Imported Reclaimed Reclaimed Untreated Seasonal Imported Reclaimed Low High Total Natural Artificial Water Water Low High Water Water Water Water MWD Storage Water Water Recharge Recharge Extraction Recharge Recharge Recharge Recharge Loss Loss Recharge Recharge Recharge Recharge Rate Discount Cost Cost Cost Cost ear acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear % % acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear $/acre-ft $/acre-ft $/acre-ft S/acre-ft m 1 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $349 $85 $264 $139 33,849,300 $4,399,200 2 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $356 $85 $271 $139 S3,941,997 $4,505,140 3 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $363 $85 $278 $139 34,036,548 $4,613,198 4 25000 10000 15000 : 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $370 $85 $285 $139 54,132,990 $4,723,418 5 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $378 $85 $293 $139 34,231,361 $4,835,842 6 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $385 $85 $300 $139 S4,331,700 $4,950,514 7 25000 10000 15000 : 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $393 $85 $308 $139 34,434,045 $5,067,480 8 25000 10000 15000 ; 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $401 $85 $316 $139 84,538,437 $5,186,785 9 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $409 $85 $324 $139 84,644,917 $5,308,477 10 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $417 $85 $332 $139 $4,753,527 $5,432,602 11 25000 10000 15000 : 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $425 $85 $340 $139 34,864,308 $5,559,210 12 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $434 $85 $349 $139 34,977,306 $5,688,349 13 25000 10000 15000 : 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $443 $85 $358 $139 $5,092,563 $5,820,072 14 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $451 $85 $366 $139 $5,210,126 $5,954,429 15 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $460 $85 $375 $139 35,330,039 $6,091,473 16 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $470 $85 $385 $139 35,452,351 $6,231,259 17 25000 10000 15000 1 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $479 $85 $394 $139 35,577,109 $6,373,839 18 25000 10000 15000 • 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $489 $85 $404 $139 35,704,363 $6,519,272 19 25000 10000 15000 : 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $498 $85 $413 $139 35,834,161 $6,667,613 20 25000 10000 15000 : 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $508 $85 $423 $139 35,966,556 $6,818,921 21 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $519 $85 $434 $139 36,101,598 $6,973,255 22 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $529 $85 $444 $139 36,239,341 $7,130,676 23 25000 10000 15000 ; 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $540 $85 $455 $139 36,379,839 $7,291,245 24 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $550 $85 $465 $139 $6,523,147 $7,455,025 25 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $561 $85 $476 $139 56,669,321 $7,622,081 26 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $573 $85 $488 $139 36.818,419 $7,792,479 27 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $584 $85 $499 $139 $6,970,498 $7,966,284 28 25000 10000 15000 : 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $596 $85 $511 $139 $7,125,620 $8,143,565 29 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $608 $85 $523 $139 $7,283,843 $8,324,392 30 25000 750000 10000 300000 15000 450000 : 2352 70560 12648 379440 750000 5% 20% 13280.4 15177.6 2469.6 2822.4 $620 $85 $535 $139 37,445,231 $8,508,836 PRESENT VALUE: AMORTIZED COSTS, $/YEAR: COST PER ACRE-FOOT: $68,515,261 $78,303,156 $4,977,559 $5,688,639 $737 $842 File: N:\3892\0005\data\costmodeI01.xls Tab: MB10.0MGD 1 of 1 1/7/00 7:59 AM TABLE D-6 PROJECT CONCEPT-MISSION BASIN 10.0 MGD CONSTANT YIELD/SEASONAUCARRYOVER STORAGE/REGIONAL USE OF WEESE Total Low High Low High Estimated Required Reclaimed Imported Imported Imported Reclaimed Reclaimed Untreated Imported Reclaimed Low High WFP Total Natural Artificial Water Water Low High Water Water Water Water MWD LTS Water Water Recharge Recharge Water Extraction Recharge Recharge Recharge Recharge Loss Loss Recharge Recharge Recharge Recharge Rate Discount Cost Cost : Cost Cost Cost ;ar acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear % % acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear $/acre-ft $/acre-ft $/acre-ft $/acre-ft r ill m 1 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $349 $141 $208 $139 $3,106,734 $3,550,553 $3,908,800 2 25000 10000 15000 . 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $356 $141 $215 $139 $3,199,431 33,656,492 $3,986,976 3 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $363 $141 $222 $139 $3,293,982 $3,764,551 $4,066,716 4 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $370 $141 $229 $139 $3,390,424 $3,874,770 $4,148,050 5 25000 10000 15000 i 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $378 $141 $237 $139 $3,488,795 $3,987,194 $4,231,011 6 25000 10000 15000 . 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $385 $141 $244 $139 33,589,133 $4,101,867 $4,315,631 7 25000 10000 15000 ^ 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $393 $141 $252 $139 $3,691,479 $4,218,833 $4,401,944 8 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $401 $141 $260 $139 $344,410 $393,612 $4,489,983 9 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $409 $141 $268 $139 $344,410 3393,612 $4,579,782 10 25000 10000 15000 • 2352 27648 5% 20% 29030.4 33177.6 2469.6 2822.4 $417 $141 $276 $139 $8,359,335 $9,553,526 $4,671,378 11 25000 10000 15000 ' 2352 27648 5% 20% 29030.4 33177.6 2469.6 2822.4 $425 $141 $284 $139 $8,601,499 $9,830,285 $4,764,805 12 25000 10000 15000 2352 12648 5% 20% 13280.4 . 15177.6 2469.6 2822.4 $434 $141 $293 $139 $4,234,739 $4,839,702 $4,860,101 13 25000 10000 15000 • 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $443 $141 $302 $139 $4,349,997 $4,971,425 $4,957,304 14 25000 10000 15000 . 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $451 $141 $310 $139 34,467,559 $5,105,782 $5,056,450 15 25000 10000 15000 . 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $460 $141 $319 $139 34,587.473 $5,242,826 $5,157,579 16 25000 10000 15000 . 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $470 $141 $329 $139 $4,709,785 $5,382,611 $5,260,730 17 25000 10000 15000 ; 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $479 $141 $338 $139 $4,834,543 $5,525,192 $5,365,945 18 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $489 $141 $348 $139 $344,410 $393,612 $5,473,264 19 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $498 $141 $357 $139 $344,410 $393,612 $5,582,729 20 25000 10000 15000 2352 27648 5% 20% 29030.4 33177.6 2469.6 2822.4 $508 $141 $367 $139 $11,010,966 $12,583,961 $5,694,384 21 25000 10000 15000 - 2352 27648 5% 20% 29030.4 33177.6 2469.6 2822.4 $519 $141 $378 $139 $11,306,163 $12,921,329 $5,808,271 22 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $529 $141 $388 $139 $5,496,775 $6,282,028 $5,924,437 23 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $540 $141 $399 $139 $5,637,273 $6,442,597 $6,042,925 24 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $550 $141 $409 $139 $5,780,581 $6,606,378 $6,163,784 25 25000 10000 15000 • 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $561 $141 $420 $139 $5,926,755 $6,773,434 $6,287,060 26 25000 10000 15000 • 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $573 $141 $432 $139 $6,075,852 $6,943,831 $6,412,801 27 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $584 $141 $443 $139 $6,227,932 $7,117,637 $6,541,057 28 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $596 $141 $455 $139 $344,410 $393,612 $6,671,878 29 25000 10000 15000 0 0 5% 20% 0 0 2469.6 2822.4 $608 $141 $467 $139 $344,410 $393,612 $6,805,315 30 25000 750000 10000 300000 15000 450000 ' 2352 56448 27648 378552 735000 5% 20% 29030.4 33177.6 2469.6 2822.4 $620 $141 $479 $139 $14,243,289 $16,278,045 $6,941,422 PRESENT VALUE: AMORTIZED COSTS, $/YEAR: COST PER ACRE-FT: $58,165,515 $4,225,661 $296 $66,474,874 $4,829,327 $339 $318 $66,901,418 $4,860,315 $341 File: N:\3892\0005\data\costmodel.xlsTab: MB10.0WFP 1 of 1 1/6/00 3:37 PM TABLE D-6A PROJECT CONCEPT - MISSION BASIN 10.0 MGD CONSTANT YIELD/SEASONAUREGIONAL USE OF WEESE Total Low High Low High Estimated Required Reclaimed Imported Imported Imported Reclaimed Reclaimed Untreated Seasonal Imported Reclaimed Low High WFP Total Natural Artificial Water Water Low High Water Water Water Water MWD Storage Water Water Recharge Recharge Water Extraction Recharge Recharge Recharge Recharge Loss Loss Recharge Recharge Recharge Recharge Rate Discount Cost Cost Cost Cost Cost Year acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear % % acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear $/acre-ft $/acre-ft $/acre-ft $/acre-ft m 1 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $349 $85 $264 $139 $3,849,300 $4,399,200 $3,908,800 2 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $356 $85 $271 $139 $3,941,997 $4,505,140 $3,986,976 3 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $363 $85 $278 $139 $4,036,548 $4,613,198 $4,066,716 4 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $370 $85 $285 $139 $4,132,990 $4,723,418 $4,148,050 5 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $378 $85 $293 $139 $4,231,361 $4,835,842 $4,231,011 6 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $385 $85 $300 $139 $4,331,700 $4,950,514 $4,315,631 7 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $393 $85 $308 $139 $4,434,045 $5,067,480 $4,401,944 8 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $401 $85 $316 $139 $4,538,437 $5,186,785 $4,489,983 9 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $409 $85 $324 $139 $4,644,917 $5,308,477 $4,579,782 10 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $417 $85 $332 $139 $4,753,527 $5,432,602 $4,671,378 11 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $425 $85 $340 $139 $4,864,308 $5,559,210 $4,764,805 12 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $434 $85 $349 $139 $4,977,306 $5,688,349 $4,860,101 13 25000 10000 15000 . 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $443 $85 $358 $139 $5,092,563 $5,820,072 $4,957,304 14 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $451 $85 $366 $139 $5,210,126 $5,954,429 $5,056,450 15 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $460 $85 $375 $139 $5,330,039 $6,091,473 $5,157,579 16 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $470 $85 $385 $139 $5,452,351 $6,231,259 $5,260,730 17 25000 10000 15000 • 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $479 $85 $394 $139 $5,577,109 $6,373,839 $5,365,945 18 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $489 $85 $404 $139 $5,704,363 $6,519,272 $5,473,264 19 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $498 $85 $413 $139 $5,834,161 $6,667,613 $5,582,729 20 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $508 $85 $423 $139 $5,966,556 $6,818,921 $5,694,384 21 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $519 $85 $434 $139 $6,101,598 $6,973,255 $5,808,271 22 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $529 $85 $444 $139 $6,239,341 $7,130,676 $5,924,437 23 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $540 $85 $455 $139 $6,379,839 $7,291,245 $6,042,925 24 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $550 $85 $465 $139 $6,523,147 $7,455,025 $6,163,784 25 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $561 $85 $476 $139 $6,669,321 $7,622,081 $6,287,060 26 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $573 $85 $488 $139 $6,818,419 $7,792,479 $6,412,801 27 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $584 $85 $499 $139 $6,970,498 $7,966,284 $6,541.057 28 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $596 $85 $511 $139 $7,125,620 $8,143,565 $6,671,878 29 25000 10000 15000 2352 12648 5% 20% 13280.4 15177.6 2469.6 2822.4 $608 $85 $523 $139 $7,283,843 $8,324,392 $6,805,315 30 25000 750000 10000 300000 15000 450000 2352 70560 12648 379440 750000 5% 20% 13280.4 15177.6 2469.6 2822.4 $620 $85 $535 $139 $7,445,231 $8,508,836 $6,941,422 PRESENT VALUE: AMORTIZED COSTS, $/YEAR: COST PER ACRE-FOOT: $68,515,261 $4,977,559 $349 $78,303,156 $5,688,639 $399 $66,901,418 $4,860,315 $341 File: N:\3892\0005\data\costmodel01.xls Tab: MB10.0WFP 1 of 1 1/6/00 3:59 PM TABLE D-7 PROJECT CONCEPT-BONSALL BASIN 4.6 MGD CONSTAhTT YIELD/SEASONAUCARRYOVER STORAGE: Total Low Year High Estimated Required Reclaimed Imported Imported Imported Untreated Imported Low High Total Natural Artificial Water Water Low High Water Water MWD LTS Water Recharge Recharge Extraction Recharge Recharge Recharge Recharge Loss Loss Recharge Recharge Rate Discount Cost Cost Cost acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear acre-fl/vear %. % acre-ft/vear acre-ft/vear $/acre-ft S/acre-ft $/acre-ft III ISl 1 7300 2800 4500 acre-ft/vear 0 4500 5% 20% 4725 5400 $349 $141 $208 $982,800 $1,123,200 2 7300 2800 4500 0 4500 5% 20% 4725 5400 $356 $141 $215 $1,015,781 $1,160,892 3 7300 2800 4500 0 4500 5% 20% 4725 5400 $363 $141 $222 $1,049,421 $1,199,338 4 7300 2800 4500 0 4500 5% 20% 4725 5400 $370 $141 $229 $1.083,734 $1,238,553 S 7300 2800 4500 0 4500 5% 20% 4725 5400 $378 $141 $237 $1,118,733 $1,278,552 6 7300 2800 4500 0 4500 5% 20% 4725 5400 $385 $141 $244 $1,154,432 $1,319,351 7 7300 2800 4500 0 4500 5% 20% 4725 5400 $393 $141 $252 $1,190,845 $1,360,966 8 7300 2800 4500 0 0 5% 20% 0 0 $401 $141 $260 $0 $0 9 7300 2800 4500 0 0 5% 20% 0 0 $409 $141 $268 $0 $0 10 7300 2800 4500 0 9000 5% 20% 9450 10800 $417 $141 $276 $2,609,025 $2,981,743 11 7300 2800 4500 0 9000 5% 20% 9450 10800 $425 $141 $284 $2,687,855 S3.071.834 12 7300 2800 4500 0 4500 5% 20% 4725 5400 $434 $141 $293 $1,384,130 $1,581,863 13 7300 2800 4500 0 4500 5% 20% 4725 5400 $443 $141 S302 $1,425,137 $1,628.728 14 7300 2800 4500 0 4500 5% 20% 4725 5400 $451 $141 $310 $1,466,965 $1,676,531 15 7300 2800 4500 0 4500 5% 20% 4725 5400 $460 $141 $319 $1.509.628 $1,725,290 16 7300 2800 4500 0 4500 5% 20% 4725 5400 $470 $141 $329 $1,553,146 $1.775.023 17 7300 2800 4500 0 4500 5% 20% 4725 5400 $479 $141 $338 $1,597,533 $1.825,752 18 7300 2800 4500 0 0 5% 20% 0 0 $489 $141 $348 $0 $0 19 7300 2800 4500 0 0 5% 20% 0 0 $498 $141 $357 $0 SO 20 7300 2800 4500 0 9000 5% 20% 9450 10800 $508 $141 S367 $3,472,186 $3,968,213 21 7300 2800 4500 0 9000 5% 20% 9450 10800 $519 $141 $378 $3,568,279 $4,078,033 22 7300 2800 4500 0 4500 5% 20% 4725 5400 $529 $141 $368 $1,833,147 $2,095,025 23 7300 2800 4500 0 4500 5% 20% 4725 5400 $540 $141 $399 $1,883,134 $2,152,153 24 • 7300 2800 4500 0 4500 5% 20% 4725 5400 $550 $141 $409 $1,934,121 $2,210,424 25 7300 2800 4500 0 4500 5% 20% 4725 5400 $561 $141 $420 $1,986,128 $2,269,861 26 7300 2800 4500 0 4500 5% 20% 4725 5400 $573 $141 $432 $2,039,175 $2,330,486 27 7300 2800 4500 0 4500 5% 20% 4725 5400 $584 $141 $443 $2,093,283 $2,392,324 28 7300 2800 4500 0 0 5% 20% 0 0 $596 $141 $455 $0 SO 29 7300 2800 4500 0 0 5% 20% 0 0 $608 $141 $467 . SO SO 30 7300 219000 2800 84000 4500 135000 0 0 9000 130500 214500 5% 20% 9450 10800 $620 $141 $479 $4,524,375 $5,170,714 PRESENT VALUE: AMORTIZED COSTS. $/YEAR: COST PER ACRE-FT: $18,469,252 $21,107,717 $1,341,771 $1,533,453 $370 $423 $396 File; N:\3892\0005\data\costmodel.xls Tab; BB4.60MGD 1 of 1 1/6/00 3:41 PM TABLE D-7A PROJECT CONCEPT • BONSALL BASIN 4.6 MGD CONSTANT YIELD/SEASONAL STORAGE: Total Low High Estimated Required Reclaimed Imported Imported Imported Seasonal Imported Total Natural Artificial Water Water Low High Water Water MWD Storage Water Low High Extraction Recharge Recharge Recharge Recharge Loss Loss Recharge Recharge Rate Discount Cost Cost Cost Year acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear acre-ft/vear % %. acre-ft/vear acre-ft/vear $/acre-ft $/acre-ft S/acre-ft m 1 7300 2800 4500 acre-ft/vear 0 4500 5% 20% 4725 5400 $349 $85 $264 $1,247,400 $1,425,600 2 7300 2800 4500 0 4500 5% 20% 4725 5400 $356 $85 $271 $1,280,381 $1,463,292 3 7300 2800 4500 0 4500 5% 20% 4725 5400 $363 $85 $278 $1,314,021 $1,501,738 4 7300 2800 4500 0 4500 5% 20% 4725 5400 $370 $85 $285 $1,348,334 $1,540,953 5 7300 2800 4500 0 4500 5% 20% 4725 5400 $378 $85 $293 $1,383,333 $1,580,952 6 7300 2800 4500 0 4500 5% 20% 4725 5400 $385 $85 $300 $1,419,032 $1,621,751 7 7300 2800 4500 0 4500 5% 20% 4725 5400 $393 $85 $308 $1,455,445 $1,663,366 8 7300 2800 4500 0 4500 5% 20% 4725 5400 $401 $85 $316 SI .492,586 $1,705,813 9 7300 2800 4500 0 4500 5% 20% 4725 5400 $409 $85 $324 $1,530,471 $1,749,109 10 7300 2800 4500 0 4500 5% 20% 4725 5400 $417 $85 $332 $1,569,113 $1,793,271 11 7300 2800 4500 0 4500 5% 20% 4725 5400 $425 $85 $340 $1,608,527 $1,838,317 12 7300 2800 4500 0 4500 5% 20% 4725 5400 $434 $85 $349 $1,648,730 $1,884,263 13 7300 2800 4500 0 4500 5% 20% 4725 5400 $443 $85 $358 $1,689,737 $1,931,128 14 7300 2800 4500 0 4500 5% 20% 4725 5400 $451 $85 $366 $1,731,565 $1,978,931 15 7300 2800 4500 0 4500 5% 20% 4725 5400 $460 $85 $375 $1,774,228 $2,027,690 16 7300 2800 4500 0 4500 5% 20% 4725 5400 $470 $85 $385 $1,817,746 $2,077,423 17 7300 2800 4500 0 4500 5% 20% 4725 5400 $479 $85 $394 $1,662,133 $2,128,152 18 7300 2800 4500 0 4500 5% 20% 4725 5400 $489 $85 $404 $1,907,408 $2,179,895 19 7300 2800 4500 0 4500 5% 20% 4725 5400 $498 $85 $413 $1,953,589 $2,232,673 20 7300 2800 4500 0 4500 5% 20% 4725 5400 $508 $85 $423 $2,000,693 $2,286,506 21 7300 2800 4500 0 4500 5% 20% 4725 5400 $519 $85 $434 $2,048,739 $2,341,416 22 7300 2800 4500 0 4500 5% 20% 4725 5400 $529 $85 $444 $2,097,747 $2,397,425 23 7300 2800 4500 0 4500 5% 20% 4725 5400 $540 $85 $455 $2,147,734 $2,454,553 24 7300 2800 4500 0 4500 5% 20% 4725 5400 $550 $85 $465 $2,198,721 $2,512,824 25 7300 2800 4500 0 4500 5% 20% 4725 5400 $561 $85 $476 $2,250,728 $2,572,261 26 7300 2800 4500 0 4500 5% 20% 4725 5400 $573 $85 $488 $2,303,775 $2,632,886 27 7300 2800 4500 0 4500 5% 20% 4725 5400 $584 $85 $499 $2,357,883 $2,694,724 .28 7300 2800 4500 0 4500 5% 20% 4725 5400 $596 $85 $511 $2,413,073 $2,757,798 29 7300 2800 4500 0 4500 5% 20% 4725 5400 $608 $85 $523 $2,469,367 $2,822,134 30 7300 219000 2800 84000 4500 135000 0 0 4500 135000 219000 5% 20% 4725 5400 $620 $85 $535 $2,526,787 $2,887,757 PRESENT VALUE: AMORTIZED COSTS, $/YEAR: COST PER ACRE-FOOT: $22,695,735 $1,648,820 $454 $25,937,983 $1,884,366 $519 $487 Fllo: N;\3B92\0005\dntn\cosIniodol01.xls Tnb: DD4.60MGD 1 ol 1 1/7/00 8:01 AM RECLAIMED WA TER COST ESTIMA TE PRODUCTION RATE (ANNUAL AVERAGE) 2 MGD 2240 AF/YR CAPITAL COSTS: TERTIARY FILTERS $ 600,000 UV DISINFECTION $ 1,000,000 MISC MECHANICAL/BLDG $ 750,000 CONTINGENCY/UNKNOWNS $ 1.350,000 TOTAL CAPITAL COST $ 3.700,000 ****DOES NOT INCLUDE RECLAIMED WATER RESERVOIR OR PUMP STATION ANNUAL OPERATING COST $ 600.000 INTEREST 6% TERM 30 YR Amortized Annual Present Worth Amortized Annual Total Facilities Cost Facilities Cost of O&M Costs O&M Cost O&M Cost Cost ($/vear) f$/acre-ft) \^ f$/vear) f$/acre-m ($/acre-ft) $268,801 $120.00 $8,258,899 $43,589 $19.46 $139