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