WHEREAS, the Indio Subbasin GSAs have jointly developed an Indio Subbasin Water Management Plan Update: Sustainable Groundwater Management Act (SGMA) Alternative Plan (Alternative Plan Update) for the Indio Subbasin and on September 27, 2021, released the Alternative Plan Update for public comment; and
WHEREAS, Coachella Water Authority GSA conducted a public hearing on December 8, 2021 for the purpose of receiving comments and considering adoption of the Alternative Plan Update for the Indio Subbasin; and
WHEREAS, Water Code section 10733.6 requires that Alternative Plan Updates be submitted to DWR for review.
NOW, THEREFORE, BE IT RESOLVED by the Board of Directors of Coachella Water Authority GSA as follows:
1. The foregoing recitals are true and correct and made an operative part of this Resolution.
2. The Alternative Plan Update for the Indio Subbasin of the Coachella Valley Groundwater Basin is hereby approved and adopted, subject to such minor, non-substantive modifications to the text agreed upon by the four Indio Subbasin GSAs prior to submittal to DWR on or before December 31, 2021. A copy of the 2022 Alternative Plan Update is attached hereto and incorporated herein by reference.
3. The Board of Directors hereby designates Dr. Gabriel Martin, or his designee, to be the Plan Manager who is authorized and directed to timely provide notification of this approval and adoption to DWR, including a copy of this Resolution, the approved Alternative Plan Update, and any additional information/documentation required by law.
PASSED, APPROVED and ADOPTED this 8th day of December 2021.
___________________________________
Steven A Hernandez
President
ATTEST:
___________________________________
Angela M. Zepeda
Secretary
Resolution No. WA-2021-10
APPROVED AS TO FORM:
___________________________________
Carlos Campos
Authority Attorney
STATE OF CALIFORNIA )
COUNTY OF RIVERSIDE ) ss.
CITY OF COACHELLA )
I HEREBY CEERTIFY that the foregoing Resolution No. W A-2021-10 was duly adopted by the Board of Directors of the Coachella Water Authority at a regular meeting thereof held on the gth day of December 2021, by the following vote of the Board:
A YES: Authority Member Delgado, Authority Member Galarza, Vice President Gonzalez, and President Hernandez.
NOES: None.
ABSENT: Authority Member Beaman Jacinto.
ABSTAIN: None.
Deputy City Clerk
Resolution No. W A-2021-10
Page4
Resolution No. 1267
RESOLUTION NO. 1267
RESOLUTION OF THE BOARD OF DIRECTORS OF
DESERT WATER AGENCY ADOPTING THE 2022 INDIO SUBBASIN
WATER MANAGEMENT PLAN UPDATE
SUSTAINABLE GROUNDWATER MANAGEMENT ACT (SGMA)
ALTERNATIVE PLAN
WHEREAS, the California Legislature enacted a statewide framework for sustainable groundwater management, known as the Sustainable Groundwater Management Act (California Water Code section 10720 et seq.), pursuant to Senate Bill 1168, Senate Bill 1319, and Assembly Bill 1739, which was approved by the Governor and Chaptered by the Secretary of State on September 16, 2014; and
WHEREAS, the Sustainable Groundwater Management Act (SGMA) went into effect on January 1, 2015; and
WHEREAS, SGMA requires all medium- and high-priority groundwater basins, as designated by the California Department of Water Resources (DWR) Bulletin 118, to be managed by a Groundwater Sustainability Agency (GSA) or multiple GSAs; and
WHEREAS, the Indio Subbasin of the Coachella Valley Groundwater Basin has been designated by DWR as a medium-priority basin (DWR Bulletin 118 No. 7-021.01); and
WHEREAS, Desert Water Agency elected on November 17, 2015 to become a GSA for the Indio Subbasin of the Coachella Valley Groundwater Basin; and
WHEREAS, a Memorandum of Understanding (MOU) dated October 5, 2016 was entered into among the following entities (Partners): the City of Coachella, acting through, and on behalf of, the Coachella Water Authority (CWA); the Coachella Valley Water District (CVWD); the Desert Water Agency (DWA); and the City of Indio, acting through, and on behalf of, the Indio Water Authority (IWA).
The purpose of the MOU is to develop a common understanding among the Partners regarding the governance structures applicable to implementation of SGMA in the Indio Subbasin; and
WHEREAS, each of the Partners has become a GSA for its service area overlying the Indio Subbasin; and
WHEREAS, on December 29, 2016, the Partners collaboratively submitted an Alternative to a Groundwater Sustainability Plan (Alternative Plan) for the Indio Subbasin to DWR in accordance with Water Code section 10733.6; and
WHEREAS, on July 17, 2019, DWR determined that the Alternative Plan for the Indio Subbasin satisfies the objectives of SGMA and notified the Indio Subbasin GSAs that the Alternative Plan was approved, and that they would be required to submit an assessment and update of the Alternative Plan by January 1, 2022, and every five years thereafter; and
WHEREAS, the Indio Subbasin GSAs have jointly developed an Indio Subbasin Water Management Plan Update: Sustainable Groundwater Management Act (SGMA) Alternative Plan
Reso. 1267
Resolution No. 1267
(Alternative Plan Update) for the Indio Subbasin and on September 27, 2021, released the Alternative Plan Update for public comment; and
WHEREAS, Desert Water Agency conducted a public hearing on December 7, 2021 for the purpose of receiving public comments and considering adoption of the Alternative Plan Update for the Indio Subbasin; and
WHEREAS, Water Code section 10733.6 requires that Alternative Plan Updates be submitted to DWR for review; and
WHEREAS, this resolution and approval of the Alternative Plan Update are not subject to the California Environmental Quality Act (CEQA) pursuant to California Code of Regulations (CCR) 15262 and SGMA 10728.6 because CEQA does not apply to planning studies for possible future actions not yet approved, adopted, or funded by this Agency (CCR 15262) or to the preparation and adoption of plans pursuant to SGMA (SGMA 10728.6), and because projects to implement actions taken pursuant to the Alternative Plan will be analyzed in accordance CEQA based on the nature of the project, environmental setting and potential environmental impacts before those projects are approved.
NOW, THEREFORE, BE IT RESOLVED by the Board of Directors of Desert Water Agency as follows:
1. The foregoing recitals are true and correct and made an operative part of this Resolution.
2. The Alternative Plan Update for the Indio Subbasin of the Coachella Valley Groundwater Basin is hereby approved and adopted, subject to minor, non-substantive modifications to the text agreed upon by the four Indio Subbasin GSAs prior to submittal to DWR on or before December 31, 2021. A copy of the 2022 Alternative Plan Update is attached hereto and incorporated herein by reference.
3. The Board of Directors hereby designates CVWD to provide notification of this approval and adoption to DWR, including a copy of this Resolution, the approved Alternative Plan Update, and any additional information/documentation required by law.
ADOPTED this 7th day of December 2021.
_______________________________
Kristin Bloomer, President
ATTEST:
______________________________
Joseph K. Stuart, Secretary-Treasurer
X:\Sylvia\Ordinances & Resolutions\Resolutions\Res 1267 - Indio SGMA Alt Plan attach links.docx
RESOLUTION NO. 1267
LINK TO INDIO SUBBASIN WATER
MANAGEMENT PLAN UPDATE SGMA
ALTERNATIVE PLAN
http://www.indiosubbasinsgma.org/wp-
content/uploads/2021/12/Indio-SGMA-
AlternativePlan-vol1-Alternative-Plan-FINAL-to-be-
Adopted-Nov-2021v3.pdf
AND
http://www.indiosubbasinsgma.org/wp-
content/uploads/2021/11/Indio-SGMA-
AlternativePlan-vol2-Appendices-FINAL-to-be-
Adopted-Nov-2021v2.pdf
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Proof of Publication
In Newspaper
STATE OF CALIFORNIA
County of Riverside
1. I am a citizen of the United States, a
resident of the City of La Quinta, County of
Riverside, State of California, and over the
age of 18 years.
2. I am the Administrator of Production
of The Public Record, a newspaper of
general circulation printed and published in
the City of Palm Springs, County of River-
side, State of California. Said The Public Re-
cord is a newspaper of general circulation
as that term is defined in Government Code
section 6000, its status as such having been
established by judicial decree of the Supe-
rior Court of the State of California in and for
the County of Riverside in Proceeding No.
Indio 49271, dated March 31, 1987, entered
in Judgment Book No. 129, page 355, on
March 31, 1987.
3. The Public Record is a newspaper of gen-
eral circulation ascertained and established
in the City of Palm Springs in the County of
Riverside, State of California.
4. The notice, of which the annexed is a true
printed copy was published in the news-
paper on the following publication dates to
with:
November 30, 2021
I Certify under penalty of perjury that the
above is true and correct.
30th Day of November 2021.
The Public Record
Administration
[email protected]
indio SubbaSin
NOTICE OF PUBLIC HEARINGNOTICE IS HEREBY GIVEN that the Indio Subbasin Groundwater Sustainability Agencies (the “GSAs”) will conduct individual public hearings to consider adoption of the 2022 Indio Subbasin Water Management Plan: Sustainable Groundwater Management Act (the “SGMA”) Alternative Plan (the “2022 Alternative Plan Update”). Oral or written comments may be provided in-person at the public hearings. Individuals may also submit written comments to the GSA Contact in advance of the meeting. The agenda is posted at least 72 hours in advance of the public hearing and can be found on the GSA website. You may also email the GSA Contact for additional information regarding public hearing participation.
GSA
Desert Water Agency( www.dwa.org)
Coachella Valley Water District (cvwd.org)
Coachella Water Authority
Indio Water Authority ( www.indio.org)
Location of Public HearingVirtual
In-person: Steve Robbins Administration Building75515 Hovley Ln E, Palm Desert, CA 92211Virtual – check agenda for Zoom details In-Person Meeting Location:Coachella City HallCouncil Chamber1515 Sixth StreetCoachella, CA Virtual – check agenda for Zoom details
In-person:City of Indio Council Chamber, 150 Civic Center Mall, Indio, CA 92201 Virtual – check agenda for Zoom details
Date and Time
December 7, 2021, starting at 8:00 AM
December 7, 2021, starting at 8:30 AM or as soon thereafter December 8, 2021 starting at 6:00 PM at
December 15, 2021, starting at 5:00 PM
ContactSylvia Baca, Board Secretary, PO Box 1710, Palm Springs, CA 92263 [email protected](760) 323-4971 ext. 114 Sylvia Bermudez, Clerk of the BoardPO Box 1058 Coachella, CA 92236 [email protected] 760.398.2651 Elected City ClerkCoachella Civic Center – 53990 Enterprise Way, Coachella, CA 92236 or via email at: [email protected] 760) 398-3502 Sabdi Sanchez, CMC, City Clerk Administrator, 100 Civic Center Mall, Indio, CA 92201 or via email at [email protected] The SGMA law requires the GSAs to update the Indio Subbasin Alternative Plan every five years with the current update due to the California Department of Water Resources by January 1, 2022. The 2022 Indio Subbasin Alternative Plan Update describes the region’s water supplies and anticipated demands through 2045, and presents the GSAs plan for maintaining groundwater sustainability as required by the SGMA. The draft 2022 Indio Subbasin Alternative Plan Update is available for inspection at IndioSubbasinSGMA.org. November 30, 2021 TPR21-2001
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APPENDIX 2-A
WORKPLAN TO DEVELOP THE COACHELLA VALLEY SALT AND NUTRIENT
MANAGEMENT PLAN AND GROUNDWATER MONITORING WORKPLAN
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PREPARED BY
Workplan to Develop the
Coachella Valley Salt and Nutrient Management Plan
PREPARED FOR
The Coachella Valley SNMP Agencies
FINAL WORKPLAN | SEPTEMBER 2, 2021
FINAL WORKPLAN | SEPTEMBER 2, 2021
EARYEAR2020
Workplan to Develop the
Coachella Valley
Salt and Nutrient Management Plan
Prepared for
The Coachella Valley SNMP Agencies
Project No. 943-80-20-01
Sept 2, 2021
Project Manager: Andy Malone, PG Date
Sept 2, 2021
QA/QC Review: Samantha Adams Date
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Table of Contents
Background and Objectives of the CV-SNMP ................................................................................. 1
1.1 Regulatory Framework ..................................................................................................................... 1
1.1.1 2009 Recycled Water Policy .................................................................................................... 1
1.1.2 2018 Recycled Water Policy .................................................................................................... 2
1.2 2015 Coachella Valley Salt and Nutrient Management Plan ............................................................ 4
1.2.1 Overview of the 2015 SNMP ................................................................................................... 4
1.2.2 Regional Board Response to the 2015 SNMP ......................................................................... 5
1.3 Update of the CV-SNMP ................................................................................................................... 7
1.3.1 Process to Prepare the CV-SNMP Development Workplan .................................................... 7
1.3.2 Workplan Organization ........................................................................................................... 9 Study Area Setting ...................................................................................................................... 11
2.1 Basin Setting ................................................................................................................................... 11
2.2 Hydrogeology ................................................................................................................................. 11
2.2.1 Subbasins and Subareas ........................................................................................................ 11
2.2.2 Occurrence and Movement of Groundwater ....................................................................... 12
2.3 Origin and Fate and Transport of N/TDS ........................................................................................ 13
2.3.1 Loading of N/TDS .................................................................................................................. 13
2.3.2 Transport and Discharge of N/TDS in the Saturated Zone ................................................... 14 CV-SNMP Groundwater Monitoring Program Workplan .............................................................. 19
3.1 Groundwater Monitoring Network ................................................................................................ 19
3.1.1 Methods for Selection of the Groundwater Monitoring Network ....................................... 20
3.1.2 Monitoring Network and Gaps – Shallow Aquifer System ................................................... 20
3.1.3 Monitoring Network and Gaps – Deep Aquifer System ....................................................... 21
3.1.4 Monitoring Network and Gaps – Perched Aquifer System ................................................... 21
3.2 Chemical Analytes and Sampling Frequency .................................................................................. 21
3.3 Monitoring and Reporting .............................................................................................................. 21
3.3.1 Groundwater Sampling and Laboratory Analysis ................................................................. 21
3.3.2 Reporting of Laboratory Results ........................................................................................... 22
3.4 Filling of Gaps in the Monitoring Network ..................................................................................... 22 CV-SNMP Development Workplan .............................................................................................. 37
4.1 Select Consultants for CV-SNMP Facilitation and Technical Services ............................................ 38
4.2 Establish CV-SNMP Stakeholder Group and Technical Advisory Committee ................................. 39
4.2.1 Convene the CV-SNMP Stakeholder Group .......................................................................... 39
4.2.2 Convene the CV-SNMP Technical Advisory Committee........................................................ 40
4.3 Characterize N/TDS Loading to the Groundwater Basin ................................................................ 41
4.3.1 Collect Data and Information ................................................................................................ 41
4.3.2 Characterize Historical and Current N/TDS Loading ............................................................. 42
4.3.3 Prepare Task Memorandum ................................................................................................. 42
4.4 Characterize Current Groundwater Quality ................................................................................... 43
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Table of Contents
4.4.1 Collect Data and Information ................................................................................................ 44
4.4.2 Prepare Tables, Maps, and Data Graphics ............................................................................ 44
4.4.3 Prepare Task Memorandum ................................................................................................. 46
4.5 Delineate Draft Management Zones and Describe Metrics to Characterize Beneficial Use Protection ............................................................................................................................................. 47
4.5.1 Delineate Draft Groundwater Management Zones .............................................................. 48
4.5.2 Describe Beneficial Uses for Management Zones and Beneficial-Use Thresholds ............... 48
4.5.3 Define AWQ Metrics and Determine Current Protection of Beneficial Uses ....................... 48
4.5.4 Prepare Task Memorandum ................................................................................................. 49
4.6 Develop Technical Approach for Forecasting N/TDS Concentrations in Groundwater ................. 49
4.6.1 Evaluate Existing MODFLOW Models ................................................................................... 50
4.6.2 Develop Procedures for Simulating Vadose Zone Processes ................................................ 51
4.6.3 Define the Appropriate Planning Period ............................................................................... 51
4.6.4 Develop Procedures for Simulating Feedback Processes ..................................................... 51
4.6.5 Define Assumptions for Future N/TDS Concentration of Colorado River Water ................. 51
4.6.6 Develop Procedures for Verifying the N/TDS Forecasting Tools .......................................... 52
4.6.7 Develop Procedures for Post-Processing Model Results ...................................................... 52
4.6.8 Prepare Task Memorandum ................................................................................................. 52
4.7 Construct N/TDS Forecasting Tools and Evaluate the Baseline Scenario ....................................... 53
4.7.1 Develop a Baseline Scenario based on the SGMA Alternative Plans .................................... 53
4.7.2 Construct N/TDS Forecasting Tools and Run the Baseline Scenario ..................................... 53
4.7.3 Prepare Task Memorandum ................................................................................................. 54
4.8 Forecast N/TDS Concentrations for CV-SNMP Scenarios ............................................................... 55
4.8.1 Evaluate Baseline Scenario Results and Recommend Implementation Measures ............... 56
4.8.2 Evaluate CV-SNMP Scenarios ................................................................................................ 56
4.8.3 Prepare Task Memorandum ................................................................................................. 57
4.9 Characterize and Compare the Cost of Baseline and CV-SNMP Scenarios .................................... 57
4.9.1 Develop Cost-Estimating Planning Criteria and a Cost Model .............................................. 57
4.9.2 Develop Cost Estimates for the Baseline and CV-SNMP Scenarios ...................................... 58
4.9.3 Prepare Task Memorandum ................................................................................................. 58
4.10 Select the Preferred CV-SNMP Scenario, Finalize Management Zones and Beneficial Uses, and Recommend TDS Objectives ................................................................................................................ 58
4.10.1 Evaluate All Forecasted Information and Select a Preferred CV-SNMP Scenario .............. 59
4.10.2 Recommend TDS Objectives based on CWC 13241 ............................................................ 59
4.10.3 Document Antidegradation Demonstration Pursuant to State Board Policy 68-16 ........... 60
4.10.4 Prepare Task Memorandum ............................................................................................... 60
4.11 Prepare Final CV-SNMP ................................................................................................................ 61 CV-SNMP Development Workplan Implementation ..................................................................... 69
5.1 Schedule ......................................................................................................................................... 69
5.2 Progress Reporting to the Regional Board ..................................................................................... 70
5.3 Cost Estimates ................................................................................................................................ 70
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Table of Contents
LIST OF TABLES
Table 3-1. SNMP Groundwater Monitoring Network – Shallow Aquifer System ................................ 24 Table 3-2. SNMP Groundwater Monitoring Network – Deep Aquifer System ..................................... 26 Table 3-3. SNMP Groundwater Monitoring Network – Perched Aquifer System ................................ 28 Table 3-4. Gaps in SNMP Groundwater Monitoring Network ............................................................. 29 Table 3-5. Analyte List for the SNMP Groundwater Monitoring Program ........................................... 30 Table 3-6. Responsibilities for Groundwater Sampling and Laboratory Analyses ............................... 31 Table 4-1. CV-SNMP Development Workplan Compliance with the 2018 Recycled Water Policy ...... 63 Table 5-1. CV-SNMP Development Workplan Implementation Schedule ........................................... 69 Table 5-2. Cost Estimates to Implement the CV-SNMP Development Workplan ............................... 71 Table 5-3. Cost Estimates to Implement the CV-SNMP Groundwater Monitoring Program ............... 71
LIST OF FIGURES
Figure 1-1. Area Subject to the Coachella Valley Salt and Nutrient Management Plan ...................... 10 Figure 2-1. Basin Setting ....................................................................................................................... 15 Figure 2-2. Hydrogeologic Map ............................................................................................................ 16 Figure 2-3. Generalized Stratigraphic Column in Lower Coachella Valley ........................................... 17 Figure 2-4. Salt and Nutrient Loading, Transport, and Discharge ........................................................ 18 Figure 3-1. Groundwater Monitoring Network and Gaps – Shallow Aquifer System .......................... 34 Figure 3-2. Groundwater Monitoring Network – Deep Aquifer System ............................................... 35 Figure 3-3. Groundwater Monitoring Network and Gaps – Perched Aquifer System .......................... 36 Figure 4-1. Conceptual Chart to Characterize Beneficial Use Protection in a Management Zone ...... 64 Figure 4-2. Conceptual Evaluation of a Hypothetical Baseline Scenario in a Management Zone ....... 65 Figure 4-3. Conceptual Evaluation of Hypothetical SNMP Scenario #1 in a Management Zone ......... 66 Figure 4-4. Conceptual Evaluation of Hypothetical SNMP Scenario #2 in a Management Zone ......... 67 Figure 4-5. Selection of a Hypothetical SNMP Scenario and TDS Objective in a Management Zone .. 68 Figure 5-1. Implementation of the CV-SNMP Development Workplan ............................................... 70
LIST OF APPENDICES
Appendix A. Groundwater Monitoring Program Workplan – Coachella Valley Salt and Nutrient Management Plan Update (December 23, 2020)
Appendix B. Example Maps and Data Graphics to Characterize Groundwater Quality Appendix C. Responses to Comments on the Draft CV-SNMP Development Workplan
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Table of Contents
LIST OF ACRONYMS AND ABBREVIATIONS
AWQ Ambient Water Quality
CPS City of Palm Springs
CV-SNMP Salt and Nutrient Management Plan for the Coachella Valley Groundwater Basin CVSC Coachella Valley Stormwater Channel
CVWD Coachella Valley Water District
CWA/CSD Coachella Water Authority and Coachella Sanitary District CWC California Water Code
DWA Desert Water Agency
DWR California Department of Water Resources
ft-bgs Feet below ground surface
IWA Indio Water Authority
GAMA Groundwater Ambient Monitoring & Assessment
GIS Geographic Information System
MC-GRF Mission Creek Groundwater Replenishment System
MDMWC Myoma Dunes Mutual Water Company
MOU Memorandum of Understanding
MSWD Mission Springs Water District
NGO Non-Governmental Organization
N/TDS Nitrate and TDS
O&M Operations and Maintenance
PD-GRF Palm Desert Groundwater Replenishment Facility
POTW Publicly Owned Treatment Works
RFP Request for Proposals
RFQ Request for Qualifications
SGMA Sustainable Groundwater Management Act of 2014
TAC Technical Advisory Committee
TDS Total Dissolved Solids
TEL-GRF Thomas E. Levy Groundwater Replenishment Facility USGS United States Geological Survey
VSD Valley Sanitary District
WRP Water Reclamation Plant
WW-GRF White Water Groundwater Replenishment Facility
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CV-SNMP Development Workplan
BACKGROUND AND OBJECTIVES OF THE CV-SNMP
The Regional Water Quality Control Board for the Colorado River Basin (Regional Board) is requiring the development of a Salt and Nutrient Management Plan for the Coachella Valley Groundwater Basin (CV- SNMP). The objective of the CV-SNMP is to sustainably manage salt and nutrient loading in the Coachella Valley Groundwater Basin (Basin) in a manner that protects its beneficial uses.
In 2015, a CV-SNMP was submitted to the Regional Board (2015 SNMP); however, the Regional Board found the 2015 SNMP insufficient (see Section 1.2 below). This document is a workplan to update the 2015 SNMP (CV-SNMP Development Workplan). It was prepared on behalf the City of Coachella Sanitary District (CSD), City of Palm Springs (Palm Springs), Coachella Valley Water District (CVWD), Coachella Water Authority (CWA), Desert Water Agency (DWA), Indio Water Authority (IWA), Mission Springs Water District (MSWD), Myoma Dunes Mutual Water Company (MDMWC), and Valley Sanitary District (VSD), collectively the CV-SNMP Agencies.
This CV-SNMP Development Workplan defines the scope of work that the CV-SNMP Agencies will follow to update the 2015 SNMP and implement a supporting monitoring and reporting program. The intent is to develop the CV-SNMP in a collaborative approach with the Regional Board, including stakeholder and public outreach and involvement.
Figure 1-1 is a map that defines spatial extent of the Basin that is subject to the CV-SNMP. The Basin is located within the northwest portion of the Salton Sea Watershed (USGS Hydrologic Unit 18100200) and is the Coachella Valley Groundwater Basin as delineated by the California Department of Water Resources (DWR Groundwater Basin No. 7-021), but excludes the San Gorgonio Pass Subbasin (DWR Subbasin 7- 021.04). Hence, the Basin, as defined for the CV-SNMP, is comprised of three of the four DWR Subbasins:
the Indio Subbasin (DWR Subbasin 7-021.01), the Mission Creek Subbasin (7-021.02), and the Desert Hot Springs Subbasin (7-021.03).
The remainder of this section includes a description of the regulatory framework behind the requirements for the CV-SNMP, the results of past efforts to develop the CV-SNMP, an overview of the process to prepare this CV-SNMP Development Workplan, and the organization of this report.
1.1 Regulatory Framework
1.1.1 2009 Recycled Water Policy
The statewide requirement to develop SNMPs for groundwater basins in California was first promulgated in 2009 when the State Water Resources Control Board (State Board) adopted the Recycled Water Policy1 (2009 Policy). The purpose of the 2009 Policy was to encourage increased use of recycled water in a manner that implements state and federal water quality laws. To accomplish this, the 2009 Policy included, among other provisions, a requirement to prepare SNMPs such that "salts and nutrients from all sources be managed on a basin-wide or watershed-wide basis in a manner that ensures attainment of water quality objectives and protection of beneficial uses." The 2009 Policy recognized that all groundwater basins are different in size, hydrogeologic complexity, and loading factors, which
1 State Water Resources Control Board Resolution No. 2009-0011. Adoption of a Policy for Water Quality Control for Recycled Water. February 3, 2009.
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necessitates locally-driven stakeholder efforts to define an appropriate SNMP that addresses the region- specific conditions.
The 2009 Policy defined general guidelines for preparing SNMPs, including the following required components:
• A basin/sub-basin-wide monitoring plan that includes an appropriate network of wells for assessing water quality and determining whether the concentrations of salts and nutrients are consistent with applicable water quality objectives. • Description of water recycling goals and objectives.
• Identification of salt and nutrient sources, and estimation of salt and nutrient loading, basin assimilative capacity, and the fate and transport of salt and nutrients. • Description of implementation measures to manage salt and nutrient loading in the basin on a sustainable basis.
• An antidegradation analysis to demonstrate that the implementation measures included within the plan will collectively satisfy the requirements of State Board Resolution 68-16 (the Antidegradation Policy).
The 2009 Policy acknowledged that not all Regional Board Water Quality Control Plans (Basin Plans) included adequate implementation measures for achieving or ensuring compliance with the water quality objectives for salts or nutrients. In addition, the 2009 Policy did not specify the methods or approaches for performing the above listed SNMP analyses. In this way, it implicitly left it to the SNMP stakeholders to define, and the Regional Boards to approve, the SNMP methods and approaches that are appropriate for the local area and the Basin Plan.
The initial deadline for completing SNMPs pursuant to the 2009 Policy was April 2014, with the option to apply for an extension through April 2016.
1.1.2 2018 Recycled Water Policy
In December 2016, the State Board adopted Resolution No. 2016-00612, which directed staff to propose amendments to the 2009 Policy, in part, to improve the SNMP guidelines based on lessons learned over the first seven years of implementation. Among the requested amendments was the inclusion of revised goals and mandates for statewide use of recycled water, clarification of recycled water monitoring and reporting requirements, recommendations for the development of representative, basin-wide groundwater monitoring networks, and an evaluation of the frequency of priority pollutant monitoring in recycled water (2018 Policy).
The State Board Staff Report supporting the 2018 Policy amendments identified the administrative and technical challenges in the development of SNMPs since 2009.3 Some of the administrative challenges identified included:
2 State Water Resources Control Board Resolution No. 2061-0061. To Reaffirm Support for the Development of Salt and Nutrient Management Plans and Direct Staff to Initiate a Stakeholder Process to Update the Recycled Water Policy. December 6, 2016. 3 State Water Resources Control Board. 2018. Final Staff Report with Substitute Environmental Documentation, Amendment to the Recycled Water Policy. December 11, 2018.
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• The incentives for participation in the SNMPs were tied to recycled water projects, which resulted in:
o Lack of involvement from key stakeholders representing major contributions to salt and nutrient loading.
o SNMPs not being developed in areas with limited or no recycled water reuse. • Management plans with implementation measures for which the stakeholders lack the regulatory authority to enforce or implement the measures.
Technical challenges included:
• A lack of readily available, representative groundwater monitoring data to assess water quality conditions. For example, monitoring programs that relied solely on deep municipal production wells for data would exclude shallow portions of the aquifer system. • Most SNMPs relied upon overly simplistic mass-balance approaches to assess current and future assimilative capacity in the basin. These simplistic approaches assumed complete mixing of salt and nutrient loads in the basin, which is not typically representative of what occurs. Such approaches can under-estimate the assimilative capacity within deep aquifers and over-estimate the assimilative capacity within shallow aquifers.
Despite the identification of these challenges, the 2018 amendments to the SNMP guidelines within the Policy primarily focused on clarifying the roles of the Regional Boards in accepting SNMPs, performing periodic SNMP reviews, and defining new compliance schedules for completing SNMPs in areas where they had either not been prepared or approved by the Regional Boards. The 2018 Policy identified the same basic components to be included in the SNMPs as were defined in the 2009 Policy and still does not prescribe methods or approaches for SNMP analyses. As before, the SNMP methods and approaches that are appropriate for the local area and Basin Plan must be defined by the stakeholders and approved by the Regional Boards.
The State Board adopted the 2018 Policy in December 20184 and it went into effect in April 2019 following adoption by the Office of Administrative Law. For groundwater basins without approved SNMPs, the 2018 Policy does not define a deadline for SNMPs to be completed and approved by the Regional Board; it only requires that the Regional Boards identify which groundwater basins require an SNMP by Executive Order or Resolution by April 2021.
In addition, with approval of the Indio Subbasin Alternative and the Mission Creek Subbasin Alternative for the Sustainable Groundwater Management Act (SGMA) Groundwater Sustainability Plan requirement, DWR staff recommended that an approved SNMP be incorporated into future iterations of the Alternatives.
4 State Water Resources Control Board. 2018. 2018 Water Quality Control Policy for Recycled Water. December 18, 2018.
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1.2 2015 Coachella Valley Salt and Nutrient Management Plan
1.2.1 Overview of the 2015 SNMP
In a letter dated February 14, 2011, the Regional Board asked the Coachella Valley stakeholders “take the necessary steps to initiate a collaborative process to prepare a salt and nutrient management plan” pursuant to the 2009 Policy.5 In June 2015, the CVWD, DWA, and IWA submitted the final Coachella Valley Groundwater Basin Salt and Nutrient Management Plan6 (2015 SNMP) to the Regional Board.
The 2015 SNMP included the following:
• Definition of the planning area, regulatory setting, stakeholder participation process, and the salt and nutrient constituents of concern: nitrate and total dissolved solids (N/TDS). • A hydrogeologic characterization of the Coachella Valley groundwater subbasins, including definition of seven groundwater management zones for the 2015 SNMP. • Characterization of current N/TDS concentrations for each management zone, including calculation of the volume-weighted estimates of ambient N/TDS concentrations within each management zone that had sufficient data available over the 15-year period of 1999-2013. • For the management zones with estimates of ambient water quality, the 2015 SNMP included:
o Assessments of assimilative capacity for N/TDS. Given the absence of numeric groundwater-quality objectives for TDS in the Basin Plan, the “upper level” for the secondary maximum contaminant level (MCL), which is 1,000 milligrams per liter (mgl), was used to compute assimilative capacity and concluded that there is assimilative capacity for loading of TDS. The 2015 SNMP also concluded that there is assimilative capacity for loading of nitrate.
o Projections of N/TDS loading by source and the change in the volume-weighted ambient N/TDS concentrations by management zone over a 30-year planning period through 2045. Based on the projections, the 2015 SNMP concluded that there will continue to be assimilative capacity for N/TDS loading over the planning period. o An antidegradation analysis to support recycled water use, which only occurs in two of the management zones. The 2015 SNMP concluded that the recycled water projects will use much less than 10 percent of the available assimilative capacity and therefore these projects can continue to be permitted in accordance with the Policy. • A listing of salt and nutrient management strategies that could help to minimize impacts of salt and nutrient loading and protect beneficial uses. No management plan was defined to implement these projects based on the findings that that there will continue to be assimilative capacity for N/TDS loading over the planning period. • A monitoring plan to guide the reasonable and adequate collection of data and information to estimate ambient water quality for the management zones. The monitoring plan
5 Perdue, R. 2011. Letter to Coachella Valley stakeholders (February 14, 2011). 6 MWH. 2015. Coachella Valley Groundwater Basin Salt and Nutrient Management Plan. June, 2015.
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identified existing and new monitoring locations and included recommendations regarding the additional data to be collected and the frequency of monitoring.
1.2.2 Regional Board Response to the 2015 SNMP
Since the submittal of the final 2015 SNMP, Regional Board staff have issued three letters to the 2015 SNMP participants detailing their comments and finding that the 2015 SNMP does not satisfy the requirements of the Policy.7 In the most recent letter issued in February 2020, the Regional Board staff reiterated the specific findings regarding which components of the 2015 SNMP were insufficient and provided specific recommendations to develop an acceptable SNMP that is consistent with the 2018 Policy.
The Regional Board concerns are related to the following five technical and/or policy issues:
• The insufficiency of the monitoring program to fill data gaps and adequately characterize the spatial and vertical distribution of water quality conditions. • The use of simple mass-balance approaches to compute current and future ambient N/TDS concentrations for the management zones.
• The use of the secondary upper MCL of 1,000 mgl for TDS to assess assimilative capacity. • The lack of an antidegradation analysis to support salt and nutrient loading from sources other than recycled water, including the use and recharge of Colorado River water. • The absence of an implementation plan for measures to manage salt and nutrient loading from all sources on a sustainable basis.
The Regional Board comments and associated recommendations to resolve the technical and policy issues are describe in more detail below.
SNMP Monitoring Program. The Policy requires a groundwater monitoring program that can determine whether the concentrations of salts, nutrients, and other constituents of concern in groundwater are consistent with groundwater quality objectives and are thereby protective of beneficial uses. The Regional Board perceived insufficiencies in the proposed monitoring plan in the 2015 SNMP. In particular, that the monitoring plan did not address:
• The identified data gaps in the management zones with no ambient water quality findings. • The need to improve the characterization of the vertical distribution of groundwater quality. • The identification of critical areas for monitoring near water supply wells, large water recycling projects, Colorado River water recharge projects, or other significant sources of salt and nutrients identified in the 2015 SNMP.
The Regional Board required that the CV-SNMP Agencies prepare a new monitoring program workplan to address these concerns by December 2020.
7 Stormo, J. 2015. Letter to Patti Reyes (August 7, 2015).
Sanford, C. 2016. Letter to Joan Stormo and Abdi Haile (March 22, 2016).
Rasmussen, P. 2020. Letter to Steve Bigley, Marc Krause, and Trish Rhay (February 19, 2020).
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Ambient Water Quality and the Capacity to Assimilate Salt and Nutrient Loading . The Regional Board believes that the findings of assimilative capacity for salt and nutrient loading to the groundwater management zones are potentially inaccurate and thereby may not be protective of beneficial uses. The Regional Board concerns are related to:
• The lack of ambient groundwater quality estimates for four of the seven proposed management zones and the ability of the monitoring program to supply sufficient data to estimate ambient groundwater quality.
• The use of a 15-year period to define ambient groundwater quality conditions. • The use of a simple mass-balance approach that:
o assumes complete and instantaneous mixing of salt and nutrient loads through the full depth of the aquifer,
o simplifies the current and projected ambient groundwater quality into a single volume- weighted concentration that represents an entire management zone, and o does not account for the spatial and vertical distribution of constituents in groundwater. • The use of the secondary upper MCL of 1,000 mgl for TDS to assess assimilative capacity.
To address these concerns, the Regional Board recommended: preparing the above noted monitoring program workplan; identifying where shallow groundwater or isolated areas within the groundwater basin may be influenced by salt and nutrient loading activities and thereby warrant additional monitoring or management techniques; a more conservative use of the mass-balance models that is capable of estimating depth-specific and site-specific ambient groundwater quality; and comparing the existing groundwater quality to all the established TDS ranges referenced in Title 22, including the "recommended" level of 500 mgl, citing that this approach will ensure that the most protective water quality standards are implemented.
Antidegradation Analysis. The 2018 Policy recognizes that while some recycled water projects have measurable salt and nutrient loading contributions to groundwater, it is other entities or activities such as agriculture, industry, wastewater treatment plant operations, and the use of imported waters that can result in significant salt and nutrient loading to groundwater. Section 6.2.4 of the 2018 Policy requires that SNMPs contain an antidegradation analysis demonstrating that the existing projects, reasonably foreseeable future projects, and other sources of loading to the basin described within SNMP will cumulatively satisfy the antidegradation requirements of State Board Order 68-16 (the Antidegradation Policy).
In the Coachella Valley, the Regional Board is specifically concerned with the TDS loading associated with the recharge of Colorado River water, and that future updates to the CV-SNMP must include an antidegradation analysis for the recharge of Colorado River water.
Implementation Measures to Manage Salt and Nutrient Loading. The 2015 SNMP discussed potential implementation measures to manage or reduce the salt and nutrient loading to groundwater, but did not include a plan to implement the measures, citing that corrective measures are not needed based on the results of the assimilative capacity and antidegradation analyses. As noted above, the Regional Board is concerned with the loading from the use and recharge of Colorado River water, which was identified as the greatest single source of salt entering the groundwater basin. The Regional Board believes that there is insufficient analytical data presented to evaluate the suspected impacts to the aquifer in the vicinity of
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any of the four active groundwater recharge facilities to conclude that mitigation measures are not needed. The Regional Board stated that the potential impacts to groundwater from the use and recharge of Colorado River water must be evaluated, and mitigation measures be proposed as warranted by the evaluations.
1.3 Update of the CV-SNMP
Following the February 19, 2020 letter, the CV-SNMP Agencies entered discussions with the Regional Board to address their comments and concerns and develop a plan and schedule to update the 2015 CV- SNMP for approval by the Regional Board. Per these discussions, and as documented in its April 27, 2020 letter,8 the Regional Board required the CV-SNMP Agencies to address its concerns by developing the CV- SNMP Development Workplan by December 2020 (subsequently postponed to April 2021) that defines the scope and schedule to prepare an updated CV-SNMP. The CV-SNMP Development Workplan is required to include a monitoring program workplan.
The CV-SNMP Development Workplan will be the guide for updating the CV-SNMP to comply with the 2018 Policy and resolve the challenges identified by the Regional Board as discussed in Section 1.2.2 above.
1.3.1 Process to Prepare the CV-SNMP Development Workplan The CV-SNMP Agencies prepared a Request for Proposals to solicit a technical consultant to assist in preparing the CV-SNMP Development Workplan. The CV-SNMP Agencies selected and contracted with Wildermuth Environmental, Inc. (now West Yost Associates) as the technical consultant in July 2020.
In September 2020, the CV-SNMP Agencies provided a progress report to Regional Board staff on preparing the CV-SNMP Development Workplan and requested a revision to the scope and schedule defined in the April 27, 2020 letter. The requested revision was for a two-step process, whereby:
• The CV-SNMP Groundwater Monitoring Program Workplan was due by December 18, 2020.
The CV-SNMP Agencies completed the CV-SNMP Groundwater Monitoring Program Workplan (final report dated December 23, 2020), and the Regional Board approved the CV-SNMP Groundwater Monitoring Program Workplan in a letter dated February 21, 2021.9 The approved CV-SNMP Groundwater Monitoring Program Workplan is included as Appendix A and is summarized in Sections 2 and 3 of this workplan.
• The remainder of the CV-SNMP Development Workplan is due to the Regional Board by April 30, 2021.10
Through discussions and advice from West Yost Associates, the CV-SNMP Agencies concluded that numeric objectives for TDS and nitrate in groundwater are necessary to resolve the concerns of the Regional Board (Section 1.2.2 above). Numeric objectives in the CV-SNMP will be necessary to:
• Demonstrate that beneficial uses are protected.
8 Rasmussen, P. 2020. Letter to Steve Bigley (April 27, 2020). 9 Rasmussen, P. 2021. Letter to Steve Bigley (February 21, 2021). 10 Rasmussen, P. 2021. Letter to Steve Bigley (March 23, 2021).
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• Quantify the magnitude of available assimilative capacity for salt and nutrient loading. • Provide a technical basis for the Regional Board to allocate the use of assimilative capacity. • Set triggers for implementation measures at appropriate locations and times.
Currently, the Basin Plan includes a nitrate-nitrogen objective of 10 mgl for groundwater in the Coachella Valley based on the primary drinking water MCL but lacks scientifically-derived numeric TDS objectives that are consistent with the provisions of Title 22. The process to recommend numeric TDS objectives needs to include technically-defensible methods and tools to answer the following questions:
• What are logical management areas within the Basin (management zones) and the beneficial uses of groundwater within the management zones?
• What is current groundwater quality? And, is current groundwater quality protective of beneficial uses?
• How is groundwater quality expected to change across the basin and within the depth-specific aquifer systems?
• Will these changes in groundwater quality impact beneficial uses? If so, where and when? • What are economically and technically feasible salt management strategies, that when implemented, will achieve the objectives of both the CV-SNMP stakeholders and the Regional Board? Economic feasibility will need to be defined and should consider the sources of revenue and the factors that could restrict the sources of revenue.
In addition, the California Water Code section 13241 describes the factors to consider when establishing the TDS objectives:
a) Past, present, and probable future beneficial uses of water. b) Environmental characteristics of the hydrographic unit under consideration, including the quality of water available thereto.
c) Water quality conditions that could reasonably be achieved through the coordinated control of all factors which affect water quality in the area.
d) Economic considerations.
e) The need for developing housing within the region.
f) The need to develop and use recycled water.
The CV-SNMP Development Workplan must include a process to address these factors when recommending numeric TDS objectives for groundwater management zones.
This final CV-SNMP Development Workplan was prepared in a collaborative process between the CV- SNMP Agencies and Regional Board staff. A draft CV-SNMP Development Workplan dated April 30, 2021 was submitted to the Regional Board staff for review. The CVWD (representing the CV-SNMP Agencies) received a letter from the Regional Board dated June 30, 2021 with comments and suggested revisions to the draft CV-SNMP Development Workplan. The CV-SNMP Agencies prepared responses to the Regional Board comments and revised the CV-SNMP Development Workplan to address the comments. The
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Regional Board’s comments and the CV-SNMP Agencies’ responses-to-comments are included in Appendix C.
1.3.2 Workplan Organization
This CV-SNMP Development Workplan describes the detailed scope of work to update the CV-SNMP by using technically-defensible methods and tools to recommend numeric TDS objectives for groundwater, answer the questions listed above, comply with State law and Policy, and resolve the concerns of the Regional Board.
The remainder of the CV-SNMP Development Workplan is organized as follows:
Section 2 – Study Area Setting. This section describes the study area that will be covered by the CV-SNMP and is included herein to provide context to the components and methods of the CV-SNMP Development Workplan.
Section 3 – CV-SNMP Monitoring Program Workplan. This section describes the detailed scope of work, schedule and budget required to implement a revised monitoring and data collection program that will support the development and implementation of the CV-SNMP. The Regional Board informed the CV- SNMP Agencies of approval of the CV-SNMP Groundwater Monitoring Program (described herein) in a letter dated February 21, 2021.
Section 4 – CV-SNMP Development Workplan. This section describes the detailed scope of work to prepare an updated CV-SNMP that complies with the State law and Policy and resolves the concerns of the Regional Board with the 2015 CV-SNMP. The scope of work includes the technical methods and approaches for applying State and Regional Board policies that will be relied upon in the development of the CV-SNMP.
Section 5 – CV-SNMP Development Workplan Implementation. This section describes the schedule and budget-level cost estimates to implement the CV-SNMP Development Workplan.
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STUDY AREA SETTING
This section summarizes the physical characteristics and dynamics of the Basin regarding surface water, groundwater, and the origin and fate and transport of salts and nutrients. Understanding the physical characteristics and dynamics of the Basin provides the foundation for defining SNMP methods and approaches that are appropriate for the local area and Basin Plan and selecting a monitoring network that will meet the objectives of the 2018 Policy.
This section was prepared from a review of past technical studies and reports; no original work or analyses were performed for this section of the workplan.
2.1 Basin Setting
Figure 2-1 is a geologic map that shows the Basin as delineated by the California Department of Water Resources (DWR Groundwater Basin No. 7-021, excluding the San Gorgonio Pass Subbasin), which represents the area subject to the CV-SNMP. The Basin is located within the northwest portion of the Salton Sea Watershed (USGS Hydrologic Unit 18100200).
Figure 2-1 shows the surface geology as generalized into natural divisions with regard to groundwater:
Unconsolidated water-bearing sediments. These are the pervious formations that comprise the Basin.
Bedrock formations. These are the semi-consolidated sediments and the consolidated bedrock formations that come to the surface in the hills and mountains that surround and bound the Basin. Groundwater can exist in pore spaces and fractures within the bedrock formations; however, the permeability of the bedrock formations typically is much less than the water-bearing sediments.
The upper 2,000 ft of the unconsolidated water-bearing sediments constitute the freshwater aquifer system that is the main source of groundwater supply in the region. The sediments tend to be finer- grained in the southeastern portions of the Basin due to the greater distance from the mountainous source areas and the lower-energy depositional environments, such as historical Lake Cahuilla.
The Whitewater River is the major drainage course in the Basin. The Whitewater River is an unlined channel, so surface water flows have the potential to infiltrate and recharge the Basin. In areas with shallow groundwater, the groundwater has the potential to discharge to interconnected surface water.
2.2 Hydrogeology
2.2.1 Subbasins and Subareas
Figure 2-2 is a map of the general hydrogeology of the area. The Basin is cross-cut by several geologic faults, which have created low-permeability zones within the water-bearing sediments that act as barriers to groundwater flow. These barriers impede, but do not eliminate, groundwater flow between subbasins.
Groundwater flow can still occur across the barriers from areas of higher groundwater levels to areas of lower groundwater levels. The map identifies the locations of faults, subbasins, and subareas that comprise the Basin, and describes the general occurrence and movement of groundwater through the Basin.
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The DWR has defined three main subbasins within the study area that are separated by geologic faults or changes in formation permeability that limit and control the movement of groundwater: the Indio Subbasin (DWR Subbasin 7-021.01), the Mission Creek Subbasin (7-021.02), and the Desert Hot Springs Subbasin (7-021.03).11 These subbasins have been further subdivided into subareas based on one or more of the following geologic or hydrogeologic characteristics: type(s) of water-bearing formations, water quality, areas of confined groundwater, forebay areas, and groundwater or surface drainage divides.
Figure 2-2 shows groundwater-elevation contours for water-year 2019 (October 1, 2018 through September 30, 2019). Lateral groundwater flow is generally perpendicular to the contours from higher to lower elevation, as indicated by the arrows on the map. Generally, groundwater flows from areas of natural recharge along the surrounding mountain-fronts toward the valley floor and then southeast toward the distal portions of the Basin near the Salton Sea. Locally, the structural and compositional features within the Basin result in groundwater conditions and flow directions that vary significantly between subbasins. Anthropogenic activities such as artificial recharge and groundwater pumping also influence groundwater-flow directions.
2.2.2 Occurrence and Movement of Groundwater
Described below is the general occurrence of groundwater, and how groundwater flows through and discharges from each subbasin:
Desert Hot Springs Subbasin. In the Desert Hot Springs Subbasin, groundwater typically flows from the Little San Bernardino Mountains to the south but is locally variable due to faulting. The aquifer system is poorly understood due to relatively poor water quality, which has limited the development of groundwater resources in the area. Faulting in the northern portion of the subbasin has resulted in thermal mineral waters in the aquifer with temperatures up to 250 degrees Fahrenheit. These thermal waters are used by several spas in the area. Groundwater discharge primarily occurs by pumping at wells or subsurface outflow. Generally, groundwater elevations in the Desert Hot Springs Subbasin are higher than in the Mission Creek and Indio Subbasins, and hence, the subsurface outflow from the Desert Hot Springs Subbasin occurs across the Mission Creek Fault into these downgradient subbasins. These subsurface flows are thought to be relatively minor based on the differences in groundwater quality on either side of the fault barriers that separate the subbasins. However, any subsurface outflow from the Desert Hot Springs Subbasin could be a source of poor-quality inflow to the Mission Creek and Indio Subbasins.
Mission Creek Subbasin. In the Mission Creek Subbasin, groundwater typically flows from northwest to southeast. The aquifer system is up to 2,000 feet thick and is predominantly unconfined. Portions of the aquifer along the Banning Fault northwest of the Seven Palms Ridge area are semi-confined as evidenced by historically flowing-artesian wells in the area. Depth to groundwater in the Mission Creek Subbasin in 2019 ranged from an estimated 600 feet-bgs (ft-bgs) upgradient of the Mission Creek Groundwater Replenishment Facility (MC-GRF) to less than 5 feet-bgs in the southeast (west of the Indio Hills).
Groundwater discharge primarily occurs by pumping at wells or subsurface flow across the Banning Fault into the Indio Subbasin.
Indio Subbasin. The Indio Subbasin is bordered on the west by the San Gorgonio Pass Subbasin and the crystalline bedrock of the Santa Rosa and San Jacinto Mountains. It is separated from the Mission Creek
11 The DWR defines the San Gorgonio Pass Subbasin (7-021.04) as part the Basin, but it is not subject to the CV-SNMP.
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Subbasin by the Banning Fault, and from the Desert Hot Springs Subbasin by the San Andreas Fault. Both faults are barriers to groundwater flow as evidenced by differences in groundwater levels across the faults. For example, groundwater-level differences across the Banning Fault, between the Mission Creek Subbasin and the Indio Subbasin, can be up to 250 feet. Subsurface flow between subbasins primarily occurs from the Desert Hot Springs and Mission Creek Subbasins into the Indio Subbasin.
In the Indio Subbasin, the aquifer system is generally unconfined in the forebay areas and across the northwestern portion of the subbasin. Generally, groundwater flows from the northwest toward the southeastern portions of the subbasin near the Salton Sea. In the southeast portion of the Indio Subbasin, the predominance of fine-grained sediments at depth has created three distinct aquifer systems, which are shown graphically in Figure 2-3 and are described below:
Perched. A semi-perched aquifer up to 100 feet thick that is persistent across much of the area southeast of the City of Indio. The fine-grain units that cause the perched conditions are likely a barrier to deep percolation of surface water. The extent of the semi-perched aquifer is shown on Figure 2-2. Shallow groundwater within the semi-perched aquifer is conveyed away from the root zone by a network of privately-owned subsurface tile drainage systems that are distributed across the agricultural land uses in the southeastern portion of the Basin. CVWD maintains a regional network of surface and subsurface drains, shown on Figure 2-4, that accumulate and convey the drainage waters from the agricultural lands to the Salton Sea.
Shallow. An upper aquifer up to 300 feet thick that is present across most of the area. The upper aquifer is unconfined except in the areas of the semi-perched aquifer where it is semi- confined.
Deep. A lower aquifer that is 500-2,000 feet thick and is the most productive portion of the Basin. In the southeast portion of the Basin, the lower aquifer is confined and is separated from the upper aquifer by a fine-grained aquitard unit that is 100-200 feet thick. Figure 2-2 displays the extent of the aquitard unit.
Groundwater discharge primarily occurs by pumping at wells, shallow groundwater discharge to subsurface tile drainage systems on agricultural lands that ultimately discharge to the Salton Sea, and subsurface outflow to groundwater underlying the Salton Sea.
2.3 Origin and Fate and Transport of N/TDS
Figure 2-4 is a map that depicts the general areas and processes of salt and nutrient loading, transport, and discharge throughout the Basin.
2.3.1 Loading of N/TDS
Salts, and in some cases nutrients, are loaded to the Basin via the following mechanisms:
• Subsurface inflow from: saturated sediments and bedrock fractures in the surrounding mountains and hills; the upgradient the San Gorgonio Pass Subbasin; and deep thermal water sources.
• Recharge of precipitation runoff in unlined stream channels that cross the Basin.
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• Artificial recharge of imported Colorado River Water at the Groundwater Replenishment Facilities (GRF).
• Percolation of treated wastewater discharge to unlined ponds. • Seepage from septic systems.
• Deep infiltration of precipitation on the land surface. • Return flows from irrigation waters applied to the overlying land uses, such as agriculture, golf courses, and urban landscapes. Loading from return flows is a complex process that involves the following mechanisms that ultimately influence the volume and associated N/TDS concentrations of waters that migrate past the root zone to the saturated zone:
o The interaction of precipitation and irrigation waters. o Evapotranspiration processes that concentrate salts in the root zone. o Geochemical and microbial processes that occur during the downward migration through the unsaturated (vadose) zone, such as absorption and chemical transformations.
o Past N/TDS loading to the vadose zone by historical overlying land uses.
Figure 2-4 shows the spatial distribution and location of these sources of salt and nutrient loading across the Basin.
2.3.2 Transport and Discharge of N/TDS in the Saturated Zone Once within the saturated zone, the dissolved salts and nutrients are transported through the aquifer system via the groundwater-flow systems shown on Figure 2-2 and Figure 2-4. Ultimately, salts and nutrients are discharged from the Basin via the following mechanisms:
• Groundwater pumping.
• Discharge to agricultural drains. As described above, throughout the lower Basin, CVWD maintains a network of surface and subsurface drains to convey shallow groundwater away from the crop root zones. These drains convey water to the Coachella Valley Stormwater Channel (CVSC) and 27 smaller open channel drains that discharge directly to the Salton Sea. • Subsurface outflow to downgradient subbasins. In the Indio Subbasin, subsurface outflow occurs to groundwater beneath the Salton Sea.
• Phreatophyte consumptive use.
Figure 2-3
From DWR (1964)
Generalized Stratigraphic Column in Eastern Coachella Valley
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CV-SNMP GROUNDWATER MONITORING PROGRAM WORKPLAN
The Groundwater Monitoring Program for the CV-SNMP consists of the following components, each further described below:
• Groundwater monitoring network
• Chemical analytes and sampling frequency
• Monitoring and reporting
3.1 Groundwater Monitoring Network
Section 6.2.4.1 of the Policy requires the implementation of a monitoring program that can determine whether the concentrations of salts and nutrients in groundwater are consistent with water quality objectives and are thereby protective of beneficial uses. The Policy also recognizes the monitoring program will be dependent upon basin-specific conditions and input from the Regional Board.
For the CV-SNMP Groundwater Monitoring Program, the Regional Board is requiring that the monitoring program:
• Cover all subbasins and subareas within the Basin. The updated CV-SNMP will require periodic mapping of groundwater quality to estimate ambient water quality and assimilative capacity. A monitoring network that is spatially distributed across all subbasins and subareas of the Basin will provide the necessary data for technically defensible mapping of groundwater quality.
• Include sampling from all three major aquifer systems: Deep, Shallow, and Perched. Section 2 of this Workplan described the hydrogeologic stratification of the aquifer system in the Basin. Groundwater quality, and the physical processes that can alter groundwater quality over time, can be significantly different between aquifer systems. This is because: (i) anthropogenic loading of salts and nutrients occur primarily at the ground surface, and hence, can influence the quality of shallower groundwaters first before influencing the quality of deeper groundwaters; (ii) thick aquitards in the southeastern portion of the Basin restrict the vertical movement of groundwater between aquifer systems; and (iii) upward hydraulic gradients, as evidenced by flowing artesian conditions in the southeastern portion of the Basin, limit the downward migration of salts and nutrients to the Deep aquifer system in this region. For these reasons, monitoring of perched, shallow and deep groundwaters is proposed herein across most of the Basin.
• Focus on critical areas near: (i) large water recycling projects, (ii) near large recharge projects, particularly where Colorado River water is used to replenish the Basin for water- supply and groundwater management purposes, and (iii) near other potential sources of salt and nutrients. It is important that monitoring occurs hydraulically upgradient and downgradient from these sources of salt and nutrient loading to characterize their influence on groundwater quality.
• Focus on critical areas near water supply wells. The water-supply wells are the main points of extraction for the ultimate beneficial uses of the Basin.
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• Identify critical gaps in the monitoring network and develop a plan and timeline to fill the gaps. The current gaps in the monitoring network are described in this section. The plan and timeline to fill the gaps are included in Section 4.
• Identify the stakeholders responsible for conducting, compiling, and reporting the monitoring data.
3.1.1 Methods for Selection of the Groundwater Monitoring Network The criteria used to select the groundwater monitoring network included the following:
Spatial Distribution. The monitoring network was designed to cover all subbasins and subareas within the Basin.
Hydrogeology. The monitoring network was designed to monitor all three major aquifer systems: Deep, Shallow, and Perched. Water-supply wells in the Basin typically pump groundwater from the Deep aquifer system and were therefore more available for inclusion in the monitoring network. Wells with screens across the Shallow and Perched aquifer systems were less abundant. Hence, most “gaps” in the proposed monitoring network are within the Shallow and Perched aquifer systems.
Areas of Salt or Nutrient Loading. The network was designed to monitor the influence of known sources of salt or nutrient loading on groundwater quality within the Basin. These sources included: the GRFs; wastewater percolation ponds; areas with septic systems; overlying land uses with irrigation returns (e.g., golf, landscapes, agriculture); and areas served non-potable waters for irrigation (e.g., recycled and/or imported waters). Monitoring of non-point-source loading, such as returns from non-potable irrigation waters and septic systems, is intended to be representative of the influence of non-point-sources of loading on groundwater quality. It is not intended to be site-specific monitoring of every area of non-point-source loading across the Basin, which would be infeasible.
Groundwater Flow. The network was designed to monitor all major groundwater-flow systems, from areas of recharge to areas of discharge, and within and between the groundwater subbasins. This is necessary in order to track the subsurface migration of salts and nutrients through the Basin.
Use of Existing Wells. Wherever possible, active municipal production or monitoring wells were preferentially selected if they currently participate in a similar monitoring program (e.g., California Division of Drinking Water [DDW] or Regional Board orders). In some areas, such wells were not available for selection. In those areas, inactive municipal production wells or private wells were selected for inclusion in the monitoring network. The use of inactive or private wells in this monitoring program will require significant coordination with the private well owners and/or physical wellhead improvements to collect groundwater samples. Lastly, if no wells were identified in an area/depth that should be monitored, a “gap” was designated in the monitoring network.
3.1.2 Monitoring Network and Gaps – Shallow Aquifer System Figure 3-1 is a map of the groundwater monitoring network for the Shallow aquifer system. Each well is labeled by a Map_ID. Because most production wells in the Basin have well screens across the Deep aquifer system, there were several identified “gaps” in the monitoring network, particularly in the Thermal Subarea of the Indio Subbasin. Table 3-1 is a list of wells shown on Figure 3-1 sorted by Map_ID. The table
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includes a summary justification for why each well was included in the monitoring program. Table 3-4 is a list of the “gaps” in the monitoring network with a summary explanation of why each gap should be filled.
3.1.3 Monitoring Network and Gaps – Deep Aquifer System Figure 3-2 is a map of the groundwater monitoring network for the Deep aquifer system. Each well is labeled by a Map_ID. Most production wells in the Basin have well screens across the Deep aquifer system; hence, there were no identified “gaps” in the Deep monitoring network. Table 3-2 is a list of wells shown on Figure 3-2 sorted by Map_ID. The table includes a summary justification for why the well was included in the monitoring program.
3.1.4 Monitoring Network and Gaps – Perched Aquifer System Figure 3-3 is a map of the groundwater monitoring network for the Perched aquifer system. Each well is labeled by a Map_ID. The map shows the extent of the Perched aquifer system which is confined to the Thermal Subarea of the Indio Subbasin. The network of CVWD’s agricultural drains that convey perched groundwater to the CVSC and the Salton Sea is also shown. The only existing wells with well screens across the Perched aquifer system are five monitoring wells owned by the CVWD; hence, there were several identified “gaps” in the Perched monitoring network. Table 3-3 is a list of wells shown on Figure 3-3 sorted by Map_ID. The table includes a summary justification for why each well was included in the monitoring program. Table 3-4 is a list of the “gaps” in the monitoring network with a summary explanation of why each gap should be filled.
3.2 Chemical Analytes and Sampling Frequency
Table 3-5 lists the chemicals that will be analyzed for dissolved concentration in each groundwater sample for the monitoring program. The table describes the justification for each chemical analyte. Testing will be performed at a laboratory accredited by the State of California for the testing of inorganic chemistry of drinking water.
The minimum sampling frequency is once every three years. Many wells chosen for this monitoring program are sampled more frequently under other required or voluntary monitoring programs.
During each groundwater sampling event, the agency responsible for sampling will attempt to obtain a static (non-pumping) depth-to-water measurement. In instances when a static depth-to-water measurement cannot be obtained, it will be noted with a description for the reason.
3.3 Monitoring and Reporting
The CV-SNMP Agencies have the following responsibilities for sampling of the wells in the monitoring network (described in Section 3.1), the laboratory analysis of chemical analytes (described in Section 3.2), and the reporting of the laboratory results pursuant to the Policy
3.3.1 Groundwater Sampling and Laboratory Analysis
For groundwater sampling and analysis:
• Municipal well owners are responsible for the groundwater sampling and laboratory analyses for their own wells.
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• For private wells within their service area, the overlying CV-SNMP Agency is responsible for coordinating with the private well owners to conduct groundwater sampling and the laboratory analyses. In areas of overlapping jurisdictions of CV-SNMP Agencies, the agencies must jointly coordinate to assign responsibility for sampling and analysis of private wells that fall within the overlapping jurisdictions. Agency responsibilities may include developing administrative agreements with the well owners (e.g., right-of-entry agreement) and making physical modifications to the wellhead to enable collection of a sample (e.g., installation of a sampling port on the well discharge pipe).
Table 3-6 lists all wells proposed for the monitoring program. For each well, the table includes a designation for the overlying CV-SNMP Agency(ies).
3.3.2 Reporting of Laboratory Results
Section 6.2.4.1.3 of the Policy requires that all data collected for the monitoring program “shall be electronically reported annually in a format that is compatible with a Groundwater Ambient Monitoring & Assessment (GAMA) information system and must be integrated into the GAMA information system or its successor.” This will centralize data generated from SNMPs at the State level and create consistency across regional water boards to allow for further analysis of monitoring data.
By March 31 of each year, the CV-SNMP Agencies will report the laboratory water-quality results from the prior calendar year to the GAMA information system.
3.4 Filling of Gaps in the Monitoring Network
Table 3-4 lists the gaps in the monitoring network that were identified during the selection of the monitoring network.
Gaps in the monitoring network will be filled in one of two ways:
Field identification of an existing well that: (i) is located near the identified gap; (ii) can be sampled, and (iii) has well screens across the appropriate depth interval (e.g., across the Shallow aquifer system). This may require the following activities: field canvassing to identify a candidate well; research and/or exploratory well surveys to confirm well screen depth intervals; and constructing any well/wellhead modifications that are necessary to collect groundwater samples.
Construction of a new monitoring well with well screens across the appropriate depth interval. This may require the following activities: a well-siting study; well-site acquisition or easement; development of technical specifications for a monitoring well; conducting a bid process to select a well drilling/construction subcontractor; obtaining the necessary permits and CEQA clearance; performing well construction with oversight; performing well development and testing; preparing a well completion report; equipping the well for sampling, and wellhead completion including any needed site improvements.
In the first year, the CV-SNMP Agencies will perform the necessary field work and research and develop a plan for how each gap in the monitoring program will be filled.
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Filling the gaps in the monitoring network is likely the most expensive, complicated element of the monitoring program. Therefore, the filling of gaps will be executed over a six-year period, subject to funding availability. The CV-SNMP Agencies will pursue grant funding to support the filling of gaps under State-run programs such as Integrated Regional Water Management and the Sustainable Groundwater Management Act.
By March 31 of each year, the CV-SNMP Agencies will report to the Regional Board on progress made toward filling the gaps in the monitoring network over the preceding calendar year (see Section 5.2 below).
Table 3-1. SNMP Groundwater Monitoring Network -- Shallow Aquifer System 1 03S04E20F01S USGS 335348116352701 Active Monitoring 600-640 S Northwest area at WW-GRF 2 03S04E20J01S USGS 335339116345301 Active Monitoring 550-590 S Northeast area at WW-GRF 3 06S07E33G02S Coachella Valley Water District TEL-GRF MW-21S Active Monitoring 230-250 S Adjacent to and downgradient of TEL-GRF 4 06S07E33J02S Coachella Valley Water District TEL-GRF MW-22S Active Monitoring 230-250 S Adjacent to and downgradient of TEL-GRF 5 06S07E34N03S Coachella Valley Water District TEL-GRF MW-23S Active Monitoring 230-250 S Adjacent to and downgradient of TEL-GRF 7 02S04E26C01S Mission Springs Water District Well 28 Inactive MUN 590-898 S Downgradient from Mission Creek GRF; near golf course and septic areas 8 02S04E28A01S Mission Springs Water District Well 34 Active MUN 550-980 S Downgradient from Mission Creek GRF 9 02S05E31L01S Mission Springs Water District Well 11 Inactive Unknown 220-285 S Downgradient of Desert Hot Springs (DHS) subbasin 10 03S04E04Q02S CPV Sentinel 03S04E04Q02S Active Unknown S Upgradient portion of Mission Creek subbasin 11 03S04E11L01S Mission Springs Water District Well 27 Active MUN 180-380 S Upgradient of Garnet Hill subarea; near potential septic areas in N. Palm Springs 12 03S05E05Q01S Hidden Springs Golf Course P27 Active Unknown 220-600 S Downgradient of DHS subbasin; near golf course and septic areas 13 City of Palm Springs Airport MW-2 Active Monitoring 240-250 S Center of Indio subbasin; near airport and areas served non-potable water (NPW) 14 City of Palm Springs MW-1 Active Monitoring 170-210 S Downgradient of Palm Springs WTP percolation ponds 15 City of Palm Springs MW-3 Active Monitoring 140-215 S Upgradient of Palm Springs WTP percolation ponds 16 City of Palm Springs MW-4 Active Monitoring 170-210 S Downgradient of Palm Springs WTP percolation ponds 17 City of Palm Springs MW-5 Active Monitoring 170-210 S Downgradient of Palm Springs WTP percolation ponds 18 City of Palm Springs MW-6 Active Monitoring 170-210 S Downgradient of Palm Springs WTP percolation ponds 19 03S03E08M01S Mission Springs Water District Well 26 Active MUN 225-553 S Monitoring of subsurface inflow from San Gorgonio Pass subbasin 20 03S03E10P02S Agua Caliente DWA P05 Active Unknown 306-906 S Upgradient of Whitewater GRF 21 03S04E12B02S Coachella Valley Water District CVWD Well 3408-1 Active MUN 270-500 S Central portion of Mission Creek subbasin; near potential septic areas 22 03S04E29F01S USGS 335304116353001 Active Monitoring 550-570 S Monitoring at southwestern area of Whitewater GRF 23 03S04E29R01S USGS 335231116345401 Active Monitoring 431-551 S Monitoring at southeastern area of Whitewater GRF 24 04S04E11Q01S Desert Water Agency DWA Well 5 Standby MUN 302-402 S Western portion of Indio subbasin; downgradient of septic areas 25 04S04E35A01S Agua Caliente Indian Canyons Well Active Unknown 360-680 S Near golf courses, septic, and areas served NPW 26 04S05E09F03S Coachella Valley Water District CVWD Well 4564-1 Active MUN 410-670 S Center of Indio subbasin; near golf courses and septic areas 27 04S05E29A02S Desert Water Agency DWA Well 25 Active MUN 166-300 S Downgradient of Palm Springs WTP percolation ponds; near golf courses and NPW areas 29 04S07E33L02S Coachella Valley Water District WRP7 MW-2S Active Monitoring 60-190 S Near WRP-7 percolation ponds 30 05S06E09M03S Coachella Valley Water District WRP10 MW-7 Active Monitoring 260-340 S Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 31 05S06E09P02S Coachella Valley Water District PD-GRF MW 2 Active Monitoring 260-340 S Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 32 05S06E10J01S Coachella Valley Water District PD-GRF MW 1 Active Monitoring 260-340 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 33 05S06E13G03S Coachella Valley Water District WRP10 MW-8 Active Monitoring 260-340 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 34 05S06E14G03S Coachella Valley Water District WRP10 MW-5 Active Monitoring 240-320 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 35 05S06E14P03S Coachella Valley Water District WRP10 MW-6 Active Monitoring 190-270 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 36 05S06E15F01S Coachella Valley Water District WRP10 MW-2 Active Monitoring 160-290 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 37 05S06E15M01S Coachella Valley Water District WRP10 MW-1 Active Monitoring 145-295 S Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 38 05S06E15P01S Coachella Valley Water District WRP10 MW-3 Active Monitoring 130-290 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 39 05S06E16A03S Coachella Valley Water District WRP10 MW-4 Active Monitoring 190-270 S Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 40 05S06E21Q04S Coachella Valley Water District PD-GRF MW 3 Active Monitoring 260-340 S Cross-gradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 41 05S06E23M02S Coachella Valley Water District PD-GRF MW 4 Active Monitoring 270-360 S Cross-gradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 42 05S07E03D02S Coachella Valley Water District WRP7 MW-4S Active Monitoring 60-190 S Near WRP-7 percolation ponds 43 05S07E04A04S Coachella Valley Water District WRP7 MW-3S Active Monitoring 50-180 S Near WRP-7 percolation ponds 44 05S07E16K02S Coachella Valley Water District CVWD Well 5737-1 Inactive Monitoring 200-415 S Center of Indio subbasin; downgradient from areas served NPW 45 05S07E19D04S Coachella Valley Water District WRP10 MW-9 Active Monitoring 260-340 S West in Indio subbasin; near golf courses and areas served NPW 46 05S07E24M02S Indio Water Authority Well 1B Active MUN 190-410 S Center of Indio subbasin; upgradient of VSD plant 47 06S06E12G01S Coachella Valley Water District CVWD Well 6650-1 Inactive Monitoring <370 S Within center of The Cove 48 06S07E34A02S Coachella Valley Water District TEL-GRF MW-25 Active Monitoring 115-135 S Downgradient from TEL-GRF and golf courses 49 06S07E34D02S Coachella Valley Water District TEL-GRF MW-24 Active Monitoring 180-200 S Directly north and downgradient of TEL-GRF 50 07S08E29P03S Coachella Valley Water District MC-3 Active Monitoring 380-440 S At Martinez Canyon GRF 51 08S09E31R03S Coachella Valley Water District CVWD Well 8995-1 Active MUN 260-390 S Southern corner of the Indio basin; near agriculture; near Salton Sea 52 03S04E17K01S Valley View MWC 03S04E17K01S Undetermined Unknown 340-375 S Cross-gradient from Whitewater GRF in Garnet Hill subarea 53 03S04E22A01S Erin Miner 03S04E22A01S Active Unknown 180-230 S Downgradient of Whitewater GRF in Garnet Hill subarea; upgradient of West Valley WWTP 54 03S05E08P02S Bluebeyond Fisheries 03S05E08P02S Active Fish Farm 200-400 S Central Mission Creek subbasin; near golf course and septic areas Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)Justification for Inclusion in SNMP Monitoring ProgramWell Use(b)
Screen
Interval
ft-bgs
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Table 3-1. SNMP Groundwater Monitoring Network -- Shallow Aquifer System Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)Justification for Inclusion in SNMP Monitoring ProgramWell Use(b)
Screen
Interval
ft-bgs
55 03S05E15N01S Too Many Palms LLC 03S05E15N01S Active Irrigation 158-320 S Distal area in Mission Creek subbasin; downgradient of DHS subbasin 56 03S05E18J01S Desert Dunes Golf Club 03S05E18J01S Active Irrigation 76-340 S Upgradient of Garnet Hill subarea; near golf course and septic areas 57 03S06E21G01S Sky Valley Mobile Home Park 03S06E21G01S Undetermined Unknown 188-248 S Western portion of Sky Valley subarea; near septic areas 58 04S05E04F01S So Pacific Trans Co #32601 04S05E04F01S Active Irrigation 276-576 S Eastern edge of Indio subbasin; downgradient from Garnet Hill subarea; near septic areas 59 04S05E23F01S Westin Mission Hills Resort 04S05E23F01S Active Irrigation 275-1165 S Center of Indio subbasin; near golf courses and septic areas 60 04S05E34C01S Manufacture Home Community Inc 04S05E34C01S Active Irrigation 240-500 S Western edge of Indio subbasin; near septic and areas served NPW 61 04S05E35Q01S Tamarisk Country Club 04S05E35Q01S Active Irrigation 171-518 S Western edge of Indio subbasin; near septic and areas served NPW 62 04S05E36L02S Annenberg Estate 04S05E36L02S Active Irrigation 252-650 S Center of Indio subbasin; near golf, septic, and areas served NPW 63 04S06E20C01S Shenandoah Ventures LP 04S06E20C01S Inactive Irrigation 250-790 S Upgradient in Thousand Palms area; upgradient of septic areas 66 05S05E12D01S Thunderbird Country Club 05S05E12D01S Active Irrigation 125-360 S Western edge of Indio subbasin; near septic and areas served NPW 67 05S06E12M01S Palm Desert Resort Country Club 05S06E12M01S Active Irrigation 140-650 S Center of Indio subbasin; near areas served NPW 68 05S07E08Q01S Bermuda Dunes Airport 05S07E08Q01S Active Domestic 203-654 S Center of Indio subbasin; near areas served NPW 69 05S07E28H02S Tricon/COB Riverdale LP 05S07E28H02S Active Domestic 162-636 S Center of Indio subbasin 70 05S08E28M02S JS Cooper 05S08E28M02S Undetermined Unknown 208-268 S Eastern edge of Indio subbasin; downgradient of VSD discharge point 71 05S08E30N03S Carver Tract Mutual Water Co 05S08E30N03S Active Domestic 270-330 S Eastern portion of Indio subbasin; downgradient from VSD plant 72 06S07E07B01S Traditions Golf Club 06S07E07B01S Active Irrigation 200-480 S Downgradient from The Cove; near golf courses and septic areas 73 06S08E02L01S Prime Time International 06S08E02L01S Undetermined Irrigation 216-407 S Eastern edge of Indio subbasin; near agriculture; upgradient from CWA/CSD WWTP 74 06S08E05K01S Peter Rabbit Farms 06S08E05K01S Active Irrigation 126-375 S Eastern portion of Indio subbasin in Coachella 75 06S08E32L01S Guillermo Torres 06S08E32L01S Undetermined Unknown 127-227 S Downgradient from TEL-GRF; agricultural area 76 07S08E27A01S Gimmway Enterprises Inc 07S08E27A01S Active Domestic 147-215 S Downgradient from Martinez Canyon GRF; near septic areas 77 07S09E14C01S Tudor Ranch Inc.07S09E14C01S Active Domestic 93-290 S Southeastern corner of Indio subbasin; near agriculture and septic areas; near Salton Sea 78 08S08E15G02S Thermiculture Management LLC 08S08E15G02S Active Irrigation 260-500 S Southern corner of Indio subbasin; near agriculture; near Salton Sea 79 Mission Springs Water District Well 25 Active MUN 330-455 S Monitoring of subsurface inflow from San Gorgonio Pass subbasin 80 Mission Springs Water District Well 1 Inactive Monitoring S Northern Miracle Hill subarea; upgradient of Mission Creek subbasin 81 Mission Springs Water District Horton WWTP MW-1 Active Monitoring 186-236 S Monitoring wells upgradient and downgradient of the Horton WWTP 82 Mission Springs Water District Horton WWTP MW-2 Active Monitoring 220-270 S Monitoring wells upgradient and downgradient of the Horton WWTP 83 Mission Springs Water District Horton WWTP MW-3 Active Monitoring 200-250 S Monitoring wells upgradient and downgradient of the Horton WWTP (a) Well Status: Well Status: "Active" means well is known to exist and currently used for original purpose; "Standby" means active backup well; "Inactive" means well exists but is no longer used as a water-supply. (b) Well Use: MUN = municipal and domestic supply
(c) Depth Code: This monitoring program assigns wells to aquifer layers by depth. P = Perched aquifer system, mainly in the Thermal subarea. S = Shallow aquifer system. D = Deep aquifer system K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 2 of 2
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Table 3-2. SNMP Groundwater Monitoring Network -- Deep Aquifer System 84 03S04E20F02S USGS 335348116352702 Active Monitoring 850-890 D Northwest area at WW-GRF 85 03S04E20J03S USGS 335339116345303 Active Monitoring 850-890 D Northeast area at WW-GRF 86 06S07E33G01S Coachella Valley Water District TEL-GRF MW-21D Active Monitoring 390-410 D Adjacent to and downgradient of TEL-GRF 87 06S07E33J01S Coachella Valley Water District TEL-GRF MW-22D Active Monitoring 520-540 D Adjacent to and downgradient of TEL-GRF 88 06S07E34N02S Coachella Valley Water District TEL-GRF MW-23D Active Monitoring 525-545 D Adjacent to and downgradient of TEL-GRF 89 07S09E30R03S Coachella Valley Water District Peggy Active Monitoring 730-770 D Downgradient of WRP-4; near agriculture; area of subsurface outflow toward Salton Sea 90 08S09E07N02S Coachella Valley Water District Rosie Active Monitoring 720-780 D Near agriculture; area of subsurface outflow toward Salton Sea 91 05S07E24L03S Indio Water Authority Well 1E Active MUN 552-815 D Center of Indio subbasin; upgradient of VSD plant 92 02S04E28J01S Mission Springs Water District Well 35 Active MUN 725-1020 D Downgradient from Mission Creek GRF 93 02S04E36P01S Mission Springs Water District Well 37 Active MUN 450-1080 D Downgradient of DHS subbasin; possibly downgradient of Horton WWTP 94 02S05E31H01S Mission Springs Water District Well 5 Inactive Monitoring 274-784 D Northern Miracle Hill subarea; upgradient of Mission Creek subbasin 95 03S03E07D01S Mission Springs Water District Well 25A Active MUN 500-740 D Monitoring of subsurface inflow from San Gorgonio Pass subbasin 96 03S04E04P01S CPV Sentinel 03S04E04P01S Active Unknown D Upgradient portion of Mission Creek subbasin 97 03S04E11A02S Mission Springs Water District Well 32 Active MUN 320-980 D Center of Mission Creek subbasin; near potential septic areas 98 03S03E08A01S Mission Springs Water District Well 26A Active MUN 320-600 D Monitoring of subsurface inflow from San Gorgonio Pass subbasin 99 03S03E10P01S Agua Caliente DWA P04 Active Unknown 476-776 D Upgradient of Whitewater GRF 100 03S04E14J01S Mission Springs Water District Well 33 Active MUN 360-650 D Along boundary of Mission Creek subbasin/Garnet Hill subarea 101 03S04E19L01S Desert Water Agency DWA Well 43 Active MUN 500-900 D Upgradient of Whitewater GRF 102 03S04E34H02S Desert Water Agency DWA Well 35 Active MUN 600-1000 D Upgradient of urban land uses in Palm Springs; downgradient of WW-GRF 103 03S04E36Q01S Desert Water Agency DWA Well 38 Active MUN 620-1000 D Upgradient of urban land uses in Palm Springs; downgradient of WW-GRF 104 04S04E02B01S Desert Water Agency DWA Well 22 Active MUN 570-1003 D Upgradient of urban land uses in Palm Springs; downgradient of WW-GRF 105 04S04E11Q02S Desert Water Agency DWA Well 18 Standby MUN 535-948 D Western portion of Indio subbasin; downgradient of septic areas 106 04S04E13C01S Desert Water Agency DWA Well 23 Active MUN 512-912 D Center of Indio subbasin; near airport 107 04S04E24E01S Desert Water Agency DWA Well 32 Active MUN 600-1000 D Western portion of Palm Springs subarea; near areas served non-potable water (NPW) 108 04S04E24H01S Desert Water Agency DWA Well 29 Active MUN 600-1000 D Upgradient of Palm Springs WTP percolation ponds 109 04S04E25C01S Desert Water Agency DWA Well 39 Active MUN 580-750 D Downgradient of Indian Canyon; near golf, septic, and areas served NPW 110 04S05E05A01S Coachella Valley Water District CVWD Well 4568-1 Active MUN 800-955 D Eastern edge of Indio subbasin; downgradient from Garnet Hill; upgradient of septic areas 111 04S05E08N01S Desert Water Agency DWA Well 41 Active MUN 610-1000 D Center of Indio subbasin; near airport, near golf courses and areas served NPW 112 04S05E09R01S Coachella Valley Water District CVWD Well 4567-1 Active MUN 855-1150 D Center of Indio subbasin; near golf courses and septic areas 113 04S05E15G01S Coachella Valley Water District CVWD Well 4521-1 Active MUN 500-800 D Center of Indio subbasin; near golf courses and septic areas 114 04S05E17Q02S Desert Water Agency DWA Well 31 Active MUN 600-1000 D Center of Indio subbasin; near airport, golf courses, and areas served NPW 115 04S05E25D02S Coachella Valley Water District CVWD Well 4507-2 Active MUN 860-1320 D Center of Indio subbasin; near golf courses and septic areas 116 04S05E27K01S Coachella Valley Water District CVWD Well 4527-1 Active MUN 850-1155 D Western edge of Indio subbasin; near NPR and septic areas 117 04S05E29H01S Desert Water Agency DWA Well 26 Active MUN 590-990 D Downgradient of Palm Springs WTP percolation ponds; near golf and areas served NPW 118 04S05E35G04S Coachella Valley Water District CVWD Well 4504-1 Active MUN 600-1000 D Western edge of Indio subbasin; near septic and areas served NPW 119 04S06E18Q04S Coachella Valley Water District CVWD Well 4630-1 Active MUN 480-990 D Upgradient in Thousand Palms area; upgradient of septic areas 120 04S06E28K04S Coachella Valley Water District CVWD Well 4629-1 Active Monitoring 496-796 D Thousand Palms area; near septic and areas served NPW 121 04S07E31H01S Coachella Valley Water District CVWD Well 4722-1 Active MUN 570-1160 D Thousand Palms area; near septic and areas served NPW 122 04S07E33L01S Coachella Valley Water District WRP7 MW-2D Active MUN 245-395 D Near WRP-7 percolation ponds 123 05S06E02C01S Coachella Valley Water District CVWD Well 5664-1 Active MUN 500-930 D Thousand Palms area; near septic and areas served NPW 124 05S06E06B03S Coachella Valley Water District CVWD Well 5630-1 Active Monitoring 455-890 D Center of Indio subbasin; near golf, septic, and areas served NPW 125 05S06E09A01S Coachella Valley Water District CVWD Well 5682-1 Active Monitoring 850-1300 D Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 126 05S06E09F01S Coachella Valley Water District CVWD Well 5637-1 Inactive MUN 450-830 D Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 127 05S06E14B02S Coachella Valley Water District CVWD Well 5665-1 Inactive MUN 400-600 D Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 128 05S06E14P02S Coachella Valley Water District CVWD Well 5603-2 Active MUN 720-975 D Downgradient of WRP-10/PD-GRF; near golf courses and areas served NPW 129 05S06E16A04S Coachella Valley Water District CVWD Well 5620-2 Active MUN 1040-1360 D Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 130 05S06E16K03S Coachella Valley Water District CVWD Well 5681-1 Active Monitoring 900-1200 D Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 131 05S06E17L01S Coachella Valley Water District CVWD Well 5667-1 Active Monitoring 470-800 D Western edge of Indio subbasin; near golf, septic, and areas served NPW 132 05S06E20A02S Coachella Valley Water District CVWD Well 5674-1 Inactive Monitoring 750-1050 D South/cross-gradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 133 05S07E03D01S Coachella Valley Water District WRP7 MW-4D Active MUN 245-395 D Near WRP-7 percolation ponds 134 05S07E04A01S Coachella Valley Water District WRP7 MW-1 Dave Price Active Monitoring 147-367 D Near WRP-7 percolation ponds 135 05S07E15N01S Indio Water Authority Well AA Active MUN 550-1230 D Center of Indio subbasin; downgradient from areas served NPW 136 05S07E19A01S Coachella Valley Water District CVWD Well 5708-1 Inactive MUN 450-970 D Western portion of Indio subbasin; near golf courses and areas served NPW 137 05S07E20J01S Indio Water Authority Well T Active MUN 580-1305 D Western portion of Indio subbasin; near golf courses and areas served NPW 138 05S07E26E02S Indio Water Authority Well 3B Active MUN 500-1200 D Center of Indio subbasin Depth
Code(c)Justification for Inclusion in SNMP Monitoring ProgramWell Use(b)
Screen
Interval
ft-bgs
Well
Status(a)Map_ID SWN Well Owner Well Name
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Last Revised: 4-16-21
Table 3-2. SNMP Groundwater Monitoring Network -- Deep Aquifer System Depth
Code(c)Justification for Inclusion in SNMP Monitoring ProgramWell Use(b)
Screen
Interval
ft-bgs
Well
Status(a)Map_ID SWN Well Owner Well Name
139 05S07E27P01S Indio Water Authority Well Z Active MUN 580-1290 D Center of Indio subbasin 140 05S07E33E01S Indio Water Authority Well S Active MUN 460-1260 D Western portion of Indio subbasin; near golf courses and septic areas 141 05S07E34P04S Indio Water Authority Well V Active MUN 460-1270 D Western portion of subbasin; near golf courses and septic areas 142 05S07E35R02S Indio Water Authority Well U Active MUN 480-1190 D Center of Indio subbasin 143 05S07E36D03S Coachella Water Authority Well 19 Active MUN 650-1250 D Center of Indio subbasin 144 05S08E31C03S Coachella Water Authority Well 11 Active MUN 513-818 D Eastern portion of Indio subbasin; downgradient from VSD plant 145 06S07E06B01S Coachella Valley Water District CVWD Well 6701-1 Active MUN 580-800 D Downgradient from The Cove; near golf courses and septic areas 146 06S07E22B02S Coachella Valley Water District CVWD Well 6726-1 Active MUN 640-1160 D North/downgradient of TEL-GRF; near golf courses, septic, and agricultural areas 147 06S07E34A01S Coachella Valley Water District CVWD Well 6728-1 Active MUN 500-750 D Downgradient from TEL-GRF; near golf courses 148 06S07E34D01S Coachella Valley Water District CVWD Well 6729-1 Active MUN 500-780 D Directly north/downgradient of TEL-GRF 149 06S08E06K02S Coachella Water Authority Well 12 Active MUN 500-1010 D Eastern portion of Indio subbasin 150 06S08E09N02S Coachella Water Authority Well 16 Active Monitoring 480-730 D Eastern portion of Indio subbasin; upgradient from CWA/CSD WWTP 151 06S08E19D05S Coachella Valley Water District CVWD Well 6808-1 Active MUN 675-1200 D Center of Indio subbasin; near septic and agricultural areas 152 06S08E22D02S Coachella Valley Water District CVWD Well 6803-1 Inactive MUN 500-1100 D Downgradient from CWA/CSD WWTP; near septic and agricultural areas 153 06S08E25P04S Coachella Valley Water District CVWD Well 6807-1 Active MUN 665-1300 D Upgradient of WRP-4; downgradient of CWA WWTP; near agriculture and septic areas 154 06S08E28N06S Coachella Water Authority Well 18 Active Monitoring 900-1190 D Eastern edge of Indio subbasin; downgradient of VSD discharge point 155 07S08E17A04S Coachella Valley Water District CVWD Well 7803-1 Active MUN 250-710 D Downgradient from TEL-GRF; in agricultural and septic areas 156 07S09E23N01S Coachella Valley Water District CVWD Well 7990-1 Inactive Unknown 530-560 D Southeastern corner of the basin; near agricultural and septic areas; near Salton Sea 157 Indio Water Authority Well 13A Active Irrigation 550-1171 D East in subbasin; downgradient from WRP-7 ponds and NPR areas 158 03S05E08B01S R.C Roberts 03S05E08B01S Undetermined Irrigation 356-516 D Downgradient of DHS subbasin; near golf course and septic areas 159 03S05E17M01S Desert Dunes Golf Club 03S05E17M01S Active Unknown 305-412 D Upgradient of Garnet Hill subarea; near golf course and septic areas 160 03S05E20H02S Donald Franklin 03S05E20H02S Active Irrigation 240-360 D Distal area in Mission Creek subbasin; upgradient of Garnet Hill subarea; near septic 161 03S06E21R01S Joel Rosenfeld 03S06E21R01S Undetermined Irrigation 355-495 D Western portion of Sky Valley subarea; near septic 162 05S05E12B03S Tandika Corp 05S05E12B03S Active Irrigation 410-800 D Western edge of Indio subbasin; near NPR and septic areas 163 05S06E13F01S PD Golf Operations LLC 05S06E13F01S Active Irrigation 400-700 D Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 164 05S06E15H01S Toscana Country Club 05S06E15H01S Active Irrigation 430-950 D Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 165 05S06E22C02S Desert Horizons Country Club 05S06E22C02S Active Irrigation 550-990 D Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 166 05S06E27A01S El Dorado Country Club 05S06E27A01S Active MUN 458-596 D South/cross-gradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 167 05S06E29P04S Bighorn Golf Club 05S06E29P04S Active MUN 530-720 D Upgradient of Palm Desert; near golf courses and septic areas 168 05S07E07F04S Myoma Dunes Mutual Water Company Well 4 Active MUN 430-730 D Center of Indio subbasin; near areas served NPW 169 05S07E08L01S Myoma Dunes Mutual Water Company Well 11 Active Unknown 500-1060 D Center of Indio subbasin; near areas served NPW 170 05S07E17K01S Myoma Dunes Mutual Water Company Well 12 Active Irrigation 450-950 D Center of Indio subbasin; near areas served NPW 171 05S08E09N03S Jamie Brack 05S08E09N03S Undetermined Unknown 480-580 D Downgradient of septic areas in Fargo subarea; upgradient of Indio subbasin 172 06S07E27B01S Andalusia Golf Club 06S07E27B01S Active Irrigation 300-780 D Downgradient of TEL-GRF; near golf course and agricultural areas 173 06S07E35L02S Castro Bros Castro Bros Active Unknown 300-400 D Downgradient from TEL-GRF; near golf courses and agricultural areas 174 06S08E11A01S Cocopah Nurseries Inc 06S08E11A01S Active Unknown 400-842 D Eastern edge of Indio subbasin; near agriculture; upgradient from CWA/CSD WWTP 175 06S08E31P01S Deer Creek Deer Creek Active Irrigation 400-550 D Downgradient from TEL-GRF, in agricultural area 176 06S08E35E02S Otto L. Zahler 06S08E35E02S Undetermined Unknown 521-596 D Center of Indio subbasin; directly upgradient of WRP-4; in agricultural area 177 07S07E02G02S Warren Webber Warren Webber Active Irrigation 380-700 D Downgradient from TEL-GRF; in agricultural area 178 07S08E01L02S Bill Wordon 07S08E01L02S Undetermined Domestic 500-880 D Center of Indio subbasin; downgradient of WRP-4, in agricultural area 179 07S08E27A02S Gimmway Enterprises Inc 07S08E27A02S Active MUN 491-811 D Downgradient from Martinez Canyon GRF; in agricultural area 180 07S09E10F01S Prime Time International 07S09E10F01S Active Unknown 360-500 D Southeast Indio subbasin; in agricultural area; near Salton Sea 181 Mission Springs Water District Well 31 Active MUN 270-670 D Upgradient of Garnet Hill subarea; near potential septic areas in N. Palm Springs (a) Well Status: Well Status: "Active" means well is known to exist and currently used for original purpose; "Standby" means active backup well; "Inactive" means well exists but is no longer used as a water-supply. (b) Well Use: MUN = municipal and domestic supply
(c) Depth Code: This monitoring program assigns wells to aquifer layers by depth. P = Perched aquifer system, mainly in the Thermal subarea. S = Shallow aquifer system. D = Deep aquifer system K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 2 of 2
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 4-16-21
Table 3-3. SNMP Groundwater Monitoring Network -- Perched Aquifer System 182 Coachella Valley Water District WRP2 MW3 Active Monitoring <90 P At WRP-2; represents subsurface discharge to Salton Sea 183 06S07E27J03S Coachella Valley Water District TEL-GRF MW-8 Active Monitoring 25-45 P North/downgradient of TEL-GRF; near golf course and agriculture 184 06S07E34A03S Coachella Valley Water District TEL-GRF MW-9 Active Monitoring 25-45 P Downgradient from TEL-GRF and golf course 185 06S08E31R01S Coachella Valley Water District TEL-GRF MW-10 Active Monitoring 25-45 P Downgradient from TEL-GRF; agricultural area 186 07S08E06P01S Coachella Valley Water District TEL-GRF MW-11 Active Monitoring 25-45 P Downgradient from TEL-GRF; agricultural area 187 Coachella Valley Water District PEW-1 Active Monitoring 10-55 P At WRP-4; agricultural area (a) Well Status: "Active" means well is known to exist and currently used for original purpose; "Standby" means active backup well; "Inactive" means well exists but is no longer used as a water-supply. (b) Well Use: MUN = municipal and domestic supply
(c) Depth Code: This monitoring program assigns wells to aquifer layers by depth. P = Perched aquifer system, mainly in the Thermal subarea. S = Shallow aquifer system. D = Deep aquifer system Well
Status(a)'Map_ID SWN Well Owner Well Name Depth
Code(c)Justification for Inclusion in SNMP Monitoring ProgramWell Use(b)
Screen
Interval
ft-bgs
K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 1 of 1
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-4. Gaps in SNMP Groundwater Monitoring Network
G1 S Monitoring of subsurface inflows from areas upgradient of Mission Creek GRF 700-1000 ft-bgs DWA, MSWD G2 S Monitoring directly downgradient of the planned MSWD West Valley WWTP 200-300 ft-bgs MSWD, DWA G3 S Monitoring of southern Miracle Hill subarea; near septic; upgradient of Desert Crest WWTP 100-300 ft-bgs CVWD G4 S Monitoring of the Fargo subarea of DHS subbasin; near septic 100-300 ft-bgs CVWD G5 S Monitoring upgradient of urban land uses in Palm Springs; downgradient of WW-GRF 300-500 ft-bgs DWA G6 S Monitoring center of Indio subbasin; near airport, golf courses, and areas served non-potable water (NPW)250-350 ft-bgs DWA G7 S Monitoring a spatial gap in western portion of Indio subbasin; near golf courses, septic and areas served NPW 200-300 ft-bgs CVWD G8 S Monitoring of subsurface inflows from areas upgradient of urban land uses in Palm Desert Canyon 250-400 ft-bgs CVWD G9 S Monitoring a spatial gap in western portion of Indio subbasin; near golf courses and septic 100-250 ft-bgs CVWD, IWA G10 S Monitoring downgradient from CWA/CSD WWTP; near septic areas and agriculture 100-250 ft-bgs CVWD G11 S Monitoring a spatial gap downgradient of TEL-GRF; near golf courses, septic, and agricultural areas 85-160 ft-bgs CVWD G12 S Monitoring a spatial gap in center of Indio subbasin; near septic areas and agriculture 100-235 ft-bgs CVWD G13 S Monitoring a spatial gap downgradient from TEL-GRF; in agricultural areas 50-150 ft-bgs CVWD G14 S Monitoring a spatial gap downgradient of WRP-4; in agricultural area; near Salton Sea 100-250 ft-bgs CVWD G15 S Monitoring a spatial gap directly upgradient of WRP-4; in agricultural area 100-275 ft-bgs CVWD G16 S Monitoring a spatial gap upgradient of WRP-4; downgradient of CWA/CSD WWTP; near agriculture, septic 100-250 ft-bgs CVWD G17 P Monitoring a spatial gap in northern portion of Perched area; downgradient from Fargo subarea <100 ft-bgs CVWD, IWA, VSD G18 P Monitoring a spatial gap on eastern side of Perched area; in agricultural area <70 ft-bgs CVWD, CWA/CSD G19 P Monitoring a spatial gap in center of Perched area; near agricultural and septic areas <90 ft-bgs CVWD, CWA/CSD G20 P Monitoring a spatial gap in southern basin; may represent subsurface discharge to Salton Sea <70 ft-bgs CVWD G21 P Monitoring a spatial gap in southern basin; may represent subsurface discharge to Salton Sea <70 ft-bgs CVWD G22 P Monitoring a spatial gap in southern basin; may represent subsurface discharge to Salton Sea <90 ft-bgs CVWD G23 S Monitoring a spatial gap in Thousand Palms area; near septic and areas served NPW 150-300 ft-bgs CVWD (b) CVWD = Coachella Valley Water District; CWA/CSD = Coachella Water Authority and Sanitary District; DWA = Desert Water Agency; IWA = Indio Water Authority; VSD = Valley Sanitary District; MSWD = Mission Springs Water District
(a) Depth Code: This monitoring program assigns wells to aquifer layers by depth. P = Perched aquifer system, mainly in the Thermal subarea. S = Shallow aquifer system.
Map_ID Approx. Depth
of Well Screens
Depth
Code(a)Justification for Inclusion in SNMP Monitoring Program Overlying SNMP Agency(b)
K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 1 of 1
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-5. Analyte List for the SNMP Groundwater Monitoring Program Analytes Justification Method Cost/Sample
Total Dissolved Solids Measure of total dissolved salt content in water E160.1/SM2540C $14 Nitrate as Nitrogen Primary nutrient in groundwater EPA 300.0 $12 Major cations: K, Na, Ca, Mg Useful in source water characterization EPA 200.7 $20 Major anions: Cl, SO4 Useful in source water characterization EPA 300.0 $18 Total Alkalinity (HCO3, CO3, OH)Useful in source water characterization SM 2320B/2330B $13 K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 1 of 1
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-6. Responsibilities for Groundwater Sampling and Laboratory Analyses 1 03S04E20F01S USGS 335348116352701 Active Monitoring 600-640 S CVWD 2 03S04E20J01S USGS 335339116345301 Active Monitoring 550-590 S CVWD 3 06S07E33G02S Coachella Valley Water District TEL-GRF MW-21S Active Monitoring 230-250 S CVWD 4 06S07E33J02S Coachella Valley Water District TEL-GRF MW-22S Active Monitoring 230-250 S CVWD 5 06S07E34N03S Coachella Valley Water District TEL-GRF MW-23S Active Monitoring 230-250 S CVWD 7 02S04E26C01S Mission Springs Water District Well 28 Inactive MUN 590-898 S MSWD 8 02S04E28A01S Mission Springs Water District Well 34 Active MUN 550-980 S MSWD 9 02S05E31L01S Mission Springs Water District Well 11 Inactive Unknown 220-285 S MSWD 10 03S04E04Q02S CPV Sentinel 03S04E04Q02S Active Unknown S DWA, MSWD 11 03S04E11L01S Mission Springs Water District Well 27 Active MUN 180-380 S MSWD 12 03S05E05Q01S Hidden Springs Golf Course P27 Active Unknown 220-600 S DWA, MSWD 13 City of Palm Springs Airport MW-2 Active Monitoring 240-250 S CPS 14 City of Palm Springs MW-1 Active Monitoring 170-210 S CPS 15 City of Palm Springs MW-3 Active Monitoring 140-215 S CPS 16 City of Palm Springs MW-4 Active Monitoring 170-210 S CPS 17 City of Palm Springs MW-5 Active Monitoring 170-210 S CPS 18 City of Palm Springs MW-6 Active Monitoring 170-210 S CPS 19 03S03E08M01S Mission Springs Water District Well 26 Active MUN 225-553 S MSWD 20 03S03E10P02S Agua Caliente DWA P05 Active Unknown 306-906 S DWA 21 03S04E12B02S Coachella Valley Water District CVWD Well 3408-1 Active MUN 270-500 S CVWD 22 03S04E29F01S USGS 335304116353001 Active Monitoring 550-570 S CVWD 23 03S04E29R01S USGS 335231116345401 Active Monitoring 431-551 S CVWD 24 04S04E11Q01S Desert Water Agency DWA Well 5 Standby MUN 302-402 S DWA 25 04S04E35A01S Agua Caliente Indian Canyons Well Active Unknown 360-680 S DWA 26 04S05E09F03S Coachella Valley Water District CVWD Well 4564-1 Active MUN 410-670 S CVWD 27 04S05E29A02S Desert Water Agency DWA Well 25 Active MUN 166-300 S DWA 29 04S07E33L02S Coachella Valley Water District WRP7 MW-2S Active Monitoring 60-190 S CVWD 30 05S06E09M03S Coachella Valley Water District WRP10 MW-7 Active Monitoring 260-340 S CVWD 31 05S06E09P02S Coachella Valley Water District PD-GRF MW 2 Active Monitoring 260-340 S CVWD 32 05S06E10J01S Coachella Valley Water District PD-GRF MW 1 Active Monitoring 260-340 S CVWD 33 05S06E13G03S Coachella Valley Water District WRP10 MW-8 Active Monitoring 260-340 S CVWD 34 05S06E14G03S Coachella Valley Water District WRP10 MW-5 Active Monitoring 240-320 S CVWD 35 05S06E14P03S Coachella Valley Water District WRP10 MW-6 Active Monitoring 190-270 S CVWD 36 05S06E15F01S Coachella Valley Water District WRP10 MW-2 Active Monitoring 160-290 S CVWD 37 05S06E15M01S Coachella Valley Water District WRP10 MW-1 Active Monitoring 145-295 S CVWD 38 05S06E15P01S Coachella Valley Water District WRP10 MW-3 Active Monitoring 130-290 S CVWD 39 05S06E16A03S Coachella Valley Water District WRP10 MW-4 Active Monitoring 190-270 S CVWD 40 05S06E21Q04S Coachella Valley Water District PD-GRF MW 3 Active Monitoring 260-340 S CVWD 41 05S06E23M02S Coachella Valley Water District PD-GRF MW 4 Active Monitoring 270-360 S CVWD 42 05S07E03D02S Coachella Valley Water District WRP7 MW-4S Active Monitoring 60-190 S CVWD 43 05S07E04A04S Coachella Valley Water District WRP7 MW-3S Active Monitoring 50-180 S CVWD 44 05S07E16K02S Coachella Valley Water District CVWD Well 5737-1 Inactive MUN 200-415 S CVWD, IWA, VSD 45 05S07E19D04S Coachella Valley Water District WRP10 MW-9 Active Monitoring 260-340 S CVWD 46 05S07E24M02S Indio Water Authority Well 1B Active Monitoring 190-410 S IWA 47 06S06E12G01S Coachella Valley Water District CVWD Well 6650-1 Inactive Monitoring <370 S CVWD 48 06S07E34A02S Coachella Valley Water District TEL-GRF MW-25 Active Monitoring 115-135 S CVWD 49 06S07E34D02S Coachella Valley Water District TEL-GRF MW-24 Active MUN 180-200 S CVWD 50 07S08E29P03S Coachella Valley Water District MC-3 Active Unknown 380-440 S CVWD 51 08S09E31R03S Coachella Valley Water District CVWD Well 8995-1 Active Unknown 260-390 S CVWD 52 03S04E17K01S Valley View MWC 03S04E17K01S Undetermined Fish Farm 340-375 S DWA, MSWD 53 03S04E22A01S Erin Miner 03S04E22A01S Active Irrigation 180-230 S DWA 54 03S05E08P02S Bluebeyond Fisheries 03S05E08P02S Active Irrigation 200-400 S CVWD 55 03S05E15N01S Too Many Palms LLC 03S05E15N01S Active Unknown 158-320 S CVWD 56 03S05E18J01S Desert Dunes Golf Club 03S05E18J01S Active Irrigation 76-340 S CVWD 57 03S06E21G01S Sky Valley Mobile Home Park 03S06E21G01S Undetermined Irrigation 188-248 S CVWD 58 04S05E04F01S So Pacific Trans Co #32601 04S05E04F01S Active Irrigation 276-576 S CVWD 59 04S05E23F01S Westin Mission Hills Resort 04S05E23F01S Active Irrigation 275-1165 S CVWD 60 04S05E34C01S Manufacture Home Community Inc 04S05E34C01S Active Irrigation 240-500 S CVWD 61 04S05E35Q01S Tamarisk Country Club 04S05E35Q01S Active Irrigation 171-518 S CVWD 62 04S05E36L02S Annenberg Estate 04S05E36L02S Active Unknown 252-650 S CVWD 63 04S06E20C01S Shenandoah Ventures LP 04S06E20C01S Inactive Irrigation 250-790 S CVWD 66 05S05E12D01S Thunderbird Country Club 05S05E12D01S Active Domestic 125-360 S CVWD 67 05S06E12M01S Palm Desert Resort Country Club 05S06E12M01S Active Domestic 140-650 S CVWD 68 05S07E08Q01S Bermuda Dunes Airport 05S07E08Q01S Active Unknown 203-654 S CVWD, MDMWC Well
Use(b)
Screen
Interval
ft-bgs
Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)
Overlying
SNMP Agency(d)
K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 1 of 3
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 4-16-21
Table 3-6. Responsibilities for Groundwater Sampling and Laboratory Analyses Well
Use(b)
Screen
Interval
ft-bgs
Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)
Overlying
SNMP Agency(d)
69 05S07E28H02S Tricon/COB Riverdale LP 05S07E28H02S Active Domestic 162-636 S CVWD, IWA, VSD 70 05S08E28M02S JS Cooper 05S08E28M02S Undetermined Irrigation 208-268 S CVWD, CWA/CSD 71 05S08E30N03S Carver Tract Mutual Water Co 05S08E30N03S Active Irrigation 270-330 S CVWD, VSD 72 06S07E07B01S Traditions Golf Club 06S07E07B01S Active Irrigation 200-480 S CVWD 73 06S08E02L01S Prime Time International 06S08E02L01S Undetermined Unknown 216-407 S CVWD, CWA/CSD 74 06S08E05K01S Peter Rabbit Farms 06S08E05K01S Active Domestic 126-375 S CVWD, CWA/CSD 75 06S08E32L01S Guillermo Torres 06S08E32L01S Undetermined Domestic 127-227 S CVWD 76 07S08E27A01S Gimmway Enterprises Inc 07S08E27A01S Active Irrigation 147-215 S CVWD 77 07S09E14C01S Tudor Ranch Inc.07S09E14C01S Active MUN 93-290 S CVWD 78 08S08E15G02S Thermiculture Management LLC 08S08E15G02S Active Monitoring 260-500 S CVWD 79 Mission Springs Water District Well 25 Active Monitoring 330-455 S MSWD 80 Mission Springs Water District Well 1 Inactive Monitoring S MSWD 81 Mission Springs Water District Horton WWTP MW-1 Active Monitoring 186-236 S MSWD 82 Mission Springs Water District Horton WWTP MW-2 Active Monitoring 220-270 S MSWD 83 Mission Springs Water District Horton WWTP MW-3 Active Monitoring 200-250 S MSWD 84 03S04E20F02S USGS 335348116352702 Active Monitoring 850-890 D CVWD 85 03S04E20J03S USGS 335339116345303 Active Monitoring 850-890 D CVWD 86 06S07E33G01S Coachella Valley Water District TEL-GRF MW-21D Active Monitoring 390-410 D CVWD 87 06S07E33J01S Coachella Valley Water District TEL-GRF MW-22D Active Monitoring 520-540 D CVWD 88 06S07E34N02S Coachella Valley Water District TEL-GRF MW-23D Active Monitoring 525-545 D CVWD 89 07S09E30R03S Coachella Valley Water District Peggy Active MUN 730-770 D CVWD 90 08S09E07N02S Coachella Valley Water District Rosie Active MUN 720-780 D CVWD 91 05S07E24L03S Indio Water Authority Well 1E Active MUN 552-815 D IWA 92 02S04E28J01S Mission Springs Water District Well 35 Active Monitoring 725-1020 D MSWD 93 02S04E36P01S Mission Springs Water District Well 37 Active MUN 450-1080 D MSWD 94 02S05E31H01S Mission Springs Water District Well 5 Inactive Unknown 274-784 D MSWD 95 03S03E07D01S Mission Springs Water District Well 25A Active MUN 500-740 D MSWD 96 03S04E04P01S CPV Sentinel 03S04E04P01S Active MUN D DWA, MSWD 97 03S04E11A02S Mission Springs Water District Well 32 Active Unknown 320-980 D MSWD 98 03S03E08A01S Mission Springs Water District Well 26A Active MUN 320-600 D MSWD 99 03S03E10P01S Agua Caliente DWA P04 Active MUN 476-776 D DWA 100 03S04E14J01S Mission Springs Water District Well 33 Active MUN 360-650 D MSWD 101 03S04E19L01S Desert Water Agency DWA Well 43 Active MUN 500-900 D DWA 102 03S04E34H02S Desert Water Agency DWA Well 35 Active MUN 600-1000 D DWA 103 03S04E36Q01S Desert Water Agency DWA Well 38 Active MUN 620-1000 D DWA 104 04S04E02B01S Desert Water Agency DWA Well 22 Active MUN 570-1003 D DWA 105 04S04E11Q02S Desert Water Agency DWA Well 18 Standby MUN 535-948 D DWA 106 04S04E13C01S Desert Water Agency DWA Well 23 Active MUN 512-912 D DWA 107 04S04E24E01S Desert Water Agency DWA Well 32 Active MUN 600-1000 D DWA 108 04S04E24H01S Desert Water Agency DWA Well 29 Active MUN 600-1000 D DWA 109 04S04E25C01S Desert Water Agency DWA Well 39 Active MUN 580-750 D DWA 110 04S05E05A01S Coachella Valley Water District CVWD Well 4568-1 Active MUN 800-955 D CVWD 111 04S05E08N01S Desert Water Agency DWA Well 41 Active MUN 610-1000 D DWA 112 04S05E09R01S Coachella Valley Water District CVWD Well 4567-1 Active MUN 855-1150 D CVWD 113 04S05E15G01S Coachella Valley Water District CVWD Well 4521-1 Active MUN 500-800 D CVWD 114 04S05E17Q02S Desert Water Agency DWA Well 31 Active MUN 600-1000 D DWA 115 04S05E25D02S Coachella Valley Water District CVWD Well 4507-2 Active MUN 860-1320 D CVWD 116 04S05E27K01S Coachella Valley Water District CVWD Well 4527-1 Active MUN 850-1155 D CVWD 117 04S05E29H01S Desert Water Agency DWA Well 26 Active MUN 590-990 D DWA 118 04S05E35G04S Coachella Valley Water District CVWD Well 4504-1 Active MUN 600-1000 D CVWD 119 04S06E18Q04S Coachella Valley Water District CVWD Well 4630-1 Active MUN 480-990 D CVWD 120 04S06E28K04S Coachella Valley Water District CVWD Well 4629-1 Active Monitoring 496-796 D CVWD 121 04S07E31H01S Coachella Valley Water District CVWD Well 4722-1 Active MUN 570-1160 D CVWD 122 04S07E33L01S Coachella Valley Water District WRP7 MW-2D Active MUN 245-395 D CVWD 123 05S06E02C01S Coachella Valley Water District CVWD Well 5664-1 Active MUN 500-930 D CVWD 124 05S06E06B03S Coachella Valley Water District CVWD Well 5630-1 Active Monitoring 455-890 D CVWD 125 05S06E09A01S Coachella Valley Water District CVWD Well 5682-1 Active Monitoring 850-1300 D CVWD 126 05S06E09F01S Coachella Valley Water District CVWD Well 5637-1 Inactive MUN 450-830 D CVWD 127 05S06E14B02S Coachella Valley Water District CVWD Well 5665-1 Inactive MUN 400-600 D CVWD 128 05S06E14P02S Coachella Valley Water District CVWD Well 5603-2 Active MUN 720-975 D CVWD 129 05S06E16A04S Coachella Valley Water District CVWD Well 5620-2 Active MUN 1040-1360 D CVWD 130 05S06E16K03S Coachella Valley Water District CVWD Well 5681-1 Active Monitoring 900-1200 D CVWD 131 05S06E17L01S Coachella Valley Water District CVWD Well 5667-1 Active Monitoring 470-800 D CVWD 132 05S06E20A02S Coachella Valley Water District CVWD Well 5674-1 Inactive Monitoring 750-1050 D CVWD K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 2 of 3
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 4-16-21
Table 3-6. Responsibilities for Groundwater Sampling and Laboratory Analyses Well
Use(b)
Screen
Interval
ft-bgs
Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)
Overlying
SNMP Agency(d)
133 05S07E03D01S Coachella Valley Water District WRP7 MW-4D Active MUN 245-395 D CVWD 134 05S07E04A01S Coachella Valley Water District WRP7 MW-1 Active Monitoring 147-367 D CVWD 135 05S07E15N01S Indio Water Authority Well AA Active MUN 550-1230 D IWA 136 05S07E19A01S Coachella Valley Water District CVWD Well 5708-1 Inactive MUN 450-970 D CVWD 137 05S07E20J01S Indio Water Authority Well T Active MUN 580-1305 D IWA 138 05S07E26E02S Indio Water Authority Well 3B Active MUN 500-1200 D IWA 139 05S07E27P01S Indio Water Authority Well Z Active MUN 580-1290 D IWA 140 05S07E33E01S Indio Water Authority Well S Active MUN 460-1260 D IWA 141 05S07E34P04S Indio Water Authority Well V Active MUN 460-1270 D IWA 142 05S07E35R02S Indio Water Authority Well U Active MUN 480-1190 D IWA 143 05S07E36D03S Coachella Water Authority Well 19 Active MUN 650-1250 D CWA/CSD 144 05S08E31C03S Coachella Water Authority Well 11 Active MUN 513-818 D CWA/CSD 145 06S07E06B01S Coachella Valley Water District CVWD Well 6701-1 Active MUN 580-800 D CVWD 146 06S07E22B02S Coachella Valley Water District CVWD Well 6726-1 Active MUN 640-1160 D CVWD 147 06S07E34A01S Coachella Valley Water District CVWD Well 6728-1 Active MUN 500-750 D CVWD 148 06S07E34D01S Coachella Valley Water District CVWD Well 6729-1 Active MUN 500-780 D CVWD 149 06S08E06K02S Coachella Water Authority Well 12 Active MUN 500-1010 D CWA/CSD 150 06S08E09N02S Coachella Water Authority Well 16 Active Monitoring 480-730 D CWA/CSD 151 06S08E19D05S Coachella Valley Water District CVWD Well 6808-1 Active MUN 675-1200 D CVWD 152 06S08E22D02S Coachella Valley Water District CVWD Well 6803-1 Inactive MUN 500-1100 D CVWD 153 06S08E25P04S Coachella Valley Water District CVWD Well 6807-1 Active MUN 665-1300 D CVWD 154 06S08E28N06S Coachella Water Authority Well 18 Active Monitoring 900-1190 D CWA/CSD 155 07S08E17A04S Coachella Valley Water District CVWD Well 7803-1 Active MUN 250-710 D CVWD 156 07S09E23N01S Coachella Valley Water District CVWD Well 7990-1 Inactive Unknown 530-560 D CVWD 157 Indio Water Authority Well 13A Active Irrigation 550-1171 D IWA 158 03S05E08B01S R.C Roberts 03S05E08B01S Undetermined Irrigation 356-516 D DWA 159 03S05E17M01S Desert Dunes Golf Club 03S05E17M01S Active Unknown 305-412 D CVWD 160 03S05E20H02S Donald Franklin 03S05E20H02S Active Irrigation 240-360 D CVWD 161 03S06E21R01S Joel Rosenfeld 03S06E21R01S Undetermined Irrigation 355-495 D CVWD 162 05S05E12B03S Tandika Corp 05S05E12B03S Active Irrigation 410-800 D CVWD 163 05S06E13F01S PD Golf Operations LLC 05S06E13F01S Active Irrigation 400-700 D CVWD 164 05S06E15H01S Toscana Country Club 05S06E15H01S Active Irrigation 430-950 D CVWD 165 05S06E22C02S Desert Horizons Country Club 05S06E22C02S Active Irrigation 550-990 D CVWD 166 05S06E27A01S El Dorado Country Club 05S06E27A01S Active MUN 458-596 D CVWD 167 05S06E29P04S Bighorn Golf Club 05S06E29P04S Active MUN 530-720 D CVWD 168 05S07E07F04S Myoma Dunes Mutual Water Company Well 4 Active MUN 430-730 D MDMWC 169 05S07E08L01S Myoma Dunes Mutual Water Company Well 11 Active Unknown 500-1060 D MDMWC 170 05S07E17K01S Myoma Dunes Mutual Water Company Well 12 Active Irrigation 450-950 D MDMWC 171 05S08E09N03S Jamie Brack 05S08E09N03S Undetermined Unknown 480-580 D CVWD, IWA 172 06S07E27B01S Andalusia Golf Club 06S07E27B01S Active Irrigation 300-780 D CVWD 173 06S07E35L02S Castro Bros Castro Bros Active Unknown 300-400 D CVWD 174 06S08E11A01S Cocopah Nurseries Inc 06S08E11A01S Active Unknown 400-842 D CVWD, CWA/CSD 175 06S08E31P01S Deer Creek Deer Creek Active Irrigation 400-550 D CVWD 176 06S08E35E02S Otto L. Zahler 06S08E35E02S Undetermined Unknown 521-596 D CVWD 177 07S07E02G02S Warren Webber Warren Webber Active Irrigation 380-700 D CVWD 178 07S08E01L02S Bill Wordon 07S08E01L02S Undetermined Domestic 500-880 D CVWD 179 07S08E27A02S Gimmway Enterprises Inc 07S08E27A02S Active MUN 491-811 D CVWD 180 07S09E10F01S Prime Time International 07S09E10F01S Active Monitoring 360-500 D CVWD 181 Mission Springs Water District Well 31 Active Monitoring 270-670 D MSWD 182 Coachella Valley Water District WRP2 MW3 Active Monitoring <90 P CVWD 183 06S07E27J03S Coachella Valley Water District TEL-GRF MW-8 Active Monitoring 25-45 P CVWD 184 06S07E34A03S Coachella Valley Water District TEL-GRF MW-9 Active Monitoring 25-45 P CVWD 185 06S08E31R01S Coachella Valley Water District TEL-GRF MW-10 Active Monitoring 25-45 P CVWD 186 07S08E06P01S Coachella Valley Water District TEL-GRF MW-11 Active Monitoring 25-45 P CVWD 187 Coachella Valley Water District PEW-1 Active Monitoring 10-55 P CVWD (a) Well Status: "Active" means well is known to exist and currently used for original purpose; "Standby" means active backup well; "Inactive" means well exists but is no longer used as a water-supply. (b) Well Use: MUN = municipal and domestic supply
(c) Depth Code: This monitoring program assigns wells to aquifer layers by depth. P = Perched aquifer system. S = Shallow aquifer system. D = Deep aquifer system (d) CVWD = Coachella Valley Water District; CWA/CSD = Coachella Water Authority and Sanitary District; DWA = Desert Water Agency; IWA = Indio Water Authority; MDMWC = Myoma Dunes Mutual Water Company; VSD = Valley Sanitary District; MSWD = Mission Springs Water District; CPS = City of Palm Springs K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 3 of 3
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 4-16-21
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CV-SNMP DEVELOPMENT WORKPLAN
This section describes:
• The logic and reasoning behind this proposed CV-SNMP Development Workplan, and how it ensures the development of a CV-SNMP that will comply with State law and Policy. • The detailed scope of work for the CV-SNMP Development Workplan.
Through discussions and advice from West Yost Associates, the CV-SNMP Agencies have concluded that numeric objectives for TDS and nitrate in groundwater are necessary for a CV-SNMP that complies with the 2018 Policy and resolves the concerns of the Regional Board with the 2015 CV-SNMP. Numeric objectives in the CV-SNMP will be necessary to:
• Demonstrate that beneficial uses are protected.
• Quantify the magnitude of available assimilative capacity for salt and nutrient loading. • Provide a technical basis for the Regional Board to allocate the use of assimilative capacity. • Set triggers for implementation measures at appropriate locations and times.
Currently, the Basin Plan includes a nitrate-nitrogen objective of 10 mgl for groundwater in the Coachella Valley based on the primary drinking water MCL but lacks scientifically-derived numeric TDS objectives that are consistent with the provisions of Title 22. The process to recommend numeric TDS objectives needs to include technically-defensible methods and tools to answer the following questions:
• What are logical management areas within the Basin (management zones) and the beneficial uses of groundwater within the management zones?
• What is current groundwater quality? And, is current groundwater quality protective of beneficial uses?
• How is groundwater quality expected to change in the future, both across the basin and within the depth-specific aquifer systems?
• Will these changes in groundwater quality impact beneficial uses? If so, where and when? • What are economically and technically feasible salt management strategies, that when implemented, will achieve the objectives of both the CV-SNMP stakeholders and the Regional Board? Economic feasibility needs to be defined and should consider the sources of revenue and the factors that could restrict the sources of revenue.
California Water Code section 13241 (CWC 13241) describes the factors to consider when establishing the TDS objectives:
a) Past, present, and probable future beneficial uses of water. b) Environmental characteristics of the hydrographic unit under consideration, including the quality of water available thereto.
c) Water quality conditions that could reasonably be achieved through the coordinated control of all factors which affect water quality in the area.
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d) Economic considerations.
e) The need for developing housing within the region.
f) The need to develop and use recycled water.
The CV-SNMP Development Workplan must address each of these factors in CWC 13241, and answer the questions above, when recommending the TDS objectives for groundwater to ensure that the Basin is put to maximum beneficial use while also protecting water quality pursuant to State law and Policy.
The proposed scope-of-work for the CV-SNMP Development Workplan is described in the subsections below, and is organized as follows:
Task 4.1 Select Consultants for CV-SNMP Facilitation and Technical Services Task 4.2 Establish CV-SNMP Stakeholder Group and Technical Advisory Committee Task 4.3 Characterize N/TDS Loading to the Groundwater Basin Task 4.4 Characterize Current Groundwater Quality
Task 4.5 Delineate Draft Management Zones and Describe Metrics to Characterize Beneficial Use Protection
Task 4.6 Develop Technical Approach for Forecasting N/TDS Concentrations in Groundwater Task 4.7 Construct N/TDS Forecasting Tools and Evaluate the Baseline Scenario Task 4.8 Forecast N/TDS Concentrations for CV-SNMP Scenarios Task 4.9 Characterize and Compare the Cost of Baseline and CV-SNMP Scenarios Task 4.10 Select the Preferred CV-SNMP Scenario, Finalize Management Zones and Beneficial Uses, and Recommend TDS Objectives
Task 4.11 Prepare Final CV-SNMP
Table 4-1 describes how this CV-SNMP Development Workplan will result in a CV-SNMP that satisfies all recommended and required components for SNMPs pursuant to the 2018 Policy.
4.1 Select Consultants for CV-SNMP Facilitation and Technical Services The objective of this task is to select a qualified consultant(s) to facilitate and execute the implementation of this workplan.
• A Facilitation Consultant will be responsible for leading and conducting stakeholder outreach and engagement efforts, leading and attending all stakeholder and technical meetings, and co- authoring all interim and final project deliverables with the Technical Consultant. Qualifications for the Facilitation Consultant include comprehensive knowledge of the legal, policy, and regulatory issues regarding SNMPs; successful experience in leading stakeholder groups; and local knowledge of the Coachella Valley and its CV-SNMP stakeholders, including the agricultural, golf, and tribal entities.
• A Technical Consultant will be responsible for executing the technical scope-of-work described in this workplan. Minimum qualifications for the Technical Consultant include: successful experience in characterizing water quality and the fate and transport of salt and nutrients; successful
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experience in water and groundwater management planning; successful experience in modeling of water quality; and local knowledge of the hydrology, hydrogeology, and water resources of the Coachella Valley. Preferred qualifications include a working knowledge and of the legal, policy, and regulatory issues regarding SNMPs and successful experience in leading technical committees.
In this task, the CV-SNMP Agencies will prepare a request for qualification (RFQ) or request for proposals (RFP) and select a qualified consultant(s) for stakeholder facilitation and technical services. Once the consultant(s) is selected, the CV-SNMP Agencies will negotiate and issue a contract(s).
4.2 Establish CV-SNMP Stakeholder Group and Technical Advisory Committee
The objective of this task is to convene a CV-SNMP Stakeholder Group and the CV-SNMP Technical Advisory Committee (TAC). The CV-SNMP Agencies and the selected consultants will organize and facilitate both groups during the implementation of the CV-SNMP Development Workplan.
4.2.1 Convene the CV-SNMP Stakeholder Group
The CV-SNMP Stakeholder Group will be comprised of the CV-SNMP Agencies, other salt and nutrient contributors to groundwater, and other interested groups. The objectives of convening the CV-SNMP Stakeholder Group are:
• Provide the CV-SNMP Agencies with a venue to engage interested parties in the CV-SNMP development process.
• Inform the CV-SNMP development process of the needs and wants of all interested parties. • Provide a venue to keep the interested parties informed through key steps of the CV-SNMP development process.
• Understand the ability/authority of the stakeholders to implement best management practices and salt and nutrient management measures.
• Provide a mechanism to receive input on draft CV-SNMP deliverables. • Garner participation from other salt and nutrient contributors to groundwater. • Identify potential cost-sharing partners and in-kind services for CV-SNMP implementation.
The CV-SNMP Agencies and the Facilitation Consultant will conduct outreach to identify stakeholders and inform them of the intent to form the CV-SNMP Stakeholder Group. Outreach activities will include but are not limited to:
• Prepare and maintain a website that is available to the public with information on the CV-SNMP development and the public’s role in the process.
• Distribute public notices on the development of the CV-SNMP and the establishment of the CV- SNMP Stakeholder Group. The public notices will include the website details and information on introductory public meetings.
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• Lead two (2) public meetings to request stakeholder engagement and explain the purpose of the CV-SNMP and the process to develop it.
• Prepare and maintain a directory of contact information of stakeholders and establish an email listserve.
Potential stakeholders include but are not limited to: the agricultural community and groups; golf course industry groups; tribes; the Coachella Valley Regional Water Management Group; the Groundwater Sustainability Agencies in the Coachella Valley; all major water and wastewater agencies; industrial dischargers; county and city land use planning agencies; Federal and State agencies; the Colorado River Basin Salinity Control Forum; Metropolitan Water District of Southern California; and non-governmental organizations (NGOs).
A critical first step will be to solicit input from the CV-SNMP Stakeholder Group as to their issues, needs and wants. This information will be collected up front so the CV-SNMP Agencies and consultants can proactively address stakeholder concerns, and potentially incorporate them in the CV-SNMP development process.
The CV-SNMP Stakeholder Group will be kept informed of CV-SNMP development progress through the website and email listserves. The group will be informed of draft deliverables and provided an opportunity to submit comments. All stakeholder comments will be noted in appendices of the final deliverables.
Group meetings will typically occur to support the review of draft deliverables, and these meetings are included in the individual tasks of this workplan.
4.2.2 Convene the CV-SNMP Technical Advisory Committee
The TAC can be composed of representatives of the CV-SNMP Agencies, technical consultants that each CV-SNMP Agency chooses to represent them, and at least one neutral technical expert (e.g., U.S.
Geological Survey [USGS] hydrologist). Regional Board staff will be encouraged to participate on the TAC in an advisory role.
The objectives of the TAC are:
• Advise the Technical Consultant on the execution of workplan tasks. • Provide review and comment on administrative draft and draft CV-SNMP deliverables.
The Technical Consultant will coordinate with the CV-SNMP Agencies to prepare a directory of contact information of TAC members and will establish an email listserve. The TAC will be kept informed of CV- SNMP development progress through the website and the email listserve. The group will be informed of all draft deliverables and will be provided an opportunity to submit comments. All TAC comments will be addressed in the final deliverables, and the comments and responses will be included as appendices of the final deliverables.
An inaugural meeting of the TAC will be held to describe the roles and responsibilities of the TAC, describe the CV-SNMP Development Workplan and its milestones and schedule, and inform the TAC of next steps.
Subsequent meetings of the TAC will typically occur for review of draft deliverables, and these meetings are included in the individual tasks of this workplan.
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4.3 Characterize N/TDS Loading to the Groundwater Basin The objective of this task is to quantify the individual components of N/TDS loading to groundwater.
The results of this task will:
• Satisfy the requirements of Section 6.2.4 of the Policy regarding the required components of SNMPs:
Section 6.2.4.3. Salt and nutrient source identification, basin or subbasin assimilative capacity and loading estimates, together with fate and transport of salts and nutrients. • Provide the information to prepare input files for the modeling of future N/TDS concentrations in groundwater.
• Support subsequent tasks in this workplan to recommend TDS objectives pursuant to CWC 13241(b): Environmental characteristics of the hydrographic unit under consideration, including the quality of water available thereto.
The general sources of N/TDS loading in the basin are described in Section 2.3.1. The characterization of N/TDS loading will be performed for a recent historical period to the present to characterize seasonal variations and long-term trends in loading and generate estimates of N/TDS loads in the vadose zone. The length of the historical period will be defined as part of this task but should be long enough to characterize the N/TDS loads in the vadose zone.
4.3.1 Collect Data and Information
The following types of data and information will be collected for the historical period:
• Existing groundwater-flow model data/estimates of historical recharge volumes over the model calibration periods.
• Groundwater-quality data from wells in adjacent, upgradient basins to characterize the quality of subsurface inflow.
• Water quality of subsurface inflow from the surrounding mountains and hills and streambed recharge:
o Water-quality data from bedrock springs, wells, and streamflow within the watersheds tributary to the Coachella Valley.
o Literature on salt-intensification and nitrogen-loss rates during streambed recharge. • Groundwater replenishment:
o Historical volumes of Colorado River water artificially recharged at GRFs. o Water-quality data for each source of Colorado River water supply. o Historical volumes and water-quality data of local runoff diverted for recharge at GRFs. • Wastewater and recycled water:
o Historical volumes of treated wastewater discharged to percolation ponds and the associated water-quality data.
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o Historical volumes of recycled water used for irrigation and the associated water-quality data.
• Septic systems data:
o Characterizations of current and future parcels using septic systems. o Literature on N/TDS concentrations of septic tank discharges. o Information on septic tank moratoriums and abatement efforts. • Applied water:
o Historical and current land use maps.
o Historical and current agriculture crop types.
o Current and future agricultural land fertilizer application practices. o Literature on crop nitrogen requirements and loading associated with the application of fertilizer.
o Literature on crop evapotranspiration and water requirements. o Local reference evapotranspiration data.
o Literature/data for historical and current agriculture and urban irrigation efficiency. o Historical and current agriculture water supply plans, including sources and associated water quality.
o Boundaries of agriculture and urban water service areas. o Historical and future water supply plans of urban water purveyors, including detail on volume and associated water quality of each supply source. o Historical and future water supply plans of other overlying water users.
4.3.2 Characterize Historical and Current N/TDS Loading The data collected will be reviewed and the Technical Consultant will prepare a draft recommendation to describe the types of tables, maps, and data graphics that can be prepared with the available data to characterize historical and current N/TDS loading to groundwater. A meeting will be held with the TAC to review the draft recommendation and receive TAC feedback.
Once the types of tables, maps, and data graphics are finalized, the time-history of the volumes and associated N/TDS concentrations will be estimated and described for each N/TDS loading term. The N/TDS concentrations will be based on historical data to the extent possible, and where needed, assumptions based on literature review.
4.3.3 Prepare Task Memorandum
A draft and final task memorandum will be prepared to document the data collected and the characterization of historical and current N/TDS loading, as described below:
• An administrative draft task memorandum will be prepared and distributed to the TAC for review and comment.
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• A meeting will be held to review the administrative draft memorandum and receive feedback from the TAC.
• A draft memorandum will be prepared based on the feedback from the TAC and distributed to the TAC for review and comment.
• The CV-SNMP Stakeholder Group will be notified of the availability of the draft memorandum for review and comment.
• A TAC meeting will be held to review the draft memorandum and receive feedback. • A final memorandum will be prepared addressing the feedback.
4.4 Characterize Current Groundwater Quality
The objective of this task is to characterize N/TDS concentrations in groundwater as of 2020 (i.e. current conditions). The characterization will include an analysis of the time history of N/TDS concentrations in groundwater that led to current conditions. The results of this task will provide the necessary information to:
• Satisfy Section 6.2.4 of the Policy regarding the required components of SNMPs. In this case, estimating current groundwater quality is necessary to compute the existence and magnitude of assimilative capacity for a basin, subbasin, or management zone:
Section 6.2.4.3. Salt and nutrient source identification, basin or subbasin assimilative capacity and loading estimates, together with fate and transport of salts and nutrients. • Understand the current trends in N/TDS concentrations in groundwater. • Support subsequent tasks in this workplan to:
o Delineate draft groundwater management zones.
o Define the methods to compute the current “ambient” N/TDS concentrations in groundwater management zones (i.e. the AWQ metric).
o Assess the current protection of beneficial uses within groundwater management zones. o Prepare input files of initial conditions of N/TDS concentrations in groundwater for the forecast modeling of N/TDS concentrations.
o Recommend TDS objectives pursuant to CWC 13241(b): Past, present, and probable future beneficial uses of water.
o Support assessment of assimilative capacity for additional loading of N/TDS.
The characterizations of current groundwater quality will primarily rely on data collected from wells in the CV-SNMP Groundwater Monitoring Network (see Section 3), since these wells are intended to be representative of groundwater quality in all subbasins, subareas, and depth-specific aquifer systems within the Basin. However, the Groundwater Monitoring Network is not yet complete, and historical data may be lacking for some wells. For this reason, other available groundwater-quality data will likely be necessary for this characterization.
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4.4.1 Collect Data and Information
The following data and information will be collected, compiled, checked, and uploaded to project databases and Geographic Information System (GIS):
• Well information
o Well ID (State Well Number)
o Well owner
o Well name
o Well use
o Well status
o XYZ coordinates
o Well screen depth intervals
• Historical groundwater-elevation data at wells
• Historical water-quality data at wells for the following constituents:
o TDS
o Nitrate
o Major cations: K, Na, Ca, Mg
o Major anions: Cl, SO4
o Total alkalinity: HCO3, CO3, OH
Some of these data have already been collected and compiled for the CV-SNMP Groundwater Monitoring Program Workplan (see Section 3).
4.4.2 Prepare Tables, Maps, and Data Graphics
The data collected will be reviewed and the Technical Consultant will prepare a draft recommendation to describe the periods of record and the types of tables, maps, and data graphics that can be prepared with the available data to characterize current N/TDS concentrations in groundwater. A meeting will be held with the TAC to review the draft recommendation and receive TAC feedback.
Described below are recommended examples of the tables, maps, and data graphics that could be prepared to characterize historical and current groundwater quality across the Basin. Examples of these types of tables, maps, and data graphics are included in Appendix B.12 Summary statistics of N/TDS concentrations at wells. These statistics characterize the data set at each well in terms of duration, depth, sample size, mean concentrations, variability, precision, and trends. The statistics can be summarized in tables that include the following fields:
• State Well Number, well owner, well name, and well status. • DWR subbasin.
• Aquifer layers penetrated by the well screens.
• Period of record of available data.
12 These examples are illustrative, and do not represent the exact tables and figures that will be prepared for this task.
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• Number of years with sample results.
• Total number of sample results.
• Minimum, maximum, median, and average N/TDS concentration statistics. • Average N/TDS concentrations for the defined historical and current periods (e.g. 2016-2020). • Standard deviation and coefficient of variance for the sample set. • Comparison to drinking water-quality standards or other beneficial use thresholds. • Mann-Kendall trend test results for N/TDS concentrations.
Table B-1 is an example of a table prepared for similar purposes.
Point and raster maps of N/TDS concentrations in groundwater. The objectives of these maps are to:
• Characterize the spatial distribution of N/TDS concentrations in groundwater relative to the sources of recharge and discharge.
• Provide the initial conditions for N/TDS concentrations in groundwater for the forecast modeling of N/TDS concentrations.
• Support the mapping of change in N/TDS concentrations over time.
On these types of maps, wells are typically labeled with the average N/TDS concentrations for a defined period (e.g. five-year period). Maps can be prepared for a historical period (e.g. 1996-2000) and a current period (e.g. 2016-2020) to facilitate characterization of historical changes in water quality. An interpolation tool in ArcGIS can be used to generate raster surfaces of average N/TDS concentrations across the Basin. The raster can be symbolized by color-ramp to illustrate the spatial distribution of N/TDS concentrations. For areas with multiple aquifer layers and sufficient data, maps can be prepared to characterize each layer. Figure B-1 is an example of such a map that was prepared for similar purposes.
If this mapping approach is adopted, the following areas and aquifer layers should be mapped:
• Northern portion of the Indio subbasin (including the Garnet Hill and Palm Springs subareas) o Shallow aquifer system (Layers 1-3)
o Deep aquifer system (Layer 4)
• Central portion of the Indio subbasin (including the Thousand Palms subarea) o Shallow aquifer system (Layers 1-3)
o Deep aquifer system (Layer 4)
• Southern portion of the Indio subbasin (including the Thermal and Oasis subareas) o Perched aquifer system (Layer 1)
o Shallow aquifer system (Layers 2/3)
o Deep aquifer system (Layer 4)
• Mission Creek subbasin
o Shallow aquifer system (Layers 1-3)
o Deep aquifer system (Layer 4)
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• Desert Hot Springs subbasin
Maps of changes and trends in N/TDS concentration in groundwater. The objectives of these maps are to:
• Identify areas (and depths) within the Basin where N/TDS concentrations are increasing, decreasing, or not changing, and potentially reveal why the changes are occurring. • Support the understanding of the fate and transport of N/TDS.
On these types of maps, wells are typically labeled by changes in average N/TDS concentrations between two defined periods (a historical period [e.g. 1996-2000] minus a current period [e.g. 2016-2020]). Wells with enough data can be symbolized by the Mann-Kendall trend test results for N/TDS concentrations. An interpolation tool in ArcGIS can be used to generate raster surfaces of changes in N/TDS concentrations across the Basin. The raster can be symbolized by color-ramp to illustrate the spatial changes in N/TDS concentrations. For areas with multiple aquifer layers and sufficient data, maps can be prepared to characterize each layer. The maps can be prepared for the same areas and aquifer layers as listed above for the point and raster maps of N/TDS concentrations. Figure B-2 is an example of such a map that was prepared for similar purposes.
Multi-variate exhibits of groundwater and surface water. The objectives of these types of exhibits is to improve understanding of the fate and transport of N/TDS in the Basin, and support interpretations of the potential causes of increasing or decreasing N/TDS concentrations in groundwater.
These exhibits can be prepared for each well in the CV-SNMP Groundwater Monitoring Network (or logical groupings of wells) over a historical to current period, and typically include:
• Time-series chart of groundwater levels at the well(s). • Time-series chart of N/TDS concentrations at the well(s), including a statistical quantification of trends using the Mann-Kendall test results.
• Time-series chart of N/TDS concentrations for nearby sources of N/TDS loading. • Piper Diagrams for the well(s) and the nearby sources of N/TDS loading. Piper Diagrams are a graphical representation of the chemistry of water samples that aid in understanding the sources of the dissolved constituents in the groundwater.
Figure B-3 is an example of such an exhibit that was prepared for similar purposes.
4.4.3 Prepare Task Memorandum
A task memorandum will be prepared to document the data collected and the characterization of current N/TDS concentrations in groundwater, as described below:
• An administrative draft task memorandum will be prepared and distributed to the TAC for review and comment.
• A TAC meeting will be held to review the administrative draft memorandum and receive feedback. • A draft memorandum will be prepared based on the feedback from the TAC and distributed to the TAC for review and comment.
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• The CV-SNMP Stakeholder Group will be notified of the availability of the draft memorandum for review and comment.
• A TAC meeting will be held to review the draft memorandum and receive feedback. • A final memorandum will be prepared addressing TAC feedback.
4.5 Delineate Draft Management Zones and Desc ribe Metrics to Characterize Beneficial Use Protection
The objectives of this task are to:
• Delineate draft groundwater management zones.
• Describe the existing and potential future beneficial uses of groundwater within each management zone.
• Define the ambient water quality (AWQ) metric in each management zone that will be used to estimate ambient water quality conditions and assess beneficial use protection. An AWQ metric is a method to estimate “ambient” N/TDS concentrations for groundwater in each manageme nt zone. The purpose of AWQ metrics is to enable the comparison of ambient N/TDS concentrations in groundwater versus the beneficial-use thresholds and water quality objectives, and thereby indicate the state of beneficial use protection. Examples of AWQ metrics include, but are not limited to:
o Volume-weighted constituent concentration within the management zone. o 5-year moving average of constituent concentration at a key well or wells within a management zone.
o Volume-weighted constituent concentration of groundwater discharge from a management zone.
The results of this task will provide the necessary information to:
• Assess the current and future protection of the beneficial uses of groundwater. • Support subsequent tasks in this workplan to:
o Post-process, display, and interpret the forecast modeling results. o Recommend TDS objectives pursuant to CWC 13241(a): Past, present, and probable future beneficial uses of water.
o Support assessments of assimilative capacity for additional loading of N/TDS.
The management zone delineations and the AWQ metrics will be considered draft at this stage. It is possible that subsequently derived information, such as understanding potential future water-quality conditions and the ability for the stakeholders to control future water-quality conditions, will indicate that modifications to management zone delineations and AWQ metrics will better support salt and nutrient management.
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4.5.1 Delineate Draft Groundwater Management Zones
The delineation of draft management zones will be based on:
• Hydrogeology of the basin.
• Locations and magnitudes of N/TDS loading.
• Location of hydrologically vulnerable areas as identified in the GAMA Groundwater Information System database.
• Current understanding of groundwater-flow directions and the fate and transport of N/TDS within the groundwater basin.
• Current N/TDS concentrations in groundwater.
• Existing and potential future beneficial uses of groundwater.
Management zones will be delineated both spatially and vertically throughout the basin.
4.5.2 Describe Beneficial Uses for Management Zones and Beneficial-Use Thresholds For each management zone, the existing and potential beneficial uses and users of groundwater will be described along with the associated beneficial-use thresholds for N/TDS concentrations.
The beneficial uses will reference those uses listed in the Water Quality Control Plan and the known existing users and uses of groundwater in each proposed management zone.
The beneficial-use thresholds will be based on regulatory standards and guidance published by the State of California on the numeric water-quality thresholds that protect the beneficial uses.
4.5.3 Define AWQ Metrics and Determine Current Protection of Beneficial Uses Draft AWQ metrics will be proposed for each management zone and used to estimate the current ambient N/TDS concentrations for groundwater in each management zone. The current ambient N/TDS concentrations will be compared to the beneficial-use thresholds to assess the current state of beneficial use protection. If the concentration of the AWQ metric is less than the beneficial-use threshold, then that specific beneficial use is protected. If the concentration of the AWQ metric is greater than the beneficial- use threshold, then that specific beneficial use is not protected.
The appropriate AWQ metric may be different in different management zones based on the size of the management zone, the beneficial users and uses within the management zone, the location and magnitude of N/TDS loading, and the fate and transport of N/TDS.
Figure 4-1 is a chart that conceptually illustrates:
• The use of a hypothetical AWQ metric that utilizes existing TDS data to estimate the “historical ambient” and “current ambient” TDS concentrations for a management zone. These features can characterize the recent trends in TDS concentration within the management zone. • A comparison of a current ambient TDS concentration in the management zone to the beneficial use thresholds for TDS. This comparison can characterize the current protection of beneficial uses.
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These types of charts will be prepared for N/TDS in each management zone over a recent historical period.
4.5.4 Prepare Task Memorandum
A task memorandum will be prepared to document the draft management zones, the beneficial uses within each management zone, the beneficial-use thresholds for N/TDS concentrations in each management zone, the proposed AWQ metrics that represent ambient N/TDS concentrations in each management zone, and the assessment of beneficial use protection in each management zone over a recent historical period, as described below:
• An administrative draft task memorandum will be prepared and distributed to the TAC for review and comment.
• A TAC meeting will be held to review the administrative draft memorandum and receive feedback. • A draft memorandum will be prepared based on the feedback from the TAC and distributed to the TAC and the CV-SNMP Stakeholder Group for review and comment. • A public meeting will be held to review the draft memorandum and receive feedback. • A final memorandum will be prepared addressing the feedback.
4.6 Develop Technical Approach for Forecasting N/TDS Concentrations in Groundwater
The objective of this task is to define the most appropriate and efficient technical approach to forecast N/TDS concentrations in groundwater.
Currently, two numerical groundwater-flow models are being updated and used to support SGMA compliance in the Mission Creek subbasin13 and the Indio subbasin. Both models are based on the USGS modular groundwater-flow model MODFLOW. Review of preliminary model documentation and discussions with the technical consultants who are preparing these model updates indicate that the appropriate strategy for making forecasts of N/TDS concentrations is to build two separate water-quality models that cascade from the Mission Creek subbasin to the Indio subbasin. In this strategy, the water- quality models will be capable of making forecasts of N/TDS concentrations in groundwater utilizing the results of MODFLOW simulations. The water-quality model results for N/TDS concentrations in groundwater will be at the same spatial and temporal resolution as the MODFLOW model results for groundwater flow. For the CV-SNMP Development Workplan, it is assumed that a water-quality model of the Mission Creek subbasin will be executed first, and its results will be used as boundary conditions that will be carried over (cascaded) to a water-quality model of the Indio subbasin.
This modeling approach for forecasting N/TDS concentrations must include the following capabilities:
• Ability to assign a volume and N/TDS concentrations to each individual source of recharge. • Ability to simulate the vadose zone processes (e.g. transport and chemical transformations).
13 The Mission Creek Subbasin Model includes the Miracle Hill subarea of the Desert Hot Springs subbasin where there may be significant subsurface flows from the Desert Hot Springs subbasin into the Mission Creek subbasin.
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• Ability to simulate the feedback cycles associated with groundwater pumping, the N/TDS concentrations of potable water supply, the N/TDS concentrations of recycled water, and the N/TDS concentrations of return flows.
• Ability to simulate the fate and transport of N/TDS with a cascading approach from the existing Mission Creek subbasin MODFLOW model domain to the Indio subbasin MODFLOW model domain. Because the domains of the two MODFLOW models overlap the Garnet Hill Subarea, consideration must be given to this boundary in the water-quality modeling approach. • Ability to calculate the volume-weighted N/TDS concentrations for each management zone by layer.
• Ability to calculate N/TDS concentration at wells.
• The ability to reasonably simulate verifiable historical groundwater-quality conditions. • Ability to efficiently simulate several CV-SNMP scenarios with modified input files that represent potential CV-SNMP management projects and programs.
• Ability to forecast N/TDS concentrations in subareas that are not covered by the model domains of the MODFLOW models, which includes the Fargo Canyon Subarea and a portion of the Sky Valley Subarea in the Desert Hot Springs Subbasin.
Formulating this modeling strategy will require a thorough understanding of the existing MODFLOW models, the model input files (particularly the recharge files that represent N/TDS loading terms), and the output files. It is likely that separate data-processing routines will need to be automated (i.e. coded) so the water-quality modeling of multiple scenarios can be performed efficiently and accurately. Such data- processing routines may include reconstructing the MODFLOW recharge input files to include the assignment of N/TDS concentrations to the individual recharge sources, automating the update of model input files to address feedback cycles to achieve appropriate convergence of model results, and the post- processing of the water-quality model results to support the cascading model approach.
The vadose zone processes (solute travel time and chemical transformations) and their effect on the N/TDS loading to groundwater will need to be analyzed and considered for inclusion in the modeling approach.
4.6.1 Evaluate Existing MODFLOW Models
Model reports and documentation are forthcoming for the updates to the Mission Creek Subbasin Model and the Indio Subbasin Model. These reports and documentation will be reviewed to gain insight into the hydrogeologic conceptual model, model assumptions, model settings, and model limitations.
The MODFLOW input files need to be understood, particularly to develop automated routines for assigning N/TDS concentrations to recharge terms. For example, the MODFLOW models include recharge input files for return flows that originate from several water sources. The SGMA modeling teams have indicated that significant pre-processing efforts are conducted to prepare the input files for recharge from the various recharge sources. To perform the water-quality modeling, the N/TDS concentrations for each water source must be estimated, and the volume-weighted concentration needs to be calculated and assigned to the water-quality models. These pre-processing efforts will likely need to be automated for the water-quality modeling, so a thorough understanding of the MODFLOW model input files, and their preparation, is necessary.
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The MODFLOW output files need to be assessed to determine whether they meet the requirements of the water-quality modeling and its cascading modeling approach.
In this subtask, it is likely that meetings and conference calls will be necessary with the SGMA modeling teams to ask questions and resolve challenges that are identified during the evaluation of the MODFLOW models.
4.6.2 Develop Procedures for Simulating Vadose Zone Processes Vadose zone processes may be important to timing and magnitude of N/TDS loading to the saturated zone, particularly for return flows from the land surface through partially saturated sediments. Criteria to consider in developing procedures for simulating the vadose zone are: microbial processes in the hyporheic zone; vadose zone thickness, hydraulic and solute lag times, the initial N/TDS conditions within the vadose zone, and the appropriate methods and tools to simulate N/TDS loading through the vadose zone to the saturated zone.
In this subtask, the Technical Consultant will evaluate the existing information developed in prior tasks and the existing models to develop a recommendation for procedures to simulate vadose zone processes in N/TDS loading.
4.6.3 Define the Appropriate Planning Period
The appropriate length of the planning period for water-quality model forecasting is partly dependent on the solute travel times through the vadose zone. In this subtask, the Technical Consultant will evaluate the solute travel times through the vadose zone and develop a recommendation for the planning period.
If the planning period is recommended for a period longer than 50 years, the modeling approach must describe how the planning period will be extended beyond the 2020-2070 period that the MODFLOW models are using in the development of the Alternatives to Groundwater Sustainability Plans to comply with the SGMA (SGMA Alternative Plans).
4.6.4 Develop Procedures for Simulating Feedback Processes The future changes in N/TDS concentrations in groundwater will influence the N/TDS concentrations in water supplies that include groundwater, such as potable water and recycled water, which in turn, can migrate back to the groundwater system as irrigation return flows. Such feedback processes can have a significant effect on the future N/TDS concentrations in groundwater and must be simulated.
In this subtask, the Technical Consultant will evaluate the existing information developed in prior tasks and the existing models to develop a recommendation for procedures to simulate feedback processes in N/TDS loading.
4.6.5 Define Assumptions for Future N/TDS Concentration of Colorado River Water Colorado River water is a major source of supplemental water that supports groundwater basin sustainability and the economy of the Coachella Valley. The future N/TDS concentrations of Colorado River water will affect the quality of groundwater.
In this subtask, the Technical Consultant will: analyze the historical N/TDS concentrations of Colorado River water; research the existing and any proposed changes to the water quality objectives for Colorado River water; review available information on the existing structures and efforts in place to help reduce
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salinity in Colorado River water; review available information on salinity projections for Colorado River water including any predicted impacts from climate change; and recommend assumptions for N/TDS concentrations of Colorado River water for water-quality modeling over the planning period.
4.6.6 Develop Procedures for Verifying the N/TDS Forecasting Tools The water-quality models cannot be calibrated using traditional methods of model calibration primarily because of a lack of historical, depth-specific groundwater-quality data. However, the water-quality models should have the ability to reasonably simulate the available data and information on historical groundwater-quality conditions.
In this subtask, the Technical Consultant will describe the process to verify the ability of the water-quality models to reasonably simulate historical groundwater-quality conditions. Likely, the water-quality models will need to be run and evaluated, and adjustments to the input files or other model assumptions will need to be tested to produce “reasonable” results.
4.6.7 Develop Procedures for Post-Processing Model Results The water-quality modeling will need efficient tools for post-processing and displaying the model results.
This is because:
• In Task 4.7, the water-quality models will need to be run and evaluated repeatedly to demonstrate their ability to produce “reasonable” results.
• In Task 4.8, the water-quality models will be used to test the effectiveness of various implementation measures to control N/TDS loading and protect beneficial uses. Hence, the water- quality model results will need to be evaluated efficiently to save cost and time in the identification of a preferred CV-SNMP Scenario.
In this subtask, the Technical Consultant will describe the post-processing tools that will be prepared to efficiently display and characterize the water-quality model results.
4.6.8 Prepare Task Memorandum
A task memorandum will be prepared to describe and document the methods, assumptions, and tools that will be used to construct and run the water-quality models and interpret the results, as described below:
• An administrative draft task memorandum will be prepared and distributed to the TAC for review and comment.
• A TAC meeting will be held to review the administrative draft memorandum and receive feedback. • A draft memorandum will be prepared based on the feedback from the TAC and distributed to the TAC for review and comment.
• The CV-SNMP Stakeholder Group will be notified of the availability of the draft memorandum for review and comment.
• A TAC meeting will be held to review the draft memorandum and receive additional feedback. • A final memorandum will be prepared addressing the feedback.
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4.7 Construct N/TDS Forecasting Tools and Evaluate the Baseline Scenario
The objectives of this task will be to:
• Construct the N/TDS forecasting tools defined in Task 4.6 and verify their ability to reasonably simulate historical groundwater-quality conditions.
• Define a “baseline” planning scenario that represents the current water-supply plans and water- management plans for the Coachella Valley (Baseline Scenario). • Forecast N/TDS concentrations to determine whether beneficial uses of groundwater are protected under the Baseline Scenario.
These objectives will be accomplished by constructing the water-quality models (and associated pre- processing and post-processing tools) and using the models to forecast N/TDS concentrations in groundwater for a Baseline Scenario over the planning period.
The evaluation of the Baseline Scenario will be used in subsequent tasks of this workplan to:
• If necessary, support the development of CV-SNMP implementation measures (i.e. projects and/or programs) to manage N/TDS loading to protect beneficial uses of groundwater on a sustainable basis.
• Finalize the management zone delineations and the AWQ metrics that are used to estimate the ambient N/TDS concentrations for each management zone.
• Recommend TDS objectives pursuant to CWC 13241(b): Environmental characteristics of the hydrographic unit under consideration, including the quality of water available thereto.
4.7.1 Develop a Baseline Scenario based on the SGMA Alternative Plans The Baseline Scenario will be based on:
• The SGMA Alternative Plans that are being developed for the Mission Creek and Indio Subbasins to comply with the SGMA.
• The N/TDS loading that is estimated to occur under the SGMA Alternative Plans (described in Task
4.3).
The Baseline Scenario will be described in enough detail to prepare model input files for the water-quality modeling efforts in Task 4.7.2 and to prepare cost estimates for the aggregate water supply in Task 4.9.
4.7.2 Construct N/TDS Forecasting Tools and Run the Baseline Scenario In this task, the water-quality models and associated pre- and post- processing tools are constructed, verified, and used to run the Baseline Scenario pursuant to the methods described in the task memorandum for Task 4.6 – Develop Technical Approach for Forecasting N/TDS Concentrations in Groundwater.
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Verification of the water-quality models will be performed by running the models over a defined historical period to verify their ability to reasonably simulate historical water groundwater-quality conditions. The model verification results will be reviewed with the TAC before running of the Baseline Scenario.
The initial conditions for N/TDS concentrations in groundwater (by model layer) will be based on the results of Task 4.4 – Characterize Current Groundwater Quality. The initial condition for N/TDS loads within the vadose will be based on the strategies outlined in Task 4.6.
Several iterative model runs and sensitivity analyses will be needed to check for the reasonableness of the water-quality model results, and if necessary, adjust various assumptions in the initial conditions and the input datasets of the Baseline Scenario. The interim results will need to be reviewed with the TAC to define changes to any assumptions.
The interim simulation results will be summarized for each model run with: N/TDS concentration maps for selected points in the planning period, maps of change in N/TDS concentration, N/TDS concentration time-series charts for wells and return flows over the planning period, and time-series charts of the draft compliance metrics for each management zone as proposed in Task 4.5.3 – Define AWQ metrics and determine current protection of beneficial uses.
Any TAC-recommended adjustments will be implemented to the Baseline Scenario, the water-quality models and associated tools will be modified accordingly, and the next simulation run for Baseline Scenario will be conducted. It is anticipated that three iterative model runs will be necessary to finalize the Baseline Scenario.
The final simulation results of the Baseline Scenario will be evaluated to determine if CV-SNMP implementation measures are potentially necessary in the future to control N/TDS loading to protect the beneficial uses of groundwater in specific management zones.
Figure 4-2 is a chart that conceptually illustrates the evaluation of a hypothetical Baseline Scenario in a hypothetical management zone. These types of charts will be prepared for N/TDS in each management zone over the planning period. Each management zone will be evaluated for:
• The long-term protection of beneficial uses in the management zone. • The potential need for, and timing of, CV-SNMP implementation measure(s) that may be necessary in the future to protect beneficial uses.
At this stage, the water-quality modeling and evaluation of the Baseline Scenario are considered final, and “buy-in” from Regional Board staff is needed to confirm that:
• The data, assumptions, tools, and methods that were used to develop and evaluate the Baseline Scenario are acceptable.
• The need for implementation measures to control N/TDS loading in specific management zones (if any) have been appropriately identified.
4.7.3 Prepare Task Memorandum
A task memorandum will be prepared to describe the methods, assumptions, results and evaluations of the Baseline Scenario and document the “buy-in” from the Regional Board, as outlined below:
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• An administrative draft task memorandum will be prepared and distributed to the TAC for review and comment. Review and comment by Regional Board staff is mandatory. • A TAC meeting will be held to review the administrative draft memorandum and receive feedback.
Attendance by Regional Board staff is mandatory.
• A draft memorandum will be prepared based on the feedback from the TAC. An appendix of comments and responses-to-comments will be included in the draft memorandum. Additional review and comment on the draft memorandum by Regional Board staff is mandatory. • The CV-SNMP Stakeholder Group will be notified of the availability of the draft memorandum for review and comment.
• A public meeting will be held to review the draft memorandum and receive feedback. Attendance by Regional Board staff is mandatory.
• A final memorandum will be prepared addressing the feedback. An appendix of comments and responses-to-comments will be included in the final memorandum. • Regional Board staff approval of the final memorandum by letter from the Executive Officer is required before proceeding with Task 4.8.
4.8 Forecast N/TDS Concentrations for CV-SNMP Scenarios Task 4.8 is necessary if Task 4.7 concludes that CV-SNMP implementation measures are potentially necessary in the future to protect the beneficial uses of groundwater in management zones. If not, then Tasks 4.8 and 4.9 in this workplan are not necessary to execute.
The objective of Task 4.8 is to develop CV-SNMP implementation measures that have the potential to control N/TDS loading and protect beneficial uses of groundwater in the Coachella Valley on a sustainable basis. The CV-SNMP implementation measures will be grouped into logical CV-SNMP Scenarios, evaluated with the water-quality models, and compared to the Baseline Scenario results. The CV-SNMP Scenarios will be evaluated in steps, with the model results of a scenario (or a set of scenarios) informing the preparation of subsequent scenarios. For cost estimating purposes, this workplan assumes an iterative, step-wise process to evaluate up to eight CV-SNMP Scenarios.
The water-quality modeling results for the CV-SNMP Scenarios will:
• Quantify the relative effectiveness of each CV-SNMP Scenario in managing the N/TDS concentrations in each groundwater management zone.
• Support subsequent tasks in this workplan to:
o Propose final management zone delineations and AWQ metrics. As stated earlier in this workplan, it is possible that understanding potential future water-quality conditions, and the ability for the stakeholders to control future water-quality conditions, will indicate that modifications to management zone delineations and AWQ metrics will better support salt and nutrient management.
o Recommend TDS objectives pursuant to CWC 13241(c): Water quality conditions that could reasonably be achieved through the coordinated control of all factors which affect water quality in the area. In other words, the results of this task will describe the water-
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quality conditions that could be achieved via the implementation of various CV-SNMP implementation measures.
4.8.1 Evaluate Baseline Scenario Results and Recommend Implementation Measures In this task, the Baseline Scenario results will be used to develop recommendations for CV-SNMP implementation measures to manage N/TDS loading in the Basin on a sustainable basis. These implementation measures will be formulated into CV-SNMP Scenarios (i.e. one or more projects or programs) with the objective to protect the long-term beneficial uses of groundwater in the management zones.
The Technical Consultant will prepare a task memorandum to describe the recommended CV-SNMP Scenarios, as described below:
• An administrative draft task memorandum will be prepared and distributed to the TAC for review and comment.
• A TAC meeting will be held to review the administrative draft memorandum and receive feedback.
• A draft memorandum will be prepared based on the feedback from the TAC. • The CV-SNMP Stakeholder Group will be notified of the availability of the draft memorandum for review and comment.
• A public meeting will be held to review the draft memorandum and receive feedback. • A final memorandum will be prepared addressing the feedback.
4.8.2 Evaluate CV-SNMP Scenarios
In this task, the recommended CV-SNMP Scenarios will be implemented in the models, the model simulations will be conducted, and the model results will be evaluated and compared against the Baseline Scenario for their effectiveness in controlling N/TDS loading and protecting beneficial uses.
The CV-SNMP Scenarios will be evaluated in steps, with the model results of one scenario (or a set of scenarios) informing the preparation of the subsequent scenarios. After each step, the results will be shared with the TAC to receive feedback on the preparation of the subsequent scenarios. This will be an iterative process to evaluate up to eight CV-SNMP Scenarios.
Figure 4-3 and Figure 4-4 are charts that conceptually illustrate the evaluation of two hypothetical CV- SNMP Scenarios in a hypothetical management zone:
• Hypothetical SNMP Scenario #1 is assumed to include a relatively aggressive and expensive implementation measure to reduce TDS loading. The TDS concentration in the management zone is projected to stabilize at concentrations significantly below the maximum beneficial use threshold over the planning period, and hence, appears to be protective of beneficial uses. • Hypothetical SNMP Scenario #2 is assumed to include a less aggressive and less expensive implementation measures to reduce TDS loading compared to Hypothetical SNMP Scenario #1.
The TDS concentration in the management zone is still projected to stabilize at concentrations below the maximum beneficial use threshold over the planning period, and hence, appears to be
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protective of beneficial uses, but at a higher TDS concentration than projected for Hypothetical SNMP Scenario #1.
The types of charts in Figure 4-3 and Figure 4-4 will be prepared for N/TDS concentrations for each scenario in each management zone over the planning period. The CV-SNMP Scenarios will be evaluated for:
• The long-term protection of beneficial uses.
• The potential need for, and timing of, other CV-SNMP implementation measure(s) that may be necessary for the long-term protection of beneficial uses in the most cost-efficient manner.
The evaluation of economic considerations between scenarios is performed in Task 4.9.
4.8.3 Prepare Task Memorandum
A task memorandum will be prepared to describe and document the methods, assumptions, and results of the evaluations of the CV-SNMP Scenarios, as described below:
• An administrative draft memorandum will be prepared and distributed to the TAC for review and comment.
• A TAC meeting will be held to review the administrative draft memorandum and receive feedback.
• A draft memorandum will be prepared based on the feedback from the TAC and distributed for review and comment.
• The CV-SNMP Stakeholder Group will be notified of the availability of the draft memorandum for review and comment.
• A public meeting will be held to review the draft memorandum and receive feedback. • A final memorandum will be prepared addressing the feedback.
4.9 Characterize and Compare the Cost of Baseline and CV-SNMP Scenarios
The objective of this task is to prepare an engineering cost analysis of the Coachella Valley water supply for the Baseline Scenario and the CV-SNMP Scenarios. The cost analysis will provide information required for recommending TDS objectives pursuant to CWC 13241(d): Economic considerations.
4.9.1 Develop Cost-Estimating Planning Criteria and a Cost Model Standard planning criteria will be developed for assumptions related to capital improvement construction and operations and maintenance (O&M) of projects to ensure consistency in estimating costs.
An engineering cost model will be developed for the purposes of estimating the annual melded unit cost of the aggregate water supply14 in the Coachella Valley over the planning period for the Baseline and the
14 Aggregate water supply is the cumulative of all water supplies produced and used in the Basin.
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CV-SNMP Scenarios. The cost model will breakdown each water purveyor’s water-supply plan into individual water-supply sources, and then assign costs for acquiring the water supply, production (energy costs associated with producing the water supply), O&M, treatment, and conveyance over the planning period. Agricultural water users and golf course water users will be analyzed in an aggregate fashion.
If applicable, the cost model will include the costs associated with the effects of potential future increases in groundwater salinity.
A description of the planning criteria and the cost model will be shared with the TAC to receive feedback from the TAC. The planning criteria and cost model will be finalized based on TAC feedback.
4.9.2 Develop Cost Estimates for the Baseline and CV-SNMP Scenarios The engineering cost model will be applied to the Baseline and CV-SNMP Scenarios to estimate and compare the annual melded unit cost of the aggregate water supply in the Coachella Valley over the planning period. These costs will be summarized into an annual melded unit cost of the aggregate water supply over the planning period and a net-present value cost for each Scenario.
This task will also include a description of the funding mechanisms available to the agencies responsible for CV-SNMP implementation and the cost impacts to those agencies and their rate payers.
4.9.3 Prepare Task Memorandum
A task memorandum will be prepared to describe and document the planning criteria and the methods, assumptions, and results of the cost analyses and cost comparisons, as described below:
• An administrative draft memorandum will be prepared and distributed to the TAC for review and comment.
• A TAC meeting will be held to review the administrative draft memorandum and receive feedback.
• A draft memorandum will be prepared based on the feedback from the TAC and distributed for review and comment.
• The CV-SNMP Stakeholder Group will be notified of the availability of the draft memorandum for review and comment.
• A public meeting will be held to review the draft memorandum and receive feedback. • A final memorandum will be prepared addressing the feedback.
4.10 Select the Preferred CV-SNMP Scenario, Finalize Management Zones and Beneficial Uses, and Recommend TDS Objectives The objective of this task is to select a preferred CV-SNMP Scenario, which will form the basis for a CV- SNMP implementation plan and any recommended updates to the Basin Plan, which could include:
• Establishment of management zone delineations and descriptions. • Groundwater beneficial use descriptions for each management zone. • Addition of numeric TDS objectives for each management zone.
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• Addition of CV-SNMP implementation measures and associated time schedules.
4.10.1 Evaluate All Forecasted Information and Select a Preferred CV-SNMP Scenario In this task, the results of the Baseline and CV-SNMP Scenarios will be compared and ranked based on the following criteria:
1. The ability of the scenario to protect the beneficial uses over the planning period.
2. The feasibility of implementation.
3. The melded unit cost of the total water supply.
4. The funding mechanisms available to the agencies responsible for CV-SNMP implementation and the cost impacts to those agencies and their rate payers.
At this stage, it is possible that results of the scenarios indicate the need for refinements to the management zone delineations and/or the AWQ metrics that are meant to represent ambient N/TDS concentrations in the management zones. If so, the model results will be re-processed to compute the revised AWQ metrics.
Based on the evaluation and ranking of the Baseline and CV-SNMP Scenarios, the consultant(s) will recommend a preferred CV-SNMP Scenario, including the final management zones, beneficial use designations, and TDS objectives.15 The evaluation, ranking, and the recommended CV-SNMP Scenario will be shared with the TAC to receive feedback. The TAC will then select the preferred CV-SNMP Scenario.
4.10.2 Recommend TDS Objectives based on CWC 13241
California Water Code (CWC) section 13241 lists the factors to consider when establishing water quality objectives without unreasonably affecting beneficial uses. These factors include:
a) Past, present, and probable future beneficial uses of water. b) Environmental characteristics of the hydrographic unit under consideration, including the quality of water available thereto.
c) Water quality conditions that could reasonably be achieved through the coordinated control of all factors which affect water quality in the area.
d) Economic considerations.
e) The need for developing housing within the region.
f) The need to develop and use recycled water.
A written demonstration will be prepared, referencing all work performed in prior tasks, to illustrate how the preferred CV-SNMP Scenario and the recommended TDS objectives collectively satisfy the requirements of CWC 13241.
15 A numeric nitrate-nitrogen objective for groundwater in the Basin is already established in the Basin Plan at 10 mgl.
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4.10.3 Document Antidegradation Demonstration Pursuant to State Board Policy 68-16 An antidegradation demonstration will be prepared as required by Section 6.2.4.5 of the 2018 Policy. The objective will be to illustrate how the preferred CV-SNMP Scenario and the recommended N/TDS objectives collectively satisfy the requirements of State Board Resolution 68-16 (the Antidegradation Policy). The key components of an antidegradation demonstration include:
• Identifying the water quality parameters and beneficial uses that will be impacted by the proposed action and the extent of the impact. In this case, the proposed action is the adoption of the CV-SNMP (including implementation of the preferred CV-SNMP Scenario) and the proposed changes to the Basin Plan (e.g. management zones, TDS objectives, and beneficial use designations).
• The scientific rationale for the determination that the proposed action will or will not lower water quality in the impacted receiving waters.
• A discussion of the alternative measures that were considered. • A socio-economic evaluation.
• The rationale for determining that the proposed action is or is not justified by socio- economic considerations.
• Comparing the potential water-quality outcomes.
• Demonstrating that any water quality degradation allowed by the CV-SNMP provides maximum benefit to the people of California.
Figure 4-5 is a chart that conceptually illustrates the evaluation of a hypothetical preferred SNMP Scenario in a hypothetical management zone. In this example, the TDS concentration objective in the management zone is selected based upon an evaluation of all factors listed in CWC 13241 and a demonstration that the scenario and the recommended TDS objective collectively satisfy the requirements of Antidegradation Policy (see Section 4.10.3 below). These types of charts will be prepared for N/TDS concentrations for each scenario in each management zone over the planning period.
4.10.4 Prepare Task Memorandum
A task memorandum will be prepared to describe: the evaluation and ranking of the Baseline and CV- SNMP Scenarios; the preferred CV-SNMP Scenario; the final management zones, beneficial use designations, and recommended TDS objectives; and how the CV-SNMP and the recommended TDS objectives collectively satisfy the requirements of CWC 13241 and the Antidegradation Policy. “Buy-in” from the Regional Board is mandatory at this stage. The memorandum will be completed as described below:
• An administrative draft task memorandum will be prepared and distributed to the TAC for review and comment. Review and comment by Regional Board staff is mandatory. • A TAC meeting will be held to review the administrative draft memorandum and receive feedback.
Attendance by Regional Board staff is mandatory.
• A draft memorandum will be prepared based on the feedback from the TAC. An appendix of comments and responses-to-comments will be included in the draft memorandum. Additional review and comment on the draft memorandum by Regional Board staff is mandatory.
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• The CV-SNMP Stakeholder Group will be notified of the availability of the draft memorandum for review and comment.
• A public meeting will be held to review the draft memorandum and receive feedback. Attendance by Regional Board staff is mandatory.
• A final memorandum will be prepared addressing the feedback. An appendix of comments and responses-to-comments will be included in the final memorandum. • Regional Board staff approval of the final memorandum by letter from the Executive Officer is required before proceeding with Task 4.11.
4.11 Prepare Final CV-SNMP
The complete findings and recommendations from the work performed to implement this CV-SNMP Development Workplan will be documented in a final plan titled: Final Coachella Valley Salt and Nutrient Management Plan (CV-SNMP). The CV-SNMP will be a compilation of the final technical memorandums and interim work products prepared in Tasks 4.1 through 4.10. The CV-SNMP will define the management activities that the CV-SNMP Agencies will implement, including the ongoing monitoring programs, to comply with the N/TDS objectives of the defined groundwater management zones.
The CV-SNMP will include a plan and schedule to implement the preferred CV-SNMP Scenario and perform the monitoring, reporting, and update activities as required by Sections 6.2.4.1.3 and 6.2.6 of the 2018 Policy. The CV-SNMP will address:
• Milestones, triggers, and schedules for implementation of any programs or facilities included in the preferred CV-SNMP Scenario.
• Milestones and schedules for implementing and updating the CV-SNMP Groundwater Monitoring Program. The monitoring program may need to be updated to address new information and data gaps identified in the implementation of this CV-SNMP Development Workplan (or during ongoing monitoring efforts) and to ensure monitoring program is robust enough to assess the impacts of implementing the preferred CV-SNMP Scenario.
• A process for performing the five-year data assessment, which must include an evaluation of:
o Observed trends in water quality data as compared with trends predicted in the CV- SNMP.
o The ability of the monitoring network to adequately characterize groundwater quality in the Basin.
o Potential new data gaps.
o Groundwater quality impacts predicted in the CV-SNMP based on most recent trends and any relied-upon models, including an evaluation of the ability of the models to simulate groundwater quality.
o Available assimilative capacity based on observed trends and most recent water quality data.
o New projects that are reasonably foreseeable at the time of the data assessment but may not have been considered when the CV-SNMP was prepared or last updated.
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The process to prepare the final CV-SNMP will include the following:
• An administrative draft CV-SNMP will be prepared and distributed to the TAC for review and comment. Review and comment by Regional Board staff is mandatory. • A TAC meeting will be held to review the administrative draft CV-SNMP and receive feedback.
Attendance by Regional Board staff is mandatory.
• A draft CV-SNMP will be prepared based on the feedback from the TAC for additional review and comment. An appendix of comments and responses-to-comments will be included in the draft memorandum. Review and comment on the draft memorandum by Regional Board staff is mandatory.
• The CV-SNMP Stakeholder Group will be notified of the availability of the draft memorandum for review and comment.
• A public meeting will be held to review the draft CV-SNMP and receive feedback. Attendance by Regional Board staff is mandatory.
• The CV-SNMP will be prepared addressing the feedback. An appendix of comments and responses-to-comments will be included in the final memorandum. • The final CV-SNMP will be submitted to the Regional Board for approval.
Workplan Section that Complies
with the 2018 Policy
Section 6.2 Development and adoption of salt and nutrient management plans Section 4.2 - Establish CV-SNMP Stakeholder Group and
Technical Advisory Committee
Section 3 - CV-SNMP Groundwater Monitoring Program
Workplan
Section 4.7 - Construct N/TDS Forecasting Tools and
Evaluate the Baseline Scenario
Section 4.3 - Characterize N/TDS Loading to the
Groundwater Basin
Section 4.4 - Characterize Current Groundwater Quality
Section 4.5 - Delineate Draft Management Zones and
Describe Metrics to Characterize Beneficial Use Protection Section 4.7 - Construct N/TDS Forecasting Tools and
Evaluate Baseline Scenario
Section 4.8 - Forecast N/TDS for up to Eight CV-SNMP
Scenarios
Section 4.10 - Select the Preferred CV-SNMP Scenario,
Finalize Management Zones and Beneficial Uses, and Set
TDS Objectives
Table 4-1. CV-SNMP Development Workplan Compliance with the 2018 Recycled Water Policy Recommended and Required Components of SNMPs
pursutant to 2018 Recycled Water Policy
6.2.4.1. A basin- or subbasin-wide monitoring plan that includes an appropriate network of monitoring locations to provide a reasonable, cost effective means of determining whether the concentrations of salts, nutrients, and other constituents of concern as identified in the salt and nutrient management plans are consistent with applicable water quality objectives. The number, type, and density of monitoring locations to be sampled and other aspects of the monitoring program shall be dependent upon basin-specific conditions and input from the regional water board.
6.2.4.5. An antidegradation analysis demonstrating that the existing projects, reasonably foreseeable future projects, and other sources of loading to the basin included within the plan will, cumulatively, satisfy the requirements of State Water Board Resolution No. 68-16, Statement of Policy with Respect to Maintaining High Quality of Waters in California (Antidegradation Policy).
6.2.4.4. Implementation measures to manage or reduce the salt and nutrient loading in the basin on a sustainable basis and the intended outcome of each measure.
6.2.4.3. Salt and nutrient source identification, basin or subbasin assimilative capacity and loading estimates, together with fate and transport of salts and nutrients.
6.2.4.2. Water recycling use goals and objectives.
6.2.1 The State Water Board encourages collaborative work among salt and nutrient management planning groups, the agricultural community, the regional water boards, Integrated Regional Water Management groups, and groundwater sustainability agencies formed under the Sustainable Groundwater Management Act to achieve the goals of groundwater sustainability, recycled water use, and water quality protection.
For basins identified pursuant to 6.1.3, the State Water Board encourages local water suppliers, wastewater treatment agencies, and recycled water producers, together with local salt and nutrient contributing stakeholders, to continue locally driven and controlled, collaborative processes open to all stakeholders and the regional water board that will result in the development of salt and nutrient management plans for groundwater basins and the management of salts and nutrients on a basin-wide basis.
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2010 2020 2030 2040 2050 2060 2070 2080 2090 2100
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Beneficial Use Thresholds
This chart displays a hypothetical maximum beneficial use threshold as a TDS concentration that is protective of all beneficial uses in the groundwater management zone.
The beneficial uses of groundwater and the beneficial use thresholds are necessary information to recommend TDS
objectives pursuant to CWC 13241(a): Past, present, and probable future beneficial uses of water.
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Figure 4-1. Conceptual Chart to Characterize Beneficial Use Protection in a Management Zone Example AWQ metric:computed from
historical measured data and used to
estimate “historical ambient” TDS
concentration in the management zone.
Example AWQ metric:computed from
recent measured data and used to
estimate “current ambient” TDS
concentration in a management zone.
Maximum beneficial use threshold
Ambient Water Quality (AWQ) Metrics
An AWQ metric is a method to estimate “ambient” N/TDS
concentrations for groundwater in each management zone.
The purpose of an AWQ metric is to enable the comparison of ambient N/TDS concentrations in groundwater versus
the beneficial-use thresholds and water quality objectives, and thereby indicate the state of beneficial use protection.
Example of an AWQ metric: the 5-year moving average of
TDS concentration at a key well (or wells) within a
management zone.
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Evaluation of the Baseline Scenario
The evaluation of the Baseline Scenario can be used to:
•Identify the need for, type of, and timing of SNMP
implementation measures to manage N/TDS loading to
protect beneficial uses.
•Assist in recommending TDS objectives pursuant to CWC
13241(b): Environmental characteristics of the
hydrographic unit under consideration, including the
quality of water available thereto.
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Figure 4-2. Conceptual Evaluation of a Hypothetical Baseline Scenario in a Management Zone Hypothetical TDS Projection for Baseline Scenario
The Baseline Scenario represents the existing water-
supply plans and water-management plans.
This hypothetical TDS projection represents the “future ambient” TDS concentration in a management zone
using the water-quality modeling results of the
Baseline Scenario, expressed as the AWQ metric.
Lower beneficial use threshold
Maximum beneficial use threshold
Results of the Baseline Scenario
In this conceptual example, the ambient
TDS concentration in the management
zone is projected to exceed the maximum
beneficial use threshold by 2063, indicating
that an SNMP implementation measure(s)
may be necessary in the future to protect
beneficial uses in this management zone.
Example AWQ metric:computed from
recent measured data and used to
estimate “current ambient” TDS
concentration in a management zone.
Example AWQ metric:computed from
historical measured data and used to
estimate “historical ambient” TDS
concentration in the management zone.
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Evaluation of SNMP Scenario #1
The evaluation of the SNMP Scenario #1 can be used to:
•Quantify the relative effectiveness of SNMP Scenario #1 in managing N/TDS concentrations in groundwater.
•Develop subsequent SNMP Scenarios for evaluation.
•Assist in recommending TDS objectives pursuant to CWC
13241(c): Water quality conditions that could reasonably be achieved through the coordinated control of all factors which affect water quality in the area.
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Figure 4-3. Conceptual Evaluation of Hypothetical SNMP Scenario #1 in a Management Zone Hypothetical TDS Projection for SNMP Scenario #1
In this conceptual example, SNMP Scenario #1 is
assumed to include a relatively intensive and expensive implementation measure to reduce TDS loading.
This hypothetical TDS projection is an estimate of the
“future ambient” TDS concentration in a management
zone using the water-quality modeling results of SNMP
Scenario #1, expressed as the AWQ metric.
Lower beneficial use threshold
Maximum beneficial use threshold
Results of SNMP Scenario #1
In this conceptual example, the ambient
TDS concentration in the management zone
is projected to stabilize at concentrations
significantly below the maximum beneficial
use threshold over the planning period.
Example AWQ metric:computed from
recent measured data and used to
estimate “current ambient” TDS
concentration in a management zone.
Example AWQ metric:computed from
historical measured data and used to
estimate “historical ambient” TDS
concentration in the management zone.
In
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1200
2010 2020 2030 2040 2050 2060 2070 2080 2090 2100
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Evaluation of SNMP Scenario #2
The evaluation of the SNMP Scenario #2 can be used to:
•Quantify the relative effectiveness of SNMP Scenario #2 in managing the N/TDS concentrations.
•Develop subsequent SNMP Scenarios for evaluation.
•Assist in recommending TDS objectives pursuant to CWC
13241(c): Water quality conditions that could reasonably be achieved through the coordinated control of all factors which affect water quality in the area.
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Figure 4-4. Conceptual Evaluation of Hypothetical SNMP Scenario #2 in a Management Zone Hypothetical TDS Projection for SNMP Scenario #2
In this conceptual example, SNMP Scenario #2 is
assumed to include less intensive and less expensive
implementation measures to reduce TDS loading
compared to SNMP Scenario #1.
This hypothetical TDS projection is an estimate of the
“future ambient” TDS concentration in a management
zone using the water-quality modeling results of SNMP
Scenario #2, expressed as the AWQ metric.
Lower beneficial use threshold
Maximum beneficial use threshold
Example AWQ metric:computed from
recent measured data and used to
estimate “current ambient” TDS
concentration in a management zone.
Example AWQ metric:computed from
historical measured data and used to
estimate “historical ambient” TDS
concentration in the management zone.
In
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Results of SNMP Scenario #2
In this conceptual example, the ambient TDS
concentration in the management zone is still projected to stabilize at concentrations below the maximum beneficial use threshold over the planning period, and hence,
appears to be protective of beneficial uses, but at a higher TDS concentration than projected for SNMP Scenario #1.
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Figure 4-5. Selection of a Hypothetical SNMP Scenario and TDS Objective in a Management Zone Selection of a Hypothetical Preferred SNMP Scenario
After evaluation and comparison of the Baseline and all SNMP Scenarios, a preferred SNMP Scenario is selected
based upon its ability to protect beneficial uses in all management zones in a cost-efficient manner that is
technically, institutionally, and economically feasible.
Lower beneficial use threshold
Maximum beneficial use threshold
TDS Objective
Example AWQ metric:computed from
recent measured data and used to
estimate “current ambient” TDS
concentration in a management zone.
Example AWQ metric:computed from
historical measured data and used to
estimate “historical ambient” TDS
concentration in the management zone.
In
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Selection of a Hypothetical TDS Objective
In this conceptual example, the TDS objective in the
management zone is recommended based upon:
•An evaluation of all factors listed in CWC 13241.
•A demonstration that the SNMP Scenario and N/TDS
objectives collectively satisfy the requirements of
State Board Resolution 68-16 (Antidegradation Policy).
Available
Assimilative
Capacity
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CV-SNMP DEVELOPMENT WORKPLAN IMPLEMENTATION
5.1 Schedule
The schedule of activities to implement the CV-SNMP Development Workplan is shown in Table 5-1 and Figure 5-1 below. The schedule assumes that Task 4.1 begins on November 1, 2021. The CV-SNMP Agencies are developing a Memorandum of Understanding (MOU) to implement this CV-SNMP Development Workplan.
Table 5-1. CV-SNMP Development Workplan Implementation Schedule Task Task Duration
Task Completion
Date
Task 4.1 – Select Consultants for CV-SNMP Facilitation and Technical Services 6 months May 1, 2022
Task 4.2 – Establish CV-SNMP Stakeholder Group and Technical Advisory Committees 3 months July 31, 2022
Task 4.3 – Characterize N/TDS Loading to the Groundwater Basin 6 months October 31, 2022 Task 4.4 – Characterize Current Groundwater Quality 5 months March 31, 2023 Task 4.5 – Delineate Draft Management Zones and Describe Metrics to Characterize Beneficial Use Protection 6 months September 30, 2023 Task 4.6– Develop Technical Approach for Forecasting N/TDS Concentrations in Groundwater 5 months February 29, 2024 Task 4.7 –Construct N/TDS Forecasting Tools and Evaluate Baseline Scenario 12 months February 28, 2025
Task 4.8 – Forecast N/TDS for CV-SNMP Scenarios 8 months October 31, 2025 Task 4.9 – Characterize and Compare the Cost of Baseline and CV- SNMP Scenarios 3 months January 31, 2026
Task 4.10 – Select the Preferred CV-SNMP Scenario, Finalize Management Zones and Beneficial Uses, and Recommend TDS Objectives
6 months July 30, 2026
Task 4.11 – Prepare Final CV-SNMP 3 months October 30, 2026 Task 4.12 – Project Management Throughout
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5.2 Progress Reporting to the Regional Board
To keep the Regional Board informed of progress and future activities during implementation of the CV- SNMP Development Workplan, the CV-SNMP Agencies will add a section to the annual progress report that will be submitted to the Regional Board for the Groundwater Monitoring Program Workplan. The annual progress report will be retitled: Annual Progress Report on Implementation of the CV-SNMP Groundwater Monitoring Program and CV-SNMP Development Workplan. It will be submitted to the Regional Board by March 31 of each year of implementation. The first annual progress report will be due by March 31, 2022 to report progress achieved during calendar year 2021.
5.3 Cost Estimates
This section summarizes the total costs to implement the CV-SNMP Development Workplan as described in Section 4 and to implement the CV-SNMP Groundwater Monitoring Program Workplan as described in Section 3.
Total Costs to implement the CV-SNMP Development Workplan. Table 5-2 below summarizes the cost estimates by major task for the implementation of the CV-SNMP Development Workplan (excluding the costs to implement the CV-SNMP Groundwater Monitoring Program). The costs in Table 5-2 are first-order estimates for work performed by the consultant(s) and are based on the 2021 rates for West Yost
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Associates. Total costs to prepare the final CV-SNMP are estimated to be about $2,870,000, which does not include the costs associated with CV-SNMP Agency staff efforts.
Table 5-2. Cost Estimates to Implement the CV-SNMP Development Workplan Task Cost
Task 4.1 – Select Consultants for CV-SNMP Facilitation and Technical Services $0 Task 4.2 – Establish CV-SNMP Stakeholder Group and Technical Advisory Committees $25,000 Task 4.3 – Characterize N/TDS Loading to the Groundwater Basin $150,000 Task 4.4 – Characterize Current Groundwater Quality $150,000 Task 4.5 – Delineate Draft Management Zones and Describe Metrics to Characterize Beneficial Use Protection $200,000
Task 4.6 – Develop Technical Approach for Forecasting N/TDS Concentrations in Groundwater $130,000
Task 4.7 – Construct N/TDS Forecasting Tools and Evaluate Baseline Scenario $850,000 Task 4.8 – Forecast N/TDS for up to Eight CV-SNMP Scenarios $500,000 Task 4.9 – Characterize and Compare the Cost of Baseline and CV-SNMP Scenarios $200,000 Task 4.10 – Select the Preferred CV-SNMP Scenario, Finalize Management Zones and Beneficial Uses, and Recommend TDS Objectives $200,000
Task 4.11 – Prepare Final CV-SNMP $75,000
Task 4.12 – Project Management $80,000
Task 5.2 – Progress Reporting to the Regional Board $50,000 Contingency (10%) $260,000
Total $2,870,000
Total Costs to implement the CV-SNMP Groundwater Monitoring Program Workplan. Table 5-3 summarizes the cost estimates by task and subtask for the first six-year period of monitoring program implementation. Total costs for the first six-year period of monitoring program implementation are estimated to be about $4,100,000 (including a contingency of 25%). Total costs are likely to be higher because these estimates do not include land acquisition, site improvement costs for new monitoring well sites, or CV-SNMP Agency staff efforts.
Table 5-3. Cost Estimates to Implement the CV-SNMP Groundwater Monitoring Program Task Cost by Sub-Task Cost by Task
Task 1 – Sampling and Analysis of Private Wells $260,175 Perform field canvass of private wells; develop access agreements $21,001 Development/execution of private well access agreements $79,924 Devise and construct and wellhead improvements to enable sample collection
$103,733
Perform two sampling and laboratory analysis events over the five- year period
$55,518
Task 2 – Filling of Gaps in the Monitoring Network $2,858,957
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Table 5-3. Cost Estimates to Implement the CV-SNMP Groundwater Monitoring Program Task Cost by Sub-Task Cost by Task
Perform field work and research; prepare plan to fill gaps in monitoring network $53,776
Prepare well-siting study to identify 23 well sites $50,828 Prepare technical specifications for of two monitoring well types $32,378 Acquire well sites and/or execute lease agreements $14,996 Conducting a bid process to select a well drilling/construction subcontractor $6,172
Obtain permits and CEQA clearance $27,899
Drill, construct, and develop six wells in the Perched aquifer system $231,144 Drill, construct, and develop 16 wells in the Shallow aquifer system $1,999,104 Drill, construct, and develop one deep monitoring well $216,294 Prepare well completion reports for 23 new monitoring wells/file with DWR
$226,366
Task 3 - Preparing Annual Progress Reports to the Regional Board $139,800 Subtotal $3,258,932
Contingency (25%) $814,733
Total $4,073,665
Groundwater Monitoring Program Workplan
Coachella Valley Salt and Nutrient Management Plan Update (Approved by Regional Board on February 21, 2021)
Appendix A
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PREPARED BY
Groundwater Monitoring Program Workplan
Coachella Valley Salt and Nutrient
Management Plan Update
PREPARED FOR
The Coachella Valley SNMP Agencies
FINAL REPORT | DECEMBER 23, 2020
FINAL REPORT | DECEMBER 23, 2020
EARYEAR2020
Groundwater Monitoring Program Workplan
Coachella Valley Salt and Nutrient
Management Plan Update
Prepared for
The Coachella Valley SNMP Agencies
Project No. 943-80-20-01
12/23/2020
Project Manager: Andrew E. Malone, PG Date
12/23/2020
QA/QC Review: Samantha Adams Date
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Table of Contents
Background and Objectives ........................................................................................................... 1 Hydrogeologic Conceptual Model of the Basin .............................................................................. 3
2.1 Basin Setting ..................................................................................................................................... 3
2.2 Hydrogeology ................................................................................................................................... 3
2.2.1 Subbasins and Subareas .......................................................................................................... 3
2.2.2 Occurrence and Movement of Groundwater ......................................................................... 4
2.3 Origin, Fate and Transport of Salts and Nutrients ............................................................................ 5
2.3.1 Salt and Nutrient Loading ....................................................................................................... 5
2.3.2 Transport and Discharge of Salts and Nutrients ..................................................................... 6 Groundwater Monitoring Program .............................................................................................. 11
3.1 Groundwater Monitoring Network ................................................................................................ 11
3.1.1 Methods for Selection of the Groundwater Monitoring Network ....................................... 12
3.1.2 Monitoring Network and Gaps – Shallow Aquifer System ................................................... 12
3.1.3 Monitoring Network and Gaps – Deep Aquifer System ....................................................... 13
3.1.4 Monitoring Network and Gaps – Perched Aquifer System ................................................... 13
3.2 Chemical Analytes and Sampling Frequency .................................................................................. 13
3.3 Monitoring and Reporting .............................................................................................................. 13
3.3.1 Groundwater Sampling and Laboratory Analysis ................................................................. 13
3.3.2 Reporting of Laboratory Results ........................................................................................... 14
3.4 Filling of Gaps in the Monitoring Network ..................................................................................... 14 Implementation Plan .................................................................................................................. 30
4.1 Schedule of Activities ..................................................................................................................... 30
4.2 Progress Reporting to the Regional Board ..................................................................................... 31
4.3 Cost Estimates ................................................................................................................................ 32
LIST OF TABLES
Table 3-1. SNMP Groundwater Monitoring Network – Shallow Aquifer System ................................. 16 Table 3-2. SNMP Groundwater Monitoring Network – Deep Aquifer System ..................................... 18 Table 3-3. SNMP Groundwater Monitoring Network – Perched Aquifer System ................................ 20 Table 3-4. Gaps in SNMP Groundwater Monitoring Network ............................................................. 21 Table 3-5. Analyte List for the SNMP Groundwater Monitoring Program ........................................... 22 Table 3-6. Responsibilities for Groundwater Sampling and Laboratory Analyses ............................... 23 Table 4-1. Cost Estimates – Initial Six-Year Implementation Period of CV-SNMP Groundwater Monitoring Program ............................................................................................................................. 34
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Table of Contents
LIST OF FIGURES
Figure 2-1. Basin Setting ......................................................................................................................... 7 Figure 2-2. Hydrogeologic Map .............................................................................................................. 8 Figure 2-3. Generalized Stratigraphic Column in Lower Coachella Valley ............................................. 9 Figure 2-4. Salt and Nutrient Loading, Transport, and Discharge ........................................................ 10 Figure 3-1. Groundwater Monitoring Network and Gaps – Shallow Aquifer System .......................... 27 Figure 3-2. Groundwater Monitoring Network – Deep Aquifer System ............................................... 28 Figure 3-3. Groundwater Monitoring Network and Gaps – Perched Aquifer System .......................... 29
LIST OF ACRONYMS AND ABBREVIATIONS
CPS City of Palm Springs
CV-SNMP Salt and Nutrient Management Plan for the Coachella Valley Groundwater Basin CVSC Coachella Valley Stormwater Channel
CVWD Coachella Valley Water District
CWA/CSD Coachella Water Authority and Coachella Sanitary District DWA Desert Water Agency
DWR California Department of Water Resources
ft-bgs Feet below ground surface
IWA Indio Water Authority
GAMA Groundwater Ambient Monitoring & Assessment
MC-GRF Mission Creek Groundwater Replenishment System
MDMWC Myoma Dunes Mutual Water Company
MOU Memorandum of Understanding
MSWD Mission Springs Water District
PD-GRF Palm Desert Groundwater Replenishment Facility
POTW Publicly Owned Treatment Works
TDS Total Dissolved Solids
TEL-GRF Thomas E. Levy Groundwater Replenishment Facility USGS United States Geological Survey
VSD Valley Sanitary District
WRP Water Reclamation Plant
WW-GRF White Water Groundwater Replenishment Facility
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Groundwater Monitoring Program Workplan
Coachella Valley Salt and Nutrient Management Plan Update
BACKGROUND AND OBJECTIVES
The Salt and Nutrient Management Plan for the Coachella Valley Groundwater Basin (CV-SNMP) must include a monitoring and reporting program pursuant to Section 6.2.4.1 of the 2018 Recycled Water Policy (Policy):
6.2.4.1. A basin- or subbasin-wide monitoring plan that includes an appropriate network of monitoring locations to provide a reasonable, cost effective means of determining whether the concentrations of salts, nutrients, and other constituents of concern as identified in the salt and nutrient management plans are consistent with applicable water quality objectives. The number, type, and density of monitoring locations to be sampled and other aspects of the monitoring program shall be dependent upon basin-specific conditions and input from the regional water board. Salts, nutrients, and the constituents identified in 6.2.1.1 shall be monitored. The frequency of monitoring shall be proposed in the salt and nutrient management plan for review by the regional water board pursuant to 6.2.3.
6.2.4.1.1. The monitoring plan must be designed to effectively evaluate water quality in the basin. The monitoring plan must focus on water supply wells, areas proximate to large water recycling projects, particularly groundwater recharge projects, and other potential sources of salt and nutrients identified in the salt and nutrient management plan. Also, monitoring locations shall, where appropriate, target groundwater and surface waters where groundwater has connectivity with adjacent surface waters.
6.2.4.1.2. The monitoring plan may include water quality data from existing wells where the wells are located and screened appropriately to determine water quality throughout the most critical areas of the basin. The State Water Board supports monitoring approaches that leverage the use of groundwater monitoring wells from other regulatory programs, such as the Irrigated Lands Regulatory Program and the Sustainable Groundwater Management Act.
6.2.4.1.3. The monitoring plan shall identify those stakeholders responsible for conducting, compiling, and reporting the monitoring data. Where applicable, the regional water board will assist by encouraging other dischargers in the basin or subbasin to participate in the monitoring program. The data shall be electronically reported annually in a format that is compatible with a Groundwater Ambient Monitoring & Assessment (GAMA) information system and must be integrated into the GAMA information system or its successor.
In its evaluation of the 2015 CV-SNMP, the Colorado River Basin Regional Water Quality Control Board (Regional Board) perceived insufficiencies in the proposed monitoring program, including: (i) a lack of data necessary to characterize groundwater quality in all areas and sub-areas of the basin; (ii) a lack of data in critical areas of salt loading (e.g., water recycling and recharge projects); and (iii) it did not propose a plan/timeline to fill the data gaps (Regional Board letter; February 19, 2020). Hence, the Regional Board is requiring the CV-SNMP stakeholders (CV-SNMP Agencies) to prepare a revised Groundwater Monitoring Program Workplan (Workplan) for the Coachella Valley Groundwater Basin (Basin) by December 2020 (Regional Board letter; April 27, 2020).
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The CV-SNMP Agencies include: Coachella Valley Water District (CVWD); Coachella Water Authority and Coachella Sanitary District (CWA/CSD); Desert Water Agency (DWA); Indio Water Authority (IWA); Myoma Dunes Mutual Water Company (MDMWC); Valley Sanitary District (VSD); Mission Springs Water District (MSWD); and City of Palm Springs (CPS).
To achieve the requirements of the Policy and address the concerns of the Regional Board, this Workplan describes the following:
The physical setting of the Coachella Valley which includes the basic hydrology and hydrogeology of the Basin and its subbasins. The physical understanding of how the groundwater basin functions is necessary to select a monitoring network that is capable of characterizing groundwater quality in all areas and subareas of the Basin, both spatially and vertically.
An initial sampling network, including the locations planned for sampling, justifications for the sampling locations, well construction details, and the SNMP Agencies responsible for conducting monitoring at each site.
The existing spatial and vertical gaps in the monitoring network, why the gaps were identified, and how the gaps will be filled.
A proposed plan to implement the monitoring program.
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HYDROGEOLOGIC CONCEPTUAL MODEL OF THE BASIN
This section summarizes the physical characteristics and dynamics of the Basin regarding surface water, groundwater, and the origin, fate and transport of salts and nutrients within the Basin. Understanding the physical characteristics and dynamics of the Basin provides the foundation for selecting a monitoring network that will meet the objectives of the Policy.
This section was prepared from a review of past technical studies and reports; no original work or analyses were performed for this section of the workplan.
2.1 Basin Setting
Figure 2-1 is a map that shows the Basin as delineated by the California Department of Water Resources (DWR Groundwater Basin No. 7-021, excluding the San Gorgonio Pass Subbasin), which represents the area subject to the CV-SNMP. The Basin is located within the northwest portion of the Salton Sea Watershed (USGS Hydrologic Unit 18100200).
Figure 2-1 shows the surface geology as generalized into natural divisions with regard to groundwater:
Unconsolidated water-bearing sediments. These are the pervious formations that comprise the Basin.
Bedrock formations. These are the semi-consolidated sediments and the consolidated bedrock formations that come to the surface in the hills and mountains that surround and bound the Basin. The permeability of the bedrock formations is much less than the water- bearing sediments.
The upper 2,000 ft of the unconsolidated water-bearing sediments constitute the freshwater aquifer system that is the main source of groundwater supply in the region. The sediments tend to be finer- grained in the southeastern portions of the Basin due to the greater distance from the mountainous source areas and the lower-energy depositional environments, such as historical Lake Cahuilla.
The Whitewater River is the major drainage course in the Basin. The Whitewater River is an unlined channel, so surface water flows have the potential to infiltrate and recharge the Basin. In areas with shallow groundwater, the groundwater has the potential to discharge to interconnected surface water.
2.2 Hydrogeology
2.2.1 Subbasins and Subareas
Figure 2-2 is a map of the general hydrogeology of the area. The Basin is cross-cut by several geologic faults, which have created low-permeability zones within the water-bearing sediments that act as barriers to groundwater flow. These barriers impede, but do not eliminate, groundwater flow between subbasins.
Groundwater flow can still occur across the barriers from areas of higher groundwater levels to areas of lower groundwater levels. The map identifies the locations of faults, subbasins, and subareas that comprise the Basin, and describes the general occurrence and movement of groundwater through the Basin.
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The DWR has defined three main subbasins within the study area that are separated by geologic faults or changes in formation permeability that limit and control the movement of groundwater: the Indio Subbasin (DWR Subbasin 7-021.01), the Mission Creek Subbasin (7-021.02), and the Desert Hot Springs Subbasin (7-021.03).1 These subbasins have been further subdivided into subareas based on one or more of the following geologic or hydrogeologic characteristics: type(s) of water-bearing formations, water quality, areas of confined groundwater, forebay areas, and groundwater or surface drainage divides.
Figure 2-2 shows groundwater-elevation contours for water-year 2019 (October 1, 2018 through September 30, 2019). Lateral groundwater flow is generally perpendicular to the contours from higher to lower elevation, as indicated by the arrows on the map. Generally, groundwater flows from areas of natural recharge along the surrounding mountain-fronts toward the valley floor and then southeast toward the distal portions of the Basin near the Salton Sea. Locally, the structural and compositional features within the Basin result in groundwater conditions and flow directions that vary significantly between subbasins. Anthropogenic activities such as artificial recharge and groundwater pumping also influence groundwater-flow directions.
2.2.2 Occurrence and Movement of Groundwater
Described below is the general occurrence of groundwater, and how groundwater flows through and discharges from each subbasin:
Desert Hot Springs Subbasin. In the Desert Hot Springs Subbasin, groundwater typically flows from the Little San Bernardino Mountains to the southeast, but is locally variable due to faulting. The aquifer system is poorly understood due to relatively poor water quality, which has limited the development of groundwater resources in the area. Faulting in the northern portion of the subbasin has resulted in thermal mineral waters in the aquifer with temperatures up to 250 degrees Fahrenheit. These thermal waters are used by several spas in the area. Groundwater discharge primarily occurs by pumping at wells or subsurface outflow. Generally, groundwater elevations in the Desert Hot Springs Subbasin are higher than in the Mission Creek and Indio Subbasins, and hence, the subsurface outflow from the Desert Hot Springs Subbasin occurs across the Mission Creek Fault into these downgradient subbasins. These subsurface flows are thought to be relatively minor based on the differences in groundwater quality on either side of the fault barriers that separate the subbasins.
Mission Creek Subbasin. In the Mission Creek Subbasin, groundwater typically flows from northwest to southeast. The aquifer system is up to 2,000 feet thick and is predominantly unconfined. Portions of the aquifer along the Banning Fault northwest of the Seven Palms Ridge area are semi-confined as evidenced by historically flowing-artesian wells in the area. Depth to groundwater in the Mission Creek Subbasin in 2019 ranged from an estimated 600 feet-bgs (ft-bgs) upgradient of the Mission Creek Groundwater Replenishment Facility (MC-GRF) to less than 5 feet-bgs in the southeast (west of the Indio Hills).
Groundwater discharge primarily occurs by pumping at wells or subsurface flow across the Banning Fault into the Indio Subbasin.
Indio Subbasin. The Indio Subbasin is bordered on the southwest by the crystalline bedrock of the Santa Rosa and San Jacinto Mountains. It is separated from the Mission Creek Subbasin by the Banning Fault, and from the Desert Hot Springs Subbasin by the San Andreas Fault. Both faults are barriers to
1 The DWR defines the San Gorgonio Pass Subbasin (7-021.04) as part the Basin, but it is not included in the CV-SNMP.
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groundwater flow as evidenced by differences in groundwater levels across the faults. For example, groundwater-level differences across the Banning Fault, between the Mission Creek Subbasin and the Indio Subbasin, can be up to 250 feet. Subsurface flow between subbasins primarily occurs from the Desert Hot Springs and Mission Creek subbasins into the Indio subbasin.
In the Indio Subbasin, the aquifer system is generally unconfined in the forebay areas and across the northwestern portion of the subbasin. Generally, groundwater flows from the northwest toward the southeastern distal portions of the subbasin near the Salton Sea. In the southeast portion of the Indio Subbasin, the predominance of fine-grained sediments at depth has created three distinct aquifer systems, which are shown graphically in Figure 2-3 and are described below:
Perched. A semi-perched aquifer up to 100 feet thick that is persistent across much of the area southeast of the City of Indio. The fine-grain units that cause the perched conditions are likely a barrier to deep percolation of surface water. The extent of the semi-perched aquifer is shown on Figure 2-2. Shallow groundwater within the semi-perched aquifer is conveyed away from the root zone by a network of privately-owned subsurface tile drainage systems that are distributed across the agricultural land uses in the southeastern portion of the Basin. CVWD maintains a regional network of surface and subsurface drains, shown on Figure 2-4, that accumulate and convey the drainage waters from the agricultural lands to the Salton Sea.
Shallow. An upper aquifer up to 300 feet thick that is present across most of the area. The upper aquifer is unconfined except in the areas of the semi-perched aquifer where it is semi- confined.
Deep. A lower aquifer that is 500-2,000 feet thick and is the most productive portion of the Basin. In the southeast portion of the Basin, the lower aquifer is confined and is separated from the upper aquifer by a fine-grained aquitard unit that is 100-200 feet thick. Figure 2-2 displays the extent of the aquitard unit.
Groundwater discharge primarily occurs by pumping at wells, shallow groundwater discharge to subsurface tile drainage systems on agricultural lands that ultimately discharge to the Salton Sea, and subsurface outflow to groundwater underlying the Salton Sea.
2.3 Origin, Fate and Transport of Salts and Nutrients
Figure 2-4 is a map that depicts the general areas and processes of salt and nutrient loading, transport, and discharge throughout the Basin.
2.3.1 Salt and Nutrient Loading
Salts, and in some cases nutrients, are loaded to the Basin via the following mechanisms:
Subsurface inflow from saturated sediments and bedrock fractures in the surrounding mountains and hills and from upgradient groundwater subbasins. Recharge of precipitation runoff in unlined stream channels that cross the Basin. Artificial recharge of imported Colorado River Water at the Groundwater Replenishment Facilities (GRF).
Percolation of treated wastewater discharge to unlined ponds.
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Seepage from septic systems.
Return flows from precipitation and irrigation waters applied to the overlying land uses (e.g., agriculture, golf courses, etc.). Loading from return flows is a complex process that is influenced by:
— The combination of precipitation and irrigation waters that ultimately result in the return flows (and their associated TDS and nitrate concentrations) that migrate past the root zone.
— During the downward migration of return flows through the unsaturated (vadose) zone, the TDS and nitrate concentrations of the return flows can be influenced by past TDS and nitrate loading to the vadose zone by historical overlying land uses.
Figure 2-4 shows the spatial distribution and location of these sources of salt and nutrient loading across the Basin.
2.3.2 Transport and Discharge of Salts and Nutrients
Once within the saturated zone, the dissolved salts and nutrients are transported through the aquifer system via the groundwater-flow systems shown on Figure 2-2 and Figure 2-4. Ultimately, salts and nutrients are discharged from the Basin via the following mechanisms:
Groundwater pumping.
Discharge to agricultural drains. As described above, throughout the lower Basin, CVWD maintains a network of surface and subsurface drains to convey shallow groundwater away from the crop root zones. These drains convey water to the Coachella Valley Stormwater Channel (CVSC) and 26 smaller open channel drains that discharge directly to the Salton Sea. Subsurface outflow to downgradient subbasins. In the Indio Subbasin, subsurface outflow occurs to groundwater beneath the Salton Sea.
Phreatophyte consumptive use.
Figure 2-3
From DWR (1964)
Generalized Stratigraphic Column in Lower Coachella Valley
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GROUNDWATER MONITORING PROGRAM
The Groundwater Monitoring Program for the CV-SNMP consists of the following components, each further described below:
Groundwater Monitoring Network
Chemical Analytes and Sampling Frequency
Monitoring and Reporting
3.1 Groundwater Monitoring Network
Section 6.2.4.1 of the Policy requires the implementation of a monitoring program that can determine whether the concentrations of salts and nutrients in groundwater are consistent with water quality objectives and are thereby protective of beneficial uses. The Policy also recognizes the monitoring program will be dependent upon basin-specific conditions and input from the Regional Board.
For the CV-SNMP Groundwater Monitoring Program, the Regional Board is requiring that the monitoring program:
Cover all subbasins and subareas within the Basin. The updated SNMP will require periodic mapping of groundwater quality to estimate ambient water quality and assimilative capacity. A monitoring network that is spatially distributed across all subbasins and subareas of the Basin will provide the necessary data for technically defensible mapping of groundwater quality.
Include sampling from all three major aquifer systems: Deep, Shallow, and Perched. Section 2 of this Workplan described the hydrogeologic stratification of the aquifer system in the Basin. Groundwater quality, and the physical processes that can alter groundwater quality over time, can be significantly different between aquifer systems. This is because: (i) anthropogenic loading of salts and nutrients occur primarily at the ground surface, and hence, can influence the quality of shallower groundwaters first before influencing the quality of deeper groundwaters; (ii) thick aquitards in the southeastern portion of the Basin restrict the vertical movement of groundwater between aquifer systems; and (iii) upward hydraulic gradients, as evidenced by flowing artesian conditions in the southeastern portion of the Basin, limit the downward migration of salts and nutrients to the Deep aquifer system in this region. For these reasons, monitoring of perched, shallow and deep groundwaters is proposed herein across most of the Basin.
Focus on critical areas near: (i) large water recycling projects, (ii) near large recharge projects, particularly where Colorado River water is used to replenish the Basin for water- supply and groundwater management purposes, and (iii) near other potential sources of salt and nutrients. It is important that monitoring occurs hydraulically upgradient and downgradient from these sources of salt and nutrient loading to characterize their influence on groundwater quality.
Focus on critical areas near water supply wells. The water-supply wells are the main points of extraction for the ultimate beneficial uses of the Basin.
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Identify critical gaps in the monitoring network and develop a plan and timeline to fill the gaps. The current gaps in the monitoring network are described in this section. The plan and timeline to fill the gaps are included in Section 4.
Identify the stakeholders responsible for conducting, compiling, and reporting the monitoring data.
3.1.1 Methods for Selection of the Groundwater Monitoring Network The criteria used to select the groundwater monitoring network included the following:
Spatial Distribution. The monitoring network was designed to cover all subbasins and subareas within the Basin.
Hydrogeology. The monitoring network was designed to monitor all three major aquifer systems: Deep, Shallow, and Perched. Water-supply wells in the Basin typically pump groundwater from the Deep aquifer system and were therefore more available for inclusion in the monitoring network. Wells with screens across the Shallow and Perched aquifer systems were less abundant. Hence, most “gaps” in the proposed monitoring network are within the Shallow and Perched aquifer systems.
Areas of Salt or Nutrient Loading. The network was designed to monitor the influence of known sources of salt or nutrient loading on groundwater quality within the Basin. These sources included: the GRFs; wastewater percolation ponds; areas with septic systems; overlying land uses with irrigation returns (e.g., golf, landscapes, agriculture); and areas served non-potable waters for irrigation (e.g., recycled and/or imported waters). Monitoring of non-point-source loading, such as returns from non-potable irrigation waters and septic systems, is intended to be representative of the influence of non-point-sources of loading on groundwater quality. It is not intended to be site-specific monitoring of every area of non-point-source loading across the Basin, which would be infeasible.
Groundwater Flow. The network was designed to monitor all major groundwater-flow systems, from areas of recharge to areas of discharge, and within and between the groundwater subbasins. This is necessary in order to track the subsurface migration of salts and nutrients through the Basin.
Use of Existing Wells. Wherever possible, active municipal production or monitoring wells were preferentially selected if they currently participate in a similar monitoring program (e.g., California Division of Drinking Water [DDW] or Regional Board orders). In some areas, such wells were not available for selection. In those areas, inactive municipal production wells or private wells were selected for inclusion in the monitoring network. The use of inactive or private wells in this monitoring program will require significant coordination with the private well owners and/or physical wellhead improvements to collect groundwater samples. Lastly, if no wells were identified in an area/depth that should be monitored, a “gap” was designated in the monitoring network.
3.1.2 Monitoring Network and Gaps – Shallow Aquifer System Figure 3-1 is a map of the groundwater monitoring network for the Shallow aquifer system. Each well is labeled by a Map_ID. Because most production wells in the Basin have well screens across the Deep aquifer system, there were several identified “gaps” in the monitoring network, particularly in the Thermal Subarea of the Indio Subbasin. Table 3-1 is a list of wells shown on Figure 3-1 sorted by Map_ID. The table includes a summary justification for why each well was included in the monitoring program. Table 3-4 is
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a list of the “gaps” in the monitoring network with a summary explanation of why each gap should be filled.
3.1.3 Monitoring Network and Gaps – Deep Aquifer System Figure 3-2 is a map of the groundwater monitoring network for the Deep aquifer system. Each well is labeled by a Map_ID. Most production wells in the Basin have well screens across the Deep aquifer system; hence, there were no identified “gaps” in the Deep monitoring network. Table 3-2 is a list of wells shown on Figure 3-2 sorted by Map_ID. The table includes a summary justification for why the well was included in the monitoring program.
3.1.4 Monitoring Network and Gaps – Perched Aquifer System Figure 3-3 is a map of the groundwater monitoring network for the Perched aquifer system. Each well is labeled by a Map_ID. The map shows the extent of the Perched aquifer system which is confined to the Thermal Subarea of the Indio Subbasin. The network of CVWD’s agricultural drains that convey perched groundwater to the CVSC and the Salton Sea is also shown. The only existing wells with well screens across the Perched aquifer system are five monitoring wells owned by the CVWD; hence, there were several identified “gaps” in the Perched monitoring network. Table 3-3 is a list of wells shown on Figure 3-3 sorted by Map_ID. The table includes a summary justification for why each well was included in the monitoring program. Table 3-4 is a list of the “gaps” in the monitoring network with a summary explanation of why each gap should be filled.
3.2 Chemical Analytes and Sampling Frequency
Table 3-5 lists the chemicals that will be analyzed for dissolved concentration in each groundwater sample for the monitoring program. The table describes the justification for each chemical analyte. Testing will be performed at a laboratory accredited by the State of California for the testing of inorganic chemistry of drinking water.
The minimum sampling frequency is once every three years. Many wells chosen for this monitoring program are sampled more frequently under other required or voluntary monitoring programs.
During each groundwater sampling event, the agency responsible for sampling will attempt to obtain a static (non-pumping) depth-to-water measurement. In instances when a static depth-to-water measurement cannot be obtained, it will be noted with a description for the reason.
3.3 Monitoring and Reporting
3.3.1 Groundwater Sampling and Laboratory Analysis
The SNMP Agencies have the following responsibilities for sampling of the wells in the monitoring network (described in Section 3.1) and the laboratory analysis of chemical analytes (described in Section 3.2):
Municipal well owners are responsible for the groundwater sampling and laboratory analyses for their own wells.
For private wells within their service area, the overlying SNMP Agency is responsible for coordinating with the private well owners to conduct groundwater sampling and the laboratory analyses. In areas of overlapping jurisdictions of SNMP Agencies, the agencies
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must jointly coordinate to assign responsibility for sampling and analysis of private wells that fall within the overlapping jurisdictions. Agency responsibilities may include developing administrative agreements with the well owners (e.g., right-of-entry agreement) and making physical modifications to the wellhead to enable collection of a sample (e.g., installation of a sampling port on the well discharge pipe).
Table 3-6 lists all wells proposed for the monitoring program. For each well, the table includes a designation for the overlying SNMP Agency(ies).
3.3.2 Reporting of Laboratory Results
Section 6.2.4.1.3 of the Policy requires that all data collected for the monitoring program “shall be electronically reported annually in a format that is compatible with a Groundwater Ambient Monitoring & Assessment (GAMA) information system and must be integrated into the GAMA information system or its successor.” This will centralize data generated from SNMPs at the State level and create consistency across regional water boards to allow for further analysis of monitoring data.
By March 31 of each year, the SNMP Agencies will report the laboratory water-quality results from the prior calendar year to the GAMA information system.
3.4 Filling of Gaps in the Monitoring Network
Table 3-4 lists the gaps in the monitoring network that were identified during the selection of the monitoring network.
Gaps in the monitoring network will be filled in one of two ways:
Field identification of an existing well that: (i) is located near the identified gap; (ii) can be sampled, and (iii) has well screens across the appropriate depth interval (e.g., across the Shallow aquifer system). This may require the following activities: field canvassing to identify a candidate well; research and/or exploratory well surveys to confirm well screen depth intervals; and constructing any well/wellhead modifications that are necessary to collect groundwater samples.
Construction of a new monitoring well with well screens across the appropriate depth interval. This may require the following activities: a well-siting study; well-site acquisition or easement; development of technical specifications for a monitoring well; conducting a bid process to select a well drilling/construction subcontractor; obtaining the necessary permits and CEQA clearance; performing well construction with oversight; performing well development and testing; preparing a well completion report; equipping the well for sampling, and wellhead completion including any needed site improvements.
In the first year, the SNMP Agencies will perform the necessary field work and research and develop a plan for how each gap in the monitoring program will be filled.
Filling the gaps in the monitoring network is likely the most expensive, complicated element of the monitoring program. Therefore, the filling of gaps will be executed over a six-year period, subject to funding availability. The SNMP Agencies will pursue grant funding to support the filling of gaps under State-run programs such as Integrated Regional Water Management and the Sustainable Groundwater Management Act. The SNMP Agencies also are developing a Memorandum of Understanding (MOU) to
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implement the CV-SNMP Monitoring Program Workplan. The MOU will assign responsibilities and cost- sharing agreements between the SNMP Agencies for the filling of the gaps in the monitoring network.
By March 31 of each year, the SNMP Agencies will report to the Regional Board on progress made toward the filling the gaps in the monitoring network over the preceding calendar year (see Section 4.2 below).
Table 3-1. SNMP Groundwater Monitoring Network -- Shallow Aquifer System 1 03S04E20F01S USGS 335348116352701 Active Monitoring 600-640 S Northwest area at WW-GRF 2 03S04E20J01S USGS 335339116345301 Active Monitoring 550-590 S Northeast area at WW-GRF 3 06S07E33G02S Coachella Valley Water District TEL-GRF MW-21S Active Monitoring 230-250 S Adjacent to and downgradient of TEL-GRF 4 06S07E33J02S Coachella Valley Water District TEL-GRF MW-22S Active Monitoring 230-250 S Adjacent to and downgradient of TEL-GRF 5 06S07E34N03S Coachella Valley Water District TEL-GRF MW-23S Active Monitoring 230-250 S Adjacent to and downgradient of TEL-GRF 7 02S04E26C01S Mission Springs Water District Well 28 Inactive MUN 590-898 S Downgradient from Mission Creek GRF; near golf course and septic areas 8 02S04E28A01S Mission Springs Water District Well 34 Active MUN 550-980 S Downgradient from Mission Creek GRF 9 02S05E31L01S Mission Springs Water District Well 11 Inactive Unknown 220-285 S Downgradient of Desert Hot Springs (DHS) subbasin 10 03S04E04Q02S CPV Sentinel 03S04E04Q02S Active Unknown S Upgradient portion of Mission Creek subbasin 11 03S04E11L01S Mission Springs Water District Well 27 Active MUN 180-380 S Upgradient of Garnet Hill subarea; near potential septic areas in N. Palm Springs 12 03S05E05Q01S Hidden Springs Golf Course P27 Active Unknown 220-600 S Downgradient of DHS subbasin; near golf course and septic areas 13 City of Palm Springs Airport MW-2 Active Monitoring 240-250 S Center of Indio subbasin; near airport and areas served non-potable water (NPW) 14 City of Palm Springs MW-1 Active Monitoring 170-210 S Downgradient of Palm Springs WTP percolation ponds 15 City of Palm Springs MW-3 Active Monitoring 140-215 S Upgradient of Palm Springs WTP percolation ponds 16 City of Palm Springs MW-4 Active Monitoring 170-210 S Downgradient of Palm Springs WTP percolation ponds 17 City of Palm Springs MW-5 Active Monitoring 170-210 S Downgradient of Palm Springs WTP percolation ponds 18 City of Palm Springs MW-6 Active Monitoring 170-210 S Downgradient of Palm Springs WTP percolation ponds 19 03S03E08M01S Mission Springs Water District Well 26 Active MUN 225-553 S Monitoring of subsurface inflow from San Gorgonio Pass subbasin 20 03S03E10P02S Unknown DWA P05 Active Unknown 306-906 S Upgradient of Whitewater GRF 21 03S04E12B02S Coachella Valley Water District CVWD Well 3408-1 Active MUN 270-500 S Central portion of Mission Creek subbasin; near potential septic areas 22 03S04E29F01S USGS 335304116353001 Active Monitoring 550-570 S Monitoring at southwestern area of Whitewater GRF 23 03S04E29R01S USGS 335231116345401 Active Monitoring 431-551 S Monitoring at southeastern area of Whitewater GRF 24 04S04E11Q01S Desert Water Agency DWA Well 5 Standby MUN 302-402 S Western portion of Indio subbasin; downgradient of septic areas 25 04S04E35A01S Indian Canyons Golf Resort 04S04E35A01S Active Unknown 360-680 S Near golf courses, septic, and areas served NPW 26 04S05E09F03S Coachella Valley Water District CVWD Well 4564-1 Active MUN 410-670 S Center of Indio subbasin; near golf courses and septic areas 27 04S05E29A02S Desert Water Agency DWA Well 25 Active MUN 166-300 S Downgradient of Palm Springs WTP percolation ponds; near golf courses and NPW areas 29 04S07E33L02S Coachella Valley Water District WRP7 MW-2S Active Monitoring 60-190 S Near WRP-7 percolation ponds 30 05S06E09M03S Coachella Valley Water District WRP10 MW-7 Active Monitoring 260-340 S Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 31 05S06E09P02S Coachella Valley Water District PD-GRF MW 2 Active Monitoring 260-340 S Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 32 05S06E10J01S Coachella Valley Water District PD-GRF MW 1 Active Monitoring 260-340 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 33 05S06E13G03S Coachella Valley Water District WRP10 MW-8 Active Monitoring 260-340 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 34 05S06E14G03S Coachella Valley Water District WRP10 MW-5 Active Monitoring 240-320 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 35 05S06E14P03S Coachella Valley Water District WRP10 MW-6 Active Monitoring 190-270 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 36 05S06E15F01S Coachella Valley Water District WRP10 MW-2 Active Monitoring 160-290 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 37 05S06E15M01S Coachella Valley Water District WRP10 MW-1 Active Monitoring 145-295 S Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 38 05S06E15P01S Coachella Valley Water District WRP10 MW-3 Active Monitoring 130-290 S Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 39 05S06E16A03S Coachella Valley Water District WRP10 MW-4 Active Monitoring 190-270 S Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 40 05S06E21Q04S Coachella Valley Water District PD-GRF MW 3 Active Monitoring 260-340 S Cross-gradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 41 05S06E23M02S Coachella Valley Water District PD-GRF MW 4 Active Monitoring 270-360 S Cross-gradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 42 05S07E03D02S Coachella Valley Water District WRP7 MW-4S Active Monitoring 60-190 S Near WRP-7 percolation ponds 43 05S07E04A04S Coachella Valley Water District WRP7 MW-3S Active Monitoring 50-180 S Near WRP-7 percolation ponds 44 05S07E16K02S Coachella Valley Water District CVWD Well 5737-1 Inactive Monitoring 200-415 S Center of Indio subbasin; downgradient from areas served NPW 45 05S07E19D04S Coachella Valley Water District WRP10 MW-9 Active Monitoring 260-340 S West in Indio subbasin; near golf courses and areas served NPW 46 05S07E24M02S Indio Water Authority Well 1B Active MUN 190-410 S Center of Indio subbasin; upgradient of VSD plant 47 06S06E12G01S Coachella Valley Water District CVWD Well 6650-1 Inactive Monitoring <370 S Within center of The Cove 48 06S07E34A02S Coachella Valley Water District TEL-GRF MW-25 Active Monitoring 115-135 S Downgradient from TEL-GRF and golf courses 49 06S07E34D02S Coachella Valley Water District TEL-GRF MW-24 Active Monitoring 180-200 S Directly north and downgradient of TEL-GRF 50 07S08E29P03S Coachella Valley Water District MC-3 Active Monitoring 380-440 S At Martinez Canyon GRF 51 08S09E31R03S Coachella Valley Water District CVWD Well 8995-1 Active MUN 260-390 S Southern corner of the Indio basin; near agriculture; near Salton Sea Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)Justification for Inclusion in SNMP Monitoring ProgramWell Use(b)
Screen
Interval
ft-bgs
K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 1 of 2
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-1. SNMP Groundwater Monitoring Network -- Shallow Aquifer System Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)Justification for Inclusion in SNMP Monitoring ProgramWell Use(b)
Screen
Interval
ft-bgs
52 03S04E17K01S Valley View MWC 03S04E17K01S Undetermined Unknown 340-375 S Cross-gradient from Whitewater GRF in Garnet Hill subarea 53 03S04E22A01S Erin Miner 03S04E22A01S Active Unknown 180-230 S Downgradient of Whitewater GRF in Garnet Hill subarea; upgradient of West Valley WWTP 54 03S05E08P02S Bluebeyond Fisheries 03S05E08P02S Active Fish Farm 200-400 S Central Mission Creek subbasin; near golf course and septic areas 55 03S05E15N01S Too Many Palms LLC 03S05E15N01S Active Irrigation 158-320 S Distal area in Mission Creek subbasin; downgradient of DHS subbasin 56 03S05E18J01S Desert Dunes Golf Club 03S05E18J01S Active Irrigation 76-340 S Upgradient of Garnet Hill subarea; near golf course and septic areas 57 03S06E21G01S Sky Valley Mobile Home Park 03S06E21G01S Undetermined Unknown 188-248 S Western portion of Sky Valley subarea; near septic areas 58 04S05E04F01S So Pacific Trans Co #32601 04S05E04F01S Active Irrigation 276-576 S Eastern edge of Indio subbasin; downgradient from Garnet Hill subarea; near septic areas 59 04S05E23F01S Westin Mission Hills Resort 04S05E23F01S Active Irrigation 275-1165 S Center of Indio subbasin; near golf courses and septic areas 60 04S05E34C01S Manufacture Home Community Inc 04S05E34C01S Active Irrigation 240-500 S Western edge of Indio subbasin; near septic and areas served NPW 61 04S05E35Q01S Tamarisk Country Club 04S05E35Q01S Active Irrigation 171-518 S Western edge of Indio subbasin; near septic and areas served NPW 62 04S05E36L02S Annenberg Estate 04S05E36L02S Active Irrigation 252-650 S Center of Indio subbasin; near golf, septic, and areas served NPW 63 04S06E20C01S Shenandoah Ventures LP 04S06E20C01S Inactive Irrigation 250-790 S Upgradient in Thousand Palms area; upgradient of septic areas 66 05S05E12D01S Thunderbird Country Club 05S05E12D01S Active Irrigation 125-360 S Western edge of Indio subbasin; near septic and areas served NPW 67 05S06E12M01S Palm Desert Resort Country Club 05S06E12M01S Active Irrigation 140-650 S Center of Indio subbasin; near areas served NPW 68 05S07E08Q01S Bermuda Dunes Airport 05S07E08Q01S Active Domestic 203-654 S Center of Indio subbasin; near areas served NPW 69 05S07E28H02S Tricon/COB Riverdale LP 05S07E28H02S Active Domestic 162-636 S Center of Indio subbasin 70 05S08E28M02S JS Cooper 05S08E28M02S Undetermined Unknown 208-268 S Eastern edge of Indio subbasin; downgradient of VSD discharge point 71 05S08E30N03S Carver Tract Mutual Water Co 05S08E30N03S Active Domestic 270-330 S Eastern portion of Indio subbasin; downgradient from VSD plant 72 06S07E07B01S Traditions Golf Club 06S07E07B01S Active Irrigation 200-480 S Downgradient from The Cove; near golf courses and septic areas 73 06S08E02L01S Prime Time International 06S08E02L01S Undetermined Irrigation 216-407 S Eastern edge of Indio subbasin; near agriculture; upgradient from CWA/CSD WWTP 74 06S08E05K01S Peter Rabbit Farms 06S08E05K01S Active Irrigation 126-375 S Eastern portion of Indio subbasin in Coachella 75 06S08E32L01S Guillermo Torres 06S08E32L01S Undetermined Unknown 127-227 S Downgradient from TEL-GRF; agricultural area 76 07S08E27A01S Gimmway Enterprises Inc 07S08E27A01S Active Domestic 147-215 S Downgradient from Martinez Canyon GRF; near septic areas 77 07S09E14C01S Tudor Ranch Inc.07S09E14C01S Active Domestic 93-290 S Southeastern corner of Indio subbasin; near agriculture and septic areas; near Salton Sea 78 08S08E15G02S Thermiculture Management LLC 08S08E15G02S Active Irrigation 260-500 S Southern corner of Indio subbasin; near agriculture; near Salton Sea 79 Mission Springs Water District Well 25 Active MUN 330-455 S Monitoring of subsurface inflow from San Gorgonio Pass subbasin 80 Mission Springs Water District Well 1 Inactive Monitoring S Northern Miracle Hill subarea; upgradient of Mission Creek subbasin 81 Mission Springs Water District Horton WWTP MW-1 Active Monitoring 186-236 S Monitoring wells upgradient and downgradient of the Horton WWTP 82 Mission Springs Water District Horton WWTP MW-2 Active Monitoring 220-270 S Monitoring wells upgradient and downgradient of the Horton WWTP 83 Mission Springs Water District Horton WWTP MW-3 Active Monitoring 200-250 S Monitoring wells upgradient and downgradient of the Horton WWTP (a) Well Status: Well Status: "Active" means well is known to exist and currently used for original purpose; "Standby" means active backup well; "Inactive" means well exists but is no longer used as a water-supply. (b) Well Use: MUN = municipal and domestic supply
(c) Depth Code: This monitoring program assigns wells to aquifer layers by depth. P = Perched aquifer system, mainly in the Thermal subarea. S = Shallow aquifer system. D = Deep aquifer system K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 2 of 2
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-2. SNMP Groundwater Monitoring Network -- Deep Aquifer System 84 03S04E20F02S USGS 335348116352702 Active Monitoring 850-890 D Northwest area at WW-GRF 85 03S04E20J03S USGS 335339116345303 Active Monitoring 850-890 D Northeast area at WW-GRF 86 06S07E33G01S Coachella Valley Water District TEL-GRF MW-21D Active Monitoring 390-410 D Adjacent to and downgradient of TEL-GRF 87 06S07E33J01S Coachella Valley Water District TEL-GRF MW-22D Active Monitoring 520-540 D Adjacent to and downgradient of TEL-GRF 88 06S07E34N02S Coachella Valley Water District TEL-GRF MW-23D Active Monitoring 525-545 D Adjacent to and downgradient of TEL-GRF 89 07S09E30R03S Coachella Valley Water District Peggy Active Monitoring 730-770 D Downgradient of WRP-4; near agriculture; area of subsurface outflow toward Salton Sea 90 08S09E07N02S Coachella Valley Water District Rosie Active Monitoring 720-780 D Near agriculture; area of subsurface outflow toward Salton Sea 91 05S07E24L03S Indio Water Authority Well 1E Active MUN 552-815 D Center of Indio subbasin; upgradient of VSD plant 92 02S04E28J01S Mission Springs Water District Well 35 Active MUN 725-1020 D Downgradient from Mission Creek GRF 93 02S04E36P01S Mission Springs Water District Well 37 Active MUN 450-1080 D Downgradient of DHS subbasin; possibly downgradient of Horton WWTP 94 02S05E31H01S Mission Springs Water District Well 5 Inactive Monitoring 274-784 D Northern Miracle Hill subarea; upgradient of Mission Creek subbasin 95 03S03E07D01S Mission Springs Water District Well 25A Active MUN 500-740 D Monitoring of subsurface inflow from San Gorgonio Pass subbasin 96 03S04E04P01S CPV Sentinel 03S04E04P01S Active Unknown D Upgradient portion of Mission Creek subbasin 97 03S04E11A02S Mission Springs Water District Well 32 Active MUN 320-980 D Center of Mission Creek subbasin; near potential septic areas 98 03S03E08A01S Mission Springs Water District Well 26A Active MUN 320-600 D Monitoring of subsurface inflow from San Gorgonio Pass subbasin 99 03S03E10P01S Unknown DWA P04 Active Unknown 476-776 D Upgradient of Whitewater GRF 100 03S04E14J01S Mission Springs Water District Well 33 Active MUN 360-650 D Along boundary of Mission Creek subbasin/Garnet Hill subarea 101 03S04E19L01S Desert Water Agency DWA Well 43 Active MUN 500-900 D Upgradient of Whitewater GRF 102 03S04E34H02S Desert Water Agency DWA Well 35 Active MUN 600-1000 D Upgradient of urban land uses in Palm Springs; downgradient of WW-GRF 103 03S04E36Q01S Desert Water Agency DWA Well 38 Active MUN 620-1000 D Upgradient of urban land uses in Palm Springs; downgradient of WW-GRF 104 04S04E02B01S Desert Water Agency DWA Well 22 Active MUN 570-1003 D Upgradient of urban land uses in Palm Springs; downgradient of WW-GRF 105 04S04E11Q02S Desert Water Agency DWA Well 18 Standby MUN 535-948 D Western portion of Indio subbasin; downgradient of septic areas 106 04S04E13C01S Desert Water Agency DWA Well 23 Active MUN 512-912 D Center of Indio subbasin; near airport 107 04S04E24E01S Desert Water Agency DWA Well 32 Active MUN 600-1000 D Western portion of Palm Springs subarea; near areas served non-potable water (NPW) 108 04S04E24H01S Desert Water Agency DWA Well 29 Active MUN 600-1000 D Upgradient of Palm Springs WTP percolation ponds 109 04S04E25C01S Desert Water Agency DWA Well 39 Active MUN 580-750 D Downgradient of Indian Canyon; near golf, septic, and areas served NPW 110 04S05E05A01S Coachella Valley Water District CVWD Well 4568-1 Active MUN 800-955 D Eastern edge of Indio subbasin; downgradient from Garnet Hill; upgradient of septic areas 111 04S05E08N01S Desert Water Agency DWA Well 41 Active MUN 610-1000 D Center of Indio subbasin; near airport, near golf courses and areas served NPW 112 04S05E09R01S Coachella Valley Water District CVWD Well 4567-1 Active MUN 855-1150 D Center of Indio subbasin; near golf courses and septic areas 113 04S05E15G01S Coachella Valley Water District CVWD Well 4521-1 Active MUN 500-800 D Center of Indio subbasin; near golf courses and septic areas 114 04S05E17Q02S Desert Water Agency DWA Well 31 Active MUN 600-1000 D Center of Indio subbasin; near airport, golf courses, and areas served NPW 115 04S05E25D02S Coachella Valley Water District CVWD Well 4507-2 Active MUN 860-1320 D Center of Indio subbasin; near golf courses and septic areas 116 04S05E27K01S Coachella Valley Water District CVWD Well 4527-1 Active MUN 850-1155 D Western edge of Indio subbasin; near NPR and septic areas 117 04S05E29H01S Desert Water Agency DWA Well 26 Active MUN 590-990 D Downgradient of Palm Springs WTP percolation ponds; near golf and areas served NPW 118 04S05E35G04S Coachella Valley Water District CVWD Well 4504-1 Active MUN 600-1000 D Western edge of Indio subbasin; near septic and areas served NPW 119 04S06E18Q04S Coachella Valley Water District CVWD Well 4630-1 Active MUN 480-990 D Upgradient in Thousand Palms area; upgradient of septic areas 120 04S06E28K04S Coachella Valley Water District CVWD Well 4629-1 Active Monitoring 496-796 D Thousand Palms area; near septic and areas served NPW 121 04S07E31H01S Coachella Valley Water District CVWD Well 4722-1 Active MUN 570-1160 D Thousand Palms area; near septic and areas served NPW 122 04S07E33L01S Coachella Valley Water District WRP7 MW-2D Active MUN 245-395 D Near WRP-7 percolation ponds 123 05S06E02C01S Coachella Valley Water District CVWD Well 5664-1 Active MUN 500-930 D Thousand Palms area; near septic and areas served NPW 124 05S06E06B03S Coachella Valley Water District CVWD Well 5630-1 Active Monitoring 455-890 D Center of Indio subbasin; near golf, septic, and areas served NPW 125 05S06E09A01S Coachella Valley Water District CVWD Well 5682-1 Active Monitoring 850-1300 D Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 126 05S06E09F01S Coachella Valley Water District CVWD Well 5637-1 Inactive MUN 450-830 D Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 127 05S06E14B02S Coachella Valley Water District CVWD Well 5665-1 Inactive MUN 400-600 D Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 128 05S06E14P02S Coachella Valley Water District CVWD Well 5603-2 Active MUN 720-975 D Downgradient of WRP-10/PD-GRF; near golf courses and areas served NPW 129 05S06E16A04S Coachella Valley Water District CVWD Well 5620-2 Active MUN 1040-1360 D Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 130 05S06E16K03S Coachella Valley Water District CVWD Well 5681-1 Active Monitoring 900-1200 D Upgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 131 05S06E17L01S Coachella Valley Water District CVWD Well 5667-1 Active Monitoring 470-800 D Western edge of Indio subbasin; near golf, septic, and areas served NPW 132 05S06E20A02S Coachella Valley Water District CVWD Well 5674-1 Inactive Monitoring 750-1050 D South/cross-gradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 133 05S07E03D01S Coachella Valley Water District WRP7 MW-4D Active MUN 245-395 D Near WRP-7 percolation ponds 134 05S07E04A01S Coachella Valley Water District WRP7 MW-1 Dave Price Active Monitoring 147-367 D Near WRP-7 percolation ponds Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)Justification for Inclusion in SNMP Monitoring ProgramWell Use(b)
Screen
Interval
ft-bgs
K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 1 of 2
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-2. SNMP Groundwater Monitoring Network -- Deep Aquifer System Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)Justification for Inclusion in SNMP Monitoring ProgramWell Use(b)
Screen
Interval
ft-bgs
135 05S07E15N01S Indio Water Authority Well AA Active MUN 550-1230 D Center of Indio subbasin; downgradient from areas served NPW 136 05S07E19A01S Coachella Valley Water District CVWD Well 5708-1 Inactive MUN 450-970 D Western portion of Indio subbasin; near golf courses and areas served NPW 137 05S07E20J01S Indio Water Authority Well T Active MUN 580-1305 D Western portion of Indio subbasin; near golf courses and areas served NPW 138 05S07E26E02S Indio Water Authority Well 3B Active MUN 500-1200 D Center of Indio subbasin 139 05S07E27P01S Indio Water Authority Well Z Active MUN 580-1290 D Center of Indio subbasin 140 05S07E33E01S Indio Water Authority Well S Active MUN 460-1260 D Western portion of Indio subbasin; near golf courses and septic areas 141 05S07E34P04S Indio Water Authority Well V Active MUN 460-1270 D Western portion of subbasin; near golf courses and septic areas 142 05S07E35R02S Indio Water Authority Well U Active MUN 480-1190 D Center of Indio subbasin 143 05S07E36D03S Coachella Water Authority Well 19 Active MUN 650-1250 D Center of Indio subbasin 144 05S08E31C03S Coachella Water Authority Well 11 Active MUN 513-818 D Eastern portion of Indio subbasin; downgradient from VSD plant 145 06S07E06B01S Coachella Valley Water District CVWD Well 6701-1 Active MUN 580-800 D Downgradient from The Cove; near golf courses and septic areas 146 06S07E22B02S Coachella Valley Water District CVWD Well 6726-1 Active MUN 640-1160 D North/downgradient of TEL-GRF; near golf courses, septic, and agricultural areas 147 06S07E34A01S Coachella Valley Water District CVWD Well 6728-1 Active MUN 500-750 D Downgradient from TEL-GRF; near golf courses 148 06S07E34D01S Coachella Valley Water District CVWD Well 6729-1 Active MUN 500-780 D Directly north/downgradient of TEL-GRF 149 06S08E06K02S Coachella Water Authority Well 12 Active MUN 500-1010 D Eastern portion of Indio subbasin 150 06S08E09N02S Coachella Water Authority Well 16 Active Monitoring 480-730 D Eastern portion of Indio subbasin; upgradient from CWA/CSD WWTP 151 06S08E19D05S Coachella Valley Water District CVWD Well 6808-1 Active MUN 675-1200 D Center of Indio subbasin; near septic and agricultural areas 152 06S08E22D02S Coachella Valley Water District CVWD Well 6803-1 Inactive MUN 500-1100 D Downgradient from CWA/CSD WWTP; near septic and agricultural areas 153 06S08E25P04S Coachella Valley Water District CVWD Well 6807-1 Active MUN 665-1300 D Upgradient of WRP-4; downgradient of CWA WWTP; near agriculture and septic areas 154 06S08E28N06S Coachella Water Authority Well 18 Active Monitoring 900-1190 D Eastern edge of Indio subbasin; downgradient of VSD discharge point 155 07S08E17A04S Coachella Valley Water District CVWD Well 7803-1 Active MUN 250-710 D Downgradient from TEL-GRF; in agricultural and septic areas 156 07S09E23N01S Coachella Valley Water District CVWD Well 7990-1 Inactive Unknown 530-560 D Southeastern corner of the basin; near agricultural and septic areas; near Salton Sea 157 Indio Water Authority Well 13A Active Irrigation 550-1171 D East in subbasin; downgradient from WRP-7 ponds and NPR areas 158 03S05E08B01S R.C Roberts 03S05E08B01S Undetermined Irrigation 356-516 D Downgradient of DHS subbasin; near golf course and septic areas 159 03S05E17M01S Desert Dunes Golf Club 03S05E17M01S Active Unknown 305-412 D Upgradient of Garnet Hill subarea; near golf course and septic areas 160 03S05E20H02S Donald Franklin 03S05E20H02S Active Irrigation 240-360 D Distal area in Mission Creek subbasin; upgradient of Garnet Hill subarea; near septic 161 03S06E21R01S Joel Rosenfeld 03S06E21R01S Undetermined Irrigation 355-495 D Western portion of Sky Valley subarea; near septic 162 05S05E12B03S Tandika Corp 05S05E12B03S Active Irrigation 410-800 D Western edge of Indio subbasin; near NPR and septic areas 163 05S06E13F01S PD Golf Operations LLC 05S06E13F01S Active Irrigation 400-700 D Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 164 05S06E15H01S Toscana Country Club 05S06E15H01S Active Irrigation 430-950 D Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 165 05S06E22C02S Desert Horizons Country Club 05S06E22C02S Active Irrigation 550-990 D Downgradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 166 05S06E27A01S El Dorado Country Club 05S06E27A01S Active MUN 458-596 D South/cross-gradient of WRP-10/PD-GRF; near golf, septic, and areas served NPW 167 05S06E29P04S Bighorn Golf Club 05S06E29P04S Active MUN 530-720 D Upgradient of Palm Desert; near golf courses and septic areas 168 05S07E07F04S Myoma Dunes Mutual Water Company Well 4 Active MUN 430-730 D Center of Indio subbasin; near areas served NPW 169 05S07E08L01S Myoma Dunes Mutual Water Company Well 11 Active Unknown 500-1060 D Center of Indio subbasin; near areas served NPW 170 05S07E17K01S Myoma Dunes Mutual Water Company Well 12 Active Irrigation 450-950 D Center of Indio subbasin; near areas served NPW 171 05S08E09N03S Jamie Brack 05S08E09N03S Undetermined Unknown 480-580 D Downgradient of septic areas in Fargo subarea; upgradient of Indio subbasin 172 06S07E27B01S Andalusia Golf Club 06S07E27B01S Active Irrigation 300-780 D Downgradient of TEL-GRF; near golf course and agricultural areas 173 06S07E35L02S Castro Bros Castro Bros Active Unknown 300-400 D Downgradient from TEL-GRF; near golf courses and agricultural areas 174 06S08E11A01S Cocopah Nurseries Inc 06S08E11A01S Active Unknown 400-842 D Eastern edge of Indio subbasin; near agriculture; upgradient from CWA/CSD WWTP 175 06S08E31P01S Deer Creek Deer Creek Active Irrigation 400-550 D Downgradient from TEL-GRF, in agricultural area 176 06S08E35E02S Otto L. Zahler 06S08E35E02S Undetermined Unknown 521-596 D Center of Indio subbasin; directly upgradient of WRP-4; in agricultural area 177 07S07E02G02S Warren Webber Warren Webber Active Irrigation 380-700 D Downgradient from TEL-GRF; in agricultural area 178 07S08E01L02S Bill Wordon 07S08E01L02S Undetermined Domestic 500-880 D Center of Indio subbasin; downgradient of WRP-4, in agricultural area 179 07S08E27A02S Gimmway Enterprises Inc 07S08E27A02S Active MUN 491-811 D Downgradient from Martinez Canyon GRF; in agricultural area 180 07S09E10F01S Prime Time International 07S09E10F01S Active Unknown 360-500 D Southeast Indio subbasin; in agricultural area; near Salton Sea 181 Mission Springs Water District Well 31 Active MUN 270-670 D Upgradient of Garnet Hill subarea; near potential septic areas in N. Palm Springs (a) Well Status: Well Status: "Active" means well is known to exist and currently used for original purpose; "Standby" means active backup well; "Inactive" means well exists but is no longer used as a water-supply. (b) Well Use: MUN = municipal and domestic supply
(c) Depth Code: This monitoring program assigns wells to aquifer layers by depth. P = Perched aquifer system, mainly in the Thermal subarea. S = Shallow aquifer system. D = Deep aquifer system K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 2 of 2
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-3. SNMP Groundwater Monitoring Network -- Perched Aquifer System 182 Coachella Valley Water District WRP2 MW3 Active Monitoring <90 P At WRP-2; represents subsurface discharge to Salton Sea 183 06S07E27J03S Coachella Valley Water District TEL-GRF MW-8 Active Monitoring 25-45 P North/downgradient of TEL-GRF; near golf course and agriculture 184 06S07E34A03S Coachella Valley Water District TEL-GRF MW-9 Active Monitoring 25-45 P Downgradient from TEL-GRF and golf course 185 06S08E31R01S Coachella Valley Water District TEL-GRF MW-10 Active Monitoring 25-45 P Downgradient from TEL-GRF; agricultural area 186 07S08E06P01S Coachella Valley Water District TEL-GRF MW-11 Active Monitoring 25-45 P Downgradient from TEL-GRF; agricultural area 187 Coachella Valley Water District PEW-1 Active Monitoring 10-55 P At WRP-4; agricultural area (a) Well Status: "Active" means well is known to exist and currently used for original purpose; "Standby" means active backup well; "Inactive" means well exists but is no longer used as a water-supply. (b) Well Use: MUN = municipal and domestic supply
(c) Depth Code: This monitoring program assigns wells to aquifer layers by depth. P = Perched aquifer system, mainly in the Thermal subarea. S = Shallow aquifer system. D = Deep aquifer system Well
Status(a)'Map_ID SWN Well Owner Well Name Depth
Code(c)Justification for Inclusion in SNMP Monitoring ProgramWell Use(b)
Screen
Interval
ft-bgs
K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 1 of 1
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-4. Gaps in SNMP Groundwater Monitoring Network
G1 S Monitoring of subsurface inflows from areas upgradient of Mission Creek GRF 700-1000 ft-bgs DWA, MSWD G2 S Monitoring directly downgradient of the planned MSWD West Valley WWTP 200-300 ft-bgs MSWD, DWA G3 S Monitoring of southern Miracle Hill subarea; near septic; upgradient of Desert Crest WWTP 100-300 ft-bgs CVWD G4 S Monitoring of the Fargo subarea of DHS subbasin; near septic 100-300 ft-bgs CVWD G5 S Monitoring upgradient of urban land uses in Palm Springs; downgradient of WW-GRF 300-500 ft-bgs DWA G6 S Monitoring center of Indio subbasin; near airport, golf courses, and areas served non-potable water (NPW)250-350 ft-bgs DWA G7 S Monitoring a spatial gap in western portion of Indio subbasin; near golf courses, septic and areas served NPW 200-300 ft-bgs CVWD G8 S Monitoring of subsurface inflows from areas upgradient of urban land uses in Palm Desert Canyon 250-400 ft-bgs CVWD G9 S Monitoring a spatial gap in western portion of Indio subbasin; near golf courses and septic 100-250 ft-bgs CVWD, IWA G10 S Monitoring downgradient from CWA/CSD WWTP; near septic areas and agriculture 100-250 ft-bgs CVWD G11 S Monitoring a spatial gap downgradient of TEL-GRF; near golf courses, septic, and agricultural areas 85-160 ft-bgs CVWD G12 S Monitoring a spatial gap in center of Indio subbasin; near septic areas and agriculture 100-235 ft-bgs CVWD G13 S Monitoring a spatial gap downgradient from TEL-GRF; in agricultural areas 50-150 ft-bgs CVWD G14 S Monitoring a spatial gap downgradient of WRP-4; in agricultural area; near Salton Sea 100-250 ft-bgs CVWD G15 S Monitoring a spatial gap directly upgradient of WRP-4; in agricultural area 100-275 ft-bgs CVWD G16 S Monitoring a spatial gap upgradient of WRP-4; downgradient of CWA/CSD WWTP; near agriculture, septic 100-250 ft-bgs CVWD G17 P Monitoring a spatial gap in northern portion of Perched area; downgradient from Fargo subarea <100 ft-bgs CVWD, IWA, VSD G18 P Monitoring a spatial gap on eastern side of Perched area; in agricultural area <70 ft-bgs CVWD, CWA/CSD G19 P Monitoring a spatial gap in center of Perched area; near agricultural and septic areas <90 ft-bgs CVWD, CWA/CSD G20 P Monitoring a spatial gap in southern basin; may represent subsurface discharge to Salton Sea <70 ft-bgs CVWD G21 P Monitoring a spatial gap in southern basin; may represent subsurface discharge to Salton Sea <70 ft-bgs CVWD G22 P Monitoring a spatial gap in southern basin; may represent subsurface discharge to Salton Sea <90 ft-bgs CVWD G23 S Monitoring a spatial gap in Thousand Palms area; near septic and areas served NPW 150-300 ft-bgs CVWD (b) CVWD = Coachella Valley Water District; CWA/CSD = Coachella Water Authority and Sanitary District; DWA = Desert Water Agency; IWA = Indio Water Authority; VSD = Valley Sanitary District; MSWD = Mission Springs Water District
(a) Depth Code: This monitoring program assigns wells to aquifer layers by depth. P = Perched aquifer system, mainly in the Thermal subarea. S = Shallow aquifer system.
Map_ID Approx. Depth
of Well Screens
Depth
Code(a)Justification for Inclusion in SNMP Monitoring Program Overlying SNMP Agency(b)
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Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-5. Analyte List for the SNMP Groundwater Monitoring Program Analytes Justification Method Cost/Sample
Total Dissolved Solids Measure of total dissolved salt content in water E160.1/SM2540C $14 Nitrate as Nitrogen Primary nutrient in groundwater EPA 300.0 $12 Major cations: K, Na, Ca, Mg Useful in source water characterization EPA 200.7 $20 Major anions: Cl, SO4 Useful in source water characterization EPA 300.0 $18 Total Alkalinity (HCO3, CO3, OH)Useful in source water characterization SM 2320B/2330B $13 K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 1 of 1
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-6. Responsibilities for Groundwater Sampling and Laboratory Analyses 1 03S04E20F01S USGS 335348116352701 Active Monitoring 600-640 S CVWD 2 03S04E20J01S USGS 335339116345301 Active Monitoring 550-590 S CVWD 3 06S07E33G02S Coachella Valley Water District TEL-GRF MW-21S Active Monitoring 230-250 S CVWD 4 06S07E33J02S Coachella Valley Water District TEL-GRF MW-22S Active Monitoring 230-250 S CVWD 5 06S07E34N03S Coachella Valley Water District TEL-GRF MW-23S Active Monitoring 230-250 S CVWD 7 02S04E26C01S Mission Springs Water District Well 28 Inactive MUN 590-898 S MSWD 8 02S04E28A01S Mission Springs Water District Well 34 Active MUN 550-980 S MSWD 9 02S05E31L01S Mission Springs Water District Well 11 Inactive Unknown 220-285 S MSWD 10 03S04E04Q02S CPV Sentinel 03S04E04Q02S Active Unknown S DWA, MSWD 11 03S04E11L01S Mission Springs Water District Well 27 Active MUN 180-380 S MSWD 12 03S05E05Q01S Hidden Springs Golf Course P27 Active Unknown 220-600 S DWA, MSWD 13 City of Palm Springs Airport MW-2 Active Monitoring 240-250 S CPS 14 City of Palm Springs MW-1 Active Monitoring 170-210 S CPS 15 City of Palm Springs MW-3 Active Monitoring 140-215 S CPS 16 City of Palm Springs MW-4 Active Monitoring 170-210 S CPS 17 City of Palm Springs MW-5 Active Monitoring 170-210 S CPS 18 City of Palm Springs MW-6 Active Monitoring 170-210 S CPS 19 03S03E08M01S Mission Springs Water District Well 26 Active MUN 225-553 S MSWD 20 03S03E10P02S Unknown DWA P05 Active Unknown 306-906 S DWA 21 03S04E12B02S Coachella Valley Water District CVWD Well 3408-1 Active MUN 270-500 S CVWD 22 03S04E29F01S USGS 335304116353001 Active Monitoring 550-570 S CVWD 23 03S04E29R01S USGS 335231116345401 Active Monitoring 431-551 S CVWD 24 04S04E11Q01S Desert Water Agency DWA Well 5 Standby MUN 302-402 S DWA 25 04S04E35A01S Indian Canyons Golf Resort 04S04E35A01S Active Unknown 360-680 S DWA 26 04S05E09F03S Coachella Valley Water District CVWD Well 4564-1 Active MUN 410-670 S CVWD 27 04S05E29A02S Desert Water Agency DWA Well 25 Active MUN 166-300 S DWA 29 04S07E33L02S Coachella Valley Water District WRP7 MW-2S Active Monitoring 60-190 S CVWD 30 05S06E09M03S Coachella Valley Water District WRP10 MW-7 Active Monitoring 260-340 S CVWD 31 05S06E09P02S Coachella Valley Water District PD-GRF MW 2 Active Monitoring 260-340 S CVWD 32 05S06E10J01S Coachella Valley Water District PD-GRF MW 1 Active Monitoring 260-340 S CVWD 33 05S06E13G03S Coachella Valley Water District WRP10 MW-8 Active Monitoring 260-340 S CVWD 34 05S06E14G03S Coachella Valley Water District WRP10 MW-5 Active Monitoring 240-320 S CVWD 35 05S06E14P03S Coachella Valley Water District WRP10 MW-6 Active Monitoring 190-270 S CVWD 36 05S06E15F01S Coachella Valley Water District WRP10 MW-2 Active Monitoring 160-290 S CVWD 37 05S06E15M01S Coachella Valley Water District WRP10 MW-1 Active Monitoring 145-295 S CVWD 38 05S06E15P01S Coachella Valley Water District WRP10 MW-3 Active Monitoring 130-290 S CVWD 39 05S06E16A03S Coachella Valley Water District WRP10 MW-4 Active Monitoring 190-270 S CVWD 40 05S06E21Q04S Coachella Valley Water District PD-GRF MW 3 Active Monitoring 260-340 S CVWD 41 05S06E23M02S Coachella Valley Water District PD-GRF MW 4 Active Monitoring 270-360 S CVWD 42 05S07E03D02S Coachella Valley Water District WRP7 MW-4S Active Monitoring 60-190 S CVWD 43 05S07E04A04S Coachella Valley Water District WRP7 MW-3S Active Monitoring 50-180 S CVWD 44 05S07E16K02S Coachella Valley Water District CVWD Well 5737-1 Inactive MUN 200-415 S CVWD, IWA, VSD 45 05S07E19D04S Coachella Valley Water District WRP10 MW-9 Active Monitoring 260-340 S CVWD 46 05S07E24M02S Indio Water Authority Well 1B Active Monitoring 190-410 S IWA 47 06S06E12G01S Coachella Valley Water District CVWD Well 6650-1 Inactive Monitoring <370 S CVWD 48 06S07E34A02S Coachella Valley Water District TEL-GRF MW-25 Active Monitoring 115-135 S CVWD 49 06S07E34D02S Coachella Valley Water District TEL-GRF MW-24 Active MUN 180-200 S CVWD 50 07S08E29P03S Coachella Valley Water District MC-3 Active Unknown 380-440 S CVWD 51 08S09E31R03S Coachella Valley Water District CVWD Well 8995-1 Active Unknown 260-390 S CVWD 52 03S04E17K01S Valley View MWC 03S04E17K01S Undetermined Fish Farm 340-375 S DWA, MSWD 53 03S04E22A01S Erin Miner 03S04E22A01S Active Irrigation 180-230 S DWA 54 03S05E08P02S Bluebeyond Fisheries 03S05E08P02S Active Irrigation 200-400 S CVWD 55 03S05E15N01S Too Many Palms LLC 03S05E15N01S Active Unknown 158-320 S CVWD 56 03S05E18J01S Desert Dunes Golf Club 03S05E18J01S Active Irrigation 76-340 S CVWD 57 03S06E21G01S Sky Valley Mobile Home Park 03S06E21G01S Undetermined Irrigation 188-248 S CVWD 58 04S05E04F01S So Pacific Trans Co #32601 04S05E04F01S Active Irrigation 276-576 S CVWD 59 04S05E23F01S Westin Mission Hills Resort 04S05E23F01S Active Irrigation 275-1165 S CVWD 60 04S05E34C01S Manufacture Home Community Inc 04S05E34C01S Active Irrigation 240-500 S CVWD Well
Use(b)
Screen
Interval
ft-bgs
Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)
Overlying
SNMP Agency(d)
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Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-6. Responsibilities for Groundwater Sampling and Laboratory Analyses Well
Use(b)
Screen
Interval
ft-bgs
Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)
Overlying
SNMP Agency(d)
61 04S05E35Q01S Tamarisk Country Club 04S05E35Q01S Active Irrigation 171-518 S CVWD 62 04S05E36L02S Annenberg Estate 04S05E36L02S Active Unknown 252-650 S CVWD 63 04S06E20C01S Shenandoah Ventures LP 04S06E20C01S Inactive Irrigation 250-790 S CVWD 66 05S05E12D01S Thunderbird Country Club 05S05E12D01S Active Domestic 125-360 S CVWD 67 05S06E12M01S Palm Desert Resort Country Club 05S06E12M01S Active Domestic 140-650 S CVWD 68 05S07E08Q01S Bermuda Dunes Airport 05S07E08Q01S Active Unknown 203-654 S CVWD, MDMWC 69 05S07E28H02S Tricon/COB Riverdale LP 05S07E28H02S Active Domestic 162-636 S CVWD, IWA, VSD 70 05S08E28M02S JS Cooper 05S08E28M02S Undetermined Irrigation 208-268 S CVWD, CWA/CSD 71 05S08E30N03S Carver Tract Mutual Water Co 05S08E30N03S Active Irrigation 270-330 S CVWD, VSD 72 06S07E07B01S Traditions Golf Club 06S07E07B01S Active Irrigation 200-480 S CVWD 73 06S08E02L01S Prime Time International 06S08E02L01S Undetermined Unknown 216-407 S CVWD, CWA/CSD 74 06S08E05K01S Peter Rabbit Farms 06S08E05K01S Active Domestic 126-375 S CVWD, CWA/CSD 75 06S08E32L01S Guillermo Torres 06S08E32L01S Undetermined Domestic 127-227 S CVWD 76 07S08E27A01S Gimmway Enterprises Inc 07S08E27A01S Active Irrigation 147-215 S CVWD 77 07S09E14C01S Tudor Ranch Inc.07S09E14C01S Active MUN 93-290 S CVWD 78 08S08E15G02S Thermiculture Management LLC 08S08E15G02S Active Monitoring 260-500 S CVWD 79 Mission Springs Water District Well 25 Active Monitoring 330-455 S MSWD 80 Mission Springs Water District Well 1 Inactive Monitoring S MSWD 81 Mission Springs Water District Horton WWTP MW-1 Active Monitoring 186-236 S MSWD 82 Mission Springs Water District Horton WWTP MW-2 Active Monitoring 220-270 S MSWD 83 Mission Springs Water District Horton WWTP MW-3 Active Monitoring 200-250 S MSWD 84 03S04E20F02S USGS 335348116352702 Active Monitoring 850-890 D CVWD 85 03S04E20J03S USGS 335339116345303 Active Monitoring 850-890 D CVWD 86 06S07E33G01S Coachella Valley Water District TEL-GRF MW-21D Active Monitoring 390-410 D CVWD 87 06S07E33J01S Coachella Valley Water District TEL-GRF MW-22D Active Monitoring 520-540 D CVWD 88 06S07E34N02S Coachella Valley Water District TEL-GRF MW-23D Active Monitoring 525-545 D CVWD 89 07S09E30R03S Coachella Valley Water District Peggy Active MUN 730-770 D CVWD 90 08S09E07N02S Coachella Valley Water District Rosie Active MUN 720-780 D CVWD 91 05S07E24L03S Indio Water Authority Well 1E Active MUN 552-815 D IWA 92 02S04E28J01S Mission Springs Water District Well 35 Active Monitoring 725-1020 D MSWD 93 02S04E36P01S Mission Springs Water District Well 37 Active MUN 450-1080 D MSWD 94 02S05E31H01S Mission Springs Water District Well 5 Inactive Unknown 274-784 D MSWD 95 03S03E07D01S Mission Springs Water District Well 25A Active MUN 500-740 D MSWD 96 03S04E04P01S CPV Sentinel 03S04E04P01S Active MUN D DWA, MSWD 97 03S04E11A02S Mission Springs Water District Well 32 Active Unknown 320-980 D MSWD 98 03S03E08A01S Mission Springs Water District Well 26A Active MUN 320-600 D MSWD 99 03S03E10P01S Unknown DWA P04 Active MUN 476-776 D DWA 100 03S04E14J01S Mission Springs Water District Well 33 Active MUN 360-650 D MSWD 101 03S04E19L01S Desert Water Agency DWA Well 43 Active MUN 500-900 D DWA 102 03S04E34H02S Desert Water Agency DWA Well 35 Active MUN 600-1000 D DWA 103 03S04E36Q01S Desert Water Agency DWA Well 38 Active MUN 620-1000 D DWA 104 04S04E02B01S Desert Water Agency DWA Well 22 Active MUN 570-1003 D DWA 105 04S04E11Q02S Desert Water Agency DWA Well 18 Standby MUN 535-948 D DWA 106 04S04E13C01S Desert Water Agency DWA Well 23 Active MUN 512-912 D DWA 107 04S04E24E01S Desert Water Agency DWA Well 32 Active MUN 600-1000 D DWA 108 04S04E24H01S Desert Water Agency DWA Well 29 Active MUN 600-1000 D DWA 109 04S04E25C01S Desert Water Agency DWA Well 39 Active MUN 580-750 D DWA 110 04S05E05A01S Coachella Valley Water District CVWD Well 4568-1 Active MUN 800-955 D CVWD 111 04S05E08N01S Desert Water Agency DWA Well 41 Active MUN 610-1000 D DWA 112 04S05E09R01S Coachella Valley Water District CVWD Well 4567-1 Active MUN 855-1150 D CVWD 113 04S05E15G01S Coachella Valley Water District CVWD Well 4521-1 Active MUN 500-800 D CVWD 114 04S05E17Q02S Desert Water Agency DWA Well 31 Active MUN 600-1000 D DWA 115 04S05E25D02S Coachella Valley Water District CVWD Well 4507-2 Active MUN 860-1320 D CVWD 116 04S05E27K01S Coachella Valley Water District CVWD Well 4527-1 Active MUN 850-1155 D CVWD 117 04S05E29H01S Desert Water Agency DWA Well 26 Active MUN 590-990 D DWA 118 04S05E35G04S Coachella Valley Water District CVWD Well 4504-1 Active MUN 600-1000 D CVWD 119 04S06E18Q04S Coachella Valley Water District CVWD Well 4630-1 Active MUN 480-990 D CVWD 120 04S06E28K04S Coachella Valley Water District CVWD Well 4629-1 Active Monitoring 496-796 D CVWD K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 2 of 4
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-6. Responsibilities for Groundwater Sampling and Laboratory Analyses Well
Use(b)
Screen
Interval
ft-bgs
Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)
Overlying
SNMP Agency(d)
121 04S07E31H01S Coachella Valley Water District CVWD Well 4722-1 Active MUN 570-1160 D CVWD 122 04S07E33L01S Coachella Valley Water District WRP7 MW-2D Active MUN 245-395 D CVWD 123 05S06E02C01S Coachella Valley Water District CVWD Well 5664-1 Active MUN 500-930 D CVWD 124 05S06E06B03S Coachella Valley Water District CVWD Well 5630-1 Active Monitoring 455-890 D CVWD 125 05S06E09A01S Coachella Valley Water District CVWD Well 5682-1 Active Monitoring 850-1300 D CVWD 126 05S06E09F01S Coachella Valley Water District CVWD Well 5637-1 Inactive MUN 450-830 D CVWD 127 05S06E14B02S Coachella Valley Water District CVWD Well 5665-1 Inactive MUN 400-600 D CVWD 128 05S06E14P02S Coachella Valley Water District CVWD Well 5603-2 Active MUN 720-975 D CVWD 129 05S06E16A04S Coachella Valley Water District CVWD Well 5620-2 Active MUN 1040-1360 D CVWD 130 05S06E16K03S Coachella Valley Water District CVWD Well 5681-1 Active Monitoring 900-1200 D CVWD 131 05S06E17L01S Coachella Valley Water District CVWD Well 5667-1 Active Monitoring 470-800 D CVWD 132 05S06E20A02S Coachella Valley Water District CVWD Well 5674-1 Inactive Monitoring 750-1050 D CVWD 133 05S07E03D01S Coachella Valley Water District WRP7 MW-4D Active MUN 245-395 D CVWD 134 05S07E04A01S Coachella Valley Water District WRP7 MW-1 Active Monitoring 147-367 D CVWD 135 05S07E15N01S Indio Water Authority Well AA Active MUN 550-1230 D IWA 136 05S07E19A01S Coachella Valley Water District CVWD Well 5708-1 Inactive MUN 450-970 D CVWD 137 05S07E20J01S Indio Water Authority Well T Active MUN 580-1305 D IWA 138 05S07E26E02S Indio Water Authority Well 3B Active MUN 500-1200 D IWA 139 05S07E27P01S Indio Water Authority Well Z Active MUN 580-1290 D IWA 140 05S07E33E01S Indio Water Authority Well S Active MUN 460-1260 D IWA 141 05S07E34P04S Indio Water Authority Well V Active MUN 460-1270 D IWA 142 05S07E35R02S Indio Water Authority Well U Active MUN 480-1190 D IWA 143 05S07E36D03S Coachella Water Authority Well 19 Active MUN 650-1250 D CWA/CSD 144 05S08E31C03S Coachella Water Authority Well 11 Active MUN 513-818 D CWA/CSD 145 06S07E06B01S Coachella Valley Water District CVWD Well 6701-1 Active MUN 580-800 D CVWD 146 06S07E22B02S Coachella Valley Water District CVWD Well 6726-1 Active MUN 640-1160 D CVWD 147 06S07E34A01S Coachella Valley Water District CVWD Well 6728-1 Active MUN 500-750 D CVWD 148 06S07E34D01S Coachella Valley Water District CVWD Well 6729-1 Active MUN 500-780 D CVWD 149 06S08E06K02S Coachella Water Authority Well 12 Active MUN 500-1010 D CWA/CSD 150 06S08E09N02S Coachella Water Authority Well 16 Active Monitoring 480-730 D CWA/CSD 151 06S08E19D05S Coachella Valley Water District CVWD Well 6808-1 Active MUN 675-1200 D CVWD 152 06S08E22D02S Coachella Valley Water District CVWD Well 6803-1 Inactive MUN 500-1100 D CVWD 153 06S08E25P04S Coachella Valley Water District CVWD Well 6807-1 Active MUN 665-1300 D CVWD 154 06S08E28N06S Coachella Water Authority Well 18 Active Monitoring 900-1190 D CWA/CSD 155 07S08E17A04S Coachella Valley Water District CVWD Well 7803-1 Active MUN 250-710 D CVWD 156 07S09E23N01S Coachella Valley Water District CVWD Well 7990-1 Inactive Unknown 530-560 D CVWD 157 Indio Water Authority Well 13A Active Irrigation 550-1171 D IWA 158 03S05E08B01S R.C Roberts 03S05E08B01S Undetermined Irrigation 356-516 D DWA 159 03S05E17M01S Desert Dunes Golf Club 03S05E17M01S Active Unknown 305-412 D CVWD 160 03S05E20H02S Donald Franklin 03S05E20H02S Active Irrigation 240-360 D CVWD 161 03S06E21R01S Joel Rosenfeld 03S06E21R01S Undetermined Irrigation 355-495 D CVWD 162 05S05E12B03S Tandika Corp 05S05E12B03S Active Irrigation 410-800 D CVWD 163 05S06E13F01S PD Golf Operations LLC 05S06E13F01S Active Irrigation 400-700 D CVWD 164 05S06E15H01S Toscana Country Club 05S06E15H01S Active Irrigation 430-950 D CVWD 165 05S06E22C02S Desert Horizons Country Club 05S06E22C02S Active Irrigation 550-990 D CVWD 166 05S06E27A01S El Dorado Country Club 05S06E27A01S Active MUN 458-596 D CVWD 167 05S06E29P04S Bighorn Golf Club 05S06E29P04S Active MUN 530-720 D CVWD 168 05S07E07F04S Myoma Dunes Mutual Water Company Well 4 Active MUN 430-730 D MDMWC 169 05S07E08L01S Myoma Dunes Mutual Water Company Well 11 Active Unknown 500-1060 D MDMWC 170 05S07E17K01S Myoma Dunes Mutual Water Company Well 12 Active Irrigation 450-950 D MDMWC 171 05S08E09N03S Jamie Brack 05S08E09N03S Undetermined Unknown 480-580 D CVWD, IWA 172 06S07E27B01S Andalusia Golf Club 06S07E27B01S Active Irrigation 300-780 D CVWD 173 06S07E35L02S Castro Bros Castro Bros Active Unknown 300-400 D CVWD 174 06S08E11A01S Cocopah Nurseries Inc 06S08E11A01S Active Unknown 400-842 D CVWD, CWA/CSD 175 06S08E31P01S Deer Creek Deer Creek Active Irrigation 400-550 D CVWD 176 06S08E35E02S Otto L. Zahler 06S08E35E02S Undetermined Unknown 521-596 D CVWD 177 07S07E02G02S Warren Webber Warren Webber Active Irrigation 380-700 D CVWD 178 07S08E01L02S Bill Wordon 07S08E01L02S Undetermined Domestic 500-880 D CVWD K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 3 of 4
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
Table 3-6. Responsibilities for Groundwater Sampling and Laboratory Analyses Well
Use(b)
Screen
Interval
ft-bgs
Well
Status(a)Map_ID SWN Well Owner Well Name Depth
Code(c)
Overlying
SNMP Agency(d)
179 07S08E27A02S Gimmway Enterprises Inc 07S08E27A02S Active MUN 491-811 D CVWD 180 07S09E10F01S Prime Time International 07S09E10F01S Active Monitoring 360-500 D CVWD 181 Mission Springs Water District Well 31 Active Monitoring 270-670 D MSWD 182 Coachella Valley Water District WRP2 MW3 Active Monitoring <90 P CVWD 183 06S07E27J03S Coachella Valley Water District TEL-GRF MW-8 Active Monitoring 25-45 P CVWD 184 06S07E34A03S Coachella Valley Water District TEL-GRF MW-9 Active Monitoring 25-45 P CVWD 185 06S08E31R01S Coachella Valley Water District TEL-GRF MW-10 Active Monitoring 25-45 P CVWD 186 07S08E06P01S Coachella Valley Water District TEL-GRF MW-11 Active Monitoring 25-45 P CVWD 187 Coachella Valley Water District PEW-1 Active Monitoring 10-55 P CVWD (a) Well Status: "Active" means well is known to exist and currently used for original purpose; "Standby" means active backup well; "Inactive" means well exists but is no longer used as a water-supply. (b) Well Use: MUN = municipal and domestic supply
(c) Depth Code: This monitoring program assigns wells to aquifer layers by depth. P = Perched aquifer system. S = Shallow aquifer system. D = Deep aquifer system (d) CVWD = Coachella Valley Water District; CWA/CSD = Coachella Water Authority and Sanitary District; DWA = Desert Water Agency; IWA = Indio Water Authority; MDMWC = Myoma Dunes Mutual Water Company; VSD = Valley Sanitary District; MSWD = Mission Springs Water District; CPS = City of Palm Springs K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 4 of 4
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
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Groundwater Monitoring Program Workplan
Coachella Valley Salt and Nutrient Management Plan Update
N-943-80-20-01-WP-R-M&R WORKPLAN
30 The Coachella Valley SNMP Agencies
December 23, 2020
IMPLEMENTATION PLAN
4.1 Schedule of Activities
The objective of the SNMP Agencies is to have a fully functioning groundwater monitoring program by March 31, 2027, including: (i) implementing the monitoring program at existing wells in the monitoring network; (ii) filling all gaps in the monitoring network identified in this Workplan; (iii) analysis of at least one groundwater sample for the constituents listed in Table 3-5 from all monitoring wells in the network; and (iv) reporting of all laboratory results to the GAMA information system or its successor.
The schedule of activities to implement the groundwater monitoring program is described below:
Active and standby municipal production wells.
— All active and standby municipal production wells, identified in this SNMP groundwater monitoring program under a DDW monitoring order, will be sampled pursuant to their existing DDW Groundwater Monitoring Schedules. Most municipal production wells are sampled at least once every three years, or more frequently for some analytes like nitrate.
— By March 31 of each year beginning in 2022, the SNMP Agencies will report to the GAMA information system the laboratory results from all groundwater samples collected during the prior calendar year for the analytes listed in Table 3-5. Active monitoring wells.
— All monitoring wells identified in this SNMP groundwater monitoring program that are participating in regulatory or voluntary monitoring programs will be sampled pursuant to their existing monitoring schedules. Typically, such monitoring wells are sampled at least once every three years, and most are sampled more frequently. At least one sample must be analyzed for the constituents listed in Table 3-5 every three years. — By March 31 of each year beginning in 2022, the SNMP Agencies will report to the GAMA information system the laboratory results from all groundwater samples collected during the prior calendar year for the analytes listed in Table 3-5. Private wells and inactive wells.
— Starting 2021, SNMP Agencies responsible for sampling at private wells or inactive wells will initiate steps to collect the first groundwater sample from these wells. This may include executing access agreements and devising and/or implementing a method to collect a groundwater sample.
— By the end of 2023, the responsible SNMP Agencies will collect and analyze one groundwater sample for every private and inactive well in the monitoring network, where feasible. By March 31 of each year beginning in 2022, the SNMP Agencies will report to the GAMA information system the laboratory results from all groundwater samples collected during the prior calendar year for the analytes listed in Table 3-5. — Thereafter, each private and inactive well will be sampled at least once every three years. It is the objective of this program to collect and analyze at least two groundwater samples for all private and inactive wells during the initial six-year implementation period.
Groundwater Monitoring Program Workplan
Coachella Valley Salt and Nutrient Management Plan Update
N-943-80-20-01-WP-R-M&R WORKPLAN
31 The Coachella Valley SNMP Agencies
December 23, 2020
Filling of Gaps in the Monitoring Network.
— In 2021, the SNMP Agencies that are responsible for filling gaps in the monitoring network will perform the necessary research and field work and develop plans to fill each gap. These plans will be summarized in the first annual progress report to the Regional Board by March 31, 2022.
— Starting in 2022, the SNMP Agencies will initiate steps to fill the gaps. The objective is to fill all gaps in the monitoring network and collect and analyze at least one groundwater sample by December 31, 2026.
— By March 31 of each year beginning in 2023, the SNMP Agencies will report to the GAMA information system the laboratory results from all groundwater samples collected during the prior calendar year for the analytes listed in Table 3-5. — It should be expected that new gaps in the monitoring network may be identified during implementation of the monitoring program. This may occur if a well in the monitoring network can no longer be sampled because it was destroyed, becomes inoperable, or otherwise is no longer available for monitoring. In such cases, the SNMP Agencies will attempt to identify a suitable replacement well (similar location and well construction) or develop a plan to fill this new gap in the monitoring network. These challenges and plans to address new data gaps will be summarized in the annual progress reports to the Regional Board (see Section 4.2 below).
4.2 Progress Reporting to the Regional Board
To keep the Regional Board informed of progress and future activities during implementation of the monitoring program, the SNMP Agencies will submit an Annual Progress Report on Implementation of the CV-SNMP Groundwater Monitoring Program to the Regional Board. The first progress report will be due by March 31, 2022 to report progress achieved during calendar year 2021. The contents of the progress report will include:
Section 1. Summary of Groundwater Monitoring Program and Implementation Schedule Section 2. Activities Accomplished or In-Progress during the Prior Calendar Year Sampling and analysis of existing municipal production wells and monitoring wells. Progress made towards sampling and analysis of inactive and private wells. Progress made towards filling gaps in the monitoring network. Wells that can no longer be sampled and other challenges in sampling.
Section 3. Activities Planned for the Next Calendar Year Plans for sampling at wells, including addressing sampling challenges. Activities to replace wells that can no longer be sampled and fill gaps in the monitoring network.
Figures.
Updated map of Groundwater Monitoring Network – Shallow Aquifer System. Updated map of Groundwater Monitoring Network – Deep Aquifer System. Updated map of Groundwater Monitoring Network – Perched Aquifer System.
Groundwater Monitoring Program Workplan
Coachella Valley Salt and Nutrient Management Plan Update
N-943-80-20-01-WP-R-M&R WORKPLAN
32 The Coachella Valley SNMP Agencies
December 23, 2020
Tables.
Updated list of wells in Groundwater Monitoring Network. Updated list of gaps in Groundwater Monitoring Network.
Appendix A. 2020 CV-SNMP Groundwater Monitoring Program Workplan
4.3 Cost Estimates
Cost estimates were derived for the first six-year period of monitoring program implementation. Costs were estimated for only those additional activities that the monitoring program would cause the SNMP Agencies to perform (that they otherwise would not perform). These activities include: (i) sampling and analysis of private wells; (ii) filling of gaps in the monitoring program; and (iii) preparing the annual progress reports to the Regional Board.
Table 4-1 summarizes the cost estimates by task and subtask. The costs described herein are first-order estimates. Actual costs may vary because monitoring program implementation may unfold differently than assumed herein. For example, a gap in the monitoring network may be filled by identifying an existing suitable well, as opposed to constructing a new well. In addition, these costs do not include land acquisition costs for new monitoring well sites or any needed site improvements, including grading, block walls, or fencing.
Sampling of private wells. Table 3-6 indicates there are 58 private wells that are proposed to participate in the monitoring program. Each well is assumed to be sampled twice over the first six years (116 samples).
The main activities associated with the sampling of private wells include:
Performing a field canvass of each well to: initiate coordination with the well owners; document the condition of the well; and determine the current ability to collect a water- quality sample.
Developing and executing an access agreement with the private well owner.
If necessary, hiring a subcontractor to construct wellhead improvements to enable sample collection. It is assumed that about half of the private wells will require such improvements at $3,000 per well.
Perform two sampling events and laboratory analyses over the six-year period. Laboratory costs are about $77 per sample.
Total costs for sampling of private wells over the first six-year implementation period are estimated at about $260,000.
Filling gaps in the monitoring network. Table 3-4 indicates that there are 23 gaps in the monitoring network that need to be filled over the first six-year period. For cost estimating purposes, it is assumed that each gap will be filled with the construction of a new monitoring well.
Six of the proposed monitoring wells are targeted for the Perched aquifer system with well depths of less than about 100 ft-bgs—these well boreholes are assumed to be drilled via a sonic method. Sixteen of the proposed wells are targeted for the Shallow aquifer system with well depths of less than about 500 ft-bgs—these well boreholes are assumed to be drilled via a mud-rotary method. One of the proposed
Groundwater Monitoring Program Workplan
Coachella Valley Salt and Nutrient Management Plan Update
N-943-80-20-01-WP-R-M&R WORKPLAN
33 The Coachella Valley SNMP Agencies
December 23, 2020
wells is estimated to have a total depth of about 1,000 ft-bgs—this well borehole is assumed to be drilled via a mud-rotary method.
The main activities associated with the drilling and construction of new monitoring wells are listed below.
Perform a well-siting study to select 23 available and appropriate well sites.
Prepare two sets of standard technical specifications for the drilling, construction, and development of two types of monitoring wells: (i) a monitoring well in the Perched aquifer system and (ii) a monitoring well in the Shallow or Deep aquifer systems.
Acquire well-site property and/or execute easements. The cost associated with land purchase or long-term land leases are unknown at this time and were therefore not estimated; however, such costs are likely to be significant.
Prepare bid package and conduct the bid process to select a well drilling/construction subcontractor. It is assumed that one contractor will construct all 23 wells.
Obtain all permits and CEQA clearance.
Drill, construct, and develop 23 monitoring wells. The wells are assumed to be comprised of 4” PVC Schedule 80 pipe with 40 feet of well screens. Well head completions are assumed to be an above ground 10-inch diameter stovepipe casing with a locking cap. Any needed well- site improvements are unknown at this time and were therefore not estimated; however, such costs are likely to be significant.
Prepare well completion reports for 23 new monitoring wells and file Well Completion Reports with the California Department of Water Resources. New monitoring wells will be added to the SNMP database.
Total costs to fill all gaps in the monitoring network over the first six-year implementation period are estimated to be about $2,900,000. These estimates do not include land acquisition costs for new monitoring well sites or any needed site improvements.
Task 3 – Preparing the Annual Progress Report to the Regional Board. As described above in Section 4.2, the SNMP Agencies will prepare an Annual Progress Report on Implementation of the CV-SNMP Groundwater Monitoring Program to the Regional Board each year to keep it abreast of progress and future activities.
Total costs to prepare five annual progress reports over the first six-year implementation period are estimated to be about $140,000.
Total Costs. Total costs for the first six-year period of monitoring program implementation are estimated to be about $4,100,000 (including a contingency of 25%). Total costs are likely to be higher because these estimates do not include land acquisition or site improvement costs for new monitoring well sites.
Table 4-1. Cost Estimates -- Initial Six-Year Implementation Period of CV-SNMP Groundwater Monitoring Program Sub-Task Task
Task 1 - Sampling and Analysis of Private Wells $152,146 $108,030 $260,175
1.1 $19,529 $1,472 $1,472 $21,001
1.2 $79,924 $0 $79,924
1.3 $16,733 $87,000 $87,000 $103,733
1.4 $35,960 $10,626 $8,932 $19,558 $55,518
Task 2 - Filling of Gaps in the Monitoring Network $1,089,443 $1,769,514 $2,858,957
2.1 $53,776 $0 $53,776
2.2 $50,828 $0 $50,828
2.3 $32,378 $0 $32,378
2.4 $14,996 $0 $14,996
2.5 $5,988 $184 $184 $6,172
2.6 $3,299 $24,600 $24,600 $27,899
2.7 a $94,608 $1,536 $89,820 $42,000 $3,180 $136,536 $231,144
2.8 a $555,712 $8,192 $1,314,720 $112,000 $8,480 $1,443,392 $1,999,104
2.9 a $51,492 $512 $158,260 $5,500 $530 $164,802 $216,294
2.10 $226,366 $226,366
Task 3 - Preparing Annual Progress Reports to the Regional Board $139,800 $0 $139,800 $1,381,389 $11,896 $1,649,800 $159,500 $24,600 $10,626 $21,122 $1,877,544 $3,258,932 $814,733
$4,073,665
Notes:
a = These estimates do not include land acquisition costs for new monitoring well sites or any needed site improvements, including grading, block walls, or fencing.
Total Reimbursable Expenses
Sub-Task
Total Project Costs
Task and Subtask Descriptions
No
t
e
s
Labor Cost
TaskSub-Task Task Lab
Other Direct Costs
Field EquipTravel
Well
Construction
Services (Sub)
E-Logging
Services
(Sub)
Permits
and
CEQA
Development/execution of private well access agreements Devise and construct and wellhead improvements to enable sample collection Perform two sampling and laboratory analysis events over the five-year period Prepare well-siting study to identify 23 well sites
Perform field canvass of private wells; develop access agreements Perform field work and research; prepare plan to fill gaps in monitoring network Prepare technical specifications for of two monitoring well types Acquire well sites and/or execute lease agreements
Conducting a bid process to select a well drilling/construction subcontractor Obtain permits and CEQA clearance
Drill, construct, and develop six wells in the Perched aquifer system Drill, construct, and develop 16 wells in the Shallow aquifer system Drill, construct, and develop one deep monitoring well
Prepare well completion reports for 23 new monitoring wells/file with DWR Project Total
Project Subtotals
Contingency (25%)
K-943-80-20-01-WP-T-MON-RPT-WORKPLAN Page 1 of 1
Coachella Valley SNMP Agencies
Coachella Valley SNMP Update
Last Revised: 11-19-20
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Example Maps and Data Graphics
to Characterize Groundwater Quality
Appendix B
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Table B-1: Example of Summary Statistics for N/TDS Concentrations at Wells Well_ID Well Name Well Owner Well Status Management Zone Aquifer Layer(s) Number of
TDS
Sample
Results
Mean of Annual
Average
Concentration
Values
Standard
Error
Standard
Deviation
1025698 MW1 Alcoa Monitoring Chino-3/Chino-North 1 49 789.49 60.13 255.12 1025699 MW2 Alcoa Monitoring Chino-3/Chino-North 1 46 1519.88 76.30 275.12 1025700 Offsite MW1 Alcoa Monitoring Chino-3/Chino-North 2 32 444.13 12.06 41.77 1025701 Offsite MW2 Alcoa Monitoring Chino-3/Chino-North 1 23 500.72 10.40 32.88 1025702 Offsite MW3 Alcoa Monitoring Chino-3/Chino-North 1 33 518.14 31.35 113.03 1025703 Offsite MW4 Alcoa Monitoring Chino-3/Chino-North 1 30 678.56 57.31 198.53 1025704 MW2A Alcoa Monitoring Chino-3/Chino-North 1 6 2700.00 237.54 411.43 1025705 NA_1006182 Almo, M.C.Monitoring Beaumont unknown 5 339.04 10.57 23.63 1025706 Arco Well 14 Arco Facility 5172 Monitoring Yucaipa 12 2 275.00 1025707 Arco Well 18 Arco Facility 5172 Monitoring Yucaipa 12 2 310.00 1025708 Arco Well 19 Arco Facility 5172 Monitoring Yucaipa 12 1 320.00 1025709 Arco Well 20 Arco Facility 5172 Monitoring Yucaipa 12 2 295.00 1025710 Arco Well 21 Arco Facility 5172 Monitoring Yucaipa 1 2 290.00 1025711 Arco Well 22 Arco Facility 5172 Monitoring Yucaipa 12 2 320.00 1025712 Arco Well 23 Arco Facility 5172 Monitoring Yucaipa 12 2 280.00 1025713 Arco Well 24 Arco Facility 5172 Monitoring Yucaipa 12 2 300.00 1025714 Arco Well 25 Arco Facility 5172 Monitoring Yucaipa 12 2 300.00 1025715 3 Baseline Gardens Mutual Water Company Active Bunker Hill A 23 1 331.40 1025716 PS & B 2 Baseline Gardens Mutual Water Company Active Bunker Hill B 1 1 579.00 1025717 BV 5th Ave. 1 Bear Valley Mutual Water Company Active Yucaipa 3 2 340.00 1025718 Cemetery Well 1 Beaumont Cemetery Active Beaumont 1 3 346.67 21.70 37.58 1025719 Cemetery Well 2 Beaumont Cemetery Active Beaumont 12 3 388.80 35.82 62.04 1025720 BCVWD 13 Beaumont Cherry Valley Water District Active Beaumont 123 2 230.00 1025721 BCVWD 12 Beaumont Cherry Valley Water District Active Beaumont 123 8 240.86 9.75 25.80
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Figure B-1: Example of Point and Raster Map of N/TDS Concentrations in Groundwater
Groundwater and Surface Water Interactions
Chino Creek Near PB-9
Figure 3-15a
Sulfa
te
(SO 4)+Chloride(Cl)C
a
l
c
i
u
m
(
C
a
)
+
M
a
g
n
e
s
i
u
m
(
M
g
)
Carbonate
(CO 3)+Bicarbonate(HC
O
3)
S
o
d
i
u
m
(
N
a
)
+
P
o
t
a
s
s
i
u
m
(
K
)
100
80 60
40 20
20 40
60 80
100
020406080100
0 20
40 60
80 100 0
Ca
Mg
1008040 60200
Cl
100
80 60
40 20
0 S
O
4 100
80 60
40 20
0 Piper Legend
Wells (screen interval in ft-bgs)
PB-9/1 (30-40)
PB-9/2 (70-95)
HCMP-3/1 (110-150)
HCMP-3/2 (344-364)
HCMP-3/3 (560-580)
Piper Legend
Surface Water
IEUA Carbon Canyon
Effluent
Dry Weather Flow at
Chino Creek at Schaefer -
Maximum Benefit Sampling
100
80 60
40 20
0 20192018201720162015201420132012
0 1,000
2,000
3,000
4,000
5,000
TD
S
mg
l
Groundwater
PB-9/1
PB-9/2
HCMP-3/1
HCMP-3/2
HCMP-3/3
Surface Water
IEUA Carbon Canyon Effluent
Dry Weather Flow at
Chino Creek at Schaefer -
Maximum Benefit Sampling
TDS Concentration in Groundwater and Surface Water
20192018201720162015201420132012
525
530
535
540
545
550
555
El
e
v
a
t
io
n
ft
-
a
m
s
l
0 200
400
600
800
1,000
1,200
1,400
Da
il
y
D
i
sc
har
ge
cf
s
Surface Water Discharge
IEUA Carbon Canyon Effluent
USGS Gage - Chino Creek at Schaefer
Prado Basin Habitat
Sustainability Committee
2018 Annual Report
Thalweg Elevation near PB-9
")
Well Location
POTW Discharge
USGS Gage
2018 Groundwater Flow
Direction (Model Layer 1)
2018 Riparian
Vegetation Extent
Map Legend
Typical Groundwater
(Shallow Aquifer)
Typical Surface Water
(Effluent Discharge)
Typical Groundwater
(Deep Aquifer)
Groundwater Elevation, Thalweg Elevation, and Surface Water Discharge Figure B-3: Example of a Multi-variate Exhibit of Groundwater and Surface Water
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Responses to Comments on the
Draft CV-SNMP Development Workplan
Appendix C
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Appendix C: Responses to Comments on the Draft CV-SNMP Development Workplan