Difference between revisions of "Monterey Peninsula Water Supply Project (MPWSP)"

From CCoWS Wiki
Jump to: navigation, search
Line 76: Line 76:
**Coastal Commission final decision <ref name="Water Supply Project"/>
**Coastal Commission final decision <ref name="Water Supply Project"/>
*'''March 23, 2018'''
*'''March 23, 2018'''
**Final EIR was released <ref name "Final EIR">[https://www.watersupplyproject.org/eir],</ref>
**Final EIR was released [[MPWSP Final EIR]] <ref name "Final EIR">[https://www.watersupplyproject.org/eir],</ref>
*'''March-August 2018'''
*'''March-August 2018'''
**Construction of desalination plant begins <ref name="Water Supply Project"/>
**Construction of desalination plant begins <ref name="Water Supply Project"/>

Revision as of 14:41, 28 March 2018

A watershed-related topic examined by the ENVS 560/L Watershed Systems class at CSUMB.

Project Summary

The Monterey Peninsula Water Supply Project (MPWSP) is a project designed to meet water production needs for the Monterey Peninsula. It will consist of a 9.6 million gpd desalination plant, slant intake wells, pipelines for brackish water and brine disposal, production water delivery pipes, and improvements to the existing Seaside Groundwater Basin Aquifer Storage and Recovery (ASR) system [1]. The draft EIR (DEIR) for the project is currently in its second round of public comment. The slant wells have been tested with varying results, and the installation of delivery pipeline has begun.

In 2009, a cease and desist order from State Water Resources Control Board (SWRCB) was enacted to prevent the Peninsula's water purveyor California American Water (CalAm) from illegally diverting water from the Carmel River by December 31, 2016[2]. The order requires a 70% reduction in water pumped from the Carmel River by the end of 2016[3]. Due to this order, an alternative water source became necessary to fulfill the demand of the 40,000 customers in CalAm's Monterey District service area[1]. In 2012, CalAm proposed the MPWSP (SCH#2006101004) to fill the growing need for water following the failure of the Regional Water Project (RWP). Additionally, the Monterey Regional Water Pollution Control Agency (MRWPCA) proposed the 3,500 acre foot per year Monterey Peninsula Groundwater Replenishment Project (MPGRP), which would reduce the desalination plant's water output from 9.6 MGD to 6.4 MGD [4]. The MPWSP has become contentious in the region due to associated ratepayer costs, results of slant well testing, and simply the scope of the project.


The MPWSP has an estimated cost of $322 million[5]. Estimated cost is based on a 6.4 Million Gallon per Day (MGD) desalination facility including cost associated pre-construction. These costs will be allocated to following portions of the project:

Aspect of MPWP Estimated Cost Spent to Date
Surface Intake Systems and Supply Return Facilities $79M 27%
Desalination Plant $115M 18%
Pipeline Facilities $128M 37%
Pre-Construction Cost $8M 100%

Rate Changes

Monterey Peninsula rate payers can expect significant bill increases with the progression and completion of the Monterey Peninsula Water Supply Project, including an annual, increasing surcharge [6]. Additionally, Peninsula water customers will experience bill increases between 58.5% and 79% in March 2017 to make up for CalAm's lost revenue from drought conservation efforts [7].

These impending rate increases have caused the formation of several groups who want to buy out, or privatize, the region's water company. Privatization, groups like Public Water Now argue, would reduce costs to customers by cutting out CalAm's profit gains [8].

Current Status

Alt text
Figure 1. MPWSP project area and preliminary facilities map[1].

CalAm purchased a 46 acre property northwest of the MRWPCA's wastewater treatment plant for the location of the desalination plant[4], and is testing nine novel, subsurface slant intake wells at the CEMEX active mining area north of Marina [1].

In December 2014, CalAm began work on a test slant intake well located at the CEMEX sand mining facility in North Marina[9]. After several setbacks, CalAm received a permit from the California Coastal Commission to operate the test slant wells until February 2018. Slant wells are being tested as an alternative to vertical wells to reduce their amount of marine organism impingement and other environmental effects. Slant wells are a new technology, and are therefore controversial. As a test technology, they did not require a CEQA review, and if they are approved following testing will remain permanently in place. The subsurface wells intake from groundwater aquifers that have been intruded with saltwater, drawing in brackish water [1].

Construction has begun on the the 7-mile water delivery pipeline running from Seaside to Pacific Grove. This pipeline will deliver water from the Seaside basin to the Peninsula, as part of the overall water supply plan [10].

On November 20, 2015, CalAm filed for a petition to modify the cease and desist order and allow more time to find alternative water sources[11]. This would extend the deadline to December 31, 2020 and set reductions to the amount of water CalAm could pump from the Carmel River. In December 2015, the test slant wells reached 92% salinity, an increase from 75% when it was first installed [12] .

The DEIR closed for public comment on March 29, 2017. The final EIR is scheduled to be released in September 2017 followed by possible approval by the CCC. The Monterey pipeline and ASR pump station is projected to be completed by December 2017, and the desalination plant is has a projected start time of 2020 [13].


  • October 20 2009
    • Cease and desist order from SWRCB enacted which prevents CalAm from illegally diverting water and requires a 70% reduction in water taken from the Carmel River by December 31, 2016[2]
  • April 12, 2011
    • Investigation begins into the RWP, ultimately leading to a project shut-down
  • April 23, 2012
    • CalAm filed an application with the California Public Utilities Commission leading to the creation of the MPWP
  • October 10, 2012
    • Notice of Preparition of the project's EIR was released[1]
  • September 2014
  • December 2014
    • Drilling of a test slant intake well began at the CEMEX sand mining facility in Marina
  • January 30, 2015
    • Reached the final depth of the slant well, testing its feasibility for the MPWSP water source[15]
  • March 30, 2015
    • Completed test slant well successfully and began pumping and returning water to the ocean[16].
  • April 2015
    • Draft of the EIR is scheduled for release[1]
  • December 2015
    • Contractors selected for source wells and pipelines [17]
  • September 2016
    • California Public Utilities Commission approves pipeline component
  • January 2017
    • Draft EIR/EIS dispersed for public comment; pipeline installation begins [18]
  • Fourth Quarter 2017
    • Final EIR published
  • First Quarter 2018
    • Estimation of CPUC's final decision
  • Jan-March 2018
    • Coastal Commission final decision [5]
  • March 23, 2018
  • March-August 2018
    • Construction of desalination plant begins [5]



  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 CPUC MPWSP[1]
  2. 2.0 2.1 Office of Ratepayer Advocates: Background - Monterey Peninsula Water Supply Project
  3. MPWSP, Home Page
  4. 4.0 4.1 California American Water. 2013. Monterey Peninsula Water Supply Project: Desalination Infrastructure-Request for Qualifications. [www.mprwa.org/wp.../03/RFQ-WSP-Desal-Infrastructure-CAW-FINAL-4-1-13.doc]
  5. 5.0 5.1 5.2 https://www.watersupplyproject.org/about
  6. California American Water. 2012. Cost workshops on Monterey Peninsula Water Supply Project.[2]
  7. Johnson J. 2017. Cal Am water bills to rise as much as 79% in March; more increases pending. Monterey Herald.[3]
  8. Public Water Now
  9. Cook I. 2014. Monterey Peninsulat Water Supply Project: Presentation to MPWSP Governance Committee. California American Water.
  10. Johnson J. 2016. Celebrating water milestones: CalAm pipeline groundbreaking, recycled water purchase agreement signing. http://www.montereyherald.com/environment-and-nature/20161017/celebrating-water-milestones-cal-am-pipeline-groundbreaking-recycled-water-purchase-agreement-signing
  11. California American Water. 2016. Monterey Peninsula Water Supply Project: Progress Report. [4]
  12. California American Water. 2015. MPWSP Anticipated Schedule. https://www.watersupplyproject.org/schedule
  13. California Water Association, CalAm Awarded $1 Million Grant for Desalination Slant Test Well
  14. Crooks I. 2015. Ian Crooks: Cal Am test slant well to deliver key data. Monterey Herald.Monterey Herald Article: Cal Am test slant well to deliver key data
  15. Conrad C. 2015. Cal-Am desalination well now pumping water. KSBW8. [5]
  16. http://www.watersupplyproject.org/#!about/cee5
  17. Monterey Peninsula Water Management District. 2016. Water supply for the Monterey Peninsula: Update on Development of Water Supply Projects.[6]
  18. [7],


This page may contain student work completed as part of assigned coursework. It may not be accurate. It does not necessary reflect the opinion or policy of CSUMB, its staff, or students.