Monterey Peninsula Water Supply Project (MPWSP)

From CCoWS Wiki
Revision as of 14:27, 7 April 2016 by Kristenh (Talk | contribs)

Jump to: navigation, search

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 desalination plant, slant intake wells, pipelines for brackish water, pipelines for brine disposal, and production water delivery pipes [1]. The MPWSP is currently in the planning phase and will not begin construction until 2017 [2]. In 2009, a cease and desist order from State Water Resources Control Board (SWRCB) was enacted to prevent CalAm from illegally diverting water from the Carmel River by December 31, 2016[3]. The order requires a 70% reduction in water pumped from the Carmel River by the end of 2016[4]. 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[5]. In 2012, CalAm proposed the MPWSP (SCH#2006101004) to fill the growing need for water following the failure of the Regional Water Project (RWP). The MPWSP will consist of a series of slant wells designed to pump water to a desalination facility in Marina [1]. This project would include a 9.6 million gallons per day (MGD) desalination facility, an aquifer storage and recovery system (ASR), and a brine discharge system [1]. 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[1].


The MPWSP has an estimated cost of $277 million[1]. These costs will be allocated to following portions of the project:

Aspect of MPWP Estimated Cost
Surface Intake Systems and Supply Return Facilities $51M
Desalination Plant $95M
Pipeline Facilities $131M

Rate Changes

With the installation of the Monterey Peninsula Water Supply Project, typical rate payers in the Monterey area can expect a 41% bill increase by 2018 [6]. The average citizen in the Monterey area uses approximately 74 units (10 cubic feet per unit) per month. These citizens' monthly bill is expected to raise from $75 to an estimated $104 by 2018. Citizens will be affected differently based on the levels of their water consumption[6].

Current Status

Alt text
Figure 1. MPWSP project area and preliminary facilities map[5].

CalAm purchased a 46 acre property northwest of the MRWPCA's wastewater treatment plant, which is the proposed location of the desalination plant[1]. Additionally, CalAm is in the process of securing permanent easements on a 376 acre property west of the proposed desalination facility, in hopes of using it for slant intake wells[1].

In December 2014, CalAm began work on a test slant intake well located at the CEMEX sand mining facility in North Marina[7]. Due to the presence of the Western Snowy Plover breeding grounds (threatened under the Endangered Species Act) near the test slant well, the location had to be returned to its original conditions by February 28, 2015[8]. The February 28th slant well installation deadline was met, preventing drilling from being setback to October 1st[8]. As of March 30, 2015 the test slant well was operational and capable of recording data for up to 2 years[9]. The overall MPWSP is on track to be completed within the scheduled four years but it will not be completed by the December 31, 2016 deadline for Carmel River pumping reduction[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] .


  • 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[3]
  • 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[5]
  • 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[14]
  • March 30, 2015
    • Completed test slant well successfully and began pumping and returning water to the ocean[9]. Data on this pumping event has been published [15]
  • April 2015
    • Draft of the EIR is scheduled for release[5]
  • December 2015
    • Contractors selected for source wells and pipelines [16]
  • 2017 - 2018
    • Construction of source wells, major pipelines and desalination plant begins [16]
  • January 2019
    • Desalination plant operations will begin, assuming no setbacks [16]



  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 MPWSP, Project Description
  2. 3.0 3.1 Office of Ratepayer Advocates: Background - Monterey Peninsula Water Supply Project
  3. MPWSP, Home Page
  4. 5.0 5.1 5.2 5.3 CPUC, MPWSP Information Page
  5. 6.0 6.1 CalAm, MPWSP Effects on Rate - Estimates
  6. In brief: Test slant well intake for Monterey Peninsula project now underway
  7. 8.0 8.1 MPWSP Temporary Slant Test Well, Project Description
  8. 9.0 9.1 KSBW Article, Cal-Am desalination well now pumping water
  9. MPWSP: Progress Report, January 2015
  10. [1]
  11. California Water Association, CalAm Awarded $1 Million Grant for Desalination Slant Test Well
  12. Monterey Herald Article: Cal Am test slant well to deliver key data
  13. MPWSP, Test Slant Well Data Published
  14. 16.0 16.1 16.2!about/cee5


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.