Monterey Peninsula Water Supply Project (MPWSP)

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 . 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. The order requires a 70% reduction in water pumped from the Carmel River by the end of 2016. 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. 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. 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.

Costs

The MPWSP has an estimated cost of $277 million. 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 . 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.

Current Status

Figure 1. MPWSP project area and preliminary facilities map.

CalAm purchased a 46 acre property northwest of the MRWPCA's wastewater treatment plant, which is the proposed location of the desalination plant. 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.

In December 2014, CalAm began work on a test slant intake well located at the CEMEX sand mining facility in North Marina. 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. The February 28th slant well installation deadline was met, preventing drilling from being setback to October 1st. As of March 30, 2015 the test slant well was operational and capable of recording data for up to 2 years. 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.

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. 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 .

Timeline

• 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
• 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
• September 2014
  • CalAm awarded $1 million grant by California Department of Water Resources for a test slant well
• 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
• March 30, 2015
  • Completed test slant well successfully and began pumping and returning water to the ocean. Data on this pumping event has been published
• April 2015
  • Draft of the EIR is scheduled for release
• December 2015
  • Contractors selected for source wells and pipelines
• 2017 - 2018
  • Construction of source wells, major pipelines and desalination plant begins
• January 2019
  • Desalination plant operations will begin, assuming no setbacks

Links

• CEQA projects on the Central Coast
• MPWSP home page
• MPWSP page at CPUC site
• CEQAnet Project Description SCH Number 2006101004

Disclaimer

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.