New Monterey desalination plan launched by Cal Am

A 5.4-9.0 MGD (20,440-34,000 m³/d) desalination plant located in North Marina employing slant well intake technology remains at the heart of California American Water (Cal Am)’s latest proposal for supplying the Monterey Peninsula.

Cal Am announced on 23 April 2012 that it had filed its much-anticipated application with the California Public Utilities Commission to construct the Monterey Peninsula Water Supply Project (MPWSP), the company’s proposed water solution to replace its current intake from the Carmel river in compliance with state-ordered pumping reductions.

The new project also includes expansion of the company’s current Aquifer Storage & Recovery program, conducted in cooperation with the Monterey Peninsula Water Management District (MPWMD). In addition, the company proposes to purchase water from the Groundwater Replenishment Project (GWR) currently proposed by the Monterey Regional Water Pollution Control Agency and the MPWMD.

“This project will require a significant investment on behalf of our customers,” said Cal Am president Rob MacLean. “But getting off the Carmel river is a matter of extreme urgency. If we cannot develop a replacement water supply, the community, which already has residential per-capita water consumption of less than 50 GPD (190 L/d), will face devastating cutbacks.”

The introduction of groundwater replenishment as a major supply component is a new feature of the Cal Am proposal. Also new are company plans to keep financing costs to a minimum with a combination of State Revolving Fund (SRF) loans and a proposal to fund a portion of the capital investment through a customer surcharge rather than through the company’s rate base – the assets upon which regulated utilities are permitted to earn a rate of return.

As part of its application, California American Water proposes to permit the desalination facility for 9 MGD (34,000 m³/d) in case the GWR is delayed and unable to deliver water in time to meet state-ordered cutbacks. The company anticipates the decision will be made in the last quarter of 2014 and will be based on how far the GWR has come in terms of its environmental review and other permitting work.

Construction for the desalination and groundwater replenishment facilities would need to begin by the first quarter of 2015. The company estimates that the project will cost between US$ 320 and US$ 370 million, depending on size and that the average bill is expected to increase by US$ 26.50 to US$ 38.50 per month to pay for the project.