Time Not Yet Right for Desalination
April 2006

By: Betty H. Olson, Ph.D.
Board Member, Santa Magarita Water District Board of Directors

South Orange County recently completed one week without importing any water from the Diemer Filtration Plant in Yorba Linda, which delivers up to 400 million gallons of water a day to south county water utilities and was shut down for earthquake retrofitting. However, because of Orange County's reliable storage infrastructure, most local water agencies did not need to ask their customers to reduce their water consumption during this disruption.

Once again, sensible, relatively low-cost storage proved its value to Orange County's water consumers. Yet, the Municipal Water District of Orange County (MWDOC) continues to pin its hopes principally on untested and costly ocean water desalination (desal) plans, de-emphasizing the need for local storage in a manner that threatens to compromise the region's water reliability and increase water rates across south county.

Santa Margarita Water District is a strong supporter of saltwater desalination. However, MWDOC's capricious quest for a desalination plant in Dana Point squanders vital resources that otherwise could have been allocated toward the development of proven and less-expensive methods to ensure the reliability of our water supply.

With a price tag of more than $140 million, MWDOC's proposed Dana Point desal plant highlights the historical problem of desalination: cost effectiveness. Juxtaposed with the operational and cost advantages of increasing local storage capacity, relying on desal to solve south county's water issues becomes alarmingly unpredictable and much too expensive to be pursued as the sole solution for MWDOC or the many cities and local water districts it supplies.

This is not to imply that desalination shouldn't be pursued in parallel with alternative sources of water supply. It's entirely reasonable to assume that desalination will play an important role in Southern California's water supply sometime in the future. The Santa Margarita Water District decided not to renew a purchase contract for desal water from Poseidon Resources because the cost was just too high, which is why we believe the allocation and management of desalinated water resources is better-suited for large regional suppliers like the Metropolitan Water District of Southern California (MWD).

MWDOC and local water agencies should redouble efforts on building new storage capacity and installing more pipelines, both of which offer immediate and cost-effective improvements to the reliability of local water supplies.

South-county water districts already are working to increase storage capacity, expand recycled water use, capture and reuse of urban runoff as well as continually promote water conservation. These efforts will create more than 1 billion gallons of extra storage capacity, miles of new pipeline and additional cost-effective and efficient water-supply solutions.

As a result of these ongoing improvements, local emergency supplies can sustain customers through approximately 10 days of a regional MWD supply interruption. Combined with demand-management measures, such as limitations on landscape irrigation, south county's emergency supplies would last more than two weeks without augmentation from MWD.

Desal simply will not be able to provide a similar amount of water anytime soon. Any hope to make it a viable supply option relies on high volume and new technology, which is why desalted water supplies should be kept as a MWD responsibility. In doing so, the onus will be placed on the regional water supplier, MWD, not local water districts, whose ratepayers are not likely to embrace desal's uncertain reliability and sky-high power costs.

Desalination technology has come a long way since it was first proposed and built in Orange County. The advancements in the membrane technology used to remove salts from water have afforded a legitimate opportunity to use desal water to supplement our current domestic water supplies.

Still, the utility of this resource remains an issue of cost competitiveness, and local water districts are not equipped to handle the uncertain costs and untested reliability of seawater desalination, especially when implemented by an agency such as MWDOC, which does not answer directly to ratepayers.

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