Reliable local water supplies surpass need for high-cost desal from the sea
By Tina Richards
With an ocean of water at our doorstep, drought-prone Orange County seems a likely candidate for a desalinization plant that could remove salts from seawater, and deliver clean, drinkable water to thirsty taps.
A Canadian company, Poseidon, has spent years gathering support for a desalinization facility it wants to build in Huntington Beach, where the old power station sits. Taking advantage of the drought and perceived threats to the local water supply, Poseidon has been wooing public officials and wholesale and retail water providers to shore up financing, capture needed approvals, and retain commitments for the purchase of its desalinated product. It even secured a memorandum of understanding from the Orange County Water District (OCWD) stating that the agency would buy all of the 56,000 acre feet of water Poseidon produced annually for 50 years.
But what seems like a simple solution to a populace just now emerging from six years of drought, isn’t as black and white to the experts tasked to deliver water, rain or shine. “It’s counter-intuitive,” admits Paul Cook, general manager of the Irvine Ranch Water District, which serves Orange Park Acres and the canyons. “It seems like a great idea, but the reality is, it’s too expensive, and I don’t believe we need it at this time.”
Walking on water
“We,” in this case, are the portions of Orange County (north, east, central) fortunate enough to sit atop a 270-sq.-mi. aquifer. That underground resource, managed and replenished by OCWD, provides approximately 70 percent of the water used by 2.5 million residents. The remaining 30 percent is imported from the State Water Project and Colorado River via the Municipal Water District of Orange County (MWDOC) and the Metropolitan Water District of Southern California (Metropolitan).
“Metropolitan is a reliable provider,” Cook says. “It has storage capacity. Orange County has never experienced a drought where local groundwater and imported water supplies were not available.” Historically, drought years are the exception, not the norm. It’s been just three years out of the last 10 that state water allocations were reduced. Local providers may have paid more for water that exceeded state-mandated restrictions, but no one was outright denied the ability to buy it.
Imported water currently costs about $970 an acre foot. An acre foot translates into 326,000 gallons, or enough to supply two average OC households for a year. Desalinated water will cost about $2,000 an acre foot. The proposed Huntington Beach plant will provide 56,000 acre feet annually, and must sell every drop of it to remain profitable. And no matter which agency buys it – OCWD, MWDOC or Metropolitan – the increased cost will be passed on to OC ratepayers.
Turn on the tap
Poseidon estimates that the higher cost of desal amounts to $2.50 to $3 per household per bill. It is not clear exactly how that increase was calculated, but it applies only to the desalinated water leaving the plant. It does not include the cost of the infrastructure (pipes, wells, pumps) needed to deliver it to water retailers and wholesalers. Factoring in the cost of delivery systems, plus the uncertainty of future pricing demanded by the privately held, for-profit company, the per-customer cost could be much higher. “That might be worth it if we needed it,” Cook asserts. “Some agencies may want seawater desalination to improve their reliability, but we don’t. Much more appropriate solutions can be implemented to improve reliability and refill the aquifer at a fraction of the price.”
IRWD is, for now, the only agency bucking the desal-for-Orange-County tide. The largest local provider, IRWD is admittedly ahead of the pack in terms of reliable supply. It has its own recycled water facilities, recycles local brackish water, and has an enormous groundwater storage facility in Kern County that increases water supply reliability. Only about 15 percent of the water it supplies to users is imported from the Metropolitan Water District. The rest is “home grown.”
Other local water providers may lack the resources of IRWD, but they benefit from OCWD’s well-managed groundwater system and reliable imported water from MWDOC and Metropolitan. OCWD operates the largest, most advanced groundwater replenishment system in the world. It purifies treated sewage piped in from the OC Sanitation District, to create drinkable water. That water is collected in basins and settles back in to the aquifer. The plant currently replenishes the aquifer with 100 million gallons per year, and OCWD plans to expand it. Orange County’s groundwater, including the retrieval process, costs about $525 per acre foot, about one-third as much as ocean desalinization.
Down the drain
Both MWDOC and Metropolitan have forecast an adequate water supply for the region through 2040. That forecast is based on a diversified supply, existing storage facilities, and ongoing conservation efforts. It includes a predicted six percent increase in demand and accounts for multiple dry years.
“Remember,” Cook cautions, “it does rain. When it does, we need to bank enough water for dry years. A viable alternative to desal is to do the best we can with the resources we already have.”
Cook is also quick to point out that desalinization may make sense for coastal counties that don’t have an aquifer; it may even make sense for north and central OC in the distant future.
But, he emphasizes, there’s no reason to build it now and pay $2,000 an acre foot for unneeded water that would end up in a reservoir or the aquifer. “With desalinated water filling up storage facilities,” Cook notes, “we’d be letting free rain water run off into the ocean.”