San Diego

Beating the Drought With Desalination, But Without the Ocean

Small district ramps up new desalination plant to augment drinking water supply.

Even as some look to the ocean as the ultimate solution to California's drought, cost and coastal environmental issues have held back all but a handful of ocean desalination projects.

But now a small water district in Ventura County has leapfrogged ahead and is producing drinking water via desalination technology--even though the ocean is not even within sight.

The source instead is so-called "brackish" groundwater, contaminated with mineral salts to the point that as it came from the well, it could no longer be used for irrigation, much less be drinkable.

It is being pumped into a plant near Camarillo, and purified into drinking water for customers of the Camrosa Water District.

"We needed to be more self-reliant," said Tony Stafford, the district's general manager.

At full capacity, the Round Mountain Water Treatment Plant is designed to produce one million gallons a day -- not enough to go far in a city the size of Los Angeles, but 10 percent of the water needs of a district serving 27,000 people.

The desalinated water will reduce the need for imported water--but not eliminate it, Stafford acknowledged. The district historically has imported 40 percent of its drinkable water from Northern California via the California Aqueduct. The major source of that water is snowmelt from the Sierra Nevada snowpack.  Wednesday's end of season survey found the snowpack at only 5 percent of normal.

The new Round Mountain plant uses reverse osmosis filtration, same as can be used for ocean water desalination. Apart from the initial construction cost, such plants require a considerable amount of electricity to push the water through the filters. But it's less costly with brackish water because it's less salty than seawater.

"We can produce it for about the same cost as imported water," said Stafford, putting the price at about $1,200 an acre-foot, compared to up to $2,000 or more for desalinated ocean water.

The new reverse osmosis plant was built on the same property as the Camrosa district's reclamation plant, which purifies sewage water for delivery through purple pipes to irrigation applications -- but not for use as drinking water.

As a Camrosa customer, the nearby Cal State University Channel Islands campus has been receiving the recycled water for landscaping, and now is receiving the desalinated water for its tap water system.

"Sweet," said student Austin Finley of San Diego.

"We've come a long ways in saving water," said Raudel Banujelos, campus director of facilities support.

Camrosa is considering building a second groundwater desalination plant in the Santa Rosa Valley. Similar plants are under consideration by other local districts served by the Calleguas Water District, a wholesaler. Calleguas built the salinity pipeline that carries the concentrated brine waste product to the ocean.

Along the Ventura County coast, there is another concern:  intrusion by ocean water into groundwater aquifers that have been drawn down by pumping, and are now being salinated. A plant to purify that brackish water has been proposed by the United Water Conservation District.

Not far up the 101 Freeway in Santa Barbara, the city council is preparing to award a contract to update and reopen the city's long idled desalination plant, said Joshua Haggmark, the coastal city's water resources manager.

The once-trailblazing plant had been built in response to the drought of the early 1990s, and completed only months before the rains returned. The cost of the power to desalinate water made it so much more expensive than other sources that the plant was mothballed.

The renovation work is expected to take as long as a year, with desalination resuming next year.

Also expected to go online next year is the even larger desalination plant being built in northern San Diego county in Carlsbad. It is being developed by the Boston-based Poseidon Water.

A sister plant has been proposed for Huntington Beach, but has yet to surmount coastal permitting and financial issues.

Ocean desalination projects are so expensive that developers require longterm commitments for the purchase of the drinking water they will produce.  Poseidon has been in negotiations with the Orange County Water District.

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