Desalination no panacea for Calif. water woes

Associated Press Modified: September 22, 2012 at 2:16 pm •  Published: September 22, 2012
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MARINA, Calif. (AP) — In the Central California coastal town of Marina, a $7 million desalination plant that can turn salty ocean waves into fresh drinking water sits idle behind rusty, locked doors, shuttered by water officials because rising energy costs made the plant too expensive.

Far to the north in well-heeled Marin County, plans were scrapped for a desalination facility despite two decades of planning and millions of dollars spent on a pilot plant.

Squeezing salt from the ocean to make clean drinking water is a worldwide phenomenon that has been embraced in thirsty California, with its cycles of drought and growing population. There are currently 17 desalination proposals in the state, concentrated along the Pacific where people are plentiful and fresh water is not.

But many projects have been stymied by skyrocketing construction costs, huge energy requirements for running plants, regulatory delays and legal challenges over environmental impacts on marine life. Only one small plant along Monterey Bay is pumping out any drinking water.

From Marin County to San Diego, some water districts are asking themselves: How much are we willing to pay for this new water?

"We found that our demand for water had dropped so much since the time we started exploring desalination, we didn't need the water," said Libby Pischel, a spokeswoman for the Marin Municipal Water District. "Right now, conservation costs less than desalination."

Desalination plants can take water from the ocean or drill down and grab the less salty, brackish water from seaside aquifers. Because of their potential impacts to marine life, the California Coastal Commission reviews each project case-by-case.

There was great fanfare in 2009 when the last regulatory hurdle was cleared to build the Western Hemisphere's largest desalination plant in Carlsbad, north of San Diego.

At the time, it was proposed that the $320 million project would suck in 100 million gallons of seawater and be capable of producing 50 million gallons of drinking water a day. It was expected to come online by this year.

Since then, the plant owner, Poseidon Resources LLC, has been negotiating a water purchase agreement and is close to clinching a 30-year deal with the San Diego County Water Authority, a wholesaler to cities and agencies that provide water to 3.1 million people.

The compact is essential for Poseidon to obtain financing to build what has become a $900 million project, which includes the seaside plant and a 10-mile pipeline. The San Diego agency hopes the plant opens in 2016 and anticipates desalination will account for 7 percent of the region's supply in 2020. It estimates the cost is comparable to other new, local sources of drinking water, such as treated toilet water or briny groundwater.

Interest is still high, but "people are realizing that desalination isn't a magic fix to the state's water issues," said coastal commission water expert Tom Luster.

Water can be de-salted in different ways. Poseidon's project will use reverse osmosis. Other plants shoot ocean or brackish water at high pressure through salt-removing membrane filters. Because pumps must be used constantly to move massive amounts of water through filters, these facilities are extremely energy intensive.

Also, in many cases, desalinated water is pricier than importing water the old-fashioned way — through pipes and tunnels. And it is cheaper to focus on conservation when possible: new technologies like low-flow toilets and stricter zoning laws that require less water-intensive landscaping have helped curb demand in communities throughout the state.

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