The sea may be (nearly) endless, but California cannot hope to solve its water problems just by converting salty seawater into something drinkable. It would take a ridiculous number of desalination plants along the coast, each sucking up tens of millions of gallons of water a day and then spitting half of it back out as super-salty brine, to slake even the coastal counties' thirst. Such plants also use gobs of electricity, destroy a certain amount of sea life and cost more than other water sources.
Water security for California will depend on a portfolio of approaches that includes reclaiming wastewater, capturing storm water and continuing to emphasize conservation. But under certain conditions, it makes sense for desalination to be part of that portfolio, especially in areas dependent on imported water. The state's first large-scale desalination plant, in Carlsbad, is scheduled to go online in late November. And now the builder, Poseidon Water, wants to construct and operate another one at the site of a power plant on the coast in Huntington Beach. After working through numerous concerns raised by the Coastal Commission, especially those related to the possible effects on marine life, Poseidon hopes to go back before the commission early next year. It has done a good job of addressing environmental and cost issues, and, with certain restrictions, the commission should give it the go-ahead.
On the financial side, there's an element of risk for water customers. Building a desalination plant means betting that the state will not be getting wetter in future years, thus making desalination — drought-proof and stable in price — a blessedly reliable and cost-competitive source of water. In Israel, desalination has been a dependable and important water supplier. Australia, however, built six desalination plants, only to shutter four of them when the country was drenched by rain in 2010. Santa Barbara built and shut its own small plant 25 years ago, and only recently moved to reopen it.
The Huntington Beach plant would produce 50 million gallons a day of drinking water, which it plans to sell to the Orange County Water District. That would provide at least 15% of the supply for the district's 2.4 million customers. But the new water source would also increase water bills by an estimated $3 a month to start, or 6% on average. The relatively small difference is because of an agreement Poseidon has offered that would cap its price at 20% above the rate set by the Metropolitan Water District, which is a major supplier to the Orange County Water District. However, that agreement would assume a rise in the MWD's rates over time in line with previous years. And unlike in Australia, the plant would not be shuttered during wet years; the agreement would involve a commitment to buy the water for 50 years.
But the gamble is a relatively safe bet. Even though El Niño conditions might soak the state this winter, climatologists predict a drier future for the state. Any agreement between the water district and Poseidon also would be subject to ratepayer scrutiny before it's approved, including multiple workshops and public hearings on whether to go forth with the deal.
Environmentalists are concerned about the pipes at the proposed plant that will take 100 million gallons a day from the sea, half of which would be turned into drinking water and half returned to the ocean as concentrated brine. Though the erstwhile power plant intake pipe would be adapted to not suck in and kill fish, it would entrap and kill an estimated three ten-thousandths of the fish larvae in that area. Environmentalists had wanted Poseidon to bury the pipe, but a joint study with the Coastal Commission concluded this wasn't economically feasible. Poseidon plans to meet the State Water Resources Control Board's standards for releasing brine by using diffusers that dissipate the water it discharges, quickly diluting it to the salt level of the sea. And it pledges to make up for any loss of sea life by restoring coastal wetlands nearby.
The Coastal Commission should approve the proposal, but with the caveat that if the effects on the marine environment are significantly worse than expected, the plant will have to shut down until it fixes them. Desalination cannot take the place of conservation and other measures, but, in this case, it can help bring water stability to an area reliant on imported water.