[LINK] "Will Turning Seawater Into Drinking Water Help Drought-Hit California?"

[rfmcdonald]

NPR, looking at a soon-to-be-activated desalination plant in Santa Barbara, California, suggests desalination may be useful but not cost-effective, perhaps not even environmentally sound. There is no easy solution.

Entering the control room and seeing its big computers with tiny memories — and floppy disk drives — feels like stepping back in time to 1992. This is "about as sophisticated as it gets for this old facility," says Haggmark.

The intake, where ocean water first enters the desalination system, is about half a mile off the beach. Once it gets to the plant, the water flows through gravel and sand filters and finally, when all the debris is gone, into the reverse osmosis membranes — salt removers.

Two gallons of ocean water go in; one gallon of drinking water comes out. The leftover gallon contains super-salty brine. This doubly salty water is mixed with the city's wastewater and then piped back out to sea and spread around, about 30 miles offshore.

That briny waste is one of many concerns raised by environmentalists and other critics of desalination plants like this one and others that are being planned and built along the California coast. "The biggest concern about desalination is that it is expensive, it's energy-intensive and it has a lot of side effects — a lot of unintended consequences to marine life both from the intake and the discharge," says Marco Gonzalez, the executive director of the Coastal Environmental Rights Foundation.

Right now, the sources of electricity available to run desalination plants are not environmentally friendly. "Really, it's going to require us to find alternative energy sources to power these plants. So as we put more renewables online, it will become more environmentally friendly and more cost-effective," says Gonzalez.

Cost effectiveness is important, because desalination is expensive. To get the Santa Barbara plant back online, the estimated cost of water for the average resident will increase by about $20 each month starting this July, even though the plant won't open until 2016.