CARLSBAD, Calif. (KPIX 5) — Under the bright Southern California sunshine, several hundred construction workers are building a pipeline to what may soon  be thought of as the state’s biggest drinking fountain, the coastline.

And it will be quite a gulp. When it’s done next year, the Carlsbad Desalination plant, the largest project of its kind ever permitted in the state, will supply San Diego County with 50 million gallons of drinking water every day.

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“It’s locally controlled. It’s drought proof and it adds a level of insurance,” said Scott Maloni, vice president of Poseidon Water. “The economy will be able to continue to grow with a safe, reliable water supply.”

Privately funded by Poseidon Water, the $1 billion reverse osmosis plant has been in the works for nearly a decade. The plant’s construction is seen as a groundbreaking engineering dream come true by those like local San Diegan Project Engineer Chris Stiedemann.

“It’s absolutely exciting,” said Stiedemann. “As a kid in 8th grade, I first heard about this plant.”

But desalination plants have long been a hot button issue in the Golden State, and the Carlsbad plant is no exception.

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Delayed by lawsuits filed by environmental groups, an arduous permitting process and cost concerns, the Carlsbad plant has some folks waiting with caution to see how it performs.

Among the most watchful, The Surfrider Foundation, who cites on its website “concerns about harm to marine life, ocean acidification and increasing greenhouse gas emissions.”

But now, the Carlsbad plant is nearly complete, and San Diego County has signed a 30-year contract with Poseidon. It will pay about $2,000 an acre foot for the water it receives from the plant. That works out to be about 5 cents per gallon. But at 50 million gallons a day, that can add up fast. Right now, the county pays the Southern California Water District about half that amount.

But with the county now importing nearly 90 percent of its current water supply, Poseidon insists the investment in the plant guarantees a reliable,  and ultimately cost effective water supply.

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“Desalinated water today is less than the cost it was just ten years ago,” said Maloni, “and costs are dropping.”