Chris Stiedemann of Poseidon Water looks over the giant filers that remove microscopic impurities from the seawater. Photo by Chris Jennewein
Chris Stiedemann of Poseidon Water looks over the giant filers that remove microscopic impurities from the seawater. Photo by Chris Jennewein

A $1 billion desalination plant — the first commercial facility in California and largest in the Western Hemisphere — was dedicated in Carlsbad Monday after lengthy environmental battles and three years of construction.

The completed plant has been testing fresh water production since early November, and officials said it would deliver 49 million gallons to the San Diego County Water Authority system on Monday.

The facility at the inlet to the Agua Hedionda Lagoon provides enough water for 400,000 families, or nearly 10 percent of the San Diego region’s needs.

“This is truly a historic day in California water,” said Water Authority Chairman Mark Weston. More than 20 years in the works, the plant gives San Diego a inexhaustible water supply that is “not dependent on snow in the Sierras” or the Colorado River.

The new plant was named in honor of former Carlsbad Mayor Claude “Bud” Lewis, who was instrumental in making Carlsbad the host city.

Poseidon Water CEO Carlos Riva (left) with Mark Weston, chairman of the San Diego County Water Authority. Photo by Chris Jennewein

The project by Boston-based Poseidon Water project also included construction of a 10-mile pipeline to carry fresh water to water authority facilities in San Marcos.

Approval was bitterly fought by the Surfrider Foundation and other environmental groups, which contend the plant will harm marine life and be expensive to operate.

“Surfrider stresses that desalination is not the solution for drought-stricken California or other states in similar conditions,” the group said in a statement on Friday. “Desalination plants not only pose significant risks to our marine habitats, but will have significant economic impacts.”

The plant takes in two gallons of seawater for every gallon of fresh water produced. The water that returns to the ocean has higher salt content, but Peter MacLaggan, a senior vice president of Poseidon, said this outflow is fully diluted within 1,000 feet of the plant.

The drought-proof supply comes at a cost, however. MacLaggan said the average family in San Diego would pay about $5 more per month to cover the cost of the desalination plant.

The reverse-osmosis technology used to produce fresh water was patented in San Diego in 1964, but commercial plants were first introduced in dryer parts of the world. The Carlsbad facility is modeled on an Israeli plant.

Similar desalination plants are under consideration for sites in Huntington Beach and Camp Pendleton. “This plant is going to change the way we look at water,” said MacLaggan.

A Poseidon Water employee walks by some of the 2,000 pressure vessels containing reverse osmosis filters. Photo by Chris Jennewein

Chris Jennewein

Chris Jennewein is Editor & Publisher of Times of San Diego.