Skip to main content

KPBS Radio is undergoing scheduled upgrade work which may result in temporary signal outages.

LATEST UPDATES: Tracking COVID-19 | Vaccines | Tokyo Olympics

Eyes Look To Carlsbad’s Desalination Plant

Many people are watching the Carlsbad desalination plant that could begin delivering drinking water by fall. And how the plant performs may affect how other desalination projects are viewed.

San Diego County water officials will soon find out if their billion-dollar wager on ocean water desalination will pay off.

Crews are putting the finishing touches on a Carlsbad plant that could start producing drinking water this fall, and there are a lot of people watching to see how it works out.

Much of the remaining work is focused on finishing the outside walls, adding parking areas and landscaping.

"The bulk of the construction is now behind us and we're in the final stages of proving out the facilities and getting it ready for operation later this fall," said Peter MacLaggan, vice president of Poseidon Water, the company building the facility.

MacLaggan is a tireless advocate for seawater desalination as a drought-proof water supply.

Photo by Nicholas McVicker

Poseidon Water Vice President Peter MacGlaggan talks about the start of operations at the Carlsbad plant on July 8, 2015.

"It's always available, regardless of whether it snows in the Sierras or the Rocky Mountains. Or whether in rains in San Diego," MacGlaggan said.

The plant is designed to produce 50 million gallons of drinking water a day, which is enough to fill an Olympic-size swimming pool every 18 minutes. The new water will represent up to 10 percent of the San Diego region's supply.

"Everybody's watching what happens here in Carlsbad to gauge how they're going to proceed with their local plans," MacGlaggan said. "The success of this plant will demonstrate the viability of this technology as a future municipal water supply for other communities."

There are 17 desalination projects in various stages of development on the West Coast. One is a Poseidon proposal in Huntington Beach. Another is an attempt to revive a desalination facility in Santa Barbara. A bumpy start here might influence the course those other projects take.

Photo by Nicholas McVicker

Blue pipes hooked up to filter canisters inside the Carlsbad desalination facility on July 8, 2015.

"It's hard to say what the long-term impacts are going to be, but people are looking (at) this plant to try to better understand what the opportunities and challenges are for California," said Heather Cooley of the Pacific Institute.

There are a lot of things for communities to consider when developing a water source that's twice as expensive as imported water, Cooley said.

"It'll depend on how low demand is and whether there's cheaper efficiency options available," Cooley said. "It'll depend on what the other supply options might be in the other area."

Critics are not ready to give up the fight, even though the plant is about to open.

Photo credit: Richard Klein

Julia Chunn-Heer speaking to KPBS about the potential environmental impacts of the Carslbad desalination plant on July 1, 2015.

Surfrider San Diego's Julia Chunn-Heer is not convinced this is the right time for large-scale desalination.

"Desalination shouldn't be the first thing that we're turning to solve our water crisis," Chunn-Heer said. "It's probably part of the equation, but there's a lot more that we can do in terms of conservation and water use, before we turn, before we get there."

Chunn-Heer said taking salt out of ocean water uses too much energy and leaves a huge carbon footprint. Plant officials plan to spend roughly $200,000 a year to buy carbon credits to offset greenhouse gas impacts created by the power used to filter water.

But there are other environmental impacts. Pulling water into the plant and discharging briny wastewater offshore puts marine life at risk.

"Our problem here is that it's not being done in a very sophisticated way," Chunn-Heer said. "They're just drawing in additional ocean water with additional marine life impacts to dilute the brine before they send it out."

State officials have already rewritten the desalination rulebook in part because of concern over the environmental impact of the Carlsbad plant. New facilities seeking a permit in California should have underground intake pipes and more sophisticated outfalls.

The Cost of Water

Metropolitan Water District: $923 per acre foot in 2015 for Tier 1 treated water

Imperial Irrigation District: about $810 per acre foot in 2015 for transferred Colorado River water

Carlsbad Desalination Plant: $1,915 to $2,140 per acre-foot

Source: San Diego County Water Authority

A 10-mile long, 56-inch pipe will carry the desalinated water across the northern part of the county to the San Diego County Water Authority's aqueduct in San Marcos. The pipeline is a critical artery that will feed the region's effort to become water independent.

But that water independence comes with a price. Desalinated water costs significantly more than imported water, but many county residents are willing to pay.

"Over 68 percent of the people polled said they'd be willing to pay something more for desalination," said Bob Yamada of the San Diego County Water Authority.

The cost of building the plant and buying the water is being paid by each water user in the county. They pay even if they don't get any of the desalinated water, Yamada said.

"The $5 a month is really a small price to pay for that additional reliability that we're going to receive by having this drought proof supply in our portfolio," Yamada said.

The desalinated water is currently about twice as expensive as imported water, but the authority projects that'll change over time.

County water managers said they locked in the cost of desalinated water for the next 30 years, while the cost of imported water is widely expected to increase over time.


San Diego News Now podcast branding

San Diego news; when you want it, where you want it. Get local stories on politics, education, health, environment, the border and more. New episodes are ready weekday mornings. Hosted by Anica Colbert and produced by KPBS, San Diego and the Imperial County's NPR and PBS station.

  • Need help keeping up with the news that matters most? Get the day's top news — ranging from local to international — straight to your inbox each weekday morning.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Photo of Erik Anderson

Erik Anderson
Environment Reporter

opening quote marksclosing quote marksI focus on the environment and all the implications that a changing or challenging environment has for life in Southern California. That includes climate change, endangered species, habitat, urbanization, pollution and many other topics.

Want more KPBS news?
Find us on Twitter and Facebook, or sign up for our newsletters.

To view PDF documents, Download Acrobat Reader.