Is Carlsbad’s desalination plant a peek at O.C.’s future?

While a developer of ocean desalination plants is working to gather permits for a proposed plant in Huntington Beach, its upcoming facility in Carlsbad may provide a glimpse of Orange County’s future.

Poseidon Water’s construction crews and engineers have been working for 27 months to complete the nearly $1-billion Carlsbad project by November. The plant will provide San Diego County with about 54 million gallons of drinkable water per day, Poseidon says. That’s enough for about 300,000 of the county’s 3.2 million residents.

“It’s gratifying, and I think [the Carlsbad plant] is going to be a game changer for California, because it’s the first large-scale plant that has been permitted,” Poseidon Vice President Scott Maloni said as he walked through the muddy construction site on a recent morning. “We expect it to open up opportunities up and down the coast for seawater desalination.”

Though it had been raining that day, the site behind the NRG Energy power plant off the 5 Freeway near Carlsbad Boulevard and Cannon Road was buzzing with noise as crews worked to install pipes and high-powered water pumps.

Site project manager Mike Page said in parts of the facility, which is about 90% completed, ocean water is being run through pipes to test whether the desalination process is operating correctly.

The treated water will be sent to the San Diego County Water Authority, which has a 30-year deal with Boston-based Poseidon to purchase water from the company for $2,014 to $2,257 per acre-foot, according to the U-T San Diego newspaper.

The desalinated water is expected to supply San Diego County with about 7% of its water needs, the paper reported.

Meanwhile, plans are still in the works for the proposed $1-billion Huntington Beach plant, which would be built next to the AES power plant at Pacific Coast Highway and Newland Street.

Huntington Beach approved the plan in 2006, and Poseidon is trying to get a development permit from the California Coastal Commission. It hopes its application will be reviewed in the fall, with construction starting in 2016. The plant is expected to take about three years to complete.

In the meantime, the company has been talking with the Orange County Water District to see if it is interested in purchasing water from the plant. Under a draft term sheet for a possible contract between the two organizations, Poseidon would own, finance, build and operate the facility, and the water district would do the same for the distribution system, as well as be responsible for finding buyers of the water and deciding whether it should use the water to replenish the county’s groundwater basin.

The term sheet, which has yet to be approved by the water district, would forge a 50-year deal in which the district would buy Poseidon’s desalinated water. The cost of the water from the Huntington facility is being negotiated.

The Orange County Water District covers most of northern Orange County, including Huntington Beach, Costa Mesa, Fountain Valley, Newport Beach, Seal Beach and Irvine.

How desalination works

Maloni said the Carlsbad and Huntington Beach facilities would be almost identical, with both using a water purification process called reverse osmosis, which uses membranes to remove impurities.

In the desalination process, seawater is filtered to remove impurities and salt. Page said at the two local plants, the seawater would be pretreated to remove large solids such as rocks and debris. The water then would go through micronic filtration to remove smaller particles.

Solids accumulated from the filtration process would be collected and sent to an off-site disposal facility.

The biggest step is the reverse osmosis process; water is passed through 17,000 membranes at high pressure to remove the sea salt, Page said.

“If you took all of the [reverse osmosis] membrane in [the Carlsbad] plant and rolled it out in a straight line, it would connect from here to the Oregon border,” Maloni said. “This is kind of the brains of the operation.”

Advancements in technology have enabled the membranes to be used longer. Maloni said they used to last three to five years, but the membranes at Carlsbad are expected to last five to seven years. The membranes at Huntington might last longer, he said.

After the Carlsbad water has gone through reverse osmosis, it will be sent to the post-treatment area, where minerals will be added and the pH level corrected before the finished product is sent via an underground pipe to the San Diego County Water Authority’s aqueduct in San Marcos, Page said.

Plans for both facilities call for them to use water pipes already being used by the neighboring electricity plants to cool their operations. The Carlsbad plant will collect water from a pipe that NRG uses to send water back to the ocean, and Huntington would tap into AES’ intake pipe to draw in water.

Criticism of the H.B. proposal

Environmentalists and some Huntington Beach residents have criticized the Huntington project’s proposed use of AES’ intake pipe. They believe the intake system could harm sea life by snaring animals in the mesh filter.

Orange County Coastkeeper, a Costa Mesa environmental group, says the facility could damage the environment by using what the group calls outdated intake and outflow pipes and by discharging brine, a highly salty byproduct of the reverse osmosis system.

Connie Boardman, a former Huntington Beach mayor and a biology professor at Cerritos College, said the state has required coastal electricity plants to convert their operations to air-cooled to protect sea life, “especially those on the bottom of the food web, like small plankton that other organisms depend on.”

“It seems highly unlikely that the state would allow a desalination plant to use the same technology, because it would have and continue the same impacts,” she said.

Opponents have asked Poseidon to convert Huntington’s intakes from open water to subsurface, in which the pipes would be buried under the sea bed and the sand used as a natural filter. A panel of experts chosen by Poseidon and the Coastal Commission reported in September that it is technically feasible to have such intakes off the Huntington Beach coast.

The second part of the report, on economic feasibility and environmental effects, is expected to be completed by June, Maloni said.

Differences between Carlsbad and Huntington

The Carlsbad and Huntington Beach projects have two primary differences.

One is the amount of water to be brought into the facilities. Plans call for the Carlsbad plant each day to take in about 304 million gallons of seawater and produce 54 million gallons of treated water. Huntington is proposed to take in about 127 million gallons per day to produce about the same amount of treated water, Maloni said.

Though it takes about 100 million gallons of seawater to produce 50 million gallons of potable water, the additional ocean water is required in Carlsbad to dilute brine before it is returned to the ocean. The Huntington facility would require less water because the outlet pipe for the brine would be deeper in the ocean and farther out to sea, Maloni said.

“We’ve always argued that at an environmental perspective, Huntington Beach is a superior project,” Maloni said. “You need less seawater to make just as much drinking water.”

The other difference is the size of the project sites. The Carlsbad plant is being built on about 5 acres behind the NRG facility, while the Huntington plant is proposed for about a 12-acre plot next to AES, Maloni said. Poseidon has a long-term lease on the land from AES, with an option to buy.

Carlsbad’s post-treatment water storage tank will hold about 2.5 million gallons and Huntington’s about 10 million gallons.

Carlsbad as a benchmark

Lessons from the Carlsbad plant’s construction and operation can be carried to the Huntington Beach facility, should the Coastal Commission approve it, officials say.

Maloni said reverse osmosis technology might be cheaper and more efficient in years to come. Page added that time could be saved on construction if some pipes were made beforehand.

“We’re going to talk over some of the issues that we’ve seen on the construction end of the project,” Page said. “We can definitely streamline that process.”

See related story: Desalination’s benefits and costs draw debate amid drought