Diablo Canyon desalination expansion plans move ahead

Citing the need for more drought resiliency, the San Luis Obispo County Board of Supervisors is enthusiastically backing a proposal to expand Diablo Canyon nuclear power plant’s desalination plant to supply as much as 1,300 acre-feet of water a year to South County residents. That would be enough water to supply 4,000 homes.

Supervisors voted unanimously Tuesday to spend $900,000 to do the planning and permitting for the project, which calls for 7 miles of pipe to be laid connecting the plant’s reverse osmosis system to the Lopez Lake pipeline in Avila Beach.

“This comes down to diversifying our water supply,” Supervisor Lynn Compton said. “If we don’t do this now, we are going to be criticized for not doing anything.”

The project is expected to take at least two years to complete and could cost as much as $36 million. The water would be used in the Five Cities and Avila Beach areas. The cost of building and operating the pipeline would be paid by the customers who use the water. Wade Horton, county public works director, said it was too early to know how much a typical customer’s water bill would increase to pay for the pipeline.

“I think this is an opportunity we can’t afford to miss,” Supervisor Bruce Gibson said.

Diablo Canyon is licensed to produce as much as 1.5 million gallons of water a day but only produces about 40 percent of that, or about 600,000 gallons. An acre-foot of water is 325,853 gallons.

The water from the desalination plant would be used by the cities of Pismo Beach, Arroyo Grande and Grover Beach and the Oceano and Avila Beach community services districts. All of those entities have submitted letters of interest in the project but have not formally signed on yet.

The South County is facing an impending water crisis. The area’s main water source is Lopez Lake, which is only 30 percent full and was not refilled as hoped by El Niño rains this winter.

The South County’s groundwater basin is dropping and is in danger of saltwater intrusion. And deliveries from the State Water Project have been unreliable in recent years because of the drought.

“We are in a very fragile situation,” Supervisor Adam Hill said. “We have only two years of water left, and we need to do something.”

Supervisor Frank Mecham said the desalination plant is attractive because it relies on seawater rather than rainfall.

“There is no free lunch here,” he said. “This is going to cost money, but I think it will be money well spent if we can get to the final process.”

PG&E, which owns Diablo Canyon Power Plant, built the desalination plant to process seawater that serves as the plant’s sole source of water. The company supports the proposal to sell its excess water to South County service providers.

“PG&E is strongly committed to supporting our local communities and finding innovative ways to support the areas in which we serve and where our employees live,” PG&E spokesman Tom Cuddy said. “This is another positive development in this process and we look forward to continuing to collaborate with the county.”

Not everyone at Tuesday’s hearing supported the desalination expansion, however.

Brad Snook of the local Surfrider Foundation said the project is too expensive and the county should be looking at cheaper options.

“You are not looking at the entire package because you are not looking at recycled water,” he said.

This story was originally published March 22, 2016 at 7:52 PM with the headline "Diablo Canyon desalination expansion plans move ahead."