With a need for supplemental water by 2023, the Oceano Community Services District will join an effort to obtain grant money to study the feasibility of building a desalination plant for future water needs.

Last summer, Arroyo Grande, Grover Beach and OCSD hired the Wallace Group to weigh the options of participating in the Nacimiento Water Pipeline project and constructing a desalination plant.

Arroyo Grande today is using 97 percent of its water supply, while Grover Beach is using 96 percent. Neither municipality has a supplemental supply.

The study recommends desal as the best option for the three communities' future water needs, and further research to determine the feasibility of building a plant.

The document was recently presented to the Arroyo Grande and Grover Beach city councils, which both voted to apply for state grant funds to develop a feasibility study.

Last week, the OCSD board of directors also unanimously agreed to join the neighboring cities and apply for Proposition 50 funds, which have a cap of $250,000.

Steve Tanaka, Wallace Group director of water resources, said if the grant money is obtained, there would likely be enough funds to develop the study and a preliminary engineering analysis for the project.

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The study also recommends that if a plant were to be constructed, the logical location is next to the South San Luis Obispo County Sanitation District Wastewater Treatment Plant in Oceano. Brine from the desalination process could be disposed of using the existing outfall line.

“It's a central location,” Tanaka said. “There appears to be space available (at the plant to build a desal facility). The footprint is relatively small for this project.”

The proposed desal project - a beach well intake system - would consist of constructing wells in and around the beach near the treatment plant that would extract sea water that would then be transported to the desal plant, where it would processed into potable water.

Tanaka also said developing the next study wouldn't commit any of the communities to building a desal plant, which the Wallace Group study estimates will cost between $17 million and $18 million.

“There should be little impact to the agency in taking that next step,” Tanaka told directors prior to the five agreeing to enter into the joint agreement with Arroyo Grande and Grover Beach.

The study was based on a plant that would annually produce 2,300 acre-feet of water at a cost of $2,600 an acre foot, which could be a little higher or lower, according to Tanaka.

The 2,300 acre-feet of production represents the combined future water needs for the three communities. Tanaka said construction of desal plant could begin in about seven years.

In comparison, the study estimates that participation in the Nacimiento Water Pipeline project would cost at least $38 million. In addition, the three communities could only garner 2,100 acre-feet from the project.

An acre-foot is equal to about 326,000 gallons, or enough to meet the average yearly water needs of two families of three.

April Charlton can be reached at 489-4206, Ext. 5016, or acharlton@santamariatimes.com.

January 30, 2006