Pismo Beach moves forward on proposal to turn sewage into drinking water

An aerial view of downtown Pismo Beach.
An aerial view of downtown Pismo Beach. jjohnston@thetribunenews.com

Pismo Beach is taking the first steps toward creating a new source of drinking water for the Five Cities area: treated, recycled sewage water.

At its April 21 meeting, the Pismo Beach City Council approved its Recycled Water Facilities Planning Study, which examined how the Five Cities could preserve and increase their water supply. It was the first of the four South County agencies — including Arroyo Grande, Grover Beach and the Oceano Community Services District — working on the project to approve the study.

Pismo Beach, like most cities in the South County, gets water from three sources: Lopez Lake, state water and the Santa Maria Groundwater Basin, all of which are strained because of the statewide drought.

The study concluded the best solution would be to update the city's sewage treatment plant to include "full advanced treatment with direct groundwater injection." The city’s plant currently treats approximately 1.1 million gallons of sewage per day to a secondary level and discharges that treated effluent into the ocean.

The new procedure would add a higher tertiary level of filtration and disinfecting so the effluent could be injected into the Santa Maria Groundwater Basin, where the South County draws a portion of its drinking water. The water could also be discharged back into the basin near the coast to provide a barrier against seawater intrusion.

The water would go through a three-step filtration system of microfiltration, reverse osmosis and disinfection.

Once complete, the project could recycle up to 950 acre-feet a year, or 309.6 million gallons. By comparison, Pismo Beach is expected to use about 2,108 acre-feet — or 686.9 million gallons— of water in 2015 for residential and municipal purposes, according to the staff report.

The city is working in tandem with the other South County agencies to establish the project, which would cost an estimated $29.7 million. They are pursuing several state and federal grants to help pay for the water treatment updates. Other funding would come from a combination of low-interest loans and cost-sharing contributions from Arroyo Grande, Grover Beach and the Oceano CSD.

"We have now joined several of our neighboring agencies in pursuing the most significant new water supply project in South County in nearly 20 years," said Ben Fine, Pismo Beach’s director of public works. "Once complete, this project will provide a local supply of water that is highly sustainable and drought proof."

The city will now go into the preliminary design phase for the project. A potential timeline for its construction has not yet been announced.

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