LOCSD, Morro Bay Join County DESAL Plan

Written by Neil Farrell

Neil has been a journalist covering the Estero Bay Area for over 27 years. He’s won numerous journalism awards in several different categories over his career.

December 15, 2022

The Los Osos Community Services District has joined a growing number of local water agencies who have signed on to participate in a regional desalination project that’s led by County Public Works, and which just getting started now, but could be a long-term solution to the county’s water supply woes.

The LOCSD Board of Directors on Dec. 1 unanimously voted for a Resolution that approved the District participating in what’s being called a “Desalination Executable Solution and Logistics (DESAL) Plan.”

That DESAL Plan effort sprung out of a County Supervisor’s meeting last March wherein Public Works laid out all the various options for improving the drinking water supplies for the entire county.

Those included: conservation, storm water capture, Nacimiento Water Project optimization, Lopez [Lake] Water Project spillway raise and optimization, Salinas Dam [Santa Margarita Lake] transfer and spillway raise, State Water Project and Water Management Tools, recycled water, produced water from oil extraction operations, cloud seeding, and regional resiliency, according to a LOCSD report.

The competition for water supplies, in particular sources that depend on rainfall, “is anticipated to increase with new regulations related to groundwater/surface water interactions and minimum sustainability thresholds, water quality, environmental flow, and housing directives.”

The County report concluded that while many of these options are in the works, any sources that rely on rainfall aren’t reliable enough to sustain the County long-term, and only desalination can do that.

“Desalination,” the County concluded, “is the longest-term and most resilient strategy since it leverages a renewable, almost inexhaustible resource that would not be diminished by insufficient rainfall or water conservation efforts. Desalination is a drought proof solution for current and projected water supply imbalances caused by strained alternative supplies, increased demand and could be scalable such that its capacity could be expanded as future needs increase.”

In the LOCSD’s Resolution (No. 2022-32) one of the “where as” statements says: “Due to proximity to the ocean, and future water supply quantity, quality and reliability needs, the 2019 San Luis Obispo County Integrated Regional Water Management Plan and 2012 Countywide Master Water Report identify desalination as a water resource management strategy to pursue.”

The Resolution declares that the LOCSD wishes to participate in the DESAL Planning Phase 1, a designation that would add Los Osos to the analysis the County plans to do to be able to size a desalination plant, decide where it should be built and how water would be distributed to the various participating agencies. It should also give some idea of what all this would cost.

LOCSD General Manager Ron Munds was appointed by the board to represent the District on the DESAL Plan working group, officially called “The Countywide Water Action Team” or CWAT.

Munds told Estero Bay News that you won’t likely hear much from CWAT over the next year or two, when they get to a point where they can release a draft plan and then start holding public meetings in the various jurisdictions. It promises to be a long process. 

Water agencies in SLO County are being given until next February to get on board with its DESAL Plan. A timeline presented by the County outlines a project that goes into 2041, as when construction might begin.

Even Phase 1 has four steps: Step 1 involves obtaining Resolutions of participation from the various water agencies; Step 2 finalizes the agreements to participate; Step 3 involves final details on the approach and presentation of a consultant contract to develop the project; and Step 4 involves approving the consultant contract and getting started on the actual planning of the project.

Morro Bay City Council also approved participating in Phase 1 of the plan, City Manager Scott Collins said.

Ironically, Morro Bay had a desalination plant but recently abandoned the brackish water wells strung along Embarcadero after they’d been inactive for years.

Indeed, the City only used its desal plant a few times since it was built in the early 1990s as an emergency response to another prolonged drought. The first time it was turned on the City discovered that the feed water was full of iron oxide (rust), which immediately plugged up the filter trains of the reverse osmosis plant. A settling tank had to be brought in to reduce the load of rust in order to use the plant. 

The City discovered its wellheads and electrical panels were ruined and no good anymore, and has since completely dismantled its desalination filter trains and is no longer counting it as a water source. 

The old plant itself was re-tooled to filter the fresh water from its Morro Creek wells and send that water to the Kings Street tank farm where it is blended with other sources. The City continues to have the State Water Project as its No. 1 source of drinking water. 

The City is currently building its $160 million Water Reclamation Facility (WRF) Project, soon to be completed, which is planning to inject highly treated wastewater into the ground in the Morro Creek aquifer to bolster the supply and block potential seawater intrusion. 

The City claims the WRF plant will be capable of producing 80% of its annual water demand by recycling wastewater via an RO system located at the new WRF treatment plant.

And given the reaction of many in town over the high cost of the WRF, asking citizens to buy-into a County DESAL Plan could be a hard sell to rate payers when the costs become known. 

Desalination is traditionally among the most costly ways to produce drinking water because of the high energy needs to run the plant.

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