Upper Salinas River Basin Conjunctive Use Project
The Templeton Community Services District is developing a new, drought resistant water supply to meet seasonal and projected annual demands. The project, called the Upper Salinas River Basin Conjunctive Use Project (US-CUP) will capture existing wastewater flows that are currently being discharged outside of the Atascadero Basin, and return these east side area wastewater flows back to the Meadowbrook Wastewater Treatment Plant (MWWTP) for treatment, discharge into the river alluvium that contains the Salinas River underflow and subsequent conveyance to District wells that divert from the underflow downstream. The amount of travel time via the conveyance of the Salinas River underflow is 28 to 35 months before eventual retrieval. The District has determined that the MWWTP’s discharges augment the river underflow at its downstream wells, with only small conveyance losses, because a clay layer in the area generally prevents those discharges from percolating into deeper groundwater.
As shown on the map, the District wastewater service area is bisected by Highway 101 into two distinct wastewater areas. The west side area flows are treated at the TCSD MWWTP and handled consistent with the process authorized by the State Water Resources Control Board’s August 17, 2012 order granting TCSD’s Wastewater Change Petition WW-65 (“WW-65”). However, the east side area flows are sent to the Paso Robles WWTP for treatment and disposal where the water is no longer available for retrieval by the District. The US-CUP facilities will redirect all of the wastewater generated in the east side area to the MWWTP where they will be treated the same as west side area flows, thereby increasing the amount of wastewater the District discharges into the underflow and increasing the amount the District can divert at its downstream wells by an additional 242 acre-feet per year (AFY).
The infrastructure improvements needed are the construction of two new lift stations and approximately 16,200 linear feet of sewer pipeline to capture and redirect east side flows to the west side collection system. From there, additional upgrades needed to convey the flows to the MWWTP include upgrading west side lift station, and finally upgrading the headworks at MWWTP. These project components are together called US CUP.
The East Side Force Main and Lift Stations (ESFM) Project components make up the bulk of the needed infrastructure improvements. After several years of effort spent obtaining environmental clearances, easements, various permits, and assembling financing, the project is under construction. The construction contract was awarded to Specialty Construction Inc on February 22, 2018 and construction is anticipated to be complete by the end of the year.