US-CUP

Upper Salinas River Basin Conjunctive Use Project 

(US-CUP) Overview 

The Templeton Community Services District has 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) captures existing wastewater flows generated within the east side of the District and returns these flows back to the Meadowbrook Wastewater Treatment Plant (MWWTP). Here the wastewater undergoes treatment and is discharged into the river alluvium that contains the Salinas River underflow providing 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 were sent to the Paso Robles WWTP for treatment and disposal where the water was no longer available for retrieval by the District. The US-CUP facilities completed in August 2019 redirects all of the wastewater flows generated in the east side area to the MWWTP where they are 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 include 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 improvements were made to convey the flows to the MWWTP include upgrading west side lift station. Collectively, these improvements are called the East Side Force Main and Lift Stations (ESFM) Project and make up the bulk of the needed infrastructure improvements. After several years of effort obtaining environmental clearances, easements, various permits, and assembling financing, the project construction began in 2017. Construction continued into summer of 2019  and the project is now fully on-line and operational. A Ribbon Cutting Ceremony was held on September 25, 2019 to mark the completion of this important District project.