The old lumber mill site was converted to a co-generation plant providing 23 Megawatts of power to local communities in the high Sierra Mountains. Using up to 80,000 gallons of water a day to cool the power plant, the client found they had a huge challenge ensuring compliance with the State Water Resource Control Board’s and Regional Water Quality Control Board’s standards for discharged water.

Studies found that the co-generation plant process water contained elevated total dissolved solids as compared to the surface water quality in Smithneck Creek which flows through the site. Building a treatment plant to reduce TDS levels to meet current discharge standards using reverse-osmosis technology would have added more than $1 million to the project’s cost. The costs were prohibitive and the client contracted Carlton Engineering to assess the problem.

Carlton recommended the existing three acre pond be improved to support spray irrigation and discharge to land. Interfacing with Dr. Roland Meyers, an agricultural expert with UC Davis, Carlton developed a plan to store, manage, and reuse the process water to provide essential irrigation and nutrients to neighboring crops.