El Dorado Hills Water Treatment Plant Expansion

The El Dorado Irrigation District is undertaking a comprehensive modernization and expansion of the El Dorado Hills Water Treatment Plant located in Placerville, California. The project aims to replace aging infrastructure, improve treatment reliability and resilience, and address seasonal source-water challenges from Folsom Lake to ensure compliance with current and future drinking water regulations. The scope includes increasing the operational capacity from 19.5 million gallons per day to 24 million gallons per day, with the installation of infrastructure designed to support a future buildout capacity of up to 31.5 million gallons per day. Key deliverables involve the removal of outdated systems and the installation of new water treatment facilities, piping, electrical systems, a chemical storage and feed facility, a UV disinfection facility, a washwater equalization basin, and a new generator and electrical building. Construction is expected to occur intermittently over a five-year period, with the exact start date contingent upon the availability of grants or alternative financing. The project will be phased to ensure the existing plant remains fully operational throughout the process. Work will require heavy machinery and must adhere to the Universal Building Code, California Building Code seismic design standards, and Stormwater Pollution Prevention Plan requirements. Specialized requirements include strict safety and documentation protocols for controlled blasting to remove subsurface rock, as well as compliance with El Dorado County Air Quality Management District and EPA standards. The project is currently in the forecast stage, with environmental reviews and impact assessments completed to address air quality, biological resources, and noise.