Lake Skinner Filtration Plant, Program Environmental Impact Report

Client: Metropolitan Water District of Southern California

Location: Riverside County, CA


UltraSystems prepared the Program Environmental Impact Report (PEIR) for the Lake Skinner Filtration Expansion and Upgrade project, located southwest of Lake Skinner in unincorporated southwestern Riverside County. Metropolitan Water District (MWD) proposed to expand and upgrade the existing treatment systems at the Skinner Plant.  The Skinner Plant treats drinking water that is supplied to Eastern Municipal Water District of Riverside County, Western Municipal Water District of Riverside County, the San Diego County Water Authority, and their sub-agencies. The Program included numerous individual projects at the Skinner Plant to augment the existing treatment processes and expand the plant’s total treatment capacity design from 520 million gallons per day (mgd) to 630 mgd.

Two primary project components were assessed: a new 110-mgd treatment module (Module No. 7) and a 630-mgd Oxidation Retrofit Program (ORP) to augment the plant’s disinfection capabilities. Two options were considered for the ORP: one using ozone as the primary disinfectant and the other using chlorine dioxide. The amount of chlorine stored onsite would not change.  In addition to these primary components, the Program would involve installation of numerous ancillary facilities needed to upgrade the treatment systems.

In addition to the preparation of the PEIR, UltraSystems provided Metropolitan with all associated technical studies. Our professional staff performed all biological resource services, aesthetics, air quality, biological resources, noise impact, fire protection, and utility and service systems. All other studies were outsourced to subconsultant partners and managed by UltraSystems.