Seawater Barrier Pilot Program IS-MND

Rincon Consultants prepared an Initial Study – Mitigated Negative Declaration for the United Water Conservation District and City of Oxnard examining the environmental impacts of a program intended to protect the Oxnard Plain from further degradation of its coastal aquifers. This program is a component of the City’s GREAT Program (Groundwater Recharge Enhancement and Treatment) that was approved and examined in a comprehensive Program EIR that was certified by the City in 2004.

The project involves the installation of a single pilot well along Hueneme Road west of Rice Road. The well will be designed for to provide an approximate 1,500 gallons per minute (gpm) injection rate and a 3,000 gpm extraction rate. The well will be connected to United Oxnard Hueneme (O-H) System and will be used to inject potable water into the deep aquifer to prevent further intrusion of coastal seawater into the Oxnard Plain. The proposed project also includes a connection of the pilot well to the Calleguas Municipal Water District’s Salinity Management Pipeline (SMP), for discharge of permitted amounts of pumped water through Calleguas’ ocean outfall. An alternative to discharge of backwash water to the ocean will be to blend the backwash water with other waters in the SMP for delivery to agricultural uses on the Oxnard Plain. The injection of potable quality water for the pilot test injection program is expected to last about 5 years. However, since the actual pilot test program could be between two and ten years or even longer, the IS-MND document examined both the short and longer term effects of the pilot program in a way that allowed for extended use of potable water injection, provided that impacts are effectively mitigated. Key issues examined in the document included air quality, cultural resources, geology/soils, hazards and hazardous materials, and transportation/traffic.

For more information about this project, please contact us.