Through two critical project phases, we helped West Basin Municipal Water District (West Basin) deliver 100 percent recycled water for seawater barrier injection, and reduce Southern California’s reliance on imported water.

Completion of Phase IV and V allowed West Basin to safely reuse billions of gallons of highly treated wastewater each year, preserve potable resources, replenish groundwater, reduce dependence on imported water, and provide a drought-proof supply.

Phase IV design included the upgrade and expansion of the barrier water treatment system capacity from 7.5 to 12.5 million gallons per day (mgd) and tertiary water capacity from 30 to 40 mgd at West Basin’s Edward C. Little Water Recycling Facility. Major components included provision of new cartridge filters, immersed microfiltration and reverse osmosis facilities, and a new ultraviolet process to provide disinfection and oxidation of trace organics including NDMA. A 14.7 mgd micro filtration unit replaced the barrier system’s lime clarification unit, which was converted for tertiary treatment.

Working closely with program managers, plant operators and West Basin staff, our team orchestrated a design-build project around a full-time operating facility. Phase V expanded the barrier system to 17.5 and the tertiary system to 50 mgd. We performed preliminary design and owner’s representative services. With the completion of the Phase V, West Basin is able to reuse 72 mgd.