The West Basin Water Management District, of Carson, Calif., operates a water recycling facility in nearby El Segundo. Effluent, from the City of Los Angeles' Hyperion Wastewater Treatment Plant arrives at the plant and is treated to produce a high quality recycled water. The treated water is used for anything from boiler feed to stocking sea water intrusion barriers. West Basin WMD sells its recycled water to agencies, cities, water and wastewater districts and oil refineries operated by Chevron and Mobil.
Since 1991, West Basin has pursued a recycled water system with some urgency. Surrounded by Los Angeles County, West Basin supplies almost 1 million people. In the next 20 years, hundreds of thousands more are expected to settle within its boundaries. West Basin keeps pace with its recycling facility, which went online in 1995, and a direct filtration system capable of producing California Title 22 regulation water for irrigation and industry. To produce a higher quality of water, for boiler feeds and sea water barrier injection, West Basin uses its reverse osmosis and micro-filtration membrane systems.
With proven recycling ability, West Basin decided to match growing water demand with raw capacity. The district proposed the $54 million Phase IV expansion project to upgrade the recycling plant's systems and expand Title 22 water production to 10 million gallons per day (mgd). An expansion of the barrier water treatment system, which pumps fresh recycled water into coastal plains to protect underground potable sources from sea-water intrusions, would increase its capacity to 12 mgd. HDR, in a joint venture with Filanc Construction, was selected to lead the expansion project.
New cartridge filters and chemical addition were installed for the barrier system as were microfiltration, ultraviolet irradiation and reverse osmosis capabilities. A 14.7 mgd micro-filtration unit replaced the barrier system's lime clarification unit and was converted for use as part of the Title 22 treatment system. Title 22 expansion included converting a clarifier and filters and adding a product water storage tank and pump station. Another upgrade incorporated ultraviolet irradiation treatment to address emerging source water contaminants, specifically NDMA levels.
Working closely with program managers, plant operators and West Basin staff, the HDR/Filanc team orchestrated a design-build project around a full-time operating facility. Weekly meetings were held from the project's start and an independent QA/QC firm was hired to ensure project integrity. Tie-ins were clearly defined and planned before execution and the team used Critical Path Method schedule development and management. Start-up planning began early in the project and regulators were involved from the start to ensure timely acceptance.
The Phase IV expansion allows West Basin Water District to more efficiently reclaim billion of gallons of wastewater into recycled water each year. In reclaiming the wastewater, West Basin preserves potable resources, replenishes groundwater, reduces dependence on imported water, and provides a drought-proof supply.