Tetra Tech has provided 20 years of continuous support to the San Antonio Water System (SAWS) to help diversify its water supply sources. Tetra Tech was selected as design engineer for treating brackish water using reverse osmosis technology for SAWS’ Brackish Groundwater Desalination Program in San Antonio, Texas. After successful completion of the facility, we were selected to design the Central Water Integration Pipeline (CWIP) Project. Source water will be piped in from 142 miles away, treated, and distributed to SAWS customers, integrating the largest non-local water supply in the City of San Antonio’s history.

For the brackish water treatment project, Tetra Tech designed the desalination facility using 3D modeling, allowing different design disciplines to work on one platform, accelerating the design process. In a typical brackish water process, about four out of five gallons is converted to fresh water, with one out of every five gallons becoming concentrated waste. For this project, Tetra Tech reduced the amount of concentrated waste to half a gallon per five gallons, creating an additional millions of gallons of drinking water each day—one of the largest recovery rates for municipal reverse osmosis in the United States.

For the CWIP Project, Tetra Tech provided design, bid, and construction administration services. CWIP will treat and distribute 50,000 acre-feet per year of water from other groundwater sources. The project includes a treatment plant, which treats the water to match the water quality in the existing SAWS distribution system. The CWIP Project helps SAWS to continue diversifying its water supply for residents of San Antonio.