San Antonio Water System
The San Antonio Water System (SAWS) has a vision for the city’s water resources. Through its innovative Wastewater Trifecta project, SAWS has developed beneficial uses for all three of the city’s major wastewater treatment byproducts: water, biosolids, and waste gas.
Part one of the Trifecta, SAWS’ Recycled Water Program, was initiated to reduce the amount of water San Antonio pumps from the Edwards Aquifer. It conserves potable water and protects endangered species habitats and critical ecosystems. The recycled-water-distribution system spans 110 miles and delivers high-quality, treated recycled water to commercial and industrial customers and to four new stream-discharge locations for aquatic ecosystem enhancement and restoration. Regular water-quality sampling at 13 locations has confirmed improvements as seen by lower turbidities, higher clarity, less algal growth, lower bacterial counts, and the return of several water-quality-sensitive, pollution-intolerant species. Access to the recycled water has also attracted several businesses to the area.
Part two of the Trifecta turns biosolids (solid organic matter produced during the wastewater treatment process) into compost for use in landscaping, gardening, and agriculture. The effort creates more than 110,000 tons each year of a useful product that contributes to improved soil quality. In 2009, 98 percent of SAWS’ biosolids were recycled and reused through composting.
For part three of the Trifecta, SAWS partnered with an energy services company to send natural gas generated from its biosolids onto the natural gas grid. Previously considered a waste and burned off into the environment, nearly 1 million cubic feet of biogas is now transferred to a natural gas pipeline each day for beneficial reuse in homes and businesses. Refined to be chemically identical to natural gas currently in pipelines, the biogas is now available for such uses as heating and cooking.
SAWS also has spearheaded several proactive water conservation programs, developing media campaigns and community-based outreach to raise public awareness and participation. The utility focuses on forming partnerships and involving stakeholders to ensure the success of its programs, which yielded nearly 1 billion gallons of ongoing water savings since 2009. Efforts included 1,842 residential water conservation consultations, resulting in a cumulative drop of more than 80 million gallons in participating household-water consumption. Other activities, such as SAWS’ Conservation Make Over program, which provides assistance to low-income neighborhoods, as well as retrofits of older buildings and other indoor programs, additionally saved more than 600 million gallons.
Conservation efforts have helped drop the system-wide gallons per capita per day (GPCD) from 136 in 2008 to 125 in 2009. SAWS has had an average annual GPCD drop of 1.5 between 2000 and 2009. Thanks to conservation programs in place since 1994, the utility is now able to serve twice as many customers using the same amount of water.
Overall, SAWS’ innovative management and well-coordinated public awareness activities have shown that cooperative efforts can reduce waste and—in SAWS’ words—save tomorrow’s water today.