Area officials at the San Antonio Water System’s Dos Rios Water Recycling Center celebrated the grand opening of a new biogas plant last week. The plant will capture methane gas generated during the sewage treatment process and clean it up so it can be sold as pipeline-grade natural gas to commercial buyers, thanks in part to a 20-year partnership with the privately-owned Massachusetts-based Ameresco, slated to sell off San Antonians’ collective gases.
The partnership, put into play in 2008, positions SAWS as owner of the first biogas plant in the nation to sell on the open market. Once operational, the plant is estimated to save the publicly-owned utility $200,000 a year.
Roughly 90 percent of material flushed down the toilets and sinks of our fair city can now be recycled, including the recycled waters already irrigating city fairways and parks and composting solids spread across local landscapes.
“We can collect 900,000 cubic feet of natural gas a day, [that’s] comparable to a natural gas well which will eventually become depleted,” said Anne Hayden, SAWS’ communications manager. “But with biogas we have a continuous supply.”
The new plant will harness methane gas for use as an energy source, whereas it was previously flared off, generating unwanted carbon dioxide emissions. “SAWS is constantly improving its operations to become more sustainable, and this project is a sound investment for our environment and our community,” Robert Puente, SAWS president and CEO, said in a prepared release. “By reusing biogas instead of burning it off, we are helping protect the city’s air quality and developing a renewable energy resource.”
While they already incorporate live wasp and purple martin colonies in lieu of insecticides to control pesky gnat problems often found at water treatment plants, future plans include solar and hydroelectric power to lower the treatment plant’s impact on the environment. “Attitudes from the public conscience have shifted in the last 10 years and we’ve paid attention,” Hayden said.
[Read more about SAWS’ environmental commitments at their website.]