The San Antonio Water System (SAWS) in Texas has announced that by October 2016 it will start up a brackish water desalination plant that will eventually become the largest in the US.
SAWS is drilling through the freshwater Carrizo aquifer into the brackish Wilcox Aquifer. Desalinating Wilcox water is part of the agency’s plan to reduce reliance on San Antonio’s main water supply, the Edwards Aquifer which provides 63% of SAWS’s water. SAWS expects the Edwards contribution to the region’s supply to 38% over the next 20 years.
The US$ 114 million desalination project will contribute 8% of the region’s water supply.
SAWS said it had devised measures to avoid contamination of freshwater aquifers with brackish supplies for the desalination facility and to deal with discharged brine. SAWS geologist, Richard Donat, said it had dismissed landfill and piping to a wastewater treatment plant on the grounds that both presented a threat t the local ecology.
“So the best option we saw was doing a deep well injection,” said Donat. The brine, Donat said, will be disposed of nearly a mile underground.