Brackish Groundwater Allows San Antonio to Go Big With Desalination
San Antonio Water System recommends rejection of three private proposals as too risky
San Antonio Water System (SAWS) staff recommended to its Board the pursuit of additional brackish groundwater supplies through a proposed groundbreaking partnership with CPS Energy to co-locate a natural gas plant on the same site as an expanded brackish desalination (desal) plant.
Beyond the currently planned desal plant in southern Bexar County, SAWS has concluded that additional desalination capacity is feasible in the local area.
"Brackish groundwater is plentiful and unused in our region, and available for centuries," said SAWS President and CEO Robert R. Puente. "The state of Texas views desalination as a solution to meet future water demands, and so do we."
With the availability of brackish supplies in adjacent counties, further expansion of a desalination facility in partnership with CPS Energy could occur on the same site as the currently planned desal plant, the existing Aquifer Storage and Recovery plant, and a third project increasing yield from the local Carrizo Aquifer in southern Bexar County. This co-location would save money on additional land as well as consolidating management and operation of several water supply projects.
As part of Monday's recommendation, Puente also announced the rejection of three private groundwater projects proposing to pipe up to 50,000 acre-ft of water per year to San Antonio from outlying areas in the state.
The private proposals would have required annual payments of up to $85 million for thirty years, and a rate increase of approximately 9% to 12% in 2019, not including infrastructure integration costs.
Instead of committing to one of the proposed projects, SAWS plans on pursuing the expansion of brackish groundwater desalination in partnership with CPS Energy to ensure long-term supplies for the region.
Costs of an expanded desalination project can be spread over time as the water is needed. A public desalination plant could also be eligible for Proposition 6 funding from the Texas Water Development Board, while the proposed projects are not.
Due to the flexibility provided by proactive planning and successful water management in recent years, an expanded desal project can be planned for the mid-2020s, instead of the 2018 date planned for the private proposals.