Now Part of the Region L’s Water Management Strategy
 rackish groundwater could provide SAWS with a potential new source of water that can be developed close to home. Up to 22,000 acre-feet* annually could be made available to our water supply to help offset future water demand. This amount is currently being studied and subject to adjustment.
Project Overview
Brackish water — water too salty for drinking — is defined as water containing greater than 1,000 parts per million (ppm) of total dissolved solids. Feasibility work has been completed on a brackish groundwater desalination project located in southern Bexar County. For a long-term project, results show that a sufficient quantity and quality of groundwater resources are available. The project is more fully described in SAWS 2009 Water Management Plan Update. Conceptually, desalination facilities as small as 1 million gallons per day (mgd) and plants larger than 100 mgd have been reviewed. The South Central Regional Planning Group, or Region L, has included brackish groundwater as a water management strategy to meet future water needs.
Brackish Groundwater
Brackish water from the Wilcox Aquifer, located in southern Bexar, Atascosa and Wilson counties, has the potential to supply up to 20 million gallons per day (22,400 acre-feet per year) for many years. This project involves the development of a water supply
facility with the capacity to treat brackish groundwater to drinking water standards. Brackish groundwater developed close to San Antonio would provide SAWS with a potential new source of water. Research on the sustainability and water quality from the Wilcox Aquifer indicates
the project is favorable for development. First-phase planning is underway for a desalination facility to be located on SAWS-owned property in southern Bexar County. SAWS will prove the “science of the project” before adding additional well fields in Wilson and
Atascosa counties to support additional phases of the project.
The 2007 Texas Legislature was successful in passing two important pieces of legislation that will assist in the development of a desalination project. House Bill 2618 provides Texas municipalities with the ability to utilize Design-Build procurement procedures
for water supply projects. Design-Build procurement has the potential to reduce construction time and cost for major projects. In addition, House Bill 2654 provides for a general permit for Class I injection wells that would be utilized to dispose concentrate from a municipal
desalination plant.
Project Development
The location of a reverse osmosis treatment plant will be located on SAWS-owned property in southern Bexar County. This site would be relatively close to the brackish water source, including areas where concentrate can be disposed of reasonably. In Phase I of Brackish Groundwater
Desalination, a well field will be developed in southern Bexar County in the Wilcox Aquifer. The treatment plant will be located on the Twin Oaks Aquifer Storage and Recovery property, initially treating up to 11,800 acre-feet per year. The treatment plant will be designed
to accommodate additional upgrades and technologies.
In the future, once the science of desalination has been proven and presented to concerned citizens, production may be added in Wilson and Atascosa counties to expand the supply, treatment, and use of brackish groundwater
from those sources. Wilson County may be considered as a location for possible brine injection.
* An acre-foot of water is equivalent to 325,851 gallons |
