BRACS: Mapping and Characterizing Texas' Brackish Aquifers

Brackish groundwater (water containing Total Dissolved Solids between 1,000 and 10,000 ppm) constitutes an important source of water supply for desalination in Texas. However, one of the more challenging issues and a potential roadblock to its more widespread use is the lack of detailed information on aquifer sections that contain brackish water.

While a 2003 Texas Water Development Board (TWDB) funded study helped lay the foundation for estimating brackish groundwater volumes in the state (almost 2.7 billion acre-feet), the study was by design regional in scope, limited in areal extent, and narrow in its assessment of groundwater quality. To improve on the 2003 study, TWDB requested and received funding from the 81^st Texas Legislature in 2009 to implement a program (the Brackish Resources Aquifer Characterization System program or BRACS) to gather more detailed information on the brackish aquifers.

The goals of BRACS are to map and characterize the brackish aquifers of the state in greater detail using existing geophysical well logs and available aquifer data, build replicable numerical groundwater flow models to estimate aquifer productivity and performance, and develop parameter screening tools to help assess the viability of brackish groundwater supplies.

Initially, as part of a pilot study we are mapping and characterizing a 1,000 to 1,500-foot-thick clastic aquifer in West Texas - the Pecos Valley Aquifer. One or two additional smaller secondary projects may be added to the pilot study. Eventually, depending on the availability of data, we plan to map all the other aquifers in the state (9 major aquifers and 21 minor aquifers).

We will prepare a full project report for the pilot study by the end of August 2011.