Desalination possible for brackish W Texas aquifer
Desalination of brackish groundwater may be one option to meet projected increasing water shortages projected for the Trans-Pecos region in West Texas, USA, according to the report of a pilot study recently published by the Texas Water Development Board (TWDB).The report, Pecos Valley Aquifer, West Texas: Structure and Brackish Groundwater, estimates that the Pecos Valley Aquifer contains about 15 million acre‑ft (18.5 billion m³) of fresh water. It also contains 85 million acre-ft (105 billion m³) of brackish groundwater (1,000-10,000 mg/L total dissolved solids (tds)), and 1 million acre-ft (1.2 million m³) of very saline water (>10,000 mg/L tds).
The brackish water is present almost everywhere in the aquifer but appears to be more prevalent in the central and western parts. These are also areas where the saturated thickness of the aquifer is the greatest.
The 2010 approved state water plan for this area (Region F) projects water shortages of about 28,887 acre-ft (35.6 million m³) in 2010, increasing to 35,342 acre-ft 43.6 million m³) in 2060.
In 2009, TWDB established the Brackish Resources Aquifer Characterization System program to map and characterize brackish groundwater in the state and facilitate the planning of desalination projects. As part of the program, the Pecos Valley Aquifer in Regional Water Planning Area F was selected for a pilot study.
Desalination of brackish groundwater present in the Pecos Valley Aquifer may be one option to meet at least some of the projected shortages, say the report's authors. They emphasise, however, that information presented in the report and that available in its datasets cannot, be a substitute for a detailed site investigation that involves test well drilling, aquifer testing and water quality analysis.
The pilot study has helped lay the foundation for future Brackish Resources Aquifer Characterization System projects by developing a database management system in which a variety of data can be stored and processed.