WATER DEMAND OF THE ENERGY INDUSTRY IN TEXAS AND IMPACT ON AQUIFERS

Texas energy mineral resources include coal, lignite, gas, oil, as well as uranium. Operations always involve water, either to help in extraction or as a by-product. Until recently, lignite extraction (lignite belt in the eastern half of the state) and oil production (waterflooding, mostly in the Permian Basin of West Texas) made up the bulk of fresh water used for energy extraction with annual water use ranging from 30 to 50 thousands acre-feet (AF). Beginning about two decades ago but particularly within the past decade, water use to extract oil and gas through hydraulic fracturing stimulation has overtaken the other energy upstream segments to become the main contributor to water consumption in the mining industry in Texas. Oil and gas production from shales and other tight formations distributed throughout the state through several tens of thousands of horizontal and vertical wells requires water consumption exceeding a hundred thousand acre feet per year. Water is used mostly for hydraulic fracturing stimulation, for drilling wells, and for secondary and tertiary oil recovery processes (oil and gas industry); for dewatering and depressurizing pits, with a small amount used for dust control (coal industry); and for dust control and washing (industrial sand, aka proppant). Operators favor surface water when it is plentiful but groundwater is a more drought-proof source. The widespread distribution of the various segments of the energy industry across the State results in impacts on many different aquifers. The Carrizo-Wilcox aquifer, extending from the Mexican border to the Louisiana state line, provides a significant fraction of the total water consumption for producing energy fuels. The aquifer has large resources but increasing use by the energy industry combined with increased reliance on the aquifer for all other sectors in times of drought can lead to local conflicts. Increasing use of brackish water and more recycling should reduce pressure on freshwater resources in the future.