Limestone County, located in east-central Texas, has small to plentiful ground-water supplies available, depending upon the location within the county. The Wilcox Group in the eastern part of the county has adequate supplies to meet the expected water demands in the foreseeable future. The thicker zones of the Wilcox Group can supply yields in excess of 500 gallons per minute. The Midway Group can supply yields in excess of 100 gallons per minute from the Tehuacana Member of the Kincaid Formation. This represents the largest well yields from the Midway Group in Texas. The Midway Group elsewhere in the State is mostly a poor water producer and is not considered an aquifer. The Taylor Marl and Navarro Group furnish only small quantities of ground water to wells in the western part of the county where these units crop out. The Hosston and Travis Peak Formations are present at depths in excess of 2,000 feet. These formations, which contain slightly saline water in the western part of the county, could be expected to produce water with a temperature of about 150°F that might be used for heating purposes.
About 0.9 million gallons per day of ground water was used for all purposes in 1980. This use has declined since 1955 but is expected to increase as additional public-supply and industrial wells are being developed. The Wilcox Group is capable of annually yielding at least 14,000 acre-feet or 11.6 million gallons per day of water to wells on a long-term basis.
Generally, the ground water is of acceptable quality for most uses. Relatively high dissolved-solids and iron concentrations are the major water-quality problems. Water-quality problems that may be the result of man's activities are limited to a small oilfield area near Mexia.
Lignite mining from the Wilcox Group is expected to take place in the foreseeable future. The collection of additional hydrologic data on the Wilcox would be desirable before, during, and after mining.
