Lignite development will place major demands on ground-water supplies.

The environmentally sensitive trace elements molybdenum, arsenic, and selenium are concentrated with uranium in ore deposits in South Texas. Cattle grazing in some pastures in mining areas have contracted molybdenosis, a cattle disease resulting from an imbalance of molybdenum and copper.

Hot springs and wells in West Texas and adjacent Mexico are manifestations of active convective geothermal systems concentrated in a zone along the Rio Grande between the Quitman Mountains and Big Bend National Park.

With the growing concern for finding new sources of energy, there has been renewed interest in an old source, lignite. In the past few years, Texas lignite has been "rediscovered", and a wave of lignite exploration rivals the early oil booms of Texas history.

Lignite deposits in Texas occur in three Eocene stratigraphic units: the Wilcox Group (lower Eocene), the Yegua Formation (upper Eocene), and the Jackson Group (upper Eocene).