Quality of stormwater runoff from an urbanizing watershed and a rangeland watershed in the Edwards aquifer recharge zone, Bexar and Uvalde counties, Texas, 1996-98

Encroachment of urban development on the outcrop of the Edwards aquifer (the recharge zone), particularly in Bexar County, has raised the issue of possible contamination of water that enters the aquifer. Increasing residential and commercial development on the recharge zone increases the potential for runoff containing toxic substances, oil spills, or leakage of hazardous materials to contaminate the regional drinking water supply.