Grayson County, Texas: drinking water report. Grayson County sits along the Texas-Oklahoma border, anchored by Sherman and Denison, with smaller
Grayson County sits along the Texas-Oklahoma border, anchored by Sherman and Denison, with smaller communities like Whitesboro, Pottsboro, and Van Alstyne drawing water from Lake Texoma, local wells, and the Red River basin. Most residents receive municipal water from systems that blend surface and groundwater sources, while rural properties often rely on private wells tapping the Trinity and Woodbine aquifers. The region's mix of agricultural land, expanding suburbs, and aging infrastructure creates varied exposure risks across the county's 18 ZIP codes.
Texas is one of 49 states where EPA detected PFAS during the 2023-2025 UCMR5 sampling cycle, and North Texas utilities have reported measurable levels of these persistent chemicals. Grayson County's water sources face contamination pressure from multiple directions. Agricultural runoff introduces nitrates and pesticides into surface water reservoirs, particularly following heavy rain events that wash fertilizers and herbicides from farmland into tributaries feeding Lake Texoma. The county's industrial history, including manufacturing facilities in Sherman and Denison, raises questions about legacy contamination in soil and groundwater near former plants.
Lead remains a concern in older neighborhoods where homes built before 1986 still have lead service lines or copper pipes joined with lead solder. Texas does not require utilities to publish individual household test results, so residents often discover elevated lead only after private testing. The state's Lead and Copper Rule compliance data shows violations occur sporadically across small Texas systems, though major utilities typically pass the 90th percentile action level of 15 parts per billion. Private well owners face different challenges entirely, with no mandatory testing requirements and full responsibility for monitoring their own water quality.
Radionuclides present another documented issue in North Texas groundwater. The Trinity and Woodbine aquifers naturally contain uranium deposits that leach into well water under certain geological conditions. EPA data shows scattered Texas counties exceed the maximum contaminant level of 30 micrograms per liter for uranium, and radium also appears in some private wells. Residents using groundwater should request testing for gross alpha particle activity and specific radionuclides, as these contaminants have no taste or odor but pose long-term health risks at elevated concentrations.
Disinfection byproducts form when chlorine or chloramine used to kill bacteria reacts with organic matter in source water. Total trihalomethanes and haloacetic acids can exceed health guidelines in systems drawing heavily from surface reservoirs during summer months when algae growth increases organic content. Texas utilities generally maintain compliance, but levels fluctuate seasonally, and pregnant women or immunocompromised individuals may want additional filtration even when water meets legal standards.
Request your utility's latest Consumer Confidence Report and compare results against EPA health guidelines, paying particular attention to PFAS, disinfection byproducts, and lead sampling data from homes in your neighborhood. Private well owners should arrange annual testing through a state-certified lab, including analysis for nitrates, bacteria, radionuclides, and pesticides common to agricultural areas. Check your water for current contamination data in your ZIP code, review the water filter guide to match treatment technology with specific contaminants, explore the detailed report for full testing information, and visit the Texas state page for regulatory context and statewide contamination patterns.