Bexar County, Texas: drinking water report. Bexar County is San Antonio and its surrounding communities – about 2 million residents relying primarily on
Bexar County is San Antonio and its surrounding communities – about 2 million residents relying primarily on the Edwards Aquifer, a karst limestone formation that is one of the most productive aquifers in the state. San Antonio Water System (SAWS) manages the bulk of the supply, supplemented by smaller utilities in suburban areas. The karst geology means water moves through dissolved channels in rock rather than filtering slowly through sand, which makes the aquifer both highly productive and highly vulnerable to surface contamination.
Bexar County has some of the best-documented military PFAS contamination in Texas. Lackland Air Force Base and Randolph Air Force Base both used AFFF firefighting foam for decades, and PFAS has been confirmed in groundwater monitoring wells surrounding both installations. The EPA's UCMR5 data shows detections across multiple SAWS sampling points, with wells nearest the bases recording the highest concentrations.
SAWS has taken some contaminated wells offline and is blending water from less impacted sources. According to the Edwards Aquifer Authority, the aquifer's karst structure means contamination can travel faster and further than in conventional groundwater systems – a fact that complicates remediation timelines.
Your PFAS exposure in Bexar County correlates strongly with geography. Northeast and northwest areas near the air force bases face the highest documented contamination levels.
Check your water to see monitoring data mapped to your ZIP code. If you are in a higher-risk zone near Lackland or Randolph, a reverse osmosis system removes over 90% of PFAS compounds. Our water filter guide compares systems by certified removal rates. Get your detailed report for trend data, and visit our Texas page for statewide patterns.
Drinking water is one exposure route. These federal datasets also cover Bexar County, TX.
The EPA places Bexar County, TX in Zone 3 - the EPA's lowest-risk category, with a predicted average indoor radon level below 2 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
38% of homes in Bexar County, TX were built before 1980, and 9% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Bexar County, TX averages 8.6 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide