Houston TX metro: water quality. Greater Houston's water supply reflects the region's size and complexity.
Greater Houston's water supply reflects the region's size and complexity. The City of Houston Public Works Department serves the core city of 2.3 million, drawing from Lake Houston, Lake Conroe, and the Trinity River system, supplemented by Gulf Coast Aquifer groundwater. But the broader metro of 7.1 million people includes Sugar Land (Fort Bend County MUD systems), Pasadena (its own municipal supply from surface and groundwater), and dozens of Municipal Utility Districts that each operate independently. These MUDs – there are over 800 in the Houston area – are a Texas peculiarity, and they mean water quality can vary block by block in the suburbs.
The metro sits along one of the most concentrated industrial corridors in the Western Hemisphere. The Houston Ship Channel, refineries, chemical plants, and associated facilities line the eastern edge of the metro, adding contamination vectors that most American cities do not contend with.
UCMR5 results show PFAS detections in multiple systems across the Houston metro. Ellington Field Joint Reserve Base, on the city's southeast side, is a confirmed source of AFFF-related PFAS contamination. The Department of Defense has been conducting site investigations at Ellington since 2019. Beyond military sources, the petrochemical industry uses PFAS compounds in manufacturing processes, and legacy contamination from decades of industrial activity has been documented in both surface water and groundwater near the Ship Channel.
Texas still lacks state-specific PFAS MCLs. The TCEQ monitors but has not moved to set enforceable limits beyond federal thresholds. A 2025 analysis by the Houston Chronicle found that at least nine public water systems in Harris County had reported PFAS detections under UCMR5, with the highest concentrations in systems drawing groundwater near industrial zones.
Our data maps contamination across the metro's many water providers, so you can see what your specific MUD or municipal system has reported rather than relying on metro-wide averages that mask real variation.
Houston's combination of industrial proximity, shallow aquifer contamination, and infrastructure stress from extreme weather events puts it among the more challenged major metros for water quality in the U.S. The February 2021 Winter Storm Uri knocked out water treatment for days across the metro, leaving millions without safe tap water. Hurricane Harvey in 2017 inundated treatment facilities with floodwater.
Compared to other Texas metros, Houston faces more industrial contamination pressure than Dallas-Fort Worth or Austin, but has invested more heavily in treatment upgrades in recent years. The Gulf Coast Aquifer that supplements Houston's supply is shallower and more vulnerable to surface contamination than the Edwards Aquifer serving San Antonio.
For more on Texas water quality, see our Texas state page.
In a metro with 800+ independent water providers, knowing your system is step one. Your MUD number or utility name determines which treatment plant and which source water feeds your home.
Check your water – we'll match your address to the right provider and show recent monitoring results. For homes near the Ship Channel, Ellington Field, or industrial zones in east Harris County, a certified water filter is a practical step while regulatory standards catch up to the science. A detailed report for your address can reveal trends that a single data point cannot – whether contamination levels are stable, declining, or getting worse over time.