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Drinking Water Quality in Texas

Most tap water in Texas starts as a river, lake or reservoir. Enter your ZIP below to see which community water system EPA lists for your county, what the federal record shows for it, and where its official annual water quality report lives. Every number on this page is EPA's, from the April to June 2026 extract, and none of it is a safety verdict in either direction.

4,749 community water systems serve 33 million people in Texas, 82 percent of them on surface water
Community water systems
4,749
People served, as reported
33 million
On surface water
82%
Counties with listed systems
254

Which water system serves your Texas address?

EPA SDWA extract, April to June 2026

Texas lists 4,749 community water systems, more than any other state, from Houston at 3 million people served down to thousands of subdivisions and mobile home parks with their own wells. The map runs from East Texas piney woods districts to El Paso, which drinks a mix of river water and desalinated brackish ground water.

County by county

Texas water systems by County

EPA's federal file lists active community water systems in 254 counties of Texas. The table below is that record, sorted by reported population served. It is an inventory, not a ranking: a county with more listed violations is often just a county whose systems and state program report more completely.

Loading the county table from the committed EPA snapshot…

A small town water tower on steel legs against a clear sky
The water tower is the visible tip of a community water system, and most of the systems in the table above are this size: a town, a district or a cooperative serving a few hundred to a few thousand people. Small systems carry most of the listed violations nationally, largely because staying on top of every sampling schedule is hardest with one part time operator. “Seelyville-Town-Hall-water-tower-in” by Brian Stansberry, CC BY 4.0
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Where it comes from

Texas mostly drinks treated surface water

By reported population served, 82 percent of community system customers in Texas are on surface water and 18 percent on ground water. That clears the 75 percent surface supermajority only 22 states reach, and it shapes everything: surface water must be filtered and disinfected continuously, so the state's water quality story is a treatment plant story. 1,247 of the state's systems buy some or all of their water wholesale from another system, so the system on your bill is not always the system running the treatment plant.

4,749
Community systems
the most of any state
3 million
Largest system, people served
City of Houston
1,247
Systems buying water wholesale
purchased ground or surface water
300
Systems with nothing listed
no reported violations, which is not a clean bill

City of Houston

3 million

people served, on surface water, serving Harris county. PWSID TX1010013.

EPA listed inventory

San Antonio Water System

2.6 million

people served, on purchased surface water, serving Bexar county. PWSID TX0150018.

EPA listed inventory

Dallas Water Utility

1.4 million

people served, on surface water, serving Dallas county. PWSID TX0570004.

EPA listed inventory

City of Austin Water & Wastewater

1.1 million

people served, on surface water, serving Travis county. PWSID TX2270001.

EPA listed inventory

Population served is self reported by each system to its regulator, and a wholesaler and the systems buying from it can both count the same household. Summed across Texas that overlap inflates the total, so read the 33 million figure as the sum of what systems report, not as a census of people.

Our summary of information published by EPA SDWA quarterly download (SDWIS federal data)

What EPA lists, in EPA's categories

Violations in the federal record for Texas

As of the April to June 2026 extract, EPA's files list at least one health based violation that began in the five years to 2026-06-30 for 1,512 of Texas's 4,749 community systems, which is 31.8 percent. 1,673 systems currently carry a violation EPA's status field marks Unaddressed. Health based is EPA's own dividing line, and it matters more than any total:

“These violations fall into three categories: Exceedances of the maximum contaminant levels (MCLs), which specify the highest allowable contaminant concentrations in drinking water; Exceedances of the maximum residual disinfectant levels (MRDLs), which specify the highest concentrations of disinfectants allowed in drinking water; and Treatment technique requirements, which specify certain processes intended to reduce the level of a contaminant.”

US EPA ECHO, SDWA Data Download Summary (health based violations)

Everything else in the record is mostly monitoring and reporting: a required test or report that did not happen on schedule. Those are the bulk of all listed violations nationally, and they say nothing about what was in the water, only that nobody checked when the rules said to. Two more of EPA's own definitions worth knowing when you read a system's record: a violation is Unaddressed when, in EPA's words, "The violation is not Resolved or Archived, and has not been addressed by formal enforcement." and Archived when it is more than five years past its end date.

“The violation is not Resolved, but is more than five years past its noncompliance period end date. In keeping with the Enforcement Response Policy, the violation no longer contributes to the public water system’s overall compliance status.”

US EPA ECHO, SDWA Data Download Summary (violation status: Archived)

And the caveat that binds this whole page, in the agency's words rather than ours:

“Compliance statistics are based on violations reported by states to the EPA Safe Drinking Water Information System (SDWIS). EPA is aware of inaccuracies and underreporting of some data in this system. We are working with the states to improve the quality of the data.”

US EPA ECHO, Drinking Water (SDWA) FAQs

“Due to the known incompleteness of the data reported by states and regions, we are careful to refer to systems as having reported violations or no reported violations.”

US EPA ECHO, Drinking Water (SDWA) FAQs

This is why Texas's percentages cannot be compared against another state's as if they measured the water. A state whose program reports quickly and completely will show more listed violations than one that lags, for the same pipes and the same rivers. We publish EPA's counts with EPA's caveats and rank nobody.

Our summary of information published by EPA ECHO Drinking Water FAQs

Concrete sedimentation and clarifier basins full of water at a drinking water treatment plant
Sedimentation and clarifier basins at a drinking water treatment plant, in an EPA photograph. Every system on this page treating a river or reservoir runs some version of this, continuously, which is what a treatment technique violation is about: not a bad sample but a required process falling short. “The coagulation and filtration processes at a drinking water treatment plant. (14868618507)” — US Environmental Protection Agency — Public domain
The official record

Where Texas's real water quality answers live

This page shows the compliance record. The actual test results, what was measured in the water and at what concentration, live in each system's annual Consumer Confidence Report, and federal law puts one in your hands every year:

“EPA requires community water systems to deliver a Consumer Confidence Report, also known as an annual drinking water quality report, to their customers. These reports provide Americans information about their local drinking water quality.”

US EPA, CCR Information for Consumers

“Reports must be sent by your water supplier each year by July 1.”

US EPA, CCR Information for Consumers

Find yours through EPA Consumer Confidence Report search or on your utility's website. Day to day regulation belongs to Texas Commission on Environmental Quality, the state's primacy agency, whose records for any single system run deeper and fresher than the federal extract this page reads. Health questions about your tap water belong to your water system, your county health department and CDC Drinking Water, not to this page.

If you are on a private well, none of the above applies to you, and that is worth saying plainly:

“The quality and safety of drinking water from private domestic wells are not regulated by the Federal Government under the Safe Drinking Water Act nor by most state governments and laws.”

US EPA, Private Drinking Water Wells

Testing a private well is the owner's job. Texas Commission on Environmental Quality and county health departments publish what to test for locally, and EPA's private wells pages cover the basics.

Common questions

Texas drinking water FAQ

Keep going

The rest of Texas's water picture

Drinking water in nearby states

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Inventory and violation counts are EPA's, from the April to June 2026 SDWA quarterly extract (published July 2026), active community water systems only. ZIP to county resolution uses the Census Bureau's ZCTA relationship file. Live checks read EPA Envirofacts. All are US Government works in the public domain. National picture: drinking water in every state