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Texas agencies reported 252 new cases of groundwater contamination during 2023 in the Texas Groundwater Protection Committee annual report.
The latest report compiles 2,870 open cases of groundwater contamination, some of which date back decades. Nearly every county in Texas is impacted by the problem. During 2023, Texas regulators notified 34 local authorities—from El Paso to Houston—that newly identified contamination could impact their public drinking water. An additional 289 property owners were notified that groundwater contamination may impact their private wells.
Groundwater contamination is costly to remediate and can linger for years or indefinitely. Public water utilities test their wells for regulated contaminants and shut off wells when necessary. But the contamination risk is more insidious at private water wells, which are not subject to water quality standards.
Texas relies on groundwater from aquifers for about 55 percent of its water supply. As the population grows and the climate changes, groundwater will make up an even larger piece of the pie. Texas voters created a $1 billion fund in 2023 to develop more water resources for the state, including desalination of brackish groundwater.
“Any groundwater contamination is a cause for concern,” said Adam Foster, the director of the Texas Alliance of Groundwater Districts (TAGD). “It needs to be reported properly and addressed.”
Annual Report Summarizes Groundwater Contamination
The Texas Groundwater Protection Committee brings together nine state agencies and TAGD, the alliance of groundwater districts. The protection committee coordinates the activities of these agencies under Texas law, which requires that “groundwater be kept reasonably free of contaminants that interfere with present and potential uses of groundwater.”
The committee releases an annual report on groundwater contamination confirmed in the previous year. This year’s report, released in October, covers groundwater contamination documented in 2023. The report, and a map with the location of existing groundwater contamination, is available on the Texas Commission on Environmental Quality website.
TCEQ, the state’s environmental regulator, and the Railroad Commission, which regulates oil and gas drilling and other extractive industries, both document cases of groundwater contamination in their jurisdiction for the report. Eighty percent of the existing contamination cases, or 2,321 cases, fall under the TCEQ. The remaining cases are with the Railroad Commission.
Currently there are 224 public water supply wells that are considered contaminated, according to the report. There are approximately 17,900 public water supply wells in the state.
But the agency indicated that two public water supply wells were added to the list in 2023. The first is the Hart Municipal Water Supply in Castro County in the Panhandle, where benzene and total xylenes were found. TCEQ spokesperson Richard Richter said the source is unknown but the water utility remains in compliance with regulations. The second is the Grayson Business Park in South Houston, where chlorobenzene and vinyl chloride were found.
The single most common groundwater pollution source in Texas is gas stations, which make up a third of all the cases. For that reason gasoline, diesel and other petroleum products such as benzene, toluene, ethylbenzene and xylenes are the most common contaminants of groundwater. In some cases the source of contamination is unknown.
New groundwater contamination confirmed in 2023 included chlorinated solvents at a dry cleaner in Collin County, total petroleum hydrocarbons from a pipeline leak in Nueces County and per-and polyfluoroalkyl substances (PFAS) at the Austin Bergstrom International Airport.
“If TCEQ-regulated activities do impact groundwater, TCEQ will investigate the possible source of contamination and notify well owners in the vicinity of any groundwater contamination,” Richter wrote in an email.
Richter said that companies or individuals violating state water protection laws are issued a notice of violation or enforcement, depending on the severity of the violation.
“In either case, the respondent would be required to undertake all corrective action necessary,” he said.
Groundwater pollution can impact plans for future water supplies. The city of Midland bought a property in Winkler County decades ago to ensure a long-term water supply. What the city didn’t count on was groundwater contamination from legacy oil and gas operations. The city is in the midst of a multi-million dollar remediation effort.
The report says TCEQ uses a “risk-based” approach to groundwater contamination. The report notes that in some cases it is not “technically possible or cost effective” to remediate the groundwater.
In addition to the 2,870 active cases of groundwater contamination, regulators have closed the files on thousands of others. In some cases, regulators remediate groundwater to meet safety standards. In other cases, regulators leave the contaminated groundwater in place and adopt restrictions, known as institutional controls, to limit use of the water. These controls can include covenants to prevent the groundwater from being used in the future.
TCEQ’s Richter said the agency does not track what proportion of cases are remediated as opposed to adopting controls to restrict use of the groundwater. TCEQ encourages members of the public seeking more information on groundwater contamination cases to contact the agency or submit public record requests.
Report Raises Questions for Rural Groundwater and Private Wells
Groundwater management is essential as the Texas economy grows and surface water availability, such as rivers and reservoirs, stays flat or declines.
“As the state continues to grow we’re relying more and more on our groundwater resources,” said TAGD’s Foster. “Pretty much all of our surface water is permitted so there’s really not any more access to surface water.”
Agriculture is the biggest consumer of groundwater statewide, according to the Texas Water Development Board. Reliance on groundwater varies around the state, which is divided into water planning regions. In region F, which stretches from the Permian Basin east toward San Antonio, groundwater makes up more than 80 percent of the water supply. In Region K, which covers the Lower Colorado River including Travis County, groundwater provides only 28 percent of the water supply.
Groundwater hydrologist Ronald Green, a contractor with the Southwest Research Institute in San Antonio, said groundwater testing in rural Texas is often limited. Green has advised groundwater districts in South Texas and the Permian Basin and found there has been little groundwater testing in rural areas with active oil and gas drilling. For that reason he thinks the actual number of groundwater contamination cases could be much higher than the report’s total.
“There just are so few wells and so few samples of wells that have been collected and analyzed,” he said of those areas. “There’s no way you have an accurate reflection of how the groundwater has been impacted.”
He said most testing is conducted around cities with municipal wells. “You find it where the light shines on it,” he said.
That could be concerning for the more than one million Texans who rely on water from private wells, which are not subject to state and federal water safety standards. Well owners are responsible for the safety of their water.
TCEQ mailed notices to 289 private well owners during 2023 about contamination potentially impacting their wells. Notices were sent to well owners in Northwest Houston near Ashburn Industries and in Bridge City near the Louisiana state line, among other locations.
TAGD’s Foster recommends that private well owners test their water at least once a year. He said testing for indicator compounds can identify potential issues for more targeted testing.
“A lot of groundwater districts have testing programs where you can come in and get your water tested for free or at a significantly reduced cost,” he said.
The Texas Water Development Board also provides informational resources for private well owners.
At least one state representative is eying additional resources for groundwater in Texas. Rep. Cody Harris, a Republican from East Texas, introduced House Bill 1400 for the upcoming 2025 legislative session. The bill would create a Groundwater Science Research and Innovation Fund that would fund activities to improve groundwater science, improve efficiency of groundwater use and protect groundwater quality.
