An old oil well near the Preserve at Medina subdivision off Highway 16 on San Antonio's far southwest side is leaking methane and hydrogen sulfide, and residents say the gas odor has grown thick enough to notice in their own yards. The well was first plugged back in 2006, but it has kept leaking through multiple subsequent attempts by state regulators to seal it for good.
According to WOAI News 4, which first reported on the leak, the Texas Railroad Commission is responsible for the well and has made multiple attempts to plug it. In its most recent report, WOAI said the state's plugging team has made four attempts to re-plug the well and is currently monitoring gas levels in the area, with plans to send more teams to investigate further. That figure conflicts with reporting published in October by the San Antonio Express-News, which put the number of replugging attempts at five, noting that gas has continued to leak regardless.
Residents in the neighborhood say they had no idea about the hazard before moving in, and that nobody has stepped up to warn them since. William Helsel, who has a son and a newborn baby at home, told WOAI News 4 that his family only learned about the leak on their own. “The front office has never notified us or told us about anything,” he said.
Fumes Keep Families Out of Their Own Yards
Helsel said the smell has changed how his family uses their property. He said he avoids spending time in front of his house after breathing fumes there, and that he can't spend time in his own yard because of the odor. He and his wife are now considering moving out of the neighborhood altogether, though he worries the leak itself could make it extremely hard to sell their home in the first place.
Crystal Morales told the station that the gas odor sometimes creeps into her sister's house through cracks. She said she believes the leak could be harming residents' health and that nothing is being done about it. Bexar County Public Works has been seen photographing oil that has turned up on nearby streets and sidewalks, according to the same report.
What Doctors Say About Hydrogen Sulfide Exposure
Dr. Alan Siqueiros, director of the medical ICU at Christus Westover Hills, told WOAI News 4 that hydrogen sulfide is highly toxic and that its effects depend heavily on concentration. At lower concentrations, exposure can cause irritation, coughing, dizziness, nausea and headaches, while long-term exposure may cause more severe effects, he said. Siqueiros added that higher exposures have been linked to neurological symptoms including memory loss, difficulty concentrating and mood changes.
State and environmental regulators told WOAI News 4 there is currently no immediate threat to health or safety in the area. Separately, the Express-News reported that soil and air monitoring near the well has detected leaking methane and hydrogen sulfide, and that the Railroad Commission has proposed replugging the well using a different strategy and materials. A commission spokesperson told the outlet that “this proposed operation is currently under review.”
A Problem Bigger Than One Neighborhood
The Preserve at Medina's trouble fits into a much larger pattern across Texas and the country. The EPA estimates there are 3.2 million abandoned oil and gas wells in the United States, and about 2.1 million of those haven't been plugged at all, according to a WOAI News 4 report on the national scope of the issue. A study cited by the EPA found unplugged, abandoned wells leaked 5,000 times more methane than plugged wells did, the station noted.
A 2024 investigation by The Examination and the Houston Chronicle, cited by Inside Climate News, found that tens of thousands of Texans live near hydrogen sulfide hotspots, and that regulators often respond to leaks without issuing penalties. In Odessa, Inside Climate News reported, TCEQ inspectors found hydrogen sulfide leaking from an Aghorn pumpjack just over 100 meters from a resident's home; the company patched the leak and the complaint was resolved with no penalty.
Similar leaks have turned dangerous elsewhere. The Express-News reported that several homes in Newport Beach, California, were evacuated in October 2025 after a methane leak from a 1920s-era oil well, and that an explosion in Wheatley, Ontario, in August 2021 injured 20 people after hydrogen sulfide migrated from a legacy gas well into a basement. Regulators also said methane from an abandoned gas well beneath a house in Trinidad, Colorado, caused an explosion during construction there in 2007, according to Inside Climate News.
The Railroad Commission has pointed to progress on the broader orphaned-well problem, saying it plugged more than 2,000 orphaned wells statewide in the past fiscal year, exceeding a legislative performance target by 300 wells. For residents of Preserve at Medina, though, the well next door remains an open question, with monitoring ongoing and no timeline yet for when the leak might finally be sealed for good.
