When her well water took on an odd odor, Linda Scoma, who has lived near Crowley in rural Johnson County for 20 years, worried something might be wrong. Then her hair suddenly turned orange after she washed it, and she knew there was a problem.
Damon Smith of the Denton County town of Dish said the water flowing from his family's well, drilled in 2002, used to run clear and clean. Now, when he pours it into a glass, Smith regularly sees sediment floating in it.
Both suspect the same source of their problems: nearby natural gas drilling activities.
While most of the discussions about the environmental impact of natural gas drilling in the Barnett Shale have centered on air quality, questions are now being raised about its potential impact on water quality as well.
Drilling critics have expressed concern that a drilling process called hydraulic fracturing -- in which millions of gallons of water and sand laced with chemicals are pumped into the ground to free up natural gas -- has the potential to contaminate groundwater supplies.
Industry advocates counter that fracturing for Barnett Shale wells typically occurs more than a mile below underground aquifers that provide drinking water. Industry practice is to install multiple layers of pipe, known as casing, and cement inside the wellbore to isolate petroleum and chemicals from groundwater.
"You're talking about 6,000 feet of strata, rock and sand separating the fracturing in the shale and the fresh water table," said Ed Ireland, executive director of the Barnett Shale Energy Education Council. "There's not any case in Texas where hydraulic fracturing has damaged a water table."
The federal government may weigh in on the issue. The Environmental Protection Agency is launching a study of fracturing that is expected to focus on effects on groundwater supplies. Congress is also considering legislation that would increase regulation of hydraulic fracturing, or fracking, including forcing companies to disclose the chemicals used in the process.
After drilling began near Scoma's home, water tests detected increasing levels of chemicals used in the drilling process. The company that conducted the tests advised the Scomas not to drink the water, and they wash their clothes at a Laundromat because the couple says the water is discolored and has an oily sheen. They have sued the drilling company.
"I was embarrassed to go out in public because of my hair," Linda Scoma said.
At Smith's well, though, testing by the Texas Railroad Commission, which regulates drilling, found no high levels of toxic materials. Contaminants detected in the water were not at a level that would violate state or federal water quality standards, officials said.
"Therefore, we would not expect any adverse health effects after ingestion of water with these concentrations," Railroad Commission spokeswoman Stacie Fowler said.
If that's true, Smith has an offer for the commission and anyone else who wonders if the water is OK.
"Come to my house. Drink a big glass of that water at my table," he said.
Read more in the Fort Worth Star Telegram