DISH — Toxicologists with the Texas Commission on Environmental Quality have recommended more study of the air quality here, according to an internal memo released this week.

The recommendations came after they reviewed a private consultant’s air quality study, which was commissioned by Dish town leaders earlier this year.

Tony Walker, the commission’s director for Region 4, pointed in particular to benzene readings found by Flower Mound-based Wolf Eagle Environmental Engineers and Consultants.

“We’ve opened an investigation specific to that site,” Walker said.

Benzene is a known carcinogen.

The commission was in the middle of a five-county study of Barnett Shale gas drilling and production when the concerns specific to Dish came to a head, Walker said, adding that the commission’s flyovers of various production sites were the first step in determining whether rules need to be changed.

“We wanted to do a phased approach,” Walker said.

The TCEQ memo also noted concerns about sulfides found by the Wolf Eagle study. Because some of the long carbon chains in the air samples were difficult to identify, state toxicologists said they could not draw accurate conclusions about the long-term health effects, and they recommended more study of those pollutants.

Dish town leaders voted to spend $10,000 to study air quality after years of complaining both to industry officials and regulators about foul odors emanating from compression and metering facilities on the edge of town.

About a dozen major gas-gathering pipelines converge in Dish. Five energy companies remotely operate plants between Tim Donald and Strader roads that prepare the gas for consumer markets.

Residents became concerned about their health at a town hall meeting earlier this month, when they learned that the consultant found elevated levels of benzene and other carcinogens, as well as sulfides and other neurotoxins.

Mayor Calvin Tillman said residents continue to complete health surveys, which will be compiled by Wilma Subra, who is nationally renowned for her work in environmental health. Subra has 15 completed surveys so far, and Tillman estimated he would send another 20 surveys to her by the end of this week.

Meanwhile, Tillman has been talking to officials at the Centers for Disease Control and Prevention about testing the community, since a complete battery of tests costs about $700 per person.

“For a family of four, that gets kind of expensive,” Tillman said.

Walker and other commission staff members attended the town hall meeting along with representatives from several environmental groups.

The Environmental Defense Fund has since released another study of TCEQ data, conducted at Rice University, showing a strong correlation between gas drilling production in Denton County and the types of pollutants found in the county’s air. That analysis showed a likely connection between four volatile organic compounds — pentane, butane, ethane and propane — detected in the county’s ambient air and the amount of condensate produced in local gas wells.

Ramon Alvarez, a scientist with the nonprofit group, said large amounts of condensate also are produced at gas wells in Wise, Hood and Parker counties.

He criticized state regulators.

“The state has not looked at years’ worth of its own data to see the signs that the Barnett Shale was having an effect,” Alvarez said.

The group has provided the commission with its latest study, he said.

TCEQ recognizes that, with Barnett Shale development, variables have changed, Walker said. The commission won’t turn down offers of quality data from anyone, including health surveys, he said.

Walker would not rule out either possible enforcement action in its Dish investigation or changes to overall regulations. Recommendations for rule changes could come as soon as the first of the year, he said.

“We’re working on getting the science data to support that,” Walker said. “We have 100-plus staff who live and work and play in the Barnett Shale region. We don’t have a pass on air quality. We really want to make sure we’re getting this right.”

PEGGY HEINKEL-WOLFE can be reached at 940-566-6881. Her e-mail address is pheinkel-wolfe@dentonrc.com .