COLLEYVILLE -- Rather than take the city's word about air quality at a fracking site, three homeowners who live near it shelled out their own money to monitor emissions.
What they found has caused debate on whether Titan Operating violated Colleyville's drilling ordinance and the Texas Commission on Environmental Quality's limits for short- and long-term exposure to chemicals called volatile organic compounds.
The city has only one approved drilling site, and Titan conducted hydraulic fracturing operations on seven gas wells there Jan. 31 through Feb. 16. No pipeline has connected to the site, so the wells were capped.
The residents' testing detected benzene, a known carcinogen, at 12.8 parts per billion over 12 hours Feb. 2 at a home 1,700 feet north of the drill site.
The tests used air canisters bought from GD Air Testing for more than $300 each.
Gordon Aalund, a Southlake resident and physician with a background in toxicology, said the industry put residents at "unneeded risk" by not taking proper precautions at the drill site, like using vapor recovery units.
"When your government fails to protect you and the company cannot be trusted, private citizens are forced to act," said Aalund, who was part of a group that sued Southlake last year to stop a drill site there.
But Colleyville officials maintain that the city's ordinance wasn't violated, citing air quality tests the city paid for, spokeswoman Mona Gandy said.
The ordinance prohibits the venting or release of gas into the atmosphere.
"We feel comfortable that the report provided by the independent inspector was an accurate reflection of activity on the site during Titan's fracking operations," Gandy said.
"Our role is to protect the public's safety, and we took every precaution to do that. We believe that the scientific processes used by the independent inspector and his findings are valid, fall within state and federal standards, and complied with our city ordinance."
In a statement, Titan Operating President Mark Schumacher said the company is in full compliance with the ordinance.
Colleyville officials did not say whether they plan to act on the data from the residents, referring only to their statement of confidence in the report by the consultant hired by the city. The city would not immediately release information on what it paid the consultant.
That consultant, Kenneth Tramm of Modern Geosciences, said he understands that the residents want to know what's in the air and whether it's safe.
But he said there are flaws in their tests, which were done at three homes within 1,100 to 1,700 feet of the Titan Operating pad site at 7504 Pleasant Run Road, near the border with Southlake.
He questioned a lack of documentation showing how the tests were conducted, who handled the canisters and why they were stored for 20 days before being analyzed.
The wind direction is also important, he said.
"You've got to understand the source, where it's going, to understand the data," he said. "It just looks like the data they have doesn't mean what they think it does."
Tramm tested the air at the drill site and found very different results.
During the initial hydraulic fracturing phase, Tramm found high levels of nitric oxide, a byproduct of the diesel exhaust from the trucks and water pumps on the site.
He likened it to what you'd find at a truck stop. No benzene was detected in that phase of the operation, which doesn't match the homeowners' tests, which show a benzene spike Feb. 2.
Tramm did start detecting hydrocarbons such as benzene, xylene and ethylbenzene during flowback Feb. 5-16 but said they didn't exceed the state commission's exposure levels.
Wilma Subra, an environmental activist in Louisiana who wrote a report accompanying the residents' data, stood by their results, saying they prove that the fracking process emitted volatile organic compounds.
"They were told that there were going to be no emissions," she said.
In January, Colleyville officials had serious concerns about Titan's ability to comply with the ordinance, and staff members told the City Council that fracking wouldn't take place unless the gas company asked for waivers.
In particular, the city was concerned about gas venting into the atmosphere during flowback, when contaminated fracking fluids are pumped out of the drill hole and natural gas is first detected.
A week later, Titan officials assured the city that the gas could be contained with almost no emissions, and the work started on schedule.
Sharon Wilson, an organizer with Earthworks' Oil & Gas Accountability Project, which directed the homeowners on where to buy air testers, said the state commission and the city failed to protect people.
"It's state and local failures like these that make plain the need to close fracking loopholes in federal environmental laws," Wilson said.