Local and state officials on Tuesday received a raft of new information about air pollution from newly drilled oil and gas wells, the result of a three-year, $1.77 million study that focused on Garfield County.

Researchers from Colorado State University spent three years capturing air samples at 21 new oil and gas sites in the Western Slope county, historically center of the state’s natural gas production — and the center of what federal researchers last week concluded was the second-biggest natural gas field in the United States.

A similar air quality study focused on Colorado’s northern Front Range, the focus of the state’s crude oil operations, is expected to be released by the end of July, Jeffrey Collett, the leader of the study and head of CSU’s Department of Atmospheric Science, said in an interview with the Denver Business Journal.

Oil and gas companies working in the county helped pay for the Garfield County study and also allowed the researchers access to their operations.

The study focused on the amount and type of air pollution, specifically volatile organic compounds (VOCs), which form ozone when cooked on sunny days, and methane, a powerful greenhouse gas, released by oil and wells during the early phases of their life cycle. The study focused on three phases: the drilling phase, the hydraulic fracturing operations and the flowback period, when a mixture of fracking fluid and water is pumped out of the well, clearing the pathway to produce oil and gas for market.

Most air quality studies have focused on older wells that are producing oil and gas for market.

Garfield County Commissioners on Tuesday heard a presentation on the study. The county, which called it the “most comprehensive assessment” of air pollution from new natural gas wells to date, contributed $1 million to the study.

“What we have done is document the types of chemicals, and the amounts of those chemicals, that are emitted when new wells are prepared,” Collett said in a statement from CSU.

“We wanted to look at drilling, fracking and flowback, because emissions from these activities have received little prior study, especially for VOCs,” Collett said

“The study focused on directly quantifying emissions, so that findings could be used to generate maps of concentrations for times and places of interest, under a variety of weather conditions, to examine issues like potential health or air quality impacts,” he said.

The data will be used by the Colorado Department of Public Health and Environment to assess health risks associated with drilling and fracking operations.

All parties to the study agreed that if Collett and his research team saw something that was “acutely dangerous” that it would be reported immediately to the authorities, Collett said during the interview with the DBJ.

“But we didn’t see anything like that out in the field,” he said.

“We had great cooperation from the outset of the study from the county and the several companies that participated,” Collett said. “That made our job easier. We found that Garfield County was a great environment to work in, most people wanted to understand what the emissions were.”

Dan Haley, president and CEO of the Colorado Oil & Gas Association, in a statement said the industry expects “some anti-energy activists will try to reinterpret or draw conclusions from the data that just do not exist in order to create unnecessary alarm for political gain.”

“We can’t stop a misinformation campaign, but [we] can state that the project outcomes do appear to be within the range of expectation,” Haley said.

Early analysis on the data indicated that air pollution levels peaked during the flowback period of the well, when the mix of fracking fluid and water is being pumped out. The research also found that methane was the biggest element of the pollution released.

Median amounts of methane emissions ranged from 2 grams per second during the drilling phase, to 2.8 grams per second during the fracking phase, to 40 grams per second during the flowback operation, according to CSU.

Emissions of other hydrocarbons, such as ethane and propane, or air toxins such as benzene and toluene, also were found during the tests, although those rates were in fractions of a gram per second.

Collett’s presentation to the Garfield County Commissioners on Tuesday is available at the county’ website.

CSU representatives expect to provide study data for public access July 1 via CSU’s online data portal.

Energy companies working in Garfield County contributed about $700,000 to the study. The money came from Encana Corp. (NYSE: ECA), WPX Energy (NYSE: WPX), Bill Barrett Corp. (NYSE: BBG), and private companies Ursa Resources Group, Caerus Oil and Gas and Laramie Energy.