Post updated 6-15-16 at 10:20 a.m.
Data from an extensive multi-year Colorado State University study of air emissions from natural gas operations in Garfield County, Colorado have been presented publicly by a CSU research team. Click here to view the slideshow presentation.
Study leader Jeffrey Collett, professor and head of CSU’s Department of Atmospheric Science, presented the study results during a session of the Garfield County Board of Commissioners June 14. The presentation was streamed live and is archived on the Garfield County government website. Read the county’s news release.
The study, Characterizing Air Emissions from Natural Gas Drilling and Well Completion Operations in Garfield County, Colorado, was commissioned in 2012 by Garfield County. It was aimed at characterizing the extent of air emissions from natural gas extraction activities.
The western Colorado county contains the Piceance Basin and has some of the highest oil and gas activity in the state. Collett and other researchers, including co-principal investigator Jay Ham, CSU professor in the Department of Soil and Crop Sciences, obtained air samples for scientific data surrounding well pad activities. Air Resource Specialists, a company that offers air quality monitoring and modeling, also contributed to the project.
Garfield County contributed $1 million toward the study, which was organized through an intergovernmental agreement between CSU and the county. Approximately $700,000 in additional support came from industry gifts to CSU from Encana Corp., WPX Energy, Ursa Resources Group, Bill Barrett Corp., Caerus Oil and Gas and Laramie Energy. A technical advisory committee comprised of air quality and emission experts from government, industry, and the National Center for Atmospheric Research periodically consulted with the research team during the study, and reviewed the findings.
The CSU researchers collected and characterized emissions from three activities during new well development: drilling, hydraulic fracturing (“fracking”) and flowback – all processes typical of unconventional natural gas extraction. They quantified air emission rates and dispersion of air toxics, ozone precursors and greenhouse gases during each of these processes.
“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. “The focus was on volatile organic compounds (VOCs) that are of concern as air toxics and as precursors to ozone formation, and on methane, a potent greenhouse gas. We wanted to look at drilling, fracking and flowback, because emissions from these activities have received little prior study, especially for VOCs. 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.”
Notably, the team observed higher rates of emission of many volatile organic compounds and methane during flowback operations than during drilling or hydraulic fracturing. Flowback is last in the chain of well completion events, and refers to groundwater and fracking fluids flowing up from the ground after injection of water and chemicals into the well, the process known as hydraulic fracturing.
Methane, a potent greenhouse gas that has been targeted for emission reductions by the state of Colorado and the federal government, was the most abundant compound in measured emissions, with median emissions of 2.0, 2.8, and 40 grams per second (g/s) for drilling, hydraulic fracturing, and flowback activities, respectively. Other emitted VOCs of interest and their overall median emission rates included ethane (median emission rate of 0.31 g/s), propane (0.15 g/s) and other short-chain hydrocarbons that are important constituents of natural gas. They also looked at air toxics such as benzene (0.04 g/s) and toluene (0.27 g/s). Wide ranges of emissions were observed both across activity types and within a given activity.
Collett’s team was charged with quantifying emissions, but not related health risks, which were not within the scope of the project. The Colorado Department of Public Health and Environment (CDPHE) plans to use the data to conduct a human health risk assessment.
“This evaluation will improve our understanding of the potential for health risks directly attributable to air emissions from oil and gas,” said Mike Van Dyke, CDPHE branch chief of Environmental Epidemiology, Occupational Health and Toxicology.
Methods of collection
The CSU field team, led by research scientist Arsineh Hecobian, and assisted by CSU graduate students, postdoctoral researchers and scientific staff, conducted a total of 21 separate experiments from 2013-15 at various natural gas operations sites in Garfield County. Access to drilling and other operation sites, thanks to industry cooperation, was critical to gathering accurate information and was key to the study’s success, Collett said. Emission measurements were conducted at well drilling and completion sites operated by Encana Corporation, WPX Energy, and Ursa Resources Group.
The team was somewhat limited by a slowdown in new well drilling over the course of the study, but they were able to complete 21 of 24 planned experiments.
They used what’s called a tracer ratio method to identify and calculate rates of emissions of compounds of interest including methane, ethane, propane, benzene and toluene. Most experiments included measurement of emissions of a suite of 48 VOCs, plus methane.
Using acetylene as the tracer gas, the researchers designed experiments with a mobile plume tracker for real-time measurements of methane, and canisters that collected air samples for three-minute periods. They released the tracer, then located it downwind of the well pad in order to capture snapshots of typical emissions. Several sets of canisters were set up at each experiment station and later analyzed in a CSU laboratory using gas chromatography. The researchers also performed real-time sampling of methane emissions at each site, using a cavity ring-down analyzer. Continuous measurements of meteorological conditions were made during each experiment to support efforts to model dispersion of emitted pollutants downwind of the well pads.
Data collected in the study will be available online at the CSU data portal by July 1.
Collett and his team are conducting a similar study of air pollutant emissions from oil and gas activity along the northern Front Range, commissioned by the state of Colorado. That study focuses on methane and VOC emissions from hydraulic fracturing, flowback, and production of oil and gas.
Bob Arrington’s comment on the study:
“I was an original ‘stakeholder’ on this project when it was put together by Garfield Health and Paul Reaser. It was turned over to the ‘experts’ technical team headed by Collett. In a last meeting at the Rifle Airport, Collett briefed about the sampling techniques to be used. They would base the sample emissions to the proportional amount of acetylene sampled vs. the known amount released on site. Collett said the EPA had and used a ‘unique’ gas, but they would use the easier obtained acetylene. I objected that the acetylene was was too common and present from many sources. Collett said they could measure upwind ‘background.’ I responded the companies could release their own amounts on site, they could even throw carbide pellets out in wet areas. This would skew measurement proportions of emissions to the light side of quantities. I brought this up again in a subsequent Parachute meeting. Collett refused using any ‘unique’ gas as the measuring comparison gas. Needless to say companies involved were always present at these conversations.
“To me, since the very heart of the program was not under tamper-proof control, accurate data measurements could be compromised at will. With all interests wanting a good outcome and was it to be ‘data’ only, what could possibly go wrong? But I did notice Collett made the remark, that quantities did not reach health threat levels — hmm … ‘Data only’ — no evaluation. Right. And companies jumped in to finance the completion on a project that they could determine where and when, and was over cost and time frame. Yep, it sure looks like everyone got their money’s worth.”
Daily Sentinel: Energy study verifies hunch
Well flowback operations accounted for the greatest air pollution emissions from oil and gas development in a landmark Garfield County study, according to results released today.
The research by a Colorado State University team measured emissions from drilling, hydraulic fracturing, flowback and other aspects of developing a well and found that measurements of methane and volatile organic compounds were highest during the flowback stage.
The study also found no indications of emission levels high enough to cause immediate public concern. However, the Colorado Department of Public Health and Environment plans to use the findings, and similar research CSU plans to release this summer based on drilling on the Front Range, in working on a health-risk assessment associated with oil and gas operations.
The findings associated with flowback, which involves bringing groundwater and fracking water back up a well after fracking operations, weren’t a surprise to researchers.
“Going into the study, our expectation was that probably flowback would have the highest emissions,” Jeffrey Collett, professor and head of CSU’s Department of Atmospheric Science, told Garfield County commissioners during a presentation this morning …
… Leslie Robinson, with the Grand Valley Citizens Alliance, wasn’t surprised about what the study found relating to flowback operations, citing impacts residents have reported in drilling around Battlement Mesa.
“It seems to me that the odor complaints in Battlement Mesa, a lot of them have been during flowback situations and so that is of great concern if there’s going to be drilling in a residential area with fracking,” Robinson said.
Ursa Resources is awaiting action by state regulators on a proposal to drill more than 50 wells from two pads in that residential community.
Robinson said she hopes regulators take the flowback findings into consideration when there’s residential drilling and fracking.
“It just doesn’t belong in residential areas because of chemical releases,” she said.
CDPHE’s plan to do a health-risk assessment is in keeping with one of the recommendations of a state task force that looked to address issues surrounding oil and gas development near residential areas.
“This evaluation will improve our understanding of the potential for health risks directly attributable to air emissions from oil and gas,” Mike Van Dyke, a CDPHE official, said in a news release from CSU on Tuesday …
… Robinson said the study was important to do given the issue of drilling near people’s homes, and she commended CDPHE for planning to follow it up with health studies. She said researchers, politicians and others don’t seem to trust what residents tell them about odors from oil and gas operations.
“They don’t trust the citizen’s nose so they’ve got to do scientific tests,” she said.
As for the industry funding of the Garfield study, Robinson said such arrangements can cause suspicion that the results will favor industry.
“I guess that’s why more health studies need to be made by independent researchers that do not rely on industry funds to conduct their tests,” she said.
Post Independent: CSU study: Emissions low during fracking
[revised from the previous version titled “CSU study: Emissions greatest after fracking is done” published on 6/14/16]
When it comes to new natural gas development, emissions are noticeably greater during the flowback process than during the actual drilling or fracking processes.
That was one of the key findings in a much-anticipated analysis of emissions from natural gas drilling and completion operations in Garfield County. The report was presented to county commissioners Tuesday morning …
… The Garfield County assessment is expected to compliment a similar study that will be wrapping up in the next month on the Front Range. That analysis is looking at the fracking, flowback and production phases, the third of which was not included in the Garfield County study.
He expects the Front Range findings to be released by the end of July.
The Colorado Department of Public Health and Environment plans to use data from the two studies to conduct a health risk assessment, which was one of nine recommendations from a governor’s oil and gas task force in early 2015.
The assessment will likely look at the potential health impacts, long-term and short-term, from exposure to certain chemicals during various phases of resource extraction.
Collett said he expects CDPHE to start that process in the near future.