By Brandon Evans | Published Thursday, November 5, 2009
In the past decade, gas production has exploded throughout the Barnett Shale. What effect has the booming industry had on the air quality of the area? That is the question the Texas Commission on Environmental Quality (TCEQ) is currently trying to answer.
"TCEQ is in the process of studying emissions from gas production and their impacts in the Barnett Shale area," said TCEQ spokesman Terry Clawson.
Thirty staff members have tested air quality at more than 60 locations in Wise, Denton, Parker, and Tarrant counties.
"The study will be ongoing, but we expect to have a report by the end of the calendar year or early next year," said Tony Walker, director of TCEQ's DFW office.
Air quality data was gathered in August and October. Staff tested for levels of nitrogen oxides and volatile organic compounds.
Barnett Shale development has placed the gas industry into many people's backyards.
"We've had oil and gas development in Texas for a long time, but it was primarily in rural areas," Walker said. "Now it is in urban and in more populated areas.
"We're studying every aspect of gas production. We will look at the drilling and fracing process, condensate tanks, compressor stations, gas lines, valves and all other possible sources of emissions."
TCEQ testing occurs in the wake of other recent studies that found a proliferation of pollutants. Most notably is a study conducted by DISH, a small town in western Denton County, near the Wise County line.
The city commissioned an air quality study by the engineering firm Wolf Creek Environmental. It was conducted in August.
"The study was performed after numerous complaints from citizens of foul smells being omitted around natural gas compressor sites located in and around the town of DISH," said DISH mayor Calvin Tillman.
Clawson said the results of the DISH study have prompted TCEQ teams to return to the Barnett Shale area later this month in a third phase of the study to monitor for sulfide related compounds, such as carbon disulfide, and other toxic chemicals that were discovered in the DISH study.
"Many chemicals identified in laboratory results at several locations tested were found to exceed TCEQ's ESL's (effects screening levels)," read the report.
All of these chemicals have the capacity to adversely affect human health after exposure. For example, the chemical benzene exceeded TCEQ limits in both short-term and long-term ESLs. Chronic exposure to benzene has lead to bone marrow damage, anemia, reduction in the number of white blood cells and blood platelets, and exposure can eventually lead to acute myelogenous leukemia.
"Many of these compounds verified by laboratory analysis were metabolites of known human carcinogens and exceeded both short-term and long-term ESLs," the report concluded.
Tillman said the findings frightened many residents in DISH. It prompted some to get tested for toxins. Several tested positive.
Another study released early 2009 by Al Armendariz, an environmental and engineering professor at Southern Methodist University, found high levels of air pollutants related to oil and gas production in the Barnett Shale.
He found that compressor engine exhausts and tanks used in gas production in the Barnett Shale release up to 212 tons per day of smog-forming compounds. By comparison, every airport in the Metroplex combined releases 16 tons per day.
Walker said if the TCEQ study finds gas producers out of compliance with agency regulations they would employ enforcement measures.
Armendariz found that with the use of newer technology energy companies could dramatically cut down on compressor engine emissions and fugitive emissions.
"It is fundamentally important to reduce emissions," said Chip Minty, a spokesperson for Devon Energy. "No matter what industry you are in it is important to cut down on emissions."
He said Devon performs what they call a "green completion." They fit wells, pipelines and valves with apparatus that better controls pressure and limits the amount of certain emissions. Minty said they have done a green completion on 95 percent of their wells.
TCEQ has planned a fourth phase of its study to examine specific characteristics of the emissions and the off-site impacts from the identified sources. Clawson said it is tentatively planned for spring 2010.
