Well water contaminants highest near natural gas drilling: study
water wells in these counties from the Texas Water Development Board groundwater database for 1989-99, prior to the proliferation of natural gas drilling.
In addition to standard water quality tests, the researchers used gas chromatography — mass spectrometry (GC-MS), headspace gas chromatography (HS-GC) and inductively coupled plasma-mass spectrometry (ICP-MS). Many of the tests were conducted in the Shimadzu Center for Advanced Analytical Chemistry on the UT Arlington campus.
“Natural gas drilling is one of the most talked about issues in North Texas and throughout the country. This study was an opportunity for us to use our knowledge of chemistry and statistical analysis to put people’s concerns to the test and find out whether they would be backed by scientific data,” said Schug, who is also the Shimadzu Distinguished Professor of Analytical Chemistry in the UT Arlington College of Science.
On average, researchers detected the highest levels of these contaminants within three kilometers of natural gas wells, including several samples that had arsenic and selenium above levels considered safe by the Environmental Protection Agency. For example, twenty-nine wells that were within the study’s active natural gas drilling area exceeded the EPA’s Maximum Contaminant Limit of ten micrograms per liter for arsenic, a potentially dangerous situation.
The areas lying outside of active drilling areas or outside the Barnett Shale did not show the same elevated levels for most of the metals.
Other leaders of the Texas Gas Wells team were Laura Hunt, who conducted her post-doctoral research in biology at UT Arlington, and Zacariah Hildenbrand, who earned his doctorate in biochemistry from the University of Texas at El Paso and performed post-doctoral research at UT Southwestern Medical Center. Hildenbrand is also the founder of Inform Environmental, LLC.
Fontenot and Hunt work for the EPA regional office in Dallas, but the study is unaffiliated with the EPA and both received permission to work on this project outside the agency.
Scientists note in the paper that they did not find uniformity among the contamination in the active natural gas drilling areas. In other words, not all gas well sites were associated with higher levels of the metals in well water.
Some of the most notable results were on the following heavy metals:
- Arsenic occurs naturally in the region’s water and was detected in 99 of the 100 samples. The concentrations of arsenic, however, were significantly higher in the active extraction areas compared to non-extraction areas and historical data. The
