Drilling in the Dark
As production of shale gas soars, the industry's effects on nature and wildlife remain largely unexplored, according to a study by a group of conservation biologists published in Frontiers in Ecology and the Environment on August 1.
The report emphasizes the need to determine the environmental impact of chemical contamination from spills, well-casing failure, and other accidents.
"We know very little about how shale gas production is affecting plants and wildlife," says author Sara Souther, a conservation fellow in the Department of Botany at the University of Wisconsin-Madison. "And in particular, there is a lack of accessible and reliable information on spills, wastewater disposal and the chemistry of fracturing fluids. Of the 24 U.S. states with active shale gas reservoirs, only five maintain public records of spills and accidents."
The 800 percent increase in U.S. shale gas production between 2007 and 2012 is largely due to the use of hydraulic fracturing. Also called fracking, the process uses high-pressure injection of water, laden with sand and a variety of chemicals, to open cracks in the gas reservoir so natural gas can flow to the well. A similar technique is used for extracting oil from "tight" geologic formations.
The chemical makeup of fracturing fluid and wastewater, which can include carcinogens and radioactive substances, is often unknown. The authors reviewed chemical disclosure statements for 150 wells in three top gas-producing states and found that, on average, two out of three wells were fractured with at least one undisclosed chemical.
Pressured by growing concern about pollution to groundwater and surface water, government and the industry have made some steps toward openness, Souther acknowledges, but she says more progress is needed.
"The Pennsylvania Department of Environmental Protection's website is one of the nation's best sources of publicly available information on spills of fracking fluid, wastewater, and other contaminants. Even so, gas companies failed to report over one third of spills in the last year," she says. "How many more unreported spills occurred, but were not detected during well inspections? We need accurate data on the release of fracturing chemicals into the environment before we can understand impacts to plants and animals."
One of the greatest threats to animal and plant life identified in the study is the cumulative impact of rapid, widespread shale development, with each individual well contributing collectively to air, water, noise and light pollution.
Continue reading at University of Wisconsin-Madison News.
Drilling image via Shutterstock.