The Dominion Post, a newspaper out of Morgantown, West Virginia, reported this morning that Equitrans, a subsidiary of Pittsburgh, Pennsylvania based EQT (formerly Equitable Gas Company), spilled approximately 500 gallons of drilling mud into Garrison Fork Creek in Greene County, Pennsylvania between noon and 1 p.m. Wednesday. While Garrison Fork does not cross into West Virginia, it is a headwater tributary of Dunkard Creek, which meanders back and forth between the West Virginia and Pennsylvania borders. The spill had nothing to do with the actual drilling of a natural gas well. Rather, the spill occurred as the result of an "inadvertent return" of drilling mud while drilling for a pipeline underneath the creek. While it is reportedly unknown what caused the inadvertent return, they sometimes occur when the drilling mud bubbles up through a natural fissure in the ground.
The spill apparently occurred in the course of horizontal directional drilling for an interstate pipeline that will run between Pennsylvania and West Virginia. According to the Dominion Post article, this particular kind of drilling is expensive, but is more environmentally safe than other forms of drilling. The process apparently causes no environmental issues 99% of the time. The purpose of the drilling mud in the process is to keep the drilling hole lubricated and to contain the drill cuttings. The mud contains small amounts of bentonite clay, which is reportedly also used as an alternative medicine to treat gas and constipation, as well as a colon cleanser. It appears that the spill was minor and does not pose a significant risk.
According to the Dominion Post, Equitrans immediately stopped drilling, notified the Pennsylvania Department of Environmental Protection ("DEP"), and began cleaning up and containing the spill. This incident appears to be an example of an oil and gas company using a relatively environmentally safe, even though more expensive, process and taking immediate action to clean up and contain a rare accidental spill. Accidents will inevitably happen in drilling for and transporting natural gas, just as they do in any industry. But the public should be comforted in knowing that, at least in this case, the company was using an environmentally safer process at the expense of additional profits, and took prompt action to remediate the effects of an unexpected accident.