I recently read a letter to the editor of a Pennsylvania newspaper which provided a blaring alarm regarding a high risk situation in Pennsylvania. A lot of space on this blog is devoted to reporting on environmental damage after it occurs -- drinking water contamination, toxic air pollution, spills and leaks, etc. When there is an opportunity to prevent harm, we'd hope that state regulators would jump on the chance, but sadly that does not seem to be the case in this situation.
The issue in this case is the risk to clean drinking water posed by old, abandoned oil or gas wells that were never properly sealed. The risks are well documented, as reported in a Scientific American article: "Government reports have warned for decades that abandoned wells can provide pathways for oil, gas or brine-laden water to contaminate groundwater supplies or to travel up to the surface."
In its "Draft Plan to Study the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources," EPA discusses the risks of pre-existing underground pathways for contaminant transport. It is very difficult for a hydraulic fracturing company to predict and control the location and length of the hydraulic fractures they are creating underground. If one of those man-made fractures ends up connecting to a pre-existing underground pathway that leads to a drinking water aquifer, the aquifer could become contaminated by fracturing chemicals, methane, and/or naturally occurring substances like arsenic or radioactive material. Therefore, the safest thing to do, before fracturing an oil or gas well, is to ensure there is a detailed site characterization that examines the potential for migration of contaminants underground.
In our June, 2011 comments to the EPA on the essential components of any guidelines for hydraulic fracturing using diesel, NRDC and our partners Earthjustice and Sierra Club set out the fundamental practices that should be followed when fracking a well. Regarding abandoned wells, we stated: within the area of review, operators must identify all wells that penetrate the producing and confining zones and provide a description of each well’s type, construction, date drilled, location, depth, record of plugging and/or completion, and any additional information the regulator may require. If any of the wells identified are improperly constructed, completed, plugged, or abandoned, corrective action must be taken to ensure that they will not become conduits for injected or formation fluids to underground sources of drinking water.
Back to the letter to the editor. It came from a resident of Washington County, Pennsylvania--a county with reports of drinking water contamination that residents believe is linked to nearby natural gas operations. The letter states: "There are eight to 10 unplugged abandoned wells located within a mile of my house. A few are still pumping, some well sites do not have any signs remaining and some have been damaged by weather or pulled down by landowners, cut up and sold for scrap. After doing some research, I found the old gas and oil wells were drilled approximately 3,000 feet." The writer goes on to report that preparation for drilling new wells has begun and that he contacted the Pennsylvania Department of Environmental Protection to report that the new drilling is planned for an area with many old abandoned wells, and was told there was nothing to worry about because "DEP does not have any documentation of contaminated water wells or blowouts from any old abandoned wells."
Yet the Scientific American article describes a 2006 incident in the same county where the state "determined that the fracking of a new well caused methane to leak through an abandoned well and into the ground and the aquifer."
The author of the letter to the editor was right on target. States should require, and companies should carry out, a complete survey of risks--both on the surface and underground--before drilling of new oil and gas wells in an area. Until more protections are put in place at the state and federal level--and identifying and properly sealing old abandoned wells is only one of them--we sadly have to anticipate that there will be more cases of drinking water contamination in the future.