Harrisburg, PA – With the results of a new study and development of an interactive mapping tool, the Pennsylvania Department of Environmental Protection (DEP) has taken a major step toward identifying environmental impacts and addressing potential public safety concerns related to abandoned wells drilled over the past 150 years of oil and gas development in the state.
“Pennsylvania’s history of natural gas extraction predates permitting regulations enacted in 1955, and that legacy has hampered the proper decommissioning of wells. Even now, these historical wells may go unnoticed,” said DEP Acting Secretary Patrick McDonnell. “Residents may live near a well without realizing it, assuming the well site is part of the landscape.”
The well may no longer be active, but stray gas can migrate into the atmosphere or water supplies, creating a safety or environmental hazard.
Due to Pennsylvania’s lack of permitting regulations prior to 1955, DEP’s maps of these historical wells are inconclusive, a weakness that was validated during a recently published field study of 207 randomly selected historical wells in western Pennsylvania, where most oil and gas drilling has taken place. The study assessed well integrity, methane gas emissions, and other potential problems.
Seventy-one wells couldn’t be located using information in DEP’s database. Of the 136 wells located, only eight were emitting methane to the atmosphere at various rates, including one that showed higher-than-anticipated volume. This well and four others have operators associated with them, and DEP is taking proactive steps to update records and evaluate compliance options.
McDonnell emphasized how important it is for the public to be aware of historical wells. “Public collaboration in identifying wells is very helpful to our efforts to update data, make the information publicly accessible, and most important, mitigate risks.” In a new video, DEP staff explain the risks and the department’s work to tackle them.
DEP’s new interactive map site integrating historical maps with aerial imagery is designed to help the public better understand the historical areas of oil and gas development in Allegheny County, learn about the environmental impacts of historical oil and gas wells, and locate wells currently known to DEP.
The Allegheny County map shows known wells and potential historical wells that aren’t currently in DEP’s database. Users can search by location for potential wells and get information on known ones. DEP plans to explore other areas of the state to expand the interactive map.
Since oil and gas development began in Pennsylvania in 1859, hundreds of thousands of wells have been drilled. Because permitting standards weren’t enacted until 1955, many abandoned historical wells have not yet been identified. In addition, a significant number of historical wells haven’t been plugged to 1984 Oil and Gas Act standards. Potential results include impacts to water supplies, a build-up of gas inside a home or other structure, and an increase in greenhouse gas emissions.
These legacy wells vary in appearance, depending on the vintage and type of well, but typical signs include steel casings and associated valves, pump jacks, small-diameter gathering pipelines, tanks and isolated areas of subsidence.
If no responsible party can be identified for a well, DEP assumes responsibility for plugging. However, available funding levels fall far short of needs. Conservative estimates indicate that as many as 200,000 wells may need to be plugged, at a cost that could approach more than $8 billion. DEP is actively seeking additional funding to support further work on this front.
Property owners who discover a well on their property should contact DEP (888-723-3721) or visit the abandoned and orphaned well website to ensure that the well has been properly identified, and any potential environmental issues are addressed.