HARRISBURG, Pa. — The Pennsylvania Department of Environmental Protection has taken a major step toward identifying abandoned wells drilled over the past 150 years of oil and gas development in the state, with the results of a new study and development of an interactive mapping tool.
“Pennsylvania’s history of natural gas extraction predates permitting regulations enacted in 1955,” said DEP Acting Secretary Patrick McDonnell.
“Even now, these historical wells may go unnoticed. 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.
Where are they?
Due to Pennsylvania’s lack of permitting regulations prior to 1955, DEP’s maps of these historical wells are incomplete, 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.
New online map
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, 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.