PA Environment Digest

After an extensive analysis, the Department of Environmental Protection has determined that longwall mining at Consol Pennsylvania Coal Company’s Bailey Mine in Richhill Township, Greene County, resulted in ground movements that damaged the Ryerson Station Dam.

“These findings were based on concrete information from Consol, the Department of Conservation and Natural Resources, DEP files and months of site observations,” said DEP’s Director of Mining Operations Michael Terretti. “The department stands behind its findings and will now move into the second phase of its investigation, which is to address the appropriate remedy.”

DEP initiated the investigation following an Allegheny County Court of Common Pleas’ decision that directed DCNR to file a claim with DEP under the state’s Bituminous Mine Subsidence and Land Conservation Act for damage sustained by the dam.

Among its findings, the interim report concludes that beyond longwall mining activity, there was no other activity in the spring and summer of 2005 that could account for the movement of and damage to the dam. The report also excluded dam instability and hillside instability as potential causes.

Underground coal mines can cause ground movement and damage at greater distances than customary mine subsidence theory typically predicts, as was the case with the Ryerson Station Dam incident where DEP found a number of examples such as pipeline buckling and road and stream heaving.

DEP also discovered several instances of ground movements in areas beyond the customary prediction area in its files and in examples Consol identified throughout Appalachian coal fields, including three in the vicinity of Bailey Mine and two in West Virginia.

Ryerson Station Dam forms a 62-acre lake that was drawn down immediately in July 2005 after joint inspections by DCNR and DEP uncovered serious structural concerns, including increased seepage and a greater number of cracks in the concrete structure.

In August 2005, the departments removed a portion of the dam spillway to prevent the reservoir from refilling after heavy rains and runoff, which could have further stressed the damaged structure.

The 1,164-acre Ryerson Station State Park opened in 1967 in the southwestern corner of Pennsylvania near the West Virginia border and provides recreational opportunities at the popular park, which also features picnicking, hiking, camping and a seasonal swimming pool. The concrete dam across the North Fork of the Dunkard Fork of Wheeling Creek was built in 1960.

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