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2012 Abandoned Mine Land Reclamation Award Winners

National Award Winner
Dents Run AML/AMD Ecosystem Restoration Project
Benezette Township, Elk County, Pennsylvania

OSMRE’s National Award for 2012 was presented to the Dents Run AML/AMD Ecosystem Restoration Project, Benezette Township, Elk County, Pennsylvania.

Aerial photo of the Dents Run watershed

This undated photo shows a small portion of the 25 square mile Dents Run watershed area.

The 25 square mile Dents Run watershed is best known for its role as a home to Pennsylvania’s elk herd and its world class trout stream. However, nine historic surface and underground coal mines dating back to the 1800s were leaching acid mine drainage so heavily into the watershed that passive treatment methods would not be effective, and active treatment would be very expensive.

To carry out such a large project, the state asked government agencies, mining companies, watershed groups and landowners to commit funding and manpower. Eventually, about 56 percent of the project cost was underwritten by non-government sources.

photo of a large pile of limestone on the Dents Run site

The state and its partners in the project, including the coal industry, environmentalists, local government and landowners, were able to keep costs down when a large deposit of limestone was discovered on the site.

Project managers also discovered that one of the targeted areas contained both marketable coal and a huge deposit of high quality limestone – more than a million and a half tons –perfect for treating acid mine drainage. In addition, the presence of the coal and the limestone helped hold down costs, and mining both helped establish a relationship with a mining company.

Before the project ended, the group graded 320 acres, and replanted it for the resident elk herd. They reclaimed ten highwalls, more than 30-thousand linear feet. They mined more than a half-million tons of limestone to provide alkalinity in the stream and in the reclaimed sites, moved more than 5000 cubic yards of coal waste, closed 23 old mine openings, installed five wet seals, and treated 14 AMD discharges.

Photo of Dents Run

Before reclamation began, the downstream portion of Dents Run was contaminated by acid mine drainage.

It took almost ten years, starting in October 2002, but in March, Pennsylvania declared the downstream portion of Dents Run as net alkaline for the first time in one hundred years. The incredibly large reclamation numbers tell one story.

Photo of elk on a hillside near Dents Run

Pennsylvania’s elk herd has more water and a better food supply. Wildlife benefited greatly from the elimination of several coal-mine related environmental problems.

But it’s the return of trout – and fishermen – and the growth of Pennsylvania’s famous Elk herd that tell the most vivid tale. In March 2012, the state declared Dents Run as “net alkaline” for the first time in 100 years, enabling fish and wildlife to return and flourish.

Link to Pennsylvania Department of Environmental Protection, Bureau of Abandoned Mine Reclamation Website at

Page Last Modified/Reviewed: 6/3/14

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