The Department of Environmental Protection Friday announced a $2,472,770 contract award for an abandoned mine reclamation project in Decatur Township, Clearfield County, that will stabilize the ground under 60 homes threatened by historic mine subsidence.
“This critically important project will eliminate the threat of mine subsidence for 60 homes in the township at no cost to the property owners,” DEP Secretary Chris Abruzzo said. “It’s an outstanding example of how the department is directly assisting citizens impacted by legacy mining problems.”
The project will stabilize the homes by filling the void space in the underground mine and upper rock strata beneath each structure with grout. A total of 30 acres of mine subsidence prone area will be stabilized in this manner.
DEP conducted an exploratory drilling project in summer 2005 to determine the subsidence potential and area of mining. The results determined that the surrounding undermined areas posed a high subsidence potential due to the depth of overburden at drill hole locations.
Since the drilling project, at least three reported subsidence events have occurred within this proposed project area related to past mining operations by the Mapleton Mine and other unknown mines that ceased operations prior to the 1930s.
The contractor will inject 15,000 to 22,000 cubic yards of grout mix through an estimated 315 drill holes into the mine voids to stabilize the overburden beneath the homes. The overburden ranges from seven to 50 feet thick, with typical overburden being 25 feet thick. There will be about 10,000 linear feet of drilling required for the project.
The project contract was awarded to Howard Concrete Pumping Co. Inc. of Cuddy,
Allegheny County. Work is expected to start before the end of March and be completed in 10 months or early 2015.
The contract was awarded on a competitive basis and is federally funded by Office of Surface Mining grants. Grant funds are supported by a fee on the modern coal industry and are distributed to states as annual grants to reclaim mine sites that were abandoned prior to passage of the federal Surface Mining Control and Reclamation Act of 1977.
For more information, call 717-783-2267.