Mine subsidence found beneath Hyde Park houses
In the spring of 2011, Shelva Corna answered the buzzer of her clothes dryer, but found a problem in her basement that would cost upward of $30,000 to fix.
As told by her son, John Corna, his mother noticed it was cold in the basement.
The cause was mine subsidence.
The incident has led to a $1.2 million project to fill mine voids under a large area of Hyde Park with a mixture of cement, fly ash, sand and water.
Sixty-eight properties lie atop the area.
The boundaries are First Street to the north; School Avenue to the south; Bluff Street to the east; and Hemlock Street to the west.
The voids are between 40 and 100 feet below the surface, said Kevin Sunday, a spokesman with the state Department of Environmental Protection.
The 5-foot-high voids are a series of tunnels from commercial and Depression-era homeowner mining, when residents took to the once-actively mined tunnels to look for coal, Sunday said.
The area was last mined in the 1940s.
It will take about 22,000 cubic yards of concrete to fill the voids, Sunday said.
The project is being paid for with money from the federal Office of Surface Mining, Sunday said. The DEP awarded the contract to Howard Concrete.
Property owners have signed easements to allow the contractor to work.
Sunday said Howard Concrete has begun boring, but has not started pouring cement.
Barring an unforeseen setback, project manager Joe Bonetti said he believes the work can be done in about eight weeks.
Howard Concrete's state contract says the company has eight months to do the work.
“This project will stabilize the area and prevent damage to homes and the community,” Sunday said.
The work is expected to be finished by September. It will not have any visible impact to the surface once done, according to Sunday.
The home of Shelva Corna and her husband, Lou, on Bluff Street is the only one that has recently been damaged by mine subsidence, said Borough Secretary Tifanie Gagen.
“They're doing this as a precaution so it doesn't happen again,” she said.
John Corna said his parents didn't have mine subsidence insurance and had to bear the full cost of repairs. His father had lived there his whole life and had never had a problem.
Mine subsidence is typically not covered by standard homeowner's insurance policies.
John Corna lives nearby on Murphy Street and, after the problem at his parents' home, he bought the insurance for his house.
“I found out just about everyone on our street already had mine subsidence insurance. Once I learned about it I went and got it immediately, as did a lot of people in town who didn't have it,” he said. “It's very affordable.”
John Corna said his parents were eating lunch while the dryer was running and didn't notice the house move. It left an 8-inch gap in the basement wall, he said.
“The whole left corner of the house sunk. It literally separated,” John Corna said.
They had to pay to rebuild the foundation, repoint all the brick, put in a new sidewalk and landscaping at a cost of $25,000 to $30,000.
The DEP did an emergency project to fill the voids under the Cornas' home. It took about 450 yards of concrete to fill the shafts and shore up the home.
Test holes in town found voids “everywhere,” John Corna said.
“It's turned out to be a positive thing for Hyde Park, getting this taken care of before anything further happens,” he said.
Despite the project, Sunday said the DEP does not recommend homeowners cancel their subsidence insurance policies.
The DEP recently announced reduced rates for mine subsidence insurance policies. The insurance covers losses resulting from abandoned coal or clay mining and from damage caused by the sudden discharge of water from a mine void.
The premium for a residence was reduced by 15 percent; premiums for nonresidences were reduced by more than 50 percent, and now match residential rates. The maximum coverage for a single structure is $500,000.
Brian C. Rittmeyer is a staff writer for Trib Total Media. He can be reached at 724-226-4701 or firstname.lastname@example.org.