An application to expand the depth of Oak Hall Quarry, located in College Township, has some residents worried about the potential risks and will be the topic of discussion at a public hearing Friday night.
Hanson Aggregates Pennsylvania LLC has made an application to the Pennsylvania Department of Environmental Protection, Moshannon District Mining Office, to revise its surface mining permit and NPDES permit, according to a public legal notice. The permit revision includes a request to increase the depth of mining to 200 feet below the existing pit floor.
Hanson is also proposing a boundary correction to take the permit area from 331 acres to 315.2 acres, according to the notice.
Sue Smith, a resident of Lemont for almost 50 years, has concerns about the risks to Spring Creek, which runs near the quarry.
She printed out 50 petitions, each with 10 spots for signatures, and passed them out to people to send to the DEP to request a public hearing on the application.
She said she handed them out to not only College Township residents, but also others who live in Centre County because “those quarrying operations affect everyone.”
“The main thing that bothers me ... is the potential for hitting a sinkhole and losing Spring Creek or having lots of massive pumping going on — or whatever they would have to do — but that’s a very real concern to me,” Smith said.
The quarry appears to be at or near the top of the water table, so they aren’t inducing stream flow into the mine — at least not much, said David Yoxtheimer, a hydrogeologist at Penn State.
If they go down 200 feet, that will increase the dewatering operation, depress the water table and likely induce some stream flow into the mine. How much is hard to say, but it has the potential to be significant, he said.
“You want Spring Creek to flow naturally and not have that kind of dewatering impact on it,” Yoxtheimer said.
Precipitation accounts for the majority of the water pumped from the quarry into Spring Creek, Jeff Sieg, director of corporate communications for Lehigh Hanson, said in an email.
“The hydrogeologic testing and analysis indicates the current maximum discharge volume is sufficient for the facility even at deeper levels,” Sieg said.
As one of the many people who enjoys Spring Creek, Jim Marden, of Lemont, said he’s concerned about the possibility of a sinkhole forming and the creek flowing into it or the the creek flow becoming reliant on the quarry pump.
There’s always potential in a karst environment — like the quarry where they’re mining limestone — for dissolution where it’s dissolved away by slightly acidic rainwater, Yoxtheimer said. If that dissolution occurs over the course of geologic time, fractures can open up wider, and ultimately there’s the potential for sinkholes to form.
Marden, a professor of biology at Penn State, said he would like to know how Hanson has analyzed the risks and he wants to see their data.
“I want to hear their justifications why our little community should take that risk for their profit, their corporate profit,” Marden said.
Hanson has competed hydrogeologic testing and a structural geology analysis over the past three years in support of this permit application, Sieg said.
“Significant impacts to Spring Creek are not indicated or anticipated,” he said. “In addition, impacts associated with sinkholes are not anticipated as a result of quarry operations.”
The public hearing will consist of two portions — a question-and-answer session and time for public comments, said John Repetz, DEP spokesman.
Public comments will be limited to five minutes each, he said.
If you go
What: Oak Hall Quarry expansion public hearing
When: 6:30 p.m. Friday
Where: Mount Nittany Middle School, 656 Brandywine Drive, State College