Treatment systems that prevent mine pollution from entering streams in northern Butler County are about 25 years old, and a grant of more than $250,000 from the Pennsylvania Department of Environmental Protection is helping to pay for a redesign.

Stream Restoration Incorporated received $251,797 from the Abandoned Mine Lands and Acid Mine Drainage Grant Program, which will pay for the first step in replacing two passive treatment systems that treat water near Boyers.

Cliff Denholm, executive director of Stream Restoration Incorporated, said the nonprofit administers grants for the Slippery Rock Watershed Coalition, which helps manage the treatment systems. According to Denholm, the treatment systems are made up of human-made ponds which use sedimentation and filtration technologies and piping to neutralize harmful leakage from mines.

“It treats acid mine drainage; it's polluted water that comes from these old, abandoned mine sites, which no one is held responsible (for),” Denholm said. “We build these passive treatment systems whenever possible that are more environmentally friendly that neutralize and remove the metals before it enters the water.”

According to the DEP, millions of structures in Pennsylvania are located over old, abandoned underground coal and clay mines, which can leak drainage that pollutes water sources and other natural areas. Pennsylvania has the largest inventory of abandoned coal mines in the nation, according to the DEP, but the commonwealth has rehabilitated 91,000 acres of abandoned mine lands so far.

Denholm said the two treatment systems the watershed coalition plans to replace treat about 200 to 250 gallons per minute of mine drainage.

With the DEP’s grant, Stream Restoration Incorporated will hire a designer to create a plan to rehabilitate the old treatment systems, which will be followed by monitoring by the watershed coalition for likely at least one year, Denholm said.

Denholm said the nonprofit plans to apply for further DEP grants to help fund the watershed coalition’s projects, to fund the rehabilitation of the systems. Construction on the treatment systems is still a long way away.

“It's going to be a couple years before we get into construction,” he said. “We'll have to hire a consultant and construction company to do the physical work.”