Many waterways in Pennsylvania are devastated by acid mine drainage, a man-made legacy from coal mining that leaves some waterways devoid of aquatic and insect life.

But efforts have been ongoing since the early 2000s by the state Department of Environmental Protection to greatly reduce the waterway poisoning — to the point that once-dead streams are being stocked with trout while supporting spawning of native species like smallmouth bass.

All of the work is culminating in some of the most significant ecological reclamation success stories in industrial Pennsylvania’s history.

Waterways that have been impacted by AMD include Bennett Branch of Sinnemahoning Creek, Dents Run and other tributaries of the West Branch of the Susquehanna River system flowing through PA Wilds lands in Clearfield and Elk counties — and through or near multiple state forests. Bennett Branch and its tributaries’ fish and aquatic insect populations were extirpated due to AMD, and since 1996 they’ve been on an impaired waters list maintained by the DEP.

But treatment to mitigate AMD since the early 2000s have in large part restored Bennett Branch, which was first stocked with trout by the Pennsylvania Fish and Boat Commission within the past decade, and where anglers also find native smallmouth.

“Taking a stream that was once dead, and now fish are being stocked and reproducing naturally, it really causes the entire ecosystem to take off,” said Tom Decker, a DEP communications manager. “It is an increased opportunity for recreation and sport fishing. In addition, Bennett Branch is large enough for kayaking during certain periods of the year so, aesthetically, the improvement of the Bennett Branch will undoubtedly increase recreational boating in the area.”

Wildlife viewing and sporting experiences in destinations like the elk lands in the Benezette area, state forests like Moshannon, Elk and Sproul and the Quehanna Wild Area will greatly benefit from the AMD mitigation as available clean water sources increase.

The goal by the DEP is to have them AMD free in the coming years, making them recreationally vital to the public as well as clean water sources for thriving ecosystems.

COAL MINING LEGACY

Coal has been mined in Pennsylvania since the 1700s. Since the late 1800s, coal mining in north central Pennsylvania was a part of the state’s overall economic identity. Mines were stripped and left abandoned throughout the ensuing decades, leaving behind bare materials that were picked up by groundwater and runoff from rain and snowmelt. Eventually, the materials found their way to brooks, creeks and rivers.

These bare materials are metals like iron, aluminum, manganese and others. Iron in particular gives the signature orange-brown look that can be found in so many Pennsylvania streams. These metals are carried by acidic water to streams and raise the overall acidity — hence the name acid mine drainage.

According to the DEP, the “safe zone” for a freshwater stream is a pH between a 6 and a 9. The pH scale is the scientific scale of acidity from 0-14 — 0 being most acidic and 14 being most basic — with both ends being bad for the health of any organism.

A pH of 7 is the ideal level for freshwater, neither basic or acidic, so the 6-9 range is the standard. Water affected by AMD can have a pH as low as 2, and because the scale is logarithmic, the water has a hundred thousand times more acidity than normal freshwater.

RECLAMATION EFFORTS

Treatment processes by the DEP on the Bennett Branch system started in 2004. It was found by DEP that dozens of sources of AMD flow into small tributaries, into Bennett Branch, then into the West Branch of the Susquehanna.

In 2006, the Hollywood AMD facility in Clearfield County began operation and today remains the largest in the state. Additional facilities, like one on Dents Run in Elk County, are part of the treatment system for the overall Bennett Branch watershed.

What the treatment facilities do is mitigate the acidity of the water. Water is collected and by adding lime (a product of heated limestone, not the citrus fruit), the pH of the AMD-affected water is raised. The lime is very basic, the opposite end of the pH scale, so it reduces the acidity of the water. When that happens, metals in the water drop out because they aren’t being dissolved by the high acidity. Once the metals are separated out, they can be disposed of.

“The (Hollywood) facility is estimated to capture and treat approximately 2.7 million gallons per day of mine drainage from 21 AMD discharges,” Decker said.

Separating millions of gallons of water from the harmful metals, the Hollywood system pumps out treated freshwater back into Bennett Branch.

It isn’t the only such operation in north central Pennsylvania — other facilities are in place in Tioga, Clearfield, Elk and Clinton counties on waterways employing the same process.

Decker said there are also new operations planned for McKean County as well. South of Port Allegany, an operation in Scaffold Lick Run is on its way to treat AMD. A facility on Gum Boot Run, a tributary of the East Branch of the Clarion River, has been earmarked for funds to take on higher capacities.

Decker said these new operations are supported by funding made available by the Infrastructure Investment and Jobs Act of 2021.

THE IMPROVEMENTS

Upticks in fish and aquatic insect populations were noted in a few years since the treatment of AMD began in 2004. Stream surveys showed the general improvement of the populations, but the most striking comparison is between two surveys done in a fishery near the Hollywood facility. In 2006, there was one species of fish found — in 2021, there were 20, including game fish like smallmouth.

Such a steady, increasing improvement in Pennsylvania waters is good news for water-related recreation around the state. With more aquatic insects breeding naturally without the hampering of acidic water, there will be more fish and more sporting opportunities.

In central Pennsylvania, the ultimate goal is reclamation of the West Branch of the Susquehanna, which has great potential as an important smallmouth fishery and for water recreation.

“DEP is making extreme progress, especially in the upper watershed,” Decker said. “Efforts on the Bennett Branch and other current and future projects will greatly increase the rehabilitation of the West Branch of the Susquehanna.”

(John Eckstrom is a 2023 graduate of Kane High School and is starting the fall semester at the University of Pittsburgh at Bradford.)