Constructed wetlands for acid mine drainage

A constructed wetland in Pennsylvania provides a place where plants and bacteria remove heavy metals and acidity from mine drainage.

Will the acid mine drainage that pollutes thousands of miles of streams in Pennsylvania and Western Maryland ever be erased? Will remaining coal waste piles, acidic streams, underground fires, dangerous high walls and barren soil ever be gone from the landscape?

The future of the cleanup effort as a whole, aimed at addressing the many lasting problems from 200 years of unregulated mining, remains to be seen. But in some places, through the efforts of state and local governments, nonprofit organizations, coal companies and citizen volunteers, success is at hand.

Take, for example, Bennett Branch, located in northwestern Pennsylvania and the Susquehanna River’s West Branch watershed. The stream runs through gorgeous mountain scenery. Many of its tributaries hold wild populations of brook trout, the state fish. It’s mostly surrounded by public lands in the heart of elk country. The only problem was that, until recently, the lower 33 miles of the stream were dead from uncontrolled, untreated acid mine drainage. Its tainted water ran red.

Bennett Branch, PA

Before it was cleaned up, Bennett Branch in the West Branch of the Susquehanna River watershed ran orange from acid mine drainage.

When Eric Cavazza, the former head of the state Bureau of Abandoned Mine Reclamation, took a 1993 tour of the area with local groups that wanted to bring back the stream, he shuddered. “I thought it was unattainable to try to clean that up. I thought their goals were too lofty.”

But the state, private groups and a coal company forged a partnership to tackle the job. Today, after remediation efforts that took place between 2003 and 2013 and cost more than $40 million, the stream is stocked with trout and runs clear.

It took 37 different projects to make it happen. Those include burning coal waste to generate electricity, re-mining some surface sites that were then restored for elk grazing by coal companies, installing lime dosers to counteract acidity in the water, creating passive water treatment systems and a $14 million treatment plant designed to deal with acid mine drainage.

Said one Elk County resident, “I only wanted to fish it before I died, and now I have.”

Farther away, in Western Maryland and West Virginia, acid mine drainage occurring since the early 1800s left the first 30 miles of the North Branch of the Potomac River and 350 miles of its tributaries essentially dead. By 1940, an estimated 86 tons of acid drainage from both active and abandoned mines were pouring into the river on a daily basis. In 1969, the pH in the river was measured at 2.4, about the acidity of lemon juice.

The first event leading to a turnaround was the building of the U.S. Army Corps of Engineers’ Jennings Randolph Lake Dam on the North Branch in 1981. The dam was designed so that a variety of water levels could be discharged downriver. Because pollution settles in layers, water of relatively good quality is released into the tailrace year-round, allowing the river to recover biologically.

Encouraged, the two states and federal Office of Surface Mining pinpointed the sources of acid drainage. In 1992, Maryland put in place two dosers to inject lime into water, neutralizing acidity. Four more were added by 1998.

After additional remediation projects, the river has bounced back so much that the section above the dam is now classified as a high-quality trout fishery. Reproducing trout and a recovering smallmouth bass fishery highlight the comeback.

Paddlers on North Branch of Potomac River

Cleanup of the North Branch of the Potomac River in Western Maryland and West Virginia succeeded in bringing back water tainted by acid mine drainage. Now, recreation from fishing and boating is pumping millions of dollars into local economies.

The remoteness and rugged beauty of the North Branch has made it a destination for trout anglers and whitewater rafters, with outfitters setting up shop in local towns. A recent study found that recreational use pumps about $3 million yearly into Garrett and Allegany counties in Maryland.

The recovery of the North Branch of the Potomac and the West Branch of the Susquehanna are two of the most dramatic turnabouts in regional coal cleanup efforts, said Greg Conrad, an attorney and consultant for abandoned mine land efforts and former head of the Interstate Mining Compact Commission.

“They used to be the poster children and now, they’ve been success stories,” he said.

Stream fixes don’t come easily

Officials in Pennsylvania and Maryland say considerable progress has been made toward addressing the safety, environmental and aesthetic problems from abandoned mine land since efforts began more than 40 years ago. Since 1977, about $1.6 billion in federal funds have has been spent to clean up abandoned mine land problems on more than 94,000 acres in the two states.

But much remains to be done. Pennsylvania officials say that only about 12% of its abandoned mine land has been cleaned to date. They estimate that, at the current funding rate, it would take $51 billion and 105 years to clean up all of the problems, including more than 800 coal waste piles, 250 miles of dangerous highwalls and, in the state’s portion of the Chesapeake Bay watershed alone, 2,000 miles of streams polluted by acid mine drainage.

Maryland estimates there are still 127 miles of tainted streams and other projects needed that would cost $59 million.

Approximately 25 kinds of heavy metals can be released in acid mine drainage, which seeps into streams from former mining sites and sometimes comes from “blow outs” in sealed tunnels.

Because water pollution from mining operations can continue for thousands of years, cleanup projects rarely eliminate the source. Instead, efforts focus on treating the acidity before it reaches waterways. Approaches and costs are varied.

One of the first and relatively less expensive approaches is the use of dosers — silos or containers that hold limestone rocks or powder very high in pH. Acidic water passes through the dosers, which neutralize the acidity to levels acceptable to fish and other aquatic life. But the dosers must be refilled manually.

Lime doser

Volunteers from the Doc Fritchey Chapter Trout Unlimited feed limestone rock into a doser on Rausch Creek in Lebanon County, PA. The treatment neutralizes acidity from abandoned coal mine drainage. Wild and stocked trout are now found in Stony Creek, a state-designated scenic stream.

At other locations, artificial wetlands are built as simple, passive treatment systems. When acidic water passes through the wetlands, it slows down, allowing oxygen and bacteria to concentrate heavy metals in plants. The bottoms of the wetlands are often lined with limestone or mushroom compost to further neutralize acidity. But the linings usually need to be replaced or replenished every 25 years.

One of the most effective but most expensive ways to treat acid mine drainage are mini treatment plants that operate around the clock, similar to sewage treatment plants. Drainage is collected in pools, then chemically treated to screen out heavy metals and reduce acidity. The water is then released into a stream. The systems require equipment and often daily supervision by licensed operators.

Acid mine drainage treatment plant

A $2.1 million treatment plant removes heavy metals and acidity from 20 discharge points of acid mine drainage in northwestern Pennsylvania.

In recent years, new initiatives have added economic incentives for addressing the legacy pollution.

One is removing acid mine drainage sludge and coal ash to salvage rare earth elements. These metals are vital to advanced electronics used in smart phones, robots and defense systems. The U.S. imports nearly all of its supply but, in recent years, studies have found high concentrations in the sludge of acid mine drainage treatment systems.

In Pittsburgh, a company is now making paint from pigments in the iron oxides derived from the sludge, and others are using the oxides for jewelry.

Another new initiative in Pennsylvania is placing solar arrays on exposed surface mines, and a partnership between the federal government and Appalachian states is planting trees on abandoned mine land for carbon capture. The Chesapeake Bay Foundation’s Keystone 10 Million Trees Partnership has made abandoned mine land in Pennsylvania a priority for plantings — about 29,000 trees so far.

Planting trees on abandoned strip mine

Volunteers with the Pennsylvania 10 Million Trees Partnership plant trees on an abandoned strip mine at the Flight 93 National Memorial to turn the land into a living memorial. Regrading land and planting trees on old strip mines is a new initiative between states and the federal government, partly driven by the need to reduce greenhouse gases. Many strip mines were recontoured as required by laws of the time but were not conducive to growing many varieties of plants.

Also, coal tunnels filled with clean water are being explored as a source of drinking water or to replenish the Susquehanna River during droughts.

Future funding in question

While energy continues to gather around restoration strategies, the momentum may soon be thwarted by funding problems.

The federal Abandoned Mine Land Reclamation Program, created in 1977, has funded the bulk of cleanup costs by charging coal companies a fee on each ton of extracted coal. But the fund expires later this year, and reauthorization by Congress is not certain. Most officials and coal industry analysts think that Congress will continue the initiative in some form.

“It would be awfully foolish for our congressional leaders to leave all that money on the table,” said John Dawes, head of the Foundation for Pennsylvania Watersheds. The federal cleanup money has leveraged millions of dollars from the private sector, he said.

Elk on coal strip mine

An old strip mine in Pennsylvania was regraded and planted with grasses to feed the state’s wild elk population.

On March 10, two Pennsylvania congressmen introduced a bill to reauthorize the landmark Surface Mining Control and Reclamation Act for another 15 years and to keep the cleanup fee on coal at the current rate. A second bill would accelerate federal funding to reclaim abandoned mine lands to help the local economies of distressed former mining communities.

If the program is not renewed, there would still be a balance of approximately $2.3 billion that would be distributed to states nationwide until money peters out, somewhere around 2032. If and when the spigot runs dry, it could be a challenge for states to continue funding the ongoing operations of acid mine drainage treatment systems already in place. There are 60 in western Maryland and more than 300 in Pennsylvania.

The Pennsylvania Department of Environmental Protection warns that loss of the fund could mean that 270 miles of restored streams could again become degraded.

And, Pennsylvania still faces an average of 77 legacy coal lands emergencies a year, with responses funded through the abandoned mine land program. They include holes opening under people’s homes, roads collapsing, waste coal piles catching fire, landslides and bottled-up acid mine drainage “breaking out” of sealed coal tunnels.

Even if the federal program continues, the use of coal in the United States continues to decline. That means less money being paid into the mandatory fund.

Heightening concerns, private-sector power plants in Pennsylvania that burn coal waste piles to produce electricity are struggling to turn a profit as cheaper natural gas floods the market. A few have closed or paused operations. Others are pleading for an increased state tax subsidy or a new federal one that recognizes the environmental benefits of the initiative. More than 100 million tons of waste coal on the landscape have been reclaimed this way.

Many people concerned about climate change would not be saddened to see coal use end. But, clearly and ironically, its demise could hamper the ability to clean up the sins of the past.

“A viable coal industry is instrumental for abandoned mine land reclamation,” said Conrad, the former chair of the Interstate Mining Compact Commission, in remarks at the 2020 Pennsylvania Abandoned Mine Land Reclamation Conference.

The Pennsylvania Game Commission, which has 90 acid mine drainage treatment systems maintained by other groups on state game lands, worries that when the systems need to be rebuilt in a few more decades, the money won’t be there.

As an added concern, some environmental and sportsmen’s groups say that the supply of volunteers who help run the treatment systems seems to be drying up.

Unexpectedly, prospects for cleaning up abandoned mine lands got a boost on March 31 when President Joe Biden unveiled his $2 trillion infrastructure plan. Included is $16 billion to clean up abandoned mine lands, as well as to pay union oil and gas workers to cap old oil and gas wells.

No matter how the challenges unfold, the legacy of coal mining will not be erased from the landscapes of Pennsylvania and Western Maryland anytime soon, if ever.

“I think there’s never going to be enough environmental funding to address all of the acid drainage and abandoned mine land in Pennsylvania. It’s the sheer magnitude,” Cavazza said.

Ad Crable is a Bay Journal staff writer based in Pennsylvania. Contact him at 717-341-7270 or

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