Thirty years ago, more than 800 waste coal piles marred the Pennsylvania landscape, poisoning streams and emitting gaseous odors, including the rotten-egg smell of hydrogen sulfide.

Then, as part of a statewide cleanup, power plants capable of burning low-quality coal began turning the waste into electricity. Indeed, some waste piles still smolder from spontaneous combustion, polluting air long after mining ceased.

However, waste coal plants have reclaimed more than 7,200 acres and 1,200 miles of streams. Once barren landscapes and contaminated streams teem with wildlife because of the ongoing reclamation.

Unfortunately, new regulations threaten to upend one of Pennsylvania’s greatest environmental comeback stories. Since 2013, five waste coal plants have closed because of regulatory or economic pressures.

“There are at least 20 years of work left for the plants,” says Jaret Gibbons, executive director of the Appalachian Region Independent Power Producers Association (ARIPPA). “However, the state and federal governments both have proposed limits on emissions that likely would make continued operations impossible. Proven technologies to meet the regulations do not exist and, if they did, probably would be too expensive.”

Indiana County is home to the Seward Generation facility, a 525-megawatt waste coal plant. Capable of producing enough electricity for 650,000 homes, Seward has removed more than 50 million tons of coal refuse during its 20 years of operation.

Yet, Jim Panaro, executive vice president of Robindale Energy, says Seward and two other plants his company operates could be even more effective in a more accommodating regulatory environment.

Although the company only removes material from the surface, it spends two to three years securing the same mining permits required of operators who excavate hundreds of feet into the earth. State regulators often exceed the 180-day timeline for permit approval, claims Panaro.

In addition, regulations sometimes add unnecessary costs. The company spent $2 million to lower the aluminum content of Seward’s water discharge below the concentration in the river that receives it.

“The water leaving the plant is cleaner than the Conemaugh River water it takes in,” says Panaro, who also fishes for trout in nearby creeks.

Attempts to link Seward emissions to “regional haze” in Virginia’s Shenandoah Valley and New Jersey’s Brigantine Wilderness are absurd to plant managers, who note a lack of evidence. Also, the proposed solution–installing a $600 million flue gas desulfurization scrubber–would force Seward’s closure.

A few years ago, former Gov. Tom Wolf’s proposal to impose a carbon tax would have limited Seward to operating at 65 percent of capacity, slowing the environmental cleanup and jeopardizing a major portion of the state’s economy. Robindale plants support 400 jobs and spend more than $245 million annually in wages, operating costs, and taxes. The future under Gov. Josh Shapiro’s recent carbon tax proposal is unclear.

Onerous regulations challenge power plants burning waste from a 5-million-ton pile at Swoyersville in Luzerne County. Hank Zielinski, vice president of Northampton Fuel Supply, says that increasing federal demands bog down businesses with paperwork and added expenses.

“Sometimes, we are required to write out long plans that simply repeat the words of the agency’s rules,” says Zielinski.

Despite regulatory obstacles, these Pennsylvania plants and one in West Virginia process an average of 6 million tons of coal waste annually. Left alone, the refuse, over time, would emit millions of tons of sulfur dioxide and methane and smaller amounts of hydrogen sulfide and mercury, according to ARIPPA. Partly because they burn greenhouse gas methane along with coal, the plants claim an annual net reduction of 29 tons of the gases said to warm the atmosphere.

The most obvious benefit, however, is the reclamation of acreage and waterways.

“The land value of reclaimed sites has gone up tremendously,” says Bobby Hughes, executive director of Eastern PA Coalition for Abandoned Mine Reclamation. Former waste locations have transformed into housing and commercial tracts, athletic fields, meadows, and woodlands. The educational complex of the Wilkes-Barre Area School District occupies one. Swoyersville will take over several reclaimed acres for the community’s use.

“By repairing damage from the past, we are providing environmental justice for already underserved communities,” says Panaro, whose company removes waste from former mining towns designated by state regulators as “environmental justice areas.”

Waste coal plants are also a cost-effective option for environmental reparation.

“Alternative ways of cleaning up Pennsylvania’s waste piles have been estimated to cost as much as $16 billion,” says ARIPPA’s Gibbons.

While reclamation costs make the plants’ electricity more expensive than other sources, the effectiveness of the cleanup and the 2,000 jobs it supports are significant benefits. The estimated value of environmental benefits and avoided cleanup costs is $300 million a year, according to one study quoted by ARIPPA.

If policymakers genuinely support “environmental justice,” waste coal plants seem like a good thing to protect.

Gordon Tomb is a senior fellow with the Commonwealth Foundation, a Pennsylvania free market think tank.