Plant’s Curative Powers : Cattails May Heal Damage From Coal Mining

Cattails sprout defiantly from the orange, acidic goo leaching from an abandoned strip mine off the bumpy back roads of western Pennsylvania.

Researchers are amazed, not by the plants’ surviving in such a wretched environment, but by the cleansing work they do. The cattails are removing iron and other metals from the water and, some believe, neutralizing the acid.

“It’s nature healing itself,” said Javed Mirza, district mining manager for the state Department of Environmental Resources. “There is something going on that lowers the iron content and makes the water less acidic. Some of these things grow in stuff you wouldn’t want to touch with your foot.”

Becomes Favored Flower

Because of these curative powers, the lowly cattail has become a favored plant of environmentalists and coal operators working to curb the toxic damage of acid drainage from mines.

The method is still experimental, but about 40 cattail marshes have been started in the last three years. Officials estimate that 100 will be planted this year, stretching the length of the Appalachian coal fields from Pennsylvania to Alabama. Others are being established in Montana and Colorado.

Acid is a nasty byproduct of coal mining. Coal seams contain deposits of pyrite, a lustrous yellow ore made of iron sulfide and commonly known as “fool’s gold.” When exposed to air and water, the pyrite becomes sulfuric acid--a smelly witch’s brew that poisons streams and kills plants.

About 5,000 miles of streams and rivers nationwide are polluted by acid mine drainage, and more than one-third of them are located in Pennsylvania, according to the state Department of Environmental Resources and the U.S. Bureau of Mines.

“I consider it the major environmental effect associated with coal mining,” said Dr. Robert Kleinmann, research supervisor with the environmental technology group of the U.S. Bureau of Mines.

Costs $1 Million a Day

“According to estimates, the mining industry is spending $1 million a day to treat acid mine drainage. Other than wetlands, there is no other technology available that is cheap, low-maintenance and applicable.

“It’s not a panacea, but we see this as being one of the best possibilities we have for correcting a lot of the acid mine seepages throughout the nation.”

Acid drainage is now being treated with caustic soda or limestone, which neutralizes the discharge. But the method means adding an expensive chemical and requires constant upkeep. If a coal company goes bankrupt, the treatment stops and nature has a chronic wound.

Cattail marshes occur naturally and are self-sustaining. Researchers know little about how and why cattail marshes work, Kleinmann said, but the method has so much promise that coal companies are rushing to plant them.

The remedy means money. Coal companies are now required to put up bonds to ensure that they return mined areas to an acceptable state. Their bonds are held up if acid drainage is bleeding from the ground.

‘It’s Low-Cost Gamble’

“The mining companies are so desperate for a solution to treatment costs they’re not waiting for research,” Kleinmann said. “Even if a car can only go 20 m.p.h. and can’t get out of first gear, it will still get you somewhere. Hey, it’s cheap. It’s a low-cost gamble.

“It’s like spending $100 on a clunker now or waiting several years to buy an expensive Cadillac. The coal operators will drive the clunker until they get the Caddy.”

Kleinmann estimates that marshes can be used in 20% of the acid mine drainage problems nationwide, particularly those with flow rates of less than 100 gallons per minute. A marsh can be built from scratch for about $20,000, depending on the size. One Pennsylvania coal operator was spending $57,000 a year on chemicals to treat acid drainage.

Wetlands have particular promise in Pennsylvania, which had produced one-third of the nation’s coal as of 1977. The state adopted strict mining guidelines in the 1960s but bears numerous mining scars.

In addition to 2,000 miles of polluted streams, the state has 200,000 acres of ground prone to the effects of collapsing mines, 45 mine fires and mountains of waste. The state Department of Environmental Resources estimates that it would cost $15 billion to correct all the ills.

Studied Healing Powers

Scientists have known for years that wetlands are nature’s way of purifying water. Researchers at Wright State University in Ohio and West Virginia University studied the healing powers of peat bogs on acid drainage in the 1970s.

Pennsylvania’s Clarion University was one of three state universities invited to submit plans to study cattail wetlands at a 310-acre abandoned strip mine in Clarion County.

The owner of the coal company died, and the companies that held the bonds were planning to default and let the state reclaim the site.

But through an agreement with the state, the companies agreed to put up research money while an operator from Distant, Pa., was hired to do the reclamation on harsh hillsides.

Researchers would like to know why the wetlands keep cleansing in the winter, when the dun-colored cattails turn to seed. Others want to know how to make the marshes work more efficiently.

Undergoes Transformation

In one marsh, acid drainage undergoes a dramatic transformation in a distance of about 100 feet. The acid level coming into the marsh has a pH of 5.3 and leaves with a pH of 6.7. On the pH scale, a lower number means more acidity, and 7.0 is neutral.

Ben Pesavento, head of Environment Analytic Service Inc. of Mercer County, is an independent designer of cattail wetlands. He did laboratory work on treating acid with marshes in 1971 and built a working wetlands in 1975.

“It was rejected by the state as being too radical, too simple. They thought I was crazy 15 years ago,” Pesavento said.

“We’ve shown a lot of people we can clean up an awful lot of water without massive amounts of chemicals. We have a lot of them where the water is blood red coming in and coming out clear on the other end. We haven’t even started to tap the potential. Ten to 15 years from now, there don’t have to be any more red streams in Pennsylvania.”

Pesavento claims a 90% success rate in removing iron and 70% success rate in lowering manganese, a metal that can make porcelain and laundry turn brown. He believes wetlands can also be used to treat industrial wastes and leaching from sanitary landfills.