Pennsylvania is trying to find a solution to a multibillion-dollar problem left over from its days as a coal production leader: What to do with the billions of gallons of orange, acidic water pouring out endlessly from its abandoned underground mines.

In one experiment, the resulting sludge is being turned into powdered metals. In another, the water may be used to make a different kind of powder: snow.

The state has so far awarded $4 million in grants to businesses, academics and entrepreneurs to find creative uses for the water and its deposits of iron oxide and, to a lesser extent, aluminum, manganese, zinc, nickel and cobalt.

"It's about having others chip in to solve the $15 billion price tag for cleaning up the problem," said Kathleen McGinty, the state environmental protection secretary.

The lessons learned here could help in other mining states, particularly in West Virginia, Kentucky and western Maryland, where the geology is similar.

Pennsylvania's mines are flooded with as much as two trillion gallons of water, according to state officials, who base the number on the amount of coal removed. That's almost two cubic miles of water, or enough to cover Los Angeles in 21 feet of water, based on calculations by the U.S. Geological Survey.

The polluted water flows out through about 5,000 mine shafts or holes and is contaminated with iron oxide, a byproduct of pyrite that was exposed by mine shafts cut deep into the earth. It has turned thousands of miles of Pennsylvania waterways acidic, coated the bottoms of some rivers with an iron-based orange paste and killed off fish and plant life.

What's worse, the water in the mines is constantly replenished by the water table. Only a small number of the leaks are treated, generating tons of doughy sludge each day with nowhere to go except a landfill.

Hundreds of millions of dollars in federal money is available to deal with mining damage around the country, but with a focus on cleanup. Taking a new tack, Pennsylvania is trying to find a way, essentially, to recycle the waste. The first grants were awarded in November.

The Loyalhanna Watershed Association, in southwestern Pennsylvania, received $211,000 to try routing high-pressure mine runoff through turbines to generate electricity at a sewage treatment plant.

Association member Floyd Eiseman remembered seeing the water blast from holes drilled into a flooded underground mine by a highway crew.

"That was spouting out at 7,500 gallons a minute, and I looked at that and I thought, `Whoa, there's no way this energy can go to waste,'" Eiseman said.

Other grants went to:

— Concurrent Technologies Corp., a western Pennsylvania company testing iron oxide from the sludge as a corrosion inhibitor on rebar in concrete construction.

— A chemistry professor at St. Vincent's College in Latrobe experimenting with mine sludge as a way to draw pollutants out of untreated sewage.

— Allegheny County, which wants to treat mine runoff and use the remaining water to make snow at a public park.

In the state's northwest corner, St. Mary's Pressed Metals makes high-end ball bearings for use in everything from automobiles to appliances. It has been experimenting with using metals from the sludge to replace more expensive powdered metals.

"We were pretty skeptical," St. Mary's general manager Jim Aiello said. "The next thing you know, we're pressing it and forming bearings."