Natural Resources Protective Association: Protecting the marine environment since 1977

A market for dredge mud? Yes

Old coal mines need to be plugged up to prevent polluted runoffs, and a mix of coal ash and dredged soil does the job nicely, Pennsylvania finds

December 28, 1999



What’s to be done with millions of tons of contaminated soil dredged from local waters?

One promising option: Filling miles of abandoned coal mines in Pennsylvania.

This method, called abandoned mine reclamation, could solve an environmental problem that has plagued coal-mining states like Pennsylvania for decades and, at the same time, give states like New York — where major waterway dredging projects are planned — an economical and safe way to dispose of contaminated dredge materials.

“It is nothing less than perfect in a less-than-perfect world,” said Andrew Voros, executive director of Clean Ocean and Shore Trust (COAST), a legislative committee formed in the mid-1990s by New York and New Jersey to address issues relating to water quality and maritime industry in both states.

COAST endorses mine reclamation as an environmentally beneficial way to dispose of contaminated soil dredged from New York and New Jersey waters.

Voros said that mixing dredged soil with coal fly ash (a by-product of coal burning) and other industrial by-products stabilizes contaminants in the dredged materials.

The final product hardens into a cement that repels water and binds to the rock walls of abandoned coal mines, preventing the polluted runoff from mines that has already tainted more than 2,500 of Pennsylvania’s 54,000 miles of waterways.

“You’re taking dredge spoils and you’re remediating an environmental disaster,” said Voros.

“We’re all pretty happy with the idea,” said Jim Scarcella, president of the Natural Resources Protective Association, a consortium of local environmental and fishing groups that opposes any ocean placement of contaminated soil.

Scarcella sees mine reclamation as an environmentally positive alternative to ocean disposal.

“It’s an environmental plus-plus,” said state Assemblyman Eric Vitaliano, who, along with state Sen. Vincent Gentile, strongly supports mine reclamation with dredged soil. Vitaliano and Gentile are both members of COAST.

Working with COAST and the Port Authority of New York and New Jersey, the Pennsylvania Department of Environmental Protection launched a pilot project in 1998 to study the use of dredged material in abandoned mines.

The project takes dredged soil from local sites, mixes it with coal fly ash and other additives, and disposes of it in the Bark Camp surface mine, in Clearfield County, Pa.

According to Voros, six months after the project began the acidity in a stream running through the site decreased dramatically, going from a pH of 1.8 to 6.9 (7.0 is neutral). Even an independent environmental committee appointed by the local township to monitor the project expresses support for the enterprise.

The Bark Camp pilot project is still in its infancy, having deposited only about 20,000 of the 550,000 tons of dredged material that is scheduled to go to the site. And Pennsylvania authorities are not about to open up their empty mines to New York’s dredged material until this new approach is proven successful. The project is scheduled for completion next June.

But this project coincides with a dramatic — if gradual — shift in public perceptions about dredged material and its potential uses.

Consolidated Technologies Inc. (CTI), a wholly owned subsidiary of U.S. Plastic Lumber Corp., is managing the Bark Camp project. Its president, Steve Sands, said disposal costs rose dramatically when new testing protocols instituted by the Environmental Protection Agency in the mid-1990s found traces of contaminants never before detected in dredged material. Public fears about the contaminants escalated, and new disposal options had to be found for that portion of material deemed unsuitable for ocean disposal.

Numerous waste management companies saw opportunity in the search for new approaches, and disposal costs escalated. A 1995 project placed dredged soil on ocean vessels, shipped it to Corpus Christi, Texas, and then transported it by rail to a Utah landfill, at a cost of $118 a ton.

Public attitudes have evolved as more and more projects utilize dredged material as a relatively clean cap over landfills, brownfields and other degraded sites. And the costs have dropped significantly as the technology improves and people find they can tolerate disposal closer to home.

The market changes, said Steve Sands, “as people understand that you can create a viable resource out of something that was considered a waste product.”

Despite the generally rave reviews from lawmakers and environmentalists, the Army Corps of Engineers’ Dredged Material Management Plan devotes only a few paragraphs to the mine reclamation option.

The Army Corps estimates that the next 10 years of harbor-dredging operations will generate 27 million tons of soil considered too contaminated for disposal at the Historic Area Remediation Site (also referred to as the Mud Dump), east of Sandy Hook. The Army Corps’ plan recommends that about six million tons (a little more than 22 percent) of this material be placed in two Pennsylvania mines, at a cost of $29 a ton. Most of the rest of the material will be placed at “various N.J. sites,” at about $29 a ton, though some smaller projects will cost as much as $33 a ton.

If implemented on a large scale, abandoned mine reclamation could cost significantly less, ranging anywhere from $20 to $29 a ton.

And as Ted Kopas of Pennsylvania’s Office of Mineral Resources points out, “There’s a lot of holes in Pennsylvania that need filling.” In fact, he said, there are enough empty mines in the state to take every bit of material dredged from local waters for generations to come.