Pennsylvania coal mine reclamation plan to use contaminated harbor sediments Pennsylvania is about to launch a coal mine reclamation experiment that could solve several thorny environmental problems. The plan, approved by the Pennsylvania Department of Environmental Protection (DEP) earlier this year, would take contaminated dredge material from the Delaware and Hudson rivers and the New York Harbor, mix it with municipal incinerator ash, then use it to reclaim an abandoned mine. It will simultaneously help restore scarred mining land and reduce acid mine drainage while resolving touchy disposal problems for tainted sediments and incinerator ash. "If it works the way scientists say it will work, it will be a win, win, win situation for everybody," said Susan Wilson, director of the Pennsylvania DEP's Citizens Advisory Council. Pennsylvania has an estimated 9000 abandoned surface mines covering some 250,000 acres. Because the state's rivers and streams have been heavily degraded by acid runoff from the abandoned mines, the search for economically feasible remediation strategies has been a high priority. Andrew Voros, executive director of the Clean Ocean and Shore Trust, a joint New YorkNew Jersey commission, said the pilot project was conceived during talks with Pennsylvania officials over other mutual issues, including the Delaware River watershed. According to the plan, the Army Corps of Engineers will provide the dredge material, the trust will ship it, and the Pennsylvania DEP will oversee the pilot reclamation project. Because it is a small-scale experiment, the only permission needed was a Beneficial Use Permit, which was granted by the Pennsylvania DEP this year. Voros said the sediment will be dredged from the clogged New York Harbor and shipped to the Pennsylvania test site by rail, starting late this year. The trust, a commission created three years ago to recommend solutions to environmental problems, has
been searching for disposal alternatives ever since a 1996 ban on ocean dumping. Efforts to find alternatives have been hampered by public concern over its disposal: The dredge material is contaminated with trace levels of dioxins and heavy metals. "This material was vilified by the move to end ocean disposal," Voros said. The remedial plan, developed by Pennsylvania State University's Barry Scheetz, a professor of cement chemistry, uses a pug mill mixer to blend sediment, incinerator ash, and lime to create a groutlike cement that is spread over the mined land. The material is compacted and eventually hardens, according to earlier tests by Scheetz. The cement's alkaline properties act as a buffer to the acidic drainage that plagues most abandoned mine sites, said Robert Dolence, DEP deputy secretary for mineral resources management. The blended material will be applied to a depth of about 20 feet, filling in a hillside area where coal had been removed. Researchers are not exactly sure how the characteristics of the fill material will change over time, although earlier research by Scheetz suggests that it will re-
main stable. They plan to use a cover material made from soil and other industrial castoffs: sludge, fly ash, and paper mill fiber—a combination that should support vegetation. The pilot project will use about 500,000 cubic yards of dredge material. Dolence said the plan is to reclaim about 15 acres of an old surface mine, then assess the environmental impact. Dolence said the monitoring scheme will include surface water and groundwater testing; years of monitoring at the site "have already given us a strong baseline to work from." Scientists also will conduct tests to see if the fill material retains its buffering capacity over time. There is no timetable for completion of monitoring—or using the technology elsewhere—until the parties involved "answer all the questions" that have been raised, Dolence said. The DEP also is planning to pay the costs of an outside consultant who will monitor the pilot project for local residents. "We're not going to push it; we plan to monitor it very closely," Dolence said. The abandoned test mine is in the Moshannon State Forest in north-central Pennsylvania, where the state has established the Bark Camp Mine Reclamation Laboratory to test a variety of remedial techniques. —RAE TYSON
The Bark Camp Mine Reclamation Laboratory in Clearfield County, Pa., is the site of a pilot project that will use contaminated dredge material to reclaim abandoned coal fields. (Courtesy Pennsylvania Department of Environmental Protection) VOL. 3 1 , NO. 10, 1997/ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS • 4 5 7 A
