An engineered slope stabilization project is in full swing along the Appalachian National Scenic Trail near Palmerton on the east side of the Lehigh Gap.

The National Park Service, in partnership with the Federal Highway Administration, has implemented the project through the use of American Reinvestment and Recovery Act funding.

Begun in mid-July, the project got off to a slow start due to a variety of reasons, such as additional analysis of the project plans, said David Reus, project coordinator, Appalachian Scenic National Trail. As a result, Reus said the contractor, Janod, has geared up to make a push to make up for lost time by working weekends.

Initially expected to be completed by April 2011, the estimated completion date is now early-May 2011, Reus said.

"What you'll see up there now is safety fencing installed on the west end of the project, as well as safety fencing being installed on the east end," Reus said. "Activity will pick up in the coming weeks as the first large talus pile of stone is removed during scaling operations."

The Appalachian Trail parking lot off Route 248 remains open in the day for hikers to use; however, there will be short periods of time during deliveries of project materials that will require the parking lot to be closed to allow large trucks adequate room to maneuver, Reus said.

In addition, Reus said signs will be posted to alert visitors to the temporary closures. Alternate Appalachian Trail parking is available off Route 873, Mountain Road, on the west side of the Lehigh River.

The trail is open, and will remain so for the duration of the project, Reus said. However, the blue-blazed Winter Trail is closed due to dangerous rockfall conditions, he said.

Visitors are requested to stay on the trail and observe posted warning signs, Reus said.

The project is a response action under the Comprehensive Environmental Response, Compensation and Liability Act to abate the ongoing migration of contaminated soil and water from the site; abate the threat to public safety from a potential rockfall at the site, and to ensure the long-term success of future revegetation efforts for the site planned in the context of the Palmerton Zinc Pile National Priorities List site remedial action.

The trail passes through a portion of the Palmerton NPL Site, which is comprised of thousands of acres. About 800 acres within the Palmerton NPL Site are parklands managed by the NPS, which includes a 71-acre area known as the Lehigh Gap site.

The contaminant-related loss of trees and other vegetative cover at the Lehigh Gap Site has led to significant erosion, enabling the ongoing mitigation of contaminated soil and water from the site. It has also eliminated natural barriers to rock falls, creating a potentially hazardous situation to motorists who pass below on state Route 248, as well as to trail visitors and workers.

The state Environmental Protection Agency is the agency responsible for the Palmerton NPL Site cleanup. The EPA has future plans to revegetate some areas, including the Lehigh Gap Site, by application of a mixture of seed, fertilizer, and lime. To complement the application, the NPS will implement engineered slope stabilization measures before revegetation.

The NPS performed a modeling of potential rockfall events, enlisted the FHWA to perform a technical review of potential slope stabilization measures, and, in the context of a CERCLA Removal Site Evaluation, reviewed existing background information about the Lehigh Gap Site and the ongoing migration of hazardous substances from the site.

Earlier this year, design and specification documents were completed by FHWA, and the project was advertised for competitive bid.