Ore Hill Mine Reclamation Project (CERCLA)

What's New: The Forest Service has recently completed a supplemental Engineering Evaluation/Cost Analysis (EE/CA) for addressing acidic, high-metal content surface water at the Ore Hill site. The report is available here, and we are seeking public comments, which can be submitted now or during a 30-day comment period to be announced (see link to EE/CA report under Project Status, below).

Location: Town of Warren, Pemigewasset Ranger District, Grafton County, New Hampshire

Project: Under Forest Service CERCLA ("Superfund Law") authority, address sources of acid mine drainage that currently impact surface water quality and aquatic habitat in one or more miles of Ore Hill Brook downstream of an abandoned mine site. Major work occurred in 2006, when approximately 36,000 cubic yards of mine waste was excavated, treated, and placed at a designated repository location on site, mitigating low pH and high concentrations of environmentally hazardous metals in the surface water. Water quality monitoring continues, and additional work is being planned in 2008 and 2009.

Project Status:

Below: Ore Hill project site map. (Click here for a large PDF version.)

Ore Hill project site map.

In 2007, the Forest Service and Plymouth State University conducted a study on a draining mine adit (a tunnel) that had been excavated in 2006. The Forest Service also initiated a supplemental Engineering Evaluation/Cost Analysis (EE/CA). The supplemental EE/CA evaluated several technologies to treat the acidic mine water draining from the adit, as well as other mildly impacted surface water within the 2006 excavation area. The report recommends a sulfate reducing bioreactor be constructed to treat the water and remove high levels of hazardous metals such as cadmium, copper, lead, and zinc. The report also recommends installing an open limestone channel to increase alkalinity of the water upstream of the bioreactor, building a settling pond, and constructing wetlands downstream of the bioreactor to further improve water quality (more). The Forest Service is planning to install a small-scale bioreactor as a treatability study/pilot project in summer, 2008, to provide further data.

The Forest Service is making the EE/CA report public, and is seeking public comments on the recommendations in the EE/CA. Comments may be submitted now or during a formal 30-day comment period to be announced in the near future.

Site Background

The abandoned, historic Ore Hill mine site in the town of Warren, western New Hampshire, discharged acidic water with high metal content, severely impacting about a mile of Ore Hill Brook. The site is also close to the Appalachian National Scenic Trail (AT). The Forest Service policy is to address acid mine drainage from abandoned mines under its CERCLA authority, and this is being done at Ore Hill.