Mine near Superior in final cleanup phase

There’s been a lot of activity at the Flat Creek Iron Mountain Mine located four miles northeast of Superior. It became a Superfund site in 2002 and the final cleanup phases are currently taking place.

“The contractor said they plan on working until Dec. 23, weather permitting,” said Joel Chavez, Project Manager with the Department of Environmental Quality.

This past fall, the project included the excavation and disposal of tailings and impacted soil. Heavy metal contamination at the site originated from the Iron Mountain Mine which produced silver, gold, lead, copper and zinc in the early to mid-1900s. The tailings from the mine contain elevated concentrations of metals and have been deposited along nearly four miles of the Flat Creek floodplain, posing a continuing source of contamination to the creek.

The tailings are being removed from the floodplain and placed in the Wood Gulch Repository and will be capped with dirt. The repository is in a location where there is no threat to the ground water.

Chavez said they will resume this spring and anticipate the cleanup project will be completed by next fall. They still need to replace about 500 feet of a secondary pipeline for Superior’s water intake, as well as reseed and stabilize the stream.

In 2009, The Flat Creek Iron Mountain Mine Superfund site was listed on EPA’s National Priorities List. In 2010 a Public Assessment report was released by the Agency for Toxic Substances and Disease Registry. Based on that report, recommendations included that the waste tailings-contaminated areas should continue to be posted as a risk to public health and that remedial actions should be considered for these areas.

The report had consisted of four components: residential soil contamination in the town of Superior, contaminated drinking water sources, abandoned mine and milling properties, and contaminated sediments in and near Flat Creek.

The report said that mine tailings were brought into Superior and used as fill, road base, and driveway material more than 40 years ago. In 2002, the EPA did a remediated clean-up of the site. Mine tailings used as fill in Superior were removed which included the high school track, portions of the county fairgrounds, and a number of private driveways and roads.

However, since Flat Creek and the downstream Clark Fork River are both fisheries, the waste piles have open public access. According to the report ecological risks include acid mine drainage from an old mining adit reaching Flat Creek and surface water run-off and flooding. This has spread piles of mining and milling waste throughout the Flat Creek floodplain. Which has contaminated the soil and surface water, causing ecological risks for fish and wildlife.

Also in 2009, the Superior Technical Assistance Committee (STAC) was formed by interested community members. According to the committee’s facilitator, Anita Bailey, the purpose of the committee was to promote public participation in the Flat Creek Iron Mountain Mine EPA Superfund project.

She also noted that the group is funded by a Technical Assistance Grant (TAG) from the EPA. This allows the group to hire an independent technical adviser, not associated with any of the government agencies, to answer questions and provide professional review for STAC and the community. Interested community members can contact the STAC office which is located in the Mineral County Chamber Office in Superior.