The DNR subsequently prepared and released an Environmental Impact Statement. The company submitted an Environmental Impact Report to the DNR.

Upon completion of mining, the open pit would have been allowed to fill with water and the remainder of the site would be revegetated. The plan called for concentrating the ore on site with a tailings disposal facility located approximately two miles to the south of the ore body. The project, as proposed in the mid-1970s, involved mining the ore body in two phases, an 11-year open pit phase followed by an 11-year underground mining operation. In addition, the weathered upper portion of the deposit contained higher grades of copper and significant concentrations of gold.īeginning in 1974, Kennecott Minerals Company initiated the process to obtain a mining permit in accordance with the newly adopted Metallic Mining Reclamation Act. The deposit contained about six million tons of ore comprised of more than 50 percent sulfide minerals, primarily pyrite (iron sulfide), with concentrations of the copper-bearing minerals chalcocite, bornite and chalcopyrite. The Flambeau deposit was delineated as a near vertically oriented tabular-shaped copper-gold deposit approximately 50 feet wide, 2,400 feet long and extending to a depth of about 800 feet. During the next several years, more than 100 additional holes were drilled into the deposit to define the grade, size and orientation of the deposit. Late in 1968, based on favorable indications from an airborne geophysical survey, Great Lakes Exploration Company, a subsidiary of Kennecott Minerals Company, drilled the first exploration drillhole into the Flambeau deposit. Located in the southwest corner of the photograph., View historical Flambeau Mine documentsĪn aerial view of the Flambeau Mine duringĪctive mining operations.The DNR gained valuable experience in its review and oversight of the Flambeau Mine and will continue to gather additional information as monitoring of the reclaimed site continues for the next several decades. Once groundwater saturated the backfilled material, the threat of ongoing acidification was largely eliminated.

Limestone, because of its neutralization capacity, was used to neutralize any acidity that developed while the rock was stored in the waste facility and also to minimize the potential for the development of acid conditions prior to reflooding. The backfilling process involved blending the stockpiled waste rock with a prescribed amount of limestone. As specified in the Reclamation Plan and Mining Permit, the open-pit was backfilled with waste rock and other materials removed during the mining process. The open-pit, copper-gold mine began operations in July 1991, and reclamation activities were substantially completed by the end of 1999. While there are other examples of successfully operated and reclaimed metallic mines in Wisconsin, the Flambeau Mine near Ladysmith in Rusk County is the only example of a metallic mine that was permitted, constructed, operated and reclaimed under the state's existing regulatory framework. Additional information regarding the industrial outlot, the petition for certification, the notice of public hearing, the draft revised mining permit and other related materials are available under the 'Industrial Outlot' tab below. The department has received Flambeau Mining Company's petition for a certificate of completion of reclamation for the remaining 32 acres of the permitted mine site, referred to as the industrial outlot.

Goldmine process monitor