Mining and metals processing can create on-site and off-site impacts to water quality, which we aim to avoid or minimize. For example, mineral waste is analyzed for geochemical characteristics to identify management opportunities for minimization of potential impacts to water resources within and adjacent to our facilities. All operations maintain systems to monitor water quality parameters for compliance with regulations and permit requirements.

During 2011, we conducted investigations of water impacts caused from surface sources, dewatering discharges, sulfate-impacted tailings seepage, and seepage of leach/process solutions at multiple operating sites and discontinued facilities (historical operations). These investigations were conducted in the United States, England, Netherlands, Spain, and the DRC. In some cases we are implementing containment and active water treatment strategies as well as providing alternative water supplies to well owners pumping sulfate-impacted groundwater.

For example, at our former Blackwell Zinc Smelter in Oklahoma that shut down in 1974, process solutions from a leaking pond impacted groundwater with cadmium and zinc. During 2011, we operated a groundwater extraction system designed to contain the impacted groundwater. We extracted 64 million gallons of water and subsequently treated it to remove the metals and discharged the clean water to a local river. Barring a technological breakthrough, we expect to operate the extraction wells and treatment plant for decades.