The U.S. Environmental Protection Agency (EPA) has announced an updated cleanup plan for the Torch Lake Superfund site located in Houghton County, Michigan. The EPA had completed its initial work at this site, which suffered contamination from years of copper production, back in August 2006.

The agency has detailed these updates in a document titled "explanation of significant differences," which modifies the existing cleanup strategy based on insights gained from the latest five-year review. The update outlines three key changes:

Firstly, Scales Creek has been added as operable unit 3 to the cleanup efforts. Secondly, shoreline protection measures were initially implemented by the EPA in areas where wave action caused erosion. During the remedial design phase, both the EPA and the Michigan Department of Environment, Great Lakes, and Energy identified two specific areas in Lake Linden that required such protection. The need for additional shoreline protection in Lake Linden is now being documented by the EPA.

Lastly, there is a clarification regarding how operable unit 2 will be assessed during future five-year reviews. While operable units are typically not included in these reviews, the EPA plans to continue including operable unit 2 for this particular site.

Superfund sites are often segmented into "operable units" to address distinct geographic areas or specific issues requiring targeted actions. Five-year reviews serve as an opportunity to assess whether a cleanup remedy continues to protect human health and the environment effectively. These reviews are generally mandated when hazardous substances remain present on-site.

For further details about the Torch Lake Superfund site and other related information, individuals can visit the EPA's website.