Aquatic Resources of National Importance (ARNI)

Aquatic Resources of National Importance (ARNI) Designation
Potential EPA Veto of Clean Water Act Section 404 Permits
            Sulfide mining usually entails the project proponent obtaining a U.S. Army Corps of Engineers permit to dredge and fill and dispose of materials in wetlands, streams or other waters of the United States, known as a Section 404 permit under the Clean Water Act. In the case of the PolyMet NorthMet open pit sulfide mining project, the mine would destroy or impair over 1,200 acres of wetlands draining into the Partridge River and would adversely affect water quality and aquatic ecosystems from the Partridge River downstream to the St. Louis River, the second largest tributary to Lake Superior.
            The St. Paul District Office of the Army Corps acknowledges that the PolyMet mine would result in the largest destruction of wetlands for which the Army Corps has ever considered a permit since passage of the Clean Water Act.
            What many communities impacted by sulfide mining may not realize is that the Army Corps does not provide the final word on whether mines can dredge and fill and dispose of materials in wetlands and other waters protected by the Clean Water Act. Under certain circumstances, where the waters are determined by the U.S. EPA to be “aquatic resources of national importance” or “ARNI,” the U.S. EPA has the authority to review a district office Army Corps decision and elevate it for review at a national policy level.
            When the EPA reviews individual permits, it also has the authority under the Clean Water Act to veto a Corps of Engineers permit if a particular mining project will have unacceptable adverse impacts, including impacts on fisheries, municipal water supplies or wildlife. 33 U.S.C. § 1344(c)(2010).
            The EPA staff letter to the Army Corps on February 18, 2010 provided notice that the EPA believes that the PolyMet project may have unacceptable impacts on an ARNI:
“EPA finds this project may have substantial and unacceptable adverse impacts on aquatic resources of national importance (ARNI). EPA believes the coniferous and open bogs, comprising a large percentage of the approximately 33,880 total wetland acres, within the Partridge River Watershed to be an ARNI due to the values they provide in terms of unique habitat, biodiversity, downstream water quality, and flood control specifically, to the Lake Superior Watershed and the Great Lakes Basin.”
            WaterLegacy reviewed the issue of ARNI designation and legal precedent supporting EPA authority. On September 14, 2010, WaterLegacy counsel sent the EPA an extensive letter and attachments stating the law and facts under which the receiving waters of the PolyMet sulfide mine should be designated ARNI. These documents also detail unacceptable adverse impacts of the PolyMet open pit mine that support an EPA veto of any proposed U.S. Army Corps of Engineers permit under the Clean Water Act.
            Along with WaterLegacy’s advocacy letter to the EPA and exhibits, see a brief summary of some of the legal research on aquatic resources of national importance and of EPA’s veto authority.
            Please contact WaterLegacy counsel, Paula Maccabee at 651-646-8890 (office), 651-775-7128 (cell), (email),
(url) if you have questions about this material or about the potential for the EPA to protect water resources from potential mining projects.