Pipeline, storage basin failures send ore tailings and road aggregate into wetlands; 2 enforcement actions result

Contact: Anne Perry Moore, 218-302-6605

Duluth, Minn. — Cleanup continues in Iron Range wetlands affected by failures in ArcelorMittal Minorca Mine Inc.’s tailings pipeline and storage basin. As a result, the Minnesota Pollution Control Agency (MPCA) has penalized the company for related permit and water-quality violations.

ArcelorMittal operates under a state-issued permit that regulates wastewater discharges at its Virginia iron ore mining and processing facility. During ore processing, fine tailings, or waste rock low in iron content, are mixed with water and pumped as a slurry through a pipeline to an upland storage basin about three miles away.

On three occasions between May 2013 and April 2014, failures in the pipeline and a breach in the tailings basin perimeter dike caused the release of about 8,500 cubic yards of tailings slurry and aggregate from a washed-out dike road into 15.3 acres of adjacent wetlands and the pipeline ditch.

When soils or other materials are accidentally introduced into a wetland, the wetland can no longer function as a natural aquatic habitat or filtration system. This ecosystem may or may not be able to be restored. If not, destroyed wetlands may be replaced in the same or similar watershed.

The Minnesota Department of Natural Resources, and the U.S. Army Corps of Engineers, which have authority over adding fill material to wetlands, are working with the company to remove the spilled tailings and road aggregate and monitor, mitigate and/or replace the affected wetlands.

In response to the incidents, an MPCA inspector visited the site, reviewed records and determined that the company had inadequately inspected and maintained the pipeline, pipeline ditch and tailings basin structures and had failed to report two of the releases in a timely manner. These conditions violate the company’s wastewater permit that regulates discharges to state waterways.

Because it did not follow the permit’s requirements, ArcelorMittal has paid a $58,000 civil penalty to the state of Minnesota and is implementing corrective actions. They include improved pipeline leak-detection equipment, more pipeline and tailings basin inspections to reduce the chance for future spills, and prompt spill reporting.

In March 2015, the U.S. Environmental Protection Agency took a separate enforcement action against ArcelorMittal under the Clean Water Act. The company was penalized $272,500 for the same wetland impacts plus an unrelated filling of about two acres of wetlands.

When calculating penalties, the MPCA takes into account how seriously the violations affected the environment, whether they were first-time or repeat violations, and how promptly the violations were reported to authorities. The agency also attempts to recover the calculated economic benefit gained by failure to comply with environmental laws in a timely manner. For a comprehensive list of enforcement actions, visit the MPCA’s quarterly summary of enforcement actions webpage.

The MPCA offers outreach and training to help facilities meet their permit requirements. For more information on wastewater permits, call John Thomas, MPCA compliance inspector, at 218-302-6616 or toll-free at 800-657-3864.