Lake near Boundary Waters listed by state as impaired with sulfate

BABBITT — Birch Lake and the small ditch flowing into it near the Boundary Waters are among the 54 streams and lakes added to the state’s draft impaired waters list this year.

Both are listed as impaired by sulfate, a naturally occurring nutrient also found in discharges from mining operations, wastewater treatment plants and industrial facilities.

The lake and the ditch identified as the Dunka River are near the shuttered Dunka taconite mining site. The site was closed almost 30 years ago and has long been a source of concern for water quality advocates.

It’s also the site of recently approved exploratory drilling by Franconia Minerals, a subsidiary of Twin Metals.

Twin Metals sought approval in the wake of a 20-year mining ban placed on any federal land within the same watershed as the Boundary Waters Canoe Area Wilderness. The exploration is taking place on state-managed land less than 30 miles from the wilderness.

The Minnesota Pollution Control Agency said this year’s additions to the impaired waters list is one of the smallest in recent years. In 2022, more than 300 water bodies were identified as impaired.

Challenges remain throughout the state, however, particularly related to pollutants such as “forever chemicals” and sulfate, which the agency says are difficult to manage.

One type of forever chemical can accumulate in fish and is transferred to humans when consumed, potentially causing adverse health effects.

The MPCA proposes three list additions due to high levels of this chemical, including Sargent Creek and Miller Creek in Duluth.

Public comments on the draft list are encouraged through Jan. 12.