BIRCH LAKE— Whether or not to list Birch Lake as an impaired water due to elevated levels of sulfate is another flashpoint in the ongoing battle over mining pollution in northeastern Minnesota lakes and streams. The issue raises further questions about the transparency of the state’s Pollution Control Agency (MPCA), which continues to claim the full backing of the federal Environmental Protection Agency for its decision to exclude the lake, located near Babbitt, from the impaired waters list.
In fact, the EPA expressed considerable concern about the MPCA’s determination to exclude Birch Lake, but agreed to defer a decision until next year on whether to override the MPCA on the issue, which it has the authority to do. The EPA, in 2021, rejected the MPCA’s impaired waters list for failure to include 30 water bodies, including the Pike River and Lake Vermilion, that are impaired due to excessive levels of sulfate for wild rice waters. The EPA did not include Birch Lake among the 30 impacted water bodies, but tribes and environmental organizations have been urging its addition to the list, arguing that portions of the lake are regularly exceeding the wild rice sulfate standard.
In response, MPCA officials have promised to gather additional information on the issue in conjunction with environmental groups and tribes, which have led the push to include Birch Lake on the impaired waters list.
Why it matters
The list of impaired waters is issued every two years based on federal requirements in the Clean Water Act and is based on exceedances of federal water quality standards for a long list of potential parameters. In northeastern Minnesota, sulfate levels above the state’s strict 10 mg/l wild rice standard are among the most common reasons for inclusion on the list, assuming that wild rice is known to be present, or has been present in the recent past, on lakes or streams in question.
Mercury levels in fish, which can also be linked to mining pollution, are another common reason for including a lake in the region on the impaired waters list. The list is used to set pollution reduction goals, known as total maximum daily load, or TMDLs, that are necessary to restore impaired waters to an improved status.
Should Birch Lake be on the list?
All sides agree that Birch Lake meets one of the requirements to be listed as an impaired water for wild rice. The natural grain, which is a key food source for many northern Minnesota residents, particularly tribal members, has grown in parts of Birch Lake for years. As such, the lake is classified as a wild rice water, which means it is subject to the 10 mg/l wild rice standard for sulfate.
That’s where the debate gets stickier.
The MPCA has gathered surprisingly little water quality data from Birch Lake since the 1970s, when state regulators were dealing with a relatively new pollution source, the outflow from the Dunka pit, which flowed through Unnamed Creek into Birch Lake’s Bob Bay. But environmental advocates have done their own extensive water quality testing in the lake, and those results have consistently shown sulfate levels above the wild rice standard, particularly in the vicinity of mining-related discharges at Bob Bay and Dunka Bay.
Testing undertaken over the past several years in three parts of the lake by the White Iron Chain of Lakes Association, or WICOLA, shows sulfate levels near Dunka Bay averaging 8.58 mg/l, or just under the 10 mg/l wild rice standard. Meanwhile, sulfate levels near the Birch Narrows and Birch Rapids, were considerably lower, with averages of 4.16 mg/l and 3.09 mg/l respectively. Most lakes in northeastern Minnesota that are unimpacted by mining pollution consistently see sulfate levels of less than 2 mg/l.
While the WICOLA data would seem to support the MPCA’s position that Birch Lake is currently compliant with the 10 mg/l standard as a whole, other test data point to a bigger problem. Dr. Patrick Brezonik, a now-retired professor of civil, environmental, and geo-engineering from the University of Minnesota who chaired the MPCA’s wild rice standard advisory panel, examined test data gathered by Northeastern Minnesotans for Wilderness, and the Northern Lakes Scientific Advisory Panel over a period of about two years.
“The grand average sulfate concentration for all 104 samples collected over that time period is 13.6 mg/l (higher than the 10 mg/l standard),” wrote Brezonik in comments he provided to the MPCA on the issue. “Substantially higher concentrations were found in Bob Bay: average = 29.6 mg/l, and Dunka Bay:average = 15.3 mg/l, as well as north of Dunka Bay: average = 11.4 mg/l. Bob’s Bay and Dunka Bay both have tributaries that drain existing or past iron mining lands.”
Based on that data, Brezonik said he has concluded that at least portions of Birch Lake, particularly areas around Dunka and Bob Bay, “are impaired by sulfate concentrations that exceed the state of Minnesota’s water quality standard for wild rice waters.” The MPCA is well acquainted with Brezonik, since the agency tapped him to chair the committee it established to update the wild rice sulfate standard.
Some of the MPCA’s critics say it’s not being forthcoming when it claims that the EPA has signed off on its impaired waters list, when the issue of Birch Lake remains unresolved. “Protecting Minnesota waters and wild rice is MPCA’s job,” said Paula Maccabee, chief legal counsel and advocacy director for Duluth-based Water Legacy. “So is disclosing EPA’s concerns with candor and working in collaboration with public interest stakeholders and tribal rightsholders to address those concerns.”
MPCA officials say they’re taking steps to address the concerns being raised about Birch Lake, and that they are open to utilizing information gathered by the public to aid decision-making. “The MPCA is committed to gathering and including the most up-to-date and accurate information when making decisions related to all our work, including the impaired waters list,” said Michael Rafferty, communications manager for the state agency. “We fully intend to include this data and are working with the groups to get it in an electronic format so it can be loaded into the database we use for assessing data and comparing it to the water quality standard.”
Whether the agency and its critics can find consensus on the issues remains to be seen. The next update to the state’s impaired waters list is set for 2024.