The first phase of a mining impacts study for the Rainy-Lake of the Woods watershed has found a great deal of connectivity between mine sites and the broader watershed, with a high percentage of wetland bodies linked to one another and a likely sizable amount of shallow groundwater flow, according to researchers. They also found significant possible data gaps that need to be explored further.
The study was commissioned by the IJC’s Rainy-Lake of the Woods Watershed Board and Health Professionals Advisory Board.
Rainy-Lake of the Woods board member Doug Franchot said there’s been a great deal of interest in the study findings due to the history of mining in the region.
The bedrock of the Rainy-Lake of the Woods basin is rich in metals such as nickel, gold, copper, and lithium, all of which are buried underneath a pristine, ecologically sensitive region. Historically the region was home to numerous iron and gold mining operations, many of which are abandoned today, and increasing interest in electrification and strategic mineral resource development has led to increased mineral exploration in recent years.
“The (watershed board’s) Citizens Advisory Group, ever since the founding of the watershed board back in 2014, has been concerned about the impact of mining,” Franchot said. “When an individual project comes along, it gets fairly thoroughly studied, but it never gets studied in the context of what else is going on (in the context of the entire watershed). So that was a big question: trying to get an accumulative perspective.”
An important problem, Franchot said, is that the area lacked any compilation and assessment of environmental data needed to assess the potential impacts and risks of new mining projects.
The project was carried out under the IJC’s International Watersheds Initiative with oversight from the two IJC boards.
In the United States, the US Geological Survey carried out the work, while the Geological Survey of Canada led on the northern side of the basin. The researchers first identified five data categories: existing mine locations, the water quality of rivers and lakes, health of the aquatic communities (including fish, plants and insects), mineral potential, and the hydrology of the basin.
Data was pulled from government sources in both countries, with information going back at least 20 years, including from Tribes and First Nations. Additionally, this included a review of existing literature.
For aquatic community health, researchers used several different indicators, including contaminants and the presence of insects that are sensitive to poor water quality, said Hazen Russell, project lead on the Canadian side. Mineral potential was teased out through data directly from government agencies as well as required permit information from mining companies that had to be filed with state and provincial governments.
The sampling processes, frequency and datasets between Canada and the United States for water quality and mine locations were quite different, and so a portion of this project included harmonizing the existing data into a cohesive whole to help create that baseline, said Aliesha Krall, who led the effort from the USGS side.
“Harmonizing involves bringing data sets together,” Krall said. “They provide the similar information, but it’s not standardized in the sense of making it apples to apples.”
With harmonized data, Krall said, the researchers were able to form a complete picture of the locations of all the active and abandoned mines in the basin, as well as much of the water quality dataset.
This isn’t the end of the project however, Krall added. Many datasets may have too many attributes or categories to easily harmonize. Other data categories were partially analyzed but will require a second phase to gain a complete understanding.
Jim Stark, a Rainy-Lake of the Woods Watershed Board member who works for the Minnesota Legislature, said phase 2 of the study will focus on identifying the areas with the highest potential for mining, and assessing the water quality, hydrologic and ecosystem data to determine how vulnerable they may be to mining impacts. It’s possible that the conclusion of phase 2 will see recommendations for additional monitoring in some parts of the Rainy watershed, he added.
