Healing the land

Using trees to combat toxic sands

Joseph Phillips
Northern Research Station

(November 20, 2024) — Walking along the shoreline of Lake Superior, you take in the view — expansive waters blending into blue skies — while beneath your feet is sandy crushed rock with the consistency of what feels like kitty litter.

But every step taken is across toxic sand laced with unsafe levels of copper, lead and other heavy metals.

In the early 20th century extensive copper mining resulted in more than 6 billion pounds of ‘stamp sands’ — stamp sand is coarse sand left over from the processing of ore — a form of toxic waste material dumped in lakes and rivers and deposited into Lake Superior. A large portion now resides on the shorelines of= Sand Point, a place held sacred by the Keweenaw Bay community, a federally recognized Ojibwa Tribe located along Lake Superior in present-day Baraga County, Michigan.

“Sand Point is a place of life. It is a place of biodiversity. It is a place to protect and assist all living things,” says Austin Ayers, Tribal Council Treasurer and an outreach coordinator for the Keweenaw Bay Indian Community.

Sadly, the stamp sands have been a source of significant threat to the sacred land and its inhabitants. The copper mining contamination has hindered the growth of shoreline native plants. In aquatic animals, such as fish, higher concentrations of heavy metals make consumption by humans potentially unsafe.

“The Tribe is connected to this place. They are tied as a people to the water and to the land,” said Erin Johnston, wildlife and habitat manager for the Keweenaw Bay community. “This community is not going to abandon this location, so it is so important that the environment becomes healthy once again so that our other planet beings — our fish, our birds — can be healthy. This in turn will make our community healthy.”

The Tribal community has explored and experimented with possible solutions to the massive pollution problem. However, with an ecological problem this large, going alone is unrealistic.

While removing the pollutants from the stamp sands by hand is not feasible, what about using trees? This is where Forest Service Research and Development enters the picture.

With the trees’ complex root structures and natural ability to absorb and break down pollutants, they can actually act as a living filter. Ron Zalesny, a research plant geneticist with the Northern Research Station of the Forest Service, and his team have been championing this concept, called phytoremediation.

The process is a bit complicated. Zalesny and his team cannot plant just any tree variety and expect the species to magically clean the soil. Rather, a careful selection process of trees and plants is employed, known to researchers as phyto-recurrent selection. The process involves identifying tree varieties that are naturally tolerant to heavy metals and can absorb and, in some cases, detoxify the contaminants.

With funding from the Bipartisan Infrastructure Law supporting the project, participants are hopeful that Sand Point’s ecological future is brighter through the harnessing of nature’s power to detoxify the landscape.

“Given the history of what happened here — the wrong that was inflicted on the land — it means a lot to have the Forest Service step forward and be willing to work with us,” Ayers said. “We wouldn’t have the capacity to manage such a huge project on our own.”

For Zalesny, this partnership is immensely rewarding.

“Seeing phyto-recurrent selection being used for phytoremediation of these afflicted lands is a highpoint of my career,” Zalesny said. “This isn’t a project that Forest Service Research and Development could do on its own.”

Working with the Tribe to understand the importance of this land, selecting appropriate trees, and then implementing phytoremediation strategies is a joint effort, Zalesny added.

One of the overarching goals of the project is to produce community guidance documents for stamp sands restoration. These resources would extend beyond the Keweenah Bay community, assisting other regions affected by stamp sands.

“The Ojibwa people speak of the concept of the seventh generation,” Johnston said. “The idea is that we look to our previous generations for hope and guidance, and in turn we look seven generations toward the future to imagine the place that we want to leave for our children.”

In a partnership with the Keweenaw Bay Indian Community, scientists from the Northern Research Station use phytoremediation techniques as nature-based solutions to the stamp sands in Baraga, MI. This project was funded by the Bipartisan Infrastructure Law and is done in collaboration with Michigan Technological University and the University of Missouri.