Out in the northeastern part of the state, in and around the Grand Portage Indian Reservation, you’ll find lakes that have been completely untouched by human development. There are no houses, no septic tanks. There's no discharge from wastewater treatment plants, and no runoff from soybean fields to sully them.
But in and around those lakes, you will find a cocktail of chemicals you wouldn’t expect – 117 different substances, including antibiotics, DEET, antidepressants, cancer drugs... and, in six specific sites impacted by wastewater effluence, cocaine.
Researchers with the University of Minnesota and the Minnesota Pollution Control Agency sampled 28 lakes both on the reservation and along Lake Superior during a thorough three-year study and found chemicals even in the most remote, pristine spots, as if transported by magic.
“There was not a single location where we found absolutely nothing,” Grand Portage Band of Lake Superior Chippewa director of biology and environment Seth Moore told MPR. He was also one of the lead researchers on the project.
“There was always at least a handful of chemicals in sediments and fish tissues and in waters,” he said. Sometimes, they were even found in levels comparable to more populated lakes. As many as 17 chemicals were found in a completely undeveloped lake.
The next step is figuring out how they got there. From wastewater, the researchers suspect – treatment plants don’t filter out pharmaceuticals and medicines, and those, by design, tend to linger for a long time in the natural environment.
But some of these lakes aren’t connected to those facilities, meaning deposition – the process through which water evaporates and is dropped elsewhere in the form of rain or snow – is at least partially to blame.
Sadly, there’s nothing particularly magical about lake cocaine, and it can have some distinctly less-than-magical effects on the environment. At such trace amounts, it’s not likely they pose a risk to human health. But the researchers aren’t quite sure yet how it’s going to affect fish and wildlife.
How is swimming through DEET and Prozac going to impact a bluegill’s ability to reproduce? How many cancer drugs and opiates can a fish digest before it affects the animal – or human – who eventually eats it?
That’s a much less than hypothetical question. The Grand Portage Band maintains hunting and fishing rights in these waters, and 35 chemicals were found in species mportant to their diet and economy.