“Minnesota pollution-control panel has approved the dumping of 13.5 tons of taconite concentrate into a Chisago County lake to battle high levels of weed-producing phosphorus.
The Minnesota Pollution Control Agency Citizens’ Board gave the Rush Lake Improvement Association clearance Tuesday, May 22, to go ahead with the experimental project. The panel signed off on it without requiring an informational review that an environmental group and other area residents had sought.
“It’s a huge disappointment,” said Don Arnosti, policy director for Audubon Minnesota, which sought the review, an exercise that can lead to a more stringent examination. “In the end, they wimped out. It’s throwaway words in a public meeting. There are no consequences.”
The pollution-control board added a few stipulations, though, after some members openly wondered why such a review, called an environmental assessment worksheet, shouldn’t be conducted.
The lake association has been trying for years to reduce levels of phosphorus, a nutrient that promotes algae growth when present in elevated concentrations. Common sources include animal waste and fertilizer.
Rush Lake, west of Rush City and Interstate 35 and north of the Twin Cities, also has curly-leaf pondweed, an invasive plant.
In 2009 and 2011, the association, working with St. Paul-based Blue Water Science, dumped 4 and 4.5 tons of iron into the lake to see if it would cut phosphorus levels.
“Results so far are encouraging in some cases but inconclusive in other cases,” said Steve McComas of Blue Water Science, contending that iron has been used for more than two decades to sequester phosphorus in lakes with high levels of it.
He specifically cited Vadnais Lake, the drinking water reservoir for St. Paul.
Now, the Rush Lake association wants to dump the particles in three areas covering up to 12 acres of the 3,059-acre lake. More than 90 percent of the product would be iron oxide.
The association, however, has run into opposition from Audubon and some area residents. Citing risks to birds, fish and even people, they say the concentrate still contains unknown ingredients that should at least be identified before the experiment proceeds.
“We don’t know how they will be affected,” said Arnosti, who even speculated the proposal was at least partially aimed at reducing curly-leaf pondweed.
Board members said they were frustrated by the seeming gap between the two sides but eventually sided with a staff recommendation that, in this case, the project was exempt from environmental review.
Association President David Cartwright said that the MPCA, along with other state agencies, had been following the effort closely for years and that no further review is needed.”
I can’t believe they don’t have to do more testing before dumping this amount of iron in the lake. They have no idea how this will affect fish and wildlife, only that the weeds will be reduced. Unbelievable.
