PolyMet Environmental Impact Statement Has Incorrect Maps

St. Paul, MN   Tuesday March 11

PolyMet Environmental Impact Statement Has Incorrect Maps

The Minnesota Department of Natural Resources has been receiving comments that maps in PolyMet’s Supplemental Draft Environmental Impact Statement are wrong. Maps in the SDEIS released on December 6, 2013 make it appear that sulfuric acid and heavy metal containing mine runoff will drain only into the already impaired Saint Louis River watershed when in fact drainage can go to two watersheds, one of which includes the unspoiled Boundary Waters Canoe Area wilderness. 

The SDEIS maps draw a much smaller swamp downhill from the mine compared to existing government maps.  According to US Government maps, the One Hundred Mile Swamp downhill from the mine is 10.4 miles long and drains to both the Saint Louis and Rainy Lake (BWCA) watersheds but SDEIS maps show a shorter 5.5 mile long swamp that is missing the portion of the swamp that drains to the BWCA. Omitting the portion of the swamp that drains to the BWCA supports PolyMet’s conclusion that seepage of mine waste water to the BWCA watershed will not occur.

Dashed, teal colored outlines of the One Hundred Mile Swamp on green satellite image maps are difficult to see and it might have been expected that the mapping discrepancy would go undetected in the 90 day public review period. Marking of important map features in such an obscure way may be seen as evidence of intent to avoid connecting an environmentally risky mine with the fragile and iconic BWCA wilderness. 

A website that provides more detailed information about the mapping issue at www.bwcasulfidemining.org is receiving increasingly serious attention.  The website documents that the first incorrect map in the SDEIS appears as Figure 4.2.3-1 on page 472 and that a comparative government map of the swamp area is available at www.nationalatlas.gov/streamer.  The downstream flow mapping feature of the www.nationalatlas.gov/streamer map was used to show that the eastern portion of the One Hundred Mile Swamp drains via Langley Creek and the Dunka River to the BWCA, and that the drainage will also affect the Quetico Provincial Park along the US – Canada border.

Real life understanding of the effect of the proposed mine on the BWCA requires determining the split of waste drainage in the swamp that goes to the St. Louis River and BWCA watersheds by hydraulic conductivity testing which has not been done. Ongoing protection of the BWCA requires periodic water testing for mine waste at Langley Creek and the Dunka River which is not provided for in the uncorrected SDEIS.

The BWCA and Quetico are sufficiently valuable that untrustworthy conclusions about sulfide mining pollution from PolyMet’s proposed mine can’t go unresolved.  The incorrect mapping in the SDEIS is expected to become a serious issue for PolyMet’s proposal.