Percolation in Wetlands

Drainage from PolyMet’s proposed mine site (magenta) that moves through the One Hundred Mile Swamp (yellow outline) will go to the BWCA via Langley Creek and Lake Superior via the Partridge River.The PolyMet SDEIS avoids the issue of drainage to the BWCA by drawing a smaller swamp that omits the portion that drains to Langley Creek .PolyMet maps further imply 100% drainage to the Partridge River by highlighting the river with blue, making it appear larger.In reality, the Partridge River is indistinct. After flowing through a culvert under the dirt road near point A, it disappears completely into the One Hundred Mile Swamp.Hill shade map of the One Hundred Mile Swamp shows the flat swamp straddles the Laurentian Divide.Disappearance of the Partridge River into the One Hundred Mile Swamp means that at some point all the water is ground water.Groundwater contours in the One Hundred Mile Swamp descend in the easterly direction towards Langley Creek.To examine potential impacts on the BWCA, hydraulic conductivity in the One Hundred Mile Swamp should be tested using a pumping well and multiple observation wells.Mine waste could move through the swamp in as little as 74 days (at 143 ft/day) Water quality testing should be done at Langley Creek and the USGS Dunka River Station.