The HHPLS identified the infiltration potential of the upland areas within the subwatershed as medium to low with some areas of variability where the soils are organic in nature (see Figure 16). The area to the north and east of Gleason Lake is of high infiltration potential as well as high aquifer sensitivity due to the outwash nature of the underlying soil deposits. The Hennepin County Geologic Atlas classifies most of the upland areas as being of low to moderate sensitivity to pollution, and the areas of outwash as highly sensitive (see Figure 17).
Most of the Gleason Lake subwatershed has been designated by the Minnesota Department of Health as a Drinking Water Sensitivity Management Area (DWSMA) and Wellhead Protection Area for City of Plymouth public wells. The MDH has designated much of this area to be of a low risk and vulnerability to contamination of the drinking water supply, with the area of high infiltration capacity and aquifer sensitivity as being moderate to high risk and vulnerability. Figure 18 shows the DWSMA and associated Wellhead Protection Areas.