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<br />According to the Bedrock Geology and Stmcture Map of the Seven-County Twin Cities <br />Metropolitan Area (MossIer and Tipping, Minnesota Geologic Survey, 2000) for the <br />project area, the uppermost bedrock units with the project area are the St. Peter Sandstone <br />over much of the project area, with the Prairie du Chien Dolomite present as the first <br />bedrock unit over the northern and western edges of the project area. The Prairie du <br />Chien is present over the entire project area, but is overlain by the St. Peter over much of <br />the proj ect. <br /> <br />Where the Prairie du Chien is present as the first bedrock unit, it is generally found at the <br />depth between 50-100 feet, classifying the area as being a "transition karst" area, as <br />opposed to an "active karst" area where depth to carbonate bedrock is less than 50 feet <br />deep. In general, areas of transition karst do not typically experience hazards such as <br />sinkholes unless changes are made to local topography to reduce depth-to-bedrock. <br />However, a minor risk for karst features developing in the project area does exist simply <br />due to the nature and depth of the bedrock in the area. <br /> <br />b. Describe the soils on the site, giving NRCS (SCS) classifications, if known. Discuss <br />soil granularity and potential for groundwater contamination from wastes or <br />chemicals spread or spilled onto the soils. Discuss any mitigation measures to <br />prevent such contamination. <br /> <br />According to Anoka County soils information, the soil types listed in the following table <br />are identified in the project area. Their locations are depicted on Figure 8. <br /> <br />Soil Types <br /> <br />Symbol I <br /> <br />Soil Name <br /> <br />Special <br /> <br />Hvdroloe:ic <br /> <br /> I I - ~ <br /> Significance * I Soil Group** <br />Af Alluvial land, mixed, I Hydric D <br /> frequently flooded <br />Bm Blomford loamy fine Hydric BID <br /> sand <br />Cu Cut and fill land -- -- <br />---- <br />Du Dundas loam Hydric, prime BID <br /> fannland if <br /> drained <br />HdB Hayden fine sandy Prime farmland B <br /> loam, 2-6% slopes <br />HdC2 Hayden fine sandy Farmland of B <br /> loam, 6-12% slopes, statewide <br /> eroded importance <br />NcA I N cssel fine sandy loam, Prime farlnlaild D <br /> D _J <br /> 1-4% slopes <br />Wb Webster loam Hydric, prime BID <br /> farmland if <br /> drained <br /> <br />16 <br />