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DRAFT <br /> <br />II. <br /> <br />Description of Investigation and Results <br /> <br />A. LAKE SEDIMENT SAMPLING <br /> <br />1. Sediment Sampling Procedures <br /> <br />Four sediment sampling locations were identified in cooperation with the Minnesota Pollution <br />Control Agency (MPCA) to characterize sediment within Lake Orono in preparation for <br />anticipated future dredging activities. Sampling locations are indicated on Figure 3. Per the <br />MPCA's suggestion, samples from the upper 6-inches of sediment were obtained with a Ponar <br />dredge at each of the four sampling locations. Sediment cores were also collected to a depth of <br />4 feet by two methods described below. <br /> <br />Sediment coring was completed using a modified Wildco K-B stainless steel core sampler. This <br />core sampler collected sediment samples that were 2 inches in diameter and 20 inches in length. <br />The K-B sampler utilized clear cellulose acetate butyrate (CAB) core liners and eggshell-type <br />core catchers. The sampler was manually lowered into the water and penetrated the sediments by <br />either the force of its own weight or by being pushed or driven as dictated by sediment <br />consistency. After the sampler reached maximum penetration, it was carefully retrieved and <br />disassembled. The filled liner was then removed from the core tube, capped and labeled. The <br />core sampler was then cleaned using a non-phosphate detergent solution and deionized water <br />rinses and reassembled with new liner tube. <br /> <br />Sediment samples were also collected utilizing a modified 3-inch stainless steel AMS bucket <br />auger. A 4-inch diameter PVC casing was first driven into the sediment. The bucket auger was <br />then utilized to manually bore into and collect the sediment from within the PVC casing. The <br /> <br />N:\0598~01 ~ELKRIVER. RPT-rlb 3 <br /> <br /> <br />