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DRAFT <br /> <br />3. Physical Analyses <br /> <br />Sediment samples were also classified by a soil engineering testing firm and grain size <br />distribution performed on sediment from the four sampling locations. In-place cores of the top <br />20-inches of sediment as well as composites of sediment collected at depths between 0-4 feet <br />were analyzed. The above analyses are contained in Appendix B. The surface cores are denoted <br />as T-l, T-2, T-3, and T-4 as samples contained in tubes. The composite samples are denoted as <br />B-l, B-2, B-3, and B-4 as samples contained in bags. The sediment samples varied in <br />composition from approximately 30 to 90 percent sand and gravel and approximately 10 to 70 <br />percent silt and clay. <br /> <br />B. WATER QUALITY MONITORING <br /> <br />1. Suspended Solids and Phosphorus Monitoring <br /> <br />Water quality monitoring was conducted on the major inflows and the outflow from Lake Orono. <br />Grab samples were collected a minimum of 18 times over a one year period from the Elk River at <br />County Road 15 (ERCR 15), Tibbits Brook at County Road 35 (TBCR 35), and the outflow of <br />Lake Orono at the dam. See Figure 3 for the location of the monitoring stations. The sum of the <br />drainage areas upstream of the two major inflow monitoring stations constitutes approximately <br /> <br />98 percent of the total Lake Orono drainage area of 388,000 acres (Figure 2). Total suspended <br />solids (TSS), total phosphorus, and ortho phosphorus were analyzed for each sampling event. <br />Volatile suspended solids (VSS) were analyzed for the last eleven sampling events. Monitoring <br />at the Elk River and Tibbits Brook stations was conducted by the Sherburne Soil and Water <br />Conservation District. Monitoring at the Lake Orono Dam was conducted by the Lake Orono <br /> <br />N:\0598\01 hELKKIVER.RPT-rlb 5 <br /> <br /> <br />