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Phosphorus is a nutrient which stimulates algae bloom or "dog days". Reducing the man <br />made sources of phosphorus will help reduce the frequency and intensity of algae blooms <br />in the lake, however, it will not eliminate these occurrences. Reducing the man made <br />sources of phosphorus should be pursued in both the Elk River and Lake Orono. <br /> <br />Fecal coliforms - In the summer of 1997, the city began monitoring the level of fecal <br />coliform at Orono Beach. The city's waste water treatment plant analyzes fecal coliform <br />levels in their discharge so they have the ability to run the tests at the beach. Diseases <br />may be associated with these waste born bacteria, so fecal coliform levels are a health <br />issue. <br /> <br />Significant levels of fecal coliform in July and August raised concerns. Staff did <br />additional tests to determine if the high levels of fecal coliforms were of humane or <br />animal origin. Fecal coliform of animal origin is not consider as much of a health threat <br />as those from humane origin. In general, the elevated levels of fecal coliform were <br />determined to be of animal origin (see page #15 of the study). It is theorized that a likely <br />source of the fecal matter is geese. Weekly monitoring for fecal coliform should be <br />conducted throughout the swimming season. <br /> <br />SEDIMENTATION <br /> <br />Suspended sediment - The study revealed that more suspended sediment is leaving the <br />lake then there is entering the lake. This was determined by monitoring the inlet and <br />outlet of the lake for suspended sediment. Staff feels suspended sediment is not a major <br />issue because the lake is not large enough to settle it out and passes it through. See page <br /># 10 of the study for details on suspended sediment. <br /> <br />Bedload - Bedload is the heavier material transported by the Elk River and deposited in <br />the lake. The study estimates that the average rate of bedload being deposited in the lake <br />is 3,000 cubic yards (CY) per year. This is not an unusually high rate. However, sources <br />of erosion upstream from the lake should be eliminated as much as feasible. See page <br />#11 of the study for the discussion on sediment load. <br /> <br />Conclusions and Recommendations - Other conclusions and recommendations of the <br />study are found on pages 16 and 17. <br /> <br />f:Xshrdoc\b&zXstever~lakeocc.doc <br /> <br /> <br />