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from 0.06 0.15 ma/1 and 4.8 - 16 mg/1 respectively. The above average concentrations are all within the "typical" ranges provided by the MPCA. The average total phosphorus concentration monitored at TBCR 35 is on the high end of the "typical" range for total phosphorus and is 25 percent higher than the average total phosphorus concentration monitored at ERCR 15. Storm event monitoring of minor tributaries to Lake Orono overall showed reasonably low total phosphorus and TSS concentrations (See Table 2). Due to the very small local drainage contribution to Lake Orono, the lake's water quality is dominated by the Elk River flow. In-lake total phosphorus and TSS concentrations in Lake Orono are very high compared to minimally impacted lakes within the NCHF ecoregion. "Typical" summer values for total phosphorus and TSS, within the NCHF ecoregion, range from 0.023.- 0.050 mg/1 and 2-6 mg/1 respectively. (Minnesota Lake Water Quality Assessment Report, Second Edition, 1990.) Average summer values for total phosphorus and TSS in Lake Orono, based on five summer samples collected as part of this study, were 0.171 mg/1 and 27 mg/1 respectively. Based on total • phosphorus data Lake Orono is classified as hypereutrophic. Poor water quality in Lake Orono is largely due to a very high watershed drainage area to lake volume ratio resulting in average residence times of only three days. Total phosphorus removal efficiencies within Lake Orono were calculated to be less than 10 percent. This is much lower than lakes with longer residence times where removal efficiencies can be on the order of 90 percent. 2. Fecal Coliform and Fecal Streptococci The City of Elk River collected fecal coliform samples at the Lake Orono City Beach during ten sampling events in July - September 1997. Results indicated fecal coliform concentrations between 200 and 4,600 organisms/100 milliliters (m1), in many cases significantly above the National Public Health Association Guideline of 200 organisms/100 ml (see Table 3). Additional sampling was conducted on August 19, 1997 at various locations along the Elk River and at the Lake Orono City Beach. Results indicate very high concentrations of fecal coliform i N.VMS\O l'EL F:RI VER.RPT-NCV 14