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been cleaned with distilled water. The jug was rinsed twice with stream water prior to collecting each sample. The sample was collected from flowing water in the center of the streams. Samples were stored in a cooler for transporting to Environmental Protection Laboratories in St. Cloud for analysis. Stream flow was measured for Tibbits Brook and for County Ditch 28 for 11 of the sampling events using a General Oceanics model 2030 flow meter. A rating curve was developed using the combined discharge of Tibbits Brook at the County Road 35 bridge and Ditch 28 where it exits the culvert beneath Country Road 35. For Tibbits Brook, three separate velocity measurements were made for each sampling event and an average velocity was calculated. When water depths were greater than 2 feet, measurements were taken at two depths for each of the three measuring points corresponding to approximately 20 percent and 80 percent of the total water depth. For Ditch 28, one flow measurement was made. The discharge was then calculated using the cross sections for each stream. For each sampling event, the water level in Tibbits Brook was measured from a point on the County Road 35 bridge for use in developing the rating curve and for estimating discharge when it was not measured directly. Monitoring at the Lake Orono Dam was conducted by the Lake Orono Improvement Association. See Table 1 40 for a summary of the water quality data. Water quality monitoring data are contained in Appendix C. In addition, minor inflows to Lake Orono were monitored during three storm events. See Table 2 for a summary of the monitoring data. Water quality monitoring data are contained in Appendix C. Grab samples were collected at five locations in total. These locations are culverts under Islandview Drive and Highway 10, and stormsewer outfalls located near 189th and Concord, Orono Road and Mississippi Road, and Orono Road at City Hall. Samples were collected at each location during selected sampling events. Stream flow measurements were made and stream flows estimated at these locations at the time of sample collection. Storm event monitoring was conducted by Wenck Associates, Inc. After sample collection, samples were immediately placed on ice in a cooler and were transported to the laboratory within 24 hours of collection. • N:\0598\01\EI.KRI VER RPT•NC W 5