STUDY OF E. COLI AND OTHER WATER QUALITY INDICATORS IN A SMALL SUBURBAN WATERSHED

Water quality is analyzed to protect wildlife and the surrounding population from potentially harmful bacteria. Eleven sites in the Dry Run Creek Watershed in Cedar Falls, Iowa were sampled and analyzed to determine its water quality. Testing was performed on field and in the laboratory. The onsite tests consisted of: temperature, dissolved oxygen (DO), pH, turbidity, total dissolved solids (TDS), and conductivity. The laboratory tests consisted of: biochemical oxygen demand (BOD), total suspended solids (TSS), phosphate, nitrates, chloride, sulfate, and fecal coliforms (E. coli). There were three sites in the southeast branch (11, 5, and 6), both agricultural and residential, that were relatively low in E. coli but were found to be considerably higher in nitrate and chloride. The west branch (2, 4, and 12), comprising the agricultural sites demonstrated variable testing results. Along the northwest branch (3 and 1), having all the residential sites, the TSS and e-coli were relatively low due to minimal flow. The north branch consisted of sites 9 and 13 within the Cedar River main course and site 8 is right before the Dry Run Creek discharges into the Cedar River. These sites were high in TDS, TSS and E. coli. The testing of these sites showed that when there is considerable amounts of rainfall within a 24 hour time frame of sampling there would be relatively higher amounts of TDS, conductivity, turbidity, E. coli, and TSS. The results that have been collected at this time so far indicate that there were high amounts of E. coli in the Dry Run Creek and Cedar River. This work is ongoing for the Dry Run Creek watershed and the overall contributions of this small suburban stream system to the main course Cedar River will soon be known.