Spatial and Temporal Variation in Water Quality Along an Urban Stretch of the Chattahoochee River and Utoy Creek in Atlanta, Georgia, 2013

The Chattahoochee River is the most utilized surface water in Georgia, and it and Utoy Creek are receiving waters for Atlanta stormwater and wastewater effluent. Population growth and record-breaking rainfall in 2013 has led to potential stress from stormwater runoff and nonpoint source loading. The goals of this research are to examine spatial and temporal variations in E. coli and the bacteriophage MS2 and relationships with DO, turbidity, rainfall, and riverflow; to determine if E. coli in water is correlated with E. coli in sediment; and to determine if wastewater effluent discharges influence downstream sample sites. Water samples were collected at fifteen sample sites and two outfall sites in the Chattachoochee, and ten sites in Utoy Creek. No significant spatial variation in E. coli was found for the Chattahoochee, although there was significant temporal variation in mean E. coli concentrations. The lowest mean DO values and the highest mean turbidity levels both occurred on the date of the highest mean E. coli concentrations. Effluent from the two outfalls did not contaminate downstream sample sites. In Utoy Creek, E. coli concentrations showed spatial and temporal variation in water samples, but not for sediment samples. Turbidity was found to be positively correlated with both E. coli in sediment and MS2. These findings suggest that nonpoint source loading is a potential cause of contamination. Since DO, turbidity, and rainfall were correlated with E. coli and MS2, these parameters could be used as indicators of pollution for future monitoring of the Chattahoochee River and Utoy Creek