THE CHATTAHOOCHEE RIVER BELOW METRO ATLANTA: THE ROLE OF URBAN RUNOFF, SEWAGE DISCHARGE, AND CHICKEN MANURE ON THE WATER QUALITY OF THE CHATTAHOOCHEE RIVER

The city of Atlanta sits in the center of the Piedmont Region of Georgia, drawing its water from the smallest watershed of any city of its size. Decades ago Atlanta was promoting itself as the “City of Trees” with its large green space and thick surrounding forest, but today rapid urban sprawl is leveling forest and farmland, turning them into housing developments, roads, strip malls, and low-density housing with septic systems. With a population of 3.5 million in 2001 and a growth rate of 2.3%, the city of Atlanta is dependent on the Chattahoochee River coupled with Lake Sidney Lanier to provide drinking water for an approximate 2.7 million people. Urban runoff, sewage discharge, and manure from farms, mainly poultry, are making an impact on the water quality of the Chattahoochee River. The upper Chattahoochee River watershed has many poultry farms competing with the urban sprawl for land on which to spread the chicken manure. Poultry farms are spread throughout Georgia, but a concentration of the poultry industry has developed northwest of Atlanta near Lake Lanier where open land is becoming hard to come by. Georgia leads the nation in the production of broiler chickens, which is a 2.5 billion dollar a year industry with the production of over 6 billion pounds of chicken a year. Much of the farmland is already saturated with nutrients from excess manure spread on the land increasing the chance of nutrients getting washed into the Chattahoochee River. Our research consists of weekly water quality monitoring of the Chattahoochee River at McIntosh Park in Carroll County, Georgia. Comparison of our results to upstream USGS monitoring stations shows that Metro Atlanta has a significant impact on the water quality of the Chattahoochee River. Atlanta’s discharge of 350 MGD of treated sewage and urban runoff lowers dissolved oxygen and increases nutrients (ammonia-N, nitrite-nitrate-N, and total phosphorus), temperature, and specific conductivity. These factors coupled with runoff from pasturelands and chicken farms washing fecal coliform bacteria and nutrients into and through tributaries feeding the Chattahoochee River cause degradation of the water quality downstream from Atlanta. We are also taking into account the added or muted impact on the water quality with seasonal variations in ambient temperature, water flow, and rainfall.