THE WATER QUALITY OF THE CHATTAHOOCHEE RIVER DOWNSTREAM OF ATLANTA, GEORGIA AND A COMPARISON TO THE WATER QUALITY OF THE ALLEGHENY, MONONGAHELA, AND OHIO RIVERS OF PENNSYLVANIA

Monitoring of the Chattahoochee River was done for extended periods of time from 1999 to 2003. Monitoring was conducted 56 miles downstream of metro Atlanta in Carroll County, Georgia. Monitoring included both weekly and 12-hour interval sampling during storm events. Water quality monitoring consisted of measuring temperature, pH, DO, turbidity, specific conductivity, nutrients (total phosphorus, ammonia-N, and nitrite-nitrate-N) and fecal coliform bacteria. The Chattahoochee River starts out as a small mountain stream in northwest Georgia. The area upstream of Atlanta consists of forests and agricultural land. The river’s water quality has historically been poor downstream of Atlanta. Today the Chattahoochee River downstream of Atlanta is in violation of fecal coliform bacteria standards and has restrictions on fish consumption because of mercury and PCBs. Phosphate and ammonia concentrations in the Chattahoochee River have been reduced by a state ban on phosphate in detergents and by improvements in sewage treatment. However, the levels of nitrite-nitrate-N have increased with population growth. The current median level of nitrite-nitrate-N is 1.81 mg/L. To improve the water quality of the Chattahoochee River and remove more nutrients will require Atlanta to spend $3 billion to upgrade sewer lines and sewage treatment plants.

Using USGS data a comparison between the Chattahoochee River and the Allegheny, Monongahela, and Ohio Rivers downstream of Pittsburgh can be made. The Chattahoochee River basin and the Allegheny, Monongahela, and Ohio River basins have different bedrock, historical land usage, and water quality problems. Coal mining in the Allegheny and Monongahela basins has resulted in high sulfate concentrations in streams that drain the mined areas and in high metal concentrations in sediments and limited fish community. Whereas in the Chattahoochee River basin the most degraded streams are those that drain urban areas. Certain sections of the Allegheny and Monongahela Rivers have restrictions on fish consumption because of PCBs and chlordane. The smaller upper Chattahoochee River basin (2430 square miles) is about 1/9 the size of the three Pennsylvania rivers at Pittsburgh. This results in severe shortages of drinking water supply for metro Atlanta during warm dry summers.