LONG-TERM TRENDS OF NUTRIENTS IN TALLAPOOSA AND CHATTAHOOCHEE WATERSHEDS OF WEST GEORGIA

Students, faculty, and staff through the Center for Water Resources at the University of West Georgia (UWG) have been part of 3 intense watershed assessments since 2001. The 2001 watershed covered two west Georgia counties with 70 sample stations that were monitored weekly to monthly for 21 water quality parameters. From 2003 to 2006 long-term monitoring was conducted monthly at critical stream and lake sites. Now underway is long-term monitoring proposed for 2007 to 2011.

The UWG is located in Carroll County. The county is within the Piedmont Province, which is undergoing a rapid increase in population (from 87,000 in 2000 to 105,000 in 2005), maintains a significant agriculture base ($120 million poultry income in 2005), and needs to protect and develop additional drinking water supplies. A significant drought affected Georgia in 1999-2000. The first 6 months of 2007 have ushered in an even more intense drought. Northeast and western Carroll County is in the Tallapoosa watershed. The largest tributary of the Tallapoosa River is the Little Tallapoosa River. It heads in northeast Carroll County, flows west across the county into Alabama. The Little Tallapoosa River is the major source of drinking water for Carrollton. The Chattahoochee River forms the southeastern boundary of Carroll County. Downstream of Carroll County both rivers flow into large reservoirs that are receiving excess nutrients and sediment.

Nutrients (nitrite-nitrate-N, ammonia-N, TKN, and total phosphorus) in surplus can cause excess algal and plant growth in freshwater lakes. Two sites (one downstream of former cattle pasture and the other downstream of discharge from a sewage treatment plant) inside the city of Villa Rica on a small tributary of the Little Tallapoosa River have the highest TKN (1.4 – 5.8 mg/L TKN) and ammonia-N (1.4 – 3.8 mg/L). Ninety-one percent of TKN and ammonia-N measurements are below 0.8 and 0.25 mg/L, respectively. Baseline data collected in 2001 show that runoff from farmland, suburban areas and cities, and discharge of treated sewage raise nitrite-nitrate-N and total phosphorus levels. Higher maximum and average nitrite-nitrate-N and total phosphorus occur downstream of a sewage treatment plant (maximums 2.14 mg/L N-N-N and 2.12 mg/L phosphorus) and a spray application field (maximums 2.63 mg/L N-N-N and 3.72 mg/L phosphorus).