VARIATIONS IN NUTRIENT COMPOSITION OF DEVELOPED AND NON-DEVELOPED WATERSHEDS OF WEST GEORGIA: GIS-ASSISTED INTERPRETATION OF WATER QUALITY ANALYSES

The purpose of this project is to analyze the variations in nutrient composition of developed and non-developed watersheds. The nutrients studied include nitrite-nitrate-N, total phosphates, TKN, and ammonia-N. The streams selected for study include two non-developed watersheds. The Clear Creek watershed is commercial forest and the Pink Creek watershed is a mixture of forest, pastureland and hay fields in rural Heard County, Georgia. Much of the pastureland is fenced so that the cattle have direct access to streams. A developed watershed near the city of Villa Rica, Georgia, was also selected for the study. It includes the upper portion of the Little Tallapoosa River and a tributary to the river, Mud Creek. The developed watershed is an area of rapid growth with related transformation of remaining forest and farmland into residencies and commercial property. The levels of nutrient concentration as a maximum, minimum, overall and seasonal average are plotted with a GIS and examined for land use and land cover correlation. Phosphorus data shows high concentrations at Pink and Mud Creek, with maximum values of 2.33 and 2.12 mg/L, respectively. Both creeks receive phosphorus from cattle farming, however the concentrations found in Mud Creek could also be attributed to sewage discharge. Although not as extreme as phosphorus concentration, average nitrite-nitrate-N concentrations at Pink Creek (0.76 mg/L) and Mud Creek (0.59 mg/L) do appear anomalous as compared to average concentrations along Clear Creek (0.09 mg/L) and the upper Little Tallapoosa River (0.22 mg/L). Average values for TKN range from 0.47 mg/L for Clear Creek to1.17 mg/L for Mud Creek. Mud Creek’ has a maximum TKN value of 5.85 mg/L. This can be attributed to the sewage discharge plant. Average ammonia-N concentrations for Mud Creek (0.60 mg/L) are higher than the averages for the other creeks. This can be attributed to cattle farming. According to this case study, the nutrient concentrations found at Mud Creek and Pink Creek suggest that cattle farming is a major contributor to high nutrient levels of total phosphorus, nitrite-nitrate-N, TKN, and possibly ammonia. Sewage discharge is also a source for a high level of nutrient concentration.