RETIRED AGRICULTURAL SITE'S IMPACT ON GROUNDWATER AND SURFACE WATER QUALITY

Agricultural activities can continue to impact the quality of both groundwater and surface water long after the activities have ceased. Previous studies in varied environments have estimated the negative impact of nutrients from agricultural runoff on streams and ponds. This study evaluates these negative impacts at Andalusia farm using a watershed systems approach. Andalusia farm has not been agriculturally active for approximately 30 years, but continues to be maintained as a tourism site for the famous Southern Gothic writer, Flannery O’Conner. Various physiochemical and water quality parameters have been monitored in the surface water and groundwater at Andalusia in the last 5 years (by various researchers). Nutrients and iron levels, physiochemical parameters, algal, soil and hydrogeologic data were analyzed to quantify internal and external nutrient loading in the surface water. The hydrologically connected system at Andalusia consists of upland runoff fields that drain into a wetland and a manmade pond. Pond water overflow and groundwater feed a small stream that drains into Tobler Creek, a tributary of the Oconee River. Preliminary results show a complex relationship among the three water sources at the site (groundwater, the pond, and Tobler Creek). Soil and hydrologic data are currently being analyzed to quantify residual soil nutrients and their potential to act as an internal source of nutrients, especially during rain events. To further understand the movement of nutrients and create a management plan, we are also developing a nutrient-transport model for this site.