THE USE OF BIOLOGICAL AND WATER QUALITY MONITORING DATA FOR MANAGING NONPOINT SOURCE POLLUTION IN FULTON COUNTY, GEORGIA

Fulton County is performing a watershed assessment to evaluate water quality for several watersheds in the County. Results from the Camp Creek Watershed are presented as they relate to land use, point and nonpoint source pollutant loadings, and other important watershed factors. The purpose of the watershed assessment is to develop a management plan to control nonpoint source pollution and improve the condition of the biological communities in these highly urbanized stream ecosystems. As a major component of the project, watershed characterization studies were conducted from August 1998 to December 1998 to gather physical, chemical, and biological data from representative stream locations selected throughout the Camp Creek and Little River Watersheds. The bioassessment approach used in this study incorporates benthic macroinvertebrate (e.g., aquatic insects, mollusks, annelids, and arthropods) and fish community structures as indicators of habitat and water quality conditions. The process of using biological community structure as a means of assessing water quality and/or stream biotic integrity developed by the U. S. EPA (EPA) is referred to as Rapid Bioassessment Protocol (RBP). In this process, the benthic macroinvertebrate and fish community assessments are performed by comparing differences between study conditions and reference conditions.The results of the biological assessment were used to set management goals or improvement guidelines and prioritize areas within the watershed that are most critical for management. By linking the biological results with the water quality monitoring data, we were able to set management goals that are specific to the watersheds being studied and are relevant to improving the condition of the biological communities. By looking at statistical correlations between water quality results and the biological data, we were able to determine which water quality parameters had the greatest effects on the biological communities and to plan our management around those parameters.Study results from 30 stations in Fulton County revealed that changes in habitat had a greater effect on the biological communities than water quality. R squared values were greater than 0.5 for habitat and much lower for all of the water quality parameters. We found that habitat was altered by sedimentation and stream hydrology. Excessive sediment covered important spawning substrates for fish, and altered hydrology increased bank erosion and sediment delivery from upland sources to the stream. Management in Fulton County will focus on setting total suspended solids (TSS) improvement guidelines and target values for habitats, as well as controlling the frequency and magnitude of hydrologic peaks.With the increasing need to manage nonpoint sources of pollution in urban watersheds, it will become important to develop a multidisciplinary management approach that can focus on chemical, physical, and biological components of stream systems. An important element in accomplishing this is to incorporate goals for managing biological communities by developing relationships between the chemical, physical, and biological components of stream systems. By integrating the biological components with the physical and chemical components, we can develop a holistic management approach that can address the complex issues facing urban streams in metro Atlanta.