INFLUENCE OF RIPARIAN BUFFER SYSTEMS ON THE REGULATION OF NUTRIENT AND BACTERIA CONCENTRATIONS: CASE STUDY IN SHENANDOAH VALLEY, VIRGINIA

The intensive agricultural practices adopted in the Shenandoah Valley Region negatively impacted on the local ecosystem health. Increase in livestock inputs resulted in runoff contamination which caused elevated levels of harmful bacteria such as E. coli. Based on a study conducted by the Virginia Department of Environmental Quality in 2021, 80% of their monitoring sites recorded elevated levels of E. coli. The Conservation Reserve Enhancement Program (CREP) of the US Department of Agriculture (USDA) encourages farmers to install vegetation strips along the waterways. These vegetation strips are known as riparian buffers, which are effective in controlling nutrient and bacterial levels and improving water quality. The present study focused on evaluating the influence of riparian buffer systems in controlling nutrient and bacterial levels in the selected farming systems in the Shenandoah Valley region of Virginia. Six farming systems will be used to collect the water samples to analyze nutrients and bacteria concentrations. These farming systems were adjacent to creeks which flow into the North or South Fork of the Shenandoah River. The collected samples will be analyzed for bacteria concentrations (mainly E. coli and total coliform) using the IDEXX Quanti-Tray method (EPA 9223B). Additionally, the samples will be analyzed for total nitrogen (Kjeldahl method) and total phosphorus concentrations (Olsen P method). Moreover, GIS tools were used to analyze the landscape characteristics (farm size, buffer length, buffer age, etc.) and their impact on the bacteria and nutrient concentrations. Results from this ongoing study revealed that the farm size and the farm type (crop or livestock) has a significant influence on the pollutant concentrations. We are currently working on analyzing the water samples for bacteria, nitrogen, and phosphorous concentrations. We hope that well managed riparian buffer systems have the capability to improve the water quality and overall ecosystem health.