Stream Water Quality and Land Use

Water Quality in Accomack County Freshwater Streams 2020

Eastern Shore Freshwater Stream

Expansion of poultry house operations and use of litter as a soil amendment has raised concerns for water quality impacts on both seaside and Bayside of the Eastern Shore of Virginia (ESVA). This ongoing investigation is examining freshwater stream water quality on the ESVA to identify water quality impairments via storm water runoff.

The sampling targets drought periods (base flow) and >1” rainfall events (storm flow) in streams at road crossings in Bayside and Seaside drainages. Dissolved Ammonia, Dissolved Nitrite + Nitrate, Total Nitrogen, Total Phosphorous, and Turbidity are determined by laboratory analysis. Temperature, Salinity, Dissolved Oxygen, and pH are recorded in the field, and flow rates determined to estimate loading rates. Estimates of land cover in the drainages for these streams were used to determine correlations between stream water quality and the presence of poultry operations, agricultural fields, residential housing, forest, and swamps.

No overall effect of poultry operations has been detected. Rainfall tends to dilute nitrogen concentrations in streams, indicating a ground water source, although total nutrient loading increased with the increasing volume of flow. Turbidity and particle associated phosphorous showed the most dramatic changes with storm events. Data on Seaside ESVA watersheds for stream nitrate values from ten years ago had an overall average value slightly lower than the overall value for the present study. Stable Isotope data suggest little to no input to stream particulate matter from poultry litter or poultry ammonium deposition.

2020 Accomack County Stream Water Quality Report (pdf)