A Water Quality Assessment of Nontidal Streams In the Sassafras River Watershed.

Recently, the Chesapeake Bay has been scrutinized for poor water quality, including high levels of nitrogen and phosphorus, large algae blooms, low levels of dissolved oxygen, and increased turbidity. Landuse and land use practices often contribute to the nutrient and sediment loadings in the Bay. The effect of land use on potential nutrient loadings from a smaller sub-watershed can be determined through weekly monitoring. The Sassafras River watershed, a sub-watershed of the Chesapeake Bay on the Eastern shore of Maryland, was selected as a study site. The objective of this research was to evaluate water quality in non-tidal streams in the Sassafras River watershed. Historical data has been collected and reported by volunteers at several sites throughout the watershed on a monthly basis for two years. This data was instrumental in determining six weekly measurement sites. The six sites chosen all had historically high nitrate concentrations for 9-12 months of the year. Additionally, phosphate concentrations at these sites were all at or above the local threshold for every measurement in the last two years. Weekly measurements of dissolved oxygen, phosphates, and nitrates, were completed in the six chosen streams. Monitored data showed that in 7 of the 9 sites, nitrate and phosphate concentrations exceeded threshold values at least 75% of the time. Historically, dissolved oxygen levels have not been a water quality issue. Only 2 of the 9 sites were consistently near threshold values. These high nutrient concentrations can be attributed, in part, to the surrounding land use. The project described was supported by Delaware EPSCoR, through National Science Foundation Grant EPS-0447610 and Wesley College.