Dodoo, Daniella, Clean Water Institute/Department of Biology, Lycoming College, One College Place, Williamsport, PA, 17702, doddani@lycoming.edu; Kaunert, Matt, Clean Water Institute, Lycoming College, One College Place, Williamsport, PA,17702, kaunert@lycoming.edu; Rieck, Leslie, O. Department of Biology Lycoming College One College Place Williamsport PA, 17702, rieck@lycoming.edu.
The Lycoming College Clean Water Institute has been tracking urban stream water quality in eight streams in the greater Williamsport region over the past eight years. All these urban waters receive discharges from Municipal Separate Storm Sewer Systems (MS4), which convey stormwater runoff to streams and must be managed by governing municipalities to ensure excess sediment and nutrient input is minimized. Stormwater is an important contributor of sediment, nutrients, and bacteria, making it a focal target in improving water quality. All five of the public entities charged with managing stormwater discharges within our study area must reduce nitrogen, phosphorus, and sediments by 10% by 2024/2025.
Here, we examined the levels of total coliforms, E. coli, and chemical water quality in the eight streams receiving MS4 discharges in the Williamsport region and compared values obtained from water collected upstream of the urban area to those downstream of all MS4 discharge points to related contamination to urban influences vs. agricultural or industrial influences.
Phosphorus was highest at an intensely modified site downstream of MS4 discharges and lowest at the site upstream of all urban influence in an area of intact, undeveloped forest. Similar results were observed for nitrate. However, there were no significant differences in nitrate, phosphorus, conductivity, fecal coliform concentrations at sites upstream vs. downstream of MS4 influence. We suggest that the land use and cover upstream of urban influence may play a large role in chemical water quality parameters, particularly nutrients in the case of upstream agricultural land use. This study continues to contribute to a growing body of knowledge regarding the influence of stormwater infrastructure on rivertown streams.
Stormwater , Urban streams , Water Quality , Nutrient management