The project goal was to determine if stormwater runoff and the legacy effects of leaking underground storage tanks (UST) posed an environmental health threat along an urban stream, Town Creek (TC). Baseflow and stormflow samples were collected from TC between March and October 2016 for physical and chemical characterization and E. coli analyses. Groundwater seeps and wells near the banks of TC were also sampled for E. coli and benzene analyses. Stormflow concentrations of E. coli were significantly (p < 0.05) elevated relative to preceding baseflow and groundwater concentrations. Overall, 80% of stormflow samples and 45% of baseflow samples exceeded the US EPA recommended standards for E. coli in recreational waters. Benzene was detected in all water samples analyzed and 50% of samples collected from a seep on the western bank of TC exceeded the maximum contaminant level. Concentrations of benzene emitted to air from contaminated soil exceeded short term exposure standards 75% of times sampled. Results suggest the drainage from TC may be a threat to environmental health. Implementation of stormwater control measures is suggested to reduce the delivery of runoff and E. coli to TC. Remediation of groundwater contaminated by leaking underground storage tanks is also suggested.

Hurricane Matthew caused flooding in Eastern North Carolina that was categorized as a one in 500-year frequency event. Matthew was the second such event in less than 20 years, following Hurricane Floyd in 1999. The frequency of intense storms is projected to increase for many coastal areas, including North Carolina, because of climate change. The goal of this study was to gain a better insight into the geochemistry of flood waters associated with major flood events. Water samples (n = 22) from the Tar River in Greenville, North Carolina were collected over a two-week period after Matthew moved across the state. Results show that total Kjeldahl nitrogen, dissolved organic carbon, phosphate, and Escherichia coli concentrations and exports were significantly (p < 0.05) higher when the river was above flood stage relative to below. Isotopic analyses of δ15N and δ18O in NO3 in flood waters suggest that wastewater, possibly from sanitary sewer and confined animal feeding operation overflows, was the major source of nitrate associated with flood waters. Regulatory efforts to reduce nutrient loading to coastal waters may be complicated by contributions associated with intense storm events, given that such storms are becoming more frequent.