An Analysis of the Major Sources of Runoff Pollution on the Purchase College Campus Adjacent to the Western Branch of Blind Brook

Abstract

Urban stormwater runoff is the most prevalent issue that waters in New York State are facing, most notably non-point source runoff. Nonpoint source runoff is such a challenging issue because it comes from a variety of sources, and it can be hard to determine exactly what they are. Some of the most problematic pollutants often found in stormwater runoff include excess nutrients, heavy metals, and sediments. Blind Brook, the key waterbody in this study, and Long Island Sound, the waterbody that Blind Brook empties out into, are both considered degraded due to high turbidity and elevated nitrates, respectively. The purpose of this study was to figure out how much Purchase College contributes to this pollution and attempt to pinpoint what parts of campus are the major contributors, taking into account the active construction site in the W1 parking lot. Samples were collected and compared from five locations on campus: upstream Blind Brook, from the W2 parking lot, from the W1 parking lot, from the retention basin wetland, and downstream Blind Brook. Results showed that, while there were many pollutants coming off of the campus, the wetland was often able filter out most, if not all, of the contaminants as they flow through. Additionally, high turbidity levels were found coming off of campus with very high levels from W1, as predicted, but both the campus and off-campus locations along Blind Brook were found to contribute elevated turbidity levels.