Harbor Island Park located in Mamaroneck Harbor was frequently closed due to the exceeding levels of enterococci found in the water. A filter system Gunderboom® BPSTM (Beach Protection System) was installed in 2002 at the beach to lower bacterial levels in the swimming area. Our previous studies in 2006 showed that the densities of E. coli and coliform bacteria recovered from water and sediment were significantly lower inside the Gunderboom® when compared to the outside and the surrounding watersheds: Mamaroneck River, Guion Creek, and Shore Acres Beach. However, higher densities of bacteria were found in Guion Creek which directly drains into the harbor. The current study focuses in the comparison of E. coli and enterococci levels from water and sediment samples collected from the upper areas of Guion Creek (Beaver Swamp, the stream at Rye Neck High School and Upper Guion Creek) and the lower areas of Guion Creek (Lower Guion Creek, outside and inside of the Gunderboom®). Water and sediment specimen were collected bi-weekly at these 6 sites from May to November of 2007, especially after heavy rainfall. The results showed that the densities of E. coli and enterococci were significantly lower inside the Gunderboom® which proved again the effectiveness of the filter in lowering bacteria in water. In addition, the densities of enterococci and E. coli were found significantly higher in water and sediment samples collected in Beaver Swamp, Rye Neck High School and Upper Guion Creek than the other 3 lower regions. In conclusion, our study suggests some non-point source bacterial contamination located in the upper areas of the Guion Creek and may contribute to the increased densities of E. coli and enterococci in the Mamaroneck Harbor.
Yeung-Cheung, Anna K.
"Comparison of Bacterial Levels from Water and Sediments among Upper and Lower Areas of Guion Creek,"
International Journal of Soil, Sediment and Water:
3, Article 3.
Available at: http://scholarworks.umass.edu/intljssw/vol2/iss3/3