An evaluation of the effectiveness of the Gunderboom in protecting waters from bacteria.

Beaches located in the narrow inlet of Long Island Sound frequently contain high concentrations of bacteria. A Gunderboom BPS (Beach Protection System) filter was installed in Harbor Island Park of Mamaroneck Harbor, New York, in 2002 to reduce bacterial levels in the water. Water and sediment collected inside and outside the Gunderboom and other areas within Mamaroneck Harbor (Shore Acres Beach, Guion Creek, and Mamaroneck River) were tested for E. coli and total coliform bacteria and compared weekly from May through September 2006. The results showed that concentrations of E. coli and total coliform bacteria in water and sediment were significantly lower inside the Gunderboom when compared to the other sites. One-third of the samples were collected within 48 hours of rainfall, and a positive correlation occurred between rainfall and bacterial levels in water. These results indicate the Gunderboom has the potential to reduce bacteria in both beach water and sediment.

The capacity of the Gunderboom in Mamaroneck Harbor on the reduction of E. coli and coliform bacteria from water and soft-shelled clams (Mya arenaria).

Harbor Island Park of Mamaroneck Harbor is one of the beaches that has been frequently closed to the public due to unsanitary swimming conditions. In 2002, a Gunderboom BPS (Beach Protection System) was reinstalled in Harbor Island Park to lower bacterial levels in swimming areas. The first Gunderboom had been destroyed by an oil spill several years before. The current Gunderboom is an 800 foot curtain made of a treated polypropylene/polyester fabric and the company claims a 99.1% coliform reduction with its use. In this study, water inside and outside the Gunderboom was tested weekly from June to August 2005, and bi-weekly from September to December 2005. Coliscan Membrane Filtration plates were used to recover the relative amounts of Escherichia coli and coliform bacteria from the water. Soft-shelled clams (Mya arenaria) living in both these areas were also tested for their E. coli and coliform bacteria level using 3M Petrifilm plates. Water was also tested from Hudson Park in New Rochelle, a frequently closed beach due to high levels of coliform bacteria, as well as from Read Sanctuary in Rye, a "pristine" beach. Our results showed the amount of E. coli and coliform bacteria recovered from the water inside the Gunderboom were significantly lower (P < 0.05) compared to outside the Gunderboom and Hudson Park. There was 81.9% reduction in E. coli and 51.6% reduction in coliform bacteria inside the Gunderboom as compared to the outside. In addition, significant differences (P < 0.05) were found with lower numbers of E. coli and coliform bacteria recovered from the clams inside the Gunderboom compared to outside the Gunderboom. In conclusion, the Gunderboom system installed in Mamaroneck Harbor resulted in a significant reduction of E. coli and coliform bacteria in the water and clam samples, thus proving its efficiency as a water filter.