In response to a request from the Beaver Dam Creek Restoration Task Force, a multi-agency/stakeholder group exploring opportunities for wetland and habitat restoration in the Beaver Dam Creek watershed, the Suffolk County Department of Health Services Office of Ecology initiated efforts to characterize the water quality of the creek in September 2002. Monitoring was conducted at eight sites on an approximate monthly basis through 2003, with additional samples collected intermittently from 2004 through early 2008 to fill data gaps and verify observed trends. In the fall of 2007, sampling was expanded to include sites in nearby Little Neck Run and Yaphank Creek.

Sampling results indicate that Beaver Dam Creek is subject to a combination of impacts from the surrounding watershed, including storm water runoff, a leachate plume from the Town of Brookhaven landfill, a marina located in the northern tidal reaches of the creek, various nearby commercial establishments, and possibly in certain locations, failing or poorly operating septic systems. The preponderance of findings from this and many other studies however, strongly suggest that the elevated levels of numerous contaminants detected in the northern reaches of the creek (particularly ammonia, manganese, iron, chlorides, chlorobenzene, diethyl ether and 1,4-dichlorobenzene, and the plasticizer bisphenol-A) have their principal origin in the landfill plume. Results of recent sampling done in Little Neck Run, a tributary to the Carmans River located east of Beaverdam Creek and downgradient of the landfill, have also revealed elevated levels of contaminants likely associated with the leachate plume. To download a copy of a report on the study, see the link below.

The Brookhaven landfill had been used for the disposal of municipal solid wastes from 1974 -1995. A leachate plume emanating from the landfill was discovered in the late 1970s, and prompted a series of studies conducted by the United States Geological Survey (USGS) to document the plumes extent and degree of contamination. As a remediation measure designed to stop the generation of leachate, the Town closed and capped the cells considered most likely to have leaks in the liner (cells 1-3) in 1993, followed by cell 4 in 1997. Town-sponsored investigations characterizing the leachate plume and its effects on area groundwater have been conducted since 1982, with sampling of the waters of nearby Beaver Dam Creek conducted on almost an annual basis since 1991.

Following the release of the SCDHS report, the Town of Brookhaven passed a resolution formally establishing a Beaver Dam Creek Working Group. Members included reps from SCDHS, NYSDEC, Brookhaven Village Association, Open Space Council, Friends of Wertheim, Hamlet Organic Garden, Dvirka & Bartilucci (consultants to the Town), SUNY Stony Brook, Trout Unlimited, USFWS, Post Morrow, and Citizens Campaign for the Environment. A primary focus of the group was to delineate the spatial extent of the plume and explore methods for remediation.

SCDHS has continued its monitoring effort in creeks downgradient from the landfill (Beaver Dam Creek, Little Neck Run and Yaphank Creek), and in an effort to further delineate the leachate plume, has been working with consultants for the town (Dvirka & Bartilucci) in redeveloping and sampling monitoring wells southeast of the landfill.

References

Beaver Dam Creek Water Quality Report