ANTHROPOGENIC HEAVY METAL CONTAMINATION IN TIDAL MARSH SEDIMENTS, FLETCHER’S CREEK, MILFORD, CT

Fletcher’s Creek tidal marsh is part of Silver Sands State Park, a 47-acre recreational beach and salt marsh facility along Long Island Sound in Milford, CT. The area had been a dumping site for local inhabitants since the 1920’s and had been used by the town of Milford as an unregulated landfill since the end of WWII. The site was officially closed in 1977 and capped with fly ash beginning in 1990. Anecdotal information indicates that, in addition to regular household waste, hazardous materials including asbestos, lead paint, pesticides, oil, battery acid, freon, toluene, PCB’s and radioactive medical waste were discarded at the site.

During restoration of the Fletcher’s Creek tidal marsh channel system during late summer, 1999, dredging, boardwalk construction and clearing of Phragmites uncovered bedded debris at the surface.

The debris field was mapped, refuse samples taken to be dated, and water samples were collected from tidal channels, pools and seeps within the debris field in 1999 – 2000, and tested spectrophotometrically for select heavy metals. The affected area was initially determined to be 242 meters south of the fenced-off landfill, extending 60 to 100 meters beyond the mapped ‘0’ limit of landfill waste, and now projected to underlie the area up to the current strandline. The debris field as currently exposed covers an area of 3.72 square kilometers. Bedded debris exposed in channels occurs to an average depth of 2 meters. Dated materials exposed on the surface cluster between 1964 –1968.

XRF analyses (winter 2001) of sediment from the debris field and within tidal channels indicate elevated concentrations of heavy metals (including chromium, copper, iron, lead, manganese, mercury, nickel, selenium and zinc) of probable anthropogenic origin. Levels exceed those of tested water samples and are consistently above pre-industrialized background.