The US Environmental Protection Agency (EPA) has started first five-year review of the remedial actions previously implemented at the former Nutmeg Valley Road Superfund Site, in west-central Connecticut near the Wolcott/Waterbury town line since its removal from the National Priorities List (NPL) in 2005. The site remains eligible for remedial actions in the unlikely event that conditions at the site change and warrant such action in the future.

The five-year reviews are mandated under the Comprehensive Environmental Response, Compensation and Liability Act (Superfund).

This five-year review will be limited in scope to evaluating whether legal mechanisms that serve to prevent human exposure to contaminated groundwater and that were in place at the time the remedy was selected in 2004 remain in place, and, whether these mechanisms continue to function sufficiently to prevent human exposure to contaminated groundwater. Should this review indicate that exposure is occurring, EPA may take additional action to determine if such exposure presents an unacceptable risk to public health and the environment.

The Nutmeg Valley Road Site consists of a dozen small manufacturing facilities, light industrial facilities and repair shops over a 28-acre area in the southern section of Wolcott, along the border with Waterbury. Private wells contaminated with volatile organic compounds were first discovered by state and local health officials in 1979. In 1986, the Town of Wolcott extended a public water supply line into the area.

EPA placed the Site on the NPL in March 1989. Early investigations focused on two machine shops on Nutmeg Valley Road with a known history of dumping waste oil and solvents onto the ground. The study area was expanded to 155 acres to include similar companies on Swiss Lane, Tosun Road, Wolcott Road and Town Line Road which were also seen as potential sources of groundwater contamination.

In 1992, EPA removed 1,150 tons of sludge waste and contaminated soil from two unlined lagoons on Tosun Road. This action addressed the threats posed by the electroplating wastes in surface soils, and removed a potential source of groundwater contamination.

Based on further studies completed by EPA and the US Geological Survey from 1995 through 2002, EPA concluded that although some contaminants were detected in groundwater, there was no evidence of a wide-spread plume of contamination and levels of contaminants in much of the study area were decreasing over time through natural degradation processes. As a result, the study area was reduced in size to its current 28 acres. EPA has determined that existing state law and a local ordinance adopted in 2004 prohibiting the use of groundwater in the remaining area of groundwater contamination, when considered together, will ensure that human exposure is prevented.