Davis Liquid Waste

Overview

Davis Liquid Waste is a 7-acre former hazardous waste disposal site in northwest Smithfield, Rhode Island. Tank trucks discharged waste into unlined lagoons during the 1970s, and drums holding chemicals, solvents, acids, metals, and pesticides were buried or crushed on site. The site was added to the National Priorities List in September 1983 and has been divided into three operable units covering a waterline replacement, on-site groundwater treatment, and on-site soil treatment.

EPA has identified 33 contaminants of concern in groundwater and soil. These include volatile organic compounds such as trichloroethene, tetrachloroethene, benzene, and chloroform, heavy metals including arsenic, lead, and manganese, chlorinated solvents such as 1,1,1-trichloroethane and carbon tetrachloride, and other substances including 1,4-dioxane and naphthalene. The biggest remaining threat is liquid-phase contamination trapped deep in bedrock fractures.

Significant cleanup work has already been completed. Between 1985 and 1986, EPA removed about 600 drums. A public water distribution system serving 127 properties was finished in 1997, replacing the private wells that had been affected by site contamination. From 1998 to 2001, settling parties removed roughly 25,000 tons of contaminated soil and treated 78,000 tons more using low-temperature thermal desorption, eliminating surface hazards. Groundwater outside the site boundaries currently meets all standards and poses no unacceptable risk. Human exposure across the entire site is considered under control, with no unacceptable exposure pathways identified at this time.

The focus now is deep bedrock groundwater. EPA issued an Interim Record of Decision in 2020 selecting treatability studies for the deep aquifer. The remedial design was approved in January 2025, and construction of the groundwater remedy started July 21, 2025, with the Davis Site Group carrying out the work under EPA and Rhode Island Department of Environmental Management oversight. The remedy will be monitored for at least 10 years before a decision is made on whether additional cleanup is needed. Long-term response actions are estimated to occur between June and August 2028. In April 2025, the Town of Smithfield approved a zoning ordinance prohibiting new wells or groundwater withdrawal in select parcels around the site. A second institutional control, an Environmental Land Use Restriction, will be recorded before remediation is complete.

Community members who want updates on cleanup activities can contact the EPA's Community Involvement Coordinator. Hard copies of documents can be requested through the same contact. Site records are available at the Greenville Public Library in Greenville, Rhode Island, and at the EPA Region 1 office in Boston. More information is at www.epa.gov/superfund/davisliquid.