Central Landfill is a 154-acre active waste disposal facility in Johnston, Rhode Island. It sits on the EPA's National Priorities List, where it has been since 1986. The site handles over 90 percent of Rhode Island's municipal solid waste and continues to operate under the Rhode Island Resource Recovery Corporation. A half-acre area called the "hot spot" inside the unlined Phase I landfill was used in the mid to late 1970s to dump large volumes of liquid industrial waste, contaminating soil and groundwater.
EPA has identified 51 contaminants of concern at the site. They were found in solid waste, groundwater, and surface water. The list includes volatile organic compounds such as benzene, trichloroethene, and vinyl chloride, heavy metals including arsenic, lead, cadmium, chromium, and mercury, and other hazardous substances like nitrate and cyanide. Groundwater also contains chlorobenzene, toluene, methyl ethyl ketone, beryllium, manganese, and vanadium.
The selected cleanup remedy includes capping the landfill, containing and treating contaminated groundwater, collecting and treating landfill gas, and putting institutional controls in place. A groundwater treatment and operation system started running in 2006. In 2013, EPA decided to move the hydraulic containment system farther downgradient once Phase VI of the landfill is completed. Main remedial action work finished in October 2016. Broadrock Renewables now converts landfill gas to electricity using 15 engine generator sets that produce about 20 megawatts, with the Superfund area contributing around 12 percent of the gas collected.
EPA completed its fifth Five-Year Review in September 2023. That review found cleanup actions are protective of human health and the environment in the short term. Human exposure is under control, and contaminated groundwater has been stabilized in its original area with no unacceptable discharge to surface water. Long-term protectiveness still requires completing the relocated hydraulic containment system, determining treatment needs for new extraction wells, installing additional monitoring wells, assessing the Phase V underdrain treatment system, and finishing a study on Phase I metals in sediment. The site has not yet been deleted from the National Priorities List. The next five-year review is estimated to occur between September and November 2028.
Community members can review site documents at the Marion J. Mohr Memorial Library in Johnston or at the EPA Region 1 records center in Boston. Institutional controls are in place to restrict land use, including zoning rules that block residential development. Anyone considering a property use at or near the site is encouraged to review site files, conduct a title search, and contact the EPA regional office directly. EPA staff are available to answer public questions.
