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EPA Provides Update on Efforts to Address Dioxin Contamination in the Woonasquatucket River

Release Date: 07/22/2011
Contact Information: Stacy Greendlinger, (617)-918-1403

(Boston, Mass. – July 22, 2011) – Interested community members were provided an update about the environmental investigations and actions at the Centredale Manor Restoration Project Superfund Site.  Representatives from the U.S. Environmental Protection Agency, RI Department of Environmental Management and RI Department of Health were on hand to answer the public’s questions.

EPA presented the findings of the Remedial Investigation that was conducted to better understand the nature and extent of site contamination and collect information needed to identify any potential human health and ecological risks.  Elevated levels of contaminants, including dioxin, polychlorinated biphenyls (PCBs), volatile organic compounds (VOCs), semi-VOCs and metals, have been found in soil, sediment, wetlands and surface water at the site.  Contamination levels are highest at the main part of the Centredale Manor Site, that is now the location of the Centredale Manor and Brook Village apartment complexes on Smith Street, North Providence (Source Area) and decrease downstream up to the Lyman Mill Pond dam.  People have the potential for exposure to the site contaminants that could result in unacceptable risks through eating fish from the Woonasquatucket River and having direct contact with sediment and floodplain soil.

Since becoming a federal Superfund site in 2000, EPA and the Potentially Responsible Parties have taken several short-term actions to control potential exposure to residents and visitors to the site’s contaminants.  These actions included capping of contaminated soil in the Source Area, installation of fences to control access to the capped areas, removal of contaminated soil from residential properties along the river, reconstruction of the breached Allendale Dam, and removal of contaminated soil to limit the movement of contamination through groundwater into the river.

EPA also presented an overview of its draft Feasibility Study which developed site cleanup objectives and cleanup levels, and evaluated a range of potential cleanup alternatives for addressing site contamination.  The Source Area cleanup alternatives range from taking no action to upgrading or reconstructing the existing caps.  For sediment and floodplain soil, the range of alternatives include:  taking no action; capping or covering contaminated soil and sediment in place; excavating and disposing of contaminated soil and sediment; and a combination of capping/covering and excavating.  Numerous disposal and treatment options were also identified for each of the soil and sediment cleanup alternatives developed.  They include engineered structures to contain excavated soil and sediment located either outside of the floodplain (upland) or within the ponds’ footprints (nearshore); on-site incineration; or off-site treatment.

EPA expects to present its proposed cleanup plan to the public this fall for a formal 60-day public comment period before making a final decision. 

The Woonasquatucket River, which forms the border between Johnston and North Providence, RI, has widespread dioxin contamination resulting from the former operations of a chemical company and a drum recycler from the early 1940s to the early 1970s. The site also includes free-flowing reaches and ponds of the Woonasquatucket River next to and downstream from the Source Area. Contamination was first found in fish in 1996.  The Rhode Island Department of Health recommends that the public not eat fish caught from the Woonasquatucket River below the Johnston/Smithfield town line.

More information on the Woonasquatucket River and Centredale Manor cleanup

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