DAVIS LIQUID WASTE
On this page:
- What Is Being Done to Clean Up the Site?
- What Is the Current Site Status?
- EPA’s Involvement at the Site
- Operable Units (opens new page)
- Cleanup Progress (opens new page)
The Davis Liquid Waste Superfund Site lies between Tarkiln and Log Roads in the northwest section of Smithfield, Rhode Island and consists of a 7-acre source area bounded to the east and west by forested wetlands and the north and south by wetlands. Surface water drains into Latham Brook and eventually enters Stillwater Reservoir, tributary to the Woonasquatucket River.
Throughout the 1970s, the owner disposed of a variety of liquid and solid wastes containing hazardous substances. Tank trucks directly discharged liquid wastes into unlined lagoons and seepage pits. Drums containing chemicals and laboratory containers were buried on site or crushed. Wastes and contaminated soil were excavated from the lagoons and pits, and were dumped at several on-site locations and covered with available soil. The Site accepted liquid and chemical wastes such as paint and metal sludges, oily wastes, solvents, acids, caustics, pesticides, phenols, halogens, metals, fly ash and laboratory pharmaceuticals. The disposal of these wastes contaminated groundwater at and surrounding the Site. Nearby private wells were found to be contaminated by wastes emanating from the Site in bedrock groundwater.
What Is Being Done to Clean Up the Site?
The remaining threat to human health and the environment is groundwater contamination. The Parties, under oversight by EPA and RIDEM, are investigating the distribution, transport and fate of groundwater contamination. The 2010 Record of Decision selected in-situ chemical treatment and enhanced biodegradation to destroy the remaining VOC contaminants present in the saturated, near surface soils. This remedy would be protective of human health and the environment, comply with Federal and State requirements that are applicable or relevant and appropriate, is cost effective, and use permanent solutions and alternative treatment technologies to the maximum extent practicable. During the course of the investigations for this remedy, the data indicate that the bulk of the contamination originates in the deeper bedrock rather than solely residing in the near-surface saturated soils. Therefore, EPA, RIDEM and the Parties are collecting additional data and examining potential means to address this new understanding of contaminant distribution and character.
What Is the Current Site Status?
The Parties have continued monitoring groundwater and surface water at the Site as well as investigating the geology controlling the migration of contaminants in groundwater. EPA developed a groundwater remedy in 2010, selecting chemical treatment and enhanced biodegradation of near surface sands and soils. However, the current investigation has identified a different, deeper source of contaminants that affects the area of the selected remedy.
EPA’s Involvement at the Site
From 1985 to 1986, EPA sampled, packed and shipped about 600 intact and crushed drums to an approved disposal facility. At the same time, the Rhode Island Department of Environmental Management (RIDEM) supplied bottled water for drinking and cooking to residences with contaminated wells. This temporary action provided a safe water supply while a permanent remedy was evaluated.
The construction of a new water distribution system serving 127 lots along Forge Road, Log Road, Burlingame Road and Bayberry Road was also completed by EPA and RIDEM in December 1997. The new system included construction of a 300,000-gallon water storage tank, a water main, pumping stations and connections to existing residences. For several undeveloped lots, EPA also brought service to the property line.
EPA completed a Remedial Investigation and Feasibility Study for the Site in 1987 selecting a remedy to protect the public and environment. In 1996 EPA signed a Consent Decree with 54 Settling Parties (the “Parties”) that EPA believed were potentially responsible for contamination at the Site. Those Parties then took over the cleanup under EPA and RIDEM oversight.
In 1998, the Parties removed approximately 5,000 tons of solid waste, soils and 800 drums and containers from the Site. Between 1999 and 2001, the Parties removed approximately 20,000 tons of contaminated soil, wastes, and debris for disposal offsite at a licensed facility and excavated and treated 78,000 tons of contaminated soil via low-temperature thermal desorption, backfilling the treated material at the Site. The disturbed areas was revegetated and over 300 trees were planted to help restore habitat value. This remedy removed surface hazards from the Site.
During cleanup, a site can be divided into a number of distinct areas depending on its complexity. These areas, called operable units (OUs), may address geographic areas, specific problems, or areas where a specific action is required. Examples of typical operable units include construction of a groundwater pump and treatment system or construction of a cap over a landfill.