Congressional District # 10
LIQUID DISPOSAL, INC.EPA ID# MID067340711
Last Updated: December, 2011
The 7-acre Liquid Disposal, Inc. (LDI) Site is located in Shelby Township in Macomb County, Michigan. LDI was a commercial liquid waste incineration facility which accepted wastes from major automobile manufacturers, chemical companies, and other industries around the state. Site facilities included an ash pit, scrubber and oil lagoons, surface and underground storage tanks, and an assortment of drums. Indiscriminate storage practices and spills led to soil and groundwater contamination with volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and numerous heavy metals, including barium, cadmium, and lead. The Site is bordered on two sides by wetlands and the Clinton River, and on the south side by an auto junkyard. The Rochester-Utica State Recreational Area and the Shadbush Tract Nature Study Area are within one mile of the site. Approximately 54,000 people live within three miles of the site; an estimated 3,500 people rely on groundwater for household use.
The United States Environmental Protection Agency (U.S. EPA) proposed the site for the National Priorities List (NPL) in December 1982 and finalized the site on the NPL in September 1983.
Site ResponsibilityThis site is being addressed through federal, state, and potentially responsible parties' actions.
Threats and ContaminantsSoil and groundwater are contaminated with VOCs, PCBs, PAHs, and numerous heavy metals, including barium, cadmium, and lead.
Between 1982 and 1986, U.S. EPA, in cooperation with the State of Michigan, removed lagoon wastes, contaminated sediments, approximately two million gallons of liquid waste, 2,800 cubic yards of heavy metal sludge, and 200 drums from the site.
U.S. EPA signed a Record of Decision (ROD) on September 30, 1987, which selected a cleanup remedy for the site. The remedy included on-site land disposal of debris, on-site solidification/fixation of soil and waste, extraction and treatment of groundwater, installation of groundwater monitoring wells, landfill slurry wall and cap construction.
Between 1987 and 1991, six settlements resolved the liability of hundreds of small generators. In 1992, 35 major potentially responsible parties (PRPs) signed a Consent Decree (CD) with U.S. EPA for final cleanup of the site.
On August 28, 1995, U.S. EPA issued an Explanation of Significant Differences (ESD) to modify the remedy defined in the ROD. Those changes included the following: extraction and treatment of off-site groundwater would not be required unless U.S. EPA finds that off-site groundwater quality has deteriorated as a result of site-related contamination; solidification of all on-site soils down to the water table was determined not to be necessary because the site contamination would be adequately contained by means of a cap, slurry wall, and on-site groundwater extraction; and target cleanup levels for some contaminants were revised to reflect current groundwater maximum contaminant levels (MCLs).
Under the 1992 Consent Decree, the PRP group completed the following work:
- Solidification with concrete of a 20-foot wide swath of perimeter site soil and highly-contaminated soil and debris on site;
- Construction of an underground slurry wall inside the 20-foot solidified swath around the perimeter of the site;
- Construction of a clay cap over the site;
- Installation of extraction wells inside the slurry wall and monitoring wells inside and outside the wall; and
- Soil replacement and revegetation of a wetlands and uplands area east of the site.
On September 4, 1997, U.S. EPA completed a final inspection at the site and determined that the PRPs had constructed the remedy in accordance with the September 1987 ROD and the August 1995 ESD. On September 15, 1997, U.S. EPA documented in a Preliminary Close Out Report that all construction was completed at the site. U.S. EPA approved the final Operation and Maintenance (O&M) Plan and final Construction Completion Report. The First and Second Five-Year Review Reports were issued in 1998 and 2003, respectively.
U.S. EPA signed the Third Five-Year Review Report on September 26, 2008. The review found that the remedy was constructed in accordance with the decision documents with the exception that the slurry wall was not completely keyed into the confining layer beneath the site. Capping of the contaminated soils has removed the possibility of human contact with contamination, and access controls that restrict use of the land are in place. The remedy included the establishment of a specific inward gradient from the extraction wells operating within the prescribed slurry wall; however, this inward hydraulic gradient has not yet been achieved. Currently, two contaminants of concern (COCs) exceed MCLs in groundwater tested side-gradient and downgradient of the Site. However, there are other contaminants, not currently included in the list of COCs, that have also been detected in exceedance of the MCLs that require further evaluation. A protectiveness determination of the remedy at the site is being deferred until further information is obtained, but groundwater monitoring and cap maintenance is continuing. Further information will be obtained by evaluating the impacts of the lack of an inward hydraulic gradient at the site, re-evaluating the current list of COCs, and evaluating the risks associated with the potential upgradient source identified at the site. It is expected that these evaluations will be completed by the spring of 2012, at which time a protectiveness determination will be made.
U.S. EPA issued a second ESD on September 10, 2010, which documents the requirement for the implementation of Institutional Controls (ICs) at the Site to ensure long-term protectiveness. ICs are non-engineered instruments such as administrative and legal controls that are designed to minimize the potential for human exposure to contamination and to protect the integrity of the remedy. ICs are required for any areas which do not allow for unlimited use or unrestricted exposure to humans. U.S. EPA has concluded that the soil, capped area, slurry wall, and groundwater should be subject to use restrictions to ensure long-term protectiveness. Therefore, the ESD was signed to provide for ICs to restrict the area of the Site that contains the cap, slurry wall, solidification/fixation zone, extraction and treatment systems, and monitoring wells at the Site.
The PRPs submitted an IC Work Plan for the Site in August 2011. A Draft Restrictive Covenant (DRC) is being drafted by the PRPs, following MDEQ DRC guidance. Since the Site is currently owned by the State of Michigan, the State will also be signatory on the DRC, which is expected to be finalized by March 2012.
ContactsRemedial Project Manager, U.S. EPA
linda kern (email@example.com)
Community Involvement Coordinator, U.S. EPA
LIQUID WASTE DISPOSAL INC
LIQUID DISPOSAL INC