Congressional District # 10
LIQUID DISPOSAL, INC.EPA ID# MID067340711
Last Updated: May, 2015
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 U.S. Environmental Protection Agency (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, 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.
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 and a landfill slurry wall, and construction of a cap.
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 EPA for final cleanup of the site.
On August 28, 1995, 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 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.
In September 1997, 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, EPA documented in a Preliminary Close Out Report that all construction was completed at the site. EPA approved the final Operation and Maintenance (O&M) Plan and final Construction Completion Report. The First, Second, and Third Five-Year Review Reports were issued in 1998, 2003, and 2008, respectively.
EPA issued a second ESD on September 10, 2010, which documents the requirement for institutional controls (ICs) at the site as part of the selected remedy. EPA has concluded that the soil, capped area, slurry wall, and groundwater should be subject to use restrictions to ensure long-term protectiveness. The 2010 ESD requires ICs to restrict the area of the site that contains the cap, slurry wall, solidification/fixation zone, extraction and treatment systems, and monitoring wells.
Subsequent to the 2010 ESD, the PRPs submitted an IC Work Plan in August 2011 and prepared a Restrictive Covenant (RC) for the site. Since the site is currently owned by the State of Michigan, the State is signatory on the RC. The RC is expected to be recorded with Macomb County by summer 2015.
EPA signed the Fourth Five-Year Review Report for the site on September 23, 2013. The five-year review found that the remedy was constructed in accordance with the ROD and the subsequent Explanation of Significant Differences (ESD) 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. Based on the results of a statistical analysis of groundwater concentrations, there are a number of monitoring wells which exhibit exceedances of site cleanup standards, including some wells located outside the slurry wall. The five-year review concluded that the remedy currently protects human health and the environment because there is no use of or exposure to groundwater by humans in the area surrounding the site and because the landfill cap adequately provides protection against direct contact with unacceptable levels of site contaminants. However, in order for the remedy to be protective in the long term, the remedy needs to function as intended by the decision documents and effective ICs need to be implemented. Specifically, steps need to be taken to achieve and then maintain the two-foot inward hydraulic gradient required by the ROD. Additionally, site remedy components need to be maintained and long-term groundwater monitoring needs to continue, including sampling for a revised list of contaminants, and landfill seeps need to be monitored.
Groundwater sampling is being performed as part of long-term operation and maintenance for the site. The additional sampling recommended in the 2013 five-year review has been completed. EPA, MDEQ, and the PRPs are continuing discussions regarding the other issues identified in the five-year review.
Long-term ICs are expected to be put in place in the near future with the anticipated recording of the RC for the site.
ContactsRemedial Project Manager, U.S. EPA
linda kern (email@example.com)
Community Involvement Coordinator, U.S. EPA
LIQUID WASTE DISPOSAL INC
LIQUID DISPOSAL INC