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Congressional District # 13


EPA ID# ILD005451711
Last Updated: May, 2015

Site Description

The Lenz Oil Service, Inc. (Lenz Oil) site is situated on four acres of land in Lemont, Cook County, Illinois. Approximately 11,300 people live within three miles of the site. From 1961 to 1985, the site was the location of an oil and solvent recycling facility. Lenz Oil picked up waste oil and solvents from commercial and industrial businesses in the area and transported the waste to the site. Generators also transported waste to the facility. Waste was stored in onsite lagoons and above- and below-ground storage tanks prior to sale to facilities in the area for use as fuel or other purposes such as dust control on roads. Based on records discovered to date, the U.S. Environmental Protection Agency (EPA) identified more than 3,000 potentially responsible parties (PRPs), primarily generators. 

EPA proposed the site for the National Priorities List (NPL) in June 1988 and finalized the site on the NPL in October 1989.

Site Responsibility

This site is being addressed through federal, state, and PRPs' actions.

Threats and Contaminants

The soil and groundwater at the site was contaminated with heavy metals, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and various volatile organic compounds (VOCs) such as benzene, tetrachloroethene, trichloroethene, xylenes, and vinyl chloride. A highly-contaminated oil layer or light nonaqueous phase liquid (LNAPL) is floating on the aquifer beneath the site.

Cleanup Progress

In 1985, the Illinois Environmental Protection Agency (IEPA) inspected the facility and observed that approximately 25 percent of the ground surface was covered with standing, oily water. In 1986, IEPA initiated investigative and removal actions at the site. Removal actions were conducted by IEPA in 1986 and 1987 and included the following: draining and filling of three onsite surface impoundments; dismantling, shredding, and proper disposal of more than thirty-five storage tanks; construction of an onsite incinerator; incineration of  250,000 gallons of liquid waste, 200 drums of hazardous substances, and 7,000 tons of contaminated soil; construction of onsite berms to reduce offsite surface water run-off; and a provision of municipal water hookups to all residences within one mile of the site. In 1989, approximately 200 PRPs entered into an administrative order on consent (AOC) with EPA to conduct a remedial investigation and feasibility study (RI/FS) at the Lenz Oil site. A supplemental investigation was conducted during September 1997 to better define the LNAPL plume area.

EPA signed the Record of Decision (ROD) for the final remedy on September 30, 1999. The final remedy consisted of the following main components: excavation of the principal threat area, treatment of the contaminated material via solidification/stabilization (S/S), and disposal of the treated material within a corrective action management unit (CAMU). The remedy also called for a pump-and-treat system for contaminants that remain in the aquifer after the above is completed.

Consent decree (CD) negotiations between EPA, the state, and the PRPs began soon after the ROD was signed, and the CD was signed on August 14, 2002. The PRPs began collecting pre-design data in fall 2003 and finished the pre-design in spring 2007. EPA issued an Explanation of Significant Differences (ESD) in April 2007 that changed the Phase I remedy alternative from excavation and treatment via solidification/stabilization to Vacuum Enhanced Recovery (VER). The PRPs submitted the Remedial Design to EPA in September 2007, and EPA approved the Remedial Design in April 2008. 

The PRPs began the remedial action in March 2009 and completed construction activities (except for punch-list items) in September 2009, and EPA signed the Preliminary Close-out Report on September 28, 2009.  EPA conducted the final inspection in June 2010. EPA later approved the Remedial Action construction completion report in November 2010.   

The PRPs are currently conducting the required operation and maintenance activities, and all required institutional controls at the site have been implemented.  

EPA completed the first five-year review for the site in March 2014. The five-year review found that the remedy is protective of human health and the environment since all known exposure pathways have been eliminated. 


Remedial Project Manager, U.S. EPA
scott hansen (hansen.scott@epa.gov)
(312) 886-1999





Site Profile Information

This profile provides you with information on EPA's cleanup progress at this Superfund site.


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