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Congressional District # 14


EPA ID# ILD980606305
Last Updated: December, 2011

Site Description

The DuPage County landfill/Blackwell Forest Preserve site is located approximately 6 miles southwest of downtown Wheaton, near Warrenville, in DuPage County, Illinois.  The site is a 40 acre landfill, centrally located within the approximately 1200 acre Blackwell Forest Preserve.  The 40 acre landfill property was purchased by the DuPage County Forest Preserve District (FPD) in 1960.  FPD purchased the surrounding 1,100 acres subsequently.  The Blackwell Forest Preserve is an open space containing woodlands, grasslands, wetlands and lakes used by the public for recreation (hiking, campling, boating, fishing, horseback riding).   There are no residents on the FPD property.  The surrounding nearby population is less than 1,000 people.  The landfill was designed as a honeycomb of one acre cells lined with clay.  Approximately 1.5 million cubic yards of waste were deposited in the landfill bewteen 1965 and 1973, creating Mt. Hoy, which is approximately 150 feet above the original ground surface.




Site Responsibility

This site is being addressed through federal, state, and potentially responsible party (PRP) actions.

Threats and Contaminants

The principal contaminants of concern for this site are the volatile organic compounds (VOCs) 1,2-dichloroethene, trichloroethene and tetrachloroethene.  These VOCs were detected in on-site groundwater at or slightly above the maximum contaminant level (MCL).  Landfill leachate contains these and additional VOCs; semivolatiles including benzene, ethylbenzene toluene, and dichlorobenzene; and metals such as lead, chromium, manganese, magnesium, and mercury.  VOCs and agricultural pesticides were also detected in private wells, downgradient of the site but at low levels.  Some metals (manganese and iron) were detected above the MCLs in downgradient private wells.

Cleanup Progress

A consent order was signed between FPD, the United States Environmental Protection Agency (U.S. EPA), and the Illinois Environmental Protection Agency (IEPA) in 1989.  FPD agreed to conduct a remedial investigation and a feasibility study (RI/FS).  The RI was completed in 1994, and the FS in 1995.  In March 1996 U.S. EPA and FPD entered into an administrative order on consent (AOC) to expedite actions at the site.  The AOC identified activities that FPD would conduct, including soil borings to delineate any areas of the landfill which do not have a minimum of two feet of low permeability cover material and repair the cap, as necessary; enhance surface drainage; install an extraction system and treat and dispose of the landfill leachate; install additional landfill gas venting and continue to maintain and utilize the 25 existing gas vents; provide evidence that trees on the landfill are not in an area where root penetration could allow percolation of rainwater; and conduct long-term groundwater monitoring.

The leachate/landfill gas extraction wells were installed in 1996. The soil borings for the cap investigation were completed, the design was developed, and the landfill cap repair was largely completed in 1997.  However, due to problems in obtaining clay, the final four acres of cap repair were not completed until 1998.  The leachate collection system was installed and began operation in November 1997. It is anticipated that long-term monitoring and operation and maintenance of the system will occur for the foreseeable future (at least 20 years).

On September 30, 1998, a record of decision (ROD) was signed.  The final remedy incorporates long-term operation and maintenance of the previously implemented response actions as well as additional response actions, including monitored natural attenuation of groundwater.  In 2001, the landfill gas venting system was reconfigured to vent all landfill gas through one stack at the top of the landfill.  On April 9, 1999, a unilateral administrative order (UAO) was issued to FPD for implementation of the ROD. They are currently complying with the UAO.

The first five-year review at this site was completed in September 2003 and found the remedy to be protective of human health and the environment.  The second five-year review was completed on July 29, 2008.  The review concluded there are no known exposure pathways that exist that result in unacceptable health risks except for groundwater use in the area of the plume that is above MCLs.  The components of the remedies selected in the Record of Decision have been implemented and remain effective under the Administrative Order on Consent, and include institutional controls.  The third five-year review is due before July 2013.



Success Story

Mt. Hoy, created by the landfill provides a viewing area of the surrounding area as well as a inner tubing run on the North sid of the landfill

Property Reuse

The constuction of Mt. Hoy allowed a scenic viewing area on the top of the landfill.  The layout of the Forest Preserve with all of the various eco systems as well as other park recreationial facilities can be viewed.  Surrounding cities can also be viewed.  The North side of Mt. Hoy is used as a inner tub run.  The park rents inner tubes to those using the hill.


Remedial Project Manager, U.S. EPA
thomas smith (smith.thomasl@epa.gov)
(312) 886-6540

Community Involvement Coordinator, U.S. EPA
mike joyce
(312) 353-5546




Site Profile Information

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


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