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Mallard Lake Landfill Site

Site Information
  • Hanover Park, IL (DuPage County)
  • Alias(es): N/A
Contact Information

Public Affairs Specialist
Rafael P. Gonzalez (gonzalez.rafaelp@epa.gov)
312-886-0269 or 800-621-8431, ext. 60269

Site Manager
Michelle Kaysen (kaysen.michelle@epa.gov)
312-886-4253 or 800-621-8431, ext. 4253

Illinois EPA Community Relations Coordinator
Carol Fuller


Illinois Department of Public Health Regional Supervisor
Joe O'Connor



(where to view written records)

Sonya Crawshaw Branch
Poplar Creek Public Library District
4300 Audrey Lane
Hanover Park

Poplar Creek Public Library District
Main Library
1405 S. Park Ave.


In October 2007, methane gas was found in probes installed around the boundaries of the Mallard Lake Landfill in DuPage County, Illinois.

Methane gas was also discovered in soil at a testing location outside the landfill prompting the need for further investigation. In response to these findings, EPA asked the operator of the landfill BFI Waste Systems of North America, to do more sampling. On Nov. 6-10, BFI's contractors sampled for underground gas in the rights-of-way and public spaces outside the western boundaries of the landfill. The results of this sampling showed the presence of high levels of methane in five locations about 40 feet below ground. A shallower sample was taken on Dec. 3 in a public space and methane was discovered about 20 feet down. Methane gas develops naturally as a result of decomposition of landfill waste.

In addition to testing for gases, EPA has asked BFI to sample ground water near the landfill. On Nov. 13 and 15, DuPage County sampled 11 private wells along County Farm Road west of the landfill. No VOCs were detected in any of the water samples from these wells.

At the same time, investigative teams consisting of EPA and BFI contractors, under EPA oversight, began testing homes near the landfill for methane and other gases. Residents were also offered combustible gas indicators. As of Dec. 15, more than 70 homes have been screened and no explosive vapors have been found. More than 50 homes have had combustible gas indicators installed.

On Dec. 4, 2007, EPA entered into a legal agreement with BFI Waste systems of North America, Inc. and the Forest Preserve District of DuPage County to further investigate and address the problems at the landfill. This agreement is called an Administrative Order on Consent or AOC and may be viewed on this web site.

Site Updates | News Releases | Fact Sheets || Technical Documents || Legal Agreements || Public Meetings

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Site Updates

January 2017

Mallard Lake Landfill has been conducting investigations and cleanup activities under EPA oversight for ten years to address off-site methane gas. It is believed gas escaped during landfill construction, but wasn’t discovered until 2006. The off-site methane that was discovered deep beneath the ground has been fully defined and much has been removed.  Methane remains in the deep subsurface, trapped more than 30 feet below the ground surface. After careful analysis, review, study, and risk analysis through a Conceptual Site Model and technical feasibility evaluation, EPA is proposing to close out the work order with Mallard Lake Landfill.

After a thorough investigation, one of the first activities to take place was significant improvements around the perimeter of the landfill to ensure gas could no longer escape. Off-site methane was then actively extracted through the application of a vacuum throughout the impacted area. Due to the location of the gas and the nature of the subsurface, some methane remains trapped. The gas is limited to a thin, discontinuous layer of sandy soil that is approximately 30 feet below the surface. This layer is covered with 30 feet of clay soil, which limits the ability to remove the gas fully and acts as a protective barrier. This limits the ability for the gas to migrate to the surface. Once the demonstration was made that gas could no longer be actively pulled out of the ground, attempts were made to passively vent the gas under monitored conditions. 

Active extraction successfully took place until gas could no longer be removed and passive venting did not produce any methane at the ground surface.  In total, the area impacted by methane has been reduced by 47% (by square footage). Based upon our study and knowledge of the geology and location of the remaining gas relative to any structures, there is no unacceptable risk to leaving the remaining gas. The technical study and evaluation determined that the only remaining method of removing the gas would be full excavation of the soil. Considering the gas is a minimum of 30 feet below ground within a residential community, this option would not be realistic.

EPA is proposing to close out the Order with Mallard Lake Landfill. We believe the on-going monitoring efforts have demonstrated no substantive changes in the subsurface for many years. Steps will be taken to ensure the gas meters within the community are still operating correctly and that those homeowners in impacted areas that may not have received a meter have an opportunity to do so. EPA will be hosting a public meeting during the first half of 2017 to discuss these plans further with the community. Meeting information will be posted as soon as it has been scheduled.   


Mallard site timeline

News Releases

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Fact Sheets

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Technical Documents

Methane Trend Analysis


Legal Agreements

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Public Meetings

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