EPA seeks public comment on proposed cleanup plan for the Matthiessen & Hegeler Zinc Co. Superfund site in LaSalle, Illinois

The agency will hold a public meeting on Wednesday, June 14

June 1, 2023

The Matthiessen & Hegeler Zinc Co. operated a zinc smelter at the industrial portion of the site from 1858 until 1961. In 2003, EPA added the site to the National Priorities List, the list of hazardous waste sites eligible for long-term remedial investigation and cleanup under the Superfund program. Since 2016, EPA has sampled soil at approximately 1,000 off-site residential properties near the facility and has cleaned up several hundred yards.

After on-site contaminated soil is contained and capped, EPA's preferred cleanup plan proposes to collect groundwater samples to determine if contaminated groundwater levels are decreasing due to containment of the contaminated soil. This temporary plan allows the agency time to evaluate long-term solutions before proposing a final remedy for groundwater contamination. The proposed interim groundwater remedy also includes the implementation of:

• institutional controls to prevent unacceptable exposures to contaminated groundwater
• a groundwater management zone that mitigates impairment caused by the release of contaminants from a site to a region of groundwater.

EPA also proposes to update the 2017 cleanup decision document to correctly state that wastes in the industrial area are not primary hazardous wastes and therefore pose a lower level of risk. The Agency will also clearly outline state requirements to close and monitor the on-site landfills.

EPA's public comment period on the proposed amendment to the cleanup plan is open from June 1 to June 30. Comments may be submitted via:

• email to Ruth Muhtsun at [email protected]
• EPA's website
• or attend the public meeting and make a comment

When: Wednesday, June 14, 2023

Time: 6 p.m.

Where: LaSalle-Peru High School Auditorium
541 Chartres St., La Salle

To learn more, visit the Matthiessen & Hegeler Zinc website.

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