The U.S. Environmental Protection Agency announces the final plan to clean up contaminated soil and sediment at the Hegeler Zinc Superfund site in Vermilion County.
In addition to zinc products, the former smelting facility produced sulfuric acid and cadmium which resulted in large amounts of slag, stored in piles on the site. Soil, sediment, groundwater and surface water are contaminated with cadmium, lead, arsenic and zinc, according to the EPA.
The design phase of the cleanup will start in about six to eight months and will last approximately two years. After that, construction will begin. The EPA anticipates the construction will take about three years, according to a press release.
The EPA’s cleanup will involve excavating contaminated sediment and soil and adding it to the existing slag pile or disposing of it off site. The agency will then install a low-permeability cover over the pile, reroute portions of a creek to ensure a safe distance from the slag pile, and continue monitoring groundwater and surface water.
The EPA received six public comments on the proposed plan.
The Hegeler Zinc site in Vermilion County is a 100-acre area that was a zinc smelting facility from 1906 until about 1954. Hegeler Zinc produced various grades of zinc slab and rolled zinc products as well as sulfuric acid. The smelting operation resulted in large amounts of slag (through a burning process), which was stored in piles on the site. The slag material contains unburned residues and metals such as lead, arsenic and zinc.
In May 2003, the EPA secured the site with fencing. It listed the site on the Superfund program’s National Priorities List (NPL) in 2005. Site investigations are ongoing.
In 2015 the EPA began cleanup of the residential properties at OU3 of the Hegeler Zinc Site. The EPA’s cleanup of lead and arsenic included digging up and removing contaminated soil from residential yards; backfilling excavated properties with clean soil; transporting excavated non-hazardous soil to the former smelting facility for stockpiling to be addressed as part of the future remedy; transporting and disposing of hazardous excavated soil to an agency approved landfill.
The EPA completed cleanup of residential yards in OU3 in 2016.
The EPA completed a review of the site's cleanup in June 2020. This type of review is required at least every five years where the cleanup is complete but hazardous waste remains managed on-site. These reviews are completed to ensure that the cleanup continues to protect people and the environment. It was this site’s first five-year review.
The review included an evaluation of: background information, cleanup requirements, effectiveness of the cleanup and any anticipated future actions, maintenance and monitoring efforts, and possible ways of operating the site more efficiently.
The review found the cleanup continues to protect people and the environment. The next scheduled review will be in 2025.
At this site, activity and use limitations that the EPA calls institutional controls are in place. Institutional controls play an important role in site remedies because they reduce exposure to contamination by limiting land or resource use. They also guide human behavior. For instance, zoning restrictions prevent land uses – such as residential uses – that are not consistent with the level of cleanup.
