Illinois EPA Releases Results of Rockton Private Well Sampling Showing Private Wells Not Impacted By Metals Detected in Groundwater Monitoring Wells

SPRINGFIELD - State and local officials have released the July 22, 2021 sample results collected from 12 private, residential wells after elevated metals (including antimony, cadmium, chromium, and nickel) were detected in groundwater monitoring wells located at the former Beloit Corporation Superfund site. Based on these sample results, there has been no contamination of private wells with the metals identified at the superfund site.

The private well samples were analyzed for volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), and metals. There were no detections of antimony, cadmium, chromium, and nickel identified in any of the private wells sampled. There were other contaminants identified in three of the 12 residential wells.  One private well exceeded the State's Groundwater Quality Standard (GWQS) for lead, which was detected at 8 parts per billion (ppb), 0.5 ppb above the Illinois GWQS. The private well also had a detection of copper that exceeded health-based guidelines.  Tetrachloroethylene (a VOC), was detected in two other private wells, but the concentrations were below the GWQS and less than Illinois Department of Public Health (IDPH) health screening values.

Based on the location of one of the wells with a tetrachloroethylene detection, it is not expected to be related to the Beloit Corporation Superfund site or the Chemtool fire. Private wells near the Beloit Superfund site were previously impacted by VOCs, and they are resampled every two years. Illinois EPA is working to compare these results with previous private well samples to identify any correlations.

The IDPH has contacted the impacted well owners and will provide a detailed interpretation of the results, including potential health impacts and appropriate mitigations, for impacted private well owners. Owners who have not been contacted by IDPH are unaffected but will also receive a summary of their results.

Residences previously impacted by the Beloit Corporation Superfund Site should NOT use their private well water for drinking water. Most of these impacted residences are connected to the Village of Rockton community water supply (CWS). Those choosing to remain on private well water should be aware they have the primary responsibility to routinely test well water for potential contaminants. Illinois EPA has recommendations private well owners can follow to help ensure that the well water is safe at https://www2.illinois.gov/epa/topics/drinking-water/private-well-users/Pages/well-water-testing.aspx. The Village of Rockton CWS is routinely tested for VOCs and metals and remains in compliance with all applicable drinking water and groundwater standards. All CWS data can be viewed on Drinking Water Watch.

Illinois EPA continues to investigate possible sources of the metals contamination identified in the groundwater monitoring wells. The private residential well sample data is available on the Agency's website on both the Beloit Corporation and the Chemtool page.