By CBS 2 Chicago Staff

CHICAGO (CBS) — More than a month after a massive fire at a chemical plant near Rockford, groundwater tests have raised new environmental concerns.

Tests have found elevated levels of some harmful metals – including including antimony, cadmium, chromium, and nickel – in the groundwater near the Chemtool plant in Rockton, Illinois, according to the Illinois Environmental Protection Agency.

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Elevated metal levels were found in 16 of 20 monitoring wells on the site of the former Beloit Corp. toxic waste Superfund site, where the Chemtool plant is now located.

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Testing of private wells near the site will begin soon.

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Until then, the Illinois Department of Public Health is warning people who live near the fire and have private wells to use bottled water for drinking and cooking.

CBS 2 Chicago Staff