SPRINGFIELD, Ill. — Documents obtained by The Associated Press show that Illinois regulators found higher-than-acceptable levels of toxins in 80 percent of the state’s rock quarries that take demolition waste as fill.

Illinois Environmental Protection Agency sampling at 92 sites licensed to backfill with clean construction and demolition debris yielded levels of heavy metals, pesticides and volatile chemicals exceeding what the state has set as safe levels.

The AP obtained the results under the Illinois Freedom of Information Act.

The results likely will re-ignite calls for groundwater monitoring around the sites. Unlike sanitary landfills, they are unlined and critics say toxins can leak into drinking water supplies underneath.

Industry representatives say the testing turned up metals naturally occurring in the environment and the testing doesn’t necessarily reveal toxic dangers.