Chicago residents filed [complaint, PDF] a class action lawsuit Thursday accusing the city of Chicago of knowingly contaminating the city’s water supply when replacing lead water pipes in the city. The elevated, unsafe levels of lead in the drinking water have persisted since 2008 when the city began construction on the old lead pipes, delivering water to 80 percent of Chicago. Lead is known to cause cancer, infertility, high blood pressure and other health related problems. The lawsuit claims that the Environmental Protection Agency and the Centers for Disease Control and Prevention have issued warnings after conducting studies about the presence of lead in water prior to pipe construction. The complaint also states that Chicago contains more lead pipes than any municipality. Lead pipes were outlawed by the Safe Drinking Water Act [summary] in 1986. Until they can be replaced, chemically treated water is used to build up a coating inside the lead pipes to prevent corrosion.

In January a federal lawsuit was filed in Flint Michigan [JURIST report] seeking the replacement of lead water pipes in the city. Flint’s drinking water supply was switched from Lake Huron water treated in Detroit to water from the Flint River treated at the Flint water treatment plant in 2014 to save money. The new supply was not treated with required corrosion control chemicals and caused lead and pathogens [report] to get into the town’s water supply from pipes. Researchers from Virginia Tech concluded that lead levels were high enough to be designated as “toxic waste” [WP report].