Over two years ago, federal researchers discovered that there were high levels of lead in Chicago water mains, which had been replaced replaced when new meters were installed. Although Mayor Rahm Emanuel has ordered work on the system, the contamination poses a number of serious health risks to residents.

A recent study from the researchers at the U.S. Environmental Protection Agency shows that when construction work disrupts service lines that connect building to the city’s water system, a brain-damaging metal (lead) can flow out of the faucets of homes for years after the initial work is done. The study also shows that almost 80% of the properties in Chicago are attached to service lines that are made of lead.

And due to the nature of the city’s testing protocols — which are based on federal rules — city residents are wont to miss high concentrations of lead in drinking water supply.

As shown in recent media coverage of the situation in Flint, MI, the aftermath of a lead-contaminated water supply can be beyond devastating.

Despite the grim details from the report, city officials failed to warn residents about the potential lead hazards in the letters sent to notify the homeowners of the new water mains beings installed. Instead, residents were merely advised to flush all faucets and taps for several minutes after work is complete. Meanwhile, the EPA feels that this solution is “grossly inadequate.”

Chicago’s current predicament serves as an example of an even broader problem that a number of U.S. cities are inevitably facing, after spending more than a century installing lead pipes in order to deliver drinking water. There are an estimated 700 water main breaks every single day in the U.S. Currently, 30% of water pipes in some of the biggest plumbing systems are up to 80 years old.

Yet instead of cautioning Chicagoans, city officials are adamantly telling residents that they have nothing to worry about.