U.S. Environmental Protection Agency researchers found spikes of lead can leach into tap water when the lead service lines Chicago installed until the mid-1980s are altered by water main replacements, meter installations or street work, the Chicago Tribune reported Wednesday.
The EPA report found high lead levels can be found in tap water for years, raising concerns that other cities with lead pipes experience similar problems.
Lead levels exceeded federal standards at all but one of 13 Chicago homes tested in areas where the service line was physically disturbed between 2005 and 2011, results published in the journal Environmental Science & Technology.
The Tribune said most homeowners probably don't know their tap water is tainted. Under federal rules, utilities rarely are required to warn residents of work being done or tell them what they can do to reduce their exposure to lead, a neurotoxin that can damage the brains of young children.
"We owe it to people to tell them that their water might not be safe to drink," Marc Edwards, a professor of civil and environmental engineering at Virginia Tech University, told the Tribune. Edwards wasn't involved with the study but drew similar conclusions in his own research.
Lead is so hazardous that the EPA and the Centers for Disease Control and Prevention say no level of exposure is safe.