Several cities have manipulated test data to conceal results showing high levels of lead in drinking water, a newspaper reports.
The Washington Post says Philadelphia, Boston and New York City are among those that threw out test results or changed the scope of their testing to keep their reported lead levels within legal limits.
State officials and the federal Environmental Protection Agency have allowed local water authorities to publicize misleading test data, the newspaper reports.
The Post's investigation of 65 major water system comes months after Washington, D.C. residents learned that officials have for months concealed reports showing that lead levels in the local water exceeded safe limits.
Lead is dangerous because it can lower IQs in children and affect kidneys in kids and adults.
Among the Post's findings:
The cities cited in the Post report denied any deliberate effort to mislead citizens or regulators.
EPA Acting Assistant Administrator Benjamin H. Grumbles, in testimony to Congress this summer, said, "We have not identified a systemic problem," in water systems.
But former EPA official Jim Elder told the Post: "Apparently, it's a real crapshoot as to what's going to come out of the tap and whether it will be healthy or not."