The Dirty Secret of Government Drinking Water Standards! The regulatory system meant to ensure the safety of America’s drinking water is broken. The inexcusable failure of the federal government’s responsibility to protect public health means there are no legal limits for more than 160 unregulated contaminants in U.S. tap water. For some other chemicals, the EPA’s Maximum Contaminant Levels, or MCLs, haven’t been updated in almost 50 years.