The Associated Press

TAINTED AT THE TAP

EPA Lead Sampling Test Results

About Tainted at the Tap

The Associated Press has analyzed 25 years' of lead sampling data collected by the EPA for a series of stories about lead-tainted water systems in the United States. The original story, published on April 9, 2016, focused on the nearly 1,400 water systems that exceeded the federal lead standard of 15 parts per billion at least once between Jan. 1, 2013, and Sept. 30, 2015. The affected systems are large and small, public and private, and include 278 systems that are owned and operated by schools and day care centers in 41 states.

As Michigan looks at dropping the over-limit level from 15 parts per billion to 10 parts per billion -- a change recommended by the World Health Organization -- the AP has done a further analysis to see how many water systems across the country would be affected if those rules went into place nationwide. This analysis is for a story slated to run Wednesday, April 27, 2016.

All data collected and prepared by AP Data Journalist Meghan Hoyer.