Lead in Drinking Water

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During the winter of 2004, the District of Columbia discovered elevated levels of lead in its drinking water—levels that exceeded federal standards by many times. The issue raised concerns about lead’s potential impact on children’s learning abilities. Sensationalist coverage in the media captured the attention of Washington policymakers by fostering the impression that there was a serious public health threat in the District and possibly in cities around the nation. After the D.C. story broke, a handful of other cities discovered that they too had excess lead in their drinking water, although at lower levels than were found in D.C. The issue forced both Congress and regulators to examine public health concerns about lead levels. However, the science clearly shows that no action was necessary because the public health threat was minimal. 

The federal drinking water regulations on lead established a treatment practice rather than setting a numeric standard as is done for other water contaminants. The rule calls for “optimum corrosion control,” which is defined as public education and lead service line replacement. Systems must use this practice if lead levels in drinking water exceed 15 parts per billion in 10 percent of samples. Systems must periodically collect and test tap water samples from homes where lead concentration would likely be the highest, such as homes that receive their water through lead pipes.

After the D.C. story broke, members of Congress held hearings and began considering beefing up the nation’s drinking water law. Legislation (H.R. 4268) offered by D.C. delegate Eleanor Holmes Norton and a companion Senate bill (S. 2377) offered by Rep. James Jeffords (I-VT) in 2004 would have demanded that public water systems begin programs to replace lead service lines—replacing portions annually until such lines are eliminated. Administration officials argued at these hearings that new federal regulations for lead were premature.1 The U.S. Environmental Protection Agency (EPA) pledged to review compliance with the lead rule around the nation and to issue revisions to the rule. In March 2005, it reported that 96 percent of the nation’s drinking water systems were in compliance. The EPA produced a new rule for lead, which was finalized in 2006. The new rule made modest revisions—while keeping the action level at 15 parts per billion—with the hope of improving communication and compliance with the rule.