After the water utility of Madison, Wis., discovered unacceptable levels of lead in its tap water, some 8,000 residences and business replaced all its lead service pipe between 2001 and 2011.
Five years after the project’s completion, Madison’s lead levels are well under the Lead and Copper Rule’s “action” threshold of 15 parts per billion. Its highest measure since 2011 is 3.5 parts per billion, which is so low that the EPA requires the utility to collect water samples every three years instead of annually.
More details here.
Source: The Washington Post