Lead and copper enter drinking water primarily through plumbing materials.
- In 1991 EPA published the Lead and Copper Rule to minimize lead and copper in drinking water.
- In 2000, EPA published revisions to the Lead and Copper rule to address implementation problems and issues arising from the 1991 Rule.
- In 2004, EPA published minor corrections to the Lead and Copper Rule to reinstate text that was inadvertently dropped from the rule during the 2000 revisions.
- In 2007, EPA published Short-term regulatory revisions and clarifications to strength the rule in the following areas: monitoring, treatment processes, public education, customer awareness, and lead service line replacement.
The rule requires systems to monitor drinking water at customer taps. If lead concentrations exceed an action level of 15 ppb or copper concentrations exceed an action level of 1.3 ppm in more than 10% of customer taps sampled, the system must undertake a number of additional actions to control corrosion. If the action level for lead is exceeded, the system must also inform the public about steps they should take to protect their health and may have to replace lead service lines under their control.