The Lead and Copper Rule (LCR) is a United States federal regulation (40 CFR 141.80 et seq.) that limits the concentration of lead and copper allowed in public drinking water at the consumer's tap, as well as limiting the permissible amount of pipe corrosion occurring due to the water itself. The U.S. Environmental Protection Agency (EPA) first issued the rule in 1991 pursuant to the Safe Drinking Water Act. The EPA promulgated the regulations following studies that concluded that copper and lead have an adverse effect on individuals. The LCR sought to therefore limit the levels of these metals in water through improving water treatment centers, determining copper and lead levels for customers who use lead plumbing parts, and eliminating the water source as a source of lead and copper. If the lead and copper levels exceed the "action levels" water suppliers are required to educate their consumers on how to reduce exposure to lead. A 2004-2005 study of the LCR by the EPA noted that the system had been effective in 96 percent of systems serving at least 3,300 people.