The U.S. Environmental Protection Agency (EPA) first issued the rule in 1991 pursuant to the Safe Drinking Water Act. EPA promulgated the regulations following studies that concluded that copper and lead have an adverse effect on individuals.lthough lead is a known poison, the mechanical and chemical characteristics of the metal continue to keep lead as an important component in many products. In water supply, lead's durability and workability selected it for use as water pipes. Lead alloys (bronze, brass) are used for plumbing fittings.