The U.S. Environmental Protection Agency (USEPA) recently imposed a regulation requiring public water suppliers to notify all their customers of the potential health effects of lead from household plumbing. The USEPA regulates public water supplies (with at least 15 service connections or servicing 25 individuals) but does not regulate private water supplies. The potential health hazard of lead is also present from household plumbing which is supplied water from a private water source.
Taraba, Joseph L., "Lead in Your Drinking Water" (1989). Agricultural Engineering Extension Updates. 43.