Lead is a toxic metal that can leach into water from old pipes and plumbing fixtures. It harms brain development in children and has no safe exposure level.

Lead has been used in plumbing for centuries due to its malleability. It can enter drinking water through corrosion of lead pipes, solder, and fixtures. The EPA measures lead in parts per billion and has set an action level of 15 ppb. Many water utilities now use corrosion control treatments to reduce lead leaching. Efforts are ongoing to replace lead service lines nationwide. Homeowners can use filters certified for lead removal as an additional precaution.