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How can lead enter drinking water from plumbing?

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Diagram of a water treatment plant showing the process from water inlet through mixing, coagulation, flocculation, settling, filtering, chemical treatment with chlorine, storage, and high-lift pumping to the distribution system. — water purification Water from inlets located in the water supply, such as a lake, is sent to be mixed, coagulated, and flocculated and is then sent to the waterworks for purification by filtering and chemical treatment. After being treated, the water is pumped into water mains for storage or distribution.

Lead can enter drinking water primarily through the process of leaching from corroded lead pipes and plumbing components within a water supply system.1

Historically, lead was used extensively for water conveyance, a practice dating back to Roman engineering. Because lead is a toxic metal that accumulates in the body over time, its presence in drinking water poses significant public health risks, including potential developmental delays in children and progressive renal disease in adults.2341

While modern water treatment focuses on eliminating pathogens, industrialized nations also prioritize managing chemical contamination to prevent chronic health issues. The corrosion of lead-based plumbing materials remains a critical concern, as it allows the metal to dissolve into the water supply. Eliminating contact with such sources is essential for preventing lead poisoning.14