Lead contamination in water is most common in homes built before 1988. Typically, lead contaminates water through corrosion of plumbing products containing lead.

The most common sources of lead in plumbing products include pipes, solder, fixtures, fittings, and valves. Contamination is not just from lead pipes. Other sources include copper pipes joined with lead solder and brass pipes and fixtures.

Homes or buildings built before 1988 could still contain leaded plumbing products and are at the highest risk for lead contaminated water. By 1988, “lead-free” materials were required to be used in both new plumbing and plumbing repairs. However, “lead-free” materials may still contain lead. The definition of “lead-free” was set at no more than 8% from 1988 to 2013, and no more than 0.25% beginning in 2014. In addition, plumbing not intended for drinking like garden hose faucets and pipes used for outdoor irrigation are exempt from lead regulations and may contain unknown amounts of lead.

Outdoor water faucet turned on.

Water catchment systems can also pose a lead exposure risk. In vog prone areas, such as Hawai‘i, water from catchment systems can become acidic and leach harmful contaminants from the roofing or plumbing products, including lead.

You cannot taste, see, or smell lead in drinking water so families should take certain actions to minimize their exposure. Before using any tap water for drinking or cooking, it is recommended to flush the water system by running cold water for 1-2 minutes. Water used for drinking, cooking, and making formula should only come from the cold water tap because hot water increases the leaching of lead from plumbing products. Families can also reduce their exposure to lead in drinking water by using a water filter that removes at least 99% of lead.