Lead and tap water

Alternative Names

Water contaminated with lead

Information

The Safe Drinking Water Act requires the Environmental Protection Agency (EPA) to set and enforce standards to protect public drinking water systems. In the United States, the EPA set the maximum allowable concentration of lead in public drinking water at 15 mcg/L (micrograms per liter).

The EPA requires all water suppliers to produce a water quality report every year. These reports include information about lead amounts. The reports are available to the public.

The EPA requires public water systems to alert you if there is a problem with your drinking water.

Lead can enter drinking water when plumbing materials that contain lead corrode. Corrosion is when metal is dissolved or worn away by a chemical reaction between water and your plumbing. Water that has high acidity or low mineral content can corrode pipes and fixtures.

The most common sources of lead in drinking water are lead pipes, faucets, and fixtures. Service lines connect the home to the water main. In homes with lead service lines, these pipes are the main source of lead in the water. Lead pipes are more likely to be found in homes built before 1986. In homes without lead service lines, plumbing with lead solder can be a source of lead in the water.

How much lead enters the water depends on:

  • The chemistry of the water and the types and amounts of minerals in the water
  • The amount of lead the water comes into contact with
  • The temperature of the water
  • The amount of wear in the pipes
  • How long the water stays in pipes
  • The presence of protective scales or coatings inside the plumbing materials

For more information, call:

  • EPA's Safe Drinking Water Hotline (800-426-4791)
  • National Lead Information Center ( 800-424-5323)

References

United States Environmental Protection Agency website. Basic information about lead in drinking water. www.epa.gov/ground-water-and-drinking-water/basic-information-about-lead-drinking-water. Updated January 27, 2023. Accessed July 7, 2023.

Review Date: 7/1/2023
Reviewed By: Jesse Borke, MD, CPE, FAAEM, FACEP, Attending Physician at Kaiser Permanente, Orange County, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

adam.com