How Lead Gets Into Drinking Water
Lead can enter drinking water when plumbing materials that contain lead corrode, especially where the water has high acidity or low mineral content that corrodes pipes and fixtures. The most common sources of lead in drinking water are lead pipes, faucets, and fixtures. In homes with lead pipes that connect the home to the water main, also known as lead services lines, these pipes are typically the most significant source of lead in the water.
Lead pipes are more likely to be found in older cities and homes built before 1986. Among homes without lead service lines, the most common problem is with brass or chrome-plated brass faucets and plumbing with lead solder.
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The Safe Drinking Water Act (SDWA) has reduced the maximum allowable lead content -- that is, content that is considered "lead-free" -- to be a weighted average of 0.25 percent calculated across the wetted surfaces of pipes, pipe fittings, plumbing fittings, and fixtures and 0.2 percent for solder and flux.
Drinking Water Requirements for States and Public Water Systems
Code of Federal Regulations - 40 CFR Part 141 Subpart I.
Lead and copper enter drinking water primarily through plumbing materials. Exposure to lead and copper may cause health problems ranging from stomach distress to brain damage.
In 1991, EPA published a regulation to control lead and copper in drinking water. This regulation is known as the Lead and Copper Rule (also referred to as the LCR). Since 1991 the LCR has undergone various revisions, see the Rule History section below.
The treatment technique for the rule requires systems to monitor drinking water at customer taps. If lead concentrations exceed an action level of 15 ppb or copper concentrations exceed an action level of 1.3 ppm in more than 10% of customer taps sampled, the system must undertake a number of additional actions to control corrosion.
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If the action level for lead is exceeded, the system must also inform the public about steps they should take to protect their health and may have to replace lead service lines under their control.
United States Lead and Copper Rule ("LCR") Revisions
Long Term Revisions
The EPA’s 2021 Revised Lead and Copper Rule better protects children and communities from the risks of lead exposure by better protecting children at schools and childcare facilities, getting the lead out of our nation’s drinking water, and empowering communities through information.
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Short Term Revisions
In 2007, EPA revised the Lead and Copper Rule to enhance implementation in the areas of monitoring, treatment, customer awareness, and lead service line replacement. The update also enhanced public education requirements and ensured drinking water consumers receive is: meaningful, timely and useful information. These changes are also known as the “Short-Term Revisions to the Lead and Copper Rule.”
EPA Requirements
The Safe Drinking Water Act (SDWA) requires EPA to establish and enforce standards that public drinking water systems must follow. EPA delegates primary enforcement responsibility (also called primacy) for public water systems to states and tribes if they meet certain requirements. Learn more at:
Link to the SDWA:
Link to SDWA Standards:
https://www.epa.gov/sdwa/background-drinking-water-standards-safe-drinking-water-act-sdwa
Link to how the EPA regulates drinking water contaminants:
https://www.epa.gov/sdwa/how-epa-regulates-drinking-water-contaminants
Link to primacy enforcement responsibility for public water systems:
https://www.epa.gov/dwreginfo/primacy-enforcement-responsibility-public-water-systems