Understanding Lead Drinking Water Regulations
Reducing lead risks from water has been a priority in the United States since the Safe Drinking Water Act (SDWA) was passed in 1974. While there remains much to be done to eliminate risks altogether, understanding the history of regulations can help contextualize current mitigation efforts and acknowledge how far we have come. Since the SDWA, we have seen drastic improvements which reduce our risks, including recent updates to the Lead and Copper Rule that require lead service line replacement within the next 10 years. Below is a brief history of laws and regulations pertaining to lead in drinking water and an explanation of enforceable lead standards.
History of Lead Regulations
1974 – Safe Drinking Water Act (SDWA)
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Established the federal framework for regulating drinking water quality and authorized EPA to set national drinking water standards.
1986 – SDWA Amendments
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Restricted lead-containing materials in drinking water plumbing. Defined “lead-free” as ≤8% lead in pipes/fittings and ≤0.2% lead in solder/flux.
1991 – Lead and Copper Rule (LCR)
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Established lead and copper action levels (15 ppb and 1.3 ppm, respectively), corrosion control requirements, monitoring, and public notification requirements. Set lead maximum contaminant level goal (MCLG) at zero.
1996 – SDWA Amendments
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Strengthened requirements for plumbing materials and authorized development of standards limiting lead leaching from plumbing products.
2011 – Reduction of Lead in Drinking Water Act (effective 2014)
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Reduced allowable lead content in wetted plumbing components from 8% to 0.25%.
2021 – Lead and Copper Rule Revisions (LCRR)
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Required lead service line inventories, improved sampling and notification requirements, and expanded consumer protections.
2024 – Lead and Copper Rule Improvements (LCRI)
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Requires identification and replacement of all lead service lines within a 10-year timeframe, strengthens sampling protocols, and improves protections for communities with lead exposure risks. Established new action level at 10 ppb.
Regulatory lead levels
In 1991, the EPA established an action level for lead through the Lead and Copper Rule at 15 parts per billion (ppb). For context, 1 ppb is roughly equivalent to one drop of ink in a 10,000-gallon swimming pool. The LCR states that additional measures must be taken if more than 10% of samples exceed the 15 ppb action level. If this does occur, then corrosion control measures must be put in place and the public must be informed of the exceedance. These notifications should include details on how to mitigate risks, including: flushing pipes, using a filter, cleaning aerators, and using cold water (see filtering vs. auto-flushing).
The Lead and Copper Rule also established a maximum contaminant level goal (MCLG) for lead. MCLGs represent the level at which there are no known health effects for a given contaminant. While not enforceable, they can be used to set goals and priorities. For lead, the MCLG is zero, since there is no safe level of lead (see effects of lead in drinking water). The EPA has maximum contaminant levels (MCLs, legally enforceable) and MCLGs (non-enforceable) for over 90 contaminants, known as National Primary Drinking Water Regulations (NPDWR). For more information about regulated contaminants other than lead, visit the EPA NPDWR website.
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