The U.S. Environmental Protection Agency has confirmed it will defend stringent lead-in-drinking-water requirements adopted in 2024, signalling continuity with the previous administration’s public health framework despite wider deregulation efforts in other environmental areas. The agency told a federal appeals court in Washington it supports a 10-year deadline for most water systems to replace lead service lines.
The decision aligns the Trump administration with a rule finalised under the Biden administration, representing one of the most significant overhauls of lead standards in more than three decades. According to the EPA, mandatory pipe replacement is necessary to meet obligations under the Safe Drinking Water Act. The agency stated that previous approaches relying primarily on corrosion control and monitoring had not prevented “system-wide lead contamination and widespread adverse health effects”.
The regulation is being challenged by the American Water Works Association, which argues that the EPA lacks authority to regulate portions of service lines located on private property and that the replacement schedule is unrealistic given workforce constraints and parallel infrastructure demands. In response, the EPA maintains that utilities have sufficient control over entire service lines and that analysis of data from dozens of systems shows most can meet the deadline. Utilities were granted three years to prepare before the 10-year clock begins, with additional flexibility for communities facing the highest concentrations of lead pipes.
The rule lowers the lead action level to 10 parts per billion, strengthens sampling methods and expands consumer notification requirements. It also revises how lead levels are measured, a change expected to increase the number of systems identified as exceeding limits.
Estimates of the scale of the challenge vary. While the previous administration projected roughly 9 million lead service lines nationwide, the EPA has since revised that figure to about 4 million, citing methodological changes and updated state data. Lead pipes remain most prevalent in older urban centres such as Chicago, Cleveland and Detroit. Although federal funding is available to support replacements, the outcome of the legal challenge will shape how rapidly the rule is implemented.
