The Environmental Protection Agency (EPA) has introduced two key regulatory programs to protect Americans from lead in drinking water: the Lead and Copper Rule Revisions (LCRR) and the Lead and Copper Rule Improvements (LCRI).
The LCRR, finalized in 2021, focused on planning, inventory development, and public education. The LCRI, finalized in 2024, builds on that foundation and clarifies what changed from the 2021 rule, including new requirements for full lead service line replacement, updated sampling protocols, and enhanced public education efforts.
In short, LCRR was about preparation, while LCRI is about implementation.
The Lead and Copper Rule Revisions (LCRR) modernized the original 1991 rule by emphasizing proactive risk management, greater public transparency, and earlier intervention to reduce exposure. The updates strengthened protections for consumers and provided a clearer path for utilities to identify and address potential lead and copper risks.
Key LCRR Requirements
Many utilities completed these inventories in 2024, providing the foundation for the replacement programs now required under the LCRI.
The Lead and Copper Rule Improvements (LCRI), finalized in October 2024, strengthen the LCRR by requiring full replacement of all lead and galvanized service lines, a lower lead action level, and greater transparency in how water systems communicate risks and track progress. Most requirements take effect November 1, 2027, three years after the rule’s promulgation.
Under the LCRI, all lead and galvanized service lines requiring replacement (GRR) must be replaced within 10 years. Utilities must replace at least 10% of their lead or GRR lines each year, calculated as a three-year rolling average. Partial replacements are no longer allowed, and utilities must make good-faith efforts to coordinate with property owners when customer-side access or consent is needed.
Inventories play a central role in this process. Systems that completed initial inventories under the LCRR by October 16, 2024, must now update and expand them to include connector materials and precise service line locations by November 1, 2027. Systems serving more than 50,000 people must post these inventories online, while smaller systems must make them available through other accessible means. (40 CFR 141.84)
The LCRI reduces the lead action level from 15 parts per billion (ppb) to 10 ppb, triggering earlier corrective action. When sampling results exceed 10 ppb, utilities must review corrosion control practices, notify customers within three days, and provide certified lead-reducing filters where necessary. (40 CFR 141.80)
Utilities must now collect both first- and fifth-liter samples, using the higher result for compliance. This method gives a clearer picture of exposure from service lines and household plumbing.
Water systems must collect both first- and fifth-liter samples at customer taps, using the higher result to determine compliance. This method better captures potential lead contributions from both service lines and indoor plumbing. Utilities must also expand sampling locations to prioritize homes with known or suspected lead lines. (40 CFR 141.86)
The LCRI increases public transparency and responsiveness. Utilities must:
These measures ensure customers are informed and empowered to take steps to protect their households. (40 CFR 141.85)
Even systems with no lead or galvanized requiring replacement lines must continue maintaining and updating inventories, verify unknowns annually, and follow sampling and notification requirements. (40 CFR 141.84)
These two programs are sequential. The LCRR required planning, including inventory creation and community education. The LCRI enforces implementation, mandating replacement and tightening the allowable lead limit.
LCRR = Inventory and awareness
LCRI = Action and accountability
Together, they establish a comprehensive roadmap to eliminate lead from U.S. drinking water systems.
While lead is the focus of both programs, copper remains the same in both. The copper action level is unchanged and continues at 1.3 milligrams per liter (mg/L). If this level is exceeded, utilities must adjust corrosion control treatments and increase monitoring.
Copper is an essential trace mineral, and elevated levels are rare in properly maintained systems. Maintaining compliance ensures water quality while preserving copper’s advantages as a plumbing material.
As utilities replace lead lines, copper remains the trusted standard for long-term reliability and public confidence. Its proven performance, system compatibility, and durability make it the preferred choice for communities committed to safety and sustainability.
Denver Water offers a leading example of copper’s dependability. The utility, which has specified copper for service lines under two inches since 1978, continues to rely on it. Katie Ross, engineering manager at Denver Water, explained that copper’s familiarity and established performance history have kept it central to their system:
“We know copper works. It’s been part of our system for over 50 years, and our crews know how to install and maintain it effectively. As we replace about 60,000 lead service lines through our Lead Reduction Program, copper continues to deliver the consistency and reliability we need.”
Because copper is non-proprietary and widely available, Denver Water avoids supply chain disruptions and unnecessary training or testing of unfamiliar materials. As Ross noted, “With copper, we’re not reinventing the wheel. It’s a material everyone in the industry is familiar with.”
By continuing to use a trusted, time-tested material, Denver Water ensures its replacement efforts are efficient, consistent, and built to last, demonstrating why copper remains the reliable choice for utilities nationwide.
As the LCRI timeline moves forward, many utilities are reviewing the information gathered through their LCRR service line inventories and becoming familiar with the updated requirements outlined in 40 CFR Part 141. This may include understanding how the LCRI affects long-term planning for lead service line replacement, how sampling protocols differ from earlier requirements, and how annual updates to service line inventories support transparency under the new framework.
Utilities are also monitoring state-level guidance, funding opportunities, and technical assistance programs that may help support future work related to lead service line replacement and customer outreach. Each utility will navigate the LCRI based on local conditions, available resources, and coordination with state drinking water regulators, but staying aware of new information and regulatory updates may help aid that process.
The following EPA and CDA resources offer clear, accessible information on the LCRR, LCRI, and best practices for lead service line replacement:
The LCRR and LCRI together represent a generational investment in cleaner, safer drinking water. By completing service line inventories, replacing lead lines, and selecting proven materials like copper, utilities can meet EPA requirements while strengthening public trust and protecting communities for decades to come.
To learn more about copper’s role in safe drinking water delivery, visit https://copper.org/applications/plumbing/water_service/.