Protecting people from lead in drinking water is a longstanding priority of the EPA. Accordingly, enforcing the Safe Drinking Water Act's Lead and Copper Rule will help reduce the public's exposure to lead. This Compliance Advisory is directed to public water systems that are classified as either community water systems or non-transient non-community water systems (collectively, water systems). This Compliance Advisory describes how the EPA intends to monitor compliance and enforce the key provisions of the 2021 Lead and Copper Rule Revisions that will remain in place after the issuance of the final Lead and Copper Rule Improvements in October 2024.