Drinking water deadlines that matter.
The recurring deadlines every community water system operates against, plus the recent federal rule publications that changed them. Every date on this page is sourced from the eCFR or the Federal Register. We do not publish dates we cannot cite — if you are looking for state-specific deadlines or specific LCRI replacement milestones that vary by system, check with your primacy agency.
The calendar every CWS lives on.
Three federal deadlines recur every calendar year. All are verified against 40 CFR § 141.155 on 2026-04-18.
Annual CCR delivery to customers
Every community water system must distribute the Consumer Confidence Report by July 1 each year, covering the previous calendar year's monitoring data. Report must be distributed using methods in § 141.155(a).
Read on eCFR →Certification to primacy agency (CCR)
No later than 10 days after the required customer distribution date, the community water system must certify to the primacy agency that the CCR was distributed and that its content is consistent with compliance monitoring data previously submitted. (July 11 when distribution is on July 1.)
Read on eCFR →Biannual CCR for systems ≥ 10,000 persons
Added by the 2024 CCR Rule Revisions. Systems serving 10,000 or more persons must distribute a second CCR by December 31, covering data and any interim violations or action-level exceedances from the first half of the calendar year.
Read on eCFR →Recent Federal Register publications.
One-time rule publications and transition windows that change the compliance landscape. Effective dates, monitoring schedules, and replacement deadlines specific to your system size may differ — confirm with your primacy agency before relying on any single date.
CCR Rule Revisions final rule
Revisions to 40 CFR 141 Subpart O, adding biannual delivery for systems ≥ 10,000 persons, the Limited English Proficiency plan requirement for systems ≥ 100,000 persons, and updates to delivery methods. Reflected in the current eCFR § 141.155.
Read the source →Lead and Copper Rule Improvements (LCRI) final rule
LCRI published in the Federal Register. Replaces the 2021 LCR Revisions and tightens lead action levels, service-line inventory, and replacement obligations. See our Lead and Copper Rule hub for the Subpart I section reference.
Read the source →LCR → LCRI transition window
During this window, community water systems and non-transient non-community water systems must comply with 40 CFR 141.2, 141.31(d), and 141.80 through 141.91 as codified on July 1, 2020, with specified supplemental requirements. Window ends November 1, 2027 — systems transition fully to LCRI thereafter.
Read the source →LEP plan required for systems ≥ 100,000 persons
Systems serving 100,000 or more persons must develop a plan for providing assistance to consumers with limited English proficiency. The first plan must be provided to the state with the first report in 2027 and updated annually thereafter with each certification under § 141.155(c).
Read the source →Dates we deliberately omit.
A few common-interest dates are intentionally not on this page because they depend on system size, source type, or primacy-state specifics we cannot generalize safely:
- LCRI service-line replacement milestones. Replacement obligations vary with lead service line inventory, PFAS co-occurrence, and primacy-state enforcement. See our LCR hub for clause references.
- PFAS monitoring and compliance dates. Initial monitoring windows and compliance dates under 40 CFR 141 Subpart Z vary by system size and detection status. See our PFAS hub for the clause structure; confirm dates with EPA and your primacy agency.
- State-specific CCR certification forms and language-access deadlines. These vary by state and are not federal. When we ship the state overlay for your primacy agency, we will expose those dates in the product.
If you need a specific date we have not published here, the eCFR and your primacy agency’s drinking water program are authoritative.
Ship your CCR before the July 1 deadline — this year or any year.
60-day free trial. No credit card. Your trial becomes your first published CCR.