The most deterministic calendar a town keeps

Drinking-water compliance is a set of exact schedules: reports due on fixed dates, notices whose clocks start when a result comes back, and state surveys on a set cycle. This paper lays out that calendar and the one kind of obligation most systems miss: the result that creates new obligations.

The fixed dates

Each community water system delivers its Consumer Confidence Report to customers by July 1 each year (40 CFR 141.152, 141.155). Through 31 December 2026, a copy goes to the state by the delivery date, followed within 3 months by a certification that the report was distributed and is correct. For the report delivered by 1 July 2026, that certification is due by about 1 October 2026, or earlier if the copy went in earlier. From 1 January 2027, the copy and the certification are due no later than 10 days after the delivery date. From 2027, systems serving 10,000 or more people distribute the report twice a year. Community systems serving more than 3,300 people certify a risk and resilience assessment (RRA) and an emergency response plan (ERP) to EPA, and recertify every five years. For systems serving 3,301 to 49,999 people, the RRA recertification was due 30 June 2026. The ERP recertification is due six months after the system's RRA recertification, and no later than 31 December 2026. In Oklahoma, the monthly operational report goes to DEQ no later than the tenth day of the following month (OAC 252:631-3-11).

Sampling that depends on who you are

Every system keeps a written sample siting plan, with a collection schedule, that represents water throughout the distribution system (40 CFR 141.853). Results go to the state within the first ten days after the month the result is received, or after the end of the sampling period the state sets, whichever is shorter (40 CFR 141.31(a)). Some of the calendar depends on the kind of system. The state surveys community ground water systems at least every three years (every five for systems with outstanding performance or adequate treatment), and non-community ground water systems every five years (40 CFR 142.16). As codified, initial PFAS sampling, including reporting results to the state, must be completed by 26 April 2027, and the PFAS limits take effect on 26 April 2029 (40 CFR 141.902, 141.61). EPA's rescission of four of those limits is proposed, as is a request-based extension to 2031 for PFOA and PFOS. Both proposals were published on 20 May 2026, and neither is law.

When a result creates new work

A coliform result that exceeds a trigger starts a Level 1 or Level 2 assessment, and the assessment form is due within 30 days after the system learns of the trigger (40 CFR 141.859). A lead result above the action level is a Tier 1 public notice today: notice within 24 hours (40 CFR 141.202(a)(10)). Until 1 November 2027 the lead action level is 0.015 mg/L at the 90th percentile; from that date it is 0.010 mg/L. A significant deficiency found in a sanitary survey of a ground water system must be corrected, or be under a state-approved plan, within 120 days of written notice (40 CFR 141.404). In Oklahoma, a system reports to DEQ within 24 hours if, among other things, lead exceeds the action level, a fecal coliform or E. coli positive is verified, or nitrate exceeds the limit (OAC 252:631-3-11(a)). A fixed calendar cannot hold these in advance, because the clock starts the day the result comes back. We check each result against the rules that apply to your system, set the deadlines that result starts, and keep the record of how each one was closed.

Notices and their clocks

Public notice comes in three tiers. Tier 1: as soon as practical and no later than 24 hours after the system learns of the violation, plus consultation with the state within 24 hours. Tier 2: no later than 30 days. Tier 3: no later than one year. The system certifies to the state within 10 days of completing a notice, and keeps copies of notices and certifications for 3 years (40 CFR 141.201 to 141.204, 141.31(d), 141.33). Separately, a failure to comply with a drinking water rule, including a missed sample, is reported to the state within 48 hours unless a rule sets a different period (40 CFR 141.31(b)). A missed coliform sample is reported within 10 days after the system discovers it (40 CFR 141.861(a)(4)).

Lead and the service-line inventory

The Lead and Copper Rule Improvements (LCRI) are final, with a compliance date of 1 November 2027 (40 CFR 141.80, 141.84). They are under challenge in the D.C. Circuit, where argument is calendared for 30 September 2026; the rule stays in effect. Until 1 November 2027 an interim version of the lead rules applies. The initial service line inventory was due on 16 October 2024. Today the inventory must be publicly accessible, and materials found during normal work are recorded as they are encountered. Oklahoma DEQ describes a customer notice for a lead service connection that is repeated every year until the connection is no longer lead. Federal law does not require periodic inventory updates to the state during the interim; that duty returns on 1 November 2027. By that date, systems submit a baseline inventory to the state, and systems with lead, galvanized-requiring-replacement or lead-status-unknown lines have a service line replacement plan. For systems on the standard schedule, replacement must be complete within 10 program years, which works out to 31 December 2037.

People: the certified operator

Community and non-transient non-community systems must have certified operators. EPA withholds 20 percent of a state's drinking water revolving fund grant if the state has no operator certification program. Under OAC 252:710, the operator in responsible charge holds a certification equal to or higher than the class of the system. Certificates renew every year by 4:30 p.m. on June 30. An expired certificate can be reactivated within two years; after that, the holder reapplies and re-tests. Annual training hours depend on the licence: A 16, B 12, C 8, D 4 and Technician 4, with 4 classroom hours in each case. In Indiana (327 IAC 8-12), continuing education is completed in each three-year period before renewal: 10 contact hours for FSO, DSS and WT1; 15 for DSM, DSL and WT2; 25 for WT3; and 30 for WT4 to WT6. At least 70 percent of the hours must be technical.

Why TheComplianceHQ

We run your compliance program as a service: the calendar, the records, the plans and the filings for your signature.
You stay the operator of record, and your people stay yours. When the work needs a credential or a field specialist, we bring in a qualified expert under contract.
Every task leaves a dated record, and a correction is a new dated entry, never a quiet edit, so the file answers the inspector's question the day it is asked.
One calendar across every system you run, so the same people, trucks and tickets are never tracked twice.

Sources

This paper is provided for orientation and is not legal advice. Operators remain responsible for compliance with all applicable federal and state requirements.