Public Notification Requirements — Quick Reference
The Three Tiers
| Tier | Timeframe | When It Applies |
|---|---|---|
| Tier 1 | Within 24 hours | Acute health risk situations |
| Tier 2 | Within 30 days | Most MCL and treatment technique violations |
| Tier 3 | Within 12 months | Monitoring, reporting, and procedural violations |
Tier 1 Triggers (24 Hours)
These are the urgent ones. Memorize them:
- E. coli MCL violation
- Nitrate or nitrite MCL exceedance
- Chlorite MCL exceedance
- Perchlorate MCL exceedance
- Lead action level exceedance (90th percentile)
- Turbidity TT violation with State Board consultation
- Waterborne disease outbreak
- Any other situation the State Board determines poses an acute risk
Tier 1 delivery must use methods reasonably calculated to reach ALL persons served. That means broadcast media, hand delivery, or posting in conspicuous locations, not just a mailing that arrives next week.
California-specific: Two Tier 1 triggers above differ from the original federal framework. Chlorite MCL exceedance is Tier 2 (30 days) under federal rules but Tier 1 (24 hours) in California, with a more stringent trigger requiring only 2 consecutive daily samples exceeding 1.0 mg/L at the entry to distribution. Perchlorate MCL exceedance is Tier 1 in California because California has a state-specific perchlorate MCL (0.006 mg/L) with no federal equivalent. If you studied from federal-only materials, you may not see either of these listed as Tier 1.
LCRR + LCRI update: The LCRR amended 40 CFR 141.202(a)(10) to make lead action level exceedance a Tier 1 violation requiring 24-hour public notification, effective October 16, 2024. California has adopted this change. The LCRI (compliance November 1, 2027) further lowers the lead action level from 0.015 mg/L to 0.010 mg/L. For T-5 exam purposes, know that lead ALE is Tier 1 today.
Tier 2 Triggers (30 Days)
All other MCL violations, treatment technique violations, and failure to monitor when the State Board determines there is a health risk. This covers most day-to-day compliance failures that aren't immediately life-threatening.
Tier 3 Triggers (12 Months)
Monitoring and reporting violations, failure to comply with testing procedures, and variance or exemption conditions. These are paperwork failures, not immediate health threats.
Required Notice Content
Every public notification must include:
- Description of the violation and its potential health effects
- Population at risk
- What the system is doing to correct the violation
- Expected timeline for return to compliance
- System contact information
- Required standard language from EPA/State Board
California-specific: Public notices must be submitted to the State Board for approval before distribution to the public, unless otherwise directed. This pre-approval requirement does not exist at the federal level.
What to Watch on the Exam
- The tier assignments are the most-tested aspect of this rule. Nitrate exceeding the MCL is Tier 1 (24 hours), not Tier 2. That catches people.
- Chlorite is Tier 1 in California but Tier 2 under federal rules. The exam tests California requirements, so know the California tier.
- Lead action level exceedance is now Tier 1 (24 hours) under LCRR §141.202(a)(10), effective October 16, 2024. Older study materials may still show it as Tier 2.
- When in doubt, default to the higher tier. Providing faster notification is never a violation. Providing slower notification is.
- Failure to provide timely notification is itself a violation. You can turn a single MCL exceedance into two violations by missing the notification deadline.
Federal Rule Implemented
40 CFR 141 Subpart Q, with CA-specific modifications under Title 22 §64463-64465.