An MCL is a maximum contaminant level. It is the federal health-based limit for a contaminant in drinking water under the Safe Drinking Water Act. The controlling rules sit in 40 CFR Part 141. If a contaminant has an MCL, the number is the standard the system is measured against.
This is compliance information, not legal advice. Confirm current limits and your sample results with your state primacy agency.
What an MCL is — and is not
An MCL is a limit on what is in the water. It is not:
See exactly what your system is up against
Search by system name or PWSID and get your EPA violation history, open requirements, and upcoming deadlines in under a minute. Free, no account, no obligation.
- A CCR (the annual report to customers)
- A public notice (the notice you issue when a rule requires one)
- An inventory deadline (LCRI, including the November 1, 2027 date the site states)
- A monitoring schedule by itself
A missed CCR or a late inventory can be a violation. That does not mean the water failed an MCL. The finding should say which rule it is, with a citation.
How Orevant treats MCLs
The Complete System Report evaluates the federal requirement set that applies to your system’s type, size, and source water. Every finding cites the controlling section and shows a retrieval date. If the official record cannot confirm a result, the finding is labeled Unable to Verify — never a violation.
Federal SDWIS can trail state files by a quarter or more. The report says so. Orevant does not sample your water and does not submit results to the state.
FAQ
Does every contaminant have an MCL?
No. Some contaminants are monitored under other parts of the rule set (for example unregulated-contaminant monitoring). If there is no citation, Orevant does not invent a limit.
Is a PFAS number an MCL?
Use the current federal rule and your state. Orevant checks PFAS obligations that apply to your system against official records. Confirm the number with your primacy agency.
Does Orevant report an MCL exceedance to the state?
No. Orevant does not submit records, tasks, findings, or applications to regulators. You decide what to share.
What if the federal record has no sample result?
The finding should say Unable to Verify unless there is a cited violation. Ask your state. Federal databases can trail state files.
Look up your official EPA profile by name or PWSID (your Public Water System Identification number).
Know where your system stands. Before your state does.
The Complete System Report is $199 once. One document: what applies, what’s due, what to do, and what funding you qualify for. No subscription.
Orevant provides compliance information tools. Content on this page does not constitute legal advice. Compliance determinations should be verified with your state primacy agency.