Quick answer
What to do first
Start with the records that identify the public water system, then move to report details and official current sources.
A detection is a reported testing result. A violation is a regulatory compliance record. An advisory or public notice is an official instruction or communication. Read the source, date, and type before treating them as the same thing.
Core distinctions
Three terms that should not be blended
The same report can include testing data, compliance records, and notice language. Each one answers a different question.
Detection.
A detection means a contaminant or result was reported in testing data. It does not automatically mean a violation, advisory, or household-level issue.
Violation.
A violation means the system failed to meet a specific regulatory requirement. The meaning depends on the type, date, status, and source.
Advisory or public notice.
A notice or advisory is an official communication that may give instructions to customers. This site may not display live notices.
How to check
Read the record in order
A careful reading keeps testing results, compliance status, and public instructions separate.
Check the source first.
Use the utility, state, or EPA record that names the system and date. Search-result snippets are not enough for current instructions.
Check the time period.
Annual reports usually cover a past reporting year. Violation records and notices have their own date ranges.
Check the category.
Some violations involve monitoring, reporting, treatment technique, public notice, or a contaminant limit. The category changes what to ask next.
Check current instructions separately.
If you received a notice or need current instructions, use the official utility, local, or state source.
Common mistakes to avoid
- Treating a detection as proof of a violation.
- Treating an old violation as a current advisory.
- Using a compliance label to decide conditions at a specific tap.
- Ignoring units, dates, and source notes.
Source and review context
- Guide source
- EPA SDWIS Federal Reporting Services
- Data updated
- 2026-07-06
- Last reviewed
- 2026-07-06
Next steps
Related pages
Use these pages to move from the guide to source-backed browse paths, examples, and limitations.