Reading EPA ECHO Compliance Quarters: What the Numbers Mean
One of the most important — and commonly misunderstood — metrics in EPA ECHO data is the "quarters with noncompliance" figure. For each of the three major environmental programs (Clean Air Act, Clean Water Act, and RCRA hazardous waste), ECHO tracks how many of the last 12 calendar quarters a facility was in "significant noncompliance" or "noncompliance" with its permit requirements. Understanding what this number means requires understanding how EPA defines and tracks violations.
The Rolling 12-Quarter Window
EPA\'s compliance data uses a rolling 12-quarter (3-year) window. A facility with 0 quarters of noncompliance has had no significant permit violations in the last 3 years. A facility with 4 quarters has had noncompliance in 4 of the last 12 quarters — about a third of the time. A facility with 12 quarters has been persistently noncompliant throughout the entire observation window. On EmissionsLookup facility profiles, we display these figures for air, water, and hazardous waste programs separately.
Significant Noncompliance vs. Minor Violations
The quarters-with-noncompliance metric captures significant noncompliance (SNC), which is a specific EPA classification for violations that exceed certain thresholds of severity or duration. Minor violations — small deviations from permit limits that are quickly corrected — may not be captured in this metric. This means a facility with 0 noncompliance quarters is not necessarily one that has never had any compliance issues; it may simply have had only minor, quickly resolved issues that didn\'t rise to the SNC threshold.
How Violations Are Classified
Violations enter ECHO from multiple sources: federal and state inspection reports, self-reported discharge monitoring reports (for water permits), and stack test results (for air permits). The data quality depends on the frequency and thoroughness of inspections — facilities in states with more active enforcement programs are more likely to have violations documented. Facilities that have never been inspected may appear cleaner in ECHO than their actual compliance record warrants.
Using This Data Responsibly
When interpreting compliance quarters, consider: How recently were the violations? (Recent violations are more concerning than those 2–3 years ago.) Are violations in one program or all three? (Multiple program violations suggest systematic management failures.) What enforcement actions followed? (EPA or state agencies may have already addressed the violations.) Browse facilities with violation history at the violations filter or explore enforcement actions at the enforcement index. For comparison to neighboring facilities, use our state browser.