Fort Defiance-Window Rock-St Michaels NTUA: EPA violation history, explained
Fort Defiance-Window Rock-St Michaels NTUA had a health-based violation within the last five years. The required corrective action was reported, but it happened recently enough to matter. 12,869 people get their water from it, across 3,763 connections.
Ranked against every other system in this dataset
159 total violations and 23 health-based ones put Fort Defiance-Window Rock-St Michaels NTUA at the 94th percentile nationally for violation burden, rank 761 of 12,903.
Against the AZ average
Fort Defiance-Window Rock-St Michaels NTUA's 23 health-based violations sit above the AZ average of 8.2, across 199 systems statewide. The filter guide explains what a violation like this actually calls for.
Most recent violation on record
Fort Defiance-Window Rock-St Michaels NTUA's most recent violation on record is dated 2025-01-02, with the most recent health-based one dated 2025-01-02. Last reported to EPA: 06/23/2026.
The concern categories on record
Fort Defiance-Window Rock-St Michaels NTUA's flagged contaminants and rule violations, grouped by what they actually mean for a filter choice rather than left as EPA's raw code list:
- Microbial contamination / treatment technique - flagged from: Coliform (TCR); Revised Total Coliform Rule
- Radionuclides - flagged from: Combined Uranium
- Other regulated metals - flagged from: Antimony, Total; Thallium, Total
- Disinfection byproducts - flagged from: TTHM
The most severe category on record is microbial contamination / treatment technique, which points toward a microbial-class filter if you want to address it directly.
What Fort Defiance-Window Rock-St Michaels NTUA's record does not cover
Everything on this page is Fort Defiance-Window Rock-St Michaels NTUA's own reported record under the Safe Drinking Water Act - a regulatory filing, not a sample of your tap. This record - 23 health-based violations on file for Fort Defiance-Window Rock-St Michaels NTUA - stops at the meter and cannot see household plumbing on the other side of it. The guide to what this data misses covers that gap.