Navajo, AZ
Transparent derived index from EPA TRI / SDWIS / Superfund extracts: not an official EPA rating. Fixed caps: facilities ≤25 pts (50+ = max), log10 releases ≤25 pts, Superfund ≤25 pts (5/site), health-violation systems ≤15 pts (3/system), high-chemical facilities ≤10 pts. Bands: High ≥60, Moderate ≥30. See methodology.
Environmental data for Navajo in Arizona · Population: 107,744
TRI sites such as Cholla Power Plant; Rhinehart Oil Co. Holbrook Bulk Plant; SDWIS systems such as CITY OF SHOW LOW; WINSLOW CITY OF; SNOWFLAKE TOWN OF anchor Navajo, AZ's EPA extract. Derived burden score 38/100 (Moderate Risk) uses fixed national caps on density, log release volume, Superfund count, and health-flagged systems - not an official EPA rating.
Health-flagged SDWIS rows in Navajo include CITY OF SHOW LOW; HOLBROOK CITY OF; Polacca, while Cholla Power Plant leads reported TRI pounds among local Form R filers. AQS median AQI 13 / peak 53 in 2024.
Burden score 38/100 (Moderate Risk) is the only weighted composite on this page. The tables below list every TRI facility, SDWIS system, and Superfund site EPA has on record for Navajo -- not just the names called out above -- reproducing the disclosure history as filed, not a current-safety verdict. Extract current as of 2026-08-25.
Release-over-release change
What changed for Navajo, AZ: EPA TRI 2023 reporting year
Same facilities, both years
-26.6%
2 facilities that filed in 2022 and 2023
Whole inventory
-26.6%
127.6 thousand lb → 93.7 thousand lb, every facility that filed
- Navajo, AZ's total reported releases fell from 127.6 thousand lb in 2022 to 93.7 thousand lb in 2023, based on EPA TRI filings.
- Navajo, AZ's air releases fell from 9.4 thousand lb in 2022 to 6.1 thousand lb in 2023, based on EPA TRI filings.
- Navajo, AZ's land releases fell from 118.2 thousand lb in 2022 to 87.6 thousand lb in 2023, based on EPA TRI filings.
- Navajo, AZ's chemicals reported fell from 23 in 2022 to 21 in 2023, based on EPA TRI filings.
Air Quality History (2020–2024)
EPA Air Quality Index (AQI) data showing how many days per year fall into each air quality category.
| Year | Good | Moderate | Unhealthy (SG) | Max AQI |
|---|---|---|---|---|
| 2024 | 359 (99%) | 2 | 0 | 53 |
| 2023 | 290 (80%) | 74 | 0 | 84 |
| 2022 | 307 (84%) | 57 | 0 | 93 |
| 2021 | 292 (80%) | 72 | 1 | 101 |
| 2020 | 314 (86%) | 50 | 2 | 136 |
Source: EPA Air Quality System (AQS) Annual AQI by County AQI categories: Good (0-50), Moderate (51-100), Unhealthy for Sensitive Groups (101-150), Unhealthy (151-200), Very Unhealthy (201-300), Hazardous (301+)
For real-time air quality readings and pollutant breakdowns in Arizona, see the EPA's AirNow.gov.
Water Systems (45)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| CITY OF SHOW LOW | 17,139 | 1 |
| WINSLOW CITY OF | 9,789 | 0 |
| SNOWFLAKE TOWN OF | 5,590 | 0 |
| PONDEROSA DWID | 5,375 | 0 |
| HOLBROOK CITY OF | 4,833 | 1 |
| TOWN OF TAYLOR | 4,190 | 0 |
| Polacca | 3,890 | 223 |
| PINETOP WATER COMMUNITY FACILITIES DIST | 3,250 | 0 |
| VOYAGER AT WHITE MOUNTAIN LAKES WC | 1,997 | 3 |
| JOSEPH CITY DWID | 1,811 | 0 |
| Shungopavi | 1,430 | 189 |
| Kykotsmovi | 1,302 | 3 |
| WHITE MOUNTAIN SUMMER HOMES DWID | 1,233 | 0 |
| Hopi High School - BIA | 1,005 | 35 |
| BIA Keams Canyon | 925 | 5 |
| TIMBERLAND ACRES DWID | 922 | 0 |
| Shonto Preparatory Boarding School BIA | 664 | 0 |
| Sipaulovi (Lower Sipaulovi/Lower Mishongnovi) | 609 | 126 |
| Kayenta Community Boarding School BIA | 500 | 0 |
| Pinon Community Dormitory School BIA | 500 | 0 |
| Mishongnovi (Upper Sipaulovi/Upper Mishongnovi) | 490 | 124 |
| WHITE MOUNTAIN WATER COMPANY | 475 | 2 |
| Dilcon Community Boarding School BIA | 473 | 5 |
| COUNTRY LANE TRAILER PARK | 450 | 13 |
| CLAY SPRINGS DWID | 425 | 0 |
| SKY HI DWID | 390 | 4 |
| Hopi Veterans Center | 388 | 1 |
| WONDERLAND ACRES DWID | 380 | 3 |
| PINEDALE DWID | 376 | 4 |
| Low Mountain Boarding School BIA | 339 | 0 |
| PORTER MOUNTAIN DWID | 322 | 1 |
| BUCKSKIN ARTISTS COMMUNITY | 320 | 4 |
| SUN VALLEY UTILITIES | 287 | 5 |
| Second Mesa Day School - BIA | 255 | 34 |
| PORTER CREEK DWID | 250 | 2 |
| Rocky Ridge Boarding School BIA | 250 | 0 |
| Seba Dalkai Boarding School BIA | 250 | 126 |
| PINEDALE ESTATES DWID | 208 | 48 |
| SWEETWATER RANCH - TOWN OF TAYLOR | 180 | 0 |
| WOODRUFF DOMESTIC WATER COMPANY INC | 140 | 6 |
| Chilchinbeto Community Day School BIA | 138 | 0 |
| HOLBROOK SDA INDIAN SCHOOL | 100 | 0 |
| RETAW WATER COMPANY | 47 | 0 |
| MISTY MOUNTAIN DWID | 44 | 0 |
| AMERICAN INDIAN CHRISTIAN MISSION | 37 | 0 |
TRI Facilities (2)
| # | Facility | Total Releases |
|---|---|---|
| 1 | Cholla Power Plant | 581.7K lbs |
| 2 | Rhinehart Oil Co. Holbrook Bulk Plant | 265 lbs |
Cities in Navajo (17)
Frequently Asked Questions
What is the environmental risk level in Navajo, Arizona? ▼
Are there Superfund sites in Navajo? ▼
How many toxic release facilities are in Navajo? ▼
What is the air quality in Navajo? ▼
Is the drinking water safe in Navajo? ▼
What environmental agencies cover Navajo? ▼
What does this county environmental profile show?
This county environmental profile rolls up EPA Toxics Release Inventory facility reports, Safe Drinking Water Information System public-water-system filings, and Superfund National Priorities List sites for the county boundary defined by the U.S. Census Bureau. Facility counts reflect facilities with a reporting address inside the county, not where downstream environmental effects may be observed. Population figures are from the most recent Census ACS 5-year estimate. The county detail page is updated whenever the upstream EPA programs publish revised data; see the methodology page for the documented ingest cadence and the editorial choices governing how aggregations are computed.
Read our methodology - how this data is sourced, computed, and verified.