Water quality · Arizona
Water quality in Arizona
Of the 7 Arizona ZIPs matched to an EPA SDWIS community water system, none reports a health-based violation in the last 3 years, though 7 carry at least one non-health-based violation. SDWIS reports the system serving the county, never an address-level test, and never private wells.
Last verified 2026-09-24 · methodology
Water quality by ZIP code in Arizona
The largest community water system EPA lists for each ZIP's county, and its health-based violations in the last 3 years.
| ZIP | Largest system | Health-based violations |
|---|---|---|
| 85004PhoenixMaricopa County | PHOENIX CITY OF | None |
| 85701TucsonPima County | TUCSON CITY OF | None |
| 85003Phoenix (Downtown)Maricopa County | PHOENIX CITY OF | None |
| 86001FlagstaffCoconino County | FLAGSTAFF CITY OF | None |
| 85258Scottsdale (McCormick Ranch)Maricopa County | PHOENIX CITY OF | None |
| 85016Phoenix (Camelback East)Maricopa County | PHOENIX CITY OF | None |
| 85283Tempe (South)Maricopa County | PHOENIX CITY OF | None |
County-level figures from EPA SDWIS, joined to each ZIP by county. None of them is a measurement at a specific address.
What lands here
Pages show the largest community water system on record for the ZIP's county, its PWSID and population served, and its health-based and total violations in the last 3 years. Lead and copper sampling results are not shown; your utility's annual water quality report (CCR) has them.
Source & refresh
EPA SDWIS. Refreshed quarterly (federal mandate). Primary source →
Arizona top concern
Radon, wildfire-WUI, water rights
Arizona has Zone 1 radon risk across most of its area per EPA's 1993 map. FEMA NFHL coverage is dense in flood-prone Maricopa + Pima counties; wildfire risk concentrates in Yavapai + Coconino + Cochise. Water-rights and utility-source diversity (CAP allotments vs. local groundwater) varies significantly between metros.
See Arizona state page for the full state-level rollup across all 12 dimensions.
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EPA Radon Zones — what 1, 2, and 3 mean and when you should test
EPA classifies every US county into Zone 1 (high), Zone 2 (moderate), or Zone 3 (low) for radon. Plain-English guide to the classifications and at-home testing.
EPA AQI categories explained — what 0–50 Good through 301–500 Hazardous mean
Plain-English guide to the six EPA Air Quality Index categories: 0–50 Good, 51–100 Moderate, 101–150 Unhealthy for Sensitive Groups, 151–200 Unhealthy, 201–300 Very Unhealthy, 301–500 Hazardous — what each level means and who is at risk.
Lead and Copper Rule 2024 — the federal lead-pipe inventory mandate
The 2024 Lead and Copper Rule Revisions (LCRR) require every US community water system to inventory and report lead service lines. Plain-English guide.