Drinking water quality · 2024
· Verified
· PWSID AZ0407095
What's in Mesa, AZ tap water
Every one of the 18 core regulated contaminants reported for Mesa, AZ came in below its federal limit.
- !2 contaminants within 20% of a limit
- !18 of 27 core regulated contaminants reported — 9 never appear in this report
- ✓Nothing over a federal limit
- ✓No open federal violations
+How this score is calculated
Every system starts at 100. Points come off for measured levels, for the federal violation record, and for how much of the core regulated set the utility actually reported. All three inputs are the utility's own published numbers and EPA's own records.
- −0 contaminants at or above a federal limit
- −8 contaminants within 20% of a limit
- −0 open health-based violations
- −0 open monitoring / reporting violations
- −0 health-based violations resolved in the last 5 years
- −1 core regulated contaminants never reported (18/27)
A 90–100 · B 80–89 · C 70–79 · D 60–69 · F below 60. A system reporting under a third of the core set is capped at C however clean its numbers look — a short report is not a clean bill of health.
Full grading methodology, constant for constant →What to worry about
- PFHxS (Perfluorohexane sulfonic acid)93% of the federal limit9.299999999999999 ng/L · limit 10 ng/L
Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
higher than 80% of U.S. systems
- Arsenic84% of the federal limit8.37 ug/L · limit 10 ug/L
A known human carcinogen; long-term exposure is linked to skin, bladder, and lung cancer.
higher than 90% of U.S. systems
+24 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| Nitrate | 7.88 mg/L | 10 mg/L |
| TTHM | 51 ug/L | 80 ug/L |
| Bromate | 5.8 ug/L | 10 ug/L |
| Gross Alpha | 5.4 pCi/L | 15 pCi/L |
| Chlorite | 0.36 mg/L | 1 mg/L |
| Lead | 0.00501 mg/L | 0.015 mg/L |
| HAA5 | 18 ug/L | 60 ug/L |
| Turbidity | 0.3 NTU | 1 NTU |
| Dehp | 1.7 ug/L | 6 ug/L |
| Fluoride | 1.11 mg/L | 4 mg/L |
| Chromium, Total | 24.7 ug/L | 100 ug/L |
| Combined Radium | 0.9 pCi/L | 5 pCi/L |
| Chlorine | 0.71 mg/L | 4 mg/L |
| Copper | 0.17 mg/L | 1.3 mg/L |
| Tetrachloroethylene | 0.62 ug/L | 5 ug/L |
| DBCP | 24 ng/L | 200 ng/L |
| Trichloroethylene | 0.54 ug/L | 5 ug/L |
| Selenium | 3 ug/L | 50 ug/L |
| Barium | 0.114 mg/L | 2 mg/L |
| Sodium | 210 mg/L | — |
| Total Coliform | 4 | — |
| TOC | 1.6 | — |
| PFBS | 15.2 ng/L | — |
| PFHxA | 3.2 ng/L | — |
What this report doesn't tell you
9 of the 27 contaminants a community water system normally reports do not appear anywhere in Mesa, AZ's data. Absent is not the same as absent-from-the-water — it means nobody published a number.
+Full detail: PFAS testing, water source, historical monitoring, and the federal violation record
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound approaching EPA limits in Mesa, AZ
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFHxS (Perfluorohexane sulfonic acid)
● Approaching limit (93%)PFBS
● Detected (no federal limit)PFHxA
● Detected (no federal limit)Where your water comes from · EPA SDWIS
Mesa, AZ's drinking water comes from ground water, drawn from 33 sources.
Source
- WL-55-629618 - CITY
- WL-55-508798 - CITY
- WL-55-511595 - DESERT
- WL-55-517843 - CITY
- + 29 more
Treatment
- TP001 - CLO2, BROWN CAP
- TP004 - CL2, AS
- TP003 - CL2
- + 3 more
Distribution
Also buys water from PHOENIX CITY OF.
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Maximum contaminant level exceededHealth-based3 violations on record · most recent Jan 2003resolved
- Other1 violation on recordresolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗