Drinking water quality · 2024
· Verified
· PWSID AZ0407092
What's in Gilbert, AZ tap water
2 contaminants in Gilbert, AZ's water sat at or above a federal limit, led by PFOS (Perfluorooctane sulfonic acid) at 2.4x the limit.
- !2 contaminants at or above a federal limit — worst is PFOS (Perfluorooctane sulfonic acid) at 2.4x
- !16 of 27 core regulated contaminants reported — 11 never appear in this report
- ✓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.
- −48 contaminants at or above a federal limit
- −0 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
- −5 core regulated contaminants never reported (16/27)
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
- PFOS (Perfluorooctane sulfonic acid)2.4× the federal limit9.799999999999999 ng/L · limit 4 ng/L
Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
higher than 80% of U.S. systems
- PFOA (Perfluorooctanoic acid)1.6× the federal limit6.5 ng/L · limit 4 ng/L
Linked to cancer, liver damage, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
higher than 80% of U.S. systems
+24 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| Arsenic | 5.8 ug/L | 10 ug/L |
| Nitrate | 4.27 mg/L | 10 mg/L |
| Bromate | 2.9 ug/L | 10 ug/L |
| Gross Alpha | 3.9 pCi/L | 15 pCi/L |
| Turbidity | 0.237 NTU | 1 NTU |
| HAA5 | 14 ug/L | 60 ug/L |
| Chlorine | 0.89 mg/L | 4 mg/L |
| Fluoride | 0.5 mg/L | 4 mg/L |
| Uranium | 3.1 ug/L | 30 ug/L |
| Chromium | 9.2 ug/L | 100 ug/L |
| Copper | 0.089 mg/L | 1.3 mg/L |
| Barium | 0.06 mg/L | 2 mg/L |
| Lead | 0.312 ug/L | 15 ug/L |
| Pce | 0.0001 mg/L | 0.005 mg/L |
| Selenium | 0.0004 mg/L | 0.05 mg/L |
| Antimony | 0 mg/L | 0.006 mg/L |
| Total Coliform | 0.083 % | — |
| TOC | 19.03 % | — |
| Combined Radium | Not detected pCi/L | 5 pCi/L |
| Dichloromethane | Not detected mg/L | 0.005 mg/L |
| PFBS | 18.1 ng/L | — |
| PFPeA | 6.2 ng/L | — |
| PFHxA | 4.4 ng/L | — |
| PFBA | 5.8 ng/L | — |
What this report doesn't tell you
11 of the 27 contaminants a community water system normally reports do not appear anywhere in Gilbert, 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)
2 PFAS compounds above EPA limits in Gilbert, 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.
PFOS (Perfluorooctane sulfonic acid)
● Over EPA limit (2.4×)PFOA (Perfluorooctanoic acid)
● Over EPA limit (1.6×)PFBS
● Detected (no federal limit)PFPeA
● Detected (no federal limit)PFHxA
● Detected (no federal limit)PFBA
● Detected (no federal limit)Where your water comes from · EPA SDWIS
Gilbert, AZ's drinking water comes from ground water, drawn from 22 sources.
Source
- WL-55-505650 -
- WL-55-510941 -
- WL-55-521875 -
- WL-55-529938 -
- + 18 more
Treatment
- TP019 - CL2
- TP020 - CL2
- TP021 - CL2, AS
- + 13 more
Distribution
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 Jul 2017resolved
- Treatment technique violationHealth-based2 violations on record · most recent Oct 2017resolved
- Other1 violation on recordresolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗