Arsenic in Fresno, CA Drinking Water
Arsenic data for Fresno, California · 620,656 residents · 58 ZIP codes
ZipCheckup's reading of Arsenic in Fresno, California: the highest detected level is 16 ppb; the EPA limit is 10 ppb. Arsenic carries a high health-risk designation.
Across the water systems that serve Fresno, California, Arsenic has appeared in EPA compliance samples - standard municipal treatment targets this contaminant, though detections in the compliance record indicate it has reached household taps at measurable levels.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-07-13
Arsenic in Fresno Tap Water
Arsenic has been detected in Fresno, California drinking water at a maximum level of 16 ug/L — 1.6x the EPA MCL.
This analysis covers 620,656 residents across 58 ZIP codes in Fresno.
Fresno's overall water quality grade is B (73/100).
Is Arsenic in Fresno Water Safe?
If you live in an affected ZIP code, consider installing a reverse osmosis filter certified under NSF 53 / NSF 58 and testing your water independently.
Arsenic Levels by ZIP Code
| ZIP Code | Arsenic Level | EPA Limit | Status |
|---|---|---|---|
| 93650 | 16 ug/L | 10 ppb | Exceeds limit |
| 93701 | 16 ug/L | 10 ppb | Exceeds limit |
| 93702 | 16 ug/L | 10 ppb | Exceeds limit |
| 93703 | 16 ug/L | 10 ppb | Exceeds limit |
| 93704 | 16 ug/L | 10 ppb | Exceeds limit |
| 93705 | 16 ug/L | 10 ppb | Exceeds limit |
| 93706 | 16 ug/L | 10 ppb | Exceeds limit |
| 93707 | 16 ug/L | 10 ppb | Exceeds limit |
| 93708 | 16 ug/L | 10 ppb | Exceeds limit |
| 93709 | 16 ug/L | 10 ppb | Exceeds limit |
| 93710 | 16 ug/L | 10 ppb | Exceeds limit |
| 93711 | 16 ug/L | 10 ppb | Exceeds limit |
| 93712 | 16 ug/L | 10 ppb | Exceeds limit |
| 93714 | 16 ug/L | 10 ppb | Exceeds limit |
| 93715 | 16 ug/L | 10 ppb | Exceeds limit |
| 93716 | 16 ug/L | 10 ppb | Exceeds limit |
| 93717 | 16 ug/L | 10 ppb | Exceeds limit |
| 93718 | 16 ug/L | 10 ppb | Exceeds limit |
| 93720 | 16 ug/L | 10 ppb | Exceeds limit |
| 93721 | 16 ug/L | 10 ppb | Exceeds limit |
| 93722 | 16 ug/L | 10 ppb | Exceeds limit |
| 93723 | 16 ug/L | 10 ppb | Exceeds limit |
| 93724 | 16 ug/L | 10 ppb | Exceeds limit |
| 93725 | 16 ug/L | 10 ppb | Exceeds limit |
| 93726 | 16 ug/L | 10 ppb | Exceeds limit |
| ...33 more ZIP codes |
Average arsenic level across Fresno: 16 ppb
EPA Violations for Arsenic in Fresno
| Date | Violation Type | Status | ZIP Code |
|---|---|---|---|
| 2022-01-01 | Arsenic (Known) | Known | 93706 |
| 2022-01-01 | Arsenic (Known) | Known | 93725 |
| 2021-10-01 | Arsenic (Known) | Known | 93706 |
| 2021-10-01 | Arsenic (Known) | Known | 93725 |
| 2021-07-01 | Arsenic (Known) | Known | 93706 |
| 2021-07-01 | Arsenic (Known) | Known | 93725 |
| 2021-04-01 | Arsenic (Known) | Known | 93706 |
| 2021-04-01 | Arsenic (Known) | Known | 93725 |
Health Effects of Arsenic
- Increased risk of skin, bladder, lung, and kidney cancer
- Cardiovascular disease and type 2 diabetes
- Skin changes (darkening, thickening, lesions)
- Developmental effects in children exposed in utero
Health risk severity: High. Governed by the Arsenic Rule (2006).
How Arsenic Gets Into Drinking Water
- Natural deposits in rock and soil (especially in western U.S.)
- Runoff from orchards and glass/electronics production
- Historical use of arsenic-based pesticides
- Well water in areas with arsenic-rich geology
What to Do About Arsenic in Fresno Water
- Install a reverse osmosis (RO) system certified under NSF 58
- Adsorptive media filters (iron-based) can also reduce arsenic
- Have well water tested if on a private supply
- Boiling water does NOT remove arsenic — it concentrates it
Look for filters certified under NSF 53 / NSF 58 for arsenic removal.