Nitrate in Clovis, CA Drinking Water
Nitrate data for Clovis, California · 131,537 residents · 4 ZIP codes
In Clovis, California, Nitrate has been detected in the public water supply — a contaminant that health agencies track because of documented effects associated with prolonged exposure at elevated concentrations.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14
Nitrate in Clovis Tap Water
Nitrate has been detected in Clovis, California drinking water at a maximum level of 8.4 ppb — below the EPA MCL of 10 mg/L (as nitrogen).
This analysis covers 131,537 residents across 4 ZIP codes in Clovis.
Clovis's overall water quality grade is B (71/100).
Is Nitrate in Clovis Water Safe?
If you live in an affected ZIP code, consider installing a reverse osmosis or ion exchange filter certified under NSF 53 / NSF 58 and testing your water independently.
Nitrate Levels by ZIP Code
| ZIP Code | Nitrate Level | EPA Limit | Status |
|---|---|---|---|
| 93611 | 8.4 ppm | 10 mg/L (as nitrogen) | OK |
| 93612 | 8.4 ppm | 10 mg/L (as nitrogen) | OK |
| 93613 | 8.4 ppm | 10 mg/L (as nitrogen) | OK |
| 93619 | 8.4 ppm | 10 mg/L (as nitrogen) | OK |
Average nitrate level across Clovis: 8.4 ppb
EPA Violations for Nitrate in Clovis
| Date | Violation Type | Status | ZIP Code |
|---|---|---|---|
| 2025-04-01 | Nitrate-Nitrite (Known) | Known | 93611 |
| 2025-04-01 | Nitrate-Nitrite (Known) | Known | 93612 |
| 2025-04-01 | Nitrate-Nitrite (Known) | Known | 93613 |
| 2025-04-01 | Nitrate-Nitrite (Known) | Known | 93619 |
| 2025-01-01 | Nitrate-Nitrite (Known) | Known | 93611 |
| 2025-01-01 | Nitrate-Nitrite (Known) | Known | 93612 |
| 2025-01-01 | Nitrate-Nitrite (Known) | Known | 93613 |
| 2025-01-01 | Nitrate-Nitrite (Known) | Known | 93619 |
| 2024-10-01 | Nitrate-Nitrite (Known) | Known | 93611 |
| 2024-10-01 | Nitrate-Nitrite (Known) | Known | 93612 |
| 2024-10-01 | Nitrate-Nitrite (Known) | Known | 93613 |
| 2024-10-01 | Nitrate-Nitrite (Known) | Known | 93619 |
Health Effects of Nitrate
- Methemoglobinemia ("blue baby syndrome") in infants under 6 months
- Increased risk of colorectal and bladder cancer (long-term)
- Thyroid disease from chronic exposure
- Possible reproductive effects
Health risk severity: High. Governed by the National Primary Drinking Water Regulations.
How Nitrate Gets Into Drinking Water
- Agricultural fertilizer runoff
- Animal feedlot operations and manure
- Septic system leachate
- Urban stormwater and wastewater discharge
What to Do About Nitrate in Clovis Water
- Reverse osmosis is the most effective method for nitrate removal
- Ion exchange systems designed for nitrate can also work
- Standard carbon filters do NOT remove nitrate
- Boiling water increases nitrate concentration — never boil for nitrate
Look for filters certified under NSF 53 / NSF 58 for nitrate removal.