Nitrate in Winnetka, CA Drinking Water
Nitrate data for Winnetka, California · 48,177 residents · 2 ZIP codes
If you rely on a public water system in Winnetka, California, Nitrate is a contaminant your utility has been required to test for — and EPA records show it has been detected at measurable levels, making it worth understanding as part of your tap water's detection record.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-06-04
Nitrate in Winnetka Tap Water
Winnetka, California has 28 EPA violations related to nitrate in drinking water.
This analysis covers 48,177 residents across 2 ZIP codes in Winnetka.
Winnetka's overall water quality grade is C (58/100).
Is Nitrate in Winnetka 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.
EPA Violations for Nitrate in Winnetka
| Date | Violation Type | Status | ZIP Code |
|---|---|---|---|
| 2025-07-01 | Nitrate-Nitrite (Open) | Open | 91306 |
| 2025-07-01 | Nitrate-Nitrite (Open) | Open | 91396 |
| 2025-01-01 | Nitrate-Nitrite (Open) | Open | 91306 |
| 2025-01-01 | Nitrate-Nitrite (Open) | Open | 91396 |
| 2024-10-01 | Nitrate-Nitrite (Open) | Open | 91306 |
| 2024-10-01 | Nitrate-Nitrite (Open) | Open | 91396 |
| 2024-07-01 | Nitrate-Nitrite (Known) | Known | 91306 |
| 2024-07-01 | Nitrate-Nitrite (Known) | Known | 91396 |
| 2024-04-01 | Nitrate-Nitrite (Known) | Known | 91306 |
| 2024-04-01 | Nitrate-Nitrite (Known) | Known | 91396 |
| 2024-01-01 | Nitrate-Nitrite (Known) | Known | 91306 |
| 2024-01-01 | Nitrate-Nitrite (Known) | Known | 91396 |
| 2023-10-01 | Nitrate-Nitrite (Known) | Known | 91306 |
| 2023-10-01 | Nitrate-Nitrite (Known) | Known | 91396 |
| 2023-07-01 | Nitrate-Nitrite (Known) | Known | 91306 |
| 2023-07-01 | Nitrate-Nitrite (Known) | Known | 91396 |
| 2023-04-01 | Nitrate-Nitrite (Known) | Known | 91306 |
| 2023-04-01 | Nitrate-Nitrite (Known) | Known | 91396 |
| 2023-01-01 | Nitrate-Nitrite (Known) | Known | 91306 |
| 2023-01-01 | Nitrate-Nitrite (Known) | Known | 91396 |
| ... | 8 more violations |
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 Winnetka 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.