Nitrate in Pasadena, CA Drinking Water
Nitrate data for Pasadena, California · 191,916 residents · 26 ZIP codes
At elevated levels, Nitrate is a recognized health concern in drinking water; in Pasadena, California, it has been detected in recent samples logged through federal compliance reporting.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14
Nitrate in Pasadena Tap Water
Nitrate has been detected in Pasadena, California drinking water at a maximum level of 7.5 ppb — below the EPA MCL of 10 mg/L (as nitrogen).
This analysis covers 191,916 residents across 26 ZIP codes in Pasadena.
Pasadena's overall water quality grade is B (80/100).
Is Nitrate in Pasadena Water Safe?
Nitrate was detected in Pasadena water but currently falls within EPA limits. However, some health organizations argue the EPA MCL may not be protective enough.
If you are concerned, a reverse osmosis or ion exchange filter can reduce nitrate levels further.
Nitrate Levels by ZIP Code
| ZIP Code | Nitrate Level | EPA Limit | Status |
|---|---|---|---|
| 91101 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91102 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91103 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91104 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91105 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91106 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91107 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91109 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91110 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91114 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91115 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91116 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91117 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91121 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91123 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91124 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91125 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91126 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91129 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91182 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91184 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91185 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91188 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91189 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| 91191 | 7.5 ppm | 10 mg/L (as nitrogen) | OK |
| ...1 more ZIP codes |
Average nitrate level across Pasadena: 7.5 ppb
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 Pasadena 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.