Nitrate in California Drinking Water
California has 20,579 public water systems. 12349 have recorded nitrate violations.
Total Systems
20,579
With Violations
12,349
EPA MCL
10
Population Served
42.7M
Nitrate in California: Key Facts
Total Water Systems
20,579
Systems with Violations
12,349
Lead Violations
142
Copper Violations
569
EPA Standard
10 mg/L as N
MCLG (goal): 10 mg/L
Water Systems with Violations in California
| System | Population | Violations |
|---|---|---|
| Grindstone Rancheria | 150 | 1214 |
| Tule River Reservation Main | 3K | 662 |
| Yurok - Weitchpec | 120 | 622 |
| Arizona Village | 3K | 607 |
| Oasis Mobile Home Park | 1K | 564 |
| ROHNERT PARK, CITY OF | 44K | 561 |
| Yurok - Kepel | 76 | 561 |
| Yurok - Wautec | 96 | 525 |
Health Effects of Nitrate Exposure
Blue baby syndrome
Infants under 6 months can develop methemoglobinemia
Thyroid effects
May disrupt thyroid function with chronic exposure
Cancer links
Potential associations with colorectal cancer at high levels
Infants below 6 months can develop methemoglobinemia ('blue baby syndrome'). May also affect adults with certain conditions.
Frequently Asked Questions
Is there nitrate in California water?
California has 20,579 public water systems. 12349 have recorded nitrate violations based on EPA SDWIS data. If you are on a private well, your water is not covered by these regulations and should be tested independently.
How can I check my California water for nitrate?
Search for your water system using the WaterCheck system lookup, or contact your utility and request a copy of your Consumer Confidence Report (CCR). The CCR is published annually and lists all detected contaminants, their levels, and the EPA MCLs. For private wells, contact a state-certified lab for independent testing.
What is the EPA limit for nitrate?
The EPA Maximum Contaminant Level (MCL) for nitrate is 10 mg/L as N. Systems that exceed MCLs are required to notify customers and take corrective action.
Nitrate at a Glance
Source
Runoff from fertilizer use; leaching from septic tanks and sewage; erosion of natural deposits
How to Filter Nitrate
- +Reverse osmosis or distillation removes nitrates
- +Boiling does NOT remove nitrates - it concentrates them
- +Do not give well water to infants under 6 months without testing