Arsenic in California Drinking Water
California has 20,579 public water systems. 12349 have recorded arsenic violations.
Total Systems
20,579
With Violations
12,349
EPA MCL
0.01
Population Served
42.7M
Arsenic in California: Key Facts
Total Water Systems
20,579
Systems with Violations
12,349
Lead Violations
142
Copper Violations
569
EPA Standard
0.01 mg/L
MCLG (goal): 0 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 Arsenic Exposure
Cancer risk
Skin, bladder, and lung cancers with long-term exposure
Cardiovascular effects
Increased risk of heart disease and stroke
Diabetes risk
Associated with increased risk of type 2 diabetes
Increased risk of cancer (skin, bladder, lung). Thickening and discoloration of skin; numbness; circulatory problems.
Frequently Asked Questions
Is there arsenic in California water?
California has 20,579 public water systems. 12349 have recorded arsenic 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 arsenic?
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 arsenic?
The EPA Maximum Contaminant Level (MCL) for arsenic is 0.01 mg/L. Systems that exceed MCLs are required to notify customers and take corrective action.
Arsenic at a Glance
Source
Erosion of natural deposits; runoff from orchards; runoff from glass and electronics production wastes
How to Filter Arsenic
- +Reverse osmosis effectively removes arsenic
- +Distillation also removes arsenic
- +Standard carbon filters do NOT remove arsenic reliably
- +Test well water annually if on a private well