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Detailed report on arsenic levels detected in San Diego's public drinking water supply. Last updated 2026-02-03.
0.0012 mg/L
Detected level is 11.8% of the EPA maximum contaminant level (0.01 mg/L)
Sample date: 2025-10-14
Overall Grade
Detected Level
0.0012 mg/L
EPA Maximum (MCL)
0.01 mg/L
Percentage of Limit
11.8%
The detected level of arsenic in San Diego's water is below 50% of the EPA's maximum contaminant level. While any detection warrants awareness, this level is considered safe by federal standards. EPA MCL: 0.010 mg/L (10 ppb).
This data is based on water quality testing performed on 2025-10-14. Water quality can vary over time, and we recommend checking for the most recent data periodically.
Long-term arsenic exposure is linked to skin damage, circulatory problems, and increased cancer risk (skin, bladder, lung). Even low levels over time can be harmful.
Residents of San Diego should be aware that arsenic has been detected in the local water supply at 11.8% of the EPA limit. Current levels are within safe limits, but ongoing awareness is important.
Certain groups face higher risks from arsenic exposure:
Arsenic occurs naturally in certain rock formations and can leach into groundwater. It can also come from industrial runoff, mining operations, and agricultural chemicals.
San Diego draws its drinking water from a mix of surface water and groundwater sources. The city is served by 1 water system, including SAN DIEGO WATER SYSTEM.
Arsenic was detected in San Diego's water at 0.0012 mg/L, which is 11.8% of the EPA maximum. This is within federal safety limits. Consider a certified water filter for extra peace of mind, particularly if you have young children or are in a vulnerable health group.
The following filtration methods are proven effective at reducing or removing arsenic from drinking water:
Reverse Osmosis
Specialty Adsorption Media
Distillation
When choosing a filter, look for NSF/ANSI certification specific to arsenic removal. Not all filters are equally effective, and certification ensures the product has been independently tested.
See Filter Recommendations for San DiegoBased on the most recent testing data, arsenic was detected in San Diego, California water at a level of 0.0012 mg/L. This is 11.8% of the EPA maximum contaminant level of 0.01 mg/L. EPA MCL: 0.010 mg/L (10 ppb).
Arsenic was detected in San Diego's water at 11.8% of the EPA limit, which is considered safe by federal standards. Long-term arsenic exposure is linked to skin damage, circulatory problems, and increased cancer risk (skin, bladder, lung). Even low levels over time can be harmful. While current levels are not considered dangerous, some health organizations suggest minimizing exposure whenever possible.
The most effective methods for removing arsenic from your drinking water are: Reverse Osmosis, Specialty Adsorption Media, Distillation. When purchasing a filter, look for NSF/ANSI certification that specifically covers arsenic removal. Installation of a point-of-use filter (at your kitchen faucet or as an under-sink system) provides targeted protection for drinking and cooking water. For whole-house protection, a point-of-entry system can treat all water entering your home.
Yes, San Diego's water utility is required by the EPA to regularly test for arsenic as part of the Safe Drinking Water Act. The most recent testing detected arsenic at 0.0012 mg/L. These results are published in the city's annual Consumer Confidence Report (CCR), also known as a Water Quality Report. You can also request additional testing information directly from your local water utility or have your home's water independently tested for a more specific assessment.
Full Water Quality Report
San Diego, California — All contaminants, scores, and violations
Filter Recommendations
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Arsenic Across California
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Is San Diego Water Safe to Drink?
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