Arsenic in Drinking Water

Reference information plus historical EPA compliance records associated with arsenic.

EPA Limit (MCL)

10 ppb

EPA Goal (MCLG)

0 ppb

Category

Inorganic

Regulatory values are a concise reference, not legal or medical advice. Confirm the current standard and rule-specific details on EPA.gov.

Health Effects

Skin damage, circulatory problems, increased cancer risk

Common Sources

Natural deposits, runoff from orchards, glass and electronics production

Treatment Considerations for Arsenic

Commonly cited treatment approaches include: Reverse osmosis, distillation. Choose treatment only after a certified water test identifies the substance and concentration; verify NSF/ANSI certification and consult a qualified local professional when needed.

20,905

Historical Violation Records

7,435

Systems With Records

Historical Arsenic Records by State

StateRecordsSystems
Pennsylvania2,6701,076
Washington2,2911,156
California1,765218
Texas1,330177
Oregon1,278376
Arizona1,230386
Connecticut1,226176
Alaska1,164300
North Carolina945613
Ohio815415
Illinois669119
Utah635254
Montana552215
Nevada47750
Oklahoma45697
Iowa453274
Colorado304154
New Jersey292189
Virginia238154
New Mexico21348

Systems With the Most Arsenic Violation Records

Frequently Asked Questions

What is Arsenic and why can it appear in drinking-water records?

Arsenic can be associated with drinking water through: Natural deposits, runoff from orchards, glass and electronics production.

What reference value does this page show?

The summarized EPA Maximum Contaminant Level is 10 ppb. Some substances use action levels or rule-specific thresholds instead, so verify the current EPA standard.

Does a historical violation record mean it is in my tap today?

No. A compliance record may be historical or resolved. Use the latest Consumer Confidence Report or a certified test for current local conditions.