πŸ’§
WaterCheckupCheck My Water β†’
Home Β· Blog Β· Wells
WellsApril 13, 2026Β·8 min read

Arsenic in Well Water: The EPA Limit and Treatment That Actually Works

Arsenic is a natural groundwater contaminant in many regions. Here is how to test, when 10 ppb matters, and what treatment options are common.

JL
By J. Letorney Β· Water treatment specialist Β· 40+ years in the field
Is your water affected?
Check the EPA report for your exact ZIP code β€” free, instant.
Check My ZIP β†’

Arsenic in groundwater is common in parts of the Southwest, New England, Appalachia, and the Midwest. It is odorless and tasteless β€” testing is the only way to know your level.

EPA standard

The MCL for arsenic in public drinking water is 10 ΞΌg/L (10 ppb). Private wells are not federally regulated β€” owners must test and treat.

Health notes

Long-term exposure to elevated arsenic is associated with increased cancer risk and other health effects. If your well is above the EPA limit, take action for drinking water β€” not just aesthetics.

Treatment

Point-of-use reverse osmosis is widely used for arsenic reduction. Specialized adsorptive media systems exist for whole-house applications β€” design and maintenance depend on your chemistry and flow rate.

Retest after install: Always verify treatment with follow-up lab testing at the tap.
TOP PICK
⚠ Arsenic needs verified treatment β€” not guesswork
Waterdrop Under-Sink RO System
RO is a common solution for drinking water when arsenic is elevated β€” confirm performance with water testing.
Get on Waterdrop β†’See on Amazon β†’
MORE GUIDES
Is PFAS in My Tap Water? What the EPA Data Actually Showsβ†’Best Water Filters for Lead Removal in 2026 (NSF Certified)β†’What Does an EPA Water Violation Actually Mean for Your Health?β†’How to Read Your Consumer Confidence Report (CCR)β†’Chloramine vs. Chlorine in Tap Water: What It Means for Filtersβ†’Private Well Water Testing 101: What to Order and How Oftenβ†’Disinfection Byproducts (TTHM & HAA5): What They Are and How to Reduce Themβ†’Hard Water Explained: Scale, Softeners, and What It Means for Your Tapsβ†’Bottled Water vs. Tap Water: Cost, Safety, and PFAS Realityβ†’Chromium-6 in Drinking Water: Should You Worry?β†’Nitrate in Well Water: Why Infants and Pregnancy Need Extra Careβ†’How to Test Your Tap Water: Mail-In Labs, Strips, and What to Orderβ†’Refrigerator Water Filters: What They Actually Removeβ†’Whole-House Water Filter vs. Under-Sink: Which Should You Choose?β†’Boil Water Advisory: What to Do, What to Avoid, and How Long It Lastsβ†’Microplastics in Drinking Water: What We Know (and What We Don’t)β†’Why Distilled Water and Reverse Osmosis Are the Two Best Systems for High Purityβ†’
Check your exact water report

Enter your ZIP code to see live EPA data, PFAS results, and violation history for your specific water system.

Check My Water Free β†’