Skip to main content
10,000+ reports checkedCheck My Water →
Home · Blog · Wells
WellsApril 13, 2026·8 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.

WC
By WaterCheckup · Editorial · NSF/WQA-aligned guidance
Is your water affected?
Check the EPA report for your exact ZIP code — free, instant.
Check My ZIP →

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

EPA standard

The MCL for arsenic in public drinking water is 10 μg/L (10 ppb). Private wells are not federally regulated — 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 — not just aesthetics.

Treatment

Point-of-use reverse osmosis is widely used for arsenic reduction. Specialized adsorptive media systems exist for whole-house applications — 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 PICKS
#1
Waterdrop G3P800 RO
EDITORS PICK
Waterdrop  ·  ~$849
Tankless 800 GPD. Removes 99%+ PFAS, lead, arsenic, nitrates. Smart TDS faucet display. 10-stage filtration.
#2
Aquasana SmartFlow RO
MOST CERTIFIED
Aquasana  ·  ~$449
WQA Gold Seal + NSF 42/53/58/401. Most certifications of any under-sink RO. Removes 90+ contaminants including PFAS.
#3
AquaTru Under-Sink RO
EASIEST FILTER CHANGE
AquaTru  ·  ~$375
NSF 42/53/58 certified. Quick-change filters swap in seconds with no tools. Compact tankless design.
MORE GUIDES
Is PFAS in My Tap Water? What the EPA Data Actually Shows→Best Water Filters for Lead Removal in 2026 (NSF Certified)→What Does an EPA Water Violation Actually Mean for Your Health?→How to Read Your Consumer Confidence Report (CCR)→Chloramine vs. Chlorine in Tap Water: What It Means for Filters→Private Well Water Testing 101: What to Order and How Often→Disinfection Byproducts (TTHM & HAA5): What They Are and How to Reduce Them→Hard Water Explained: Scale, Softeners, and What It Means for Your Taps→Bottled Water vs. Tap Water: Cost, Safety, and PFAS Reality→Chromium-6 in Drinking Water: Should You Worry?→Nitrate in Well Water: Why Infants and Pregnancy Need Extra Care→How to Test Your Tap Water: Mail-In Labs, Strips, and What to Order→Refrigerator Water Filters: What They Actually Remove→Whole-House Water Filter vs. Under-Sink: Which Should You Choose?→Boil Water Advisory: What to Do, What to Avoid, and How Long It Lasts→Microplastics in Drinking Water: What We Know (and What We Don’t)→Why Distilled Water and Reverse Osmosis Are the Two Best Systems for High Purity→Is Tap Water Safe to Drink? The Honest Answer by City and Water Source→Why Does My Tap Water Taste Bad? The 7 Most Common Causes→Fluoride in Tap Water: Is It Safe? What the Latest Research Shows→Reverse Osmosis Water Filters: Pros, Cons, and Who Actually Needs One→Lead in Tap Water: Signs, Symptoms, and How to Know If Your Home Is at Risk→Best Water Filter Pitchers of 2025: Ranked by What They Actually Remove→Radon in Drinking Water: Risk, Testing, and Treatment for Well Water Users→What Water Filters Actually Remove PFAS? (NSF Certified Options Ranked)→Is Tap Water Safe During Pregnancy? What OBs and the EPA Say→Best Reverse Osmosis Systems for PFAS Removal in 2025→Moving to a New City? Check the Water Quality First→PPM, PPB, PPT: What Those Numbers on Your Water Report Actually Mean→Top 10 US Cities With the Hardest Tap Water (and What to Do About It)→
NOT SURE WHICH FILTER IS RIGHT FOR YOU?
Take the 3-question filter quiz
Answer 3 questions about your water source, biggest concern, and home situation — we match you to the right certified filter.
Find My Filter →
CHECK YOUR CITY'S WATER
San Antonio, TX →Chicago, IL →Houston, TX →Los Angeles, CA →Phoenix, AZ →Philadelphia, PA →Dallas, TX →Miami, FL →Boston, MA →Seattle, WA →Denver, CO →New York, NY →
View all 135+ city reports →
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 →