Arsenic in Drinking Water in Vermont
What residents of Vermont need to know about arsenic in drinking water — including natural geological sources, private well risk, which utilities have documented violations, and how to remove arsenic from tap water.
Source: EPA SDWIS, Vermont Department of Health, USGS · Last reviewed: 2025-01-01
Quick Answer
Is arsenic in drinking water a concern in Vermont?
Yes — Vermont is one of the most arsenic-affected states in New England for private well users. The state's granite and metamorphic bedrock is naturally arsenic-bearing, and approximately 50% of Vermont residents — the highest rate in the Northeast — use private wells drilled into this bedrock. Vermont Health surveys have found elevated arsenic in a substantial percentage of private bedrock wells throughout the state.
Where does arsenic come from in Vermont's water?
Granite, schist, and metamorphic bedrock is the overwhelmingly dominant arsenic source in Vermont. Private wells drilled into these crystalline formations — the standard residential well type throughout rural Vermont — are the primary exposure pathway. Vermont's ancient Precambrian and Paleozoic crystalline rocks have had billions of years to concentrate arsenic in mineral form. No contamination event is required — the arsenic is geologically inherent.
What should Vermont residents know?
All Vermont private well owners should test for arsenic — it is arguably the single most important water quality test for Vermont well owners. Vermont DOH provides free consultation and a certified laboratory list. Vermont has subsidized testing programs for low-income residents. Standard pitcher and refrigerator filters do not remove arsenic. Reverse osmosis or NSF-certified activated alumina is required.
Key Facts
| EPA MCL | 10 µg/L (10 ppb) |
| MCLG | Zero |
| Primary source | Granite and metamorphic bedrock statewide — highest private well rate (50%) in Northeast |
| Survey finding | Estimated 10–15%+ of Vermont bedrock wells exceed 10 ppb MCL |
| State programs | Free consultation, subsidized testing for low-income residents, certified lab list — Vermont DOH |
| State regulator | Vermont Department of Health |
| Health effects | Bladder, lung, skin cancer; cardiovascular; diabetes risk |
| Effective treatment | Reverse osmosis or activated alumina — pitcher filters do NOT remove arsenic |
Why Arsenic Matters in Vermont
Vermont has the highest private well usage rate in the Northeast at approximately 50% of the population. With arsenic-bearing bedrock geology underlying virtually the entire state, this creates a large population at potential risk. Vermont DOH has documented arsenic as the top priority water quality concern for private well owners and has invested in public education, testing subsidies, and guidance. Studies have found that 10–15% or more of Vermont bedrock wells may exceed the 10 ppb MCL, and a much higher fraction may exceed lower health-advisory thresholds.
Vermont Arsenic Program
Vermont DOH has documented arsenic in private wells across Vermont's crystalline rock, with the highest rates in Orange, Windsor, and Addison counties. Vermont's granite and schist geology is naturally arsenic-bearing. The state recommends arsenic testing for all private wells and provides technical guidance for homeowners. Vermont's arsenic problem, while less publicized than its PFAS issues, affects a significant portion of private well users.
How Does Arsenic Get Into Drinking Water?
Arsenic in drinking water is almost always naturally occurring — it leaches from arsenic-bearing rocks and minerals into groundwater over time. New England granite, Southwest volcanic geology, and Upper Midwest glacial aquifers are the primary high-risk formations. It has no taste, odor, or color.
Full arsenic overview — geology maps, health effects, all 50 statesWho Should Pay Closest Attention
Private well owners throughout Vermont face arsenic risk from bedrock geology. Windsor, Orange, Caledonia, Orleans, Essex, and Lamoille counties in central and northeastern Vermont have among the highest documented rates, but no county is free of risk. Vermont's rural character means the majority of well owners in any county may be at risk.
Private well owners near mining districts or agricultural areas
Residents in states with documented volcanic or geothermal geology
Long-term consumers of water from small groundwater systems
Households in homes built before 1960 with older well casings
Residents whose well water has never been tested for arsenic
Anyone living in a state where bedrock wells are common
How to Check Your Situation in Vermont
- 1
Identify your water source. If you use a public utility, use the ZIP lookup on this page to find your system and check its compliance record.
- 2
If on public water, review your utility's most recent Consumer Confidence Report (CCR) for arsenic monitoring data. The MCL is 10 ppb — your report should show recent test results.
- 3
If on a private well, order an arsenic test from a Vermont Department of Health-certified laboratory. A basic arsenic test costs $15–$40. The state agency website maintains a certified lab list.
- 4
Test your well at the tap — not just at the wellhead. The entire water distribution system within your home can affect water quality.
- 5
If your test shows arsenic above 5 ppb, install certified treatment immediately. If above 10 ppb, do not use the water for drinking or cooking until treatment is installed.
- 6
Retest after installing treatment to confirm it is working as certified. Replace filter media on the manufacturer's schedule — an exhausted filter may not perform as rated.
Treatment Options for Arsenic
Boiling does not remove arsenic — it concentrates it. Standard activated carbon filters (Brita, etc.) do not effectively remove arsenic. Certified treatment is required.
NSF/ANSI Standard 58 — Reverse Osmosis
RO systems certified to NSF/ANSI 58 remove 85–95% of arsenic. Under-sink installation. Most effective for removing multiple contaminants simultaneously. Replace membranes and pre-filters on schedule.
Activated Alumina Filters
Activated alumina is specifically designed for arsenic and fluoride removal. Point-of-use or whole-house options available. Must be certified by NSF International or WQA for arsenic reduction. Requires periodic media regeneration or replacement.
Iron/Manganese Oxidation Filters
Effective for arsenic in iron-rich well water, which is common in the Midwest and New England. Oxidation converts dissolved iron and arsenic to a form that can be filtered out. Best when arsenic is co-occurring with high iron levels.
What does NOT work for arsenic
Standard activated carbon filters (Brita, refrigerator filters, most pitcher filters) do NOT effectively remove arsenic. Boiling concentrates arsenic. Water softeners do not remove arsenic. Only use products with NSF certification specifically for arsenic reduction.
Take Action Now
If you use a private well in Vermont, test for arsenic — especially if you are in a region with granite, volcanic, or sedimentary geology. A basic arsenic test costs $15–$40 at a state-certified lab.
Public water users: check your utility's Consumer Confidence Report (CCR) for arsenic results. The EPA MCL is 10 ppb — any detection warrants attention.
If arsenic is detected above 10 ppb (or even below it, given MCLG is zero), install an NSF/ANSI 58-certified reverse osmosis system for drinking and cooking water.
Standard carbon filters do NOT remove arsenic — do not rely on a Brita or refrigerator filter for arsenic protection.
Frequently Asked Questions
Related Pages
Arsenic — National Overview
All U.S. utilities with arsenic records
Vermont State Overview
All utilities and water quality data
Vermont Well Water Guide
Testing, risks & certified labs for private wells
Reverse Osmosis Guide
Removes 85–95% of arsenic
Best Arsenic Filter Guide
What actually works (carbon doesn't)
PFAS in Drinking Water
The 'forever chemical' contamination overview
All Contaminants
Complete reference library
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.
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Vermont Department of Health ↗