Arsenic in Drinking Water in Nevada
What residents of Nevada 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, Nevada Division of Environmental Protection, USGS · Last reviewed: 2025-01-01
Quick Answer
Is arsenic in drinking water a concern in Nevada?
Yes — Nevada has among the highest naturally occurring arsenic in the western United States. The state's Basin and Range geology, extensive geothermal activity, and history of gold, silver, and copper mining create widespread arsenic occurrence in groundwater. Multiple Nevada communities — particularly in the rural Great Basin and Mojave Desert areas — have documented arsenic above the MCL, and Nevada has one of the highest proportions of small water systems requiring arsenic treatment in the West.
Where does arsenic come from in Nevada's water?
Geothermal and volcanic geology throughout Nevada's Basin and Range province is the dominant natural arsenic source. Arsenic-bearing hydrothermal mineral deposits are widespread across Nevada's mountain ranges. Historic gold and silver mining throughout the state has amplified naturally occurring arsenic through ore processing and tailings. Rural Nevada communities relying on local groundwater — rather than Colorado River water — face the highest risk.
What should Nevada residents know?
Rural Nevada communities throughout the Great Basin, particularly those relying on local groundwater from Basin and Range aquifers, face significant arsenic risk. Communities in Elko, Lander, Eureka, White Pine, Mineral, Esmeralda, and Nye counties have documented elevated arsenic. Nevada NDEP has been active in arsenic compliance and treatment assistance for small communities.
Key Facts
| EPA MCL | 10 µg/L (10 ppb) |
| MCLG | Zero |
| Primary source | Basin and Range geothermal/volcanic geology; historic gold/silver/copper mining statewide |
| State arsenic profile | Among highest naturally occurring arsenic states in U.S. — widespread small community exposure |
| State regulator | Nevada Division of Environmental Protection (NDEP) |
| Health effects | Bladder, lung, skin cancer; cardiovascular; diabetes risk |
| Effective treatment | Reverse osmosis or activated alumina — both critical for rural Nevada communities |
Why Arsenic Matters in Nevada
Nevada's Basin and Range geology makes arsenic a near-universal concern for rural communities relying on local groundwater. The state's geothermal systems — among the most active in the continental U.S. — contribute arsenic to aquifer systems across a wide area. Historic mining in the Comstock Lode area, Battle Mountain, Carlin Trend, Ely, and dozens of other Nevada mining districts has left arsenic-bearing tailings across much of the state. Las Vegas draws from Lake Mead (Colorado River water) with generally lower arsenic, but rural Nevada communities outside the Colorado River service area face significant arsenic risk from local geology.
Nevada Arsenic Program
Nevada NDEP has an active arsenic compliance program, as Nevada is one of the most arsenic-affected states in the country due to its volcanic Basin and Range geology. Many Nevada community water systems required treatment after the 2006 MCL change. The Las Vegas area draws primarily from Lake Mead (lower arsenic), but rural Nevada communities relying on local groundwater face high arsenic risk. Private well owners in rural Nevada should test.
Largest Nevada Water Utilities
No arsenic violations on record in EPA SDWIS for Nevada utilities in our database. Browse the largest utilities to review their full water quality record.
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
Rural Nevada communities throughout the Great Basin region — particularly in Elko, Lander, Eureka, White Pine, Mineral, Esmeralda, and Nye counties — and private well users near any Nevada mining district face the highest arsenic risk. Tribal communities in rural Nevada relying on local groundwater should prioritize testing.
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 Nevada
- 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 Nevada Division of Environmental Protection-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 Nevada, 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
Nevada State Overview
All utilities and water quality data
Nevada 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.
Find Your Utility
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Nevada Division of Environmental Protection ↗