Arsenic in Drinking Water: Health Risks, Sources, and How to Remove It
Arsenic is an inorganic contaminant that can be found in drinking water. The U.S. Environmental Protection Agency (EPA) has established a Maximum Contaminant Level (MCL) of 10 μg/L for this substance to protect public health. Understanding its risks and sources is essential for ensuring safe drinking water.
Health Effects
Exposure to arsenic in drinking water is associated with serious health concerns. Consuming contaminated water can lead to skin damage and circulatory system problems. Furthermore, exposure to this contaminant is linked to an increased risk of cancer.
How Arsenic Gets Into Tap Water
Arsenic can enter water supplies through natural processes or human industrial activities. It is found in natural underground deposits and can leach into water sources. Additionally, mining runoff, industrial discharge, and wood preservatives contribute to its presence in drinking water.
How to Remove Arsenic From Your Water
Various water treatment methods are capable of removing arsenic from water supplies. Effective options include ion exchange and reverse osmosis systems. Activated alumina filtration is also commonly used to reduce the concentration of this inorganic contaminant.
Should You Test Your Water?
If you are concerned about arsenic in your water, you can inspect your local water utility's annual water quality report or search WaterQ. Testing is particularly important for private well owners, who should have their water analyzed by a certified laboratory. You can also look up your local water system on WaterQ or check the Arsenic data page for reported levels in your area.
Frequently Asked Questions
Is Arsenic dangerous in drinking water?
Yes, arsenic poses serious health risks when present in drinking water. Long-term ingestion can cause skin damage and circulatory system problems. It also carries an increased risk of developing cancer.
How does Arsenic get into tap water?
Arsenic enters tap water through natural deposits in the ground. It can also come from human activities like mining runoff, industrial discharge, and wood preservatives.
How can I remove Arsenic from my water?
Arsenic can be removed from water using specific treatment methods. These include ion exchange, reverse osmosis, and activated alumina systems.
Source: EPA National Primary Drinking Water Regulations and WaterQ National Database. For more contaminants, visit our contaminant library.
What actually removes arsenic
Carbon filters do essentially nothing for arsenic, which is why pitcher filters are the wrong tool here. Reverse osmosis is the practical home fix. One nuance worth knowing: arsenic exists as As(V) and As(III), and RO removes As(V) far more completely — well water is more likely to contain As(III), which needs oxidation first. If you are on a private well, test for both species before buying.
Works
- Reverse osmosis (NSF 58)The broadest removal available at home: arsenic, nitrate, fluoride, PFAS, TDS.
- Activated aluminaTargeted media for fluoride and arsenic V where RO is impractical.
- Anion exchangeWhole-house option for nitrate and uranium on well water.
Will not fix this
- Basic activated carbon (NSF 42)
- Carbon certified for lead (NSF 53)
- Ion-exchange water softener
- UV disinfection (NSF 55)
- Boiling Makes it worse — evaporation concentrates what's left behind.
Test before you buy.Arsenic can't be seen, tasted or smelled, and the right hardware depends on the concentration you actually have. A certified lab test costs a fraction of the wrong filtration system. Start with your local water quality report, and get a mail-in lab test if you're on a private well.
Options that carry the right certification
Ordered cheapest-adequate first. Prices are indicative bands and move often.
| Product | Certification | Upfront | Per year | |
|---|---|---|---|---|
| APEC ROES-50 EssenceUnder-sink | Built with WQA-certified components to NSF/ANSI 58.Catch:Needs an under-sink drain connection and a spare hole for the dedicated faucet. Strips minerals — some people dislike the flat taste. | $180–240 | $50–80 | Check price |
| iSpring RCC7AK 6-Stage ROUnder-sink | WQA Gold Seal certified to NSF/ANSI 58.Catch:The alkaline remineralization stage adds minerals back, which slightly raises TDS readings — expected, not a fault. | $200–280 | $60–90 | Check price |
| AquaTru Countertop Reverse OsmosisCountertop | NSF/ANSI 42, 53, 58, 401 and P473 certified.Catch:Takes counter space and you refill a tank by hand. Wastes some water as brine, like all RO. | $400–500 | $80–130 | Check price |
Certification listings change. Before buying, confirm the current listing for the exact model in the NSF certified products database — a manufacturer's marketing page is not a certification. WaterQ earns a commission on purchases made through these links at no extra cost to you; see our affiliate disclosure. This is general information, not medical or engineering advice.
For a full breakdown of certifications, running costs and the models worth considering, see our buying guide for arsenic.