How To Remove Arsenic From Your Drinking Water

How to remove arsenic from water - filter guideThanks to crime novelists like Agatha Christie, arsenic is a well known as a poison. As the symptoms of arsenic poisoning are similar to the ones in patients with Cholera, it was often misdiagnosed in former times.

What is Arsenic?

Arsenic is also chemical element and present in groundwater all over the world. Especially in deeper levels. And well owners should be aware of this problem.

Does your tap water contain arsenic?

Very likely.

Although, municipal water suppliers in the U.S. have the legal obligation to remove excessive amounts of arsenic before they deliver it to their customers.

But is that enough?

Recent studies show, that even small amounts consumed over a long period of time do pose a health risk.

How to find out if my water contains arsenic?

Arsenic is tasteless, colorless, and odorless. To find out if, and how much arsenic is in your water, you need to test it.

Or call your water supplier.

Another way would be to take a look at the Environmental Working Group's database.

For those of you who want to test yourself, arsenic water test kits exist.

Is arsenic regulated?

EPA Maximum Contaminant Level (MCL)10 ppb)10 μg/L
EWG Health Guideline)0.004 ppb)0.004 μg/L
WHO Recommended Limit in drinking-water)10 ppb)10 μg/L
ppb = parts per billion
μg/L = Microgram/liter

The higher EPA MCL seems to be a compromise between health risk and economic concerns. If the legal limit were lower, water treatment plants would have to shoulder significantly higher costs.

Arsenic Health Effects - How dangerous is it?

Arsenic has some quite serious effect on your health. Especially when consumed over a long period of time or in higher concentration.

It can cause cancer, harm the brain and your central nervous system, damages skin and increases the risk diabetes. Arsenic is also known to change blood vessels and the heart, leading to a higher risk of heart disease or stroke. Small amounts also may harm your lung.

What are the Symptom of Arsenic Poisoning?

Overexposure to arsenic leads to common symptoms like stomach pain, diarrhea, nausea, vomiting.
Not so common effects are numbness in hand and feet, paralysis and blindness as arsenic effects the nervous system.

Additionally the skin may be discolored and is thickening.

How to remove Arsenic from Drinking Water?

If you are worried about arsenic in your drinking water, home water filters can help.

The caveat is that you first need to find out which type of arsenic hides in your water. The most common types are arsenic III and arsenic V.

Unfortunately, each one requires a different approach to remove it from water.

How to remove Pentavalent Arsenic (also known as Arsenic (As) V or Arsenat)?

Recommended treatment technologies for arsenic V are

Reverse osmosis systems are available as under-sink or countertop units. Whole house systems also exist, but they are expensive to maintain.

Anionic exchange systems are typically whole house systems only. You need to add salt regularly or your system may fail and release all arsenic from the raisin at once. Without knowing, you would suddenly have a very high concentration of arsenic in your water.

How to remove Trivalent Arsenic (also known as Arsenic (As) III or Arsenite)?

First the bad news. Trivalent arsenic is very difficult to remove from water. And even water filters certified by NSF to reduce arsenic, usually only reduce arsenic V.

So, what should you do?

A common solution is to add chlorine to the water. It will react with arsenic III and turn it into arsenic V.

This is a feasible solution for well owners, but not if you get your water from a public water supplier.

Why, they usually add chlorine, don‘t they?

Yes, but ...

Many water suppliers use a combined form of chlorine called chloramines. And chloramines are not as effective as pure chlorine. Same is true for chlorine dioxide, UV and monochloramine.

Simply put, chloramines do not turn all arsenic III into arsenic V 3.
.

Best course of action is to call your water supplier and ask what they use.

Alternative ways to turn As III into As V are the use of permanganate, ozone and manganese-oxide-based solid media. Maybe they use one of these alternatives, so you can use a reverse osmosis system.

A word of caution, the presence of Fe II, Mn II and sulfide and other reductants will reduce or slow down the oxidization of As III into As V.3.

So, what works on trivalent arsenic?

Your best choice are Iron Oxide Filters2.

Public water suppliers use iron oxide filter systems for a long time. Now the same technique is also available in small filters for home use.

Best Water Filter for Arsenic V Removal - Certified Filter Guide

Please notice certification by NSF/ANSI standard 58 is a bit tricky. This is the standard for point-of-use reverse osmosis systems. Just read this:

"The scope of NSF/ANSI 58 includes material safety, structural integrity, total dissolved solids (TDS) reduction and other optional contaminant reduction claims." (from NSF, bolded by us. Full text of the standard here.)

What does hat mean?

Not every water filter certified by NSF Standard 58 does reduce arsenic sufficiently.

That is why we list the ones that can reduce arsenic here.

Reverse Osmosis Systems certified for arsenic reduction

Which one you should choose depends mainly on your budget and other contaminants in your water.

If you have the money, go for one with a low waste water ratio. That is good for your budget and helps the environment by saving water.

Filter NameList PriceAmazon PriceDaily Production Rate (gpd) of system (membrane gdp is higher)Certified ReductionSpecial Features
APEC RO-90$425.00Check Now36Barium, Cadmium, Copper, Fluoride, Hexavalent Chromium, Lead, Arsenic (V) (less than 50 ppb reduction), Radium 226/228, Selenium, TDS, Trivalent Chromium, Turbidity
APEC RO-PH90$460.00Check Now36Barium, Cadmium, Copper, Fluoride, Hexavalent Chromium, Lead, Arsenic (V) (less than 50 ppb reduction), Selenium, Radium 226/228, TDS, Trivalent Chromium, Turbidityalkaline filter
Watts Premier RO-Pure$ 195.00Check Now18.43Barium, Cadmium, Copper, Cyst, Fluoride, Hexavalent Chromium, Lead, Arsenic (V) (less than 50 ppb reduction), Radium 226/228, Selenium, TDS, Trivalent Chromium, Turbidity
Watts Premier RO-Pure Plus$ 199.00Check Now18.43Barium, Cadmium, Copper, Cyst, Fluoride, Hexavalent Chromium, Lead, Arsenic (V) (less than 50 ppb reduction), Radium 226/228, Selenium, TDS, Trivalent Chromium, Turbidity, VOC (as chloroform)
Watts Premier WP5-50$ 249.00Check Now17.32Barium, Cadmium, Copper, Cyst, Fluoride, Hexavalent Chromium, Lead, Nitrate, Nitrite, Arsenic (V) (less than 300 ppb reduction), Radium 226/228, Selenium, TDS, Trivalent Chromium, Turbidity
Watts Premier RO-TFM-4SV-W50$ 195.00Check Now17.32Barium, Cadmium, Copper, Cyst, Fluoride, Hexavalent Chromium, Lead, Arsenic (V) (less than 300 ppb reduction), Radium 226/228, Selenium, TDS, Trivalent Chromium, Turbidity
Watts Premier RO-TFM-5SV-W50$ 199.00Check Now17.32Barium, Cadmium, Copper, Cyst, Fluoride, Hexavalent Chromium, Lead, Arsenic (V) (less than 300 ppb reduction), Radium 226/228, Selenium, TDS, Trivalent Chromium, Turbidity
Nimbus Water WM5-50 (various configurations)n/aCheck Now14.61Arsenic (V) (less than 300 ppb reduction), Cyst, Fluoride, Lead, TDS, Barium, Cadmium, Hexavalent Chromium, Trivalent Chromium, Copper, Turbidity, Radium 226/228low waste water ratio
iSpring RCC7
Read review
$319.98Check Now17.3Barium, Cadmium, Copper, Fluoride, Hexavalent Chromium, Trivalent Chromium, Lead, Radium 226/228, Selenium, TDS, Turbidity, Arsenic (V) (less than 50 ppb reduction)
iSpring RCC7AK
Read review
$366.38Check Now17.3Arsenic (V) (less than 50 ppb reduction), Barium, Cadmium, Copper, Fluoride, Hexavalent Chromium, Trivalent Chromium, Lead, Radium 226/228, Selenium, TDS, Turbidityalkaline filter
iSpring RCC7AK-UV
Read review
$479.98Check Now17.3Arsenic (V) (less than 50 ppb reduction), Barium, Cadmium, Copper, Fluoride, Hexavalent Chromium, Trivalent Chromium, Lead, Radium 226/228, Selenium, TDS, Turbidityalkaline and UV filter
iSpring RCC7P
Read review
$431.98Check Now17.3Arsenic (V) (less than 50 ppb reduction), Barium, Cadmium, Copper, Fluoride, Hexavalent Chromium, Trivalent Chromium, Lead, Radium 226/228, Selenium, TDS, Turbiditybooster pump
iSpring RCC7P-AK
Read review
$463.98Check Now17.3Arsenic (V) (less than 50 ppb reduction), Barium, Cadmium, Copper, Fluoride, Hexavalent Chromium, Trivalent Chromium, Lead, Radium 226/228, Selenium, TDS, Turbiditybooster pump, alkaline filter
Pelican PRO-RO-6$599.00Check Now17.9Arsenic (V) (less than 300 ppb reduction), Cyst, Fluoride, Lead, TDS, Barium, Cadmium, Hexavalent Chromium, Trivalent Chromium, Copper, Turbidity, Radium 226/228alkaline filter
Brondell RC100
Read review
$399.00Check Now56.9Barium, Radium 226/228, Fluoride, Cadmium, Hexavalent Chromium, Trivalent Chromium, Copper, Selenium, TDS, Lead, Arsenic (V) (less than 50 ppb reduction)low waste water ratio
EcoPure$159Check Now18.46arsenic, barium,cadmium, chromium (hexavalent), chromium (trivalent),copper, cysts, lead, nitrate (as N), nitrite (as N), radium 226/228, selenium, turbidity and TDSlow waste water ratio

More information on how to choose a reverse osmosis system

Best Water Filters for Arsenic III Removal

NameList PriceTypeTechniqueCapacity 
Chrystal Quest Arsenic Countertop Water Filter System$130 Countertopiron oxide resin1000 gal.read more
Chrystal Quest Disposable Countertop Water Filter System$144 Countertopiron oxide resinn.a.read more
Chrystal Quest Inline Arsenic Filter$134Inlineiron oxide resin500 gal.read more
Chrystal Quest Undersink Arsenic Multi Water Filter$153Undersinkiron oxide resin500 gal.read more

arsenic faq

Arsenic FAQ

Does boiling help to reduce Arsenic?

No, on the contrary. It can make matters worse. When you boil water, some water evaporates and the concentration of arsenic in the water is higher than before.

Is it safe to shower when my water contains arsenic?

While arsenic in higher concentration can cause skin damage, it usually does not enter the body through your skin.

When you have to shower or bathe with arsenic contaminated water make sure you not swallow it.

Usually the absorption of arsenic through intact skin is minimal. The most common way it enters your body is via contaminated food or water.

But there is a lack of controlled studies on this subject. According to the National Research Council (US) Subcommittee on Arsenic in Drinking Water (National Research Council (US) Subcommittee on Arsenic in Drinking Water.) a small percentage of inorganic arsenic is absorbed through the skin.

Can you smell arsenic?

No, arsenic in water does not change the smell of the water.

Does arsenic change the color of water?

No, arsenic in water is not detectable by just looking at it. It does not change color, smell or odor of your water.

Are there different types of arsenic in water?

The two most common types in groundwater are trivalent arsenic (III) and pentavalent arsenic (V).

What is the difference between arsenic III and arsenic V?

Both types of arsenic are poisonous and should not be present in drinking water. The main difference is that arsenic III and arsenic V require different filter techniques. Also, AS III poses a greater health risk.

Can I use a TDS meter to test for arsenic?

A TDS meter can only detect dissolved solids in water – and arsenic is not one of them.

Do fridge filters remove arsenic?

A usual carbon refrigerator filter reduces only a minimal amount of arsenic V. Nowadays special iron oxide inline filters are available.

Do Brita Pitchers remove arsenic?

The manufacturer Brita does not claim arsenic reduction for their filters. Furthermore, in a pitcher test by Barnabya et al. 2017 1., published in Environmental Research, the Brita filter failed to reduce arsenic sufficiently.


Further reading:

1 Barnabya, R, Liefelda, A, Jackson, B, Hampton, T & Stantona, B October 2017, Environmental Research vol. 158, pp. 610-615, last viewed 4 Dec 2019, https://www.sciencedirect.com/science/article/pii/S0013935117303419. - return to text↩

2Devi, R.R., Umlong, I.M., Das, B. et al., "Removal of iron and arsenic (III) from drinking water using iron oxide-coated sand and limestone" Appl Water Sci (2014) 4: 175. https://doi.org/10.1007/s13201-013-0139-5, last viewed 8 Dec 2019 - return to text↩

3Dr. Dennis Clifford and Ganesh Ghurye, "Oxidizing Arsenic III to Arsenic V for Better Removal", University of Houston / March 14, 2001 https://www.roadsbridges.com/oxidizing-arsenic-iii-arsenic-v-better-removal - return to text↩

4 Hou, Yizhi, "An Improved Method of Arsenic (III) Removal By Reverse Osmosis Membrane" (2017). Master's Theses (2009 -). 424. last viewed Dec 8 2019 http://epublications.marquette.edu/theses_open/424 - return to text↩

https://www.ewg.org/cancer/2016/09/high-rates-bladder-cancer-linked-arsenic-drinking-water

https://www.cancer.org/cancer/cancer-causes/arsenic.html

https://www.ewg.org/enviroblog/2017/09/cancer-causing-arsenic-contaminates-tap-water-70-million-americans

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