Discussion Removing arsenic from well water


Mar 14, 2020
I sent samples of my well water out for testing at the New Hampshire water resources lab. I had them test for pretty much everything including bacteria. I got the results back today and with two exceptions everything that was detectable is below the EPA limit. Almost everything was non-detectable.
The exceptions are Radon and Arsenic. The Radon is not high enough to need water treatment. I need to test the air before deciding if any action is necessary.

What I am most concerned with is the Arsenic. The drinking water limit is 0.005 mg/L. The testing showed a level of 0.0364 mg/L. I want to install a point of entry system to filter out the Arsenic. I do not want to bother with point of use filtration systems because I don’t want to be limited to one water source or have to install multiple point of use systems. Based on what I’ve read so far, a reverse osmosis system is the best filtration method for this. I will consult a certified water filtration professional but before I do that, I want to be as informed as possible.
Does anyone have any experience with such a system, things to be aware of, estimated cost, any other information?


Diamond Member
Feb 26, 2005
RO is the best way to make nearly perfect drinking water. we have uranium and lots of iron and some other metals in our water. we use 3 stages for household use and RO for drinking and cooking from a separate faucet in the kitchen. stage one is 2 4in x 20in particulate filters, one at 20 micron and one at 5 micron, then a resin bed ion exchange tank that removes metals like uranium and iron. next stage is a water softener which i use 50% iron buster, a dash of citric acid to clean the resin beads ( maybe .5% or less and 50% standard softener salt. this gives us great water for domestic use that is perfectly safe. we only use the RO water for cooking and drinking as an extra measure. It is really quite easy to get used to. I have been happy with the filters we purchased from https://www.uswatersystems.com/ their housings are very high quality and the autoship for filters is great. the large size filters last us about 4 months. ymmv, we have a lot of particulate esp. in the winter when our irrigation canal is off and we are drawing water from almost 300 feet down in our well. in the summer our well is artesian, which presents another whole set of very interesting issues.

the filter housings and filters we use:

The rest of the equipment was here when we moved in and is culligan, which has also been working fine for us.

whole house RO is overkill in almost all situations.

I was in the past a NRC ( Nuclear regulatory commission) credentialled worker, I have a ton of health physics training. our exposure rates with our situation cause an almost 0 risk over a 50 year period with the water after treatment.
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