How do I remove arsenic from my water ? Here in Maine, we have a bunch of private residential wells with high levels of naturally occurring arsenic. There are several ways to remove arsenic. The best technologies are filter media or resin. Reverse Osmosis usually has disappointing results. Most filter media’s can handle both arsenic 3 & arsenic 5. Reverse Osmosis is only effective at removing arsenic 5. Therefore, pre-treatment is required to convert 3 into 5. It gets messy. So fair warning. Buying and installing a Reverse Osmosis system alone may end up being a waste of time & money. That said…. Reverse Osmosis is incredible at removing most other dissolved solids. It certainly has it’s place. Just not arsenic. Also, due to the nature of arsenic & the human body, It is my opinion that we remove arsenic from all the water by installing a filter media based system in the basement or mechanical room to remove arsenic from all the water in the house. Most of these whole house systems will run at about $3,800. (includes installation). Some a little lower. Some a bit higher. It all depends on the installation site & conditions. If you have arsenic in your water, call me. Once we talk and I get a look at a water analysis, I can give you a firm price. 207-907-9772.