There are different alternatives to fixing the problem. There Point of Use and Point of Source treatment systems. The former being the less expensive option, adding a small treatment system(typically R.O. , reverse osmosis) to for example below the kitchen sink; the latter being a larger, more expensive system that will treat the water at the "source" as it enters the home... it will treat water before it goes to any point of use... sinks, tubs, toilets... so while it does the best job... it also treats more water than needed...

Point of source units treat the water in the same manner but only at the faucet being treated... so you must consider cooking, drinking, ice cubes, bathing (particularly with smaller children as arsenic is cumulative).

In my opinion and I have no knowledge of resale values... a home with an R.O. unit would give me piece of mind that my entire home is treated... regardless.

Feel free to contact me with any additional questions or clarification...
Jeff

Hi Kim - It may affect resale in a relatively minor way. Some buyers, like you, might be a bit hesitant. Most buyers will be OK with it, with a water test that shows the water after treatment. It will certainly not be unsaleable. It would not stop me from purchasing a home but I am also used to well water. Personally, I prefer a well so that I know exactly what I am drinking. It is a good idea to test your well water once a year.

Here is a link for a flyer with more info on arsenic in water. It includes a phone number for state officials that you can call to ask questions.
http://www.maine.gov/dhhs/eohp/wells/documents/ASBROCH3.pdf