Well Water quality and what it contains. First there are a number of people who will not like what I will be saying because I am going to deal with the benign issues first and that is how most of the money is made in water treatment systems, treating what will not hurt you and may even be good for you.
Water hardness is the first issue and this area of New England is classified as moderate when it comes to water hardness. What is hardness? Basically, calcium and magnesium in your water. Calcium is actually something that you will actually get into your body drinking water and it is a good thing. Magnesium also has no health negative issues, so why treat it? If we were in the mid West, that would not be a question because levels out there are so high, they will clog pipes, but in Connecticut, that level of hardness is rare. I believe maybe 1% of the wells in Stamford face that problem. There is also a fight over even what is hard water, the USEPA says 200 mg/L is hard, Treatment people will say anywhere from 80 to 150 is hard. They also use the term grains, because that is how they sell softeners.
So hardness will not cause you harm and generally does not cause trouble for pipes in this area, why treat? Ascetics! The drops of water drying on shinny new fixtures dry white and when you boil water you will get a white residue in the pan and that means you have to spend time whipping them off or cleaning them out.
That is it, the entire reason.
The solution is you buy a softener which takes out most of the calcium and magnesium and replaces it with sodium of potassium. You also buy salt so that the stuff in the softener can be reused. You get slick, poor tasting water (I forgot to mention that calcium hardness makes the water taste good) that still leaves some residue in the pot and on those fixtures, but it is greatly reduced. Go Figure!