Steel Knives by Victorinox Corrode and Pit From My Well Water

I am a retired butcher of 37 years in the trade, I have used R.H.Forschner Co. knives for most of those years and have never had a problem until cleaning them in my water at home. I live in a rural area on well water and I am concerned at what could be causing the pitting in the steel and what I should be having the water supply checked for. If you can direct me on what to check for it would be greatly appreciated.
SINCERELY,

Low pH, below about 5.5-6.0, or chloride more than a few dozen parts per million might accelerate corrosion, but I think if you dry them after cleaning, there shouldn't be a real problem. Why not wash, dry, and wipe on a little edible oil?