Sending prayers for the little guy.
Filter your water or bring bottled in. I highly doubt it is causing lymphoma, but stranger things have happened. I would be very concerned for your family if there is in fact, some kind of link!
On second thought, bring bottled water in. Don't even chance it for now.
The other thing is that I have seen people who end up "specializing" in certain diseases, not by their own accord. I hope for you all, lymphoma is not yours......
After doing some searching, don't drink the water nor cook with it until you have it tested:
Bad Water on Military Bases
This article is on well water, but I saw another that said a city was using some well water, so how do you know?
Well Water & Cancer