Are you on well water? it's not just about what you are drinking (when it comes to the water)...you shower/bathe in water too. If it is well water and it's is contaminated in some way, then you can pick up things via water getting in your eyes, ears, mouth, etc.

You can contact your local health dept for companies that do water testing. It's not usually very costly, we just went through this and paid $45 for professional lab testing on our well water.