Allworth wrote:
When an RV sits unused, even with the tanks and lines drained, small amounts of water remain trapped in low spots both in the lines and on the floor of the tank. (RV tanks are not perfectly flat in the belly of the beast) This water becomes the perfect medium for formation of fungus and mold and the bacteria which feed on them. Either of these will make you sick. Just because you have gone for years without a bad result doesn't make you safe. Sooner or later it will get you. Even if you just shower or wash hands with it.
Sanitize the system. 50 or 100 gallons of water is not wasted if flushing it out prevents one case of intestinal illness. Run it on the flowers or the grass. The amount of chlorine in it won't hurt anything (including your skin).
My degree in Civil/Sanitary Engineering is from the University of Florida. My Professional Engineering experience is 37 years of Public Works management.
Listen to the man when he tells you to sanitize the system!
(Yes, I have experienced illness probably caused by working in and around water and sewer treatment plants. It is not fun!)
Fresh water tanks do not have the nutrients needed for mold or fungus to grow and bacteria don't "feed" on either. Most likely your illness was some sort of fecal contamination from sewage, not fresh water. Personal choice is wonderful though!