FWIW, Truck Camper Magazine did an article on hurricane preparedness for truck camper owners. It's here:
https://www.truckcampermagazine.com/weekly-blog/7-reader-tips-hurricane-preparedness/?singlepage=1Note the following:
*1. Don’t Fill Your Fresh Water Tank Until You Evacuate*
“Great advice, Gordon. I’m in the water supply business. One should
not keep fresh water tanks full between trips. Potable water is often
disinfected (usually with chlorine or chloramines), which has residual
disinfection capability of a week. After that, bacteria will begin to
regrow, which is not good.
For the purposes of an emergency evacuation vehicle, and assuming we
have a couple of days warning, one should keep fresh water tanks empty
until the general alert is published/broadcasted. Then fill the tank at that time.
This advice also holds true during normal camping expeditions when you
fill the tank and then plug into city water at campgrounds day after
day. Don’t allow the water in your tank to mature past a week.
