I never drink water from my 75-gallon tank. For drinking purposes, I use bottled water. I do, however, use the water to wash dishes and shower. However, before doing so, I make sure it is well chlorinated. I add a full cup of bleach to the tank when I fill it, and while this is far more than necessary to sterilize the water, I just feel better about it. There is a recommended formula for water sterilization, which if I recall correctly is 8 to 16 drops per gallon. And, if you cannot smell the chlorine when running water from the tap, there's a good chance that there is not a sufficient amount in the water to make it sterile.
My boat has been sitting for a couple weeks, therefore, next week, I'll completely drain and flush the entire freshwater system, then after refilling, hit it with an extra load of chlorine, flush it through the system until the tank is half empty, then fill it to capacity. This should make the water safe enough for pretty much everything when I make that next 3-day cruise down the bay.