We sanitize our system, flush with fresh water, and use it out of our taps. I like to run straight drinking water through a Brita but I do that at the house too. The only water that goes into our rig is from sources that are deemed " good enough" or potable. We use the blue sediment filter to keep grit our of our plumbing. As long as we don't have crud in our lines, we're good.
Most people don't know where their water comes from (even the bottled stuff).The tap water here is sucked out of the Potomac river, filtered and treated with chemicals until it is deemed "good enough" and run through old, sometimes damaged pipes to the house. In the summer you can smell the chlorine in it when you shower. If we put some in a jar and let it settle, we can see sediment and unidentified stuff in it. I haven't looked under a microscope but I'm sure there would be swimmers in there. The wastewater here is treated and dumped back into the Potomac to cycle through again. Unless you live at the source of the river, your drinking water includes the waste water from plants upstream. Some bottled water comes from similar places.
I've also backpacked and pulled gritty brown water out of an almost-dry spring that animals had probably slurped from and added in the rainwater running off a filthy, rusty metal AT shelter roof onto my dirty tarp, and strained it through my not-so-clean bandanna. I then sucked it through a backpack filter and boiled it for three minutes. Voila, potable water. It was probably cleaner than our tap water. I didn't get sick and I'm not dead. You'd be amazed at what stomach acid can kill off.
We taste and smell the water at campsites before filling our tanks. We got bad water once at a campground from their freshwater tap. I got sick and we emptied and sanitized the system - lesson learned. We carry a small backpack filter for camping where the rig can't go and it doubles as an emergency filter for drinking water if we can't find clean stuff. We've never needed it but it might give you peace of mind.
My advice, sanitize your system before a trip and use it. You control your water supply.