I have a "Y" on the end of the fresh water hose. It has shut off valves. I have a short hose with a quick disconnect from one side of the "Y" to the flush connection. The other side goes to the fresh water connection. The flush system also has an anti-siphon valve. When I need to dump and flush, I attach the short hose and turn that side on... AFTER I turn the fresh water side off. After flushing, I turn the flush side off and disconnect that hose. I then turn the fresh water supply back on. If I am at a dump station, I use a separate hose, not my fresh water hose. I store everything in appropriately designated areas. I always hook up fresh water before any sewer water connections and I wear rubber gloves for waste water handling. I'm very careful not to contaminate fresh water. We have two filters, but we still don't drink water from the tank.... ever. It is for cooking and hygiene only.
Jerry and Katie
More than 20 great years motorhoming and still loving it...
2004 DSDP 3810 (more than I needed...less than I wanted)
2004 Trailblazer (too heavy but well worth dragging)