Jon,
Very interesting!

I read your mail a few times to ensure you weren't criss/crossing lines and intermingling potable water with non-potable water. Those bugs can swim around the valves that they grow on when the water is still.

In the industry, when they intermingle water systems, they use a back flow protector, (they are required in Massachusetts, not sure elsewhere). It works similar to a pressure regulator with a blow off valve. When the non-potable water system's pressure surpasses the potable system's water pressure, the blow off valve relieves the non-potable out a pipe on a separate branch. This forces the user to shut off and isolate the system not being used.

You really keep yourself busy with these trailer projects eh?

What kind of Airstream?

Rich Walbridge
WBCCI#3371
'73 Excella 500