Serious Plumbing Considerations

[Joe Cannarozzi]

It was suggested to me, I'm absolutly sure with good intent, in another post of another thread, that I might be trying to reinvent the wheel.
Hmmmmmmmmmm.

[JIM CHALOUPKA]

Karl M., How are these plumbing issues addressed in the boating world? It seems to me they would be quite similar. Wouldn't three separate pumps work here. Drinking, Grey,Black. JIM

[Jon Wehrenberg]

Joe, We waved and I grabbed the CB, but I now remember you don't use one.

The plumbing issue would benefit from fresh thinking. To be safe there needs to be an air gap between the waste and fresh water side. That way the waste water cannot flow back into the fresh water tank.

Jim, the problem is unrelated to pumps or the number of them. It is the principle of how the valve works. That particular valve in concert with the toilet piping sets up a high speed high volume momentary flow that evacuates the toilet bowl by creating a low pressure area in the bowl. As designed it would not work with any kind of air gap.

In your quest to find the perfect coach don't dwell on issues like this one because there are ways to minimize or eliminate any cross contamination as long as the system is well maintained.

[JIM CHALOUPKA]

Well all I can think to say now is. If I spend BEAUCOUP BUCKS on a camper and tell my wife she can't drink the water, what side of the moon do you think I will be calling in from? JIM

[Jon Wehrenberg]

Even with cross connections you can drink the water. Just install all the necessary purification devices plus a UV light on a line, and you are good to go.

The key is to eliminate the potential for cross contamination. I know of at least four coaches on this forum right now that need to address this issue and it is likely there are more. (Mine is one of them.)

[rmboies]

Even with cross connections you can drink the water. Just install all the necessary purification devices plus a UV light on a line, and you are good to go.
)

Jon,
interesting thread and I am printing all your information out for Bob-00. When we purchased our first coach, I contacted a local environmental company to have them test the water in the drinking tank. It was good to go. However, the nurse in me still had a problem with water sitting in a tank, un-used, so we chose to drink bottled water and use the other water for showers etc. Having read your posts, I can see now that just having the tank tested once is no guarantee. Is it possible to design an air barrier/baffle to eliminate cross contamination?

[Jon Wehrenberg]

Debi,

This is an issue that is not hard to visualize. If you have a HeadHunter type toilet with the associated flush valve picture in your mind a toilet bowl with water in it. The water in the bowl is in direct contact with the waste line going to the black water holding tank, and it is also in direct contact with the fresh water used for the flush cycle.

What separates that toilet bowl water from the fresh water holding tank is the flush valve that under almost all circumstances seals so tight, it shuts off fresh water that is under pressure from leaking past the valve. That seal also prevents any water in the toilet from backflowing into the holding tank.

It is only when the flush valve fails to seal, or shut off the flow, that problems occur. In any coach in which the flush valve has functioned properly it is unlikely the fresh water holding tank has been soiled. In fact, in some cases the converter has taken steps which prevent the contamination of the fresh water holding tank by installing a check valve between the pump and the flush valve, thus making contamination even more unlikely.

When we started "camping" in our first coach our concerns were like yours and we just decided to never ingest water from our holding tank, instead preferring to use bottled water. Even when I modify our plumbing system to almost completely eliminate cross contamination we are unlikely to change our practices.

In the context of the toilets and valves discussed above an air gap is not possible. It would require the valve to be mounted above the toilet, and to allow the water to flow into the toilet from above the water flood level. The way the toilet is designed it requires the high volume flow into the waste line below the bowl to create a very low pressure area to "vacuum" out the contents of the bowl. It is a very effective design, but like I said originally, it is a compromise.

[Jerry Winchester]

I never drink the water. Jim, I would spend beaucoup bucks + the cost of a case of Ozarka water and never look back.