By passed Black Tank Flush back flow preventer

I'm still waiting to hear how, in the real world, and not some theoretical world in a different universe or the comedy world of the movie "RV", fecal laced water can be vacuumed back through the black tank line into the local water system, if the spray head inside the black tank is not submerged in said fecal laced water. Especially when said black water tank is 39 gallons large.

Is most everyone saying the vacuum created inside the black tank is so great it can pull water from the bottom of the tank through the air inside the tank and into the water hose, and hence to the local water system?

I don't want any thing, device etc anywhere inside my trailer,
whether by the silver ware tray, or inside a storage compartment that "designed" to possibly, or probably, expel water.

I'm trying like heck to keep any water outside my trailer other than inside the water lines and inside sinks, etc.

Lynnmor wrote:
My vacuum breaker was installed next to my silverware drawer and above the electrical inlet. On the manufacturers website, it clearly states that the breaker may expel water and should be installed in a location where that water will not cause harm. Here is a spoon to stir your coffee.

Atlee wrote:
I'm still waiting to hear how, in the real world, and not some theoretical world in a different universe or the comedy world of the movie "RV", fecal laced water can be vacuumed back through the black tank line into the local water system, if the spray head inside the black tank is not submerged in said fecal laced water. Especially when said black water tank is 39 gallons large.

Is most everyone saying the vacuum created inside the black tank is so great it can pull water from the bottom of the tank through the air inside the tank and into the water hose, and hence to the local water system?

You would be surprised at how many people forget to turn off the water and accidentally leave the flush line running. This board alone has several such stories from people forgetting the flush or fill lines running.

Regardless, it doesn’t take much contamination for the process to start, merely vacuuming the little bit of contaminated water in the tip and then air from the enclosed space of the tank would be plenty.

Back in 2000 a small amount of E. Coli contaminated ground water made its way into a municipal well serving a small town near here. Even in the treated water of the towns water system it spread and multiplied to the point that 7 people died and 2,300 of the 5,000 people in town were very sick. If not for the Government allowing a drug in clinical trials to be given to the sick they figure at least 10 more children would have died also.

Atlee wrote:
I don't want any thing, device etc anywhere inside my trailer,
whether by the silver ware tray, or inside a storage compartment that "designed" to possibly, or probably, expel water.

I'm trying like heck to keep any water outside my trailer other than inside the water lines and inside sinks, etc.

Lynnmor wrote:
My vacuum breaker was installed next to my silverware drawer and above the electrical inlet. On the manufacturers website, it clearly states that the breaker may expel water and should be installed in a location where that water will not cause harm. Here is a spoon to stir your coffee.

For reference, see page 4:

Expelled Water

Atlee wrote:
I'm still waiting to hear how, in the real world, and not some theoretical world in a different universe or the comedy world of the movie "RV", fecal laced water can be vacuumed back through the black tank line into the local water system, if the spray head inside the black tank is not submerged in said fecal laced water. Especially when said black water tank is 39 gallons large.

Is most everyone saying the vacuum created inside the black tank is so great it can pull water from the bottom of the tank through the air inside the tank and into the water hose, and hence to the local water system?

So no one has EVER filled their POOP tank to the top??????

I am not much of a "what if" type of guy but this is a situation that is possible and the results would be terrible.

Atlee wrote:
I'm still waiting to hear how, in the real world, and not some theoretical world in a different universe or the comedy world of the movie "RV", fecal laced water can be vacuumed back through the black tank line into the local water system, if the spray head inside the black tank is not submerged in said fecal laced water. Especially when said black water tank is 39 gallons large.

Is most everyone saying the vacuum created inside the black tank is so great it can pull water from the bottom of the tank through the air inside the tank and into the water hose, and hence to the local water system?

All it takes is for someone to forget they a flushing their tanks with a Flush King or flush tank with discharge valve and you create a plausible scenario. It happens plenty of threads on this forum alone where it happens. Now consider when it does contamination could occur.

This is my way of not forgetting I am flushing my tanks! VERY easy to get distracted.

We were in a large CG with a few hundred feet elevation difference from upper to lower sites. Someone at the bottom left their site and forgot to remove their city water hose. It ripped the faucet off and the CG had to shut their main supply valve off. So that set up the scenario for water being drained by gravity from all sites above the damaged faucet into the water distribution PLUS water from lower sites being siphoned back into the system. And if someone were flushing their tank and had no backflow prevention, could have contaminated the entire CG. We were leaving the CG that morning and didn't have to worry.

There are many, many real life scenarios where backflow and contamination can occur. It's not a theoretical other universe possibility. Go talk to your local public health authority and see what they say instead of being ignorant and possibly making others sick (or worse).

I'm not being ignorant.

1) I'm going to get a portable back flow preventer to put on my non potable water hose when the spigot I'm using doesn't already have one. If the spigot I'm using already has a back flow preventer, then bad water can't back up anyway.

2) I don't hook up my black water tank flush until it's time to use it.

3) I dump my black tank before I used the black tank flush. I don't hook it up while the black tank is full. Nor do I use the black tank flush to fill the black tank.

5) As for water, I'm beginning to not even hook up the city water to my trailer. I will use the fresh water in the tank. When it nearly empties, I just put some more fresh water in the fresh water tank.

myredracer wrote:
We were in a large CG with a few hundred feet elevation difference from upper to lower sites. Someone at the bottom left their site and forgot to remove their city water hose. It ripped the faucet off and the CG had to shut their main supply valve off. So that set up the scenario for water being drained by gravity from all sites above the damaged faucet into the water distribution PLUS water from lower sites being siphoned back into the system. And if someone were flushing their tank and had no backflow prevention, could have contaminated the entire CG. We were leaving the CG that morning and didn't have to worry.

There are many, many real life scenarios where backflow and contamination can occur. It's not a theoretical other universe possibility. Go talk to your local public health authority and see what they say instead of being ignorant and possibly making others sick (or worse).

I just love the rationalization in any "why the rules don't apply to me" posts.