Why you should not leave your grey valve open - Sewer Rats

I always keep it closed to avoid pyramids. If it's always open, all the liquids drain out and leaves the solids to dry out and get stuck in the black tank.

BurbMan wrote:
Wait, how much for the bridge? Is it one of those big ones

It's a big, blue, suspension bridge; it goes between the UP and the LP in Michigan (it's called the Mackinac Bridge). But you better hurry, it looks like there could be a few other people that are really interested in it.

I did this one time but will never do it again, thanks for sharing.

Rats coming up the sewer lines into a toilet and out into your house? Happens a lot. Think about it. Your sewer line or, in this case, your sewer hose usually has no water flow unless it's used to drain material like waste from a sink or waste from the toilet. Well if the dump valve is left open, a rat has absolutely no problem getting up the hose and into the black water tank. How it would get past the flapper valve thing in the toilet is another thing. Hopefully it doesn't happen when the toilet is in use and the valve is opened. In houses the rat only has to swim down and up through the p trap that's built into the toilet. Rats are excellent swimmers and often enter homes through broken sewer lines or through clean outs when the covers are left off.

Well it is certainly possible. You guys assume there is a 3',4',5' vertical drop. of the sewer before connecting to the horizontal line, But there doesn't have to be. The sewers can be quite shallow with no vertical drop at all and the rat could simply run up the pie. Remember the line only needs to fall 1/4"/foot.
These are campgrounds we are talking about. I'm sure the sites are not always plumbed to code.
Furthermore consider that the sewers can flood/overflow and the critter could simply swim up the pipe or get washed up with the back flowing sewer water.
I have read stories of RV's flooding do to sewage back ups.
I have personally witnessed homes flooding do to sewage back ups.
Yes in those back ups toilet paper and #2 does come up and end up in basements. A critter could easily wash up or in with the backflow of water.
I have witnessed sewage flies in sewers and getting into homes and businesses so it's easy for me to see flies getting into a RV.
Rats are a bit more of a stretch but it is conceivable.
I believe rats do have access and live in the sewers from there it's not hard to imagine one crawling up or being washed up a pipe and into a waste tank.
The video mentions it is a rare occurrence. While I no first hand knowledge of a rat in a tank I do believe it is possible.

Better reason is sewer bugs/insects. They happen in outhouses too. They can fly/crawl up the empty hose and in thru the drains. We keep both of our valves closed until it's time to dump.

Wait, how much for the bridge? Is it one of those big ones

BurbMan wrote:
Fake news! Even if your dump valve was open, how would a rat crawl up the CG dump pipe, and through the sewer hose?

Exactly, you have a better chance of me selling you a bridge.

The only time I've had my bathroom stick when I flush the toilet with the vent fan on, is when I had it connected to the dump station with valves open. These days, my black tank stays closed until it is 3/4 full, then dump it. Just to keep stuff from piling up (literally), I squirt some Dawn dish soap in the tank after emptying.

Fake news! Even if your dump valve was open, how would a rat crawl up the CG dump pipe, and through the sewer hose?