Dump station etiquette

[lvcat2004]

So we probably "shouldn't" flush the black water tank at the individual site where there is only "potable" water supply.

Is that safe to say??

In that case, I think I would probably not even empty the black water tank and just wait to empty/flush at the dump station.......

[Lumatic]

Originally Posted by lvcat2004

So we probably "shouldn't" flush the black water tank at the individual site where there is only "potable" water supply.

Is that safe to say??

In that case, I think I would probably not even empty the black water tank and just wait to empty/flush at the dump station.......

The black water tank does not care if you are using potable water or something else. If you are paying for full hookups, why not use it? Just use common sense and avoid contaminating your campsite with black water waste.

[lvcat2004]

Originally Posted by Lumatic

The black water tank does not care if you are using potable water or something else. If you are paying for full hookups, why not use it? Just use common sense and avoid contaminating your campsite with black water waste.

I know THAT but that's not what I'm talking about. I have read several posts that said "don't use potable water supply to flush black water tank".

Perhaps that person meant don't use potable water "hose" to flush black water, i.e. use different hose to flush black water tank, which makes sense.

But I swear I read don't use potable water "supply" to flush black water tank, perhaps because of "possible" contamination....I don't know.

[markdoane]

I'd rather not see someone flushing their tanks at their campsite. I'd prefer they only do that at the dump station using the non-potable water supply.

Based on what I see, not many people appreciate how real the risk of cross-connection or backflow is when using these flushing devices.

And most of them won't be there to suffer the effects. It'll be their neighbor, or the next family that pulls into the site.

At least use bottled water for cooking, drinking, and brushing your teeth. And sanitize your dishes after you wash them.

[eubank]

I think what people are saying is that you should be very careful about contamination if you are using potable water. Make sure that your backflow preventer is working properly, replace as necessary; do not under any circumstances allow overfilling; don't touch with unwashed hands any parts of the water system that might permit contamination. If you are unsure, then use a non-potable source of water, where contamination is an issue of such immediate magnitude.

Lynn

[markdoane]

I hate to be a **ick about this, but you can't "make sure your backflow preventer is working properly", because it's not a testable device. You don't have any way to know if it's working or not. That's why most state plumbing boards and the ASSE don't allow them in a highly hazardous situation like flushing sewage tanks.

Yes, I know they still sell them. They also sell rat poison.

[Lumatic]

Originally Posted by markdoane

I'd rather not see someone flushing their tanks at their campsite. I'd prefer they only do that at the dump station using the non-potable water supply.

What I was talking about is my 70s technology. While the trailer is still hooked up at the campsite i dump the tank, close the dump valve, let the toilet run, and dump the tank again. There are no additional tank flushing features and no chance of cross contamination.

[eubank]

Originally Posted by markdoane

I hate to be a **ick about this, but you can't "make sure your backflow preventer is working properly", because it's not a testable device. You don't have any way to know if it's working or not. That's why most state plumbing boards and the ASSE don't allow them in a highly hazardous situation like flushing sewage tanks.

Yes, I know they still sell them. They also sell rat poison.

Good question. Here I do a visual inspection of the device, making sure that the plastic one-way valve on the inside is not broken or stuck. Then I can hook one up to any faucet, turn the water on, turn it back off, and watch. A good backflow preventer will squirt water out the sides as the faucet tries to suck water back down; a bad one won't.


Lynn

[lvcat2004]

Well then....I wonder if there are a lot of people who flush their black water tank with potabler water supply at their camp site......

[eubank]

Originally Posted by lvcat2004

Well then....I wonder if there are a lot of people who flush their black water tank with potabler water supply at their camp site......

In a word: Yes.

[Minnie's Mate]

I have a back flow preventer in the flush system. I also disconnect the hose from the trailer first after turning the water off. This prevents any back-flow that might occur from getting in the hose. But one thing to remember is that the inlet for the tank flush is several feet away from the actual black tank. It is reasonable that the water doesn't flow through the whole system to get inside the hose and work its way back to the faucet through the length of the hose in the second or two that it takes to get from the faucet to the hose connection to the trailer. Plus, the water in the hose is under pressure still and keeps the water away from the faucet.

[markdoane]

Originally Posted by eubank

Good question. Here I do a visual inspection of the device, making sure that the plastic one-way valve on the inside is not broken or stuck. Then I can hook one up to any faucet, turn the water on, turn it back off, and watch. A good backflow preventer will squirt water out the sides as the faucet tries to suck water back down; a bad one won't.


Lynn

Lynn,

Appreciate your comments but it wasn't a question.

There are well defined requirements for different sanitary applications and risk levels. The difference between a testable and a non-testable device is well defined. Many jurisdictions only allow 'testable' backflow prevention devices in a medium and high risk application.

The hose bib antisiphon devices and check valves are rated as non-testable devices, which is why some places don't allow them as backflow preventers for flushing sewage tanks.

And since they are suitable in low risk situations, you can still buy them at your local hardware store. It's up to you, and your neighbors, to know when they can be used (like at the dump station) and when you shouldn't use them.

Otherwise, it's a crap shoot. Nothing worse then a good case of gastroenteritis when you're on a camping trip.

[RedSHED]

Originally Posted by Minnie's Mate

I have a back flow preventer in the flush system. I also disconnect the hose from the trailer first after turning the water off. This prevents any back-flow that might occur from getting in the hose. But one thing to remember is that the inlet for the tank flush is several feet away from the actual black tank. It is reasonable that the water doesn't flow through the whole system to get inside the hose and work its way back to the faucet through the length of the hose in the second or two that it takes to get from the faucet to the hose connection to the trailer. Plus, the water in the hose is under pressure still and keeps the water away from the faucet.

It is one thing to bet one's own resistance to giardia on such a setup; it is quite another to bet someone else's.

In all probability what you've described will work OK for very much of the time. However, I still wouldn't do it (personally), as I'd hate to bet on the backflow preventer having a failure rate of zero.
Also, there remains the physical connection - and the hands, even gloved hands, making one connection then the other then undoing both. The same hands are contacting all surfaces and are capable of spreading parasites. I suppose you could develop a procedure that involved two glove changes and three handwashings, but would the next guy follow it?

I'm not normally squeamish, but this makes me feel not-so-good.

[RedSHED]

Originally Posted by markdoane

...
Otherwise, it's a crap shoot....

Nice touch.