Septic tank hole in the ground question

[annb99]

I have a house on my property that was demolished but the hole in the ground that the toilet sat on is still there. Can I run something from the rvs toilet to the hole in the ground instead of using the holding tank in the rv?

 

[John From Detroit]

It depends on the size of the septic system but the short answer is "Perhaps"

Some septic systems are small. dumping an RV's tanks might overload it.
However if you dump frequently should not be an issue.
Some RV's the black tank is hundreds of gallons.. others 20 gallons. Most inbetween)

 

[Larry N.]

Some RV's the black tank is hundreds of gallons.

That would have to be one HUGE RV, John. A typical 45 ft DP might be around 70-75 gallons gray and 45-55 gallon black tanks, with 100 gallon, or so, fresh water tanks.

 

[NY_Dutch]

Is this truly just a "hole in the ground"? Or is it an actual septic tank and leach field setup. You will still need to use your black holding tank, only emptying it when it's at least 1/2 to 3/4 full minimum. Otherwise there's not enough water momentum to carry the solid out of the tank, allowing them to build up under the toilet creating the dreaded "poop pyramid". The grey tank can be left open though, since it gets minimal amounts of food particle solids, etc.

 

[Rene T]

I assume you’re planning on bypassing the holding tank and just flush the rv toilet into that pipe. If that’s what you’re planning, I would say no. The reason being is that a setup like that, you need alot of water to float the solids down through the pipe and eventually into the tank.
A friend of mine removed his rv toilet and installed a standard toilet like you have in a house. He bypassed the holding tank and it works great.

 

[dabrooks]

It sounds like you are asking if you can connect to the hole where the toilet was and leave the black tank open instead of using the holding tank. That is a bad practice. If you want to use the hole to dump it will probably work but if you leave the black tank valve open you may end up with a poop pyramid.

 

[Rene T]

In the OP’s post he said he does not want to use the holding tank so that means repipiping to bypass the tank. At least that’s how I read it

 

[annb99]

It depends on the size of the septic system but the short answer is "Perhaps"

Some septic systems are small. dumping an RV's tanks might overload it.
However if you dump frequently should not be an issue.
Some RV's the black tank is hundreds of gallons.. others 20 gallons. Most inbetween)

Ya but do I run PVC from the RV to that hole in the ground?

 

[Henry J Fate]

Best to have a qualified specialist come by and evaluate what this hole in the ground is and what you can do with it. A Civil Engineer would be the professional that would normally respond to this sort of inquiry however, there are local contractors who build septic systems that may offer good enough information.

 

[Gary RV_Wizard]

Condensing the replies...

• The "hole in the ground" is probably a feed to a septic system, but you need to verify that and make sure it is functioning. The house toilet would not be sitting directly over the septic tank, so it would have had a drain pipe off to wherever the tank is (outside the house itself).
• You still need the RV holding tank if you keep the RV gravity toilet.
• You could replace the RV toilet with a residential flush toilet and bypass the RV holding tank

 

[Ex-Calif]

If I read your post correctly you have a fitting in some sort of house pad (cement?) with a fitting similar to the one in my photo - toilet mount.

1/ My concern is if the rest of the plumbing is still on the pad there are other drains (sinks/showers/etc). Any blockage in the sewer line could cause a potential back up in the system and black waste to spill on the ground. You likely can generate smells out of the other drains as well.

2/ If the sewer to septic lines are done right and depending on the distance to the septic there should be a cleanout. If I were to do this I would locate the septic, dig out the main pipe and tie into it there. But I would seal off the rest of the old house.

3/ Then there is the legality of it. In my county In FL) in order to hook up an RV an RV occupancy permit must be obtained. In my case it required the septic to be pumped out and certified as part of the county permitting process.

For those following along my situation is basically exactly like OP. A collapsed mobile home with existing septic tank and I went through the permit process and redid the sewer/septic plumbing with a 4 inch threaded clean out to hook the RV pipe into.

 

[Kirk]

Ya but do I run PVC from the RV to that hole in the ground?

Do you know what you have beyond that hole? Are you sure that it is a working septic system? Even if it is you still need to use the black tank or it could collect solids and in time become plugged up. That same thing could be a problem with the hole in the ground.

 

[annb99]

Best to have a qualified specialist come by and evaluate what this hole in the ground is and what you can do with it. A Civil Engineer would be the professional that would normally respond to this sort of inquiry however, there are local contractors who build septic systems that may offer good enough information.

If I read your post correctly you have a fitting in some sort of house pad (cement?) with a fitting similar to the one in my photo - toilet mount.

1/ My concern is if the rest of the plumbing is still on the pad there are other drains (sinks/showers/etc). Any blockage in the sewer line could cause a potential back up in the system and black waste to spill on the ground. You likely can generate smells out of the other drains as well.

2/ If the sewer to septic lines are done right and depending on the distance to the septic there should be a cleanout. If I were to do this I would locate the septic, dig out the main pipe and tie into it there. But I would seal off the rest of the old house.

3/ Then there is the legality of it. In my county In FL) in order to hook up an RV an RV occupancy permit must be obtained. In my case it required the septic to be pumped out and certified as part of the county permitting process.

For those following along my situation is basically exactly like OP. A collapsed mobile home with existing septic tank and I went through the permit process and redid the sewer/septic plumbing with a 4 inch threaded clean out to hook the RV pipe into.

Yes it is similar to the photo. There is a house still on the septic tank so it works. Only part of the house was demolished leaving the hole where a toilet used to be the hole like the one in your photo. We are using a sink, shower and a toilet on the same septic tank.

 

[Ex-Calif]

Yes it is similar to the photo. There is a house still on the septic tank so it works. Only part of the house was demolished leaving the hole where a toilet used to be the hole like the one in your photo. We are using a sink, shower and a toilet on the same septic tank.

That explains things a lot better - You have a partially fallen house, the remaining house is using this same septic still and you want to dump the RV into that.

I would say yes - The easiest way is to just use the RV black tank like you normally do - black valve closed, plenty of flush water and then roll out your black hose and do a dump/flush. I doubt any RV black tank would overwhelm a septic tank designed for single family home use.

Others are eluding to modifying your RV system so that you can permanently plug into the sewer system. I personally would not do that because as dabrooks said along with someone else, an RV toilet does not "flush" a bunch of water with the waste like a home toilet so you are risking making a poo pile or a blockage. Putting in a home toilet as suggested probably means you can't travel with and use the RV as an RV any longer. You might get away with it at full hook up sites but you wouldn't be able to go to sites with no hook up because you basically don't have a holding tank any longer.