Install an RV dump on your home septic system

The following tip comes to RV Tip Of The Day from a fellow RVer who is a plumber by trade.

I installed septic systems for quite a few years and have seen some weird things people have done with their systems.

Installing an RV sewer dump into a home septic system is very easy. Remember sewer lines should not have quick drops because the water will leave the solids if there are any. Large elevation changes should be made with 90 degree drops. One inch of drop in a one hundred foot line is almost overkill, we always tried for no more than a half inch drop per hundred foot, but that is hard to do using plastic line. Ideally the solids are kept with the liquid and casually float to the septic tank entrance.

Connect your RV dump line into the septic system between the house and septic tank, never into the drain field. Another option is to drop the discharge from you RV directly into the top of the septic tank, preferably before the baffle, but after the baffle will work if that is the only possibility.

A macerator or other grinder will help but is not a requirement. I have installed RV dump lines into several septic systems, used both methods and never had a problem with them. First one I installed was in about the early 1970’s and it is still being used to dump RV septic waste.

The reason I mentioned to install the dump line between the house and septic tank is that I had a dear friend that decided to put in his own septic dump for their RV and hooked it in AFTER the tank and before the leach lines. Needless to say it took us a while digging up the lines and replacing them to get his system working properly again.

If the dump is being used daily or very frequently one needs to make sure to hook in between the house and tank, but for occasional use dumping into the tank after the baffle will work. The baffle in septic tanks is an insurance policy to ensure that the solids go down, not across the top of the liquid in the tank and out into the drain lines.

If dumping in after the baffle, it is a good idea to make sure the waste enters perpendicular, and even to drop the end of the dump down into the water level a few inches. This helps direct the solids to the bottom. I always put the dump about six inches down into the water. NEVER bring waste in AFTER the baffle in a horizontal configuration as the agitation could send the solids across the top of the liquid right into the drain field outlet.

Dumping a forty five gallon tank all at once won’t if the RV dump line is installed as I describe.

When installing new septic systems on lots lots that were big enough for RV’s to be parked I always offered to install an RV dump free of charge and connected it between the house and tank whenever possible. I figured it would save digging up the yard later to install one, and the additional cost of the pipe was minimal.



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19 Responses to "Install an RV dump on your home septic system"

  1. Hello, I am in the process of purchasing a 5th Wheel for my mother to live in at my house. We would like to hook directly into the home septic. The only direct access is the clean out pipe. Everything else is buried. What would be the best way to approach hooking into the septic from the 5th Wheel?


  2. You should be able to purchase all the items you need at any well-stocked RV store, just tell the clerk what you want to do and he should be able to supply your needs.

  3. Hello. My parents own an RV and will be parking it at our house for about a month or two every year and staying in it. We have a septic system. They will be parked less than 15 feet from the manhole cover and inspection cover. We are trying to determine the best way to provide a hookup that is permanent for when they are here. We had looked for a manhole cover that had an access on top for the drainage pipe to go into, but did so to no avail. We are looking for the safest way to do this (as we have little kids that like to investigate) without having to just lift the cover every couple of days or living it partially opened to have the pipe fit. Based on your comments, I think it is after the baffle if it goes into the manhole directly. Thank you for any assistance you can provide. Sorry if the terminology is not accurate.

  4. You could make a cover to use while your parents are visiting. I would use several thickness’s of plywood, however many required to make it sturdy enough. It should be easy to cut a hole in the plywood cover for the drain connector. Use a pipe flange to connect it to the cover. You could even add a pipe extension under the cover to direct the waste to the proper part of the tank.

    Hope that helps.

  5. How do you find someone in your local area who can come take a look and makesure its done properly and an estimated

  6. That’s a job for a plumber. Finding a good plumber is like finding any other good tradesman. Start by asking family members and friends for recommendations. (Ask them on facebook). Check out online review sites etc. Call plumbers and ask questions.

  7. I have house and septic. I have an rv i need to clean out. Priblem is both house and septic are higher than i can put rv. What can i do i cant move rv to higher ground

  8. I have a Tiny House on wheels and would like to connect the sewage line from the Tiny House to my home sewer system. I have a clean out on my property. Is this legal in Washington State of King County?

  9. This article was intended to provide a solution to RVer who, arriving home for a camping trip, need a way to dump their tanks. As such, we are assuming the connection to the cleanout would be made using an RV sewer hose and tempory. If this is what you had in mind then it should be okay since your tiny house is technically considered an RV.

    If you plan a long-term connection… I assume someone will be living in the tiny house… then you may run into legal issues. Is it legal to live in a backyard tiny home where you are?

  10. I don’t have a septic system but I am purchasing an rv next spring. I am renovating my house and want to install a dump station at my home. What am I looking at for a process etc? Can I even do it?

  11. Hey Steven, this is by far the best information I’ve found online so far! Thanks for the education for those of us who are clueless. If you are still up for answering a question or two, I have at least one. So, I really want to install one of those campground like pvc pipes with a screw on lid that would go straight into our septic tank. The lid to the tank (that is supposedly before the baffle, even though it is farthest from the house) is a big plastic piece. Could I just drill a hole in it and put in a 4 inch pvc trap like pipe with a screw in top to avoid having to take the whole lid off of the tank top every time I want to dump black and gray tank into it with a hose?

  12. I had some help with this article from a fellow RVer who was a plumber by profession so I cannot offer authoritative advice about this. In theory, I would think your idea is sound but, because I am not an expert, I have to advise you to consult with a plumber so you know you are doing things properly.

  13. I want to put in hookups for my Rv but feel I should have professional company do it. I have a septic system and would need dump and electric run. Are there any suggestions on a company or how would I locate one that would help me with this. I am located in central Florida.

  14. Hi Steven! My wife and I just moved into a stationary fifth wheel that is connected to a septic tank. However there is still a black water holding tank. Would recommend keeping the tank open or keeping it closed and draining it into the septic tank when full? We don’t want solids to get stuck to the black water holding tank, however we are also afraid of flooding the septic. Thank you

  15. The black tank valve should be closed until it is nearly full. You need to do this to ensure solids get flushed out and do not build up in the tank. You can keep the gray tank valve open if you want but, since gray tanks can get stinky, you should close it on a schedule that works for you and let the tank fill to flush the tank. Maybe use some chemical too. I would recommend letting the gray tank fill the day before you empty the black tank. That way you can use the gray water to flush the sewer hose after dumping the black tank.

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