How Often To Dump RV Black Water Tank

RVing is perhaps the only hobby where you will discover people enthusiastically talking about bathrooms and the business they entail.

This is because waste, particularly from the bathroom is an important factor in RVing. If your RV is not connected to a municipal sewer hook-up, then it is easy for one to think of an RV as a large portable toilet with wheels.

Being able to deal with waste, particularly, waste from a black water tank and the general unpleasantness associated with it is a process that every RVer has to learn.

Thankfully, the majority of campgrounds and RV parks come with dump stations which make it much easier to dump waste, letting you get back to your adventure as soon as possible.

People that have owned RVs for years are no stranger to the black tank and the steps required to dump it. This article aims to provide newbie RVers with a walkthrough of what a black tank is and how it can be dumped.

So, how often should you dump an RV Black Water Tank? We recommend waiting until your black water tank is at least two-thirds of the way full, as this increases the flow rate and gives waste time to break down.  Alternatively, wait no longer than two weeks to empty the tank and top up with water to increase the fill level before emptying

What Impacts How Often Should You Dump A Black Water Tank?

An RV’s black tank or black water tank can be described as a tank that stores a particular type of waste.

I say a particular type of waste as the black water tank simply holds wastewater that comes from the toilet.

Additionally, if your RV does not have a grey water tank, the wastewater from the shower and sink will flow to the black water tank.

A black water tank is also known as an RV septic tank or a wastewater tank. Now that a black water tank is clearly defined, it is time to discover just how often you should dump your RV’s black water tank and the process involved in doing it.

A great tip that most RVers use is to wait till their tank is two-thirds of the way full. Doing this means that the tank can be flushed efficiently.

If your tank is not two-thirds full, and you intend on flushing it, perhaps for storage purposes, you should fill the tank up with water to make it easier for you to flush.

What do you need to have when dumping your black tank’s waste?

You will need to have the following to efficiently dump your black water tank:

  • Wastewater hose
  • Disposable gloves
  • Hose clamp or elbow
  • Garden hose to help rinse 
  • Sanitation items like hand sanitizer and bleach

The basic steps involved in dumping an RV’s black water tank

When you notice that your Rv’s black water tank is two-thirds or more full, you should drive to the nearest dump station. It is important that you try to have your RV’s black water tank outlet as close as possible to the dump station’s hook-up.

  • Wear disposable gloves for sanitary purposes
  • Ensure that your RV’s black tank valve is tightly shut.
  • Connect the RV’s included sewage pipe or hose to the correct output. There are certain RV’s that have different outputs for the black and grey water tanks. If your RV is one of such, it is imperative that you ensure it is connected to the right outlet. The right outlet will most likely be labeled as black water or sewage. Once you have connected your hose, ensure that it is completely clamped to the output by using an additional ring clamp.
  • Connect the unattached end of the hose to the dump station’s hook-up using a 45° pipe elbow. Doing this ensures that connecting the pipes is much easier as well as ensuring the occurrence of spills is lessened. If your RV’s black water tank does not come with an elbow, you have to ensure the hose is connected at least 1 feet down into the waste receptacle. 
  • Take the time to ensure every connection is completely clamped down. Once this is done, open the black tank’s value. At this point, there should be an audible sound of water flowing, pay attention to it till the sound of rushing water dies down.
  • When this happens, head into the RV to flush the toilet numerous times. Doing this ensures that every bit of waste is flushed out. If your RV has a black water tank cycler, you can utilize it.
  • If necessary, you can fill your black tank with water and dump it again to ensure every bit of waste is dumped out. You can choose to fill and dump as many times as you want.
  • Once done, shut your black water release valve off and disconnect the sewage pipe, first from the RV, and then from the dump station.
  • At this point, take the time out to rinse the dump hose as well as the dump area. Move to store your dump pipe in its storage area. You could also use this time to chemically treat your RV’s black water tank if you so desire.

Where can you dump your black water tank?

Free RV Dump

Free dump stations are available all across the country. The conditions you meet, however, will of course vary. Free dump stations can sometimes be found at welcome centers.

That being said, it is not every free dump station that will have non-potable and potable water. There are some dump stations that have just a sewer connection.

In the event that you require potable water when dumping your black water tank, it is always best to call ahead of time to know if that facility has what you need and if you are able to fill your freshwater tank up.

RV Dump stations that charge a fee

Truck stops, RV service providers, gas stations, and RV parks all have dump stations which they charge RVers a fee to use.

An RVer can expect to pay anything from a few bucks to $35 to use a gas station. If you are unable to locate a free RV dump station, then you can call around to discover if the RV parks in the area charge a fee for use of their facility.

These facilities that charge a fee tend to have both non-potable and potable water, so you do not need to find another facility to fill up your freshwater tank.

Complete Hook-up sites

Most RVers that stay at complete hook-up sites tend to connect just electric and water hook-ups.

If the sewer connection is connected the valve is usually closed until it is time to dump. While it is possible to leave your grey water tank connection open, closing it helps to stop odors and critters from using the hose to get into the RV.

Your black water tank valve should remain closed till it is time to dump, as doing otherwise could cause the liquid in the tank to drain while the solids collect in the tank.


Dumping the black water tank out is something that will get easier with time the more you drive your RV.

With more experience comes knowledge of how long you can go without dumping your tank, the intricacies of your RV’s sewage system, and how you can maximize its efficiency.

It will get to a point that you are even able to help others dump their RV’s black water tank.

You might also like:   RV Toilet Leaking On Floor: Fixes And Troubleshooting