dump station sign


The Dark Side of RVing Revealed


Dumping the holding tanks on an RV rental or camper rental is sometimes a mystery to newbies. Think of an RV being like a house with its various systems such as electric, plumbing, HVAC, sewer, etc. Yes, there’s a sewer system— the stuff has to go somewhere! Sure, this is not the fun part of RVing, but it’s essential. And it’s really not difficult and does not take very long if you follow these techniques.

Understanding the Holding Tanks on an RV Rental

Your RV rental has two sewer tanks. One tank is named Gray and the second tank is called Black. The Gray tank holds liquid waste from the kitchen sink, bathroom sink and shower/bath. The Black tank holds solid and liquid waste from the toilet. Get it now? Black is the dirtiest stuff and gray is not quite so foul. At the end of these tanks which are located under the RV, there is an outlet where you will connect the sewer hose in order to empty these tanks. Like we stated before—the stuff has to go somewhere!

When Should You Dump the Sewer Tanks on a Camper Rental?

You should empty the sewer holding tanks on a camper rental when they are full or near full. There is a gauge on the RV that shows the status of each holding tank. Usually it’s stated, Empty, 1/3 Full, 2/3 Full and Full. On a side note, in addition to the Gray and Black tanks there is a Fresh Water tank for usage when not connected by hose to “city” water. One reason to empty the Black tank when it is at least 2/3 full is because the weight of the waste effectively creates the gravitational force that pushes the matter out of the tank and down the hose to the sewer when the valve is opened. This concept is why you do not simply leave the Black tank valve open all the time and the hose connected to the outside dump hole and expect the tank to fully empty. FYI-If you rent a camper for just a few days, then the Black tank may not fill up which is what you want before dumping. If so you can fill it by flushing the toilet until the gauge shows full and then dump it. Generally, if you return an RV rental to the dealer with the sewer tanks not empty you will be charged an extra fee. However, a few dealers offer tank dumping within an all-inclusive price. Inquire to find out the policy with your camper rental.

Equipment / Supplies Required for Dumping the Tanks on an RV RentalRV Sewer Hose

Dumping holding tanks on an RV rental is not difficult but you need to follow a procedure to ensure it is done properly. Furthermore, you need to bring several items with you in the RV storage bay(s). These items may or may not be provided by the RV rental dealer. Ask and verify. Here is the list of essential items:

  • RV Sewer Hose and connectors; if you think your sewer hose is too short then carry two hose and their connectors
  • Disposable Gloves
  • Holding Tank Deodorant •A Garden Hose (i.e., used just for holding tank maintenance and not drinking water)
Detailed Procedure for Dumping Holding Tanks in an RV Rental

Carefully read the below steps and then perform them in the same sequence for the successful dumping of holding tanks without any foul-ups:

  1. You may need to move your camper rental to a dumping station if your campsite does not have full hook-ups that include a sewer dump hole.
  2. Put on the disposable gloves.
  3. Pull out the sewer hose and connect it to the dumping hole if not already connected.
  4. You must empty the Black tank first but before that ensure the valve of both Black and Gray tanks are closed.
  5. Now, remove the cap of the Black tank and fix the sewer hose tightly if not already connected with the help of its adapter and/or clamp. Double-check it to make sure it is secure.
  6. Go to the other end of the sewer hose, which you have already placed into the dumping hole and ensure it is almost 6 inches inside or screwed on tight.
  7. If not the screw on type, then place a weight on the sewer hose at this end (dumping hole’s end) to ensure it does not come out when you open the valve of black tank. The weight can be anything like a brick, cover of dumping hole, etc.
  8. Now, it is the time to empty Black tank first. Open its labeled Black valve by pulling out on it. As soon as you open the valve, solid and liquid waste will move out of the holding tank down through the sewer hose and go into the dumping hole. This process will take a few minutes to complete so wait until this process is finished. When this process ends, you will experience a trickling sound within the hose. If in doubt, you can pick-up the hose to feel that it’s empty.
  9. Do not close the valve of Black tank. You are still left to fit the garden hose in the black tank flush/rinser (if equipped). This step is only for those who have an RV equipped with a black tank flush which is usually found near the tank valve and labeled as such. Those who don’t have black tank flush can ignore steps 11 – 14 and close the Black valve at this time (i.e., step 15).
  10. Connect the garden hose (i.e., the one to be used only for dumping maintenance) to the black tank flush from one side and to the dump station or campsite’s water supply on the other side. Note: you may have to remove the “city” water supply hose to do this if there is no other available spigot.
  11. Once the garden hose is connected, turn on the water supply all the way.
  12. Keep the water supply on so that the Black tank flush can clean the tank from inside. Keep the water supply on for at least 5 minutes.
  13. After this, close the valve of the Black tank.
  14. Remove the garden hose from Black tank flush, but not the spigot.
  15. Now, open the Gray tank(s). Dirty soapy water from the sinks and shower will flow down the hose thus “cleaning” out any waste left over from the Black tank.
  16. Once the Gray tank is also empty, close its valve, remove the sewer hose, and close the outlet cover.
  17. Next, hold the sewer hose from the tank side and lift it so that it drains out into the dumping hole. You can rinse the dumping hose with the water hose to ensure it is clean from inside and out.
  18. It is the time to remove the sewer hose form the dumping hole. To do this, remove the weight or unscrew it from the sewer hose and pull it out from the dumping hole.
  19. Clean the surroundings around the dumping hole and hose attachments with running water to ensure nothing has been left out there.
  20. After this, you can add the holding tank’s deodorant treatment to both Gray and Blank tanks with the required amount of water. This is done from the sink and toilet inside the RV. Most people treat the toilet at every dumping and only treat the sinks periodically; however, treating the sink every time is a good idea to avoid any smells especially during warm weather.
  21. Remove the disposable gloves and wash your hands.
  22. Congratulations—you are now done!

Dumping Holding Tanks

We hope this tutorial has been helpful and after going through this exercise, you are able to easily and effectively empty the holding tanks on your camper rental. Once done, the bright side is that you can now go explore the great outdoors and have some fun in your camper rental!