How to Dump an RV Black Water Tank?

By Kyle & Olivia Brady | Founders of Drivin' & Vibin' | We use affiliate links and may receive a small commission on purchases.

How to Dump an RV Black Water Tank?

There are a handful of RV mistakes you don’t want to make. Dumping your black tank incorrectly is one of them.

One simple slip-up can get you covered in poop. You won’t believe some of the things people have done wrong when dumping an RV black water tank.

From not securing the fittings correctly to using a drinking water hose, black water incidents happen almost daily at high traffic campgrounds.

It’s all bad if not done right. That is why we put this guide together. We’ll help you learn the proper way to dump your RV black water tank.

Pro Tip: This also applies to RV portable waste tanks. These help you extend your off-grid camping adventures without breaking camp.

Grey Water vs. Black Water Tanks

Your RV has two types of wastewater tanks; the grey tank and the black tank.

The grey water tank is water waste from your sinks and showers. The black water tank is where human waste is stored (meaning is going number one and number two).

When it comes to these, tanks there are specific valves. That keeps the two types of wastewater separate from each other. 

The reason for this is you don’t want your human waste (black water) to contaminate the grey water tank.

Your waste is full of bacteria that will make you very sick if consumed. So, it’s important to keep everything away from the black water tank. Especially anything that you come into contact with for consumption. 

An RV sewer hose is essential for RV vacations. Buying the right one can save you from a messy situation.

How Often Should You Dump Your RV Black Water Tank?

When it comes to the frequency of dumping, you should really avoid dumping before your tank is at least two-thirds full. You don’t want to dump your RV black water tank too often when it isn’t full.

You want to allow the chemicals to break down the waste and make sure there’s enough fluid for it to flow out. If everything doesn’t get flushed out enough times the dreaded poop mountain starts to form. 

Where to Dump an RV Black Water Tank

When it comes to dumping your RV black water tank it must be done in a designated dump station. These stations have pipes that run to the city waste management centers that appropriately handle the waste.

If you dump it down the street drain like Uncle Eddie in Christmas Vacation they get washed out to local waterways. 

If you’re not camping at an RV park, you still have many alternative dump locations. Here’s where to dump your tanks if you’re camping off-grid.

The Dirty Secrets of RV Camping – Black Water is #1

Necessary Equipment ror Dumping an RV Black Water Tank

To have a successful dumping of your RV black water tank there is some equipment that you need. 

  • Disposable Gloves – these are important to keep your skin from coming into contact with any human waste that might be present.
  • RV Sewer Hose – you need to have an RV sewer hose to dump your grey and/or black tanks. These hoses are made to fit your RV.
  • Clear Elbow Attachment – having a clear elbow attachment helps you see that your tanks have been cleaned out thoroughly. It can be gross to watch but it is helpful. 
  • Garden Hose (NOT your potable water hose) – you absolutely need to have a separate hose from your drinking water hose. Any contact with non-potable water or any contact with your black tank will contaminate your drinking water. You will get sick from this.
  • Disinfecting Wipes or Spray & Paper Towels – after dumping it’s good to disinfect the areas and your hands to keep you from getting sick.
  • Sturdy Garden Bag or Plastic Bin – storing your RV waste hose separate from everything else is also important to keep out contaminants. 

Step-by-Step How to Dump Your RV Black Water Tank

Step 1: Drive up to the dump station. Make sure your sewer valves are aligned with the hole in the ground. You don’t want to have to stretch your hose to its brink when dumping. 

Step 2: Before handling anything make sure to put on your gloves.

Step 3: Remove sewer hose from storage and properly attach it to your RV dump valve. 

  • If you have a clear elbow attach the elbow first to the RV then the hose.
  • Make sure you also have the adaptor attached so it can properly fit in the sewer dump hole.

Step 4: After attaching the hose to the RV securely place the other end in the dump hole so that it won’t come loose once you start dumping.

Step 5: Next you open the valve to start dumping. It’s very important that you do it in this very specific order. Always dump your black tank first.

Step 6: Once the black is emptied run a little water in the tank to make sure to fully flush it out. 

Step 7: Then close the black tank valve and open the grey water valve. You run the grey water valve after the black to help wash out the black water waste.

Step 8: Before closing the grey valve again runs some water through the tank to fully flush. 

Step 9: Close the grey valve and disconnect the hose from the RV side, leaving the hose still in the ground.

Step 10: If there is a water spigot turn it on and rinse out the rest of the hose.

Step 11: After rinsing make sure to empty all fluid out of the house into the dumping station hole and place back into its storage container.

Step 12: Sanitize your RV dumping valve and area.

Step 13: Close up and make sure you treat your tanks.

The Black Tank is Intimidating, but Manageable

When it comes to dumping your RV black water tank there is definitely a right way and a wrong way. It may sound like a lot of steps, but once you do it a few times you will become a pro. Best of all, you won’t risk getting sick.

And now that you know how to do it right you can sit back and watch all those that don’t have a clue what they are doing.

Maybe you can even help them!

PRO TIP: If you love free camping (off grid boondocking), investing in a portable waste tank can help extend your stays. It’s the same concept of dumping your tanks, but into a portable unit that you carry.

11 comments

  1. You mentioned in your dumping process that after flushing the tanks to be sure to treat the tanks after dumping. Just wondering what you do to treat your tanks after flushing them. Thanks for all the info!

    1. Most Walmarts sell black water treatment it comes in either liquid or you can buy pods the problem with pods is overtime the gelatin packaging on the pods deteriorate to where they break open and they just become a mess in your container we like to use the liquid in individual bottles it’s easier than buying a big bottle and measuring out so much each time.

      1. What you are referring to is not “black water treatment”. It is however “Holding Tank Deodorant”. This chem is similar to what you will find in a porta-pottie. It does not treat or breakdown solids. It just kills the smell. Eventually the chem will be overcome with too much poo and pee that it will loose its effectiveness. When this happens, time to dump.

  2. I don’t know where people get the idea that they need a separate hose, there is a vacuum breaker between the water inlet and the sprayer. On top of that the piping goes above both the inlet and the sprayer so backwash won’t happen.

  3. I have a question, sometimes when I unscrew my sewer cap. A tiny bit of “sludge leaks out before I have a chance to attach the slinky. What are some tips to prevent this from happening?

    1. The best way to alleviate this issue is push more water through the tank. What I do, dump the black water tank. Fill it back up to 2/3 to full. Dump again. Fill once more and dump again. It’s is nearly impossible to get it all out so some will more than likely find its way to the cap. One thing to remember this is not a septic tank. This is a cesspool. Microbial break down does not occur as one would think like a sewage system. By the time anything actually breaks down it will be time to dump under normal use. Only way to get rid of the smell is get rid of the poop!

  4. I put a secondary gate on then attach the slinky to that. That allows me to remove the cap and attach the slinky, then open the gate. I bought the gate from Amazon and attaches the same way as the slinky.

  5. If you don’t want to install another gate valve then run your pipe in the sewer first then hold the pipe near your outlet and slowly uncap so any residue goes into your hose then screw on your hose

  6. Wrong. Put hose in sewer dump first. Then bring hose to your discharge and slowly undo cap. Incase of residue. Then screw on your hose to continue.

Leave a Reply

%d bloggers like this: