Where Does Waste Go in an RV

Where Does Waste Go In an RV?

Share with a friend

Last Updated on April 14, 2023 by Jessica Lauren Vine

Are you wondering, “Where does waste go in an RV?”

After fears of towing or driving a heavy RV, the part of RV life which the uninitiated fear the most is what to do with the waste disposal in an RV. Fortunately, RVs have been in existence since 1910, when Pierce-Arrow debuted their Touring Landau at Madison Square Garden, and waste disposal systems have been constantly improved.

If the system is set up correctly, there is enough water in the black tank, and a suitable blank tank treatment has been used, the waste in an RV should get stored in the internal black tank system until it is emptied into the RV Dump Station in the RV park or at a municipal repository.

Learning about the black tank in your RV and the best way to keep it clean and odor-free is worthwhile. Most systems work very effectively and enable an odor-free transfer of the contents of the black tank into the municipal sewer systems.

What Happens To The Waste In An RV?

Over the years, both the manufacturers and the users have learned a trick which has made the modern systems very clean and easy to dispose of.

Modern RVs have two waste storage systems: the grey tank and the black tank.

The grey tank handles all non-sewerage wager waste, including water from the sinks, shower, and bath.

The black tank handles the sewerage waste from the toilet.

When they are full enough, the black tanks are emptied into a suitable repository, RV dump stations, and the waste is transported to the municipal sewerage system.

What Are The Components Of An RV Blackwater System?

To fully understand how an RV blackwater system works, it is worthwhile to look at the components which make it work.

The Toilet

The toilet normally has a flush pedal which activates a spray of water around the bowl and simultaneously releases the ball valve at the outlet point.

The outlet is connected to the black tank directly below via a drain.

The black tank is made up of three components.

The Quantity Sensor

An electrical sensor system displays the levels within the black tank. These are notoriously unreliable and should not be trusted!

Venting Pipe

A pipe that routes out of the tank and upwards through the RV roof and vents the gasses out.

The Flush Port

The black tank flush port is a sprayer inside the RV black tank, which allows the RV owner to spray water inside the black tank and clean off hard residue which may be stuck on the wall of the tank.

The flush port is plumbed into a connection point outside the RV.

On the bottom of the black tank, there is a drain with a valve on it.

When the valve is opened, it sends the waste to a pipe outside the RV. This pipe is hooked up to a flexible sewer hose which is then emptied into the RV dump station or another outlet that connects to the municipal sewer system.

How To Clean The Black Tank System Of An RV

Cleaning the RVs black tank starts before the system is used for the first time.

Always keep an amount of water equaling 10% of the black tank’s capacity in the black tank. It helps keep it clean and odor-free. After each empty black tank, add in 10% fresh water.

A good rule is to pour five gallons of fresh water into the black tank after emptying it.

The freshwater dilutes all the waste as it enters the system and should prevent anything from sticking to the bottom of the tank or its walls.

 Because the tanks are installed directly below the toilet pan, solid waste falls into the same place building a “poop pyramid.”

If there is no water in the black tank, the poop pyramid forms faster and hardens, making moving it more difficult to remove.

How Do You Pour Water Into The RVs Black Tank?

There are three ways to add fresh water to the black tank.

The first way is to press the flush pedal and wait for sufficient water to flow. It takes longer, and you cannot measure how much water has been passed into the black water tank.

The next method is to empty a bucket of water into the tank with the flush pedal depressed.

The last method is to fit a flow meter to the end of the garden hose. Attach the end of the hose pipe in the flush port firring outside the RV and turn the hose on.

It allows you to turn the hose on and very accurately (normally with a digital gauge) measure the quantity of water you pour into the black tank.

A benefit of keeping water in the black tank is that it keeps the ball valve lubricated, which in turn helps it to keep a better seal and prevent the odors from becoming airborne.

Use Black Tank Treatments

The purpose of the black tank treatments is to treat the contents of the black tank with probiotic bacteria enzyme.

The enzymes bounce around when the RV moves, effectively breaking down the

 solid waste.

Without using treatments, it doesn’t matter how thoroughly the black tank is kept clean the odors will always find a way into the living space of the RV.

Black tank treatments prevent the famed “poop pyramid” from forming and make the emptying and rinsing so much more effective.

Typical black tank treatments can be found here.

Some General Hints And Tips With Black Tank Management

Over the years, campers learn their tips and tricks, and these tips simplify the whole process of black tank management.

Hint 1

After hooking up the sewer hose to dump, open the grey tank for a few seconds first to ensure that the connections are good and the sewer hose hasn’t sprung any leaks or deteriorated.

It’s better to have the grey tank contents on the ground unexpectedly than black tank contents.

After a few seconds, close the grey tank valve and open the black tank valve. When the black tank is empty, finish emptying the grey tank to flush the hose.

Hint 2

Leave the black tank valve open, raise the sewer hose about 2 ft above the valve, and then open the grey tank valve.

Leave it open for about 30 seconds to allow 10-15 gallons of soapy grey water to run into the black tank, loosening up any stuck deposits.

Close the grey valve and lower the sewer hose, allowing the soapy grey water to drain out of the black tank, taking any remaining deposits.

Shut the black valve and drain the rest of the water in the grey tank normally.

Hint 3

Once a week, squirt a little extra dishwashing liquid down the sink to help keep the grey tank clean and grease-free.

Hint 4

When about to embark on a long trip, place ice into the black tank, which will move around while the RV travels, cleaning off any stuck residue.


If you carefully carry out the steps in this post, maintaining the black tanks in your RV is easy and will be odor-free. As long as you keep a sufficient level of clean water in the black water tank and use a microbial enzyme black tank treatment, you should have no issues.

Follow me

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top