What is the Average RV Black Water Tank Size?

average size rv waste tank

With time, RVs are getting advanced and a lot of new upgrades are available to provide better comfort and ambiance. One of the best things about water tanks is their water holding capacity. They come in many sizes and different tanks have different purposes and capacities. Most people don’t have the proper information regarding the RV water tank size, especially the black water tank. And it can become a problem if you are planning to buy an RV.

The tank size depends on the type of RV you are choosing. Class A RVs are the largest and they have huge water storage capacity and most of them have 70 to 100 gallons water tank size. Though the majority of people prefer to choose to medium or small RVs and the average RV black water tank sizes range to 30 gallons (36 1/4 x 12 5/8 x 16 3/4) to 50 gallons (36 7/8 x 19 x 19 5/8).




How Many Gallons Does The Average RV Black Water Tank Hold?

An RV is divided into three water tanks. One is a fresh water tank, the second is a grey water tank and the third is a blackwater tank. When you will go to buy an RV, it will tell you something 65-25-30. This means the fresh water tank will hold 65 gallons, the greywater will hold 25 gallons and the black will hold under 30 gallons. Though it depends on the RV class, the average RV black water can hold up to 35 gallons of water.

What Are the Purpose of RV Water Tanks?

As mentioned above that there are three tanks types of water tanks installed on an RV and every water tank has a different purpose. Down below is a detailed explanation of all three tanks:

1- Freshwater Tank

The major tank that has the highest storage capacity is the fresh water tank. Class A RV fresh tanks can hold up to 150 gallons of water. As the name sounds, it is used to store freshwater that can be used for many purposes. Generally, the water comes from the taps is from the fresh water tank and it is used for drinking too. So it is important to keep the fresh water tank clean and take all the safety measures to avoid any waterborne disease. You can also use bleach to purify your water.

2- Grey Water Tank

The grey water tank is used to store all the water waste from plumbing, showering, bathroom sink, kitchen sink, washing machine, etc. The average size of the Greywater tank is 50 gallons. The water stored in grey tanks has some bacteria and other particles that can easily be recycled. You can use recycled water for different purposes like watering your lawn or washing your car. The recycling process cleans all the dangerous bacteria that can be harmful to your health. Still, it is not recommended to drink the grey tank water.

3- Black Water Tank

The black water tank contains human waste. It stores all the waste from the toilet, that’s why it requires proper cleaning. In some RVs, the grey water tank is not available and all the shower waste also goes to the black water tank. The black water tank has a hole on the top that works as a passage and the waste directly goes into the black water tank, helps in preventing clogs. Both Black and Greywater tanks are generally separated and it is recommended to treat the black water first to maintain the hygiene. You should never use the fresh water hose to clean the drain pipe. Make a separate hose for these types of cleaning purposes.

How To Dispose of The Black Tank Water??

Untreated black water tanks can cause a lot of problems and its time to time cleaning is very important. The first thing that you need to do is finding an approved septic dumping area. You should always dump your black water tank first. If you are planning a long trip, then make sure to carry a portable RV waste tank. After dumping the waste, you will need a good chemical cleaner or deodorizers to clean and maintain the water tank. Along with that, also make sure to do regular flushing to prevent the tank from clogging.


I'm Wayne, owner of Bestgarbagedisposalunits.com. I'm a father of 2. I love reviewing products and showcasing the very best in my best of review lists. I want people to make an informative decision by going through these reviews before purchasing their selected products.

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