What Is a Vault Toilet?

Feb 15, 2021 | Bed Bath Reviews, What To Buy

Vault toilets are an effective and simple solution for providing a permanent bathroom in rural areas with no running water. 

These toilets are inside a small room, with a toilet positioned on a concrete slab floor. An underground tank or vault stores the waste in an airtight compartment that blocks odor. This waste must be routinely pumped out by a waste management company and transported to a wastewater treatment plant. Vault toilets are hygienic, environmentally friendly, and effective.

What Is a Vault Toilet?

Vault toilets are a better alternative to using portable bathrooms like Porta Potties. For a toilet to classify as a vault, there has to be a vault (storage tank) stored underground that holds the waste. 

The vault can be plastic, concrete, or the most popular choice for its environmental safety, reinforced cross-linked polyethylene, ranging in size from 1,000 gallons up to 13,000. The criteria to serve as a vault for human waste is that it won’t leak, crack, or degrade while buried. 

To install a vault toilet, the vault goes underground with a concrete slab poured over the top that serves as a foundation for your bathroom floor and a base for the walls. The building can be wood, polyethylene, concrete, or other materials. Many look like mini log cabins.

A toilet goes inside over the drainage hole in the slab. There’s also a vent pipe, which keeps the room odor-free. 

These toilets can be a single, double, or unisex setup. Vault toilets have an advantage over porta-potties because they’re more hygienic, permanent, and sturdy. They rarely have a bad smell because the waste is stored underground instead of inside a tank under the toilet, and the vent allows fresh air circulation.

Where Are Vault Toilets Used?

Vault toilets are not a typical home bathroom option. These toilets are most common for rural locations where there’s the need for bathrooms but no running water to source plumbing. Vault toilets don’t flush, so there’s no need for water.

These toilets are often a public bathroom solution for recreational spots, parks, hiking trails, campgrounds, and national historic sites. Many people also refer to vault toilets as camping toilets. According to the U.S. Forest Service, they’re “sweet-smelling toilets.”

How Much Does a Vault Toilet Cost?

The cost to install a vault toilet varies from $500 up to $5,000. This price includes the labor and materials necessary for installation. 

Installing a vault toilet is not a complicated process, so a lot of it can be done without having to hire expert specialists. You may need someone with experience to set up the vent line, but digging the hole and setting the vault can be done by anyone who can handle a shovel.

Building the foundation structure is also easy enough for anyone with experience constructing a building and knows how to cut the materials properly. 

Pouring the concrete slab can be a DIY job if you have experience. Otherwise, you may want to leave it up to an expert, so you have a smooth, properly cured concrete slab.

How Does a Vault Toilet Work?

Vaulted toilets have a simple operation. There’s no need for running water or flushing the toilet to remove the waste. Since there’s no water, there are no water pipes to transfer the waste. 

Instead, the human waste goes underground, where it goes into a leak-proof, airtight vault that varies in size. The size of the tank determines how often it needs emptying.

To remove the tank’s waste, professional waste management staff drain the vault using a specialized tank intended for storing human waste. These remains then go to a wastewater plant for proper disposal. 

The Forest Service calls these toilets “sweet-smelling toilets” because the vent built into the structure pulls out the smelly vapors. Chemicals added into the vault can help prevent the foul stench of decaying waste, but even these smells can turn sour.

The vent also allows fresh air to flow into the room, pushing out the bad smells. But when the wind isn’t blowing, it can cause a “green cloud” to form due to lack of moving ventilation. Sun exposure on the vent pipe is crucial for helping pull out smells by warming the rising air. 

If you build a vault toilet in a secluded area where trees block most of the sunlight, you may run into problems with ventilating your vault toilet. 

Pros and Cons of Vault Toilets

There are numerous pros and a few downsides of using vault toilets as a source of public bathrooms in secluded or rural areas where there’s no water to allow for standard plumbing.

One of the biggest downsides of vault toilets is their need for direct sunlight for the vent to operate correctly. In the winter or during rainy seasons, when there’s little sun, things can get smelly. Overly populated groves of trees can also cause an issue with blocking the sun.

Another issue about using vault toilets is that they can become blocked up due to typical bathroom garbage disposals such as toilet paper, feminine products, and other trash. It’s best to post clear warnings to deter these actions. 

And finally, the riser inside the vault can rise as it gets full, exposing the vault’s wastes. It can be quite a repulsive sight that can be expensive to repair.

Now that we’ve discussed the cons let’s take a look at the many reasons why vault toilets are a fantastic solution for public toilets.


One benefit of building single vault toilet structures is that it provides the user with more privacy than going into a bathroom lined with multiple stalls.

Low Maintenance

Another benefit of vault toilets is their low maintenance needs. Since there’s no water, you don’t have to worry about leaking or busted pipes, rust stains, clogged toilets, or overflowing.

Depending on the size, most vault toilets need to be drained and sanitized every two to three weeks. And the inclusion of a well-placed vent can prevent horrible smells, reducing the need for air fresheners or a clothespin to the nose.


Vault toilets are an affordable solution. There’s no water usage, so there’s no water bill. The easy maintenance means there are few cleaning necessities. Even building a vault toilet from scratch can cost less than a few thousand dollars.

The only real expense you incur with vault toilets is having to pay a professional service to drain and clean your vault once or twice a month.


Vault toilets are an excellent and preferred alternative to Porta Potties, primarily due to their better ventilation and sanitation. 

And since there’s no water required, you can set these up anywhere, making them preferable for recreational centers and parks.

Tips for Surviving a Vault Toilet Experience

Your first experience with a vault toilet may make you feel incredibly grateful for your modern plumbing at home. And you may walk away with mad respect for our ancestors who had to use these outhouses as a permanent bathroom solution for hundreds of years. 

To help you survive a vault toilet experience, we’ve gathered a few helpful tips. Following these suggestions can keep you safe and unscarred from your vault toilet experience.

  • Examine the surroundings before entering. Since most vault toilets are in rural areas, check for flies, spiders, wasps and other stinging insects, and snakes. 
  • Another suggestion is always to bring toilet paper. There’s no guarantee the vault toilets get regularly checked. You might be SOL without TP. Or, you’ll be stuck with the thin one-ply kind that leaves you chafed and unclean.
  • Show respect for other users by not putting the trash into the toilet. Feminine products and other trash can cause blockages. Bring a small trash bag to dispose of any trash, as many toilets will not have a garbage can.
  • There may or might not be a working sink in vault toilets. At a minimum, bring hand sanitizer to clean your hands. You could also bring a bottle of water and a small bar or bottle of liquid hand soap.

4 Ways to Reduce Bad Odors From a Vault Toilet

Positioning a vault house in a location where the vent gets an ideal amount of sunlight is one of the best ways to reduce odors. The wind is your second best way to remove foul odors.

But there’s going to be times when the vault house doesn’t get an adequate amount of wind and vent. Here are four additional ways to reduce odors from a vault toilet.

  • Light a match or strike a lighter and hold it up to the vent. The flame will react with the gases, eliminating the odor.
  • Add an organic filler into the vault. This material will transform the ammonia and hydrogen sulfide – what causes the smell – into nitrogen gas, which is odorless.
  • You can also deodorize the gas with activated carbon.
  • Some places decide to bury long pipes that move the vault’s wastes to an uninhabited area, like deep forest areas.

Pit Toilets vs. Vault Toilets

Many people get confused about the difference between pit toilets and vault toilets. They have the same basic concept of a toilet that neither needs water. 

But with vault toilets, the waste stores in an underground container, which is routinely drained and sanitized to remove the waste. On the other hand, pit toilets have a trench dug under the toilet where the waste goes. This waste stays in the hole and decomposes into compost.

Vault Toilet Alternatives

Some vault toilets are so horrendous and terrifying that you’d rather skip a bathroom break all together than risk walking in the door. There are alternatives you can use if you want to avoid the potential horrors of a vault. 


Cassette toilets are a small portable commode that you can take along for use in vans, tents, RVs, or boats. These devices work by attaching a toilet lid to a removable waste storage tank. 

You can empty these after each use or full by dumping the wastes in a regular toilet or transporting them to a waste dump station. Most campgrounds have these facilities on site. Replace the tank on the toilet when empty.


Composting toilets are a dry toilet that does not require water to flush. The waste empties into a bin that’s filled with sawdust or peat moss. These ingredients cause the waste material to turn into compost. 

You can then use this compost on your flower beds. It’s not for use in vegetable gardens or on any plants that humans will consume.

How to Maintain Your Vault Toilet

All types of toilets, including vault styles, can attract disease-carrying organisms and harmful bacteria. It’s essential to keep your vault toilet sanitized and regularly emptied. 

Another way to keep a vault toilet sanitized and safe is to add septic treatments. A great option is RTB 760, which will disinfect the space.


Vault toilets are an everyday staple on campgrounds, national parks, and properties run by the U.S. Forest Service, and road stop rest areas. Some of these toilets are well maintained and have a “sweet smell” due to proper ventilation. But others can be terrifying enough to come right out of a Hollywood horror scene. We’ve told you everything to know about vault toilets. 


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