For tiny houses with a plumbing system similar to a regular house, discarding grey water and black water shouldn’t be a big problem. But if you prefer the tiny house to be off-grid, dumping water wastes might be an issue.

So what are the best tiny house greywater and blackwater maintenance practices? Firstly, grey water and blackwater should have designated dump stations. Grey water can still be stored and recycled to a certain extent before dumping. Blackwater, on the other hand, can be collected and disposed of using different toilet types such as regular, macerating, dry flush, composting, and incinerating.

The Basics of Tiny Home Plumbing

Before planning the plumbing system of a tiny house, it’s important to determine first if the tiny home will be on-grid or off-grid. On-grid tiny houses have lines connected to a city or an RV park. 

On the other hand, off-grid tiny homes utilize separate water tanks for their clean water supply and liquid wastes.

So what’s the difference between grey water and black water? Grey water is the dirty water collected after a shower or washing the dishes in the kitchen. Black water typically holds the human waste that accumulates in the toilet. Typically, both wastewaters have designated dumping sites. But in reality, it might be hard to spot the nearest dumping site especially when you’re constantly traveling from one place to another. 

Knowing how to effectively manage your wastewaters, even without consistent access to dumping grounds, is crucial to keeping your tiny home sanitary. 

Different Ways to Recycle or Get Rid of Grey Water

Grey water is the non-sewage water in your tiny home. It’s dirty because it contains soap, dirt, food, grease, bacteria, and traces of house cleaning products. Your first instinct might be to empty your greywater tank as soon as it’s full. Consider recycling it first before emptying it and dumping it out of your tiny house. 

Recycling Greywater

Recycling greywater is simple. It’s commonly used to water non-edibles in gardens or as an extra source of water your tiny house may need. 

There are a few things to consider when building a grey water system for a tiny house:

  • Different states have varying regulations for grey water. Be sure to check with the local authorities first before building a grey water system. Skip this step and you might be slapped with a non-compliance fine. 
  • Create a system that won’t store the grey water inside the tiny house for more than 24 hours. Storage can cause some of the nutrients to break down immediately, leading to foul odors and decay. 
  • Build the system so that it won’t be in contact with human waste or animals. It might get contaminated on its way to the plants.
  • Make sure that the recycled grey water only pools in one place like a dedicated water tank. It’s also important to research different plants and whether using greywater is a viable source of hydration.
  • Start using natural and biodegradable products whenever you clean the tiny home’s shower. Utilizing products with harsh chemicals might pollute the soil and plants.

Bucket

The simplest, if not a little medieval way, to collect greywater in a tiny home is by placing a bucket under the sink or in the shower. Once the bucket is filled, use the greywater to water the plants. If the tiny house has a standard toilet, grey water can also be used to flush out human wastes.

Filtration Buckets

Gravity water filtration buckets can also help filter contaminated water so it’s a lot cleaner when you reuse it. This simple system doesn’t need plumbing or electricity to work – gravity and the water’s weight will do all the work for you. Gravity water filters can be bought in the market but building one of your own is a lot cheaper at $75 - $100. Here’s how to build one that surely works:

  1. Gather the materials. You will need:
    • Two plastic buckets (preferably food-grade, but anything works as long as they have lids and are not damaged)
    • Dome water filter
    • Spigot
    • Drill
  1. Drill a hole into the lower bucket where the spigot will be secured. Ensure that there will be no leaks.
  2. Place the water filter on the bottom of the upper bucket. Use a marker to measure it and drill the bottom surface of the bucket.
  3. Get the lower container’s lid and put it below the upper bucket. Drill a hole onto the lid to match that of the upper bucket.
  4. Put both containers together. Don’t forget to install the dome filter inside the upper container.

Wetland

Even after recycling your greywater, there’s still bound to be some excess from time to time. If this happens way too often, creating a wetland might be a great idea. A wetland is a small marshland or pond that filters contaminants from the greywater. The filtered water is then directed somewhere it is needed.

This option might only be viable for tiny house owners who don’t move their tiny home as much. Setting this up can be particularly complicated for people who don’t really need a constant supply of filtered water to water their gardens.

Branched Drain System

A branched drain system doesn’t involve filtering the greywater. Instead, it redistributes the wastewater from the tiny house over to a wider area. If you have smaller plants around the tiny house, this system is ideal to keep them watered.

In this system, water flows freely into drains that split into smaller branches leading to a mulch basin. What’s great about this water drain system is that it can be recreated with simple tools. All that’s needed is a garden hose manifold connected to multiple hoses.

Different Toilet Types for Blackwater Collection and Disposal

One of the many challenges when it comes to living in a tiny house is the disposal of human waste. Unlike greywater, black water should be disposed of immediately because it contains toxic substances. It’s particularly challenging for off-grid tiny homes that don't have access to regular sewage systems.

Thinking twice about what toilet you put in your tiny house is essential, especially if you’re going off the grid.  Here are six of the commonly installed toilet types:

 ProsCons
Regular ToiletYou’re already familiar with how it works.It needs to be connected to a sewage system.
Composting ToiletIt is cheap to build and it can produce rich compost.Homemade versions might produce unpleasant smell if not created right.
Macerating ToiletIt works similar to regular toilets but requires less plumbing.You may need the help of a professional to install it.
Incinerating ToiletIt works in any climate and doesn’t require water.Commonly one of the more expensive toilet types. 
Dry Flush ToiletIt is odorless and easy to maintain.It won’t be as environmentally friendly as other options because the waste can’t be used for compost.
Biogas Digester ToiletIt produces usable biogas for cooking. It’s also a good idea to combine this with composting toilets.It’s not ideal to be used at places with low temperatures.

Regular Toilet

Regular toilets are something all of us are familiar with. If you’re planning to have a tiny home fixed in one place, regular toilets can be connected to a sewer or septic system. It might be a great choice if you’re not willing to get used to an alternative toilet just yet.

Composting Toilet

With this toilet type, bacteria naturally breaks down the waste. For an effective composting toilet, only three things are needed:

  1. Ventilation – allows the aerobic processes to take place and break down the waste.
  2. Urine Diverter – separates the water containing urine from the solid waste.
  3. Bulking materials – like coconut husks or sawdust encourage good bacterial growth for a faster decomposition process.

Macerating Toilet

Macerating toilets are similar to regular toilets in terms of structure. The only difference is that macerating toilets grind the waste, producing liquid slurry that’s easier to store or dispose of. This toilet is fully functional even with little water, as long as there is electricity.

Incinerating Toilet

Incinerating toilets are commonly used by people at sea or those with remote cabins. It’s an effective disposal system that burns the waste as soon as you’re done in the bathroom. They were made to look like regular toilets, but once it’s done burning the waste, all that’s left is sterile ash.

The main problem with incinerating toilets is that they don’t exactly produce pleasant smells as they burn the waste. However, manufacturers claim that recent models were made to address this problem.

Dry Flush Toilet

Instead of storing the waste or composting it, dry flush works by wrapping the waste for easy dumping. It works similar to regular toilets, except when you press the flush button, water doesn’t come out to flush the waste down. Instead, the wrapping material moves down and twists the bag, making it easier to dispose of the sealed container.

Dry flush toilets work on battery power alone. They can be bought for around $500 per unit.

Biogas Digester Toilet

If you’re going for the most environmentally-friendly option for a toilet, a biogas digester toilet is a right choice. Aside from breaking down the waste through bacterial anaerobic digestion, it can also produce cooking gas and organic fertilizer.

The toilet looks like a regular one, but biogas digester toilets utilize systems of tanks filled with bacterial colonies. The whole process produces carbon dioxide and methane, some of the components found in biogas.

The Importance of Maintaining Greywater and Blackwater in a Tiny Home

For a healthier tiny home, it’s important to dispose of wastewater regularly. If the tiny house is on-grid, there won’t be much problem since the plumbing system works just as it would in a regular home.

But if you’re living in a tiny house on wheels and off-grid, trying out alternative disposal systems might be more helpful. It keeps the tiny home clean as you wait around for the next designated disposal site to discard wastewater.

About Us

Manuela and Ivan from Tiny House Bloom

Hey, there! We're Ivan and Manuela from Croatia, and we're crazy about tiny houses. We don't own one (yet).

This website is a result of our passion to share all the knowledge, photos, tips and tricks that we were able to learn while studying everything possible about the tiny house movement.