Eco-throne: dry composting toilet

The Eco-throne is our latest iteration of our dry composting toilet. It looks good, smells good, and is eco-friendly. This is the perfect composting toilet for our PanGoPods, for other Tiny Homes, informal dwellings, for cabins, or even for a traditionally-plumbed household.

Eco-throne composting toilet
Eco-throne composting toilet “in the wild”, can fit in nicely with any existing plumbing fixtures.

Why are we re-thinking the toilet?

1. Access to safe and clean sanitation

For millions of South Africans living in informal settlements, and particularly women and children, safe and equitable access to decent sanitation options remains a major problem. Ultimately, we need to help folks move into formal housing which has adequate sanitation. Until that happens, a portable dry composting toilet, such as the Eco-throne, provides a great way for residents in informal settlements to have a safe, clean, and private sanitation option in their dwelling. We would like to get to a point where we donate an Eco-throne for every Eco-throne sold.

2. Water security

A traditional flush toilet flushes away 10 L of perfectly good drinking water with every flush. In the last decade there have been major innovations in this space, such as dual flush loos, and additional devices for reducing flush volume. However, as residents in drought situations (e.g. Cape Town in 2016 to 2018, or the Eastern Cape in 2018 and 2019) can attest, when Day Zero approaches, even low-flush volumes can be difficult to provide (even if you are using grey water for loos). Water scarcity and reduced water security will only increase in frequency with Climate Change, and our “new normal” needs to include approaching sanitation differently. Even beyond Climate Change or Day Zero factors, there are still millions of South Africans in informal settlements who don’t have adequate access to safe drinking water – let alone water for flush loos. The Eco-throne, or a different dry composting toilet, provides one possible solution to the problem.

3. Off-gridding

Worldwide, there is a movement away from relying upon large-scale public or private utility providers. Just as off-grid solar can help a household move away from relying upon Eskom (in South Africa), using an Eco-throne can help a household move away from relying upon government sanitation services. One of the concerns in Cape Town from 2016 to 2018 was how solid waste might clog up the sanitation system as Day Zero loomed. There was talk of requiring a “royal flush” during which Cape Town residents would be asked to simultaneously flush around the city to provide enough water velocity in the system for unblocking pipes. This sort of possible crisis can be prevented with widespread use of the Eco-throne. In your own household, a dry composting toilet, such as the Eco-throne, provides a great option at all times, but especially during crises, such as Day Zero events.

Eco-throne composting toilet - functional and aesthetically pleasing!
Eco-throne composting toilet – functional and aesthetically pleasing!

How does it work?

There is a funnel below the seat of the Eco-throne that diverts urine to a collection tank. This collection tank can easily be emptied. If you live in a PanGoPod, you empty this into a greywater collection tank that dilutes the urine. Urine is sterile (except in the case of urinary tract infections) and in diluted form is an incredible fertiliser. If you live in a traditionally-plumbed house, you can periodically empty the urine into a regular toilet, and use one flush to remove several litres of urine, without having to leave urine standing in the toilet bowl.

Solids and paper go into the bucket in the loo. When you are finished you place some cover material over the top (something like sawdust). The bucket can be vented to the outside. With the airvent and the cover material, the contents dry out and leave no odour. When the bucket needs emptying, it can be taken outside and emptied into the compost tumbler that we supply. Composting bags can be used to line the bucket to make this process a little easier (but this is not required). The compost tumbler should be rotated every three days. In the sun, the tumbler heats up, killing any pathogens, and within a few months the contents have decomposed to form compost.

Learn more …

You can find out more about composting toilets in general from the Green Building Alliance, and the Global Water Pathogen Project. You can find out more about our off-grid PanGoPods in which we use the Eco-throne, here. You can also contact director@thebdi.org if you have any questions or would like to order an Eco-throne.