Tiger worm toilets – all you need to know!

  • Date: May 14, 2022

Tiger Worm Toilets, also known as vermifilter/vermicomposting/tiger toilets, contain worms that digest human waste and turn it into a rich vermicompost. Trialed in a variety of settings, Oxfam have installed more than a thousand of these toilets – and they seem to have been successful for use both individually and communally. This is perhaps no surprise. Although they require water and a worm supply, once installed they are cheap, less smelly and easy to maintain. Let’s take a closer look…

Advantages of tiger worm toilets (TWTs)

Fairly inexpensive

Despite costing a similar amount to put in place as a standard latrine pit, over the course of their lifespan TWTs are thought to be more cost-effective. Once they are installed, they do not need much maintenance or regular emptying. The standard pit, on the other hand, requires a sludge treatment infrastructure in place – much more complex.

Less odor

When compared with a standard pit latrine – a common sanitation solution – they also prove to be less smelly and more hygienic. Due to the aerobic digestion process, the TWTs do not have the same bad odor as different sanitation solutions. As well as having less disease-carrying flies in the vicinity, the lack of unpleasant odor makes toilet use a more attractive proposition. More hygienic all round!

TWTs are eco-friendly

Vermifilter toilets don’t need any chemicals to run smoothy. They don’t need any electricity either.  Once set up, they maintain themselves. It really can be a perfect sanitation alternative to some communities. As well as not harming the environment, they are also contributing to it by producing a rich vermicompost.

Simple maintenance/emptying

TWT are extremely convenient in terms of how often they need emptied. They tend to only need emptied every 3 to 5 years. The design of the toilets generally makes them easier to empty too with the compost level monitored through a hatch and easily emptied with a spade.  

Disadvantages of tiger worm toilets

Worms needed

Composting worms are needed – this adds an additional cost to the toilet cost, whether these are bought or produced in a wormery.

Worms in the toilet may be a bit off-putting for some people – but these can’t wriggle up the toilet seat and if they are kept in optimal conditions they won’t even want to escape. Why would they with such a feast?! More information about the composting worms can be found here.

Although composting worms can be easily found in many countries worldwide, they may not be straightforward to source in sufficient amounts. Reproducing your own from an initial batch can be achieved fairly easily with a homemade wormery. However, this adds time and cost to the process. It can take two months to double the weight of a batch of worms – not a quick process!

Some water needed

Water is required to ensure that the worms have a moist environment to digest the waste. It requires between 1 and 1.5 liters of water after use. In areas that water is in short supply, this TWTs may not be suitable. Dry composting toilets may be a better option in these areas, although they come with their own different set of pros and cons.

Soil infiltration

Water must not fill the pit under any circumstances.  It is vital that the soil can absorb the fluid output from the TWT and the water table must not rise into the pit. Infiltration assessments must take place before selecting the appropriate design for the pit. In some areas they may simply not be practical, despite design alterations.

The bottom line

Although TWTs have several benefits, they are not ideal for all communities. Water is needed after each use and adequate soil irrigation is required. However, if these two conditions are in place, TWTs can be an eco-friendly, inexpensive and less smelly alternative to other sanitation solutions. Less regular emptying and the production of nutrient rich vermicompost make the TWT even more appealing. It is a great sanitation solution all round.