WHEELIE BIN COMPOSTER FOR COMPOSTING TOILETS
SPARK HOSTED WORKSHOP
AUG. 9, 2025
10:00 AM– 4:00 PM
Hornby Island’s SPARK, in association with Aquarian Systems, will be hosting a one day workshop to build a composting bin for composting toilets. Participants will learn how to modify a 240 litre wheeled recycling bin so that it can be used to compost humanure.
Bins and all other materials will be supplied by SPARK. The bins are rated for use for organics. Other wheeled recycling bins are not suitable because most of them have a steel grab bar for machine pick up. These bars penetrate the body of the bin allowing compost leachate to leak out, contaminating the space the bins are in, and creating a potential health hazard.
An effective compost chamber allows for drainage and ventilation. Without effective drainage, liquids in the compost drain to the bottom of the mass creating anaerobic conditions not suitable for good composting. Durable materials (stainless steel) will be provided to create a raised floor from the bottom of the bin, to facilitate drainage. A vent pipe will channel air from the top of the bin to the bottom space allowing for air to be available to the bottom of the mass to aid the composting process as well as to be available for worms (red wigglers) to work their magic, while they dine on their bounty, transforming the humanure to worm castings.
A drain will be installed near bin bottom in order to drain off the liquid precipitating from the pile. The vent pipe providing air to the bottom space is designed so that water can be introduced in the top of the pipe in order to flush out the slurry that inevitably builds up. This is flushed out the bottom to drain to a suitable location or receptacle.
These bins can be used in a number of ways. If there is enough room beneath the bathroom floor, they can be placed directly beneath the throne, to fill directly. Approximately 48” headroom is required beneath the floor joists. When the bin is full, it can be wheeled out to be placed in a suitable location for processing until fully matured/cured. Another bin is then put beneath the throne while the first one is composting. The number of bins can be added to, depending on the number of residents using the system.
If there is not enough room under the floor to place a bin, then a smaller receptacle can be used directly beneath and then emptied into the bin until the bin is full. This bin is then set aside for composting while a second one is filled. This is similar to the ‘Humanure’ system that uses a five gallon container system that gets emptied every few days into an active composting bin. One can see the Humanure systems online.
In order to provide air to the top of the compost mass, there is a second vent near the top of the bin that allows the mass to breathe from the top and to facilitate air flow from the bottom to the top of the pile. If the bin is placed beneath the bathroom floor, this top vent can be hooked up to a 4” pipe that vents up above the roof of the house, thus eliminating odours from the toilet area.
This workshop is for those who are handy with tools and would like to learn how to modify one of these wheeled bins for their personal use, or if one is so inclined, offer a service providing compost bins for people wanting to purchase one. Their is a potential business here for someone.
The cost of the workshop is $395.00. This covers the cost of one bin, materials, and use of the SPARK space and tools, and $345.00 for a second bin and materials. It is highly recommended getting two bins right off, as a second one will be needed when the first one is full. These bins (specifically designed for organics and no grab bar) are only available by the pallet (11 bins) at wholesale cost. There is no local retailer for them and the wholesaler will not sell less than a full pallet at a time.
Maximum number of participants is 10-12 people. Sign up early to make sure you get a space. Registration deadline is July 15th. We need to know the number of registrants in order to procure enough bins and materials for everyone. Payment will be required at time of registration to pay for materials.
To register contact Peter Mills at (250) 335-1847. For more information call Peter or Ed Hoeppner at (250) 335-2037.
Detailed photos and description of the bins can be seen at aquariansystems.ca.
