5.0 Dry compost toilet

Introduction

This system is based on a urine separation toilet, an 80-litre industrial wheelie-bin worm processing compost container and an air vent.

The compost container is located under the house in a rodent tight plywood box.

A full wheelie-bin is replaced with empty ones as required. The composting process continuous in the wheelie-bin for one year, then transferred to a nearby composting facility where it is left for another year.

5.0 Dry compost toilet

Introduction

This system is based on a urine separation toilet, an 80-litre industrial wheelie-bin worm processing compost container and an air vent.

The compost container is located under the house in a rodent tight plywood box.

A full wheelie-bin is replaced with empty ones as required. The composting process continuous in the wheelie-bin for one year, then transferred to a nearby composting facility where it is left for another year.

The following key features of the set-up are explained in more detail below:

· Urine Separator

· Compost Container

· Cover Material

· Vent Fan

· Composting Facility

· Management Considerations

The Urine separator is a pre-fabricated ceramic toilet that excludes urine from the solids receptacle and sends it to the 500 L urine storage container for dispersal as fertiliser. The fertiliser will be used only outside of main traffic and potential kids play areas, and away from vegetable crops.

The following key features of the set-up are explained in more detail below:

· Urine Separator

· Compost Container

· Cover Material

· Vent Fan

· Composting Facility

· Management Considerations

The Urine separator is a pre-fabricated ceramic toilet that excludes urine from the solids receptacle and sends it to the 500 L urine storage container for dispersal as fertiliser. The fertiliser will be used only outside of main traffic and potential kids play areas, and away from vegetable crops.

Compost Container

for solid human waste located

under the suspended timber floor

Cover material

· A cup or two of cover material is sprinkled on top of each toilet deposit.

· The material comprises of a mixture of garden soil/compost (microbe source), and untreated sawdust/wood shavings (carbon source) and fine gravel (air source).

· The cover material performs several functions:

- to cover deposits to reduce odour

- this also reduces attractiveness to flies

- provides a carbon source for subsequent composting

- provides a diverse microbe source for subsequent composting

- Improves the aesthetics of the toileting experience.

- And looks something like this.

Urine distribution

Vent fan

Installed in the same cavity as the collection container, the fan fits inside a 100mm PVC pipe and is vented above the roof line, ensuring consistent negative pressure in the air around the bucket, removing all possibility of odour in the toilet room.

Composting facility

Full compost container are stored for one year, maintained checking the needs of the worms, then emptied into the composting facility and is then left to break down further through worm and microbial activity. The youngest material will be no less than two years old when it is used as mulch around ornamental perennial plants or in their planting holes. Finished compost is only to be used outside of main traffic and potential kids play areas, and away from vegetable crops.

The composting facility is:

· Fly proof, rain proof and rodent proof.

· Nearby and easily accessible.

· Open to the soil below to allow free movement of worms and microbes.

· Split into 3 compartments of 0.3 m3 each – this sizing is very conservative and provides ample time for the 1^st compartment to fully mature and be used up before the 3rd compartment is full.

· The compost facility will be of timber construction and resemble the image shown above, with the addition of: a cover to keep rain water out and 10 mm welded galvanised mesh underneath to exclude rodents while maintaining contact between the compost and the soil.

Management considerations:

· It is expected that with a family of 2, the wheelie will need changing approximately every 4^th month, and the changeover will take 3-5 minutes.

· Long rubber spray gloves are always to be worn when moving buckets of fresh material.

· Three spare containers with lids will allow for a quick change and give time before emptied into the compost facility.

· All full containers will be topped off with a layer of cover material and transported (and potentially stored short term) with lids on, reducing potential for contact with raw material.

· After emptying a container into the compost facility, it will need cleaning with a dedicated brush prior to re-use.

· Each new bucket going into the toilet will be primed with a layer of cover material including worms and efficient microorganism for an easy composting start.

· All wash water is to be tipped onto the top of the active compost bay.

· Standard composting procedures such as laying a base of carbonaceous material under each new pile will mitigate any potential leachate from leaving the compost.

The system is simple, relying on no complicated contraptions. Simple hygiene considerations and easy clean design and build detailing will see this system operating effectively for many years.