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Composting Toilets

Composting Toilets

Updated 7 November 2016 11:13am

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Composting toilets are ‘waterless’ toilets designed to take toilet waste and turn the solid materials into compost. Some of the benefits of composting toilets include:

  • producing a useable product – compost / soil enhancer
  • Reduced household water consumption
  • Reduced household wastewater output  
  • No sewage outlet required
  • Reduced impact on the environment
  • Great for properties that are not used very often, such as holiday homes and bachs
  • Can be installed in areas which would not accommodate other systems, for example properties with a high water table.

Composting toilets come in various models based on the intended amount of use, and can be electric, non-electric, provided with mixers, ventilation, etc. A fully automatic composting toilet will typically control heat, ventilation and be equipped to mix sewage and mulch together. For example, some fully automatic toilets mix each time the seat is lowered.

To ensure the composting process is efficient, there needs to be minimal moisture in the system, therefore liquid waste is separated from the solid material and an organic bulking material (ie, sawdust, mulch, ground peat, chopped straw) is added to improve air circulation and speed up the composting process.

Depending on the type of system, a portion of the mature compost will need to be periodically removed from the toilet.

What you need to know about composting toilets

A composting toilet is a permitted activity under the Proposed Natural Resource Plan (PNRP), see Composting toilets, rule 72. This means that resource consent is not required provided the following conditions are met:

  • The discharge (compost) must be composted for at least 12 months from the last addition of raw wastewater before it can be used
  • Disposal of the compost must occur on the property where the composting toilet is located
  • The compost must not be used within 50 m of a waterway (ie, streams, ponds, springs), gully or groundwater bore. This is to prevent potential contamination of waterways or nearby drinking water supplies.
  • Any smells from the compost must not affect the neighbours.


1. A correctly installed and well-functioning composting toilet will not smell because there is a continuous positive suction of air through the toilet. Only toilets which are overloaded, or which have not been correctly installed or maintained, will produce smells. For further information available, please refer to:

2. To find out if you need a resource consent or if you are unsure about any of the conditions, please contact the Greater Wellington,  or 0800 496 734.

3. Approval may also be needed from your local city or district council. Please contact them directly for further advice.

example of a composting toilet

Source: Kiwibog







This information is intended to provide a guideline to the requirements of the Proposed Natural Resources Plan for the Wellington Region. Please also be aware of the requirements in the current operative plan as well as the provisions mentioned in this user guide.