Why can some commercial composting facilities take compostable packaging and some not?

In New Zealand, commercial composters use a variety of methods to create compost such as windrow,  aerated static piles; vermicomposting or in-vessel methods and the compostable items that go into a commercial composting system are called feedstock.

Composting facilities need to apply for a resource consent to operate and the conditions of the resource consent can limit and/or restrict the type of feedstock they can accept.  Composting facilities in New Zealand can generally be classified as:

Greenwaste processing facilities

These facilities process garden waste, bark and wood chip to make compost or mulch and generally don’t have a resource consent or an appropriate composting process to accept food waste or compostable packaging.

Industrial composting facilities

These facilities process complex waste streams such as food waste, waste from abattoirs or fish processing facilities, sludge etc. and are more likely to be able to process compostable packaging. However, resource consent conditions can vary and may not allow for compostable packaging.

Litter is an issue as lightweight compostable packaging is susceptible to being wind-borne and litter management is a requirement of a commercial composter receiving a resource consent. This is particularly problematic if a composting facility is located near waterways or the ocean. 

Other reasons that composting facilities may be unable to accept compostable packaging include:

• contamination issues (i.e. unwanted materials ending up in the mix)
• a lack of means to clearly identify certified compostable materials
• the length of a facility’s processing time
• issues with ratios of nitrogen-rich material (i.e. garden and food waste) versus carbon-rich material (i.e. compostable packaging)
• organic input restrictions, for example, organic certification (such as New Zealand’s BioGro organic certification) excludes any PLA (polylactic acid, plant-based plastic) feedstock.

To view the up-to-date list of commercial composting facilities and community organisations in Aotearoa New Zealand that currently accept compostable packaging (subject to each facility’s specific criterion) please click here.