Ensuring compost quality and compliance
By
Virginia Brunton
This report is general in nature and readers should not rely on it for compliance in any particular jurisdiction
This post is a copy of a report Virginia Brunto provided in April 2025 to LOccal and will be published on that website soon. LOccal is a national body representing local composting people and organisations across Australia.
Dear Michael,
RE: Ensuring compost quality and compliance
Introduction
Producing compost for use beyond the gate carries with it responsibilities in terms of human and environmental health. The users of compost expect that it will be beneficial, safe and provide positive soil health outcomes, and one would accept that there is a general, personal or moral obligation not to pollute or to cause damage to someone else’s garden or land.
The questions posed to me from this alliance therefore were:
1. What regulations and standards apply to small scale community composting enterprises?
2. How can we ensure that our products are safe, beneficial and comply with standards?
Regulations and standards
Licence thresholds
Each state has regulations that apply to the processing of organic wastes. Through licencing, these regulations ensure the environmental performance of facilities by controlling the amount and type of waste received, approving the type of infrastructure or processing system and placing limits on odour, traffic, location and operating hours etc.
The requirement to have a licence (or environmental approval – each state has different terms) is based on a receival tonnage threshold.
• Table 1 State regulations and licencing thresholds for composting facilities
1 Note that in NSW the Resource Recovery Framework includes specific orders and exemptions that allow and describe the restriction on use of particular wastes. The Compost RRO/E is one such document. IF a compost producer is under the licence threshold the Orders and Exemption do not apply, therefore small operators do not need to meet the conditions of the Compost RRO or RRE.
Compost Standards
The Australian Standard for Composts, Soil Conditioners and Mulch AS4454 -2012, is a voluntary standard that sets out the minimum requirements for compost quality and processing. It is supported by industry and actively used as a marketing standard. It provides limits and thresholds for physical, chemical and biological contamination as well as descriptions of process controls – time and temperature criteria to achieve pasteurisation.
Many of the criteria listed in AS4454 are relevant to composts for most applications, as they specify the basic suitability of compost for land applications.
The general product specifications for composts are presented in Table 2. These are provided for reference and guidance.
• Table 2 General product characteristics for compost (Reference: AS4454)
Acceptable contamination levels
All commercially produced composted recycled organics are likely to have some level of physical and chemical contamination due to feedstock contamination. However, composts made from specially sourced and controlled local organics waste should be free from the types of contamination seen in kerbside organics.
Table 3 provides the maximum acceptable levels of contaminants.
• Table 3 Maximum acceptable level of contaminants
Testing products to meet these requirements is expensive and not required for non-commercial, non-licenced producers. However, compost producers should ensure products are safe. The following provides some measures that can be used to assess compost quality in a low-cost manner.
Compost quality assessments
At a minimum compost should be pasteurised, have little or no physical contamination and be mature enough as to not cause damage to plants, gardens or crops.
Table 4 sets out methods that can be used to assess these parameters for small scale composting systems.
• Table 4 Methods for assessing and ensuring compost quality
These test methods are affordable and able to be conducted by the producer with minimal effort. Routinely maintaining records and conducting these tests will provide some surety that the composts produced will perform as expected and pose minimal risk to the environment, animals or humans.
Please feel free to contact me for more information or support.
Yours Sincerely,
Virginia Brunton / Director Organics and Sustainability