The Environment Protection Act 2017 and the Environment Protection Regulations 2021 outline how waste needs to be managed in Victoria.

The act is a duties-based framework, with the general environmental duty (GED) at its centre. The GED requires anyone engaging in an activity that may give rise to risks of harm to human health or the environment from pollution or waste to minimise those risks so far as reasonably practicable.

In addition to the GED, waste duties apply to all businesses that generate, transport or receive waste. This means if your business generates, transports or receives industrial waste, you must comply with duties on how you manage the waste and where it goes. This includes digestate.

Digestate is the waste output from anaerobic digestion, an organic recovery process that generates biogas, which is used to create heat and energy.

Digestate can improve plant growth and soil quality, reducing the need for fertilisers. But it can also pose a risk to the environment and human health if the risks are not appropriately managed, such as the presence of contaminants, air emissions and contamination of land. That’s why it’s important to process, transport and use digestate safely.

This guide provides an overview of the requirements that apply to digestate. It is intended to help producers, transporters and receivers of digestate to implement their obligations and to manage the risks of harm to human health and the environment.

It covers:

producing digestate
transporting digestate
applying digestate to land
receiving digestate for secondary processing
unpasteurised digestate
on-site management
complying with the designation.

This guide does not:

Provide detailed industry-specific guidance on controlling risks associated with other industrial wastes, such as other agricultural wastes. See the ‘Resources’ section of this guide for references to other useful information.
Cover other laws that may apply to anaerobic digestion or digestate in Victoria, for example
- Agricultural and Veterinary Chemicals (Control of Use) (Fertilisers) Regulations 2015 (Victoria)
- Livestock Disease Control Act 1994 (Victoria)
- Agricultural and Veterinary Chemicals Code Act 1994 (Federal).

EPAs approach for regulating digestate

EPA classifies digestate as reportable priority waste in Schedule 5 of the regulations. The appropriate waste code is N205: Residues from industrial waste treatment/disposal operations, including digestate, bottom ash and char.

Those managing reportable priority wastes are subject to certain duties under the EP Act. These duties include requirements to track movements of the waste using Waste Tracker.

EPA has released two tools for managing low-risk digestate:

Designation - Classification of digestate for composting or other secondary processing or use
Determination – Specifications acceptable to the Authority for receiving digestate.

The designation allows you to reclassify low-risk digestate. Low-risk digestate means digestate that meets the specifications of the designation. If the digestate meets the specifications, it will no longer be reportable priority waste. This means permissions are not required to supply and transport it. It also means waste tracking is not required. But digestate remains industrial waste and priority waste and the duties for industrial and priority waste still apply.

The determination creates a lawful place for digestate classified under the designation. This allows a person or premises to receive low-risk digestate for use such as land application, without a permission for the activity.

These tools can apply to anyone managing digestate, if they meet the conditions.

Requirements for managing digestate

Producing digestate

As a producer of digestate, you must abide by the industrial waste and priority waste duties. These are detailed within guidance (EPA publication 1990.1) Managing industrial waste – Your duties as a waste producer.

You must obtain the appropriate EPA permission for producing digestate. The designation does not remove the permission requirements for producing digestate. The type of permission required depends on your specific activity. Further information is available in EPA’s Permissions webpage.

However, you don’t need a permission to supply the digestate for use if you produce digestate that meets the conditions in the designation.

Unpasteurised digestate

The designation can apply to digestate that is not pasteurised.

You can classify unpasteurised digestate under the designation if it is being sent for composting to a permissioned organics processing facility (A07).

Digestate can be used as a feedstock for organics processing. Once organic processing is complete, you may be eligible to receive composted waste for use under the processed organics determination. This only applies if the processed organic waste meets the specifications in the determination. EPA Determination – Specifications acceptable to the Authority for receiving processed organics does not apply to digestate.

Transporting digestate

If you are transporting digestate classified under the designation, you do not need an EPA vehicle registration. Waste tracking is also not required.
However, the industrial waste and priority waste duties continue to apply. Your transport requirements are detailed with EPA’s Transporting waste webpage.

Receiving digestate

If you are receiving digestate, you have a duty to ensure that you only accept waste you are lawfully authorised to receive. This is called lawful place. Once you accept digestate, you must meet your GED.

Receiving digestate for application to land

The determination creates lawful place for low-risk digestate. This means a person receiving it for application to land does not need a permission for this activity.

Receiving digestate for secondary processing

Some duty holders may wish to further process digestate. You don’t need an A01 licence to receive digestate classified under the designation. You still must have an appropriately permissioned site.

These facility types may include:

A07 organics processing facilities, for incorporating into processed organics streams
A13 resource recovery centres, for secondary processing.

The permission for the premises must establish lawful place. The determination does not apply to activities that require a permission, such as further processing.

The permission must include the appropriate waste code to receive that waste type.

Onsite management

Onsite management means you’re managing waste all at the one premises. It is not taken offsite. This includes:

generation
processing
application to land.

Onsite management does not remove you from your obligations under the waste framework. The risk to the environment is the same whether waste is retained onsite or transported offsite.

If using digestate onsite, you should still follow the conditions of the designation. This information will help you comply with the waste duties and the GED. It also forms part of your state of knowledge.

How to comply with the determination

You can only receive digestate under the determination if:

it meets the requirements of the designation, which you confirm through the information that the waste generator provides; and
the activity for its use does not require a permission.

If you cannot meet these requirements, then you cannot receive it under the determination and you must therefore seek an EPA permission.

How to comply with the designation

The designation has three main risk control measures:

Feedstock controls
Pasteurisation requirements
Contamination thresholds

Feedstock controls

The designation specifies what feedstocks you can use for producing low-risk digestate. Some feedstocks are classified as elevated risk. Digestate produced with elevated risk feedstocks need additional pasteurisation. You can see the pasteurisation requirements below.

The designation does not allow biosolids or sewage sludge. This is due to the high risks of contamination from these waste types.

Pasteurisation requirements

The designation has two options for pasteurisation. You must apply one of these options to comply with the pasteurisation requirements of the designation.

Process-based pasteurisation
Outcome-based pasteurisation

Process-based pasteurisation

The process-based pasteurisation option uses time and temperature for reducing risk.

Low-risk feedstocks must meet one of the process-based pasteurisation requirements. Elevated-risk feedstocks must undergo both process-based pasteurisation requirements.

Digestion or pasteurisation requirements

Low-risk feedstocks

For anaerobic digestion (AD): maintain temperature at 55°C or above for a minimum of 72 hours

For treatment pre-AD or post-AD: maintain temperature at 70°C or above for a minimum of one hour.

Elevated-risk feedstocks

For anaerobic digestion (AD): maintain temperature at 55°C or above for a minimum of 72 hours

AND

For treatment pre-AD or post-AD: maintain temperature at 70°C or above for a minimum of one hour.

Outcome-based pasteurisation

The outcome-based pasteurisation does not rely on time and temperature for pasteurisation.

Using this option, you need control risks with:

a risk assessment
process validation
a monitoring program
microbial contaminant thresholds.

These requirements are specific to the outcome-based pasteurisation option. However, we expect you to understand this information to produce safe digestate.

Contamination thresholds

The designation sets out contamination limits for chemical, physical and microbial contaminants. The digestate cannot exceed the specified upper limits for any of the contaminants and pathogen indicators set out in Appendix 1 of the designation.

When using digestate, you should also consider the impacts of any other contaminants of concern, which may be present but are not be listed within the designation, and ensure that you are effectively managing your risks of harm and meeting your obligations under the GED.

Risk assessment

The risk assessment must:

identify potential biological hazards associated with the feedstocks and process used
show how the process reduces these risks
provide metrics and parameters for risk reduction
include assessment for typical and foreseeable atypical operating conditions and situations.

Validation

The outcome-based pasteurisation method must show:

a reduction in indicator organisms
the material is below the thresholds for microbial contamination.

Monitoring program

You must establish a monitoring program and implement it to ensure microbial risk reduction. It must include:

monitoring process parameters
adequate sampling
analysis to show the findings.

You must determine the frequency of monitoring and validation in line with best practice for risk management.

You must maintain the following documents and records:

the process and risk assessment of the process
validation test records
records of implementation of the monitoring program, including sampling and analysis
sampling and test records and analysis.

Disclaimer

EPA guidance does not impose compliance obligations. Guidance is designed to help duty holders understand their obligations under the Environment Protection Act 2017 and subordinate instruments, including by providing examples of approaches to compliance. In doing so, guidance may refer to, restate, or clarify EPA’s approach to statutory obligations in general terms.

It does not constitute legal or other professional advice and should not be relied on as a statement of the law. Because it has broad application, it may contain generalisations that are not applicable to you or your particular circumstances.

You should obtain professional advice or contact EPA if you have specific concerns. EPA has made every reasonable effort to provide current and accurate information, but does not make any guarantees regarding the accuracy, currency or completeness of the information.