New South Wales Is Modernising the “Approved Methods”
In March 2026, the NSW Environment Protection Authority (EPA) launched a major review of the Approved Methods for the Modelling and Assessment of Air Pollutants, the statutory framework that underpins how air emissions from stationary sources are assessed across the state.
The consultation, open until 4 May 2026, represents the most significant update to the Approved Methods in many years. For industry, developers, and environmental practitioners, the review signals a clear shift toward more contemporary, data‑driven, and site‑specific assessment practice.
Why the Approved Methods Matter
The Approved Methods define how emissions must be modelled and assessed for facilities regulated under the Protection of the Environment Operations Act. They are routinely applied to projects involving:
- Industrial facilities and processing plants
- Mining and extractive operations
- Landfills and waste facilities
- Energy and infrastructure projects
- Large remediation programs
Where the EPA or a statutory approval references the Approved Methods, their application is not optional, they are the benchmark against which impacts and compliance are judged.
For many projects, alignment (or misalignment) with the Approved Methods can influence approval timeframes, mitigation requirements, and ongoing regulatory scrutiny.
What Is Driving the Review?
According to the EPA, the review is intended to ensure that air quality modelling in NSW reflects contemporary science, modern technology, and emerging risks rather than legacy assumptions or outdated tools.
Several factors are driving this modernisation:
- Advances in dispersion modelling and meteorological analysis
- Increased expectations around transparency and reproducibility
- Greater emphasis on cumulative and episodic impacts
- Evolving community expectations around air quality and amenity
- Alignment with the NSW Clean Air Strategy and climate policy
In practical terms, the EPA is signalling that historical “business as usual” approaches may no longer be sufficient for complex or high‑risk proposals.
Key Themes Emerging from the Draft Updates
While the draft Approved Methods span a wide range of technical detail, several consistent themes are evident.
- Greater Emphasis on Site‑Specific Data
The EPA is actively promoting the use of site‑specific meteorological, source, and operational data over generic, regional or default inputs. This reflects a growing recognition that local conditions can materially influence impact outcomes, and that generic datasets may mask worst‑case or episodic risks. For proponents, this may mean more upfront data collection, but also the opportunity for more realistic and defensible impact assessments.
- Modernised Modelling Expectations
The draft updates seek to modernise accepted modelling tools and approaches, with a focus on improving consistency and accuracy across assessments. Reliance on legacy dispersion models or unsupported assumptions is increasingly likely to draw scrutiny, particularly for proposals in sensitive or constrained environments.
- Clearer Triggers for Mitigation
The EPA is proposing clearer guidance on when mitigation is required, rather than relying solely on compliance at discrete assessment points. This is particularly relevant for pollutants characterised by short‑term peaks, intermittent emissions, or strong meteorological dependence.
- More Prescriptive Treatment of Dust and Odour
Dust and odour, two of the most common drivers of community complaint, receive explicit attention in the draft updates. The proposed changes include more prescriptive requirements for dust control and updated approaches to odour assessment, including in non‑urban environments where traditional criteria can be difficult to apply.
Implications for Projects and Approvals
For new developments, major modifications, and remediation projects, the revised Approved Methods are likely to affect:
- The scope and timing of baseline data collection
- The level of conservatism expected in modelling inputs
- The evidentiary burden placed on proponents
- Approval timeframes where methodologies are contested
Projects that rely heavily on older modelling studies, generic buffers, or screening‑level analyses may face increased requests for justification or re‑assessment once the updated methods are finalised.
Why Early Engagement Matters
Although the consultation closes in early May, the practical effects of this review will extend well beyond 2026. Once finalised, the updated Approved Methods will reset regulatory expectations across NSW.
Projects already in planning (or likely to enter assessment over the next 12–24 months) should be considering now whether their air quality strategies will remain fit‑for‑purpose under the modernised framework.
Early, realistic, and well‑scoped assessments are consistently associated with smoother approvals and fewer downstream surprises.
How PJRA Can Assist
PJRA works with proponents, regulators, and planners to navigate changes in air quality regulation and guidance. We support clients by:
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Interpreting draft and final Approved Methods updates
- Reviewing existing assessments against emerging expectations
- Designing site‑specific monitoring and modelling programs
- Preparing regulator‑ready air quality and odour assessments
If your project relies on air quality modelling, or if you are preparing submissions to the NSW EPA consultation, now is the right time to engage.