For developers and planners working out whether a site near a landfill needs a landfill gas risk assessment or a full environmental audit. Last reviewed June 2026.
A landfill gas risk assessment is a focused technical study of whether landfill gas could migrate from a current or former landfill to your site and reach people or buildings. A Part 8.3 environmental audit is a broader, statutory assessment of contamination and risk on a site, carried out and certified by an EPA-appointed environmental auditor. They are not interchangeable: EPA Victoria's framework is staged and risk-based, and your site's circumstances decide which (if either) applies. The two sit at different tiers of the same process — a risk assessment is the lighter, scoped study, while an audit is the heavier, independently certified one.
When development is proposed on or near a current or former landfill, the council (as planning authority) and EPA Victoria's landfill buffer guideline (2024) determine what level of assessment your planning permit needs. The current guidance is the Landfill buffer guideline (EPA Publication 1950), alongside the Separation distance guideline (EPA Publication 1949), both finalised in August 2024. Publication 1950 superseded the older Publication 1642, so if you find references to 1642 online, treat them as out of date.
The framework is deliberately staged. Depending on the landfill's characteristics — waste type, size and age — and the type of development proposed, the outcome falls into one of three tiers:
Behind those tiers sits a defined scoring method in the 2024 guideline. EPA Victoria assigns a proposal score from 1 to 3 based on what you are building — 1 for minor alterations to an existing building, 2 for a new building or structure with no below-ground spaces, and 3 where there are basements or lift shafts — and a landfill score that adds together the landfill's size, waste type and age. Multiplying the two gives an overall score from 1 to 45, which maps to the three tiers above: 1–8 means no further assessment, 9–25 calls for a landfill gas risk assessment, and 26–45 calls for an environmental audit. The guideline still has to be applied to your specific site by a suitably qualified consultant, and it is your council's planning requirement that actually triggers the work — but the banding shows why sensitive, below-ground proposals close to a large, recent landfill are the ones most likely to need an audit.
A landfill gas risk assessment looks at one question in technical detail: can landfill gas — approximately 50% methane and approximately 50% carbon dioxide, plus trace gases — travel from the landfill through the ground to your site and reach people or buildings? It uses the Source–Pathway–Receptor model and the CIRIA C665 risk framework, the standard for assessing hazardous ground gases.
The hazards are specific. Methane is flammable in air between about 5% and 15% by volume, so the concern is gas accumulating in a confined space such as a basement, lift shaft or void under a slab where it could meet an ignition source. Both methane and carbon dioxide can also displace oxygen in enclosed spaces. Outdoors the gas disperses; the risk is about gas entering enclosed or below-ground spaces.
A typical risk assessment runs in stages:
The output is a report with conclusions and, if needed, recommended gas protection measures. A clearly low-risk site may be resolved on the desktop study alone; a site that needs monitoring takes longer because the rounds must span varied weather conditions.
A Part 8.3 environmental audit is the statutory tier, conducted under the Environment Protection Act 2017. Unlike a risk assessment — which an environmental consultant can carry out and report on — an audit must be performed and certified by an environmental auditor appointed by EPA Victoria. It is broader in scope: it assesses the condition of the land and the risk it poses to human health and the environment, and produces a formal statement or certificate that carries regulatory weight in the planning process.
A common front-end step is a Preliminary Risk Screen Assessment (PRSA), also delivered by an appointed auditor. A PRSA is a lighter, earlier screen that can confirm whether a full audit is actually needed, or recommend the appropriate pathway — which can save time and cost where a full audit would be disproportionate.
Note the terminology carefully: it is a Part 8.3 environmental audit (Part 8.3 of the 2017 Act), not "section 8.3". Getting this right matters when you're reading EPA guidance or briefing an auditor.
If your council, a consultant or an older document refers to a "section 53V audit", that is the legacy term. It comes from the now-repealed Environment Protection Act 1970 and applied before 1 July 2021. Under the current Environment Protection Act 2017, the equivalent is the Part 8.3 environmental audit. They are not two different products — "section 53V audit" is simply the old name that many people still search for and use out of habit. If you've been asked for a "53V audit", you're being asked for what is now a Part 8.3 environmental audit.
You usually won't choose — the council and the EPA guideline decide, applied to your specific site. As a rough guide, a development at the lower end of concern may need no further assessment; a site where gas migration is plausible but the risk is manageable typically needs a landfill gas risk assessment; and higher-risk situations may require an environmental audit. The closer and more recently active the landfill, the more sensitive the proposed use, and the more below-ground space involved, the further up the tiers your site tends to sit.
A practical starting point is to search your address on Victoria Unearthed, the Victorian Government's free public map of potentially contaminated land and current and former landfills. Treat a clear result with caution, though: many old or closed tips are poorly documented or unregistered, so a clear map is not a guarantee. A professional desktop review checks historical aerial photos and other records that the map doesn't capture.
If your council has asked for a landfill gas assessment, Automated Environmental can scope it for your site — request a free LFG RA quote or read more about our landfill gas risk assessments.
A landfill gas risk assessment is a focused technical study of whether landfill gas can migrate to your site and reach people or buildings, using the Source–Pathway–Receptor model and the CIRIA C665 framework. An environmental audit is broader and statutory — a Part 8.3 environmental audit under the Environment Protection Act 2017 must be carried out and certified by an EPA-appointed environmental auditor and assesses the overall condition and risk of the land. The risk assessment is the lighter, scoped tier; the audit is the heavier, independently certified tier.
It is a statutory environmental audit under Part 8.3 of the Environment Protection Act 2017, carried out and certified by an environmental auditor appointed by EPA Victoria. It assesses the condition of the land and the risk it poses to human health and the environment, and produces a formal statement that carries weight in the planning process. A Preliminary Risk Screen Assessment, also done by an appointed auditor, is often used first to confirm whether a full audit is needed. Note that it is "Part 8.3", not "section 8.3".
In effect, yes. "Section 53V audit" is the legacy term from the now-repealed Environment Protection Act 1970, used before 1 July 2021. Under the current Environment Protection Act 2017 the equivalent is the Part 8.3 environmental audit. They are the same idea under different legislation, so if you have been asked for a 53V audit you are being asked for what is now a Part 8.3 environmental audit.
That is decided by your council and EPA Victoria's landfill buffer guideline (2024) applied to your specific site, not by you. The outcome is one of three tiers: no further assessment, a landfill gas risk assessment, or an environmental audit. It depends on the landfill's waste type, size and age, how close your development is, and how sensitive the proposed use is. A consultant can review your site against the guideline and tell you the likely pathway before you commit.
An environmental audit is a bigger, longer process than a risk assessment — typically many months, and potentially longer, because it is a formal, independently certified statutory process. By comparison, a desktop landfill gas risk assessment can take days to a couple of weeks, with months added if ground gas monitoring is required across different weather conditions. All timeframes are indicative and depend on your site.
Related reading: Do I need a landfill gas risk assessment for a planning permit? · Landfill gas risk assessment cost and process · Landfill buffer distances in Victoria
This article is general information, not legal or professional advice. EPA Victoria guidance should be read in full and professional advice obtained for your specific site and circumstances.