For developers, builders and planners weighing up the cost and timeline of a landfill gas risk assessment in Victoria. Last reviewed June 2026.
There is no official published price for a landfill gas risk assessment, and any figure you see should be treated as indicative only. As a rough guide, a straightforward desktop assessment for a clearly low-risk site sits at the lower end, while sites that need a site walkover and months of ground gas monitoring cost more. Because cost is site-specific, the reliable figure comes from a written quote for your site, not a list price. The reason is simple: the cost tracks the amount of investigation your specific site actually needs, and that is not known until the first stage is done.
A landfill gas risk assessment is a staged, risk-based investigation, not a fixed product. Two sites a kilometre apart can need very different amounts of work depending on the landfill's age and history, the local geology, the type of development proposed, and what your council and EPA Victoria's landfill buffer guideline require. A genuine quote reflects how far down the staged process your site is likely to go — so a consultant who quotes a single flat number sight-unseen is guessing.
The assessment follows the Source–Pathway–Receptor (SPR) model and the CIRIA C665 risk framework ("Assessing risks posed by hazardous ground gases to buildings"). The question it answers is whether landfill gas — approximately 50% methane (CH₄) and approximately 50% carbon dioxide (CO₂), plus trace gases — can migrate from a current or former landfill through the ground and reach people or buildings on your site. Methane is flammable in air between about 5% and 15% by volume, and both methane and carbon dioxide can displace oxygen in confined spaces, so the real concern is gas accumulating in basements, lift shafts or enclosed voids under a slab. How much investigation that question needs is what sets the cost.
A handful of factors move the price up or down:
In short, the cost is proportional to the risk picture. Where the desktop study shows a clearly low-risk site, you may stop there; where it flags real uncertainty, the extra stages — and the extra cost — are what give you (and your council) a defensible answer.
A typical landfill gas risk assessment moves through up to three stages, stopping as soon as the evidence is sufficient:
The assessment closes with a report setting out the conclusions and, if required, recommended gas protection measures. On timeline: a desktop assessment can be quick — days to a couple of weeks — but if ground gas monitoring is required it adds months, because the rounds have to be spread across varying conditions and cannot be rushed. These timeframes are indicative; your site's facts decide where it lands.
Monitoring is the stage that turns a fast desktop job into a multi-month exercise, and it is unavoidable when the desktop study cannot rule out a credible gas pathway. A single snapshot reading proves little, because gas behaviour changes with the weather — falling barometric pressure can draw gas out of the ground, so a calm, high-pressure day can read low and mislead. Capturing that variation means multiple monitoring rounds over months, plus the cost of installing and reading the wells. That is exactly why no one can give you a final price up front: until the desktop study tells you whether monitoring is needed, the largest cost item is still unknown.
If your council has asked for a landfill gas assessment, Automated Environmental can scope it for your specific site so you know what stages — and what cost — are actually likely. You can request a free LFG RA quote or read more about our landfill gas risk assessments.
Because the scope is unknown until the desktop study is done, a sound quote is usually staged: a fixed price for the desktop assessment, then a clear scope and price for any walkover or monitoring only if the evidence shows it is needed. That keeps you from over-paying for monitoring a low-risk site doesn't need, while protecting you from an under-scoped report your council won't accept. When you ask for a quote, expect to be asked about the site address, the development proposed and any council correspondence — that is what lets a consultant estimate how far the staged process is likely to run.
There is no official published price, so any figure is indicative only. A straightforward desktop assessment for a clearly low-risk site is at the lower end, and the cost rises where a site walkover and months of ground gas monitoring are required. The right figure for your site depends on how much investigation it actually needs.
The main drivers are how much investigation is required (desktop only, plus a walkover, or full ground gas monitoring), the landfill's age and history, the local geology and pathways, the receptors involved, and the type of development proposed. Sensitive or below-ground uses near a poorly documented tip with permeable ground tend to need the most work, and therefore cost more.
A desktop assessment can be quick — days to a couple of weeks. If ground gas monitoring is required it adds months, because the readings have to be taken over several rounds across different weather and barometric-pressure conditions. These timeframes are indicative and depend on your site.
Gas behaviour changes with the weather, and falling barometric pressure can draw gas out of the ground, so a single reading is not reliable. Capturing that variation requires multiple monitoring rounds over months, plus the cost of installing and reading monitoring wells. It is the stage that turns a fast desktop job into a multi-month one.
You can usually get a fixed price for the desktop assessment, but the full cost cannot be fixed up front because the scope of any walkover or monitoring is unknown until the desktop study is done. A sound quote is staged: a set price for the desktop study, then a clear scope and price for further work only if the evidence shows it is needed.
Related reading: Do I need a landfill gas risk assessment for a planning permit? · Landfill gas risk assessment vs environmental audit · 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.