Risks of Over-Extracting Landfill Gas: For Site Owners

Are you looking to learn more about the risks of over-extracting landfill gas? Join me as I run through what site owners should know about maintaining their project without exploiting it.

If you own a landfill site that’s leased to a third-party landfill gas operator, you’re probably relying on them to extract gas efficiently. This way, they’ll be able to generate electricity for the duration of their lease.

But what if they’re over-extracting gas? Or running engines that are too large for the available landfill gas supply? Both can cause your gas reserves to deplete prematurely, reducing the long-term financial potential of your site.

I’ve seen some operators justify this approach as maximising short-term output. However, this process ultimately leads to inefficiencies, operational challenges and lost revenue.

In this article, I’ll outline exactly how over-extraction happens. I’ll also highlight the risks of over-extracting landfill gas, the warning signs to watch out for and ways to protect your long-term revenue.

What Happens When Landfill Gas Is Over-Extracted?

Landfill gas (LFG) is a natural byproduct of decomposing waste. It’s mostly composed of methane, which can be used to generate electricity.

If extracted correctly, this gas flows steadily over several decades. But if too much gas is drawn down too quickly, production levels drop prematurely. This means there’ll be less electricity and lower long-term income for site owners.

Why does this happen?

Some landfill gas operators prioritise short-term efficiency over long-term sustainability.

After all, their income depends on maximising electricity output. So they may be tempted to extract as much gas as possible in the short term to meet power generation targets and revenue expectations.

Some operators may also install larger engines than the landfill can sustainably supply. Or, they may delay downsizing equipment as the gas production naturally declines. This can lead to the equipment leaching out more gas than it’s intended to.

It can also be a huge issue if your operator doesn’t keep an eye on the extraction process and leaves the engines running at full capacity.

So, instead of adjusting engine sizes to match declining gas flows, they keep running oversized engines. This process forces excessive gas extraction. This approach might seem efficient, but it’s a short-sighted tactic that ultimately results in lost revenue.

But that’s not all.

The site operator may also be failing to balance gas collection effectively. Or perhaps they’re under pressure from long-running Power Purchase Agreements (PPAs) that require consistent output levels. In some cases, it’s just down to improper gas flow monitoring.

But whatever the cause, this premature gas depletion shortens the lifespan of the project and makes operations less efficient over time.

Want to understand where landfill gas operations are heading? Read more in our future of landfill gas outlook.

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Signs of Over-Extraction

If you’re seeing these red flags, it’s time to act.

As a landfill site owner in the UK, ensuring the profitability and environmental compliance of your site is key.

But it requires seriously diligent oversight of the best landfill gas (LFG) extraction practices.

Oxygen and nitrogen levels creeping up

When you extract gas too aggressively, it creates a strong vacuum effect that pulls in atmospheric air. This usually leads to increased oxygen and nitrogen levels within the landfill gas system.

If these gases are present, it’s a strong sign that air is seeping into the landfill. These gases can disrupt the natural anaerobic decomposition process.

Over time, this reduces methane production and negatively impacts the efficiency of gas-to-energy operations.

Methane levels dropping

As I’ve mentioned, methane is the primary component of landfill gas and the key driver of revenue for landfill site owners.

A steady decline in methane concentration suggests that gas reserves are being depleted faster than they should be. This is especially true if your project is still forecasted to have decent gas reserves for a few years.

Over-extraction accelerates this process. It cuts short the productive lifespan of the site and reduces long-term revenue potential.

So, if methane levels are dropping unexpectedly, it’s a sign that your site operator needs to adjust extraction rates to a more sustainable level.

Rising landfill temperatures

I covered this briefly in my first point, but excessive gas extraction often leads to oxidation reactions inside the landfill. This oxidation process causes internal temperatures to rise.

This is a very serious risk, as higher temperatures can increase the likelihood of underground fires. These fires are extremely difficult to control and can cause significant structural and environmental damage.

So to keep your site’s impact to a minimum, monitoring temperature trends at your site is crucial. If temperatures are rising, it could indicate that over-extraction is disturbing the landfill’s internal balance.

Unstable gas flow rates

A well-managed landfill gas system should have relatively stable and predictable gas flow rates. If you’ve owned the site for some time, you should be able to measure this with relative accuracy year on year.

If flow rates fluctuate wildly or show a sharp decline, it may be a sign that gas is being drawn out too quickly.

Sudden drops in flow can indicate that the available gas supply is being exhausted prematurely. On the other hand, erratic fluctuations suggest improper wellfield management.

It’s critical to regularly review flow data to help you identify and address these issues before they impact long-term productivity.

How to Avoid Over-Extraction

Monitor extraction rates carefully

Regularly obtain gas composition reports from your operator so you can compare them against expected landfill gas production rates. Check for a decline in methane levels beyond anticipated rates (which may indicate over-extraction at your site).

To give you some context, the UK generated approximately 215 million tonnes of waste in 2024. About 8.5 million tonnes of this was sent to landfill, which is a staggering figure. In 2020, UK landfills were responsible for approximately 13.6 million tonnes of CO2 equivalent emissions.

With UK’s net-zero targets in mind, monitoring these emissions is crucial for maintaining optimal gas recovery and environmental compliance.

Ensure you have the correct-sized equipment

As gas production in a landfill site naturally declines over time, it’s essential that operators adjust the capacity of gas collection equipment accordingly.

The UK has implemented stringent controls on landfill gas emissions. So proper equipment sizing is vital to minimise operational issues and any environmental impact.

If high-capacity equipment continues to operate despite reduced gas volumes, it may signal over-extraction practices.

Include stronger lease clauses

When renewing landfill gas contracts, consider incorporating provisions that mandate:

• Adjustment of equipment capacity: Site operators should be required to downsize gas collection systems as production declines to prevent over-extraction. They may be unwilling to do so, but it’s important to avoid damaging the site and going against environmental legislation.

• Prevention of excessive oxygen intrusion: Proper management of gas extraction systems is necessary to avoid oxygen intrusion. This can inhibit methane generation and potentially lead to subsurface fires.

• Adherence to best practices: Operators should follow industry best practices for sustainable gas extraction. This is something I’ll always recommend, as it’s the path that’s least likely to land you in hot water. Looking at guidelines in the Environmental Services Association (ESA) Industry Code of Practice for the Management of Landfill Gas is a great start.

Seek independent assessments

It’s always worth engaging an independent landfill gas expert to audit your site and evaluate the management of extraction rates.

Third-party assessments can identify unsustainable practices and hold operators accountable. After all, they’re not involved with the project and will be more likely to give you an objective view of the situation.

The ESA’s guidelines recommend that adjustments to gas collection systems be made in small increments. This should then be followed by routine re-monitoring to assess their impact on operations.

By getting an expert involved, you’ll have a clearer picture of what your site requires and whether you’re meeting national requirements.

The Financial Risks of Over-Extracting Landfill Gas

Research indicates that aggressive or inefficient gas extraction can reduce overall efficiency and may accelerate declines in methane production.

While the exact impact varies depending on site conditions, poor management over several years could result in a measurable reduction in total gas recovery.

This could lead to a significant loss in electricity revenue and lower-than-expected income for landfill owners.

Final Thoughts

As you can see, proactively managing your site’s extraction levels is crucial if you want to maintain your site’s income and stay environmentally compliant.

It’s true that over-extraction may provide short-term gains for operators. But the risks of over-extracting landfill gas pose serious long-term financial and environmental problems for site owners.

To protect your interests, I always recommend starting with your lease. By reviewing and strengthening your lease agreement from the get-go, you can include provisions that promote sustainable extraction practices.

If operators face legal trouble when they break these terms, then they’re less likely to over-extract.

It’s also key to implement regular monitoring and data extraction to detect any problems as they arise. The quicker you can pinpoint issues, the faster you’ll resolve them.

By taking these steps, you can safeguard your site’s revenue and be a better environmental steward.

In short, it’s a win-win.

If you’d like to learn more about landfill gas sites and how to optimise their performance, just get in touch. Our team is always happy to answer your questions and provide expert insights that could transform your site.

In the meantime, we can help you assess your project to ensure you’re maximising revenue and securing the best possible returns.