Odour management at Tamala Park

Reducing the impact of odour on nearby homes and businesses is our number one priority at Mindarie Regional Council (MRC).

This page has been created to help you understand where landfill odours come from, the challenges we face in this work and our plans to control odours now and in the future.

Note: This page is regularly updated with new information. Please keep checking back, here, for the latest updates and notices on odour management and relevant landfill operations.

Frequently asked questions (FAQ)

What is causing the smell?

With yellow recycling bins and green garden waste bins now commonplace across Perth, the contents of your general household waste bin (which goes to landfill) is largely dedicated to food waste – much more so than in the past.

It is this ‘red bin’ waste and other types of ‘putrescible’ waste (waste which rots) which are responsible for creating odours in a landfill.

In the case of Tamala Park, we receive nearly 60,000 red bins each weekday from seven local authorities across the Perth Metro Area (the cities of Joondalup, Wanneroo, Stirling, Perth, Vincent and the towns of Cambridge and Victoria Park).

Contrary to popular belief, this waste only creates a low-level odour when it is first deposited on the surface of the landfill, which is not usually perceptible unless you are in the immediate vicinity. Once the freshly delivered waste is covered, its odour is much less noticeable. However, when it has been sitting under the landfill surface for some time (often after two-to-three months), it begins to decompose and produce much more pungent odours in the form of ‘landfill gas’.

What is landfill gas?

Landfill gas is a naturally occurring byproduct of decomposing organic waste in a landfill.

Despite its name, landfill gas is not composed of a single gas, but several. These include methane, carbon dioxide and smaller amounts of other gases like nitrogen, oxygen, ammonia and sulphides.

Extensive investigations of odours at Tamala Park and in the communities surrounding the site have confirmed that the vast majority of odours experienced by nearby residents originate from landfill gas.

Landfill gas is found at every landfill which deals with putrescible waste. This is why modern landfills are designed with landfill gas management in mind.

How is landfill gas managed?

At Tamala Park, we have a dedicated landfill gas extraction and disposal system which is part of the on-site Landfill Gas Power Station. This uses a network of wells and pipelines to remove landfill gas before it can find its way out of the landfill mass and into the surrounding air.

Once extracted, landfill gas is disposed of (burned) as part of the power station process.

MRC, in conjunction with the Landfill Gas Power Station operator – Energy Developments Pty Ltd (EDL) – is continuously upgrading and optimising the collection network, including the installation of new wells and pipelines in the landfill as areas are completed.

What is different about Tamala Park?

The biggest difference between odour management at Tamala Park compared to other landfills is its proximity to medium-to-high density housing, which borders the site to the north and south, with more homes currently being built to the north east and north west.

It is a fact that all landfills which handle putrescible waste must deal with some level of odour. That is why landfills are usually built in isolated locations, far away from heavily populated areas.

In 1991 – when the Tamala Park landfill first opened – the surrounding area was almost exclusively native bushland. Over time, that bushland has been cleared for new suburbs and residential areas.

This land clearing has also removed a natural buffer (bushland and established trees) which, in previous years, helped to prevent odours from travelling beyond the immediate vicinity of the site and even helped to absorb some of the gases produced by waste within the landfill.

A satellite image of Tamala Park and the surrounding area in 1991 (left) and 2020 (right). Note the newly laid Marmion Avenue and Mindarie Marina, still under construction, to the north west of Tamala Park.

In short, although other landfills might produce as much odour (or even more) than Tamala Park, it would often go unnoticed in remote isolated areas.

This difference makes our job of managing odours uniquely challenging and means that the levels of odour deemed acceptable for Tamala Park are much lower than they might be for a similar landfill site in an isolated, undeveloped location.

Why is the smell often worse in winter?

There are several factors which can limit the effectiveness of odour management at Tamala Park, but winter weather conditions is perhaps the most common and difficult to address.

Heavy rains (common in Perth during the winter months) can flood the wells and pipelines we use to extract landfill gas. This is problematic for two reasons: first, flooded wells cannot extract landfill gas efficiently; and second, if rainwater is drawn through the pipelines and into the landfill gas power station, it can damage the engines and even result in a full shut down if not spotted early enough. This means that the landfill gas extraction network is less efficient in winter than it is in dryer conditions.

Equally, low-pressure in the atmosphere (common during cloudy, windy, colder spells) reduces the force acting upon the landfill surface, which encourages gas to work its way to the surface, rather than into the landfill gas management system.

Other contributing factors are more straight forward. Strong winds mean odours can be blown away from the site more easily and across greater distances, while a combination of a saturated landfill and the heavy machinery used on site can create an odorous ‘mud-like’ substance in high traffic areas.

These issues are not unique to Tamala Park and are problems all landfills face.

What does MRC do to reduce odours during winter?

Since experiencing a record number of odour reports from the community during winter 2024, MRC has invested considerable money and resources to reducing the impact of wet and windy weather on odour management at Tamala Park.

As well as making substantial improvements to the landfill gas capture system, we have increased the amount of limestone cover used in the active tipping area, reprofiled huge areas of the landfill to prevent rainwater from pooling, sealed and capped nearly a third of the landfill surface and introduced ‘temporary rainfall barriers’ across another third.

These barriers (which we call TeRBs) not only prevent rainwater from waterlogging the landfill surface; they also prevent landfill gas from escaping during periods of low atmospheric pressure.

In total, we’ve installed more than 20,000 square metres of TeRBs in the past few months, which – together with the newly capped and covered areas – have diverted more than 20 million litres of water away from the landfill surface in 2025.

Where water cannot be diverted away – and to prevent muddy and odorous conditions – we use naturally occurring zeolite to keep the landfill surface as dry as possible.

What else is MRC doing to reduce odours?

Working closely with the regulator (DWER) we’ve put a number of measures in place to reduce odours on site and prevent them from travelling into the neighbouring suburbs.

• increasing the amount of limestone cover used on each day’s waste;
• reducing the size of the landfilling area, used to deposit fresh waste, prior to covering;
• stopping the delivery of waste at night and ceasing deliveries of commercial-scale odorous waste;
• installing ‘misters’ near areas where odours exist, capturing odour molecules in a plume of water vapour and preventing them from leaving the site, and;

• conducting regular odour inspections and audits – both on site and in the community – to monitor odour hotspots and trace odour sources back to the landfill for management.

We know that there is still much more work to do. That is why we are investing more money and resources than ever before to reduce the impact of odours from the landfill on the local community.

Is the smell damaging my health?

Both the Department of Water and Environmental Regulation (DWER) and the Department of Health have confirmed that, while it might be unpleasant, there are no health risks associated with odours from the landfill.

"The department has liaised with the Department of Health in relation to the odour emissions and it has confirmed that the odour from the Tamala Park landfill is not hazardous to human health"

WA Department of Water and Environmental Regulation

This supports MRC’s own findings (and those of independent experts). However, if you are concerned about your health, or the health of your family, you should speak to a medical practitioner.

What is the Environmental Protection Notice?

On 28 November 2024, MRC received an Environmental Protection Notice (EPN) from the regulator, DWER.

MRC had been working alongside the regulator for several months while the EPN was being prepared and provided detailed information on odour management – both written and during several meetings and site visits.

We are pleased to have complied with all of DWER’s requirements to-date.

For more information on the EPN and our progress on each requirement, click here.

What is leachate and how is it managed?

Leachate is the term used to refer to rainwater which has travelled down through the top of a landfill and into the landfill mass. It can also refer to the liquid waste produced when organic material breaks down within the landfill mass.

Leachate is found in all landfills and although it has a relatively low-level of odour, if it is left unmanaged, it can create other issues and make odour management more difficult.

For example, leachate can interfere with the capture of odours from decomposing waste within the landfill (landfill gas) by flooding extraction wells and pipelines.

In WA, landfills take advantage of the dry hot summers to reduce the volume of leachate by pumping it to the surface and into specially constructed ‘evaporation mats’. For the majority of Tamala Park’s operational life, evaporation is the method we have used to reduce the amount of leachate on site.

Controlling levels of leachate present within the landfill is important to prevent contamination of the groundwater and nearby land. For this reason, independent testing and groundwater monitoring has taken place at Tamala Park since 1998 and reports regularly submitted to the regulator. To-date, neither we, nor the regulator have identified any health risk to the community from the leachate at Tamala Park.

When is the landfill going to close?

We predict that the landfill will close in 2028 or 2029. This is based upon the current volumes of household waste being delivered to us and our plans to send some of that waste to a ‘waste-to-energy’ plant in the near future.

Our work to secure a waste-to-energy contract with a facility south of Perth will allow us to bring landfill operations to a gradual, controlled end.

Why can't it close sooner?

When it was approved by the WA Environmental Protection Authority (EPA) in 1990, it was on the condition that MRC completed the landfill to a very specific design.

Put simply, the final profile of the landfill will create a gentle hill which allows rainwater to run off the surface, away from the completed landfill.

Of 10 million cubic metres of landfill space created, only 1 million cubic metres remain. This means that the landfill is very close to its final profile. In fact, large portions of Tamala Park are already ‘capped’ (sealed) and revegetated to meet the design which was approved back in 1990.

Closing the landfill sooner would mean ‘reprofiling’ these capped areas to accommodate a new, smaller design. This would involve digging up large amounts of old waste which has been in the landfill for several years.

This process would create a significant amount of odour, perhaps for months at a time, with no ability to completely control emissions.

That is why completing the landfill to its original design is the quickest and least disruptive way to close the site in a timely and controlled manner.

Odours from Tamala Park are affecting me – how do I report this?

Reporting any odour you experience is important. It allows us to measure how effective our odour management is and helps us use our resources more strategically.

All reports are taken seriously and investigated. You will receive an automated response to your report within the hour and a more detailed response within two to three working days.

As part of our commitment to reducing the impact of odour on the community, we have created the Odour Management Key Stakeholder Working Group. Your complaint will be passed on to this working group to help guide its work in this area.

A form for submitting your report can be found below.

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