Odour management at Tamala Park

Reducing the impact of odour on nearby homes and businesses is our number one priority and is the focus of all our work 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)

Why do landfills smell?

All landfills which deal with ‘putrescible’ waste (waste which rots) create 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 residential areas, to the extent that Tamala Park is now bordered to the north, south, south east and north west by houses. Some of these are no more than a few metres from our site boundary.

A satellite image of Tamala Park and the surrounding area in December 1991 (left) and June 2024 (right)

This 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.

Where do the smells come from?

The smells we usually deal with at Tamala Park originate as household waste. Today, nearly 60,000 residential red bins are delivered to us each weekday, from seven local government areas across the Perth metro area. (See our Landfill Operations page for more information).

Odours at Tamala Park fall into three broad categories:

• Odours from fresh waste - waste which has been deposited on the surface of the landfill that day
• Odours from decomposing waste – the gases produced by rotting waste within the landfill mass, sometimes known as landfill gas
• Odours from leachate – the low-level odours from rain water which has mixed with waste

Of these three, odours from fresh waste are the most difficult to control. This is because landfill operations require waste to be deposited in the open on the active landfill surface until it is covered (buried) at the end of each day. On particularly windy or rainy days, odours from uncovered fresh waste can be quite easily blown off site and towards nearby homes.

Odours from decomposing waste within the landfill mass is an issue all landfills deal with when handling putrescible waste. At Tamala Park, the odorous gases produced are extracted from the landfill by a network of wells and pipelines and safely disposed of in our on-site power station.

Odours from leachate are the least potent of the three and are usually only experienced when standing very close to areas where leachate is collected or stored. How odorous leachate is depends on the type waste the rainwater has come into contact with.

What is MRC doing to control odours?

Mindarie Regional Council (MRC) is working closely with the Department of Water and Environmental Regulation (DWER) in response to community concern about odours from Tamala Park.

Together with the regulator, we have put a number of measures in place with the aim of eliminating odours at source and – where that isn’t possible - to prevent them from leaving the site.

These measures include:

• increasing the amount of limestone cover used on each day’s waste;
• reducing the size of the 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;
• using natural odour eliminating compounds (like zeolite and EcoSorb) to reduce odours on the landfill surface, and;
• increasing pipeline and well infrastructure to remove odorous gases from the landfill before they can escape.

MRC is also investing heavily in new technologies, trials and methods to improve our odour management practices. This will continue for as long as the landfill remains in operation.

How is MRC responding to 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 weeks while the EPN was being prepared and had provided detailed information on odour management – both written and during several meetings and site visits.

We welcome the EPN and believe that the requirements set out by DWER are achievable. In fact, many of those requirements are already part of our ongoing work to manage odours at Tamala Park.

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

Are there any health concerns associated with the odours?

No. Both the Department of Water and Environmental Regulation (DWER) and the WA Department of Health have confirmed that the odours experienced by residents living near Tamala Park are not hazardous to human health.

"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 conclusion supports MRC’s own findings and those of its independent consultants.

If you are concerned about your health or your family’s health, you should seek the advice of a medical practitioner.

How does MRC manage leachate?

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

As rainwater works its way down through the landfill, it mixes with waste and picks up odours. It can take a long time for water to reach the bottom of the landfill to the lining system and it may even become trapped somewhere along the way and not travel any further.

Although leachate itself has a relatively low-level odour, if it is left unmanaged, it can create other issues which make odour management more difficult.

Leachate sitting within the landfill can form a barrier which prevents rainwater filtering down from above. In very rainy conditions, this can result in the top of the landfill becoming waterlogged and more odorous.

Leachate can also interfere with the capture of odours from decomposing waste within the landfill (landfill gas) by flooding extraction wells and pipelines.

In Western Australia, most landfills use evaporation ponds or mats to manage their leachate levels. For the majority of Tamala Park’s 33-year operational life, the method used to reduce the amount of leachate on site was evaporation.

In February 2023, in response to growing concerns over odour, MRC made the decision to pause evaporation in order to reduce total odour. This had a detrimental – but unintended effect – on odour management over the winter of 2024, when the Perth metro area received 62 rain effected days between June and September – the most for 28 years.

Recognising this fact, MRC has made a formal request to the regulator (DWER) to recommence evaporation at Tamala Park. We are currently awaiting a response to this request.

When will the landfill close?

Based on our current projections, we estimate that the Tamala Park landfill will close in 2028 or 2029.

Once the landfill has closed, we will begin the important process of completing the capping of the site, preparing the ground for planting and – finally – revegetating with native plants typical of the surrounding area.

To ensure the site’s long-term safety and amenity, an environmental management presence will be necessary at the site for many years, post closure.

Why can’t the landfill close sooner?

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

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

Of the 10 million cubic metres of landfill space available, only around 1.2 million cubic metres remain. This means that the landfill is well on its way to meeting its final profile. In fact, large portions of Tamala Park are already ‘capped’ (sealed) and revegetated to meet the final design.

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

This process would create a significant amount of odours, perhaps for months at a time. It would be almost impossible for MRC to control this odour.

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

What is Waste to Energy / FOGO and how will it affect the closure of Tamala Park?

Energy Recovery (also known as Waste to Energy/W2E) and Food Organics/Garden Organics recycling (commonly known as FOGO) are methods of diverting waste away from landfill.

Both are part of our long term plans to gradually reduce the amount of waste arriving at Tamala Park as we get closer to closure. This will not only help to reduce odours by limiting the amount of odorous waste we receive, but also make odour management more effective at a time when the operational footprint of the landfill is more constrained and higher on the landscape.

The MRC Council is currently progressing with plans for W2E and FOGO and these form part of our projected closure of the landfill in 2028/29.

W2E and FOGO will allow the Tamala Park landfill to close in a timely and controlled manner and ensure that there is a long-term plan for waste produced by each of MRC’s seven member council local government areas.

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

We do our best to minimise any odours coming from our site, but we recognise that sometimes this isn’t enough to prevent their impact on your home or place of work.

Reporting odours you experience from Tamala Park is important as it allows us to measure how effective our odour management is and helps inform what resources or technologies we might need to put in place and where.

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 response to a recent increase in complaints about odour, MRC has set up the Odour Management Key Stakeholder Working Group. Your complaint will be passed on to this working group to help guide our work in this area.

A form for submitting your report can be found below.

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