NSW Environmental Protection Agency NSW Government
 

Sydney Olympic Park odours

The NSW EPA is actively investigating the cause of odours affecting residents at Lidcombe, Sydney Olympic Park, and Newington. 

Since November 2025, the EPA has received numerous community reports of unpleasant odours that have been described as rotten-egg, garbage, burning, and chemical smells. 

What we are doing

In response to community reports, the EPA is working with industry in the area to reduce odour impacts on the community, has conducted multiple odour surveys and investigating several potential odour sources. These include:

  • Cleanaway Liquid Waste Treatment Plant
  • Cleanaway Waste Transfer Station
  • Haslams Creek

Actions include:

  • Requiring Cleanaway, through Pollution Reduction Programs on its Licences, to investigate opportunities to update its infrastructure, maintenance and operations to ensure that odour emission from its facilities is minimised.
  • Requiring Cleanaway to improve its monitoring and sampling practices at its facilities to identify odour generation and implement solutions as quickly as possible.
  • Investigation of odour reports to identify potential trends, patterns and weather conditions associated with odour reports. This assist the EPA in conducting targeted surveys and inspections during conditions when odours are more likely to occur.
  • Inspection of Cleanaway’s Liquid Waste Treatment Plant and Waste Transfer Station sites to assess potential odour-generating activities, pollution controls and compliance with licence conditions.
  • Installing hydrogen sulphide monitors around Sydney Olympic Park to track odours and identify whether they come from natural sources around Haslams Creek or from nearby industry.

What Cleanaway is doing

Cleanaway has committed to the following actions at the Liquid Waste Treatment Plant and the Waste Transfer Station: 

  • Install and upgrade hydrogen sulphide monitors at key potentially odour-generating locations across both sites.
  • Carry out daily odour and cleanliness checks of the biological tank and wastewater pit for the Liquid Waste Treatment Plant.
  • Work towards the establishment of a Community Reference Group to encourage ongoing discussion, share information, and gather feedback to help identify and confirm the odours as and where they occur.

What you can do

Community reports are essential to help us understand which odours occur when and where, providing key information for our investigation. 

When reporting an odour, please provide:

  • the location where you experienced the odour
  • the time you first noticed the odour
  • how long the odour lasted
  • what the odour smelled like.

If you are experiencing offensive odour, please contact the 24-hour Environment Line on 131 555 or email [email protected]. Information about persistent odour can also be recorded using the fact sheet and odour log sheet, which can then be emailed to us. 

If you believe the odour originates from Cleanaway's facilities, we also encourage you to report it directly through Cleanaway’s complaints and enquiries process by calling 1800 213 753 or emailing [email protected]. This helps Cleanaway investigate potential odour sources in real time. 

Hydrogen sulphide monitors in the community

We have installed five electronic monitors in the local area to detect hydrogen sulphide, a colourless gas that smells like rotten eggs, and can be a component in other odours.

These monitors:

  • are small (about the size of a litre carton of milk) and automatic.
  • take an air sample every 10 minutes and analyse it for hydrogen sulphide, detecting levels as low as 3 parts per billion (ppb).
  • help us combine community reports, EPA surveys, and monitor data to pinpoint odour sources.

Hydrogen sulphide is being detected at very low concentrations unlikely to affect human health.

The data collected will be updated weekly.

Odours and health

NSW Health advises people can smell hydrogen sulphide at very low levels. Most people notice it at around 8 ppb but some people can smell it at levels as low as 0.5 ppb. 

Exposure to hydrogen sulphide concentrations of 5,000–30,000 ppb may cause irritation of the eyes, nose, or throat, and difficulty breathing in people with asthma. Repeated exposures at these levels can cause anxiety and distress and result in indirect symptoms such as headaches and nausea. 

These effects are usually mild and temporary. Hydrogen sulphide does not accumulate in the body, and symptoms generally resolve once the air clears. If residents are concerned about their symptoms or if symptoms persist once the odours have ceased, they should seek advice from their doctor.

Hydrogen sulphide levels

The interactive charts show levels of hydrogen sulphide detected at five locations in the local area. To explore the data use the slider at the bottom of each chart.