Water sampling in Avondale

We have completed targeted surface water sampling along the upper section of Mullet Creek near the Huntley Waste Emplacement (Huntley Landfill) in Avondale.

Background

In September 2025, EPA testing detected elevated levels of pollutants, including ammonia and PFAS in Heritage Creek and Mullet Creek downstream of Huntley Waste Emplacement, known as the Huntley Landfill, at Avondale. These findings prompted us to expand sampling and offer water testing to residents on properties immediately downstream of the landfill.

The EPA has issued a Prevention Notice to the landfill operator to prevent polluted water from leaving the site. The Environment Protection Licence (10997) and Prevention Notices can be viewed on the EPA’s Public register. We will continue to closely monitor the landfill as part of our on-going compliance activities by undertaking regular inspections to assess the management of water and leachate.

Avondale surface water testing – 3 November 2025

We collected surface water samples from 7 locations in Heritage and Mullet creeks at Avondale. The sampling aimed to investigate levels of metals, nutrients and per- and polyfluoroalkyl substances (PFAS) downstream of the Huntley landfill. The results of this testing are on the Avondale water sampling results webpage.

Residents living on properties bordering Mullet Creek in Avondale (upstream of Ena Avenue) have been issued precautionary advice to minimise their exposure to PFAS.

Sampling sites

• HC-1 – Heritage Creek on site of the landfill premises
• HC-2 – Heritage Creek immediately downstream of the landfill
• MC-2 – Mullet Creek immediately downstream of the confluence where Heritage Creek flows into Mullet Creek
• MCR1 – Mullet Creek, between 500 and 2000 m downstream of the landfill
• MCR2 – Mullet Creek between 500 and 2000 m downstream of the landfill
• MCR3 – Mullet Creek between 500 and 2000 m downstream of the landfill
• MC-1 – Mullet Creek approximately 500 m upstream of the landfill

Sampling results

Both Heritage and Mullet creeks show signs of elevated pollutants, with water quality poorest at the sampling sites closest to the Huntley landfill and improving with distance downstream. 

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

All PFAS and nutrient levels were below recreational water quality guidelines. Metal concentrations were below recreational guidelines in Mullet Creek, however manganese exceeded the guideline in Heritage Creek at the boundary of the landfill. Metal and nutrient levels were below livestock drinking water guidelines. Chloride, sodium and boron exceeded the irrigation guidelines for sensitive crops in Heritage Creek, but all other nutrients and metals were below irrigation guidelines.

PFAS compounds were detected at all sampling locations. PFOS exceeded the ecological water quality guideline at all sites with the highest PFOS concentrations measured in Heritage Creek (immediately downstream of the landfill). There are no livestock and irrigation water guidelines for PFAS. 

The presence of PFOS in water samples does not necessarily mean there is a risk to human health or livestock. 

There were some exceedances of ecological water quality guidelines, notably from PFOS, ammonia and nitrogen. 

Ecotoxicity testing on freshwater cladocerans showed significant acute toxicity at the sites in Heritage Creek, with decreasing toxicity moving downstream as it feeds into Mullet Creek. No toxicity was reported for the upstream sample. 

The results of this testing are on the Avondale water sampling results webpage.