People may have recently read the media coverage concerning lack of testing for PFAS chemicals in drinking water throughout Australia. What was not touched on in the reporting was the ongoing issue of PFAS contamination of waste water treatment plants including the PFAS contamination of hundreds of thousands of tonnes of biosolids produced across Australia.
Friends of the Earth Australia sent off a GIPA (Government Information Public Access) request to Sydney Water on May 8 2024 regarding detections of PFAS chemicals in drinking water, recycled water, biosolids and effluent. A response was sent back from Sydney Water on May 29 2024.
Since 2018, Sydney Water's PFAS testing has concentrated on biosolids and effluent. Almost no testing has been conducted for drinking water and none for recycled water. There has also been some soil testing at sites near waste water treatment plants.
Biosolids around Australia are frequently contaminated with PFAS. PFAS is bioaccumulative, with each application of biosolids adding to the cumulative PFAS burden. The long term problem regarding sewerage and PFAS was recently revealed at Adelaide's West Lakes Development where PFAS was detected in waterways decades after sewerage waste was applied.
The biosolids situation is so serious in some areas of the United States, that farmers are now taking legal action for having PFAS contaminated biosolids applied to their farmland. Will this secnario also occur sometime in the future, in Australia?
Under current biosolid scenarios where ~500,000 tonnes of biosolids are being applied to agricultural land in Australia each year, Friends of the Earth is opposed to any levels of PFAS (or other contaminants) being applied to productive agricultural land/soil in Australia.
For many years, biosolids have been sold throughout Australia, with little mention that they could be contaminated with PFAS.
Sydney Water produce about 180,000 wet tonnes of Biosolids per year.
Biosolids are discussed at length in the NEMP 3 for PFAS chemicals. The NEMP 3 have devised a complicated system where they created proposed contaminant thresholds for several relevant land uses. eg the lowest levels for biosolids are for direct contact plus milk (combined fodder and soil) to the highest being direct contact with the biosolids only.
As there are NO treatments available to remediate/remove PFASs from biosolids, it could be argued that the NEMP was produced by the Federal and State Environment ministers to continue to legally contaminate the land with PFAS. The PFAS NEMP measures will have the effect of doing long-term /permanent contamination /damage to the environment through PFAS pollution of soil, groundwater and ambient air.
According to the NEMP draft 3.0 "The 'restricted use' biosolids scenario in the HHERA (Human Health and Ecological Risk Assessment) assumed that biosolids are land applied and incorporated into the soil for agricultural use. The 'unrestricted use' biosolids scenarios assumed biosolids are applied to soil without any restrictions on the application rate."
These different scenario's are stated with the NEMP draft acknowledging p9 "dilution is not acceptable for example in soil, air, compost or other wastes or products" and p70 "Dilution of PFAS contamination is not an acceptable waste management strategy to create material suitable for reuse". NSW regulations however do not allow situations where biosolids are not mixed into the soil at a site.
Under the NEMP this apparently means that 'where PFAS concentrations in biosolids are high enough to prohibit their beneficial re-use they must be treated or disposed of in accordance with jurisdictional requirements for PFAS contaminated wastes'. In turn this could be understood as meaning that biosolids with concentrations considered 'high' (between 0.0062mg/kg and 0.031mg/kg depending on the margin of safety in the restricted use category) the only options available to water authorities are landfilling or thermal treatment (gasification/pyrolysis or incineration).
In 2023/2024 PFOS+PFHxS concentrations in biosolids detected by Sydney Water system ranged from
In 2023/24 almost 86% of monitored treatment plants reported average PFOS+PFHxS levels above the draft NEMP unrestricted use contaminant threshold. This occurred at 19 of the 22 monitored plants.
All 340* PFOS (72.8%) and 2 (0.4%) PFOA detections were above the draft contaminant threshold for PFOS+PFHxS for unrestricted biosolid listed in the PFAS NEMP 3.0 (consultation draft). These detections in 86% of treatment plants also breached the MASCC (Maximum Allowable Soil Contaminant Concentration).
In 2023/24 almost 23% of monitored treatment plants reported average PFOS+PFHxS levels above the draft NEMP restricted use contaminant threshold. This occurred at 5 of the 22 monitored plants. Quakers Hill, Riverstone, Woolongong and Wallacia. Richmond detections were above the guidelines, but were sampled from a holding basin, not biosolids.
105 PFOS (22.5%) and no PFOA concentrations were above the draft contaminant threshold for PFOS+PFHxS for restricted biosolid use biosolids listed in the PFAS NEMP 3.0 (consultation draft). Does this mean that approximately 25% of Sydney Water Biosolids (40,500 tonnes) require to be landfilled or treated thermally elsewhere? Will the rest be allowed to contaminate farmland where they are applied?
