Narrung Street Sewage Treatment Plant Wagga
“Wagga Wagga City Council operates a Sewage Treatment Plant (STP) at Narrung Street, approximately 2 km north of the CBD. It is the largest plant in the government area and its main objective is to treat sewage collected from Wagga Wagga, Sth Wagga, Bourkelands, Ashmont, Turvey Park, Mt Austin, Tolland, Glenfield Park, Cartwrights Hill, Estella and the northern industrial area. Sewage from the industrial area initially undergoes pretreatment at the new Bomen Industrial Sewage Treatment Facility (BISTF).
The treatment load consists of a mixture of domestic and industrial, with each having a separate process stream. The domestic treatment unit includes screening, grit removal, primary sedimentation, trickling filtration, humus tanks and tertiary ponding. The industrial treatment process begins with a sequencing batch reactor (SBR) at BISTF, followed by screening, extended aeration, secondary clarification and tertiary ponding. Sludge at the plant is treated by biological digestion and is stored in two sludge lagoons. The sludge is periodically removed to licensed landfill.
The final effluent from both processes is discharged to either the Murrumbidgee River or into the network of effluent reuse/irrigation projects administered by the Council.”
https://wagga.nsw.gov.au/services/stormwater-and-sewers/sewers/sewage-treatment
Biosolids from Narrung Street have been dominated by PFOS, which account for 69% of PFAS in biosolids since 2019. Has the storage of biosolids contaminated groundwater under the sewage treatment plant?
“Contract for removal and processing of biosolids Council approved the recommendation to accept the offer of the Trustee for the Bannatyne
Family Trust for the removal and processing of biosolids from Narrung Street Treatment Works and Kooringal Treatment Works as per EPA guidelines.
CONF-1 RFT2023-25 REMOVAL AND PROCESSING OF BIOSOLIDS”
https://news.wagga.nsw.gov.au/_media/documents/media-releases/2023/october-2023/Media-Release-Summary-of-Councils-9-October-2023-Ordinary-Meeting_10-Oct-23.pdf
PFOS and PFDA dominate PFAS detections at Narrung Street in biosolids, since 2019. PFAS amounts in biosolids from Narrung Street are approximately double those from Kooringal STP.
Narrung Leachable Reporting
An inspection at 6 locations at Narrung in November 2024 found that PFOS and PFHxS dominated PFAS at Narrung. It is unclear if this inspection was of surface water or groundwater.
Leachable reporting at Narrung Street is dominated by the short chain PFAS chemical PFBA. Increases in PFOS have occurred since 2024. PFOS and PFBA are the only detectable PFAS chemicals between October 2024 and January 2026.
PFBA levels dominate leachable reporting at Narrung Street.
PFOS levels have been consistent since October 2024
Narrung St STP is located 600 metres north of West Wagga Bore 5 which provides drinking water to Wagga.
Comprehensive Investigation of Per- and Poly- Fluoroalkyl Substances (PFAS) at RAAF Base Wagga Department of Defence Detailed Site Investigation FINAL (Rev3) 5 June 2018 (Jacobs)
1.WAGGA Council Sewerage Treatment Plants
(a)Extract Page 51 Table 7.2: Results from NSW EPA sampling of treated effluent Council STP (Sewerage Treatment Plants)
Narrung Street STP 1
PFHxA 0.049 ug/l
PFOA 0.07 ug/l
Footnotes
1. The Narrung Street STP is located north of the Wagga Wagga CBD Treated effluent is discharged to either the Murrumbidgee River or into the network of effluent reuse/irrigation projects administered by the Council.