**Ti-Tree Bend Sewage Treatment Plant**

**Inlet**

1/7/19 Ti-Tree Bend STP Inlet 6:2 FTA 0.04ug/L, PFOS 0.02ug/L

**Effluent**

1/7/19 Ti-Tree Bend STP Effluent 6:2 FTA 0.02ug/L, PFHxS 0.01ug/L, PFOS 0.01ug/L

**Biosolids**

1/7/19 Ti-Tree Bend STP Biosolids 10:2 FTS 6.5ug/kgDMB, 6:2 FTA 17ug/kgDMB, 8:2 FTA 2.1ug/kgDMB, 8:2 FTS 3.6ug/kgDMB, FOSA 1.2ug/kgDMB, FOSAA 5.7ug/kgDMB, N-EtFOSAA 5.8ug/kgDMB, N-MeFOSAA 3.4ug/kgDMB, PFDA 4.9ug/kgDMB, PFDoDA 2.3ug/kgDMB, PFHxA 0.9ug/kgDMB, PFOS 22ug/kgDMB, PFUnDA 1.3ug/kgDMB

**Ti Tree Bend Sewage Treatment Plant Biosolids/Sludge**

INV – TTB 1 26/11/20: 10:2 FTS 0.0019mg/kg, 8:2 FTS 0.0009mg/kg, EtFOSAA 0.0049mg/kg, FOSE 0.0012mg/kg, MeFOSAA 0.0074mg/kg, MeFOSE 0.0015mg/kg, PFDA 0.0032mg/kg, PFDoDA 0.0018mg/kg, PFHpA 0.0008mg/kg, PFHxA 0.0029mg/kg, PFHxS 0.0004mg/kg, PFNA 0.0004mg/kg, PFOA 0.0026mg/kg, PFOS 0.0137mg/kg, PFPeA 0.0016mg/kg, PFUnDA 0.0009mg/kg. Sum of PFAS 0.0461mg/kg, Sum of PFAS (WA DER List) 0.0229mg/kg, Sum of PFHxS & PFOS 0.0141mg/kg

INV – TTB 2 26/11/20: 10:2 FTS 0.0016mg/kg, 8:2 FTS 0.0006mg/kg, EtFOSAA 0.0036mg/kg, FOSE 0.0013mg/kg, MeFOSAA 0.0044mg/kg, MeFOSE 0.0039mg/kg, PFDA 0.0023mg/kg, PFDoDA 0.0013mg/kg, PFHxA 0.0017mg/kg, PFOA 0.0015mg/kg, PFOS 0.0093mg/kg, PFPeA 0.0004mg/kg, PFUnDA 0.0005mg/kg. Sum of PFAS 0.0324mg/kg, Sum of PFAS (WA DER List) 0.0135mg/kg, Sum of PFHxS & PFOS 0.0093mg/kg

INV – TTB 3 26/11/20: EtFOSAA 0.0016mg/kg, FOSE 0.0005mg/kg, MeFOSAA 0.0022mg/kg, PFDA 0.0015mg/kg, PFDoDA 0.0006mg/kg, PFHxA 0.0003mg/kg, PFOA 0.001mg/kg, PFOS 0.0063mg/kg, PFUnDA 0.0003mg/kg. Sum of PFAS 0.0148mg/kg, Sum of PFAS (WA DER List) 0.0076mg/kg, Sum of PFHxS & PFOS 0.0063mg/kg

INV – TTB 4 26/11/20: PFOS 0.0004mg/kg. Sum of PFAS 0.0004mg/kg, Sum of PFAS (WA DER List) 0.0004mg/kg, Sum of PFHxS & PFOS 0.0004mg/kg

INV – TTB 5 26/11/20: 10:2 FTS 0.0008mg/kg, EtFOSAA 0.0025mg/kg, FOSE 0.0007mg/kg, MeFOSAA 0.0026mg/kg, MeFOSE 0.0005mg/kg, PFDA 0.0022mg/kg, PFDoDA 0.0007mg/kg, PFHpA 0.0003mg/kg, PFHxA 0.0015mg/kg, PFHxS 0.0002mg/kg, PFNA 0.0002mg/kg, PFOA 0.0023mg/kg, PFOS 0.0087mg/kg, PFPeA 0.0006mg/kg. Sum of PFAS 0.0238mg/kg, Sum of PFAS (WA DER List) 0.0136mg/kg, Sum of PFHxS & PFOS 0.0089mg/kg

INV – TTB 6 26/11/20: 10:2 FTS 0.0018mg/kg, 8:2 FTS 0.0007mg/kg, EtFOSAA 0.0049mg/kg, FOSE 0.0017mg/kg, MeFOSAA 0.0072mg/kg, MeFOSE 0.0028mg/kg, PFDA 0.0031mg/kg, PFDoDA 0.0012mg/kg, PFHpA 0.0006mg/kg, PFHxA 0.0026mg/kg, PFHxS 0.0011mg/kg, PFNA 0.0003mg/kg, PFOA 0.0021mg/kg, PFOS 0.0131mg/kg, PFPeA 0.0012mg/kg, PFUnDA 0.0008mg/kg. Sum of PFAS 0.0452mg/kg, Sum of PFAS (WA DER List) 0.0214mg/kg, Sum of PFHxS & PFOS 0.0142mg/kg

INV – TTB 7 26/11/20: 10:2 FTS 0.0007mg/kg, EtFOSAA 0.002mg/kg, FOSE 0.0003mg/kg, MeFOSAA 0.0026mg/kg, PFDA 0.0012mg/kg, PFDoDA 0.0007mg/kg, PFHpA 0.0002mg/kg, PFHxA 0.0015mg/kg, PFOA 0.001mg/kg, PFOS 0.0039mg/kg, PFPeA 0.0006mg/kg, PFUnDA 0.0004mg/kg. Sum of PFAS 0.0151mg/kg, Sum of PFAS (WA DER List) 0.0072mg/kg, Sum of PFHxS & PFOS 0.0039mg/kg

INV – TTB 8 26/11/20: EtFOSAA 0.0003mg/kg, MeFOSAA 0.0005mg/kg, PFDA 0.0003mg/kg, PFOS 0.0014mg/kg. Sum of PFAS 0.0025mg/kg, Sum of PFAS (WA DER List) 0.0014mg/kg, Sum of PFHxS & PFOS 0.0014mg/kg

INV – TTB 9 26/11/20: EtFOSAA 0.0003mg/kg, MeFOSAA 0.0006mg/kg, PFDA 0.0003mg/kg, PFHxA 0.0003mg/kg, PFOA 0.0002mg/kg, PFOS 0.0014mg/kg. Sum of PFAS 0.003mg/kg, Sum of PFAS (WA DER List) 0.0018mg/kg, Sum of PFHxS & PFOS 0.0014mg/kg

INV – TTB 10 26/11/20: 10:2 FTS 0.0021mg/kg, 8:2 FTS 0.0009mg/kg, EtFOSAA 0.0036mg/kg, FOSE 0.0016mg/kg, MeFOSAA 0.0052mg/kg, MeFOSE 0.0029mg/kg, PFDA 0.0035mg/kg, PFDoDA 0.0013mg/kg, PFHxA 0.0016mg/kg, PFNA 0.0003mg/kg, PFOA 0.0017mg/kg, PFOS 0.0124mg/kg, PFPeA 0.0004mg/kg, PFUnDA 0.0012mg/kg. Sum of PFAS 0.0387mg/kg, Sum of PFAS (WA DER List) 0.0170mg/kg, Sum of PFHxS & PFOS 0.0124mg/kg

INV – TTB 11 26/11/20: 10:2 FTS 0.0012mg/kg, EtFOSAA 0.0025mg/kg, FOSE 0.001mg/kg, MeFOSAA 0.0062mg/kg, MeFOSE 0.002mg/kg, PFDA 0.0024mg/kg, PFDoDA 0.0009mg/kg, PFHxA 0.0012mg/kg, PFNA 0.0003mg/kg, PFOA 0.0027mg/kg, PFOS 0.0091mg/kg, PFPeA 0.0002mg/kg. Sum of PFAS 0.0297mg/kg, Sum of PFAS (WA DER List) 0.0132mg/kg, Sum of PFHxS & PFOS 0.0091mg/kg

**TasWater – Customer Water Investigation Ti Tree Bend Biosolid Operator**

Sample 1 21/5/21: PFDA 0.0026mg/kg, PFHxA 0.0031mg/kg, PFOA 0.0032mg/kg, PFOS 0.007mg/kg. Sum of PFAS 0.0159mg/kg, Sum of PFHxS & PFOS 0.007mg/kg

Sample 2 21/5/21: PFOS 0.0067mg/kg. Sum of PFAS 0.0067mg/kg, Sum of PFHxS & PFOS 0.0067mg/kg

Sample 3 21/5/21: PFHxA 0.0031mg/kg, PFOS 0.0056mg/kg. Sum of PFAS 0.0087mg/kg, Sum of PFHxS & PFOS 0.0087mg/kg

Sample 4 21/5/21: PFHxA 0.0036mg/kg, PFOA 0.003mg/kg, PFOS 0.0073mg/kg, PFPeA 0.0028mg/kg. Sum of PFAS 0.0167mg/kg, Sum of PFHxS & PFOS 0.0073mg/kg

Sample 5 21/5/21: PFHxA 0.0035mg/kg, PFOA 0.0031mg/kg, PFOS 0.0078mg/kg, PFPeA 0.0028mg/kg. Sum of PFAS 0.0172mg/kg, Sum of PFHxS & PFOS 0.0078mg/kg

Sample 6 21/5/21: PFOS 0.0063mg/kg. Sum of PFAS 0.0063mg/kg, Sum of PFHxS & PFOS 0.0063mg/kg

Sample 7 21/5/21: PFDA 0.0031mg/kg, PFHxA 0.0026mg/kg, PFOA 0.0044mg/kg, PFOS 0.0092mg/kg. Sum of PFAS 0.0193mg/kg, Sum of PFHxS & PFOS 0.0092mg/kg

Sample 8 21/5/21: PFHxA 0.0034mg/kg, PFOA 0.0033mg/kg, PFOS 0.0076mg/kg. Sum of PFAS 0.0143mg/kg, Sum of PFHxS & PFOS 0.0076mg/kg

Sample 9 21/5/21: PFDA 0.0031mg/kg, PFHxA 0.0033mg/kg, PFOA 0.0037mg/kg, PFOS 0.0087mg/kg. Sum of PFAS 0.0188mg/kg, Sum of PFHxS & PFOS 0.0087mg/kg

Sample 10 21/5/21: PFHxA 0.0027mg/kg, PFOA 0.0027mg/kg, PFOS 0.0067mg/kg. Sum of PFAS 0.0121mg/kg, Sum of PFHxS & PFOS 0.0067mg/kg

Sample 11 21/5/21: PFHxA 0.0031mg/kg, PFOA 0.003mg/kg, PFOS 0.0078mg/kg. Sum of PFAS 0.0139mg/kg, Sum of PFHxS & PFOS 0.0078mg/kg

Sample 12 21/5/21: PFDA 0.0036mg/kg, PFHxA 0.003mg/kg, PFOA 0.0045mg/kg, PFOS 0.0122mg/kg. Sum of PFAS 0.0233mg/kg, Sum of PFHxS & PFOS 0.0122mg/kg

Sample 13 21/5/21: PFDA 0.0033mg/kg, PFHxA 0.0026mg/kg, PFOA 0.0044mg/kg, PFOS 0.0139mg/kg. Sum of PFAS 0.0242mg/kg, Sum of PFHxS & PFOS 0.0139mg/kg

**Ti Tree Bend Sewage Treatment Plant Biosolids. **

26/2/23: 10:2 FTS 0.0008mg/kg, 8:2 FTS 0.0007mg/kg, EtFOSAA 0.0093mg/kg, FOSE 0.002mg/kg, MeFOSAA 0.0034mg/kg, PFDA 0.0026mg/kg, PFHxA 0.0006mg/kg, PFOA 0.0006mg/kg, PFOS 0.0213mg/kg, PFUnDA 0.0008mg/kg. Sum of PFAS 0.0421mg/kg, Sum of PFAS (WA DER List) 0.0232mg/kg, Sum of PFHxS & PFOS 0.0213mg/kg

26/3/23: 10:2 FTS 0.0009mg/kg, 8:2 FTS 0.0006mg/kg, EtFOSAA 0.0073mg/kg, FOSE 0.0017mg/kg, MeFOSAA 0.0052mg/kg, PFDA 0.0024mg/kg, PFDoDA 0.0019mg/kg, PFOA 0.0008mg/kg, PFOS 0.0195mg/kg. Sum of PFAS 0.0403mg/kg, Sum of PFAS (WA DER List) 0.0209mg/kg, Sum of PFHxS & PFOS 0.0195mg/kg

30/4/23: PFDA 0.0035mg/kg, PFDoDA 0.0025mg/kg, PFOS 0.0178mg/kg. Sum of PFAS 0.0238mg/kg, Sum of PFAS (WA DER List) 0.0178mg/kg, Sum of PFHxS & PFOS 0.0178mg/kg

28/5/23: 8:2 FTS 0.0012mg/kg, EtFOSAA 0.0027mg/kg, MeFOSAA 0.0021mg/kg, PFDA 0.0025mg/kg, PFOA 0.0006mg/kg, PFOS 0.0161mg/kg. Sum of PFAS 0.0252mg/kg, Sum of PFAS (WA DER List) 0.0179mg/kg, Sum of PFHxS & PFOS 0.0161mg/kg

25/6/23: 10:2 FTS 0.0009mg/kg, 8:2 FTS 0.001mg/kg, EtFOSAA 0.007mg/kg, FOSA 0.0009mg/kg, MeFOSAA 0.0038mg/kg, PFDA 0.0019mg/kg, PFDoDA 0.0011mg/kg, PFOA 0.0007mg/kg, PFOS 0.0261mg/kg. Sum of PFAS 0.0434mg/kg, Sum of PFAS (WA DER List) 0.0278mg/kg, Sum of PFHxS & PFOS 0.0261mg/kg

30/7/23: MeFOSAA 0.0015mg/kg. Sum of PFAS 0.0015mg/kg.

27/8/23: 10:2 FTS 0.0014mg/kg, 8:2 FTS 0.0006mg/kg, EtFOSAA 0.0092mg/kg, FOSA 0.0009mg/kg, MeFOSAA 0.005mg/kg, PFDA 0.0025mg/kg, PFDoDA 0.0014mg/kg, PFDS 0.0054mg/kg, PFOA 0.0009mg/kg, PFOS 0.0289mg/kg. Sum of PFAS 0.0562mg/kg, Sum of PFAS (WA DER List) 0.0304mg/kg, Sum of PFHxS & PFOS 0.0289mg/kg

24/9/23: 10:2 FTS 0.0035mg/kg, MeFOSAA 0.0027mg/kg, PFOS 0.0172mg/kg. Sum of PFAS 0.0234mg/kg, Sum of PFAS (WA DER List) 0.0172mg/kg, Sum of PFHxS & PFOS 0.0172mg/kg

**A mass estimate of perfluoroalkyl substance (PFAS) release from**

**Australian wastewater treatment plants**

Chemosphere 208 (2018) 975e983

C. Gallen a, *, G. Eaglesham a, D. Drage b, T. Hue Nguyen a, J.F. Mueller a

**4. Conclusions**

PFAS were ubiquitously detected in Australian wastewater and

biosolids samples. At 11 of 14WWTPs, effluent PFAS concentrations

exceeded concentrations in the influent by an average of almost 10

times, a likely result of the degradation of precursor chemicals

during the treatment process. To date, there have been no studies

investigating the identities of PFAS-precursors present in Australian

WWTPs. For three of the nine studied PFAS, only a relatively

small proportion (an average of 1% or less of the total loads discharged

from the participating WWTPs) are removed to the biosolids,

with the majority of the load released in the effluent. As PFAS

chain length increased, the proportion of PFAS loads contained

within the biosolids increased. PFAS concentrations were shown to

vary widely between individual WWTPs, suggesting that WWTPs

may be a useful means to identify PFAS-use ‘hotspots’ as well as

cost effectively assessing changes in PFAS use, human exposure and

environmental release over time. While many known point sources

of PFAS such as airports are under scrutiny and undertaking

remediation, WWTPs remain ongoing and largely unregulated

sources. Despite the successful elimination of most PFOS and PFOA

products from large-scale use, the use of other PFAS-containing

products appears to be continuing in Australia. The resistance to

degradation processes together with typically long service lives of

the products that contain PFAS, means that the management of

PFAS in Australian waste will be ongoing, potentially for decades.