PFAS are a class of manufactured chemicals that have been used since the 1950s to make products that resist heat, stains, grease and water. PFAS has been identified as an emerging contaminant and investigations are underway in all Australian jurisdictions.

PFAS in Katherine

Power and Water carries out an extensive sampling program throughout the year on its drinking water sources, in accordance with Department of Health approvals and the Australian Drinking Water Guidelines (ADWG).

These results represent the average results from 1098 tap water samples, 251 bore water and 230 river water samples and 143 PFAS treated water samples to 31 July 2020.

Power and Water is undertaking regular sampling of drinking water in Katherine. Testing for PFAS is conducted by laboratories interstate. Results of tests are provided to the Department of Health and updated each month. The test results of samples provided are below the Health Based Guidance Values for PFAS.

Based on results that have been submitted to Department of Health, Dr Hugh Heggie Chief Health Officer has advised that public drinking water in Katherine is safe for consumption.

Average PFAS1 Levels µg/L 
(ie micrograms per litre)

Location

Description

ΣPFHxS and PFOS

PFOA

Reference value

FSANZ Health Based Guidance Values for drinking water quality2

0.07 µg/L

0.56 µg/L

Katherine Reticulation

Reticulation (tap) water

0.004

0.002

Katherine

Raw bore water

0.2

0.005

Katherine

Raw surface water

<0.001

<0.001

Katherine

PFAS treated water - final tank

<0.001

<0.001

1 Î£PFHxS and PFOS = sum of PFHxS and PFOS

2 Whole of life exposure health based guidance values for use in site investigations in Australia

* All values reported preceded with < indicate the value is below the level of detection of the analysis method.

PFAS in the Northern Territory

In response to a request from Department of Health in 2017, PFAS is now included as part of our water quality testing program.

Power and Water is undertaking regular sampling of drinking water. Testing for PFAS is conducted by laboratories interstate. Results of tests are provided to the Department of Health and updated each month. The test results of samples provided are below the Health Based Guidance Values for PFAS.

Based on results that have been submitted to Department of Health, Dr Hugh Heggie Chief Health Officer has advised that public drinking water is safe for consumption.

Current average results of PFAS testing of drinking water to 31 May 2019:

Average PFAS1 Levels µg/L 
(ie micrograms per litre)

Location

Description

ΣPFHxS and PFOS

PFOA

Reference value

FSANZ Health Based Guidance Values for drinking water quality2

0.07 µg/L

0.56 µg/L

Alice Springs

Reticulation (tap) water

<0.001*

<0.001*

Darwin

Reticulation (tap) water

<0.001

<0.001

Tennant Creek

Reticulation (tap) water

<0.001

<0.001

Yulara

Reticulation (tap) water

<0.001

<0.001

Adelaide River

Reticulation (tap) water

0.01

0.001

Batchelor

Reticulation (tap) water

0.01

0.001

Cox Peninsula

Reticulation (tap) water

<0.001

<0.001

Borroloola

Reticulation (tap) water

<0.001

<0.001

Garawa

Reticulation (tap) water

<0.001

<0.001

Daly Waters

Reticulation (tap) water

<0.001

<0.001

Elliot

Reticulation (tap) water

<0.001

<0.001

Gunn Point

Reticulation (tap) water

<0.001

<0.001

Kings Canyon

Reticulation (tap) water

<0.001

<0.001

Larrimah

Reticulation (tap) water

<0.001

<0.001

Mataranka

Reticulation (tap) water

<0.001

<0.001

Newcastle Waters

Reticulation (tap) water

<0.001

<0.001

Pine Creek

Reticulation (tap) water

0.009

0.002

Ti Tree

Reticulation (tap) water

<0.0001

<0.0001

Timber Creek

Reticulation (tap) water

<0.001

<0.001

1 Î£PFHxS and PFOS = sum of PFHxS and PFOS

2 Whole of life exposure health based guidance values for use in site investigations in Australia

* All values reported preceded with < indicate the value is below the level of detection of the analysis method.

PFAS in remote communities

Preliminary investigations have been conducted at five communities in close proximity to Katherine. Results indicate that all samples of the drinking water are well below the Australian guidance values released on 3 April 2017. Additional monitoring will be undertaken in liaison with Department of Health.

Maximum PFAS1 Levels µg/L 
(ie micrograms per litre)

Location

Description

ΣPFHxS and PFOS

PFOA

Reference value

New FSANZ Health Based Guidance Values for drinking water quality2

0.07 µg/L

0.56 µg/L

Barunga

Raw surface water

<0.02

<0.01

Binjari

Raw bore water

<0.02

<0.01

Jilkminggan

Reticulation (tap) water

<0.02

<0.01

Eva Valley

Reticulation (tap) water

<0.02

<0.01

Kybrook Farm

Raw bore water

<0.02

<0.01

1 ΣPFHxS and PFOS = sum of PFHxS and PFOS

2 Whole of life exposure health based guidance values for use in site investigations in Australia

* All values reported preceded with < indicate the value is below the level of detection of the analysis method.

PFAS testing at wastewater facilities

Power and Water has undertaken testing for PFAS at seven wastewater treatment facilities. This is part of a coordinated program to gauge PFAS contamination in the Northern Territory.

Results to date indicate that none of the facilities have contaminated surface waters and are not a source of contaminated surface water to the environment.

Table 1: The contamination thresholds for individual PFAS in surface waters PFOS or PFOA concentrations (NSW EPA 2016)

Trigger Point 1

Elevated contamination

10 μg/L

Trigger Point 2

Current screening guideline

0.1 μg/L

Trigger Point 3

Low level of contamination

0.05 μg/L

Trigger Point 4

Limits to analytical methodologies

**0.01 μg/L

**The laboratory used by Power and Water had Limits of Reporting PFOS=0.00042, PFHxS=0.00022, PFOA=0.00018

Table 2: Screening level results Power and Water wastewater facilities - January 2017

Location

Average concentration (µg/L)

 

PFOS

PFHxS

PFOA

Alice Springs

   

Influent onsite

0.0011

<0.00022

0.0014

Effluent onsite (no discharge)

0.017

0.0049

0.016

Recycled water

0.00083

0.0023

0.011

Katherine

   

Influent on site

0.014

0.018

0.0023

Effluent on site (no discharge)

0.016

0.015

0.0047

Tennant Creek

   

Influent onsite

0.0061

0.0047

0.0036

Effluent onsite (no discharge)

0.0036

0.0011

0.0069

Darwin

   

Ludmilla

   

Influent onsite

0.010

0.005

0.016

Effluent offsite

0.0044

0.0016

0.0012

Leanyer Sanderson

   

Influent onsite

0.013

0.0060

0.0019

Effluent offsite

0.013

0.0051

0.023

Palmerston

   

Domestic Influent onsite

0.00063

<0.00022

0.0011

Trade Waste Influent onsite*

<0.0003

<0.0003

<0.0003

Effluent offsite

0.0034

0.0005

0.00061

Berrimah

   

Influent onsite

0.0080

0.0056

0.002

Effluent offsite

0.013

0.010

0.012

*The trade waste stream was sampled in December 2016 and sent to a different laboratory with Limits of Reporting PFOS=0.0003, PFHxS=0.0003, PFOA=0.0003

REFERENCES

NSW EPA Environmental Risk Sciences Pty Ltd (enRiskS) (2016)

Proposed Decision Tree for Prioritising Sites Potentially Contaminated with PFASs

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