Ayr (Queensland) – PFAS
After receiving a directive from the Department of Health advising drinking water service providers test their drinking water for PFAS as soon as practicable and after an internal risk assessment,
BSC commenced PFAS sampling with the 6 bores at Nelsons Borefield in Ayr.
Results for initial samples taken by Queensland Health on 29 March 2018 showed levels in all bores in Nelsons, South Ayr and Home Hill tested below the draft ADWG guideline limit of 0.07 ug/L total PFOS/PFAxS. Queensland Health decided to resample on 9 May 2018. Test results received on Friday 25th May showed Bores 2 and 5 Nelsons over the draft limits with results as
• Bore 2 – 0.22 ug/L
• Bore 5 – 0.18 ug/L
Bores 2 and 5 Nelsons were immediately turned off and tagged out within an hour of results being received
• The Mayor and Chief Executive Officer were informed in relation to test results and actions
• DNRME, the Water Supply Regulator was informed of the test results by phone at 3pm via the DWQI hotline and in writing by 5pm
• Resampling of all Nelsons zone area plus three reticulation locations South Ayr – Basin Tap, Council Chambers and Ayr Water Tower was performed on 28 May 2018. Bores 1, 3, 4, 5 and 6 plus the three reticulation samples all returned results under the guideline value.
• Follow up sample results for PFOS/PFAxS as follows:
o 28/05/2018 – Nelsons Bore 2 – 0.43 ug/L
o 28/05/2018 – Nelsons Bore 5 – 0.03 ug/L
o Reticulation network samples on 7 June and 12 June 2018 returned results well below the guideline value.
o 14 June 2018 – Bore 2 Nelsons – 0.42 ug/L (standing) and 0.43 ug/L (running)
o 14 June 2018 – Bore 5 Nelsons – 0.029 ug/L (standing) and 0.066 ug/L (running)
Bores 2 and 5 Nelsons remain switched off and no longer in use. Council is investigating the installation of additional bores for the Ayr/Brandon network in areas with no PFAS detection.
Monitoring of PFAS is ongoing in both the BSC’s raw water and reticulation network. These samples will be added to the Verification Monitoring Schedule of the Council’s DWQMP.
Drinking Water Quality Management Plan
Annual Report 2017/18 Burdekin Shire Council
“Coliforms are Gram-negative, non-spore-forming, rod-shaped bacteria that are capable of aerobic and facultative anaerobic growth in the presence of bile salts or other surface active agents with similar growth-inhibiting properties. They are found in large numbers in the faeces of humans and other warm-blooded animals, but many species also occur in the environment.
Thermotolerant coliforms are a sub-group of coliforms that are able to grow at 44.5 ± 0.2°C. E. coli is the most common thermotolerant coliform present in faeces and is regarded as the most specific indicator of recent faecal contamination because generally it is not capable of growth in the environment. In contrast, some other thermotolerant coliforms (including strains of Klebsiella, Citrobacter and Enterobacter) are able to grow in the environment and their presence is not necessarily related to faecal contamination. While tests for thermotolerant coliforms can be simpler than for E. coli, E. coli is considered a superior indicator for detecting faecal contamination…” ADWG 2011