1997/2017 – Oakey (Queensland) – Trihalomethanes, PFAS, Hardness, Total Dissolved Solids

Oakey (Queensland) – Trihalomethanes

2016/17: Oakey – Reticulation (Queensland) – Trihalomethanes 287μg/L (highest detection)

2016/17: Oakey – Transmission (Queensland) – Trihalomethanes 295μg/L (highest detection)

2016/17: Oakey – Water Treatment Plant (Queensland) – Trihalomethanes 316μg/L (highest detection)

(Toowoomba Regional Council DWQMP Annual Report 2016-17 Appendix B)

Trihalomethanes Australian Guideline Level 250μg/L (0.25mg/L)

Why and how are THMs formed?
“When chlorine is added to water with organic material, such as algae, river weeds, and decaying leaves, THMs are formed. Residual chlorine molecules react with this harmless organic material to form a group of chlorinated chemical compounds, THMs. They are tasteless and odourless, but harmful and potentially toxic. The quantity of by-products formed is determined by several factors, such as the amount and type of organic material present in water, temperature, pH, chlorine dosage, contact time available for chlorine, and bromide concentration in the water. The organic matter in water mainly consists of a) humic substance, which is the organic portion of soil that remains after prolonged microbial decomposition formed by the decay of leaves, wood, and other vegetable matter; and b) fulvic acid, which is a water soluble substance of low molecular weight that is derived from humus”. US EPA

Oakey (Queensland) – PFAS Background


Chapter 2

Army Aviation Centre Oakey and RAAF Base Williamtown revisited

2.19      Oakey has been supplied with potable water from the Mt Kynoch Water Treatment Plant since the commissioning of the Toowoomba Oakey Pipeline (TOP) on 15 December 1997. Previously, water was supplied exclusively from bores that were put down most likely during the Second World War. Consequently, the water quality in Oakey was ‘…fairly poor. Any hot water systems or any filters were blocked up pretty quickly’:[22]

The bore water associated with the local ball field out here had a reasonable mineral load in it—a mineral load based on conductivity and total dissolved solids—and it was also quite hard. The hardness values of that water were around 500 milligrams per litre and, based on the National Health and Medical research Council guidelines, good quality water should be between 60 and 200 milligrams per litre.[23]

2.20      For a decade from 1999, the region experienced a significant drought. The Toowoomba Regional Council submission described measures that were taken in an effort to drought-proof the community:

In 2006 the State Government provided funding to construct a Reverse Osmosis (RO) Water Treatment Plant as part of the overall drought response measures to supplement dwindling reserves in the Toowoomba supply storages.[24]

2.21      The Oakey bore field was brought back on line for approximately four years from October 2008 to supply feed water to the newly-commissioned Oakey Reverse Osmosis Water Treatment Plant (Oakey RO WTP) before the plant was taken offline for maintenance in November 2012. That meant that water coming out of the bores through the RO process was blended with more water from the bores and further blended with water from Toowoomba to supplement the supply for Oakey:

Extraction from the bore field continued until the RO WTP and supply bores were taken out of service on 30 November 2012. Since the cessation of the supplementary supply from the RO WTP, water supply in Oakey has been exclusively sourced from the Mt Kynoch WTP via the Oakey Toowoomba pipeline.[25]

2.22      It was likely that the RO process would have removed any chemical of concern, including PFOS or PFOA, at that time as it is able to remove large molecules. Council was of the view that while the water going into the system contained contaminants, it ‘…would have been in-line with health guidelines that were around, if there were any at the time’.[26] At the 9 May public hearing, Council elaborated:

It is about an 80-20 mix. It is 80 per cent water going through the RO plant, which is pure water, mixed with about 20 per cent of raw bore water to make a shandy, which then went to the large reservoirs on the hill here. Then it was blended with a further 30 per cent—a 30-70 blend—of Toowoomba water. The blend, we believe, would have been well below the limits that were around at the time…It was 0.3 micrograms per litre, I think.[27]

2.23      Council advised that because AACO is located on the same aquifer from which Oakey RO WTP draws feed water ‘…the presence of perfluoroalkyl substances (PFAS) in the aquifer originating from prolonged use of firefighting chemicals at the Centre…meant that the Oakey RO WTP could not be returned to service due to the risk of toxicity that PFAS presents’.[28] Any maintenance activities have been put on hold due to the groundwater contamination.

2.24      Council further assured the committee that the residents of Oakey currently have access to clear, clean water: ‘You can rest assured that is the case for everybody who is connected to the reticulated supply…provided by the Toowoomba Regional Council [which] is up to the Australian Drinking Water Guidelines’.[29]

Impact of contamination on the Oakey community

2.25      Evidence presented to the committee demonstrates that while contamination has caused significantly elevated levels of PFOS/PFOA in the blood of many Oakey residents, the health implications flowing from these elevated levels are far from clear. Shine Lawyers argued that while scientific opinion around the world varies as to the water quality guidance value for PFOS in freshwater, ‘…what is obvious is that levels at Oakey are many multiples of what is considered a “safe” level of exposure from drinking water’. This includes elevated levels of PFOA in the town water supply bore 8 located at the Oakey showgrounds, and PFOS concentrations above the adopted drinking water limit at 42 of the 112 bores tested, one of 13 creek samples tested and 39 of 43 drainage line locations tested.[30]

2.26      Dr Donaldson advised the committee that he had investigated the distribution of several perfluorinated compounds in the plume area with the cooperation of neighbours and other residents and with the assistance of colleagues:

To my chagrin and surprise my results exposed a much greater level of exposure than expected. As a matter of professional courtesy I sent some of my results to the Department of Defence. The results were subsequently confirmed.[31]

2.27      Dr Donaldson expressed the view that the media has presented a ‘…damning portrayal of Oakey by linking the whole district to health threatening contamination’,[32] as a consequence of ill-advised public meetings and injudicious statements by public officials (such as ‘do not drink the bore water’ and ‘PFOS is the new Asbestos’). His submission argued that the adverse perceptions of Oakey ‘…should not be allowed to fester as there is potential for far reaching damage’.[33]

Concerns of residents

2.28      The committee received many submissions from residents concerned about elevated levels of PFOS/PFOA in their blood, the sudden decrease in value of their properties and the stress the contamination issue has placed on their families.[34] The overall sense of anxiety was captured by the submission from Ms Robyn Wilkins:

I am really concerned about the valuation of my property due to the contamination from the Oakey Army Base through no fault of my own…Neither the Queensland Government or the Commonwealth Government have done anything to help us, we feel like we have been abandoned. Our property is set up for horse training and this requires a substantial and secure water supply. We can’t go on like this. I just don’t know what to do. We are in dire need of any assistance you can give to end the indefinite hanging in the air. We desperately need a resolution to this problem the Army has created.[35]

2.29      Similar evidence was received from Mr Brad Hudson, whose property is located approximately 400 metres from the Army base, about the effects of using contaminated bore water for over 15 years to shower, wash, clean, drink, water stock and hose gardens. His submission described how he, his wife and three children have ‘extremely high’ levels of PFOS in their blood and are worried about the effects on their future health:

My 5 year old daughter has high levels already at her young age. God knows how this will effect her in her future life. My levels…are extremely high and concerning since I have already had testicular cancer at my age of 42. It is extremely hard to close my eyes at night thinking about my family and our futures with these contaminants in our systems at the high levels that they are…

Wouldn’t mind if someone from government was to live a life of uncertainty like we are forced to do. Deal with the stress and headaches that come with our lives now, which is at time unbearable. To try waking up one day and realising that their $700000 property is worth next to nothing now.

We need the government…and the army to step up and take full responsibility of the situation and to do whatever it takes to fix this problem. Our futures are depending on it.[36]