2012/17 + 2021 – Mount Morgan Water Treatment Plant (Queensland) – Giardia, E.coli, Turbidity, Aluminium, Taste & Odour

Rockhampton Regional Council to provide a full emergency water supply to Mount Morgan

9 April 2021

Rockhampton Regional Council has commenced using water tankers to provide a full emergency water supply to Mount Morgan following the drop in quality of the water left in the No. 7 Dam.

Around 20 truckloads of water a day will deliver drinking water from Gracemere to the Mount Morgan Water Treatment Plant, which will provide 160 litres of water per person per day.

This announcement comes after issues raised by residents about the taste and odour of the water coming from the dam.

Rockhampton Region Mayor Tony Williams has assured Mount Morgan community that the water is still very much safe to drink.

“We know that as the dam level has fallen – it’s now sitting at 8.6% – residents have experienced a change in the taste of the water coming from their taps as the dam water continues to slowly deteriorate,” Mr Williams said .

“We tried a number of things to tackle this, including bringing a few truckloads of water up a day and adding an extra step to our water treatment process.

“While there has been a small improvement it’s not enough, so we will now start bringing this emergency water supply up from Gracemere.”

In early March, the Council carried out successfully a trial to test the logistics of getting water tankers from Gracemere to Mount Morgan.

The Council is currently taking six truckloads of water a day to Mount Morgan, and Mayor Williams said this will be ramped up to 20 over the next week.

“The State Government had been covering the cost of trucking water to Stanthorpe until their recent rainfall, and we are in discussions with them to do the same for the people of Mount Morgan,” he said.

“This is a temporary emergency measure to ensure the residents have access to good quality drinking water, but Council is absolutely committed to finding a long term sustainable solution for Mount Morgan’s water security and I am looking forward to the public meeting next Tuesday.”

Water and Supporting a Better Environment Councillor Donna Kirkland said there would be no change to how people accessed their water.

“We knew this would be a possibility if there was no significant rainfall, so over a month ago we carried out trials to fine tune the arrangements and logistics of trucking the water up to ensure that we were ready to go,” Ms Kirkland said.

“Around 20 truckloads a day will be driven up via the Razorback, with the water placed into the reservoir at the Mount Morgan Water Treatment Plant.

“There’s no need for Gracemere residents to worry about their supply; we’ll be sending extra water that way if required.

“The water will then be disinfected again just to make sure its quality is still high after the journey, and will then be distributed using the same water distribution system that supplies water to the Mount Morgan community now. You will be able to turn on your taps as normal.

“We will be able to answer questions about this, as well as exploring options for the long term water security of Mount Morgan, at the public meeting next week.”

Divisional Councillor Cherie Rutherford said Council was listening to residents and taking action.

“Every call that’s come through, every email that’s been sent, and every conversation residents have had with us directly: they all play a really important role in our decision making,” Ms Rutherford said.

“There is still enough water left in the dam for a few months, and once treated it’s safe to drink, but we have heard what people have said about the change in the taste.

“We tried a range of things to address that taste, unfortunately from resident feedback it would seem these measures weren’t as effective as we’d hoped. Once this trucking gets going residents should see a real difference.

2015/2016 – Mt Morgan WTP (Queensland) – Giardia

As part of the annual verification monitoring program, samples were collected from the Mount Morgan WTP (potable water) and No. 7 Dam (raw water source) for Giardia analyses. The result obtained for the potable water sample was 1 cyst per 20L while the raw water sample had <1 cyst per 20L. The test results for the potable sample did not contain any other unusually high or non-compliant results for a range of physical-chemical parameters including turbidity.
At the day of sampling, the daily in-house water testing results measured a turbidity of 0.62 NTU, a free chlorine residual of 1.61 mg/L and a pH of 7.53. There were no known excursions to normal operations at the WTP during days prior to the time of sampling. The telemetry data were also within the normal operating range. There was no known immediate impact for the Giardia detection within and downstream of the WTP.

“Although known as a human parasite for 200 years, Giardia has been regarded seriously as an agent of disease only since the 1960s. It has been identified as an important waterborne pathogen, and linked to many outbreaks of illness associated with drinking water, particularly in North America. Although the importance of this organism has been established, there are large gaps in knowledge about it, and there are no tests for identifying the presence of human infectious species in water.

Giardia has a relatively simple life cycle involving two stages: a flagellate that multiplies in the
intestine, and an infective thick-walled cyst that is shed intermittently but in large numbers in faeces. Concentrations of cysts as high as 88,000 per litre in raw sewage and 240 per litre in surface water havebeen reported (Wallis et al. 1996). Giardia is typically present in larger numbers in Australian sewagethan Cryptsoporidium. Cysts are robust and can survive for weeks to months in fresh water.

There are a number of species of Giardia, but human infections (giardiasis) are usually assigned to one, G. intestinalis (= G. lamblia and G. duodenalis). G. intestinalis infections have been reported from domestic and wild animals, but the host range of human infectious species is uncertain. Although substantial advances have been made in the sampling and counting of cysts, there are currently no established methods to identify human infectious organisms in water. Waterborne outbreaks of giardiasis have generally been linked to consumption of untreated or unfiltered surface water and contamination with human waste.

Consumption of contaminated drinking water is only one of several mechanisms by which transmission (faecal-oral) can occur. Recreational waters, including swimming pools, are also emerging as an important source of giardiasis. However, excluding outbreaks, by far the most likely route of transmission is by direct contact with a human carrier. Transmission of Giardia can also occur by contact with infected animals and occasionally through contaminated food.” ADWG 2011

2014 June – Mt Morgan WTP (Queensland) – E.coli

A reticulation sample collected on 22 June 2014 from the Mt Morgan water supply scheme tested positive (1 MPN/100ml) for E. coli. At the time of the sampling the free chlorine residual
measured from the sampling point and supply reservoir were 0.48 mg/L and 1.63 mg/L, respectively. A second split (parallel) sample collected on the 22 June for general physico-chemical testing was also analysed for E. coli but tested negative for the bacteria. All follow-up samples taken from the sample site, supply reservoir, and other reticulation sampling points tested negative for E. coli.

“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

2012/13 – Mount Morgan WTP  (Queensland) Turbidity

2012/13 Mount Morgan WTP (Queensland)

High turbidity WTP Flow rate reduced; Adjusted coagulation dose rates

Chlorine-resistant pathogen reduction: Where filtration alone is used as the water treatment
process to address identified risks from Cryptosporidium and Giardia, it is essential
that filtration is optimised and consequently the target for the turbidity of water leaving
individual filters should be less than 0.2 NTU, and should not exceed 0.5 NTU at any time
Disinfection: A turbidity of less than 1 NTU is desirable at the time of disinfection with
chlorine unless a higher value can be validated in a specific context.
Aesthetic: Based on aesthetic considerations, the turbidity should not exceed 5 NTU at the
consumer’s tap.

Mount Morgan WTP (Queensland) – Aluminium

2017/18: Mount Morgan WTP Aluminium 0.59mg/L (max), 0.176mg/L (av.)

According to the ADWG, no health guideline has been adopted for Aluminium, but that the issue is still open to review. Aluminium can come from natural geological sources or from the use of aluminium salts as coagulants in water treatment plants. According to the ADWG “A well-operated water filtration plant (even using aluminium as a flocculant) can achieve aluminium concentrations in the finished water of less than 0.1 mg/L.

The most common form of aluminium in water treatment plants is Aluminium Sulfate (Alum). Alum can be supplied as a bulk liquid or in granular form. It is used at water treatment plants as a coagulant to remove turbidity, microorganisms, organic matter and inorganic chemicals. If water is particularly dirty an Alum dose of as high as 500mg/L could occur. There is also concern that other metals may also exist in refined alum.

While the ADWG mentions that there is considerable evidence that Aluminium is neurotoxic and can pass the gut barrier to accumulate in the blood, leading to a condition called encephalopathy (dialysis dementia) and that Aluminium has been associated with Parkinsonism dementia and amyotrophic lateral sclerosis, the NHMRC, whilst also acknowledging studies which have linked Aluminium with Alzheimer disease, has not granted Aluminium a NOEL (No Observable Effect Level) due to insufficient and contradictory data. Without a NOEL, a health guideline cannot be established. The NHMRC has also stated that if new information comes to hand, a health guideline may be established in the future.

In communication with Aluminium expert Dr Chris Exley (Professor in Bioinorganic Chemistry
The Birchall Centre, Lennard-Jones Laboratories, Keele University, Staffordshire UK) in March 2013 regarding high levels of Aluminium detected in the South Western Victorian town of Hamilton
“It is my opinion that any value above 0.5 mg/L is totally unacceptable and a potential health risk. Where such values are maintained over days, weeks or even months, as indeed is indicated by the data you sent to me, these represent a significant health risk to all consumers. While consumers may not experience any short term health effects the result of longer term exposure to elevated levels of aluminium in potable waters may be a significant increase in the body burden of aluminium in these individuals. This artificially increased body burden will not return to ‘normal’ levels when the Al content of the potable water returns to normal but will act as a new platform level from which the Al body burden will continue to increase with age.