2011/18: Garawa (Northern Territory) – E.coli, Lead, pH

Garawa (Northern Territory) – E.coli
6/12/2017: Garawa (Northern Territory) E.coli 43 and 109 MPN/100ML
The Garawa E. coli detection in December 2017 was at the tank outlet. The primary response was to ensure adequate chlorination of the tank and water supply, followed by an investigation into the cause of the contamination. Corrective actions were taken quickly so consequently DoH did not need to issue alerts in response to the E. coli detection. Samples were collected after the corrective actions and showed that the water was free of E. coli. The investigation found that the chlorination system was unreliable and planning to improve was started.
Power and Water Corporation Water Quality Report 2018
The Gunn Point incident was likely due to low level faecal contamination from small animals, while inadequate chlorination due to a chlorination system disruption is likely to have contributed to identification of E.coli in samples from the Garawa and Newcastle Waters
water supplies.
Power and Water Corporation Water Quality Report 2016
Garawa 14 August 2013: Samples with E.coli detections (1). Number of E.coli detected in sample: 9 (MPN/10ml)

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

Garawa (Northern Territory) – Lead
“Lead was detected from a single sample site in Garawa and a precautionary alert was issued. An investigation concluded internal plumbing was the cause and repairs have since resolved the issue.” Note that in the 2018 Annual Drinking Water Report the lead sample was known as a “anomalous lead result” and the result was excluded from publication!? (Power and Water Annual Drinking Water Quality Report 2018)
Highest Lead Detections Garawa 2011-18:
2011/12: 0.001mg/L
2012/13: 0.01mg/L
2013/14: 0.005mg/L
2014/15: 0.007mg/L
2015/16: 0.014mg/L
2016/17: 0.01mg/L
2017/18: >=0.01mg/L?

Lead Australian Drinking Water Guideline 0.01mg/L

“… Lead can be present in drinking water as a result of dissolution from natural sources, or from household plumbing systems containing lead. These may include lead in pipes, or in solder used to seal joints. The amount of lead dissolved will depend on a number of factors including pH, water hardness and the standing time of the water.

Lead is the most common of the heavy metals and is mined widely throughout the world. It is used in the production of lead acid batteries, solder, alloys, cable sheathing, paint pigments, rust inhibitors, ammunition, glazes and plastic stabilisers. The organo-lead compounds tetramethyl and tetraethyl lead are used extensively as anti-knock and lubricating compounds in gasoline…ADWG 2011

Indigenous mining town residents demand blood tests after lead found in water


Indigenous residents in the Northern Territory mining town of Borroloola are calling on the Health Department to blood test families, amid revelations their water supply has been contaminated with lead.

Key points:

  • Residents resort to buying bottled water after town camps advised not to drink water supplies
  • Glencore says ‘no indication’ contamination linked to McArthur River Mine
  • Separate lead contamination incidents detected in 2014

The Territory Government posted notices around the remote community on Thursday, telling residents of the Garawa 1 and Garawa 2 town camps not to drink, cook, or brush their teeth with the water.

The notices advise the contamination is a “short-term problem”, and babies, young children and pregnant woman are “most likely to be affected by drinking water with lead in it”.

It said the government-owned Power and Water Corporation (PWC) was investigating the problem, and would test the water in Garawa again to ensure it was safe to drink.

The Department of Health released a statement confirming that routine testing of the Garawa community water supply, near Borroloola, had identified that one sampling point had returned an elevated level of lead.

Another sampling point returned an elevated level of lead and manganese.

Gawara community leader Keith Rory said the community was extremely concerned.

“It’s frightened us. It’s frightened people all over the region. People are very scared,” he said.

“Its a big concern, not only for the Garawa camps, but for all the clan groups.

“People are getting bottled water from the shop now.”

Residents not ‘jumping to conclusions’

Indigenous residents have feared lead would show up in their drinking water since 2014, when it was revealed Glencore’s McArthur River Mine lead-zinc operation had contaminated cattle and fish.

The company was forced to admit it was the source of the pollution after the Northern Territory Environment Centre carried out its own tests on water in McArthur River tributaries. 

In a separate revelation, the company was found to be responsible for the lead contamination of up to 400 head of cattle — but this was not made public until 2015, a year after it was found to have occurred.

Mr Rory said that while residents were not jumping to conclusions until all possible sources for the water contamination had been ruled out, the community wanted the Health Department to start blood testing their children immediately.

“We don’t know whether it’s coming from old pipes, or there’s lead in the water itself. Those are the two options we are thinking about now,” he said.

“I want them to take it deeper, investigate, not only testing the water.

“I also want to see the little babies, who aren’t drinking only breast milk, and kids, from small to big, start getting tested.”

Mr Rory and other community leaders have been pushing for blood tests since the mine lead contamination incidents were revealed.

In a statement Glencore said: “There is no indication this incident is in any way related to McArthur River Mining’s operations.

“McArthur River Mining undertakes comprehensive monthly water quality testing in a number of locations in and around the site, including from McArthur River near the Borroloola community.

“These results have consistently shown lead levels to be significantly below the Australian Drinking Water Guidelines.”

Mine applying to expand

Glencore is currently going through an Environment Impact Assessment application to the Northern Territory and Federal Governments to double the size of the mine.

Mr Rory said the application should be refused if any evidence came to light that the water contamination had been caused by a discharge from one of the mine dams into the McArthur River, or run-off or seepage from the mine’s reactive waste rock dump.

“If it is, the mine should close, otherwise people in Borroloola will get sick. Maybe even me, from drinking this all up,” he said. 

“We have been saying all the time that we want to fight for our land and for our water and our hills and trees so that our new generation coming up will see good things happening.”

Mr Rory said despite Power and Water Corporation advising the community there was “some concern” about the water last year, a notification to stop drinking it was not offered until yesterday.

The ABC has sought response from the organisation as to when the contamination was found and when the source is expected to be identified.

In a statement, the Department of Health said PWC was undertaking an investigation to determine the cause, but advised the water bore itself did not contain elevated levels of lead and manganese.

It said sampling and testing of water from the reticulation system was being expedited.

“In the interim a water tanker has been organised, and will be located in the community to provide a short term alternative drinking water supply,” the statement said.

Garawa (Northern Territory) – pH (acidic)

2011/12: Garawah pH 5.8

2012/13: Garawah pH 6.0

2013/14: Garawah pH 6.0

2014/15: Garawah pH 6.0

2015/16: Garawah pH 5.8

2016/17: Garaway pH 5.8

Based on the need to reduce corrosion and encrustation in pipes and fittings, the pH of
drinking water should be between 6.5 and 8.5.

New concrete tanks and cement-mortar lined pipes can significantly increase pH and
a value up to 9.2 may be tolerated, provided monitoring indicates no deterioration in
microbiological quality.

pH is a measure of the hydrogen ion concentration of water. It is measured on a logarithmic scale from 0 to 14. A pH of 7 is neutral, greater than 7 is alkaline, and less than 7 is acidic.

One of the major objectives in controlling pH is to minimise corrosion and encrustation in pipes and fittings. Corrosion can be reduced by the formation of a protective layer of calcium carbonate on the inside of the pipe or fitting, and the formation of this layer is affected by pH, temperature, the availability of calcium (hardness) and carbon dioxide. If the water is too alkaline (above pH 8.5), the rapid deposition and build-up of calcium carbonate that can result may eventually block the pipe.