2006/17: Laramba (Napperby) Northern Territory. Uranium, E.coli, Hardness, Iodine, Total Dissolved Solids, Silica

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Laramba (Napperby) Northern Territory – Uranium

Highest Uranium levels recorded recently in breach of Australian Drinking Water Guidelines in Northern Territory:

2007/08: Laramba Uranium 0.04mg/L

2008/09: Laramba Uranium 0.044mg/L

2009/10: Laramba Uranium 0.02895mg/L

2010/11: Laramba Uranium 0.038mg/L

2013/14: Laramba Uranium 0.039mg/L

2015/16: Laramba Uranium 0.04064mg/L

2016/17: Laramba Uranium 0.047mg/L

Uranium (Information Sourced From 2011 Australian Drinking Water Guidelines)
“Based on health considerations, the concentration of uranium in drinking water should not exceed 0.017 mg/L.”

Friends of the Earth Australia An Introduction to Drinking Water Quality Issues.
February 2012

‘Our kids need proper water’: Families plead for action over uranium in drinking water


Some of Australia’s poorest communities have been drinking water high in uranium, and residents have accused governments of ignoring the problem.

Key points:

  • At least three communities in central Australia have levels of uranium in drinking water that exceed health guidelines
  • Dozens of other communities not meeting aesthetic guidelines, which ensure taste, feel and smell are up to standard
  • Residents fear water could be harming them and say governments have failed to act

Many of us turn on the tap without a second thought — high-quality drinking water is supplied to most cities and regions across the country.

But in the Aboriginal community of Laramba, north of Alice Springs, drinking water contains more than double the recommended levels of uranium, and it’s been like that for a decade.

Billy Briscoe, a long-term resident, is deeply concerned about the impact that water is having on his family.

“The really important thing is about kids. Our kids need proper water, not with uranium. They need quality, really good water,” he said.

“We all drink the bore water … if there’s no water, how can you survive?

Official data obtained by the ABC’s 7.30 program shows Laramba’s water supply contains uranium at higher than 0.04 milligrams per litre (mg/L).

Australia’s drinking-water guidelines outline it should not exceed 0.017mg/L.

“The main toxic effect of short-term exposure to high concentrations of uranium is inflammation of the kidney,” according to the National Health and Medical Research Council.

“Little is known about the long-term exposure to low concentrations.”

Most communities in the Northern Territory rely on bore water, pumped up from an aquifer deep underground, which often contains high concentrations of naturally occurring minerals and contaminants — like uranium.

Laramba residents said their appeals for help had been overlooked.

“You have to write letters, you have to email it, but even then [action] don’t come in one day or two days, so you will have to wait one year or two years … It’s just a waiting game,” Mr Briscoe said.

The Australian Medical Association (AMA) said access to safe water was a basic human right and urged governments to invest in treatment facilities in remote parts of the country.

“It is difficult to understand how this hasn’t already been implemented and addressed,” the AMA said in a statement last year.

Laramba (Northern Territory) – E.coli

2006/07 Laramba E.coli 3 samples exceeding trigger level. 93.6% samples within trigger level

2008/09: Laramba E.coli  1 Number of e.coli detections

2009/10: Laramba E.coli 2 e.coli detections 94% performance over year

Laramba (Napperby) 24 March 2011 Significant levels of E. coli were detected in Laramba’s water supply and a Precautionary Advice was issued. Power and Water undertook an inspection to identify the source of contamination and dosed the production bores and storage tanks. The system was then comprehensively flushed to draw the chlorinated water through the rising main and reticulation system to ensure disinfection of the whole water supply system. Following this, analyses of additional water samples confirmed that the water was clear from E. coli and other indicator bacteria and the Department of Health lifted the Precautionary Notice on 11 April.

“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

Laramba – Northern Territory – Hardness

2007/08: Laramba Hardness 332mg/L

2008/09: Laramba Hardness 276mg/L

2009/10: Laramba Hardness 272mg/L

2010/11: Laramba Hardness 272mg/L

2013/14: Laramba Hardness 288mg/L

2015/16: Laramba Hardness 302mg/L

2016/17: Laramba Hardness 304mg/L


“To minimise undesirable build‑up of scale in hot water systems, total hardness (as calcium
carbonate) in drinking water should not exceed 200 mg/L.

Hard water requires more soap than soft water to obtain a lather. It can also cause scale to form on hot water pipes and fittings. Hardness is caused primarily by the presence of calcium and magnesium ions, although other cations such as strontium, iron, manganese and barium can also contribute.”

Australian Drinking Water Guidelines 2011

Laramba – (Northern Territory) – Iodine

2007/08: Laramba Iodine 0.35mg/L

2009/10: Laramba Iodine 0.35mg/L

2013/14: Laramba Iodine 0.29mg/L

2015/16: Laramba Iodine 0.24mg/L

2016/17: Laramba Iodine 0.18mg/L

Iodide: Based on health considerations, the concentration of iodide in drinking water should
not exceed 0.5 mg/L.
Iodine: No guideline value has been set for molecular iodine.
The element iodine is present naturally in seawater, nitrate minerals and seaweed, mostly in the form of iodide salts. It may be present in water due to leaching from salt and mineral deposits. Iodide can be oxidised to molecular iodine with strong disinfectants such as chlorine.
Molecular iodine solutions are used as antiseptics and as sanitising agents in hospitals and laboratories.
Iodine is occasionally used for the emergency disinfection of water for field use but is not used for disinfecting larger drinking water supplies. Iodide is used in pharmaceutical and photographic materials. Iodine has a taste threshold in water of about 0.15 mg/L.
Iodide occurs in cows’ milk and seafood. Some countries add iodide to table salt to compensate for iodide-deficient diets.

Laramba – Northern Territory – Total Dissolved Solids

2016/17: Laramba Total Dissolved Solids 647mg/L


“No specific health guideline value is provided for total dissolved solids (TDS), as there are no
health effects directly attributable to TDS. However for good palatability total dissolved solids
in drinking water should not exceed 600 mg/L.

Total dissolved solids (TDS) consist of inorganic salts and small amounts of organic matter that are dissolved in water. Clay particles, colloidal iron and manganese oxides and silica, fine enough to pass through a 0.45 micron filter membrane can also contribute to total dissolved solids.

Total dissolved solids comprise: sodium, potassium, calcium, magnesium, chloride, sulfate, bicarbonate, carbonate, silica, organic matter, fluoride, iron, manganese, nitrate, nitrite and phosphates…” Australian Drinking Water Guidelines 2011

Laramba (Northern Territory) – Silica

2016/17: Laramba (Northern Territory). Silica 85mg/L

To minimise an undesirable scale build up on surfaces, silica (SiO2) within drinking waters should not exceed 80 mg/L.
Silica present in water is usually referred to as amorphous silica (i.e. lacking any crystalline structure). When silica is dissolved within water it forms monosilicic acid:
SiO2 + 2H2O à Si(OH)4
When the concentrations of monosilicic acid increase, polymerisation of the silica occurs, forming polysilicic acids followed by formation of colloidal silica. Monosilicic acid and polysilicic acids are the forms of silica analysed when determining dissolved silica content.
The deposition of silica from solutions can occur via various mechanisms. The deposition of silica that can cause the most problems for the water industry is via silica’s ability to deposit on solid surfaces that have hydroxyl (OH) groups present. Surfaces that commonly have hydroxyl groups present are glass and metallic surfaces. For example, dissolved silica will react with the surfaces of glass and begin to form a white precipitate. The silica forms silicates on the surface, resulting in silica build-up. In cases where customer complaints occur due to scale build-up, water hardness and silica concentrations should be investigated to determine the cause.
Silica can be a problem in water treatment due to its ability to cause fouling of reverse osmosis (RO) membranes (Sheikholeslami and Tan, 1999, Ning 2002, Sahachaiyunta and Sheikholeslami 2002). This occurs when the dissolved silica of the concentrate becomes super-saturated, causing silicates to form in the presence of metals, and these deposit on the membrane surface. The silicate then dehydrates, forming hard layers on the membrane that reduce the effectiveness of the process… 2011 ADWG