2003/22: Ti Tree (Northern Territory) – E.coli, Nitrate, Hardness, Iodine, Silica, Uranium

Ti-Tree (Northern Territory) – E.coli

2007/8 Ti-Tree E.coli 2 exceedances.  96.1% of samples within guidelines

“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

Ti Tree (Northern Territory) – Nitrate

2005/6: Ti Tree Nitrate 52.1mg/L (95th %)

2006/07: Ti-Tree Nitrate 52.1mg/L

2007/08: Ti-Tree Nitrate 52mg/L

2008/2009: Ti Tree Nitrate 67mg/L

2009/10: Ti Tree Nitrate 64mg/L

2010/11: Ti-Tree Nitrate 58mg/L

2011/12: Ti-Tree Nitrate 58mg/L (95th %)

2012/13: Ti-Tree Nitrate 56mg/L (95th %)

2013/14: Ti-Tree Nitrate 60mg/L (95th %)

2014/15: Ti-Tree Nitrate 62mg/L (95th %)

2015/16: Ti-Tree Nitrate 61mg/L (95th %)

2016/17: Ti-Tree Nitrate 60mg/L (95th %)

2018/19: Ti-Tree Nitrate 60mg/L (95th %)

2019/20: Ti-Tree Nitrate 55mg/L (95th %)

2020/21: Ti-Tree Nitrate 60mg/L (av.)

Nitrate: ADWG Guideline 50mg/L. Nitrate is the product of oxygenated nitrogen created from the breakdown of organic matter; lightning strikes; inorganic pesticides; or explosives. The Australian Drinking Water Guidelines recommend that nitrate levels between 50-100mg/L are a health consideration for infants less than three months, although levels up to 100mg/L can be safely consumed by adults. Mainly a problem in Northern Territory and some communities in Western Australia. “Cue, Meekatharra, Mount Magnet, New Norcia, Sandstone, Wiluna and Yalgoo have been granted an exemption from compliance with the nitrate guideline by the Department of Health. The water supplied is harmless to adults and children over the age of 3 months of age. Carers of infants younger than three months should seek advice from the Community Health Nurse regarding the use of alternative water sources for the preparation of bottle feeds. The Water Corporation provides bottled water free of charge for this purpose.”

Ti Tree – Northern Territory – Hardness

2003/04: Ti-Tree Hardness 230mg/L

2004/05: Ti Tree Hardness 203mg/L

2005/06: Ti Tree Hardness 203mg/L

2006/07: T- Tree Hardness 206mg/L

2007/08: Ti-Tree Hardness 206mg/L

2008/09: Ti Tree Hardness 208mg/L

2010/11: Ti-Tree Hardness 202mg/L

2011/12: Ti-Tree Hardness 201mg/L

2012/13: Ti-Tree Hardness 205mg/L

2013/14: Ti-Tree Hardness 209mg/L

2014/15: Ti-Tree Hardness 222mg/L

2015/16: Ti-Tree Hardness 223mg/L

2016/17: Ti-Tree Hardness 228mg/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

Ti Tree (Northern Territory) Iodine

2006/07: Ti-Tree Iodide 0.11mg/L

2007/08: Ti-Tree Iodide 0.11mg/L

2008/09: Ti Tree Iodide 0.18mg/L

2009/10: Ti-Tree Iodide 0.17mg/L

2010/11: Ti-Tree Iodide 0.17mg/L

Ti Tree (South Australia) – Silica

2012/16: Ti-Tree Silica 94mg/L

2016/17: Ti-Tree Silica 89mg/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

Ti-Tree (Northern Territory) – Uranium

2003/4: Naturally occurring uranium concentrations above the guideline value have been identified in the drinking water supply at Ti Tree and Pmara Jutunta. The community has been informed and the Department of Health and Community Services has stated that there is no immediate threat to public health. A new groundwater supply has been developed close to Pmara Jutunta that has both uranium and total dissolved solids below guideline values. Power and Water is in the process of building a pipeline that will connect the new bore water supply to Ti Tree/Pmara Jutunta. The new borewater supply will be operational in 2004-2005.

2002-04: Ti Tree (Northern Territory) Uranium 0.04mg/L

Australian Drinking Water Guidelines 2011

Uranium (Information Sourced From 2011 Australian Drinking Water Guidelines)
“Based on health considerations, the concentration of uranium in drinking water should not exceed 0.02 mg/L.”