Santa Teresa (Northern Territory) – E.coli

2006/07: Santa Teresa E.coli. 4 samples exceeding trigger level. 90.9% within trigger level

“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

Santa Teresa – Northern Territory – Hardness

2007/08: Santa Teresa Hardness 255mg/L

2008/09 Santa Teresa Hardness 255mg/L

2009/10: Santa Teresa Hardness 248mg/L

2010/11: Santa Teresa Hardness 249mg/L

2013/14: Santa Teresa Hardness 254mg/L

2015/16: Santa Teresa Hardness 251mg/L

2016/17: Santa Teresa Hardness 269mg/L

2021/22: Santa Teresa Hardness 300mg/L (av.)

GUIDELINE

“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.”

Santa Teresa (Northern Territory)  Selenium

2009/2010: Santa Teresa Selenium 0.003mg/L (max)

2010/2011: Santa Teresa Selenium 0.003mg/L (max)

2013/2014: Santa Teresa Selenium 0.003mg/L (95% percentile)

2015/2016: Santa Teresa Selenium 0.003mg/L (95th percentile)

Based on health considerations, the concentration of selenium in drinking water should not exceed 0.004 mg/L (2011-2025 guideline 0.01mg/L). “General description Selenium (Se) and selenium salts are widespread in the environment. Selenium is released from natural and human-made sources (such as the burning of coal). Selenium is also a by-product of the processing of sulfide ores, chiefly in the copper refining industry. The major use of selenium is in the manufacture of electronic components. It is used in several other industries, and selenium compounds are used in some insecticides, in hair shampoos as an antidandruff agent, and as a nutritional feed additive for poultry and livestock. Selenium copper alloys have also been identified as a potential replacement for lead copper alloys in plumbing products. Further information on lead replacements in plumbing products (such as selenium copper alloys) is available in Information Sheet 4.1 – Metal and metalloid chemicals leaching from plumbing products. Selenium concentrations in drinking water source waters are generally very low and depend on local geochemistry, climatic conditions (e.g. drought), pH and the presence of iron salts. Selenium in water is mainly present as inorganic compounds, predominantly selenate. Weathering of rocks and soil may result in low levels of selenium in water, which may be taken up by plants (SLR 2022). Food is the major source of intake for Australians. Cereal and grain products contribute most to intake, while fish and liver contain the highest selenium concentrations.” ADWG 2025

2006/22 – Santa Teresa (Northern Territory) – E.coli, Hardness, Selenium

Santa Teresa (Northern Territory) – E.coli 2006/07: Santa Teresa E.coli. 4 samples exceeding trigger level. 90.9% within trigger level “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 Santa Teresa – Northern Territory – Hardness 2007/08: Santa Teresa Hardness 255mg/L 2008/09 Santa Teresa Hardness 255mg/L 2009/10: Santa Teresa Hardness 248mg/L 2010/11: Santa Teresa Hardness 249mg/L 2013/14: Santa Teresa Hardness 254mg/L 2015/16: Santa Teresa Hardness 251mg/L 2016/17: Santa Teresa Hardness 269mg/L 2021/22: Santa Teresa Hardness 300mg/L (av.) GUIDELINE “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.” Santa Teresa (Northern Territory)  Selenium 2009/2010: Santa Teresa Selenium 0.003mg/L (max) 2010/2011: Santa Teresa Selenium 0.003mg/L (max) 2013/2014: Santa Teresa Selenium 0.003mg/L (95% percentile) 2015/2016: Santa Teresa Selenium 0.003mg/L (95th percentile) Based on health considerations, the concentration of selenium in drinking water should not exceed 0.004 mg/L (2011-2025 guideline 0.01mg/L). “General description Selenium (Se) and selenium salts are widespread in the environment. Selenium is released from natural and human-made sources (such as the burning of coal). Selenium is also a by-product of the processing of sulfide ores, chiefly in the copper refining industry. The major use of selenium is in the manufacture of electronic components. It is used in several other industries, and selenium compounds are used in some insecticides, in hair shampoos as an antidandruff agent, and as a nutritional feed additive for poultry and livestock. Selenium copper alloys have also been identified as a potential replacement for lead copper alloys in plumbing products. Further information on lead replacements in plumbing products (such as selenium copper alloys) is available in Information Sheet 4.1 – Metal and metalloid chemicals leaching from plumbing products. Selenium concentrations in drinking water source waters are generally very low and depend on local geochemistry, climatic conditions (e.g. drought), pH and the presence of iron salts. Selenium in water is mainly present as inorganic compounds, predominantly selenate. Weathering of rocks and soil may result in low levels of selenium in water, which may be taken up by plants (SLR 2022). Food is the major source of intake for Australians. Cereal and grain products contribute most to intake, while fish and liver contain the highest selenium concentrations.” ADWG 2025