2016/22: Marla (South Australia) – E.coli, Nitrate, Temperature

Marla Non-potable drinking water supply
Marla (South Australia): E.coli

22/3/22: Marla Non Potable E.coli E.coli 1 MPN/100ml

23/5/22: Marla Non Potable E.coli E.coli 1 MPN/100ml

“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

Marla (South Australia) – Nitrate – Non Potable

2019/20: Marla (South Australia)  Nitrate + Nitrate as NO3 63.35mg/L (max), 58.47mg/L (av.) non-potable

26/8/20: Marla (South Australia) Nitrate + Nitrate as NO3 58.92mg/L (Non potable system-Non Potable Zone)

18/11/20: Marla (South Australia) Nitrate + Nitrate as NO3 64.24mg/L (Non potable system-Non Potable Zone)

24/2/21: Marla (South Australia) Nitrate + Nitrate as NO3 51.83mg/L (Non potable system-Non Potable Zone)

26/5/21: Marla  (South Australia) Nitrate + Nitrate as NO3 61.13mg/L (Non potable system-Non Potable Zone)

14/2/22: Marla Non Potable Nitrate + Nitrite 65.56mg/L (max) (av. 2021/22 48.36mg/L)

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.”

Marla – South Australia – Temperature

NON POTABLE DRINKING WATER

August 15 2016: Marla (South Australia) – Temperature 21C

November 22 2016: Marla (South Australia) – Temperature 33C

February 21 2017: Marla (South Australia) – Temperature 34C

May 23 2017: Marla (South Australia) – Temperature 25C

Marla Non Potable Temperature 11/8/21-22/3/22 >20C. 22/3/22 32C (max)

GUIDELINE

“No guideline is set due to the impracticality of controlling water temperature.
Drinking water temperatures above 20°C may result in an increase in the number of
complaints.

Temperature is primarily an aesthetic criterion for drinking water. Generally, cool water is more palatable than warm or cold water. In general, consumers will react to a change in water temperature. Complaints are most frequent when the temperature suddenly increases.

The turbidity and colour of filtered water may be indirectly affected by temperature, as low water temperatures tend to decrease the efficiency of water treatment processes by, for instance, affecting floc formation rates and sedimentation efficiency.

Chemical reaction rates increase with temperature, and this can lead to greater corrosion of pipes and fittings in closed systems. Scale formation in hard waters will also be greater at higher temperatures…

Water temperatures in major Australian reticulated supplies range from 10°C to 30°C. In some long, above-ground pipelines, water temperatures up to 45°C may be experienced…

The effectiveness of chlorine as a disinfectant is influenced by the temperature of the water being dosed. Generally higher temperatures result in more effective disinfection at a particular chlorine dose, but this may be counterbalanced by a more rapid loss of chlorine to the atmosphere (AWWA 1990).

Chlorine reacts with organic matter in water to produce undesirable chlorinated organic by-products, and higher temperatures increase the rate of these reactions.

Temperature can directly affect the growth and survival of microorganisms. In general the survival time of infectious bacteria and parasites is reduced as the temperature of the contaminated water increases.

Australian Drinking Water Guidelines 2011