https://southeastwater.com.au/SiteCollectionDocuments/AboutUs/Annual_Drinking_Water_Quality_Report_2012-13.pdf
Escherichia coli should not be detected in any 100 mL sample of drinking water. If detected
in drinking water, immediate action should be taken including investigation of potential
sources of faecal contamination.
“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
Pakenham (Victoria) – Colour
2006/7: Pakenham (Victoria) – Colour Apparent 20 HU (Highest Level Only)
Based on aesthetic considerations, true colour in drinking water should not exceed 15 HU.
“… Colour is generally related to organic content, and while colour derived from natural sources such as humic and fulvic acids is not a health consideration, chlorination of such water can produce a variety of chlorinated organic compounds as by-products (see Section 6.3.2 on disinfection by-products). If the colour is high at the time of disinfection, then the water should be checked for disinfection by-products. It should be noted, however, that low colour at the time of disinfection does not necessarily mean that the concentration of disinfection by-products will be low…
Pakenham – Victoria – Turbidity
2006/7: Pakenham (Victoria) – Turbidity 7.4 NTU (Maximum detection during year)
2012/13: Pakenham (Victoria) – Turbidity 9.2 NTU (Maximum detection during year)
Chlorine-resistant pathogen reduction: Where filtration alone is used as the water treatment
process to address identified risks from Cryptosporidium and Giardia, it is essential
that filtration is optimised and consequently the target for the turbidity of water leaving
individual filters should be less than 0.2 NTU, and should not exceed 0.5 NTU at any time
Disinfection: A turbidity of less than 1 NTU is desirable at the time of disinfection with
chlorine unless a higher value can be validated in a specific context.
Aesthetic: Based on aesthetic considerations, the turbidity should not exceed 5 NTU at the
consumer’s tap.
Petrochemicals 2023 – Source South East Water Drinking Water Quality Report 2022/23
“On 19 May 2023, we attended to a taste and odour complaint at a group of factories in
Pakenham. This comprised 12 factories all supplied from an internal privately-owned ring
main, with a suspected petrochemical contamination of their internal water supply.
The inspection by the water quality technician revealed strong hydrocarbon odours at
several factories.
The garden tap adjacent to the water meter (the meter outlet being the extent of our asset responsibility) had no odour or taste. The hydrant out the front of the property, located on our water main, was also checked with no odour detected.
A low hazard dual check backflow device was present after the water meter. The backflow
device was replaced with a high hazard device by the owners corporation at our request.
The technician then found barrels of chemicals including paint thinner sitting outdoors
behind one of the factories, assumed to be illegally dumped by an unknown person. An inspection of the drums showed they were leaking out of the bottom and the area smelled
strongly of thinners.
The original plumber was contacted, who confirmed that the internal pipework was
polyethylene pipe.
We notified the owners corporation to advise them about the issue, including the need to
notify occupants not to consume the water or use it for washing purposes. The water was for
toilet flushing only.
Water quality testing was conducted, with a number of factories sampled, as well as at the
meter coming into supply, and also from a hydrant on our water main.
The results of the water sampling were received a few days later, confirming that there was
no petrochemical detection in our supply main, but there were petrochemical compounds
detected in the private main. The factory with the dumped barrels yielded the higher
concentrations within the complex, albeit none of the parameters exceeding ADWG health
limits.
The occupants at the property were all notified of the issue, with water quality results
showing no contamination within our network.
In our view, the contamination was caused by petrochemicals leaching through the wall of
the medium density polyethylene internal plumbing pipework, most likely from the leaking
barrels on site. We provided assistance and advice to the owners corporation upon request
while they undertook their own investigation and fixed the issue.” SEW