2006/8 + 2016/17+21 – Koo Wee Rup (Victoria) – E.coli, Colour, Turbidity, Boil Water Alert

Boil Water Advisory for Koo Wee Rup Lifted.

Precautionary boil water advisory – your water may not be safe to drink.

We’re currently investigating the cause of possible contaminated water entering the local water supply in Koo Wee Rup. We are working to return the water supply to normal, however contaminated water is still in some areas. This has resulted in potentially unsafe water entering the drinking water system and customer taps.

We’re working closely with Department of Health to resolve this issue, and as a precautionary measure, a boil water advisory is being issued until completely resolved.

This applies to the Koo Wee Rup in South East Water’s service area.

Our teams are working around the clock to address this issue.

Until we can guarantee that the water is safe to drink again, we ask customers who live and work in Koo Wee Rup to boil their water.

To ensure your water is safe

We advise you to bring water to a rolling boil before drinking, preparing beverages, washing and preparing food, preparing baby formula, brushing teeth and making ice until further notice.

  • Boil water in a kettle with an automatic cut-off or on the stove until it boils strongly, with a rapid stream of air-bubbles from the bottom of the kettle or pan.
  • Once you have boiled the water, allow it to cool.
  • You can store it in the fridge in clean, closed containers for drinking or food preparation – you do not need to boil it again.

Take care not to injure or scald yourself when you handle boiling water, especially around children

Unboiled water can still be used for showering and bathing, flushing toilets, washing dishes and clothes and garden watering. Ensure you do not drink water when you are in the bath and take extra care when bathing infants.

Unboiled water can still be used to wash your hands

Emergency drinking water is available from tankers in Koo Wee Rup.

We will have water tankers on site from 8.00 am to 8.00 pm to provide emergency drinking water at the following locations:

·         Koo Wee Rup Primary School, 28-34 Moody Street, Koo Wee Rup

Customers will need to bring their own bottles, pots, kettles, etc. to fill up from the tankers.

We are working to ensure that emergency drinking water is available to those who need it. If you have special needs and require assistance, please contact us on 131 694.

What to do if you feel unwell

Contaminated water can cause gastro-like symptoms. If you experience any of these symptoms, please contact your GP and advise your GP about this notice.

This is a precaution

Boiling water is recommended as a precaution to minimise any health risks. Special care should be taken with young children, people whose immune system is compromised and the elderly.

We are working to return water supply to normal as soon as possible. If you have further concerns, please call us 24 hours a day on 131 694.

Koo Wee Rup  – (Victoria) – E.coli

The fourth E. coli detection in a routine sample was at Koo Wee Rup Lower Level Tank, on 3 January 2008 (19 E. coli organisms per 100mL) with a free chlorine residual of 0.02mg/L. The tank is supplied by the Tarago- Westernport Pipeline. No customers are supplied water from Koo Wee Rup Lower Level Tank, but are supplied from Koo Wee Rup Higher Level Tank which undergoes secondary chlorination to maintain a chlorine residual of 0.5 to 0.7mg/L, before entering the distribution system to supply customers in the Koo Wee Rup distribution zone.

All system checks were clear and the re-sample at the same tap taken on the following day was clear of E. coli. This incident was notified late to the DHS, but South East Water has since put in place a protocol to ensure that this cannot occur again.
The eighth E. coli detection in a routine sample was at Koo Wee Rup Lower Level Tank, on 28 February 2008 (1 E. coli organism per 100mL) with a free chlorine residual of 0.03mg/L. The tank is supplied by the Tarago- Westernport Pipeline. No customers are supplied by water from Koo Wee Rup Lower Level Tank, but are supplied from Koo Wee Rup Higher Level Tank which undergoes secondary chlorination to maintain a chlorine residual of 0.5 to 0.7mg/L, before entering the distribution system to supply customers in the Koo Wee Rup distribution zone.
All system checks were clear and the re-sample at the same tap taken on the following day was clear of E. coli.
https://southeastwater.com.au/SiteCollectionDocuments/LearnAboutWater/WaterQuality/WaterQualityReport200708.pdf
The third E.coli detection was from a routine sample taken at Koo Wee Rup Low Level Tank on 4 December 2008 (10 E.coli organisms per 100mL) with a free chlorine residual of 0.01 mg/L. This tank is supplied from Cardinia via the Tarago-Westernport Pipeline. No customers are
supplied with water directly from Koo Wee Rup Lower Level Tank, but are supplied from Koo Wee Rup Higher Level Tank which undergoes secondary chlorination, before entering the distribution system to supply customers in the Koo Wee Rup distribution zone. The tank was isolated and cleaned before being retested and put back online. The re-sample was clear of
E.coli.
https://southeastwater.com.au/SiteCollectionDocuments/LearnAboutWater/WaterQuality/WaterQualityReport200809.pdf
The first notification was for a sample collected on 22 March 2017 from Koo Wee Rup Low Level Tank with a recorded E. coli result of 1 org/100mL. The sample tap is located on the side of the tank adjacent to the tank inlet pipe.
The incoming supply to Koo Wee Rup Low Level Tank is off Melbourne Water’s Tarago– Westernport Pipeline. Water from Koo Wee Rup Low Level Tank is dosed on the outlet using sodium hypochlorite (chlorine) before being pumped to Koo Wee Rup High Level Tank and Lang Lang Basin. The water is then stored in the Koo Wee Rup High Level Tank and Lang Lang Basin before being supplied directly to the customers.
The Koo Wee Rup Low Level Tank was isolated, with Koo Wee Rup High Level Tank and Lang Lang basin both having enough capacity to supply all downstream customers until Koo Wee Rup Low Level Tank could be spot-dosed. The tank was inspected for signs of damage or ingress. No issues were identified. There were no treatment plant issues at Melbourne Water’s Tarago Water Treatment Plant, and there were no works in the area that affected the supply to Koo Wee Rup Low Level Tank. The sample tap was checked and there were no signs of contamination on the fitting. A resample was taken from the Koo Wee Rup Low Level Tank, with the results showing E. coli of 0 orgs/100mL.
Additional samples were taken upstream of the original sample location, as well as two samples collected from customer sample taps within the reticulation system, with the results from all these locations also showing E. coli of 0 orgs/100mL.
Following the resamples, the Koo Wee Rup Low Level Tank was spot-dosed with sodium hypochlorite and another sample was taken the following day. The results from the post dose resamples showed E. coli of 0 orgs/100mL.
Based on the results and investigation and after consultation with the Department of Health and Human Services, it was agreed this positive result was not representative of the drinking water supplied to the Koo Wee Rup water sampling locality, and was deemed to be a false positive as per the definition of the E.coli standard in the Safe Drinking Water Regulations 2015.

https://southeastwater.com.au/SiteCollectionDocuments/AboutUs/WaterQualityReport201617.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

Koo Wee Rup (Victoria) – Colour

2006/7: Koo Wee Rup (Victoria) – Colour Apparent 30 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…

Koo Wee Rup – Victoria – Turbidity

2006/7: Koo Wee Rup (Victoria) – Turbidity 5.3 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.