2005/06 – 2010: Tallangatta (Victoria) – Aluminium, Turbidity, Taste & Odour

Tallangatta (Victoria) – Aluminium

“One of the reported aluminium  incidents resulted in reports of illness.  This occurred in the water locality of  Tallangatta, where reports of illness  were received after a plant malfunction
caused an excess amount of aluminium to enter the system. All reported instances of illness related to short-lived feelings of nausea upon drinking the water. Upon becoming aware of the
issue the relevant water business, North East Water, took prompt corrective action to ensure that customers did not consume the water and that the problem  was fixed.” Annual Report on Drinking Water Quality 2005-06

Tallangatta (Victoria) – Turbidity

17/10/10–19/10/10 Tallangatta Dirty Water – elevated turbidity in reticulation (~8NTU)

Heavy rainfall resulted in increased turbidity in Lake Hume at Tallangatta. Despite instrumentation shutting down the WTP, a slug of dirty water passed through the filters and entered the CWS. The turbid water was not identified by operational staff until it began to supply the reticulation. Once identified, the bulk of the turbid water was able to be flushed from the reticulation within a few hours. Additional monitoring was also undertaken.

As similarities and timing of both dirty water events coincided, similar long term actions were implemented. Additionally, checks of CWS water quality is linked to incident

response procedures were implemented.

18/02/11-approx. 2 months Tallangatta Widespread public complaint Due to rise in Lake Hume, high algal presence caused Taste and Odour compounds to be present in the drinking water. This caused widespread public complaint. Powdered Activated Carbon dosing was initiated, however took time to optimise. Further monitoring and improved operations at the plant reduced the levels of the T&O compounds.

“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.”