2007/8 Castlemaine E.Coli. 1orgs/100ml 98.5% samples no e.coli (1 positive)
2010/11 Castlemaine E.coli 1/100mL (98.5% samples no e.coli ) (1 positive)
28/2/12 Castlemaine (Kalimna) E.coli 1/100mL
21/3/12 Castlemaine (Kalimna) E.coli 1/100mL
6/1/20: Castlemaine (Kalimna Basin). (Drinking Water Locality Impacted-Castlemaine, Guildford, Harcourt). A routine sample collected on 6 January 2020 at the outlet of the Kalimna Basin in the Castelamine water supply system was positive for the presence of E. coli (25 Orgs/100mL). The E. coli detection was most likely the result of the combination
of the following issues: potential pathways for rainwater ingress into the basin, a rainfall event on the day the sample was collected, and low chlorine disinfectant residual in the basin.
Performance of the Castlemaine WTP and upstream distribution network were verified, with no
issues identified. Kalimna Basin was inspected, with possible points of ingress of rainwater through the roof identified. The ingress points were repaired and tested to avoid a similar event
occurring in the future. The basin was dosed with sodium hypochlorite from 7 – 9 January
2020 targeting a free chlorine residual of 0.8 mg/L.
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
Castlemaine (Victoria) – Nickel
7 Nov 2016 – Castlemaine (Victoria) – Nickel 0.1mg/L
5/2/18: Castlemaine (Victoria) – Nickel 0.066mg/L
A sample, collected from the distribution system as part of Coliban Water’s sampling
program, had an elevated level of nickel (0.066 mg/L), exceeding the health-based guideline value for nickel (0.02mg/L) in the ADWG. The investigation undertaken has concluded that the nickel exceedance appears to be an unexplainable anomaly. It was an isolated incident and not an ongoing issue, and the probable cause of the elevated nickel result was contamination during sampling procedures.
Nickel: ADWG Health Guideline 0.02mg/L. A chemical element and silvery white corrosion resistant metal with a golden tinge. 60% of nickel production is used in nickel steel (particularly stainless steel). In water, mainly a problem with nickel plated fittings. Main releases to the environment are from the burning of fossil fuels and in waste discharges from electroplating industries.
2005/6 – Castlemaine (Victoria) – Turbidity
2005/6 – Castlemaine (Victoria) – Turbidity 7NTU (maximum detection)
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