20/2/20: A routine sample collected on 20 February 2020 at a sampling point on a trunk main that supplies treated drinking water to Spring Gully water sampling locality in the Bendigo water supply system tested positive for the presence of E. coli (1 Orgs/100mL). No probable root cause that could have led to secondary microbial contamination in the Bendigo
distribution network was identified.
Performance of the Bendigo WTP was reviewed with no issues identified A review of the upstream network distribution identified low chloramine disinfection residual in some parts of the affected locality. A number of actions are being undertaken to improve the chlorine residual in the Bendigo distribution network in order to prevent similar issues occurring in the future,
which includes the following: 1. Improved water quality monitoring; 2. A system wide, short-term period of free chlorination is being considered for the 2020/21 summer to manage
nitrification in the distribution system.
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
Bendigo – Spring Gully (Victoria) Lead
2007/08 – Bendigo – Spring Gully (Victoria) – Lead 0.011mg/L
Lead Australian Drinking Water Guideline 0.01mg/L
“… Lead can be present in drinking water as a result of dissolution from natural sources, or from household plumbing systems containing lead. These may include lead in pipes, or in solder used to seal joints. The amount of lead dissolved will depend on a number of factors including pH, water hardness and the standing time of the water.
Lead is the most common of the heavy metals and is mined widely throughout the world. It is used in the production of lead acid batteries, solder, alloys, cable sheathing, paint pigments, rust inhibitors, ammunition, glazes and plastic stabilisers. The organo-lead compounds tetramethyl and tetraethyl lead are used extensively as anti-knock and lubricating compounds in gasoline…ADWG 2011
Bendigo/Spring Gully (Victoria) Nickel
25/1/18 Bendigo/Spring Gully Nickel 0.036mg/L
A sample, collected from the distribution system as part of Coliban Water’s sampling
program, had an elevated level of nickel (0.036 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.