2/3/12 Echuca E. coli 4 org/100 mL Reticulation 3 org/100 mL Tank

Echuca (Victoria) – Anabaena circinalis

29/12/06: Echuca A.Circinalis 9500 cells/mL Increased monitoring and general surveillance. PAC considered but not used.

Due to the lack of adequate data, no guideline value is set for concentrations of saxitoxins.
However given the known toxicity, the relevant health authority should be notified
immediately if blooms of Anabaena circinalis (Dolichospermum circinalis)1 or other producers
of saxitoxins are detected in sources of drinking water.
GENERAL DESCRIPTION
There are three types of cyanobacterial neurotoxins: anatoxin a, anatoxin a-s and the saxitoxins. The saxitoxins include saxitoxin, neosaxitoxin, C-toxins and gonyautoxins (Chorus and Bartram 1999 Chapter 3). The anatoxins seem unique to cyanobacteria, while saxitoxins are also produced by various dinoflagellates under the name of paralytic shellfish poisons (PSPs). A number of cyanobacterial genera can produce neurotoxins, including Anabaena (Dolichospermum), Oscillatoria, Cylindrospermopsis, Cylindrospermum, Lyngbya and Aphanizomenon, but to date in Australia, neurotoxin production has only been detected from Anabaena circinalis (Dolichospermum circinalis), and the Australian isolates appear to
produce only saxitoxins (Velzeboer et al. 1998). As with most toxic cyanobacteria, A. circinalis (D. circinalis) tends to proliferate in calm, stable waters, particularly in summer when thermal stratification reduces mixing. The toxicity of individual populations of A. circinalis (D. circinalis) is variable, and one extensive survey of the toxicity across the Murray-Darling Basin indicated that 54% of field samples tested were neurotoxic (Baker and Humpage, 1994). A natural population may consist of a mixture of toxic and non-toxic strains and this is believed to explain why population toxicity may vary over time and between samples (Chorus and Bartram 1999 Chapter 3). The saxitoxins are a group of carbamoyl and decarbamoyl alkaloids that are either non-sulfated (saxitoxins), singly-sulfated (gonyautoxins), or doubly-sulfated (C-toxins). The various types of toxins vary in potency, with saxitoxin having the highest toxicity. The prevalent toxins in Australian blooms of A. circinalis are the C-toxins. These can convert in the environment or by acidification or boiling to more potent toxins (Negri et al. 1997, Ravn et al. 1995). The half-lives for breakdown of a range of different saxitoxins in natural water have been shown to vary from 9 to 28 days, and gonyautoxins may persist in the environment for more than three months (Jones and Negri, 1997).

AUSTRALIAN SIGNIFICANCE
Blooms of A. circinalis (D. circinalis) have been recorded in many rivers, lakes, reservoirs and dams throughout Australia, and A. circinalis (D. circinalis) is the most common organism in riverine blooms in the Murray-Darling Basin (Baker and Humpage 1994). In temperate parts of Australia blooms typically occur from late spring to early autumn. The first reported neurotoxic bloom of A. circinalis (D. circinalis) in Australia occurred in 1972 (May and McBarron 1973). The most publicised blooms occurred in the Murray-Darling System in 1991, 2009 and 2010 (NSWBGATF 1992, NSW Office of Water 2009, MDBA 2010). The first bloom extended over 1,000 kilometres of the Darling-Barwon River system in New South Wales (NSWBGATF 1992). A state of emergency was declared, with a focus on providing safe drinking water to towns, communities and landholders. Stock deaths were associated with the occurrence of the bloom but there was little evidence of human health impacts. The blooms in 2009 and 2010
affected several hundred kilometres of the River Murray on the border between NSW and Victoria and included Anabaena, Microcystis and Cylindrospermopsin. Alerts were issued about risks to recreational use, primary contact by domestic users, livestock and domestic animals. A bloom of A. circinalis (D. circinalis) in a dam in New South Wales was shown to have caused sheep deaths (Negri et al. 1995). Relatively low numbers of A. circinalis (D. circinalis) (below 2,000 cells/mL) can produce offensive tastes and odours in drinking water due to the production of odorous compounds such as geosmin… ADWG 2011

Echuca (Victoria) – Aluminium

2016/17: Echuca (Victoria) Aluminium 1mg/L (Highest Level Only)

According to the ADWG, no health guideline has been adopted for Aluminium, but that the issue is still open to review. Aluminium can come from natural geological sources or from the use of aluminium salts as coagulants in water treatment plants. According to the ADWG “A well-operated water filtration plant (even using aluminium as a flocculant) can achieve aluminium concentrations in the finished water of less than 0.1 mg/L.

The most common form of aluminium in water treatment plants is Aluminium Sulfate (Alum). Alum can be supplied as a bulk liquid or in granular form. It is used at water treatment plants as a coagulant to remove turbidity, microorganisms, organic matter and inorganic chemicals. If water is particularly dirty an Alum dose of as high as 500mg/L could occur. There is also concern that other metals may also exist in refined alum.

While the ADWG mentions that there is considerable evidence that Aluminium is neurotoxic and can pass the gut barrier to accumulate in the blood, leading to a condition called encephalopathy (dialysis dementia) and that Aluminium has been associated with Parkinsonism dementia and amyotrophic lateral sclerosis, the NHMRC, whilst also acknowledging studies which have linked Aluminium with Alzheimer disease, has not granted Aluminium a NOEL (No Observable Effect Level) due to insufficient and contradictory data. Without a NOEL, a health guideline cannot be established. The NHMRC has also stated that if new information comes to hand, a health guideline may be established in the future.

In communication with Aluminium expert Dr Chris Exley (Professor in Bioinorganic Chemistry
The Birchall Centre, Lennard-Jones Laboratories, Keele University, Staffordshire UK) in March 2013 regarding high levels of Aluminium detected in the South Western Victorian town of Hamilton
“It is my opinion that any value above 0.5 mg/L is totally unacceptable and a potential health risk. Where such values are maintained over days, weeks or even months, as indeed is indicated by the data you sent to me, these represent a significant health risk to all consumers. While consumers may not experience any short term health effects the result of longer term exposure to elevated levels of aluminium in potable waters may be a significant increase in the body burden of aluminium in these individuals. This artificially increased body burden will not return to ‘normal’ levels when the Al content of the potable water returns to normal but will act as a new platform level from which the Al body burden will continue to increase with age.

Echuca – Victoria – Total Dissolved Solids

2005/06: Echuca (Victoria) – Total Dissolved Solids 1100 μS/cm (max), 1000μS/cm (min)

GUIDELINE

“No specific health guideline value is provided for total dissolved solids (TDS), as there are no
health effects directly attributable to TDS. However for good palatability total dissolved solids
in drinking water should not exceed 600 mg/L.

Total dissolved solids (TDS) consist of inorganic salts and small amounts of organic matter that are dissolved in water. Clay particles, colloidal iron and manganese oxides and silica, fine enough to pass through a 0.45 micron filter membrane can also contribute to total dissolved solids.

Total dissolved solids comprise: sodium, potassium, calcium, magnesium, chloride, sulfate, bicarbonate, carbonate, silica, organic matter, fluoride, iron, manganese, nitrate, nitrite and phosphates…” Australian Drinking Water Guidelines 2011

Echuca (Victoria) – Taste & Odour

21/3/12 Echuca Taste Flooding upstream of the raw water supply caused very high levels of taste and odour compounds in the raw water, exceeding the treatment capacity for some taste and odour compounds.

12/1/23: Echuca • Elevated concentrations of Taste & Odour (T&O) compounds, but mainly geosmin, were impacting the Murray River which is the source water for Echuca Water Treatment Plant (WTP).
• The concentration of T&O compounds in the raw water exceeded the capacity of the treatment process to fully remove them
• The treated water leaving the WTP exceeding the T&O threshold (10 ng/L), mentioned in the ADWG.

Corrective actions:
• The PAC system was run to capacity.
• Communication to public was via Coliban Water’s website, social media, and ABC radio (who had made direct enquiry).

Echuca (Victoria) Nickel

7/8/17: Echuca Nickel 0.05mg/L

A sample, collected from the distribution system, as part of Coliban Water’s sampling program, had an elevated level of nickel (0.05 mg/L), exceeding the health-based guideline value for
nickel (0.02mg/L) in the ADWG. The investigation concluded that the nickel exceedance was an
anomaly. No obvious cause of the exceedance was found, and the investigation showed this was an isolated incident and not an ongoing issue.

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.

2022 – Echuca (Victoria) – Turbidity

13/10/22: • The stormwater pumps within the Echuca WTP were unable to keep up with the amount of water flowing across the site (specifically at one location)
• This area was adjacent to where the below ground treated water storages are located,
• Turbidity data indicated stormwater had entered one of the treated water storages.
• A BWA was put in place as there was potentially unsafe drinking water being
supplied to customers.

Corrective actions:
• The impacted tank was immediately isolated.
• Flushing of the network was undertaken.
• Chlorine and turbidity sampling was undertaken at the contact point at the WTP and customer tap sample points across the Echuca WSL.
• Water sampling results confirmed the water was safe to drink.
• Consulted with DH following review of sampling results information, enabling lifting of the BWA
• A tank reinstatement plan was developed and implemented.
• Tank brought back on-line in early December 2022.
Preventative measures
• Stormwater drainage pit size to be verified
• Additonal pumps installed.

24/10/22: • A high turbidity reading on SCADA from the Treated Water Storage (TWS) (only
one storage on-line, because of the ingress issue on 13/10/22 described above) raised a potential quality issue.
• Maintenance works at the WTP required the online TWS to be run lower than usual, and when it was being refilled it filled faster than normal, as only one tank was on-line.
• This high velocity fill disturbed sediment on the bottom of the tank.

Corrective actions:
• A tank inspection was undertaken externally, and no signs of infiltration were found.
• An operator looked and listened inside the tank and could not hear or see any infiltration.
• The off-line storage was also checked to ensure that it remained the same, verifying that there was no cross contamination.
• Chlorine and turbidity results were verified and were found to be within drinking water guidelines.
• Customers were advised that the colour of their water may be not as clear as normal.

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

Echuca (Victoria) – Manganese

27/10/22: • Flood water in the Murray River was high in manganese,
• Colour of the drinking water triggered some customer complaints.

Corrective actions:
• The water treatment process was enhanced to manage manganese and optimise its removal.
• Customers were communicated to via Coliban Water’s website and social media channels (Facebook & Twitter)

Manganese: ADWG Guidelines 0.5mg/L. ADWG Aesthetic Guideline 0.1mg/L
Manganese is found in the natural environment. Manganese in drinking water above 0.1mg/L can give water an unpleasant taste and stain plumbing fixtures and laundry.