Council has a public health responsibility when it comes to providing advice to members of the public on the suitability of Lake Colac, Kennett River and Wye River for swimming/recreational activity.
The water quality standards, objectives and indicators identifies environmental values that the Victorian community want to achieve and maintain so it is important for those managers of the waterbodies to understand what these values are.
We want to protect the public health of recreational users of the waterbody as best we can.
These waterbodies are also important environmental assets so it is useful to gain data around microbial standards.

Water based recreation water quality standards have short term indicators and objectives for different waterbodies (marine/freshwater/estuarine).
The most common indicator organisms for assessing public health risks in recreational waters, are enteric bacteria, such as faecal coliforms namely enterococci or E.coli.
Our monitoring program starting in November 2023 tests for Enterococci and E.coli organisms.

Any water sample found to contain 200 or more Enterococci organisms (the trigger value) or 260 or more E.coli organisms (freshwater) will result in precautionary signage being erected as soon as possible.
These limits have been set in consultation with the EPA Victoria.
Council has decided to increase the number of tests during periods of expected high activity, such as school holidays and long weekend.
In addition to our testing program we will be making observations in relation to weather conditions and presence of animals/birds and recreational use on the day of sampling (where practicable).
We will identify occasions where the levels have been exceeded and not likely to be related to rain events.

Bacterial indicators are imperfect measures of the health risks associated with swimming in recreational waters and can be explained by:

1. bacterial indicators demonstrate the presence of faecal material, not necessarily the presence of viable pathogens and therefore potential risk to human health.
2. Analysis of bacterial indicators takes 24 to 48 hours, so it is not possible to know the potential risk at the time of swimming/sampling.
3. Water quality can change due to environmental factors after test results receipt and before the next sample is taken, however.

The Environment Reference Standard from the EPA is a tool made under the Environment Protection Act 2017.
It provides a way to assess environmental values in various locations across Victoria for primary contact recreation.

Notes

1. For short term assessment for primary contact water-based recreation, data must be single samples regularly collected during periods of high recreational use.
2. Microbial water quality objectives must be assessed against only dry weather water quality data if warning about risk to water quality from stormwater pollution following rain is communicated to the public by – (i) daily water quality forecasting; and (ii) permanent signs warning of risk after stormwater pollution.
3. Site-specific short term objectives may be derived from a risk assessment approach, following industry best practice and guidance published or approved by EPA to reflect potential health outcomes.

For more information, visit The Environment Reference Standard

Enterococci is a group of various bacteria and common in the gut of mammals and birds, yet they are also opportunistic pathogens that cause millions of human and animal infections annually.

Their abundance in human and animal feces, the ease with which they are cultured, and their correlation with human health outcomes in fresh and marine waters have led to their widespread use as tools for assessing recreational water quality worldwide

The enterococci are most frequently used as fecal indicator bacteria (FIB), or general indicators of fecal contamination.

Infections caused by Enterococci include - but are not limited to - urinary tract infections, skin infections, endocarditis, bacteremia, neonatal infections, central nervous system (CNS) infections, and abdominal and pelvic infections.

Escherichia coli (E. coli) is a bacterium that is commonly found in the gut of humans and warm-blooded animals and could produce a powerful toxin that damages the lining of the small intestine.

E. coli and fecal coliform bacteria indicate that the water may be contaminated with human or animal wastes.

E.Coli is typically a food/water-borne pathogen. It is transmitted to humans primarily through consumption of contaminated foods and water, such as raw or undercooked ground meat products and raw milk. Faecal contamination of water and other foods, as well as cross-contamination during food preparation (with beef and other meat products, contaminated surfaces and kitchen utensils), will also lead to infection.

Symptoms can include severe stomach cramps, bloody diarrhea and vomiting.

E. coli bacteria can easily travel from person to person, especially when infected people don't wash their hands properly.

Lake Colac

Additional results

Wye River & Kennett River

2023-2024 Colac:

2023-2024 Wye River / Kennett River:

*Due to a lab error, only E.coli results were obtained in December 2022.