Monitoring E. coli in lakes and rivers

Escherichia coli (E. coli) is a common bacteria found in the digestive system of warm-blooded animals, including humans. Because E. coli can survive for a few weeks in freshwater environments it is a useful indicator of the presence of faecal matter of human or animal origin. If E. coli is detected, there may be other pathogens present that can cause illness.

Common sources of E. coli in rivers and lakes are discharges of human wastewater, livestock faeces, bird droppings and stormwater. Management practices to reduce E. coli in waterbodies include stock exclusion, riparian planting, erosion control and pest eradication.

E. coli is a key attribute in the National Policy Statement for Freshwater Management 2020 and councils are required to monitor recreational sites in lakes and rivers at monthly intervals, or more frequently, according to the level of risk of infection. Long-term monitoring of E. coli may be useful for assessing the effectiveness of land mitigation actions.