Watching waste in waterways
2022 saw record-breaking, heavy flooding along Australia’s east coast. In the months that followed, water pollutants travelled along the Murray Darling from Queensland, through New South Wales & Victoria to South Australia, leading to the worst mass fish deaths in Menindee. What’s clear is that issues occurring upstream affect communities downstream that rely on water for survival.
How does climate change increase water pollution?
Menindee is not an isolated incident and illustrates how climate change impacts our access to safe drinking water. As global temperatures rise, humidity levels in the atmosphere also rise, increasing risk of flash flooding events in Australia. In the past decade, Australia has seen a 10% increase in flash flooding events. This rain washes pollutants such as animal fecal matter into waterways. In a 2014 study, E. coli concentrations peaked at 3x higher than average, two days after heavy rainfall (>15mm/24hrs) from sewerage and animal waste enter into waterways.
Australian rainfall deciles
Rainfall deciles map legend
How is water hygiene monitored
Coliform and E.coli are the standard bacteria tests for environmental contamination. Presence of coliform via a total coliform count test, is the first sign a water system has been contaminated. Most coliform is harmless, but a subset of coliform referred to as E. coli or O157:H7 is responsible for causing disease.
By measuring both Coliform and E. coli, water management authorities can ensure water is safe for consumption and where the contamination has originated from.
Total Coliform, Fecal Coliform, and E. coli
Human Health - E. coli contamination increases risk of1:
- Gastrointestinal discomfort
- Severe stomach cramps
- 3-5% fatality risk
Sources of e-coli O157:H7 contamination:
- Aerosol deposition
- Tree litter
- Animal fecal matter
- Indigenous growth in biofilms and sediments
- Sewerage run-off
- Storm water overflow
- Agricultural run-off
- EC Blue Bottles & Sachets
- Whirlpak Thio Bag
- Compact Dry EC
- Microfast EC
- View Murray Darling River Water Quality Map
- View NSW water quality incidents
- Learn about United Nations Sustainable Development Goal (UN SDG) 6: Clean Water and Sanitation
1 E. coli (no date) World Health Organization. World Health Organization. Available at: https://www.who.int/news-room/fact-sheets/detail/e-coli (Accessed: May 8, 2023).