Yes, that’s right. Sydney Water, along with other states and territories have been testing wastewater for the presence of COVID-19. Well, more accurately, they’ve been testing for COVID-19 fragments, namely the SARS-Cov-2 virus which causes COVID-19. What they’ve been finding is that there’s a strong correlation between where they find these fragments, and in what quantities, and the presence of COVID-19 in surrounding areas. Scientists expect that widespread monitoring of wastewater can be used to confirm outbreaks and provide health professionals with more data to help fight the virus.
How does COVID-19 get into sewage in the first place?
COVID-19 is passed into wastewater from infected people bathing, washing hands, flushing used tissues and just using the toilet. People can still shed the virus for several weeks beyond the infectious period. These factors make testing wastewater a useful tool in tracking virus outbreaks in communities.
Aerial view of sewage treatment plant
Wait, does that mean COVID-19 can survive in water?
Yes, COVID-19 can survive in water for quite a few days and even weeks. The length of time varies depending on the water temperature. However, the tests on wastewater are not necessarily looking for the live virus, just virus fragments which are inactive.
Regarding drinking water possibly being contaminated, there are no studies indicating that COVID-19 can be classified as a waterborne disease. While the virus is transmitted in water droplets aerated by infected people coughing or sneezing nearby, thereby showing it can indeed be carried by water, there are two reasons we can rest assured that our drinking water and swimming pools are quite safe.
Firstly, COVID-19 is very susceptible to chlorine. It is in fact amongst the types of viruses that are easiest to kill with chlorine, so it is unlikely to survive our municipal water treatment process or proper pool maintenance. Water also dilutes the virus, so even without chlorine it is extremely unlikely to be present in sufficient quantities to cause infection. Due to these two factors, COVID-19 is yet to be detected in any drinking water supplies, and there have been no recorded cases of people becoming infected from drinking water.
Similarly, you are not likely to become infected due to exposure to water while swimming at the beach or in public swimming pools. However, these areas can still be places to catch the virus if infected people are present, so social distancing rules still apply. Also be mindful of things that infected people may have touched such as pool gates, door knobs and stair rails.
Can you catch COVID-19 from sewage?
Sewage is treated before it is allowed back into the environment so exposure to treated wastewater is likely to be quite safe. Untreated raw sewage may be another matter if the amount of chlorine remaining in the wastewater has not been sufficient to kill any residual COVID-19 virus. Also, while COVID-19 is unlikely to be present and alive in sufficient quantities to cause infection even in raw sewage, there are a host of other pathogens that may be present, so we definitely don’t recommend drinking or swimming in untreated wastewater, should you be so inclined. (Eww!)