COVID-19 Wastewater Surveillance Program
To protect the health and wellbeing of all South Australians and help stop the spread of COVID-19, a range of surveillance measures are in place to rapidly detect COVID-19 in the community.
SA Health and SA Water test wastewater for fragments of SARS-CoV- 2, the virus that causes Coronavirus disease (COVID-19).
Samples are collected at a number of wastewater treatment plants and at selected subcatchment locations across South Australia.
Testing wastewater can help track COVID-19 infections in the community and provide early warning of cases.
An infected person can shed virus in their faeces even if they do not have any symptoms. Shedding can continue for several weeks after they are no longer infectious.
Wastewater sample collection sites
Wastewater samples will be routinely collected in the below areas.
Additional wastewater testing may be conducted in other locations, in addition to regular surveillance across the sites below.
For a full list of suburbs in the subcatchment areas, see Wastewater sample collection sites by suburb (PDF 271KB).
Metropolitan wastewater treatment plants
|Sample site||Sample site name||Subcatchment areas|
|M02||Bolivar High Salinity||Subcatchments BH1-3|
|M04||Christies Beach||Subcatchments C01-4|
Rural wastewater treatment plants
|Sample site||Sample site name||Subcatchment areas|
Weekly Wastewater Surveillance Program reports
Frequently asked questions
What is the Sewage Surveillance Program?
The South Australia Wastewater Surveillance Program tests untreated wastewater for fragments of SARSCoV- 2, the virus that causes Coronavirus disease (COVID-19), at more than 30 treatment plants and sub catchment areas across South Australia to support the State’s response to COVID-19. It is part of a collaborative research program involving Australian states and territories and New Zealand to understand the occurrence of coronavirus (COVID-19) viral fragments in wastewater
Why is sewage being tested?
Testing wastewater can help provide an early warning signal of COVID-19 infections in people living in a particular wastewater catchment area.
Why is COVID-19 in our wastewater?
Fragments of the virus that causes COVID-19 can enter wastewater through an infected person, or recently infected person’s faeces or when washed off a person’s hands or body through toilets, sinks, showers etc.
How is wastewater tested for COVID-19?
Testing wastewater for fragments of SARS-CoV-2 is a specialised test. SA Health works very closely with SA Water to ensure testing is of a high standard. Wastewater is filtered and processed before the laboratory looks for genetic material (target sequences of SARS-CoV-2 RNA, or ribonucleic acid). This is done using a process called PCR (polymerase chain reaction).
How long does COVID-19 survive in wastewater?
It is not yet well understood how long SARS-CoV-2 survives in wastewater. Survival of the virus depends on many different conditions such as temperature, presence of other bacteria, protozoa, viruses, and the amount of organic matter. However, SARS-CoV-2 is easily inactivated (killed) by detergents which are present in wastewater. SARS-CoV-2 is not expected to remain infectious in wastewater for a long period.
If COVID-19 is detected in wastewater, does that mean there is a person with COVID-19 in that catchment area?
There are several reasons why fragments of the SARS-CoV-2 can be found in wastewater:
- One or more people who are infectious with COVID-19 are in the catchment area.
- There have been one or more people in the catchment area who have previously had COVID-19 and have recently recovered and are no longer infectious.
- A person with COVID-19 may have been in the area and has since left.
People who have recently recovered from COVID-19 can sometimes continue to shed virus fragments into the sewerage system for several weeks even after they are no longer infectious.
What happens after a positive wastewater sample is detected?
Any positive detection in wastewater samples will be assessed by SA Health and the Communicable Disease Control Branch. Further investigations will be undertaken, including immediate resampling if there any doubts about the source of the virus fragments. If there are known positive cases in the catchment area (e.g. in a medi-hotel) where a positive sample is identified, this will be taken into consideration during the investigation.
A confirmed positive wastewater test result is particularly important if there are no known recent positive COVID-19 cases in that area. Public health advice will be issued where action is required by the community. This might include messaging to people in the area to get tested, particularly if they have symptoms of COVID-19 and also might include providing additional testing locations in the area.
Can COVID-19 be detected if only one or two people have been in the area?
This will depend on the number of people who are in the catchment area along with other factors such as a decrease in virus shedding in people who have had the infection over time, dilution of the virus within wastewater, and the presence of chemicals (such as detergents) and other bacteria, protozoa and viruses in the wastewater. SA Health is involved with ongoing national research to help better understand some of these issues.
Can people become infected with COVID-19 from contact with wastewater?
It is highly unlikely a person can be infected with the SARS-CoV-2 virus through contact with wastewater. The virus is easily inactivated (killed) by usual wastewater treatment processes, including chlorine and ultraviolet (UV) disinfection. Wastewater is treated before it is used in recycled water schemes or discharged back into the environment, with most wastewater subject to UV light or chlorine disinfection.
Where does the wastewater from medi-hotels go?
South Australia’s medi-hotels are located in the Adelaide CBD. Positive SARS-CoV-2 virus detection is expected in catchment areas B10 – Adelaide and B11 – Adelaide where positive cases from overseas are regularly detected in people who have arrived from overseas and are in medi-hotel quarantine. These people have mandatory COVID-19 tests during quarantine.
Where does wastewater from the Royal Adelaide Hospital?
Wastewater from the Royal Adelaide Hospital is in B11 – Adelaide. This does not include medical waste.
Is drinking water safe?
Drinking water is subject to the Safe Drinking Water Act administered by SA Health, with the great majority of South Australians provided with drinking water by SA Water. Existing drinking water treatment and disinfection processes, including chlorination are designed to remove or inactivate harmful microorganisms. These processes will be effective against SARS-CoV-2. South Australian drinking water is safe to drink unless SA Health or your drinking water provider informs you otherwise.