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 in Metropolitan Adelaide and regional areas of South Australia.
Testing wastewater can help track COVID-19 infections in the community including changes over time, provide information on case detection rates and assist in detecting variants of the virus.
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 from the three major Metropolitan wastewater treatment plants (Bolivar, Glenelg and Christies Beach) and from regional centres (Pt Augusta, Whyalla and Mt Gambier).
Additional wastewater testing may be conducted in other locations from time to time.
Frequently Asked Questions
What is the Wastewater Surveillance Program?
The South Australian Wastewater Surveillance Program tests untreated wastewater for fragments of SARS-CoV- 2, the virus that causes Coronavirus disease (COVID-19), at a number of metropolitan and regional wastewater treatment plants to support the State’s response to COVID-19. The program was developed in collaboration with a national research program involving all Australian states and territories and New Zealand to understand the occurrence, detection and value of monitoring for SARS-CoV- 2 viral fragments in wastewater.
Why is wastewater being tested?
Testing wastewater can provide an indication of short-term and long-term changes in numbers of virus COVID-19 infections. It can also provide information on case detection rates and the presence of variants of the virus.
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. Wastewater is either filtered or collected on passive samplers (sewage subs) 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). The genetic material detected by this process can be sequenced using further specialised testing to identify the presence of variants of the virus.
How long does COVID-19 survive in wastewater?
SARS-CoV-2 is not expected to remain infectious in wastewater for a long period. 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.
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.
What happens after a positive wastewater sample is detected?
All positive detections in wastewater samples will be assessed by SA Health and COVID Operations. The significance of short term and long-term changes in concentrations of virus fragments will be assessed and compared to known numbers of cases.
Can the concentrations of virus in wastewater be used to determine numbers of cases?
The concentrations of virus in wastewater cannot be used to determine the numbers of cases. The sensitivity of surveillance at different wastewater treatment plants varies due to the influence of a number of factors including the presence of chemicals such as detergents and salts, temperature and detention time in sewage systems. However, changes in the concentrations of virus at individual wastewater treatment plants will provide an indication of whether numbers of cases have changed.
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.