Photop: Suez

As the COVID-19 pandemic becomes part of our daily lives in Australia, attempts to mitigate the spread have been rapid and severe, but, while the “big boxes” are being ticked, other less attention grabbing areas are being ignored. One such area is domestic wastewater dispersal and the spread of COVID-19 and other waterborne and airborne diseases in Australia. 

In my home state of Queensland, local governments have overseen the installation of approximately 300,000 on-site domestic systems treating sewage and wastewater. 

Most off grid domestic wastewater systems use old style techniques, relying on pumps and mechanics and needing quarterly maintenance. One of the features of these systems is the fact that the treated effluent is dispersed above ground, often into gardens or onto lawns via an above ground sprinkler system.  

We know viruses can be spread through the dispersal of treated effluent, or liquid waste, in above ground systems and that viruses such as SARS-CoV-2 and other infectious bacteria and parasites are readily transmitted in aerosol form. Early evidence is indicating that faecal transmission of SARS-CoV-2 may be a significant additional pathway for exposure.

Recently, traces of COVID-19 were detected in sewerage samples tested in the Netherlands by the Dutch National Health Institute for Public Health and the Environment. This is to be expected in areas where the virus is active, but, it’s a concern as to whether this can become a channel of contamination if not properly treated or freely dispersed above ground.

Above ground dispersal systems often need to use additional chlorine dosing which can reduce but not necessarily eliminate bacteria and viruses. In addition, many of these systems are not properly maintained. As a result, the quality of the water being disposed aboveground cannot be guaranteed.

In the face of such uncertainty, and as the COVID-19 virus hits home, the absence of any definitive understanding of the risks of above ground, treated wastewater dispersal is concerning. 

Clearly, COVID-19 is part of a bigger picture. Various viruses, such as SARS, MERS and bird flu, have caused concern over the last decade or so, as the ease of global travel, global trade and the general increased connectivity of our world give these outbreaks every opportunity to spread. The “super-bug” phenomenon is well and truly with us. The infection rate is often so fast and wide that it challenges even the most advanced health systems and economies, as we are seeing now.

This virus is not the first to give us all something to think about in the last two decades, nor is it likely to be the last.   

Millions of Australians have aboveground treated effluent dispersal systems in place. Many of these may well be safe and healthy where they are properly maintained, but some may not be, especially in relation to COVID-19, and they may be spreading coronavirus, and other viruses we don’t even know about yet. 

In Queensland, a local council approved a septic system with an above ground dispersal system in a 3000 square metre backyard, with an adjacent swimming pool. The approved design has 14 above ground sprinklers dispersing treated effluent into the air and onto the ground that, with even a light breeze, could end up on the house roof, where water runs off for drinking water, into the pool and so on. 

The COVID-19 outbreak highlights the fact our current wastewater treatment standard is not fit for purpose in the current environment. As the whole country is shut down and the population isolates, there has been no apparent risk assessment done on whether above ground dispersal of treated effluent via off grid septic systems could be an additional risk factor in relation to the spread of COVID-19. 

It is difficult to understand how local and state governments and Standards Australia still allow the above ground disposal of potentially harmful septic wastewater to be approved and installed without a proper risk assessment regarding COVID-19. 

To their credit, I know that a number of concerned Queensland councils have recognised the potential risks and are moving away from above ground wastewater dispersal.  Unfortunately, there does not appear to be any policy direction or leadership from Queensland Health or similar state and federal bodies around the country on this matter.

All public bodies need to assess COVID-19 safety factors across their range of expertise and responsibility. This means looking at not just their own practices but at the instruments, policies, regulations and laws that fall within their landscape of operations.  

For instance, Standards Australia, which provides the basis for various regulations on wastewater systems installations, has ignored systems which safely disperse treated effluent underground and designed a standard that suits above-ground systems. 

We should consider whether regulating out proven innovations and ignoring the potential risks of old style above-ground effluent dispersal systems is wise in the current situation. It might be too much to call for a moratorium on above ground wastewater dispersal systems but, in the words of the executive director of the World Health Organisation, “Be fast…If you need to be ‘right’ before you move, you will never win.” 

Surely it’s time to move now.

Paul Magee is an environmental scientist and a recently (November) retired chemical hazard specialist for Brisbane City Council, where he worked for 40 years.


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