WEST investigates coronavirus detection and inactivation in wastewater

In a recent article entitled “Coronavirus in wastewater – Rushing for answers," WEST researchers Charles Gerba, Walter Betancourt, and Ian Pepper report on current research investigating the occurrence of coronavirus in water/wastewater and the inactivation of the virus in existing wastewater treatment processes.  The article was printed in the July/Aug 2020 issue of World Water, the premier international magazine published by the Water Environment Federation.

In the article, WEST researchers explain some key characteristics of the SARS-CoV-2 as well as research findings and areas of ongoing investigation:

• Pathogens are always evolving.  Without previous exposure to the SARS-CoV-2 virus (the virus responsible for causing COVID-19) , humans do not have antibody resistance, so the virus is able to spread rapidly.
• Coronaviruses are relatively large compared to enteric viruses and are surrounded by a lipid envelope.  Their structure impacts their performance in the environment.
• Research shows that coronaviruses typically do not survive long in water and are inactivated by wastewater treatment and disinfection processes.
• Studies with human coronavirus 229E (one of the causes of the common cold) and SARS-CoV-1 have shown these viruses can remain infectious for several days in both tap water and wastewater, which is much less than the non-enveloped viruses. Research is underway to determine if the SARS-CoV-2 virus remains infectious in wastewater.
• The SARS-CoV-2 genome can be detected in wastewater using polymerase chain reaction (qPCR). Wastewater-based epidemiology provides information about total community infection (including asymptomatic cases) and can act as an early detection system.  Studies at WEST have followed the decrease and increase in virus concentration in wastewater corresponding to stay-at-home orders and their subsequent lifting in Arizona.
• WEST researchers have detected the novel coronavirus by qPCR in wastewater before chlorine disinfection, but not after chlorine treatment. This result indicates that the genome (nucleic acid) is destroyed by the action of chlorine. The virus is also considered to be sensitive to inactivation by ultraviolet disinfection (UV). Currently, dosing studies are being conducted at the WEST Center to determine the concentration and time (Ct value) needed for chloramines and UV light to inactivate coronaviruses.

To read the full World Water article, open the pdf below or go to Coronavirus in wastewater - Rushing for answers.