As the global health community tracks the spread of this virus, it’s important for water and wastewater professionals to keep updated on potential impacts.
It's hard to miss the headlines. The recent outbreak of novel coronavirus (2019-nCoV or COVID-19) has dominated news cycles in recent weeks. The World Health Organization (WHO) is calling it “public enemy number one.” But what information do we have that is related to coronaviruses in water and wastewater systems? And what can water- and wastewater-system operators do to protect public health?
Modern water and wastewater treatment systems play an important role in public health protection. With the potential for environmental transmission, water and wastewater operators need to know the potential for survival of this type of virus in water and wastewater treatment systems.
Coronaviruses, named for the crown-like spikes on their surface, were first identified in the mid-1960s. Currently, seven coronaviruses are known to infect people and make them ill. Three of these — MERS-CoV, SARS-CoV, and COVID-19 — emerged in the last 20 years and are examples of how some coronaviruses that infect animals can evolve to infect humans. COVID-19 is a new variety of coronavirus and is an enveloped, single-stranded (positive-sense) RNA virus.
So, what is the fate of coronavirus in sewage and wastewater treatment plants? Or in the aquatic environment? And should we be worried about the efficacy of water treatment filtration and disinfection processes for coronavirus removal and inactivation?
The short answer: No — if we take proper precautions and risk considerations.
The long answer: This is a new virus without an extensive body of literature on the effectiveness of water and wastewater treatment processes. And real-life experiences will vary due to water quality and treatment plant details.
According to a 2008 University of Arizona study, coronaviruses have not been found to be more resistant to water treatment than other microorganisms such as E. coli, phage, or poliovirus — which are commonly used as surrogates for treatment performance evaluations. Results from bench-scale studies suggest that the survival of coronaviruses is temperature dependent, with greater survival at lower temperatures. Therefore, coronavirus is expected to be reduced in raw wastewater and surface waters in warmer seasons.