What’s the risk of the Covid-19 virus – or other viruses – from being present in the water in my cooling tower? Here’s why I think that the risk is very low.
Viruses – especially SARS-type viruses like Covid-19 – are very uncommon in potable and surface waters.
In the U. S., the quality of potable water typically exceeds the minimum requirements for purity. As shown in Figure 1, water treatment plants that use nanofiltration (or an even smaller pore-size technology, reverse osmosis) will remove viruses; ultrafiltration will remove some viruses, depending on the fiber’s pore size and the size of the virus.
In surface waters, the most common viruses are adenovirus, astrovirus, hepatitis A and E viruses, rotavirus, norovirus and other caliciviruses, and enteroviruses, including coxsackieviruses and polioviruses.
The SARS (Severe Acute Respiratory Syndrome) viruses (including Covid-19) are particularly susceptible to the standard disinfectant treatment at U. S. public and private water treatment plants (WHO-2019-NcOV-IPC_WASH-2020.1-eng.pdf) and in cooling towers. In addition, the U. S. EPA has released the following statement, “The COVID-19 virus has not been detected in drinking-water supplies. Based on current evidence, the risk to water supplies is low. Americans can continue to use and drink water from their tap as usual.” (https://www.epa.gov/coronavirus/coronavirus-and-drinking-water-and-wastewater)