The World Health Organization (WHO) Guidelines on Sanitation and Health should always be followed. At present, no additional measures specific to COVID-19 are recommended by WHO, U.S. Centers for Disease Control and Prevention (CDC), or Occupational Health and Safety Administration (OSHA). While the genetic material of SARS-CoV-2 has been widely detected in untreated wastewater, there have been limited reports of SARS-CoV-2 detection in partially treated wastewater and receiving waters impacted by untreated or partially treated wastewater. There are no reports of SARS-CoV-2 being transmitted via treated or untreated wastewater.
Properly designed and functioning wastewater treatment plants (WWTP) and on-site sanitation systems that include safe disposal in-situ or an emptying and transport service chain to a faecal sludge treatment plant, should reduce the risk posed by faecal pathogens, including SARS-CoV-2. As an additional precaution, WWTPs might consider adding a final disinfection step (often known as tertiary treatment) to further reduce risk posed by viral pathogens like SARS-CoV-2 before discharge. Chlorine disinfection of wastewater effectively inactivates the SARS-CoV-1 (the virus responsible for SARS) at low concentrations (0.5 mg/L free chlorine residual) though standard dosing recommendations should be followed. Chlorine disinfection is not recommended for wastes containing large amounts of solid organic matter (like sludges or pit latrine contents) as it is less effective in these types of waste. Where WWTPs are not available, properly managed waste stabilization ponds are a simple treatment alternative that can effectively reduce pathogen loads. Wastewater treatment processes, including a final disinfection step, may not completely eliminate infectious viruses from effluent or treated sludge and safe disposal remains important.
For information on special considerations for sanitation workers during COVID-19, please see the resource “COVID-19 preventative measures that should be adopted by sanitation workers.”