Wastewater Treatment and COVID-19
Coronaviruses are susceptible to the same disinfection conditions in the healthcare setting as other viruses, so current disinfection conditions in wastewater treatment facilities is expected to be sufficient. This includes conditions for practices such as oxidation with hypochlorite (i.e., chlorine bleach) and peracetic acid, as well as inactivation through the use of ultraviolet irradiation.
There is no evidence to suggest that additional, COVID-19-specific protections are needed for employees involved in wastewater management operations, including those at wastewater treatment facilities. Wastewater treatment plant operations should ensure workers follow routine practices to prevent exposure to wastewater, including using the engineering and administrative controls, safe work practices, and PPE normally required for work tasks when handling untreated wastewater.
On Feb. 5, 2020, the U.S. Occupational Safety and Health Administration (OSHA) released its new wastewater worker guidance stating that current disinfection conditions in WRRFs, such as oxidation with hypochlorite or peracetic acid, and inactivation by ultraviolet irradiation, are expected to be sufficient to protect wastewater workers and public health. The recommendation is based on coronavirus disinfection data from healthcare settings and corresponds with OSHA’s position on the susceptibility of coronaviruses to disinfection.
These recommendations are likely to be broadly applicable, although more research may be warranted for disinfectants such as peracetic acid and combined chlorine (chloramines), where coronavirus specific data is lacking or evidence suggests higher bacterial susceptibility to disinfection compared to viruses. Although coronaviruses have not been tested, peracetic acid has been found to have some efficacy against some non-enveloped viruses (e.g., Norovirus) that are known to be more resistant than enveloped viruses.
Chlorine is extensively used for wastewater disinfection due to its effectiveness, low cost, and ease of application. It typically reacts with ammonia present in wastewater to form combined chlorine (chloramines), which behaves differently than free chlorine during disinfection. Thus, it is important for each facility to understand the chlorine species that are present and their relative abundance within the disinfection process. Additional research could provide reassurance on the effectiveness of wastewater disinfection processes, specifically against coronaviruses and at lower doses and contact times.
How Can I Stay Informed?
The organizations below are reputable and reliable sources that are frequently updated.
In an effort to increase transparency and communication, major publishers have created Coronavirus information centers, where relevant and current research is freely available. This includes Springer Nature, Elsevier and Wiley. Several major journals have done the same, including: The Lancet, New England Journal of Medicine and The British Medical Journal.