Pool water treatment during the COVID-19 pandemic

Even though there is still much to learn about the new coronavirus disease aka COVID-19, (COVID-19), we have learnt from similar viruses that its spread from person-to-person happens most commonly among close contacts, that is to say 6 feet of distance.

It has been proved that the transmission of the virus most commonly occurs through respiratory droplets. It is thus normal that questions regarding how to ensure a correct pool water treatment during the COVID-19 crisis arise. On the other hand, current evidence suggests that the corona virus remains alive for hours to days on surfaces made from different kinds of materials.

Water parks, recreational pool facilities, school and college pools or even gated community pools are regarded as communal or collective settings. Even though there is no evidence that the corona virus can be spread among humans via the use of swimming pools or spas, it is important to take all necessary precautions in order to prevent its spread.

Which are the key factors to ensure a correct pool water treatment during the COVID-19 pandemic?

• It is of vital importance in preventing a proper maintenance and disinfection by means of automated chlorinators and brominators. Proper disinfectant levels are 1–10 parts per million free chlorine or 3–8 ppm bromine, being 7.2–8 for pH. Both chlorine and bromine are very effective sanitizers, but bromine is more stable and thus highly recommended in warm water environments such as spas or hot tubs.

• The biocide action of UV irradiation is even effective against particularly harmful microorganisms that can survive in a pool despite the presence of chlorine or bromine. Its disinfectant power is such that it even destroys the genome of bacteria, fungus and coronaviruses. Although the standard sanitizers have proved its effectiveness against SARS-CoV-2, UV irradiation can be additionally used providing extra protection once the common chemical disinfection method has been applied.
• In order to avoid potential infections, facilities will need to reconsider their ventilation system in order to shorten the time it takes respiratory droplets to be removed from the air.
• Not only does the pool water treatment require special attention during the COVID-19 but also the disinfection of the surrounding premises. Appropriate cleaning should be taken both inside and outside the pool to protect the community.
• Last but not least, employers should work with their local health departments to ensure appropriate health guidelines and train their staff accordingly. Apart from this, operators of community pools should follow this interim guidance for businesses and employers to respond to the coronavirus crisis.

This short guidance provides recommendations on the cleaning and disinfection of communal pool areas in order to limit the survival of COVID-19. On the other hand, the Model Aquatic Health Code (MAHC) is a voluntary guideline that can help the aquatics sector make swimming and other water activities healthier and safer.