Disinfection

Onsite wastewater treatment systems distributing wastewater on the ground surface are required to include a disinfection component as part of the advanced pretreatment process. Additionally, some subsurface drip systems applying wastewater into shallow soils require disinfection prior to dispersal. Disinfection is the destruction or inactivation of disease-causing organisms. The disinfection component reduces the concentration of the pathogenic constituents to an acceptable level. This usually relates to a health standard or a maximum required number of organisms for infection.

Wastewater can be disinfected with many methods. Chlorine, ultraviolet light, and ozone will be discussed to provide a greater understanding of how they operate. For onsite wastewater treatment systems, the most common form of disinfection is chlorination.