They produce better wastewater treatment.

A variety of treatment facilities are septic tanks with a biofilter. They produce better wastewater treatment. This type of septic tank is a treatment plant in which water first defends, and then passes through a biofilter filled with some drainage, for example, expanded clay. As in the first case, a film made of microorganisms is formed on the surface, which affect the particles dissolved in water and besiege them in the form of silt. This silt is subsequently removed using an assenicing machine. Water with this type of septic tank is cleaned by 85-90%.