A method and an apparatus for disinfecting drainage are provided. A bromine-based or iodine-based disinfectant is added to water to obtain disinfecting water, and the disinfecting water is added to predetermined drainage. The apparatus has a device for producing disinfecting water from a disinfectant and drainage, a sand basin, and a channel for introducing the disinfecting water into the sand-basin, and the drainage is disinfected while the drainage is dwelling in the sand basin.
