Effluent characteristics
Urban drainage

Rainwater, which is soft and free of impurities when it is formed, is loaded in the atmosphere with dissolved gases and suspended and dissolved matter, and even with noxious products above large industrial cities, as well as bacteria.

After running off onto pavements or into gutters, this water is also laden with non-fermentable products (sand, road abrasion, oils, greases), as well as organic products from animals living with humans (birds, pets)...