In the separate sanitary sewers, the sanitary water and rain water are channelled through two different pipelines to the Treadment plant and to the receptor media, respectively. This kind of networks demands the total separation of the channelling, so that the rainwater and wastewater are not mixed, which is very difficult, almost impossible. It is also necessary to control the residues dumped into the rainwater network through the drains, since they are channelled irremediably to the receptor media without being treated.
The use of the storm tanks to connect the rainwater network with the wastewater network solves the problems concerning the separative systems, since the storm tanks avoid that waste and residues flow directly into the receptor media, and they also cause a decantation of the rainwater before it is released.
