Abstract: The invention relates to a system for controlling the concentration of a detrimental substance, in particular H2S, in a sewer network. The system comprises a monitoring device arranged at a monitoring location in the sewer network and at least one dosing controller arranged at a dosing location upstream the monitoring location. The monitoring device is arranged for providing a signal indicating a measured H2S concentration at the monitoring location and for transmitting a radio frequency signal carrying information about the H2S concentration. The dosing controller is arranged for receiving the radio frequency signal, deriving a concentration signal based on the radio frequency signal, calculating a dose of a preselected additive based on the derived concentration signal, and supplying a dosing signal to a dosing device, causing the dosing device to add the calculated dose at the dosing location.