Since pollution of the Rhine has been greatly reduced by the construction of sewage treatment plants, the significance of accidents for water quality has become obvious. Most accidents are of only local importance, but after an incident in 1969 the water for fighting the Sandoz warehouse fire caused the second long distance death of fish in the river in 1986.
Many waterworks are effectively protected from pollution surges by a bank filtration for the water. Waterworks with direct water intake shut their intakes down temporarily when a pollution wave is flowing past.
Both wastewater discharges and the river Rhine are continuously and carefully monitored. Rapidly responding biological tests and screening processes are being used to an increasing extent. A well equipped water protection police service is an additional important control element.
Safety during transport and transfer of goods by ship is controlled by the regulations on transporting hazardous goods on the Rhine. Special care and safety measures are taken for loading and unloading of ships. Routine cost-free bilge emptying is an important contribution to water protection too.
Accidental pollution incidents with cooling water discharges or from the outlet from treatment plants can occur from the bank. Rapid recognition and elimination of faults are essential for cooling water protection.