Rainwater treatment

As ground surfaces, particularly in cities, are being increasingly sealed off, the pollutant loads of rainwater flowing over these surfaces is steadily rising. To reduce these loads from the separation systems, the Ministry for Climate Protection, Environment, Agriculture, Conservation and Consumer Affairs (MKULNV) of North Rhine-Westphalia (NRW) has published the decree “Requirements for Rainfall Drainage in Separation Processes”.

The decentralised systems can be compared with the central plants according to the separation decree when the retention rating of fine filterable substances is greater than 50% and when the operational test results positively certify they can be compared with rain clarifiers.