When you move the mouse from the bottom to the top of the image the differences between an effective backpressure protection system and a nonexistent backpressure protection will be simulated.
In the left part of the building, we simulate how effective backpressure protection works by installing a sewage disposal unit with a backpressure loop. According to DIN EN 12056, the road level at the connecting point is considered as backpressure level, except when otherwise stipulated locally. Drainage facilities situated below the backpressure level must be connected to the local sewage system by means of a sewage disposal unit with a backpressure loop.
The right partof the building illustrates what happens when no backpressure protection is installed and in case of heavy rainfall the backwater from the local sewage system is flooding the basement.