When confronted with rocky subsoil and a steep hillside, the re-planning of wastewater disposal structures always requires a detailed comparison of variants. The dynamic cost comparison calculation showed that a drainage of Waldhof-Falkenstein with 1.9 km of vacuum sewer, 22 sewer chambers, and a monitoring system is the most economic option. Basic evaluation, cost comparison calculation, planning and construction supervision of the Waldhof Falkenstein vacuum system were carried out by engineering firm Dr. Bruch & Partner. IWR GmbH handled the site management of the pneumatic sewer system in Waldhof-Falkenstein and was happy to contribute specialised knowledge.

The main reason for the smooth operation of the MBR package plant (50 population equivalent), installed downstream of the pneumatic sewer system, was the fact that through the pneumatic drainage, three inflow points were identified very quickly (sewer chambers with stroke monitoring). Therefore, almost from the beginning only domestic wastewater without infiltration water arrived at the MBR package plant.