Domestic waste water - discharge and infiltration

Not everywhere in the urban area is it possible to connect to a public wastewater disposal system. In such cases, adequately sized on-site sewage treatment plants must be installed, the effluent of which is infiltrated on site or discharged into a surface water body.

Both the discharge into a surface water body and the discharge into the groundwater (infiltration) constitute a use of water bodies and require permission under water law from the lower water authority.

The application for infiltration or discharge into a surface water body must be submitted in duplicate with the following documents:

• Cadastral extract (copy from the real estate map)
• Drainage plan M 1 : 500 or 1 : 1000 with identification of the following components:
  • Small sewage treatment plant
  • Waste water pipes
  • for infiltration: seepage shaft and infiltration trenches
  • for discharge into surface water: discharge point
• for infiltration: hydrogeological report
• Calculation of the dimensioning of the infiltration system
• Copy of the test mark of the small sewage treatment plant

If the building project is located in a drinking water protection area of drinking water protection zone III, an informal application for the granting of an exemption from prohibitions in drinking water protection zones must also be submitted to the lower water authority.

• Federal Water Act (WHG)