Drainage below ground

5.3.2Provision of information

Designs and specifications shall be produced in a clearly understandable format, include all relevant information and be distributed to all appropriate personnel.

Design and specification information should be issued to site supervisors, relevant specialist subcontractors and suppliers, and include the following information:

  • Proposed drain layout.
  • Invert levels and locations of existing sewers.
  • Junctions.
  • Ground floor levels of homes.
  • External finished levels.
  • Inspection and access points.
  • Method of disposal of both foul and surface water.
  • Position of any septic tank or cesspool in relation to adjacent buildings.
  • Results of percolation tests where treated effluent disposal is through field drains or surface water through soakaways.
  • Length of field drains and their layout (including details of trench width as this is critical to the functioning of the system).
  • Depth of field drains.
  • Details of drains or sewers intended for adoption.
  • Details of soakaways (including size or volume and surrounding details).