Where the development involves the disposal of trade waste or the disposal of foul sewage effluent other than to the public sewer, then a fuller foul drainage assessment, or FDA, will be required includng details of the method of storage, treatment and disposal. An FDA should include a full assessment of the site, its location and suitability for storing, transporting and treating sewage. Where connections to the mains sewer is not practical, then the foul/non-mains drainage assessment will be required to demonstrate why the development cannot connect to the public mains sewer system and show that the alternative means of disposal are satisfactory. Guidance on what should be included in a non-mains drainage assessment is given in DETR Circular 03/99 and Building Regulations Approved document Part H and in BS6297.
If the proposed development results in any changes/replacement to the existing system or the creation of a new system, scale plans of the new foul drainage arrangements will also need to be provided. This will include a location plan, crosss sections/elevations and specification. Drainage details that will achieve Building Regulations approval will be required. If connection to any of the above requires crossing land that is not in the appplicants' ownership, other than on a public highway, then notice may need to be served on the owners of that land.