WSA TN 14 - 2022 Information Guidance Note Sewage Flows from Fixture Units

The purpose of this Technical Note is to provide a guide in determining the flows from developments with known fixture units when no other suitable method is provided by WSA 02:2014-3.2.

It is therefore not proposed to replace other methods provided by WSA 02:2014-3.2.  It may however be used as a check of flows determined by WSA 02:2014-3.2.

Where no other suitable method is provided by WSA 02:2014-3.2, the methodology may be used for residential, commercial, or dry industrial developments. 

An additional purpose of this Technical Note is to remind designers that provision needs to be made for ground water infiltration (GWI) and rainfall dependent inflow and infiltration (RDI), as described in WSA 02:2014-3.2.