Storm and Sanitary Sewer Network Design Handbook

BNQ 3660-004
Storm and Sanitary Sewer Network Design Handbook

In 1989, the then Ministère de l’Environnement published Directive 004 on sewer networks. This document presented the Ministère’s recommendations regarding storm and sanitary sewer network design; it was used for many years by design engineers for the design of this type of structure.

In 2018, the Ministère de l'Environnement expressed the need to update Directive 004 to modernize it and adapt it to current practices.

The BNQ was thus given a mandate by the Ministère de l'Environnement to lead work on standardization with a view to developing a consensus standard to replace Directive 004 with a municipal sewer network design handbook. The new design handbook addresses the following topics:

• the general elements of design;
• the presentation of a project;
• the hydraulic design of the pipes; 
• the structural design of the pipes; 
• the design of a dual drainage storm sewer network (minor network and major network); 
• the design of a sanitary sewer network;
• the design of pumping stations;
• overflow structures.

The design handbook takes into account certain considerations such as ease of maintenance and operation of the structures, along with aspects related to user safety regarding the facilities and buildings.

In the case of a storm sewer network, which includes a minor network and major network (dual drainage), strategic choices have to be made by the design engineer to respond to conditions such as the rainfall intensities (intensity-duration-frequency [IDF] curves) considered in order to handle climate change.

Furthermore, the notion of infrastructure resilience is also addressed in the design handbook. Among other things, a method for the analysis of hydraulic transients in the pressure pipes is provided.

Finally, flow charts illustrating the steps for the design of storm and sanitary sewers are also presented to guide the design engineer.