Non conventional sewerage services

When to choose this option, how to implement this solution
  • Jean-Marie Ily (pS-Eau), Christophe Le Jallé (pS-Eau), Julien Gabert (Gret), Denis Desille (pS-Eau)
  • External publication, Studies and reports
  • Editor : pS-Eau
  • Language : Anglais, Français
  • Year : 2014
  • 112 p.

  • Lire en ligne

There are two main types of sanitation system that can be used to meet household demand for sanitation services in developing countries: on-site sanitation, whereby individual facilities are built for each household; and conventional sewerage, such as that used in many towns and cities. However, in some areas, installing these types of sanitation is not always possible and alternative sewerage systems have had to be developed. These systems, called ‘non-conventional sewerage’ in this guide (and which include both simplified and settled sewers), overcome some of the constraints associated with conventional sewerage (smaller diameter pipes, which are laid at shallower depths, and simplified connections, etc.), which results in a lower investment cost.

Non-conventional sewerage services also differ from conventional sewerage by virtue of their scope (covering a residential area rather than the whole town), allocation of responsibilities and the management method used. Consequently, non-conventional sewerage is an option that is only suitable for specific types of urban area. Before embarking on a non-conventional sewerage project, it is important to be fully aware of the complexities of managing a non-conventional sewerage service and ensure that all the necessary conditions for launching such a service are in place.

This guide is based on a number of case studies of non-conventional sewerage services around the world. Its aim is to support contracting authorities, local decision-makers and their partners to develop their sanitation service by providing them with decision-making tools and practical methodological approaches. This guide will help these stakeholders determine whether non-conventional sewerage really is the most appropriate option for the area concerned. If this option is selected, it will also help them coordinate their project effectively and provide them with a clear understanding of the management methods that can be used and of the skills and know-how required.

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