Översvämmad gatubrunn

Inflow and infiltration reduction program Ekebyhov's Wastewater Treatment Plant

Written by Erika Bjerner

It is common for municipalities to be required to develop a plan to actively work to reduce the amount of non-sewage water in the sewage pipe network, a so-called Inflow and infiltration reduction program (IIRP).

An IIRP consists of an investigation of sources of non-sewage water in a specific wastewater treatment plant's catchment area, as well as an action plan with activities for how the non-sewage water can be reduced. When Roslagsvatten received a request from the supervisory authority to produce an IIRP for the Ekebyhov wastewater treatment plant, AFRY was contacted for support, structure and guiding of the work.

During the work on the IIRP, AFRY has closely collaborated with the employees at Roslagsvatten in order to produce the material and documentation required. After thorough analyses of submitted material AFRYs water experts compile an IIRP that provides a description of the current situation, a list of proposed measures both updating of routines and strategies and further investigative work, as well as an action plan. It also contains suggestions on how the IIRP can be implemented in Roslagsvatten's routines and control programs.

During the work, Roslagsvatten has been involved in the results that have emerged and been able to influence which measures and activities that should be prioritized and planned.

 - One of Roslagsvatten's overall goals is to reduce the amount of additional water in the sewage treatment process. To get a restart of this work and an external view of the problem, AFRY was hired for consultation. AFRY has in a professional and pedagogical way helped us to develop a so-called inflow and infiltration reduction plan. This has been done through, among other things, analysis of our existing measurement and map data, interviews and workshops with operating staff as well as processing of existing reinvestment plans. This has resulted in a delivery that we can take support for in order to continue to get to know our pipe network in depth and be able to continue our work to clean up the pipe network from additional water. We are very pleased with the cooperation, says Staffan Björk, Head of Production Pipeline at Roslagsvatten


For more information please contact:


Paulina Stenvall

Nathalie Stärner

Kjell Lundqvist