Kemira Oyj/Kemira M&I ABSTRACT Vesa Kettunen ... - Svenskt Vatten

Title: Focusing of sewer network renovations
Authors: Laakso, Tuija; Vahala, Riku, Aalto University
E-mail addresses: tuija.laakso@aalto.fi, riku.vahal@aalto.fi
Abstract for a platform presentation to be held in English.
Abstract
Getting accurate and up-to-date information on the renovation need of sewer assets is difficult; on
the other hand, the sewer network needs to be renovated periodically. Traditionally, in Finland, the
sewer network inspections and renovations have been made based on few sources of data (e.g., pipe
age and material) and not necessarily using a systematic planning approach. In such a context, the
EfeSus project aims at developing a systematic, comprehensive and a partly automated procedure
for deciding which assets to renovate in the network and when. The main aim of this paper is to
present the project and its objectives as an example on how the improvement of sewer network can
be challenged in practice.
Efesus, financed largely by the Finnish Funding Agency for Technology and Innovation (Tekes),
focuses on the separate sewer network of the Finnish city Espoo (population of around 250 000) and
analyzes in detail 20 representative network areas. The data utilized in the assessment include:
GIS data from the utility’s network information system:
o pipe locations and depths, pipe diameters, slopes, materials, installation years;
o closed circuit television (CCTV) inspections;
o occurred operational disturbances;
o water consumption in different network areas (on annual level).
Flow data from the utility’s telemetry system.
Rainfall data.
Environmental data concerning:
o ecological status of groundwater areas;
o ecological status of surface water areas;
o road type classifications.
In order to achieve efficient prioritization of the sewer renovations these data need to be collected,
evaluated and analyzed. Efesus starts by gathering and combining from different sources data that
are considered useful for renovation planning. Similar to the projects CARE-S (Saegrov 2005) and
COST-S (Savic et al 2005), the approach in EfeSus is includes: 1) decision-making based on
available data, and 2) automated data analysis and decision support by means of a software
(prototype) created in the project. The software, using as inputs all the different data collected,
assesses each pipe with respect to its estimated structural and operational condition, as well as to its
importance in the network structure and the vulnerability of the surrounding environment.
As a result of the analysis, an index will be assigned to each pipe indicating how often the pipe
should be inspected and what its renovation need is. After this, so-called renovation entities are
built up from a number of pipes that can be considered similar enough to be renovated at the same
time. Based on this assessment, further on-site investigations such as CCTV inspections, smoke
tests and manhole inspections as well as actual renovations can be targeted and scheduled much