Quality control - the key to sewer success

Aug 28, 2006

Well-respected pipe expert Professor Stein urges network operators to think of future generations and ensure long-term pipeline sustainability.

Professor Stein, Germany, is considered one of Europe’s leading experts on pipe systems. He has spent the greater part of his life working with underground infrastructures. Together with his colleagues and associates in Stein & Partner he has carried out numerous studies on pipe systems and has delivered consultant services to a wide range of network operators, pipe manufacturers, urban planners and property and building societies. Asked to identify the most important factors to ensure a well-working sewer system, he answers without hesitation: installation quality and quality control.
It is clear from Professor Stein's extensive research and long experience that the single biggest challenge for a sewer system is defective installation. Defective installation accounts for the majority of leakages and is much more important than all other factors such as system age and network design.
"There are three things to be done about defective installation. They are: excessive quality control during the whole process of planning and construction; excessive quality control during the whole process of planning and construction; and excessive quality control during the whole process of planning and construction," says Professor Stein.
Unfortunately, however, the need to cut costs may make constructors replace experienced people by untrained workers. Similarly, limited resources may lead to less control by the network operator. In combination, these two factors are the cause of most of the installation problems.
The way to go about this is, in Stein’s view, to adhere to a holistic net management systems and a strict management system for planning, construction, operation maintenance and rehabilitation.
A shared challenge

Most European countries are facing the shared challenge of aging sewer lines, and in the years to come, network operators across the continent will have to deal with rather extensive rehabilitation and replacement projects. It is highly important that this task is handled responsibly.
"The maintenance of sewer systems should follow an unwritten agreement between the generations as, due to the longevity of such systems, one generation passes the systems on to the next. But sewer systems deteriorate and the rehabilitation action taken is not always sufficient to stop or reverse the process," says Professor Stein.
Insufficient rehabilitation efforts are often due to the lack of finances or to ignorance of the consequences of deficient network maintenance. Network operators walk a fine line between costs and risks, and too often, the need to cut costs today stands in the way of ensuring sustainable sewer systems for tomorrow.
"The challenge of the present maintenance and rehabilitation urgently requests coordinated action and long-term planning in order to guarantee sustainable sewer infrastructures," says Professor Stein.
Such coordinated action and long-term planning includes flexibility and adaptability in network layout in reaction to changed customer needs and behaviour to prevent replacement before the end of the planned service life.
  • The Sustainable Municipal Pipes Study from 2005 examines the environmental effects of leakage and defects in sewer systems and compares the performance of flexible versus rigid pipe materials – that is, plastic versus non-plastic pipes. The study looks at sewer pipe lines in Germany, Sweden and the Netherlands.
  • The study found the overall defect rates of flexible pipe systems to be, on average, 20 % of the rates of rigid pipe systems. The study furthermore found that the environmental impact caused by infiltration or exfiltration for flexible pipes was only 15 % of that for rigid pipe systems.
  • Click here for more information about the Sustainable Municipal Pipes Study [www.teppfa.org].
    Click here for more information about pipe specialists Stein & Partner [www.stein.de].
This interview was first published on www.plastic-pipes.com.



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