IFAT 2008 − A growing market in the rehabilitation of drains and sewers

In May the international environmental technology sector will be converging on Munich for IFAT 2008, the International Trade Fair for Water – Sewage – Refuse – Recycling. This event, the world´s largest environmental trade fair, is even bigger than the previous event three years ago: it now boasts 22,000 square metres more exhibition space, bringing the total to 192,000 square metres.

One of the sections at the fair that is experiencing most growth is the section on the renovation, inspection, cleaning and maintenance of drains and sewers. Here, stand space has risen by almost 32 percent to 14,500 square metres. This expansion is very much in line with other market observations. For example, the IKT, Institut für Unterirdische Infrastruktur (Institute for Underground Infrastructure) of Gelsenkirchen carried out a major survey of German drain and sewer system operators last year to find out about the level of investment in building and maintaining their systems. This revealed that there was a downward trend in investment in the construction of new sewerage systems, while growth was expected in renovation and rehabilitation work. In particular as regards the latter, the IKT believes there will be more attention paid to this area in 2008. Another survey, conducted by the Deutsche Vereinigung für Wasserwirtschaft, Abwasser und Abfall (DWA, Hennef – German Association for Water, Wastewater and Waste) in 2004, showed that around Germany roughly 20 percent of the 486,000-kilometre network of public sewerage systems were in need of repair and renovation in the short to medium term. An IKT study identified for North-Rhine Westphalia that 14 percent of the public sewerage network and nine percent of the shafts were damaged. Dr.-Ing. Bert Bosseler, Scientific Head of the IKT, sums up the economic potential: “Around six to eight billion euros needs to be invested in renovation of the sewerage system in North-Rhine Westphalia over the coming twelve years. If you scale this up to the national level, we are talking of expenditure in the order of 33 to 44 billion euros.”

The main problem of ailing sewerage networks are leaks which can lead to sewage entering the groundwater, depending on what level the groundwater is at in the particular location. Problems with the stability of the pipes can also occur in areas that are subject to heavy traffic. Typical damage includes missing or rotted seals between the pipes, shifts in the position of the pipes, cracks, the build-up of shear stresses and breaks in the pipes and blockages due to foreign bodies building up in the system and invasive roots.

A popular technique when renovating main sewerage pipes is to insert a lining. Here, a plastic pipe, treated with synthetic resin, is inserted into the pipe and folded back over the ends. An alternative is the close-fit lining technique, in which a PE-HD pipe, folded lengthwise, is inserted into an old, cleaned pipe and pulled through. When the pipe is taken back into service, heat and pressure then ensure that this ‘inliner’ unfolds and is pressed against the inner wall of the original pipe to give a tight fit. In smaller-scale repair work, mainly shortliners and inner sleeves are used, as well as injection and grouting techniques.

“In developing new techniques for rehabilitating sewers and drains the impact of statutory regulations is of great significance,” says Bosseler. “At present the subject of wastewater from private property is providing new impetus. For example, a new paragraph in the regional water law (§61a Landeswassergesetz) of North-Rhine Westphalia sets out for the first time that wastewater systems on private property are to be included in general renovation plans. This means that when local drainage and sewerage networks are being rehabilitated, property owners can also be called upon to overhaul the systems on their land. The regional government of North-Rhine Westphalia is making funding available for this.”

The extensively branched drainage networks are presenting new challenges to process manufacturers and service companies, because of the small nominal widths of the pipework. Often, for example, bends in the pipes can restrict access for cleaning, inspection and renovation equipment. There are also problems where access from above is only possible with great difficulty, for example, under the floor slab of a building. It is common for inspection hatches to be closed over when cellars were fitted out, e.g. by wall tiles, wood panelling, laminate flooring etc.

All of these difficulties require innovative thinking if they are to be overcome. “While in recent years in the area of cleaning and renovating public sewerage networks, progress has taken place through the further development of existing products and techniques, for example by modifying material components and steps in the processes, when it comes to surface drainage brand new renovation techniques are needed, to meet the particular requirements of small nominal widths, bends and shaftless branches,” says Bosseler.

An estimated 1.5 million cubic metres of private sewerage and drainage systems in Germany give some indication of the scale of the renovation market in this country alone. A glance over the German borders shows that the EU accession countries are particularly interesting markets. Bosseler again: “These countries have had extensive drainage systems for many years, and in the past they have been able to invest little in their maintenance. Now, as a part of the EU single market, they offer optimum conditions for the export of technology and investment in new locations, particularly in view of the strongly regionalised nature of the sewers and drains construction and renovation market.”