Duesseldorf International Airport

Flughafen Duesseldorf GmbH has been expanding and renovating its rainwater treatment and waste water drainage systems at great expense for years. In these large construction projects, those responsible rely on fully welded wastewater sewers, especially in sewer construction. The PLASSON LightFit wastewater program is used, which guarantees long-lasting, tight pipe connections and manhole connections in the sense of a fully welded sewer network.

Duesseldorf Airport (www.duesseldorf-international.de) is the third largest airport in Germany and the largest in North Rhine-Westphalia (NRW). More than 20 million passengers can fly to over 180 national and international destinations in around 50 countries with up to 60 airlines. This makes Duesseldorf Airport the most important international hub for the state of NRW. The high performance of the Airport results from a perfectly functioning and coordinated infrastructure. The existing sewer network with the associated special structures also makes an important contribution to performance. Especially when it rains, the sometimes-enormous amounts of rain that fall on the sealed areas of the airport, such as the runway and taxiway areas, must be drained off quickly and reliably in order to ensure safe airport operations. Against this background, several systems for rainwater treatment and drainage, including sewage systems, were successfully renovated by Flughafen Duesseldorf GmbH as part of various large-scale construction projects.

The “RKB Ost” project involved the construction of a new 5,400 cubic meter rainwater treatment system, two stormwater treatment tanks each with a capacity of around 1,500 cubic meters, a pumping station, a light liquid separator, an operating building with the control and monitoring electronics and, especially in the rainwater tank area, several hundred meters of newly laid wastewater sewages made of weldable plastic pipes made of polyethylene and numerous concrete manholes (see Fig. 1).

With the project “U81”, Duesseldorf Airport will be connected to the city rail network in the future. The implementation will take place in a total of four construction phases with planned commissioning in 2024. The total costs are around 230 million euros. During the construction process, the existing supply and disposal pipelines are laid out of the required construction site. In this context, welded sewage pipes up to a dimension of 800 mm are laid outside the construction site of the shell construction measure (see Fig. 2).

In view of the sewers to be laid, in particular, those responsible decided to use a fully welded PE sewer network based on years of excellent experience from previous large-scale projects. PLASSON LightFit waste water fittings are used, such as fully welded manhole connections, electrofusion couplers and wastewater connecting saddles up to d 800 mm, which result in safe, watertight pipe and manhole connections designed for sustainability (see Fig. 3).

The core of the massive overall is construction of the three rainwater tanks
and the pumping station. However, special attention was also paid to construction of the required canal system, which connects the rainwater tanks to the pumping station via appropriate manholes.
Use of welded pipe connections and manhole connections is essential to ensure that no sewage gets into the ground and groundwater in an uncontrolled manner or that groundwater does not infiltrate the sewers.
As these sewers reach a depth of 9.0m below ground, seasonal rising of groundwater can lead to pipe system overflowing, to which the welded system provides a good solution.

When laying and processing the PE pipes and fittings, particular attention was paid to connecting the sewers to the precast concrete and in-situ concrete manholes. Material transitions or manhole connections in particular, often represent weak points of a drainage system when it comes to the criterion of tightness.
In order to ensure a reliable, watertight and durable manhole connection, the decision to use a fully welded manhole connection system was made as early as the planning phase. With use of PLASSON LightFit concrete manhole adapter, a component is available for this application to permanently connect sewers made of
PE to the concrete manhole in a tight and root-resistant manner, while at the same time reliably meeting requirements for flexible manhole connections (see Fig. 4).

PLASSON LightFit manhole connection system consists of the concrete manhole adapter and a corresponding electrofusion coupler. In practice, installation of the concrete manhole adapter already takes place in the concrete plant, where it is professionally integrated into the precast concrete manholes. The manhole adapter is then homogeneously welded to the supplied electrofusion coupler and the PE pipe on site. As part of the large-scale project, precast concrete manhole bodies with an individual weight of up to 28 tons were manufactured in the concrete factory and delivered to the construction site with the integrated LightFit concrete manhole adapters (see Fig. 5).

On the other hand, it was necessary, particularly due to the huge manhole structures constructed using in-situ concrete, to anchor the concrete manhole adapter precisely with reinforcement and form it on the construction site.
This took comparatively more time to process and required manual formwork for the manhole adapter. But here, too, the installation quality is completely convincing: all PLASSON LightFit concrete shaft adapters were professionally and safely integrated into the in-situ concrete manholes (see Fig. 6).

connections, connection saddles and manhole connections would also be used in this dimension range. This required a custom-made product according to customer requirements, especially for the necessary manhole connections, since commercially available welded manhole connection systems are usually available up to d 630 mm.
The technicians and engineers from PLASSON Ltd. R&D department then took over the development and construction of a manhole adapter for the special size d 800 mm based on existing system and production drawings and combined the concrete manhole lining with an 800 LightFit electrofusion coupler. After being appraised by the planning
engineering office, the custom-made product created in this way was specified as the lead product in the tender and was thus specified (see Fig. 7).

As part of the project, a LightFit manhole connection-system in the dimension d 800 mm was welded for the first time in Germany. Thanks to the excellent and fast cooperation between PLASSON LTD and PLASSON GmbH, the large-diameter pipe project could be realized to the complete satisfaction of the customer.

With implementation of the major construction measures at the airport, latest state of the art is now being met. The airport operator is thus making a safe start into the future. The fully welded wastewater system made of polyethylene makes an important contribution to environmental protection and sustainable use of materials.