Buffering and infiltration of stormwater with tunnel elements

More and more clients are discovering the unique benefits of StormTech tunnel elements for buffering and infiltrating rainwater. A system that has already been used in more than 40,000 projects (!) worldwide. For over 20 years, the StormTech tunnel elements have perfectly matched Nering Bögel's drainage and wastewater treatment products. But, what makes the StormTech tunnel elements so unique?

The StormTech tunnel elements are manufactured by ADS pipe systems, an American producer of corrugated pipe (since 1966) and a manufacturer of the tunnel elements made from polypropylene for more than 25 years. "In theory, the bottom surface of an infiltration system should not be included as available infiltration surface. This is because with many infiltration systems, the soil surface becomes silted up and does not function or does not function sufficiently. StormTech contradicts this reasoning because the system has proven in practice that the soil surface also continues to function," says Richard Janssen, director-owner of Nering Bögel. The operation of the StormTech system is based on the operation of the gravel box principle, one of the simplest functioning infiltration systems. "However, the net storage capacity in a gravel box is only 40%. By applying the tunnel elements in a gravel box, a system is created with the advantages of a gravel box, but also with the required hollow buffer space for rainwater," Janssen clarified. 

Capturing pollution

Any infiltration system is susceptible to contamination. "Depending on the situation and environment, unwanted pollution can be captured as much as possible in the preliminary stage," says Janssen. "This can be done using Nering Bögel Multi-columns, Nering Bögel separators or with a sludge trap provided in the sewer system. But the StormTech system can also be equipped with one or more so-called Isolator Row. Freely translated, this is a separate filter row in the system. This filter row receives the rainwater according to a "first flush" principle, leaving any contaminants behind and easily removed. This makes the system not only inspectable, but actually maintainable for guaranteed operation."

Loadable by heavy traffic

Depending on the average highest groundwater level, the StormTech elements can be used in various sizes. Because the elements are parabolic in shape, the Roman arc principle is used in combination with the filling material, so that the system is also loadable for heavy traffic. "Recently we were able to deliver an infiltration system with a capacity of over 300 m³ for the municipality of Horst aan de Maas and we are currently in the process of delivering three infiltration systems for the municipality of Helmond with a combined capacity of over 1,000m³. In both projects MC 3500 tunnel elements were used and the Isolator Row was made physically accessible by means of access shafts." 

Contractors on duty are often a bit skeptical about using systems unfamiliar to them, Janssen acknowledges. "That feeling is quickly dispelled during installation of the StormTech system. This is because the tunnel elements are very quick and easy to install, without separate fasteners, and can be easily placed on top of each other. The supply pipes can also be easily connected to the system, without fittings."