By constructing a storage-settling sewer of approx. 1.7 km Zevenaar Council has achieved its objective of improving the water quality of the waterways and ditches and reducing odour nuisance and fish mortality.
Visser & Smit Hanab used the Closed Front Drilling technique to construct the concrete storage-settling pipe with an internal diameter of 1800 mm and an external diameter of 2160 mm, using 4 shield drillings. The drilling lengths varied ranged from 197 metres to an impressive 713 metres.
The storage-settling sewer was constructed from two drill pits measuring 12 x 6 metres, with a depth of approx. 9 metres. From these two thrust pits the three receiver pits
were drilled into. These three receiver pits, measuring 9 x 5 metres are necessary in order to receive the drilling machine and to connect the storage-settling sewer with the