It started with rats at the hot-dog stand and settlement damage at one of the entrances to the train station. Later on it turned out that major parts of the sewer system under the train station were in need of thorough renovation.

”We have been working for DSB, the Danish State Railway, at the central station since last autumn. The rat problem and the settlement damage originated from the run-down sewer system. Rats had dug through leaky sewer pipes that were no longer in use and found their way into the sewers and all the way up to the hot-dog stand on the pavement”, says Aarsleff Project Manager Jan Fogtmann.

When executing the first acute repair on the sewer system, Pipe Technologies found that many of the other pipes were in a very poor condition. They were leaky and full of various deposits.

Thorough inspection, evaluation and rehabilitation of the sewer system were initiated. ”During the spring and summer, we have flushed, cleaned and TV-inspected 80% of the lower level sewers”, says Jan Fogtmann and continues; ”in addition to this, we rehabilitated an 80m long main pipe because there were visible signs that the pipe could collapse any time. Specific hollows in the asphalt were one of the signs indicating this”.

During October and November laterals, pipes, manholes and downpipes as well as the basement outlets have been rehabilitated. In order to avoid future rat’s nests in dry pipes, only laterals in use have been opened. Furthermore, several of the manholes have been equipped with rat preventive measures to keep the rats from entering into the sewer system.