The port city Kotka at the mouth of the Kymijoki River and its neighbouring villages Pyhtää, Hamina and Kouvala are planning a new, alternative main supply of drinking water in case the existing main pipeline fails. A new route with a total length of 25 km will be built from the Kymenlaakson waterworks to the settlement area. In a section of approx. 10,000 m, pipes made of PE 100-RC with an additive protective jacket made of PP were used due to aggravating soil conditions, in order to be able to guarantee a high-quality laying by means of pipe pulling in the HDD method. The laying work, including the production of necessary pipe string connections using the butt welding method, was partly carried out at temperatures as low as -25°C and supervised by the employees of the pipe manufacturer GERODUR. In this way, this sensitive section of the route could be completed on time and at low cost.