Environmentally friendly rehabilitation of drinking water pipelines in Münster – with rapid installation through the nature reserve

The transport of drinking water from the waterworks in Münster is now carried out by fully welded egeplast pipe systems. The rehabilitation of the old drinking water pipelines was also intended to expand the capacities of the drinking water and surface water pipelines of the Hohe Ward waterworks. The Stadtnetze Münster faced the challenge of ensuring environmentally friendly installation when crossing a nature reserve. They opted for 20-meter pipe sections, which allowed for a high installation speed and reduced costs.

Between early 2024 and mid-2025, old cast iron pipes were replaced by nearly 5 km of modern PE drinking water pipes in the Hiltrup district of Münster, between the Hohe Ward waterworks and the Hiltruper See parking lot. The client is Stadtnetze Münster, which commissioned Ludwig Freytag as the contractor and pipe layer, and selected the egeplast egelen PE 100-RC drinking water pipe as the pipe system.

The starting point for the extensive rehabilitation was the fact that the old cast iron pipelines from 1906 had reached their maximum service life. Leaks and drip leakages increasingly occurred, especially at the hemp-sealed joints. In addition, the planning of the new pipeline system had to consider an expansion of the capacities of the Hohe Ward waterworks. For cost reasons, among others, a fully welded pipe variant was chosen, which was laid in 20-meter sections using open trench construction. This reduced the number of welded joints and allowed for a high installation speed.

However, a railway line had to be crossed and a nature reserve traversed along the route, which made precise planning and work steps more important. New steel protection pipes were pre-pressed under the railway line, into which the new PE-HD pipes were pulled. For this purpose, accessible concrete shaft structures were installed on both
sides of the railway line for visual inspection of the newly laid PE-HD pressure pipes, in accordance with railway specifications. The construction phase for crossing the nature reserve was continuously monitored by ecologists to ensure standard-compliant and environmentally friendly installation. Special requirements included, among other things, that all equipment and machinery had to be operated with bio-oil. This requirement increased the complexity of the construction project, especially for pressing systems, for which this is generally not the case.

After almost one and a half years of construction, the project was completed in summer 2025. The pipes now transport water from the Dortmund-Ems Canal to the Hohe Ward waterworks. After multi-stage treatment, the water is fed into Münster’s drinking water network.