A new retention basin replaces two combined sewer overflows , Vejle

Rentetion basins for rain and sewage

Weholite pipes limit the overflow of untreated wastewater during heavy rainfall

Project Facts:

  • Vejle, Denmark
  • Municipal infrastructure
  • Completion: 2006

Uponor involvement

  • 6 x 36 m, diameter 2400 mm Weholite pipes, connected to 1000 mm diameter manifold consisting of 6 450 mm rising pipes and 2 1250 mm distribution chambers

In the strategy of Vejle Municipality to improve the water environment, the Højen wastewater treatment plant was planned to be either expanded or closed in 2005-2006.

Højen Wastewater Treatment Plant, which was located about 4 km south of Vejle, was facing a thorough renovation. In the end, the municipality chose to close down the treatment plant and instead pump the sewage to the central wastewater treatment plant of Vejle. By establishing a new retention basin as a buffer for the pump station, the municipality simultaneously was able to close down 2 combined sewer overflows with overflow to Højen Stream. The rainwater and sewage from the entire catchment area is now led to the retention basin.

Højen Stream is one of Denmark’s priority targeted streams. Due to this project, the daily discharge of treated wastewater was removed and the amount of overflow water to the stream was significantly reduced.

The new retention basin consists of 6 pipes of 36 meters with a diameter of 2400 mm. They can hold a total of 976.8 m3, which reduces the risk of overflow to the surroundings quite considerably.

The 6 x 36 meter pipes actually consist of 12 pipes of 18 meters, which have subsequently been welded together on site – an outstanding advantage with pipes of this size.

Another advantage of the Weholite pipes is the relatively low weight. This makes it possible to produce and ship large units. This gives relatively few assemblies which in turn reduces the risk of leakages.

Project Information




Project Type
New Build

Building Type
Municipal infrastructure

Product Lines
Weholite for sewer gravity
Weholite for gravity renovation


Project: Retention basin to withhold rainwater and sewage
Builder: Vejle Municipality', Technical Administration
Contractor: Construction Company Østergaard A/S
Installation: Uponor Infra A/S

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