Scandinavian Group visit Norsk Vann’s waste-water treatment facility at Bekkelaget in Oslo

Members from Norway, Sweden and Denmark met for the Scandinavian Group AGM, held at Oslo's Nobel Peace Center, followed by a visit to Oslo's underground waste-water treatment plant at Bekkelaget and a social afterwards.

The IMechE Scandinavian committee used their AGM to discuss the results of a phone survey of members to agree the program for the year ahead.  In the light of tightened budgets it was agreed to focus our efforts on four areas: Oslo, Stavanger, Gothenberg and Copenhagen.

The visit to Bekkelaget, the group's third technical visit, was hosted by Norsk Vann and their contractor BVAS.  What most impressed the visitors was the entire facility is situated in man-made caves underground. It is located in the Ekeberget hill 3 km south of the city centre and serves a population of around half a million. There are 10 cave tanks typically 150m long and 20m wide and 15 m deep, plus equipment rooms.

All the city’s drains and sewers feed into the facility at approx. 2500 litres per second. The treatment is in four stages:  coarse filtration (material to land fill), sedimentation and biological removal of nutrients, (sand filtered water transferred to the fjord), sludge digestion (bio gas) and sludge dewatering.  

This means that Oslo’s residents are producing useful fertiliser which is given to local farmers and bio gas which after upgrading/compression is used to power 80 of Oslo’s buses! The water discharged meets required specifications for clean discharge into the fjord. The facility is currently the largest of its type in Norway. 

The group also enjoyed the artistic installation of a sound system with computer-generated music echoing in the caves throughout the day. John Pretlove, the group's Vice Chairman was particularly impressed that the facility could run unmanned throughout the night, relying on sensors to detect and report problems. He remarked, “It is quite astonishing that such an important facility in the life of a city, is quietly working away out of sight and sound of the population. It serves another very good example of improving the world through engineering!”  

Find out more about the Scandinavian committee or to attend future events in Norway, Sweden and Denmark.