North Weston Odour Control Project


The MVIS is a 2m diameter sewer that transports a significant amount of Canberra’s sewage loading (2/3) to Lower Molonglo Water Quality Control Centre; Population and density growth means that we need to continue to retrofit the existing infrastructure to ensure it can take the load; not be impacted by corrosion; and not cause odour issues.


The purpose of the project is to remove foul air from the existing sewerage infrastructure - the Molonglo Valley Interceptor Sewer - and disperse it to the atmosphere.  This will protect the existing infrastructure and reduce odour complaints from residents.

The scope of the new works is summarised as the construction of:

Stage 1:

  • 450m of 1200mm diameter pipework from the existing offtake structure to a new fan house
  • 70m of 1200mm diameter pipework from the new fan house to a new vent stack
  • a new vent stack that rises 14m above the natural surface
  • a 1600m x 20m corridor for a new power supply to the fan house.

Stage 2:

  • a new offtake structure on the existing trunk sewer (MVIS)
  • a new fan house located on Ryan’s Hill
  • a new 1600m long high voltage overhead power supply installed along this corridor.


The works will be delivered in two stages as indicated above with timeframes given as follows.

Original timeline of Stage 1 of the project:

There have been some delays experienced by Stage 1 of the project that will cause the pipeline construction to extend from 23 December to March 2017. Therefore Clos Crossing (MVIS Bridge) will remain closed for the majority of this time. Note that it will be opened temporarily during the Christmas period while work ceases (23 December 2016 to 15 January 2017). Note that while this crossing is closed there are alternative river crossings available as shown in the aerial view below.

MVIS North Weston Odour Project closures

Visual elements of the project include:

  • Retaining structure near embankmen
  • New fan house will be reinforced concrete structure on Ryan’s Hill    
  • New vent stack to be painted stainless steel structure.

Restoration of the area:

  • The majority of the disturbed areas will be restored using topsoil and a dryland grass seed mix.
  • A maintenance period of 18 months will be applied to these areas after consolidation has been achieved.During this period scouring from run-off will be managed along with weed management.    
  • Remaining disturbed areas will be the existing tracks and they will be restored to their current condition.

Below: The Molonglo Valley Interceptor Sewer carries about two thirds of Canberra's sewage load to the Lower Molonglo Valley Control Centre.