Improving waste management practices though a voluntary
grouping of seven local authorities in Northern Ireland.

In-Vessel Composting


In-Vessel Composting or Bio-Drying is a natural biological process which takes place in a series of long concrete rooms known as tunnels.

  • After waste has been mechanically sorted, the resulting fine material is transferred to a tunnel.
  • The entire floor space (approximately 150 square metres) is covered to a height of up to four metres.
  • The tunnel is then sealed at both ends.
  • The tunnel has a perforated floor allowing warm air, driven by fans, to circulate
  • Over the next two to three weeks, this warm air helps compost the material, releasing carbon dioxide and water vapour
  • This reduces the mass of the material by about 30%.

The final product is a stable compost-like material which can be easily landfilled or used as a fuel source.

Supported by
  • Strategic Investment Board
  • Department of the Environment
© North West Region Waste Management Group
  • Ballymoney District Council
  • Coleraine District Council
  • Derry District Council
  • Limavady District Council
  • Magherafelt District Council
  • Moyle District Council
  • Strabane District Council