What goes in our landfill?

A part of our role in responsibly disposing of Wellington's waste is a landfill SWAP analysis.

Text in image: Buried Treasure. What we are throwing into our landfill. Sitting in front of green hills with wind turbines atop is the landfill with its earth movers. By the rubbish pile are buildings marked landfill gas and power that connect to power poles.

What is a SWAP analysis?

SWAP, which stands for Solid Waste Assessment Protocol, is a standardised method, endorsed by the Ministry of the Environment, used by waste managers to understand the composition of waste being placed at kerbside by residents, what is being received at the landfill and who is sending the waste to the landfill.

SWAP analysis allows solid waste managers to track the changing composition of waste which allows Council to:

  • understand the amount, the types of waste and who is producing the waste that is received at our landfill
  • alter the existing landfill operations and inform future investments, designs and engineering of landfills. For example, how much methane will be generated in the future and the best way to capture it
  • identify potential ‘problematic’ waste streams assisting us in finding solutions
  • track the effectiveness of waste minimisation policies
  • prioritise future waste minimisation activities and policies.

The survey

The SWAP analysis had two collection sources.

  1. We randomly selected 491 households and had their kerbside rubbish collections analysed.
  2. We surveyed 500 vehicles arriving at the Southern Landfill.

Key findings of the survey

SWAP (Solid Waste Analysis Protocol) results at a glance. View accessible PDF for breakdown of data.

View SWAP results at a glance as an accessible PDF (122KB PDF)

Text summary

  • The Southern Landfill receives 1745 tonnes per week.
  • Of this 1745 tonnes, Household Waste makes up 585 tonnes which is 34% of the total volume of waste per week.
  • Special Waste (mainly asbestos and sewage sludge) and Industrial, Commercial or Institutional Waste (mainly contaminated soil) were 454 tonnes each, which is around 26% per week.
  • 67.4% of Household Waste and 40% of all waste coming to the landfill could potentially be diverted, for example, plastics that could've been recycled.
  • The largest proportion of Household Waste placed at the kerbside that could be diverted is organic waste (kitchen and green waste) making up to 57.8% of what could potentially be diverted, assuming the diversion options are economically viable.
  • The largest proportion of waste received that could potentially be diverted is Kitchen Waste making up 14% of what could potentially be diverted.

View executive summary of the SWAP report (228KB PDF)

View full SWAP report (1.4MB PDF)