Scottish Government publishes independent review of waste incineration

Scotland’s independent review of the role of waste incineration in the waste hierarchy has been released, as commissioned by Lorna Slater.

IncineratorBackground to the Review

The review looked at whether Scotland’s residual waste management aligns with its carbon reduction ambitions. In its Climate Change Plan update, the Government outlined 2025 targets to end landfilling of biodegradable municipal waste, reduce the percentage of all waste sent to landfill to five per cent, and recycle 70 per cent of all waste.

The treatment of household (HH) and commercial and industrial (C&I) waste streams was a focus, with these streams being chosen as they are likely to be affected by the Government’s new landfill targets. These streams also ‘comprise a large proportion of waste incinerated’ – this treatment has ‘increased significantly since 2013’, with municipal waste incinerators ‘often the object of stakeholder concerns’.

The review asked five key questions:

  1. Given Scotland's waste management ambitions and current progress towards these, what capacity is required to manage residual waste in Scotland?
  2. What are the options for managing residual waste?
  3. What are the economic, environmental and social trade-offs of those residual waste management options?
  4. How do we decide where capacity should be located, and in what form?
  5. What can be done to improve existing residual waste treatment facilities in terms of carbon performance and societal impacts?

Responding to these questions, the review examined existing evidence and commissioned additional ‘capacity modelling, an appraisal of waste treatment options and a rapid evidence review of the potential health impacts of incinerating waste.’

Research found shortfalls in the ‘accessibility, quality and quantity of some data around waste management’, with the review recommending improvements to waste management data and transparency.

Scottish residual waste management capacity

Analysis suggested that there is likely to be a capacity gap in 2025, when the ‘biodegradable municipal waste (BMW) ban comes into force.’ The report said that this gap will ‘be exacerbated’ if the ban extends to include all non-municipal biodegradable waste.

While this capacity gap could be closed by Scotland achieving its waste and recycling targets, the report notes that stakeholders are concerned about the likelihood of achieving these targets, using experience and comparisons with other nations as evidence of what could be possible.

The report identified difficulties in using infrastructure with long operational life spans alone to treat residual waste, due to the short term capacity gap being balanced against the long term likelihood of overcapacity. Risks of lock-in in waste management contracts were also highlighted, with the review recommending that local authorities specifically address this within their contracts.

Residual waste treatment and incineration

According to the review, the best way to treat residual waste is primarily through reduction, as well as recycling. Recommendations urged the Scottish Government to do more to ‘reduce the proportion of recyclable materials in the residual waste stream.’

Taking this assessment into consideration alongside social, health and climate factors, the review contemplated incineration's current place within the waste hierarchy. Its current place in the hierarchy as ‘preferable to other forms of residual waste treatment, but less desirable than reducing and recycling waste’ was seen as correct, with the review recommending that the ‘most feasible waste treatment options’ are incineration, landfill and export of waste.

The review suggested that Scotland should ‘limit the granting of further planning permissions for incineration infrastructure’, with an ‘indicative cap’ to be developed for Scotland’s residual waste treatment needs. This should decline ‘as Scotland transitions towards a fully circular economy.’

Research found that, currently, incineration is less damaging to the environment than landfill. However, ‘increased incineration, changes to waste composition and wider decarbonisation’ will over time make this opinion ‘less favourable’. To monitor this change, the Review recommends separate greenhouse gas (GHG) emissions reports on incineration.

Separate work has been commissioned to inform further decarbonisation opportunities in residual waste treatment infrastructure, with the main focus on waste incineration.

Whilst this is carried out, the review ‘provisionally’ recommends improving pre-treatment processes before incineration, focusing on plastics. The review also ‘provisionally’ recommends that ‘combined heat and power should be pursued for as many incineration facilities as possible.’