Doing it differently: AD and composting in Scotland
Tompkins, D.1, Litterick, A.2, McKinnie, A.3, 1Aqua Enviro Ltd, 2Earthcare Technical Ltd, 2Zero Waste Scotland
(free)
Abstract
Scotland has an ambitious Zero Waste Plan which aims to make the most efficient use of resources. An organics recycling strategy forms a key part of this plan, which includes strict targets for recycling and landfill avoidance that go well beyond those required by European legislation. The targets and proposed bans mean that action has been taken and will be taken in future to increase the quantity, and quality, of resources which are sent for composting and anaerobic digestion. In addition to the on-going divergence between Scottish and English recycling targets, there are also differences in regulatory approaches.
The increased availability of compost and digestate has stimulated the development of new markets for these materials in Scotland, but whilst agriculture remains the most significant market, it is in some ways the most precarious. This paper describes the differences between the organics recycling sectors in Scotland and England and draws conclusions on the impact of government targets incentives, government targets, the regulatory regimes, recent research and market demands on the development of composting and anaerobic digestion in each country.
Keywords: Compost, digestate, Scotland, organics recycling, Waste Regulations, Zero Waste Plan, anaerobic digestion, composting
Introduction
Scotland has an ambitious Zero Waste Plan which aims to make the most efficient use of resources by minimising the country’s demand on primary resources, and maximising the reuse, recycling and recovery of resources instead of treating them as waste (Scottish Government, 2010). The vision describes a Scotland where resource use is minimised, valuable resources are not disposed of in landfills, and most waste is sorted into separate streams for reprocessing, leaving only limited amounts of waste to go to residual waste treatment, including energy from waste facilities.
An organics recycling strategy forms one key part of the Zero Waste Plan, and this includes strict targets for recycling and landfill avoidance that go well beyond those required by European legislation. The two main routes for recycling waste organic materials are composting and anaerobic digestion, and (to a large extent in response to Scottish Government targets and incentives) the Scottish organics recycling sector has developed from a very low base around 10 years ago to a thriving industry, where approximately 0.54M tonnes of organic waste were recycled into compost and digestate in 2013 (Zero Waste Scotland, 2014).
The increased availability of compost and digestate has stimulated the development of new markets for these materials in Scotland, from agriculture to large scale brownfield site restoration. Whilst agriculture remains the most significant market, it is in some ways the most precarious. Key farming stakeholders have set their own rules on compost and digestate quality to which their associated farmers, growers and licensees must adhere if they wish to use these materials.
Whilst this approach initially caused some consternation within the organics recycling sector, the focus on quality has ultimately had a beneficial effect, with both producers and users developing a clear understanding of what is expected in Scotland. This paper outlines the organics recycling sector in Scotland and summarises the ways in which the sector differs from that in England and Wales.
