1. Safe Sludge matrix available at: http://adlib.everysite.co.uk/resources/000/094/727/SSMatrix.pdf
2. Waste Management Licensing Regulations (Scotland) 2011: Under regulation 17 (7), an exemption can only apply if the type and quantity of waste and the method of disposal or recovery are consistent with attainment of the objectives in para 6(1)(a) of Part I of Schedule 4, and in this case 6(1)(a)(ii) is relevant: "causing nuisance through noise or odours".
3. Sniffer is a registered charity delivering knowledge-based solutions to resilience and sustainability issues. Report written in 2008 is entitled "Human health and the Environmental Impacts of using sewage sludge on Forestry and for Restoration of Derelict land.