Western Isles Area Waste Plan

Anaerobic digestion The anaerobic decomposition of biodegradable waste, by the action of micro-organisms under controlled conditions, in order to produce methane in the form of biogas and, as residue, a fiber fraction (digestate) and a liquid fraction (liquor).

Avoidance Strict Avoidance involves the complete prevention of waste generation by virtual elimination of hazardous substances or by reducing material or energy intensity in production, consumption and distribution, as defined by Organisation for Economic Co-operation and Development – Strategic Waste Prevention 2000. See Waste Prevention

Best Value Places a duty on local authorities to deliver services (including waste collection and waste disposal management) to clear standards - covering both cost and quality - by the most effective, economic and efficient means available.

Biological treatment The stabilisation of residual municipal waste, unsorted waste or any other biodegradable waste in order to reduce the fermentability and volume of the waste.

Central composting Large-scale schemes that process biodegradable material from the surrounding area in a centralised location.

Commercial waste Waste arising from premises which are used wholly or mainly for trade, business, sport, recreation or entertainment, excluding household and industrial waste. (As defined in Environmental Protection Act 1990 Section 75)

Community sector Including charities, campaign organisations and not-for-profit companies.

Composting The controlled biological decomposition and stabilisation of biodegradable materials (such as organic garden and kitchen wastes) under predominantly aerobic (oxygen-rich) conditions to produce a humus rich, sanitised and stabilised product that can be beneficial to soil.

Controlled waste Household, industrial and commercial waste or any such wastes that require a waste management licence for treatment, transfer or disposal (as defined by Environmental Protection Act 1990 Section 75).

EC Directive A European Community legal instruction which is binding on all Member States and must be implemented through the legislation of Member State governments within a prescribed timescale.

Energy from waste The recovery of energy value from waste by burning the waste directly, or by burning a fuel produced from the waste, such as refuse-derived fuel (gaseous or solid) or landfill gas.

Gasification Heating waste in a low-oxygen atmosphere at temperatures typically of 800 - 1400°C to give off a fuel gas. This technology was used to produce gas from coal, although it is relatively new process in its application to waste treatment

Green Waste ‘Green and wood waste’ means vegetable waste from gardens and parks, tree cuttings, branches, grass, leaves (with the exception of street sweepings), sawdust, woodchips and other wood waste not treated with heavy metals or organic compounds.

Home composting Compost can be made at home using a traditional compost heap, a purpose designed container or a wormery.

Household waste Waste from domestic properties including waste from caravans, residential homes and premises forming part of an educational establishment and part of a hospital or nursing home.

Incineration A combustion treatment process involving waste. This includes the incineration by thermal oxidation of wastes. The EU Directive on Incineration defines other processes such as gasification and pyrolysis as incineration in as far as the substances resulting from the treatment are subsequently incinerated.

Industrial Waste Waste from a factory (within the meaning of the Factories Act 1961) or from any premises used for or in connection with:

Inert waste ‘Waste that does not undergo any significant physical, chemical or biological transformations’ as defined by the EU Landfill Directive (99/31/EEC).

Integrated waste management Involves a number of key elements, including: recognising each step in the waste management process as part of a whole; involving all key players in the decision-making process; and utilising a mixture of waste management options within the locally determined sustainable waste management system.

In-Vessel composting The composting of biodegradable material in a closed reactor where the composting process is accelerated by optimising air exchange, water content and temperature control.

Kerbside segregated collection Any regular collection of recyclables or compostable materials from premises. Excludes collection services delivered on demand.

Land use planning The Town and Country Planning system regulates development and use of land in the public interest and has an important role to play in achieving sustainable waste management.

Landfill Directive A key European Directive agreed in April 1999, aims to prevent or reduce as far as possible the negative effects of landfilling on the environment and human health. The main requirements of the directive include treatment of most wastes before landfilling; banning the co-disposal of hazardous and non-hazardous waste; banning certain wastes from landfill completely; and targets for the reduction of biodegradable municipal waste to landfill.

Landfill sites Areas of land in or on which waste is deposited.

Materials recovery facility (MRF) A facility to process wastes for the purpose of recovering useful materials using a variety of processes to separate out different materials, ranging from manual sorting to advanced mechanical separation techniques.

Mixed waste processing facility Any facility using one or more mechanical, biological or thermal processes to extract more than one useful product (recyclables and/or compost and/or fuel or energy and/or other recovered materials) from a mixed wastes stream. This covers a range of existing and emerging technologies, many of which are capable of treating either mixed waste (before or after source separation) or source segregated materials, thus offering flexibility.

Packaging waste Comprises waste arising from “all products made of any materials of any nature to be used for the containment, protection, handling, delivery and presentation of goods, from raw materials to processed goods, from the producer to the user or the consumer….”

Pyrolysis In this treatment, organic waste is heated in the absence of air at temperatures typically of 400 – 800°C. This produces a predominantly gaseous fuel product, occasionally some liquid fuel and a solid inert residue (mainly carbon). Pyrolysis can take different waste streams but generally requires a consistent feedstock. Pyrolysis does enable energy to be recovered from the waste.

Recovery Generating value from wastes from a wide variety of activities such as recycling, composting and energy recovery.

Recyclables Materials that are capable of being recycled.

Recycling Using waste materials in manufacturing other products of an identical or similar nature, as defined by Organisation for Economic Co-operation and Development – Strategic Waste Prevention 2000.

Reduction at Source Minimising use of toxic or harmful substances and/or minimising material or energy consumption, as defined by Organisation for Economic Co-operation and Development – Strategic Waste Prevention 2000. See Waste Prevention.

Refuse Derived Fuel A solid, liquid or gaseous fuel derived from waste which typically will be used as a fuel product on site or by a third party user.

Reuse Involves the multiple use of a product in its original form, for its original purpose or for an alternative, with or without reconditioning, as defined by Organisation for Economic Co-operation and Development – Strategic Waste Prevention 2000. See Waste Prevention.

Source separation Separation of materials for recycling or composting (e.g. paper, cans, glass, textiles, garden waste, household organics, plastic, steel, etc.) at the point of origin. The separation either takes place within the household (or business/institution) through the use of different containers, or parts of containers, for individual materials, or at street level when materials are sorted into the collection vehicle.

Sustainable development Development that meets the needs of the present without compromising the ability of future generations to meet their own needs. This definition can be extended to address waste and resources, i.e. development that recognises the need to limit the use of resources and production of waste to levels which do not damage the ability of natural ecosystems to remain stable and healthy. This will involve efficient use of
resources including the reuse and recovery of wastes and a move from resources whose supply is finite to renewable.

Thermal treatment A broad generic term covering processes that involve the use of heat to treat waste. Incineration is the most common thermal treatment process. Pyrolysis and gasification are other high temperature processes but there are also low temperature processes used, for example, in technologies producing refuse derived fuel.

Waste Any substance or object in the categories set out in Annex 1 of the Waste Framework directive (91/156/EEC), which the holder discards or intends or is required to discard.

Waste arisings The amount of waste generated in a given locality over a given period of time.

Waste hierarchy Seeks to capture the desirability of different waste management options in descending order of preference, from Avoidance, Reduction and re-using waste, through recycling and composting, energy recovery and finally disposal. The concept is meant as a guide to thinking rather than a rigid rulebook.

Waste minimisation Preventing and/or reducing the generation of waste at the source: improving the quality of waste generated, such as reducing the hazard, and encouraging reuse, recycling and recovery, as defined by Organisation for Economic Co-operation and Development – Strategic Waste Prevention 2000.

Waste prevention Includes in descending order of preference: Strict Avoidance, Reduction at Source and Product Reuse, as defined by Organisation for Economic Co-operation and Development – Strategic Waste Prevention 2000. These terms are defined under the relevant headings.

Waste transfer station A site to which waste is delivered for sorting and/or bulking prior to transfer to another place for recycling, treatment or disposal.

Windrow composting An open-air method of composting in which biodegradable materials are placed in long piles, which are turned periodically to aid the composting process. The term originates from the farming practice of piling hay in rows so that it will dry out in the wind.