2.6 National Waste Strategy Principles

The National Waste Strategy: Scotland (NWSS) establishes key principles, which need to be taken into account in establishing a sustainable future for waste management. A number of these have influenced the development of the Orkney and Shetland AWP. These are:

• The Waste Hierarchy
  

• The proximity principle and self sufficiency
  

• Best Practicable Environmental Option.

How these principles will affect the development of waste-management systems and methods in Orkney and Shetland is described below.

2.6.1 The Waste Hierarchy

The waste hierarchy provides a framework within which waste-management options are prioritised. The objective of the Hierarchy is firstly to prevent and minimise the production of waste and thereafter increase the percentage of waste that is reused, recycled and recovered (in that order of preference). Ultimately the percentage of waste being disposed of to landfill should continue to reduce.

Waste Prevention
The need has never been greater to prevent waste occurring and, wherever possible, minimise and reuse waste. Waste prevention, therefore, forms a key element of the National Waste Strategy: Scotland. Waste prevention can be achieved at a number of stages including pre-product design stage, changes to management and production processes and the development of clean or 'wasteless' technologies.

Waste prevention initiatives must address two distinct waste streams:

• household waste
  

• commercial and industrial waste.

Household waste is by far the greatest proportion of MSW. The prevention - i.e. avoidance, minimisation and reuse - of household waste will save money in the transport and subsequent management of waste throughout the islands; this money could used for other purposes. Waste prevention can be achieved by households and businesses through customer decisions about what to buy and how much packaging to accept, and householders choices about how efficiently to use the products they buy and what to do with the products when they are finished - bin them, pass them on to someone who can use them, use them again or use them for something different.

For commercial and industrial wastes there is a great deal of evidence, which demonstrates that waste can be significantly minimised at various stages of manufacturing processes providing both a financial benefit to the company as well as reducing the environmental impact of waste. Local companies in the Orkney and Shetland could become more efficient and therefore more competitive by addressing waste prevention in a systematic way.

In recent years there has been a decline in the reuse and refurbishment of consumer durables as the cost of replacing them has fallen in relation to the cost of repair. However, as well as removing items from the waste stream, reuse and refurbishment are linked to job creation and economic improvement. There are already reuse and refurbishment schemes in operation in Orkney and Shetland ranging from the reuse of old clothing through to the repair and subsequent reuse of old bicycles. However, there remains considerable potential for future expansion and opportunity for stimulating this type activity in Orkney and Shetland.

Recycling, Composting and Anaerobic Digestion
Recycling is the separation of a material for processing, followed by preparation and sale onto a market to replace an existing virgin material. The most commonly recycled materials include newspaper, cardboard and glass. As such there are often numerous environmental benefits, such as reduced air emissions, reduced impacts of extraction, energy savings, lower disposal impacts and more efficient use of raw materials. There are often other benefits such as encouraging producers to take responsibility for their wastes and economic benefits such as improved competitiveness or greater employment opportunities.

The collection of wastes as separate material fractions reduces contamination and the need for additional separation processes. This retains the quality and value of the waste materials.

Composting is the aerobic decomposition of organic material to produce a stable material containing organic matter and plant nutrients. There are often benefits in applying this material to land, including nutrient addition, improved soil structure and improved water retention. These benefits are often only realised through the use of source segregated uncontaminated compostable wastes.

Anaerobic digestion is a similar process to that of composting, except the micro-organisms degrading the waste operate in an oxygen-free environment - i.e. where composting processes focus on enhancing conditions for micro-organisms that thrive in the presence of oxygen, anaerobic digestion targets those that thrive without. The potential advantage of anaerobic digestion systems is that methane gas is produced as a by-product of the anaerobic process, and this can be used not only to fuel the operation of the plant, but typically also to power other processes in the vicinity of the digestion plant.

The BPEO for MSW put forward by this plan will increase the amount of this type of waste that is recycled and composted. Future development of the AWP to address BPEO(s) for non-MSW streams will seek to provide cross-sector solutions and increase the proportion of total waste arising that is recovered by these various routes.

Other Recovery
Energy recovery involves recovering part of the energy value from waste, for example by burning or thermally treating the waste directly (for example incineration) or by burning a fuel produced by the waste (as with Refuse Derived Fuel or landfill gas). The energy conversion efficiency of the plant will depend on the specific design, e.g. recovery of energy through combined heat and power.

The recovery process at the existing Lerwick facility utilises the energy contained in MSW by direct combustion to provide district heating for up to around 1000 houses in the vicinity of the plant. The plant is highly efficient, with an overall energy recovery rate of 80%, which is comparable to the most efficient combined and heat and power systems.

For further guidance on energy recovery from wastes, reference should be made to SEPA's "Guidelines and Approach to Thermal Treatment and Energy From Waste" available at www.sepa.org.uk/nws.

Waste Disposal
Landfill disposal sits at the base of the waste hierarchy for the following reasons:

• potential pollution to land, air and water
  

• it is a waste of resources and is considered to be unsustainable.

Landfill will, however, continue to form part of an integrated waste-management system of treatment and disposal options for the foreseeable future.

2.6.2 The Proximity Principle and Self-Sufficiency

This means waste should be disposed of as near as possible to the point at which it arises. Most of the waste originating in Orkney and Shetland is managed within the area, with the exception of wastes requiring specialist treatment, such as hazardous wastes, and wastes being sent to the mainland for recycling, e.g. scrap metal. This waste is often then subsequently transported as far as the south of England. Although this is likely to continue to be the case to some extent, as greater quantities of material for recycling are collected then greater efforts should be made to exploit local opportunities for the development of commercial reprocessing operations and product markets in Orkney and Shetland.

Due to the isolation of the islands, and the associated exceptional high cost of waste transport, the principles of proximity and self-sufficiency are key drivers in developing the area's BPEO.

2.6.3 The Best Practicable Environmental Option (BPEO)

BPEO is the outcome of a systematic and consultative decision-making procedure, which emphasises the protection, and conservation of the environment across land, air and water. The BPEO procedure establishes, for a given set of objectives, the option that provides the most benefits or the least damage to the environment as a whole, at acceptable cost, in the long term as well as in the short term. In the way this has been applied within the NWS framework this includes balancing social, economic and environmental costs and benefits. The Orkney and Shetland AWP describes the BPEO for MSWs and sets out the process by which the BPEO will be determined and implemented for all other wastes. The process of assessing the Orkney and Shetland BPEO for MSW placed particular emphasis on proximity and self-sufficiency, and the need to recover as much value from waste locally, to provide social and economic benefits. This same emphasis will be applied in developing non-MSW BPEO(s).