1. Introduction
Waste management is one of many specialised fields and economic activities that make up the National economy and has a direct involvement and influence on (and is influenced by) the production and consumption of goods and services. As such it is one component of the economic cycle and interacting associated natural cycles such as the carbon cycle. The economic cycle includes the extraction of raw materials from the environment, the processing of those materials to form intermediate and final products, the consumption of those products and the ultimate disposal of the materials involved back to the environment.
There are 2 major overarching environmental and sustainability considerations in the management of wastes and material resources these being:
a. to enable the conservation of non-renewable and other resources through waste minimisation, re-use, recycling, and recovery by energy production and composting
b. the protection of human health and the environment. In particular to mitigate the effects of global warming by preventing the discharge of the potent green-house gas, methane from landfill facilities, or by displacing the use of fossil fuels in energy generation.
Government policy on sustainable waste management aims at breaking the link between economic growth and waste production and to drive the management of waste up the waste hierarchy. It also considers that waste should be viewed as a resource to be put to good use and considering waste disposal as a final option.
2. Conservation of non-renewable resources
Many of the raw materials used such as oil and metal ores are of limited availability due to their presence in reserves of finite global quantity. Such material resources are only replaceable in nature on geological time scales of tens or hundreds of millions of years. The world economy continues to expand with China and India making rapid progress in domestic production leading to increasing demands for these finite resources. This inevitably leads to price increases for materials which in turn stimulate further extraction of ores etc.
Clearly there is an essential need for the waste manager to act to protect such scarce resources through waste minimisation, re-use, recycling and recovery hence ensuring that irreplaceable materials are kept within the commercial cycle for as long as is practicable. It may well be that materials will be subjected to multiple episodes of recycling and re-use before they finally are discharged back into the natural environment. This is an essential principle of sustainability to enable conservation of resources for future generations to cater for their needs.
However it is far from clear whether current global policies on sustainable production and consumption will be robust enough to ensure conservation of finite resources, particularly in view of the continuously expanding world economy and the fact that many reserves of scarce resources are located in third world countries, many of which rely on earnings from these exports. Extraction of natural resources may also be problematic and can result in considerable environmental damage without adequate controls.
Though plastics are composed of non-renewable materials, in recent times they have not been awarded the attention they deserve, particularly in the domestic waste stream where early crude tonnage based compulsory targets have made non-renewables such as green wastes much more attractive for recovery, despite the fact that their separate collection tends to lead to increased waste tonnages overall. However these targets have been an essential tool to boost the recycling of household/municipal wastes to meet the requirements of the Landfill Directive. In fact European nations are probably at the forefront in terms of their approach to sustainability issues, though there is much further to be achieved and refinement of some of the earlier targets referred to above is necessary.
3. Protection of the Environment and Human Health
There are local environmental issues applying to most waste management activities including the prevention of contamination of land, water and air together with the health protection for people living and working nearby or within waste facilities. These are controlled through various items of legislation including the Health and Safety at Work Act, the Environmental Protection Act as well as various European Directives including the Landfill Directive and the Hazardous Waste Directive.
A major concern currently is global warming and the contribution that waste management can make to the mitigation of warming effects. The prevention or minimisation of methane discharge from landfill activities has already been referred to, but other issues include the displacement of fossil fuels by use of refuse derived fuels (rdf – solid, liquid or gaseous) or directly by generating energy from waste (efw) through incineration. It has to be acknowledged that waste used for recovery of energy, often has a component that is derived from fossil fuel sources, i.e. plastics, and hence cannot be considered as entirely renewable itself. However the net displacement of fossil fuels by rdf or efw should make an important contribution to the mitigation of global warming.
4. Sustainable production and consumption
The world economy continues to expand as people in the developing nations seek a better standard of living as experienced currently by the western developed nations. The environmental impacts from consumption and production of goods and services are substantial, and it is important to efficiently use resources. To fail to do so threatens the competitiveness of the Economy as well as further reducing the availability of scarce resources to future generations.
At the 2002 World Summit on Sustainable Development in Johannesburg, the UK Government committed itself to encourage and promote the development of a ten year framework of programmes to speed up the move towards sustainable consumption and production.
Sustainable Consumption and Production (SCP) involves achieving economic growth whilst safeguarding the environment and making use of resources, particularly scarce resources, in a sustainable way and is a global as well as a local and national issue.
The UK strategy for sustainable development, “Securing the Future” was issued in March 2005. Sustainable consumption and production (SCP) was and is a key issue for UK action. A range of activity is indicated to take the SCP agenda forward including promotion through:
1 better products and services, which reduce the environmental impacts from the use of energy, resources, or hazardous substances
2 cleaner, more efficient production processes, which strengthen competitiveness,
3 and shifts in consumption towards goods and services with lower impacts.
5. Mass Balance
To achieve SCP it has been accepted that good data on material flows is essential for resource management. Ideally this would be on a global basis but currently it is difficult enough to obtain reasonable figures on a national basis. However landfill tax funding has been utilised through the Biffaward scheme to research material flows within the UK economy which resulted in the report “Mass Balance – an essential tool for understanding resource flows” (2006). 30 unique projects were instigated dealing with different sectors of the economy and geographic areas as part of this intensive exercise.
The principle of mass balance is a scientific principle that matter can neither be created nor destroyed, i.e. the mass of input raw materials (solid, liquid or gaseous) must equal the outputs of products and wastes. However for efficient resource management the mass balance data would need to cover the whole Economy, which would be a major task. One hope of the report authors was that the system of resource accounts being produced could be developed into national resource accounts which could be the basis of national sustainable resource management in the UK.