Principles of Waste Avoidance and Utilization
The minimization of wastes requiring disposal is increasingly important as available disposal options become more and more constrained, and particularly as more substances enter everyday use which are not readily decomposed in the natural environment and which can present long term hazards. This note sets out some basic principles for waste minimization in industrial processes, where 'minimization' is taken to include avoidance of the generation of wastes where practical and the productive utilization of any wastes which are generated.
In some rural or non-industrialized areas, wastes are typically organic or inert and do not pose major disposal problems, particularly as wastes are often utilized for animal food or other purposes. However, as the level of industrialization increases or even simply as a result of growing access to packaged and consumer goods, waste disposal becomes an increasing problem in virtually all societies. The problems are typically associated with non-biodegradeable or bio-accumulative substances, such as waste pesticides, solvents, heavy metals, chemical sludges. These are often production wastes but can also arise from inappropriate application (pesticides) or poor consumer behavior (waste motor oils). The development and widespread use of new substances such as plastics and the products that they have made possible have improved the standards of living for millions but they have also introduced new threats to the environment as typified by the histories of DDT and PCBs.
The long term solution to the problems of persistent or hazardous wastes, in particular, must lie in approaches which find alternatives to the hazardous substances but in the meantime high priority should be given to minimizing the use of resources and reducing the discharge of wastes.
Added weight is given to the need to avoid or minimize the release of complex organic or inorganic substances into the environment because of the uncertainty that surrounds their effects on human health and the natural environment and the very high costs of retrofitting or clean-up. At the same time a realistic attitude must be maintained in developing countries. Much of the industrial and product design is based on industrialized country practice and almost all of the fundamental science on which regulation is based has been carried out in the more advanced economies. Although there will be some opportunities to leap-frog to more advanced systems, the priority in developing countries should be to ensure that the policy makers and regulators are up to date and informed and avoid repeating fundamental mistakes of industrialization.
A particular challenge of the developing countries is to take advantage of affordable and productive technologies from industrialized countries without allowing the importation of outdated or outlawed equipment or substances. Technologies and materials science are changing rapidly but at the same time so are the sources of information. Environmental agencies in developing countries which can do not have the resources to carry out their own research can find much of the necessary information publicly available through a number of sources but it will frequently require an investment in time and resources to find the appropriate answers.
'Waste minimization' is one of a number of related terms and concepts which have similar overall goals and which are often used interchangeably but which may have significant differences in basic principles and in emphasis. In the present context, waste is used to refer to a material, from a manufacturing process, which has no value to the manufacturer and which has to be disposed of in some manner. (The waste of energy is a very important related issue, which is addressed elsewhere.)
'Avoidance' of waste refers to actions by the producer to avoid generating the waste, while 'utilization' includes the range of actions which make that waste a useful input to other processes and thus avoids the need for disposal. Waste minimization thus comprises both avoidance and utilization. Processes which reduce the toxicity or potentially harmful impacts of a waste can in some cases be included as minimization although in other circumstances such changes represent treatment before disposal.
Although the terminology used may vary, a number of important activities can be distinguished: reuse refers to the repeated use of a 'waste' material in a process (often after some treatment or make-up); recycling refers to the use by one producer of a waste generated by another; and recovery is the extraction from a waste of some components which have a value in other uses.
Hierarchy of Approaches
Waste avoidance and utilization can be seen as part of a broader hierarchy of approaches to achieving sustainable development. At the highest level are approaches which seek to satisfy human needs and requirements in ways which do not waste resources or generate harmful byproducts or residuals. These approaches include changing consumer behavior as well as re-examining the range and character of products and services produced. At a slightly lower level are efforts to re-design the products and services as well as raising the awareness of consumers about the impacts of their decisions. Applications of techniques such as Life Cycle Analysis (LCA) are part of the difficult analysis of the overall impacts of products and services on the environment. Such approaches are at present adopted mainly by the more advanced organizations in industrialized countries.
More directly relevant to industrial activity in developing countries are approaches focused on improvements in production processes. These approaches include cleaner production, pollution prevention, waste minimization etc., all of which relate -- to a greater or lesser degree -- to better management, improvements in production processes, substitution of hazardous inputs, reuse and recycling of wastes and so on.
The next step, which should be minimized but is not to be neglected, is treatment and proper disposal of wastes. The lowest level in the hierarchy and the one which all the other levels strive to eliminate is remediation of the impacts of wastes discharged to the environment. Unfortunately, clean-up is more costly than prevention.
Policy and Regulatory Framework
A clear and effective governmental framework for waste management is necessary, which should include the delegation of relevant powers to the lower levels of government which are typically responsible for implementation. The framework should be based on a clear and broadly accepted long term policy and should include a predictable and flexible regulatory regime and targeted economic incentives. At the same time, programs should be put in place to increase awareness and education, with the long term objective of changing the behavior of manufacturers and consumers towards minimizing wastes generated.
Producers and Consumers
Efforts must be made to involve both producers and consumers in waste minimization and utilization. Producers can improve their performance through both management changes and technological improvement and some producers in industrialized countries are now making serious efforts to examine the impacts not only of their production processes but also of the products themselves. Life Cycle Analysis (LCA) is still a developing tool but does focus attention on the overall impact of the production, use and disposal of products.
Consumers in some of the wealthier countries are moving towards a greater awareness about the need for waste reduction, with participation in recycling schemes and some demand for environmentally friendly products. However, progress is often slow and there is a need for ongoing education and awareness as well as careful analysis of options and incentives.
At the same time, in less developed countries, the demand for resources often leads to a significant level of recycling of materials such as glass, metals and plastics. These recycling systems have important social and economic consequences at the local level and 'improvement' of such systems must be approached with care.
Waste management efforts are linked closely with income levels and there is a broad progression from recycling of most materials in the poorest societies, through increasing consumerism often with little concern for waste problems in low to middle income countries, to the environmental activism of some rich countries. The appropriate waste avoidance and utilization strategy for any situation must take into account the level of the economy, the capabilities of government at different levels and the environmental circumstances.
As with any other environmental strategy, there is a need for public involvement and political support in the identification of priorities and the implementation of the necessary enabling measures.