Hierarchy of Waste Management Strategies
Many firms are not implementing technologies aimed at waste reduction and minimisation, despite their availability. The ESD working group on manufacturing says that 'in many industries, a range of technologies for green products and cleaner production are already available but have not been generally adopted' (p. 98).
Efforts to clean up the environment have tended to concentrate on 'cleaning technologies' rather than 'clean technologies'&emdash;that is, on technologies that are added to existing production processes to control and reduce pollution (end-of-pipe technologies and control devices) rather than changes to the production processes themselves. Cleaner technologies are preferable to end-of-pipe technologies because they avoid the need to extract and concentrate toxic material from the waste stream and deal with it. The ESD working group on manufacturing has categorised waste management strategies according to a hierarchy of desirability, ranging from clean technologies to disposal methods&emdash;the latter being the least desirable.
The alternative to end-of-pipe technologies is to adopt new 'clean' technologies that alter production processes, inputs to the process and products themselves so that they are more environmentally benign. It is suggested by Cramer and Zegveld (1991, pp. 461&endash;2) that process technologies should be used that require less water (for example, by alternative drying techniques), energy and raw materials, and that reduce waste discharges (for example by developing detection and separation machinery and process-integrated flue-gas cleaning and filter systems). Also, raw material inputs and processes can be changed so that, for instance, solvent-free inks and paints, and heavy metal-free pigments are used. The end products can be redesigned to reduce environmental damage during both manufacture and use, and waste flows can be reused within the production process rather than dumped.