Typology of Waste

Industrial waste is defined as any substance not required by a generator and is therefore to be discarded from the site at which the substance is located. This definition can be applied more broadly to commercial waste, such as from hotels, offices, hospitals, retail stores, and residential properties. In such cases, the occupier of the premises is construed to be the generator. The definition can be extended further if the concept of “site” includes entities such as modes of transport, in which cases the corresponding generators are the people who operate them. A definition might describe a unique, immutable relationship or phenomenon, such as the area of a circle in relation to its radius, or it may indicate a group of phenomena that is to be considered for a specific purpose. Definitions of waste are examples of the latter category, some formulated for purposes that might produce unintended consequences. A case in point is the all-inclusive definition of industrial waste formulated by some agencies as the basis of strategies for protecting the environment. Such definitions may facilitate regulatory action but they might also inhibit the use of waste in practice, to the detriment of the environment. A typology of waste may help to mitigate this and similar difficulties in relation to the consumption of waste.

The notion of “want,” as expressed by the phrase not required, is the defining criterion of waste, from the perspective of its generator. The notion of want is also a criterion for this typology but from the perspective of a potential user, as implied by the concept of demand. If waste is wanted by a user for a beneficial purpose, then the notional status of that substance may change accordingly, even though the substance might remain physically or chemically unaltered. Notwithstanding that waste may be wanted by a potential user, it may remain unused because the costs of supply, such as handling, storage, and transport, may be prohibitive. The significance of cost is represented by the concept of “tradability,” which correlates demand with actual use. Waste is deemed to be traded when some form of consideration is made for the cost of its supply to the user. The consideration may be in cash or in kind, according to the relationship between the generator and the user and may be made by one to the other or by a third party to either. The user may pay nothing for the waste, or may even be paid to receive it. In such cases, the generator is usually the payer, although subsidies might be available from government or other third parties.