Changes in legislation and regulation seem to have two main drivers. The first is the advent of new kinds of waste such as electronic waste. The large quantities, increasing rates of disposal and potential toxicity of these materials has forced many governments to implement a variety of mechanisms to encourage their recovery and reduce potential hazards. These measures have included landfill bans, deposit and buy back schemes, collection service provision and partnerships.
The other driver has been the advent of new waste processing technologies. Waste to energy for example, is both a method of waste disposal and a way of generating more sustainable power and heat. In some cases the regulatory environment has had to be changed in order to allow and encourage WtE facilities to be built.