“best available technology not entailing excessive cost” is a concept closely associated with BPEO—and, unsurprisingly, derives from the early BPM construct. The ideology behind the BPEO is based largely on the basis of its early counterparts, but is intended to harmoniously merge the primary concerns behind BPM, BAT, and other like-minded concepts—environmental, economic, and social concerns. Reason for Establishment The concept of the BPEO was introduced by the RCEP due its identification of the “need for a more unified approach to regulatory control over pollutant discharges than that which prevailed at the time”. Prior to the development of the BPEO, “separate and effectively independent controls over the disposals of waste to air, water and land” had been in effect; the UK, however, desired a more uniform approach to waste management. Further, the RCEP sought to identify the “optimum overall environmental solution for any given waste stream”—and so the BPEO came to be, with the intention to direct pollution "to the medium where the least damage would be done”. At the time of creation, a primary reason for the development of the BPEO was to develop a “systematic audit trail” that would allow for transparent decision making. This audit trail involved the development of the BPEO's seven key stages: (1) “define the objective”, (2) “generate options”, (3) “evaluate the options”, (4) “summarise and present the evaluation”, (5) “select the BPEO”, (6) “review the BPEO”, and (7) “implement and monitor”. The development of these stages was a notable event in the early history of the BPEO concept, as this procedural development extended the idea beyond its early focus, pollution control, and prompted the expansion of the scope to include “all projects affecting the environment”—while simultaneously expanding the reasoning behind the establishment of the BPEO concept to include the need for broader considerations of environmental factors, as well as the demand for the establishment of more cost-effective and socially feasible waste management options. In the simplest of terms, the BPEO idea was established as an attempt to institute a method that could determine the soundest waste disposal practices using a holistic approach. With respect to the reasoning for the development of the BPEO, it is critically important to note that the UK's RCEP recognized the demand for a structured concept, rather than a rigid decision making tool—and, therefore, put forth the BPEO process as a “framework concept, linked to an underlying systematic process”