What is Best Practicable Environmental Option?

Legal Definition
The Best Practicable Environmental Option (BPEO) (Twelfth Report, FEB 1988, Cm 310), is a set of procedures adopted by Great Britain with the goal of managing waste and other environmental concerns. According to the Royal Commission on Environmental Pollution, BPEO "emphasises the protection and conservation of the environment across land, air and water. The BPEO procedure establishes for a given set of objectives, the option that provides the most benefits or the least damage to the environment, as a whole, at acceptable cost, in the long term as well as in the short term."
-- Wikipedia
Legal Definition
The UK practice of controlling pollution without penalties. The costs of pollution are covered by economic benefits. It allows more that would be standard emissions. AKA best practicable means.