The obligation under an environment protection licence to maintain plant in a 'proper and efficient condition' refers to preserving the plant in a state that minimises environmental risk, not to the carrying out of maintenance work. The standard is assessed by reference to the function the plant is serving at the relevant time. An integrated system must be assessed as a whole, not component by component. There is no bright line between the maintenance condition (O2.1(a)) and the operation condition (O2.1(b)); the same conduct may engage both.
The full text is available to signed-in members, including the 6 later cases that cite this judgment.
1 of the 6 citing cases carry a classified treatment. How each court treated it is available to signed-in members.