摘要：The author examines the recent spate of constitutional cases involving hydrocarbon pipelines which has led to the emergence of the "essential" test as the governing principle determining whether or not a related facility is an integral part of or is necessarily incidental to a federal pipeline undertaking. These cases suggest that if a facility is "essential" (rather than being merely helpful or beneficial) to a federal pipeline undertaking, it will be deemed to have the necessary nexus with the undertaking and to be an integral part of it. The author then applies the "essential" test to jurisdictional questions surrounding several major pipeline facilities in Western Canada, including the NOVA network in Alberta. The author concludes that the "essential" test has much to recommend it. It corresponds more closely to the realities of the situation than some other factors considered by courts in the past. While it unavoidably involves some judgmental elements, the necessary facts can be presented in evidence and the test lends itself to the application of common sense. Finally, from a philosophical perspective, it seems appropriate that something which is essential to the operation of an undertaking should be treated as an integral part of that undertaking.
