Principles of international environmental protection - Introduction to International Environmental Law - page 101

An interesting point is that both countries at fi rst relied on their own sover-
eignty: Canada on its sovereign right to permit legal activity taking place within
its territory, and the USA on its right to territorial integrity to argue that it
should not have to tolerate harmful interference from Canada.
Initially, the countries fi rst referred the dispute to the boundary water treaty
between the USA and Canada and to its Commission, which in 1931 decreed that
Canada pay US$350,000. The parties refused to accept this and decided by agree-
ment ( compromise ) to establish an arbitration tribunal to resolve the dispute. The
arbitration tribunal gave its interim decision in 1938 and its fi nal decision in 1941.
The arbitrators working to resolve the Trail Smelter dispute realized that
international law as it currently stood could not resolve the case. Of course,
sovereignty both protects a state's right to pursue legal activities in its territory
and its territorial integrity against pollution from other states. Sovereign states
cannot be arranged in 'rank order' since they are equal in international law, and
in this example both states were relying on the same principle of sovereignty.
Evidently, the state of origin cannot permit any legal activity irrespective of its
impact on other states, but at the same time, an affected state has no veto over
legal activities conducted by or in another state. The tribunal therefore developed
a new set of principles practically 'from scratch' (at least from an international
law point of view) by which to resolve the dispute. Both Canada and the USA
pleaded their sovereignty, but the arbitrators applied an old Roman principle,
sic tuo utere , which they considered applicable in intergovernmental disputes as
well: 'So use your own as not to injure another's property.'
It was essential to fi nd a principle according to which the tribunal could
roughly defi ne what kinds of pollution impacts from one state to another were
permissible. As the tribunal could not fi nd help in the international legal arena,
it based its decision largely on the practice of federal states in corresponding
cases - especially on the way in which similar environmental disputes between
US states had been resolved.
The tribunal stated in its decision of 1941:
The Tribunal, therefore, fi nds that the above decisions, taken as a whole,
constitute an adequate basis for its conclusions, namely, that, under the
principles of international law, as well as of the law of the United States,
no State has the right to use or permit the use of its territory in such a
manner as to cause injury by fumes in or to the territory of another or the
properties or persons therein, when the case is of serious consequence and
the injury is established by clear and convincing evidence. 17
So, the tribunal was able to fi nd criteria according to which the territorial
sovereignty of neither state was absolute; only considerable transboundary
environmental damage is illegal.