As seen in Figure 1, the Canadian North includes the following physiographic regions: High Arctic, Low Arctic, Sub-Arctic and Boreal. During several months of the year, the Boreal regions display many characteristics typical of Arctic regions, especially very low temperatures and winter snowfalls. Despite the fact that these regions experience wide differences from a geographical and climatic standpoint, they often share the same environmental challenges.

The territories of the Canadian North include the Yukon, Northwest Territories, Nunavut and Nunavik, as well as the northern part of seven provinces. As illustrated in Figure 1, the southern limit of the Arctic is located at lower latitudes in Eastern Canada. The Sub-Arctic region, for instance, which is close to the 65^th parallel in Western Canada, extends to the 50^th parallel in Quebec and Ontario.

Among the various Canadian regions, the Arctic has been the least disturbed by human activity due to the sparseness of its population, its harsh winter conditions and its relative remoteness. Over the last 50 years, several sites have nevertheless been contaminated by mining operations, oil exploration and production, the presence of military installations and a constantly increasing local population. Today, the various levels of government and private firms are more concerned with the environmental heritage resulting from human and industrial activities, particularly when it concerns the land used for thousands of years by aboriginal people in the Arctic’s fragile and vulnerable ecosystem. This explains why a large number of sites have been characterized and remediated since the early 1990s, while several others will also undergo the same treatment within the next few years.