NWT RESEARCH DATABASE

Regions: Dehcho Region

Tags: water quality, environmental impact, biology, fish habitat, hydrology, geotechnical survey, industrial development, ice thickness, pipeline corridor, fish population

Objective(s): Imperial Oil Resources Ltd., Aboriginal Pipeline Group, ConocoPhillips Canada (North) Ltd., Shell Canada Ltd., and ExxonMobil Canada Properties conducted a number of baseline studies during 2001 through 2004 as part of the Mackenzie Gas Project. These studies are continuing in 2005. Local knowledge and technical/scientific research, in combination with a synthesis of existing technical information, is being used to develop a suitable knowledge base for planning, assessment of impacts, and development of environmental protection plans. The Mackenzie Project Environment Group, administered by AMEC Earth and Environmental Ltd., has been retained to conduct the baseline studies. A late winter aquatics survey is required to assess overwintering conditions for fish and watercourse freezing conditions in the vicinity of the pipeline crossing sites. This will complete the multiseason assessment of watercourses begun in 2002 (spring, summer, fall programs). A spring survey will be conducted at watercourses crossed by all-season (temporary and permanent) roads. Since road crossings will be in place year-round, spring studies will be required to determine the use of watercourses by fish during the period of spring flow. A late winter groundwater survey is needed to further assess the groundwater discharge conditions at proposed borrow sources, infrastructure sites, and access roads.

Project Description: The researchers did a number of baseline studies during 2001 through 2004 as part of the Mackenzie Gas Project. These studies are continuing in 2005. Local knowledge and technical/scientific research is being used to design plans, assess impacts, and develop environmental protection plans. The aquatics field crews will consist of two Mackenzie Project Environment Group researchers and a local assistant. Access to sites will primarily be by helicopter. ATV's and snowmobiles may also be used to access selected sampling locations; where these are needed, they will be hired locally. The field crews will be based in Fort Simpson. The researchers expect that any particular waterbody will be visited just once during the winter or spring aquatics studies, and most visits will be less than 12 hours. For streams with ice cover, holes will be augered through the ice to determine ice thickness and water depth below the ice. Under-ice water quality will be measured, including temperature, dissolved oxygen, conductivity, and pH. Stream discharge will be measured and the presence or absence of bottom ice conditions will be noted. Limited fish sampling will be done in potential overwintering locations, such as deep pools, that were identified during 2003 and 2004 detailed surveys. Under-ice fish sampling will be done to assess overwintering use by fish in streams with suitable habitat conditions. In streams with open water (likely indicators of groundwater input), other methods may also be used to assess winter fish use. A survey of lakes will determine the overwintering potential for fish species by sampling of ice and water depths, temperature and dissolved oxygen levels within the water column, as well as other water quality information, including conductivity and pH. Limited fish sampling will be undertaken in a subset of lakes. Seven streams that will be crossed by proposed all-season roads will be surveyed in late May or June. Surveys will determine use by spring spawning species, especially during periods of flow. Fish sampling will be done to determine presence/absence of spawners and deposited eggs. Flow data and water quality information, such as temperature, dissolved oxygen, conductivity and pH will also be measured. For the groundwater surveys, the researchers will look for icings at proposed borrow and construction locations.