NWT RESEARCH DATABASE

Tags: water quality, water chemistry, sediment quality, engineering

Objective(s): To conduct surface water and sediment quality and quantity sampling.

Project Description: Proposed surface water and sediment quality and quantity programs involves two rounds of field sampling proposed in mid-July to early August and in late September 2019, to capture typical summer stream flows and low stream flow conditions. Each field program may take between eight to ten days. The objectives of the programs are to confirm and update the fluvial geomorphic classification of each stream crossing; to collect discrete stream discharge and stream flow levels; to collect water quality field data as well grab samples for laboratory analysis for general chemistry included total and dissolved metals; and to characterize stream sediment distribution for substrate characterization and the collection of samples for metals testing and particle size analysis to qualitatively assess sediment transport capability. This field data will support modeling and desktop exercises to produce the summary of the general hydrologic streamflow regime of the Howards Pass Access Road (HPAR) area; summary of upstream/downstream watershed characteristics (sediment sources, permafrost influences); stream channel form and processes; and summary of the crossing type, hydraulic characteristics, and design peak streamflows. Baseline information will also be collected for air quality monitoring. Surface water and sediment quality/quantity programs will take place in mid to late July and mid to late September, and will be conducted by a team of two traveling by truck. Each stream crossing data and sample collection is expected to require two to four hours depending on site conditions. The following activities will take place: The field review of each stream crossing to confirm/update the fluvial geomorphic and crossing type classification will be completed during a desktop exercise. The collection of a stream discharge measurement following standard hydrometric techniques, through wading or from a bridge using a flow tracker or a price type-aa current meter. The collection of surface water quality samples for suspended sediment, dissolved and total metals and other general chemistry parameters. The water quality sampling will include a standard quality assurance and quality control programs involving replicas, field blanks and travel blanks. The stream sediment distribution using a gravelometer to document typical substrate according to the fluvial geomorphology of each stream type along the HPAR and to provide a qualitative comment on sediment transport capacity of the respective water course. The collection of sediment samples for metals analyses and the assessment of potential sites for the installation of a hydrometric station. Air quality baseline will be assessed by the placement of dust canisters as appropriate to determine background ambient levels. Selwyn Chihong Mining LTD (SCML) has formal Cooperation Agreements with both Sahtu (Tulita District) and Dehcho (Naha Dehé Dene Band) communities that cover the life of the project. Through these agreements, SCML, Sahtu communities and Nahanni Butte have committed to work together in a spirit of cooperation and mutual respect. The communities have been involved with the HPAR work at every step along the way. Through existing community agreements with Nahanni Butte Dene Band and Tulita Land Corporation, Potential local training and recruitment opportunities will be integrated into the field programs. Consultation with the communities will continue around the 2019 field programs and project updates as required. Continued consultation with the communities will keep the communities informed about the programs. Brief summaries or overview will be presented to the communities. The environmental assessment for the HPAR Access Road Upgrade Project is a highly public process that is managed by the Mackenzie Valley Review Board. This will ensure transparency for communities, including the results of the 2019 baseline program proposal. In addition, SCML will be working with community partners at all stages during the field work to ensure there are communication issues or concerns. The fieldwork for this study will be conducted from May 16, 2019 to November 29, 2019.