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étiquettes: contaminants, site remediation, water quality, geotechnical survey, soil chemistry

Objectif(s): To remove and dispose of exposed historic solid waste (including barrels, batteries, debris, wood and other waste); and, to finalize construction of a contaminated soil and waste containment structure to contain impacted soil excavated from areas at the site.

Description du projet: The objectives of the Site Remediation Program (scheduled to be completed in 2019 and 2020) are: 1) to remove and dispose of exposed historic solid waste (including barrels, batteries, debris, wood and other waste); and 2) to finalize construction of a contaminated soil and waste containment structure to contain impacted soil excavated from areas at the site. The 2019 Site activities may include several investigations and inspections in support of the remedial program: 1) Thermal Monitoring – In 2017, thermistor strings were installed in the footprint of the containment structure to facilitate remote temperature monitoring at different areas and depth intervals. The thermistor string installation will be completed, and associated equipment will be inspected and repaired (if required) to facilitate remote data collection on thermal performance. 2) Groundwater Sampling - Four monitoring wells will be installed around the perimeter of the containment structure to analyze groundwater in 2020 and during several post-construction monitoring Site visits as per Inuvialuit Water Board requirements. 3) Background Soil Sampling - Soil sampling locations will be established within a two to four metre radius of each of the monitoring wells - for each location, two samples will be collected (one shallow, one deep) and analyzed. 4) Topographic Survey – As was done in 2017 prior to begin of the construction, a topographic survey is planned to be conducted at the containment structure and the borrow areas. The survey will be conducted upon completion of all construction and borrow activities. It will capture the layout of ground control points for the UAV (unmanned aerial vehicle) survey. The survey will also be used to determine the installation of permanent bench marks. The monitoring wells and environmental sample locations will be tied in. 5) UAV Survey Field Program – A low altitude UAV survey of the containment structure, the borrow areas and ground control points is planned to be performed again. At the end of the 2018 field season, heavy equipment and some camp supplies were securely stored at the camp sites over winter. In June 2019, some materials and supplies, additional camp components and the field crew will be mobilized through Mould Bay to Satellite Bay to complete the remediation project. Two temporary camps will again be established, one at each site. The 2019 work will include the completion of the containment structure with a thermal cover at the site. The thermal cover will provide a cap on the contaminated material that is sufficiently thick (approximately 2.4 m) to contain estimated seasonal thawing within the cap, thereby ensuring that all buried waste and contaminated soils remain at ground temperatures less than 0°C. The construction will also include again the development and short-duration operation of a borrow area, designed to maintain positive drainage, avoid the creation of water collection points and maintain excavation geometry to facilitate the later grading and re-contouring. The duration of the planned 2019 project will be approximately 8 weeks in July and August. Two temporary camps will be required. One 20-person, temporary camp will first be established at Mould Bay to be used during mobilization and demobilization phases of the project. It is anticipated that this camp will not be utilized during the construction phase. One 24-person temporary camp will then be established at Satellite Bay for approximately 6 weeks during construction activities. As in previous project-related research at the site, upon completion of the program, Repsol will submit a follow-up report to the Hunters and Trappers Committees of all Inuvialuit communities, the Government of the Northwest Territories Lands Department, Indigenous and Northern Affairs Canada, the Inuvialuit Water Board and the Aurora Research Institute. This will include a plain language summary of investigation findings. The fieldwork for this study will be conducted from July 8, 2019 to September 10, 2019.