As part of the NWMO’s site investigations, we are currently drilling, as well as planning for the future drilling of, boreholes in order to advance our understanding of the subsurface geology in a study area.
A borehole, such as those we are drilling as part of site assessment work, is a small diameter hole made in the ground using drilling equipment. Our borehole process involves drilling the borehole and retrieving cylinder-shaped rock samples called core.
A wide range of testing is performed on samples of the core, and in the borehole, to investigate various geoscientific properties of the rock and advance understanding of the geology in the area.
For each area, the number, location and type of borehole to be drilled depend on the stage of the site evaluation process, the geoscientific uncertainties to be addressed and the geological setting in general – crystalline rock in northern Ontario or sedimentary rock in southern Ontario.
Boreholes are drilled using a conventional truck-mounted or skid-mounted rotary drill rig. A drill site is about 50 metres by 70 metres, or about the size of two NHL-sized hockey rinks side by side.
Trailers will be set up at the site for use as field offices, for on-site equipment storage, and for a small field lab for on-site geological logging, testing and preserving of rock core and water samples.
For a borehole approximately one kilometre deep, the borehole drilling and on-site testing process lasts about 120 days, depending on the number of shifts worked each day and the nature of the rock encountered.
In 2017, the NWMO initiated borehole drilling in the Ignace area as the next step in our geoscientific studies.
The NWMO plans to drill two exploratory boreholes to confirm understanding of geology at the site in South Bruce, Ont. Site preparation activities for boreholes will occur in fall of 2020 so drilling can begin in 2021. As part of drilling best practices, the NWMO will test private water wells at and near the borehole sites.
Once a site for further studies is identified and a borehole is drilled, geoscientists review and analyze the data. The findings from borehole drilling and other geoscientific studies, along with those from earlier assessments, inform and guide us in working with communities to plan future studies. As data is reviewed, analyzed and interpreted, updates are shared with the community.
Ultimately, the project can only proceed with the involvement of the community, First Nation and Métis communities in the area, and surrounding communities.