Environmental Design Differentiator
The Wynyard Project is designed to avoid conventional surface tailings piles, a meaningful differentiator for investors focused on responsible resource development. Solid salt generated by the process is expected to be partly used to backfill mined-out caverns, with remaining salt dissolved and injected into the Deadwood Formation along with waste brines. Testing of the Deadwood Formation confirmed sufficient injection capacity for waste brine disposal, with two disposal wells expected to meet Phase 1 and Phase 2 requirements and additional capacity required for Phase 3.
Permitting Status and Responsible Development
Karnalyte received approval for an Environmental Impact Statement in 2013 for Phase 1 of the project, and correspondence from the Ministry of Environment in 2022 indicated that Phase 1 approval remains valid. As per Section 16 of The Saskatchewan Environmental Assessment Act, the expanded potash production through Phases 2 and 3 and the addition of a magnesium processing facility is expected to require an amendment. The project’s responsible development mandate to backfill mined-out caverns with a portion of the solid salt produced and disposing of the remaining salt and waste brines through deep-well injection into the Deadwood Formation, eliminating the need for conventional surface waste piles as required by other Saskatchewan potash operations.
Environmental impact is minimized through the following:
No Tailings Management Area
Salt and insoluble minerals, also called solid wastes, are used to backfill spent caverns; this helps to recover more brine from a cavern and to provide additional support to reduce subsidence. Liquid tailings (MgCl2 and NaCl brine) will be injected into deep disposal wells, a standard practice for potash mines in Saskatchewan. These methods greatly reduce the plant footprint and eliminates the liability of surface storage. Industry standard tailings reclamation plans can exceed 1000 years.
Non-potable Water
Water is produced on site from the Blairmore formation which is approximately 500m beneath the surface. Blairmore water is similar to seawater, with a slightly higher salt content making it unsuitable for agricultural and most industrial use.
On-Site Surface Runoff Collection
The plant drainage system collects precipitation runoff from the Phase 1 plant site in a large freshwater pond. This water will be used to supplement process water requirements in the plant, and does not get released into the local environment.
Directional Drilling
Multiple caverns are directionally drilled from a single surface location, minimizing the affected surface area of drilling pads. Well surface casings are cemented through the groundwater bearing horizons, and down 200m below the surface, to prevent possible contamination from mining. Additionally, production tubing is cemented down to the top of the potash horizon, about 900m deep.
Subsidence and Well Abandonment
Caverns are backfilled with salt/insolubles tailings to provide support and reduce subsidence. Caverns are then filled with MgCl2 brine to prevent further dissolution. When mining operations cease, wells are cemented shut, cut, and capped below the surface. Surface piping and infrastructure is removed, and the land is returned to agricultural use.