The impact to water quality is expected to be minimal – this has been predicted through the completion of a comprehensive environmental assessment process that is subject to both Federal and Provincial regulatory oversight. ISR mining at Phoenix occurs 400 metres below surface; the data collected from the area indicates the rate that water from the orebody migrates to surface is incredibly slow (less than 1 metre per 1 year). This means that the risk of migration to surface lakes is very low and would only occur after the mining area is remediated and the freeze wall removed.   

The freeze wall will be in place during operation and will surround the mining zone as a supplemental environmental control. Within this freeze wall, fluid flows are highly controlled to ensure containment and recovery of the dissolved uranium. The characteristics  of ISR mining allow Denison to recycle water used in mining – the amount of water used, water treated, and water released to the environment during operations are anticipated to be much lower than other northern Saskatchewan mine sites. Regardless, all site water will be tested and when required, treated to meet regulatory requirements, to ensure the downstream environment remains protected.

ISR mining has gained in prominence in the global uranium sector in the last 20 years with the development of multiple uranium mines in Kazakhstan, Australia, and the United States. When Cigar Lake and McArthur were developed in Saskatchewan, ISR mining was less common and was not considered applicable to the Athabasca Basin. Since then, advancements in ISR and ground freezing technology have allowed Denison to design an ISR mine that is suitable for certain deposits in the Athabasca Basin.

The people and Indigenous nations of northern Saskatchewan have clear ideas of how they want to work with the next generation of uranium mining operations; determining what kind of positive legacy Denison will have within the north must be determined by the people of northern Saskatchewan and Denison together.

Before construction can begin, we first must complete the permitting and licensing process. We anticipate receipt of the final regulatory approvals to permit the commencement of construction in the first half of 2026.  Construction is expected to last for approximately 2 years, and the site is expected to be in operation for approximately 10 years. Closure and reclamation procedures will last for approximately 8 years after completion of operations.

Denison has a defense-in-depth containment strategy to ensure groundwater and the environment are protected. This multi-layered containment approach includes injection and recovery wells that are pressure-grouted and integrity-tested. Wells have an inward hydraulic gradient to ensure controlled flow toward recovery wells. The freeze wall provides an additional layer of containment, and containment is verified by the monitoring network. The CNSC and the Saskatchewan Ministry of Environment have confirmed that the wellfield containment plan meets regulatory requirements.