Rose Lithium-Tantalum

Advising on all project stages to respect and preserve the natural nocturnal area lighting.

The Rose Lithium-Tantalum project, aims to develop a modern mining complex with an open pit to extract lithium and tantalum and concentrate them on site. The project’s expected lifetime is 19 years. It will result in the provision of a quality supply source for these elements, which are prized worldwide.

Indeed, the growing demand for lithium is particularly felt by battery manufacturers: those who supply the increasingly successful hybrid and electric car market as well as those who deal with other applications, including renewable energy storage technologies.

As for tantalum, it is a highly corrosion-resistant ore and a good substitute for platinum. It is primarily used in manufacturing capacitors for electronic devices, such as mobile phones, DVD players, video game consoles and computers. It is also extensively used in the construction, medical, automotive and military sectors.

Lighting needs that could potentially affect the environment

WSP is a member of the multidisciplinary team selected to conduct the project’s environmental impact assessment. For safety purposes, the mining installations and site must be constantly lit, as project operations will take place both day and night. Lighting in traffic and work areas will increase nocturnal levels of artificial light at night.

In collaboration with the developer, WSP’s lighting specialists worked to optimize the project, given that the new light sources could potentially modify sky quality; project intrusive light outside project area boundaries (to the detriment of neighbours, habitats and wildlife); and change night landscape visibility.

Ensuring and prioritizing ecological lighting

Because the scheduled construction work is significant and because there are few sources of nocturnal light in the area (other than the Nemiscau substation and the Eastmain-1 hydroelectric development), ensuring ecological, respectful lighting was a top priority. The project area consists of Cree camps, used for intermittent traditional activities throughout the year. Sky quality is almost optimal, and night landscapes are devoid of artificial light sources.

Mitigating impacts of artificial light at night

Finally, WSP ensured that the project’s impacts on the artificial light at night will be mitigated by realistic and applicable measures such as installing lighting only where needed, limiting lighting time and duration by installing timers and motion detectors, reducing building contrast levels by using finishes with low reflectance values and maintaining visual vegetation screens.

Skyward light emission results show a low level of light intensity. The calculated average at 100 m above the highest tailing site in winter is 0.2 lux, and the maximum for the entire area under development is 7.5 lux. Illumination results at the boundary of the calculation area show that the project generates no intrusive light at ground level (outside the 300 m limit used for calculations). The results obtained show that the light emitted by the future installations will form a luminous halo, which will be visible from a certain distance. This will have an impact on the area’s night landscape.

The WSP team’s contributions have demonstrated that the project’s residual effects on the artificial light at night will be minimal and inconsequential.


  • Baseline inventorying of current conditions, via field surveys;
  • Collaborating in the analysis of lighting needs;
  • Designing ecological lighting concepts;
  • Conducting photometric simulations to validate the results of proposed lighting concepts;
  • Presenting computerized visual renderings of new construction lighting;
  • Evaluating project impacts on sky quality and intrusive light emissions for the human and biological environment (habitats and wildlife);
  • Conducting realistic visual simulations of new construction lighting on night landscape photographs;
  • Photographing night landscapes.