Mining hydrogeology

Hydro-Ressources specializes in hydrogeology applied to mining industry. This expertise is divided into three main components: 1) analysis of impacts caused by the presence of a mine on the environment, 2) mine dewatering and 3) analysis of soil or water contaminated in a mining environment.

1) The analysis of impacts

At the start of a new mining project, it is required to perform an analysis that will assess the impacts, on a hydrogeological and hydrological point of view, that may have a potential mine on the surrounding environment. Indeed, a mine must necessarily dewater its facilities, either pumped into the bottom of a pit, the lowest level of an underground mine or at the edge of the mine. This dewatering can generate environmental impacts in drying rivers or decreasing their flow.

The analysis of these impacts is often done using numerical simulation. This analysis method actually helps make predictions about the rate it will be required to pump and the influence of this pumping on the nearby waterways. To perform a proper analysis, some field testing is required. These tests may include drilling, permeability tests and packer testing (shutters). The method of profile tracer tests recently adapted by Hydro-Ressources shows much more conclusive results than most other techniques (shutters, velocity measurements, etc.). This method is very useful for acquiring information on the underground flow, whether for a feasibility study, or a mine dewatering.

2) Mine dewatering

When a mine is in operation, it is necessary to carry out the mine dewatering. If the walls are stables, dewatering can be done in the bottom of the mine with the adapted pumps. In other hand, if the walls are unstable or that water inflows decrease productivity, it is better to conduct the dewatering plan in outskirts with water-wells, or directed drilling, acting as drains.

Peripheral water-wells are therefore used to eliminate the seepage on walls that can affect their stability. In underground mining, peripheral dewatering eliminates or limit water seepage in some galleries. However, the drainage from galleries is often the best method to adopt because it’s economically more advantageous.

Various analysis methods can help optimize dewatering. Again, the numerical simulation is an efficient tool and tracer tests can be particularly useful for targeting well/drain location or even plan an adequate grouting.

3) Contamination case

Mining environments can often generate contaminants from tailings. It is therefore required to analyze the impact of the presence of these contaminants in groundwater or define solutions to eliminate contamination. Sometimes water from the dewatering is a contaminant itself as groundwater collected in depth often contains a high mineral content.

Various methods of analysis are used to make valid predictions. In all cases, it is required to obtain information on the ground that help to perform the analysis.

mining hydrogeology