Our country is one of the main recipients of investment in mining projects. During 2021, the mining sector made investments of 4 million pesos, an increase of 809% compared to what was invested in 36.1. [1].
However, mining activity has faced various criticisms arising from its impact on the environment, so it is common that the exploitation of some deposits can be hindered by social opposition. One of the most sensitive points for mining projects is the exploitation of water, since mining activity requires a large volume of water for its processes, where it is mixed with dangerous substances, for example, the leaching of minerals such as gold and silver using cyanide.
Therefore, from the planning stage of a project and during its execution, its owners must consider and implement strategies to save water, prevent its contamination and not affect riverbeds.
In this regard, in addition to the recommendations that any project may have regarding the use of water and discharge of wastewater, our professional practice has allowed us to identify some points that are advisable to verify, in order to guarantee compliance with its obligations regarding the use of water, among which are the following:
1. Ensure the volume of water required for the mining project and consider future expansions. It is becoming increasingly common for the start or expansion of mining projects to be affected by a lack of water. In this regard, their holders must obtain national water concession titles issued by the National Water Commission (CONAGUA), in addition to ensuring their compliance to avoid losing them.
It is advisable to explore other sources of water supply, for example, desalination of seawater and its conduction through aqueducts, or the use of wastewater from other industries close to the mining project. It should be noted that, in many cases, these types of alternatives also require permits from CONAGUA, the Ministry of Environment and Natural Resources (SEMARNAT) and other authorities.
2. Promote hydraulic infrastructure works for the population that does not have this resource. Often, the society surrounding a mining project opposes its implementation due to the lack of water supply, even though there is water available for everyone. In this regard, it is advisable that the project owner supports or collaborates with other authorities for the construction of a drinking water network.
It should be noted that this type of initiative can be considered as a measure to mitigate the impacts of a project and, thus, speed up the obtaining of some key environmental authorizations for mining operations. In addition, it will help the neighbors of the project to have a favorable opinion of it.
3. The issuance of concession titles to exploit water may require indigenous consultation. This is especially true in areas where there are indigenous communities with precarious access to water. Failure to consult may result in communities initiating a legal defence that would compromise the water supply for the mining project.
4. Exploitation of working waters [2] does not require a CONAGUA concession titleThe mining concession title issued by the Ministry of Economy allows the exploitation of working waters for mining activities. However, certain obligations must be met as if it were a CONAGUA concession title, including the payment of fees. If the use of working waters for the mining project is not required, it is advisable to reinject them into the subsoil to avoid CONAGUA demanding payment of fees.
5. Build monitoring wells and detect any contaminants in time. These water quality monitoring wells, which will be located around the project, will help verify whether any substance is contaminating the groundwater. The construction of these wells requires permits from CONAGUA, especially if they are in restricted areas.
6. Obtain certifications for the responsible use of some hazardous substances. To strengthen the comprehensive management of this process and prevent damage to the environment. For example, the certification of the cyanide code.
7. Some water runoff is considered national property under the responsibility of CONAGUA. Mining projects require large spaces adjacent to the pit for the construction of tailings dams or leachate lagoons, so it is common for these facilities to be built on water runoffs that, regardless of their size, could be riverbeds. In order to build on them, a concession title from CONAGUA is required.
In this regard, before building the facilities, it is recommended to verify with CONAGUA whether these runoffs are considered national assets under its responsibility and, if so, to process the corresponding concession title.
Building without the corresponding concession could give rise to environmental, administrative and even criminal liability. In addition, buildings built on national property will be considered property of CONAGUA, which can preserve them or order their demolition.
The mining sector is of great importance to the country. Some localities even depend entirely on this activity. However, mining project owners must consider the magnitude of their impacts on the environment and implement appropriate measures to prevent, mitigate or compensate for them.
[1] Fuente: https://www.gob.mx/se/acciones-y-programas/mineria#:~:text=El%20sector%20minero%2Dmetal%C3%BArgico%2C%20en,(INEGI)%2C%20en%202021.
[2] Working water is groundwater found in a mining project.