Tailings dams are critical infrastructures in mining operations to store byproducts—known as tailings—from ore processing. Tailings contain hazardous substances, including heavy metals (like lead, mercury, and arsenic) and various chemicals used in processing ores. These pollutants pose significant risks to the environment by contaminating soil, water bodies, and ecosystems, thereby affecting biodiversity and public health. Despite their utility, the environmental footprint of tailings dams is significant, raising concerns over the sustainability of mining practices.
Impact on Water Bodies
The presence of tailings dams near water bodies can lead to contamination as pollutants seep into rivers, lakes, and groundwater, deteriorating water quality. This contamination adversely affects aquatic life, disrupting ecosystems by altering water chemistry, reducing oxygen levels, and harming aquatic organisms.
Impact of Tailing Dam
Impact on Land and Biodiversity
The disposal of tailings results in landscape alteration and land degradation, creating barren areas devoid of vegetation. Habitat loss due to dam mismanagement or failures devastates wildlife and plant species, undermining biodiversity. Tailings contamination disrupts ecosystems, posing a threat to species survival.
Read more: Tailing Dam Safety: The Multi-sensor Approach in Mining
Tailings Dam Failures
Historical data highlight the severity of tailings dam failures, with 366 documented accidents releasing over 279 million cubic meters of tailings, resulting in 3,043 fatalities and environmental devastation across 4,868 kilometers. The most common construction method, the upstream method, is frequently implicated in these failures, primarily due to overtopping. Also,trends over the past two decades show an increase in the frequency and severity of such incidents, particularly in large dams.
Tailings dam failures have led to severe environmental disasters. For instance, between 2008 and 2017, collapses resulted in over 340 fatalities, extensive property damage, river contamination, and the disruption of fisheries. Even without catastrophic failures, the modification of natural stream flows and the alteration of water temperature and metal concentrations can cause long-lasting environmental harm, necessitating costly and extensive cleanup efforts.
Read more: Understanding Geo-Hazard Risks in Tailings Storage Facilities: A Detailed Analysis
Conservation and Remediation Efforts
Efforts to mitigate the environmental impacts of tailings dams include reclamation projects aimed at re-vegetation, soil stabilization, and habitat restoration. Innovations in dam design, the use of liners, and monitoring systems are some proactive measures to prevent leaks and failures.