Balangero asbestos mine, 20 km northwest of Turin, Italy
Photo: E. Sacchi/ Italy
Mining can transform landscapes and economies, but it can also alter the movement and quality of water. In mining areas, groundwater and rivers may be affected by acid mine drainage, dissolved metals, salts and other contaminants. Understanding whether these substances originate from mining activities, natural geological processes or other human pressures is essential for protecting water resources and supporting evidence-based decisions.
A recently completed IAEA Coordinated Research Project (CRP), "Development and Application of Isotope Techniques for Efficient Water Resources Management in Mining Areas" , demonstrated how isotope hydrology can provide this evidence. Over four years, researchers from 17 countries applied isotope, hydrochemical and hydrological methods in a wide range of mining environments, including uranium, coal, potash, asbestos, mineral sands, pyrite, mercury and polymetallic deposits. The project examined water challenges across the full life of a mine, from sites still in the planning stage, through active operations, to legacy and closed mines, reflecting the different water management questions that arise at each stage.
Uncovering water pathways in mining environments
Environmental isotopes act as natural tracers of water and dissolved substances. Stable and radioactive isotopes, including oxygen-18, hydrogen-2, tritium, sulphur-34, radon-222, strontium isotope ratios, uranium-series isotopes, noble gases, and metal and nutrient isotopes, were used to identify groundwater origin and recharge pathways, estimate groundwater residence times, map groundwater-surface water exchanges, trace acid mine drainage and contaminant transport, and distinguish geogenic signatures from mining-related impacts.
"These findings demonstrate that isotope hydrology provides the scientific evidence needed to better understand water systems in mining regions, distinguish natural from mining-related impacts, and support informed decisions for the sustainable management of water resources," said Tzanka Kokalova Wheldon, Director of the IAEA's Division of Physical and Chemical Sciences.
Technical Experts collecting samples from the Balangero asbestos mine, 20 km northwest of Turin, Italy
Photo: E. Sacchi/ Italy
From scientific evidence to better water management
More than 13 000 isotope and hydrochemical analyses were completed across the CRP. The project produced 29 scientific publications, supported 5 PhD theses, 14 master's degrees and one postdoctoral study, and contributed to an open-access state-of-the-art review on isotope techniques for sustainable water resources management in mining-related environments.
By combining isotope data with hydrochemistry, hydrology and modelling, scientists developed more robust conceptual models of groundwater recharge, flow, mixing and contaminant transport. These models strengthen monitoring strategies, support mine-water management during operation and closure, and help regulators and practitioners select appropriate tracers, sampling designs and interpretation approaches.
The CRP also strengthened scientific capacity in participating institutions by training researchers to design isotope investigations, interpret multi-tracer datasets and translate results into practical water management information. This is especially important for countries dealing with legacy mine sites, limited monitoring networks and/or growing competition between mining, ecosystems, agriculture and drinking water supply.
The findings show that isotope hydrology is not only a research tool but also a practical approach for managing water in mining regions. By revealing hidden water pathways and contamination processes, isotopic techniques can help protect ecosystems, safeguard drinking and irrigation water, improve remediation planning and support more sustainable mining practices.
