In 1996, Peru and Bolivia created an Autonomous Binational Authority of the Lake Titicaca (ALT) - Desaguadero River - Lake Poopo - Coipasa Salt Lake System (TDPS System), to regulate water resources. Bolivian and Peruvian mineral extraction and exploitation constitute an important part of the economy. States regulate mining permissions giving grants to extractive companies on lands. However, without any efficent regulation, mining contaminates surface waters and groundwaters. As water transcends borders and a large number of indigenous communities live around Lake Titicaca, in case of contamination, indigenous peoples' lands are contaminated even if mineral extraction is not located on indigenous lands. Hence, this paper assesses indigenous peoples' rights to lands and natural resources beside mining companies' rights to have land access and extract minerals in the context of groundwater contamination in the Lake Titicaca region. The research question is answered through a critical assessment of international, regional and national laws regarding indigenous peoples' rights, mining law, international water law and the law of transboundary aquifers. International law provides an international legal framework and in the context of the Lake Titicaca region, the law and the policy of the ALT are examined as well as Peruvian and Bolivian national laws, to provide a comprehensive analysis.
The paper concludes that the ALT does not clearly embrace the interconnection between surface waters and groundwaters and does not include the aquifers in the TDPS System, particularly the one underlying Lake Titicaca shared by Bolivia and Peru. The ALT also fails to include, in proper terms, the rights of the populations living in the TDPS System, although Peru and Bolivia gather a large number of indigenous peoples, particularly around Lake Titicaca due to its traditional and cultural history. While Peru and Bolivia legally include the obligation to conduct an environmental impact assessment, they do not guarantee the consent of indigenous communities for mining production. Moreover, although the law of Bolivia related to indigenous peoples' rights to lands and natural ressources is the most impressive, it does not provide any legislation about groundwater. Conversely, Peruvian legislation includes groundwater and protects indigenous peoples' rights over all water resources. However, it does not clarify whether indigenous rights to lands and natural resources include groundwater, although within the ILO Convention No. 169, the interpretation of the total environment should include groundwater and aquifers if it infringes the survival and physical integrity of the affected persons. Hence, these failures have led to various indigenous protests in these countries because of breaches of international indigenous peoples' law and national legislation. In addition, the mining economy often takes priority over indigenous peoples' rights.
Therefore, while science is crucial to consider the interconnection between surface waters and groundwaters and to analyse the level of water contamination, science is also essential for indigenous peoples' understanding to claim their rights over their lands and natural resources as well as over the aquifers underlying their territories.