The Yanacocha Gold Mine began operations in the department of Cajamarca in 1993. Yanacocha, the largest gold mine in South America, comprised of six open pit mines, four leach pads and three processing facilities. In June 2000, a contractor to Minera Yanacocha spilled 151 kg of elemental mercury along a 41 km stretch of road between the mine site and the town of Choropampa. A number of local people, unaware of the nature of the chemical, were exposed and subsequently experienced adverse health effects.

In March 2006, 30 canal users jointly lodged a complaint with CAO requesting assistance in obtaining information about the current and potential impact of mining activities on the water quantity in the canals, rivers and streams surrounding the project. The petition expressed satisfaction with the collaborative process undertaken by the Mesa and CAO in relation to water management and an interest in extending these efforts through an independent mechanism such as CAO.

In May 2006, CAO conducted a site visit to liaise with canal users and mine representatives in order to gauge the parties’ willingness to work collaboratively on strategies for sharing information concerning water quantity. The petitioners agreed that their concerns in relation to water quantity ought to be addressed within the confines of a facilitated meeting. This forum was intended to be conducive to a fluid exchange of information and open discussion.

In July 2006, CAO Ombudsman facilitated an information sharing workshop with the petitioners and mine representatives. Although the initial petition to CAO requested an independent water quantity study, CAO sought first to understand the canal users’ specific concerns, and to solicit from Yanacocha a comprehensive list of all the available water quantity studies and information. With this information, CAO encouraged the parties to work together to determine what studies were necessary, if any, and whether the existing studies sufficiently addressed the canal users’ concerns. In the Exit Report, completed in September 2006, CAO recommended that Yanaococha honor its commitment to distribute relevant documentation to canal users and ensure it is accessible to all interested parties.