The Proaño project, also known as Fresnillo mine, is an underground mine complex located on one side of the city of Fresnillo, Zacatecas and is Fresnillo PLC property. The mines date back to 1554, when Captain Diego Fernandez de Proaño began operating at the site of Fresnillo.
Mexican Official Standard NOM-023-STPS-2012 establishes the health and safety standards at work for underground mines. One of them request to conducting a hydrogeological study to assess flood risks, together with control procedures. Fresnillo PLC contracted Bertone & Associates to establish the hydrogeologic study required by the Official Mexican Standard NOM-023-STPS-2012 to assess flood risks was at Fresnillo mine.