Defective concentrate plug activated Contingency Plan in Santa Rosa

• Control measures were immediately activated

At approximately 10 a.m. on Wednesday July 25th, our Mineral Ore Pipeline monitoring system identified a concentrate load leak inside the VS1 valve station resulting in the immediate activation of its Contingency Plan which consists of closing the valves at this station, located at Km 110 along the highway between Pativilca and Conococha.  

The event occurred inside the control station and was the result of a defect in a ¾ inch plug positioned in a 90º pipe elbow, which created a minor leak of ore concentrate.  There is a contingency well located inside this station which has received and contained most of the load with a small amount flowing into a ditch, where it has been blocked and contained by Antamina’s emergency equipment.

Antamina confirms that the event is under control and that it will remain in permanent contact with the pertinent local authorities and the population concerning the evolution of this event. 

It is worth mentioning that this event has caused no harm to the environment or to the health of individuals.

It should be pointed out that Antamina immediately activated its Contingency and Emergency Plan which consists of reducing risks and controlling the events. 

Huaraz, July 25, 2012

Office of Corporate Communications
Compania Minera Antamina S.A.