Compania Minera Antamina operates an open-pit mine and a milling and ore concentrating facility in the municipality of San Marcos in the Ancash region of Peru. The facility produces copper, zinc, lead, bismuth, silver and molybednium. The concentrates extracted from the mine are transported via an underground pipeline through the Department of Ancash to Punta Lobitos in the Municipality of Huarmey. At Punta Lobitos, the water is separated from the concentrate and loaded onto ships to be transported to global markets. In September 2000, a local union chapter of the Federation of Peruvian Fishermen lodged a complaint with CAO.

The complaint raised the following concerns:

1. Inadequate consultation with local people and coordination of the resettlement process;

2. Insufficient disclosure in relation to mining activities and the environmental impacts in construction of the concentration plant and loading dock at Huarmey.

At the time of the complaint, the Antamina mine was the Multilateral Investment Guarantee Agency’s (MIGA) largest project that it had been involved with. MIGA issued six guarantees totaling $107.5 million in support of the project during 1999 and 2000. In September 2000, CAO Ombudsman assessed the complaint and the CAO Vice President requested that a Compliance Review of MIGA’s social and environmental due diligence be undertaken.