I. INTRODUCTION AND SUMMARY OVERVIEW

Richard Kamp figured he had seen the worst wastelands the mining industry was able to create. But that was before the American environmentalist – a specialist on the U.S.-Mexican border area – laid eyes on La Oroya, home to Centromin, Peru’s biggest state-owned mining company. Last month, as his car rattled toward the town through hills that once were green, Kamp fell silent. Dusted with a whitish powder, the barren hills looked like bleached skulls. Blackened slag lay in heaps on the roadsides. At La Oroya, Kamp found a dingy cluster of buildings under wheezing smelter smokestacks. Pipes poking out of the Mantaro River’s banks sent raw waste cascading into the river below. ‘This,’ he said, ‘is a vision from hell.’ “How Brown Was My Valley,” Newsweek, April 18, 19941

1. This investment dispute arises from the Republic of Peru’s sale in 1997 of its State-owned smelting and refining complex in La Oroya, Peru (the “La Oroya Complex” or the “Complex”) to a consortium led by Claimant The Renco Group, Inc., and Respondent Peru’s (i) subsequent refusal to honor its contractual and legal commitment to assume responsibility and liability for third-party claims of injury from environmental contamination at the Complex (including failure to remediate the soil which would have mitigated these damages), and (ii) pattern of mistreatment of Claimant and its investments relating to the Complex when Claimant’s locally-incorporated subsidiary requested a reasonably—and contractually permitted—extension of time to complete the final environmental modernization project.