The dispute concerns some 20,000 tons of arsenic-laden smelting waste that Boliden off-loaded in the mid-1980s to an inexperienced Chilean enterprise that claimed it could “process” the waste, but in fact just dumped it on the outskirts of town. Boliden claims the dumping wasn’t its fault; the Chileans say Boliden was negligent...Boliden admits it created the 20,000 tons of toxic waste. It does not claim that its own conduct was affected by some accident beyond its control: the waste was shipped and off-loaded according to plan...Boliden claims it properly relied on the Chilean company’s representations that it could process the waste. But the claimants say that the so-called “processing facility” was so woefully inadequate that Boliden’s engineers must have known it was a sham.The legal argument Boliden is most focused on...“you can’t prove it’s our arsenic.” Boliden points to other arsenic-laden shipments that Promel received over the years that the company says lies right next to Boliden’s waste...