A Latin American judge could soon rule in a case that many believe could be the costliest corporate ecological disaster in world history. The case against Texaco and its parent company Chevron Corp., which has languished in U.S. and Ecuadorian courts for more than a decade, stems from 16 billion gallons of oil drilling byproduct released in the Amazon basin over more than a quarter of a century. Local families claim that the pollution ruined their livelihoods and sickened their families. A court-appointed panel of experts has already recommended that Chevron pay as much as $27 billion in damages.