In a ruling that could have serious implications for the environment, an independent NAFTA tribunal decided on Wednesday that Mexico must pay a California company $16.7 million in damages because municipal authorities prevented the company from opening a hazardous waste treatment plant in the state of San Luis Potosi. Mexico is appealing the decision, arguing that it violates the constitutional powers of municipal governments. Mexican officials say the company, Metalclad, bought a dump under the condition that it would clean up hazwaste pollution in the area, but the company changed its plans and tried to expand the dump. Michelle Swenarchuk of the Canadian Environmental Law Association said the decision confirms some environmentalists’ fears that NAFTA and the environment are at odds. Swenarchuk said, “This case is a terrible example of how necessary environmental controls can become near impossible for local communities.”