A federal appeals court has affirmed a $105 million judgment for New York City against Exxon Mobil Corp. over the petroleum giant's contamination of groundwater with the gasoline additive methyl tertiary butyl ether, or MTBE, used until the mid-2000s to reduce emissions. On Friday, a three-judge panel of the U.S. Court of Appeals for the Second Circuit rejected Exxon's arguments that the city's claims were preempted by the federal Clean Air Act and that the trial was tainted by juror misconduct. New York City's case against Exxon is one of a slew of similar cases over MTBE contamination filed by cities, states and individuals around the country.