New York Gov. George Pataki (R) yesterday set strict new limits for drinking water pollution from the gasoline additive MTBE, responding to growing concerns about its health effects. MTBE makes gasoline burn cleaner and helps reduce air pollution, but it has been found to contaminate wells and water supplies, and a federal panel this summer recommended that its use be severely limited. Within the past month, Pataki has also proposed tighter emissions standards for old power plants and new automobiles. Enviros are pleased with Pataki’s new greener stances, but some are wondering if the governor has ulterior motives for burnishing his environmental image. Some people speculate that he is feeling competition from the state’s new Democratic attorney general, who is cracking down on polluting power plants, and others say he is hoping to be chosen as a running mate by GOP presidential frontrunner George W. Bush, who has been vulnerable to attacks by enviros and could use a green boost.