UPDATED 19:54 PM EST, January 15, 2013
But it also set a May 2014 deadline for utilities that rely on their own or contracted generators for non-emergency peak demand power to switch to sources that meet air pollution limits, three years earlier than it first proposed.
EPA stressed that large generators will be allowed to run without pollution controls during weather-related and other emergencies that cut electricity flows.
The rule also applies to stationary generators at farm, industrial and oil and gas production sites, including offshore rigs and platforms.
