The US government has eased clean air rules so that power plants and refineries can expand their operations without having to install expensive new anti-pollution equipment. The long anticipated easing of the rules, sought by the utility, coal and oil industries, were first proposed in June by the Environmental Protection Agency (EPA), which is responsible for protecting clean air and water in the US. Environmentalists and Northeast states, home to some of America's dirtiest generating stations that were due to be shut down, opposed the changes to the New Source Rules (NSR). EPA administrator Christie Whitman argued that the former NSR program "deterred companies from implementing projects that would increase energy efficiency and decrease air pollution." The Clean Air Act of 1970 requires new plants and utilities to install the best available pollution control technology, but some old power plants were exempt unless they intend to make improvements that would extend a plant's life. At that point they create a "new source" of emissions and would have to install further pollution controls. The new rules effectively make it economic to extend the lives of some of these power plants.