Seventeen states have adopted or are in the process of adopting rigorous auto emissions standards, based on those passed in California in 2005. Yet not one state has been able to implement them. California has sued the U.S. Environmental Protection Agency for withholding permission to implement its new standards, which are stricter than those set by the Clean Air Act. (An EPA waiver is required by the act.) Meanwhile, automakers persist in their efforts to block California's standards, arguing that any attempts to cut emissions by increasing fuel economy fall under federal authority. But September brought some good news: a federal court in Vermont ruled that the auto companies had not proven that compliance with California's emissions regulations would be technologically impossible, and it rejected their other arguments that it would "create economic hardship for the automobile industry, cause significant job loss, or undermine safety." NRDC's David Doniger led the states and environmental groups in crafting legal arguments in defense of California's standards.