SAN FRANCISCO --- A federal court ruled Tuesday that the Bush administration violated a 1992 law designed to reduce foreign oil dependence, global warming and air pollution. Federal District Court Judge William Alsup ruled that the Department of Energy’s failure to impose an alternative-fuel vehicle purchasing requirement on private and municipal fleets was illegal. The judge ordered the agency to revise the law's petroleum reduction goal to an achievable number, and then use the new goal to assess whether to impose alternative-fuel vehicle purchasing requirements on private and municipal fleets. In passing the Energy Policy Act of 1992, Congress sought to replace 30 percent of petroleum vehicle fuel with cleaner alternative-fuel vehicles by 2010. Two conservation groups, Center for Biological Diversity and Bluewater Network, filed suit last year arguing that the Bush administration’s had failed to implement the law.