The Sierra Club is planning lawsuits to halt construction of coal plants in seven states, arguing that the mercury-spewing plants violate the Clean Air Act. Noting that a federal appeals court ruled in February that the Bush administration’s mercury regulations were too lax, the green group seeks to require the coal plants to get new state permits meeting tougher emissions standards. “We want to give moms across the country some peace of mind this Mother’s Day,” says Bruce Nilles of the Sierra Club. “That’s why we’re taking action … to ensure that these coal plants make every effort to keep their toxic mercury pollution out of our communities.”