Northshore Mining wants air quality requirement dropped

Lawyers will be in U-S District Court in St. Paul today arguing both sides of a proposal by Northshore Mining. That company wants the state to drop a requirement that it meet an air quality standard which Northshore says is no longer relevant. It's called the "control-city standard," and Minnesota Public Radio's Stephanie Hemphill talked with Morning Edition's Cathy Wurzer to provide some background on the case.