The environmental safety of the Koch Refinery is in question again. Concerns about possible health risks from air emmissions from the refinery have delayed the company's request for a new air quality permit. The Minnesota Pollution Control Agency citizens board plans to take a second look at a massive study that assured local citizens the air around Koch's Rosemount refinery was safe to breathe. Minnesota Public Radio's Mary Losure reports. Koch Refining Company's request for a new, flexible air quality permit had already been under intense scrutiny because of the company's poor environmental track record. The permit could allow Koch t