U.S. EPA issued Holcim a NOV and FOV on July 17, 2006 for alleged violations of the Michigan SIP for the state opacity limit of 15% for Kiln #1 and Kiln #2 and for Holcim's baghouse inlet temperature limit as specified by the Portland Cement NESHAP. Both Opacity and baghouse inlet temperature limits are incorporated into Holcim's Renewable Operating Permit (Title V permit). U.S. EPA believes that in order for kiln emissions at Holcim to continuously meet their opacity and baghouse inlet temperature standard, HJolcim must choose to use either their carbon injection and baghouse system or their baghouse and scrubber/regenerative thermal oxidizer (RTO) system. Based on information U.S. EPA received from Holcim, it appears that Holcim has chosen to pursue the option of operating the baghouse and scrubber/RTO system to achieve compliance. U.S. EPA supports this decision.