EPA issued Graymont a Notice of Violation on December 18, 2012. The NOV alleged that From March 13, 2012, to August 10, 2012, Graymont exceeded Kiln No. 4?s permitted NOx limit of 1.55 lbs/tsf at least 82 times, as measured on a 3-hour rolling average basis, and its permitted NOx limit of 56 lbs/hr at least seven times, as measured on an hourly basis.
EPA identified the violations after Graymont installed a temporary NOx CEMS on Kiln No. 4 and collected the equivalent of 92 days of NOx emissions data, from March 13 to August 10, 2012, pursuant to a 114 request.
Following the NOV, Graymont agreed to install a permanent NOx CEMS on its Kiln No. 4. This ACO memorializes the CEMS installation and will ensure Graymont?s compliance with the NOx emission limit for Kiln No. 4 in its Title V Operating Permit.