Effective July 27, 2015, EPA amended key components of the National Emission Standard for Hazardous Air Pollutants (NESHAP) for new and existing portland cement kilns.  The changes, in part, were necessary to comply with a federal court’s ruling.

EPA originally promulgated emission limits for hazardous air pollutants (HAPs) from cement kilns in 2010.  The EPA standards established new stringent emission controls as a result of revised emission limits for mercury (Hg), hydrogen chloride (HCl), total hydrocarbons (TH), and particulates (PM).  Facilities must be in compliance by September 9, 2015.

In 2014, a federal court vacated the portion of the NESHAP that provided an “affirmative defense” to violations during equipment malfunctions.  Accordingly, EPA’s amended NESHAP permanently removes that defense from the regulation.

The new rule also clarified confusing portions of the rules:

• “Rolling average” is now defined as the weighted average of all monitoring data collected during a specified time divided by all production of clinker during those same production hours;
• “Run average” as used in monitoring requirements is amended to be the “average of the recorded parameter values for a run,” not the 1-minute parameter values for that run;
• Kilns may establish a relationship between average SO2 emissions to HCl concentrations as an alternative operating limit in certain circumstances.
   

A kiln must now meet NESHAP limits during malfunctions and, along
with other revisions, work harder to demonstrate compliance with federal requirements.

80 Fed. Reg. 44771 (July 27, 2015).