MEMORANDUM
SUBJECT: 	Bounding Analysis for Portland Cement MACT Floors 
TO:		Docket No. EPA-HQ-OAR-2011-0817
DATE:		May 14, 2012

EPA re-evaluated the floor calculations used in the final NESHAP for the Portland cement source category.  75 FR 54970 (Sept. 9, 2010).  This analysis is a bounding analysis which removes from the Portland cement database any cement kiln which combusts a non-hazardous secondary material. This analysis is not intended to determine which kilns are CISWI and which remain cement kilns.  Rather, it determines what floors would be on the extreme hypothetical assumption that any cement kiln which combusts a non-hazardous secondary material is not a cement kiln.  The analysis then determines what the floors would be under this extreme assumption, bounding the possible floors which could result from the data set.   
The results of this analysis are presented below:
                                   Pollutant
          Kilns that do not combust non-hazardous secondary materials
                           Promulgated  -  All Kilns
                                       
                                   Existing
                                      New
                                   Existing
                                      New
Hg
                                       
                                       
                                       
                                       
No. of Kilns 
                                                                             26
                                                                             26
                                                                             89
                                                                             89
No. in Floor 
                                                                              4
                                                                              1
                                                                             11
                                                                              1
UPL (lb/MM tons clinker)
                                                                          66.60
                                                                          46.48
                                                                          54.10
                                                                          20.30
Average (lb/MM tons clinker)
                                                                          44.75
                                                                          35.20
                                                                          31.70
                                                                          13.90
HCl
                                                                              
                                                                              
                                                                              
                                                                              
No. of Kilns 
                                                                             11
                                                                             11
                                                                             21
                                                                             21
No. in Floor 
                                                                              2
                                                                              1
                                                                              3
                                                                              1
UPL (ppm)
                                                                           0.56
                                                                           0.34
                                                                           0.52
                                                                           0.34
Average (ppm)
                                                                           0.40
                                                                           0.34
                                                                           0.41
                                                                           0.34
PM
                                                                              
                                                                              
                                                                              
                                                                              
No. of Kilns 
                                                                             18
                                                                             18
                                                                             45
                                                                             45
No. in Floor 
                                                                              3
                                                                              1
                                                                              6
                                                                              1
UPL (lb/ton clinker)
                                                                           0.05
                                                                           0.01
                                                                           0.04
                                                                           0.01
Average (lb/ton clinker)
                                                                           0.03
                                                                           0.01
                                                                           0.00
                                                                           0.01
THC
                                                                              
                                                                              
                                                                              
                                                                              
No. of Kilns 
                                                                             10
                                                                             10
                                                                             15
                                                                             15
No. in Floor 
                                                                              2
                                                                              1
                                                                              2
                                                                              1
99[th] percentile (ppm)
                                                                          14.98
                                                                          10.84
                                                                          24.00
                                                                          24.00
Average (ppm)
                                                                           5.69
                                                                           5.68
                                                                           5.20
                                                                           4.70

The attachment to this memo (Attachment A) contains the calculations supporting these results.    Attachment A-9 details the kilns identified as CISWI at reconsideration.  These kilns were removed from all MACT floor calculations as part of the bounding analysis.  Additionally, any kilns identified as combusting non-hazardous secondary material from the 2007 portland cement ICR were removed from the MACT floor calculations.  Attachment A-10 details the kilns that were identified as combusting non-hazardous secondary materials. 

	We note further that although the HCl floor ostensibly changes (slightly) in this analysis, in fact there is no reason that the HCl floor would change.  This is because the floor is effectively determined by the analytic detection limit, and there are a large group of cement kilns which performed identically to the best performers.  See 76 FR at 28322 n. 11.  The reason for the (slightly) different value in this bounding analysis is due to the different number of sources in the database, not to any difference in measured performance.  Since there is no actual difference in kiln performance for HCl, there is no reason that the floor should be altered.

	We also note that no cement kilns are reclassified as incinerators in this bounding analysis due to processing non-hazardous secondary materials as ingredients.  This is because none of the non-hazardous materials identified by cement kilns as being used as ingredients are combusted, as explained at 76 FR 28322. 

	Even under the extreme assumptions of this analysis, EPA does not believe that the technology basis for the PM, HCl, THC or mercury standards would change were these bounding analysis floors to be adopted as standards.

 
