| From:  "Ciriello, Deidra" <DCiriello@cement.org>                                                                                           

| To:  Keith Barnett/RTP/USEPA/US@EPA                                                                                                      

| Cc:  Mary Johnson/RTP/USEPA/US@EPA                                                                                                       

| Date:  09/22/2009 02:52  

| Subject:  PCA letter                                                                                                                          

Keith,

Attached please find PCA’s response to your email regarding the use of THC as  

a surrogate for HAP and clarification of PCA’s comments on the Subpart Y NSPS.  

Please let me know if you have any questions.

Deidra

Deidra Ciriello

Director, Energy and Environmental Policy Portland Cement Association 500 New  

Jersey Avenue, NW 7th Floor Washington, DC  20001

Ph: (202) 408‐9494

Fx: (202) 408‐0877

e‐mail: dciriello@cement.org

(See attached file: EPA THC surrogate letter.pdf)
September 22, 2009

Emission Standard Division

Office of Air Quality Planning and Standards

U.S. Environmental Protection Agency

Research Triangle Park, NC 27711

Dear Mr. Barnett,

RE: Scope of NSPS Subpart Y

We appreciate the opportunity to comment on your question regarding the use of total 

hydrocarbon (THC) as a surrogate for organic HAP and clarify PCA's comments on the 

Proposed Standards of Performance for Coal Preparation Plants (Subpart Y NSPS).

U.S. cement plants are equipped with stand alone coal mills and in-line coal mills.

Stand alone coal mills are now and should continue to be subject to Subpart Y regulations 

exclusively. However, in more modern cement plants, a small portion of the kiln gases or those 

from clinker coolers are routed to the coal mill to convey and dry the coal within the mill before 

the coal is transmitted to the kiln for combustion. This configuration is designed mainly for heat 

recovery, which maximizes the fuel efficiency of the entire system. Typically, a small portion of 

heated gases from the kiln or in some cases from the clinker cooler are quenched to an optimum 

temperature before entering the coal mill.

There are two configurations for an in-line coal mill within the cement industry. In the first 

configuration, air pollution control devices from the in-line coal mills vent directly to the 

atmosphere. Whereas in the second configuration, the in-line coal mill exhaust is commingled 

with that of the main kiln stack i.e., their exhaust is not routed through the main kiln stack. PCA 

believes that in-line coal mills venting directly to the atmosphere should remain regulated by 

Subpart Y and that in-line coal mills vented through the main kiln stack should be exempt from 

Subpart Y and regulated by Subpart LLL. This would greatly simplify compliance for plant 

operations. In the latter configuration, in-line coal mill gases make up approximately 10% of the 

total stack gases and the kiln gases and/or clinker cooler gases make up the other 90% of the total 

gases in the main kiln stack. 

With regard to using volatile organic carbon (VOC) as a surrogate for THC, PCA believes that 

VOC should not be used as a surrogate for organic HAP. The use of VOC would complicate

compliance, as it would require the installation of new monitoring equipment. EPA would also 

need to establish a separate VOC standard to use as a surrogate. PCA understands that EPA is 

suggesting the use of VOC to address the potentially higher THC concentrations in kiln exhaust 

that may occur in plants that commingle gases from the kiln and coal mill. PCA believes, 
alternatively, that a new THC subcategory under Subpart LLL should be considered for plants 

with this configuration. This would address the increase in THC due to commingling of gases 

and provide a better alternative to the use of VOC as a surrogate for organic HAP.

As you know, we've been considering subcategorization of in-line coal mills that commingle 

their gases and vent through the main kiln stack as part of the ongoing discussions regarding 

potential changes to Subpart LLL. PCA believes that for this particular plant configuration,

subcategorization is appropriate. We are aware that additional THC data may be needed to 

facilitate this subcategorization. PCA will be providing additional THC data regarding this 

matter to EPA.

We appreciate the opportunity to clarify these issues. If you have any questions, please contact 

me or Deidra Ciriello at (202) 408-9494, or aohare@cement.org or dciriello@cement.org.

Sincerely,

 

Andrew T. O’Hare

Vice President, Regulatory Affairs

cc: Mary Johnson