From:      O’Hare, Andrew <AOhare@cement.org>         

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

Date:      08/28/2009 01:23 PM     

Subject:    Draft THC Data Colllection Plan  

Keith,

Attached please find a draft THC data collection plan.  We will discuss with  

you on the call later this afternoon.

Regards,

Andy

Andrew T. O'Hare, CAE

Vice President, Regulatory Affairs

Portland Cement Association

500 New Jersey Avenue, N.W., 7th Floor

Washington, DC 20001

PH: (202) 408‐9494

FX: (202) 408‐0877

CELL: (202) 270‐0094

e‐mail: aohare@cement.org

(See attached file: Draft PCA THC plan 8‐28‐09.DOC)
August 28, 2009 

8-28-09 

PCA Plan for Supplementing the MACT Decision Making Record 

With Additional THC CEMS Data 

Background

In December 2006, EPA finalized its rulemaking for a revised PC MACT. At the 

same time the rule was published in the Federal Register, EPA also published a second 

notice advising that it was reconsidering the rule. 

Due to continued pressure and court actions by those challenging the rulemaking 

and the timeliness of EPA’s efforts to issue a final rule, in March 2007, EPA set out a 

Section 114 notice to the nine largest cement companies requesting that they provide 

emissions data for mercury, THC, and HCl. EPA sent the request to only nine 

companies, because requesting information from the entire industry would have required 

time consuming procedural steps that would have slowed down the data collection 

process. EPA was therefore limited to collecting information from less than ten 

companies via the Section 114 process. 

Those companies represented only 89 of the 167 PC MACT kilns in the United 

States at the time. The Section 114 request mandated that facilities collect raw material 

and fuel samples for 30 consecutive days in June 2007, and have them analyzed for 

mercury and total organic carbon (TOC). EPA planned to use these data to develop 

material balances needed to estimate mercury and THC emissions from cement kilns. In 

addition to the raw material and fuel sampling, EPA also requested that these companies 

provide all stack testing and CEMS data in their possession related to mercury, THC, and 

HCl. All data was collected and submitted to EPA prior to the end of 2007. 

EPA reviewed and analyzed the data provided by the cement industry for several 

months. Near the end of 2008, EPA concluded that they could not effectively estimate 

THC emissions from the TOC data provided (because they did not request stack testing in 

conjunction with raw material testing), and instead, decided to rely on the THC CEMS 

data provided by approximately 11 plants (14 kilns). These data consisted of less than 30 

days to, in very few cases, more than 2 years of data. EPA then ranked these data, and 

using a MACT basis of the average of the best 12% performing units with CEMS data, 

established a THC MACT floor for kilns and raw material dryers relying on an average 

of the two lowest emitting kilns. No data was collected for raw material dryers. 

 

Current Status of Available Data

Since the time of the submittal of the Section 114 data, all of the sources that 

reported THC CEMS data have collected additional data. These data will be submitted to 

EPA as part of PCA’s comments on the proposed rulemaking. Based on PCA’s analysis 

of this longer term data, PCA believes that EPA will be comfortable that there is enough 

THC CEMS data to develop a defensible floor for most of the industry. In the next 

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couple of days, PCA will send to EPA this data and will welcome the opportunity to 

discuss the data with you. 

PCA has analyzed this longer term data (now all > 1 year in duration) from 5 

kilns along with data provided by EPA for other kilns not included in the original Section 

114 data request, to determine a revised MACT floor. The analysis shows that there is 

sufficient data to establish a MACT floor based on the 99th percentile. Using the data, 

PCA will propose a THC MACT floor in its comments to the proposed rule. Further 

THC CEMS data from a random selection of kilns will likely not impact a MACT floor 

analysis beyond the data currently being reviewed, and PCA believes that gather of such 

data will not be helpful to EPA and will impose an unnecessary burden on the industry. 

The data does not show, however, whether the limestone reserves available to 

units in the existing data pool or other units have significant variations in the nature and 

amount of organics. To address this uncertainty, PCA welcomes the opportunity to work 

with EPA on conducting an industry-wide effort to gather more THC CEMS data to 

address this issue and possibly provide support for subcategories given the variations in 

the raw materials. Such a focused effort to gather longer term THC CEMS data is 

warranted for several reasons: 

• It is likely that the high THC levels for some kilns can be attributed to a 

combination of the level of organics in the limestone, the form of the organics in 

the limestone and a kiln configuration that has one or more source of organic 

releases downstream of the kiln (in particular in-line raw mills and in-line coal 

mills venting to the main stack.) While a few of the units with THC CEMS have 

high THC emissions, the data on limestone organics have not been collected or 

correlated to these kiln emissions. 

• EPA has assumed the stand alone raw mills and coal mills operated on kiln gases 

should meet the kiln THC limit, but EPA has no data to show that this is an 

appropriate extension of kiln THC measurements. We have limited data that 

suggests that these units have low volume, higher THC emissions than kilns. 

• Separate standards (which could be a subcategory or distinct affected source) for 

stand alone raw mills operated with supplemental fuel firing, raw material dryers 

and those kilns with high THC levels due to organics in the co-located quarry may 

be appropriate. This cannot be done without a strong database of THC CEMS 

readings and feed material characteristics supporting the best possible 

presentation on the need for one or more added subcategories for THC limits. 

• However, for stand alone raw mills that use supplemental fuels and coal mills that 

use kiln or cooler gases, there is no data to suggest that organic HAPs are even 

emitted. 

THC Monitoring Program Goals

The first goal of the testing program is to gather sufficient kiln THC emissions 

CEM data and raw materials organics characterization data (over several months) such 

that PCA can determine if there is a basis for one or more subcategories for high THC 

emissions kilns related to the characteristics of the limestone. Furthermore, where either 

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August 28, 2009 

3

coal mill and/or raw material dryer exhaust are co-mingled with the kiln stack emissions, 

it is important to determine whether either case warrants subcategorization. The second 

goal will be to collect organic HAP data for stand alone raw material dryers and coal 

mills that use kiln gases for drying to determine whether these sources emit organic 

HAPs. If it is determined that these sources emit significant HAPs, then CEMS 

monitoring may be necessary to establish a floor. Prior to commencing such an 

investigation, PCA will statistically design the project to ensure all elements are included. 

Program Approach

Once candidate plants have been identified, member companies will install CEMS 

and gather raw material samples and complete analyses consistent with a standard project 

protocol. PCA will hire a third-party contractor to oversee the testing program, working 

with the individual firms on completing the monitoring activities and then interpreting the 

data. Each of the selected facilities will be required to install a THC CEMS at their own 

expense and collect data for at least 6 months. In parallel, the limestone will be analyzed 

during the same period for organics content as well as the level and nature of releases 

during grinding and drying. 

Proposed Schedule

As you know, the majority of PCA's and its member companies' efforts are 

currently focused on preparing comments on the proposed rule, which are due next week. 

By September 15, PCA will develop a proposed test plan for EPA review. PCA is 

committed to working with EPA to ensure that the test plan is supported by EPA and the 

scope and objectives are clearly established and known to all parties. After obtaining 

EPA's concurrence on the scope and schedule of the study by September 30, PCA will 

initiate testing with the expectation of providing data to EPA in the spring of 2010.