Mr. Telander 

Included with this letter are our written comments and questions relative to the Pre-Panel Outreach 

Meeting for Brick and Structural Clay Products Manufacturing NESHAP of March 14, 2013. Possibly 

additional information, comments and questions will be submitted on our behalf by Susan Miller, ofthe 

Brick Industry Association. We have been working, to a small extent, with her office, and we have 

communicated most of the information contained with these documents. Should you receive further 

comments or additional information, presented by BIA, on our behalf please add it to, and consider it 

along with the enclosed documents. 

Also enclosed with our written comments and question is an attachment detailing the major and 

significant differences between large and small tunnel kilns. This issue was raised during the pre-panel 

meeting and, in response to an EPA request; the attachment was forwarded to Susan Miller on March 

20, 2013. That document may also have been submitted by BIA on our behalf. If so, please consider the 

sum of both documents as description of the various differences between large and small kilns. 

If there are any questions or concerns with the submittals on your part or with EPA please let us know. 

Sincere regards, 

~~ 

President 

Mutual Materials Company 

www.mutualmaterials.com 

PO Box 2009 

Bellevue, WA 98009 

605 !19th Avenue NE 

Bellevue, WA 98005 

425.452.2300 office 

425.454.7732 fax 
Re: Written Comments pertaining to Pre-Panel Outreach Meeting for Brick and Structural Clay Products 

Manufacturing NESHAP 

Mr. Jutras, 

Regarding the above referenced matter Mutual Materials Company would have the following comments 

and questions along three general lines of concern relating to development of the new rule. 

The first general line of concern relates to categories or sub-categories within the rule. In the previous 

version of the rule, vacated in 2007, subcategories were created to separate kilns smaller or larger than 

10 tons per hour fired capacity. Subcategories were included to distinguish between periodic fired kilns 

or batch kilns and tunnel or continuous fired kilns. EPA mentioned that categories or sub-categories 

must be based on differences in operating procedures, methods or conditions. To address that concern, 

we have included an attachment we think clearly outlines the differences between large and small 

tunnel kilns. These differences may have a significant effect on actual emissions and operating 

performance of various control devices. It seems unreasonable to mandate a control device for all 

tunnel kilns based on measured performance of that device applied to a kiln of a specific style, design, 

size, and firing properties. Categorizing tunnel kilns by size, age or some combination would seem 

appropriate. The differences between periodic and tunnel kilns is significant and should allow 

categorizations or alternate standards by work practice at a minimum. The same standards should not 

be applied to tunnel and periodic kilns. 

A second area of concern and cause for comment is about health risk based standard setting. The 

concept of health risk based standards is clearly offered as an alternative to hard numerical limits within 

the language and scope of the Clean Air Act. The concept of a health risk based standard is well founded 

and very valid if it can be demonstrated to EPA that all emissions sources within an industrial category 

for which the NESHAP rule promulgation process is underway can prove and comply with a health risk 

based formula, devised by EPA. When such data, across an entire industry, can be demonstrated to 

present no significant health risks to the general population or the environment, health risk based 

standards are appropriate and acceptable. The Brick Industry Association (BIA} has compiled a complete 

data set for all known brick tunnel kilns in the subset of coverage this NESHAP process will cover. That 

www.mutualmaterials.com 

PO Box 2009 

Bellevue, WA 98009 

605 119th Avenue NE 

Bellevue, WA 98005 

425.452.2300 office 

425.454.7732 fax 
considered. By BIA data calculations using absolute worst case numbers the highest index value is Jess 

than 0.5. Less than half the allowable or acceptable index value of 1.0. We believe that if EPA takes the 

time to review and fairly evaluate the data provided by BIA, that EPA will conclude in this case (Brick 

NESHAP), that a health risk based standard is an appropriate, acceptable, and defensible approach to 

meeting all requirements of the Clean Air Act. Further we would add that reasons cited by EPA for not 

setting health risk based standards for other industries (Portland Cement, Boilers, Utilities) are not 

relevant to, repeated within, or existent to the brick industry. BIA has modeled all major sources for 

consideration of the health based standard, not a selected subset. BIA considered all related HAP 

emissions (HF, HCI, Cl2) unlike other industries. In previous attempts to consider health risk based 

standards, the industry involved did not consider other emission sources at the facility, where the brick 

industry has no other sources than the kiln from which HAP emissions occur. 

The final general area of concern relates to the methodology EPA plans to use for calculating the 

numerical limits should they not decide to adopt a health risk based standard. Data from a very 

selective process EPA used to obtain samples from kilns recently installing control devices, if used, 

would not be appropriate in terms of standard or previously used methods. This selective testing 

creates a biased subset from which EPA would then propose to set a standard. Using the average of the 

best 12% of a total population is the appropriate and usual process. Using an average of the best 12% of 

a very selective subset ofthat population is not the usual or prescribed method. Assuming the total 

population can achieve the emissions levels of the best 12% of the very best subset within an industry is 

a flawed assumption. Raw material input is very different within the total population due to type and 

mineralogical composition. This can vary significantly by geographic region. The standard should not be 

based on data which is skewed by creation of a select subset that by good fortune has raw materials low 

in potential emissions. Within the industry we use what we have as feed stock material and to assume 

everyone should meet some ideal or super MACT standard created by such a selection process, 

distorted by some errant mathematical process is wrong. 

To summarize, we believe that EPA has many options that should be given fair evaluation, and that 

more than sufficient and complete data has been presented to support those options. Categorization 

within the standard is appropriate, consistent with the act and defensible. It would allow the act to 

fairly regulate various kiln sizes and operating parameters. Health risk based standards, in the brick 
MACT standards are fair, equitable, and reasonable, but most importantly achievable. We would ask 

that EPA not rush into another unwise or untenable rule simply to satisfy some court imposed deadline. 

There is no substitute for doing the right thing. Please take all necessary time to consider our concerns, 

review the health risk based data BIA has provided, and develop the new standard, with all possible 

correctness. 

d :!Bowen 

President 

Mutual Materials Company 
2) Kiln top design. 

a. Older smaller kilns tend to have been built with arched tops or crowns that have a significant 

volume of excess space above the topmost brick on the car. 

b. Newer larger kilns typically were built with a suspended flat roof or crown, greatly reducing 

the amount or space overhead relative to the top brick on the car. 

3) Vestibule I Inner door 

a. Older smaller kilns typically do not have an inner door to operate as a vestibule when 

charging the kiln with a new car 

b. Newer larger kilns tend to have such an inner door and vestibule arrangement to isolate kiln 

environment during the charge process. 

4) Kiln Construction. 

a. Older smaller kilns were typically built with massive amounts of heavy refractory brick, 

thicker walls and wider hearths in the high temperature firing zones. 

b. Newer larger kilns have usually been constructed with more efficient refractory materials. 

Fiber linings, insulating brick, etc. have allowed for tighter sidewalls and smaller hearths. 

5) Burner location 

a. Older smaller kilns are generally bottom fired with less efficient burners firing under the car 

deck. A significant amount of the heat input is absorbed by the car deck which acts as a hot 

plate 

b. Newer larger kilns more often have high efficiency top burners in the roof or crown which 

fire down into the load. less heat input is absorbed by the car refractory. 

These general differences between older and smaller kilns compared to larger and newer kilns, in 

combination, are what produce differences in operating behavior or characteristics of the sub-categories of 

kilns. These categorical differences contribute significantly to fuel efficiency (Btu/pound), volumes of exhaust 

gas generated per pound or ton of product, consistency of flow volumes and temperatures across a given 

time frame, and emissions quantities per unit volume of exhaust over time. The differences outlined are 

significant also in terms of how the kilns are actually operated. 

Most notably among the differences is the variability of kiln atmosphere during the charge process of kilns 

without inner doors compared to those with inner doors or vestibules. An inner door isolates the kiln 

atmosphere and exhaust flow while the outer door is opened to charge a new car into the kiln. With such a 

process the flow volumes and emissions characteristics stay fairly constant. Without that inner door the 

exhaust flow volume and emissions characteristics change drastically due to the sudden inflow of ambient air 

while the outer door is open to charge a new car. The flow volume and emission stream is then shifted 

significantly toward the other extreme when the outer door is closed. The kiln then catches up with the 

exhaust build up that occurred with the door open and the temporary overload of ambient air. 

Older smaller kilns typically operate without much if any automated control, requiring more operator 

attention and activity. Newer larger kilns often have more automation and control.