From: Cassidy Mike [mailto:MICHAEL.CASSIDY@kohler.com]

Sent: Saturday, March 07, 2015 1:49 PM

To: Nizich, Sharon

Subject: FW: EPA Proposed Clay MACT Rule

Hi Sharon,

Some follow-up to last Thursday’s conference call. The attached email below shows some 

temperature and ware throughput rate relationships. As shown, this is a summary for tunnel kiln 

10 at our Spartanburg SC facility. This is the kiln we installed in 2005 under the old Clay 

MACT. This kiln was tested under the Clay MACT ICR in August 2010, and this is the kiln on 

which EPA made us restart the shutdown wet scrubber for ICR emissions testing. This summary 

shows that over the 6 year period from 2005 through 2010, the kiln ran as fast as a 6-hr cycle time, 

and as slow as a 12-hr cycle time. It also shows the peak temperature was 165o

F lower on the 

slowest cycle. This is our second newest kiln, it is also our smallest kiln with respect to ware 

capacity. It’s possible that because this kiln holds less ware mass that it is subject to wider 

temperature variations from cycle rate changes. I understand that our other tunnel kilns, which are 

all larger than TK 10, will experience a temperature variation of 50-75o

F from fast to slow 

cycles. I’m still trying to obtain documentation of such, but these are not records typically kept for 

kiln operation.

This is normal, representative tunnel kiln operation because kilns are operated based on the “heat 

work” needed. This is a time and temperature relationship. Simply, for all kilns, more time equals 

lower temperature and less time equals higher temperature to achieve the same heat work. We 

make A1 ware regardless of the cycle time. I will likely include in my comment letter a request for a 

temperature variance for ongoing operation and compliance demonstration to the effect of 

whatever the average temperature was per the performance test minus 150o

F, to account for this 

normal variation. Might this be an acceptable approach to EPA to address this need for 

operational flexibility?

I will also include two additional comments related to an operational temperature limitation for the 

kilns.

1) When a facility has a temporary production shutdown, say for 2-8 days, such as around 

Christmas, the fuel is throttled back as “dummy ware” is cycled into the kiln. This “dummy” 

ware is comprised of previously fired ware and refractory material, not greenware. There 

are no HAP emissions from use of this “dummy” ware, and the tunnel kiln can be throttled 

back several hundred degrees as a stand-by condition, saving significant quantities of fuel, 

and associated GHG emission reduction. In this standby condition, the kiln temperature will 

certainly drop below the temperature limit established per the performance test, but there is 

no reason this should constitute a permit violation, as certainly no emission limit will be 

exceeded. Your thoughts on how to address this in the Clay MACT?

2) It is not uncommon for power outages to affect a facility, and so affect tunnel kiln operation 

by shutting down the natural gas fuel train. It can take a few hours to get kilns relit and 

operating, and as a result, the kiln temperature can drop a few hundred degrees in 

response to the outage, and so may fall below the operating limit for temperature. Will such 

a power outage event be classified as a non-compliance event or a deviation? Your 

thoughts on how these types of events should addressed in the Clay MACT?

Thanks.

Mike
Michael J. Cassidy

EHS Specialist

Kohler Co.

444 Highland Drive

Mail Stop 009

Kohler, WI 53044

p. (920) 457-4441, x 77263

f. (920) 459-1682

mike.cassidy@kohler.com

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From: Clark Gene

Sent: Friday, March 06, 2015 9:09 AM

To: Cassidy Mike; Weber Andy (Spartanburg)

Subject: RE: EPA Proposed Clay MACT Rule

Mike,

Period 2005 to 2010

On Kiln 10 History>

Gene