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July 19, 2011

Summary of July 18 EPA-PCA Meeting 

Meeting Attendees

EPA:

Keith Barnett, OAQPS

Peter Tsirigotis, OAQPS

Steve Silverman, OGC

PCA: (by conference phone)

Craig Campbell, Lafarge

Paul Detterline, Capital

Nancy Garnett, TXI

Juge Gregg, Sidley

Curtis Lesslie, Ash Grove

Brett Lindsay, Salt River Materials

Tim Matz, Lehigh

Jason Morin, Holcim

Dan Nugent, Buzzi Unicem

Andy O’Hare, PCA

Mike Pelan, Lafarge

Satish Sheth, CEMEX 

1. Clinker Pile Standards: 

July 18 Recommendation: Eliminate clinker pile design and management standards under 

Section 63.1343(c). Include “open clinker piles” among the list of affected sources under 

Section 63.1340(b). Define “open clinker piles” under Section 63.1341. An “open clinker pile” 

is: “an outdoor, unenclosed accumulation of clinker on the ground, which contains in excess of 

X tons of clinker, and is utilized for a continuous period in excess of X days.” In doing the 

foregoing, fugitive emissions from open clinker piles would be addressed by the NESHAP 

general duty to minimize emissions under Section 63.1348(d).

Summary of Meeting Discussion: EPA is willing to drop the clinker pile design and management 

standards in exchange for some type of obligation to minimize emissions from clinker piles. The 

Agency would like PCA to share a list of work practice methods the industry employs to 

minimize clinker pile emissions, such as tarps, water sprays, surfactants, foams, etc (Subpart Y 

may have examples for coal piles) and the effectiveness of these strategies. The Agency may 

then explain these practices in proposed changes to the NESHAP as a means of justifying 

dropping design and management standards. EPA would also like to know whether there are 
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any permanent outdoor stockpiles of clinker (it was explained that the vast majority of these 

piles are seasonal, intended to address market conditions).

2. The affirmative defense for malfunctions: This issue was not discussed during the July 18 

meeting. 

3. Modifications to the THC Standard: 

July 18 Recommendation: Plants that opt to comply with the oHAP limit would be allowed to 

either: (1) demonstrate compliance with the oHAP limit annually without having to 

continuously monitor THC emissions, or (2) through testing, establish a surrogate THC emission 

limit proportional to the 9 ppmv oHAP limit and continuously monitor THC emissions to verify 

compliance with the THC surrogate standard. 

Summary of Meeting Discussion: EPA is willing to propose either of these alternatives, though 

was more inclined to support the option with continuous monitoring (option 2).

4. HCl Monitoring During Start-up and Shutdown: 

July 18 Recommendation: EPA should apply at least a 23 ppm (risk-based threshold) HCl 

standard during periods of start-up and shutdown. HCl continuous emission monitors during 

start-up and shutdown would be required only for those facilities that DO NOT employ a wet or 

dry scrubbing technology (see issue below).

Summary of Meeting Discussion: EPA generally agreed that HCl continuous emission monitors 

should not be required for facilities that elect to employ dry scrubbers (as is the case for 

facilities that use wet scrubbers), while at the same time, rejected the PCA suggested risk-based 

HCl emission standard for start-up and shutdown. There was then an extended discussion 

regarding the difficulties of monitoring HCl (or any other pollutant for that matter) during startup and shutdown because of irregular gas flows. etc. EPA explained that the Agency is not 

obliged to set an emission standard if it can be demonstrated that emissions may not be 

reliably measured during these periods. PCA agreed to consider this issue further and may 

request an analysis to support the difficulty in monitoring during these periods. If it is 

demonstrated that emissions may not be measured, EPA may then apply a work practice 

designed to minimize emissions in lieu of an emission limit. 

5. HCl Continuous Emission Monitor (CEM) for Dry Scrubbers: 

July 18 Recommendation: As indicated above, those facilities equipped with a wet scrubber or 

dry scrubbing device (meeting the following criteria) to limit HCl emissions would not be 

required to use an HCl CEM. For dry scrubbers to qualify, cement plant operators would have 
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to demonstrate that the device when operating is capable of ensuring compliance with the 3 

ppm standard during normal operations. 

Summary of Meeting Discussion: As indicated above, EPA generally concurred that facilities 

equipped with a dry scrubber would not have to continuously monitor HCl emissions, provided 

they demonstrate compliance with the emission limit through testing when the dry scrubber is 

operating. In a perfect world, EPA would like to have actual data verifying the efficacy of dry 

scrubbers to continuously achieve the HCl emission limit during normal operations. PCA 

explained that such data is not, and will not likely be, available in the near future. Finally, EPA 

suggested, that in lieu of continuous emission monitoring for dry scrubbers, EPA may require 

facilities to do some type of parametric monitoring, as currently required for wet scrubbers. 

Or, alternatively rely on SO2 monitors as a surrogate for HCl emissions. 

6. Alternative Particulate Matter (PM) Standard Equation: 

July 18 Recommendation: See below:

PM alt = 0.004 x 1.65 x Qs/7000 (Eq. 1)

PM alt= 0.004 x 1.65 x (Qs + Qb)/7000 (Eq. 2)

Where: 0.004 is the PM exhaust concentration (gr/dscf) equivalent to 0.04 lb per ton clinker 

where clinker cooler and kiln exhaust gas are not combined.

1.65 is the conversion factor of lb feed per lb clinker

Qs = Qk + Qc + Qm + Qb (inputs to the equation based on plant’s gas flow configuration vented 

to the main kiln stack, reflecting maximum kiln production)

Qb is the exhaust flow from an alkali bypass stack (dscf/ton raw feed)

Qk is the exhaust flow of the kiln (dscf/ton raw feed)

Qc is the exhaust flow of the clinker cooler (dscf/ton raw feed)

Qm is the exhaust flow of the coal mill (dscf/ton raw feed).

Equation 2 would be used by those plants equipped with a separate alkali bypass stack.

Summary of Meeting Discussion: EPA concurred with the PCA recommended approach for 

calculating a new PM limit for commingled sources. There was then an extended discussion 

regarding by-pass stacks and whether and how to continuously monitor their emissions. Three

alternatives were identified and will require additional thought, as follows: (1) do continuous 

monitoring of the by-pass stack, (2) duct the by-pass to the main stack, or (3) conduct an annual 

test of by-pass emissions and subtract them from the main stack emissions (for Hg and PM). 
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7. Continuous Monitoring for Mercury and PM during Start-up and Shutdown: 

July 18 Recommendation: The NESHAP stipulates the use of a 7-day rolling average when 

computing compliance with the PM and mercury standards. The rule further stipulates that the 

7 day period be consecutive operating days, were an operating day is any daily 24-hour period 

during which the kiln operates. This creates confusion, as one could interpret the rule to 

require compliance only when the start-up/shutdown period lasts at least 7 consecutive days.

This situation may be remedied by applying one of the two options:

1. Employ a total of 168 hours rolling for any start-up or shutdown period.

2. Use a weighted average-daily value during start-up or shutdown periods.

Option 1 would eliminate any bias created when an operating day has one or a fewer operating 

hours. It would allow hours to be carried forward to the next startup/shutdown period. This 

would facilitate calculation of a true 168-hour rolling average.

Option 2 would require that the source track emissions and number of hours per day, thereby 

allowing it to calculate a weighted-average value for the 7-day startup/shutdown period.

Additionally, the calculation is carried forward to the next startup/shutdown event, so a true 7-

day rolling average can be calculated for any startup/shutdown period.

Summary of Meeting Discussion: This issue was addressed during the discussion of Issue 

number 4 above. If the industry demonstrates that it is impossible to accurately monitor 

emissions of these pollutants during start-up and shutdown, EPA may impose some type of 

work practice geared to minimize emissions in lieu of an emission standard. 

8. Regulatory Status of Coal Mills: The three categories of coal mills include:

a. Coal Mills Receiving Only Hot Air from Clinker Coolers, Vented through a Separate Stack 

b. Coal Mills Receiving Kiln Gases, Vented through a Separate Stack 

c. Coal Mills Receiving Kiln Gases, Vented back to the Kiln Exhaust

July 18 Recommendation: The first two categories of coal mills would be regulated under NSPS 

Subpart Y for particulate matter emissions only (Subpart Y PM limit), as there is no separate 

combustion source used to dry coal in the mill for these process configurations. For the third 

category of “inline coal mills,” as indicated above under issue 6, the PM equation for 

commingled sources would be modified to account for the PM coming from coal mills and for 

THC, the oHAP compliance alternative would be employed. 
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Summary of Meeting Discussion: There was an extended discussion regarding the three 

configurations. EPA was in general agreement that the first configuration should be regulated 

under Subpart Y for PM. For the second configuration, EPA did not object to the 

recommendation that these be regulated under Subpart Y, though the Agency wondered how 

the reduced main stack emissions would impact compliance with the NESHAP. It was suggested 

that for the second and third configurations a plant may be obliged to confirm compliance with 

the NESHAP standards before the kiln gases are routed to the coal mill. 

9. PM Limit for Modified Sources under NSPS: 

July 18 Recommendation: Applying the existing source NESHAP PM standard (as modified 

through potential rule changes) is preferred to what was in the final NSPS rule, however, this 

issue is being litigated and resolution may need to wait the outcome of the DC Circuit decision.

Summary of Meeting Discussion: Though this issue was not discussed in great detail, it was 

suggested that if EPA planned to apply the NESHAP existing source PM limit to modified NSPS 

facilities that EPA should simply indicate in modifications to the NSPS rule that there is no new 

regulatory obligation fpr PM, as all existing facilities must comply with the new existing source 

PM NESHAP standard.