1

Permit Amendment

Source Analysis & Technical Review

Company Ash Grove Texas, L.P. Permit Number 1

City Midlothian Project Number 173601

County Ellis Account Number ED-0034-O

Project Type Amend Regulated Entity Number RN100225978

Project Reviewer Mr. Tan Nguyen, P.E. Customer Reference Number CN600132161

Site Name Cement Manufacturing Facility

Project Overview

Ash Grove Texas, L.P. (Ash Grove) owns and operates a portland cement manufacturing plant in Midlothian, Texas. Ash Grove 

submitted a permit amendment application on January 17, 2012. The amendment proposes to decommission Kilns 1 and 2 and

reconstruct Kiln 3 from a 1,080 ton per day (tpd) clinker wet process kiln to a preheater/precalciner kiln system with an average 

production rate of 2,600 tpd clinker. With the project, the plant-wide maximum annual clinker production will drop from 1,182,600 tons 

per year (tpy) to 949,000 tpy. Other new sources to be constructed include a clinker cooler, a clinker cooler discharge belt, two solid 

fuel mill feed belts, a solid fuel mill, two pulverized fuel bins and an emergency generator. Additionally, various permits by rule 

(PBRs), standard exemptions (SEs), and standard permits (SPs) are being incorporated by consolidation or reference.

Emission Summary

Air Contaminant Current Allowable Emission 

Rates (tpy)

Proposed Allowable 

Emission Rates (tpy)

Change in Allowable Emission 

Rates (tpy)

PM 805.24 301.64 -503.60

PM10 682.56 279.86 -402.70

PM2.5 1.21(a) 169.35 168.14

VOC 122.4 69.52 -52.88

NOX 9528 721.39 -8806.61

CO 1314 587.59 -726.41

SO2 9198 190.04 -9007.96

H2SO4 --

(b)

38.22 38.22

Pb --

(b)

0.04 0.04

Hg --

(b)

0.01 0.01

NH3 -- 78.03(c) 78.03

(a) PM2.5 was not speciated for almost all EPNs in the previously issued MAERT because it was not required at the time those sources were 

permitted. This project is expected to result in a decrease in PM2.5 since PM is decreasing.

(b) These emissions are not in the current permit but they are inherent in the process and have always existed at the plant site. These emissions are 

expected to decrease as a result of this project.

(c) SNCR was authorized under SP Registration No. 80048; this registration is being incorporated by consolidation into the NSR permit.

Compliance History Evaluation - 30 TAC Chapter 60 Rules

A compliance history report was reviewed on: 05/16/2012

Compliance period: 01/17/2007 - 01/17/2012

Site rating & classification: 1.63 - average

Company rating & classification: 2.39 - average

If the rating is 40<RATING<45, what was the outcome, if any, based 

on the findings in the formal report: n/a

Has the permit changed on the basis of the compliance history or 

rating? No
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Source Analysis & Technical Review

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Public Notice Information - 30 TAC Chapter 39 Rules

Rule Citation Requirement

39.403 Is Public Notice Required? No

If no, give reason: This project will not result in a net emissions increase for any pollutants.

Construction Permit & Amendment Requirements - 30 TAC Chapter 116 Rules

Rule Citation Requirement

116.111(a)(2)(G) Is the facility expected to perform as represented in the application? Yes

116.111(a)(2)(A)(i) Are emissions from this facility expected to comply with all TCEQ air quality Rules & 

Regulations, and the intent of the Texas Clean Air Act?

Yes

116.111(a)(2)(B) Emissions will be measured using the following 

method:

Existing kilns: NOx, CO, and SO2 CEMS; 

Reconstructed kiln: NOx, CO, SO2, PM, 

THC, and Hg CEMS.

Comments on emission verification:

116.111(a)(2)(D) Subject to NSPS? Yes

Subparts A, F, Y, OOO, and IIII

116.111(a)(2)(E) Subject to NESHAP? No

Subparts 

116.111(a)(2)(F) Subject to NESHAP (MACT) for source categories? Yes

Subparts A, LLL, and ZZZZ

116.111(a)(2)(H) Is nonattainment review required? No

Is the site located in a nonattainment area? Yes

Is the site a federal major source for a nonattainment pollutant? Yes

Is the project a federal major source for a nonattainment pollutant by itself? No

Is the project a federal major modification for a nonattainment pollutant? No

Did the project emission increases for nonattainment pollutant minus the two-year average 

actual emissions trigger netting? Yes

Is the contemporaneous increase significant? No

If the contemporaneous increase is significant a nonattainment review is required.

116.111(a)(2)(I) Is PSD applicable? No

Is the site a federal major source (100/250 tons/yr)? Yes

Is the project a federal major source by itself? No

Is the project a federal major modification? No

Did project emission increases, without decreases, for pollutant of concern, minus the twoyear average actual emissions trigger netting? Yes

Was the contemporaneous increase significant? No

If yes, explain:

Is the change excluded by 40 CFR 52.21(b)(2)(iii)? No

If yes, explain:

116.111(a)(2)(L) Is Mass Emissions Cap and Trade applicable to the new or modified facilities? No

If yes, did the proposed facility, group of facilities, or account obtain allowances to operate: n/a

116.140 - 141 Permit Fee: $ 75,000 Fee certification: Yes

Title V Applicability - 30 TAC Chapter 122 Rules

Rule Citation Requirement

122.10(13)(A) Is the site a major source under FCAA Section 112(b)? No

Does the site emit 10 tons or more of any single HAP? No

Does the site emit 25 tons or more of a combination? No

122.10(13)(C) Does the site emit 100 tons or more of any air pollutant? Yes

122.10(13)(D) Is the site a non-attainment major source? Yes
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122.602 Periodic Monitoring (PM) applicability:

PM is applicable since the site is subject to 30 TAC Chapter 122 and currently holds Title V Permit No. O1054. The 

NSR permit specifies the following Periodic Monitoring requirements to demonstrate compliance: weekly visible 

emission/opacity observations for applicable EPNs, quarterly property line visible emission observations, monthly 

sorbent or stain tube testing for ammonia or alternately use an ammonia CEMS for the kilns, and annual fuel sulfur 

analysis or recordkeeping of vendor fuel specifications for the emergency diesel generator.

122.604 Compliance Assurance Monitoring (CAM) applicability: 

CAM is potentially applicable since the site is subject to 30 TAC Chapter 122. The existing kilns use ESPs and SNCR

and the reconstructed kiln will use a baghouse and SNCR to control PM and NOx emissions, respectively. Also, the 

kilns each have a pre-control potential-to-emit (PTE) for PM and NOx emissions greater than the associated major 

source thresholds; therefore, CAM is applicable to these emission sources and the specific pollutants. The NSR permit 

requires PM and NOx CEMS to demonstrate compliance. The permit also requires CEMS for other pollutants, however, 

these are not specific to CAM. EPNs 3, 7, 5, 9, 10, 11, and 5-2A for the clinker coolers, finish mills, cement silos, and 

silo No. 3 each have the pre-control PTE for PM emissions greater than the major source threshold and are equipped 

with baghouses to control PM emissions. Therefore, CAM is applicable and the NSR permit requires daily visible 

emission/opacity observations to demonstrate compliance.

Request for Comments

Received From Program/Area Name Reviewed By Comments

Region: 4 Luke Jones/Sam

Madison

The regional office had comments on 

recordkeeping and sampling requirements.

City: Midlothian n/a

County: Ellis n/a

Toxicology: n/a

Compliance: n/a

Legal: n/a

Comment resolution 

and/or unresolved 

issues:

The draft permit was revised to add recordkeeping requirements and revise/clarify sampling 

requirements as requested by the regional office.

Process/Project Description

The Ash Grove Midlothian plant currently has three existing wet kilns. For a wet kiln, raw materials are mixed with water, and the 

resulting slurry is fed directly to the kiln. Ash Grove is proposing to decommission Kilns 1 and 2 and reconstruct Kiln 3 from a 1,080 

tpd clinker wet process kiln to a preheater/precalciner kiln system with an average production rate of 2,600 tpd clinker. The 

reconstruction primarily involves reducing the existing Kiln 3 length by half and adding a preheater/precalciner tower.

Ash Grove will continue to create raw material slurry using the existing equipment. However, rather than feeding the slurry directly to 

the reconstructed kiln, the slurry will be fed into a new dryer/crusher where the slurry will be flash dried by hot kiln and precalciner 

gases. The flash dried material will be crushed and preheated as it passes through the dryer/crusher and into a preheater cyclone. The 

preheater cyclone will separate the preheated kiln feed from the gas that will exhaust through a new baghouse and stack. The preheated 

material will then enter the precalciner to be calcined. The hot gases leaving the kiln as well as gases generated from fuel combustion in 

the precalciner will provide the heat to the precalciner. A cyclone will separate the calcined kiln feed from the hot kiln and precalciner 

gases and send the kiln feed to the kiln. The kiln and precalciner gases will then be routed to the dryer/crusher to provide the heat 

source for the flash drying of the slurry. The “kiln system” refers to the entire pyroprocess comprised of the kiln, preheater, precalciner, 

and dryer/crusher. According to Ash Grove, there is only one other kiln system in the country that is configured similar to the new kiln 

system that Ash Grove is proposing - the kiln system at the Buzzi Unicem plant in Greencastle, Indiana. The reconstructed kiln will be 

capable of burning the same fuels that the existing wet kilns are capable of burning, including coal, petroleum coke, natural gas, fuel oil, 

used oil, tire derived fuel (TDF), and woodchips.
Permit Amendment 

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While the majority of the kiln gas will be routed directly to the precalciner, some gas will be diverted to a new bypass baghouse. Dust 

removed from the bypass baghouse will be transferred to the existing cement kiln dust (CKD) handling system. The exhaust from the 

bypass dust collector will rejoin the kiln exhaust entering the dryer/crusher.

The precalciner will have the ability to combust coal, petroleum coke, natural gas, TDF, and woodchips. Further, the precalciner can be 

fueled by tires, where the tires will be combusted in a “hot disk reactor”. The combustion of fuel in the precalciner will generate 

significant heat that together with the heat in the kiln gas will serve to calcine the kiln feed coming from the preheater cyclone. The heat 

that remains in the kiln and precalciner gases is used to flash dry the slurry in the dryer/crusher, and further preheat the kiln feed that has 

been flash dried.

In addition to the main baghouse for particulate matter (PM) control, other emission reduction measures have been designed into the 

reconstructed kiln system. Dry low-NOx burners (DLN) and Selective Noncatalytic Reduction (SNCR) will be used to reduce NOx 

emissions from the kiln, and activated carbon injection (ACI) or other sorbent may be used to reduce mercury emissions from the kiln. 

Further, the dryer/crusher is being designed to be in-line with the reconstructed kiln. Constructing the kiln and dryer/crusher as an inline system allows the kiln exhaust to pass through the dryer/crusher to provide a heat source to flash dry the slurry (in addition to heat 

generated from combustion in the precalciner). This heat recovery mechanism reduces the kiln system’s fuel requirements, thus, lowers

combustion emissions. Further, it allows any sulfur compounds or acid gases in the kiln exhaust to be absorbed by the kiln feed.

Clinker produced in the reconstructed kiln will be transferred to a new clinker cooler where it will be cooled using ambient air. Clinker 

leaving the new clinker cooler will be handled by a new conveyor belt (FIN 3-4H) that will transport the material to existing material 

handling equipment. When the solid fuel mill is operating, the hot (ambient) air from the clinker cooler will pass through a new cyclone 

that will capture any coarse clinker material entrained in the air and combine it with the product from the clinker cooler. The hot air 

will then route to a new indirect fired solid fuel mill, where the heat in the air will dry the coal (and other applicable solid fuels) in the 

mill. When the solid fuel mill is not operating, the cooler exhaust will pass through a process dust collector and heat exchanger 

(existing) and be recirculated back to the clinker cooler. The material collected in the process dust collector will be combined with the 

product from the clinker cooler. Some recirculation of the clinker cooler exhaust through the process dust collector and heat exchanger 

may also occur when the solid fuel mill is operating, although at a significantly lower rate.

The pulverized fuel from the mill will be transferred with the exhaust from the solid fuel mill to a new baghouse. The baghouse will 

separate the pulverized coal (and other applicable solid fuels) from the exhaust air and the pulverized solid fuel will be routed to the two 

new pulverized fuel bins. Each bin has a vent with a small dedusting filter. Pulverized solid fuel from the new bins will be conveyed to

the kiln and the precalciner burner pipes. As Ash Grove is uncertain on the VOC emission rate from the solid fuel mill, Ash Grove will

install a regenerative thermal oxidizer (RTO) on the solid fuel mill to maintain VOC emissions from the project to less than the 

calculated potential emissions.

In order to ensure adequate drying of the solid fuel, a natural gas fired hot gas generator (15 MMBtu/hr) will be used to make hot gas 

that can supplement the heat in the clinker cooler air on an as needed basis or that can be used as the sole heat source for the solid fuel 

drying if the kiln and clinker cooler are not operating at adequate temperature to dry the solid fuel. Any clinker cooler gas that cannot 

be sent to the solid fuel mill will be diverted back to the clinker cooler heat exchanger, cooled and used to cool the hot clinker. Due to 

the design of the clinker cooling system, there will not be a dedicated clinker cooler exhaust stack emission point.

After the new clinker cooler belt, FIN 3-4H, the clinker produced in the reconstructed kiln will be handled using existing equipment. 

Since both raw materials and product will be handled using existing equipment, the changes to the plant are limited to construction of 

the converted preheater/precalciner kiln system, a clinker cooler (and associated conveyor belt), and a solid fuel mill. Two new belt 

conveyors will be installed to transfer coal and other applicable solid fuels from the existing Solid Fuel Day Tank (FIN 6-9) to the new

solid fuel mill. Both of the conveyors will utilize baghouses for dust control. For emergency situations, a 400 kW output (473 kW 

input, 635 hp input, 536 hp output) emergency generator will be installed. It will only operate during critical times, such as power 

outages, to run the auxiliary kiln drive, burner pipe emergency fan, and other sensitive equipment and will replace old units currently in 

use at the plant.

A summary of the new emission sources to be added (or reconstructed in the case of Kiln 3) as a result of the Kiln 3 reconstruction 

project is as follows:

 Kiln 3 (part of kiln system) – FIN 431.KL100, EPN 331.SK410

 Dryer/Crusher (part of kiln system) – FIN 411.DC100, EPN 331.SK410
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 Precalciner (part of kiln system) – FIN 421.CI400, EPN 331.SK410

 Preheater Cyclone (part of kiln system) – FIN 421.CN010, EPN 331.SK410

 Precalciner Cyclone (part of kiln system) – FIN 421.CN110, EPN 331.SK410

 Clinker Cooler – FIN 441.CC100, EPN 461.SK405

 Solid Fuel Mill – FIN 461.RM100, EPN 461.SK405

 Hot Gas Generator – FIN 461.HG700, EPN 461.SK405

 Clinker Cooler Belt – FIN 3-4H, EPN F-MB2

 Solid Fuel Transfer Solid Fuel Day Tank to BC050 – FIN 6-15A/B/C, EPN 6-15

 Solid Fuel Transfer BC050 to BC080 – FIN 461.BC050, EPN 461.BF020

 Solid Fuel Transfer BC080 to Solid Fuel Mill – FIN 461.BC080, EPN 461.BF040

 Pulverized Fuel Bin A – FIN 461.BI550A, EPN 461.BF560A

 Pulverized Fuel Bin B – FIN 461.BI550B, EPN 461.BF560B

 Emergency Diesel Generator – FIN EG1, EPN EG1.SK1

A summary of existing equipment associated with the Kiln 3 reconstruction project is as follows:

 Slag/Mill Scale Silo 3 Weigh Belt – FIN 1-16A, EPA 1-16A1 and 1-16A2

The existing weigh belt listed above is the conveyor that currently sends raw materials, such as slag, to the existing Kiln 3. Following 

the Kiln 3 reconstruction project, the conveyor will continue to handle raw material or product, but the amount handled could be greater 

than it is now.

A summary of equipment to be decommissioned as a result of the Kiln 3 reconstruction project is as follows:

 Kiln 1 and the associated electrostatic precipitator (ESP) (FIN 2-1, EPN 2)

 Kiln 2 and the associated ESP (FIN 2-2, EPN 6)

 Kiln 3 ESP (EPN 12)

 Kiln 1 Clinker Cooler (FIN 3-1, EPN 3)

 Kiln 2 Clinker Cooler (FIN 3-2, EPN 7)

 Kiln 3 Clinker Cooler (FIN 3-3, EPN 131)

 Kiln 1 Clinker Cooler Belt (FIN 3-4A, EPN F-MB22)

 Kiln 2 Clinker Cooler Belt (FIN 3-4B, EPN F-MB23)

 Kiln 3 Clinker Cooler Belt (FIN 3-4C, EPN F-MB24)

 Solid Fuel Mills 1, 2, and 3 (FIN 6-10A/B/C, EPN 6-10)

 Slag/Mill Scale Silo 1 (FIN 1-14, EPN 1-125)

 Slag/Mill Scale Silo 1 Weigh belt (FIN 1-14A, EPN 1-14A1, EPN 1-14A2)

 Slag/Mill Scale Silo 2 (FIN 1-15, EPN 1-126)

 Slag/Mill Scale Silo 2 Weigh Belt (FIN 1-15A, EPN 1-15A1, EPN 1-5A2)

 Kiln 1 Auxiliary Drive Engine (FIN 1-43, EPN 1-43)

 Kiln 2 Auxiliary Drive Engine (FIN 1-44, EPN 1-44)

 Kiln 3 Auxiliary Drive Engine (FIN 1-45, EPN 1-45)

Additionally, various permits by rule (PBRs), standard exemptions (SEs), and standard permits (SPs) are being incorporated by

consolidation. They are as follows: (See BACT below for additional information.)

 PBR Registration No. 82608 (EPNs F-RM2, 1-29, 1-30, 1-31, 3-19 and F-RM4)

 PBR Registration No. 90808 (EPNs 6-11, 6-13, 6-14, and 6-12)

 PBR Registration No. 76379 (EPNs 6-1, 6-2, 6-3, 23, and 6-4D)

 PBR Registration No. 74145 (EPNs 3-15, F-RM1, F-RM2, 1-29, 1-30, and 1-31)

 SE 91 Registration No. 34329 (EPNs 10 and 11)

 SE 106 (APD-CERT 03/11/2005) (EPN 6-4C)

 SP Registration No. 74149 (EPN 3-15)

 SP Registration No. 80048 (EPNs 7-1-1, 7-1-3, 7-4, 7-5, 7-6, and 7-7)

PBR Registration No. 71845 (CKD Silo 3 and Pug Mill) is being incorporated by reference per the applicant's request since the 

authorized sources do not directly impact any permitted facilities.
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Pollution Prevention, Sources, Controls and BACT- [30 TAC 116.111(a)(2)(C)]

Reconstructed No. 3 Cement Kiln (kiln, dryer/crusher, precalciner, and preheater), EPN 331.SK410

NOx

NSPS Subpart F limits emissions of NOx for new and reconstructed kilns to less than 1.5 lb/ton clinker, based on a 30-day rolling 

average. Ash Grove will comply with the NOx limit by using DLN (staged combustion) in combination with SNCR. SNCR is the most 

efficient NOx reduction technology demonstrated on U.S. cement kilns. A NOx limit of 1.5 lb/ton clinker (30-day rolling average), as 

required by NSPS Subpart F, is lower than the NOx BACT determinations made for other recently permitted kilns. Thus, using DLN in 

combination with SNCR to meet a limit of 1.5 lb/ton clinker (30-day rolling average) for NOx is BACT for the kiln system.

CO and VOC

CO and VOC emissions are generated as products of incomplete combustion and as a result of the decomposition of organic material in 

the kiln feed. There are add-on control devices such as oxidizers that can reduce emissions of CO and VOC. However, there are no 

kilns in the U.S. for which a BACT determination has resulted in the installation of these devices. Recent BACT determinations for CO 

and VOC have relied on good combustion practices as a means of limiting CO and VOC emissions. Ash Grove evaluated the economic 

feasibility of an RTO. The methodology specified in the EPA Air Pollution Control Cost Manual - Sixth Edition (EPA 452/B-02-001) 

was used to calculate the economic feasibility in annual $/ton pollutant removed. The resulting economic cost was $132,318/ton VOC 

controlled, $11,464/ton CO controlled, or $10,277/ton CO+VOC controlled. None of the costs are economically feasible. Since RTO 

is not cost effective, and recent BACT determinations have relied on good combustion practice, Ash Grove will use good combustion 

practices as BACT for CO (1.23 lb/ton clinker, 30-day rolling average) and VOC (0.138 lb/ton clinker, 12-month rolling period) for the 

kiln system.

PM/PM10/PM2.5

The new kiln system will be subject to both NSPS Subpart F and NESHAP Subpart LLL. The NSPS and NESHAP limit emissions of 

filterable PM for new and reconstructed kilns to 0.01 lb/ton clinker, based on a 30-day rolling average. This is an extremely low PM 

limit, resulting in potential filterable PM emissions from the new kiln system of less than 5 tpy. A baghouse is the most efficient control 

device for controlling filterable PM, as well as PM10 and PM2.5. Ash Grove will install a baghouse to meet a limit of 0.01 lb/ton clinker 

for filterable PM/PM10/PM2.5, based as a 30-day rolling average, to comply with the NSPS and NESHAP limits. This is BACT for the 

kiln system.

SO2 and H2SO4

NSPS Subpart F limits emissions of SO2 for new and reconstructed kilns to less than 0.4 lb/ton clinker, based on a 30-day rolling 

average, or 90% control. This limit is lower than the SO2 BACT determinations made for other similar kilns in Texas. Ash Grove will

comply with the SO2 limit by operating a dryer/crusher in line with the kiln. The dryer/crusher is part of the “preheat” portion of the 

overall preheater/precalciner kiln system, with the primary purpose of grinding, flash drying and preheating the wet kiln feed slurry 

using heat contained in the kiln and precalciner gases. While the primary purpose of the dryer/crusher is to heat, dry and grind the 

slurry, it also acts as an inherent scrubber for SO2 and acid gases in the kiln exhaust (similar to the inherent scrubbing experienced in an 

in-line raw mill). Thus, meeting a limit of 0.4 lb/ton clinker (30-day rolling average) for SO2 through process inherent scrubbing is 

BACT for the kiln system. A portion of the SO2 generated in the process is converted to H2SO4. Therefore, limiting SO2 emissions will 

also limit H2SO4 emissions, which is BACT.

Hg

NESHAP Subpart LLL limits emissions of Hg for new and reconstructed kilns to 21 lb/million tons clinker, based on a 30-day rolling 

average. This is a very low emission limit, and BACT for Hg has generally not been evaluated for previous similar kilns in Texas. Ash 

Grove will comply with the NESHAP limit by installing an activated carbon injection system or other sorbent system to control Hg

emissions from the kiln. This is BACT.

NH3

An alternative case specific specification (pursuant to 30 TAC 117.3125) for an ammonia emission limit of 35 ppm for the kilns was 

approved under a permit alteration issued on June 1, 2010. This is BACT and will apply to the reconstructed kiln.
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Clinker Cooler/ Solid Fuel Mill (EPN 461.SK405)/ Pulverized Fuel Bins (EPNs 461.BF560A and 461.BF560B)/ Solid Fuel Transfers

(EPNs 461.BF020 and 461.BF040)/ Clinker Cooler Belt (EPN F-MB2)

The new clinker cooler will not have a direct emission point; emissions will be routed to the solid fuel mill.

Emissions from the solid fuel mill stack and the two solid fuel transfer points preceding the solid fuel mill will be routed to baghouses 

that will control emissions of filterable PM for these sources to 0.01 gr/dscf. This is BACT.

Emissions from the pulverized fuel bins will be routed to dedusting filters that will control emissions of filterable PM for these sources 

to 0.01 gr/dscf. This is BACT.

Solid fuel from the exiting solid fuel day tank will be transferred to a new belt conveyor. The transfer will occur inside a well-enclosed 

building. The inherent moisture content of the fuel (> 7%) along with the well-enclosed building will control PM emissions to at least 

90%. This is BACT.

Similarly, the new clinker cooler belt conveyor will transfer material to the existing clinker handling system in an enclosure and within a 

building to obtain at least 90% PM control. This is BACT.

Ash Grove does not have VOC data for the new solid fuel mill. Further, no BACT determinations have ever been made for VOC from 

solid fuel mills (i.e., coal mills). Ash Grove is estimating that the concentration of VOCs in the exhaust gas, resulting from the hot air 

drying the coal (and other applicable solid fuels), is 10 percent of the NESHAP standard for THCs for the kiln system. The NESHAP 

standard is 24 ppmvd at 7% oxygen. The actual predicted conditions for the kiln stack are 5.7% oxygen and 40.4% moisture, resulting 

in an actual stack THC concentration of 15.6 ppmv. This results in a concentration of 1.56 ppmv VOC for the solid fuel mill. Thus, Ash 

Grove is expecting to achieve a VOC concentration in the solid fuel mill exhaust of 1.56 ppmv or less. This is much less than the VOC 

limit that qualifies for an exemption from control requirements in 30 TAC Chapter 115, Subpart B, Division 2. This is BACT.

Hot Gas Generator

The hot gas generator will be fired with natural gas and operated with good combustion practices. NOx emissions will be limited to 

30 ppmvd corrected to 3 percent O2. This is BACT.

Emergency Generator

The emergency generator will be fired with diesel containing no more than 15 ppm sulfur and will be certified to NSPS Subpart IIII

Tier 3 standards. This is BACT.

PBR Sources Incorporated by Consolidation

EPN Facility BACT

6-2 Coal Unloading Conveyor Belt

Limited drop distance and high inherent 

moisture content (> 7%) and low emissions.

6-3 Drop from Coal Stacker to Stockpile

6-4D Stacker Pile Movement

6-12 Reserve Solid Fuel Stockpile

6-4C Solid Fuel Unloading - Drop from Front End Loader to Stockpile

6-11 Reserve Solid Fuel Transfer Point (at Main Stockpile)

6-13 Reserve Solid Fuel Reclamation Transfer Point (at Reserve Stockpile)

6-14 Reserve Solid Fuel Reclamation Transfer Point (at Main Stockpile)

F-RM1 Raw Material Building (Transfer onto Limestone Inside Stockpile)

Building enclosure and limited drop distance 

and low emissions.

F-RM2 Raw Material Building (Limestone Feed Hopper/Incline Conveyor)

F-RM4 Clinker Transfer to Inside Pile (RM Building)

6-1 Railcar Unloading Hopper
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EPN Facility BACT

3-19 Clinker Transport Loading (outside pile) Limited drop distance and low emissions 

(< 0.01 tpy PM).

3-15 Clinker Reclaim Conveyor No. 6 Baghouse

Emissions routed to fabric filter dust 

collector with an outlet grain loading of 

equal to or less than 0.01 gr/dscf.

1-29 Limestone Bin Dust Collector

1-30 Limestone Transfer onto Finish Mill Collection Belt 1

1-31 Limestone Transfer onto Finish Mill Collection Belt 2

23 Railcar Unloading Baghouse

32 CKD Tank 1 Baghouse

10 Cement Silo 1 Baghouse

11 Cement Silo 2 Baghouse 

Impacts Evaluation - 30 TAC 116.111(a)(2)(J)

Was modeling conducted? Yes Type of Modeling: AERMOD

Will GLC of any air contaminant cause violation of NAAQS? No

Is this a sensitive location with respect to nuisance? No

[§116.111(a)(2)(A)(ii)] Is the site within 3000 feet of any school? No

Additional site/land use information: 

Summary of Modeling Results 

AERMOD modeling was submitted by the applicant. The modeling was audited and approved by the Air Dispersion Modeling Team.

The modeling results indicate that the maximum off-property predicted concentrations for SO2 (1-hr, 3-hr, 24-hr, and annual averaging 

periods), PM10 (24-hr averaging period), PM2.5 (24-hr and annual averaging periods), NO2 (1-hr and annual averaging periods), and CO 

(1-hr and 8-hr averaging periods) are below the respective de minimis concentrations and no further analysis is required.

Modeling Results for Minor NSR De Minimis

Pollutant Averaging Time GLCmax (μg/m3

) De Minimis (μg/m3)

SO2 1-hr 6.9 7.8

SO2 3-hr 5 25

SO2 24-hr 1.5 5

SO2 Annual 0.01 1

PM10 24-hr 2.8 5

PM2.5 24-hr 1.18 1.2

PM2.5 Annual 0.003 0.3

NO2 1-hr 6.9 7.5

NO2 Annual 0.04 1

CO 1-hr 22 2000

CO 8-hr 9 500

Additionally, the modeling results indicate that the state property line regulations for SO2 (1-hr averaging period) and H2SO4 (1-hr and 

24-hr averaging periods) are not exceeded.
Permit Amendment 

Source Analysis & Technical Review

Permit No. 1 Regulated Entity No. RN100225978

Page 9

9

Project-Related Modeling Results for State Property Line

Pollutant Averaging Time GLCmax (μg/m3

) De Minimis (μg/m3)

SO2 1-hr 11.2 20.4

H2SO4 1-hr 0.05 1

H2SO4 24-hr 0.01 0.3

The Modeling and Effects Review Applicability (MERA) analysis was conducted for non-criteria pollutants. All pollutants for the 

project fell off the MERA at Step 1C (there is no overall net increase in both short-term and annual emissions). Therefore, no further 

analysis is necessary.

Based on the above information, the project is not expected to have an adverse effect on human health or the environment.

Permit Concurrence and Related Authorization Actions

Is the applicant in agreement with special conditions? Yes

Company representative(s): Scott Nielson

Contacted Via: phone

Date of contact: 05/23/2012

Other permit(s) or permits by rule affected by this action: Yes

List permit and/or PBR number(s) and actions required or taken: PBR, SE, and SP Registration Nos. 34329, 74145, 74149, 

76379, 80048, 82608, and 90808 have been incorporated by 

consolidation and will be voided with this permit action.

Project Reviewer Date Team Leader/Section Manager/Backup Date