Iowa

State Implementation Plan

Fine Particulate Matter

Muscatine, Iowa

Iowa Department of Natural Resources

Environmental Services Division

Air Quality Bureau

7900 Hickman Rd Suite 1

Windsor Heights, IA 50324

February 18, 2014
Table of Contents

i. Executive Summary...............................................................................................................................4

1. Background ...........................................................................................................................................5

National Ambient Air Quality Standards for PM2.5..................................................................................5

Muscatine, Iowa........................................................................................................................................5

Muscatine PM2.5 Air Quality Data ...........................................................................................................6

Affected Facilities......................................................................................................................................7

2. SIP Call...................................................................................................................................................9

Emissions Data ..........................................................................................................................................9

Modeling Demonstration........................................................................................................................10

Control Measures....................................................................................................................................10

GPC......................................................................................................................................................10

MPW ...................................................................................................................................................11

UTLX ....................................................................................................................................................12

PM2.5 Emissions Reductions Summary ..............................................................................................12

Co-Benefits of Emissions Reductions at GPC ......................................................................................12

Projected Attainment Date.................................................................................................................13

Contingency Measures............................................................................................................................13

Ambient Air Quality Monitoring .........................................................................................................14

Contingency Plans...............................................................................................................................14

3. Administrative Materials.....................................................................................................................17

Submittal Letter......................................................................................................................................17

Evidence of State Adoption ....................................................................................................................17

Necessary Legal Authority ......................................................................................................................17

Evidence of Public Notice........................................................................................................................17

Certification of Public Hearing ................................................................................................................18

Compilation of Public Comments and the State’s Responses................................................................18

Process for SIP Revisions.........................................................................................................................27

Attachment A. Modeling Demonstration......................................................................28

Attachment B. GPC Administrative Consent Order .......................................................54

Attachment C. Implementation Schedule for GPC Control Measures...........................55

Attachment D. MPW Control Measures and Timeline ..................................................56

Attachment E. MPW Air Construction Permits..............................................................57

Attachment F. UTLX Control Measures and Timeline....................................................58

Attachment G. UTLX Air Construction Permits..............................................................59

2
Attachment H. Proof of Publication..............................................................................60

3
i. Executive Summary

On July 14, 2011, the U.S. Environmental Protection Agency (EPA) Region 7 found that the Iowa State 

Implementation Plan (SIP) was substantially inadequate to maintain the 2006 24-hour National Air 

Quality Standard (NAAQS) for fine particulate matter (PM2.5) in Muscatine County, Iowa (76 FR 41424). 

PM2.5 measurements from a PM2.5 monitor located at Garfield School (also referred to as Muscatine 

High East Campus) show that the site oscillates in and out of attainment with the 2006 24-hour PM2.5 

NAAQS. Recent three year design values including 2005-2007, 2007-2009, and 2008-2010 have violated 

the 24-hour PM2.5 NAAQS.

EPA’s finding requires the State to revise the SIP and include measures to attain and maintain the 2006 

24-hour PM2.5 NAAQS in Muscatine. Specifically, EPA required that the SIP revision include a modeling 

demonstration showing the reductions needed to attain and maintain the PM2.5 NAAQS, control 

measures necessary to attain and maintain the PM2.5 NAAQS, and enforceable commitments to adopt 

and implement contingency measures if the PM2.5 NAAQS is not attained or maintained at the violating 

monitor.

The Iowa Department of Natural Resources (DNR) determined that three major sources of air pollution

in the Muscatine area significantly contribute to predicted (modeled) PM2.5 exceedances of the 

standard in the vicinity of the Garfield School monitor. These facilities are Grain Processing Corporation

(GPC), Muscatine Power & Water (MPW), and Union Tank Car Company (UTLX). The DNR collaborated 

with these facilities to develop air pollution control measures that will result in expeditious attainment 

of the 24-hour PM2.5 NAAQS through reductions of ambient air impacts of PM2.5 emissions from each 

facility.

Changes that have been made or will be made at these facilities generally include various combinations 

of the following:

• Installation of new particulate controls or improvements to existing particulate controls on a 

number of sources;

• Cessation of operation of various existing equipment; 

• Replacement of several existing operations with new, more efficient equipment;

• Regular sweeping and watering of road surfaces;

• Increasing select stack heights; and

• Restricting operation of certain processes.

It is estimated that PM2.5 emissions from these three facilities combined will be reduced by nearly 370 

tons per year from 2007 and 2008 actual emissions levels. The majority of the PM2.5 emissions 

reductions will come from GPC. Due to the scale and complexity of the changes at GPC, GPC has 

developed a phased implementation schedule that begins in 2013 and concludes in December 2016. 

The controls and other changes that will be implemented at GPC are also estimated to result in 

significant emissions reductions for several other regulated air pollutants.

Based on the current attaining 24-hour PM2.5 design values in Muscatine, the planned schedule for 

implementation of the control strategy, and on-going implementation of federal regulations that will 

continue to reduce regional levels of PM2.5, DNR believes that attainment requirements established by 

EPA in the SIP call will continue to be achieved. 

4
1. Background

National Ambient Air Quality Standards for PM2.5

Revisions to the fine particulate matter less than or equal to 2.5 microns (PM2.5) National Ambient Air 

Quality Standards (NAAQS) were published by the U.S. Environmental Protection Agency (EPA) in the 

Federal Register on October 17, 2006. EPA lowered the 24-hour average standard from 65 micrograms 

per cubic meter (ug/m3) to 35 ug/m3. The Iowa Department of Natural Resources (DNR) has adopted 

by reference the revised 2006 standard into 567 Iowa Administrative Code Chapter 28. 

On December 14, 2012, EPA revised the annual PM2.5 NAAQS to improve public health protection. 

EPA strengthened the primary annual average standard first set in 1997 for PM2.5 from 15 μg/m3 to 12 

μg/m3. The secondary annual average standard remained at 15 μg/m3.

The primary NAAQS define levels of air quality which are necessary to protect public health. The 

secondary NAAQS define levels of air quality which protect public welfare from any known or 

anticipated adverse effects of a pollutant. The PM2.5 NAAQS are shown in Table 1.

Fine particulate matter (PM2.5) consists of solids and liquids with a nominal aerodynamic diameter less 

than or equal to 2.5 micrometers. Significant impacts on human health and welfare are associated with 

PM2.5 exposure. An extensive body of scientific evidence shows that exposure to fine particle pollution 

can cause premature death and adverse cardiovascular effects, including increased hospital admissions 

and emergency department visits for heart attacks and strokes. Contact with fine particulate pollution 

also causes respiratory effects, including asthma attacks. The people most at risk from exposure to 

PM2.5 include people with heart or lung disease (including asthma), older adults, children, and people of 

lower socio-economic status.

Table 1. National Ambient Air Quality Standards for PM2.5

Pollutant Averaging 

Time 

Level Form

Primary Annual 12 μg/m3 annual mean, averaged over 3 years

24-hour 35 μg/m3 98th percentile, averaged over 3 years

Secondary Annual 15 μg/m3 annual mean, averaged over 3 years

24-hour 35 μg/m3 98th percentile, averaged over 3 years

Muscatine, Iowa

Muscatine has a population of 22,886 people (2010 U.S. Census), and is located along the western shore 

of the Mississippi River in Muscatine County, adjacent to the border between Iowa and Illinois. Most of 

the town is situated on low bluffs approximately 45-60 meters above the Mississippi River. Immediately 

to the south and southwest of the bluffs lies a large flood plain. The plain is approximately 3 meters

above the river. Land use in the area of the plain from the bluff line to approximately 2.5 kilometers 

5
south of the bluffs, to approximately 1 kilometer west of the river, consists of industrial development, 

residential housing, and general commercial use.

Muscatine PM2.5 Air Quality Data

The 24-hour averaged, or daily, PM2.5 standard “...is met when the 3-year average of the 98th 

percentile of 24-hour concentrations is equal to or less than 35 μg/m3. The computation of this 3-year 

average of the 98th percentiles of 24-hour concentrations is commonly referred to as the design value 

and is based on the most recent three years of quality assured data” (Final PM2.5 SIP Call, 76 FR 41424; 

p 41425). 

The Garfield1 School PM2.5 monitor site (Site ID 191390015) in the city of Muscatine, Iowa, is a 

neighborhood spatial scale site intended to measure population exposure to ambient PM2.5 

concentrations. The site is located approximately 500 meters west of Grain Processing Corporation, a 

major source of PM2.5 emissions in the area. Land use within two kilometers of the Garfield School 

monitor site includes residential and commercial properties, other schools, city parks and athletic 

complexes, day care facilities, and a cemetery.

The site includes a PM2.5 monitor on a daily operating schedule that has measured violations of the 24-

hour PM2.5 NAAQS. Historical design values for this site (Table 2) show that the site oscillates in and 

out of attainment with the 2006 24-hour PM2.5 NAAQS. Recent design values including 2005-2007,

2007-2009, and 2008-2010 have violated the 24-hour PM2.5 NAAQS (see also Figure 1). In addition to 

the PM2.5 filter samplers on the roof of Garfield School, the DNR also operates a continuous monitor in 

a trailer on the school grounds. The continuous PM2.5 monitoring data is used for real time reporting of 

the air quality index, and the filter sampler data is used for establishing NAAQS compliance.

Table 2. Historical 24-hour Averaged PM2.5 Design Values at the Garfield School monitor

Monitoring Years Design Value (μg/m3)

2003–2005 38

2004–2006 34

2005–2007 36

2006–2008 35

2007–2009 38

2008–2010 37

2009-2011 35

2010-2012 32

The DNR currently operates three other PM2.5 monitor sites in Muscatine. One site is located at 

Greenwood Cemetery, a second at Franklin School, and a third at Musser Park. Current design values at 

the Greenwood Cemetery and Franklin School sites are less than the 24-hour PM2.5 NAAQS (Figure 1). 

1 In 2012 the Garfield School Building (which formally housed an elementary school) became the new home of the 

East Campus of Muscatine High. For monitor location identification purposes, the rooftop monitor site is now 

referred to as the Muscatine High E. Campus-Rooftop site. For brevity and consistency with the identification of 

this monitoring site in 76 FR 41424, the school will continue to be referred to as Garfield School in this document.

6

 
 

Figure 1. Muscatine PM2.5 24-hour Design Value Trends

The Musser Park PM2.5 monitor began operation on January 1, 2011. No design value can be 

determined for this site as only two years of data are available. This monitor recorded 98th percentile 

values of 30.6 and 25.0 μg/m3 for 2011 and 2012, respectively.

Affected Facilities

There are three major facilities in the Muscatine area that were determined to be significant 

contributors to predicted (modeled) exceedances in the vicinity of the Garfield School monitor. (See 

Attachment A for additional information on the determination of affected facilities.) The facilities that 

were included in the PM2.5 control strategy are Grain Processing Corporation, Muscatine Power & 

Water, and Union Tank Car. The location of these facilities relative to the location of the Garfield School 

monitor is depicted in Figure 2.

The largest source of PM2.5 near the Garfield School monitor is Grain Processing Corporation (GPC). 

GPC is approximately 500 meters east/southeast of the monitor. GPC is located immediately adjacent to 

the river between 1500 and 2200 meters south of the bluff line. GPC processes grain into industrial, 

beverage and fuel-grade ethanol, as well as a variety of grain based food products, industrial products

and animal feeds. The GPC facility currently includes nearly 200 PM2.5 emission points, including coal 

and gas-fired boilers, dryers, coolers and associated material handling and storage equipment. 

7
Figure 2. Affected Facility Locations Relative to Garfield School Monitor

The Muscatine Power & Water (MPW) municipal electrical generating station is located approximately 

1.6 kilometers south and east of the monitor. MPW is located immediately adjacent to the river and 

GPC, approximately 2.5 kilometers south of the bluff line. Primary sources of PM2.5 at MPW include 

three coal-fired boilers, Units 7, 8, & 9, and associated material handling and storage equipment. 

The Union Tank Car Company (UTLX) facility is approximately 1.6 kilometers southwest of the monitor. 

UTLX supplies and reconditions rail tank cars for use through rental agreements. UTLX is not a major 

source of PM2.5 but is located near the monitor and was found to contribute to predicted violations of 

the PM2.5 NAAQS in the area addressed by the PM2.5 control strategy. The primary sources of PM2.5 

from UTLX are from the removal of paint from rail tank cars, repair of rail tank cars and spraying new 

paint on the rail tank cars. 

8
2. SIP Call

The Muscatine area is currently designated as attainment of the 2006 24-hour PM2.5 NAAQS. However, 

EPA determined that the current State Implementation Plan (SIP) was inadequate to maintain 

attainment with the 2006 24-hour PM2.5 NAAQS due to the Garfield School PM2.5 monitor recording 

data violating the standard. A final rule stating that the Iowa SIP was inadequate to maintain the 2006 

24-hour average PM2.5 NAAQS in Muscatine County was published in the Federal Register on July 14, 

2011 (76 FR 41424) and was effective on August 15, 2011. EPA’s authority for this action is found in 

section 110(k)(5) of Clean Air Act.

This finding, referred to as a ‘SIP Call,’ requires the state to revise the SIP and include measures to attain 

and maintain the NAAQS. The SIP revision must include several elements, summarized as:

1) An emissions inventory of sources expected to contribute to the violating monitor,

2) A modeling demonstration showing the reductions needed to attain and maintain the PM2.5 

NAAQS,

3) Control measures necessary to attain and maintain the PM2.5 NAAQS,

4) Enforceable commitments to adopt and implement contingency measures if the PM2.5 NAAQS 

is not attained or maintained at the violating monitor.

The SIP revision was originally due February 15, 2013, consistent with the Clean Air Act which provides 

up to eighteen months for a state to submit a SIP revision following a finding of inadequacy (CAA 

110(k)(5)). DNR used additional time beyond the 18 months to complete administrative processing and 

submittal of the SIP document.

Emissions Data

The SIP call includes the required submittal of an emissions inventory, consistent with 40 CFR 51.114(a), 

for all sources and source types of PM2.5 emissions that could be expected to contribute to PM2.5 

concentrations at the violating monitor. The average 2007 and 2008 facility-wide actual emissions from 

the facilities shown to contribute significantly to violations of the 24-hour PM2.5 NAAQS are provided in 

Table 3. The actual emissions represent direct PM2.5 emissions that were reported by the facilities to 

the DNR on the annual emissions inventory questionnaires. PM2.5 actual emissions values for many of 

GPC’s emission points were further refined using hourly emission rates derived from a combination of 

PM10 and PM2.5 stack testing data and information regarding the fraction of PM2.5 in emissions 

sampled by GPC. 

The average actual emissions were used as the baseline for calculating the PM2.5 emissions reductions 

resulting from implementation of the PM2.5 control strategy. Emissions of PM2.5 precursors that may 

contribute to violations are accounted for in background concentrations included in the air dispersion 

model.

The DNR did not identify any other potential emissions sources in the area of the violating monitor, such 

as area and mobile sources, as contributing significantly to the NAAQS violations. Background 

concentrations are added to modeled results to account for the regional transport of fine particulate 

matter and any unidentified local sources such as mobile and area sources not explicitly included in the 

model.

9
Table 3. Facility-Wide Actual PM2.5 Emissions

Facility Name Facility ID Actual PM2.5 Emissions

(tons/year)

Grain Processing Corporation 70-01-004 537.6

Muscatine Power & Water 70-01-011 58.3

Union Tank Car Company 70-01-048 3.0

Total 598.9

Modeling Demonstration

The SIP call requires the DNR to submit a modeling demonstration (consistent with Appendix W to 40 

Code of Federal Regulations (CFR) Part 51) showing what reductions will be needed to attain and 

maintain the PM2.5 NAAQS in Muscatine. The modeling methodology, model option selections and 

inputs, and model results used by the DNR to identify the reductions needed to attain and maintain the 

PM2.5 NAAQS in Muscatine are provided in Attachment A of this SIP document. 

DNR’s proposed modeling methodology and model option selections were provided to EPA in an April 

29, 2010 protocol. This protocol was approved with revisions on February 10, 2011. The protocol was 

amended in February 2013 to address updates in the meteorological data and methodology for 

accounting for PM2.5 background contributions. The modeling demonstration was completed using the 

EPA approved protocol with the February 2013 amendment. 

Control Measures

Control measures were developed based on dispersion modeling and facility operational considerations. 

These control measures provide for expeditious attainment of the 24-hour PM2.5 NAAQS through 

reductions of ambient air impacts of PM2.5 emissions from operations at GPC, MPW, and UTLX. The 

control measures at these facilities combine to constitute the PM2.5 control strategy for the Muscatine 

area.

GPC

Changes that have been made or will be made to sources at GPC to reduce PM2.5 emissions and the 

associated timelines for implementing the changes are specified in Attachment B. GPC’s control 

measures will be made federally enforceable through the Administrative Consent Order (ACO) in 

Attachment B and subsequent issuance of air construction permits. When completed, the air 

construction permits will be submitted as amendments to the PM2.5 SIP for Muscatine.

A summary of control measures being implemented by GPC include:

• New particulate controls or improvements to existing particulate controls on a number of 

sources;

• Cessation of operation of various existing equipment; 

• Replacement of several existing operations with new, more efficient equipment;

• Regular sweeping and watering of road surfaces;

• Increasing select stack heights; and

• Restricting operation of certain processes.

Full implementation of the control measures at GPC will reduce PM2.5 emissions from GPC by an 

estimated 367.9 tons per year. 

10
Other control measures include restricting public access to the levee that is located between GPC’s 

property and the Mississippi River. Beginning July 14, 2013, GPC will restrict public access to the levee 

by posting signs warning of restricted access on the north and south fence lines that intersect the levee. 

The signs will also state that loitering and fishing on the levee in the restricted access areas is prohibited. 

In-person surveillance of the levee will be conducted by GPC security staff periodically throughout the 

day with documentation as to surveillance times and locations. The levee requirements are included in 

Attachment A of GPC’s ACO (Attachment B) and will be included in a future permit to ensure on-going 

implementation and enforceability. 

Due to the scale and complexity of the changes at GPC, GPC has developed a phased implementation 

schedule that begins in 2013 and concludes in December 2016. Information supporting a phased 

implementation of control measures is provided in Attachment C. Given the extent and number of the 

modifications being made, the DNR believes that the schedule projected by GPC for implementation of 

the proposed control measures is realistic and achievable, and will allow for the 24-hour PM2.5 NAAQS 

to be attained and maintained as expeditiously as possible in the area. 

A phased implementation of the control strategy at GPC is supported by 24-hour PM2.5 design values 

depicted in Figure 1 of this document. The 24-hour design values at the Garfield School monitor have 

been declining for the last three design value periods. The most recent three year design value (2010-

2012) is 32 ug/m3. Design values at Franklin School and Greenwood Cemetery have also shown a 

decline, with the 2010-2012 design values for both locations at 28 ug/m3. These declines could be 

attributed to a number of causes. On-going implementation of the control strategy combined with the 

reduced design values should ensure that future design values stay below the 24-hour PM2.5 NAAQS, 

eliminating the oscillation of the design values above and below the level of the 24-hour PM2.5 NAAQS 

as has been seen in the past.

To further reduce emissions in the area, GPC has also voluntarily implemented a corn truck queuing and 

idling policy. This policy is designed to reduce overall corn truck wait time, and will result in lower 

emissions of PM2.5 from truck idling. GPC has significant daily corn truck traffic at the facility. As the 

corn is delivered, each truck is graded by GPC and then proceeds to the unloading stations. Prior to 

grading as well as prior to unloading, corn trucks can experience wait time at GPC’s facility. During the

wait time, the corn trucks may be running in an idle mode. Reductions in this idling time will be 

achieved through scheduling and processing practices described in GPC’s policy and the use of more 

orderly queuing procedures. These voluntary actions on the part of GPC will reduce PM2.5 emissions 

and emissions of oxides of nitrogen and sulfur dioxide, pollutants which can react in the atmosphere to 

generate additional PM2.5 emissions from the corn trucks, and alleviate some of the truck traffic 

congestion in the vicinity of the facility.

MPW

A detailed summary of the control measures for MPW is included in Attachment D. MPW’s control 

measures are made federally enforceable through the issuance of air construction permits (Attachment 

E).

Control measures being implemented by MPW include:

• Regular watering of road surfaces;

• Paving one unpaved road and water road surfaces;

• Removing lime silo and mixing tank, 3 diesel engines, and wet fly ash truck loading;

• Restricting operation of certain processes; 

11
• Reducing the capacity on the limestone hopper loading and handling systems; 

• Installing a roofed enclosure with three sides on the limestone hopper;

• Reducing the size of the coal pile, limestone pile, and synthetic gypsum pile; and

• Increasing the stack height and reconfiguring the coal reclaim handling dust collector and the 

dust collector for the coal crusher feeders.

Full implementation of the control measures at MPW will reduce PM2.5 emissions from MPW by an 

estimated 0.7 tons per year. 

UTLX

A detailed summary of the control measures for UTLX is included in Attachment F. UTLX’s control 

measures are made Federally enforceable through the issuance of air construction permits (Attachment 

G).

Control measures being implemented by UTLX include:

• Installation of new particulate controls on a number of emission points;

• Increasing select stack heights; and 

• Restricting operation of certain processes.

Full implementation of the control measures at UTLX will reduce PM2.5 emissions from UTLX by an 

estimated 0.3 tons per year. 

PM2.5 Emissions Reductions Summary 

The estimated net reductions in PM2.5 emissions from the 2007 and 2008 baseline actual emissions as a 

result of implementing the control measures at GPC, MPW, and UTLX is summarized in Table 4. The 

majority of the PM2.5 reductions will come from GPC. The need for GPC to make the largest emissions 

reductions is consistent with the level of GPC’s PM2.5 emissions and model predictions of the 

magnitude and frequency of GPC’s contributions to predicted exceedances. 

Table 4. Summary of Estimated PM2.5 Emissions Reductions from Implementation of Control Strategy

Facility Actual Emissions

(tons/year)*

Reductions

(tons/year)

Estimated Percent 

Reduction

GPC 537.6 367.9 68.4%

MPW 58.3 0.7 1.2%

UTLX 3.0 0.3 10.0%

Total 598.9 368.9 61.6%

* Based on average of 2007 and 2008 production data

Co-Benefits of Emissions Reductions at GPC

The controls and other changes that will be implemented at GPC to affect the PM2.5 emissions 

reductions will also result in emissions reductions (or co-benefits) for several other regulated air 

pollutants emitted by GPC. Reductions in emissions of these other pollutants is not a requirement of

the plan, but is viewed by the DNR as having a positive or beneficial impact on the air quality in 

Muscatine. The estimated percentage reduction of these air pollutants by 2017 are summarized in Table 

5. 

12
Table 5. Estimated Co-Beneficial Emissions Reductions in Emissions from 2011 to 2017 at GPC*

Pollutant Estimated Percentage Reduction

Sulfur Dioxide (SO2) 84

Hazardous Air Pollutants (HAPs) 82**

Volatile Organic Compounds (VOC) 48

Nitrogen Oxides (NOx) 18

Carbon Monoxide (CO) 13

*These emission estimates were provided by GPC and have not been verified by DNR.

** Reductions in acetaldehyde emissions are included in this percentage reduction. Seventy-one percent of 

the reduction is due to decreased Hydrogen Chloride (HCl) emissions from the coal-fired boilers.

Projected Attainment Date

The State was required in EPA’s SIP call (76 FR 41424) to establish a specific date by which the Muscatine 

area will attain the 2006 PM2.5 NAAQS. EPA’s expectation as stated in the SIP call was that the date for 

attainment would be the first full calendar year following the implementation of controls. Based on 

DNR’s model predictions of the impact of implementation of the PM2.5 control strategy in Muscatine, 

the design value trends in Figure 1, and on-going implementation of Federal regulations that will reduce 

PM2.5 background levels on a regional scale, the DNR believes the attainment requirements established 

by EPA in the SIP call can be achieved and maintained by December 31, 2017. This projection is 

contingent on the successful implementation of control strategies on the schedules provided by the 

facilities. 

Contingency Measures

EPA indicated in the SIP Call (76 FR 41424) that the requirement to implement contingency measures 

would be triggered if the 98th percentile value for the calendar year after completion of implementation 

of the control strategies, or in any subsequent year, exceeded the 24-hour PM2.5 standard at the 

Garfield School monitor. The DNR believes that this criteria for triggering local contingency measures 

does not adequately consider the potential role of regional (non-local) events. Statewide historical 98th

percentile PM2.5 monitoring data for the past 10 years was reviewed. The review showed that if the 

98th percentile value for one calendar year of monitoring data is used to establish attainment instead of 

the three-year design value, many communities in eastern Iowa that are not adjacent to direct sources 

of PM2.5 would have been designated as nonattainment areas for the 24-hour PM2.5 NAAQS (due to 

regional PM2.5 episodes). The criteria also fail to account for the documented year-to-year variability of 

meteorological conditions. The annual variability of meteorological conditions is currently accounted for 

in the form of the 24-hour PM2.5 standard by using a three-year average of 98th percentile values. 

Based on these considerations, DNR will use a violation of the 2015-2017 (or any subsequent) PM2.5 

design value as measured at the Garfield School monitor to determine whether contingency measures 

should be implemented. The deadline for the full implementation of contingency measures is as 

expeditiously as practical, but no later than EPA’s 24 month regulatory backstop. 

If contingency measures are triggered, then the 98th percentile for any subsequent calendar year 

following the implementation of contingency measures would be used to determine the need for 

additional contingency measures. If the 98th percentile for any subsequent calendar year following the 

implementation of contingency measures is above the level of the 24-hour PM2.5 NAAQS, then 

additional contingency measures would be implemented. The deadline for the full implementation of 

the additional contingency measures would be as expeditiously as practical, but no later than 24 

13
months after the second tier of contingency measures is triggered. Like the contingency measures 

implemented as a result of the design value trigger (first tier trigger), the additional contingency 

measures implemented as a result of the 98th percentile trigger (second tier trigger) would continue 

indefinitely and become part of the permanent control strategy for the area. 

Ambient Air Quality Monitoring

DNR will maintain the current PM2.5 ambient air monitoring network in Muscatine unless circumstances 

beyond its control (for example, loss of federal air monitoring funding, or revocation of site access by 

property owners) force it to abandon air monitoring sites. Air monitoring data from filter sampling sites 

is available one to two months after the sampling day. Air monitoring from the continuous PM2.5 

monitor in Muscatine is available in real time.

Contingency Plans

In the event that the 2015-2017 24-hour PM2.5 design value exceeds the 24-hour PM2.5 NAAQS at the 

Garfield School monitor, DNR will require the submission of an emissions control program from 

applicable sources in the area. The determination of sources that may be required to submit an 

emissions control program will be based on the circumstances that triggered the contingency measures 

process. 

Potential contingency measures which may provide some additional reductions include but are not 

limited to:

1) Evaluate and install as needed additional control equipment;

2) evaluate and implement as needed changes in stack parameters and stack configuration to improve 

dispersion of emissions;

3) evaluate and implement as needed additional equipment operating hour or throughput restrictions;

4) evaluate and implement as needed process changes that could reduce particulate formation and 

emissions;

5) review operations and maintenance procedures to determine if improvements can be made;

6) re-evaluate traffic flow patterns into/out of the facilities, and vehicle miles traveled, to determine if 

changes that will reduce idling and congestion can be made; 

7) re-evaluate material and product unloading, handling, and loading procedures and patterns, etc., to 

determine if improvements can be made;

8) re-evaluate facility best management practices associated with housekeeping, including cleaning 

internal and external areas, such as floors, roofs and decks, as necessary to minimize dust to the 

atmosphere when the facility is receiving, transferring, or loading out materials and products.

9) consider planting vegetation in specific areas to help control dust flow patterns and scavenge fugitive 

particulate emissions; and 

10) identify and implement other improvements that may become evident based on potential source(s) 

of particulate emissions identified during investigation. 

Specific actions that DNR would take to address air quality issues if the area is not meeting the standard 

are outlined below. A schedule for adoption and implementation of contingency measures from the 

trigger date (T) is included below (Table 6).

14
Table 6. Contingency Measures Adoption and Implementation Schedule

Activity Completion Date (T=trigger date)

1) Evaluate circumstances of trigger; ID sources T + 1 month

2) Identify additional control measures T + 2 months

3) Facility(s) submit emission control program T + 4 months

4) Issue order or permits T + 6 months

5) Facility(s) implement additional control measures Within T + 24 months

Activities 2 through 5 would only be accomplished if the evaluation of the circumstances of the trigger 

unequivocally indicated that PM2.5 emissions from one or more of the three affected sources in the 

control strategy primarily resulted in the tripping of the contingency measures trigger. The emissions 

control plan for any facility required to submit a plan (Activity 3) would include the necessary supporting 

technical information, emissions calculations, construction permit applications (if necessary), and air 

quality evaluation to make the additional control measures enforceable through the issuance of an 

order or construction permits. This approach requires each affected facility to create and implement an 

emissions control plan with targeted control measures appropriate to the circumstances of the situation 

that triggered the contingency measures. 

Activity 4 provides a specific time limit for completion of actions by the DNR. The completion date for 

full implementation of contingency measures (Activity 5) would be as expeditiously as practicable, but 

no later than the 24-month backstop specified in the SIP call. The maximum completion date for Activity 

5 would allow an affected facility(s) up to 18 months to complete any needed physical modifications to 

the facility specified in the permits issued under Activity 4.

As outlined below, DNR already has statutory and administrative rule provisions in place that will 

support the submission and implementation of an emissions control program in an expeditious and 

timely fashion. 

 

Permitting Mechanisms: The construction of new or modified sources which may impact the 

maintenance of attainment is regulated by 567 IAC paragraph 22.3(1)"b," which requires that the 

expected emissions from the proposed source, in conjunction with all other emissions, will not prevent 

the attainment or maintenance of the ambient air quality standards. Paragraph 567 IAC 22.3(3)"f" 

establishes additional authority for DNR to establish more stringent emissions standards and to require 

the installation of additional control equipment for portable equipment to ensure the attainment or 

maintenance of ambient air quality standards.

DNR has the authority to modify a condition of approval or an existing permit for a major stationary 

source or an emission limit contained in an existing permit for a major stationary source if necessary to 

attain or maintain the NAAQS (567 IAC 22.3(5)). 

The impact of major stationary sources on ambient air quality is also regulated under regulations at 567 

IAC chapter 33 “Special regulations and construction permit requirements for major stationary sources –

Prevention of Significant Deterioration (PSD) of air quality.”

Emissions Monitoring: The DNR may require specific source monitoring for those sources most 

significant to attainment of the PM2.5 NAAQS in the area. Emissions monitoring will be accomplished 

through periodic stack testing, as detailed in the construction permits issued to facilities, and review of 

15
this data by the DNR. These tests will ensure that the emissions limitations in the permits that were 

used to show modeled attainment of the NAAQS are not exceeded. In addition, recordkeeping and 

reporting requirements established in the construction permits will provide DNR with a mechanism to 

monitor and check the operations of the facilities and their emissions sources. 

Compliance Verification: Persons responsible for equipment are required to provide to the DNR 

information necessary to characterize emissions at the facility (567 IAC subrule 21.1(3)). Facilities in the 

Title V operating permit program, which includes GPC, MPW and UTLX, are required to identify instances 

of deviations from permit requirements in semi-annual reports to the DNR, including deviations 

attributable to upset conditions, the cause of the deviations, and any corrective actions or preventive 

measures taken (567 IAC subrule 22.108(5)). In addition, facilities are required to report and take 

corrective action in response to incidences of excess emissions (567 IAC chapter 24). Chapter 24 

establishes DNR’s authority to require the establishment of maintenance plans where a continued 

pattern of excess emissions indicates inadequate operation or maintenance of equipment.

The provisions of 567 IAC Chapter 25 allow DNR to require monitoring and reporting of emissions for 

certain equipment. Under the same provisions, DNR can conduct or require the facility to conduct 

emission tests to determine emissions.

DNR field inspectors have authority to conduct onsite inspections to review the compliance status of the 

facility (Iowa Code section 455B.103(4)). While conducting an investigation DNR personnel may, at any 

reasonable time, enter in and upon any private or public property to investigate any actual or possible 

violation, provided the owner or a person in charge is notified.

16
3. Administrative Materials

The Administrative Materials discussed below are discussed in the same order as listed in Section 2.1 of 

Appendix V of 40 CFR Part 51 (Criteria for Determining the Completeness of Plan Submissions).

Submittal Letter

A formal letter of submittal from the Governor of the State of Iowa, requesting EPA approval of the 

proposed revision to the SIP for the State of Iowa, was included with the SIP submittal. 

Evidence of State Adoption 

Subsequent to a 30-day public notice and a public hearing, the Iowa Environmental Protection 

Commission, on February 18, 2014, approved this plan for submittal to EPA as a revision of the State’s 

Implementation Plan for PM2.5 for the Muscatine area. The DNR followed all applicable procedural 

requirements of the State’s laws and constitution in obtaining the adoption of this plan.

Necessary Legal Authority

The DNR is the regulatory agency with primary responsibility for outdoor air quality permitting and 

compliance activities in the state of Iowa. The DNR’s authority is set forth in chapter 455B of the Code 

of Iowa and implemented through 567 Iowa Administrative Code (IAC) chapters 10 and 20-35, and 561 

IAC chapters 2 and 7. The DNR’s permitting and compliance programs, and rules, have previously been 

approved by EPA as part of the State of Iowa’s SIP. 

The State of Iowa has the necessary legal authority under State statute to adopt and implement this 

plan. Iowa Code section 455B.133(3) provides that the Iowa Environmental Protection Commission shall 

“adopt, amend, implement, or repeal emission limitations or standards for the atmosphere of this state 

on the basis of providing air quality necessary to protect the public health and welfare.” The federal 

National Ambient Air Quality Standard for PM2.5 is adopted by reference at 567 IAC chapter 28. Iowa 

Code section 455B.134 (9) states that it is the duties of the director to “issue orders consistent with rules 

to cause the abatement or control of air pollution, or to secure compliance with permit conditions.”

Evidence of Public Notice

Notice of the DNR’s intention to revise the PM2.5 State Implementation Plan for the Muscatine area and 

providing a 30-day public comment period and hearing was published for the first draft of the SIP 

document on May 21, 2013 in the Muscatine Journal. Proof of publication is included in Attachment H. 

The information was also on the Muscatine Journal website. A list serve notice regarding the public 

comment period and public hearing was transmitted on May 21, 2013 to over 500 list serve members. A 

press release on the public hearing was sent out via the DNR’s EcoNewsWire on May 23, 2013. 

In response to public comments received from the first public comment period, the draft SIP document 

was revised and a second notice of a 30-day public comment period and hearing was published on 

November 16, 2013 in the Muscatine Journal. Proof of publication is included in Attachment H. The 

information was also on the Muscatine Journal website. A list serve notice regarding the public 

comment period and public hearing was transmitted on November 15, 2013, to over 500 list serve 

members. 

17
For both public comment periods, an electronic copy of the SIP call document in a pdf format was 

posted on the DNR’s Public Input Webpage at www.iowacleanair.gov. A hardcopy of the SIP call 

document was made available to the public at the Musser Park Library, 304 Iowa Ave. in Muscatine 

throughout both public comment periods. 

The first public comment period was started on May 21, 2013, and extended through June 25, 2013. 

The second public comment period was started on November 16, 2013, and extended through 

December 20, 2013.

Certification of Public Hearing

In accordance with the information provided in the published in the first public hearing notice, a public 

hearing was conducted at 2 pm on June 24, 2013. The hearing was held at the Muscatine City Hall 

Council Chambers, 215 Sycamore St. in Muscatine.

In accordance with the information provided in the second published public hearing notice, a public 

hearing was conducted at 1 pm on December 18, 2013. The hearing was held at the Muscatine County 

Conservation Board’s Environmental Learning Center, 3300 Cedar Street, in Muscatine. 

Compilation of Public Comments and the State’s Responses

During the first public hearing, the DNR received three oral comments. Eight written comments were 

submitted to DNR by the close of the public comment period on June 25, 2013. Two comments were 

received from individuals while the remaining nine comments were from businesses, associations, 

organizations, and the U.S. Environmental Protection Agency. Copies of all comments received, 

including a transcription of the oral comments, and the DNR’s response to the comments, are available 

from the DNR upon request.

The DNR received two oral comments during the second public hearing. Five written comments were 

submitted to DNR by the close of the public comment period on December 20, 2013. One of the written 

comments was also presented as an oral comment during the public hearing. Two comments were 

received from individuals, three comments were received from environmental groups or organizations, 

and one comment was received from the U.S. Environmental Protection Agency. Copies of all 

comments received, including a transcription of the oral comments, are available from the DNR upon 

request. 

Since many of the issues and concerns relayed in the comments from the second public comment period 

conveyed identical or similar concepts, the DNR responded to the general topics and issues 

communicated by the commenters, rather than to individual commenters or comments. 

The general comment topics and issues and the DNR’s responses to the comments from the second 

public comment period are provided below.

1) Comment

Three comments were provided regarding future DNR oversight of implementation of the control 

strategy at the affected sources. One commenter requested that DNR be vigilant in monitoring GPC to 

18
ensure that they follow through with the permit requirements to reduce PM2.5. The same commenter 

stated that enforcement actions needed to be serious enough to force compliance if emissions in 

Muscatine are not reduced and maintained within permit levels. Another commenter emphasized that 

GPC is the largest source of PM2.5 emissions in the area and expressed their concerns that past 

monitoring of GPC had been lax. A third commenter noted that it will take diligence and oversight, such 

as regular onsite inspections on DNR’s part to achieve the goal of cleaner air sooner rather than later.

Department Response

DNR will be vigilant in monitoring compliance with all applicable requirements for all facilities included 

in the control strategy. For GPC, a provision in Section V of the Administrative Consent Order (ACO) 

included in the draft SIP revision document requires GPC to submit written reports semi-annually to the 

DNR detailing progress toward completion of the requirements of the ACO.

There are administrative rules related to compliance already in place that apply to facilities included in 

the control strategy. For example, the facilities are required to identify instances of deviations from 

permit requirements in semi-annual reports to the DNR, including deviations attributable to upset 

conditions, the cause of the deviations, and any corrective actions or preventive measures taken (567 

IAC sub rule 22.108(5)). In addition, the facilities are required to report and take corrective action in 

response to incidences of excess emissions (567 IAC chapter 24). DNR has authority to require the 

establishment of maintenance plans where a continued pattern of excess emissions indicates 

inadequate operation or maintenance of equipment.

DNR will use its existing authority in 567 IAC Chapter 25 as necessary to require monitoring and 

reporting of emissions from equipment at each facility included in the control strategy. The DNR is 

requiring performance testing for the emission points listed in Attachment C of the ACO. Performance 

testing is required to verify compliance with applicable emission limits as specified in Attachment A. To 

ensure continued compliance with limits in Attachment A; GPC is required to monitor and maintain 

operations and control equipment per the work practice standards specified Attachment D of the ACO. 

Similar performance testing and operations and maintenance requirements have also been included as 

applicable in the air construction permits already issued to MPW and UTLX. 

Onsite inspections to review the compliance status of the facility will be conducted by DNR field 

inspectors under the authority in Iowa Code section 455B.103(4). These inspections will be conducted 

at a minimum of once every two years.

2) Comment

One commenter expressed concern that the level of pollution leaving the GPC property and entering 

the levee and Mississippi River air space is so high that the public must be denied access to the area. 

The commenter stated that public access to the river near the GPC plant needs to be restored as quickly 

as possible. The commenter stated that it was not acceptable to restrict public access to public land 

beyond 2016 rather than require the pollution source to comply with the law. 

Department Response

Sources are required to demonstrate that their emissions are not exceeding the applicable ambient air 

quality standards. Ambient air is defined in 567 Iowa Administrative Code (IAC) 20.2 as “...that portion 

of the atmosphere, external to buildings, to which the general public has access.” The definition also 

19
states that “ambient air does not include the atmosphere over land owned or controlled by the source 

and to which public access is precluded by a fence or other physical barriers.” 

The levee is under the jurisdiction of the U.S. Army Corp of Engineers. GPC has arranged with the Corp 

to restrict public access to a limited portion of the levee that runs adjacent to GPC’s facility, using the 

measures specified in the draft SIP revision document. These measures, combined with the physical 

barrier provided by the river, have been found to be acceptable to preclude public access in similar 

situations in other locations, when implemented as described in the draft SIP revision document. 

Implementation of these measures effectively extends the point where ambient air begins, from the 

levee to the edge of the river. Air quality modeling predicts that the 24-hour PM2.5 NAAQS will be 

attained on the river when the control strategy is fully implemented. The levee access restriction is 

intended to limit public exposure to areas where the air quality modeling predicts higher 

concentrations. The restriction of access to the levee may be re-evaluated using updated air quality 

modeling after the control strategy is fully implemented. The restricted access has been made federally 

enforceable through the addition of provisions in Attachment A of GPC’s ACO. 

3) Comment

Two comments were received regarding DNR’s proposed date for attainment (December 31, 2017). 

One commenter stated that EPA’s SIP call was explicit about the required timeline for implementation 

of control measures and the required date for attainment/maintenance of the PM2.5 standard. EPA 

noted in their comments that DNR’s proposed attainment date was not consistent with the date 

identified in EPA’s SIP call (76 FR 41424), but recognized that the attainment date identified in EPA’s SIP 

call had passed. EPA will carefully review the information when DNR submits the SIP to EPA for action.

Department Response 

EPA’s SIP call required the State to establish a specific date in its SIP revision by which the Muscatine 

area will attain the standard. The date must be as expeditiously as practicable based upon 

implementation of federal, state, and local measures. EPA stated in the SIP call that they expected

(emphasis added) that the date for attainment would be the first full calendar year following the 

required implementation of controls. EPA specified in the SIP call that adopted measures, to achieve 

reductions as determined through the modeling demonstration, should (emphasis added) be 

implemented no later than two years after issuance of the SIP call (August 15, 2013). Had the controls 

all been implemented per the SIP call schedule, the attainment date would be December 31, 2014. The 

SIP call also stated that EPA would establish a specific date for attainment at the same time it takes final 

action (emphasis added) on the State’s implementation plan revision in response to the SIP call.

DNR believes that EPA’s SIP call language established expectations regarding the timeline for 

implementation of controls and attainment of the NAAQS but was not explicit in doing so. The SIP call 

language provides a framework that gives both DNR and EPA flexibility to develop and implement a 

workable control strategy as expeditiously as practical. DNR’s implementation timeline and attainment 

date in the proposed SIP revision is reasonable, considering the number of facilities involved in the 

control strategy and the scope of the changes being made at the facilities, and meets the intent and 

purpose of EPA’s SIP call. 

DNR’s proposed timeline and phased implementation of control measures is supported by recent trends 

in the monitored PM2.5 values in Muscatine, as provided in Figure 1 of the draft SIP revision document. 

The 24-hour design values at the Garfield School (East Campus) monitor have been declining for the last 

20
three design value periods. The most recent three year design value (2010-2012) is 32 ug/m3

, which is 3 

ug/m3 below the standard. Design values at Franklin School and Greenwood Cemetery have also shown 

a decline, with the 2010-2012 design values at both locations at 28 ug/m3

. Full implementation of the 

control strategy combined with the reduced design values should ensure that future design values stay 

below the 24-hour PM2.5 NAAQS, eliminating the oscillation of the design values above and below the 

level of the 24-hour PM2.5 NAAQS as has been seen in the past. 

4) Comment

Three commenters expressed concerns regarding the timeline to fully implement the control strategy. 

One commenter stated that the proposed timeline was unreasonably long given that the technologies 

to clean the air have been around for years. Another commenter noted that DNR has chosen to pursue 

the vast majority of PM2.5 reductions from GPC. The commenter suggested that DNR should look for 

reductions elsewhere, including potentially sources outside of the county, if GPC’s control measures are 

truly not capable of being implemented until December 31, 2016. EPA requested that DNR enhance the 

justification regarding the delay in the implementation of controls with further details and explanation 

to demonstrate that the proposed control strategy is being implemented as expeditiously as 

practicable. 

Department Response 

The three facilities included in the control strategy are using proven and accepted technologies and 

techniques to affect the necessary reductions in PM2.5 impacts. The design, engineering, 

procurement, and construction work needed to affect the changes, especially at GPC, could not all be 

accomplished in the time period provided in the SIP call. A phased implementation schedule was 

developed to address these limitations. Control measures are being implemented as soon as possible at 

each of the three facilities. 

As noted in the draft SIP document, GPC has the highest PM2.5 emissions levels. Therefore, the largest 

emissions reductions occur from control measures being implemented at GPC. These measures require 

GPC to undertake significant construction projects that will be accomplished as expeditiously as 

practical through 2016. It is important to note that GPC’s control measures are being implemented in 

phases starting in 2013 and concluding in 2016. GPC is not waiting until 2016 to implement all control 

measures. Information supporting GPC’s phased implementation of control measures was provided in 

Attachment C of the draft SIP document. Additional details that support the timeline for the phased 

implementation of GPC’s control measures have been added to Attachment C of the final SIP revision 

document to further detail timing constraints.

Consideration of other sources for PM2.5 reductions was addressed in the early phases of the modeling 

demonstration (Attachment A of the draft SIP document). All major sources (38 total) located within 50 

kilometers of the Garfield School monitor were evaluated for inclusion in the control strategy 

development. The sources located outside of a 5 kilometer radius of the Garfield School monitor were 

predicted to have impacts of less than the PM2.5 significant impact level of 1.2 ug/m3

. This result 

indicates that PM2.5 reductions from sources located outside of the county would not significantly 

mitigate the PM2.5 levels monitored at Garfield School. Emissions from these sources were considered 

to be accounted for through the inclusion of a PM2.5 background concentration in the model results. 

5) Comment

One comment was submitted stating that DNR should pursue greater reductions at MPW. Specifically, 

the commenter asked whether DNR evaluated the impact of requiring a switch to alternative fuel 

21
sources and whether a switch would result in attainment/maintenance of the PM2.5 standard sooner 

than under the current proposal. 

Department Response

Control measures were developed for the control strategy based on emission impacts on ambient air 

and facility operational considerations. Each facility was responsible for identifying the ambient air 

impact reduction measures that they could implement to address their contributions to the PM2.5 

exceedances predicted in the dispersion modeling. 

Many of the PM2.5 emissions sources at MPW, including the Unit 7, 8, and 9 boilers (EPs 70, 80, and 90, 

respectively), were already well controlled due to existing permit conditions that were in place to limit 

emissions of PM10. Dispersion modeling indicated the need to reduce the ambient air impacts of PM2.5 

emissions from other sources at the facility. This approach led to a smaller overall PM2.5 emissions 

reduction but significantly reduced PM2.5 impacts from several sources that MPW identified as 

necessary to address their contributions to the predicted exceedances. 

Modeling indicates that the maximum 24-hour PM2.5 impacts from MPW under the control strategy will 

be reduced by nearly 35% (approximately 13 ug/m3

) from baseline (pre-control) concentration levels. 

For perspective, the worse-case predicted 24-hour PM2.5 impacts from EPs 70, 80, and 90 combined is 

approximately 3 ug/m3 when firing coal. These results show that PM2.5 emissions from the coal fired 

boilers have a low impact in the local area. MPW has identified control measures that address their 

contributions to predicted exceedances within the time frames established in the SIP call. There is no 

technical or regulatory basis to require that MPW switch to an alternate fuel source.

6) Comment

DNR needs to provide more details regarding GPC’s extended timeline for compliance with the Boiler 

MACT. If switching to alternate fuel sources at GPC can be accomplished sooner than controlling coal 

firing, then the SIP revision needs to require that control measure, rather than presenting it as an option 

for GPC to evaluate.

Department Response

Under 40 CFR Part 63, subpart DDDDD (Boiler MACT), GPC has until January 31, 2016, to comply with 

the requirements of this standard. Modeling results indicate that the PM2.5 emissions reductions from 

the boilers as a result of implementation of the Boiler MACT will do little to reduce PM2.5 levels in the 

area.

Emissions from the boilers at GPC are emitted from the EP1 stack, also referred to as the GEP stack. 

PM2.5 emitted from this 219 foot high stack undergoes significant dispersion and yields low surfacelevel PM2.5 concentrations. Dispersion modeling of the PM2.5 emissions from EP1 at the pre-control 

strategy emission rates showed that EP1’s maximum 24-hour ambient concentration was 3.98 ug/m3

. 

For perspective, the pre-control strategy maximum predicted 24-hour impact of all PM2.5 emissions 

from GPC overall was 98.4 ug/m3

. EP1 is one of 192 emissions points included in the GPC control 

measures. Reducing the EP1 PM2.5 emissions by approximately 254 tons as specified in the control 

strategy results in reducing the maximum 24-hour concentration to 1.74 ug/m3

. 

22
These results show that while the PM2.5 emissions from EP1 are high, they have a low impact in 

Muscatine. Given this analysis, there is limited benefit for maintaining the 24-hour PM2.5 standard in 

Muscatine to require GPC to provide more details regarding their plans for compliance with the Boiler 

MACT or to require that GPC switch to an alternate fuel source.

7) Comment

Two commenters expressed concerns regarding the trigger period proposed by DNR for implementation 

of the contingency measures and the lack of specific contingency measures in the draft SIP revision. 

EPA noted in their comments that DNR’s proposed tiered trigger process to implement contingency 

measures is inconsistent with EPA’s SIP call and that EPA will carefully review the information when 

DNR submits the SIP to EPA for action. Another commenter said that DNR must revise the plan to 

include a one year trigger period. 

EPA requested that DNR provide specific information about the measures to be adopted, a schedule 

and procedure for adoption and implementation, and a specific time limit for action by the DNR. EPA 

describes adequate contingency measures as the implementation of emissions reductions to address air 

quality issues, not simply a commitment to study the reasons why the contingency measures were 

triggered. Another commenter noted that the SIP revision does not include an enforceable 

commitment to implement contingency measures.

Department Response

Clean Air Act section 175A(d) provides that “Each plan revision submitted... contain such contingency 

provisions as the Administrator deems necessary to assure that the State will promptly correct any 

violation of the standard which occurs...” The approach to contingency measures that was deemed 

necessary by EPA in this instance was included in EPA’s SIP call. Specifically, EPA required that the SIP 

revision contain an enforceable commitment to adopt and implement sufficient contingency measures, 

once triggered (emphasis added), in an expeditious and timely fashion that is comparable and 

analogous to the requirements for contingency measures in section 175A(d). To accomplish this, EPA 

deemed that the SIP revision should (emphasis added) clearly identify measures which could be

(emphasis added) timely adopted and implemented, a schedule and procedure for adoption and 

implementation, and a specific time limit for action by the State. Regarding the schedule for adoption 

and implementation, the SIP call specifies that it should be as expeditious as practicable, but no longer 

than 24 months after being triggered. 

No objections were submitted by EPA to the DNR regarding the technical validity of DNR’s proposed 

two tier trigger for contingency measure implementation. DNR maintains that the design value for the 

24-hour PM2.5 NAAQS should be used to account for the historical role of regional PM2.5 events on 

design values and the year-to-year variability of meteorological conditions. Use of the 98th percentile 

value for one year of monitoring data does not adequately account for these factors. The two tier 

trigger approach allows for the triggering of contingency measures on the same time schedule that 

would have been applicable with a trigger based only on the 98th percentile value for the calendar year 

after complete implementation of the control strategies. With these considerations, the two tier trigger 

approach is “comparable and analogous” to the requirements in the SIP call and in section 175A(d) of 

the Clean Air Act. 

23
The revised draft SIP revision clearly identified six measures which could be timely adopted and 

implemented in the event that the need for contingency measures was triggered. There was no 

requirement in the SIP call (or Clean Air Act) to identify specifically which options would be 

implemented on which emissions points at one or more of the three affected facilities. This step would 

occur during the development of the emissions control plan described in the “Contingency Plans” 

section of the revised draft SIP revision document. 

In an effort to provide more specificity regarding what contingency measures may be considered during 

the development of the emissions control plan, the draft SIP revision document has been updated to 

include an expanded list of contingency measures that may be considered. Potential contingency 

measures which may provide some additional reductions include but are not limited to:

1) Evaluate and install as needed additional control equipment;

2) evaluate and implement as needed changes in stack parameters and stack configuration to improve 

dispersion of emissions;

3) evaluate and implement as needed additional equipment operating hour or throughput restrictions;

4) evaluate and implement as needed process changes that could reduce particulate formation and 

emissions;

5) review operations and maintenance procedures to determine if improvements can be made;

6) re-evaluate traffic flow patterns into/out of the facilities, and vehicle miles traveled, to determine if 

changes that will reduce idling and congestion can be made; 

7) re-evaluate material and product unloading, handling, and loading procedures and patterns, etc., to 

determine if improvements can be made;

8) re-evaluate facility best management practices associated with housekeeping, including cleaning 

internal and external areas, such as floors, roofs and decks, as necessary to minimize dust to the 

atmosphere when the facility is receiving, transferring, or loading out materials and products.

9) consider planting vegetation in specific areas to help control dust flow patterns and scavenge fugitive 

particulate emissions; and 

10) identify and implement other improvements that may become evident based on potential source(s) 

of particulate emissions identified during investigation. 

Additionally, a schedule and procedure for adoption and implementation of the contingency measures 

has been added to the “Contingency Plans” section of the draft SIP revision document in an effort to 

provide specific actions that DNR would take to address air quality issues if the area is not meeting the 

standard. A schedule for adoption and implementation of contingency measures from the trigger date 

(T) is included below.

Activity Completion Date (T=trigger date)

1) Evaluate circumstances of trigger; ID sources T + 1 month

2) Identify additional control measures T + 2 months

3) Facility(s) submit emission control program T + 4 months

4) Issue order or permits T + 6 months

5) Facility(s) implement additional control measures Within T + 24 months

24
Activities 2 through 5 would only be accomplished if the evaluation of the circumstances of the trigger 

unequivocally indicated that PM2.5 emissions from one or more of the three affected sources in the 

control strategy primarily resulted in the tripping of the contingency measures trigger. The emissions 

control plan for any facility required to submit a plan (Activity 3) would include the necessary 

supporting technical information, emissions calculations, construction permit applications (if 

necessary), and air quality evaluation to make the additional control measures enforceable through the 

issuance of an order or construction permits. 

This approach requires each affected facility to create and implement an emissions control plan with 

targeted control measures appropriate to the circumstances of the situation that triggered the 

contingency measures. As referenced in “Contingency Plans” section of the draft SIP revision 

document, the statutory and administrative rule requirements pertaining to permitting mechanisms, 

emissions monitoring, and compliance verification are already in place to support the submission and 

implementation of an emissions control program in an expeditious and timely fashion. 

Activity 4 provides a specific time limit for completion of actions by the DNR. The completion date for 

full implementation of contingency measures (Activity 5) would be as expeditiously as practicable, but 

no later than EPA’s 24 month backstop specified in the SIP call. The maximum completion date for 

Activity 5 would allow an affected facility(s) up to 18 months to complete any needed physical 

modifications to the facility specified in the permits issued under Activity 4. 

DNR believes that these changes to the SIP revision document provide additional specificity regarding 

potential contingency measures, a schedule and procedure for adoption and implementation, and a 

specific time limit for action by the DNR, in the event that contingency measures are triggered.

8) Comment

The GPC ACO includes language in Sections III and VI that EPA finds unacceptable, and if the language is 

included with DNR’s SIP submission to EPA, will affect the approvability of the SIP. Section III 

"Statement of Facts" states that IDNR and GPC are entering into the administrative consent order 

"pursuant to an understanding that EPA will and does approve IDNR's SIP." Section VI "Failure to Accept 

Proposed PM2.5 SIP" states, "...if for any reason EPA does not accept and approve all the terms and 

provisions of the PM2.5 SIP call within 22 months of the execution of this administrative consent order, 

GPC or DNR may withdraw from the terms and conditions of this administrative consent order, and 

upon such written withdrawal, the terms and conditions of this administrative consent order shall be 

null and void in their entirety and for all purposes." By including this language in the ACO, the ACO does 

not contain permanent and enforceable measures as required by CAA § 110(a)(2)(A) and precludes 

public comment. Further, the ACO circumvents the EPA's SIP review process which includes a review of 

completeness, adequacy of the control strategy, enforceability, how the state intends to attain and 

maintain the standard, and provides an opportunity for public comment.

Another commenter noted that Section V of the order contains a provision which requires GPC to 

submit construction permit applications within 90 days of signing the order. However, the order states 

that applications for EP1, EP143, EP158, and EP199 must be submitted within 90 days of a final 

resolution of State of Iowa vs. Grain Processing Corporation, which is currently pending in the Iowa 

District Court for Muscatine County. Those four emission points represent the vast majority of PM 2.5 

25
reductions under the entire plan. The administrative order negates the certainty and enforceability 

which it was supposed to provide by stating that GPC shall take action on these emission points at some 

future, undetermined date. 

Department Response

The GPC ACO is intended to be an intermediate instrument to continue implementation of GPC’s portion 

of the PM2.5 control strategy in Muscatine until construction permits can be issued for all affected 

emission points at GPC. Construction permit applications have been submitted to DNR for the majority 

of the emission points included in GPC’s control strategy. Issuance of the construction permits cannot 

proceed until resolution is reached in the State of Iowa vs. Grain Processing Corporation suit. DNR 

anticipates that resolution of the suit and issuance of the construction permits will occur well within 22 

months of the execution of the ACO, removing any doubts about the ability of the state to ensure that 

GPC’s control measures and timeline for implementation are “permanent.” 

EPA has had considerable involvement and oversight to date in the development of both the overall 

control strategy and the conditions included in the GPC ACO. DNR believes that the control strategy will 

ensure on-going attainment of the 24-hour PM2.5 NAAQS in Muscatine when fully implemented and is 

fully enforceable through GPC’s ACO and the construction permits already issued to MPW and UTLX. 

EPA provided no other substantive comments on the draft SIP revision that would affect approvability of 

the SIP revision and appears to support the SIP revision otherwise. When the SIP revision is submitted 

to EPA in February 2014, EPA will have until December 2015 (22 months) to approve the SIP under the 

regulatory review and approval timelines. This time period exceeds the 18 months provided for in 

Section 110 of the Clean Air Act. Section 110 provides 6 months for a completeness finding and another 

12 months for EPA to act on the SIP submission. Implementation of the control strategy will continue 

during the 22 month time period. The MPW and UTLX control strategies will be fully implemented 

during this time period and the majority of the control measures at GPC will have been implemented in 

this time period. 

DNR believes that the practical aspects of the implementation of overall control strategy as presented 

above should alleviate concerns regarding the full completion of the control strategy implementation. 

However, given EPA’s concern over the approvability of the SIP due to language in Sections III and VI of 

the GPC ACO (regarding EPA’s approval of all terms and provisions of the PM2.5 SIP call within 22 

months of the execution of GPC’s ACO), DNR will request that this provision of the ACO not be included 

in the SIP revision request when the final SIP revision document is submitted to EPA.

Regarding application submittal dates for EP1, EP143, EP158, and EP199, it should be noted that 

applications for all of these emission points have already been submitted to DNR. The construction 

permit application for EP199 is considered complete at this time. Pending the resolution of the State of 

Iowa vs. Grain Processing Corporation suit, GPC will provide the appropriate updates to the construction 

permit applications for EP1, EP143 and EP158.

As provided for in Attachment A of GPC’s ACO, the construction/operational modification completion 

dates for EPs 1, 143, 158, and 199 are not until 2016. DNR believes that sufficient time is available to 

26
settle the suit, obtain updated construction permit applications, review and issue construction permits, 

and complete any necessary modifications at GPC prior to applicable completion dates. Regardless, the 

construction/operational modification completion dates for these emission points are part of the 

enforceable control strategy and will have to be met by GPC. 

Process for SIP Revisions

Facilities included in the control strategy may request modification of construction permits or 

administrative consent orders included in the SIP by written application to the DNR as provided for in 

567 IAC 22.7. Written application for modifications to construction permits or administrative consent 

orders shall include all necessary construction permit application forms. The forms shall be completed 

in their entirety. Modifications to construction permits may result in the requirement for the affected 

facility to complete a modeled attainment demonstration using approved dispersion modeling 

techniques, if requested by DNR. All construction permit modifications shall be placed on a 30-day 

public notice prior to approval of the modification. Once issued, the modified permits or administrative 

consent orders will be submitted to EPA for incorporation into the SIP and are subject to federal 

approval. 

27
Attachment A. Modeling Demonstration

28
Dispersion Modeling Demonstration for the 

Muscatine PM2.5 SIP

Project Purpose and Scope

On July 14, 2011 EPA Region 7 found that the Iowa State Implementation Plan (SIP) was substantially 

inadequate to maintain the 2006 24-hour National Air Quality Standard (NAAQS) for fine particulate 

matter (PM2.5) in Muscatine County, Iowa. As part of this finding, the Iowa Department of Natural 

Resources (DNR) is required to submit a modeling demonstration consistent with Appendix W to 40 CFR 

Part 51 showing what reductions will be needed to attain and maintain the PM2.5 NAAQS in Muscatine. 

This section outlines the modeling methodology used by the DNR to identify the reductions needed to 

attain and maintain the PM2.5 NAAQS in Muscatine. 

Model Selection and Options 

Air Quality Model Selection: The dispersion model used for this analysis was the American 

Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD). The most 

current version of AERMOD available at the time was used for each step in the development of the SIP 

modeling demonstration. All analyses were conducted with EPA’s regulatory default options. The final 

cumulative PM2.5 emissions control strategy modeling was conducted using AERMOD version 12345.

Extent of Receptor Grid: The 2008 Technical Support Document developed by the DNR to evaluate 

proposed PM2.5 non-attainment boundaries in Muscatine County strongly suggested that the Grain 

Processing Corporation (GPC) had a controlling role in causing or contributing to the monitored 

exceedances in Muscatine, therefore emissions from GPC were used to determine the extent of the 

receptor grid for the PM2.5 SIP modeling. This initial modeling used GPC’s 2006-2008 PM2.5 actual 

emissions, 2006-2008 meteorological data, and a receptor grid with 1-kilometer receptor spacing that 

extended 50 kilometer from the GPC facility. Based on this initial analysis, it was determined that the 

grid should extend approximately five kilometers from the GPC property boundary. The final grid used 

in the remaining modeling for the PM2.5 emissions reduction strategy was extended to include the full 

property boundaries of all facilities with PM2.5 emissions included in the modeling for the emissions 

reduction strategy.

Receptor Grid Spacing: The receptor grid spacing used in the emissions reduction strategy analysis was 

consistent with Iowa’s guidelines for both PSD and non-PSD modeling, with 50-meter spacing along all 

facility property boundaries. The one exception to this was the HNI HON Downtown facility where no 

facility boundary was evaluated. This facility is located in downtown Muscatine, consists of several 

buildings and it was unclear at the time where the property boundary was located. All area outside of 

the buildings was considered as ambient air. The 50-meter grid spacing extends from the GPC property 

29
boundary 0.5 kilometers, 100-meter spacing out to 1.5 kilometers, 250-meter spacing out to 3 

kilometers and 500-meter spacing beyond 3 kilometers. 

Terrain Elevations: The most recent version of AERMAP was used to import terrain and source 

elevations from the National Elevation Dataset (NED) in North American datum 1927. Facilities located 

along the Mississippi River have a levee that is approximately 9 meters higher than the normal river 

level. Elevations of receptors located along this levee are reflected in the elevations derived from the 

NED. 

Downwash: All building downwash analyses were conducted using the most recent version of EPA’s 

Building Profile Input Program with Plume Rise Enhancements (BPIP-Prime). 

Meteorological Data: For all stages of development of the PM2.5 emissions reduction strategy 

modeling, the most recent and representative meteorological data were used. At the time that the 

initial modeling was conducted to determine the extent of the grid, develop the emissions inventory, 

and for the baseline modeling analyses, the Cedar Rapids meteorological station had been determined 

to be representative for the modeling domain. A detailed representivity analysis to support the use of 

the Cedar Rapids meteorological data is included in Appendix A of this modeling demonstration . These 

analyses were conducted using the surface station data from Cedar Rapids and upper air data from 

Davenport and used consecutive years from the most recent, readily available 5-year period (2004 –

2008), per section 8.3.1.2 of 40 CFR Part 51 Appendix W. 

Meteorological data for the entire state was revised in November 2011 and again in January 2013. The 

revised November 2011 meteorological data used the most recent, readily available five-year period 

(2005 – 2009), included new sites, incorporated the recent upgrades to AERMET, and included one 

minute wind data. Use of new sites and additional refinement of the representativeness of the data 

resulted in a change from the Cedar Rapids to the Davenport meteorological data set for the PM2.5 

emissions reduction strategy modeling. The representivity analysis to support the switch to the 

Davenport data is included as an addendum to Appendix A of this modeling demonstration. This 

meteorological data was re-processed in January 2013 due to a new version of AERMET released by EPA 

on December 17, 2012. The final cumulative PM2.5 emissions reduction strategy modeling was 

conducted using the 2005 – 2009 Davenport meteorological data processed with AERMET version 

12345.

Modeling Methodology

Phased Analysis: Although the EPA finding that required this analysis occurred in June of 2011, the 

initial modeling to develop an emissions reduction strategy for Muscatine began in September 2009. 

Preliminary baseline modeling was conducted between 2009 and 2011 to determine the size of the 

receptor grid, which facility emissions to include in the analyses, and then determining which of those 

facilities would be part of the emissions control strategy. This baseline modeling was further revised in 

2011. 

30
Following the preliminary analyses, a three phased analysis to develop the final emissions control

strategy was conducted between 2011 and 2013. Phase I required individual facilities included in the 

emissions reduction strategy to submit a model demonstrating that potential PM2.5 emissions from 

their facility would not cause highest, first-high predicted concentrations over 35 μg/m3. For Phase II 

the DNR combined these individual facility-wide modeling analyses into a cumulative model along with 

the emission rates from the other facilities in the Muscatine SIP analysis. The other facilities included in 

the SIP analysis were evaluated at emissions that reflect their highest PM2.5 emission rates when 

operating at maximum capacity. Phase III mitigated the predicted exceedances and determined the 

reductions necessary to attain and maintain the 24-hour PM2.5 NAAQS in Muscatine.

Inventory Development: A modeling analysis was conducted for all major facilities located within 50 

kilometers of the Muscatine ambient air monitor at Garfield School (also referred to as Muscatine High 

School East Campus) to develop the inventory of sources to include in the Muscatine PM2.5 SIP 

modeling. Any major source with a significant impact (1.2 μg/m3 for the 24-hour averaging period) 

within the five kilometer receptor grid was included in the PM2.5 SIP modeling. 

These facilities were evaluated at their actual PM2.5 emission rates based on the average of their 2007 

and 2008 emissions data as reported by the facilities in their annual Title V Emissions Inventory 

Questionnaires. Fugitive emissions from the facilities located within the five kilometer receptor grid 

were also included in the evaluation. The major facilities that were evaluated for inclusion in the SIP 

modeling are listed Table 1 along with their locations as listed in their Title V operating permits. 

Differing methods of evaluation were used for the facilities located within and outside of Muscatine. 

Major facilities located within Muscatine were modeled using their actual stack parameters and actual 

site layouts. Although the site locations for MidAmerican Louisa Generating Station, SSAB/Multiserve 

and Central Iowa Power Coop are listed in their Title V permits as being located in Muscatine, in 

actuality they are located outside the city of Muscatine: MidAmerican Louisa Generating Station is 

located approximately 9.5 kilometers to the south of the Garfield School monitor. SSAB/Multiserve and 

Central Iowa Power Coop are located over 20 kilometers to the northeast of the monitor. Major 

facilities located outside the city of Muscatine were evaluated with emissions exhausting from the one 

stack determined to have the highest PM 2.5 emission rate. This represents an acceptable 

approximation for more distant sources, and allowed for more reasonable model run times. 

All major facilities located outside the city of Muscatine had highest, first-high predicted impacts below 

the significant impact level of 1.2 μg/m3

. The highest predicted impact from any one of these major 

facilities was 0.47 μg/m3 from Central Iowa Power Coop. Therefore the major facilities located outside 

of Muscatine were not included in the PM2.5 SIP modeling. Emissions from the major facilities located 

outside of Muscatine are considered to be accounted for in the inclusion of a background concentration 

to the model results.

31
Table 1. Major Facilities within 50 Kilometers of the Garfield School Monitor

Facility Site City

Gerdau Ameristeel US Inc. Wilton

Xerxes Corporation Tipton

United States Gypsum Mediapolis

IAC Iowa City, LLC Iowa City

University of Iowa - campus Iowa City

University of Iowa - power plant Iowa City

Enterprise NGL Pipeline Iowa City

Loporex, Inc. Iowa City

Iowa City Sanitary Landfill Iowa City

MidAmerican Energy Corporation -Coralville turbines Coralville

Magellan Pipeline Company, LP Coralville

Natural Gas Pipeline Co. of America - Columbus Junction Columbus Junction

Natural Gas Pipeline Co. of America - Letts Letts

ALCOA, Inc. Riverdale

Blackhawk Foundry & Machine Company Davenport

Linwood Mining & Minerals Corporation Davenport

Nichols Aluminum Davenport

Nichols Casting Davenport

John Deere Davenport Works Davenport

Scott County Landfill Davenport

Sivyer Steel Bettendorf

MidAmerican Company – Riverside Station Bettendorf

Arch Mirror North Bettendorf

Veolia Water NA Bettendorf

Lafarge North America, Inc. Buffalo

ACO YP, Inc Riverdale

ACH Foam Technologies, LLC Washington

MidAmerican Energy Company - Louisa Generating Station Muscatine

Grain Processing Corporation Muscatine

SSAB/Multiserve Muscatine

Central Iowa Power Coop – Fair Station Muscatine

H J Heinz Company, LP Muscatine

HNI Allsteel Muscatine Components Muscatine

HNI HON Downtown Muscatine

McKee Button Company Muscatine

Monsanto Company Muscatine

Muscatine Power & Water Muscatine

Union Tank Car Company Muscatine

 

All major facilities located within the city of Muscatine had highest, first-high predicted impacts greater 

than the PM2.5 significant impact level of 1.2 μg/m3 and therefore were included in the PM2.5 SIP 

modeling analysis. These eight facilities and their highest predicted impacts within the five kilometer 

grid is listed in Table 2. The relative locations of the major facilities in Muscatine to the Garfield School 

monitor are shown in Figure 1. 

32
Table 2. Facilities Predicted to have at least a Significant Impact (SIL = 1.2 μg/m3

)

Facility H1H impact within the grid

Grain Processing Corporation (GPC) 98.4

H J Heinz Company , LP 1.7

HNI Allsteel 2.5

HNI HON Downtown 21.6

McKee Button Company 4.0

Monsanto Company 39.6

Muscatine Power & Water (MPW) 38.5

Union Tank Car Company 93.4

33
Figure 1. Location of Major Facilities in Muscatine

34
Preliminary Baseline Modeling: The eight facilities determined to be part of the PM2.5 SIP analysis 

were evaluated to determine which of these facilities should be part of the PM2.5 emissions control

strategy. Individual modeling analyses were conducted for each of the eight facilities identified to be 

included in the PM2.5 SIP modeling using their actual emission rates. The results from these individual 

analyses were combined in a Microsoft Access database to determine the percentage of predicted 

NAAQS exceedances to which each facility significantly contributed. The preliminary baseline modeling 

results indicated that four facilities (GPC, MPW, Union Tank Car, and Monsanto) each had a significant 

contribution to at least one percent of the predicted 24-hour NAAQS exceedances.

Revised Baseline Modeling: The four facilities identified as having a significant contribution to at least 

one percent of the predicted PM2.5 NAAQS exceedances in the preliminary baseline analysis were 

contacted to inform them of the initial baseline modeling results. The DNR modeling files and emissions 

data was provided to allow the facilities to review the DNR data including the DNR determined potential 

and actual PM2.5 emission rates for their facilities. Revised information was provided by these four 

facilities. In addition, updated information was provided for the two HNI facilities (Allsteel and HON 

Downtown). 

The baseline modeling analyses was re-accomplished with the revised data and the percentage of 

predicted NAAQS exceedances to which each facility significantly contributed was determined. A chart 

depicting the percent of NAAQS exceedances that each facility had a significant contribution to was 

developed. The revised baseline analysis indicated that GPC, MPW and Union Tank Car each had a 

significant contribution to at least one percent of the predicted 24-hour NAAQS exceedances. 

Monsanto had a significant contribution to less than 0.005 percent of the predicted 24-hour NAAQS 

exceedances, and was no longer considered to be part of the PM2.5 emission control strategy. The 

chart of the percentage of predicted 24-hour PM2.5 NAAQS exceedances to which each facility 

significantly contributed is shown in Figure 2.

Cumulative Modeling: A three phased approach was used to develop the PM2.5 emission control

strategy. For Phase I, the facilities determined to be part of the emission control strategy (GPC, MPW, 

and Union Tank Car) were required to submit a modeling scenario for their individual facility with 

predicted highest, first-high impacts below the 24-hour NAAQS of 35 μg/m3

using potential emission 

rates and excluding background concentrations. Since these facilities were determined to be a part of 

the emissions control strategy, the potential emission rates used in the cumulative modeling analysis for 

the SIP submittal will become the facility’s permitted emission rates. 

35
Figure 2. Revised Baseline Modeling Results

In Phase II, the DNR combined the data from the individual facilities into one cumulative modeling 

analysis. The submitted individual modeling scenarios for these three facilities were combined with 

emissions from the remaining five facilities that are part of the SIP. Since these five facilities are not 

considered to be part of the emissions reduction strategy, their modeled emission rates were based on 

the highest predicted PM2.5 emission rates when the source is operating at maximum capacity. These 

emission rates will not become their permitted emission rates, with the exception of Monsanto. The 

Monsanto facility requested that their modeled PM2.5 emission rates become enforceable. These 

PM2.5 emission rates were made enforceable through modified air construction permits issued October 

24, 2012. This cumulative analysis evaluated the highest, eighth-high concentrations including 

background concentrations (see background discussion in the section below). The Phase II modeling 

analysis continued to result in numerous predicted exceedances of the NAAQS.

Phase III of the analysis evaluated facility-wide contributions to the predicted exceedances, including 

background concentrations, to develop the final emissions control strategy. Results from the Phase II 

modeling analysis were provided to GPC, MPW and Union Tank Car along with the specific receptor 

locations with predicted exceedance of the NAAQS where only their individual facility had a significant 

contribution. These facilities were then required to submit modeling analyses that either demonstrated 

that there were no longer any predicted exceedances of the NAAQS at these receptor locations, or that 

their facility no longer had a significant contribution to any of these NAAQS exceedances. The final 

cumulative analysis resulted in predicted exceedances of the 24-hour PM2.5 NAAQS, however the three 

36
facilities determined to be part of the mitigation strategy do not cause any predicted exceedances and 

do not have a significant contribution to any predicted exceedance. 

Background Value Selection: Background values are intended to account for emissions from natural 

sources, nearby minor sources not included in the analysis, unidentified sources, and in the case of 

PM2.5, secondary formation from other sources. Based on discussions with monitoring staff and EPA 

Region VII, the Iowa City monitoring site was initially determined to be representative of background 

concentrations for Muscatine. The Iowa City 24-hour 98th percentile monitored PM2.5 concentration for 

2006-2008 was 29.0 μg/m3

. 

Current EPA PM2.5 modeling guidance (March 2010 Stephen Page memorandum) indicates that 

combining the highest average of the maximum modeled 24-hour averages across five years of 

meteorological data with the monitored 24-hour design value may be overly conservative. This 

guidance also states that in some cases “...a Second Tier modeling analysis may be considered that 

would involve combining the monitored and modeled PM2.5 concentrations on a seasonal or quarterly 

basis, and re-sorting the total impacts across the year to determine the cumulative design value.” At 

this time no additional guidance has been provided by EPA on the details of this approach or the 

circumstances where this approach may be appropriate.

On January 7, 2011, the National Association of Clean Air Agencies (NACAA) PM2.5 Modeling 

Implementation Workgroup provided EPA with recommendations regarding PM2.5 background 

concentrations for ambient air quality demonstrations required for New Source Review. In this 

document NACAA recommends that EPA include the option of a “Paired-Sums” approach where 

continuous data from a single monitor site could be combined with modeled concentrations prior to 

determining the design value.

Because a more refined approach was required for this situation, the DNR used a “Paired-Sums” 

approach for the cumulative modeling analyses. A data set of hourly background values was developed 

for the 2005 - 2009 period. The data was based on monitored concentrations from Iowa City with 

missing data filled (by order of preference) from Davenport, Des Moines, or the highest value observed 

at the Iowa City monitor (by month of year).

The AERMOD dispersion model version 11059 was enhanced in February 2011 to allow users to specify 

background concentrations to be added to the impacts from modeled emissions sources to determine 

cumulative impacts. Specifying background concentrations is discussed in section 2.5 of EPA’s 

addendum to the AERMOD user’s guide (version 12345). This section warns that since modeled 

concentrations are not calculated for hours with calm or missing meteorological data, background 

concentrations are also omitted for those hours, possibly resulting in lower than expected background 

concentration. A scaling factor was developed by the DNR to alleviate the potential of underestimating 

the background contribution due to any calm hours in the meteorological data. 

37
Modeled Emission Rates and Stack Parameters

The 24-hour PM2.5 emission rates and source release parameters for the emission sources at GPC, 

MPW and Union Tank Car are summarized in the attached spreadsheets:

• PM25 SIP Modeling Parameters – GPC.xlsx

• PM25 SIP Modeling Parameters – MPW.xlsx

• PM25 SIP Modeling Parameters – UTC.xlsx

All point sources with a horizontal, downward or obstructed discharge were modeled with an exit 

velocity set equal to 0.001 m/s per the DNR modeling guidelines. This allows for buoyancy-induced 

plume rise while restricting momentum-induced plume rise that is prevented by a non-vertical stack.

Dispersion Modeling Results

The final cumulative Muscatine PM2.5 SIP modeling analysis resulted in predicted exceedances of the 

24-hour PM2.5 NAAQS, however the three facilities determined to be part of the mitigation strategy, 

GPC, MPW and Union Tank Car do not cause any predicted exceedances and do not have a significant 

contribution to any predicted exceedance. 

The model results of the highest, eighth-high modeled impacts (including the “paired-sums” background 

concentrations) indicate that predicted concentrations remain above the 24-hour PM2.5 NAAQS at 

fifteen receptor locations in the vicinity of the HJ Heinz and HNI HON Oak Steel facilities. The highest 

contribution to these exceedances by any facility in the mitigation strategy is 0.8 μg/m3

. Predicted 

exceedances in the vicinity of these two facilities will be resolved through DNR construction permit 

program and will not be addressed as part of the SIP evaluation. 

At the remaining 3,986 receptors in the grid, the highest, eighth-high predicted impact (including the 

“paired-sums” background concentrations) was 35.30 μg/m3

. Per conversation with EPA Region VII, 

modeled concentrations below 35.49 μg/m3 are sufficient for demonstrating compliance with the 24-

hour PM2.5 NAAQS. This modeling analysis was conducted consistent with Appendix W to 40 CFR Part 

51 and demonstrates what reductions will be needed to attain and maintain the PM2.5 NAAQS in 

Muscatine.

Table 3 summarizes the change in worse-case 24-hour PM2.5 concentrations between the most recent 

(revised) baseline modeling analysis and the post-control modeling analysis for the three sources 

included in the control strategy. The PM2.5 concentrations are the modeled maximums.

Table 3. Comparison of Predicted 24-hour Baseline and Post-Control PM2.5 Concentrations

Facility Baseline 24-hour Concentration 

(ug/m3)

Post-Control 24-hour 

Concentration (ug/m3)

GPC 98.2 20.4

MPW 38.5 25.3

UTLX 113.6 9.3

38
Appendix A

Introduction

This is an analysis of the representativeness of the Cedar Rapids meteorological data for use in the 

ongoing PM2.5 modeling in the Muscatine area. During a conference call on July 13, 2010 EPA Region 

VII indicated that this analysis should address the differences in surface characteristics between the 

Cedar Rapids measurement site and the application site in Muscatine. EPA and DNR agreed that the 

analysis should focus on the area near the Grain Processors Corp (GPC) facility, and that the analysis 

would be applicable for the entire modeling domain. Due to the expansive nature of the GPC facility, 

the DNR proposed to center the analysis on the GEP stack (EP001). EPA approved this approach, and 

EPA and DNR also agreed that the analysis should consider the variation of surface characteristics from 

different wind direction sectors due to the proximity of the Mississippi River immediately to the East of 

the facility.

The comments provided by EPA on the proposed modeling protocol indicated that this analysis should 

follow the requirements of 40 CFR, Part 51, Appendix W, Section 8.3 [1]. This section states that the 

representativeness of meteorological data is dependent on four factors:

• Instrument Exposure – The exposure of the meteorological monitoring site.

• Temporal Proximity – The period of time during which data are collected.

• Spatial Proximity – The proximity of the meteorological monitoring site to the area under 

consideration.

• Geographic Features and Land Cover – The complexity of the terrain.

Each of these criteria is covered in detail in the Department’s “Meteorological Data Representivity 

Analysis” document [2]. The information in that document that directly applies to this analysis, as well 

as the requested comparison of surface characteristics at the measurement and application sites is 

presented herein.

Instrument Exposure

Instrument exposure refers to the ability of the instruments to measure meteorological conditions 

without the influence of manmade or natural obstructions. If obstructions are present, they can 

influence the measurements of the meteorological monitoring site. For example, a tree located near an 

instrument tower could alter the speed and direction of the wind at the instrument. These effects, or 

any others like them, are not desirable, and any instrument affected by such local-scale influences 

should not be used to develop meteorological data for use in a dispersion model.

The Cedar Rapids meteorological site is an Automated Surface Observing Station (ASOS), and is located 

at the Cedar Rapids airport. Airport-based ASOS stations are purposely sited with good exposure so that 

they may provide accurate weather information for the aviation community. It is stated that “the NWS 

will follow the guidelines documented in the Federal Standard for Siting Meteorological Sensors at 

Airports” when siting ASOS stations [3]. These standards include siting and exposure requirements that 

limit the effects of any obstructions within 1000 feet of the anemometer [4]. Because of this it was 

determined that instrument exposure would not affect the representativeness of the Cedar Rapids data.

39
Temporal Proximity

“Consecutive years from the most recent, readily available 5-year period are preferred” for use with 

regulatory air dispersion modeling analyses [1]. At the time this analysis began, 2008 was the most 

recent year available. Therefore the years 2004 – 2008 were used in the processing of the AERMOD 

meteorological data set.

Spatial Proximity

The nearest existing meteorological site is at the Muscatine airport. This site is only 5 miles to the West, 

and within the river valley in which the entire modeling domain is located. However, the Muscatine 

data contains over 20% calms. Model concentrations tend to increase during periods of low wind 

speeds. Unfortunately, calms are generally reported during these same periods. Since AERMOD 

interprets calms as missing data, excessive amounts of calms during low wind speed periods would 

result in an overall reduction in predictions during the period with the highest likely concentration. This 

sort of under-prediction bias is not desirable, and thus the Muscatine data was eliminated as a 

possibility for this analysis.

The three nearest meteorological stations for which the Department has processed data for use in 

AERMOD are Moline, IL (29 miles); Burlington, IA (43 miles); and Cedar Rapids, IA (48 miles). For reasons 

described in the following section, Cedar Rapids was chosen as the most representative of these nearby 

stations.

Geographic Features and Land Cover

Geographic features can affect meteorological patterns in an area due to uneven heating and cooling of 

land and water, and physical redirection of atmospheric flow. It is difficult to quantify these effects 

analytically, but they can be observed to some extent by reviewing historical measurements. As 

described in the Department’s “Meteorological Data Representivity Analysis” document, wind roses can 

be used to view the wind patterns caused by terrain influences. It can be assumed that two locations 

with similar wind roses either have similar terrain effects, or that the terrain does not significantly alter 

the mesoscale atmospheric flow.

As stated in the previous section, the Muscatine airport is located within the river valley included in the 

modeling domain, but is unusable for the modeling analysis because of the large number of missing 

data. Even so, because of the proximity of the Muscatine airport to the modeling domain, the data that 

is available can be used as a comparison to other sites with more complete records. The wind rose for 

the Muscatine airport and the three next nearest sites for which the Department has AERMOD-ready 

meteorological data are shown in Figures A1 – A4 [2].

The nearest site, Moline, is the least similar to the wind rose observed at Muscatine. That location was 

eliminated as a possibility, leaving two sites. Both Burlington and Cedar Rapids have wind roses that are 

very similar to the wind rose from Muscatine. However, the dominant wind directions appear rotated 

approximately 40 degrees clockwise at Burlington, as does the direction of the most common lower 

wind speed (which is an important consideration for design concentrations). On the other hand the 

dominant wind directions at Cedar Rapids match those observed at the Muscatine airport very well.

40
In EPA’s comments to the original modeling protocol for this analysis, concern was expressed that using 

wind roses alone as a surrogate for terrain and land cover influences may not be sufficient in this 

application. Specific concern was expressed regarding the ability of the Cedar Rapids data to accurately 

represent the planetary boundary layer in the modeling domain due to differences in surface roughness 

between airports and industrial sites.

Based on the AERMOD Implementation Guide, a comparison of the surface characteristics between the 

National Weather Service (NWS) measurements site and the facility location, coupled with a

determination of the importance of those differences relative to predicted concentrations, is 

appropriate in this case [5].

An AERSURFACE analysis was conducted for both the Cedar Rapids meteorological site and the area 

around the GPC facility. The analysis at GPC was centered on the GEP stack at the facility as agreed 

upon by EPA Region VII. Of main concern with regard to the representivity of the surface characteristics 

is the notable contrast between the low roughness of the Mississippi River to the East of the modeling 

domain and the high roughness of the industrial area to the West (where surface roughness varies from 

near zero over the river to nearly one meter over the land). Whereas the surface roughness around the 

meteorological measurement site is much more homogenous, with nearly the entire area being either 

cropland or grassland with only a scattering of other land use types. The most notable variation in 

surface roughness around the meteorological measurement site is the change from croplands in the 

south to grassy areas around the runways to the north (where surface roughness varies from around 0.1 

meters over the grassy areas to 0.2 meters over the cropland in the summer and early fall, and is nearly 

identical during the remainder of the year). For this reason, it was decided to focus on the application 

site when selecting the sectors to be analyzed. Therefore, results were calculated for two separate 

sectors. Sector 1 covers wind directions from 0 to 140 degrees and encompasses wind directions that 

cross the river at the application site. Sector 2 covers the remainder of the compass directions (140 –

360 degrees) and represents wind directions that cross the land at the application site. See Figure A5 

for a depiction of the National Land Cover Data (NLCD) and the two sectors used in the analysis. 

41
Figure A1. Muscatine Wind Rose Figure A2. Burlington Wind Rose

Figure A3. Cedar Rapids Wind Rose Figure A4. Moline Wind Rose

42
The net differences between the measurement and application sites are presented in Table A1. Positive 

numbers indicate a higher value at the measurement site, while negative numbers indicate a lower 

value.

Table A1. Surface Characteristic Differences Calculated by AERSURFACE

Sector Albedo Bowen Ratio Surface Roughness

(m)

1 – Over River (0° – 120°) + 0.03 + 0.06 + 0.05

2 – Over Land (120° – 360°) + 0.03 + 0.06 – 0.41

Average + 0.03 + 0.06 – 0.18

Possible Range 0.1 – 0.6 0.1 – 6.0 0.0001 – 1.3

The albedo at both sites is very comparable. The albedo at the measurement site is slightly higher than 

at the application site. The net difference (+ 0.03) is equivalent to only 6% of the possible range of 

albedo values in AERSURFACE (0.1 – 0.6). This very small difference is not expected to have any 

significant effect on predicted concentrations.

The Bowen Ratio at both sites is also very comparable. The Bowen Ratio at the measurement site is 

slightly higher than at the application site. The net difference (+ 0.06) is equivalent to only 1% of the 

possible range of Bowen Ratio values in AERSURFACE (0.1 – 6.0). This very small difference is not 

expected to have any significant effect on predicted concentrations.

As expected, the difference in surface roughness between the two sites is more significant than the 

other two surface characteristics. For the over-river sector, the surface roughness is only slightly higher 

at the measurement site than at the application site. However, for the over-land sector, the surface 

roughness is much lower at the measurement site than at the application site. The net differences for 

sectors 1 and 2 (+ 0.05 and – 0.41) are equivalent to 4% and 32% of the possible range of surface 

roughness values in AERSURFACE (0.0001 – 1.3).

A known issue with the use of the 1992 NLCD in AERSURFACE is the fact that transportation areas (low 

roughness) are included in the same category as residential and industrial areas (high roughness). The 

AERSURFACE user guide estimates that roads and runways would have a roughness value of 0.05 meters 

(based on the bare rock/sand/clay category), and residential and industrial areas have a roughness value 

of between 0.54 meters and 1.0 meter. AERSURFACE also assumes that the roughness value for 

industrial areas not at an airport already contain 20% transportation (estimated using the bare 

rock/sand/clay category). Low intensity residential assumes no transportation, but does include 10% 

grassy areas (also a lower roughness value). High intensity residential includes neither transportation 

nor grassy areas [6].

Further investigation of the application site indicates that the amount of Industrial and Residential land 

use in the area is greatly over-estimated in the 1992 NLCD. For this reason a separate analysis was 

performed outside of AERSURFACE to determine the extent of the over-estimation.

43
An aerial photograph from 2009 (Figure A6) was examined and several types of general land use were 

manually applied based on the image (Figure A7). As can be seen when comparing Figures A5 and A7, 

there is a large portion indicated as Industrial or Residential (shades of red and pink in Figure A5) in the 

1992 NLCD where the true land cover is either roadways, parking lots or barren ground (yellow in Figure 

A7), or grassy areas (light green in Figure A7). The result is an overestimation of the surface roughness 

values when using AERSURFACE. 

To determine the effect that this discrepancy has on the roughness values the percentage of mislabeled 

Residential and Industrial land cover in sector 2 was determined. This was accomplished by overlaying 

that portion of the manual land use analysis indicated as roadway, barren or grassland on areas in the 

1992 land use image that were indicated as being either Industrial or Residential (see Figure A8). Only 

areas that were originally labeled as either Industrial or Residential in the 1992 NLCD are shown. Areas 

that were neither Residential nor Industrial, or that were not in Sector 2, are shown in white. The areas 

that are still depicted in shades of red and pink were correctly labeled as Residential or Industrial. The 

areas depicted in yellow are areas that should have been labeled as roadways or as barren land. The 

areas depicted in light green are areas that should have been labeled as grassland.

44
Figure A5. 1992 National Land Cover Data with Analysis Sectors.

45
Figure A6. 2009 Aerial Photograph with Analysis Sectors

46
Figure A7. Manual Land Use Analysis Using 2009 Aerial Photograph

47
Figure A8. Evaluation of Mislabeled Residential and Industrial Areas in 1992 NLCD

This analysis indicates that approximately 58% of the flat open areas (roads, barren or grassland) in 

sector 2 were mislabeled as Industrial or Residential in the 1992 NLCD, greatly increasing the surface 

roughness calculated by AERSURFACE. A direct adjustment to the surface roughness calculated by 

AERSURFACE is not possible because it is based on a distance-weighted average. However, it is certain 

that the true roughness in this area is much lower than that calculated by AERSURFACE. In addition, this 

analysis was centered on the most concentrated area of Industry in the modeling domain. The surface 

roughness determined at this location is likely to be higher than at any other location in the modeling 

domain. Per the CFR, the surface characteristics at the measurement site should be compared to those 

that “generally describe the analysis domain” [1]. These things considered, the surface roughness in the 

48
over land sector is likely to be slightly higher, but generally similar to the general surface roughness of 

the measurement site.

As depicted in Figure A9, model concentrations tend to increase as surface roughness increases for 

elevated sources (due to an increased rate of mixing of emissions down to the surface), and to decrease 

as surface roughness increases for ground-based sources (due to increased dispersion in the lower 

portion of the boundary layer) [7]. Based on this, and the generally higher surface roughness seen in the 

over land sector, the application of Cedar Rapids meteorological data in the Muscatine modeling domain 

is expected to cause increased concentrations from elevated sources and decreased concentrations 

from ground-based sources in the Eastern portion of the modeling domain. The magnitude of these 

effects cannot be known, but it appears that the discrepancies between surface roughness at the 

measurement and application sites will be relatively small. As such, the effects on predicted 

concentrations are also expected to be relatively small.

Figure A9. Depiction of Model Sensitivity to Surface Roughness

49
Conclusion

The Cedar Rapids meteorological station easily meets the exposure, temporal proximity and spatial 

proximity criteria outlined in the CFR when applied in the Muscatine modeling domain. There is also 

good agreement between the sites for terrain influences, and the albedo and Bowen Ratio surface 

characteristics. The main concern between these sites is the surface roughness. As described herein, 

the differences in surface roughness between the two sites are relatively minor once the discrepancies 

in land cover data are considered. These minor differences are expected to increase predicted 

concentrations caused by some sources and decrease the concentrations caused by others. Given the 

good agreement of the majority of representivity criteria, and the counter-balancing effects of the minor 

surface roughness discrepancies, the Cedar Rapids meteorological data is considered representative of 

the Muscatine modeling domain. 

References

1. Code of Federal Regulations, Title 40 (Protection of the Environment) Appendix W to Part 51 –

Guideline on Air Quality Models, Section 8.3.

2. Iowa DNR – Air Quality Bureau, 2006. Meteorological Data Representivity Analysis, 

http://www.iowadnr.gov/air/prof/tech/files/representivity_analysis.pdf. 

3. McCarthy, D. H. et al, 2005. Instrument Requirements and Standards for the NWS Surface 

Observing Programs (Land), p. 4. http://www.nws.noaa.gov/directives/sym/pd01013002curr.pdf.

4. Wright, J. M., 1994. Federal Coordinator for Meteorological Services and Supporting Research, 

Federal Standard for Siting Meteorological Sensors at Airports, Section 2.5. FCM-S4-1994 Washington 

D.C. http://www.ofcm.gov/siting/text/a-cover.htm.

5. U.S. EPA, 2009. AERMOD Implementation Guide. 

http://www.epa.gov/ttn/scram/7thconf/aermod/aermod_implmtn_guide_19March2009.pdf.

6. U.S. EPA, 2008. AERSURFACE User’s Guide.

7. Long, G. E., Cordova, J. F. and Tanrikulu, S., 2004. An Analysis of AERMOD Sensitivity to Input 

Parameters in the San Fransisco Bay Area. 13th Conference on the Applications of Air Pollution 

Meteorology with the Air & Waste Management Association. p. 4.

50
Addendum to Appendix A of the Modeling Protocol for the Muscatine PM2.5 SIP Revision

The Department completed processing of a new meteorological data set for the period 2005 – 2009 for 

use in dispersion modeling analyses performed as part of the pre-construction permit application review 

process in February of 2013. Several additional sites were discovered that met the 90% data 

completeness requirement described in Appendix W, as well as having 1-minute data available to be 

used in the newest version of the AERMET meteorological data preprocessor. One of these additional 

sites is the Davenport airport (KDVN). 

The Department has determined that the Davenport data is representative of the area being analyzed in 

the Muscatine PM2.5 SIP modeling, and will utilize 2005 – 2009 Davenport data for the remaining 

portions of the Muscatine PM2.5 SIP analysis instead of the 2004 – 2008 data from Cedar Rapids.

Analysis of Wind Roses

Shown below are the 2005 – 2009 wind roses for the meteorological sites in question (Figures 1 – 3). All 

three wind roses indicate similar predominant wind directions (NW and S). Both Cedar Rapids and 

Davenport include a similar amount of calm winds, while the Muscatine data includes a much larger 

percentage of calms. This higher percentage of calms is likely caused by the lower quality 

instrumentation at the Muscatine airport, and is one reason why the Muscatine data is inappropriate for 

use in the dispersion model.

To determine representivity the Department calculated the correlation coefficient between the wind 

roses at the various meteorological sites in and around Iowa. Figure 4 depicts different levels of 

correlation between the wind field at the Muscatine airport and the wind fields in other areas of the 

state. The blue-shaded area indicates a distance-weighted correlation coefficient of 0.9 or higher and 

the green-shaded area indicates a distance-weighted correlation coefficient of 0.8 or higher. All other 

areas have a correlation coefficient lower than 0.8. Based on this analysis, the data from Davenport 

were determined to be slightly more correlated to the data from Muscatine than are the data from 

Cedar Rapids.

Analysis of Surface Characteristics 

Another concern expressed by EPA during the review process for the Muscatine PM2.5 SIP modeling 

protocol was the difference in surface characteristics around the meteorological data measurement site

and the application site. A thorough analysis of the differences in surface characteristics between Cedar 

Rapids and the modeling domain in Muscatine was provided in the previously approved modeling 

protocol. The land use characteristics around the Davenport airport are very similar to those around the 

Cedar Rapids airport, resulting in very similar exposures for the meteorological instruments located at 

both locations. Aside from the airport runways and terminals, the areas surrounding both sites are 

comprised almost entirely of cropland. Therefore, switching from Cedar Rapids to Davenport data 

should have only a minimal effect on the surface characteristics analysis, and the assertions made in the 

analysis in the previously approved modeling protocol should remain valid.

51
Upper Air Data

Consecutive years of upper air data from Davenport were previously used with the Cedar Rapids surface 

data. Consecutive years of upper air data from Davenport will also be used with the Davenport surface 

data.

Figure 1. Muscatine Figure 2. Davenport

Figure 3. Cedar Rapids

52
Figure 4. Distance-weighted Correlation to Muscatine Wind Field

53
Attachment B. GPC Administrative Consent Order

54








ATTACHMENT A - GPC Control Strategy and Timeline

Version 4 - Dated 10/14/13

1 GEP Stack (Blrs 1-4 and 6-7) NONE MULTICLONES / ESP 

ON BOILER 7 ONLY EP1.0 add dry FGD, baghouse and carbon injection OR limit boilers to gaseous fuels only January 31, 2016 36.400 January 31, 2016

2 PH, Ash Silo 77-A-357-S1 BAGHOUSE EP2.0 NA 0.017 July 14, 2013

3 WM, #1 Wet Germ Cyclone NONE CYCLONE EP14.0 NA 0.028 July 14, 2013

4 WM, #1 & #2 Germ Dryers 79-A-194-S1 CYCLONE EP15.0 NA 0.239 July 14, 2013

5 Starch, #1 P&S Dryer NONE NONE EP24.1 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

6 Starch, #2 P&S Dryer NONE NONE EP24.2 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

7 Starch, #3 P&S Dryer NONE NONE EP24.3 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

8 Starch, #4 P&S Dryer NONE NONE EP24.4 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

9 Starch, #1 P&S Dryer NONE NONE EP25.1 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

10 Starch, #2 P&S Dryer NONE NONE EP25.2 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

11 Starch, #3 P&S Dryer NONE NONE EP25.3 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

12 Starch, #4 P&S Dryer NONE NONE EP25.4 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

13 Starch, #1 P&S Dryer NONE AERODYNE EP26.1 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

14 Starch, #2 P&S Dryer NONE AERODYNE EP26.2 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

15 Starch, #3 P&S Dryer NONE AERODYNE EP26.3 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

16 Starch, #4 P&S Dryer NONE AERODYNE EP26.4 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

17 DH1, #1 Product Aerodyne 71-A-003 AERODYNE EP28.1 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

18 DH1, #2 Product Aerodyne 71-A-003 AERODYNE EP28.2 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

19 DH1, #3 Product Aerodyne 71-A-003 AERODYNE EP28.3 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

20 DH1, #1 Rotary Dryer NONE EXP CHAMBER EP32.1 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

21 DH1, #2 Rotary Dryer NONE EXP CHAMBER EP32.2 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

22 DH1, #3 Rotary Dryer NONE EXP CHAMBER EP32.3 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

23 DH1, #4 Rotary Dryer NONE EXP CHAMBER EP32.4 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

24 DH1, #5 Rotary Dryer NONE EXP CHAMBER EP32.5 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

25 DH1, #6 Rotary Dryer NONE EXP CHAMBER EP32.6 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

26 DH2, Gluten Day Bin 71-A-067-S3 BAGHOUSE EP38.0 Impose PM2.5 emission limit NA 0.027 July 14, 2013

27 DH2, Rotary Dryer 74-A-130-S3 SCRUBBERS EP40.0 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

28 DH2, Dry End Pickup NONE CYCLONE EP41.0 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

29 DH2, #1 Mill Aerodyne NONE HE CYCLONE EP42.0 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

REQUIRED PM2.5 EMISSION 

LIMIT 

(pounds/hour)

MODIFY SOURCE CHARACTERISTICS

LINE

ESTABLISH OPERATIONAL RESTRICTION 

CONSTRUCTION/OPERATIONAL 

MODIFICATION COMPLETION DATE 

(no later than date listed below)

EMISSION LIMIT EFFECTIVE DATE 

(beginning on or before date listed below*)

SOURCE NAME

CURRENT 

PERMIT 

NUMBER

CURRENT 

CONTROL 

EQUIPMENT

EMISSION 

POINT ID

ADD CONTROL
ATTACHMENT A - GPC Control Strategy and Timeline

Version 4 - Dated 10/14/13

REQUIRED PM2.5 EMISSION 

LIMIT 

(pounds/hour)

MODIFY SOURCE CHARACTERISTICS

LINE

ESTABLISH OPERATIONAL RESTRICTION 

CONSTRUCTION/OPERATIONAL 

MODIFICATION COMPLETION DATE 

(no later than date listed below)

EMISSION LIMIT EFFECTIVE DATE 

(beginning on or before date listed below*)

SOURCE NAME

CURRENT 

PERMIT 

NUMBER

CURRENT 

CONTROL 

EQUIPMENT

EMISSION 

POINT ID

ADD CONTROL

30 GP1, #1 & #2 Scrubber Units 75-A-087 SCRUBBERS EP43.1 improve control of current scrubber by changing to higher 

collection efficiency packing and improving operation increase stack height from 96 feet to 140 feet. August 1, 2016 1.140 August 1, 2016

31 GP1, #3 Unit Scrubber 75-A-089 SCRUBBER EP46.0 permanently cease operation of emission unit(s)/ 

emission point April 30, 2015 0.000 April 30, 2015

32 Starch, #7 P&S Dryer 72-A-155 HE CYCLONE EP59.1 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

33 Starch, #7 P&S Dryer 72-A-155 HE CYCLONE EP59.2 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

34 Starch, #7 P&S Dryer 72-A-155 HE CYCLONE EP59.3 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

35 Starch, WHSE, Quonset Bulk Loading 02-A-952 BAGHOUSE EP60.0 NA 0.068 July 14, 2013

36 Maltrin, #1 Spray Dryer 72-A-199-S1 SCRUBBER EP66.0 increase stack height from 124 feet to 144 feet September 1, 2016 0.872 July 14, 2013

37 Maltrin, Product Filter NONE BAGHOUSE EP67.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

38 Maltrin, Dust System Bag Filter NONE BAGHOUSE EP68.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

39 DH3, Primary Dryer (NW) 73-A-137 CYCLONE EP79.0 permanently cease operation of emission unit(s)/ 

emission point

April 30, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

April 30, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

40 DH3, Primary Dryer (SW) 73-A-138 CYCLONE EP80.0 permanently cease operation of emission unit(s)/ 

emission point

April 30, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

April 30, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

41 DH3, Primary Dryer (SE) 73-A-139 CYCLONE EP81.0 permanently cease operation of emission unit(s)/ 

emission point

April 30, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

April 30, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

42 DH3, Primary Dryer (NE) 73-A-140 CYCLONE EP82.0 permanently cease operation of emission unit(s)/ 

emission point

April 30, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

April 30, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

43 DH2, Mill Aerodyne 73-A-135 AERODYNE EP85.0 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

44 Starch, #9 P&S Dryer, #1 Wet Stack 74-A-009 NONE EP91.1 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

45 Starch, #9 P&S Dryer, #2 Wet Stack 74-A-009 NONE EP91.2 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

46 Starch, #9 P&S Dryer 74-A-009 AERODYNE EP91.3 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

47 Starch, #10 P&S Dryer, #1 Wet Stack 74-A-010 NONE EP92.1 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

48 Starch, #10 P&S Dryer, #2 Wet Stack 74-A-010 NONE EP92.2 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

49 Starch, #10 P&S Dryer 74-A-010 AERODYNE EP92.3 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

50 Starch WHSE, So. Bulk Loading 75-A-246-S1 BAGHOUSE EP95.0 NA 0.068 July 14, 2013

51 WM, #2 Wet Germ Cyclone 74-A-014 CYCLONE EP96.0 NA 0.013 July 14, 2013

52 WM, #3 Germ Cyclone 74-A-015-S1 CYCLONE EP97.0 NA 0.134 July 14, 2013

53 Expeller, Dry Germ Cyclone 74-A-016-S2 BAGHOUSE EP98.0 replace cylone with baghouse increase stack height from 75 feet to 98.67 feet and slight 

changes to other stack parameters (diameter, flowrate) Already Complete 0.034 July 14, 2013

54 Starch, #8 P&S Dryer, #1 Wet Stack 74-A-008 HE CYCLONE EP101.1 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

55 Starch, #8 P&S Dryer, #2 Wet Stack 74-A-008 HE CYCLONE EP101.2 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

56 Starch, #8 P&S Dryer 74-A-008 HE CYCLONE EP101.3 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

57 PH, Blr #8 73-A-191 LNB EP103.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

58 PH, Blr #9 74-A-159 LNB EP104.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

59 DH4, #1 Rotary Dryer 75-A-210 EXP CHAMBER EP108.1 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

60 DH4, #2 Rotary Dryer 75-A-211 EXP CHAMBER EP108.2 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

61 DH4, #3 Rotary Dryer 75-A-212 EXP CHAMBER EP108.3 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

62 DH4, #1 Mill Aerodyne 75-A-343-S1 AERODYNE EP110.0 permanently cease operation of emission unit(s)/ 

emission point March 31, 2016 0.000 March 31, 2016
ATTACHMENT A - GPC Control Strategy and Timeline

Version 4 - Dated 10/14/13

REQUIRED PM2.5 EMISSION 

LIMIT 

(pounds/hour)

MODIFY SOURCE CHARACTERISTICS

LINE

ESTABLISH OPERATIONAL RESTRICTION 

CONSTRUCTION/OPERATIONAL 

MODIFICATION COMPLETION DATE 

(no later than date listed below)

EMISSION LIMIT EFFECTIVE DATE 

(beginning on or before date listed below*)

SOURCE NAME

CURRENT 

PERMIT 

NUMBER

CURRENT 

CONTROL 

EQUIPMENT

EMISSION 

POINT ID

ADD CONTROL

63 DH4, #2 Mill Aerodyne 75-A-344 AERODYNE EP111.0 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

64 DH4, #3 Mill Aerodyne 75-A-345 AERODYNE EP112.0 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

65 DH4, # 1 Mill Product 75-A-346-S1 BAGHOUSE EP113.0 permanently cease operation of emission unit(s)/ 

emission point March 31, 2016 0.000 March 31, 2016

66 DH4, #2 Product Aerodyne 75-A-347 AERODYNE EP114.0 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

67 DH4, #3 Product Aerodyne 75-A-348 AERODYNE EP115.0 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

68 DH WHSE, #1 Feed Cooler 75-A-353-S1 BAGHOUSE EP119.0 replace cylone with baghouse

increase stack height from 50 feet to 80 feet. Change stack 

from vertical obstructed to wertical unobstructed and slight 

changes to other stack parameters (diameter,flowrate)

Baghouse Already Complete/Stack Modification 

December 31, 2013 0.100 July 14, 2013

69 Starch, #11 P&S Dryer, #1 Wet Stack 76-A-209 NONE EP121.1 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

70 Starch, #11 P&S Dryer, #2 Wet Stack 76-A-210 NONE EP121.2 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

71 Starch, #11 P&S Dryer 76-A-211 HE CYCLONE EP121.3 permanently cease operation of emission unit(s)/ 

emission point December 31, 2016 0.000 December 31, 2016

72 Starch, WHSE, Pearl Starch 76-A-262-S1 BAGHOUSE EP122.0 NA 0.064 July 14, 2013

73 DH4, #4 Rotary Dryer 79-A-196 EXP CHAMBER EP125.0 permanently cease operation of emission unit(s)/ 

emission point

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

0.000

March 31, 2015 or no later than 6 months after the 

start-up of any of the new emission unit associated 

with Dryer House 5, whichever is sooner

74 WM, #4 Germ Dryer 79-A-195-S1 CYCLONE EP126.0 NA 0.120 July 14, 2013

75 DH4, #5 Rotary Dryer 09-A-707-S1 EXP CHAMBER EP 127.0 Add wet scrubber to expansion chamber

increase stack height from 98 feet to 110 feet. Relocate stack 

to UTM 662038.24, 4584857.17 (NAD 27, Z15) and slight 

changes to other stack parameters (temp, flowrate, diameter)

November 1, 2016 0.180 November 1, 2016

76 DH4, #4 Mill Aerodyne 80-A-113-S1 AERODYNE EP128.0 permanently cease operation of emission unit(s)/ 

emission point March 31, 2016 0.000 March 31, 2016

77 DH4, #4 Product Aerodyne 80-A-114-S1 BAGHOUSE EP129.0 permanently cease operation of emission unit(s)/ 

emission point March 31, 2016 0.000 March 31, 2016

78 Starch WHSE, Bagger Dust Control 02-A-760-S1 BAGHOUSE EP 130.0 NA 0.030 July 14, 2013

79 Maltrin, #3 Spray Dryer (E) 80-A-149-S4 VENTURI SCRUBBER EP132.1 improve control of current venturi scrubber by adding 

packed bed sections and insulating the stack increase stack height from 126 feet to 150 feet September 1, 2016 0.900 September 1, 2016

80 Maltrin, #3 Spray Dryer (W) 80-A-150-S4 VENTURI SCRUBBER EP132.2 improve control of current venturi scrubber by adding 

packed bed sections and insulating the stack increase stack height from 126 feet to 150 feet September 1, 2016 0.900 September 1, 2016

81 CoPo, Disc Dryer Product Handling NONE BAGHOUSE EP 133.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

82 CoPo, Disc Dryer Product Transfer 83-A-082 BAGHOUSE EP134.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

83 Maltrin #4, Spray Dryer (E) 85-A-031-S1 PB SCRUBBER EP135.0 increase stack height from 94 feet to 164 feet September 1, 2016 0.800 July 14, 2013

84 Maltrin #4, Spray Dryer (W) 85-A-032-S1 PB SCRUBBER EP136.0 increase stack height from 94 feet to 164 feet September 1, 2016 1.000 July 14, 2013

85 DH4, #6 Rotary Dryer 85-A-033 EXP CHAMBER EP137.0 Add wet scrubber to expansion chamber

increase stack height from 98 feet to 110 feet. Relocate stack 

to UTM 662039.93, 4584853.45 (NAD 27, Z15) and slight 

changes to other stack parameters (temp, flowrate, diameter)

November 1, 2016 0.210 November 1, 2016

86 DH4, #5 Milling Aerodyne 85-A-034 HE CYCLONE EP138.0 permanently cease operation of emission unit(s)/ 

emission point March 31, 2016 0.000 March 31, 2016

87 DH4, #6 Milling Aerodyne 85-A-035-S1 HE CYCLONE EP 139.0 permanently cease operation of emission unit(s)/ 

emission point March 31, 2016 0.000 March 31, 2016

88 DH4, #5 Product Aerodyne 85-A-036 HE CYCLONE EP140.0 permanently cease operation of emission unit(s)/ 

emission point March 31, 2016 0.000 March 31, 2016

89 DH4, #6 Product Aerodyne 85-A-037 AERODYNE EP141.0 permanently cease operation of emission unit(s)/ 

emission point March 31, 2016 0.000 March 31, 2016

90 PH, Boiler #10 85-A-038 LOW EXCESS AIR EP142.0 increase stack height from 70 feet to 110 feet December 31, 2013 0.700 July 14, 2013

91 Starch, #1 Flash Dryer 85-A-039 SCRUBBER EP143.0 increase stack height from 137 feet to 177 feet Add burner and restrict fuel to natural gas only December 31, 2016 2.640 July 14, 2013

92 Starch WHSE, Food Grade Bagger 90-A-307 BAGHOUSE EP144.0 Install new baghouse increase stack height from 33 feet to 140 feet Already Complete 0.210 November 1, 2013

93 Starch WHSE, Food Grade Bagger 85-A-041 BAGHOUSE EP145.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

94 WM, #1-4 Corn Cleaner 85-A-043-S1 BAGHOUSE EP147.0 increase stack height from 16 feet to 80 feet No later than 180 days after receiving approval 

from the Army Corp of Engineers 0.200 July 14, 2013

95 Starch WHSE, #1 Bin Vent 85-A-081-S1 BAGHOUSE EP149.0 NA 0.020 July 14, 2013

96 Starch WHSE,#2 Bin Vent 85-A-082-S1 BAGHOUSE EP150.0 NA 0.020 July 14, 2013

97 Starch WHSE, #3 Bin Vent 85-A-083-S1 BAGHOUSE EP151.0 NA 0.020 July 14, 2013

98 Starch WHSE, #4 Bin Vent 85-A-084-S1 BAGHOUSE EP152.0 NA 0.020 July 14, 2013

99 PH, Boiler #11 85-A-135 LOW EXCESS AIR EP153.0 increase stack height from 70 feet to 110 feet December 31, 2013 0.700 July 14, 2013

100 Maltrin, #1 Agglomerator 89-A-084 BAGHOUSE EP154.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

101 Starch WHSE, Super Sacker 89-A-085 BAGHOUSE EP155.0 NA 0.068 July 14, 2013
ATTACHMENT A - GPC Control Strategy and Timeline

Version 4 - Dated 10/14/13

REQUIRED PM2.5 EMISSION 

LIMIT 

(pounds/hour)

MODIFY SOURCE CHARACTERISTICS

LINE

ESTABLISH OPERATIONAL RESTRICTION 

CONSTRUCTION/OPERATIONAL 

MODIFICATION COMPLETION DATE 

(no later than date listed below)

EMISSION LIMIT EFFECTIVE DATE 

(beginning on or before date listed below*)

SOURCE NAME

CURRENT 

PERMIT 

NUMBER

CURRENT 

CONTROL 

EQUIPMENT

EMISSION 

POINT ID

ADD CONTROL

102 Maltrin, #2 Agglomerator 89-A-146 BAGHOUSE EP156.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

103 Maltrin, bagger 89-A-162-S1 BAGHOUSE EP157.0 NA 0.057 July 14, 2013

104 Starch, #2 Flash Dryer 90-A-258 SCRUBBER EP158.0 increase stack height from 139 feet to 179 feet Add burner and restrict fuel to natural gas only December 31, 2016 3.550 July 14, 2013

105 Starch WHSE, #5 Starch Silo (N) 90-A-259 BAGHOUSE EP159.0 NA 0.030 July 14, 2013

106 Starch WHSE, #6 Starch Silo (E) 90-A-260 BAGHOUSE EP160.0 NA 0.030 July 14, 2013

107 Starch WHSE, #7 Starch Silo (S) 90-A-261 BAGHOUSE EP161.0 NA 0.030 July 14, 2013

108 Starch WHSE, #8 Starch Silo (W) 90-A-262 BAGHOUSE EP162.0 NA 0.030 July 14, 2013

109 Starch WHSE, Track 3A Loadout 90-A-263 BAGHOUSE EP163.0 NA 0.083 July 14, 2013

110 DH4, #7 Rotary Dryer 90-A-264 EXP CHAMBER EP164.0 Add wet scrubber to expansion chamber

increase stack height from 98 feet to 110 feet. Relocate stack 

to UTM 662041.71, 4584849.89 (NAD 27, Z15) and slight 

changes to other stack parameters (temp, flowrate, diameter)

November 1, 2016 0.210 November 1, 2016

111 DH WHSE, #2 Feed Cooler 90-A-111 BAGHOUSE EP167.0 increase stack height from 19 feet to 80 feet December 31, 2013 0.110 July 14, 2013

112 Maltrin, #5 Spray Dryer (A Stack) 90-A-309-S1 SCRUBBER EP168.0 increase stack height from 152 feet to 162 feet September 1, 2016 0.873 July 14, 2013

113 Maltrin, #5 Spray Dryer (B Stack) 90-A-310-S1 SCRUBBER EP169.0 increase stack height from 152 feet to 162 feet September 1, 2016 0.753 July 14, 2013

114 Starch WHSE, #9 Starch Silo (NE) 90-A-359 BAGHOUSE EP171.0 NA 0.030 July 14, 2013

115 Starch WHSE, #10 Starch Silo (NW) 90-A-360 BAGHOUSE EP172.0 NA 0.030 July 14, 2013

116 GP2, #4 Gluten Flash Dryer 91-A-067-S2 SCRUBBER EP173.0 NA 1.010 July 14, 2013

117 GP2, #4 Gluten Pre-Mill 91-A-068-S1 BAGHOUSE EP174.0 NA 0.150 July 14, 2013

118 Maltrin, Product Silo Receiver (N) 91-A-069 BAGHOUSE EP175.0 NA 0.035 July 14, 2013

119 Maltrin, Nuisance Duct Collector (W) 91-A-070 BAGHOUSE EP176.0 NA 0.034 July 14, 2013

120 PH, Boiler #12 93-A-110 LOW NOX BURNERS EP177.0 NA 1.500 July 14, 2013

121 WM, #5 Germ Dryer 91-A-176 CYCLONE EP178.0 NA 0.230 July 14, 2013

122 GP2, #1 Feed Truck Loadout (West) 92-A-383-S1 BAGHOUSE EP179.0 increase stack height from 38 feet to 75 feet and make stack 

vertical unobstructed instead of vertical obstructed Already Complete 0.150 July 14, 2013

123 GP2, #2 Feed Truck Loadout (East) 92-A-385 BAGHOUSE EP180.0 increase stack height from 38 feet to 75 feet and make stack 

vertical unobstructed instead of vertical obstructed Already Complete 0.150 July 14, 2013

124 Elevator, South Corn Rail Receiving 76-A-264 BAGHOUSE EP181.1 NA 0.170 July 14, 2013

125 Elevator, South Corn Truck Receiving 76-A-268 BAGHOUSE EP181.2 NA 0.125 July 14, 2013

126 Maltrin, #1 Bulk Filter Aid Storage Bin (W) 93-A-032 BAGHOUSE EP182.0 restrict operation to 1 out of 4 bins may be filled at 

a time July 14, 2013 0.010 July 14, 2013

127 Maltrin, #2 Bulk Filter Aid Storage Bin (N) 93-A-033 BAGHOUSE EP183.0 restrict operation to 1 out of 4 bins may be filled at 

a time July 14, 2013 0.010 July 14, 2013

128 Maltrin, #3 Bulk Filter Aid Storage Bin (N) 93-A-034 BAGHOUSE EP184.0 restrict operation to 1 out of 4 bins may be filled at 

a time July 14, 2013 0.010 July 14, 2013

129 Maltrin, #1 Bulk Carbon Storage Bin (W) 93-A-035 BAGHOUSE EP185.0 restrict operation to 1 out of 4 bins may be filled at 

a time July 14, 2013 0.010 July 14, 2013

130 Maltrin, #6 Spray Dryer (Stack A) 94-A-055 SCRUBBER EP186.0 increase stack height from 137 feet to 147 feet September 1, 2016 0.663 July 14, 2013

131 Maltrin, #6 Spray Dryer (Stack B) 94-A-061 SCRUBBER EP187.0 increase stack height from 137 feet to 147 feet September 1, 2016 0.663 July 14, 2013

132 G-Starch, G-Starch Process 96-A-1028-S1 BAGHOUSE EP188.0 NA 0.774 July 14, 2013

133 PH, Lime Silo 02-A-759 BIN VENT FILTER EP189.0 NA 0.012 July 14, 2013

134 GP2, Gluten Loadout Transfer 02-A-781-S1 BAGHOUSE EP190.1 NA 0.021 July 14, 2013

135 GP2, Gluten Truck Loadout 02-A-782-S1 BAGHOUSE EP190.2 NA 0.002 July 14, 2013

136 PH, Bulk Salt Tank Vent 02-A-787 BIN VENT FILTER EP191.0 limit operation to no more than 1 hour per day July 14, 2013 0.200 July 14, 2013

137 CoPo, Corn Bran Dryer 06-A-215 BAGHOUSE EP192.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

138 WM, #3 Germ Transfer & Receiving 02-A-783-S1 CYCLONE EP194.0 NA 0.020 July 14, 2013

139 DH4, Spent Germ Receiving 09-A-482-S1 BAGHOUSE EP195.0 increase stack height from 30 feet to 66.5 feet Already Complete 0.028 July 14, 2013

140 DH1, DH2 and DH4 Product Receiver Cyclone 10-A-563 BAGHOUSE EP196.0 add baghouse to bypass stack Already Complete 0.140 July 14, 2013

141 Maltrin Hoffman Dust Collection 10-A-285 BAGHOUSE EP197.0 vent source directly to atmosphere instead of inside 

production building Already Complete 0.011 July 14, 2013

142 Germ Receiving Bin NONE NONE EP198.0 NA 0.009 July 14, 2013

143 DH4 & DH5, New Milling Equipment & Product Conve NONE BAGHOUSE EP199.0 replace existing DH4 milling aerodynes with new 

milling equipment with baghouse controLs March 1, 2016 0.650 March 1, 2016

144 Starch WHSE, Ind. Modified Starch 03-A-079 BAGHOUSE EP471.0 NA 0.065 July 14, 2013

145 Elevator, Grain Unloading "A" & "B" 02-A-687-S2 BAGHOUSE EP490.0 NA 0.220 July 14, 2013

146 GP1, Pneunatic Transport System 03-A-471 BAGHOUSE EP531.0 NA 0.122 July 14, 2013

147 GP1, Hulls' Milling System 03-A-1369 BAGHOUSE EP536.0 NA 0.013 July 14, 2013

148 Starch WHSE, Modified Starch Pneumatic 03-A-1370 BAGHOUSE EP537.0 NA 0.030 July 14, 2013

149 Maltrin, #1 Spray Dryer System Cooler 03-A-1371 BAGHOUSE EP538.0 NA 0.100 July 14, 2013

150 WWT, #1 Biogas Flare Stack 04-A-548 FLARE EP542.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

151 WWT, #2 Biogas Flare Stack 04-A-549 FLARE EP543.0 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

152 Mash Fermenters 1-29 05-A-926-S3 SCRUBBERS EP544.0 NA 0.185 July 14, 2013

153 Expeller, #1 Spent Germ Pickup 06-A-1261 BAGHOUSES EP545.0 NA 0.365 July 14, 2013

154 DH4, #3 Alpha Laval (formerly #4 Sharples) 11-A-338 NONE EP546.0 vent source directly to atmosphere instead of inside 

production building

replace existing sharples with new alpha laval 

centrifuge Already Complete 0.001 July 14, 2013

155 WWTP Anaerobic Digesters #1 - #3 11-A-661 BIOGAS DESULFURIZATION 

SYSTEM / FLARE EP548.0 add source to replace EP542.0 and EP543.0 Already Complete 0.260 July 14, 2013

156 Tank 4C and 5C NONE FLARE EP550.0 NA 0.220 July 14, 2013

157 East Tank and C-400 Thru Tanks NONE NONE EP551.0 NA 0.011 July 14, 2013

158 DH5, Swiss Combi Dryer 11-A-339 TO / SO2 SCRUBBER EP600.0 replace existing DH1, DH2 and portions of DH4 and 

replace with new DH5 March 31, 2015 2.700 March 31, 2015

159 DH5, Spent Germ Pneumatic Transport 11-A-340 BAGHOUSE EP601.0 replace existing DH1, DH2 and portions of DH4 and 

replace with new DH5 March 31, 2015 0.030 March 31, 2015

160 DH5, Cage Mill Feed Baghouse 11-A-342 BAGHOUSE EP603.0 replace existing DH1, DH2 and portions of DH4 and 

replace with new DH5 March 31, 2015 0.160 March 31, 2015
ATTACHMENT A - GPC Control Strategy and Timeline

Version 4 - Dated 10/14/13

REQUIRED PM2.5 EMISSION 

LIMIT 

(pounds/hour)

MODIFY SOURCE CHARACTERISTICS

LINE

ESTABLISH OPERATIONAL RESTRICTION 

CONSTRUCTION/OPERATIONAL 

MODIFICATION COMPLETION DATE 

(no later than date listed below)

EMISSION LIMIT EFFECTIVE DATE 

(beginning on or before date listed below*)

SOURCE NAME

CURRENT 

PERMIT 

NUMBER

CURRENT 

CONTROL 

EQUIPMENT

EMISSION 

POINT ID

ADD CONTROL

161 DH5, Building Scrubber NONE SCRUBBER EP605.0 replace existing DH1, DH2 and portions of DH4 and 

replace with new DH5 March 31, 2015 0.010 March 31, 2015

162 Grnd & Whole Grains Unloading (KENT) NONE CYCLONE E1 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

163 Pellet Cooler (KENT) NONE CYCLONE E2A permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

164 Pellet Cooler (KENT) NONE CYCLONE E2B permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

165 Pellet Cooler (KENT) NONE CYCLONE E2C permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

166 Pellet Screen (KENT) NONE CYCLONE E3 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

167 Pellet Cooler (KENT) 03-A-1414-S3 BAGHOUSE E4 NA 0.086 July 14, 2013

168 Ingredient Mixer (KENT) NONE CYCLONE E5 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

169 SBM Bin (KENT) NONE NONE E7a limit operation to no more than 1 hour per day NA 0.020 July 14, 2013

170 SBM Bin (KENT) NONE NONE E7b limit operation to no more than 1 hour per day NA 0.020 July 14, 2013

171 SBM Bin (KENT) NONE NONE E7c limit operation to no more than 1 hour per day NA 0.020 July 14, 2013

172 SBM Bin (KENT) NONE NONE E7d limit operation to no more than 1 hour per day NA 0.020 July 14, 2013

173 SBM Bin (KENT) NONE NONE E7e limit operation to no more than 1 hour per day NA 0.020 July 14, 2013

174 SBM Bin (KENT) NONE NONE E7f limit operation to no more than 1 hour per day NA 0.020 July 14, 2013

175 Pellet Conveyor (KENT) NONE CYCLONE E8 permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

176 Loadout Bins (KENT) NONE NONE E9a limit operation to no more than 2.5 hours per day NA 0.077 July 14, 2013

177 Loadout Bins (KENT) NONE NONE E9b limit operation to no more than 2.5 hours per day NA 0.077 July 14, 2013

178 Loadout Bins (KENT) NONE NONE E9c permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

179 Loadout Bins (KENT) NONE NONE E9d permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

180 Pellet Cooler (KENT) 03-A-1415-S4 BAGHOUSE E10 NA 0.034 July 14, 2013

181 Maltrin Storage Bins 1-4 & Kice Product Reciever NONE BAGHOUSE/BIN VENT 

FILTERS MALT14 NA 0.040 July 14, 2013

182 Maltrin Storage Bins 5-8 NONE BAGHOUSE/BIN VENT 

FILTERS MALT58 NA 0.005 July 14, 2013

183 Sulfur Burner NONE ABSORBTION TOWER SULFURBURN permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

184 Coal Barge Unloading NONE NONE COALBARG

operate only in the months March through 

November and a minimum daily average coal 

moisture content of 8.7%

NA 0.060 July 14, 2013

185 Coal Pile NONE NONE COAL PILE

no more than 266,263 tons per 12-month rolling 

period and a minimum daily average coal moisture 

content of 8.7%

NA NA July 14, 2013

186 Feed Barge Unloading NONE TELESCOPING SPOUT FEEDBARG operate only in the months March through 

November NA 0.020 July 14, 2013

187 Feed Railcar Loading NONE SPOUT WITH SOCK RAILCR1 NA 0.004 July 14, 2013

188 Feed Railcar Loading NONE SPOUT WITH SOCK RAILCR2 NA 0.004 July 14, 2013

189 Wet Feed Loading NONE NONE WETFEED loadout no more than 37,000 tons of wet feed per 

12-month rolling period NA 0.003 July 14, 2013

190 Corn Storage Pad NONE NONE CORNSTOR permanently cease operation of emission unit(s)/ 

emission point Already Complete 0.000 Already Complete

191 Kent Feeds Flat Corn Storage Pad NONE NONE FLATSTOR store no more than 26,000 tons of material per 12-

month rolling period NA 0.002 July 14, 2013

192 Haul Roads NONE NONE ND use PM10 efficient sweeper (a minimum of every other day) silt loading of no more than 0.4 g/m2 NA NA July 14, 2013

193 River Levee NONE NONE NONE

restrict access to levee by posting signs warning of 

restricted access on the north and south fence lines 

that intersect the levee. A third sign will be posted 

in the area of highest modeled concentrations 

prohibiting loitering and fishing. In-person 

surveillance of the levy will be conducted by GPC 

security staff periodically throughout the 24-hour 

day with documentation as to surveillance time 

and location.

Already Complete NA NA

* If emission unit is operational before emission limit effective date, the date the unit becomes operational is the effective date of the PM2.5 emission limit








Attachment C. Implementation Schedule for GPC Control Measures

55
Information Supporting GPC's Schedule for Implementation of Control Measures

Updated January 2014

Action Date Completion Schedule Rationale & Comments

Increase stack height of #1 & #2 Crown Coolers 30 feet to 80 feet 

EP 119.0 & EP 167.0

December 31, 2013 Completed.

Increase stack height of Natural Gas Boilers #10 & #11 approx 40 feet to 110 feet each 

EP142.0 & EP 153.0

December 31, 2013

Completed.

Increase stack height of Corn Cleaner Baghouse (EP 147.0) up to 70 ft

June, 2014

This project requires structural design and fabrication, stack design and fabrication, and installation. This project 

was subject to Corp Of Engineers approval, since the stack will be constructed on the Mississippi River levee. 

The approval was received in December 2013.

Add Sources EP600.0, EP601.0, EP603.0, & EP605.0

Remove Sources 28.1, 28.2, 28.3, & EP32.1 - EP32.6 

Remove EP40.0, EP41.0, EP42.0 & 85.0

Remove EP108.1, 108.2, 108.3, & 125.0

Remove sources EP 111.0, 112.0, 114.0, & 115.0

March 31, 2015

These sources are associated with DH5 coming on line and the existing dryer house sources that go out of 

service. DH5 is an extremely complex project, that must be designed, have materials procured, bid packages 

assembled, contracts awarded and construction completed for a dryer building, evaporator building, dewatering 

building, and milling building - all buildings contiguous. Also tie-ins to connect the DH5 process to the existing 

plant processes are complex and require coordinated, planned process shutdowns. Design, construction 

logistics, and complexity, dictate the March 31, 2015 completion of this large project. Construction is on schedule 

for this substantial, multi-year project.

Decommission DH3 dryer

Remove EP79.0, EP80.0. EP81.0, EP82.0

April 30, 2015

Requires modification of existing #10 conveyor, installation of a new 16"screw conveyor, and modifications of 

spouting from #1 conveyor through new conveyor to the existing drag conveyor from DH3 to DH4. Project will be 

completed by April 30, 2015 or no later than 6 months after the start up of any new emissions unit associated 

with Dryer House 5, whichever is sooner. Hulls drying by this dryer is required to maintain plant operation until 

DH5 comes on line.

Decommission GP1 #3 Dryer (EP 46.0) April 30, 2015 This project is tied to completion of the DH5 project and DH5's successful startup. DH5 startup is scheduled for 

March, 2015.

Limitations on coal boilers to control particulate emissions January 1, 2016

GPC evaluated options to control coal-firing or switch to alternate fuels to meet the requirements of the Boiler 

MACT (40 CFR 63, Subpart DDDDD). Controlling coal fired emissions will take a minimum of three years to 

engineer and construct; switching of fuels will require consuming currently contracted coal and assuring that 

alternate fuel quantities are available and can be delivered to the power house. GPC is in the process of 

engineering for adequate fuel supplies and associated construction to meet Boiler MACT requirements by the 

middle of 2015 to early 2016. Currently, there is a capital project commencing in the spring of 2014 to enable 

GPC to meet Boiler MACT requirements. This project may take up to 18 months to complete and is necessary 

to provide adequate equipment and supplies to operate the boilers.

DH4 milling systems through new baghouse 

Remove EP110.0, EP113.0, EP 138.0, EP139.0,

EP140.0,& EP 141.0

March 31, 2016

This project requires a new multi-story process building; new pneumatic transport systems for product

leaving dryers 5,6, and 7; a product pneumatic receiving baghouse; high static LO. fan; airlock; spouting; and a 

54" Stedman cage mill. This sizeable project scope's execution overlaps with the DH5 project execution, as well 

as several other environmental compliance projects. This project also requires coordinated process shutdowns 

for the completion of tie-ins. Completion of this project overlaps with DH5 startup and because some of the 

existing DH4 real estate is reused for the DH5 Product Transfer System and requires a good portion of this 

project to be operational for DH5 to be operational, work has already commenced on this system and will likely be 

completed ahead of the March 31, 2016 schedule. ·

Improve GP1 Units 1&2 Dryers' and Scrubber's performance and increase stack height to 

140 feet

Modify EP 43.1

August 1, 2016

Permit approval for the #8 Gluten Rotary Vacuum Filter at GP2 will allow GPC to reduce average dewatering and 

drying load from GP1 and shift to GP2 Dryer. This will allow GPC to consistently run GP1 dryers at lower rates 

which will improve fine particulate emissions from these dryers and existing scrubber. The existing scrubber 

stack extension will require the design, fabrication and construction of a structural truss, tied back to the existing 

building steel, for structural support. Process shutdowns will have to be coordinated and completed to allow for 

tie-ins to complete this work. The large number of parallel engineering projects is a big factor in the completion 

timeframe of this subproject.
Modify #3 Maltrin Scrubber and add extensions to all Maltrin Stacks 

EP132.1, EP132.2, EP066.0, EP 135.0, EP136.0,

EP168.0, EP169.0, 186.0, EP187.0

September 1, 2016

This is a fairly extensive and complex scope of work. Packed bed sections must be designed and added to both 

venturi scrubbers on SD #3, structural cages/trusses, as well as stack extensions, will have to be designed, 

fabricated, and installed for nine separate emission stacks on the Maltrin building roof. Process shutdowns must 

be planned and executed to complete numerous tie-ins. Again, this project work is happening in parallel to 

project work for DH5, and other plant environmental improvements. Primary focus will be to address #3 Maltrin 

SD scrubbers first, then consecutive stack extensions will be address - all while minimizing process interruption 

and product availability for our customers. From a resource availability standpoint, GPC estimates 

approximately 18 months after DH5 startup for this subproject.

Install scrubbers on DH4 Rotary Dryers 5, 6, 7 & Relocate Stacks

EP 127.0, EP137.0, & EP 164.0

November 1, 2016

There are similar considerations for this project, as the project above. Installation of three separate scrubber 

systems, including scrubbers, fans, circulation pumps, heat exchangers, and filters are required. Structural 

modifications are required at MR2 building to accommodate the scrubber equipment and stacks. Several 

process shutdowns must be coordinated and executed to tie-in new equipment to existing systems. With the 

possible addition of other control equipment downstream from these scrubbers, additional design and layout will 

be necessary, resulting in additional engineering and construction time. This is a fairly complex subproject, and 

when coupled with a large number of parallel environmental projects, GPC expects this project to be completed 

20 months after DH5 is operating. 

Decommission all P & S dryers; Flash Dryers 1 & 2 on natural gas 

Remove EP24.1, EP24.2, EP24.3, EP24.4

EP25.1, EP25.2, EP25.3, EP25.4 EP26.1, EP26.2, EP26.3, EP26.4

EP91.1, EP91.2, EP91.3 EP92.1, EP92.2, EP92.3

EP121.1, EP121.2, EP121.3

December 31, 2016

The improvements to Flash Dryer 1 & 2 are required before decommissioning of the P&S Dryers can be 

requested due to customer requirements. There is a minimum 12 month design, procurement and construction 

schedule for these dryers. Therefore these PM2.5 emission reductions will not occur until at least 18 months after 

final permits are received from DNR. Because of possible PSD implications, which may be necessary to permit 

this conversion, GPC anticipates permits will not to be issued before January 1, 2016. Both flash dryers require a 

complete redesign of large inlet ductwork systems, including the design of burner sections and BMS (burner 

management systems), outside contractor review of burner design and fuel train safety provisions, removal of 

existing steam coils, steam and condensate handling piping and equipment. New ductwork modifications will be 

designed, built and installed to accommodate the new burner sections, and allow space for future heat recovery 

coils. Civil/Structural design, burner/duct design, bid package generation, mechanical and electrical contracts, 

materials procurement, and construction of all the pieces, and coordination of process shutdowns for tie-ins, 

dictate that this project will require a duration of 12 months after permit approval.

Increase stack height of Flash Dryer #1 (EP 143.0) 40 feet to 177 feet 

Increase stack height of Flash Dryer #2 (EP 158.0) 40 feet to 179 feet

December 31, 2016

This project would coincide with the Flash Dryer 1 & 2 conversion to natural gas which has a anticipated 

completion date of December 31, 2016.
Attachment D. MPW Control Measures and Timeline

56
Attachment D - Muscatine Power Water Control Measures and Timeline

1 COAL HANDLING (RAIL UNLOADING) 93-A-288-S3 BAGHOUSE AND DUST SUPPRESSION 

SYSTEM 21 0.00121 NA 0.0000

2 COAL HANDLING (RAIL UNLOADING) 93-A-289-S3 BAGHOUSE AND DUST SUPPRESSION 

SYSTEM 22 0.00060 NA 0.0000

3 COAL HANDLING 93-A-290-S3 DUST SUPPRESANT SYSTEM 23A 0.0725 NA 0.0000

COAL PILE (RADIAL STACKER DISCHARGE) NONE 0.0403 NA 0.0000

COAL PILE (CONVEYOR TRUCK UNLOADING) NONE restrict operation to between 8am and 4pm 0.0014 August 21, 2013 0.0000

COAL PILE (BULLDOZING) NONE restrict operation to between 6am and midnight 0.8877 August 21, 2013 0.0000

COAL PILE (WIND EROSION) NONE reduce size of coal pile from 23 acres to 20 acres Work Practice August 21, 2013 -0.1423 estimate based on reduction of pile size

5 BARGE COAL UNLOADING 13-A-140 NONE 300

restrict operation to between 6am and midnight and 

only between the months of March through 

November

0.0431 August 21, 2013 0.0000

6 COAL HANDLING (COAL RECLAIM) 80-A-193-S3 BAGHOUSE 301

change stack to vertical 

release instead of horizontal 

and increase height from 7 

feet to 10 feet

0.0167 September 20, 2013 0.0000

7 BARGE COAL UNLOADING (BUF DISCHARGE/UC-1 LOAD) 13-A-141 NONE 302

restrict operation to between 6am and midnight and 

only between the months of March through 

November

0.0431 August 21, 2013 0.0000

8 RECLAIM FEEDER/CONVEYORS (RF-2 DISCHARGE/RC-2 LOAD) 00-A-683-S1 NONE 310B restrict operation to between 6am and 10pm 0.022 August 21, 2013 0.0000

9 LIVE COAL STORAGE SILO 80-A-194-S3 BAGHOUSE 311 restrict operation to between 6am and 10pm 0.103 August 21, 2013 0.0000

10 CONVEYORS (RC-2 DISCHARGE/LSCS-2 LOAD) 00-A-684-S1 NONE 311B restrict operation to between 6am and 10pm 0.0218 August 21, 2013 0.0000

11 SILO FEEDER (SF1-4/LSC-1) 93-A-286-S5 BAGHOUSE 312 0.0003 NA 0.0000

12 CONVEYORS (LSCS-2 DISCHARGE/SF-6 LOAD) 00-A-686-S1 NONE 312B 0.0058 NA 0.0000

13 CONVEYORS (SF-6 DISCHARGE / RC-3 LOAD) 00-A-687-S1 NONE 313B 0.0058 NA 0.0000

14 SILO FEEDER AND EPC-1 CONVEYOR LOAD 80-A-196-S4 BAGHOUSE 314 0.0155 NA 0.0000

15 UNIT 7 & 8 COAL CRUSHER FEEDERS 01-A-193-S2 BAGHOUSE 320 increase stack height from 14 feet to 24 feet 0.0823 September 20, 2013 0.0000

16 UNIT 7 & 8 COAL CRUSHERS 80-A-006-S3 BAGHOUSE 322 0.028 NA 0.0000

17 TRUCK UNLOADING - TRACK HOPPER A CONV. 13-A-153 NONE 330 restrict operation to between 8am and 4pm 0.0058 August 21, 2013 0.0000

18 TRUCK LOADING - TRACK HOPPER A CONV. 13-A-154 NONE 330A restrict operation to between 8am and 4pm 0.0058 August 21, 2013 0.0000

19 CONVEYOR SYSTEM LOAD 80-A-007-S3 BAGHOUSE 333 0.061 NA 0.0000

20 CONVEYOR SYSTEM DISCHARGE 00-A-638-S1 BAGHOUSE 341 0.061 NA 0.0000

21 UNIT 9 CRUSHER HOUSE (DC-11 EXHAUST) 06-A-650-S3 BAGHOUSE 351 0.0341 NA 0.0000

22 PSC-9 CONVEYOR / 4 COAL SILOS 80-A-197-S2 BAGHOUSE 360 0.034 NA 0.0000

23 SOC-1 CONVEYOR DISCHARGE/RSC-1 CONVEYOR 93-A-283-S2 BAGHOUSE 370 0.00029 NA 0.0000

24 LIMESTONE HOPPER LOADING 13-A-155 NONE 40 add three-sided enclosure with roof reduce capacity of system from 400 TPH to 200 TPH 

and restrict operation to between 8am and 4pm 0.1475 August 21, 2013 -0.0007 average of 2007/2008 EIQ assuming 41% reduction in emissions for reduced wind speed from enclosure

25 LIMESTONE HANDLING SYSTEM 80-A-202-S2 BAGHOUSE 41 0.088 NA 0.0000

LIMESTONE PILE (TRUCK UNLOADING) NONE

reduce capacity of system from 400 TPH to 50 TPH 

and limit source to receiving no more than 6 loads of 

limestone per day and 90 tons per day. Restrict 

limestone delivery to between 6am and 4 pm

0.0625 August 21, 2013 0.0000

LIMESTONE PILE (WIND EROSION) NONE reduce size of limestone pile from 2 acres to 1 acre Work Practice August 21, 2013 -0.0456 estimate based on reduction of pile size

27 AUXILIARY BOILER (29.26 MMBTU/HR) 13-A-152 NONE 60 0.567 NA 0.0000

28 UNIT 7 BOILER (289 MMBTU/HR) 74-A-175-S3 MULTICLONE/ESP 70 8.57 NA 0.0000

29 UNIT 8 BOILER (870 MMBTU/HR) 95-A-373-P2 OFA/ESP 80 37.57 NA 0.0000

30 FLY ASH SILO/ DRY FLY ASH TRUCK LOADING 00-A-639-S1 CARTRIDGE FILTER 810 0.056 NA 0.0000

31 WET FLY ASH TRUCK LOADING NA NONE 811 permanently remove emission unit(s) 0.0000 NA -0.0009

32 FLY ASH SILO 01-A-218-S1 BIN VENT FILTER 814 only one operation at a time: either truck loadout or 

silo filling 0.0013 August 21, 2013 0.0000

ASH/SLAG STORAGE PILES (TRUCK LOADING) NONE restrict operation to between 7am and 7pm 0.0031 August 21, 2013 0.0000

ASH/SLAG STORAGE PILES (TRUCK UNLOADING) NONE restrict operation to between 7am and 7pm 0.0031 August 21, 2013 0.0000

ASH/SLAG PILE (BULLDOZING) NONE Restrict operation to between 7am and 7pm. Allow 

the operation of only one bulldozer instead of three 0.0742 August 21, 2013 -0.0228 estimate of removing additional bulldozers

ASH/SLAG PILE (WIND EROSION) NONE Work Practice NA 0.0000

34 UNIT 9 BOILER (1556 MMBTU/HR) 80-A-191-P2 2 ESP/2 SCRUBBERS 90 43.59 NA 0.0000

35 REVERSING CONVEYOR A (LOAD/DISCHARGE) 13-A-157 NONE 912A 0.00121 NA 0.0000

36 REVERSING CONVEYOR B (LOAD/DISCHARGE) 13-A-158 NONE 912B 0.00121 NA 0.0000

39 RADIAL STACKER LOAD/DISCHARGE 13-A-159 NONE 916B reduce capacity of system from 40 TPH to 20 TPH and 

restrict operation to between 7am and 7pm 0.0012 August 21, 2013 0.0000

SYNTHETIC GYPSUM STORAGE PILE (TRUCK LOAD) NONE restrict operation to between 7am and 7pm 0.00121 August 21, 2013 0.0000

SYNTHETIC GYPSUM STORAGE PILE (TRUCK LOAD TRAFFIC) NONE restrict operation to no more than 9 gypsum trucks 

per day and operation to between 7am and 7pm Work Practice August 21, 2013 0.0000 currently load out 2-3 trucks per day

SYNTHETIC GYPSUM STORAGE PILE (RADIAL STACKER) NONE restrict operation to between 7am and 7pm 0.00121 August 21, 2013 0.0000

SYNTHETIC GYPSUM STORAGE PILE (PILE FORM) NONE restrict operation to between 7am and 7pm 0.0125 August 21, 2013 0.0000

SYNTHETIC GYPSUM STORAGE PILE (WIND EROSION) NONE reduce size of pile from 2 acres to 0.5 acres Work Practice August 21, 2013 -0.2273 based on reducing emissions from 0.0682 lb/hr to 0.0163 lb/hr

41 FLY ASH SILO 80-A-201-S1 BIN VENT FILTER 920 0.0058 NA 0.0000

42 FLY ASH STORAGE 80-A-200-S1 CARTRIDGE FILTER 920A

change stack to vertical 

unobstructed release and 

increase stack height from 12 

feet to 13.83 feet

Allow only one of either EP920A or EP920B to 

operate at any one time 0.122 September 20, 2013 0.0000 currently how emission units operate

43 FLY ASH STORAGE 13-A-147 CARTRIDGE FILTER 920B

change stack to vertical 

unobstructed release and 

increase stack height from 12 

feet to 13.83 feet

Allow only one of either EP920A or EP920B to 

operate at any one time 0.122 September 20,2013 0.0000 currently how emission units operate

44 DRY FLY ASH TRUCK LOADING/ UNLOADING 13-A-148 ENCLOSED SPOUT 924 restrict operation to between 7am and 4pm 0.032 August 21, 2013 0.0000

45 DRY FLY ASH TRUCK UNLOADING 01-A-456-S1 NONE 925 restrict operation to between 7am and 4pm 0.040 August 21, 2013 0.0000

46 ASH SILOS/DRY ASH TRUCK LOADOUT 01-A-457-S5 BAGHOUSE 926 restrict operation to between 7am and 4pm 0.018 August 21, 2013 0.0000

47 FLY ASH HOPPER LOADING 04-A-617-S1 WIND SCREEN 926A2 restrict operation to between 7am and 4pm 0.0084 August 21, 2013 0.0000

48 FLY ASH PILE FORMATION 04-A-618-S1 NONE 926A3 restrict operation to between 7am and 4pm 0.00095 August 21, 2013 0.0000

49 HAUL ROAD FLY ASH PILE TO HOPPER 04-A-619-S1 DUST SUPPRESANT 926A4 restrict operation to between 7am and 4pm Work Practice August 21, 2013 0.0000

50 FLY ASH VACUUM PUMP (5 GPH) NA NONE 928A permanently remove emission unit(s) 0.0000 October 12, 2013 -0.0098 average of 2007/2008 EIQ

51 FLY ASH BLOWER DIESEL EXHAUST (2 GPH) NA NONE 928B permanently remove emission unit(s) 0.0000 October 12, 2013 -0.0066 average of 2007/2008 EIQ

52 PORTABLE DIESEL GENERATOR (14.3 GPH) NA NONE 928C permanently remove emission unit(s) 0.0000 October 12, 2013 -0.0060 average of 2007/2008 EIQ

53 HYDRATED LIME SILO NA BAGHOUSE 990 permanently remove emission unit(s) 0.0000 Already Complete 0.0000 emission unit(s) not used since at least 2007

54 HYDRATED LIME MIXING TANK NA NONE 991 permanently remove emission unit(s) 0.0000 Already Complete 0.0000 emission unit(s) not used since at least 2007

55 12 PORTABLE GASOLINE ENGINES (4.83 GPH TOTAL) 13-A-150 NONE 7890 restrict operation to between 6am and 10pm 0.0604 August 21, 2013 0.0000

56 PORTABLE DIESEL ENGINE (4.0 GPH TOTAL) 13-A-151 NONE 7892 restrict operation to between 6am and 10pm 0.187 August 21, 2013 0.0000

57 PORTABLE DIESEL ENGINE - WELL PUMP (24.6 GPH) 11-A-562-S1 NONE V168 0.187 NA 0.0000

58 HAUL ROADS (POINT A - B) 13-A-160-S1 NONE 9999

apply water to road surface 

to reduce silt content 50% 

from 13.5 g/m2 to 6.75 g/m2

gypsum operation: restrict operation between 7am 

and 7pm. Limestone operation: restrict operation 

between 6am and 4pm. Ash/Slag Operation: restrict 

operation between 7am and 7pm

Work Practice August 21, 2013 -0.0668 based on reducing silt on road surface from 13.5 g/m2 to 

6.75 g/m2; increase by 0.0049 tpy due to Chem Mod

59 HAUL ROADS (POINT B - C) 13-A-160-S1 NONE 9999

apply water to road surface 

to reduce silt content 50% 

from 13.5 g/m2 to 6.75 g/m2

gypsum operation: restrict operation between 7am 

and 7pm. Limestone operation: restrict operation 

between 6am and 4pm. Ash/Slag Operation: restrict 

operation between 7am and 7pm

Work Practice August 21, 2013 -0.0554 based on reducing silt on road surface from 13.5 g/m2 to 

6.75 g/m2; increase by 0.0077 tpy due to Chem Mod

they currently do not receive more than 6 loads of limestone per day

33 13-A-143 860

40 13-A-146 919

4 13-A-139 24

26 13-A-142 45

ESTIMATED ACTUAL 

PM2.5 EMISSIONS 

REDUCTION (TPY)

LINE SOURCE NAME DRAFT 

PERMIT NUMBER

CURRENT 

CONTROL 

EQUIPMENT

EP ID ADD CONTROL MODIFY SOURCE 

PARAMETERS ESTABLISH OPERATIONAL RESTRICTION 

REQUIRED PM2.5 

EMISSION LIMIT 

(pounds/hour)

CONSTRUCTION/OPERATIONAL 

MODIFICATION COMPLETION DATE 

(no later than date listed below)
Attachment D - Muscatine Power Water Control Measures and Timeline

ESTIMATED ACTUAL 

PM2.5 EMISSIONS 

REDUCTION (TPY)

LINE SOURCE NAME DRAFT 

PERMIT NUMBER

CURRENT 

CONTROL 

EQUIPMENT

EP ID ADD CONTROL MODIFY SOURCE 

PARAMETERS ESTABLISH OPERATIONAL RESTRICTION 

REQUIRED PM2.5 

EMISSION LIMIT 

(pounds/hour)

CONSTRUCTION/OPERATIONAL 

MODIFICATION COMPLETION DATE 

(no later than date listed below)

60 HAUL ROADS (POINT C - B) UNPAVED 13-A-160-S1 NONE 9999

Pave road surface and apply 

water to road surface keep 

silt content at 6 75 g/m2

restrict operation between 7am and 7pm Work Practice August 21, 2013 -0.0147 based on reducing silt on road surface from 13.5 g/m2 to 6.75 g/m2

61 HAUL ROADS (POINT C - D) 13-A-160-S1 NONE 9999

apply water to road surface 

to reduce silt content 50% 

from 13.5 g/m2 to 6.75 g/m2

gypsum operation: restrict operation between 7am 

and 7pm. Limestone operation: restrict operation 

between 6am and 4pm. Ash/Slag Operation: restrict 

operation between 7am and 7pm

Work Practice August 21, 2013 -0.0918 based on reducing silt on road surface from 13.5 g/m2 to 

6.75 g/m2; increase by 0.0067 tpy due to Chem Mod

62 HAUL ROADS (POINT D - I) 13-A-160-S1 NONE 9999

gypsum operation: restrict operation between 7am 

and 7pm. Limestone operation: restrict operation 

between 6am and 4pm

Work Practice NA 0.0000

63 HAUL ROADS (POINT I - F) 13-A-160-S1 NONE 9999 restrict operation between 7am and 7pm Work Practice NA 0.0000

64 HAUL ROADS (POINT I - E) 13-A-160-S1 NONE 9999 restrict operation between 6am and 4pm Work Practice NA 0.0000

65 HAUL ROADS (POINT E - H) UNPAVED 13-A-160-S1 NONE 9999 restrict operation between 6am and 4pm Work Practice NA 0.0000

66 HAUL ROADS (POINT A - G) 13-A-160-S1 NONE 9999 restrict operation between 7am and 7pm Work Practice NA 0.0000

67 HAUL ROADS (POINT G - J) UNPAVED 13-A-160-S1 NONE 9999 restrict operation between 7am and 7pm Work Practice NA 0.0000

68 HAUL ROADS (POINT J - J) UNPAVED - see above 13-A-160-S1 NONE 9999 restrict operation between 7am and 7pm Work Practice NA 0.0000

69 LEVEE 13-A-161 NONE LEVEE restrict access to levee per plan included in 

construction permit NA August 21, 2013 0.0000

* If emission unit is operational before emission limit effective date, the date the unit becomes operational is the effective date of the PM2.5 emission limit -0.6906 TONS

1.19 % REDUCTION

58.2673 TONS
Attachment E. MPW Air Construction Permits

(See separate attachment document)

57
Attachment F. UTLX Control Measures and Timeline

58
Attachment F - Union Tank Car Control Measures and Timeline

1 Railcar Exterior Grit Blast Booth 93-A-251-S5 Baghouse EP-1 0.0156 J2 Railcar Interior Grit Blast (South) 93-A-252-S5 Baghouse and Panel Filter EP-2 Add additional filter to reduce particulate emissions emission point shall only vent inside production building 0.0095 Sept

3 Railcar Interior Grit Blast (North) 93-A-253-S5 Baghouse and Panel Filter EP-3 Add additional filter to reduce particulate emissions emission point shall only vent inside production building 0.0095 Sept

4 Railcar Vapor Removal & Flare 93-A-254-S3 Flare EP-4 0.0075 5 Railcar Exterior Painting 93-A-255-S7 Dry Filters EP-5A 0.08 6 Railcar Exterior Painting 96-A-629-S3 Dry Filters EP-5B 0.08 7 Railcar Exterior Painting 96-A-630-S5 Dry Filters EP-5C 0.08 8 Railcar Exterior Painting 96-A-631-S3 Dry Filters EP-5D 0.08 9 Railcar Interior Painting/Stencil & Touchup 96-A-636-S3 Pleated Filter EP-6A Add filter to reduce particulate emissions 0.021 Sept

10 Railcar Interior Painting/Stencil & Touchup 00-A-529-S2 Pleated Filter EP-6B Add filter to reduce particulate emissions 0.021 Sept11 Railcar Interior Painting/Stencil & Touchup 00-A-530-S2 Pleated Filter EP-6C Add filter to reduce particulate emissions 0.021 Sept12 Railcar Interior Painting/Stencil & Touchup 00-A-531-S2 Pleated Filter EP-6D Add filter to reduce particulate emissions 0.021 Sept13 Railcar Interior Painting/Stencil & Touchup 00-A-532-S2 Pleated Filter EP-6E Add filter to reduce particulate emissions 0.021 Sept14 Railcar Interior Painting/Stencil & Touchup 00-A-533-S2 Pleated Filter EP-6F Add filter to reduce particulate emissions 0.021 Sept

15 Railcar Interior Painting/Stencil & Touchup 93-A-256-S6 None EP-6G 0.04 16 Railcar Interior Painting/Stencil & Touchup 96-A-632-S5 None EP-6H 0.04 17 Railcar Interior Painting/Stencil & Touchup 96-A-633-S5 None EP-6I 0.04 18 Railcar Interior Painting/Stencil & Touchup 96-A-634-S5 None EP-6J 0.04 19 Railcar Interior Painting/Stencil & Touchup 96-A-635-S5 None EP-6K 0.04 20 Rubber Lining of Tank Cars 00-A-1089-S2 Cell Filter EP-7A Add filter to reduce particulate emissions 0.02 Nov21 Rubber Lining of Tank Cars 00-A-1090-S2 Cell Filter EP-7B Add filter to reduce particulate emissions 0.02 Nov22 Rubber Lining of Tank Cars 00-A-1091-S2 Cell Filter EP-7C Add filter to reduce particulate emissions 0.02 Nov23 Rubber Lining Building Ventilation 10-A-043-S2 Cell Filter EP-7D Add filter to reduce particulate emissions Changed stack orientation from horizontal to vertical, unobstructed 0.02 Nov

24 Rubber Lining Building Ventilation 10-A-044-S1 None EP-7E permanently cease operation of emission unit(s)/ emission point 0.000 Alre25 Inline Tank Car Qualification Process 09-A-009-S2 Pleated Filter 9A Add filter to reduce particulate emissions 0.027 Sept26 Inline Tank Car Qualification Process 09-A-010-S2 Pleated Filter 9B Add filter to reduce particulate emissions 0.027 Sept

27 Water Blast Operation 94-A-434-S2 None EP-27 0.037 28 Inline Tank Car Qualification Process 00-A-1086-S2 Pleated Filter EP-M1 Add filter to reduce particulate emissions Replace fan to increase airflow from 5000 scfm to 20,000 scfm 0.033 Sept

29 Inline Tank Car Qualification Process 00-A-1087-S2 Pleated Filter EP-M2 Add filter to reduce particulate emissions Replace fan to increase airflow from 5000 scfm to 20,000 scfm 0.033 Sept30 Inline Tank Car Qualification Process 00-A-1088-S2 Pleated Filter EP-M3 Add filter to reduce particulate emissions Replace fan to increase airflow from 5000 scfm to 20,000 scfm 0.033 Sept

* If emission unit is operational before emission limit effective date, the date the unit becomes operational is the effective date of the PM2.5 emission limit ** Compliance with emission limit may occur sooner if UTLX determines can meet required emission limit of 0.02 lb/hr without additional control equipment 

APPROXI

LINE SOURCE NAME ADD CONTROL

CURRENT PERMIT 

NUMBER

CONTROL 

EQUIPMENT

EP ID

MODIFY SOURCE PARAMETERS ESTABLISH OPERATIONAL RESTRICTION 

REQUIRED PM2.5 

EMISSION LIMIT 

(pounds/hour)

CONSTRUC

MODIFICATI

(no later th
Attachment G. UTLX Air Construction Permits

(See separate attachment document)

59
Attachment H. Proof of Publication

60