i

Regional Air Quality Analyses for

Ozone, PM2.5, and Regional Haze: 

Draft Modeling Protocol

August 2, 2010 (updated November 5, 2010)

States of Illinois, Indiana, Michigan, Ohio, and Wisconsin
ii

Table of Contents

Section-Title Page

1.0 Overview of Modeling Analysis Project 1

1.1 Regulatory Requirements 2

1.2 Management Structure 4

1.3 Technical Committees 4

1.4 Participating Organizations 4

1.5 Schedule 5

1.6 Description of Conceptual Model 5

2.0 Model and Modeling Inputs 7

2.1 Model Selection 7

2.2 Modeling Domain and Grid Spacing 7

2.3 Initial and Boundary Conditions 8

2.4 Episode Selection 8

2.5 Meteorological Modeling 9

2.6 Base Year Emissions 9

2.7 Future Year Emissions 15

2.8 Quality Assurance Procedures 16

3.0 Base Case Modeling 17

3.1 Ambient Data Base 17

3.2 Model Evaluation Procedures 17

4.0 Future Year Modeling 20

4.1 Model Future Year Control Scenarios 20

4.2 Apply Attainment Test 20

5.0 Weight-of-Evidence Demonstration 22

5.1 Ambient Data Analyses 22

5.2 Modeling Analyses 22

6.0 Procedural Requirements 23

6.1 Documentation 23

6.2 Deliverables 23

6.3 Resources 23

7.0 References 24

Appendix I Modeling Technical Details
1

Section 1.0

Overview of Modeling Analysis Project

This document describes the plans of the Lake Michigan Air Directors Consortium (LADCO) to 

conduct an air quality assessment in support of state implementation plans (SIPs) for ozone, 

fine particles (PM2.5), and regional haze for the States of Illinois, Indiana, Michigan, Ohio, and 

Wisconsin. The assessment will be conducted in accordance with U.S. Environmental 

Protection Agency (EPA) guidance: “Guidelines on the Use of Models and Other Analyses for 

Demonstrating Attainment of Air Quality Goals for Ozone, PM2.5, and Regional Haze”, EPA454/B07-002, April 2007. As EPA’s guideline changes (and as new information becomes 

available), this protocol document will be updated. Additional technical details for the new air 

quality assessment are provided in Appendix I.

The assessment will focus on attainment of the National Ambient Air Quality Standards 

(NAAQS) for ozone (2008 version) and PM2.5 (2006 version), and reasonable progress goals for 

regional haze. In addition, as discussed below, revised NAAQS for ozone and PM2.5 are 

expected soon. As necessary, the assessment will address these new standards.

A regional, multi-pollutant approach will be taken for technical reasons (e.g., commonality in 

precursors, emission sources, atmospheric processes, transport influences, and geographic 

areas of concern), and practical reasons (e.g., more efficient use of program resources). 

Furthermore, EPA has consistently encouraged multi-pollutant planning in its rule for the haze 

program (64 FR 35719), and its implementation guidance for ozone (70 FR 71663) and PM2.5

(72 FR 20609). 

The assessment includes the following tasks:

• A 2007/2008 base year emissions inventory will be prepared by the States and LADCO. 

2007 and 2008 data will be provided for EGU point, nonroad, and biogenics. 2008 data 

(only) will be provided for the other sectors (on-road, non-EGU point, and area). For 

these other sectors, LADCO will consult with the States and examine various emission 

surrogates (e.g., population, employment, and VMT) to determine whether the 2008 

emissions can be used “as is” to represent 2007 or whether they need to be adjusted to 

approximate 2007. 

• Both 2007 and 2008 meteorology will be used. Base case modeling to evaluate model 

performance will be performed for both years. 

• Future year modeling will be performed for three years: (TBD). Depending on the 

source sector, either the 2007/2008 emissions will be adjusted (by applying appropriate 

growth and control factors) or direct emission estimates will be made (using emission 

models) to derive the future year emissions. A decision will be made later based on 

technical reasons (e.g., meteorological and photochemical model performance) and 

policy reasons (e.g., ensure protection of public health) on which year(s) of meteorology

to use in the future year modeling.

• Sensitivity analyses will be conducted and probing tools will be applied to support the 

development of candidate control strategies.
2

• Control strategy modeling will include an initial scenario consisting of “on the books/on 

the way” controls. Additional strategies will be identified by the LADCO Project Team.

• Supplemental air quality analyses will be conducted as part of a “weight-of-evidence” 

demonstration. In particular, the results of the ambient data and alternative modeling 

analyses will be used to provide a more robust assessment of expected future year air 

quality. 

The report is organized in the following sections. This section provides a summary of regulatory 

requirements and background information on regional planning. Section 2 reviews the model 

and modeling inputs. Section 3 discusses the model performance evaluation and Section 4 

discusses the proposed strategy analyses, including application of EPA’s attainment test. The 

weight-of-evidence demonstration, based on the modeling and supplemental analyses, is 

addressed in Section 5. Section 6 reviews the plans to document the technical analyses and 

key project deliverables.

1.1 Regulatory Requirements

On March 12, 2008, EPA announced that it was strengthening the 8-hour primary (and 

secondary) ozone standard from the 1997 level of 0.08 parts per million (ppm) to 0.075 ppm. 

For the 2008 version of the ozone standard, EPA started the designation process by calling on 

states to submit their nonattainment recommendations by March 2009. Based on these 

recommendations and a review of the most recent air quality data, EPA indicated its intent to 

promulgate designations by March 2010.

On January 6, 2010, EPA proposed to tighten the 8-hour primary ozone standard to a level 

within the range of 0.060-0.070 ppm, and to establish a cumulative, seasonal secondary 

standard at a level within the range of 7-15 ppm-hours. The form of the primary standard 

remains the same (i.e., compliance is based on the 3-year average of 4th high 8-hour values). 

The form of the new proposed secondary standard is a “cumulative peak-weighted index,” 

called W126. In conjunction with this action, EPA delayed the designations for the 2008 (0,075 

ppm) standard from March 2010 to March 2011 in order to allow EPA to complete its 

reconsideration of the 2008 standard before determining whether designations are necessary. 

If, as a result of the reconsideration, EPA issues different ozone standards in 2010, then the 

new ozone standards would replace the 2008 ozone standards and implementation 

requirements associated with the 2008 ozone standards, including area designations, would no 

longer apply. Instead, EPA would begin a new process to designate areas for the 2010 ozone 

NAAQS on an accelerated schedule.

On September 21, 2006, EPA revised the NAAQS for particulate matter (PM). The revisions 

address two categories of particulate matter: fine particles (PM2.5), which are 2.5 micrometers in 

diameter and smaller; and inhalable coarse particles (PM10), which are smaller than 10 

micrometers in diameter.1

 1 On February 24, 2009, the U.S. Court of Appeals for the D.C. Circuit remanded the PM2.5 NAAQS to EPA for 

reconsideration of the annual level of the standard and reconsideration of the secondary PM2.5 NAAQS. EPA has 

yet to act on the Court’s decision and has indicated that it will do so as part of next review of the standard, which it 

expects to propose in November 2010.

EPA strengthened the 24-hour PM2.5 standard from 65 micrograms 

per cubic meter (μg/m3

) to 35 μg/m3, and retained the current annual PM2.5 standard at 15 
3

μg/m3. EPA also retained the existing national 24-hour PM10 standard of 150 μg/m3 and 

revoked the annual PM10 standard.

On December 22, 2008, EPA announced 

designations for 211 counties (or portions 

thereof) in 25 states, including Illinois, Indiana, 

Michigan, Ohio, and Wisconsin, as not meeting 

the NAAQS for PM2.5 based on 2005 – 2007 data. 

Because air quality monitoring data for 2008 was 

expected to become available shortly after EPA’s 

action, EPA indicated that it would evaluate the 

status of an area based on 2006, 2007, and 2008 

air quality data. On November 13, 2009, EPA 

published final area designations for the 24-hour 

national air quality standards for PM2.5.based on 

2006 – 2008 data. EPA designated 31 areas, 

including some or all of 120 counties, as 

nonattainment areas, including five areas in the 

LADCO region: Milwaukee, Detroit, Cleveland, 

Canton, and Steubenville.

Figure 1. Counties designated as 

nonattainment of the daily PM2.5 standard

These areas will need to develop and implement plans to meet the 24-hour PM2.5 standards 

within three years after the effective date of the designations. Nonattainment areas are required 

to meet the standards by 2014. 

For haze, the Clean Air Act sets “as a national goal the prevention of any future, and the 

remedying of any existing, impairment of visibility in Class I areas which impairment results from 

manmade air pollution.” There are 156 Class I areas, including two in northern Michigan: Isle 

Royale National Park and Seney National Wildlife Refuge2

 2 Although Rainbow Lake in northern Wisconsin is also a Class I area, the visibility rule does not apply 

because the Federal Land Manager determined that visibility is not an air quality related value there.

. EPA’s visibility rule (64 FR 35714, 

July 1, 1999) requires reasonable progress in achieving “natural conditions” by the year 2064. 

Per the Omnibus Appropriations Act of 2004, the first regional haze SIP was due in December 

2007 and must address the initial 10-year implementation period (i.e., reasonable progress by 

the year 2018). SIP requirements (pursuant to 40 CFR 51.308(d)) include setting reasonable 

progress goals, determining baseline conditions, determining natural conditions, providing a 

long-term control strategy, providing a monitoring strategy (air quality and emissions), and 

establishing BART emissions limitations and associated compliance schedule. 

EPA’s visibility rule also requires a report every five years “evaluating the reasonable progress 

goal for each mandatory Class I Federal area”. The first progress report is due five years from 

submittal of the initial implementation plan. Because all the LADCO States have yet to submit a 

complete haze SIP, the due date for the first progress report is uncertain. However, the LADCO 

Project Team has agreed to assume a due date of about July 1, 2015. To assist the states in 

tracking progress for haze (as well as other pollutants, including ozone and PM2.5), LADCO will 

prepare an annual air quality summary report. At the appropriate time, this report will be 

expanded to provide other required information (e.g., emissions trends) for the first progress 

report.
4

1.2 Management Structure

The technical work will be coordinated and/or conducted by LADCO3

Figure 2. LADCO Organizational Structure

. LADCO was established 

by the States of Illinois, Indiana, Michigan, and Wisconsin in 1989. The four states and EPA 

signed a Memorandum of Agreement (MOA) that initiated the Lake Michigan Ozone Study and 

identified LADCO as the organization to oversee the study. Additional MOAs were signed by 

the States in 1991 (to establish the Lake Michigan Ozone Control Program), 2000 (to broaden 

LADCO’s responsibilities), and 2004 (to update LADCO’s mission and reaffirm the commitment 

to regional planning). In 2004, Ohio joined LADCO. LADCO consists of a Board of Directors 

(i.e., the State Air Directors), a technical staff, and various workgroups. The main purposes of 

LADCO are to provide technical assessments for and assistance to its member states, and to 

provide a forum for its member states to discuss regional air quality issues. 

1.3 Technical Committees

The LADCO organization includes the LADCO staff and several LADCO committees – see 

Figure 2. The LADCO staff, working with these committees and, as necessary, contractors, will 

be responsible for conducting the technical work described in this document. Overall planning 

will be provided by the Project Team and policy direction by the state Air Directors (Technical 

Steering Committee) and Environmental Commissioners (Policy Steering Committee).

1.4 Participating Organizations

Given the large spatial extent of the modeling domain and the importance of transport in the 

eastern U.S. for PM2.5 and ozone, a process is needed to provide consistency and coordination 

between regional planning efforts by the Midwest, Southeast, and Northeast States. Unlike the 

 3 Between 2000 and 2009, a similar entity known as the Midwest Regional Planning Organization (MRPO) helped to 

coordinate and/or conduct technical and regulatory activities for the LADCO States for regional haze. The MRPO 

was led by the five LADCO States and involved tribes in Michigan and Wisconsin, EPA, and Federal Land Managers. 

EPA discontinued the RPOs in 2009 when it eliminated funding for these groups.
5

previous round of SIP modeling where the Regional Planning Organizations (RPOs) helped 

provide this function, there is no formal structure in place at this time to support the next round 

of SIPs. As such, the following process is proposed to ensure inter-regional consistency:

• The Eastern Regional Technical Advisory Committee (ERTAC) should continue its

efforts, given its recent success to ensure consistency in area source methodologies and 

to provide a rail inventory for the eastern U.S. Other areas of collaboration include 

agricultural ammonia emissions, EGU emissions (i.e., temporal profiles and growth 

methodologies), and data format/transfer.

• A group of met modelers should continue its work to support meteorological modeling for 

2007 using the WRF model.

• A group of photochemical modelers should work together to coordinate domain/grid 

configurations, model performance evaluations, and other issues, as necessary. 

This process consists of mainly state-led initiatives. Further discussion is needed to determine 

the appropriate role of EPA (and Federal Land Managers) and stakeholders. Involvement of 

these groups will provide for a more open process and, possibly, result in additional assistance

needed to accomplish key technical activities.

1.5 Schedule

Base case modeling is currently underway. Future year strategy modeling is expected to begin 

in early 2011. Approximate dates (and timeframes) for the modeling work are identified in 

Figure 3. 

Figure 3. Schedule for SIP Modeling

1.6 Description of Conceptual Model

An extensive network of air quality monitors in the 5-state region provides data for ozone (and 

its precursors), PM2.5 (both total mass and individual chemical species), and visibility. These 

data are used to determine attainment/nonattainment designations, support SIP development, 

and provide air quality information to public (see, for example, www.airnow.gov).

Analyses of the ambient monitoring data were conducted previously to produce a conceptual 

model, which is a qualitative summary of the physical, chemical, and meteorological processes 
6

that control the formation and distribution of pollutants in a given region. Section 2 of “Regional 

Air Quality Analyses for Ozone, PM2.5, and Regional Haze: Final Technical Support Document”, 

April 25, 2008 

http://www.ladco.org/reports/technical_support_document/tsd/tsd_version_iv_april_25_2008_fin

al.pdf) reviews these data analyses and describes our understanding of ozone, PM2.5, and 

regional haze with respect to current conditions, data variability (spatial, temporal, and 

chemical), influence of meteorology (including transport patterns), precursor sensitivity, and 

source culpability. 

The analyses will be revised with more recent air quality data and studies, including the 

following new technical reports: 

“A Conceptual Model of PM2.5 Episodes in the Midwest”, LADCO, January 2009

PM2.5

Blanchard, C. and S. Tanenbaum,”Analysis of Inorganic Particulate Matter Formation in the Midwestern 

United States”, Final Report, November 30, 2008

Schauer, J.J., A. Rutter, D. Snyder, E. Stone, M. Olson, J. Zhou, C. Worley, T. Katzman, R. Collins, R. 

Bader, T. Dallmann, J. DeMinter, M. Mieritz, B. Shelton, and A. Plourde, “LADCO Organic Molecular 

Marker Study”, Final Report, July 17, 2009, University of Wisconsin-Madison

Sullivan, A.P., and J.L. Collett, “Biomass Burning Impacts on Air Quality in the Upper Midwest”, Final 

Report, January 28, 2009, Colorado State University

Baek, J., G. Caremichael, S. R. Lee, J. Oleson, N. Riemer, T. Rohlf, S. Sousan, S. Spak, and C. Stanier, 

“Episodic Air Pollution in Wisconsin (LADCO Winter Nitrate Study) and Georgia (SEARCH Network) 

During Jan-May 2009”, Draft Phase I Report, July 22, 2010, University of Iowa and University of Illinois

Kenski, D., “Updated CART Analysis for Ozone through 2008 (Preliminary Draft)

Ozone

Following completion of these analyses, an updated conceptual model will be prepared.
7

Section 2.0

Model and Modeling Inputs

All modeling analyses will be conducted in accordance with EPA guidance: “Guidelines on the 

Use of Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for 

Ozone, PM2.5, and Regional Haze”, EPA-454/B07-002, April 2007. 

The new regional modeling will build upon the analyses conducted by LADCO, its member 

states, and its contractors to address the 1997 version of the ozone and PM2.5 standards, and 

regional haze. The prior modeling, which reflects a 2005 base year (Base M), is documented in 

“Regional Air Quality Analyses for Ozone, PM2.5, and Regional Haze: Final Technical Support 

Document”, April 25, 2008

http://www.ladco.org/reports/technical_support_document/tsd/tsd_version_iv_april_25_2008_fin

al.pdf).

This section reviews the modeling system to be used and the development of model inputs. 

Model evaluation and model application (i.e., attainment demonstration) are covered in the 

following sections.

2.1 Model Selection

The proposed modeling system for the new modeling consists of:

Emissions – CONCEPT (the most current version will be used)

Meteorology – MM5 or WRF (see Section 2.5)

Photochemical - CAMx (the most current version will be used). Model set-up is 

summarized below:

CB05 gas phase chemistry SOA chemistry updates

Wesley-based dry deposition scheme ISORROPIA inorganic chemistry

SOAP organic chemistry RADM aqueous phase chemistry

PPM horizontal transport

CAMx is recommended for the following reasons: (1) familiarity and reliability (i.e., the 

LADCO States have been using CAMx for several years), (2) operator considerations 

(i.e., ease of application and resource requirements), and (3) model extensions (2-way 

nesting, plume-in-grid, and source apportionment). 

Base case modeling will also be performed with CMAQ. The performance of CAMx and 

CMAQ will be considered in deciding whether to also use CMAQ for some of the future 

year modeling runs

2.2 Modeling Domain and Grid Spacing

The proposed modeling domain will provide greater spatial coverage and finer horizontal grid 

spacing compared to the previous regional modeling. Specifically, it is proposed that the new 

modeling will use an expanded U.S. domain (36km grid spacing), a slightly modified Midwest 

subdomain (12km), and Lake Michigan and Detroit-Cleveland subgrids (4km) – see Figure 4.
8

Figure 4. Proposed modeling domains – 36 and 12 km grids (left) and 12 and 4 km grids (right)

The air quality model will resolve the atmosphere up to 15 km with 16(??) vertical layers, with 

higher resolution in the boundary layer. 

For PM2.5, a full year of met data will be run with the 36 and 12km grids. For ozone, a summer 

season (May – September) will be run with the 36, 12, and 4 km (Lake Michigan and DetroitCleveland) grids

2.3 Initial and Boundary Conditions

Boundary conditions represent pollution inflow into the model from the lateral edges of the grid 

and initial conditions provide an estimation of pollution that already exists. The effect of 

boundary conditions is minimized by focusing on areas far removed from the edge of the 

modeling domain, and the effect of initial conditions is minimized by assuming a “spin-up” period 

of a couple weeks.

 

The initial conditions from the previous LADCO regional modeling (Base M), which were based 

on GEOS-CHEM, were used. New boundary conditions were derived from NCAR’s “Model for 

Ozone and Related Chemical Tracers” (MOZART) using scripts and programs prepared by a 

contractor for LADCO.

2.4 Episode Selection

The new modeling will use meteorological data for two recent full years: 2007 and 2008. 

Specifically, base case modeling will be performed for both years to evaluate model 

performance. A decision will be made later based on technical and policy reasons on which 

year(s) to use in the future year modeling.

In addition, to provide a more complete model performance evaluation, the periods associated 

with LADCO’s recent special monitoring studies will be considered (e.g., Biomass Burning Study 

and Molecular Marker Study: June-July 2007 and January–February 2008, and Winter Nitrate 

Study: December 2008-March 2009). 
9

2.5 Meteorological Modeling

Two sets of meteorology will be considered for use in the modeling. First, MM5 was used by 

Alpine Geophysics, under contract to the Midwest Ozone Group, to generate meteorological 

fields for 2007 and 2008. Further discussion of this meteorological modeling, including an 

evaluation of model performance, is provided in “Evaluation of 36/12 m MM5 for Calendar Year 

2007 over the Continental and Midwest/Eastern United States”, August 31, 2009. The initial 

regional modeling will rely on these meteorological fields. Key findings of this performance 

evaluation include:

• Temperature bias performance on both the 36 and 12 km grids indicated only a few 

minor issues (i.e., the +0.5K benchmark was not met in some areas for certain months). 

Temperature error statistics, however, indicated difficulty in meeting the 2.0K 

benchmark, especially in western areas.

• Mixing ratio bias and error statistics were typically good at all levels on both the 36 and 

12 km grids.

• The model showed mixed results for the wind index of agreement, with good 

performance in western areas and poorer performance in eastern areas.

• The model does a reasonable job of replicating rainfall, but does overpredict the 

magnitude of rainfall and the spatial extent of rainfall, especially in the summer months.

• Compared to other recent MM5 applications, the 36 and 12 km results from the current 

simulation were similar, although the 12 km mixing ratio results reflect slightly poorer 

performance.

Second, as noted above, an ad hoc group of met modelers produced meteorological data for 

2007 using the WRF model. These meteorological fields will be evaluated, and a decision will 

be made on whether to use the MM5 data or the WRF data.

2.6 Base Year Emissions 

The emissions base year for the new regional modeling is 2007/2008. 2007 and 2008 data will 

be provided for EGU point, nonroad, and biogenics. 2008 data (only) will be provided for the 

other sectors (on-road, non-EGU point, and area). Based on consultation with the States, 

LADCO believes that based on examination of various emission surrogates (e.g., population, 

employment, and VMT), the 2008 emissions for these sectors can be used “as is” to represent 

2007. 

For on-road, off-road, ammonia, and biogenic sources, emissions will be estimated by LADCO 

using emission models. Three other off-road categories are not accounted for by the 

NONROAD emissions model: commercial marine, aircraft, and rail. Marine emissions will 

continue to be based on LADCO’s Base M (2005) inventory. Aircraft emissions will be provided 

by the States. Rail emissions will be based on the new (2008) inventory prepared by ERTAC. 

For point and area sources, emissions will be prepared using data supplied by the LADCO 

States and other regional organizations. Table 1 summarizes the development of the base year 

inventory. Further discussion is provided below for each source sector for the LADCO region. 

For the rest of the modeling domain, the latest base year and future year inventories from other 

regional organizations will be used. (Note, Base M inventories will be used in the interim until 

more recent inventories are available from other regional organizations.)
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Table 1. Overview of Base Year Emissions Development

Sector Method Responsible Group

EGU Point State NEI data, supplemented w/ CEM data (2007,

2008)

States and S.Edick/LADCO, 

w/ ERTAC-derived temporal 

profiles

Non-EGU Point State NEI data (2008) States

Area State NEI data based on ERTAC methods (2008) States

Off-road NONROAD + LADCO fixes (2007, 2008) Grant Hetherington

Marine, Aircraft, and Rail 

(MAR)

Marine - LADCO inventory (Base M)

Aircraft - State data

Rail - ERTAC data (2008)

States, EPA, and ERTAC

Agricultural Ammonia CMU-based emissions (initially).

UC-Riverside process-based model w/ local data

LADCO + state-supplied 

data, w/ ERTAC assistance

Biogenics MEGAN in CONCEPT (2007, 2008) Supplied by MOG 

contractor (Environ)

On-road Select link-level networks run with CONCEPT (2008) MPOs/States and LADCO

Fires Satellite-based data (2007, 2008) S.Spak (Univ of Iowa)
11

On-Road Sources: To support regional emissions inventory development for upcoming 

photochemical modeling, LADCO will rely on EPA’s new MOVES2010 model for on-road motor 

vehicles. MOVES2010, which was released by EPA in December 20104

• For the five LADCO States, a state-level run will be conducted using national defaults for 

each month to produce a weekday and weekend emission estimate (for each month). 

The purpose of these runs is to produce a temporal profile for each state as a function of 

pollutant, emission type (exhaust and evaporative), and vehicle type (gasoline and 

diesel).

, was developed for 

state/local air quality and transportation agencies to use in preparing on-road inventories for 

SIPs and transportation conformity. MOVES2010 replaced the previous model for estimating 

on-road mobile source emissions, MOBILE6.2. EPA guidance is for states to use MOVES2010 

“in ozone, CO, PM, and NO2 SIP development as expeditiously as practicable.” Furthermore, 

EPA stated that MOVES2010 “must be used for developing on-road mobile source inventory for 

the 2006 PM2.5 NAAQS SIPs”. 

MOVES2010 was developed principally to be run in an “inventory” mode (i.e., monthly average, 

county-level emission estimates), which is what state/local agencies need for their SIP 

inventories and conformity demonstrations. For photochemical modeling, however, more 

refined temporal and, perhaps, spatial information is desired. Two options exist for providing 

this more refined information: (1) running MOVES2010 for each hour (using concurrent 

meteorological conditions) to provide the appropriate emission factor, or (2) developing 

MOVES2010 “look-up” tables which cover the expected ranges of key meteorological variables 

and then using the tables to provide the emission factor for each hour based on the concurrent 

meteorological conditions. Initial PC-based modeling showed that the first option was 

prohibitive (i.e., model test run times with default meteorology were on the order of 2 calendar 

days per county group; assuming 150 county groups in the eastern U.S. and 2 fuel seasons, the 

total time to complete a model run is about 600 days!). Subsequent Linux-based modeling 

produced a factor of 2 decrease in model run times, but still suggested that the look-up table 

option was preferable.

Using a Linux-based version of MOVES2010 created by Wisconsin DNR, initial on-road motor 

vehicle inventories will be prepared as follows:

• For the five LADCO States (and neighboring states: MN, IA, and MO5

), a county-level 

run will be conducted using national defaults for January and July to produce a weekday 

and weekend emission estimate for these two months. 

• The temporal profiles (from the state-level runs) will then be applied to the county-level 

emission estimates (for January and July)6

 4 In September 2010, EPA released an updated version of MOVES2010 (i.e., MOVES2010a). Although 

MOVES2010 was used in LADCO’s initial modeling, MOVES2010a will be used in any subsequent 

modeling.

5 County-level runs were also completed for KY, TN, and WV as part of the initial Base B MOVES 

processing, but were not included in the regional modeling inventory files.

6 The monthly emission estimates derived from applying the temporal profiles to the January-July countrylevel emissions will match the specific January and July values.

to produce a more weekday and weekend 
12

emission estimate for each month. (Note, for the non-LADCO States, either the 

temporal profile for the closest LADCO State will be used or the July result will be used 

to represent the summer months, and the January result will be used to represent the 

other months.)

• The resulting county-level weekday and weekend emission estimates for the nine states 

will be processed as an area source in EMS. Emission processing assumptions include:

Temporal: Weekday emissions assigned to Monday-Friday, and weekend emissions 

assigned to Saturday-Sunday. It should be noted that the emission files already 

reflect hourly values.

Spatial: Applied 2002 surrogates based on roadway type.

Speciation: Exhaust and evaporative emissions by vehicle type (gasoline and diesel) 

speciated separately.

To produce more refined on-road emission estimates for the 5-state LADCO region, the 

following steps will be taken:

• LADCO to read the 2007 and 2008 met data and identify appropriate ranges (and 

intervals) for key meteorological variables (e.g., ambient temperature). Use a default 

curve defined by min and max temperature to define hourly temperatures for the 

evaporative species. 

• LADCO States to provide MOVES2010a inputs for the 2007 emissions base year, and 

identify the appropriate county groups in their state. LADCO will use this information to 

run the Linux-based version of MOVES2010a to produce two sets of look-up tables for 

2007 - one for the summer and one for the non-summer fuel seasons - as a function of 

county group.

• Integrate the MOVES2010a look-up tables into CONCEPT

Subsequent versions of the on-road inventory will reflect the use of link-level data for five (or six)

core networks (Chicago, Gary, Milwaukee, Cleveland, Detroit, and, perhaps, Cincinnati) for a 

weekday/Saturday/Sunday for each month (36 days) and 12-20 additional episode days, as 

time permits. For the other networks in the LADCO region, the existing 2005 networks will be 

grown to reflect 2007 VMT. For these networks (and for other parts of the country), the best 

available MOVES-based emissions will be used

Off-Road Sources: NMIM2008 will be run (using default monthly temperatures) by Wisconsin 

DNR for the 2007 and 2008, and the future years of interest for the five LADCO States plus MN, 

IA, and MO. Additional off-road sectors (i.e., commercial marine, aircraft, and railroads [MAR]) 

will be handled separately7

 7 Although EPA is preparing a national commercial marine inventory, questions have been raised about 

EPA’s methods. As such, LADCO will work with the States to update, if necessary, the 2005 Great Lakes 

commercial marine inventory developed by a contractor for Base M. Also, States will provide aircraft 

emissions and ERTAC’s 2007 rail inventory will be used.

. Local data for agricultural equipment, construction equipment, 

commercial marine, recreational marine, and railroads were prepared previously by contractors 
13

(Environ, 2004, E.H. Pechan, 2004, and Environ, 2007b, 2007c). These data, along with any 

new information for rail developed by ERTAC, will be used.

Area and Point Sources: CONCEPT (or EMS) will be run by LADCO using data supplied by the 

LADCO States to produce weekday, Saturday, and Sunday emissions for each month. The 

ERTAC recommendations on area sources will be followed in preparing these data. For EGUs, 

the annual and summer season emissions will be temporalized for modeling purposes using 

profiles prepared by Scott Edick (Michigan DEQ) based on CEM data.

Biogenics: Environ, under contract to the Midwest Ozone Group, produced day-specific 

biogenic emissions for the full modeling domain using the CONCEPT/MEGAN biogenics model

for 2007 and 2008. These emissions, which are generally consistent with preliminary MEGAN 

modeling by LADCO, will be used in the modeling.

Ammonia: LADCO will produce an agricultural ammonia inventory for the full modeling domain. 

An updated version of the process-based ammonia emissions model was recently delivered by 

a contractor. Previously (i.e., for Base M), the process-based model (Zhang, et al, 2005, and 

Mansell, et al, 2005) was used to develop temporal factors for the CMU-based (Base K) 

ammonia emissions. (Note, 2002 Base K emissions were first projected to 2005 using growth 

factors from the Round 4 emissions modeling.) For the initial new modeling, this same 

approach will be used. It is hoped that the updated process-based model will be available to 

use in subsequent versions of the modeling inventory.

Canadian Emissions: Scott Edick (Michigan DEQ) processed the 2005 Canadian National 

Pollutant Release Inventory, Version 1.0 (NPRI) and will determine if a newer version of the 

inventory is available.. A subset of the NPRI data (emissions and stack parameters) relevant to 

the air quality modeling were reformatted and will be used in the new regional modeling.

Fires: the University of Iowa will produce an inventory based on MODIS satellite data from 

NCAR for 2007 and 2008. In addition, EPA is preparing a national inventory for wild fires, 

prescribed fires, and agricultural burns. These two inventories will be examined and a decision 

will be made about which will be used in the modeling.

The base year inventory will be developed in phases, as described in Table 2. Outstanding 

issues for the base year inventory include: 

• Reliability of the MOVES-based on-road emission estimates. (Note, a separate effort 

is underway to do a top-down evaluation of these emissions using ambient 

monitoring data – i.e., a comparison of ambient and emissions ratios for select 

species.)

• Acceptability of new MEGAN emission estimates

• Development of agricultural ammonia emission estimates

• Use of improved PM and VOC speciation profiles

• Incorporation of ERTAC rail emissions and improved commercial marine emissions

• Inclusion of both PM-filterable and PM-condensible emissions
14

Table 2. Contents of Basecase Inventory

Sector Base A Base B Base C

EGU Point 2007 CEM data (annualized w/ 

2005-2007 temporal)

2007 CEM data (annualized w/ 

2005-2007 temporal)

2007 CEM data (annualized w/ 

updated temporal)

(updated EGU-nonEGU splitting)

Non-EGU Point Base M (new grid) 2008 State data

2008 State data

(updated EGU-nonEGU splitting)

Area Base M (new grid) 2008 State data 2008 State data

Nonroad Base M (new grid) 2007, 2008 NONROAD2008 2007, 2008 NONROAD2008

MAR Base M (new grid)

Rail – Base M (new grid)

Marine - Base M (new grid)

Aircraft - 2008 State data

Rail - ERTAC

Marine – Modified Base M

Aircraft - 2008 State data

Agricultural 

Ammonia Base M (new grid) Base M (new grid) Base M (new grid) or new ammonia emissions model

Biogenics MEGAN w/ 2007 met (new grid) MEGAN w/ 2007 met (new grid) MEGAN w/ 2007 met (new grid)

On-road Base M (new grid) MOVES-based emissions (national 

default inputs)

MOVES-based emissions (state 

inputs)

Fires (not included) 2007, 2008 data (S.Spak) 2007, 2008 data (S.Spak)

Non-LADCO 

Region Base M (new grid) Base M (new grid) New 2007 emissions (per State Collaborative process) or EPA data
15

2.7 Future Year Emissions

The future years of interest for the new regional modeling are: (TBD).

For on-road and nonroad sources, the future year emissions will be estimated by models (i.e., 

CONCEPT and NMIM, respectively). Future year data will be supplied for five select networks.

For area, MAR, and non-EGU point sources, the future year emissions for the LADCO States 

will be derived by applying growth and control factors to the base year inventory. Given 

resource constraints, the growth factors from the previous regional modeling (E.H. Pechan, 

2007) be used, subject to review and, if necessary, modification by a workgroup of state and 

local agency personnel.

For EGU point sources, ERTAC will be developing an appropriate growth methodology.

Due to a lack of information on future year conditions, the biogenic VOC and NOx emissions, 

and all Canadian emissions8

• Federal Motor Vehicle Emission Control Program, low-sulfur gasoline and ultra-low sulfur 

diesel fuel

will be assumed to remain constant between the base year and 

future years.

A “base” control scenario will be prepared based on the following “on the books” controls:

On-Highway Mobile Sources

• Inspection - maintenance programs

• Reformulated gasoline

Off-Highway Mobile Sources

• Federal control programs incorporated into NONROAD model (e.g., nonroad diesel rule), 

plus the evaporative Large Spark Ignition and Recreational Vehicle standards

• Heavy-duty diesel (2007) engine standard/Low sulfur fuel

• Federal railroad/locomotive standards

• Federal commercial marine vessel engine standards

Area Sources

• Consumer solvents

• AIM coatings

• Aerosol coatings

• Portable fuel containers

Power Plants

• CAIR or proposed Transport Rule

Other Point Sources

• VOC 2-, 4-, 7-, and 10-year MACT standards

• Combustion turbine MACT

• Consent decrees (e.g., petroleum refineries, ethanol plants, and ALCOA in Indiana)

• NOx RACT

• BART emission limitations for units subject to BART

 8 Future year Canadian emissions will be used, if available.
16

Further discussion (and coordination with other regions and EPA) is needed to confirm the list of 

“on the books” controls. Additional control scenarios will be modeled based on direction from 

the LADCO Project Team.

2.8 Quality Assurance Procedures

In its September 1, 2004, “Quality Management Plan”, LADCO describe its policies and 

practices to ensure the integrity and accuracy of the information produced. The plan was 

approved by EPA on January 26, 2005. In accordance with the plan, the following quality 

assurance activities will be conducted: 

• Review model inputs and outputs – each emissions modeler will review the model input files, 

and the graphical and tabular model outputs for reasonableness and consistency 

Emissions 

• Benchmark modeling – each modeling group will duplicate a set of standard modeling results 

• Reports - a standard set of graphical and tabular model outputs will be generated and 

reviewed

• Documentation – appropriate written reports will be prepared which summarize the modeling 

analyses 

• Establish consistent file naming convention 

Modeling 

• Review model inputs – each modeling group will review the air quality model emission (and, if 

appropriate, meteorological) input files (e.g., compare emission totals with EMS reports, and 

examine spatial maps of emissions) 

• Benchmark modeling – each modeling group will duplicate a set of standard modeling results 

• Duplicative modeling – a few runs will be modeled by more than one group 

• Reports - a standard set of graphical and tabular model outputs will be generated and 

reviewed

• Documentation – appropriate written reports will be prepared which summarize the modeling 

analyses 
17

Section 3.0

Base Case Modeling

The purpose of the base case modeling is to evaluate model performance (i.e., assess the 

model's ability to reproduce the observed concentrations). The model performance evaluation 

will focus on the magnitude, spatial pattern, and temporal of modeled and measured 

concentrations. This exercise is intended to build confidence in the model prior to its use in 

examining candidate control strategies.

Model performance will be evaluated by comparing modeled and monitored concentrations. For 

ozone, species of interest include ozone, total NMOC, select VOCs and carbonyls (e.g., 

benzene and formaldehyde), and NOx (and/or NOy). The relevant averaging times for these 

species are 1-hour and 8-hour. For PM and haze, species of interest include PM2.5 -mass 

(gravimetric and RCFM), SO4, NO3, NH4, EC, OC, soil, bscat, coarse mass, as well as several 

gaseous precursors, such as NH3, HNO3, and SO2. The relevant averaging times for these 

species are 1-hour and 24-hour.

3.1 Ambient Data Base

For 2007 and 2008, ground-level air quality measurements from routine state/local-operated 

ambient monitoring stations will be obtained from EPA’s Air Quality System (AQS). Other 

sources of air quality measurements include data from LADCO-sponsored field studies (i.e., 

Molecular Marker Study, Biomass Burning Study, and Winter Nitrate Study).

3.2 Model Evaluation Procedures

EPA’s modeling guidelines identify two ways to evaluate the performance of an air quality 

model: 

(1) how well is the model able to replicate observed concentrations of PM2.5

components, ozone and/or precursors (surface and aloft), and

(2) how accurate is the model in characterizing the sensitivity of ozone and/or PM2.5 to 

changes in emissions? 

An operational evaluation is performed to answer the first question, while a more in-depth, 

diagnostic evaluation is performed to answer the second question. This second questions is 

important given that the modeled attainment tests use models to predict the response of ozone 

and PM2.5 to changes in emissions and then applies the resulting relative response factors to 

ambient monitoring data. 

The proposed operational evaluation of model performance consists of the following 

comparisons of modeled and monitored concentrations:

Time series plot of mean bias

• Peak daily 8-hour ozone with 40/60/80 ppb thresholds

• Monthly average PM2.5 by chemical species

Scatterplots

• Ozone – hourly concentrations

• PM2.5 – daily concentrations
18

Spatial concentration plots

• Ozone: May 22-24, 2007 (or May 29-31, 2007), June 15-18, 2007, Aug 1-3, 2007, 

and July 16-18, 2008

• PM2.5: May 29-June 2, 2007, Aug 2-3, 2007, Dec 18-21, 2007, Feb 23-24, 2008, 

and July 18-19, 2008

Individual monitor time series – one for 2007, and one for 2008

Ozone

Warren OH 391650007 Cincinnati – Taft 390610040

PM2.5

Ashtabula OH 390071001 Cleveland-G.T. Craig 390350060 

Holland MI 260050003

Port Huron MI 261470005 Detroit-Dearborn 261630038

Sheboygan WI 551170006 Green Bay WI 550090005

Chiwaukee WI 550590019 Milwaukee – SE Hdqs 550790026

St.Louis – W. Alton 291831002 Granite City IL 171630010

Chicago – Springfield 170310057

Minn. – Anderson 270530963

Columbus OH 390490029 Steubenville OH 390810017

Noblesville IN 180570005 Indianapolis-18th St 180970081

Charlestown IN 180190008 Jeffersonville IN 180190006

New Paris OH 391351001 New Paris OH 391351001

Mayville WI 550270007 Mayville WI 550270007

Port Stanley ON Port Stanley ON

Northbrook IL 170314201 Gary IITRI 180890022

Ozone precursors (NOx or NO2, and VOC – which species??)

Detroit - E. 7 mile 261630025 Milwaukee - SE Hdqs 550790026

Cincinnati – Taft 390610040 Braidwood IL 171971011

The model-to-monitor comparisons will be paired in time and space. The modeled values should 

be taken from grid cells “near” a monitor (e.g., from the 3x3 grid cells centered on the monitor 

for 12 km modeling). 

No rigid acceptance/rejection criteria will be used for this study. Instead, the statistical 

guidelines recommended by EPA and other modeling studies (e.g., modeling by the other 

RPOs) will be used to assess the reasonableness of the results here. 

The proposed diagnostic evaluation of model performance will focus on the change in ambient 

ozone and PM2.5 concentrations between 2002, 2005, and 2008. A previous operational 

evaluation by LADCO compared observed and modeled ozone concentrations for the summers 

of 2002 and 2005 (Baker, 2007). Figure 5 below shows the paired change in observed 

concentration (x-axis) and modeled concentration (y-axis). Even though the model tends to 

underestimate higher observed absolute ozone concentrations, the figure shows that the model 

response matches the observed response.
19

Figure 5. Paired observed concentration change and modeled concentration change (absolute 

values in red and percentage values in blue)
20

Section 4.0

Future Year Modeling

The purpose of the future year modeling is to assess the effectiveness of existing and possible 

additional control programs. The model will be used in a relative sense to project future year 

values, which are then compared to the NAAQS to determine attainment/nonattainment. 

Further discussion of the future year control scenarios and application of EPA’s attainment test 

is provided below.

4.1 Model Future Year Control Scenarios

A “base” control scenario reflecting “on the books” controls will be modeled: Additional control 

scenarios will be identified by the LADCO Project Team.

To help guide the development of control scenarios, sensitivity modeling will be conducted. The 

purpose of these model runs is to assess the effect of changes in the amount, type, and location 

of primary and precursor emissions. Possible sensitivity tests include: 

• General control path analyses, such as “matrix” runs, which examine the effect of 

reductions by species, source categories, and geographic area. 

• Focused attainment analyses, which attempt to estimate the type and amount of 

emission reductions needed to meet the ambient standards using USEPA’s attainment 

tests.

Probing tools, such as OSAT/PSAT and DDM, will also be used to provide information on 

source contributions and source sensitivity, respectively.

4.2 Apply Attainment Test

The absolute modeled concentrations from the future year control scenario modeling will be 

processed to assess attainment of the NAAQS. The basic analysis steps are as follows:

(1) Calculate base year design values: For ozone and PM2.5, the base year design 

values will be derived by averaging the three 3-year periods centered on the base 

year:

2007 base year: 2005-2007, 2006-2008, and 2007-20099

(2) Estimate future years values: For each grid cell, a relative reduction factor (RRF) is

calculated by taking the ratio of the future year and baseline modeling results. For 

Ground-level air quality measurements for 2005 - 2009 from routine state/localoperated ambient monitoring stations will be obtained from EPA’s Air Quality System 

(AQS). 

 9 As noted above, a decision will be made later based on technical and policy reasons on whether to use 

2007 or 2008 meteorology to use in the future year modeling. For the purpose of this document, it is 

assumed that 2007 meteorology will be used.
21

each grid cell (with a monitor), the RRFs are multiplied by the base year design 

values to project the future year values

Ozone concentrations will be estimated for those grid cells/counties with ozone

monitors. PM2.5 concentrations will be estimated for those grid cells/counties with 

FRM (PM2.5-mass) monitors. Spatial mapping will be performed to extrapolate 

PM2.5-speciation data from STN and IMPROVE sites to FRM sites. 

 

EPA’s attainment test program (referred to as MATS) will be used. Issues to be 

considered in applying the attainment test include:

• Cell Selection: For a given monitor, how far away should modeled values be 

taken?

• Model Performance: Should only those days with good model performance be 

used in the calculation?

• Concentration Threshold: A threshold concentration of 70 ppb will be assumed in 

calculating RRFs for ozone (i.e., only those days with base case modeled values 

equal to or greater than 70 ppb will be used). 

(3) Assess attainment: Future year values are compared to the NAAQS to determine

attainment or nonattainment.

The modeling results will be presented in graphs, such as scatter plots, 

concentration difference plots, threshold difference plots, and time series plots, and 

in tables.

Consistent with EPA’s modeling guidance, an “unmonitored area analysis” will also 

be performed to identify areas where absolute modeled values are predicted to be 

greater than the NAAQS (see Baker, 2005).
22

Section 5.0

Weight of Evidence Demonstration

This section provides an overview of information that will be considered along with the future 

year modeling in a “weight of evidence” demonstration of whether an area is likely to attain the 

NAAQS by the applicable date. EPA guidance recommends that “supplemental evidence 

should accompany all model attainment demonstrations.” In particular, EPA encourages 

analyses that “help determine whether the model likely overpredicts, underpredicts, or 

accurately predicts the air quality improvement projected to occur by the attainment date.” 

5.1 Ambient Data Analyses

The following analyses of monitoring data will provide information on the effect of emission 

reductions by pollutant, geographic area, and source category:

• observation-based modeling;

• trends in air quality and emissions (e.g., how have reductions in certain precursors 

affected ozone and PM2.5 concentrations over time?);

• trajectory analyses (e.g., what can we say about the contribution from individual states 

on certain downwind locations); and

• monitor-based source apportionment analyses (e.g., what can we say about the 

contribution of individual source categories on PM2.5 nonattainment areas).

For example, based on the results of several air quality studies, LADCO prepared a White 

Paper which identified measures which will be effective in lowering PM2.5 daily concentrations 

in the Midwest. This document will be updated using more recent studies and expanded to 

address other pollutants.

5.2 Modeling Analyses

The following modeling analyses will be provide information on source contributions and the 

likelihood of attaining the standards:

• alternative modeling (i.e., use of the guideline modeling described in the previous 

sections with different assumptions, such as alternative calculation of base year design 

values);

• additional modeling (e.g., EPA’s latest regional ozone and PM2.5 modeling as part of the 

proposed Transport Rule will be considered as corroborative information); and

• model-based source apportionment using the source apportionment tools in CAMx to 

estimate the impact of specific geographic source regions and specific source sectors at 

monitoring sites in the region.
23

Section 6.0

Procedural Requirements

This section summarizes several important procedural issues related to the air quality 

assessment, including documentation, deliverables, and resources.

6.1 Documentation

To document the air quality assessment, technical memoranda will be prepared for the following 

topics:

• Base year and future year emission inventories

• Base year and future year modeling

• Conceptual model

In addition, appropriate work products, including data files, tables, graphics, technical 

memoranda and reports will be made available on LADCO’s website (see Technical Activities 

page: http://www.ladco.org/tech/).

6.2 Deliverables

As the technical analyses proceed, periodic updates will be provided at Project Team meetings 

and conference calls. Results will also be shared with interested stakeholders at public 

workshops.

Upon completion of the analyses, a Technical Support Document will be prepared, similar to the 

document from the last assessment – see “Regional Air Quality Analyses for Ozone, PM2.5, and 

Regional Haze: Final Technical Support Document”, April 25, 2008 

http://www.ladco.org/reports/technical_support_document/tsd/tsd_version_iv_april_25_2008_fin

al.pdf).

6.3 Resources

No additional federal or state funding for contractor assistance is expected to be available for 

the new air quality assessment. If such funding does become available, then using these funds 

may be used for contractor assistance for certain key activities, such as:

• Updated growth and control factors

• Link-based motor vehicle emissions

• Agricultural ammonia emissions

• Review and improve nonroad emission estimates

• White papers for candidate control strategies.
24

Section 7.0

References

Alpine Geophysics, 2009, “Evaluation of 36/12 m MM5 for Calendar Year 2007 over the 

Continental and Midwest/Eastern United States”, August 31, 2009. 

Baker, K. “Hot Spot Test (Draft)”, Lake Michigan Air Directors Consortium, March 23, 2005.

Baker, K. and D. Kenski, “Diagnostic and Operational Evaluation of 2002 and 2005 Estimated 8-

hr Ozone to Support Model Attainment Demonstrations”, October 2007, CMAS Conference, 

North Carolina.

Blanchard, C. and S. Tanenbaum,”Analysis of Inorganic Particulate Matter Formation in the 

Midwestern United States”, Final Report, November 30, 2008

EPA, “Guidelines on the Use of Models and Other Analyses for Demonstrating Attainment of Air 

Quality Goals for Ozone, PM2.5, and Regional Haze”, EPA-454/B07-002, April 2007.

Kenski, D., “Updated CART Analysis for Ozone through 2008 (Preliminary Draft)”, Lake 

Michigan Air Directors Consortium, 2008

LADCO, “Quality Management Plan”, September 1, 2004

LADCO, “Regional Air Quality Analyses for Ozone, PM2.5, and Regional Haze: Final Technical 

Support Document”, April 25, 2008

LADCO, “A Conceptual Model of PM2.5 Episodes in the Midwest”, LADCO, January 2009

LADCO, “White Paper: Approaches for Attaining the PM2.5 Daily Standard”, October 8, 2009

Schauer, J.J., A. Rutter, D. Snyder, E. Stone, M. Olson, J. Zhou, C. Worley, T. Katzman, R. 

Collins, R. Bader, T. Dallmann, J. DeMinter, M. Mieritz, B. Shelton, and A. Plourde, “LADCO 

Organic Molecular Marker Study”, Final Report, July 17, 2009, University of Wisconsin-Madison

State Collaborative Modeling Workgroup, “Regional Modeling for the Eastern U.S.: Technical 

Support Document”, July 9, 2009

Sullivan, A.P., and J.L. Collett, “Biomass Burning Impacts on Air Quality in the Upper Midwest”, 

Final Report, January 28, 2009, Colorado State University