WESTERN REGIONAL AIR PARTERNERSHIP

REGIONAL HAZE RULE

REASONABLE PROGRESS SUMMARY REPORT

Prepared for: 

Tom Moore 

Western Governors' Association

WRAP Air Quality Program Manager

tmoore@westgov.org 

Prepared by: 

June 28, 2013
TABLE OF CONTENTS

Section Page

GLOSSARY OF TERMS v

EXECUTIVE SUMMARY xi

1.0 INTRODUCTION 1-1

2.0 REGULATORY REQUIREMENTS 2-1

2.1 Section 308 2-2

2.1.1 Monitoring and Emissions Data Summary Requirements 2-2

2.1.2 SIP Evaluation Requirements 2-3

2.2 Section 309 2-5

2.2.1 Monitoring and Emissions Data Summary Requirements 2-5

2.2.2 SIP Evaluation Requirements 2-5

2.3 2064 Natural Conditions 2-6

2.4 Tribal Considerations 2-7

3.0 DATA SOURCES 3-1

3.1 IMPROVE Monitoring Data 3-1

3.1.1 Data Completeness Requirements 3-4

3.1.2 RHR Progress Period Calculation Considerations 3-5

3.1.2.1 Identification of 20% Worst Days 3-6

3.1.2.2 Discreet 5-Year Averages vs. Trends 3-8

3.1.2.3 Averaging Considerations for Deciview Calculations 3-9

3.2 Emissions Inventories 3-11

3.2.1 Inventory Descriptions 3-11

3.2.1.1 Contiguous WRAP States 3-13

3.2.1.2 Alaska 3-21

3.2.1.3 Hawaii 3-21

3.3 The WRAP TSS 3-23

3.3.1 Data Updates 3-23

3.3.2 Class I Area Summary Table 3-24

3.3.3 Monitoring 3-26

3.4 Emissions Summary Tools 3-28

4.0 WRAP REGIONAL SUMMARIES 4-1

4.1 Monitoring Data 4-2

4.1.1 Annual Trends 4-7

4.1.2 Regional Events 4-16

4.2 Emissions Data 4-23

4.2.1 EGU Summary 4-34

5.0 SECTION 309 REGIONAL SUMMARIES 5-1

5.1 Monitoring Data 5-3

WRAP Regional Haze Rule Reasonable Progress Report Support Document i 
5.2 Emissions Data 5-12

6.0 STATE AND CLASS I AREA SUMMARIES 6-1

6.1 Alaska 6-2

6.1.1 Monitoring Data 6-4

6.1.1.1 Current Conditions 6-4

6.1.1.2 Differences between Current and Baseline Conditions 6-6

6.1.1.3 Changes in Visibility Impairment 6-11

6.1.2 Emissions Data 6-12

6.1.2.1 Changes in Emissions 6-14

6.2 Arizona 6-21

6.2.1 Monitoring Data 6-24

6.2.1.1 SIAN1 Data Substitutions 6-24

6.2.1.2 Current Conditions 6-28

6.2.1.3 Differences between Current and Baseline Conditions 6-31

6.2.1.4 Changes in Visibility Impairment 6-37

6.2.2 Emissions Data 6-40

6.2.2.1 Changes in Emissions 6-42

6.2.2.2 EGU Summary 6-52

6.3 California 6-53

6.3.1 Monitoring Data 6-56

6.3.1.1 Current Conditions 6-56

6.3.1.2 Differences Between Current and Baseline Conditions 6-62

6.3.1.3 Changes in Visibility Impairment 6-74

6.3.2 Emissions Data 6-78

6.3.2.1 Changes in Emissions 6-80

6.3.2.2 EGU Summary 6-90

6.4 Colorado 6-91

6.4.1 Monitoring Data 6-93

6.4.1.1 Current Conditions 6-93

6.4.1.2 Differences Between Current and Baseline Conditions 6-96

6.4.1.3 Changes in Visibility Impairment 6-101

6.4.2 Emissions Data 6-103

6.4.2.1 Changes in Emissions 6-105

6.4.2.2 EGU Summary 6-115

6.5 Hawaii 6-116

6.5.1 Monitoring Data 6-117

6.5.1.1 Haleakala Baseline Estimate 6-118

6.5.1.2 Current Conditions 6-121

6.5.1.3 Differences between Current and Baseline Conditions 6-124

6.5.1.4 Changes in Visibility Impairment 6-128

6.5.2 Emissions Data 6-130

6.5.2.1 Changes in Emissions 6-132

6.6 Idaho 6-138

6.6.1 Monitoring Data 6-140

6.6.1.1 Current Conditions 6-140

6.6.1.2 Differences between Current and Baseline Conditions 6-142

WRAP Regional Haze Rule Reasonable Progress Report Support Document ii
6.6.1.3 Changes in Visibility Impairment 6-147

6.6.2 Emissions Data 6-148

6.6.2.1 Changes in Emissions 6-150

6.6.2.2 EGU Summary 6-160

6.7 Montana 6-161

6.7.1 Monitoring Data 6-163

6.7.1.1 Current Conditions 6-163

6.7.1.2 Differences Between Current and Baseline Conditions 6-166

6.7.1.3 Changes in Visibility Impairment 6-171

6.7.2 Emissions Data 6-174

6.7.2.1 Changes in Emissions 6-176

6.7.2.2 EGU Summary 6-186

6.8 Nevada 6-187

6.8.1 Monitoring Data 6-188

6.8.1.1 Current Conditions 6-189

6.8.1.2 Differences between Current and Baseline Conditions 6-191

6.8.1.3 Changes in Visibility Impairment 6-195

6.8.2 Emissions Data 6-196

6.8.2.1 Changes in Emissions 6-198

6.8.2.2 EGU Summary 6-208

6.9 New Mexico 6-209

6.9.1 Monitoring Data 6-211

6.9.1.1 Current Conditions 6-211

6.9.1.2 Differences between Current and Baseline Conditions 6-214

6.9.1.3 Changes in Visibility Impairment 6-219

6.9.2 Emissions Data 6-222

6.9.2.1 Changes in Emissions 6-224

6.9.2.2 EGU Summary 6-234

6.10 North Dakota 6-235

6.10.1 Monitoring Data 6-236

6.10.1.1 Current Conditions 6-237

6.10.1.2 Differences between Current and Baseline Conditions 6-239

6.10.1.3 Changes in Visibility Impairment 6-243

6.10.2 Emissions Data 6-244

6.10.2.1 Changes in Emissions 6-246

6.10.2.2 EGU Summary 6-256

6.11 Oregon 6-257

6.11.1 Monitoring Data 6-259

6.11.1.1 Current Conditions 6-259

6.11.1.2 Differences Between Current and Baseline Conditions 6-263

6.11.1.3 Changes in Visibility Impairment 6-268

6.11.2 Emissions Data 6-270

6.11.2.1 Changes in Emissions 6-272

6.11.2.2 EGU Summary 6-282

6.12 South Dakota 6-283

6.12.1 Monitoring Data 6-284

WRAP Regional Haze Rule Reasonable Progress Report Support Document iii
6.12.1.1 Current Conditions 6-285

6.12.1.2 Differences between Current and Baseline Conditions 6-287

6.12.1.3 Changes in Visibility Impairment 6-292

6.12.2 Emissions Data 6-293

6.12.2.1 Changes in Emissions 6-295

6.12.2.2 EGU Summary 6-305

6.13 Utah 6-306

6.13.1 Monitoring Data 6-307

6.13.1.1 Zion Baseline Estimate 6-308

6.13.1.2 Current Conditions 6-314

6.13.1.3 Differences between Current and Baseline Conditions 6-316

6.13.1.4 Changes in Visibility Impairment 6-321

6.13.2 Emissions Data 6-322

6.13.2.1 Changes in Emissions 6-324

6.13.2.2 EGU Summary 6-334

6.14 Washington 6-335

6.14.1 Monitoring Data 6-337

6.14.1.1 Current Conditions 6-337

6.14.1.2 Differences between Current and Baseline Conditions 6-340

6.14.1.3 Changes in Visibility Impairment 6-345

6.14.2 Emissions Data 6-346

6.14.2.1 Changes in Emissions 6-348

6.14.2.2 EGU Summary 6-358

6.15 Wyoming 6-359

6.15.1 Monitoring Data 6-361

6.15.1.1 Current Conditions 6-361

6.15.1.2 Differences between Current and Baseline Conditions 6-363

6.15.1.3 Changes in Visibility Impairment 6-368

6.15.2 Emissions Data 6-369

6.15.2.1 Changes in Emissions 6-371

6.15.2.2 EGU Summary 6-381

7.0 REFERENCES 1

WRAP Regional Haze Rule Reasonable Progress Report Support Document iv
GLOSSARY OF TERMS

Aerosols: Suspensions of tiny liquid and/or solid particles in the air. 

Ammonium nitrate (NH4NO3): Ammonium nitrate is formed in the atmosphere from reactions 

involving nitrogen dioxide (NO2) emissions, which are dominated by anthropogenic 

sources. Common sources include virtually all combustion activities, especially those 

involving cars, trucks, power plants, and other industrial processes. 

Ammonium sulfate ((NH4)2SO4): Ammonium sulfate is formed in the atmosphere from 

reactions involving sulfur dioxide (SO2) emissions. Anthropogenic sources include coalburning power plants and other industrial sources, such as smelters, industrial boilers, and 

oil refineries, and to a lesser extent, gasoline and diesel combustion. 

Anthropogenic: Produced by human activities. 

Area sources: Sources that are treated as being spread over a spatial extent (usually a county or 

air district) and that are not movable (as compared to non-road mobile and on-road 

mobile sources). Because it is not possible to collect the emissions at each point of 

emission, they are estimated over larger regions. Examples of stationary area sources are 

residential heating and architectural coatings. Numerous sources, such as dry cleaning 

facilities, may be treated either as stationary area sources or as point sources.

BART: Best Available Retrofit Technology, a process under the CAA to evaluate the need and, 

if warranted, install the most effective pollution controls on an already existing air 

pollution source. 

Baseline period: The baseline period, or baseline conditions, are the basis against which 

improvements in worst day visibility, and lack of degradation for the best day visibility, 

are judged. For initial RHR implementation plan purposes, the baseline is the average 

visibility impairment as measured by IMPROVE monitors during the 2000-2004 5-year 

period. 

Biogenic emissions: Biogenic emissions are based on the activity fluxes modeled from biogenic 

land use data, which characterizes the types of vegetation that exist in particular areas.

Emissions are generally derived using modeled estimates of biogenic gas-phase 

pollutants from land use information, emissions factors for different plant species, and 

meteorology data. 

Class I area (CIA): As defined in the Clean Air Act, areas that were in existence as of August 7, 

1977: national parks over 6,000 acres, national wilderness areas and national memorial 

parks over 5,000 acres, and international parks. 

Clean Air Act (CAA): The basic framework for controlling air pollutants in the United States, 

originally adopted in 1963, and amended in 1970, 1977, and 1990. The CAA was 

designed to “protect and enhance” air quality. Section 169A of the Clean Air Act (CAA), 

established in the 1977 Amendments, set forth a national goal for visibility which is the 

WRAP Regional Haze Rule Reasonable Progress Report Support Document v 
‘‘prevention of any future, and the remedying of any existing, impairment of visibility in 

Federal Class I areas (CIAs) which impairment results from manmade air pollution.’’

Coarse mass (CM): Coarse mass refers to the mass of large particles greater than 2.5 and 

smaller than 10 μm in diameter. 

Colorado Plateau: A high, semi-arid tableland in southeast Utah, northern Arizona, northwest 

New Mexico, and western Colorado. 

Current conditions: For purposes of this report, current conditions represent the most recent 

successive 5-year average after the 2000-2004 baseline conditions, or the 2005-2009 

period. 

Current progress period: For purposes of this report, the current progress period, also referred 

to as the first progress period, represents the most recent successive 5-year average after 

the 2000-2004 baseline conditions, or the 2005-2009 period. 

Deciview (dv): The deciview metric is used to track regional haze in the RHR. The Haze Index 

(measured in deciviews) was designed to be linear with respect to human perception of 

visibility. A one deciview change is approximately equivalent to a 10% change in 

extinction, whether visibility is good or poor. A one deciview change in visibility is 

generally considered to be the minimum change the average person can detect. 

Dust: Dust emissions may have a variety of sources that could include anthropogenic sources, 

natural sources, and natural sources that may be influenced by anthropogenic activity.

Fugitive dust includes sources such as road dust, agricultural operations, construction and 

mining operations and windblown dust from vacant lands. Windblown dust includes 

more of the natural influences such as wind erosion on natural lands. 

Elemental carbon (EC): Elemental carbon, also known as light absorbing carbon (LAC), is the 

primary light absorbing compound in the atmosphere. These particles are emitted directly 

into the air from virtually all combustion activities, but are especially prevalent in diesel 

exhaust and smoke from wild and prescribed fires. 

Environmental Protection Agency (EPA): The EPA is an agency of the U.S. federal 

government which was created for the purpose of protecting human health and the 

environment by writing and enforcing regulations based on laws passed by Congress.

Extinction (bext): Extinction is a measure of the fraction of light lost per unit length along a sight 

path due to scattering and absorption by gases and particles, expressed in inverse 

Megameters (Mm-1).

Fine soil: Particulate matter composed of pollutants from the Earth’s soil that enters the air from 

dirt roads, fields, and other open spaces as a result of wind, traffic, and other surface 

mechanical disturbance activities. Fine soil includes soil particles with an aerodynamic 

diameter less than 2.5 microns. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document vi
Fire: Fire sources may have a mix of natural and anthropogenic influences. Natural sources 

include wildland fires, while anthropogenic sources can include agricultural and 

prescribed fires.

First progress period: For purposes of this report, the first progress period, also referred to as 

the current progress period, represents the most recent successive 5-year average after the 

2000-2004 baseline conditions, or the 2005-2009 period. 

Grand Canyon Visibility Transport Commission (GCVTC): In 1990, amendments to the 

Clean Air Act established the Commission to advise the EPA on strategies for protecting 

visual air quality on the Colorado Plateau. 

Haze Index (HI): The Haze Index (measured in deciviews) is used to track regional haze in the 

RHR. It was designed to be linear with respect to human perception of visibility, where a

one deciview change is approximately equivalent to a 10% change in extinction, whether 

visibility is good or poor. A one deciview change in visibility is generally considered to 

be the minimum change the average person can detect. 

Interagency Monitoring of Protected Visual Environment (IMPROVE): A collaborative 

monitoring program governed by a steering committee composed of representatives from 

Federal and regional-state organizations to establish present visibility levels and trends, 

and to identify sources of man-made impairment

Inverse megameters (Mm-1): A measurement unit used for light extinction, the higher the 

value, the hazier the air is.

Least impaired days: The least impaired, or best, days refers to the average visibility 

impairment (measured in deciviews) for the twenty percent of monitored days in a 

calendar year with the lowest amount of visibility impairment.

Light extinction: A measure of how much light is absorbed or scattered as it passes through a 

medium, such as the atmosphere. Aerosol light extinction refers to the absorption and 

scattering by aerosols. Total light extinction refers to the sum of aerosol light extinction, 

the absorption by gases (such as NO2), and the atmospheric light extinction (Rayleigh 

scattering). Extinction is often expressed as a measure of the fraction of light lost per unit 

length in units of inverse Megameters (Mm-1).

Mandatory Federal Class I areas: Certain national parks (over 6,000 acres), wilderness areas 

(over 5,000 acres), national memorial parks (over 5,000 acres), and international parks 

that were in existence as of August 1977. 

Most impaired days: The most impaired, or worst, days refers to the average visibility 

impairment (measured in deciviews) for the twenty percent of monitored days in a 

calendar year with the highest amount of visibility impairment. 

Natural background condition: Naturally occurring phenomena that reduce visibility as 

measured in terms of light extinction, visual range, contrast, or coloration. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document vii
Natural conditions: Natural conditions include any naturally occurring phenomena that reduce 

visibility as measured in terms of light extinction, visual range, contrast, or coloration. 

Off-road mobile sources: Off-road mobile sources are vehicles and engines that encompass a 

wide variety of equipment types that either move under their own power or are capable of 

being moved from site to site. Examples include agricultural equipment such as tractors 

or combines, aircraft, locomotives and oil field equipment such as mechanical drilling 

engines. 

Off-shore: Commercial marine emissions comprise a wide variety of vessel types and uses. 

Emissions can be include deep draft vessels within shore and near port using port call 

data, and offshore emissions generated from ship location data. 

Oil and gas sources: Oil and gas sources consist of a number of different types of activities 

from engine sources for drill rigs and compressor engines, to sources such as condensate 

tanks and fugitive gas emissions. The variety of emissions types for sources specific to 

oil and gas activity can, in some cases, overlap with mobile, area or point sources, but 

these can also be extracted and treated separately.

On-road mobile sources: Vehicular sources that travel on roadways. Emissions from these 

sources can be computed either as being spread over a spatial extent or as being assigned 

to a line location (called a link). Emissions are estimated as the product of emissions 

factors and activity data (vehicle miles traveled (VMT). Examples of on-road mobile 

sources include light-duty gasoline vehicles and heavy-duty diesel vehicles.

Oxides of nitrogen (NOX): A mixture of nitrogen dioxide and other nitrogen oxide gases. 

Nitrogen is the most common gas in the atmosphere. In high temperature and/or high 

pressure burning (as in an engine), the air's nitrogen is broken down and combined with 

oxygen, forming unstable or reactive NOX gases. Nitrogen dioxide (NO2) is yellowish 

brown, and thus contributes directly to haze. All the NOX gases react in the air to form 

haze-causing aerosols and smog. 

Particulate organic aerosol (POA): Particulate organic aerosol represents organic aerosols that 

are emitted directly as particles, as opposed to gases.

Particulate organic mass (POM): Particulate Organic Mass is also referred to as Particulate 

Organic Carbon and Organic Mass Carbon (OMC). Particulate organic mass can be 

emitted directly as particles, or formed through reactions involving gaseous emissions. 

Natural sources of organic carbon include wildfires and biogenic emissions. Man-made 

sources can include prescribed forest and agricultural burning, vehicle exhaust, vehicle 

refueling, solvent evaporation (e.g., paints), food cooking, and various commercial and 

industrial sources.

Point sources: These are sources that are identified by point locations, typically because they are 

regulated and their locations are available in regulatory reports. In addition, elevated 

point sources will have their emissions allocated vertically through the model layers, as 

opposed to being emitted into only the first model layer. Point sources can be further 

subdivided into electric generating unit (EGU) sources and non-EGU sources, 

WRAP Regional Haze Rule Reasonable Progress Report Support Document viii
particularly in criteria inventories in which EGUs are a primary source of NOX and SO2. 

Examples of non-EGU point sources include chemical manufacturers and furniture 

refinishers.

Prevention of significant deterioration (PSD): A program established by the Clean Air Act

Amendments of 1977 that limits the amount of additional air pollution that is allowed in 

Class I and Class II areas. 

Rayleigh: Light scattering of the natural gases in the atmosphere. At an elevation of 1.8 

kilometers, the light extinction from Rayleigh scattering is approximately 10 inverse 

megameters (Mm-1). 

Reasonable progress: Reasonable progress refers to progress in reducing human-caused haze in 

Class I areas under the national visibility goal. The Clean Air Act indicates that 

"reasonable" should consider the cost of reducing air pollution emissions, the time 

necessary, and the energy and non-air quality environmental impacts of reducing. 

Reconstructed aerosol extinction: The percent of total atmospheric extinction attributed to each 

aerosol and gaseous component of the atmosphere. 

Regional haze: Regional haze refers to visibility impairment that is caused by the emission of 

air pollutants from numerous sources located over a wide geographic area. 

Regional Haze Rule (RHR): Federal rule that requires states to develop programs to assure 

reasonable progress toward meeting the national goal of preventing any future, and 

remedying any existing, impairment of visibility in mandatory Class I Federal areas. 

Relative humidity: Partial pressure of water vapor at the atmospheric temperature divided by 

the vapor pressure of water at that temperature, expressed as a percentage.

Scattering efficiency: The amount of light scattered relative to the particle’s size.

Sea salt: Sea salt is a natural aerosol emitted in coastal areas. In practice, chloride ion 

measurements are used to represent sea salt in IMPROVE measurements, and 

measurements may sometimes show anthropogenic or crustal influences at inland 

monitors. 

Sulfur dioxide (SO2): SO2 gas is associated with emissions from processes such as burning 

fuels, manufacturing paper, or smelting rock. SO2 is converted in the air to other sulfur 

oxides (SOX) or haze-causing aerosols (sulfates).

State Implementation Plans (SIPs): A detailed description of the programs a state will use to 

carry out its responsibilities under the Clean Air Act. State implementation plans are 

collections of the regulations used by a state to reduce air pollution. Plans devised by 

states and tribes to carry out their responsibilities under the Clean Air Act. SIPs and TIPs 

must be approved by the U.S. Environmental Protection Agency and include public 

review.

WRAP Regional Haze Rule Reasonable Progress Report Support Document ix
Visibility impairment: Any humanly perceptible change in visibility (light extinction, visual 

range, contrast, coloration) from that which would have existed under natural conditions. 

Visibility: Refers to the visual quality of the view, or scene, in daylight with respect to color 

rendition and contrast definition. 

Visual range (VR): Visual range is the greatest distance a large black object can be seen on the 

horizon, expressed in kilometers (km) or miles (mi).

Volatile organic compound (VOC): A carbon-containing material that evaporates, such as 

gasoline, some paints, solvents, dry cleaning fluids, and the like. VOCs contribute to the 

formation of particulate organic mass. 

Western Regional Air Partnership (WRAP): A partnership of state, tribal and federal land 

management agencies to help coordinate implementation of the GCTVC’s 

recommendation. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document x 
EXECUTIVE SUMMARY

The United States Environmental Protection Agency’s (EPA’s) 1999 Regional Haze Rule 

(RHR)1 was designed to improve visibility conditions in the nation’s largest National Parks and 

Wilderness Areas. The goal of the RHR, as stated in the Clean Air Act (CAA) 1977 

Amendments, is the “prevention of any future, and the remedying of any existing, impairment of 

visibility.”2 The RHR mandates that states identify and implement pollution control strategies to 

progress towards a “natural conditions” goal, or conditions without any manmade impairment, 

by the year 2064. States were required to submit initial RHR implementation plans in 2007 

which identified goals and strategies for visibility improvement. States are then required to revise 

implementation plan every 10-years, and submit progress reports at interim points between 

implementation plan submittals. This support document has been prepared for the Western 

Regional Air Partnership (WRAP), on behalf of the 15 western state members in the WRAP 

region, to provide technical basis for use by the western states to develop the first of their RHR 

progress reports, assessing progress towards goals as defined in their initial SIPs. 

The visibility improvement goal, as stated in the RHR, is to ensure that visibility on the 

worst days improves towards a natural conditions goal, and that visibility on the best days does 

not get worse. To measure progress towards natural conditions, the EPA provided the concept of 

a linear, or uniform, rate of reasonable progress between the 2000-2004 baseline period and a 

default natural conditions goal year of 2064.3 The RHR specifies that progress is determined for 

“current conditions”, and RHR guidance released in 2003 specifies that progress be tracked 

against the 2000-2004 baseline period using corresponding averages over successive 5-year 

periods (i.e. 2005-2009, 2010-2014, etc.).4 More recent guidance, released in April, 2013, 

indicates that progress reports “should include the 5-year average that includes the most recent 

quality assured public data available at the time the state submits its 5-year progress report for 

public review,”5 and suggests assessing changes using a rolling 5-year period average. Per 

original 2003 guidance, progress for this support document is reported as changes in monitored

between baseline conditions and the first successive 5-year progress period (2005-2009) data. 

Additionally, for summaries here, annual average trend statistics as measured for each aerosol 

species during the 2000-2009 10-year period are reported to support assessments of changing 

conditions. 

This report includes regional, state, and CIA specific summaries that characterize the 

difference between the baseline conditions and first successive progress period. Assessments 

include changes in visibility impairment as measured using aerosol data collected by the

1 See CFR 40 Part 51 Regional Haze Regulations; Final Rule, July 1, 1999, available online at 

http://www.epa.gov/airquality/visibility/actions.html. 2 See Section 169a of the 1977 CAA Amendments. 3 Note that “default” natural conditions as defined by the EPA are subject to revisions, and that States can extend the 

period of time needed to achieve natural conditions, beyond the nominal 2064 in the RHR, defining and defending 

new interim reasonable progress rates, and adjusting the 2064 end year as needed (see CFR Section 51.308). 4 See page 4-2 in EPA’s September 2003 Guidance for Tracking Progress Under the Regional Haze Rule. 5

 See page 9 in EPA’s April 2013 General Principals for the 5-Year Regional Haze Progress reports for the Initial 

Regional Haze State Implementation Plans (Intended to Assist States and EPA Regional Offices in Development and 

Review of the Progress Reports).

WRAP Regional Haze Rule Reasonable Progress Report Support Document xi

 
Interagency Monitoring of Protected Visual Environments (IMPROVE) network, and

assessments of progress also include the differences between emissions inventories for years that 

represent both the baseline and progress periods. Specific regulatory questions addressed in this 

report include:

• What are the current visibility conditions for the most impaired (worst) and least 

impaired (best) days? 

• What is the difference between current visibility conditions and baseline conditions 

for the most impaired and least impaired days? 

• What is the change in emissions that occurred between the baseline period and the 

progress period? 

The RHR also requires states to evaluate the sufficiency of current implementation plan

elements and strategies to meet reasonable progress goals. Determining the status of emissions 

reductions and evaluation of state-selected goals are beyond the scope of this report, and will be 

addressed separately by individual states. Specific regulatory questions that address evaluation

requirements include: 

• What is the status of implementation of all measures included in the implementation 

plan?

• What emissions reductions have been achieved through implementation of these 

measures?

• What emissions from within or outside of the state have limited or impeded progress 

in reducing pollutant emission and improving visibility? 

• Are current implementation plan elements and strategies sufficient to enable the state 

or other states with mandatory federal CIAs affected by the state, to meet all 

established reasonable progress goals?

Visibility impairment is tracked using a Haze Index (HI) in units of deciviews (dv), 

which is related to the cumulative sum of visibility impairment from individual aerosol species 

as measured by monitors in the IMPROVE Network. Emissions which affect regional haze 

include a wide variety of natural (e.g., wildland fires) and anthropogenic, or man-made, sources 

(e.g., industry sources and vehicles). Per regulatory requirements, differences between emissions 

inventories representing both the baseline and progress periods are presented here. Baseline 

emissions in most cases are represented using the 2002 inventory that was originally developed, 

with support from the WRAP, to represent emissions for the initial implementation plans. 

Current emissions are represented here by leveraging recent work by the WRAP to develop an 

updated and comprehensive inventory for the year 2008 for use in modeling projects. Emissions 

inventory comparisons in this report were complicated by the fact that a number of changes and 

enhancements have occurred between development of the baseline and current period

inventories, such that some of the differences between inventories are more reflective of changes 

in inventory methodology, rather than changes in actual emissions. Characterizations here focus 

more on differences in the actual monitored data, which are thought to be more reflective of 

WRAP Regional Haze Rule Reasonable Progress Report Support Document xii
progress than differences between the emission inventories. Some notable results were as 

follows: 

• Analysis of monitored data, in terms of comparisons between the 5-year average 

deciview metrics, showed improved visibility conditions on the best days at nearly all 

of the WRAP CIAs. Most sites showed improved conditions on the worst days, but 

some sites showed a decline in visibility conditions for the worst days. 

• Looking at differences between 5-year averages for individual measured species, 

most sites that did not show improved deciview conditions on the worst days were 

affected by large particulate organic matter measurements related to wildland fire. 

• Ammonium nitrate, in most cases, showed the largest decreases in 5-year averages 

and the largest decreasing annual trends. This was consistent with mobile source 

inventory comparisons which showed large decreases in oxides of nitrogen (NOX), 

which are among the precursors for ammonium nitrate particulate formation. 

Decreasing emissions were due in large part to federal and state emissions standards 

that have already been implemented for mobile sources. 

• In many of the plains states, the 5-year average of ammonium sulfate increased, but 

annual averages showed decreasing trends. Sulfur dioxide (SO2) emissions, which are 

precursors for ammonium sulfate particle formation, showed decreases in most cases,

especially from EGUs and other point sources. Many of the highest ammonium 

sulfate measurements spanned large regions. Possible contributions to measured 

visibility impairment from international sources were not quantified here. 

• In southern Oregon and northern California, increasing ammonium sulfate trends 

were evident at several coastal sites. State emissions inventory comparisons did not 

reflect these increases, but marine vessel emissions were not quantified for summaries 

here. 

• Also, in northeastern Montana and northwestern North Dakota, increasing ammonium 

sulfate trends were evident at several sites. State emissions inventory comparisons did 

not reflect these increases, but these sites are along the Canadian border, and possible

influences from nearby international sources were not quantified here. 

• In Hawaii, dramatic increases in ammonium sulfate were related to natural emissions, 

with increased volcanic emissions accounting for most of the SO2 emissions

inventoried. 

• Coarse mass extinction trends were variable and not statistically significant in most 

cases, but an area represented by several IMPROVE sites in eastern Arizona and 

western New Mexico did show increasing coarse mass trends. Emission inventories 

indicated that natural windblown dust is the largest contributor to coarse mass 

measurements in this area, but significant changes in the development of the 

windblown dust inventories did not allow for definitive comparisons between 2002 

and 2008 inventories for these emissions. 

More detailed summaries are provided in this report on a regional, state and CIA specific 

basis. These summaries are also supported by interactive tools available from the online WRAP 

WRAP Regional Haze Rule Reasonable Progress Report Support Document xiii
Technical Support System (TSS).6 Summaries presented here were developed cooperatively with 

representatives from each state in the WRAP region. This report and accompanying data analysis 

results were developed to support state development of RHR progress reports, the first of which 

are due in 2013, but should also serve as an important interim step informing the next round of 

full implementation plan revisions which come due in 2018. 

6 The WRAP TSS, available at http://vista.cira.colostate.edu/tss/, is an online tool developed to support the air 

quality planning needs of western state and tribes, which has been recently updated with summaries of current 

IMPROVE monitoring data, and recent emissions to support development of RHR progress reports. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document xiv

 
1.0 INTRODUCTION

The United States Environmental Protection Agency’s (EPA’s) 1999 Regional Haze Rule 

(RHR)7 was designed to address visibility impairment in Class I areas (CIAs), where CIAs 

include many of the nation’s largest National Parks and Wilderness Areas. The RHR mandates 

that each CIA progress towards a natural conditions goal, or conditions without any man-made 

influences, by the year 2064. Each state is required to periodically assess the rate of progress 

towards visibility improvement goals for each CIA in that state, and for CIAs affected by 

transport from that state.

The RHR requires states to develop state implementation plans (SIPs) every 10 years 

which identify strategies designed to meet a series of interim goals over the long term regional 

haze planning period. The first of these SIPs were due in 2007 and were required to identify a 

baseline starting point using the average of monitoring data for the 2000-2004 5-year period, and 

demonstrate progress towards visibility improvement that is expected to occur by the first 

interim goal in 2018. In addition to SIPs, the RHR requires each state to assess progress towards 

interim visibility improvement goals between each 10-year SIP submittal, where the first 

progress report addressing changes between the 2000-2004 baseline conditions and current 

conditions. The individual, state-submitted, progress reports for the western states are due at 

various times between 2013 and 2017, depending on respective approval dates for each state’s 

initial implementation plan.

This progress report support document has been prepared by the Western Regional Air 

Partnership (WRAP)8

, on behalf of the 15 western state members in the WRAP region, to 

provide the technical basis for use by States to develop the first of their individual reasonable 

progress reports for the 116 Federal CIAs located in the western states. Data are presented in this 

report on a regional, state, and CIA specific basis that characterize the difference between 2000-

2004 baseline conditions and current conditions, represented here by the most recent successive 

5-year average, or the 2005-2009 period. Changes in visibility impairment are characterized 

using aerosol measurements from the Interagency Monitoring of Protected Visual Environments 

(IMPROVE) network, and the differences between emissions inventory years representing both 

the baseline and current progress period. 

Analysis and summaries provided in this report were developed cooperatively with 

representatives from each state in the WRAP region, and were designed to provide western states 

with the technical basis necessary to support their evaluation of the current or proposed elements 

and strategies as outlined in their initial RHR implementation plans. Summaries here are also 

7 See CFR 40 Part 51 Regional Haze Regulations; Final Rule, July 1, 1999, available online at 

http://www.epa.gov/airquality/visibility/actions.html. 8 The WRAP is a collaborative effort of tribal governments, state governments and various federal agencies 

representing the western states that provides technical and policy tools for the western states and tribes to comply 

with the EPA’s RHR regulations. Detailed information regarding WRAP support of air quality management issues 

for western states is provided on the WRAP website (www.wrapair2.org) and data summary descriptions and tools 

specific to RHR support are available on the WRAP Technical Support System website 

(http://vista.cira.colostate.edu/tss/).

WRAP Regional Haze Rule Reasonable Progress Report Support Document 1-1 

 
supported by interactive tools available from the online WRAP Technical Support System 

(TSS).9 Any questions regarding the content of this report should be addressed to:

Tom Moore, WRAP Air Quality Program Manager

Western Governors' Association

tmoore@westgov.org 

970-491-8837 

or 

Cassie Archuleta, Primary Author 

Emily Vanden Hoek, Emissions Data Analyst 

Air Resource Specialists, Inc.

carchuleta@air-resource.com

evandenhoek@air-resource.com

970-484-7941 

9 The WRAP TSS, available at http://vista.cira.colostate.edu/tss/, is an online tool developed to support the air 

quality planning needs of western states and tribes; it has been recently updated with summaries of current 

IMPROVE monitoring data, and recent emissions to support development of RHR progress reports. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 1-2 

 
2.0 REGULATORY REQUIREMENTS

In regulatory context, Section 169A of the Clean Air Act (CAA), established in the 1977 

Amendments, set forth a national goal for visibility which is 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.”10 In 1999, the Environmental Protection Agency’s (EPA) 

promulgated regulations that provided the requirements for states to develop and submit state 

implementation plans (SIPs) to address regional haze in Federal CIAs (40 CFR 51.308 and 

51.309), where SIPs address each state’s strategy to progress towards meeting the long term 

natural condition visibility impairment goal by the year 2064. 

The first of these SIPs were due by December 17, 2007, and were required to address a 

uniform rate of reasonable progress towards an interim 2018 goal. Each state is required to 

submit a revised implementation plan by July 31, 2018 and every 10 years thereafter (51.308(f)). 

Additionally, at 5-year intervals between SIP revisions, states are required to submit periodic 

progress reports evaluating progress towards the reasonable progress goals defined the SIPs. The 

first progress report is due 5 years from the approval of the initial implementation plan

(51.308(g)), or, for states who submitted a SIP under 40 CFR 51.309, by December 31, 2013. To 

support development of Regional Haze Rule (RHR) SIPs, the EPA has released several guidance 

documents, including: 

• EPA’s September 2003 Guidance for Tracking Progress Under the Regional Haze 

Rule

• EPA’s September 2003 Guidance for Estimating Natural Visibility Conditions Under 

the Regional Haze Rule

• EPA’s April 2013 General Principals for the 5-Year Regional Haze Progress reports 

for the Initial Regional Haze State Implementation Plans (Intended to Assist States 

and EPA Regional Offices in Development and Review of the Progress Reports)

EPA’s September 2003 guidance specifies that progress is tracked against the 2000-2004 

baseline period using corresponding averages over successive 5-year periods, i.e. 2005-2009, 

2010-2014, etc.11 EPA’s more recent guidance, released in April 2013, indicates that progress 

reports “should include the 5-year average that includes the most recent quality assured public 

data available at the time the state submits its 5-year progress report for public review,”12 and 

suggests assessing changes using a rolling 5-year period average. The new EPA guidance was 

released as this report and analysis were finalized and, per the original 2003 guidance, progress 

for this support document is reported as changes in monitored between baseline conditions and 

the most recent successive 5-year progress period, or the 2005-2009 period. Figure 2.0-1 below 

presents an idealized glide slope indicating linear progress in successive 5-year increments for

10 See section 169A of the Clean Air Act (CAA) 1977 Amendments. 11 See page 4-2 in EPA’s September 2003 Guidance for Tracking Progress Under the Regional Haze Rule. 12 See page 9 in EPA’s April 2013 General Principals for the 5-Year Regional Haze Progress reports for the Initial 

Regional Haze State Implementation Plans (Intended to Assist States and EPA Regional Offices in Development and 

Review of the Progress Reports)

WRAP Regional Haze Rule Reasonable Progress Report Support Document 2-1 

 
improvement on the worst days towards a 2064 natural conditions goal. Specific references for 

RHR Section 308 and 309 regulatory requirements are provided in this section. 

Figure 1.0-1. Idealized RHR Glide Slope Representing Linear Progress from a 2000-2004 

Baseline Average to a 2064 Natural Conditions End Goal. Also Represented Are 

the 2018 Interim Goal and Successive 5-Year Progress Periods.

2.1 SECTION 308 

Section 51.308(g) of the RHR contains the requirements for periodic progress reports. 

Each state is required to submit a report evaluating progress towards the reasonable progress 

goals outlined in its regional haze state, or in some cases federal, implementation plan (SIP or 

FIP).13 These state progress reports are required to summarize recent changes in monitoring and 

emissions data, and evaluate the adequacy of the current SIP to meet interim progress goals. 

Specific regulatory text related to Section 308 progress report requirements is summarized here.

2.1.1 Monitoring and Emissions Data Summary Requirements

Sections 51.308(g)(3) and 51.308(g)(4) of the RHR contain the monitoring and emissions 

data summary requirements for RHR progress reports. These requirements are addressed in this 

report on a regional, state and Class I Area specific basis. Monitoring and emissions summary 

requirements for progress reports include the following: 

• How has visibility changed at the CIAs in the state in the last 5 years (51.308(g)(3))? 

Specifically listed under this requirement are the following elements: 

13 Note that implementation plan references to SIPs in this report are also intended to include any full or partial FIPs.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 2-2 

 
- What are the current visibility conditions for the most impaired and least impaired 

days (51.308(g)(3)(i))?

- What is the difference between baseline visibility conditions and current visibility 

conditions for the most impaired and least impaired days (51.308(g)(3)(ii))? 

- What is the change in visibility impairment for the most impaired and least

impaired days over the past 5 years (51.308(g)(3)(iii))? 

• For pollutants that affect visibility at CIAs, how have total emissions in the state 

changed over the past 5 years (51.308(g)(4))? 

Monitoring data summaries presented in this report include data collected by the 

Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring network.

14

For monitoring data summaries, baseline visibility conditions are defined as the average 

deciview values for the 20% most impaired, or worst, and 20% least impaired, or best, days 

averaged over the 2000-2004 5-year period. Current visibility conditions are represented here per 

EPA’s 2003 guidance as the most recent successive 5-year average period available, or the 

2005-2009 period.15

Per regulatory requirements, differences between emissions inventories representing both 

the baseline and progress are presented here. Baseline emissions in most cases are represented 

using a 2002 inventory that was originally developed, with support from the WRAP, to represent 

emissions for the initial implementation plans. Changes in emissions are represented using 

differences between the baseline inventory, and more recent inventory development work 

sponsored by the WRAP for the year 2008.16

2.1.2 SIP Evaluation Requirements

The RHR progress report stipulations require individual states to determine if the current 

visibility monitoring strategy and existing implementation plans are sufficient, or if 

modifications are necessary. Evaluation of current SIPs is not within the scope of this support 

document, but monitoring and emissions data summaries presented here have been designed to 

provide the western states with the technical basis to assist with their evaluation of current or 

proposed implementation plan elements and strategies. Specific regulatory questions relating to 

SIP evaluations are listed below. 

• What is the status of implementation of all measures included in each state’s regional 

haze SIP (51.308(g)(1))? 

- Note that, for most states, 2018 projections provided by the WRAP for use in the 

initial SIPs were conservative estimates that did not include best available retrofit 

technology (BART) controls. 

14 Descriptions of IMPROVE Network monitoring data and visibility calculations are provided in Section 3.1 of this 

report.

15 See page 4-2 in EPA’s September 2003 Guidance for Tracking Progress Under the Regional Haze Rule. 16 See emission inventory descriptions in Section 3.2 of this report.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 2-3 

 
• What emission reductions have been achieved through implementation of regional 

haze SIP measurers (51.308(g)(2))? 

- Note that emissions data summaries presented in this report include a comparison 

of emission inventories representing both the baseline and current period, but a 

determination of what reductions may be related to implementation of SIP 

measures will be made by individual states. 

• Have there been significant changes in emissions over the past 5 years from within or 

outside the state that have impeded progress in improving visibility at each state’s 

Federal CIAs (51.308(g)(5))? 

- As noted previously, emissions data summaries presented in this report include a 

comparison of emission inventories representing both the baseline and current

period, but a determination of whether specific emissions have limited or impeded 

progress will be made by individual states. 

• Is the state’s SIP sufficient to enable the state, and other states with CIAs affected by 

emissions from your state, to meet their reasonable progress goals (51.308(g)(6))? 

• Based on these assessments, are any changes in the state’s visibility monitoring plan 

necessary (51.308(g)(7))? 

• Based on the state’s assessment of the adequacy of the existing monitoring plan, the 

State is also required to take one of the following actions (51.308(h)): 

- Submit a declaration that the plan is adequate and further revisions are not 

necessary ((51.308(h)(1)); or 

- If the implementation plan is determined to be inadequate, the state must take 

steps to develop additional strategies to address the plans deficiencies 

((51.308(h)(2), (3) and (4)).

The Regional Haze Rule also includes requirements for each state to coordinate and 

consult with federal land managers (FLMs) when assessing progress for current visibility 

conditions and SIP strategies. Specific requirements related to consultation with FLMs include: 

• Has the state provided FLMs an opportunity for consultation in person 60 days prior 

to holding any public hearing on a regional haze SIP revision? (51.308(i)(2)) 

• Has the state included a description in your SIP revision on how the state addressed 

FLM comments? (51.308(i)(3)) 

• Has the state provided procedures for continuing consultation with FLMs in the 

regional haze SIP revisions and 5-year progress reports? (51.308(i)(4)) 

Development of this progress report has included regional coordination, offering 

opportunities for consultation with surrounding states. Also, this project has facilitated some 

opportunities for feedback from FLMs through summary calls and meetings.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 2-4 
2.2 SECTION 309

Under Section 309 of the RHR, 9 western states and tribes within those states had the 

option of submitting plans to reduce regional haze emissions that impair visibility at 16 CIAs on 

the Colorado Plateau. Five states, including Arizona, New Mexico, Oregon, Utah, and Wyoming, 

initially exercised this option by submitting plans to the EPA by December 31, 2003. Oregon 

elected to cease participation in the program in 2006 and Arizona elected to cease participation 

in 2010. As used in this document, Section 309 states refer to the states of New Mexico, Utah, 

and Wyoming and the city of Albuquerque/Bernalillo County. 

Section 309 of the RHR specifically requires participating states to submit progress 

evaluations in 2013 (51.309(d)(10)), as opposed to the more general requirement of 5-years from 

initial SIP approvals, as referenced in Section 308. Specific regulatory text related to Section 309 

progress report requirements is summarized here.

2.2.1 Monitoring and Emissions Data Summary Requirements

Section 51.309(d)(10) contains the monitoring and emissions data summary requirements 

for progress reports for Section 309 states. These requirements address the 16 CIAs on the 

Colorado Plateau (Grand Canyon National Park, Sycamore Canyon Wilderness, Petrified Forest 

National Park, Mount Baldy Wilderness, San Pedro Parks Wilderness, Mesa Verde National 

Park, Weminuche Wilderness, Black Canyon of the Gunnison Wilderness, West Elk Wilderness, 

Maroon Bells Wilderness, Flat Tops Wilderness, Arches National Park, Canyonlands National 

Park, Capital Reef National Park, Bryce Canyon National Park, and Zion National Park). 

Specific monitoring and emissions summary requirements are listed below, and are addressed in 

this progress report support document on a regional, state, and CIA basis.

• How has visibility changed at the CIAs in the state in the last 5 years (51.309(d)(3))? 

Specifically listed under this requirement are the following elements: 

- What are the current visibility conditions for the most impaired and least impaired 

days (51.309(d)(10)(i)(C))?

- What is the difference between baseline visibility conditions and current visibility 

conditions for the most impaired and least impaired days (51.309(d)(10)(i)(C))? 

- What is the change in visibility impairment for the most impaired and least 

impaired days over the past 5 years (51.309(d)(10)(i)(C))? 

• For pollutants that affect visibility at CIAs, how have total emissions in the state 

changed over the past 5 years (51.309(d)(10)(i)(D))?

2.2.2 SIP Evaluation Requirements

Section 309 of the RHR requires that progress reports include a determination of whether 

the current visibility monitoring strategy and existing implementation plans are sufficient, or if 

modifications are necessary. Evaluation of current SIPs is not within the scope of this support 

document, but monitoring and emissions data summaries presented here have been designed to 

help states with their evaluation of current or proposed implementation plan elements and 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 2-5 
strategies. Specific regulatory requirements relating to Section 309 SIP evaluations are listed 

below. 

• What is the status of implementation of all measures included in the implementation 

plan for achieving reasonable progress goals (51.309(d)(10)(i)(A))? Note that there 

are also some specific interim report requirements referenced separately in the RHR:

- What is the status of mobile source emissions (51.309(d)(5)(ii))?

- What is the status of progress towards renewable energy goals (51.309(d)(8)(vi))? 

• What emission reductions have been achieved through implementation of regional 

haze SIP measures (51.309(d)(10)(i)(B))?

- Note that emissions data summaries presented in this report include a comparison 

of emission inventories representing both the baseline and current period, but a 

determination of what reductions may be related to implementation of SIP 

measures will be made by individual states.

• Have there been significant changes in emissions over the past 5 years from within or 

outside the state that have impeded progress in improving visibility at your states 

Federal CIAs (51.309(d)(10)(i)(E))?

- As noted previously, emissions data summaries presented in this report include a 

comparison of emission inventories representing both the baseline and current

periods, but a determination of whether specific emissions have limited or

impeded progress will be made by individual states. 

• Is your state’s SIP sufficient to enable your state, and other states with CIAs affected 

by emissions from your state, to meet their reasonable progress goals 

(51.309(d)(10)(i)(F)? 

- Specifically noted is a requirement to assess whether annual SO2 emissions 

milestones have been met (51.309(d)(4)(i)). Note that the WRAP has supported 

work addressing the SO2 milestone requirements for 309 states. These annual 

regional SO2 emissions and milestone reports are located on the WRAP website at 

http://www.wrapair2.org/reghaze.aspx. 

• Based on the state’s assessment of the adequacy of the existing monitoring plan, the 

state is also required to take one of the following actions (51.309(d)(10)(ii)):

- Submit a declaration that the plan is adequate and further revisions are not 

necessary (51.309(d)(10)(ii)(A)); or 

- If the implementation plan is determined to be inadequate, the state must take 

steps to develop additional strategies to address the plans deficiencies 

((51.309(d)(10)(ii)(B), (C) and (D)).

2.3 2064 NATURAL CONDITIONS

The concept of “natural conditions” in regional haze represents the long term goal of 

improving visual conditions in our national parks and wilderness areas. EPA provided the 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 2-6 
concept of a linear, or uniform, rate of reasonable progress between the 2000-2004 baseline 

period and the nominal natural conditions goal year in 2064.17 With each 10-year SIP revision 

The States have the opportunity to further refine natural conditions estimates. Separate from this 

report, the WRAP has prepared summaries of the progression and current status of natural 

condition estimates, including the original EPA default estimates18 and the revised natural 

conditions II estimates.19 Also included in the WRAP report are considerations and 

recommendations for future natural condition refinements, and some recommended adjustments 

to regional haze management strategies.20

As of 2013, the initial SIPs/FIPs have not been approved for all WRAP states, and as 

such, not all reasonable progress goals have been defined and/or approved at the time this 

support document was prepared. Through consultation with state representatives, it was 

determined that this progress report support document would not address state specific 

reasonable progress goals or natural conditions. Only summaries of the differences between 

baseline and current progress period aerosol measurements and emissions inventories are 

provided here as the technical basis for use by states to determine if they are on track to meet or 

exceed their individual reasonable progress goals towards natural conditions.

2.4 TRIBAL CONSIDERATIONS 

Under the Tribal Air Rule, Tribal governments may elect to implement air programs in 

much the same way as States, including development of Tribal implementation plans (TIPs). 

Also, as sovereign nations, Indian tribes have the right under the Clean Air Act to have the EPA 

classify their lands as CIAs, but this does not provide for the inclusion of the Tribal CIAs as 

Federal CIAs mandated for protection under the RHR. 

Even if a Tribe does not seek authority to implement an RHR TIP, it may be desirable for 

a Tribe to participate in the regional planning efforts to address visibility and to consult with 

neighboring states as they develop their regional haze SIPs. Tribes, along with states and federal 

agencies, are full partners in the WRAP, having equal representation on the WRAP Board as 

states. Several Tribal nations in the United States have been classified as CIAs, and IMPROVE 

visibility monitors are located in 4 tribal CIAs in the WRAP. Because these IMPROVE monitors 

do not represent federally mandated CIAs, summaries for these monitors are not included in this 

progress report support document. 

17 Note that states can extend the period of time needed to achieve natural conditions, beyond the nominal 2064 in 

the RHR, defining and defending new interim amounts of reasonable progress, and adjusting the 2064 end year as 

needed (see Section 51.308(d)(1)(i)(B) and 501.308(d)(1)(B)(ii) of the RHR).

18 Default natural conditions estimates are described in EPA’s September 2003 Guidance for Estimating Natural 

Visibility Conditions Under the Regional Haze Rule. 19 See Copeland’s 2008 Regional Haze Rule Natural Level Estimates Using the Revised IMPROVE Aerosol 

Reconstructed Light Extinction Algorithm, available at http://vista.cira.colostate.edu/improve/publications/graylit/

032_NaturalCondIIpaper/Copeland_etal_NaturalConditionsII_Description.pdf. 20 WRAP’s archived repository of natural conditions information, projects and references is available at 

http://www.wrapair.org/forums/aamrf/projects/NCB/index.html. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 2-7 

 
3.0 DATA SOURCES

This report includes summaries of monitoring and emissions data designed to support the 

first regional haze progress reports for the Western Regional Air Partnership (WRAP) member

states. Monitoring data described here includes data collected by the Interagency Monitoring of 

Protected Visual Environments (IMPROVE) network, with the addition of some data substitution 

and baseline estimates. Emissions data summaries use inventories previously developed by the 

WRAP to represent baseline conditions for the initial Regional Haze Rule (RHR) 

implementation plans, and a more current inventory that leverages emissions estimates that have 

been recently collected and enhanced to support modeling work currently in progress by the 

WRAP. Detailed descriptions and references for these data sources as used in this report are 

described in this section. Also described here are recent changes to dynamic data summary tools 

available from the WRAP Technical Support System (TSS) website 

(www.vista.cira.colostate.edu/tss/), which has been updated to support development of RHR 

progress reports.

3.1 IMPROVE MONITORING DATA

Visibility is reduced by the absorption and scattering of light by particles and gases in the 

atmosphere. Light extinction, or the fraction of light lost due to scattering and absorption by 

gases and particles, can be estimated from measurements of speciated aerosol mass. The 

IMPROVE Network is a multi-agency, nation-wide visibility monitoring network which began 

in 1988, and expanded significantly in 2000 in support of the EPA’s RHR. Each Federal Class I 

area (CIA) is represented by at least one IMPROVE monitor, as depicted for the WRAP region 

in Figure 3.1-1. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-1 
WRAP

Federal CIAs and

IMPROVE Sites

Federal CIA

IMPROVE Monitor

Figure 3.1-1. Map of Federal CIA IMPROVE Monitors in the WRAP Region. 

IMPROVE aerosol samplers collect 24-hour integrated filter samples every third day. 

Each monitoring location operates four samplers (designated Module A through D) designed to 

quantify aerosol species that are related to visibility impairment. The aerosol species collected 

for regional haze purposes include: 

• Ammonium Sulfate: Ammonium sulfate is formed in the atmosphere from reactions 

involving sulfur dioxide (SO2) emissions. Anthropogenic sources include coalburning power plants and other industrial sources, such as smelters, industrial boilers, 

and oil refineries, and to a lesser extent, gasoline and diesel combustion. 

• Ammonium Nitrate: Ammonium nitrate is formed in the atmosphere from reactions 

involving nitrogen dioxide (NO2) emissions, which are dominated by anthropogenic 

sources. Common sources include virtually all combustion activities, especially those 

involving cars, trucks, power plants, and other industrial processes. 

• Particulate Organic Mass (POM): Particulate organic mass can be emitted directly as 

particles, or formed through reactions involving gaseous emissions. Natural sources 

of organic carbon include wildfires and biogenic emissions. Man-made sources can 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-2 
include prescribed forest and agricultural burning, vehicle exhaust, vehicle refueling, 

solvent evaporation (e.g., paints), food cooking, and various commercial and 

industrial sources.

• Elemental Carbon (EC): Elemental carbon is the primary light absorbing compound 

in the atmosphere. These particles are emitted directly into the air from virtually all 

combustion activities, but are especially prevalent in diesel exhaust and smoke from 

wild and prescribed fires. 

• Fine Soil: Soil, as reported by the IMPROVE Network, refers to fine soil (less than 

2.5 μm in diameter) that enters the air from dirt roads, fields, and other open spaces as 

a result of wind, traffic, and other surface mechanical disturbance activities.

• Coarse Mass (CM): Coarse mass refers to large particles (larger than 2.5 and smaller 

than 10 μm in diameter), and generally includes similar sources as fine soil, but can 

also include coarse fraction ammonium nitrate and ammonium sulfate at some sites. 

Speciated coarse mass is not routinely analyzed by the IMPROVE Network. 

• Sea Salt: Sea salt is a natural aerosol emitted in coastal areas. In practice, chloride ion 

measurements are used to represent sea salt in IMPROVE measurements, and 

measurements may sometimes show anthropogenic or crustal influences at inland 

monitors. 

These different particle species scatter and absorb light in the atmosphere with different 

efficiencies. For example, the elemental carbon fraction of particle pollution is about ten times 

more efficient at absorbing light than the soil fraction is at scattering light. Some particle species, 

including ammonium sulfate and ammonium nitrate, will absorb water as relative humidity 

increases, which effectively increases the size and the light scattering efficiencies of these 

particles. In addition to aerosol scattering, light extinction due to natural background gases in a 

clean atmosphere, or Rayleigh scattering, will contribute to total light extinction. Aerosol 

extinction from each of these species is additive, so the sum of the individual aerosol extinction 

species, plus Rayleigh scattering, represents total extinction. 

The IMPROVE program has developed an algorithm for estimating light extinction from 

speciated aerosol and relative humidity data. The original algorithm, as cited in RHR guidance, 

was revised in 2005.

21 IMPROVE data are available from the IMPROVE Network through the Federal 

Land Manager Database online repository (http://views.cira.colostate.edu/fed/) and are also reported 

along with data summary charts and tables specifically designed to address RHR planning efforts 

on the WRAP TSS (www.vista.cira.colostate.edu/tss/). 

Once extinction has been calculated from speciated aerosol mass, it can be converted to 

other metrics that describe visibility impairment. Figure 3.1-2 presents a comparison of the most 

commonly used metrics, which are described below: 

21 The revised IMPROVE algorithm is described in detail in Hand’s 2006 Review of the IMPROVE Equation for 

Estimating Ambient Light Extinction Coefficients - Final Report available at 

http://vista.cira.colostate.edu/improve/Publications/GrayLit/016_IMPROVEeqReview/IMPROVEeqReview.htm. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-3 

 
• Extinction (bext) – Extinction is a measure of the fraction of light lost per unit length 

along a sight path due to scattering and absorption by gases and particles, expressed 

in inverse Megameters (Mm-1).

• Deciview (dv) – This is the metric used for tracking regional haze in the RHR. The 

Haze Index (measured in deciviews) was designed to be linear with respect to human 

perception of visibility. A one deciview change is approximately equivalent to a 10% 

change in extinction, whether visibility is good or poor. A one deciview change in 

visibility is generally considered to be the minimum change the average person can 

detect. 

• Visual Range (VR) – Visual range is the greatest distance a large black object can be 

seen on the horizon, expressed in kilometers (km) or miles (mi). 

Figure 3.1-2. Comparison of Extinction (Mm-1), Deciview (dv) and Visual Range (km) units. 

3.1.1 Data Completeness Requirements

As described in Section 2.0, progress for the RHR is determined using 5-year average 

visibility conditions. EPA’s 2003 Guidance for Tracking Progress Under the Regional Haze 

Rule22 includes data completeness requirements designed to ensure that calculated averages 

include sufficient data to represent each daily, annual and 5-year period. EPA’s 2003 Guidance 

specifies that the 2000-2004 baseline period, and each subsequent 5-year average progress 

period, meet the following conditions: 

• Individual samples must contain all species required for the calculation of light 

extinction (ammonium sulfate, ammonium nitrate, POM, EC, soil, coarse mass, and 

sea salt)

• Calendar seasons must contain at least 50% of all possible daily samples

• Calendar years must contain at least 75% of all possible daily samples

• Calendar years must not contain more than 10 consecutive missing daily samples 

• The 5-year baseline and each 5-year progress period averages must contain at least 3 

complete years of data

22 Data completeness requirements are listed in Section 2.2 (step 7) of EPA’s September 2003 Guidance for 

Tracking Progress Under the Regional Haze Rule. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-4 

 
RHR guidance specifies that if a 5-year period has less than three complete years of data, 

then estimates should be prepared for the missing data.

23 In the WRAP states, two data 

completeness issues were addressed to support progress summaries in document: 

• Incomplete Progress Period Data: The 2005-2009 progress period did not have 

complete data available for one site in the WRAP. The SIAN1 site, representing the 

Sierra Ancha Wilderness Area in Arizona, did not meet RHR data completeness 

criteria for the years 2006, 2007, and 2008, which did not leave the 3 complete years 

required for a 5-year average. Data substitutions for these years were performed in a 

manner similar to that previously performed by the WRAP for incomplete 2000-2004 

baseline years at 10 IMPROVE sites in the WRAP. Detailed methods are summarized 

in the Arizona state monitoring section (Section 6.2.1).

• Monitor Relocation: For two CIAs, Zion National Park in Utah and Haleakala 

National Park in Hawaii, it was determined that the original IMPROVE monitors 

sited to represent the parks did not adequately represent the CIAs. New sites were 

installed to better represent the parks, but because these sites were installed later, 

2000-2004 baseline data averages are not available for the new locations. The RHR 

requires that the state establish baseline values using the most representative 

monitoring data for 2000-2004.24 Detailed methodologies used to approximate 

baseline averages for these sites are summarized in the Hawaii and Utah monitoring 

sections (Sections 6.5 and 6.12, respectively).

All regional and state summaries presented in this report include the SIAN1 substituted 

data, and baseline estimates calculated for the ZICA1 and HACR1 sites.

3.1.2 RHR Progress Period Calculation Considerations

The goal of the RHR is to ensure that visibility on the 20% most impaired, or worst, days 

continues to improve, and that visibility on the 20% least impaired, or best, days does not get 

worse, as measured in units of deciviews, calculated using data measured at IMPROVE 

monitoring sites. As described previously, progress for this report is measured for discreet 5-year 

average increments, beginning with the 2000-2004 baseline average, and proceeding with the 

most recently available subsequent 5-year average (2005-2009).25 Some of the more subtle, but 

important, considerations for RHR calculations using IMPROVE data measurements are 

described below. 

23 Section 2.2 (step 7) of the September 2003 Guidance for Tracking Progress Under the Regional Haze Rule states 

“If 3 years with complete data are not available, estimates for baseline of current conditions should be prepared in 

consultation with the Environmental Protection Agency’s Office of Air Quality and Planning Standards 

(EPA/OAQPS).”

24 Section 308(d)(2)(i) of the RHR states, “For mandatory Class I Federal areas without onsite monitoring data for 

2000-2004, the State must establish baseline values using the most representative available monitoring data for 

2000-2004, in consultation with the Administrator or his or her designee.”

25 EPA’s September 2003 Guidance for Tracking Progress Under the Regional Haze Rule specifies that progress is 

tracked against the 2000-2004 baseline period using corresponding averages over successive 5-year periods, i.e. 

2005-2009, 2010-2014, etc. (see page 4-2 in the Guidance document).

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-5 

 
3.1.2.1 Identification of 20% Worst Days 

As described in Section 3.1, visibility impairment is the result of the cumulative effect of 

several different particle pollutant types. Many of these pollutants have individually consistent 

seasonal patterns. For example, ammonium nitrate is temperature sensitive, and formation often 

favored during colder winter months, while ammonium sulfate formation may be favored during 

warmer summer months. Other pollutants, such as particulate organic mass, may be impacted by 

large and variable episodic events such as wildland fires, which generally occur during the 

summer. 

To determine the 5-year average of the 20% best and worst days, the highest and lowest 

20% of days for each complete year are first selected and averaged on an annual basis, with a 

5-year average calculated from these annual averages. The timing for identification of the 20% 

best and worst days may be significantly influenced by large episodic events (e.g., wildland 

fires) which may occur at different time during different years. As a result, the identification of 

more best or worst days during different seasons of different years may affect the averages for 

individual species in ways that are independent from actual increases or decreases of individual 

pollutants from one 5-year period to the next. 

As an illustration of the effect of large episodic events on worst day averages, consider 

daily average aerosol extinction calculated from IMPROVE data at the CHIR1 site in Arizona. 

Figures 3.1-3 and 3.1-4 present daily aerosol extinction measurements for 2002 and 2008 at 

CHIR1, with the 20% worst days represented by an orange box with an “x” below the day. 

Similar daily aerosol charts depicting the 20% worst days are included for each Class I area in 

state specific Appendices. For 2002, large wildfire events in June and July contributed to high 

particulate organic mass (POM) measurements, resulting in more worst days selected during this 

period. In 2008, more of the worst days were selected in August and October. 

As an illustration of the seasonal patterns of individual compounds, consider the monthly 

averages of aerosol extinction calculated from IMPROVE data at the CHIR1 site. Figure 3.1-5 

presents monthly average aerosol pollution for CHIR1 measured during 2002, and Figure 3.1-6 

presents monthly averages in 2008. State specific appendices included with this document 

present similar monthly average plots for each year at each site. The seasonal patterns for both 

years indicated that ammonium sulfate was generally higher between May and July than in 

October. 

Because of the seasonal ammonium sulfate patterns, the identification of more worst days 

between May and July (e.g., 2002 at CHIR1) will show a higher ammonium sulfate average than 

a year with more worst days in October (e.g., 2008 at CHIR1), even though annual ammonium 

sulfate levels may not have increased. For this case, Table 3.1-1 presents the annual averages of 

ammonium sulfate for both the 20% worst days and all measured days. For these years, the 

annual average of ammonium sulfate extinction for all measured days decreases, while the 20% 

worst day average actually increased.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-6 
Figure 3.1-3. Daily Aerosol Extinction measured by the Chiricahua CHIR1 IMPROVE 

monitor during 2002. 

Figure 3.1-4. Daily Aerosol Extinction measured by the Chiricahua CHIR1 IMPROVE 

monitor during 2008. 

Figure 3.1-5. Monthly Average Aerosol Extinction measured by the CHIR1 IMPROVE 

monitor in 2002. 

Figure 3.1-6. Monthly Average Aerosol Extinction measured by the CHIR1 IMPROVE 

monitor in 2008. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-7 
Table 3.1-1 

CHIR IMPROVE Site

Comparison of Ammonium Sulfate Average 

All Days and 20% Worst Days 

Year

All Days

Amm. Sulfate

Average (Mm-1)

20% Worst Days

Amm. Sulfate

Average (Mm-1)

2002 5.3 7.8 

2008 4.9 9.0 

Difference -0.4 Mm-1 +2.2 Mm-1

3.1.2.2 Discreet 5-Year Averages vs. Trends

The 2003 RHR Guidance prescribes that progress be measured using discreet 5-year 

average increments,

26 but states that determining trends for all the individual species that 

contribute to haze is especially helpful in tracking progress. Individual high or low years can 

affect the 5-year averages, while trend statistics are more resistant to extreme events and may 

better represent the effects of emissions controls.

27 For this reason, looking at annual trends in 

addition to the differences between 5-year averages can also be instructive in determining the 

long term behavior of pollutant measurements. 

Generally, the 10-year trends are consistent with the 5-year average differences, but in 

some cases annual trends and differences between 5-year averages may show different 

characteristics. Trends for annual averages of each species at each site are presented in this report 

as calculated using Kendall-Theil statistics, which are often used in environmental applications 

because these statistics are resistant to outliers.28 Figure 3.1-7 shows an example of an increase 

in the 5-year average deciview metric for ammonium sulfate measured on the 20% most 

impaired days at the Salt Creek Wilderness Area (SACR1) IMPROVE site (16.7 Mm-1 to 18.9 

Mm-1), but a decreasing annual deciview trend (-0.5 Mm-1/year). The increase in the 5-year 

average was driven by uncharacteristically high average ammonium sulfate measured in 2005. 

For all sites included in this report, both 5-year average differences and trends is reported, and 

any differing characteristics are noted and described. 

26 As noted previously, EPA’s September 2003 Guidance for Tracking Progress Under the Regional Haze Rule

specifies that progress is tracked against the 2000-2004 baseline period using corresponding averages over 

successive 5-year periods, i.e. 2005-2009, 2010-2014, etc. (see page 4-2 in the Guidance document).

27 Section 4.7 of EPA’s September 2003 Guidance for Tracking Progress Under the Regional Haze Rule states that 

“In the long-term, tracking trends of species contributions to haze provides information that can be useful in 

determining whether implemented emissions controls are having the expected effects.”

28 Trend statistics used in this report are also used in EPA’s National Air EPA’s National Air Quality Trends Reports 

(http://www.epa.gov/airtrends/) and the IMPROVE program trend reports 

(http://vista.cira.colostate.edu/improve/Publications/improve_reports.htm) 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-8 

 
Figure 3.1-7. Annual Averages, Period Averages and Trend Statistics for Ammonium Sulfate 

Measured at the SACR1 IMPROVE Site in New Mexico. 

3.1.2.3 Averaging Considerations for Deciview Calculations 

The RHR haze index, as defined using deciviews (dv), does not provide information 

regarding the relative contributions of individual species to overall visibility. The deciview

metric for extinction is logarithmically related to total extinction (bext), e.g. dv=10ln(bext/10), 

where bext is the sum of extinction as calculated from individual species mass measurements. 

Looking at individual species extinction is necessary for RHR considerations because each

species that contributes to regional haze can have different sources and control options. For 

example, some species (e.g. sulfate and nitrate species) originate from largely anthropogenic 

sources, while others (e.g. organic species) from a mixture of both anthropogenic and natural 

sources. Because of the logarithmic nature of deciviews, it is not possible to separate this metric 

into individual species, so a representation of total extinction in units of inverse megameters 

(Mm-1) is useful.

EPA’s Guidance for Tracking Progress Under the Regional Haze Rule (EPA 2003) 

specifies that the 5-year average deciview value is calculated as an average of annual values, 

which are in turn calculated as averages of daily values.

29 In most cases, an increase/decrease in 

the deciview metric corresponds to an increase/decrease in total extinction. In some cases, 

because the 5-year deciview value is effectively the average of logarithmic values, the average 

deciviews may change in a different direction than the average of total extinction. As an 

29 Calculation of the 5-year average deciview metric is described in Section 4.3 of EPA’s September 2003 Guidance 

for Tracking Progress Under the Regional Haze Rule.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-9 

 
example, consider the following extinction measurements presented in Table 3.1-1 for a 

contrived dataset of 2 days for each of 2 periods. The table shows both daily and period average 

extinction, and corresponding deciview calculations. Note that the average total extinction

decreases (70 to 55 Mm-1), while the average deciview value increases (15.9 to 17.0 dv). 

Table 3.1-1 

Example Calculation

Decreasing bext Averages With Increasing deciview Averages

Averaging Periods Extinction

(Mm-1) 

Deciviews (dv)

10×ln(bext/10)

Period 1 Day 1 20 6.9

Day 2 120 24.8

Period 1 Average 70 15.9

Period 2 Day 1 50 16.1

Day 2 60 17.9

Period 2 Average 55 17.0

Difference -15 Mm-1 +1.1 dv

For comparisons between the 2000-2004 baseline period and the 2005-2009 progress 

period, decreasing 5-year average deciview metrics, but increasing extinction for the 20% most 

impaired, or worst, days was observed at 9 WRAP Federal CIA sites, and slightly increasing 

deciview associated with decreasing average extinction was observed at 1 site, as listed in Table 

3.1-2. 

Table 3.1-2 

20% Most Impaired Visibility Days

Total Extinction and Deciview Average Differences

State Site

Extinction (Mm-1) Deciviews (dv)

Baseline

Period

(2000-

2004)

Progress 

Period 

(2005-

2009)

Difference

Baseline

Period

(2000-

2004)

Progress 

Period 

(2005-

2009)

Difference

AZ SYCA1 47.2 47.4 +0.2 15.3 15.2 -0.1

CA

DOME1 71.7 76.7 +5.0 19.4 19.2 -0.2

PINN1 65.1 65.7 +0.6 18.5 18.4 -0.1

TRIN1 68.0 91.8 +23.8 17.3 17.3 0.0

OR

CRLA1 47.9 47.7 -0.2 13.7 13.8 +0.1

HECA1 69.1 71.9 +2.8 18.6 18.1 -0.5

MT GAMO1 31.8 32.9 +1.1 11.3 11.2 -0.1

WA WHPA1 37.1 37.9 +0.8 12.8 12.7 -0.1

WY 

BRID1 31.6 31.7 +0.1 11.1 10.7 -0.4

YELL2 34.5 36.1 +1.6 11.8 11.5 -0.3

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-10
3.2 EMISSIONS INVENTORIES 

To demonstrate RHR progress, states are required to report how total emissions in the 

state have changed over the past 5 years (51.308(g)(4)), and to determine if there have been 

significant changes in emissions from the state or from other states affecting visibility at each 

Federal CIA which has impeded progress in improving visibility (51.308(g)(5)). Comparisons 

between emissions inventories in this report use the inventories that represent both baseline and 

current conditions. Baseline emissions in most cases are represented using the 2002 inventory 

that was originally developed, with support from the WRAP, to represent emissions for the initial 

implementation plans. Current emissions are represented here by leveraging recent work by the 

WRAP to develop an updated and comprehensive inventory for the year 2008 for use in 

modeling projects. For non-contiguous states (Alaska and Hawaii), alternate inventories 

representing the progress periods were obtained in consultation with the states. 

Emissions inventories in this report were complicated by the fact that a number of 

changes and enhancements have occurred between development of the baseline and current 

period inventories, such that many of the differences between inventories are more reflective of 

changes in inventory methodology, rather that changes in actual emissions. Differences in 

emissions are presented for all categories in this report, but summaries focus on aspects of source 

categories that have been more consistently inventoried over time, while noting any changes in 

methodologies that may affect differences in other categories. Detailed references regarding 

emissions inventories are presented in this section.

3.2.1 Inventory Descriptions

Emissions related to the different particle species that affect regional haze are varied and 

complex, including a number of both anthropogenic and natural source possibilities. Emissions 

estimates vary by source category according to the different characteristics and attributes of each

category, and how the emissions are modeled. A number of anthropogenic, or man-made, 

sources such as motor vehicles and electric generating units (EGUs) are reported by states and 

may be subject to controls. Natural emissions, such as fires, biogenic emissions and some 

categories of dust can have large regional haze impacts, but are not subject to control strategies. 

Source categories for both anthropogenic and natural sources are listed and described briefly 

below, followed by information related to inventory development and comparisons for the 

contiguous states, Alaska, and Hawaii.

• Point Sources: These are sources that are identified by point locations, typically 

because they are regulated and their locations are available in regulatory reports. In 

addition, elevated point sources will have their emissions allocated vertically through 

the model layers, as opposed to being emitted into only the first model layer. Point 

sources can be further subdivided into EGU sources and non-EGU sources, 

particularly in criteria inventories in which EGUs are a primary source of NOX and 

SO2. Examples of non-EGU point sources include chemical manufacturers and 

furniture refinishers.

• Area Sources: Sources that are treated as being spread over a spatial extent (usually a 

county or air district) and that are not movable (as compared to non-road mobile and 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-11
on-road mobile sources). Because it is not possible to collect the emissions at each 

point of emission, they are estimated over larger regions. Examples of stationary area 

sources are residential heating and architectural coatings. Numerous sources, such as 

dry cleaning facilities, may be treated either as stationary area sources or as point 

sources.

• On-Road Mobile Sources: These include vehicular sources that travel on roadways. 

Emissions from these sources can be computed either as being spread over a spatial 

extent or as being assigned to a line location (called a link). Emissions are estimated 

as the product of emissions factors and activity data, such as vehicle miles traveled 

(VMT). Examples of on-road mobile sources include light-duty gasoline vehicles and 

heavy-duty diesel vehicles.

• Off-Road Mobile Sources: Off-road mobile sources are vehicles and engines that 

encompass a wide variety of equipment types that either move under their own power 

or are capable of being moved from site to site. Examples include agricultural 

equipment such as tractors or combines, aircraft, locomotives and oil field equipment 

such as mechanical drilling engines. Emissions from marine vessels are included here 

separately as offshore emissions.

• Off-shore: Commercial marine emissions comprise a wide variety of vessel types and 

uses. Emissions can be estimated for deep draft vessels within shore and near port 

using port call data, and offshore emissions generated from ship location data. 

• Oil and Gas Sources: Oil and gas sources consist of a number of different types of 

activities from engine sources for drill rigs and compressor engines, to sources such 

as condensate tanks and fugitive gas emissions. The variety of emissions types for 

sources specific to oil and gas activity can, in some cases, overlap with mobile, area 

or point sources, but these can also be extracted and treated separately.

• Biogenic Emissions: Biogenic emissions are based on the activity fluxes modeled 

from biogenic land use data, which characterizes the types of vegetation that exist in 

particular areas. Emissions are generally derived using modeled estimates of biogenic 

gas-phase pollutants from land use information, emissions factors for different plant 

species, and meteorology data.

• Dust: Dust emissions may have a variety of sources that could include anthropogenic 

sources, natural sources, and natural sources that may be influenced by anthropogenic 

activity. In order to better distinguish between the natural and anthropogenic sources, 

the WRAP undertook a Definitions of Dust project, with a final report available here: 

http://www.wrapair.org/forums/dejf/documents/defdust/index.html. For emissions 

summary purposes, dust is classified here as fugitive dust and windblown dust.

Fugitive dust includes sources such as road dust, agricultural operations, construction 

and mining operations and windblown dust from vacant lands. The windblown dust 

category includes more of the natural influences such as wind erosion on natural 

lands. 

• Fire: Fire sources are difficult to predict and control, and may have a mix of natural 

and anthropogenic influences. Natural sources include wildland fires, while 

anthropogenic sources can include agricultural and prescribed fires. In order to better 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-12
distinguish between natural and anthropogenic fires, the WRAP has created an 

operational policy level definition of fire activity as discretely natural or 

anthropogenic, which included allowing certain types of prescribed fires to be treated 

as natural.30

3.2.1.1 Contiguous WRAP States

As noted previously, baseline and current period emissions are summarized here using 

two discreet years, where one year is used to represent baseline emissions, and other is used to 

represent the current progress period. For contiguous states, the baseline period inventories 

summarized here for comparison to current conditions is the 2002 inventory that was developed 

for WRAP states in support of the original SIPs, termed “plan02d” (or “plan02c” in California). 

Development of the plan02 inventories were a cooperative effort sponsored by the WRAP in 

cooperation with WRAP states. This effort built upon 2002 emissions reported by states, and 

included work with contractors and WRAP workgroups, in consultation with states, to enhance 

specific categories (e.g., point, area, on- and off-road mobile, oil and gas, fire, and dust) to better 

characterize regional haze implications. Detailed descriptions of inventory development are 

available from the WRAP Technical Support System website 

(http://vista.cira.colostate.edu/TSS/Results/Emissions.aspx).

The WRAP has continued to support emissions data tracking and related technical 

analyses focused on understanding current and evolving regional air quality issues in the western 

states. Methods for estimating emissions of many of the source categories that affect regional 

haze have continued to evolve and be refined over time. This is especially true for inventories of 

natural emissions categories including windblown dust and biogenic emissions, and also for 

rapidly evolving industries such as oil and gas exploration. To represent current conditions, this 

progress report support document leverages 2008 emissions data inventories which have been 

recently developed as part of the WRAP’s West-wide Jumpstart Air Quality Modeling Study 

(WestJumpAQMS) and Deterministic and Empirical Assessment of Smoke’s Contribution to 

Ozone (DEASCO3) study, which are described briefly below: 

• The WestJumpAQMS project (http://wrapair2.org/WestJumpAQMS.aspx) sponsored 

by the WRAP includes coordination and harmonization with the EPA 2008 National 

Emissions Inventory (2008 NEI v2). Among other goals, this project is intended to 

provide technical updates and improvements for multiple air quality issues, including 

regional haze, ozone, particulate pollution and nitrogen deposition. 

• The DEASCO3 study (http://www.wrapfets.org/deasco3.cfm) is a project sponsored 

by the Joint Fire Sciences Program (JFSP) that looks at impact of weather and fires 

on ozone formation. This project has included the development of a detailed and 

comprehensive 2008 fire emissions inventory, which will eventually be incorporated 

into the WestJumpAQMS project.

30 The WRAP Policy for characterizing fire emissions is available at 

http://www.wrapair.org/forums/fejf/documents/nbtt/firepolicy.pdf. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-13

 
Because these inventories have been refined over time, there is not necessarily continuity 

between the 2002 and 2008 inventories, which affects data comparisons for particular source 

categories. Detailed references and major methodology differences for the emissions inventories 

compared here are summarized in Table 3.2-1. In addition to comparing baseline and progress 

period inventories, regional and state summary sections in this report include annual averages 

tracking changes in regional and state totals for SO2 and NOX emissions for EGU as tracked in 

the EPA’s Air Markets Program Database for permitted Title V facilities in the state 

(http://ampd.epa.gov/ampd/). 

Table 3.2-1

Emissions Inventory Descriptions 

Contiguous WRAP States

Inventory 

Sector

2002 Baseline Inventory

(Plan02c/Plan02d) 31

2008 Progress Period 

Inventory

(WRAP WestJump08) 32

Comments

Point 

Sources

Most WRAP states used the 

Plan02d point source 

inventories, while California 

used the Plan02c inventory for 

their initial SIP. 

These inventories were 

generated using hourly EPA 

CAMD CEM data for EGUs. 

Other point were developed in 

consultation with states by the 

ERG contractor.

Note that the WRAP also 

generated point source 

inventories for both actual 

reported 2002 (Base02b) EGU

and all other point source data, 

and for a 2000-2004 average 

of EGU point sources (Plan02c 

and Plan02d). Plan02 

emissions are summarized in 

this report because they are 

consistent with what was 

reported as baseline conditions 

for most initial WRAP region 

SIPs.

The WRAP WestJump 2008 

inventories were generated 

using hourly EPA CAMD 

CEM data for EGUs. Other 

point sources are from the 

2008 NEI v2. 

Note that point source oil and 

gas inventories were 

inventoried separately for 

WestJump08, but included in 

the point source totals here for 

comparisons with 2002 

inventories.

Because point source 

definitions vary by state, any 

changes or additions for an 

individual state will affect 

comparisons of 2002 and 

2008. 

Note that baseline conditions 

presented here represent a 5-

year average for EGUs, while 

progress period conditions are 

represented with 2008 data.

In addition to inventory 

changes for these two years, 

year-to-year variations are also 

presented separately for Title 

V Major Sources on a regional 

and state basis.33

31 Detailed inventory descriptions for development of the WRAP Base02b, plan02c and plan02d inventories are 

available on the WRAP TSS website http://vista.cira.colostate.edu/TSS/Results/Emissions.aspx and archived on the 

original WRAP website http://www.wrapair.org/forums/ssjf/pivot.html. 32 Detailed inventory descriptions for development of the WRAP WestJump08 inventory are available on the WRAP 

project page http://wrapair2.org/WestJumpAQMS.aspx. 33 Annual EGU emissions for each state were obtained from EPA’s Air Markets Program Database for permitted 

Title V facilities (http://ampd.epa.gov/ampd/). 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-14

 
Table 3.2-1

Emissions Inventory Descriptions 

Contiguous WRAP States

Inventory 

Sector

2002 Baseline Inventory

(Plan02c/Plan02d) 31

2008 Progress Period 

Inventory

(WRAP WestJump08) 32

Comments

Area 

Sources

Most WRAP states used the 

Plan02d point source 

inventories, while California 

used the Plan02c inventory for 

their initial SIP.

These inventories were 

developed by the ERG 

contractor in consultation with 

states. 

The WRAP WestJump 2008 

used state reported area source 

inventories from the 2008 NEI 

v2.

34

Note that, beginning in 2008, 

some source categories such as 

Class I and II commercial 

marine vessels, Class III 

vessels on in-land waterways 

and in-transit locomotive 

emissions, were defined as 

area sources (moved from offroad inventory). To reflect 

these changes, EPA now refers 

to the area source category as 

the “non-point” emissions.

Note that area oil and gas 

sources are reported separately

in this report. 

Area source estimates 

represent broad areas, and 

include calculations which are, 

in part, based on population 

estimates and activity data.

Because of this, changes in are 

source definitions and changes 

in calculation methods (which 

can be different from state to 

state and year to year), as well 

as changes in inputs such as 

population can affect 

differences between these 

inventories.

One important example of 

methodology differences is the 

addition of some sources 

previously considered “offroad” into the area (also 

referenced as non-point) 

source category.

34 EPA’s 2008 NEI inventory estimates are available at http://www.epa.gov/ttn/chief/net/2008inventory.html. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-15

 
Table 3.2-1

Emissions Inventory Descriptions 

Contiguous WRAP States

Inventory 

Sector

2002 Baseline Inventory

(Plan02c/Plan02d) 31

2008 Progress Period 

Inventory

(WRAP WestJump08) 32

Comments

Area Oil 

and Gas

These inventories were 

developed for specific oil and 

gas basins using WRAP Phase 

II emissions methodologies.

35

Where WRAP Phase II 

emissions were not available, 

area source oil and gas 

emissions as reported by the 

state were used. Phase II 

emissions process estimated 

for 2002 included: 

• Drill Rigs

• Wellhead Compressor 

Engines

• CBM Pump Engines

• Heaters

• Pneumatic Devices

• Condensate and oil tanks

• Dehydrators

• Completion Venting

 

These inventories were 

developed for specific oil and 

gas basins using WRAP Phase 

III emissions methodologies. 

Where WRAP Phase III 

emissions were not available, 

area source oil and gas 

emissions as reported by the 

state were used. Phase III 

emissions process estimated 

for 2008 included: 

These inventories used 2008 

production data, which was

updated with State-reported 

data in some cases. The 

following additional categories 

were included in addition to 

those listed for 2002:

• Lateral compressor engines

• Workover rigs

• Salt-water disposal engines

• Artificial lift engines 

• Vapor recovery units 

(VRUs)

• Miscellaneous or exempt 

engines

• Flaring

• Fugitive emissions

• Well blowdowns

• Truck loading

• Amine units (and gas 

removal)

• Water tanks

Oil and gas development is a 

rapidly evolving industry, and 

significant efforts to better 

characterize emissions have 

occurred between development 

of the 2002 and 2008 

inventories. In addition to 

expanded development, some 

notable emission inventory 

difference include:

• Regulatory changes specific 

to each state may have 

required more sources to be 

reported in 2008 than were 

reported in 2002.

• New and/or revised 

estimation methodologies, 

especially for VOC 

emissions rates, were used 

for more source categories 

in Phase III. 

• Phase III estimates included 

surveys which provided 

detailed information about 

specific sources (e.g. counts 

by device type such as lowbleed vs. high-bleed) among 

other improvements to 

activity data. These sources 

included small area source 

equipment typically not 

inventories by the states. 

Phase II did not have that 

information available, since 

no surveys were made in 

Phase II.

• Phase III used the highquality and complete IHS 

commercial database of 

O&G production data by 

well by basin. For Phase II, 

the state O&G Commission 

databases, which have been 

improved quite a bit over 

time, were used.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-16
Table 3.2-1

Emissions Inventory Descriptions 

Contiguous WRAP States

Inventory 

Sector

2002 Baseline Inventory

(Plan02c/Plan02d) 31

2008 Progress Period 

Inventory

(WRAP WestJump08) 32

Comments

On-Road 

Mobile

The 2002 inventory for most 

WRAP states used the EPA 

MOBILE6 model as applied 

by ENVIRON using inputs 

from states.

California provided emissions 

separately using their

EMFAC2002 model.

The 2008 on-road mobile

inventory used the EPA 

MOVES2010 model applied to 

state inputs in inventory mode. 

The California EMFAC2011 

data were downloaded in 2012 

from the California ARB 

website.

Differences in models

contribute to some differences 

in emissions reported, but 

other differences are due to a 

combination of VMT 

differences and new controls 

on vehicles.

Off-Road 

Mobile

The 2002 inventory for most 

WRAP states used the draft 

NONROAD2004 model as 

applied by ENVIRON using 

inputs from states.

California provided emissions 

separately. 

The 2008 off-road mobile 

inventory was obtained from 

the NEIv2.0 using the 

NONROAD model estimates 

within the National Mobile 

Inventory Model (NMIM). 

Note that, beginning in 2008, 

some source categories were 

removed from the off-road 

mobile category to the 

area/non-point category. These 

emissions included Class I and 

II commercial marine vessels, 

Class III vessels on in-land 

waterways and in-transit 

locomotive emissions.

California supplied non-road 

emissions calculations using a 

California state-specific offroad model.

The off-road models include 

both emission factors and 

default county-level population 

and activity data.

One important methodology 

change was the reclassification of some sources 

previously labeled off-road as 

non-point (area) sources in 

2008.

35Additional Phase II oil and gas inventory descriptions are archived on the original WRAP website 

http://www.wrapair.org/forums/ogwg/documents/2007-10_Phase_II_O&G_Final)Report(v10-07%20rev.s).pdf. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-17

 
Table 3.2-1

Emissions Inventory Descriptions 

Contiguous WRAP States

Inventory 

Sector

2002 Baseline Inventory

(Plan02c/Plan02d) 31

2008 Progress Period 

Inventory

(WRAP WestJump08) 32

Comments

Offshore For the baseline inventories, 

off-Shore emissions were 

treated as a region rather than a 

source category. 

For the 2008 inventories, 

specific SCCs do not 

distinguish between regions 

(e.g. Atlantic, Pacific and 

Gulf), so these are presented as 

a sum of all offshore 

emissions.

Note that while offshore 

emissions are available from 

both datasets, comparisons are 

not presented in this report. 

These emissions were not 

comparable, as baseline 

emissions were presented as a 

region, and not explicitly 

associated with any of the 

coastal states for summaries 

here, and progress period 

summaries totaled all offshore 

emissions for the US (e.g. 

Atlantic, Pacific and Gulf) 

Fugitive 

Dust and 

Road Dust

The WRAP 2002 inventory by 

ENVIRON began with inputs 

from states.

For 2002, note that vegetative 

scavenging factors were 

applied pre-processing at the 

county level, as opposed to 

grid-level for 2008 data.

These emissions were 

extracted from state reported 

area source emissions for 2008 

(NEI08v2).

For the NEI08v2 inventories, 

the State of California notes 

that they have changed the 

way they calculate and report 

paved road dust.

For 2008, note that vegetative 

scavenging factors were 

applied post-processing at a 

higher resolution grid cell 

level, as compared to 2002 

data.

Note that fugitive dust and 

road dust categories were 

available separately in the 

WRAP Plan02d inventories, 

but are combined for summary 

purposes here. For the 2008 

inventory, vegetative 

scavenging factors were 

applied to the combined 

sources; thus these source 

categories were not easily 

separated.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-18
Table 3.2-1

Emissions Inventory Descriptions 

Contiguous WRAP States

Inventory 

Sector

2002 Baseline Inventory

(Plan02c/Plan02d) 31

2008 Progress Period 

Inventory

(WRAP WestJump08) 32

Comments

Windblown 

Dust 

Generated using WRAP 

Windblown Dust Model and 

2002 MM5 meteorology, at 

36km grid cell resolution.

Vegetative scavenging factors 

were applied pre-processing at 

the county level. 

Generated using WRAP 

Windblown Dust Model and 

2008WRF meteorology, at 

4km and 12km grid cell 

resolution for the WRAP 

region.

Vegetative scavenging factors 

applied post-processing at the 

grid cell level. 

Significant updates to enhance 

the accuracy of the WRAP 

Windblown Dust Model will 

affect comparisons between 

the 2002 and 2008 inventories. 

Specific differences between 

the inventories include: 

• Different meteorological 

models; MM5 (2002) vs. 

WRF (2008) met models

• Higher resolution of grid 

cells in 2008, which led to 

higher average wind speeds 

in individual cells, and

increased windblown dust 

emissions aggregated at the 

county level.

• MM5 Layer 1 used 36 meter 

height winds vs. WRF 

average winds across lowest 

3 layers spanning ~40 meter 

height.

• An error in 2002 WBD 

model was corrected where 

rainfall in centimeters was 

treated as inches.

Biogenic The 2002 biogenic inventory 

used the BEIS3.12 model with 

BELD3 landuse and 2002 

MM5 meteorology data, at 

36km grid cell resolution. 

The 2008 biogenic inventory 

used the MEGAN2.10 with 

2008 WRF meteorology data, 

at 4 and 12 km grid cell 

resolution.

Significant model changes 

designed to enhance the 

accuracy of the biogenic 

emissions estimates will affect 

comparisons between the 2002 

and 2008 inventories. Specific 

differences between the 

BEIS3.12 and MEGAN2.10 

model outputs include:

• Different meteorological 

years and models (2002 

MM5 vs. 2008 WRF).

• Higher temporal and spatial 

variability of land cover and 

other environmental input 

factors.

• Improved emissions factors 

based on better sources of 

data (e.g., satellites and field 

studies).

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-19
Table 3.2-1

Emissions Inventory Descriptions 

Contiguous WRAP States

Inventory 

Sector

2002 Baseline Inventory

(Plan02c/Plan02d) 31

2008 Progress Period 

Inventory

(WRAP WestJump08) 32

Comments

Fires

(Natural 

and 

Anthropogenic)

Baseline estimates used the 

WRAP Phase III fire 

inventory, which represent a 

2000-2004 5-year average of 

fire activity. Inventories 

included both anthropogenic 

and natural emissions.

2008 estimates use DEASCO3

fire summaries, which account 

for fires in 2008, and include 

separate reporting of 

anthropogenic and natural 

fires. 36 

Baseline conditions are 

represented with a 5-year 

average of fire, while progress 

period conditions are 

represented with 2008 data.

Comparisons between these 

inventories are complicated by 

the variable and sporadic 

nature of wildfires. Also, 

differences between

methodologies will affect 

comparisons of inventories 

used for 2002 and 2008 

estimates.

36 Additional details regarding fire inventory descriptions for development of the DEASCO3 inventory are available 

on the WRAP project page at http://www.wrapfets.org/deasco3.cfm. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-20

 
3.2.1.2 Alaska

Current emissions summaries for the contiguous states use inventories developed for 

modeling purposes, but the States of Alaska (and Hawaii) were not included in the modeling 

effort, so these current year inventories were not available. Baseline conditions were represented 

with data originally used to represent baseline emissions in the initial Alaska implementation

plan. For current progress period summaries, inventories were assembled through consultation 

with the Alaska Department of Environmental Control (DEC). Table 3.2-2 presents data 

references for source categories used to represent emissions in Alaska.

Table 3.2-2 

Emissions Inventory Descriptions 

Alaska

Source Categories 2002 Inventory 2008 Inventory

Point WRAP 2002 point source inventory37 Provided by Alaska DEC 

Area 2002 emissions from the Alaska DEC “Big 

3” 38 Criteria Inventories and

2005 emission from the Alaska DEC Rural 

Inventory39

2008 WestJump40

On-Road and

Off-Road Mobile

NEI2008v341

Aviation WRAP 2002 Aviation Report42

Commercial 

Marine Pechan Report43

Fire WRAP 2003 Phase III Inventory44 Alaska Interagency Coordination Center

(AICC) Incident Support Website45

3.2.1.3 Hawaii 

Current emissions summaries for the contiguous states use inventories developed for 

modeling purposes, but the States of Hawaii (and Alaska) were not included in the modeling 

37 The WRAP 2002 point source inventory is available from http://www.wrapair.org/forums/ssjf/pivot.html. 38 Alaska “Big 3” inventories include Anchorage, Juneau and Fairbanks.

39 Alaska “rural” inventories refers to remaining boroughs and census areas outside of Anchorage, Juneau and 

Fairbanks. The 2005 Alaska rural inventory is available at 

http://www.epa.gov/region10/pdf/tribal/wrap_alaska_communities_final_report.pdf. 40 WRAP 2008 WestJump inventories are available on the WRAP project page

http://www.wrapfets.org/deasco3.cfm 41 EPA’s 2008 NEI inventory estimates are available at http://www.epa.gov/ttn/chief/net/2008inventory.html. Note 

that only lead (Pb) emissions totals were available from the NEI2008v3 data set, so 2008 emissions are not included 

from this source for comparison purposes.

42 Aviation inventories are available from the 2005 WRAP report, Alaska Aviation Emissions Inventory Report, 

developed by Sierra Research, available at http://www.wrapair.org/forums/ef/inventories/akai/. 43 Commercial marine inventories are available from the 2005 Pechan report, Commercial marine inventories for 

select Alaskan ports : final report. 44 The WRAP Phase III fire inventory is available at http://wrapair.org/forums/fejf/tasks/FEJFtask7Phase3-4.html. 45 Alaska wildland fire data are available from the Alaska Interagency Coordination Center (AICC) Incident support 

website at http://fire.ak.blm.gov/administration/awfcg_committees.php.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-21

 
effort, so these current year inventories were not available. Baseline conditions were represented 

the data that were used to represent baseline emissions in the initial Hawaii implementation plan. 

For current progress period summaries, alternate inventories were obtained through consultation 

with Hawaii Department of Health (DOH).

For Hawaii, summaries for the baseline period are represented with a 2005 inventory, and 

the current progress period is represented with a 2008 inventory. The year 2005 was selected, 

with EPA approval, as the baseline inventory because it was the most complete inventory 

available at the time technical work commenced. Categories summarized for Hawaii are listed 

below: 

• Point 

• Area

• On-road Mobile

• Off-road Mobile 

• Marine

• Fire

• Biogenic 

• Volcano 

• Sea Spray

• Wind Blown Dust 

Data summaries for both 2005 and 2008 presented in this report were obtained from the 

Technical Support Document for the Proposed Action on the Federal Implementation Plan for 

the Regional Haze Program in the State of Hawaii, developed by EPA Region 9,

46 except for 

area source SO2 inventories, which were provided separately by the Hawaii Department of 

Health, Clean Air Branch (HIDOCAB). The EPA inventories were largely compiled by 

ENVIRON under direction from DOH. Hawaii DOH further refined the mobile inventories in 

conjunction with ICF International to incorporate the latest release of the MOVES model.

46 The May 2012 Technical Support Document for the Proposed Action on the Federal Implementation Plan for the 

Regional Haze Program in the State of Hawaii developed by the EPA Region 9 Air Quality Division is available at 

www.epa.gov/region9/air/actions/pdf/hi/hi-haze-tsd.pdf.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-22

 
3.3 THE WRAP TSS

The WRAP Technical Support System (TSS) (http://vista.cira.colostate.edu/tss/) is an 

online, dynamic tool designed to provide a single portal to technical data and analytical results 

coordinated by the WRAP. The data, results, and methods displayed on the TSS are intended to 

support the air quality planning needs of western state and tribes, and were designed to be 

maintained and updated to support the development of RHR SIPs, progress reports, and other 

western air quality analysis and management needs. The TSS has recently been updated to 

support the first RHR progress reports, providing access, visualization, analysis, and retrieval of 

technical data and regional analytical results that complement the RHR progress analysis 

provided in this report. 

The TSS integrates a number of different information resources and incorporates 

applicable data sets, analysis results, and documentation under one web-based umbrella. Full 

documentation, including tutorials and detailed descriptions of TSS tools are available directly 

from the website. Figure 3.3-1 shows the interactive menu options available from the “Haze 

Planning” section on the TSS, where each of these selection option interfaces with a variety of 

summary options. This section briefly describes some of these summary options that have been 

updated to support the development of RHR progress reports for western states. 

Figure 3.3-1. The WRAP TSS Summary Tools Interface.

3.3.1 Data Updates 

IMPROVE data were updated through 2011, using IMPROVE data downloaded from the 

FED47 database, and emissions data were updated with county and state level emission from the 

WestJumpAQMS 2008 inventory.48 In addition to data updates, some of the averaging 

conventions were changed on the TSS, which affected some of the data summaries that may have 

previously been obtained from the TSS for initial SIP development. Specifically, the TSS 

originally reported data first rounded to 2 decimals, which were then rounded to 1 decimal. In 

this update, changes were made to round directly from full decimal resolution to 1 decimal. 

47 IMPROVE data are available from the IMPROVE Network through the Federal Land Manager Database online 

repository (http://views.cira.colostate.edu/fed/) 

48 See Emissions Inventory descriptions in Section 3.2.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-23

 
While this was a small change, it did have the effect of changing the reported deciview average 

for the 2000-2004 progress period at a few sites by no more than 0.1 dv, which is much less than 

the 1 deciview change which is considered perceptible to the human eye. Figure 3.3-1 below 

presents a list of sites where the 5-year 2000-2004 deciview average has changed since originally 

published for use in initial SIPs, as reported by the TSS. 

Table 3.3-1 

Changes in TSS Reported Deciview Averages

2000-2004 Baseline Period

State Class I area(s) Site Group

Deciview Average

2000-2004 Baseline Period

Extended 

Decimal 

Resolution

Previous 

Rounding 

Convention

Current

Rounding 

Convention

AZ

Mount Baldy WA BALD1 Worst 11.847 11.85→11.9 11.8

Mazatzal WA

Pine Mountain WA IKBA1 Worst 13.345 13.35→12.5 12.4

CA

Lassen Volcanic NP

Thousand Lakes WA

Caribou WA

LAVO1 Worst 14.146 14.15→14.2 14.1

Marble Mountain WA

Yolla-Bolly-Middle-Eel WA

TRIN1 Worst 17.349 17.35→17.4 17.3

HI Haleakala NP HALE1 Best 4.547 4.55→4.6 4.5

MT U L Bend WA ULBE1 Best 4.749 4.75→4.8 4.7

NM Guadalupe Mountains NP

Carlsbad Caverns NP GUMO1 Best 5.945 5.95→6.0 5.9

UT

Bryce Canyon NP BRCA1 Worst 11.649 11.65→11.7 11.6

Arches NP

Canyonlands NP CANY1 Best 3.746 3.75→3.8 3.7

3.3.2 Class I Area Summary Table

The Class I Area Summary Table calculates metrics to support regional haze analysis by 

species, total light extinction, and deciview, and presents a tabular display of associated values. 

To support progress reports, a new selection option, “Table Type: Reasonable Progress”, was 

added as the default summary option. Original table summary options developed to support the 

initial RHR SIPS are available under “Table Type: Baseline to 2018 Projections”. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-24
The new Reasonable Progress Table presents monitoring data averages for each 

measured species extinction value, for total extinction and for deciview extinction. Periods 

represented include the 2000-2004 baseline period, the 2005-2009 next successive 5-year period, 

and the 2006-2010 and 2007-2011 rolling period averages. Table 3.2-2 presents an example 

Table for Rocky Mountain National Park (the ROMO1 IMPROVE monitor) in Colorado. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-25
Table 3.3-1 

WRAP Technical Support System Product 

Example of a Class I Area Summary Table

3.3.3 Monitoring

For the “Monitoring” summary option, IMPROVE data were updated through 2011, and 

options were added to represent current 5-year averages. From the “Monitoring” options, two 

types of plots are available; “Time Series” plots and “Glide Slope” plots. For the “Time Series” 

plots, 5-year periods were added to the “averaging” option. The tool enables a comparison of 

either the 2000-2004 baseline period and the 2005-2009 most recent successive 5-year period, or 

the 2000-2004 period and the most recently available 2007-2011 5-year period. Options are 

available to display deciview averages, or any combination of species extinction and mass. 

Figure 3.3-2 presents an example display of 5-year period averages for the Rocky Mountain 

National Park ROMO1 site. The “Show Data” link below the display provides the data shown in 

the display in a table (this functionality is available on all TSS tools). 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-26
Figure 3.3-2. Example TSS Comparison of 2000-2004 and 2005-2009 period averages for 

Rocky Mountain National Park in CO. 

For the “Glide Slope” plots, options were added to display 5-year period averages for 

both “successive” and “rolling” period average. As noted in Section 2.0, EPA’s September 2003 

guidance specifies that progress is tracked against the 2000-2004 baseline period using 

corresponding averages over successive 5-year periods, i.e. 2005-2009, 2010-2014, et cetera,

49

but EPA’s more recent guidance principals, released in April 2013, suggest that progress be 

tracked using rolling 5-year period averages. This support document assessed change using the 

successive periods, but rolling period averages have been made available through the TSS. 

Options are available to display either successive or rolling averages, with or without 2064 

Natural Conditions estimates, for deciview averages and any combination of species extinction. 

Figure 3.3-3 presents an example of successive 5-year period averages, plotted along with annual 

averages, for the Rocky Mountain National Park ROMO1 site, and Figure 3.3-4 presents an 

example of rolling period averages. 

49 See page 4-2 in EPA’s September 2003 Guidance for Tracking Progress Under the Regional Haze Rule. 

(http://www.epa.gov/ttnamti1/files/ambient/visible/tracking.pdf) 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-27

 
Figure 3.3-3. Example TSS Plot of 5-Year Successive Averages, Showing the 2000-2004 

Baseline Average and 2005-2009 Period Averages for Rocky Mountain National 

Park in CO.

Figure 3.3-4. Example TSS Plot of 5-Year Rolling Averages, Showing the 2000-2004 Baseline 

Average and Rolling Averages Beginning With 2001-2005 through 2007-2011, 

for Rocky Mountain National Park in CO. 

3.4 EMISSIONS SUMMARY TOOLS

For the “Emissions” summary option, the WestJumpAQMS 2008 emissions dataset was 

added. For display purposes, source categories were aligned with those used in the baseline 

planning period and display options were added for the 2008 data, including side-by-side 

comparisons of 2008 and 2002 data under the “Emissions Review Tool” link. Only state level 

summaries have been presented in this report, but county level summaries are available through 

the TSS. Figure 3.3-5 presents an example of a side-by-side comparison of 2002 and 2008 

emissions for counties in Arizona. Note that these summaries are not available from the TSS for 

Alaska and Hawaii.

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-28
Figure 3.3-4. Example TSS Plot Showing Side-by-Side Comparisons of 2002 and 2008 

Emission Inventories for Counties in Arizona. 

WRAP Regional Haze Rule Reasonable Progress Report Support Document 3-29