Technical Support Document

for the

Proposed Action on the Federal 

Implementation Plan for the Regional Haze

Program in the State of Hawaii

Air Division

U.S. EPA Region 9

May 14, 2012
ii

For information on this technical support document, please contact:

Carol Bohnenkamp

Office of Air Quality Assessment and Analysis

U.S. Environmental Protection Agency – Region 9

75 Hawthorne Street

San Francisco, California 94105

(415) 947-4130

bohnenkamp.carol@epa.gov

Greg Nudd

Office of Air Planning

U.S. Environmental Protection Agency – Region 9

75 Hawthorne Street

San Francisco, California 94105

(415) 947-4107

nudd.gregory@epa.gov
iii

Table of Contents

I. Regional Haze and Hawaii.......................................................................................................1

I.A. Background on Regional Haze .........................................................................................1

I.B. Regional Haze Requirements............................................................................................1

I.C. Visibility Impairment Goals..............................................................................................2

I.C.1. Natural, Baseline, and Current Visibility Conditions..................................................2

I.C.2. Estimation of Visibility Impairment - The Original and the Revised IMPROVE 

Equations ............................................................................................................................3

I.C.3. Measures of Visibility..............................................................................................5

I.D. Unique Nature of Regional Planning in Hawaii ................................................................6

II. Description of Hawaii‟s National Parks ..................................................................................6

II.A. HALEAKALA NATIONAL PARK................................................................................6

II.A.1. Park Description ......................................................................................................7

II.A.2. Visibility Conditions ................................................................................................9

II.A.3. Causes of Haze.......................................................................................................11

II.A.4. Comparison of Baseline 2001-2004 data to 2005 Data............................................13

II.A.4. Uniform Rate of Progress.......................................................................................14

II.A.5. Visibility Trends at Haleakala from 2001-2009 ......................................................16

II.B. HAWAII VOLCANOES NATIONAL PARK...............................................................21

II.B.1. Hawaii Volcanic National Park Description............................................................21

II.B.2. Visibility Conditions: baseline and natural (20% best and worst days)...................23

II.B.3 Causes of Haze ........................................................................................................24

II.B.4. Comparison of Baseline 2001-2004 data to 2005 Data............................................27

II.B.4. Uniform Rate of Progress.......................................................................................27

II.B.5. Visibility Trends from 2001-2009...........................................................................30

III. Summary of Previous Visibility Assessments at the Haleakala and Hawaii Volcanoes 

National Parks...........................................................................................................................33

III.A. NOAA Assessment of Causes of Haze for Hawaii‟s Two Class I Areas .......................33

III.B. Hawaii Department of Health Source Apportionment Results ......................................34

III.B.1. Hawaii DOH Park Visibility Assessment of Haleakala National Park - Summary of 

Results ..............................................................................................................................35

III.B.2. Hawaii DOH Park Visibility Assessment of Hawai‟i Volcanoes National - Summary 

of Results ..........................................................................................................................36
iv

IV. Emissions Inventory............................................................................................................37

IV.A. Statewide Emissions Inventory ....................................................................................37

IV. B. Review of the Emissions Inventory for Completeness and Accuracy...........................40

IV.C. Assessment of the Emissions Inventory .......................................................................40

V. Causes of Haze in Hawaii (including volcanic emissions).....................................................41

V.A. Island-Specific Emissions Inventory .............................................................................41

V.B. Synthesis of Emissions Inventory, Monitoring Data, and PMF analysis.........................42

V.C. Visibility Impairing Pollutants Subject to Evaluation ....................................................43

VI. Best Available Retrofit Technology (BART).......................................................................44

VI.A. BART Requirements ...................................................................................................44

VI.B. Identify BART Eligible Sources ..................................................................................45

VI.C. Identify BART- Subject Sources..................................................................................45

VI.C.1. Subject to BART Modeling for the State of Hawaii...............................................46

VI.C.2. Review of Subject to BART Modeling ..................................................................48

VI.C.3. Assessment of Subject to BART Modeling ...........................................................48

VI.C.4. Results of Subject to BART Modeling ..................................................................48

VI.D. BART Determination and Federally Enforceable Limits..............................................49

VI.D.1 BART for NOx and Particulate Matter (PM)...........................................................50

VI.D.2 BART for SO2 .......................................................................................................51

VII. Reasonable Progress ..........................................................................................................54

VII.A. Unique Regional Haze Planning Challenge for Hawaii...............................................54

VII.B. Identification of Pollutants for Reasonable Progress ...................................................55

VII.C. Determining Reasonable Progress Through Island-Specific Emissions Inventories.....55

VII.C.1. Four Factor Analysis for NOx sources on Maui and the Big Island .......................58

VII.C.2 Four Factor Analysis for SO2 Emissions on Maui .................................................59

VII.C.3 Four Factor Analysis for SO2 emissions on the Big Island (Hawaii)......................62

VII.D. Benefits of the Emission Control Area on Emissions from In Transit Marine Vessels.64

VII.E. Reasonable Progress Goals - 2018 Visibility Projections.............................................65

VII.F. Visibility Improvement Compared to URP and Number of Years to Reach Natural 

Conditions.............................................................................................................................69

VIII. Monitoring Strategy..........................................................................................................70

VIII.A. IMPROVE Monitoring Network ...............................................................................70

VIII.B. Analysis of the Haleakala (HALE1) IMPROVE monitoring site and newer Haleakala 

Crater (HACR1) Monitoring site ...........................................................................................71
v

Appendix A

Subject-to-Best Available Retrofit Technology (BART) Modeling for the State of Hawaii, 

Application of the CALPUFF Modeling System

Prepared for Hawaii State Department of Health, Environmental Management Division Clean 

Air Branch by Alpine Geophysics, LLC. March 3, 2010.

Appendix B

MM5 Application for 2005 Over the Hawaiian Islands, 

Prepared for Hawaii State Department of Health, Environmental Management Division, Clean 

Air Branch by Alpine Geophysics, LLC 
1

Technical Support Document

for the

Proposed Action on the Federal Implementation Plan for the 

Regional Haze Program in the State of Hawaii

I. Regional Haze and Hawaii 

I.A. Background on Regional Haze

Regional haze is visibility impairment that is produced by a multitude of sources and 

activities that are located across a broad geographic area and emit fine particulates (PM2.5) (e.g., 

sulfates, nitrates, organic carbon (OC), elemental carbon (EC), and soil dust), and their 

precursors (e.g., sulfur dioxide (SO2), nitrogen oxides (NOx), and in some cases, ammonia (NH3) 

and volatile organic compounds (VOC)). Fine particle precursors react in the atmosphere to form 

PM2.5, which impairs visibility by scattering and absorbing light. Visibility impairment reduces 

the clarity, color, and visible distance that one can see. PM2.5 can also cause serious health 

effects and mortality in humans and contributes to environmental effects such as acid deposition 

and eutrophication. 

Data from the existing visibility monitoring network, the “Interagency Monitoring of 

Protected Visual Environments” (IMPROVE) monitoring network, show that visibility 

impairment caused by air pollution occurs virtually all the time at most national parks (NPs) and 

wilderness areas (WAs). The average visual range1in many Class I areas (i.e., NPs and memorial 

parks, WAs, and international parks meeting certain size criteria) in the western United States is 

100-150 kilometers, or about one-half to two-thirds of the visual range that would exist without 

anthropogenic air pollution. In most of the eastern Class I areas of the United States, the average 

visual range is less than 30 kilometers, or about one-fifth of the visual range that would exist 

under estimated natural conditions. 64 FR 35715 (July 1, 1999).

I.B. Regional Haze Requirements

The Regional Haze Rule (RHR) sets out specific requirements for states‟ initial regional 

haze implementation plans. In particular, each state‟s plan must establish a long-term strategy 

that ensures reasonable progress toward achieving natural visibility conditions in each Class I 

area affected by the emissions from sources within the state. In addition, for each Class I area 

within the state‟s boundaries, the plan must establish a reasonable progress goal (RPG) for the 

first planning period that ends on July 31, 2018. The long-term strategy must include enforceable 

emission limits and other measures as necessary to achieve the RPG. Regional haze plans must 

also give specific attention to certain stationary sources that were in existence on August 7, 1977, 

but were not in operation before August 7, 1962. These sources, where appropriate, are required 

 

1 Visual range is the greatest distance, in kilometers or miles, at which a dark object can be viewed against the sky.
2

to install Best Available Retrofit Technology (BART) controls to eliminate or reduce visibility 

impairment. More details on regional haze plan requirements are summarized in the Federal 

Register notice for this action.

I.C. Visibility Impairment Goals

The goal of the regional haze rule is to restore natural visibility conditions by 2064 

through implementation of measures that make “reasonable progress” toward this goal by 

reducing anthropogenic emissions that cause haze. Baseline visibility is determined (through a 

calculation using the IMPROVE equation) from particulate concentration data that is converted 

into visibility data (reconstructed light extinction). 

I.C.1. Natural, Baseline, and Current Visibility Conditions 

The goal of the regional haze rule is to restore natural visibility conditions at the 156 

Class I areas identified in the 1977 Clean Air Act Amendments. 40 CFR 51.301(q) defines 

natural conditions: “Natural conditions include naturally occurring phenomena that reduce 

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

regional haze SIPs must contain measures that make “reasonable progress” toward this goal by 

reducing anthropogenic emissions that cause haze. 

For each Class I area, there are three metrics of visibility that are part of the 

determination of reasonable progress: 1) natural conditions, 2) baseline conditions, and 3) current 

conditions.

“Natural” visibility is determined by estimating the natural concentrations of visibility 

pollutants and then calculating total light extinction. Natural background visibility, as defined in 

Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Program, EPA454/B-03-005, September 2003, is based on annual average concentrations of fine particle 

components. Natural background visibility for the 20% worst days is estimated by assuming that 

fine particle concentrations for natural background are normally distributed and the 90th 

percentile of the annual distribution represents natural background visibility on the 20% worst 

days.

The natural visibility value estimations for 2064 for Hawaii do not include an estimate of 

the visibility impairment from the emissions from the Kilauea volcano, which is located in the 

Hawaii Volcanoes National Park. The emissions from the volcano vary from year to year, and it 

is therefore not possible to estimate the emissions from the volcano or the effect they will have 

on Class I area visibility in the year 2064. 

“Baseline” visibility is the starting point for the improvement of visibility conditions. 

EPA requires the calculation of baseline conditions [(40 CFR 51.308(d)(2)(i) and (ii)]. The 

baseline condition for each Class I area is defined as the five year average (annual values for 

2000 - 2004) of Interagency Monitoring of Protected Visual Environments IMPROVE 

monitoring data (expressed in deciviews)2for the most-impaired (20% worst) days and the leastimpaired (20% best) days. The comparison of initial baseline conditions to natural visibility 

conditions indicates the amount of improvement necessary to attain natural visibility by 2064. 

The baseline conditions for this first regional haze FIP submittal for Hawaii are the reference 

 

2A one deciview change in the haze index is likely humanly perceptible under ideal conditions regardless of 

background conditions. The deciview is discussed in greater detail in Measures of Visibility, below.
3

point against which visibility improvement is tracked. For subsequent RH SIP updates (in the 

year 2018 and every 10 years thereafter), baseline conditions will be used to calculate progress 

from the beginning of the regional haze program. 

“Current conditions” are assessed every five years as part of the SIP review where actual 

progress in reducing visibility impairment is compared to the reductions committed to in the SIP. 

Current conditions for the best and worst days are calculated from a multiyear average, based on 

the most recent 5-years of monitored data available [40 CFR 51.308(f)(1)]. This value will be 

revised at the time of each periodic SIP revision, and will be used to illustrate: (1) The amount of 

progress made since the last SIP revision, and (2) the amount of progress made from the baseline 

period of the program. 

I.C.2. Estimation of Visibility Impairment - The Original and the Revised IMPROVE 

Equations

Each IMPROVE monitor collects particulate concentration data which are converted into 

reconstructed light extinction (bext, defined in greater detail in the following section) through a 

complex calculation using the IMPROVE equation. The IMPROVE equation is used to convert 

measured or modeled concentrations into extinction for each pollutant chemical species, and then 

total them, accounting for the effect of relative humidity; it also includes the Rayleigh scattering 

that occurs in pure air. The extinction total is then used to calculate deciviews for use in visibility 

progress assessments. 

In December 2005 the IMPROVE Steering Committee revised the IMPROVE equation 

after a scientific assessment of its implications for regional haze planning. In particular, when 

compared to nephelometer direct measurements of visibility extinction, the original IMPROVE 

equation over-predicts for low extinction conditions and under-predicts for high extinction. 

These biases have direct relevance for estimates for the best 20% and worst 20% visibility days 

that are used to assess progress. 

Original IMPROVE equation:

bext = 3 * f(RH) * [sulfate]

+ 3 * f(RH) * [nitrate]

+ 4 * [organic mass]

+ 10 * [elemental carbon]

+ 1 * [fine soil]

+ 0.6 * [coarse mass]

+ 10

Each term in the equation is the extinction due to a particular measured component; 

bracketed quantities are concentrations of as measured at IMPROVE monitors. The organic mass 

is assumed to be 1.4 times the organic carbon mass that is measured by IMPROVE monitors. 

The 10 is for Rayleigh scattering which is due to the interaction of light with molecules of air 

itself with no pollutants, and is assumed to be the same for all locations, The f(RH) is a water 

growth factor for sulfate and nitrate, which are hygroscopic (their particles tend to attract water). 

Its value depends on relative humidity, ranging from 1 at low humidity to 18 at 98% humidity.

New IMPROVE equation:
4

bext = 2.2 * fs(RH) * [small sulfate] + 4.8 * fL(RH) * [large sulfate]

+ 2.4 * fs(RH) * [small nitrate] + 5.1 * fL(RH) * [large nitrate]

+ 2.8 * [small organic mass] + 6.1 * [large organic mass]

+ 10 * [elemental carbon]

+ 1 * [fine soil]

+ 1.7 * fss(RH) * [sea salt]

+ 0.6 * [coarse mass]

+ Rayleigh scattering (site-specific)

+ 0.33 * [NO2 (ppb)]

Sulfate is assumed to be all “large sulfate” if total sulfate is over 20 μg/m3, otherwise its 

fraction of the total is assumed to increase uniformly between 0 and 1 when the total is in the 

range between 0 and 20. I.e., large sulfate = (total sulfate/20)*total. A similar definition applies 

for nitrate and for organic mass. The organic mass is assumed to be 1.8 times the organic carbon 

mass that is measured by IMPROVE monitors, an increase over the original 1.4. Sea salt is 

estimated as 1.8 * [chloride] (or chlorine if chloride not available). Finally, the fs, fL, fss are 

water growth factors for small (“S”) and large (“L”) fractions of sulfate and nitrate, and for sea 

salt (“SS”). Their values depend on relative humidity, ranging from 1 at low humidity to over 5 

at 95% humidity.

The new equation has five changes: 1) greater completeness though the inclusion of sea 

salt, which can be important for coastal sites; 2) increased organic carbon mass estimate, based 

on more recent data for remote areas; 3) Rayleigh scattering using site-specific elevation and 

temperature, a refinement over the older network-wide constant; 4) separate estimates for small 

and large particles of visibility impacts and humidity-dependent particle size growth rates, which 

could affect estimates at the low and high ends; and 5) greater completeness though the inclusion 

of NO2 (Pitchford, 2006)3.

The new equation shows broader scatter overall, but less bias in matching visibility 

measurements under high and low visibility conditions. That is, though it has a somewhat worse 

fit considering all the data, it has a better fit under visibility conditions most relevant to regional 

haze planning, the best and worst 20% of days. The looser overall fit can cause a slightly 

different set of days to be the ones chosen than the 20% worst, but the chemical species 

composition for such days is little changed (IMPROVE technical subcommittee for algorithm 

review, 2001, pp. 11-12), and so this makes little difference for assessing the contribution of 

emission sources to current conditions, and for projecting the effect of emission controls. The 

split between small and large particles was the main factor in reducing the biases.

The organic carbon (OC) measured by the IMPROVE network does not include all 

organic matter (OM); based on 1970s urban data, a scaling factor of 1.4 is embedded in the 

original equation to account for the full mass. Based on recent data more relevant to relatively 

remote Class I areas, the revised IMPROVE equation embeds an OM/OC factor of 1.8. In 

practice, for the worst days, the biggest effect of switching to the revised IMPROVE equation is 

 

3

Pitchford, Marc, 2006, "New IMPROVE algorithm for estimating light extinction approved for use", The 

IMPROVE Newsletter, Volume 14, Number 4, Air Resource Specialists, Inc.; web page:

http://vista.cira.colostate.edu/improve/Publications/news_letters.htm

direct link: http://vista.cira.colostate.edu/improve/Publications/NewsLetters/IMPNews4thQtr2005.pdf
5

this increased organic carbon mass, since the worst days are dominated by organic carbon from 

fires, rather than the sulfates and nitrates that come more from anthropogenic sources.

EPA is using the new IMPROVE equation for the Hawaii Regional Haze FIP.

I.C.3. Measures of Visibility 

As discussed in Section 2. Estimation of Visibility Impairment - The Original and the 

Revised IMPROVE Equations, above, particulate concentration data are converted into 

reconstructed light extinction through a complex calculation using the IMPROVE equation. The 

relationship between of measures of visibility; light extinction (Mm-1), haze index (dv), and 

visual range, is discussed below.

Light Extinction (bext). Light extinction is the attenuation of light due to scattering and 

absorption as it passes through a medium. Reconstructed light extinction (denoted as bext) is 

expressed in units of inverse megameters (1/Mm or Mm-1). Light extinction is the most useful 

measure for evaluating the relative contributions of pollutants to visibility impairment. Light 

extinction affects the clarity and color of objects being viewed.

Haze Index (deciview). The Regional Haze Rule requires the tracking of visibility 

conditions in terms of the Haze Index (HI) metric, expressed in the deciview (dv) unit. 

Generally, a one deciview change in the haze index is likely humanly perceptible under ideal 

conditions regardless of background conditions. The deciview is a useful measure for tracking 

progress in improving visibility, because each deciview change is an equal incremental change in 

visibility perceived by the human eye.

Relationship between extinction (Mm-1) and haze index (dv). There is a logarithmic 

relationship between the haze index and reconstructed light extinction expressed by the 

following conversion equation: 

HI = 10 ln(bext/10) 

Where: HI is the Haze Index 

ln is the natural log 

Bext is the reconstructed light extinction 

Visual Range. Visual range is the greatest distance, in kilometers or miles, at which a 

dark object can be viewed against the sky.

The relationship between extinction (Mm-1), haze index (dv) and visual range (km) are 

indicated by on the scale in Figure I-1. Relationship between extinction Mm-1), haze index (dv) 

and visual range (km).

Figure I-1 Relationship between extinction Mm-1), haze index (dv) and visual range (km)
6

I.D. Unique Nature of Regional Planning in Hawaii

Nonanthropogenic emissions are a significant fraction of total SO2, VOC, and PM

emissions in Hawaii. The Kilauea volcano dominates statewide SO2 emissions. Emissions from 

the volcano were estimated to be above 900,000 tons per year, and comprised over 96% of the 

SO2 emissions in 2005. On days when the volcano is erupting and the winds are carrying those 

emissions over the Class I area monitors, these natural emissions dominate the measurements.

Nonanthropogenic sources also comprise the majority of VOC and PM emissions. 

In addition to the difficulty of assessing the effect of nonanthropogenic emissions on 

visibility in the National Parks, there are several unique challenges for Hawaii regional haze 

planning in this planning period. There is no modeling available for this planning period that can 

reliably predict the change in visibility due to changes in the emission inventory for all sources 

(shipping, mobile sources, point sources, etc.).4In absence of reliable visibility modeling for 

2018, EPA is using the island-specific inventories as a surrogate for judging whether reasonable 

progress is being made during this planning period. Visibility projections for 2018 are based on 

EPA‟s estimate of the effect that the changes in the island specific inventories will have on the 

aerosol composition for each of the parks.

II. Description of Hawaii’s National Parks 

EPA has reviewed IMPROVE monitoring data, the Causes of Haze Assessment provided 

through the Western Regional Air Partnership (WRAP), and information from the National Park 

Service (NPS), and the National Oceanic and Atmospheric Administration (NOAA) as a basis 

for this technical support document. In addition, EPA reviewed visibility assessments of each 

park by the Hawaii Department of Health (HDOH). 

II.A. HALEAKALA NATIONAL PARK 

 

4 There is acceptable modeling for point sources for the BART and the reasonable progress analysis for point source. 

This modeling is discussed in Identify BART Subject Sources. 
7

Figure II.A-1. HALEAKALA NATIONAL PARK

National Park Service Photo

II.A.1. Park Description 5

Haleakala National Park consists of 30,183 acres in central to eastern portions of the 

island of Maui, 24,719 acres of which are designated wilderness. The slopes of the Haleakala, or 

East Maui, volcano comprise the central and western Park areas. The Kipahulu Valley occupies 

eastern Park areas. Park elevations range from 3,055 m (10,023 ft) at the summit of Haleakala to 

sea level at the mouth of Kipahulu Valley on the extreme eastern boundary. The Park thus 

includes a wide variety of climate zones, from high mountain elevations above the Marine 

Boundary Layer, to leeward lowlands that are dry relative to windward lowlands at the same 

elevation.

Air quality in Haleakala NP is generally excellent, with few man-made sources of air 

pollution nearby. By far the largest source of air pollution is Kilauea Volcano on the island of 

Hawaii. Southeasterly “kona” winds transport volcanic gases and particles to Haleakala NP. This 

volcanic smog, or “vog,” contains sulfur dioxide, sulfuric acid, and sulfate particles and affects 

air quality and visibility. Locally, anthropogenic sources can affect air quality and visibility. 6

 

5

http://www.coha.dri.edu/web/state_analysis/Hawaii/HaleakalaNP_metdesc.html

6

http://www.nature.nps.gov/air/permits/aris/hale/?CFID=16689542&CFTOKEN=67492682
8

Figure II.A-2. The Haleakala National Park Visibility Monitoring Sites: IMPROVE sites: 

HALE1 and HACR1.

Visibility Monitoring Sites

Currently there are two IMPROVE monitoring sites operating in or near the Haleakala 

National Park. The Haleakala (HALE1) IMPROVE monitoring site is located well outside of the 

Haleakala National Park near to the Maui Central Valley, at an elevation of 1153 meters. The 

HALE1 IMPROVE monitoring site began operation at end of 2000. The Haleakala Crater 

(HACR1) IMPROVE monitoring site is at the park‟s Western boundary, at an elevation of 2158 

meters. The HACR1 IMPROVE monitoring site began operation in 2007. A discussion 

comparing the data collected at the HALE1 and HACR1 IMPROVE monitoring sites is 

presented in Section VIII.B. Analysis of the Haleakala (HALE1) IMPROVE monitoring site and 

newer Haleakala Crater (HACR1) Monitoring site.

Nearby Population/Industrial Centers and Local Sources

Kahului and the Wailuku area are about 24 km west-northwest and downslope from 

HALE1, with no major intervening terrain features. The major active volcano, Kilauea on the 
9

Big Island, is 188 km southeast of HALE1. With northeasterly trade winds, SO2 emissions from 

Kilauea have been observed to be eddy-transported clockwise around the west side of the Big 

Island, and impact on Haleakala National Park is possible Sea salt spray is a natural aerosol 

source.

Wind Patterns

During trade-wind conditions, which predominate 80 to 95% of the time from May 

through September, and 50 to 80% during the rest of the year, prevailing wind directions at 

HALE1 should be generally northeast to southwest, typically with speeds of 5 mps or greater. 

Downslope winds from Haleakala should be evidenced at the site by nighttime southeasterly 

directions, and daytime northwesterly directions. Exceptions to these conditions would occur 

during frontal passages associated with synoptic weather systems, and, at the site elevation, 

during upper atmosphere low-pressure system passages. 

Monthly Kahului wind roses show typical wind patterns at this sea level station 24 km 

northwest of HALE1, with northeasterly surface flow year round and an additional southerly 

component in the winter. 

Inversions/Trapping

The predominant inversion phenomenon is the Trade-layer inversion, or Marine 

Boundary Layer. The Marine Boundary Layer is more constant and has less diurnal variability 

than continental inversions because of the oceanic influence. Typical trade-layer inversion 

heights in the vicinity of Haleakala NP are around 2000 m above sea level, with some variability 

(+/- ~1000 m) due to seasonal effects. The HALE1 site, at an elevation of 1158 m (3799 ft), 

would thus probably be within this layer most of the time when trade-wind conditions 

predominate. During this condition, relative humidity will be typically be high, 70% or greater. 

When the Marine Boundary Layer height is below the monitoring site, relative humidity will be 

much lower.

II.A.2. Visibility Conditions 

Baseline Conditions at HALE1 in deciview (20% best and worst days)

The baseline visibility is determined from the HALE1 monitoring site for the 20% worst 

and the 20% best days for the years 2001 through 2004 as specified in the Regional Haze 

regulations under 40 CFR §51.308(d)(2)(i). Data from the year 2000 is not being used because 

data from that year is not complete. The baseline visibility for the Haleakala National Park is 

calculated at 13.3 deciviews for the 20% worst day and 4.6 deciviews for the 20% best days. 

Figure II.A-3 below, shows the baseline data for the 20% worst days for each of the years 2001-

2004. Figure II.A-4, below, shows the baseline for the 20% best days for each of the years 2001-

2004. 
10

Figure II.A-3: Haleakala National Park (HALE1); Baseline Visibility for the 20% Worst 

Days 2001 - 2004. 

Figure II.A-4: Haleakala National Park (HALE1); Baseline Visibility for the 20% Best 

Days 2001 - 2004. 

Natural Condition in deciview (20% best and worst days)

Natural visibility represents the visibility condition that would be experienced in the 

absence of human-caused impairment. Based on EPA guidance,

7

the natural visibility for the 

Haleakala National Park is 2.7 deciviews for the 20% best days and 7.4 deciviews for the 20% 

worst days.

The natural visibility value estimations for 2064 do not include an estimate of the 

visibility impairment from the emissions from the Kilauea volcano, which is located in the 

Hawaii Volcanoes National Park. The emissions from the volcano vary from year to year, and it 

is not possible to estimate the emissions from the volcano or the effect they will have on Class I 

area visibility in the year 2064. 

 

7

http://www.epa.gov/ttn/oarpg/t1/memoranda/rh_envcurhr_gd.pdf
11

II.A.3. Causes of Haze 

The aerosol composition measured at the Haleakala (HALE1) IMPROVE monitor on the 

20% best and 20% worst days for the years 2001-2004 is presents in Figures II.A-5 through II.A7, below. The charts show the contribution of aerosol species to light extinction (bext)

Figure II.A-5: Haleakala National Park; Aerosol Composition (contribution to Light 

Extinction) on 20% Best and 20% Worst Days for years 2001-2004. 

Figure II.A-6: Haleakala National Park (HALE1); Aerosol Composition (contribution to 

Light Extinction) on the 20% Worst Days for years 2001-2004. 
12

Figure II.A-7: Haleakala National Park (HALE1); Aerosol Composition (contribution to 

Light Extinction) on the 20% Best Days for years 2001-2004.

Sulfate is the largest cause of visibility degradation on the 20% worst days at Haleakala 

National Park, contributing to approximately 60% of the visibility degradation. Sulfate is also the 

largest cause of visibility degradation on the 20% best days at the park, contributing to 

approximately 37% of the visibility degradation. Natural causes of sulfate include the emissions 

from the Kilauea volcano, located in the Hawaii Volcanoes National Park, and natural marine 

sulfates. The emissions of the volcano vary substantially from year to year. Source 

apportionment assessments have estimated that the volcano causes approximately 60% of the 

visibility impairment at Haleakala National Park on the 20% worst days.

89

 The contribution 

from natural marine sulfate is expected to be much smaller.10 International transport may also 

contribute to sulfur visibility impairment. The major anthropogenic sources of sulfur are point 

sources (oil combustion) and shipping. 

Nitrate contributes 9% to the visibility degradation on the 20% worst days at Haleakala. 

The major anthropogenic sources of nitrate on Maui are point sources, on-road and non- road 

mobile sources, and shipping. Non-anthropogenic sources of NOx include wildfires and biogenic 

emissions. 

Coarse mass contributes to 9% of the visibility degradation on the 20% worst days and 

17% on the 20% best days at the Haleakala. The local sources of coarse mass include fugitive 

dust from paved and unpaved roads. The understanding of the sources that contribute to the 

coarse mass at Haleakala is fairly uncertain. For the next planning period, a detailed study of the 

source contribution to coarse mass and soil measured at the Haleakala Crater Class 1 area 

monitors may be needed to address this uncertainty.

Organic Carbon contributes 10% of the visibility degradation at the Haleakala (HALE1) 

monitor for the year 2001-2004. Sources of organic carbon include agricultural burning, 

 

8 Haleakala National Park Visibility Assessment, and IMPROVE PMF Factor Identification notes Positive Matrix 

Factorization Analysis of HALE1 & HAVO1 IMPROVE data sets April 20, 2012, State of Hawaii, Department of 

Health, Clean Air Branch

9 M. Pitchford, “Causes of Haze for Hawaii‟s Two Class I Areas”, presented at United States Department of 

Agriculture, Agricultural Air Quality Task Force Meeting, Wailea, Hawaii, November 13 and 15, 2005; 

http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs143_008844.pdf

10 Yvon and Saltzman 1996, Atmospheric Sulfur Cycling in the Tropical Marine Boundary Layer. J. Geophys. Res. 

101, 6911-6918.
13

wildfires, oil combustion, and international transport. A comparison of recent monitoring data at 

the Haleakala Crater monitoring site (HACR1) shows approximately half the level of organic 

carbon measured at the HALE1 site.11 This is discussed in greater detail in Section II. D.2.,

Analysis of the Haleakala (HALE1) IMPROVE monitoring site and newer Haleakala Crater 

(HACR1) Monitoring site, below. 

Elemental Carbon contributes to 5% of the visibility degradation at the Haleakala 

(HALE1) IMPROVE monitoring site monitor, which is located outside of the park. A 

comparison of recent data collected at the Haleakala Crater monitoring site (HACR1) shows

lower levels of elemental carbon than data measured the HALE1 site.12 This is discussed in 

greater detail in VIII.B. Analysis of the Haleakala (HALE1) IMPROVE monitoring site and 

newer Haleakala Crater (HACR1) Monitoring site. 

Soil contributes to 1% of the visibility degradation at the Haleakala National Park. The 

soil impact varies seasonally, with the highest levels in the springtime, and appears to be 

associated with international transport.

Sea Salt contributes to 1% of visibility impairment of the 20% worst days at Haleakala 

National Park, and 18% on the 20% best days. 

II.A.4. Comparison of Baseline 2001-2004 data to 2005 Data

For the Hawaii Regional Haze SIP, Hawaii DOH and EPA have selected 2005 as the base 

year inventory because Hawaii‟s 2005 inventory includes a more accurate inventory of point 

sources emissions than Hawaii‟s 2002 inventory. Since 2005 is not within the baseline period of 

2000-2004, it is necessary to compare the level and the aerosol composition of visibility 

impairing pollutants in the year 2005 to the year 2001-2004 baseline time period.

The Haleakala National Park (HALE1); Aerosol Composition (contribution to Light 

Extinction) on 20% Best and 20% Worst Days for the year 2005 is presented in the figure below. 

The level of light extinction is comparable for the 20% best days (4.6 Mm-1in 2005 compared to

5.8 Mm-1in 2001-2004) and 20% worst days (29 Mm-1in 2005 compared to 28.7 Mm-1in 2001-

2004). The aerosol composition is similar for the two time periods.

 

11 Review of VIEWS2.0 2009-2010 Haleakala National Park Organic and Elemental Carbon Data, March 30, 2012,

State of Hawaii, Department of Health, Clean Air Branch, and Comparison of Haleakala National Park HALE1 and 

HACR1 IMPROVE Monitoring Site 2007-2008 Data Sets, March 30, 2012, State of Hawaii, Department of Health, 

Clean Air Branch.

12 Ibid.
14

Figure II.A-8: Haleakala National Park (HALE1); Aerosol Composition (contribution to 

Light Extinction) on 20% Best and 20% Worst Days for the year 2005. 

Since the measured visibility impairing pollution in 2005 was consistent with the baseline 

years, it is reasonable to assume that for the purposes of Regional Haze Planning that the 2005 

emissions were sufficiently consistent with the emissions in 2000-2004 for this year to be used as 

the baseline for the Regional Haze Plan.

II.A.4. Uniform Rate of Progress

The Regional Haze Rule requires that, in setting RPGs, states must consider the rate of 

progress needed to reach natural visibility conditions by 2064 (referred to as the “uniform rate of 

progress” (URP) or the “glide path”) and the emission reduction measures needed to achieve that 

rate of progress over the period of the SIP. 40 CFR 51.308(d)(1)(i)(B). 

For the 20% worst days, the URP in deciviews per year (i.e. slope of the glide path) is 

determined by the following equation: 

URP = [Baseline Condition - Natural Condition] / 60 years 

By multiplying the URP by the number of years in the planning period one can calculate 

the amount of progress needed by 2018 to be on the path to achieving natural visibility 

conditions by 2064. This first Regional Haze implementation plan covers the fourteen-year 

period of 2004-2018. Thus: 

2018 UPG = [URP] x [14 years]

See EPA‟s Guidance for Setting Reasonable Progress Goals Under the Regional Haze Rule § 

2.2 (June 1, 2007). For the best days at each Class I area, the State must ensure no degradation in 

visibility for the least-impaired (20% best) days over the same period. As with natural 

conditions, the URP can be adjusted as new visibility information becomes available. 
15

Figure II-9 shows the 2018 URP chart for the worst 20% days at Haleakala National Park. 

Figure II.A-9: Haleakala National Park: Uniform Rate of Progress, Worst 20% Visibility 

Days.13

Table II.A-1 shows the Haleakala National Park URP for the Worst 20% Visibility Days

and Table II.A- 2 shows the Baseline and Natural Conditions for the Best 20% Visibility Days.

14

 

Table II.A-1: Haleakala National Park- Summary of Uniform Rate of Progress for 20% 

Worst Days

Baseline

Condition 

(deciview)

Natural 

Visibility 

(deciview)

Total 

Improvement by 

2064 

(deciview)

URP 

(deciview/

year)

2018 URP

Goal

(deciview)

Improvement 

needed by 

2018

(deciview)

13.3 7.4 5.9 0.098 11.92 1.38

Table II.A-2: Haleakala National Park- Summary of Baseline and Natural for 20% Best 

Days

Class I Area

Baseline

Condition 

(deciview)

Natural Visibility 

(deciview)

Haleakala National Park 4.6 2.7

 

13 http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx

14 http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx
16

II.A.5. Visibility Trends at Haleakala from 2001-2009

The Haze Index (in deciview) at Haleakala National Park, shown in Figure II.A-10

appears to indicate that the visibility on the worst 20% days is not improving over the year 2001 

through 2009. The monitoring data indicates that the level of light extinction due to sulfates is 

increasing, most likely due to the increase in volcano activity, as shown in Figure II.A-11: 

Haleakala National Park; Aerosol Composition (contribution to Light Extinction) on the 20% 

Worst Days for years 2001-2009. The degree of light extinction due to species other than sulfate 

appear to be approximately level, as shown in Figure II.A-12: Haleakala National Park; Non –

sulfate Aerosol Composition (contribution to Light Extinction) on the 20% Worst Days for years 

2001-2009. The monitoring data for the 20% Best days shows that the visibility has changed 

very little over from 2001 to 2009. 

Figure II.A-10: Haleakala National Park; Haze Index (in deciview) on the20% Worst Days 

for years 2001-2009.

Figure II.A-11: Haleakala National Park; Aerosol Composition (contribution to Light 

Extinction) on the 20% Worst Days for years 2001-2009
17

Figure II.A-12: Haleakala National Park; Non – sulfate Aerosol Composition (contribution 

to Light Extinction) on the 20% Worst Days for years 2001-2009

Figure II.A-13: Haleakala National Park; Aerosol Composition (contribution to Light 

Extinction) on the 20% Best Days for years 2001-2009

Organic and Elemental Carbon at the two IMPROVE monitors (HALE1 and HACR1) at 

Haleakala National Park, 2009-201015

Currently there are two IMPROVE monitoring sites operating in or near the Haleakala 

National Park. The Haleakala (HALE1) IMPROVE monitoring site is located outside of the 

Haleakala National Park near to the Maui Central Valley, at an elevation of 1153 meters. The 

HALE1 IMPROVE monitoring site began operation at end of 2000, and will close in May of

2012. The Haleakala Crater (HACR1) IMPROVE monitoring site is at the park‟s Western 

boundary, at an elevation of 2158 meters. A comparison of the data for all species is discussed in 

 

15 A comparison of the data for all species is discussed in detail in the Section VIII.B. Analysis of the Haleakala 

(HALE1) IMPROVE monitoring site and newer Haleakala Crater (HACR1) Monitoring site. 
18

detail in the Section VIII.B. of this document, Analysis of the Haleakala (HALE1) IMPROVE 

monitoring site and newer Haleakala Crater (HACR1) Monitoring site.

Organic and elemental carbon data for the two IMPROVE monitors (HALE1 and 

HACR1) at Haleakala National Park for 2009 and 2010 is presented in Figures II.A-14 through 

II.A-17, below. The levels of organic and elemental carbon are low at both monitoring sites for 

most days. At the HALE1 site, the measured fine organic mass is below 1 μg/m3, except for 5 

days. At the HACR1 site, the measured levels of organic carbon are below 1 μg/m3 for all days.

(Note that the vertical axis scale differs between the HALE1 and HACR1 graphs). At the 

HALE1 site, the measured elemental carbon is below 0.2μg/m3, except for 5 days. At the 

HACR1 site, the measured elemental carbon is below 0.2 μg/m3 for all days. 

Figure II.A-14: Haleakala National Park (HALE1); Organic carbon (μg/m3)
19

Figure II.A-15: Haleakala National Park (HACR1); Organic carbon (μg/m3)

Figure II.A-16: Haleakala National Park (HALE1); Elemental carbon (μg/m3)
20

Figure II-17: Haleakala National Park (HACR1); Elemental carbon (μg/m3)
21

II.B. HAWAII VOLCANOES NATIONAL PARK

II.B.1. Hawaii Volcanic National Park Description16

Hawaii Volcanoes National Park (NP) was first established as Hawaii NP in 1916 to 

protect the volcanoes, Kilauea and Mauna Loa on Hawaii and Haleakala on Maui.17 The park 

now encompasses 209,695 acres ranging over varied ecosystems from the volcano‟s summit to 

the Pacific Ocean, with many unique plant and wildlife species.

Air quality in Hawaii Volcanoes NP is affected by a number of emission sources, 

primarily Kilauea Volcano. Currently the volcano emits between 1,000 and 2,000 tons of sulfur 

dioxide each day, as well as other gases, including hydrogen sulfide, hydrogen chloride, 

hydrogen fluoride, and trace metals like mercury. Sulfur dioxide reacts with sunlight, oxygen, 

dust particles, and water in the air to form a mixture known as volcanic smog or "vog." The vog 

not only creates a haze that obscures visibility, but it is very acidic, causing acid rain and 

affecting human health, cultural resources, and vegetation. Adding to the haze are marine 

aerosols, which can further diminish visibility. In addition, when hot lava reaches seawater, large 

clouds of mist are formed, called laze, which contain hydrochloric acid and other airborne 

contaminants harmful to human health. Although the volcano dominates total emissions, local 

anthropogenic sources like power generating stations and automobiles can also affect air quality 

and visibility, releasing nitrogen oxides, particulates, and other pollutants as well as sulfur 

dioxide.

Sulfur dioxide is a significant health concern in Hawaii Volcanoes NP and downwind, so 

sulfur dioxide is monitored at two locations, Jaggar Museum and the Kilauea Visitor Center. The 

park posts current sulfur dioxide concentrations from both monitors on its website.

Visibility Monitor Location

The Hawaii Volcanoes National Park IMPROVE Site is located on the east to 

southeastern slopes of Mauna Loa on the island of Hawaii18. More specifically, it is situated on 

the northeastern rim of the Kilauea crater. The site elevation is 1204 m (3949 ft), some 124 m 

above the crater floor at 1080 m (3542 ft). Volcanic emissions (SO2) from the Kilauea crater 

(caldera) presently amount to 100 to 200 metric tons per day. This area is all part of the active 

Kilauea Volcano. There are other sources, including lava flows and other craters along the East 

Rift Zone extending out to ~ 20 km to the east-southeast from the monitoring site. The most 

recent and continuing activity, which has been in progress since 1983, is along the East Rift Zone 

extending out to ~ 20 km to the east-southeast from the monitoring site. The most recent and 

continuing activity, which has been in progress since 1983, is centered on the Pu‟u O‟o crater 

some 20 km (12 miles) east-southeast from the monitoring site. SO2 Emissions from Pu‟u O‟o 

 

16 http:// www.coha.dri.edu/web/state_analysis/Hawaii/HawaiiVolcanoesNP_metdesc.html, Hollingshead, Anette T., 

S. Businger, R. Draxler, J. Porter, and D. Stevens. Dispersion Modeling of the Kilauea Plume. Boundary Layer 

Meteorology 108: 124-144. 2003.,and Okamura, Arnold, Hawaii Volcanoes Observatory, personal conversation 

with Dan Freeman

17 http://www.nature.nps.gov/air/Permits/aris/havo/?CFID=16689542&CFTOKEN=67492682

18 http://www.coha.dri.edu/web/state_analysis/Hawaii/HawaiiVolcanoesNP_metdesc.html
22

amount to 1000 to 2000 metric tons per day, mostly from the main vent at an elevation of ~ 600 

m (2000 ft) (Okamura, 2003).

Besides the Kilauea Volcano system, the major terrain feature affecting meteorology and 

air quality at the monitoring site is the 4170 m (13,681 ft) high Mauna Loa cone, about 35 km 

(22 mi) to the west of the monitoring site.

Wind

Located on the Southeast slope of Mauna Loa, the monitoring site is well exposed to the 

east-to-west trade-wind flow. During trade-wind conditions, which predominate 80 to 95% of the 

time from May through September, and 50 to 80% during the rest of the year, prevailing wind 

directions should thus be generally east to west, typically with speed of 5 mps or greater. During 

northeast trade-wind conditions, a clock-wise eddy is produced to the west of the island that has 

significant effects on transport of local (volcanic) emissions to the islands lee-side (west side). 

Mountain-valley slope flow should be evidenced at the site by nighttime westerly to northerly 

drainage flow and daytime easterly to southerly upslope flow. Exceptions to these conditions 

would occur during frontal passages associated with synoptic weather systems, and, at the site 

elevation, during upper atmosphere low-pressure system passages.

Inversions

The predominant inversion phenomenon is the Trade-layer inversion, or Marine 

Boundary Layer. The marine layer will have much less diurnal variability than continental 

inversions because of the oceanic influence. Typical trade-layer inversion heights in the vicinity 

of Volcanoes NP are probably near 2000m above sea level, with some variability due to seasonal 

effects. At the site elevation of 1204 m the monitoring site would thus probably be within this 

layer most of the time, when trade-wind conditions predominate. During this condition, relative 

humidity will be typically be high, 70% or greater. When the trade-wind layer height is below 

the monitoring site, relative humidity will be much lower. 

If more continental types of inversions occur, say within the Kilauea crater during periods 

when the trade winds are absent or light and variable, they would occur over a much smaller 

scale, with significant diurnal variability. Over a period of time aerosol concentrations could 

presumably build up due to SO2 emissions within the crater, although it is not clear that such 

conditions can occur with any frequency. 

Meteorological Indicators

A unique atmospheric phenomenon of this region is the so-called vog (volcanic smog) 

that occurs when SO2 and other volcanic pollutants react with oxygen and atmospheric moisture. 

Information on this phenomenon is available at: http://wrgis.wr.usgs.gov/fact-sheet/fs169-97/

Thus, volcanic emissions are a likely candidate for the source of aerosols monitored at 

the IMPROVE site, which are typically high in particulate sulfate composition. There are 

nevertheless other potential sources, particularly sea salt sulfate or transported Asian dust, that 

also typically have high sulfate composition. Asian dust emissions have been detected at the 

NOAA Mauna Loa Observatory. A good indicator of Asian dust as a significant aerosol source at 

the monitoring site would be high correlation with Asian dust events, or occurrence during low 

relative humidity conditions, when the site is above the trade-wind layer. Local volcanic 

emissions might be indicated by a strong correlation of high mass concentrations with wind 

direction from sources to the east southeast clockwise to southwest and low or negligible 
23

concentrations during light downslope (northerly) winds, or by buildup during calm or light wind 

periods. At low concentrations, a significant sea sulfate contribution might be indicated by high 

correlation with Haleakala NP measurements when both sites are within the trade-wind layer and 

have similar relative humidity measurements. (Note however that significant volcanic plume 

impaction has been observed at Haleakala NP when transported from the vicinity of Volcanoes 

NP). (Hollingshead et al., 2003) 

Nearby Data Stations

Meteorology is monitored at the site, in addition to aerosol composition, and this is 

probably the best source for representative surface meteorological data (wind direction, wind 

speed, temperature, relative humidity, etc.) For information on regional vertical structure, 

especially the height of the marine layer at the monitoring site, twice-daily upper air sounding 

data are collected at the NWS upper air site at Hilo. Vertical temperature profile data from Hilo 

are probably the best routinely collected and long-term data representative of conditions at 

Volcanoes NP.

II.B.2. Visibility Conditions: baseline and natural (20% best and worst days)

Baseline Conditions for the 20% best and worst days at HAVO1 in deciview

Baseline visibility for this plan is determined from the HAVO1 monitoring site for the 

20% best and the 20% worst days for the years 2001 through 2004, as specified in the Regional 

Haze regulations under 40 CFR §51.308(d)(2)(i). The baseline visibility for the Hawaii 

Volcanoes National Park is calculated at 4.1 deciviews for the 20% best days and 18.9 deciviews 

for the 20% worst days. . Figure II.B-1, below, shows the baseline for the 20% worst days for 

each of the years 2001-2004. Figure II.B-2, below, shows the baseline for the 20% best days for 

each of the years 2001-2004. 

The natural visibility value estimations for 2064 do not include an estimate of the 

visibility impairment from the emissions from the Kilauea volcano, which is located in the 

Hawaii Volcanoes National Park. The emissions from the volcano vary from year to year, and it 

is not possible to estimate the emissions from the volcano or the effect they will have on Class I 

area visibility in the year 2064. 
24

Figure II.B-1: Hawaii Volcanoes National Park; Baseline Visibility for the 20% Worst 

Days 2001 - 2004

Figure II.B-2: Hawaii Volcanoes National Park; Baseline Visibility for the 20% Best Days 

2001 - 2004

Natural Conditions (20% best and worst days)

Natural visibility represents the visibility condition that would be experienced in the 

absence of human-caused impairment. Based on EPA guidance, the natural visibility for the 

Hawaii Volcanoes National Park is 2.2 deciviews for the 20% best days and 7.2 deciviews for 

the 20% worst days.

II.B.3 Causes of Haze

The aerosol composition measured at the Hawaii Volcanoes National Park (HAVO1) IMPROVE 

monitor on the 20% best and 20% worst days for the years 2001-2004 is presents in Figures II.B3 through II.B-5 II.A.2.c.1-3, below. The charts show the contribution of aerosol species to light 

extinction (bext).
25

Figure II.B-3: Hawaii Volcanoes National Park; Aerosol Composition (contribution to 

Light Extinction) on 20% Best and 20% Worst Days for years 2001-2004

Figure II.B-4: Hawaii Volcanoes National Park; Aerosol Composition (contribution to 

Light Extinction) on 20% Worst Days for years 2001-2004
26

Figure II.B-5: Hawaii Volcanoes National Park; Aerosol Composition (contribution to 

Light Extinction) on 20% Best Days for years 2001-2004

Sulfate is the largest cause of visibility degradation on the 20% worst days at Hawaii 

Volcanoes National Park, contributing to approximately 90% of the visibility impairment.

Sulfate is the also the largest cause of visibility degradation on the 20% best days at the park, 

contributing to approximately 42% of the visibility impairment. Natural causes of sulfate include 

the emissions from the Kilauea volcano, located in the Hawaii Volcanoes National Park, and 

natural marine sulfates. The emissions and impact of the volcano varies substantially from year 

to year. Source apportionment assessments have estimated that the volcano causes approximately 

90% of the visibility impairment at Hawaii Volcanoes National Park on the 20% worst days.19, 20

The natural marine sulfate impact is expected to be much smaller.21 Anthropogenic sources of 

sulfur on the Island of Hawaii include point sources (oil combustion), and shipping. 

Nitrate contributes 1% to the visibility degradation on the 20% worst days at Hawaii 

Volcanoes National Park.

Organic Carbon contributes 4% of the visibility degradation at the Hawaii Volcanoes 

National Park during the 2001 – 2004 time period. Natural sources of organic carbon comprise 

the majority of the emission inventory and include wildfires and biogenic emissions. 

Anthropogenic sources of emissions include area sources and mobile sources.

Elemental Carbon contributes to 1% of the visibility degradation at Hawaii Volcanoes 

National Park. 

Coarse mass contributes to 1% of the visibility degradation at the Hawaii Volcanoes 

National Park. The sources of coarse mass include fugitive dust, for paved and unpaved roads.

Soil contributes to 1% of the visibility degradation at each of the Class I Areas. The soil 

impact varies seasonally, with the highest levels in the springtime, and appears to be associated 

with international transport. 

 

19 Hawaii Volcanoes National Park Visibility Assessment, and IMPROVE PMF Factor Identification notes Positive 

Matrix Factorization Analysis of HALE1 & HAVO1 IMPROVE data sets April 20, 2012, State of Hawaii, 

Department of Health, Clean Air Branch

20 M. Pitchford, “Causes of Haze for Hawaii‟s Two Class I Areas”, presented at United States Department of 

Agriculture, Agricultural Air Quality Task Force Meeting, Wailea, Hawaii, November 13 and 15, 2005;

21 Yvon and Saltzman 1996, Atmospheric Sulfur Cycling in the Tropical Marine Boundary Layer. J. Geophys. Res. 

101, 6911-6918.
27

Sea Salt contributes to 1% of visibility impairment of the 20% worst days at Hawaii 

Volcanoes National Park, and 17% on the 20% best days. 

II.B.4. Comparison of Baseline 2001-2004 data to 2005 Data

For the Hawaii Regional Haze SIP, Hawaii DOH and EPA have selected 2005 as the base 

year inventory because Hawaii‟s 2005 inventory includes a more accurate inventory of point 

sources emissions than Hawaii‟s 2002 inventory. Since 2005 is not within the baseline period of 

2000-2004, EPA has performed a comparison of the aerosol composition of the 2005 data and 

2001-2004 data for Hawaii Volcanoes National Park. 

The Hawaii Volcanoes National Park (HAVO1); Aerosol Composition (contribution to 

Light Extinction) on 20% Best and 20% Worst Days for the year 2005 is presented in the figure 

below. The level of light extinction is comparable for the 20% best days (4.3 Mm-1in 2005 

compared to 5.8 Mm-1in 2001-2004) and 20% worst days (90.9 Mm-1in 2005 compared to 66.5

Mm-1in 2001-2004). The level of organic carbon is lower on 2005 than for the 2001-2004 time 

period, but similar to the level of organic carbon for the years 2003 and 2004. The difference in 

the level of sulfate reflects the difference in volcano activity. The levels of nitrate, coarse mass, 

elemental carbon, sea salt and soil are similar for the two time periods. 

Figure II.B-6: Hawaii Volcanoes National Park; Aerosol Composition (contribution to 

Light Extinction) on 20% Best and 20% Worst Days for the year 2005 

Since the measured visibility impairing pollution in 2005 was consistent with the baseline 

years, it is reasonable to assume that for the purposes of Regional Haze Planning, that the 2005 

emissions were sufficiently consistent with the emissions in 2000-2004 for this year to be used as 

the baseline for the Regional Haze Plan.

II.B.4. Uniform Rate of Progress

Figure II.B-6 shows the 2018 URP for the Worst 20% days at Hawaii Volcanoes National Park.
28

(See section II.A.4 for an explanation of URP). Table II.B-1, Summary of Uniform Rate of 

Progress for 20% Worst Days, shows the Uniform Rate of Progress for Hawaii Volcanoes 

National Park. 

Figure II.B-6: Hawaii Volcanoes National Park: Uniform Rate of Progress, Worst 20% 

Visibility Days.22

Table II-B-1 shows the Hawaii Volcanoes National Park URP for the Worst 20% Visibility Days

and Table II.B-2 shows the Baseline and Natural Conditions for the Best 20 % Visibility Days.

23

 

Table II.B-1: Hawaii Volcanoes National Park- Summary of Uniform Rate of Progress for 

20% Worst Days

Class I 

Area

Baseline

Condition 

(deciview)

Natural 

Visibility 

(deciview)

Total 

Improvement 

by 2064 

(deciview)

URP 

(deciview

/year)

2018 URP 

Goal

(deciview)

Improvement 

needed by 

2018

(deciview)

Volcanoes 18.9 7.2 11.7 0.19 16.17 2.73

Table II.B-2: Hawaii Volcanoes National Park- Baseline and Natural Conditions for 20% Best 

Days

Class I Area

Baseline

Condition 

(deciview)

Natural Visibility 

(deciview)

Hawaii Volcanoes National Park 4.1 2.2

 

22 http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx

23 http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx
29

Figures II.B-7 and Figures II.B-8 show historic visibility photos that are representative of 

the Worst 20% days and the Best 20% days at Hawaii Volcanoes National Park.

Figure II.B-7: Photograph of Hawaii Volcanoes National Park- Worst 20% days 24: 19 

deciview

 

24 Hawaii Volcanoes National Park, Hawaii, Photographic Archive 1986 – 1990

http://vista.cira.colostate.edu/Datawarehouse/IMPROVE/Data/Photos/HAVO/html/IMG0003.htm
30

Figure II.B-8: Photograph of Hawaii Volcanoes National Park- Best 20% days: 4 deciview

II.B.5. Visibility Trends from 2001-2009

The Haze Index (in deciview) at Hawaii Volcanoes National Park, shown in Figure II.B-9

appears to indicate that the visibility on the worst 20% days is not improving over the years 2001 

through 2009. The monitoring data indicates that the level of light extinction due to sulfates is 

increasing, most likely due to the increase in volcano activity, as shown in Figure II.B-11: 

Hawaii Volcanoes National Park; Aerosol Composition (contribution to Light Extinction) on the

20% Worst Days for years 2001-2009. 

The degree of light extinction due to species other than sulfate appears to be 

approximately level, as shown in Figure II.B-11: Hawaii Volcanoes National Park; Non – sulfate 

Aerosol Composition (contribution to Light Extinction) on the 20% Worst Days for years 2001-

2009. The light extinction attributed to particulate organic mass is higher in the years 2001-2002 

than in the following years 2003-2009. The monitoring data for the 20% Best days show that the 

visibility is fairly constant from 2001 to 2009. 
31

Figure II.B-9: Hawaii Volcanoes National Park; Haze Index on 20% Worst Days for years 

2001-2009

Figure II.B-10: Hawaii Volcanoes National Park; Aerosol Composition (contribution to 

Light Extinction) on 20% Worst Days for years 2001-2009
32

Figure II.B-11: Hawaii Volcanoes National Park; Non-sulfate Aerosol Composition 

(contribution to Light Extinction) on 20% Worst Days for years 2001-2009

Figure II.B-12: Hawaii Volcanoes National Park; Aerosol Composition (contribution to 

Light Extinction) on 20% Best Days for years 2001-2009
33

III. Summary of Previous Visibility Assessments at the Haleakala and 

Hawaii Volcanoes National Parks.

The causes of visibility impairment at the Haleakala and Hawaii Volcanoes National 

Parks have been assessed by the NOAA and also by the Hawaii DOH. The results of these 

studies are briefly summarized below. EPA reviewed these assessments as part of the basis for 

determining causes of haze for the Haleakala National Park and the Hawaii Volcanoes National 

Park. 

III.A. NOAA Assessment of Causes of Haze for Hawaii’s Two Class I Areas 

The causes of haze for the Haleakala and Hawaii Volcanoes National Parks were 

examined by Marc Pitchford of NOAA in 2005.

25 This work identified the possible causes of 

visibility impairment within each of Hawaii‟s two Class I National Parks, based on wind 

trajectories and a source apportionment analysis using Positive Matrix Factorization (PMF).

Pitchford found that “wind trajectories provided a good indication that the SO2 was 

primarily coming from the Kilauea volcano‟s Pu‟u „O‟o rift zone.” Particle trajectory 

calculations for key days indicated that there were some days when high sulfate concentrations 

were detected at both HAVO1 and HALE1, and other days where high sulfate concentrations 

were only detected at HAVO1. These results indicated that “volcanic sulfate is likely impacting 

haze on at least some of the worst days for Haleakala”. 

The Positive Matrix Factorization (PMF) analysis used combined IMPROVE PM2.5 data 

from both the HALE1 and HAVO1 monitors to determine six PMF factors: Volcano Sulfate,

Sulfate & Nitrate, Smoke, Nitrate, Dust, and Sea Salt. The results for each of the 6 factors were

based on PM2.5 concentrations at HALE1 and HAVO1 on the Worst 20% Days, as well as all 

days, and are shown in Table III-1: Contribution to PM2.5 Concentration, below. The results 

indicate that:

• Hawaii Volcanoes National Park has much greater impacts from the “volcano” PMF 

factor than Haleakala National Park.

• The “volcano” PMF factor is responsible for most of the haze impacts on worst visibility 

days at Hawaii Volcanoes National Park, and many, but not all of the worst case days at 

Haleakala National Park.

• Haleakala National Park has greater impacts from “smoke”, “dust”, and “sulfate/nitrate” 

PMF factors compared to Hawaii Volcanoes National Park.

 

25 M. Pitchford, “Causes of Haze for Hawaii‟s Two Class I Areas”, presented at United States Department of 

Agriculture, Agricultural Air Quality Task Force Meeting, Wailea, Hawaii, November 13 and 15, 2005; 

http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs143_008844.pdf

http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx

http://www.powershow.com/view/4f998-YmIxN/Causes_of_Haze_Update_flash_ppt_presentation
34

Table III-1. Contribution to PM2.5 by PMF Source Factors

Volcano 

Sulfate %

Sulfate and 

Nitrate %

Smoke

%

Nitrate % Dust % Sea Salt %

HAVO1

Worst 20% 

Days

88 3 3 4 1 1

HAVO1

All Days

70 7 7 6 3 7

HALE1

Worst 20% 

Days

41 20 19 11 7 2

HALE1

All Days

33 16 22 14 8 7

Pitchford finds that for the year of 2003 at Haleakala IMPROVE Monitor (HALE1), 

“about half of worst case days are associated with volcano emissions, while the others are 

associated with different factors (e.g. smoke, secondary sulfate and nitrate).” For the Hawaii 

Volcanoes IMPROVE monitor (HAVO1) in 2003 he find that “all worst haze days are 

dominated by the volcano sulfate factor”. The recommendations for follow-on work include: 

examination of the smoke factor with respect to burning (e.g. agricultural) events; attribution of 

dust to local (e.g. high winds) or global (e.g. Asian dust) sources; including coarse mass into the 

PMF calculations to support possible attribution to local and non-local (e.g Asian dust) sources; 

and attribution of the “nitrate” and “sulfate/nitrate” PMF factors. 

III.B. Hawaii Department of Health Source Apportionment Results

Hawaii Department of Health has conducted visibility assessments for the Haleakala and 

Hawaii Volcanoes National Parks.26 The purpose of these efforts was to identify candidate 

sources of visibility impairment for Haleakala National Park and Hawaii Volcanoes National 

Park and estimate the associated impacts.

The visibility assessments discuss the potential sources of visibility impairment for the 

two National Parks, examine pollutant monitoring data and visibility impacts, present pollutant 

source apportionment results, and examine additional select pollution sources that could 

potentially impact visibility. The effort fused pollutant monitoring data, particle trajectories 

based on gridded wind data and select pollutant sources (forest fire and agricultural burning). 

 

26 Haleakala National Park Visibility Assessment, Hawai‟i Volcanoes National Park Visibility Assessment, and 

IMPROVE PMF Factor Identification notes Positive Matrix Factorization Analysis of HALE1 & HAVO1 

IMPROVE data sets April 20, 2012, State of Hawaii, Department of Health, Clean Air Branch.
35

The effort sought to gather information about all pollutants and sources. The large magnitude 

and temporal variability of Kilauea volcano emissions from the island of Hawaii are significant 

drivers for the work. 

The source apportionment analysis was based on IMPROVE data and associated Positive 

Matrix Factorization (PMF) analyses. The PMF categorized visibility impacts into 8 source types

for Haleakala National Park, and 6 source types for Hawaii Volcanoes National Park. The results 

provide insight into potential sources, both within and external to the islands of Hawaii.

Summaries of the results for each park are presented below. EPA has reviewed the 

Hawaii DOH Visibility Assessment for Haleakala and Hawaii Volcanoes National Park. EPA 

concurs with Hawaii DOH that the Volcano PMF factor and the Asian Dust PMF factors appear 

to be most reliable. The remaining six factors are less certain. For example, power plants and 

ships burn similar fuels, so as noted by Hawaii DOH, this PMF factor may have been incorrectly 

attributed to shipping versus other potentially consistent PMF factors.

III.B.1. Hawaii DOH Park Visibility Assessment of Haleakala National Park - Summary 

of Results

The estimation of contribution to light extinction (Bext for 2005/2003-2008 data sets, 

respectively) are presented below, and are base on IMPROVE data for the worst 20% Days 

visibility.

(1) The Volcano PMF Factor (46%/56% aerosol Bext for 2005/2003-2008 data sets, 

respectively) should be attributed to emissions from the Kilauea volcano on the island of Hawaii. 

The very high sulfur content of this factor, and the relatively good correspondence with the time 

history of one of the HAVO1 volcano factors are the two primary reasons for this attribution. 

(2) The Dust (Asian) PMF Factor (10%/2% aerosol Bext) should be attributed to emissions from 

Asia. The good correspondence between with the HAVO1 Dust (Asian) factor time history 

indicates a very large plume size consistent with long range transport. The seasonal nature of the 

time history, and the presence of dust constituents (Al, Ca, Fe, Si, Ti) are also key reasons for 

this attribution. Source apportionment calculations combined particle trajectory calculations with 

pollutant concentration levels and indicated several potential source areas in Asia. 

For the next five PMF factors, the results were inconclusive in a number of cases. In 

some cases, there appeared to be strong indications that at least portions of the source were 

located beyond the islands of Hawaii. In one case, there are indications that the source is close, 

likely small, and unlikely to contribute significantly to visibility impairment. Despite these 

indications, the results are not yet sufficiently conclusive to attribute the visibility impacts to 

other than local sources. For the same reason, visibility impacts are treated as if they impacted 

the entire National Park. Future source attribution analyses (using new monitoring data and 

gridded wind modeling results) could help resolve these uncertainties and perhaps enable better 

attribution of visibility impacts. 

(3) The Nitrate/Sulfate-Rich Secondary PMF factor (7%/16% aerosol Bext) appears consistent 

with potential sources beyond the islands of Hawaii. Trajectory and source apportionment 

calculations indicated that impacts were consistent with sources in Asia and Western CONUS. 
36

(4) The Smoke PMF factor (14%/6% aerosol Bext) is likely due to Maui sources. Two likely 

sources of smoke impacts, agricultural burning and forest fires, were investigated and found to 

not correspond well to the IMPROVE measurements at HALE1. Due to the presence of bromine 

in the factor, automobile exhaust is a possible contributor. An examination of the measurement 

differences between the primary IMPROVE site on Maui, HALE1, and the newer HACR1 site 

found that HALE1 concentration levels were generally approximately twice those of HACR1. It 

is believed likely that the elevated smoke levels at HALE1 are due to nearby sources that would 

not impact overall visibility within the National Park. 

(5) The Oil Combustion PMF factor (15%/10% aerosol Bext) appears consistent with potential 

sources both on the island of Hawaii and beyond the islands of Hawaii. The 2008 National 

Emission Inventory identified fuel (oil) combustion for power generation as significant 

contributors to local anthropogenic emissions. 

(6) The Sea Salt/Nitrate-Rich Secondary PMF factor (4%/6% aerosol Bext) appears consistent 

with sources beyond the islands of Hawaii.

(7) The Shipping PMF factor (2%/3% aerosol Bext) could be the result of sources on Maui, 

beyond the islands of Hawaii, or a combination of sources. This factor was attributed to shipping 

largely upon the relatively large quantity of zinc, which was also a characteristic in a prior PMF 

assessment of Hawaii emission sources. However, this PMF factor may have been incorrectly 

attributed to shipping, versus other potentially consistent PMF factors (e.g. Nitrate/Sulfate-Rich 

Secondary, Oil Combustion, or Sea Salt/Nitrate-Rich Secondary). 

(8) The Brush Fire/Burning Vegetation PMF factor (2%/0% aerosol Bext) is likely the result of 

sources on Maui. 

III.B.2. Hawaii DOH Park Visibility Assessment of Hawai’i Volcanoes National -

Summary of Results

The estimation of contribution to light extinction (Bext for 2005/2003-2008 data sets, 

respectively) are presented below, and are based on IMPROVE data for Worst 20% Days 

visibility.

(1) The three Volcano PMF Factors (93.4%/94.2% aerosol Bext for 2005/2003-2008 data sets, 

respectively) should be attributed to non-anthropogenic emissions from the Kilauea volcano on 

the island of Hawaii. The very high sulfur content of two of these factors is the primary reasons 

for this attribution. Source apportionment modeling for these two factors indicates emission sites 

that are consistent with the volcanic emissions and associated inter-island “vog” visibility 

impairment. For the third volcanic faction, the fraction of total sulfur is relatively low (~1%), but 

the source apportionment strongly indicates an emission site consistent with the Kilauea volcano. 

(2) The Dust (Asian) PMF Factor (1.3%/0.4% aerosol Bext) should be attributed to emissions 

from Asia. The good correspondence between with the HALE1 Dust (Asian) factor time history 

indicates a very large plume size consistent with long range transport. The seasonal nature of the 
37

time history, and the presence of dust constituents (Al, Ca, Fe, Si, Ti) are also key reasons for 

this attribution. Source apportionment calculations combined particle trajectory calculations with 

pollutant concentration levels and indicated several potential source areas in Asia. 

For the remaining four PMF factors, the results were inconclusive in a number of cases. 

In some cases, there appeared to be strong indications that at least portions of the source were 

located beyond the islands of Hawaii. Despite these indications, the results are not yet 

sufficiently conclusive to attribute the visibility impacts to other than local sources. For the same 

reason, visibility impacts are treated as if they impacted the entire National Park. Future source 

attribution analyses (using new monitoring data and gridded wind modeling results) could help 

resolve these uncertainties and perhaps enable better attribution of visibility impacts. 

(3) The Smoke PMF factor (1.2%/1.4% aerosol Bext) could be the result of on-island emissions, 

but there are some indications of potential sources beyond the islands of Hawaii. Forest fires 

were investigated and found to not correspond well to the IMPROVE measurements at HAVO1. 

The fire data did not match well with either the spatial locations indicated by the PSCF results, or 

the time-histories associated with any of the HAVO1 IMPROVE visibility impacting species or 

PMF Factors. Due to the presence of bromine in the factor, automobile exhaust is a possible 

contributor. 

(4) The Oil Combustion PMF factor (1.1%/1.5% aerosol Bext) could be the result of sources on 

Hawaii, the Americas, Asia, or a combination of those source regions. The emissions inventory 

in Section IV of this document identifies fuel (oil) combustion for power generation as 

significant contributors to local anthropogenic emissions. 

(5) The Sea Salt/Nitrate-Rich Secondary PMF factor (1.5%/2.0% aerosol Bext) appears 

consistent with sources beyond the islands of Hawaii. 

(6) The PMF Shipping PMF factor (1.4%/0.4% aerosol Bext) could be the result of sources on 

Hawaii, Maui, beyond the islands of Hawaii, or a combination of sources. This factor was 

attributed to shipping largely upon the relatively large quantity of zinc, which was also a 

characteristic in a prior PMF assessment of Hawaii emission sources. However, this PMF factor 

may have been incorrectly attributed to shipping, versus other potentially consistent PMF factors 

(e.g. Nitrate/Sulfate-Rich Secondary, Oil Combustion, or Sea Salt/Nitrate-Rich Secondary). 

IV. Emissions Inventory

IV.A. Statewide Emissions Inventory

40 CFR 51.308(d)(4)(v) requires that EPA maintain a statewide inventory of emissions of 

pollutants that are reasonably anticipated to cause or contribute to visibility impairment in any 

mandatory Class I Federal area. The inventory must include emissions for a baseline year, 

emissions for the most recent year for which data are available, and estimates of future projected 

emissions. The Regional Haze Rule does not specify the baseline year for the inventory, but EPA 
38

has recommended that 2002 be used as the inventory base year.27 2002 is generally appropriate 

as the baseline year for Regional Haze SIPs because it corresponds with the 2000-2004 period 

for establishing baseline visibility conditions, based on available ambient monitoring data, 

pursuant to 40 CFR 51.308(d)(2)(i). 

For this first Hawaii Regional Haze implementation plan, Hawaii DOH initially selected 

2005 as their base year because it was the most recent year with a full inventory when they began 

their technical work.28 Since 2005 is not within the baseline period of 2000-2004, EPA has 

performed a comparison of the aerosol composition of the 2005 data and 2001-2004 data for 

each Class I Area in Sections II.A., II.B, and III.B of this document. That analysis found that the 

2005 inventory is sufficiently representative of the base period that it is appropriate to use as the 

base inventory for the plan. That is, since the measured visibility impairing pollution in 2005 was 

consistent with the baseline years, it is reasonable to assume that for the purposes of Regional 

Haze Planning, that the 2005 emissions were sufficiently consistent with the emissions in 2000-

2004 for this year to be used as the baseline for the Regional Haze Plan.

The majority of the 2005, 2008 and 2018 inventories were derived from a 2010 study 

conducted by consulting firm Environ on behalf of the Hawaii DOH.29 The numbers developed 

by Environ were then refined and improved by HI DOH.30 Between the time when the Environ 

Study was conducted and the development of this FIP, the EPA finalized a new model for the 

estimation of emissions from on road vehicles. This new model, MOVES provides for a more 

accurate estimation of emissions from these sources. So, the EPA worked with the University of 

North Carolina (UNC) and consulting firm ICF International to develop a new emissions 

inventory for on road vehicles for Hawaii for the years 2005, 2008 and 2018.31 Tables III-1 

through III-3 reflect these revised emissions numbers. 

The EPA also worked with UNC and ICF to improve the 2018 emissions estimates for 

marine sources. The Environ work used the best data that was available at the time, but failed to 

account for the impact of the economic recession on marine vessel activity, cruise ships in 

particular. In addition, the Environ work did not take into account the impact of the North 

American Emissions Control Area (NA ECA). The United States Government, together with 

Canada and France, established the NA ECA under the auspices of Annex VI of the International 

Convention for the Prevention of Pollution from Ships (MARPOL Annex VI), a treaty developed 

by the International Maritime Organization. This ECA will require use of lower sulfur fuels in 

ships operating within 200 nautical miles of the majority of the U.S. and Canadian coastline, 

including the U.S. Gulf Coast and Hawaii, beginning in August 2012. The ECA will result in 

lower NOx and SO2 emissions from marine sources in Hawaii. Therefore, UNC and ICF have 

 

27 Memorandum from Lydia N. Wegman, “2002 Base Year Emission Inventory SIP Planning: 8-Hour Ozone, 

PM2.5 and Regional Haze Programs” (Nov. 18, 2002).

28 E-mail from Priscilla Ligh, Hawaii DOH, to Gregg Nudd, EPA, May 3, 2012. 

29 “Final Emission Inventory Report: Data Population for Air System for Hawaii Emissions Data (AirSHED)”, 

Environ International Corporation, April 12, 2010.

30 See email from Priscilla Ligh, HI DOH to Greg Nudd, USEPA, on 11/18/2011 and associated document: “RevA 

Emissions inventory response to EPA 11-17-11 for EPA.doc” The document also explains any differences between 

the Hawaii DOH numbers and the emissions inventory in the National Emission Inventory for Hawaii.

31 Technical Analysis for Hawaii‟s Regional Haze FIP Report – Task 16: On-Road Mobile Emissions Inventory, ICF 

International, March 23, 2012
39

updated the 2018 inventory to include the benefits of the ECA. The 2018 marine emissions 

estimates in Table III-3 are based on this more recent work by UNC and ICF.32

Table III-1 Statewide Inventory for 2005

Source Category NOx SO2 VOC PM NH3

Point Sources 22,745 27,072 2,695 3,536 12

Area Sources 1,509 3,716 16,920 33,408 11,136

Windblown Dust 46,808 

Wildfire 2,156 591 4,729 9,771 540

Agricultural Burning 406 178 535 1,567 60

Other fire 1 7 7 

On Road Mobile Sources 20,642 321 12,066 638 1,085

Non Road Mobile Sources 4,750 534 6,121 484 5

Aircraft 1,541 135 262 165 

In and Near Port Marine 2,572 2,201 92 183 

Underway Marine (<30

nm33)

3,052 1,418 117 215 

Trains 5 

Volcano 961,366 

Sea Spray 382,637 

Biogenic 4,617 130,153 

Total 63,996 997,532 173,697 479,419 12,838

Anthropogenic Total 59,379 36,166 43,544 96,782 12,838

Table III-2 Statewide Inventory for 2008

Source Category NOx SO2 VOC PM NH3

Point Sources 20,246 25,849 2,544 3,389 12

Area Sources 1,166 15,767 18,025 34,917 11,275

Windblown Dust 46,808 

Wildfire 2,156 591 4,729 9,771 540

Agricultural Burning 406 178 535 1,567 60

Other fire 1 8 7 

On Road Mobile Sources 14,239 97 8,526 547 1,124

Non Road Mobile Sources 4,573 78 4,912 422 5

Aircraft 2,568 260 628 123 

In and Near Port Marine 12,432 2,638 308 605 

Underway Marine (<30nm) 562 282 18 42 

Trains 5 

Volcano 1,195,314 

Sea Spray 382,637 

 

32 “Technical Analysis for Hawaii‟s Regional Haze FIP Report – Task 16: Commercial Marine Inventory”, ICF 

International, April 2, 2012

33 nautical miles
40

Biogenic 4,617 130,153 

Total 62,971 1,241,054 170,386 480,835 13,017

Anthropogenic Total 58,354 45,740 40,233 98,198 13,017

Table III-3 Statewide Inventory for 2018

Source Category NOx SO2 VOC PM NH3

Point Sources 28,594 36,212 4,157 5,052 13

Area Sources 1,723 3,524 20,054 43,506 12,530

Windblown Dust 46,808 

Wildfire 2,156 591 4,729 9,771 540

Agricultural Burning 406 178 535 1,567 60

Other fire 1 8 7 

On Road Mobile Sources 5,058 72 3,883 400 1,478

Non Road Mobile Sources 3,090 7 4,579 297 7

Aircraft 1,920 167 466 194 

In and Near Port Marine 2,097 117 92 50

Underway Marine (<30nm) 1,867 68 78 33

Trains 5 

Volcano 683,746 

Sea Spray 421,222 

Biogenic 4,617 130,153 

Total 51,533 724,681 168,734 528,908 14,628

Anthropogenic Total 46,916 40,935 38,581 107,686 14,628

IV. B. Review of the Emissions Inventory for Completeness and Accuracy

The EPA has reviewed the methods used by Environ, the Hawaii Department of Health 

and the ICF Corporation in developing this inventory. We propose to find that the best available 

emissions factors and activity data were used in developing the emissions estimates. We also 

propose to find that the inventory captures all of the emissions sources relevant to the 

development of a Regional Haze Plan.

IV.C. Assessment of the Emissions Inventory

There are a few interesting and relevant facts to draw from the results in Tables III-1 

through III-3.

First, nonanthropogenic emissions are significant for SO2, VOC and PM. As one can see 

from the tables above, the volcano dominates statewide SO2 emissions. Emissions from the 

volcano comprise over 96% of the SO2 emissions in 2005 and 2008. On days when the volcano 

is erupting and the winds are carrying those emissions over the Class I area monitors, these 
41

natural emissions will dominate the measurements. Nonanthropogenic sources also comprise the 

majority of VOC and PM emissions. 

Second, total statewide anthropogenic emissions of NOx and VOC are decreasing. 

Human-made NOx pollution is projected to be 21% lower in 2018 than in 2005. Human-made 

VOC pollution is projected to decrease by 11%. These reductions are primarily due to EPA 

regulations for on-road vehicles. Emissions from cars and trucks are decreasing dramatically, 

even accounting for economic and population growth. This is due to older, higher emitting 

vehicles being replaced by ones with more modern air pollution controls. NOx emissions in this 

category are projected to decrease by over 15,000 tpy and VOC emissions by over 8,000 tpy 

between 2005 and 2018.

However, anthropogenic SO2 emissions are expected to increase between 2005 and 2018, 

largely due to increased emissions from point sources. The lower sulfur marine fuels required by 

the ECA are expected to result in a 95% reduction in emissions from shipping, but those 

reductions are overwhelmed by the increases from point source emissions. The growth rate of 

point source emissions is very sensitive to assumptions about future economic growth. The 

Environ report, from which this data is derived, assumes robust economic growth between 2005 

and 2018. Given the economic recession that began in late 2008 this level of emission growth 

will likely over-predict future anthropogenic emissions. Nevertheless, this is the best data 

available. 

Our analysis of the monitoring data indicates that SO2 is the principal pollutant of 

concern for the regional haze plan. (See sections II.A., II.B, and III.B of this TSD.) The visibility 

impacts of NOx and VOC emissions are of secondary importance. The increase in anthropogenic 

SO2 emissions indicates that some additional pollution reductions are needed to ensure 

reasonable progress toward the goal of eliminating anthropogenic visibility impairment in 

Hawaii‟s mandatory class I areas. Our proposal to achieve these reductions is set forth in section 

VII of this TSD. 

V. Causes of Haze in Hawaii (including volcanic emissions)

V.A. Island-Specific Emissions Inventory

The island specific emission inventory for the years 2005 and 2018 is presented below. 

These tables are derived from the same set of references and assumptions as in the Emissions 

Inventory section.

Table V-1. Hawaii (Big Island) Anthropogenic Emissions Inventory34

2005 Inventory 2018 Inventory

Source Category NOx SO2 NOx SO2

Point 1,036 4,551 1,736 5,266 

Nonpoint 1,849 808 1,882 872 

On-Road Mobile 3,217 53 839 11 

Non-Road Mobile 784 95 428 1 

 

34 Does NOT include volcano SO2 emissions of 961,366 tons/year.
42

Aircraft 177 18 207 21 

Agricultural Burning 2 0 2 0 

Wildfires 1,712 469 1,712 469 

in/near port Marine 537 418 546 20 

Total 9,314 6,412 7,352 6,661 

Table V-2. Maui Anthropogenic Emissions Inventory

2005 Inventory 2018 Inventory

Source Category NOx SO2 NOx SO2

Point 4,492 4,559 4,597 4,625

Nonpoint 462 481 548 571

On-Road Mobile 2,957 47 758 10

Non-Road Mobile 496 57 305 2

Aircraft 310 27 376 33

Agricultural Burning 298 132 298 132

Wildfires 52 14 52 14

in/near port Marine 699 569 836 32

Total 9,765 5,887 7,770 5,420

V.B. Synthesis of Emissions Inventory, Monitoring Data, and PMF analysis

Sulfate is the largest cause of visibility degradation on the 20% worst days at both 

Haleakala National Park and Hawaii Volcanoes National Park. Natural causes of sulfate include 

the emissions from the Kīlauea volcano, located in the Hawaii Volcanoes National Park, and 

natural marine sulfates. The emissions and impact of the volcano varies substantially from year 

to year. Source apportionment assessments have estimated that the volcano causes approximately 

90% of the visibility impairment at Hawaii Volcanoes National Park and approximately 60% of 

the visibility impairment at Haleakala National Park on the 20% worst days. The natural marine 

sulfate impact is expected to be much smaller.35 International transport may also contribute to 

sulfur visibility impairment. Anthropogenic sources of sulfur include oil combustion, and 

shipping. 

Nitrate contributes 9% to the visibility degradation on the 20% worst days at Haleakala. 

Nitrate contributes 1% to the visibility degradation on the 20% worst days at Hawaii Volcanoes 

National Park. The major anthropogenic sources of nitrate are point sources, on-road sources,

and marine emissions. The natural sources of nitrate include wildfire and biogenic emissions.

Organic Carbon contributes 10% of the visibility degradation at the Haleakala (HALE1) 

monitor, which is located outside of the park. Sources of organic carbon include agricultural 

burning, oil combustion, and international transport. A comparison of recent monitoring at the 

Haleakala Crater monitoring site at Park (HACR1) shows a lower level of organic carbon than

 

35 Yvon and Saltzman 1996, Atmospheric Sulfur Cycling in the Tropical Marine Boundary Layer. J. Geophys. Res. 

101, 6911-6918.
43

the HALE1 site. 36 Organic Carbon contributes 4% of the visibility degradation at the Hawaii 

Volcanoes National Park during the 2001 – 2004 time period. Organic carbon levels measured at 

the park from 2003-2009 are much lower, as discussed in the section regarding visibility trends 

at Hawaii Volcanoes Park, above.

Elemental Carbon contributes to 5% of the visibility degradation at the Haleakala 

(HALE1) monitor, which is located outside of the park. A comparison of recent monitoring at 

the Haleakala Crater monitoring site at Park (HACR1) shows a lower level of elemental carbon 

of the HALE1 site.37

Coarse mass contributes to 9% of the visibility degradation at the Haleakala (HALE1) 

monitor and 1% of the visibility degradation at the Hawaii Volcanoes National Park. The 

potential sources of coarse mass include fugitive dust, international transport, and shipping. 

Soil contributes to 1% of the visibility degradation at the Hawaii Volcanoes National 

Park. The soil impact varies seasonally, with the highest levels in the springtime, and appears to 

be associated with international transport. 

V.C. Visibility Impairing Pollutants Subject to Evaluation

EPA has evaluated the six particulate pollutants (ammonium sulfate, ammonium nitrate, 

organic carbon (OC), elemental carbon (EC), fine soil and coarse mass (CM)) that contribute to 

visibility impairment at Hawaii‟s two mandatory Class I federal areas. Sulfate is the primary 

cause of visibility impairment at each of Hawaii‟s Class I Areas, and EPA proposes that the first 

Regional Haze Plan RP evaluation should focus on primarily on significant sources of SO2 

(sulfate precursor). NOx (nitrate precursor) is a secondary concern, as it contributes to 9% of the 

visibility degradation on the 20% worst days at Haleakala.

Coarse mass contributes to 9% of the visibility degradation at the Haleakala, and is also 

of concern. However, the sources of coarse mass (CM) are uncertain because of emission 

inventory limitations associated with natural sources (predominantly wildfires) and uncertainty 

of fugitive (windblown) emissions. Because of the difficulty in attributing the sources of 

visibility impairment for this pollutant, EPA has determined that it is not reasonable in this 

planning period to recommend emission control measures for coarse mass. Coarse mass 

contribution to visibility impairment, emissions sources, and potential control measures should 

be addressed in future Regional Haze plan updates.

Because fine soil appears to be primarily attributable to international transport, EPA has 

determined that it is not reasonable in this planning period to recommend emission control 

measures for fine soil. Although organic and elemental carbon contribute to base year visibility 

impairment, recent monitoring at the Haleakala Crater (HACR1) monitoring site and the Hawaii 

Volcanoes (HAVO1) show low contributions to visibility impairment from organic and 

elemental carbon. 

 

36 Review of VIEWS2.0 2009-2010 Haleakala National Park Organic and Elemental Carbon Data, March 30, 2012, 

State of Hawaii, Department of Health, Clean Air Branch, and Comparison of Haleakala National Park, HALE1 and 

HACR1 IMPROVE Monitoring Site 2007-2008 Data Sets, March 30, 2012, State of Hawaii, Department of Health, 

Clean Air Branch.

37 Ibid.
44

VI. Best Available Retrofit Technology (BART)

VI.A. BART Requirements

Section 169A of the CAA directs states, or EPA if implementing a FIP, to evaluate the 

use of retrofit controls at certain larger, often uncontrolled, older stationary sources in order to 

address visibility impacts from these sources. Specifically, section 169A(b)(2)(A) of the CAA 

requires states to revise their SIPs, or for EPA to implement a FIP, to contain such measures as 

may be necessary to make RP towards the natural visibility goal, including a requirement that 

certain categories of existing major stationary sources38 built between 1962 and 1977 procure, 

install, and operate the “Best Available Retrofit Technology” as determined by the state, or EPA 

if implementing a FIP. Under the Regional Haze Rule, states, or EPA if implementing a FIP, are 

directed to conduct BART determinations for such “BART-eligible” sources that may be 

anticipated to cause or contribute to any visibility impairment in a Class I area. 

On July 6, 2005, EPA published the Guidelines for BART Determinations Under the 

Regional Haze Rule at Appendix Y to 40 CFR Part 51 (hereinafter referred to as the “BART 

Guidelines”) to assist states, or EPA if implementing a FIP, in determining which of their 

sources should be subject to the BART requirements and in determining appropriate emission 

limits for each applicable source. 70 FR 39104. In making a BART determination for a fossil 

fuel-fired electric generating plant with a total generating capacity in excess of 750 megawatts 

(MW), a state, or EPA if implementing a FIP, must use the approach set forth in the BART 

Guidelines. A state, or EPA if implementing a FIP, is encouraged, but not required, to follow the 

BART Guidelines in making BART determinations for other types of sources. Regardless of 

source size or type, a state, or EPA if implementing a FIP, must meet the requirements of the 

CAA and our regulations for selection of BART, and the state‟s, or EPA‟s if implementing a 

FIP, BART analysis and determination must be reasonable in light of the overarching purpose of 

the regional haze program.

The process of establishing BART emission limitations can be logically broken down 

into three steps: first, states, or EPA if implementing a FIP, identify those sources which meet 

the definition of “BART-eligible source” set forth in 40 CFR 51.30139; second, states, or EPA if 

implementing a FIP, determine which of such sources “emits any air pollutant which may 

reasonably be anticipated to cause or contribute to any impairment of visibility in any such area” 

(a source which fits this description is “subject to BART”); and third, for each source subject to 

BART, states, or EPA if implementing a FIP, then identify the best available type and level of 

control for reducing emissions.

States, or EPA if implementing a FIP, must address all visibility-impairing pollutants 

emitted by a source in the BART determination process. The most significant visibility impairing 

pollutants are SO2, NOx, and PM. 

Under the BART Guidelines, states, or EPA if implementing a FIP, may select an 

exemption threshold value for their BART modeling, below which a BART-eligible source 

would not be expected to cause or contribute to visibility impairment in any Class I area. The 

 

38 The set of “major stationary sources” potentially subject to BART is listed in CAA section 169A(g)(7).

39 BART-eligible sources are those sources that have the potential to emit 250 tons or more of a visibility-impairing 

air pollutant, were not in operation prior to August 7, 1962, but were in existence on August 7, 1977, and whose 

operations fall within one or more of 26 specifically listed source categories. 40 CFR 51.301.
45

state, or EPA if implementing a FIP, must document this exemption threshold value in the SIP,

or FIP, and must state the basis for its selection of that value. Any source with emissions that 

model above the threshold value would be subject to a BART determination review. The BART 

Guidelines acknowledge varying circumstances affecting different Class I areas. States, or EPA 

if implementing a FIP, should consider the number of emission sources affecting the Class I 

areas at issue and the magnitude of the individual sources‟ impacts. Any exemption threshold set 

by the state, or EPA if implementing a FIP, should not be higher than 0.5 deciview. 40 CFR part 

51, appendix Y, section III.A.1.

A regional haze SIP, or FIP, must include source-specific BART emission limits and 

compliance schedules for each source subject to BART. Once a state, or EPA if implementing a 

FIP, has made its BART determination, the BART controls must be installed and in operation as 

expeditiously as practicable, but no later than five years after the date of EPA approval of the 

regional haze SIP, or FIP. CAA section 169(g)(4) and 40 CFR 51.308(e)(1)(iv). In addition to 

what is required by the Regional Haze Rule, general SIP, or FIP, requirements mandate that the 

SIP, or FIP, must also include all regulatory requirements related to monitoring, recordkeeping, 

and reporting for the BART controls on the source. See CAA section 110(a). 

VI.B. Identify BART Eligible Sources

In 2008, the Hawaii DOH conducted a survey of the major sources in the state to identify 

which sources were BART eligible. This survey was completed and certified by the responsible 

official at each major source. Through that process, the following facilities were identified as 

BART eligible: HC&S Puunene facility, Chevron Refinery, Tesoro Refinery, Hu Honua 

Bioenergy –Pepeekeo facility, MECO – Kahului facility, HELCO Kanoelehua Hill, HECO –

Waiau facility, HECO – Kahe facility.

These sources were further analyzed to determine which were subject to BART.

VI.C. Identify BART- Subject Sources

On 6 July 2005, the U.S. Environmental Protection Agency (EPA) published final 

amendments to its 1999 RH Rule in the Federal Register, including 40 CFR Part 51, Appendix 

Y, the final guidance for BART determinations (BART Guideline; EPA, 2005; 70 FR 39104-

39172). The rule applies to any BART-eligible source that “emits any air pollutant which may 

reasonably be anticipated to cause or contribute to any impairment of visibility” in any 

mandatory Class I federal area. States retain the authority to exempt certain BART-eligible 

sources based on dispersion modeling demonstrating that the source cannot reasonably be 

anticipated to cause or contribute to visibility impairment in a Class I area. 

According to 40 CFR Part 51, Appendix Y, a BART-eligible source is considered to 

“contribute” to visibility impairment in a Class I area if the modeled 98th percentile change in 

deciviews is equal to or greater than the “contribution threshold.” Any BART-eligible source, 

through modeling, determined to cause or contribute to visibility impairment above the threshold 

in any Class I area is subject to BART. The EPA BART Guidelines suggest a contribution 

threshold of no greater than a 0.5 change in deciview be used. The State of Hawaii chose to use 

the recommended 0.5 deciview threshold for Subject-to-BART determination.
46

Generally, if a source is a smaller emitter or is located far from a Class I area, and its Q/D 

is less than 1040, the source is not expected to contribute to visibility impairment at a Class I area. 

Using this approach, the Hawaii DOH determined that the Kauai Utilities Port Allen facility 

should not be Subject-to-BART. For the other BART eligible sources, the contribution to any 

impairment of visibility” in the Hawaii Class I areas is based on dispersion modeling.

VI.C.1. Subject to BART Modeling for the State of Hawaii

CALPUFF Modeling System

Subject to BART Modeling was performed by Alpine Geophysics on behalf of Hawaii 

DOH41, EPA proposes to use this modeling as a basis to determine which sources are subject to 

BART. This modeling is described briefly below, and in greater detail in the modeling protocol 

and final report which are included in Appendix A of this document. 

CALPUFF was applied separately for each Class I Area (Haleakala National Park and 

Hawaii Volcanoes National Park) on the island of Maui and Hawaii. The CALPUFF modeling 

system, shown in Table 1, was the regulatory approved versions, except for the CALPOST 

processor. CALPOST version 6.221which was used to enable the application to use the most upto-date FLAG (6-29-2008) guidance. The CALMET model was run using the August 20, 2009, 

“EPA-FLM Recommended CALMET input File Values.” Detailed parameter settings for

CALPUFF, CALMET, and CALPOST are provided in Appendix A to this document.

Table VI-1: CALPUFF Modeling System

Program Version Level

CALMET 5.8 060911

CALPUFF 5.8 060911

CALPOST 6.221 080724

POSTUTIL 1.56 070627

The application generally followed the recommendation of the IWAQM and FLAG guidance 

documents:

1) The calendar year 2005 CALMET input file were developed by Alpine Geophysics, LLC 

and be provided as input-ready to CALPUFF.

 

40

 Q = Potential Emissions (tons/year) of SO2+NOx+PM10 from all eligible units within a facility

 D = Distance (kilometers) between the eligible source and the boundary of the nearest Class I area

41 Subject-to-Best Available Retrofit Technology (BART) Modeling for the State of Hawaii, Application of the 

CALPUFF Modeling System; Prepared for: Hawaii State Department of Health, Environmental Management 

Division Clean Air Branch by Alpine Geophysics, LLC. March 3, 2010.
47

2) The Subject-to-BART modeling examined the visibility impairment on Class I areas 

within 300km of each single source or facility. The computational modeling domain is 

sufficient to include all Class I areas within a 300km radius of a source.

3) Pasquill-Gifford Dispersion coefficients are used.

4) MESOPUFF-II chemistry algorithms are used.

5) Puff splitting is not used, following the recommendations of the FLMs.

6) Source elevations are based on the same terrain files as the receptor elevations.

7) The CALUTIL is used to perform HNO3/NO3 repartitioning using the parameters in 

Appendix B.

Natural Background

The BART Guideline references EPA‟s “Guidance for Estimating Natural Conditions 

under the Regional Haze Rule” (EPA, 2003a). This guidance lists three sets of Natural 

Conditions corresponding to Annual Average, Best 20% Days and Worst 20% Days. Due to 

limited access to available meteorological data, the 20% best natural days were used, in lieu of 

annual average natural days, to represent natural visibility background in Class I areas. This 

definition of natural background is consistent with the intent of the BART Guideline.42

Table VI-2: 20% Best Natural Conditions – Concentrations and Rayleigh Scattering By 

Class I Area.

Background Extinction Coefficients (20% Best Days)

Class I 

Area

(NH4)2SO4

μg/m3

NH4NO3

Μg/m3

OM

μg/m3

EC

μg/m3

Soil

μg/m3

CM

μg/m3

Sea 

Salt

μg/m3

Rayleigh

Mm-1

Haleakala 

National 

Park 0.05 0.04 0.24 0.01 0.11 1.59 0.13 10

Hawaii 

Volcanoes 

National 

Park 0.03 0.04 0.27 0.01 0.06 0.64 0.11 10

Background ozone was assumed to be at an annual constant level of 40 ppb. A review of 

the ammonia emissions inventory for Hawaii in comparison with mainland agricultural areas 

indicate a background of 1.5 ppb to be representative based on land use and agricultural and 

livestock activity.

Meteorological Data

Alpine was contracted to apply the Pennsylvania State University/National Center for 

Atmospheric Research (PSU/NCAR) Mesoscale Model (MM5) (Dudhia, 1993; Grell et al., 1994: 

UCAR, 2003a) for calendar year 2005 to provide data for the CALMET/CALPUFF modeling as 

well as for additional modeling and analytical studies conducted for the Hawaiian Islands. A 

 

42 Federal Register Vol. 70, No. 128, p 39125.
48

complete description of the modeling approach and a statistical evaluation of the annual MM5 

model are described in McNally and Wilkinson, 200843, in Appendix B of this document.

 

VI.C.2. Review of Subject to BART Modeling

EPA proposes to use a contribution threshold of 0.5 deciviews for determining which 

sources are subject to BART. EPA believes this threshold is appropriate, considering the number 

of sources affecting the Class I areas and the magnitude of the individual sources impacts. This is 

consistent with the State of Hawaii‟s recommendation to use a 0.5 deciview threshold for the 

Subject-to-BART determination. 

The U.S. EPA Region 9, U.S. National Park Service (NPS), and the U.S. Fish and 

Wildlife Service (FWS) were consulted during development of the modeling protocol for the 

CALPUFF modeling used for the subject to BART determination. The EPA has reviewed the 

methods used by Alpine for the Hawaii Department of Health in the application of the 

CALPUFF modeling for the subject to BART analysis. EPA proposes to find the modeling 

procedures appropriate for the subject to BART determination.

VI.C.3. Assessment of Subject to BART Modeling 

EPA believes the CALPUFF modeling used for the subject to BART determination is the

most appropriate modeling to use for the proposed Regional Haze FIP. However, the modeling 

was based on a single year of mesoscale meteorological data. A minimum of three years of 

mesoscale meteorological model output is recommended for conducting the initial step in the 

first-level analysis. However, meteorological data sets for more than 2005 were unavailable for 

the modeling domain at the time the CALPUFF modeling was performed for Hawaii DOH. More 

recently, three years (2005 -2007) of MM5 meteorological data for Hawaii were developed by 

JCA.44 This data may be an appropriate basis for the mesoscale meteorological modeling for 

future regional haze plans.

VI.C.4. Results of Subject to BART Modeling 

Table VI-3: Individual BART-Eligible Source Visibility Impacts on Hawaii Class I Areas

Source and Unit Class I Area

Maximum 

24-Hour

98th Percentile

Visibility 

Subject to 

BART or 

Exempt

 

43 MM5 Application for 2005 Over the Hawaiian Islands, prepared for Hawaii State Department of Health, 

Environmental Management Division, Clean Air Branch Prepared by: Alpine Geophysics, LLC., October 31, 2008.

44 MM5 Meteorological Dataset Development For Hawaii, Draft December 2008, JCA, Prepared 

for Hawaiian Electric Company, Inc., Maui Electric Company, Inc. Hawaiian Electric Light Company, Ltd.
49

Impact 

(deciview)

HC&S Puunene facility

(Bagasse)

HC&S Puunene facility

(Coal)

Haleakala

Hawaii Volcanoes 

Haleakala

Hawaii Volcanoes

0.059

0.008

0.133

0.039

Exempt

Exempt

Chevron Refinery Haleakala

Hawaii Volcanoes

0.021

0.016

Exempt

Tesoro Refinery Haleakala

Hawaii Volcanoes

0.025

0.017

Exempt

Hu Honua Bioenergy –

Pepeekeo facility 

Haleakala

Hawaii Volcanoes

0.323

0.540

Subject to 

BART

MECO – Kahului facility, Haleakala

Hawaii Volcanoes

0.232

0.108

Exempt

HELCO Kanoelehua Hill Haleakala

Hawaii Volcanoes

0.808

2.334

Subject to 

BART

HECO – Waiau facility Haleakala

Hawaii Volcanoes

0.083

0.038

Exempt

HECO – Kahe facility Haleakala

Hawaii Volcanoes

0.221

0.132

Exempt

The Hu Honua Bioenergy – Pepeeko facility has had its permit revoked. The facility has been 

issued a new permit to burn exclusively biomass materials. This new permit included the 

application of Best Available Control Technology. As a result of these changes, the facility is no 

longer BART eligible. The one remaining facility that is subject to BART is the HELCO 

Kanoelehua Hill facility. This facility was analyzed to determine BART controls.

VI.D. BART Determination and Federally Enforceable Limits

The third step of a BART evaluation is to perform the BART analysis. The BART 

Guidelines (70 FR 39164 (July 6, 2005)) describe the BART analysis as consisting of the 

following five steps:

Step 1: Identify All Available Retrofit Control Technologies;
50

Step 2: Eliminate Technically Infeasible Options;

Step 3: Evaluate Control Effectiveness of Remaining Control Technologies;

Step 4: Evaluate Impacts and Document the Results; and

Step 5: Evaluate Visibility Impacts.

In determining BART, the state, or EPA if implementing a FIP, must consider the five 

statutory factors in section 169A of the CAA: (1) the costs of compliance; (2) the energy and 

non-air quality environmental impacts of compliance; (3) any existing pollution control 

technology in use at the source; (4) the remaining useful life of the source; and (5) the degree of 

improvement in visibility which may reasonably be anticipated to result from the use of such 

technology. See also 40 CFR 51.308(e)(1)(ii)(A). The actual visibility impact analysis occurs 

during steps 4 and 5 of the process.

As mentioned previously, the only source in Hawaii subject to BART is the Kanoelehua 

Hill Generating Station on the Big Island. Specifically, there are two residual fuel-oiled fired 

boilers at this plant that are subject to BART (Hill 5 & Hill 6). Hill 5 is a 14 MW front-fired 

boiler. Hill 6 is a 21 MW tangentially fired boiler. Both boilers currently burn residual (~ No. 6) 

oil with sulfur content not to exceed 2% by weight. Table V-1 summarizes the baseline emission 

rates and modeled visibility impact of these sources. The annual emissions are based on 2009 

operations. 

Table VI-1 Baseline Emissions and Visibility Impacts of Hill

SO2 emissions tons per year [tpy] 2,778

NOx emissions [tpy] 735

PM emissions tpy 70

Visibility impact on Haleakala45 ∆ deciview [∆/dv] 0.44

Visibility impact on Volcanoes [∆/dv] 1.56

Trinity Consulting, on behalf of the Hawaii Electric Company, the plant operator, 

performed a five-factor analysis for this plant46. 2009 was used as the baseline for the analysis 

because that was the most current, complete year available when Trinity performed the BART 

analysis in 2010. We have reviewed this analysis and believe it appropriately addresses the five 

BART factors. Although the BART guidelines are not mandatory for Hill because the plant‟s 

total generating capacity is less than 750 megawatts, the Trinity analysis generally adheres to the 

guidelines. Our analysis of the five factors is largely based on the Trinity work.

VI.D.1 BART for NOx and Particulate Matter (PM)

The Trinity report appropriately examined BART controls for NOx and PM. However, 

 

45 These results are from Trinity‟s modeling. These indicate a lower impact than was indicated by the Alpine 

modeling. But, even in Trinity‟s modeling, the baseline impacts are high enough to make the source subject to 

BART. 

46 BART FIVE FACTOR ANALYSIS Prepared for Hawaiian Electric Light Company, October 2010, Trinity 

Consultants
51

due to the overwhelming contribution of sulfate to visibility impairment at the nearby Hawaii 

Volcanoes Class I area, it is unlikely that reductions in these pollutants from this site would have 

a measurable impact on visibility at that area.

For PM, the Trinity report considered the following technologies: Dry Electrostatic 

Precipitator (ESP), Wet Electrostatic Precipitator (ESP), Fabric Filter, Wet Scrubber, Cyclone 

and Fuel Switching. Dry ESPs, Cyclones and Fabric Filters are not appropriate for the type of 

particulate emitted by this plant. A wet scrubber would work, but these types of devices are 

better suited to larger particulate than is emitted from an oil-fired boiler and their control 

efficiency would be small. A wet ESP would have good control efficiency and is technically 

feasible. Similarly, switching to distillate fuel would be an effective and technically feasible

control for PM. Trinity estimated the cost effectiveness of a wet ESP as $13,000 per ton of PM 

controlled. They estimated the cost effectiveness of switching to distillate fuel as $170,000 per 

ton. Neither of these controls would be cost effective for PM.

For NOx, the Trinity report considered both combustion controls such as flue gas 

recirculation and low-NOx burners as well as post-combustion controls such as selective 

catalytic reduction (SCR). There were no technical barriers to implementing any of these 

controls. The post-combustion controls were not found to be cost effective. Low-NOx burners 

were found to be cost effective by the Trinity report. However, given the monitoring data on 

Hawaii, EPA finds that the emission reductions provided by low-NOx burners is unlikely to 

provide a measurable visibility benefit at Hawaii Volcanoes or Haleakala.

Based on our consideration of the five BART factors, EPA has determined that no control 

for NOx and PM at the Hill plant is consistent with BART, given the unique conditions in 

Hawaii. NOx reductions may need to be pursued in future planning periods as anthropogenic 

sulfates are reduced and nitrates become a larger portion of anthropogenic visibility impairment. 

VI.D.2 BART for SO2

The principal visibility-impairing pollutant from the Hill Plant is SO2. Sulfates are the 

largest component of visibility impairment at Hawaii Volcanoes and at Haleakela, even on the 

best days. The Hill Plant is by far the largest source of anthropogenic SO2 emissions on the Big 

Island. 

The Trinity report considered both flue gas desulfurization (FGD) and fuel switching as 

possible controls. The report found that no other oil-fired electric generating unit had installed 

FGD technology and due to the lack of industry experience, the technology was infeasible. Even 

if it were feasible, the control effectiveness would be in question. EPA agrees that FGD 

technology is unproven for this application and concurs with Trinity‟s decision to focus on fuel 

switching. However, the Trinity analysis only looked at switching to distillate fuel oil. Distillate 

fuel oil is substantially more expensive than residual fuel oil and it provides less energy per 

gallon. As a result, it is not a cost effective control measure. 

EPA requested HECO to consider switching to lower sulfur residual fuel oil, which 

would be a less expensive option. HECO responded with their cost effectiveness estimate47. The 

lowest cost option, residual fuel oil no more than 1% sulfur by weight had a cost effectiveness of 

between $6,677/ton and $7,363/ton. 

 

47 Letter from Brenner Munger, Manager, Environmental Department, Hawaiian Electric Company to Tom Webb, 

U.S. EPA Region 9, January 27, 2012
52

EPA considered this cost estimate too high in light of available market data and 

conducted our own analysis, which is summarized in Table VI-2, below. Based on this analysis,

we estimate the cost effectiveness of this control to be approximately $5,600/ton.

Table VI-2: Cost and Benefits of Switching Hill to 1% Fuel Oil

Baseline Weight % S 1.57

Baseline Fuel Consumption [gal/yr] 18,650,604 

Baseline Emissions [tons SO2/yr] 2,344 

New Fuel Weight % S 1.00

Cost Differential [$/gal] 0.255

Controlled Emissions [tons SO2/yr] 1493

Annual Costs [$/yr] $4,755,904

Annual Emission Reductions [tons SO2/yr] 851

Cost Efficiency [$/ton SO2 reduced] $5,587 

In Table VI-2, the baseline sulfur content is the average of two years of fuel oil analysis 

conducted by the electric utility for fuel they have received at Maui and the Big Island. This is 

more representative than taking the actual fuel sulfur content for the year 2009. The fuel is 

guaranteed by the suppliers to be less than 2% sulfur, but the actual sulfur content varies 

depending on feedstock. The fuel consumption numbers are from the Trinity BART analysis. 

The SO2 emissions were calculated based on stack testing conducted at Kanoelehua Hill, and 

adjusting for sulfur input for the new fuel. The new fuel is conservatively assumed to have 

exactly 1% sulfur, although in practice the actual sulfur content is likely to be lower. 

The key assumption in Table VI-2 is the cost differential between the current residual 

fuel oil and the cost of a lower sulfur fuel, which is estimated here as 0.255 $/gallon, based on 

the following analysis. Removing sulfur from the crude oil feedstock is a cost for the refinery, so 

a lower sulfur level usually means a higher cost. The Energy Information Agency (EIA) tracks 

the prices of refinery products over time. The 5 year average cost differential between residual 

fuel oil with a sulfur content greater and 1% and residual fuel oil with a sulfur content less than 

1% is 0.184 $/gal (2005-2010). The ten year average is 0.165 $/gal (2000-2010)48. But the EIA 

data is for the continental United States. However, the EIA data is for the continental United 

States and does not reflect various factors that influence fuel oil supply and costs in Hawaii. In 

order to obtain a more accurate estimate of the cost differential for Hawaii, EPA looked at the 

long-term average costs of residual fuel oil delivered to Oahu, Maui and the Big Island. 

All of the state‟s fuel is received or refined on Oahu and is shipped by barge to the 

neighboring islands. Because of the additional distance, fuel oil delivered to the Big Island is 

roughly 0.050 to 0.060 $/gal more expensive than fuel delivered to Maui. The more difficult 

question is how to estimate the cost differential due to the lower sulfur. EPA looked at the cost 

differential between the lower sulfur fuel burned on Oahu and the 2% sulfur fuel burned on 

Maui. The power plants on Oahu burn oil that is no more than 0.5 sulfur by weight. This is 

waxier oil that can‟t be burned in power plants on Maui or the Big Island without some 

modification of the storage and shipping infrastructure. Nevertheless, it is reasonable to assume 

that 1% sulfur fuel oil would cost no more than the 0.5% sulfur fuel burned on Oahu. So, using 

the Oahu product as an upper limit, EPA assumes that 1% sulfur fuel oil will on average cost 

 

48 http://www.eia.gov/dnav/pet/PET_PRI_RESID_DCU_NUS_M.htm
53

0.190 $/gal more than the 2% sulfur fuel oil currently being burned. This is the six-year (2006-

2011) average cost differential between 0.5% fuel oil used on Oahu and the 2% fuel oil used on 

Maui and the Big Island. This 0.190 $/gal estimate is consistent with and a little higher than the 

EIA data. Since Hill is on the Big Island, we needed to account for transportation costs. So, we 

added 0.065 $/gal to the estimate for a total of 0.255 $/gal. The 0.065 $/gal estimate is derived 

from the six-year (2006-2011) cost differential between residual fuel oil delivered to Maui and 

the same oil delivered to the Big Island49. EPA considers this estimate to be reasonable and 

conservative. 

Figure VI-1 Fuel Oil Costs Over Time

Figure VI-1 shows the variation in costs between low sulfur fuel oil delivered to Oahu (LSFO) 

and the 2% sulfur residual fuel oil (also known as number 6 fuel oil or No. 6) delivered to Maui 

and the Big Island (BI). The costs are in $/barrel. There are 42 gallons in a barrel of oil.

With these assumptions, EPA estimates an annual increase in fuel costs of over $4.8 

million/year. EPA contracted with energy economics consulting firm Energy Strategies to 

estimate the impact of these increased fuel costs on electric rates. Based on their analysis50, these 

increased costs would translate into a roughly 1% increase in retail electric rates on the Big 

Island. The benefit of this change would be a reduction in SO2 emissions of 851 tons per year. 

The next factors to consider are (2) the energy and non-air quality environmental impacts 

of compliance; (3) any existing pollution control technology in use at the source; and (4) the 

remaining useful life of the source. There are no existing pollution controls at the site for SO2. 

We have considered factors (2) and (4) in the context of the Hawaii Clean Energy Initiative, 

which sets the goal of 70% clean energy by 2030. The Initiative includes the 2009 Clean Energy 

Omnibus Bill (ACT 155 (09), HB 1464, signed June 25, 2009). This statute calls for 30% 

 

49 EPA Hawaii Residual Fuel Oil Summary Spreadsheet

50 Fuel Cost Screening Tool (r1 4-18-12), Energy Strategies Incorporated, April 18, 2012

$50.00 

$60.00 

$70.00 

$80.00 

$90.00 

$100.00 

$110.00 

$120.00 

$130.00 

$140.00 

Jul-09

Aug-09

Sep-09

Oct-09

Nov-09

Dec-09

Jan-10

Feb-10

Mar-10

Apr-10

May-10

Jun-10

Jul-10

Aug-10

Sep-10

Oct-10

Nov-10

Dec-10

Jan-11

Feb-11

Mar-11

Apr-11

May-11

Jun-11

Oahu - LSFO Maui - No.6 BI No.6
54

reduction in energy use via efficiency and increases the renewable portfolio standard to 40% by 

2030. EPA contracted with UNC and ICF to project the 2018 emissions of power plants 

considering the requirements of the Clean Energy Omnibus Bill. These projections are compared 

to the current 2018 projections based on the most recent Integrated Resource Plan (IRP) for 

Hawaii electric utilities51. This IRP predates the 2009 bill and so does not account for its 

requirements. Table V-5 compares the baseline emission projections for 2018, derived from the 

current IRP and the projections that take into account the requirements of the Clean Energy Bill.

Table IV-3: Range of 2018 Emissions Projections for Hill [tons per year]

2018 SO2

Emissions

2018 SO2

Emissions

IRP Clean Energy Bill

Kanoelehua Hill Generating Station 3,264 765

The projections based on the goals of the Clean Energy Bill assume that the energy 

conservation and renewable energy goals will be met in a more or less even fashion year to year. 

So, by 2018, most of these projects will be in place. This is a fairly optimistic scenario, but it 

gives some insight into the impact of the Clean Energy Bill on these plants. By 2018 Hill is 

projected to be operating at a significantly lower capacity factor and/or burning biofuels with 

much less sulfur. 

The final factor to consider is the visibility benefits of controls. Trinity modeled the 

lower emission rates associated with lower sulfur fuels and estimated the following visibility 

benefits. The delta deciview [∆/dv] dropped from 1.56 for baseline conditions to 1.05 when 

burning the 1% sulfur fuel, which represents approximately 0.5 dv benefit. 

Taking into consideration all of these factors, we propose to determine that BART for 

Hill is no additional controls. In particular, although we consider 0.5 dv to be a significant 

improvement in visibility, we do not believe it justifies the imposition of a control with a cost 

effectiveness of approximately $5,600/ton in this case. We are particularly concerned about 

unduly increasing electricity rates in Hawaii, given that these rates are already three times the 

national average according to the Energy Information Agency.52 Therefore, we propose to 

determine that no BART controls be required for Hill.

VII. Reasonable Progress

VII.A. Unique Regional Haze Planning Challenge for Hawaii

In determining if reasonable progress is being made, states, or EPA if implementing a 

FIP, are required to consider the following factors established in section 169A of the CAA and in 

our Regional Haze Rule at 40 CFR 51.308(d)(1)(i)(A): (1) the costs of compliance; (2) the time 

necessary for compliance; (3) the energy and non-air quality environmental impacts of 

compliance; and (4) the remaining useful life of any potentially affected sources (“the four RP 

 

51 Email from Juanita Haydel, ICF Corporation to Greg Nudd, U.S. EPA Region 9, April 4, 2012, with spreadsheet 

titled: “Hawaii Emissions Values_Revised_040412_FTC.xlsx”

52 http://205.254.135.7/state/state-energy-rankings.cfm?keyid=18&orderid=1
55

factors”). Once these factors have been considered, the typical method for determining if a state 

is making reasonable progress is to use meteorological and air quality computer models to 

predict the visibility at Class I areas for the end of the planning period (2018). Those modeling 

results are then assessed to ensure that visibility is not degrading on the best days and that it is 

improving on the worst days at a reasonable rate, taking into consideration the relevant statutory 

factors, as well as the base period visibility conditions and the goal of zero anthropogenic 

visibility impairment by 2064. 

In the case of Hawaii, though, a different method of determining reasonable progress is 

required. As explained in sections II.A., II.B, and III.B., the dominant cause of visibility 

impairment at Hawaii‟s Class I areas is sulfate compounds and over 96% of the sulfate emissions 

in Hawaii are from the volcano [see section IV.A. Statewide Emissions Inventory]. However, 

because the volcanic eruptions vary greatly from year to year with no discernible pattern, it is

impossible to predict future volcanic emissions. The emissions vary by hundreds of thousands of 

tons per year. As a result, there is little value in attempting to model visibility at the Class I areas 

in 2018. 

VII.B. Identification of Pollutants for Reasonable Progress

EPA has evaluated the six particulate pollutants (ammonium sulfate, ammonium nitrate, 

organic carbon (OC), elemental carbon (EC), fine soil and coarse mass (CM)) that contribute to 

visibility impairment at Hawaii‟s two mandatory Class I federal areas. Sulfate is the primary 

cause of visibility impairment at each of Hawaii‟s Class I Areas, and EPA has determined that 

the first Regional Haze Plan RP evaluation should focus on primarily on significant sources of 

SO2 (sulfate precursor). NOx (nitrate precursor) is a secondary concern, as it contributes to 9% 

of the visibility degradation on the 20% worst days at Haleakala.

Coarse mass contributes to 9% of the visibility degradation at the Haleakala, and is also 

of concern. However, the sources of coarse mass (CM) are uncertain because of emission 

inventory limitations associated with natural sources (predominantly wildfires) and uncertainty 

of fugitive (windblown) emissions. Because of the difficulty in attributing the sources of 

visibility impairment for this pollutant, EPA has determined that it is not reasonable in this 

planning period to recommend emission control measures for coarse mass. Coarse mass 

contribution to visibility impairment, emissions sources, and potential control measures should 

be addressed in future Regional Haze plan updates.

Because fine soil appears to be primarily attributable to international transport, EPA has 

determined that it is not reasonable in this planning period to recommend emission control 

measures for fine soil. Although organic and elemental carbon contribute to base year visibility 

impairment, recent monitoring at the Haleakala Crater (HACR1) monitoring site and the Hawaii 

Volcanoes (HAVO1) show low contributions to visibility impairment from organic and 

elemental carbon. 

VII.C. Determining Reasonable Progress Through Island-Specific Emissions Inventories

Due to the absence of modeling to project visibility at Hawaii‟s Class I areas in 2018, 

EPA is focusing its reasonable progress analysis on reducing anthropogenic visibility impairing 
56

pollution. The EPA is focusing on the broader goals of the Regional Haze Program. Specifically, 

we are focusing on the reduction of anthropogenic visibility impairing pollution. The discussion 

earlier in this document determined that the key anthropogenic pollutants of concern are SO2 and 

NOx, especially SO2. So, we will look at trends in the emission of anthropogenic SO2 and NOx in 

order to judge if reasonable progress is being achieved.

Rather than use a full statewide inventory to judge reasonable progress, it makes sense to 

focus on the inventories for the islands where the Class I areas are located: Maui and the island 

of Hawaii. Population, economic activity and therefore anthropogenic emissions in the state of 

Hawaii are concentrated on the island of Oahu. But, as explained below, our analysis indicates 

that those emissions do not significantly impair visibility at the Class I areas. Prevailing winds at 

the Honolulu Airport on Oahu are from the east-north-east53. The prevailing winds on Maui are 

from the northeast54. The Class I areas are south and west of Oahu. Therefore, these trade winds 

tend to transport pollution from Oahu away from the Class I areas. 

Air quality modeling of sources on Oahu support this determination. In order to identify 

point sources that may be candidates for additional air pollution control under this Regional Haze 

Plan, the Hawaii Department of Health (DOH) contracted with Alpine Geophysics to conduct air 

quality modeling of large pollution sources statewide. This modeling is described more 

completely elsewhere in this document (see section VI.C.) This modeling was designed to 

estimate the visibility impact of currently operating individual sources of pollution on the Class I 

areas in the state. Several of the highest emitting sources on Oahu are shown in Table VII-1, 

below along with their estimated visibility impacts on the Class I areas. The visibility impacts are 

expressed in terms of the change in deciviews or ∆ deciview [∆/dv].

Table VII-1: Modeled Visibility Impacts of Major Sources on Oahu

Emissions [tpy] Impact [∆/dv]

Source Nox PM-10 SO2 VOC HALE HAVO

HECO - Kahe Power Plant 4,848 694 6,684 83 0.221 0.132

HECO - Waiau Power Plant 2,597 310 2,970 37 0.083 0.038

Chevron Hawaii Refinery 751 133 2,128 1,106 0.021 0.016

Tesoro - Campbell Industrial Park & Barbers Point 

Marine Loading

1,204 88 816 543 0.025 0.017

The Kahe Power Plant is a very highly polluting source with combined NOx and SO2

emissions that exceed 11,500 tons per year. This power plant is 197 kilometers (about 122 miles) 

from the Haleakala(HALE) monitor. But, even this very large source has a relatively small 

visibility impact on Haleakela (0.221 deciview change). 

Given these modeling results and the prevailing winds in Oahu and Maui for this 

planning period, we will focus our reasonable progress analysis on the islands that contain the 

Class I areas. The tables below show the emission inventories for the islands of Maui and 

Hawaii. These tables are based on methods and assumptions described in the Emissions 

Inventory chapter of this TSD.

Table VII-2 Maui Anthropogenic Emissions Inventory

 

53 See prevailing winds data from the Western Regional Climate Center 

(http://www.wrcc.dri.edu/htmlfiles/westwinddir.html#HAWAII)

54 Ibid.
57

2005 Inventory 2018 Inventory

Source Category NOx SO2 NOx SO2

Point 4,492 4,559 4,597 4,625 

Nonpoint 462 481 548 571 

On Road Mobile 2,957 47 758 10 

Non-Road Mobile 496 57 305 2 

Aircraft 310 27 376 33 

Agricultural Burning 298 132 298 132 

Wildfires 52 14 52 14 

in/near port Marine 699 569 836 32 

Total 9,765 5,887 7,770 5,420 

Table VII-2.1 Maui Point Source Emissions

2005 2018

NOx SO2 NOx SO2

MECO - Kahului Power Plant 536 3,198 542 3,233

Maalaea Generating Station 3,255 913 3,291 923

HC & S - Puunene Sugar Mill 617 424 760 469

Ameron Hawaii Camp 10 Quarry 4 0 4 0

Maui Pineapple Co. 80 24

Total 4,492 4,559 4,597 4,625

Table VII-3 Hawaii (Big Island) Anthropogenic Emissions Inventory

2005 Inventory 2018 Inventory

Source Category NOx SO2 NOx SO2

Point 1,036 4,551 1,736 5,266 

Nonpoint 1,849 808 1,882 872 

On Road Mobile 3,217 53 839 11 

Non-Road Mobile 784 95 428 1 

Aircraft 177 18 207 21 

Agricultural Burning 2 0 2 0 

Wildfires 1,712 469 1,712 469 

in/near port Marine 537 418 546 20 

Total 9,314 6,412 7,352 6,661 

Table VII-3.1 Hawaii (Big Island) Point Source Emissions

2005 2018

NOx SO2 NOx SO2

HELCO - Kanoelehua Hill Generating 

Station

514 2,822 595 3,264
58

HELCO - Puna Power Plant 241 1,345 279 1,556

HELCO - Keahole Power Plant 154 157 178 182

HELCO - Shipman Power Plant 38 222 28 166

Pepeekeo Power Plant/9-16-10 Hu Honua 

Bioenergy

420 78

Tradewinds Forest Products, LLC 133 15

HELCO - Waimea Power Plant 89 5 103 5

Total 1,036 4,551 1,736 5,266

VII.C.1. Four Factor Analysis for NOx sources on Maui and the Big Island

On Maui, NOx emissions are being reduced by almost 2,000 tpy between 2018 and 2005, 

even while assuming fairly robust economic growth. This is over a 20% reduction in emissions 

of a pollutant that is of secondary concern for this planning period. In general, EPA finds this to 

be a reasonable amount of NOx reductions, considering the small part the pollutant plays in 

visibility impairment in Hawaii. 

Point sources of NOx in Hawaii are predominantly electric utility units. Emissions from 

the Camp 10 quarry are quite small and not expected to impact visibility at the Class I areas. The 

Maui Pineapple plant closed in 2008. The HC&S Puunene Sugar Mill on Maui was modeled by 

Alpine Geophysics and the modeling indicated that the plant would have no more than a 0.286 

deciview impact at the nearest Class I area, Haleakela. Any additional controls are not likely to 

be cost effective, given the small impact of this source. The other sources are electric utility 

sources. Considering the costs of compliance and the 20% reduction in emissions from existing 

regulations, and the small contribution of nitrates to visibility impairment, the EPA does not 

consider it reasonable to require additional NOx controls for point sources in this planning 

period. 

Mobile sources of NOx (on road, non-road, aircraft and marine) constitute the largest 

fraction of base year emissions on these islands (48%). The NOx emissions from these categories 

are projected to drop by over 7,100 tpy between 2005 and 2018. These decreases are largely 

attributable to a dramatic drop in emissions from on-road mobile sources, resulting from the 

replacement of older, higher emitting vehicles with new vehicles that must meet more stringent 

standards under the Clean Air Act. In addition to these requirements for on-road source, EPA 

regulations also require newer non-road and marine mobile sources to meet stricter control 

requirements. Collectively, these federal mobile source requirements will result in substantial 

NOx reductions over the course of the first planning period.

Given this context and taking into consideration the four reasonable progress factors, we 

believe that requiring additional NOx controls on mobile sources would not be reasonable at this 

time. Therefore, we are not proposing any additional NOx controls for mobile sources for this 

implementation period. 
59

Agricultural burning is a notable NOx source on Maui. EPA has evaluated the 

monitoring data for the Class I areas and determined that there is no evidence that agricultural 

burning is significantly affecting visibility at the Class I areas. See TSD Sections II.A., II.B, and 

III.B. The current Hawaii DOH agricultural burning permitting process appears to be sufficient 

to prevent visibility impacts at the Class I areas.

Wildfires have been included in the anthropogenic emissions inventory because the 

Hawaii DOH and EPA have not been able to determine if the fires had natural causes or not. 

Nevertheless, it would not be helpful to introduce further restrictions on wildfires, because these 

are by definition, not intentional. So, regulations restricting them would not have any appreciable 

effect.

VII.C.2 Four Factor Analysis for SO2 Emissions on Maui

Our analysis shows that current controls will result in net reductions of anthropogenic 

emissions of SO2 on Maui during this first planning period. So it is reasonable to assume that the 

visibility at Haleakela on the best days is not getting worse. Similarly, with this drop in 

emissions, it is reasonable to assume that the worst visibility days will be getting better.

VII.C.2.1 Mobile Source SO2 Emissions on Maui

Mobile source SO2 emissions on Maui (on road, non-road, aircraft and marine) are 

dropping 89% under current regulations, driven primarily by reductions in marine emissions due 

to the ECA. This control measure is in addition to the benefits of fleet turnover as described 

above in the discussion NOx. Given the existing benefits from the ECA (see section IV.A.) and 

the fleet turnover benefits that take into account the four factors, EPA finds that no additional 

SO2 reductions from mobile sources on Maui are needed in order to show reasonable progress. 

VII.C.2.2 Point Source SO2 Emissions on Maui

Point Sources comprise 77% of the SO2 emissions on Maui and are expected to increase 

slightly by 2018. However, this increase is more than offset by the reduction in SO2 from mobile 

source emissions. The principal point sources on Maui are the Kahului Power Plant and the 

Maalaea Power Plant, neither of which are BART-eligible. Maalea is downwind of the Class I 

area and its SO2 emissions are not expected to impact visibility at Haleakala. Prevailing winds 

should also transport emissions from Kahului away from Haleakala. Alpine Geophysics 

estimated the visibility impact of Kahului plant using the CalPUFF computer model. The result 

was an estimated change in visibility of 0.667 deciviews at Haleakala. The modeling assumed 

the plant would be running at its maximum 24-hr capacity and burning the highest sulfur content 

fuel that it is authorized to burn (2% sulfur by weight). While these are very conservative 

assumptions that are unlikely to occur during normal operations, we believe this level of 

modeled impact is sufficient to warrant further scrutiny of this source under the four reasonable 

progress factors. 

The first factor to consider in reasonable progress is costs of compliance. The HECO (the 

electric utility) performed a detailed analysis of the cost of reducing SO2 emissions at the 
60

Kanoelehua Hill Generating Station as part of the BART analysis for that source55. EPA 

reviewed and largely concurred with the results of that analysis. With Hill, the most costeffective control measure is to reduce the amount of sulfur in the fuel. This is also true for 

Kahului. However, even that method is expensive. The lowest cost method for reducing SO2

emissions at these plants is to switch to a fuel with no more than 1% sulfur by weight. To 

estimate the total cost of the converting this plant to 1% fuel oil and estimate the impact of those 

costs on electric rates, EPA developed a base case scenario derived from 2009 operating 

conditions56. This scenario is summarized in Table VII-4 below. This analysis indicates that the 

cost effectiveness of this control is approximately $4,200 per ton of SO2 reduced. 

Table VII-4: Costs and Benefits from Switching to 1% Sulfur Fuel Oil

Kahului

Baseline Weight % S 1.57

Baseline Fuel Consumption [gal/yr] 19,790,111

Baseline Emissions [tons SO2/yr] 2,489

New Fuel Weight % S 1.00

Cost Differential [$/gal] 0.190

Controlled Emissions [tons SO2/yr] 1,586

Annual Costs [$/yr] $3,760,121

Annual Emission Reductions [tons SO2/yr] 904

Cost Efficiency [$/ton SO2 reduced] $4,160

In Table VII-4, the baseline sulfur content is the average of two years of fuel oil analysis 

conducted by the electric utility for fuel they have received at Maui and the Big Island. This is 

more representative than taking the actual fuel sulfur content for the year 2009. The fuel is 

guaranteed by the suppliers to be less than 2% sulfur, but the actual sulfur content varies 

depending on feedstock. The fuel consumption numbers are from emissions inventory reports 

submitted by the utility to the Hawaii Dept. of Health. The SO2 emissions were calculated based 

on stack testing conducted at Kanoelehua Hill and assuming that Kahului also had a more than 

99% conversion rate of fuel sulfur to SO2. The new fuel is conservatively assumed to have 

exactly 1% sulfur, although in practice the actual sulfur content is likely to be lower. In Table 

VII-4, we assume that the cost differential between the current fuel and the 1% sulfur fuel to be 

0.190 $/gal based on an analysis of prices historically paid for lower sulfur fuel in Hawaii, as 

described in the BART analysis for Hill. The price is lower than for Hill, because the fuel is 

delivered to Maui, not the Big Island.

With these assumptions, EPA estimates an increase in fuel costs of over $3.7 

million/year. EPA contracted with energy economics consulting firm Energy Strategies to 

estimate the impact of these increased fuel costs on electric rates. Based on their analysis57, these 

increased costs would translate into a roughly 1% increase in retail electric rates on Maui. The 

benefit of this change would be a reduction in SO2 emissions of 900 tons per year.

 

55 BART Five-Factor Analysis Prepared for Hawaiian Electric Light Company, October 2010, Trinity Consultants.

56 2009 was selected because it was consistent with the year used in the BART analysis for Hill. It is also a year 

where the actual capacity factors for the electric plants on the Big Island were comparable to the 4-year average.

57 Fuel Cost Screening Tool (r1 4-18-12), Energy Strategies Incorporated, April 18, 2012
61

The second factor to consider is the time necessary for compliance. The switch to a lower 

sulfur version of the residual fuel oil currently being burned does not require any capital 

investment or construction, but it does require time to get new fuel contracts into place with the 

new sulfur limits. It may take time for the fuel suppliers to secure the new fuel and it will take 

time for the current fuel inventory to be consumed. 

The third and fourth factors to consider are the energy and non-air quality impacts of 

control measures and the remaining useful life of the source. EPA considered these factors in the 

context of the Hawaii Clean Energy Initiative that sets the goal of 70% clean energy by 2030. 

The Initiative includes the 2009 Clean Energy Omnibus Bill (ACT 155 (09), HB 1464, signed 

June 25, 2009). This statute calls for 30% reduction in energy use via efficiency and increases 

the renewable portfolio standard to 40% by 2030. EPA contracted with UNC and ICF to project 

the 2018 emissions of power plants considering the requirements of the Clean Energy Omnibus 

Bill58. These projections are compared to the current 2018 projections based on the most recent 

Integrated Resource Plan (IRP) for Hawaii electric utilities. This IRP predates the 2009 bill and 

so does not account its requirements. Table VII-5 compares the baseline emission projections for 

2018, derived from the current IRP and the projections that take into account the goals of the 

Clean Energy Bill. 

Table VII-5: Range of 2018 Emissions Projections for Key Power Plants on the Maui [tons 

per year]

2018 SO2

Emissions

2018 SO2

Emissions

IRP Clean Energy Bill

Kahului Power Plant 2,822 0

Maalaea Generating Station 923 591

The projections based on the goals of the Clean Energy Bill assume that the energy 

conservation and renewable energy goals will be met in a more or less even fashion year to year. 

So, by 2018, most of these projects will be in place. Under this scenario, Kahului will cease 

operations by 2018 and Maalaea will operate at a significantly lower capacity factor and/or burn 

biofuels that contain much less sulfur than their current fuel. 

VII.C.2.3 Conclusion of Reasonable Progress Analysis for SO2 Emissions on Maui

Based on the foregoing analysis for the four RP factors, we propose to determine that it is 

not reasonable to require additional SO2 controls for point sources on Maui in this planning 

period. In addition, as mentioned above, electric utility rates in Hawaii are over three times the 

national average. Even in the absence of the Hawaii Clean Energy Bill, emissions on Maui are 

projected to decrease during this planning period. Therefore, based on our consideration of the 

four RP factors, EPA proposes to determine that this level of emissions reduction is reasonable 

for this planning period.

 

58 Email from Juanita Haydel, ICF Corporation to Greg Nudd, U.S. EPA Region 9, April 4, 2012, with spreadsheet 

titled: “Hawaii Emissions Values_Revised_040412_FTC.xlsx”
62

VII.C.3 Four Factor Analysis for SO2 emissions on the Big Island (Hawaii)

Unlike on Maui, EPA is projecting that without additional controls SO2 emissions on the 

Big Island will increase between 2005 and 2018. As noted above, SO2 is the key anthropogenic 

visibility-impairing pollutant in Hawaii. Therefore, we propose to determine that additional SO2

control measures are needed on the Big Island in order to ensure reasonable progress toward the 

national goal of no anthropogenic visibility impairment. 

VII.C.3.1 Mobile Source SO2 Emissions on the Big Island (Hawaii)

Mobile source emissions of SO2 on the Big Island are dropping 91% under current 

regulations, driven primarily by reductions in marine emissions due to the ECA. This control 

measure is in addition to the benefits of fleet turnover as described above in the discussion NOx. 

Given the existing benefits from the ECA and the fleet turnover benefits and taking into account 

the four reasonable progress factors, EPA proposes to determine that no additional SO2

reductions from mobile sources on the Big Island are needed in order to show reasonable 

progress. 

VII.C.3.2 Point Source SO2 Emissions on the Big Island (Hawaii)

Point sources comprise roughly 71% of the anthropogenic SO2 emissions on the Big 

Island. All of these emissions come from electric power plants. Therefore, all of these power 

plants were considered for additional controls. Because of their relatively low emission rates and 

distance from the Class I areas, EPA eliminated the Keohole and Waimea Power Plants. Due to 

their emission rates and positions close to and upwind of Hawaii Volcanoes National Park, Hill, 

Shipman and Puna are the focus of the review. Alpine Geophysics estimated the visibility impact 

of these plants using the CalPUFF computer model. The results are summarized below:

Table VII-6: Modeled Visibility Impacts of Key Power Plants on Hawaii

Visibility Impact 

[∆/dv]

HAVO HALE

HELCO - Kanoelehua Hill Generating Station 2.334 0.808

HELCO - Puna Power Plant 1.594 0.358

HELCO - Shipman Power Plant 0.777 0.321

These plants were also modeled with the same conservative assumptions as Kahului. The 

results for Hill and Puna indicate that these plants may be causing visibility impairment at 

Hawaii Volcanoes. In addition, the results indicate that Hill may be contributing to impairment at 

Haleakala and Shipman may be contributing to visibility impairment at Hawaii Volcanoes. 

The first factor to consider in reasonable progress is the costs of compliance. The HECO 

(the electric utility) performed a detailed analysis of the cost of reducing SO2 emissions at Hill as 

part of the BART analysis for that source59. EPA reviewed and largely concurred with the results 

of that analysis. As described previously, the most cost-effective control measure is to reduce the 

amount of sulfur in the fuel. This is also true for Shipman and Puna. Table V-7 provides the full 

 

59 BART Five-Factor Analysis Prepared for Hawaiian Electric Light Company, October 2010, Trinity Consultants
63

cost/benefit calculation for the Big Island sources. Based on this analysis, EPA estimates that the 

cost effectiveness of this control is approximately $5,500 per ton of SO2 reduced for sources on 

the Big Island. 

Table V-7: Costs and Benefits from Switching to 1% Sulfur Fuel Oil

Hill Shipman Puna

Baseline Weight % S 1.57 1.57 1.57

Baseline Fuel Consumption [gal/yr] 18,650,604 2,241,876 9,930,648 

Baseline Emissions [tons SO2/yr] 2,344 282 1,249 

New Fuel Weight % S 1.00 1.00 1.00

Cost Differential [$/gal] 0.255 0.255 0.255

Controlled Emissions [tons SO2/yr] 1493 180 796

Annual Costs [$/yr] $4,755,904 $571,678 $2,532,315 

Annual Emission Reductions [tons 

SO2/yr] 851 102 454

Cost Efficiency [$/ton SO2 reduced] $5,587 $5,583 $5,583 

Total Annual Cost $7,859,89

Total Annual Emissions Reduction 1,407

In Table V-7, most of the assumptions are the same as in Table V-4, but the cost 

differential is a bit higher due to the extra transport costs. We added 0.065 $/gal to the estimate 

for a total of 0.255 $/gal. The 0.065 $/gal estimate is derived from the six-year (2006-2011) cost 

differential between residual fuel oil delivered to Maui and the same oil delivered to the Big 

Island. 

With these assumptions, EPA estimates an annual increase in fuel costs of over $7.9 

million/year. EPA contracted with energy economics consulting firm Energy Strategies to 

estimate the impact of these increased fuel costs on electric rates. Based on their analysis60, these 

increased costs would translate into a 2% increase in retail electric rates on the Big Island. The 

benefit of this change would be a reduction in SO2 emissions of at least 1,400 tons per year. 

The second factor to consider is the time necessary for compliance. The considerations 

here are the same as for Maui. 

The third and fourth factors to consider are the energy and non-air quality impacts of 

control measures and the remaining useful life of the source. In order to fully consider the energy 

and non-air quality impacts of control measures and the remaining useful life of the source, EPA 

is taking into account the anticipated results of the Clean Energy Bill described above. Table 

VII-8 compares the baseline emission projections for 2018 and the projections that take into 

account the goals of the Clean Energy Bill. 

 

60 Fuel Cost Screening Tool (r1 4-18-12), Energy Strategies Incorporated, April 18, 2012
64

Table VII-8: Range of 2018 Emissions Projections for Key Power Plants on the Big Island 

[tons per year]

2018 SO2

Emissions

2018 SO2

Emissions

IRP Clean Energy Bill

HELCO - Kanoelehua Hill Generating Station 3,264 765

HELCO - Puna Power Plant 1,566 365

HELCO - Shipman Power Plant 166 0

Again, these are optimistic assumptions, but they are useful. Under this scenario, 

Shipman is projected to cease operations by 2018 and Hill and Puna are projected to be operating 

at a significantly lower capacity factor and/or burning biofuels with much lower sulfur content 

than their current fuel. 

VII.C.3.3 Conclusion of Reasonable Progress Analysis for SO2 Emissions on the Big 

Island (Hawaii)

Some additional, federally enforceable SO2 reductions are needed on the Big Island to 

ensure reasonable progress. Based on the above analysis of the four reasonable progress factors, 

EPA believes that any control measure for SO2 should be structured so that it could be achieved 

through increased energy efficiency and increased reliance on renewable energy. Therefore, EPA 

is proposing to cap total emissions at the fuel oil-fired boilers at Hill, Shipman and Puna at 3,500 

tons per year, beginning in January 1, 2018. This is a reduction of 1,400 tons per year from the 

baseline estimate of emissions in 2018. If HECO is on track with implementing the Hawaii Clean 

Energy Bill, it should be able to meet this cap with no additional costs to the ratepayers. In the 

worst case scenario where the cap has to be met with a lower sulfur fuel oil, the utility should be 

able to meet this cap at a cost of roughly $7.9 million/year. EPA is structuring this control 

requirement to allow the utility to minimize costs. We are taking the other three factors into 

account by structuring the control requirement to be consistent with the State‟s goals for energy 

conservation and reduced dependence on fossil fuels.

VII.D. Benefits of the Emission Control Area on Emissions from In Transit Marine Vessels

In addition to reducing emissions from ships in and near ports, the ECA also significantly 

reduces emissions from ships traveling from port-to-port. As part of the evaluation of the 

benefits of the ECA, EPA asked UNC and ICF to calculate the 2005 and 2018 emissions from 

ships passing within 150 km of each of the Class I areas. Table V-9 summarizes these results. 

Since the 150 km includes some ports and those ports are already accounted for in the “In and 

Near Port Marine” category in the island-specific inventories, those emissions have been 

excluded from Table V-9.
65

Figure VII-2: Class I Visibility Areas

Table VII-9: Benefits of the ECA from In Transit Shipping within 150 km of the Class I 

Areas

2005 2018

Class I area NOx SO2 NOx SO2

Haleakala 2,740 2,610 3,419 141

Hawaii Volcanoes 566 530 447 15

EPA considered this as supplemental information when determining whether reasonable 

progress is being made with existing regulations. These emission reductions are expected to 

benefit visibility at the Class I areas, but it is difficult to determine by how much. For example, 

prevailing winds may transport the emissions away from the Class I areas. Specifically, much of 

the reductions for the Haleakala zone are from ships traveling to and from Oahu. These SO2

emission reductions from shipping in the vicinity of Maui support our decision not to require 

additional SO2 controls on that island in this planning period.

VII.E. Reasonable Progress Goals - 2018 Visibility Projections

There is no modeling available for this planning period that can reliably predict the 

change in visibility due to changes in the emission inventory for all sources (shipping, mobile 

sources, point sources, etc.).61 In absence of reliable visibility modeling for 2018, EPA is using

projections based on the island-specific inventories as a surrogate for judging whether reasonable 

progress is being made.

 

61 EPA believes that there is acceptable modeling for point sources for identifying BART Subject Sources and for 

the reasonable progress analysis. This modeling is discussed in Section IVC: Identify BART Subject Sources, 

above. 
66

In order to show the how the future emission changes may affect the aerosol levels in 

each of the parks, EPA estimated the effect that the changes in the island specific inventories for 

NOx and SO2 may have on the levels of nitrate and sulfate for each of the parks. EPA projected 

visibility conditions in 2018 using the following assumptions:

1. Sea salt, Soil, Coarse mass, Organic Carbon, and Elemental Carbon are assumed to be 

constant for the 20% best days and 20% worst days for both the Haleakala and Hawaii 

Volcanoes National Parks.

2. Nitrate is projected based on the change (in percentage) in the 2018 anthropogenic 

NOx inventory, compared to the 2005 inventory on each island. Nonanthropogenic 

emissions are assumed to be unchanged from the year 2005 inventory. Benefits from the

ECA in transit shipping emissions are not considered in the projections. 

3. Sulfate for Haleakala National Park. Sulfate visibility impact is projected based on the 

reductions in the 2018 anthropogenic SOx inventory, compared to the 2005 inventory on 

the island of Maui. The anthropogenic visibility impact is assumed to be 33% of the total 

for the Island of Maui on the 20% worst days, and 70% of the total on the 20% best days. 

The FIP option projection is based on a 1400 ton per year reduction of SO2 on the Island 

of Hawaii. Although this reduction would likely reduce sulfate at Haleakala National 

Park to some extent, this reduction is not reflected in the projections for 2018.

4. Sulfate at Hawaii Volcanoes National Park. Sulfate visibility impact is projected based 

on the percentage reductions in the 2018 anthropogenic SO2 inventory, compared to the 

2005 inventory on the island of Hawaii. The anthropogenic visibility impact is assumed 

to be 10% of the total on the Island of Hawaii on the 20% worst days and 70% of total on 

the 20% best days. The FIP option assumed a 1400 ton per year reduction of SO2 on the 

Island of Hawaii. This reduction is reflected in the 2018 projections for the FIP option.

The visibility projections for 2018, based on these assumptions, are shown below.

Visibility Projection Results

The projected visibility (light extinction (bext) in Mm-1) in the year 2018 is shown in the 

figures below. At Hawaii Volcanoes National Park, the projected visibility for the year 2018, 

without the emission reductions form the FIP, is slightly worse than the visibility for the year 

2005. With the emission reductions from the FIP, there is a slight improvement in visibility 

conditions in the year 2018 compared to the year 2005 for both the 20% best and 20% worst 

days. At Haleakala National Park, there is a slight improvement in visibility conditions in the 

year 2018 compared to the year 2005 for both the 20% best and 20% worst days. 

Figure VII-3: Projected Visibility (light extinction, bext Mm-1) for Hawaii Volcanoes 

National Park – 20% best days. 
67

Figure VII-3: Projected Visibility (light extinction, bext Mm-1) for Hawaii Volcanoes 

National Park – 20% worst days.

Figure VII-4: Projected Visibility (light extinction, bext Mm-1) for Hawaii Volcanoes 

National Park – 20% worst days – with revised axis to highlight changes from 2005 to 2018.

0

1

2

3

4

5

Hawaii Volcanos NP

Estimate of Light Extinction (bext)

Best 20% Days 

2005 2018 2018 

With FIP SeaSalt Extinction

CM Extinction

Soil Extinction

EC Extinction

OMC Extinction

Nitrate Extinction

Sulfate Extinction

0

20

40

60

80

100

Hawaii Volcanos NP

Estimate of Light Extinction(bext)

Worst 20%

2005 2018 2018 

With FIP SeaSalt Extinction

CM Extinction

Soil Extinction

EC Extinction

OMC Extinction

Nitrate Extinction

Sulfate Extinction
68

Figure VII-5: Projected Visibility (light extinction, bext Mm-1) for Haleakala National 

Park – 20% best days. 

80

85

90

95

Hawaii Volcanos NP 

Estimate of Light Extinction (bext)

Worst 20% Days

2005 2018 2018 

With FIP

SeaSalt Extinction

CM Extinction

Soil Extinction

EC Extinction

OMC Extinction

Nitrate Extinction

Sulfate Extinction

0

1

2

3

4

5

Haleakala NP

Estimate of Light Extinction (bext)

20% Best Days

2005 2018 2018 

With FIP

SeaSalt Extinction

CM Extinction

Soil Extinction

EC Extinction

OMC Extinction

Nitrate Extinction
69

Figure VII-6: Projected Visibility (light extinction, bext Mm-1) for Haleakala National 

Park – 20% worst days. 

VII.F. Visibility Improvement Compared to URP and Number of Years to Reach Natural 

Conditions

The amount of improvement needed (Δ deciview) to meet the Uniform Rate of Progress 

for 2018 for Haleakala National Park is 1.38 Δ deciview. Based on the projections of visibility, 

discussed above, the amount of improvement by 2018 would be 0.25 Δ deciview. This would 

result in a 2018 level of visibility of 13.0 deciview. The amount of improvement needed (Δ 

deciview) to meet the Uniform Rate of Progress for 2018 for Hawaii National Park is 2.73 Δ 

deciview. Based on the projections of visibility, discussed above, the amount of improvement by 

2018 would be 0.18 Δ deciview. This would result in a 2018 level of visibility of 18.7 deciview.

Based on the projections for 2018, discussed above, the URP will not be met at either 

National Park. Because RPGs are not achieving URP by 2018 and natural conditions by 2064, EPA 

is required by the Regional Haze rule to re-calculate and state the length of time necessary to achieve 

natural conditions, as shown below. EPA has calculated the number of years it would take to reach 

natural conditions, based on the rate of visibility improvement in this first planning period. 

Because the baseline conditions include the effect of the emissions from the volcano, the 

calculation of number of years to reach natural conditions may not represent a realistic scenario 

in this case. In addition, the visibility projections for 2018, discussed above, are based on very 

simplified assumptions. 

Instead of achieving natural conditions in 2064 (60 years) at the two Class I areas, the year 

and the length of time is re-calculated. The rate of improvement at Haleakala is approximately 

0.018 Δ deciview per year and the needed improvement to reach natural conditions is 5.9 

deciview. Therefore, at this rate of improvement natural conditions would be met in 

approximately 300 years. The rate of improvement at Hawaii Volcanoes National Park is 0.013 

0

10

20

30

40

Haleakala NP

Estimate of Light Extinction (bext)

20% Worst Days 

2005 2018 2018

With FIP 

SeaSalt Extinction

CM Extinction

Soil Extinction

EC Extinction

OMC Extinction

Nitrate Extinction
70

Δ deciview per year, and the needed improvement to reach natural conditions is 11.7 deciview. 

Therefore, at this rate of improvement natural conditions would be met in approximately 900 

years.

VIII. Monitoring Strategy

VIII.A. IMPROVE Monitoring Network

The Regional Haze SIP is to be accompanied by a strategy for monitoring regional haze 

visibility impairment. Specifically, the regional haze rule states at 40 CFR 51.308(d)(4): 

“(4) Monitoring strategy and other implementation plan requirements. The State must submit 

with the implementation plan a monitoring strategy for measuring, characterizing, and reporting 

of regional haze visibility impairment that is representative of all mandatory Class I Federal 

areas within the State. This monitoring strategy must be coordinated with the monitoring strategy 

required in §51.305 for reasonably attributable visibility impairment. Compliance with this 

requirement may be met through participation in the IMPROVE network. The implementation 

plan must also provide for the following: 

(i) The establishment of any additional monitoring sites or equipment needed to assess 

whether reasonable progress goals to address regional haze for all mandatory Class I 

Federal areas within the State are being achieved. 

(ii)-(vi) [Other implementation plan requirements that pertain to reporting and use 

of monitoring data and an emission inventory.]” 

Such monitoring is intended to provide the data needed to satisfy four objectives: 

1. Track the expected visibility improvements resulting from emissions reductions 

identified in this SIP. 

2. Better understand the atmospheric processes of importance to haze 

3. Identify chemical species in the ambient particulate matter and relate them to 

emissions from sources 

4. Evaluate regional air quality models for haze and construct relative response factors for 

using those models 

The primary monitoring network for regional haze, both nationwide and in Hawaii is the 

IMPROVE network. Given that IMPROVE monitoring data from 2001-2004 serves as the 

baseline for the regional haze program, the future regional haze monitoring strategy must 

necessarily be based on, or directly comparable to, IMPROVE. The IMPROVE measurements 
71

provide the only long-term record available for tracking visibility improvement or degradation 

and therefore EPA and Hawaii intend to rely on the IMPROVE network for complying with the 

regional haze monitoring requirement in the Regional Haze Rule. 

Data produced by the IMPROVE monitoring network will be used nearly continuously 

for preparing the 5-year progress reports and the 10-year SIP revisions, each of which relies on 

analysis of the preceding five years of data. Consequently, the monitoring data from the 

IMPROVE sites needs to be readily accessible and to be kept up to date. Presumably, IMPROVE 

will continue to process information from its own measurements at about the same pace and with 

the same attention to quality as it has shown in the recent past. The VIEWS web site has been 

maintained by the WRAP and the other Regional Planning Organizations to provide ready access 

to the IMPROVE data and data analysis tools.

There are two IMPROVE monitoring sites currently operating in or near the Haleakala 

National Park. The Haleakala (HALE1) IMPROVE monitoring site is located outside of the 

Haleakala National Park and the Haleakala Crater (HACR1) IMPROVE monitoring at the park‟s 

Western boundary. In this proposal, EPA is using monitoring data from the HALE1 monitoring 

site, as the HACR1 site was not yet in operation for the base year time period of 2000-2004.

Hawaii DOH has prepared two reports comparing data from the two sites. The 

conclusions from these reports are summarized section II.D. 2. Analysis of the Haleakala 

(HALE1) IMPROVE monitoring site and newer Haleakala Crater (HACR1) Monitoring site, 

below. The reports conclude that, based on the available data, the HACR1 IMPROVE 

monitoring site is more representative of visibility conditions within the Haleakala National Park

than the HALE1 IMPROVE monitoring site. 

VIII.B. Analysis of the Haleakala (HALE1) IMPROVE monitoring site and newer 

Haleakala Crater (HACR1) Monitoring site

Currently there are two IMPROVE monitoring sites operating in or near the Haleakala 

National Park. The Haleakala (HALE1) IMPROVE monitoring site is located outside of the 

Haleakala National Park near to the Maui Central Valley, at an elevation of 1153 meters. The 

HALE1 IMPROVE monitoring site began operation at end of 2000, and will close in May 2012. 

The Haleakala Crater (HACR1) IMPROVE monitoring site is at the park‟s Western boundary, at 

an elevation of 2158 meters. The HACR1 IMPROVE monitoring site began operation in 2007. 

In this proposal, EPA is using monitoring data from the HALE1 monitoring site, as the HACR1

site was not yet in operation for the base year time period of 2000-2004. 
72

Figure VIII-A: HALE and HACR Monitoring Locations

Hawaii DOH has prepared two reports comparing the two IMPROVE monitoring sites at 

Haleakala National Park62, including a detailed comparison of organic and elemental carbon data 

at the two sites.63 The reports find that the most significant difference between data measured at the 

two sites appears to be that HALE1 site has higher levels of organic and elemental carbon. The levels of 

the other species are generally lower at the HACR1 IMPROVE monitoring site than at the 

HALE1 monitoring site. The reports conclude that, based on the available data, the HACR1 

IMPROVE monitoring site is more representative of visibility conditions within the Haleakala 

National Park than the HALE1 IMPROVE monitoring site.

 

62 Comparison of Haleakala National Park HALE1 and HACR1 IMPROVE Monitoring Site 2007-2008 Data Sets, 

March 30, 2012, State of Hawaii, Department of Health, Clean Air Branch

63 Review of VIEWS2.0 2009-2010 Haleakala National Park Organic and Elemental Carbon Data, March 30, 2012, 

State of Hawaii, Department of Health, Clean Air Branch, and Comparison of Haleakala National Park HALE1 and 

HACR1 IMPROVE Monitoring Site 2007-2008 Data Sets, March 30, 2012, State of Hawaii, Department of 

Health, Clean Air Branch
73

Background Information on the Haleakala HALE1 IMPROVE Site64

HALE1 is located at an elevation of 1,158 m (3,799 ft) on the northward slope of 

Haleakala, ~5.7 km northwest of the Park Boundary. In general, aerosol measurements at 

HALE1 should be representative of ambient concentrations at National Park locations at the 

same elevation. However, the extreme climate variability over the range of elevation and 

exposure in the National Park compels caution in aerosol source attribution, especially with the 

sensitivity of particle size to moisture. Rainfall gradients in Hawaii are among the steepest in the 

world. The HALE1 site has exposure to northeasterly trade winds and may be more susceptible 

to rain caused by orographic lifting than are most National Park areas on the leeward side. Being 

at an elevation that is lower than the typical Marine Boundary Layer height most of the time, the 

HALE1 IMPROVE site may frequently be more representative of aerosols near the surface with 

different back trajectories than those of upper air aerosols transported from distant global scale 

source regions by upper level winds. 

Hawaii DOH Comparison of the Haleakala (HALE1) and Haleakala Crater (HACR1) 

IMPROVE Monitoring Sites -Summary

Hawaii DOH examined the 2007 - 2008 IMPROVE Data from the HACR1, HALE1, and 

HAVO1 monitoring sites using the EPA Positive Matrix Factorization (PMF) 3.0 code. The 

monitoring data from each site was analyzed separately. The focus of the Hawaii DOH document 

was the correspondence between monitored values at the HACR1 and HALE1 site. 

For the 7 visibility impacting mass concentrations (e.g. Ammonium Sulfate), the mean 

HALE1 values are typically about a factor of two larger than for HACR1. The exception to this 

is Fine Soil, which is approximately equal. This approximate equivalence in Fine Soil 

measurements appears consistent with long-range transport of dust (e.g. Asian Dust). The most 

significant difference between mean data measured at the two sites appears to be that HALE1 is 

impacted more by organic and elemental carbon associated with the Positive Matrix 

Factorization Smoke factor. This appears to be consistent with the relatively close proximity and 

location of the HALE1 monitor with respect to agricultural burning in the Central Valley of 

Maui. 

For HACR1, the largest organic carbon and elemental carbon IMPROVE measurements 

occurred in late January 2007. The character of the organic carbon and elemental carbon time 

histories for HACR1 appear significantly different than for those of HALE1. The HACR1 

measurements show a few very large mass concentrations in January and April 2007 followed by 

much lower values throughout the rest of 2007 and 2008. The HALE1 measurements, while 

showing variability, do not have such large outliers. While the average HACR1 mass 

concentrations for organic carbon and elemental carbon are approximately 50% of those for 

HALE1, the maximum HACR1 organic carbon mass concentration is approximately 600% the 

HALE1 value and the maximum HACR1 elemental carbon mass concentration is approximately 

300% the HALE1. 

The HACR1 IMPROVE measurements appear consistent with a 2291acre forest fire in 

Census Tract 303 that was also produced numerous MODIS detections. The second largest 

organic carbon and elemental carbon IMPROVE measurements at HACR1 occurred in early 

April 2007. These measurements appear consistent with a HC&S field burns that was also 

 

64 http://www.coha.dri.edu/web/state_analysis/Hawaii/HaleakalaNP_metdesc.html
74

produced 2 MODIS detections. While the details of why HACR1 was impacted significantly 

more than HALE1 for these two isolated cases during 2007 and 2008 would require a more 

extensive examination of the winds patterns for those days, the available data seems sufficient to 

conclude that these few measurements are not representative of HACR1 measurements. 

The remaining HACR1 and HALE1 monitoring measurements appear consistent with the 

general observation that HACR1 IMPROVE monitoring values are generally much lower than 

those at HALE1. The available data indicates that HACR1 IMPROVE monitoring data is more 

representative of visibility conditions within the Haleakala National Park.
75

Appendix A

Subject-to-Best Available Retrofit Technology (BART) Modeling for the State of Hawaii, 

Application of the CALPUFF Modeling System

Prepared for Hawaii State Department of Health, Environmental Management Division Clean 

Air Branch by Alpine Geophysics, LLC. March 3, 2010.
76

Appendix B

MM5 Application for 2005 Over the Hawaiian Islands, 

Prepared for Hawaii State Department of Health, Environmental Management Division, Clean 

Air Branch by Alpine Geophysics, LLC, October 31, 2008