FEDERAL IMPLEMENTATION PLAN 

FOR REGIONAL HAZE FOR THE 

UNITED STATES VIRGIN ISLANDS
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Table of Contents

1.0 Background and Overview .............................................................................................. 1-1

1.1 General Background of the Clean Air Act and the Federal Regional Haze Rule 1-1

1.2 Virgin Islands Class I Area .................................................................................. 1-2

2.0 Visibility Monitoring in the Virgin Islands ..................................................................... 2-3

2.1 IMPROVE Program Objectives........................................................................... 2-4

2.2 Monitoring Information and Strategy for the Virgin Islands National Park Class 

I Areas.................................................................................................................. 2-5

3.0 Assesment of Baseline and Natural Conditions............................................................... 3-7

3.1 Requirement, Data, and Methods Used ............................................................... 3-7

3.2 Virgin Island Baseline Visibility ......................................................................... 3-9

3.3 Natural Visibility ............................................................................................... 3-12

3.4 Contributions to Visibility Impairment in the Virgin Islands............................ 3-13

3.4.1 Area of Influence for the Virgin Islands National Park......................... 3-13

3.4.2 Pollutants Contributing to Visibility Impairment (2000-2004 Baseline 

Data)....................................................................................................... 3-18

3.5 Class I Areas Affected by Emissions from the Virgin Islands .......................... 3-20

4.0 Emissions Inventory and Modeling Analysis................................................................ 4-21

4.1 Sources of Emissions......................................................................................... 4-22

4.2 Modeled Baseline Emissions............................................................................. 4-23

4.2.1 HOVENSA St. Croix............................................................................. 4-23

4.2.2 St. John Point Sources - Generators....................................................... 4-24

4.2.3 St. John Marine Sources ........................................................................ 4-24

4.2.4 St. John Marine Sources with Emissions Reductions............................ 4-25

4.2.5 St. John Paved and Unpaved Road Fugitive Sources............................ 4-25

4.2.6 Aggregate St. John Burning................................................................... 4-25

4.2.7 St. John Residential Boilers................................................................... 4-25

4.2.8 St. John Miscellaneous Industrial Processes -- Construction ................ 4-26

4.2.9 St. John Motor Vehicle Emission Sources............................................. 4-26

4.2.10 Sample Puerto Rico Source ................................................................... 4-26

4.2.11 St. Thomas Sources................................................................................ 4-26

4.2.12 Other St. Croix Sources......................................................................... 4-27
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4.2.13 Aggregate British Virgin Islands Sources.............................................. 4-27

4.2.14 Simulated BVI Sources.......................................................................... 4-27

4.2.15 St. John Off-road Sources...................................................................... 4-28

4.3 Emissions Inventory Characteristics.................................................................. 4-28

4.3.1 Sulfur Dioxide (SO2).............................................................................. 4-28

4.3.2 Nitrogen Oxides (NOx) .......................................................................... 4-29

4.3.3 Particulate Matter (PM) ......................................................................... 4-30

4.4 Modeling Results............................................................................................... 4-32

4.5 Future Year Emission Control Inventories........................................................ 4-38

5.0 Evaluation of Reasonable Control Measures................................................................. 5-39

5.1.1 HOVENSA ............................................................................................ 5-39

5.1.2 St. John Point Sources -Generators........................................................ 5-39

5.1.3 St. John Marine Sources ........................................................................ 5-40

5.1.4 St. John Paved and Unpaved Road Fugitive Sources............................ 5-40

5.1.5 Aggregate St. John Burning................................................................... 5-40

5.1.6 St. John Residential Boilers................................................................... 5-41

5.1.7 St. John Miscellaneous Industrial Processes -- Construction ................ 5-41

5.1.8 St. John Motor Vehicle Emission Sources............................................. 5-41

5.1.9 Sample Puerto Rico Source ................................................................... 5-41

5.1.10 St. Thomas Sources................................................................................ 5-42

5.1.11 Other St. Croix Sources......................................................................... 5-42

5.1.12 Aggregate British Virgin Islands Combustion Sources......................... 5-42

5.1.13 Simulated BVI Sources.......................................................................... 5-42

5.1.14 St. John Off-Road Sources..................................................................... 5-43

6.0 Best Available Retrofit Technology .............................................................................. 6-43

6.1 The BART Rule ................................................................................................. 6-43

6.2 Potential BART Sources in the Virgin Islands.................................................. 6-44

6.2.1 Cap-Outs and Shutdowns....................................................................... 6-46

6.3 Sources Subject to BART.................................................................................. 6-46

6.4 Anticipated Visibility Improvement as a result of BART ................................. 6-47

6.4.1 Reasonably Attributable Visibility Impairment..................................... 6-48
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6.5 Determination of BART Requirements for Identified BART-Eligible Sources 

and Analysis of Best System for Each Source................................................... 6-48

6.5.1 Five Factor Analysis for Each BART Source........................................ 6-48

6.5.2 BART Determinations........................................................................... 6-62

6.5.3 BART Determinations including Other Types of Standards................. 6-63

6.6 Description of BART Alternative for Any Source ............................................ 6-63

6.7 Schedule for BART Implementation ................................................................. 6-64

7.0 Long-Term Strategy....................................................................................................... 7-64

7.1 Overview of the Long-Term Strategy Development Process............................ 7-65

7.2 Emission Reductions Due to Ongoing Air Pollution Programs......................... 7-65

7.2.1 Other Point Source Controls Expected by 2018 Due to Ongoing Air 

Pollution Control Programs................................................................... 7-66

7.2.2 Controls on Non-road Sources Expected by 2018 due to Ongoing Air 

Pollution Control Programs................................................................... 7-67

7.2.3 Mobile Source Controls Expected by 2018 due to Ongoing Air 

Pollution Control Programs................................................................... 7-67

7.2.4 Source Retirement and Replacement Schedules.................................... 7-68

7.3 Additional Reasonable Strategies...................................................................... 7-69

7.3.1 Analysis of the Four Statutory Factors .................................................. 7-69

7.3.2 Best Available Retrofit Technology ...................................................... 7-70

7.3.3 Changes to Emissions by 2018 .............................................................. 7-70

7.4 Additional Measures Considered....................................................................... 7-72

7.4.1 Caribbean Emissions Control Area........................................................ 7-72

7.4.2 Measures to Mitigate the Impacts of Construction Activities ............... 7-73

7.4.3 Agricultural and Forestry Smoke Management..................................... 7-73

7.5 Enforceability of Emission Limitations and Control Measures......................... 7-73

7.6 Consultation on the Long-Term Strategy .......................................................... 7-74

8.0 Reasonable Progress Goals............................................................................................ 8-74

8.1 Calculation of Uniform Rate of Progress........................................................... 8-75

8.2 Reasonable Progress Goals for the Class I Area in the State............................. 8-76

8.2.1 Consideration of Other Air Quality Requirements................................ 8-77

8.2.2 Additional Reasonable Controls within Virgin Islands......................... 8-78

8.2.3 Visibility Impacts of Additional Reasonable Controls.......................... 8-78
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8.2.4 Impacts of BART Controls in the Virgin Islands .................................. 8-78

8.2.5 Impacts of other Federal Controls in the Virgin Islands........................ 8-78

8.2.6 Results of Best and Final Modeling....................................................... 8-79

8.3 Demonstration that the Goals are based on Reasonable Controls ..................... 8-80

9.0 Consultation and Coordination ...................................................................................... 9-81

9.1 Regional Planning.............................................................................................. 9-81

9.2 State/Tribe and Federal Land Manager Coordination ....................................... 9-82

10.0 Comprehensive Periodic Implementation Plan Revisions........................................... 10-83

11.0 Commitment to Determine the Adequacy of the Existing Plan................................... 11-84

12.0 Summary Of The Federal Plan For Visibility In The National Park On St. John In The 

United States Virgin Islands........................................................................................ 12-85
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Tables

Table 3-1: IMPROVE Information for Virgin Islands and Selected Class I Areas 3-9

Table 3-2: Baseline Visibility for the Twenty Percent Worst Days and Twenty Percent Best Days 

for 5 Years (from 2000-2004) in Selected Class I Areas 3-11

Table 3-3: Summary of Baseline Visibility and Natural Conditions for the Twenty Percent Worst 

and Twenty Percent Best Visibility Days 3-13

Table 3-4: Summary of Trajectory Analyses for Top Four Days with the Highest Visibility

Impairment for Each Species 2000 - 2004 3-15

Table 4-1: Summary of Emissions St. John, Virgin Islands 4-22

Table 4-2: Results of Modeling the Virgin Islands Emission Inventory’s Impact at the 

IMPROVE site on St. John – All Emission Sources Combined. 4-35

Table 6-1: BART-eligible Sources in the Virgin Islands: 6-45

Table 6-2: Individual BART-Eligible Source Visibility Impacts on Virgin Islands Class I Area6-

48

Table 6-3: Sulfur Dioxide Emissions Evaluations for Potential BART Sources 6-50

Table 6-4: Nitrogen Oxides Emissions Evaluation for Potential BART Sources 6-51

Table 6-5: PM10 Emissions Evaluation for Potential BART Sources 6-52

Table 7-1: Emissions from Point, Area and Mobile Sources on St. John, Virgin Islands (SO2 tpy)

7-71

Table 7-2: Emissions from Point, Area and Mobile Sources on St. John, Virgin Islands (NOx 

tpy) 7-71

Table 7-3: Emissions from Point, Area and Mobile Sources on St. John, Virgin Islands 7-71

Table 7-4: Emissions from HOVENSA (tons per year) 7-72

Table 8-1: Uniform Rate of Progress Calculation 8-75

Table 12-1: Virgin Islands National Park Visibility Improvement Due to the FIP 12-85

Figures

Figure 2-1: The IMPROVE Monitoring Site at the Virgin Islands National Park ...................... 2-6

Figure 2-2: Virgin Islands National Park IMPROVE Monitor Location .................................... 2-6

Figure 3-1: Wind Rose for St Thomas, Virgin Islands, based on 2007 - 2010 National Weather 

Service Data ............................................................................................................................... 3-14

Figure 3-2: Back Trajectories of Day with Highest Impact on Visibility from Fine Soils – notice 

the orgin for two layers of wind in the Saharan Desert. ............................................................ 3-17

Figure 3-3: Above: Percent Contributions to Total Light Extinction from all particles, Baseline 

Conditions (2004 data used as an example) Below: List of particles contributing to reduced 

visibility, color-coded, with possible sources listed. ................................................................. 3-18
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Figure 3-4: 2004 Visibility for St. John IMPROVE Data – higher values are poorer visibility3-19

Figure 3-5: Contribution of particulate to reductions in visibility on the days with the best 

visibility. (2004 data.)................................................................................................................ 3-20

Figure 4-1: Modeled SO2 Emissions on St. John Compared to Surrounding Areas.................. 4-29

Figure 4-2: Modeled NOx Emissions on St. John Compared to Surrounding Areas................. 4-30

Figure 4-3: Modeled PM2.5 Emissions at St. John and Surrounding Areas ............................... 4-32

Figure 4-4: Yellow Diamonds are Locations of Receptors for Modeling ................................. 4-34

Figure 4-5: Modeled Impacts at IMPROVE Monitoring Site on St. John by Emissions Grouped 

Type of Emission ....................................................................................................................... 4-37

Figure 8-1: Projected Progress Goals and Modeled Progress at Virgin Islands National Park. 8-80

Appendices

Appendix A – Reserved for FLM Comments

Appendix B – Natural Background and Reasonable Progress Calculations

Appendix C1 – Preliminary Contractor Report on Air Modeling for the Virgin Islands Regional 

Haze Analysis

Appendix C2 – Draft Final Contractor Report on Air Modeling for the Virgin Islands Regional 

Haze Analysis

Appendix C3 - Final Contractor Report on Air Modeling for the Virgin Islands Regional Haze 

Analysis (Reserved)

Appendix D – BART Analysis

Appendix E – Contractor Report on St. John Emissions Inventory

Appendix F – Trajectory Analyses

Appendix G - December 20, 2006 Section 110 letter, Virgin Islands’ lack of contribution to 

transported pollutants
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1.0 BACKGROUND AND OVERVIEW

This document is a Federal plan that identifies human-caused interference with visibility

in the United States National Park on St. John in the Virgin Islands. It describes the progress 

toward the national goal of improving visibility on days with poor visibility and preventing good 

visibility days from becoming worse. The United States Environmental Protection Agency

(EPA) is working with the government of the Territory of the United States Virgin Islands to 

prepare this Federal Implementation Plan (FIP). This Plan will need to be revised and extended 

no later than 2018, and at any point this Federal Plan can become a State Implementation Plan of 

the Virgin Islands’ Government. 

1.1 General Background of the Clean Air Act and the Federal Regional Haze Rule

In amendments to the Clean Air Act (CAA) in 1977, Congress added Section 169 (42 

U.S.C. 7491) setting forth the following national visibility goal:

Congress hereby declares as a national goal the prevention of any future, and the 

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

which impairment results from man-made air pollution.

Mandatory Class I areas, as defined in the CAA, included the Virgin Islands National 

Park, which is the only Class I area in the Caribbean Islands. 

From 1977 to present, modest steps were taken to address the visibility problems in Class 

I areas. In 1980, the Environmental Protection Agency implemented rules affecting individual 

sources of pollution (45 FR 80084). If a plume from a source affected the visibility in a Class I 

area, emissions from that source would be reduced to improve the view. New sources had to 

assess their impact on visibility and visibility reduction was one of many factors that determined 

the level of control for new sources of air pollution.

Congress amended the CAA in 1990, adding Section 169B (42 U.S.C. 7492), authorizing 

further research and regular assessments of the improvements in visibility. In 1993, the National 

Academy of Sciences concluded that “current scientific knowledge is adequate and control 

technologies are available for taking regulatory action to improve and protect visibility.”

The CAA’s requirements for improving visibility by reducing human-caused emissions 

that can impair visibility of scenic views were the basis for the EPA’s Regional Haze Rule
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(RHR), which was adopted July 1, 1999, and went into effect on August 30, 1999. This rule 

seeks to address the combined visibility effects of various pollution sources over wide 

geographic regions. While better known for its establishing regional visibility organizations, this 

Rule also applies to regional sources of haze that affect the Class I area on St. John in the Virgin 

Islands.

After several legal challenges to the RHR, the EPA finalized the Regional Haze 

Regulations.

The EPA is working with the government of the Virgin Islands to prepare this regional 

haze FIP. In various other regions of the continental United States, states have joined to work 

together on developing the information needed to support their haze plans. Since the Virgin 

Islands are separated from the continental United States by over a thousand miles, this plan was 

developed without the assistance of the multi-state planning organizations that the continental 

states organized. The EPA supported the work of these multi-state planning organizations; 

because of the impact these states had on air quality in neighboring states, much work needed to 

be done with extensive inventories and modeling. The negative aspect of having little interaction 

with the continental states, from an air pollution point of view, was that the Virgin Islands was 

not able to leverage its resources by combining them with those from other states to help lay the 

groundwork for a State Implementation Plan (SIP) for haze in the Virgin Islands. Thus, the EPA 

is taking the lead, working with the Virgin Islands’ government, to prepare a FIP to address 

anthropogenic visibility impairment in the National Park on St. John. 

1.2 Virgin Islands Class I Area

The U.S. Virgin Islands contains one Class I area, the Virgin Islands National Park. The 

Friends of the Virgin Islands National Park website describes the beauty of the park, which 

covers more than half of the Island of St. John, plus Hassel Island (near St. Thomas). The park 

was established by law in 1956. In 1962, the enabling legislation was amended to add 5,650 

acres of submerged land “...in order to preserve for the benefit of the public significant coral 

gardens, marine life, and seascapes in the vicinity there of...” In 1978, the legislation 

establishing Virgin Islands National Park was again amended to add Hassel Island, located in 

Charlotte Amalie harbor adjoining St. Thomas, to the Park.
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Within its borders lie protected bays of crystal blue-green waters teeming with coral reef 

life, white sandy beaches shaded by seagrape trees, coconut palms, and tropical forests providing 

habitat for over 800 species of plants. The Park protects a rich cultural history, with relics from 

the Pre-Colombian Amerindian Civilization, remains of the Danish Colonial Sugar Plantations, 

and reminders of African Slavery and the Subsistence Culture that followed during the 100 years 

after Emancipation.

Scenic views in the Park showcase the green hillside, sparkling blue water and tropical 

blue skies. When visibility is reduced, the sky is a milky white and colors of landmarks are 

muted. Most times, reduced visibility is caused by dust raised in the Sahara Desert and 

transported across the Atlantic Ocean via a deep layer of trade winds moving from east to west.1

This plan cannot reverse reduced visibility caused by Saharan Dust or volcanic ash from 

Montserrat. The goal of the FIP is to evaluate and remedy the causes of reduced visibility due to 

human sources. These sources include sulfates and nitrates from combustion in refineries, power 

plants, boilers and ships.

Many regional haze plans across the United States assess the impact of a state on Class I 

areas where their emissions cause or contribute to visibility reduction. However, emissions in 

other parts of the United States do not cause or contribute to visibility reductions in the Virgin 

Islands. In addition, there are no other Class I areas in the Caribbean. The Virgin Islands are 

sufficiently distant from other Class I locations in the United States that the sources in the Virgin 

Islands do not affect other Class I areas, the closest of which is the Everglades National Park, 

1,200 miles away in Florida. [See correspondence regarding Sec. 110a2d, December 20, 2006,

from VIDPNR, in Appendix.]

2.0 VISIBILITY MONITORING IN THE VIRGIN ISLANDS

The Interagency Monitoring of Protected Visual Environments (IMPROVE) program 

was initiated in 1985 to establish current visibility conditions, track changes in visibility, and 

help determine the causes of visibility impairment in Class I Areas. The IMPROVE network 

 

1

Prospero, J.M. (1999) Long-range transport of mineral dust in the global atmosphere: Impact of African dust on 

the environment of the southeastern United States. Proc. Natl. Acad. Sci. USA Vol. 96, pp. 3396–3403, March 

1999 Colloquium Paper
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collects particulate matter data at air monitoring sites in the Virgin Islands National Park and 

other Class I areas, which are used in calculations that quantify the obscuration of visibility from 

the captured particles. These monitors collect information on the quantity and chemical 

composition of the particles, because both of these qualities affect light scattering and visibility. 

Visibility conditions representative of those within the Virgin Islands National Park are 

monitored by the federally operated IMPROVE program. The IMPROVE monitoring program 

was established to measure visibility impairment in mandatory Class I areas throughout the 

United States. This monitoring is designed to aid the creation of Federal and State 

implementation plans for the protection of the visibility in Class I areas stipulated in the 1977 

amendments to the CAA. Data from the IMPROVE monitoring program have been collected 

since 1990 at the Virgin Islands National Park.

The IMPROVE monitoring sites are operated and maintained through a formal 

cooperative relationship between the U.S. Environmental Protection Agency, the U.S. National 

Park Service, the U.S. Fish and Wildlife Service, the Bureau of Land Management, and the U.S. 

Forest Service. In 1991, several additional organizations joined the effort. These organizations 

include the National Association of Clean Air Agencies (formerly State and Territorial Air 

Pollution Program Administrators and the Association of Local Air Pollution Control Officials), 

Western States Air Resources Council, Mid-Atlantic Regional Air Management Association, and 

the Northeast States for Coordinated Air Use Management.

2.1 IMPROVE Program Objectives

Data collected at these sites are used by land managers, industry planners, scientists, 

public interest groups, and air quality regulators to understand and protect the visual air quality 

resource in Class I areas. Most importantly, the IMPROVE program scientifically documents for 

American citizens the visual air quality of their wilderness areas and national parks. Program 

objectives include:

 Establish current visibility and aerosol conditions in mandatory Class I areas.

 Identify chemical species and emission sources responsible for existing 

anthropogenic visibility impairment.
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 Document long-term trends for assessing progress towards the national visibility

goals.

 Provide regional haze monitoring representing all visibility-protected federal 

Class I areas where practical, as required by EPA’s Regional Haze Rule.

2.2 Monitoring Information and Strategy for the Virgin Islands National Park Class I 

Areas

Section 51.308(d)(4) of EPA’s Regional Haze Rule requires a monitoring strategy for 

measuring, characterizing, and reporting regional haze visibility impairment that is representative 

of all mandatory Class I areas within the Virgin Islands. The monitoring strategy for the Virgin 

Islands relies upon the continued availability of the IMPROVE network.

As part of the IMPROVE network, visual air quality in the Virgin Islands National Park 

has been monitored using an aerosol sampler (1990 – present) and a nephelometer (1998 –

2005). The IMPROVE monitor for the Virgin Islands National park (indicated as VIIS1 in the 

IMPROVE monitoring network database) is located at the Biosphere Reserve Complex at Lind 

Point on the island of St. John. The monitor is at an elevation of 46 meters, a latitude of 

18.3363°, and a longitude of -64.7962°. Figure 2-1 is a northward facing photograph of the 

monitoring site and Figures 2-2 and 2-3 show the location of the monitoring site on the island of 

St. John.

In addition to the regional haze monitor, a National Atmospheric Deposition/National 

Trends Network (NADP/NTN) wet deposition monitor and a Clean Air Status and Trends 

(CASTNet) dry deposition monitor have been operating at the Virgin Islands National Park since 

1998. Ozone was continuously monitored from 1998 through 2003. Concentrations of ozone 

were well below past and present ozone air quality health standards.
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Figure 2-1: The IMPROVE Monitoring Site at the Virgin Islands National Park

Figure 2-2: Virgin Islands National Park IMPROVE Monitor Location
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Figure 2-3. Location of IMPROVE monitor in the Virgin Islands National Park on St. 

John. Blue markers are the grid from the air quality modeling.

3.0 ASSESMENT OF BASELINE AND NATURAL CONDITIONS

3.1 Requirement, Data, and Methods Used

Under the CAA, the Regional Haze Plans must contain measures to make reasonable 

progress toward the goal of achieving natural visibility, which EPA’s Regional Haze Rule notes 

is to be accomplished by 2064. Each State or Territory containing a Class I area must determine 

baseline and natural visibility conditions for their Class I area(s) in consultation with the 

following: 1) the FLMs, and 2) States identified as containing sources whose emissions 

contribute to visibility impairment in Class I areas. Comparing baseline conditions to natural 
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visibility conditions determines the uniform rate of progress that must be considered as haze 

plans set reasonable progress goals for each Class I area. 

The Clean Air Act also stipulates that haze plans should achieve these visibility goals by

improving the visibility on the worst days for visibility, while ensuring that visibility does not 

degrade on the days with the best visibility. To address this requirement, the average visibility

impairment over the worst one-fifth (top twenty percent impaired days) and the best one-fifth 

(best twenty percent) days are calculated. 

Data from the Virgin Islands National Park IMPROVE monitor (VIIS1) are 

representative of the Class I Area in the Virgin Islands, as described in the Monitoring Section of 

this FIP (Section 2). This haze plan shall use the IMPROVE data to calculate the baseline and 

natural conditions for the Virgin Islands National Park in accordance with 40 CFR 

51.308(d)(2)(i).

In addition to data from the Virgin Islands National Park monitor, data from additional 

IMPROVE monitors (Table 3-1) are presented throughout this FIP to provide context for the 

Virgin Island data. Data from Brigantine Wilderness Area and Acadia National Park are

presented as sites with humid climates that are considered clean areas, but affected by emissions 

across the eastern and midwestern United States. Florida’s Everglades National Park data show 

a park that has a tropical climate similar to the Virgin Islands; however, the Everglades are 

affected by more sources of pollution than the Virgin Islands. Arizona’s Grand Canyon National 

Park is included because it is representative of a remote Class I area with a dry climate that is 

distanced from major urban areas and sources of pollution. While the Virgin Islands National 

Park is remote from major urban areas and has less industry nearby, like the Grand Canyon 

National Park, the Virgin Islands’ more humid climate allows particulates, especially sulfates, to 

have a greater effect on reducing visibility than at the Grand Canyon. 

In September 2003, EPA issued guidance for the calculation of natural background and 

baseline visibility conditions. The guidance provided a default method and describes certain 

refinements that States could evaluate to tailor these estimates to a specific Class I area, if it was 

poorly represented by the default method. In 2006, the IMPROVE Steering Committee adopted 

an alternative reconstructed extinction equation to revise certain aspects of the default method. 

The revised aspects of the extinction equation were scientifically well understood, and the 
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Committee determined that revisions improved the performance of the equation at reproducing 

observed visibility at Class I sites. 

The baseline and natural conditions reported herein were calculated using the alternative 

method approved by the IMPROVE Steering Committee in 2006 because these equations 

represent the most updated understanding of the science.

Table 3-1: IMPROVE Information for Virgin Islands and Selected Class I Areas

Class I Area IMPROVE Site

Location 

(latitude and 

longitude)

State

Virgin Islands National Park VIIS1 18.34N, 64.80W US Virgin Islands

Acadia National Park ACAD1 44.38N, 68.26W Maine 

Brigantine Wilderness Area BRIG1 39.47N, 74.45W New Jersey 

Everglades National Park EVER1 25.39N, 80.68W Florida

Hance Camp at Grand Canyon National Park GRCA2 35.97N, 111.98W Arizona

Source: VIEWS (http://vista.cira.colostate.edu/improve/), prepared on 10/14/11

3.2 Virgin Island Baseline Visibility

How visibility is measured 

or “What’s a deciview?”

EPA uses a unit called a ‘deciview’ to quantify visibility for the haze plans. 

The deciview scale varies in a similar way to how the human eye sees how 

visibility changes. For example, a change in visibility of one deciview unit is 

noticeable to a typical human observer. Higher deciviews values mean worst 

visibility and lower values mean clearer air. 

To calculate visibility in deciviews, we can use measurements of how far an 

observer can see (visual range) or calculate deciviews from extinction in 

megameters-1. Extinction is the amount of obscuration occurring because of 

particles that fill the air that make it harder to see distant objects. A formula 

coverts visual range or extinction to deciviews to account for how the eye sees 

changes in visibility. 
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The IMPROVE program has calculated the baseline (2000-2004) and natural visibility

conditions for the twenty percent best and worst visibility days at each IMPROVE monitoring 

site, including the Virgin Island National Park site. These values are posted on the Visibility

Information Exchange Web System (VIEWS)2. The VIEWS site lists the worst visibility days as 

a 5-year average for 2000-2004 using the alternative IMPROVE algorithm approved in 2006 by

the IMPROVE Steering Committee. The VIEWS site also provides the natural background 

visibility for the twenty percent worst and the twenty percent best visibility days. 

Table 3-2 presents the baseline visibility for the twenty percent best and worst visibility

days for a select subset of Class I areas. 

The baseline visibility conditions in the Virgin Islands National Park are better than 

conditions in the eastern United States, as seen in the data in Table 3-2. However, even the best 

days in the Virgin Islands have more obscuration than most days in dry western locations, like 

the Grand Canyon National Park. As mentioned in Section 3.1, the difference in natural 

background visibility between the Virgin Islands National Park and the Grand Canyon National 

Park is largely due to differences in humidity. As humidity increases, the light scattering 

properties of the sulfate component of particulate matter is enhanced, which results in decreased 

visibility. Hence, sites in dry regions, like the western United States, have better visibility than 

sites in humid regions, like the southeastern United States and the Virgin Islands. The western 

United States also have the advantage of fewer sources of pollutants that affect visibility than the

eastern United States, and lack of impact from transported Saharan Dust.

 

2

 VIEWS available online at http://vista.cira.colostate.edu/views/
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Table 3-2: Baseline Visibility for the Twenty Percent Worst Days and Twenty Percent Best 

Days for 5 Years (from 2000-2004) in Selected Class I Areas

Class I Area 

(IMPROVE Monitor) Year 20 % Worst DaysDeciviews (dv)

20 % Best Days

Deciviews (dv)

Virgin Island National Park 

(VIIS1)

2000 19.57* 9.93*

2001 16.76 9.08

2002 16.39 8.31

2003 17.38 8.14

2004 17.56 8.61

5-Year Average 17.53 8.81

Acadia National Park 

(ACAD1)

2000 21.64 8.89

2001 23.28 8.87

2002 23.91 8.77

2003 23.65 8.77

2004 21.98 8.56

5-Year Average 22.89 8.77

Brigantine Wilderness Area 

(BRIG1)

2000 28.95 14.26

2001 28.38 13.82

2002 29.31 14.83

2003 29.79 14.39

2004 28.59 14.36

5-Year Average 29.01 14.33

Everglades National Park 

(EVER1)

2000 * * * *

2001 20.93 11.45

2002 20.64 10.97

2003 24.44 12.22

2004 23.21 12.1

5-Year Average 22.31 11.69

Hance Camp at Grand Canyon 

National Park (GRCA2)

2000 11.12 2.89

2001 * * * *

2002 11.62 1.98

2003 12.74 1.82

2004 11.18 1.98

5-Year Average 11.67 2.17

Values, in deciviews, are the average for each 20% group.

*For the Virgin Islands site, the year 2000 data have too many missing samples to be part of the valid multi-year 

average. While 2000 is included in this table’s average value, data from 2000 is not included in calculating the 

values used to determine the starting point and reasonable progress rate used later in this FIP.

* * Data do not exist for this monitoring year. However, according to the EPA document entitled, Guidance for 

Tracking Progress Under the Regional Haze Rule, states that, “...a minimum of 3 years of data meeting these 

completeness requirements is sufficient to calculate the 5-year averages within each 5-year period...the 3-year 

completeness criterion allows for the calculation of baseline conditions at sites with less than 5 years of data.”

Source: VIEWS (http://vista.cira.colostate.edu/improve/Data/IMPROVE/summary_data.htm), prepared on 10/14/11.
Draft Regional Haze SIP 3-12

US Virgin Islands Tuesday, June 26, 2012

3.3 Natural Visibility

Natural visibility is the visibility for each Class I area representative of the conditions 

before human activities affected air quality in the area. Certain natural phenomena can reduce 

visibility. A Clean Air Act goal is to remedy visibility impairment resulting from human activity. 

A 5-year average (2000 to 2004) visibility in deciviews was calculated for each selected 

Class I Area for the twenty percent best and twenty percent worst days in accordance with 40 

CFR 51.308(d)(2) and detailed in the EPA document Guidance for Tracking Progress Under the 

Regional Haze Rule. The deciview visibilities for these worst and best days are based on 

calculations and data included in Appendix B of this FIP. 

For the Virgin Islands site, the year 2000 is missing some data and is not used in this 

calculation. However, four years of valid data are acceptable, according to EPA’s Regional Haze 

Rule.

This calculated natural visibility does not include the impact of locally important natural 

obscurers of visibility. In the Virgin Islands, for example, Saharan Dust can noticeably reduce 

visibility. Less obvious sources are airborne sea salt, and marine life - phytoplankton that 

produce sulfates (Tombach, 2005).

During the May 28, 2008 meeting with the FLM, EPA Region 2 staff discussed the 

calculation of natural background conditions in the Virgin Islands National Park. At this 

meeting, EPA Region 2 representatives noted that the default calculation of natural background 

conditions did not include the large impact of non-anthropogenic impacts from Saharan Dust and 

biogenic emissions. The FLM agreed that the information presented (and described in this FIP) 

showed the large influence of Sahara Dust on visibility in the Virgin Islands National Park. 

However, the FLM noted that more work would need to be done to more precisely calculate the 

impact on natural sources on visibility in the Virgin Islands National Park. The FLM suggested 

that the current implementation plan focus on implementing reasonable controls on sources that 

affect visibility in the Virgin Islands National Park. The FLM further suggested that the issues 

relating to the impact of natural sources on visibility in the Virgin Islands National Park should 

be researched for possible revised natural background conditions in the 2018 comprehensive 

implementation plan revision. 
Draft Regional Haze SIP 3-13

US Virgin Islands Tuesday, June 26, 2012

Table 3-3 displays the baseline visibility for the twenty percent worst and the twenty

percent best visibility days based on the 5-year average for 2000-2004, natural visibility for the 

twenty percent worst and the twenty percent best visibility days, and the difference between 

baseline and natural visibility conditions for each selected Class I area.

Table 3-3: Summary of Baseline Visibility and Natural Conditions for the Twenty Percent 

Worst and Twenty Percent Best Visibility Days

Class I Area

2000-2004 

Baseline (dv)

Natural 

Conditions (dv) Difference (dv)

Worst 

20 %

Best 

20%

Worst 

20 %

Best 

20%

Worst 

20 %

Best 

20%

Virgin Island National Park* 17.02 8.81 10.68 4.41 6.34 4.40

Acadia National Park 22.89 8.77 12.43 4.66 10.46 4.11

Brigantine Wilderness Area 29.01 14.33 12.24 5.51 16.77 8.82

Everglades National Park 22.31 11.69 12.15 5.22 10.16 6.47

Hance Camp at Grand Canyon National Park 11.67 2.17 7.04 0.31 4.63 1.86

* Using valid data from 2001- 2004.

Source: VIEWS (http://vista.cira.colostate.edu/improve/Data/IMPROVE/summary_data.htm), prepared on 10/14/11.

EPA Region 2 staff informed the FLM about progress on the haze plan for the Virgin 

Islands through the series of national conference calls sponsored by EPA’s Office of Air Quality

Planning and Standards. These calls were held as often as twice a month. EPA Region 2 set up 

a formal consultation meeting via conference call with representatives of the FLM on May 28, 

2008 to discuss the calculation of baseline and natural background conditions in the Virgin 

Islands National Park. The FLM agreed with the calculation of the baseline conditions and the 

estimate of progress needed to reach natural conditions. EPA Region 2 met with the FLMs on 

May 2, 2012 via conference call to discuss the haze plan the EPA was likely to propose and to 

listen to their comments on the plan.

3.4 Contributions to Visibility Impairment in the Virgin Islands

3.4.1 Area of Influence for the Virgin Islands National Park

Many of the National Parks and other areas covered by haze plans are affected by sources 

of human pollution nearby and from hundreds of miles away from the parks. The Virgin Islands 

National Park is not affected to a large extent from anthropogenic sources outside the Virgin 
Draft Regional Haze SIP 3-14

US Virgin Islands Tuesday, June 26, 2012

Islands. The Virgin Islands are upwind of Puerto Rico (see the wind rose for St. Thomas in 

Figure 3-1). Even the large refinery on the island of St. Croix, 40 miles south of St. John, is 

located crosswind from St. John. Trajectory analyses for the days with the worst visibility in the 

park are available in the docket that supports this Plan. Results are summarized in Table 3-4. 

Figure 3-1: Wind Rose for St Thomas, Virgin Islands, based on 2007 - 2010 National 

Weather Service Data 

WRPLOT View - Lakes Environmental Software

WIND ROSE PLOT:

Charlotte Amalie, St. Thomas, Virgin Islands - 2007-2010

WBAN # 11640, WMO # (n/a)

COMMENTS: COMPANY NAME:

MODELER:

DATE:

3/6/2012

PROJECT NO.:

NORTH

SOUTH

WEST EAST

9%

18%

27%

36%

45%

WIND SPEED

(m/s)

>= 11.1

8.8 - 11.1

5.7 - 8.8

3.6 - 5.7

2.1 - 3.6

0.5 - 2.1

Calms: 5.17%

TOTAL COUNT:

34153 hrs.

CALM WINDS:

5.17%

DATA PERIOD:

2007 2008 2009 2010 

Jan 1 - Dec 31

00:00 - 23:00

AVG. WIND SPEED:

4.50 m/s

DISPLAY:

 Wind Speed

Direction (blowing from)
Draft Regional Haze SIP 3-15

US Virgin Islands Tuesday, June 26, 2012

Table 3-4: Summary of Trajectory Analyses for Top Four Days with the Highest Visibility 

Impairment for Each Species 2000 - 2004

Species Total Light 

Extinction (bext)

Source Region (Height of Trajectory in Meters Above Ground Level)

Local Regional Long-Distance

All 

Aerosols

Combined

79.5 St. John (100, 500) Anguilla (100) NW Africa (500, 1000)

77.4 St. John (100, 500, 1000) None NW Africa (1000)

71.8 St. John (100, 500, 1000) Anguila (500) Central Africa (1000)

71.1 St. John (100, 500) Anguila (100) 

St. Martin (500) African Coast (1000)

Fine Soil

19.9 None None Central Africa (500, 1000)

17.9 St. John (100, 500, 1000) None NW Africa (1000)

17.3 None Guadeloupe (100) Central Africa (1000)

16.9 St. John (1000) Guadeloupe (100, 

500) Central Africa (1000)

Sea Salt

24.2 St. John (100, 500, 1000) None None

21.8 St. John (100) Anguila (100) None

18.9 St. John (100, 500) Anguila (100) 

St. Martin (500) African Coast (1000)

17.9 St. John (100, 500, 1000) None None

Sulfate

42.0 St. John (100) Puerto Rico (1000) None

34.9 St. Thomas (100)

Puerto Rico (100, 

500) Dominican Rep. 

(1000)

Florida (500)

26.8 None Guadeloupe (100) Central Africa (1000)

26.6 None Montserrat (500) Western U.S. (1000)

Nitrate

5.2 St. John (100, 500, 1000) Anguila (500)

Barbuda (1000) None

4.8 None St. Martin (100)

Barbuda (500) Canada (100, 500, 1000)

4.52 St. John (100, 500) Anguila (100) 

St. Martin (500) African Coast (1000)

4.52 Puerto Rico (500, 1000) Dominica (100)

Guadeloupe (500) None

Elemental 

Carbon

15.5 St. John (500, 1000)

BVI (100) None Central Africa (1000)African Coast (500)

14.0 None St. Martin (100)

Mideast U.S. (100)

Mexico, Florida (500, 

1000)

13.3 None St. Martin (100, 500) None

10.3 None BVI (100, 500) Canada, N.E. U.S. (100)

Organic 

Carbon

18.4 None St. Martin (100)

Mideast U.S. (100)

Mexico, Florida (500, 

1000)

17.2 St. John (500, 1000)

BVI (100) None Central Africa (1000)African Coast (500)

7.09 St. John (100, 500, 1000) None Central Africa (1000)

7.05 None St. Martin (100, 500) None

Coarse PM

34.4 None None Central Africa (500, 1000)

33.4 St. John (100, 500) Anguilla (100) NW Africa (500, 1000)

30.5 St. John (100, 500, 1000) BVI (100, 500, 1000) W Africa (100, 500, 1000)

28.8 St. John (500, 1000) BVI (100, 500) None
Draft Regional Haze SIP 3-16

US Virgin Islands Tuesday, June 26, 2012

We use the trajectory analysis to find likely source areas for the visibility problems 

included the top four days with the greatest impact on visibility from each kind of particulate that 

contributes to reduced visibility. On the worst days, we would expect to find that the air came 

from areas that contributed to the reduced visibility on those days. We used the HYSPLIT3

model, which uses weather data from every three hours, converted to a grid for each hour of the 

day. The user specifies the starting point (in our case, the monitoring site on St. John), how long 

to run the model (2 weeks) and the height above ground at the monitoring site. We used three 

heights above the monitoring site within the well-mixed tropical surface layer, since tropical air 

is well mixed over land at these heights and different heights can have different trajectories when

wind direction changes with height. 

 Since the trade winds mostly blow from east to west across the Virgin Islands, it is not 

surprising that when the winds are traced backwards from the sampling site on the western end 

of St. John, the path that the air takes almost always passes over the island of St. John. Many

trajectories pass over neighboring islands like Antigua and St. Martin. Some trajectories pass 

over the islands of the British Virgin Islands, located to the northeast of St. John. However, there 

is not any particular pattern where days with the highest amounts of light-scattering particles 

have trajectories that commonly pass through one or more of these likely sources of human air 

pollution. For example, only one of the days with high levels of haze that may be from 

combustion has trajectories that pass over St. Croix, home to a major industrial center. These 

trajectories show that even on days when visibility is reduced due to sulfates, nitrates, and carbon 

(likely suspects from sources of combustion), the air affecting the park usually does not pass 

over St. Croix, St. Thomas, or Puerto Rico. 

More often, days with high concentrations of fine soil or coarse particulates in the 

atmosphere occur when air travels from Africa’s Sahara Desert. For example, Figure 3-2 shows a 

set of backward trajectories originating at the Virgin Islands National park for 100, 500, and 

 

3

 Draxler, R.R. and Rolph, G.D., 2012. HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) Model 

access via NOAA ARL READY Website (http://ready.arl.noaa.gov/HYSPLIT.php). NOAA Air Resources Laboratory, 

Silver Spring, MD.

Rolph, G.D., 2012. Real-time Environmental Applications and Display sYstem (READY) Website 

(http://ready.arl.noaa.gov). NOAA Air Resources Laboratory, Silver Spring, MD. EPA Region 2 gratefully 

acknowledges the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport model and the

READY website (http://ready.arl.noaa.gov) used in our analysis.
Draft Regional Haze SIP 3-17

US Virgin Islands Tuesday, June 26, 2012

1,000 meters above ground level for September 26, 2002, which is typical of days with high 

visibility impairment due to fine soils. This illustrates how a significant causes of reduced 

visibility in the Virgin Islands National Park is dust transported from the Sahara Desert, located 

over 5,000 miles away in Africa. The Virgin Islands can also be affected by other various natural 

sources, such as sulfate produced by plankton in the ocean and ash from the Montserrat Volcano, 

located over 200 miles away to the southeast. The effects of these natural sources on visibility

can be very noticeable on some days, especially because there are not as many anthropogenic 

sources of pollution in the Islands in comparison with the more urban areas of the continental 

United States.

Figure 3-2: Back Trajectories of Day with Highest Impact on Visibility from Fine Soils –

notice the orgin for two layers of wind in the Saharan Desert.

More examples of trajectories are in the Appendix and the docket for this action has all of 

the data used for the trajectories.
Draft Regional Haze SIP

US Virgin Islands

3.4.2 Pollutants Contributing to Visibility Impairment (2000

Section 51.308(d)(3)(iv) of 40 CFR part 51 requires each State to identify all 

anthropogenic sources of visibility impairment considered by the State in developing its long

term strategy. EPA’s Guidance for Setting Reasonable Progress Goals

Program (June, 2007) notes that this process begins with the identification of key pollutants and 

source categories that contribute to visibility impairment at the Class I area(s) affected by 

emissions from the State.

Figure 3-3 shows how much each of the types of particles

IMPROVE site contribute to reducing visibility. This graph is the average impact of

component on extinction, calculated from the 

Islands is coarse mass (cm_bext

percent of total interference with visibility

Islands National Park. The next largest contributor is sea salt (seasalt_bext) at 20 percent

sulfate (amnso4f_bext) at 19 percent;

percent.

Figure 3-3: Above: Percent Contributions to Total Light Extinction from 

Baseline Conditions (2004 data used as an example) Below: List of particles contributing to 

reduced visibility, color

Tuesday, June 26, 2012

Pollutants Contributing to Visibility Impairment (2000-2004 Baseline Data) 

Section 51.308(d)(3)(iv) of 40 CFR part 51 requires each State to identify all 

anthropogenic sources of visibility impairment considered by the State in developing its long

Guidance for Setting Reasonable Progress Goals Under the Regional Haze 

(June, 2007) notes that this process begins with the identification of key pollutants and 

source categories that contribute to visibility impairment at the Class I area(s) affected by 

how much each of the types of particles on the filters from the 

IMPROVE site contribute to reducing visibility. This graph is the average impact of

calculated from the 2004. The largest contributor to haze 

– the all particles larger than 2.5 microns) which 

interference with visibility on the twenty percent haziest days at the Virgin 

The next largest contributor is sea salt (seasalt_bext) at 20 percent

(amnso4f_bext) at 19 percent; soils (soilf_bext) were the fourth largest contributor at 

Percent Contributions to Total Light Extinction from 

Conditions (2004 data used as an example) Below: List of particles contributing to 

reduced visibility, color-coded, with possible sources listed.

 3-18

Tuesday, June 26, 2012

Baseline Data) 

Section 51.308(d)(3)(iv) of 40 CFR part 51 requires each State to identify all 

anthropogenic sources of visibility impairment considered by the State in developing its longUnder the Regional Haze 

(June, 2007) notes that this process begins with the identification of key pollutants and 

source categories that contribute to visibility impairment at the Class I area(s) affected by 

on the filters from the 

IMPROVE site contribute to reducing visibility. This graph is the average impact of each 

haze in the Virgin 

which accounts for 36

percent haziest days at the Virgin 

The next largest contributor is sea salt (seasalt_bext) at 20 percent; then 

largest contributor at 13

Percent Contributions to Total Light Extinction from all particles, 

Conditions (2004 data used as an example) Below: List of particles contributing to 
Draft Regional Haze SIP

US Virgin Islands

There is nothing to be done about portion of light extinction attributable to sea salt, as it 

is an entirely from sea spray generated by wave action and winds. 

As shown in the graph, below, t

visibility have the highest amounts of coarse particulates and fine soil, which indicate the 

presence of Saharan Dust (Data from 2004

Figure 3-4:2004 Visibility for St. John IMPROVE Data 

As noted by Tombach and Brewer (2005), African dust transported from the Saharan 

desert can represent more than 40 percent of the total soil emiss

United States and an even larger component for the Virgin Islands. While impacts from Saharan 

dust are episodic, impacts can be seen 9 months out of the year in the Virgin Islands and can 

easily represent more than 3 μg/m

Tuesday, June 26, 2012

There is nothing to be done about portion of light extinction attributable to sea salt, as it 

is an entirely from sea spray generated by wave action and winds. 

As shown in the graph, below, the days with the highest contributions to reduced 

visibility have the highest amounts of coarse particulates and fine soil, which indicate the 

(Data from 2004, plotted from the VIEWS data generator web site

2004 Visibility for St. John IMPROVE Data – higher values are poorer visibility

As noted by Tombach and Brewer (2005), African dust transported from the Saharan 

desert can represent more than 40 percent of the total soil emissions throughout the southeast

and an even larger component for the Virgin Islands. While impacts from Saharan 

dust are episodic, impacts can be seen 9 months out of the year in the Virgin Islands and can 

easily represent more than 3 μg/m3of the total fine particulate mass (Perry et al., 1997). 

 3-19

Tuesday, June 26, 2012

There is nothing to be done about portion of light extinction attributable to sea salt, as it 

ontributions to reduced 

visibility have the highest amounts of coarse particulates and fine soil, which indicate the 

from the VIEWS data generator web site.)

higher values are poorer visibility

As noted by Tombach and Brewer (2005), African dust transported from the Saharan 

ions throughout the southeastern 

and an even larger component for the Virgin Islands. While impacts from Saharan 

dust are episodic, impacts can be seen 9 months out of the year in the Virgin Islands and can 

of the total fine particulate mass (Perry et al., 1997). Looking 
Draft Regional Haze SIP 3-20

US Virgin Islands Tuesday, June 26, 2012

at the mass of particles in the fine particulate fraction, soils make up 5.90 μg/m3of the total mass 

of PM2.5 on the twenty percent worst visibility days during the baseline period, which is more 

than half of the total fine mass. Part of the soils component could be attributed to tilling or other 

disruptions of the ground that would allow dust to escape into the air and blown by the wind. 

Motor vehicles or construction are two other sources of disruption resulting in dust lofted into 

the winds. For this reason, EPA commissioned a search for emissions on the island of St. John, 

which will be discussed more in the section on emission inventories.

Figure 3-5: Contribution of particulate to reductions in visibility on the days with the best 

visibility. (2004 data.)

On the clearest days, with the best visibility, the small amount of interference with seeing 

the view is mostly from coarse particulates, followed closely by sulfates. The impact of fine soil, 

a sign of transported dust, is very small on these clean days.

Since little can be done to control sea salt or Saharan dust emissions, sulfate emerges as

the most controllable of the major constituents of haze-forming fine particle pollution in the

Virgin Islands. As a result of this larger role of sulfate in the formation of regional haze in the 

Virgin Islands and sulfates’ unique ability to scatter light more effectively in a humid 

atmosphere, control of sulfur emissions (if feasible and cost-effective) would have the largest 

effect on visibility in the Islands, per ton of emissions reduced. However, the effects of sulfur 

controls may be overwhelmed by the impact of natural sulfate and Saharan Dust.

3.5 Class I Areas Affected by Emissions from the Virgin Islands

There are no other Class I areas in the Caribbean islands, including Puerto Rico. The U.S. 

Virgin Islands are located more than 1,200 miles from the closest Class I area in the continental 
Draft Regional Haze SIP 4-21

US Virgin Islands Tuesday, June 26, 2012

United States (Everglades National Park). As described in section 4, emissions from the Virgin 

Islands are much lower in comparison to most urban areas in the continental United States. If the 

east to west trade winds were to bring emissions from the Virgin Islands, any such emissions 

reaching the continental United States would be highly diluted after having traveled so far across 

the Atlantic Ocean. Therefore, it is reasonable to conclude that emissions from the Virgin Islands 

do not significantly affect other Class I areas in the United States. In fact, EPA and the 

government of the Territory of the Virgin Islands made that determination when deciding that the 

Islands did not need a long-range transport SIP under section 110 of the Clean Air Act4. 

4.0 EMISSIONS INVENTORY AND MODELING ANALYSIS

Section 51.308(d)(4)(v) of EPA’s RHR requires a statewide emission inventory of 

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

mandatory Class I area. The pollutants that affect fine particle formation, and thus contribute to 

regional haze are sulfur oxides (SOx), nitrogen oxides (NOx), ammonia (NH3), volatile organic 

compounds (VOCs), and particles with an aerodynamic diameter less than or equal to 10 and 2.5 

μm (i.e., primary PM10 and PM2.5, respectively). Because emissions from the Virgin Islands in 

available databases (i.e., the National Emissions Inventory) are not as developed as those from 

the continental United States, an independent list of emission sources throughout the Virgin 

Islands and Puerto Rico was developed, as described below. The pollutants inventoried include 

sulfur dioxide (SO2), NOx, PM10 (modeled as PM2.5), PM2.5 and elemental carbon (EC).

EPA noted in its proposed rule on BART evaluations (69 FR 25184) that EPA 

determined in the NOx SIP Call notice (63 FR 57356) that VOCs do not contribute in a large 

amount to the formation of particulate matter in rural areas. EPA also noted in its final guidance 

on BART determinations (70 FR 39144) that EPA does not agree that rural VOC emissions can 

be completely ruled out as a significant contributor to particle formation and may play a 

significant role where NOx emissions are high. The complicated and rapidly evolving state of 

knowledge of particle formation by VOCs lead EPA to the conclusion that any determination of 

 

4

 See December 20, 2006 letter from DPNR to EPA, an Appendix to this document.
Draft Regional Haze SIP 4-22

US Virgin Islands Tuesday, June 26, 2012

whether VOC emissions are precursors to PM2.5 formation should be completed on a case-bycase basis. In the case of the Virgin Islands, where development of an emission inventory for 

VOC is in its early stages, EPA will defer evaluation of the impact of VOC emissions’ 

contribution to visibility reduction to the next round of visibility plans covering 2018 to 2028.

4.1 Sources of Emissions

Section 51.308(d)(3)(iv) of 40 CFR part 51 requires the Virgin Islands to identify all 

anthropogenic sources of visibility impairment in developing its FIP and long-term strategy.

Due to its proximity to the National Park, an emission inventory for the island of St. 

John, and of major sources nearby islands, is most important for this haze plan. For the reasons 

described above in Section 3.0, the emphasis in developing this FIP was placed on sources of 

sulfur emissions, SO2, which are precursors to sulfate. Emissions inventory analysis shows that 

point sources dominated the 2002 inventory of SO2 emissions. The largest source category of 

sulfur dioxide in the region is the Hovensa Refinery, followed by electric generating units 

(EGUs). These facilities are also the largest contributors to NOx emissions as well.

Additional SO2 source categories analyzed include marine sources and the mobile source 

sector.

Table 4-1: Summary of Emissions St. John, Virgin Islands

by Pollutant in Tons per Year

The post-control inventory is the base inventory minus the emissions reductions 

anticipated for the ships that sail to and from St. John.

Typically, for most haze plans, emissions are summed for the entire state (in this case, all 

of the Virgin Islands). But since a complete inventory is not available for St. Thomas and St. 

Croix, the FIP inventory for the base and post-control runs will include only the emissions on the 

Emissions on 

St. John

Sulfur 

Dioxide

Nitrogen 

Dioxide

Particulate 

Matter

Elemental 

Carbon

2002 Base 

Inventory

156.73 826.68 83.88 0.84

2018 Postcontrol 

inventory

76.77 572.09 76.60 0.77
Draft Regional Haze SIP 4-23

US Virgin Islands Tuesday, June 26, 2012

island of St. John and ship emissions in the nearby waters. For modeling the impact of sources in 

and near the Virgin Islands, the largest emission sources are modeled from point sources on St. 

Thomas and St. Croix, as well as notable emissions from nearby islands not part of the United 

States and a sample major point source from Puerto Rico. The inventory is described in more 

detail in the upcoming sections.

4.2 Modeled Baseline Emissions

Section 51.308(d)(3)(iii) of 40 CFR part 51 requires the Virgin Islands haze plan to 

identify the baseline emissions information on which the long-term strategy is based.

The EPA provided lists of sources for the contractor to use in modeling regional haze for 

the Virgin Islands. Sources of these lists include: the base 2002 EPA inventory developed using 

surrogate emissions for air toxics modeling, the emission inventory developed for EPA for 

sources on St. John (including nearby marine vessels), point source inventories from new source 

review applications, and EPA estimates of emissions from other nearby islands, as well as an 

example of a major source in Puerto Rico. In summary, these inventories include local emission 

sources on the island of St. John as well as other large sources in the islands with the potential to 

affect visibility at the Virgin Islands National Park. The modeled emissions are in the Appendix 

from the air modeling contractor and are summarized in Section 7.3. 

The sources were split into 15 groups, each of which is explained in more detail below. 

Details regarding the emission rate calculations for these sources can be found in the final report 

for the Virgin Islands National Park Regional Haze Modeling Analysis.

4.2.1 HOVENSA St. Croix

Sources in this group were selected from Table 6-4 of the AEG Anguilla Project Report. 

In the original modeling (prior to modeling BART-eligible sources), this group contained seven 

sources (six of the largest sources and one aggregate of the remaining sources), representing a 

total of approximately 75% of St. Croix’s total emissions. Since there were over 170 sources on 

St. Croix, the model was limited to modeling all the emissions combined into major emission 

points which were the electric utilities and the top 3 emitters of PM, SO2, or NOX. St. Croix 

sources were split between Groups 1 and 6, with Group 1 representing only the HOVENSA
Draft Regional Haze SIP 4-24

US Virgin Islands Tuesday, June 26, 2012

refinery, and Group 6 representing Water and Power Authority (WAPA) St. Croix sources. St. 

Croix WAPA were modeled separately, as described in Section 4.2.12. The aggregated source 

consisted of the non-BART sources. Emission rates for the aggregate source do not include any

BART-eligible sources (i.e., no double counting of emissions).

For this modeling effort, BART-eligible boilers, heaters, flares, and reciprocating gas 

compressors at HOVENSA were explicitly modeled. The result was 65 BART-eligible point 

sources. 

Emissions of the flares were provided as a sum for the entire facility, with potential to 

emit rates of 1200 tpy SO2, 1897 tpy NOX, and negligible PM emissions. Ten flares were 

identified at HOVENSA in the AEG Anguilla inventory, with zero emissions for two of them. 

Per email correspondence on May 11, 2012, only five flares are BART-eligible. A proportion of 

the total emissions (5 BART flares / 8 total flares) was used to approximate the BART flare 

emissions.

4.2.2 St. John Point Sources - Generators

These sources represent actual point sources on St. John. This group contains six sources: 

Caneel Bay Resort, Gallows Point Resort, Grand Bay Resort, Myrah Keating Smith Community

Health Center, Sirenusa, and Virgin Islands Water and Power Authority. The modeling included

emissions from a back-up power generator at Caneel Bay Resort, two propane laundry dryers 

and a backup power generator at Gallows Bay Resort, a backup power Generator at the Myrah 

Keating Smith Clinic, and a backup power generator at the Virgin Islands Water and Power 

Authority. Fuel use data was collected from each facility and was used to estimate emissions.

4.2.3 St. John Marine Sources

This group represents the marine sources at St. John, including ferries, cruise ships, and 

cargo ships. Emissions are based on ship call data pulled from the Virgin Islands Water and 

Power Authority website. Emissions from all three source types were modeled as point sources 

located at the Cruz Bay docks. The stack parameters for the three different types of ships were 

selected based on typical cruise ship data specifications.
Draft Regional Haze SIP 4-25

US Virgin Islands Tuesday, June 26, 2012

4.2.4 St. John Marine Sources with Emissions Reductions

This group represents an alternative set of emission rates for the marine sources at St. John. The 

source parameters are identical to Group 3, but emissions of particulate matter (PM) and SO2

have been reduced by 85 percent and 80 percent, respectively. These reductions are based on the 

agreement to implement the Caribbean ECA (Emissions Control Area) for ocean vessels. 

Beginning in 2015, fuel used by all vessels operating in these areas cannot exceed 0.1 percent 

fuel sulfur (1,000 ppm). This requirement is expected to reduce PM and SOx emissions by more 

than 85 percent. Beginning in 2016, new engines on vessels operating in these areas must use 

emission controls that achieve an 80 percent reduction in NOx emissions. 

This group is not modeled simultaneously with Group 3, but is instead used to examine 

the benefits of reductions in emissions from marine sources.

4.2.5 St. John Paved and Unpaved Road Fugitive Sources

This group was modeled as a single area source representing fugitive dust emissions from 

roadways on St. John. The emissions were calculated based on total vehicle miles traveled 

(VMT) on St. John in 2002 based on data from the Federal Highway Administration and 

emission factors taken from Sections 13.2.1 and 13.2.2 of U.S. EPA’s AP-42 emissions factor 

compilation. More recent studies indicate that emissions of fugitive dust kicked up from the 

roads by traffic are overestimated by a factor of five. So the inventory used in modeling has 

reduced the emissions from this category by 80 percent from the AP-42 calculated values.

4.2.6 Aggregate St. John Burning

This group was modeled as a single area source and represents all sources of fires on St. 

John, including open burning, forest fires, and structure fires. Emissions were based on 

information acquired through a questionnaire sent to the Virgin Islands Fire Service in 

November 2009. The area is conservatively modeled as 8.6km by 3.4km rectangle (about 29.4 

km2) that is contained mostly within the land mass of St. John.

4.2.7 St. John Residential Boilers

This group was modeled as a single area source and represents emissions from residential 

boiler use on St. John. Essentially, these emissions are from heating hot water for homes. 

Emissions were based on fuel usage data from Development of 2002 Regional Haze Area, Point, 
Draft Regional Haze SIP 4-26

US Virgin Islands Tuesday, June 26, 2012

Non road Mobile and On road Mobile Source Inventories for the St. John, VI, Final Report June 

2010. The source was modeled as a 3 km x 3 km square region located at Cruz Bay settlement, 

St. John.

4.2.8 St. John Miscellaneous Industrial Processes -- Construction

This group was modeled as a single area source and represents emissions from other 

industrial sources on St. John. This group includes emissions from the Majestic Concrete facility 

and fugitive dust from residential construction. Emissions from Majestic Concrete were based on 

information acquired through a questionnaire sent to Majestic Concrete in February of 2010. 

Emissions from residential construction were based on the number of residential building permits 

issued on St. John in 2002. The area source was modeled as a 3 km x 3 km square region located 

at Cruz Bay settlement, St. John.

4.2.9 St. John Motor Vehicle Emission Sources

This group represents motor vehicle emissions on St. John. The emissions were based on 

highway mobile source activity data and emissions developed in support of the 2002 NEI. The 

area source was modeled as a 5 km x 10.4 km rectangular region, representing an area equal to 

that of the total land area of St. John.

4.2.10 Sample Puerto Rico Source

This group represents the AES Puerto Rico, L.P. 454 megawatt (MW) coal-fired power 

plant in Guayama, Puerto Rico. The stack parameters are based on a similarly sized coal-fired 

boiler. For modeling purposes, it was placed at the eastern end of Puerto Rico, on the shore 

facing the Virgin Islands. This way, if the source had a negligible impact on St. John, it would 

confirm that sources on Puerto Rico have no readily discernible effect on reducing visibility in 

the Virgin Islands and controls in Puerto Rico would not be effective at improving visibility in

the Class I area on St. John.

4.2.11 St. Thomas Sources

Emissions from this group are based on the Virgin Islands Water & Power Authority’s 39 

MW turbine that burns no. 2 distillate fuel oil. The stack parameters were based on an 

engineering estimate for similarly sized turbines.
Draft Regional Haze SIP 4-27

US Virgin Islands Tuesday, June 26, 2012

4.2.12 Other St. Croix Sources

This group represents all St. Croix emissions except for HOVENSA. The sources are 

from Table 6-4 of the AEG Anguilla Power Renewable Energy Power Generation Project (AEG, 

2010). The project details over 170 separate point sources. In order to reduce the computational 

demand on the model, seven actual sources were modeled and emissions for the remaining 

sources were modeled as a single point source having the same stack parameters and location as 

the largest emitter of PM10 on St. Croix—the Hovensa wet scrubber. The group comprises seven 

sources that represent approximately 75 percent of St. Croix’s total emissions. The St. Croix 

sources were split between groups 1 and 6, with group 1 representing the HOVENSA refinery.

4.2.13 Aggregate British Virgin Islands Sources

This group represents emissions from total oil usage on the British Virgin Islands (BVI). 

Oil usage data was taken from the Central Intelligence Agency (CIA) World Factbook. Since the 

Department of Energy (DOE) indicates that residual oil is not consumed in significant quantity in 

the BVIs, only a distillate emission factor was estimated. The distillate oil emission rates were 

calculated based on AP-42 emission factors assuming sulfur content of 0.5 percent. This group 

was modeled as a single area source representative of the island of Tortola, the closest of the 

BVIs to St. John. The source has dimensions of 2.5 km x 2.5 km and represents Road Town, the 

largest city on Tortola.

4.2.14 Simulated BVI Sources

Because of concerns of the residents of St. John that open burning on Tortula in the 

British Virgin Islands might be reducing visibility, we decided to model the effects of open 

burning on Tortula on visibility on St. John. This group represents general land clearing via open 

burning and was modeled as a single area source. The emission factors were taken from AP-42 

Chapter 11.9, Table 11.9-1 for overburden. The modeled area was 100 m x 100 m and the 

location was selected based on sensible and possible locations of future land clearing.
Draft Regional Haze SIP 4-28

US Virgin Islands Tuesday, June 26, 2012

4.2.15 St. John Off-road Sources

These are emissions from the engines of off-road vehicles on St. John. The data are from 

a 2002 non-road mobile emission inventory developed by EPA Headquarters staff, using default 

factors. These emissions were modeled as an area source on St. John.

4.3 Emissions Inventory Characteristics

This section describes emission characteristics by pollutant and source type (e.g., point, 

area, and mobile) for the island of St. John in the U.S. Virgin Islands. The modeled emissions at 

St. John are also compared to the aggregate modeled emissions from surrounding areas within 

the modeling domain with the potential to affect regional haze at St. John (i.e., Puerto Rico, BVI, 

St. Thomas, and St. Croix). 

Note that St. John has a complete emission inventory, and the emissions from nearby

areas are not complete, but it include the most significant sources. For St. Thomas and St. Croix, 

the inventory includes point sources only. The emissions for Puerto Rico are from a typical 

power plant, so we could determine if a major point source on Puerto Rico had any effect on 

visibility on St. John. The emissions from the British Virgin Islands - fuel combustion and open 

burning - are simulated as area sources.

4.3.1 Sulfur Dioxide (SO2)

Sulfur dioxide is the primary precursor pollutant for sulfate particles. Sulfate particles 

account for about 19 percent of the particle-related light extinction on the worst twenty percent 

days in the Virgin Islands. Hence, SO2 emissions are a reasonable choice for maximizing 

reductions in human-caused regional haze. 

Figure 4-1 shows that SO2 emissions are high on St. Croix, primarily due to emissions 

from the HOVENSA Refinery. Non-road sources, which consist primarily of marine vessel

sources, dominate SO2 emissions on St. John.
Draft Regional Haze SIP 4-29

US Virgin Islands Tuesday, June 26, 2012

Figure 4-1: Modeled SO2 Emissions on St. John Compared to Surrounding Areas.

4.3.2 Nitrogen Oxides (NOx)

NOx emissions contribute to visibility impairment by forming light scattering nitrate 

particles. Nitrate particles formed from combustion of sulfur in fuels account for about 14 

percent of the visibility impairment on the worst twenty percent haze days in the Virgin Islands.

Figure 4-2 shows the percent contribution from different source categories to the modeled 

NOx emissions at St. John and the aggregate NOx emissions of the surrounding areas within the 

modeling domain. Similar to SO2, non-road sources dominate NOx emissions at St. John, mostly

from marine vessel emissions. Mobile sources are the next largest contributor to the modeled 

NOx emissions from St. John, contributing approximately 7 percent of the total modeled 

emissions. The modeled emissions of NOx on St. Croix are higher than the other islands, due 

primarily to emissions from the Hovensa refinery.

0 5 10 15 20 25 30

St. John

BVI

Puerto Rico

St. Croix

St. Thomas

1,000 tons per year
Draft Regional Haze SIP 4-30

US Virgin Islands Tuesday, June 26, 2012

Figure 4-2: Modeled NOx Emissions on St. John Compared to Surrounding Areas 

Top graph: Total emissions modeled for each area.

Bottom graph: Percentage of four source categories – note that only St. John has a 

complete inventory of Point, Area, Non-road and On-road Mobile; the British Virgin 

Islands was modeled as an area source only and only point source emissions are in the 

inventory for Puerto Rico, St. Croix and St. Thomas.

4.3.3 Particulate Matter (PM)

Particles suspended in the ambient air are categorized in a variety of ways depending on 

their composition and genesis. Directly-emitted or “primary” particles are those that are emitted 

in non-gaseous form directly from the source. Secondary particles form in the atmosphere 

through chemical reactions involving precursor pollutants like SO2 and NOx.

0 5 10 15 20 25 30 35

St. John

BVI

Puerto Rico

St. Croix

St. Thomas

1,000 tons per year

0%

25%

50%

75%

100%

St. John BVI Puerto Rico St. Croix St. Thomas

Point Nonroad Area Mobile
Draft Regional Haze SIP 4-31

US Virgin Islands Tuesday, June 26, 2012

A further distinction is made between particles with an aerodynamic diameter less than or 

equal to 10 micrometers and smaller particles with an aerodynamic diameter less than or equal to 

2.5 micrometers (i.e., primary PM10 and PM2.5, respectively). For the purpose of the Virgin 

Islands regional haze modeling, all PM emissions were modeled as PM2.5. This may overestimate 

the impact of particles on haze, since PM2.5, that is, fine particulate less than 2.5 microns, 

reduces visibility more than particles larger than 2.5 microns.

Figure 4-3 shows that non-road sources dominate primary PM emissions at St. John, with 

area and mobile emissions both contributing between 7 and 8 percent of the total modeled PM 

emissions. Area sources dominate the PM emissions at BVI while only point sources were 

modeled from Puerto Rico, St. Croix, and St. Thomas. The largest source of PM emissions from 

St. John is reentrained dust from paved and unpaved roadways.

In addition to total PM2.5, elemental carbon particles were also modeled. For the purposes 

of the Virgin Islands regional haze modeling, emissions of elemental carbon were modeled as 10 

percent of total PM emissions. EC is a PM species that is emitted directly into the air from 

various combustion activities such as fireplaces, cooking, forest fires, gasoline engines, and 

agricultural activities, but are especially prevalent in diesel exhaust and woodsmoke. EC 

particles typically reside in the smaller size modes and tend to reduce visibility by absorbing

rather than scattering light.

0 1 2 3 4

St. John

BVI

Puerto Rico

St. Croix

St. Thomas

1,000 tons per year
Draft Regional Haze SIP 4-32

US Virgin Islands Tuesday, June 26, 2012

Figure 4-3: Modeled PM2.5 Emissions at St. John and Surrounding Areas 

Top graph: Total emissions modeled for each area. Bottom graph: Percentage of four 

source categories – note that only St. John has a complete inventory of Point, Area, Nonroad and On-road Mobile; the British Virgin Islands was modeled as an area source only 

and only point source emissions are in the inventory for Puerto Rico, St. Croix and St. 

Thomas.

4.4 Modeling Results

An EPA contractor used these emission inventories and the CALPUFF model to predict 

the impact of all these sources together and each category of sources separately (see Appendix 

for the full report from the contractor). Meteorological data was used from 2007-2010 because 

those years had more weather stations, in order to provide better predictions.

The BART Guidelines provide that we may use the CALPUFF5 modeling system or 

another appropriate model to predict the visibility impacts from a single source on a Class I area 

and to, therefore, determine whether an individual source is anticipated to cause or contribute to 

impairment of visibility in Class I areas, i.e., “is subject to BART.” The Guidelines state that we 

find CALPUFF is the best regulatory modeling application currently available for predicting a 

 

5 Note that our reference to CALPUFF encompasses the entire CALPUFF modeling system, which includes the 

CALMET, CALPUFF, and CALPOST models and other pre and post processors. The different versions of 

CALPUFF have corresponding versions of CALMET, CALPOST, etc. which may not be compatible with previous 

versions (e.g., the output from a newer version of CALMET may not be compatible with an older version of 

CALPUFF). The different versions of the CALPUFF modeling system are available from the model developer at 

http://www.src.com/calpuff/calpuff1.htm.

0%

25%

50%

75%

100%

St. John BVI Puerto Rico St. Croix St. Thomas

Point Nonroad Area Mobile
Draft Regional Haze SIP 4-33

US Virgin Islands Tuesday, June 26, 2012

single source’s contribution to visibility impairment (70 FR 39162 (July 6, 2005)). The BART 

Guidelines also recommend that a modeling protocol be developed for making individual source 

attributions, which in this case is the EPA-approved work plan developed by the contractor. 

To determine whether each BART-eligible source has a significant impact on visibility,

we propose to use the CALPUFF modeling to estimate daily visibility impacts above estimated 

natural conditions at the Class I area, which is the Virgin Islands National Park, covering much 

of St. John as well as Hassel Island near St. Thomas. There are no other Class I areas within 300 

kilometers (km) of any BART-eligible facility in the Virgin Islands. Emissions were modeled 

with four years worth of meteorological data, from 2007 through 2010. We used these years 

because more meteorological stations were available and the output provided from the modeling 

was closer to the actual monitored data than the period 2001 to 2004. The modeling evaluated 

the impact of three BART sources on the Class I area. EPA believes that this modeling provides 

a reasonable estimate of daily visibility impacts above estimated natural conditions at the Class I

area. Therefore, we propose to use the results of this CALPUFF modeling to determine whether 

each BART-eligible source has a significant impact on visibility. 

The next figure is a map with St. John on the right side and St. Thomas on the left side

showing receptor locations, that is, where the model predicted concentrations of pollutants. Then 

the model converted these concentrations into visibility impairment estimates. These receptors 

are placed inside the National Park, which is the Class I area. Impact of pollutants on visibility

varies across the Park. This FIP will describe the impacts of the sources on the receptor at the 

IMPROVE monitoring site in the National Park on St. John, as impacts on other locations in the 

Park do not change the conclusions of this Plan.
Draft Regional Haze SIP 4-34

US Virgin Islands Tuesday, June 26, 2012

Figure 4-4 Yellow Diamonds are Locations of Receptors for Modeling

Receptors for the CALPUFF modeling, covering the Class I area – Virgin Islands National Park 

– consisting of much of the island of St. John (on the right) and Hassel Island (in the harbor of 

the island of St. Thomas, on the left). For this FIP, we used impacts at the IMPROVE monitor 

on St. John, and some analysis was done of the impacts on Hassel Island near St. Thomas.

Modeling impact results are in the following table. This is the impact of all sources together

predicted for the location of the IMPROVE monitor on St. John.

2020

2022

2024

2026

2028

2030

2032

2034

2036

2038

293 298 303 308 313 318

U

T

M

N

orthing (km)

UTM Easting (km

Receptors
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US Virgin Islands Tuesday, June 26, 2012

Table 4-2: Results of Modeling the Virgin Islands Emission Inventory’s Impact at the 

IMPROVE site on St. John – All Emission Sources Combined.

Modeling 

Results at 

IMPROVE Site

BEXT 

(Source)

BEXT 

(BKG)

BEXT 

(Total)

Percent 

CHANGE

BEXT 

SO4

BEXT 

NO3

BEXT 

EC

BEXT 

PMF

dv 

(total)

dv 

(bkg)

∆dv

(source)

Mm-1 Mm-1 Mm-1 % Mm-1 Mm-1 Mm-1 Mm-1

2007

Best 20% Days 2.68 15.64 18.33 17.16 0.08 0.00 0.24 2.36 6.05 4.47 1.58

2007 

Worst 20% Days 17.54 15.67 33.23 112.10 3.09 0.62 1.26 12.57 11.86 4.49 7.37

2008

Best 20% Days 2.80 15.62 18.42 17.95 0.05 0.00 0.25 2.50 6.11 4.46 1.65

2008

Worst 20% Days 10.73 15.71 26.45 68.36 1.05 0.21 0.86 8.61 9.65 4.52 5.13

2009

Best 20% Days 2.89 15.62 18.51 18.49 0.04 0.00 0.26 2.59 6.15 4.46 1.70

2009

Worst 20% Days 12.53 15.70 28.24 79.88 1.77 0.32 0.95 9.49 10.19 4.51 5.68

2010

Best 20% Days 2.95 15.58 18.53 18.95 0.01 0.00 0.27 2.67 6.17 4.43 1.73

2010

Worst 20% Days 8.83 15.70 24.54 56.32 2.32 0.51 0.55 5.46 8.85 4.51 4.34

Average Best 

20% Days 2.83 18.45 0.05 0.00 0.26 2.53 6.12 1.67

Average Worst 

20% Days 12.41 28.12 2.06 0.42 0.91 9.03 10.14 5.63

Key to Modeling Results Table: BEXT is beta extinction; the amount of light removed along 

the light’s path to an observer over a standard distance. The larger the number, the worse the 

visibility. In this case, light lost over per one million meters (giving a unit of Mm-1, usually

called ‘inverse megameters’)

dv is deciviews, a unit of visibility impairment where a change of 1 dv is an amount of change 

people can see. 

See the box in section 3.2 for a comparison of the units used for visibility.

 BEXT (Source) – Modeled beta extinction coefficient from the source’s emissions

 BEXT (BKG) – Background beta extinction coefficient (from a formula of annual 

background)
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 BEXT (Total) – beta extinction coefficient of modeled plus background visibility 

impairment

 Percent Change – percent of source’s impact compared to background (e.g., 100% 

means the impact is equal to the background visibility, that would double the visibility 

impairment over the estimated background

 BEXT SO4 – beta extinction coefficient of modeled impact of sulfate on visibility

 BEXT NO3 – beta extinction coefficient of modeling impact of nitrates on visibility

 BEXT EC – beta extinction coefficient from IMPROVE monitor elemental carbon;

 BEXT PMF – beta extinction coefficient from IMPROVE monitor fine particulate matter;

 dv (total) – deciview haze index from modeled emissions + calculated background;

 dv (bkg) – estimated background deciview haze index

 ∆dv (source) – change in deciview haze index due to the impact of the individual source 

or source categories on visibility

Modeling results are shown for the IMPROVE monitoring site on St. John. Data are also 

available for a receptor on Hassel Island, in the harbor on the southern end of St. Thomas. See 

the modeling report for details.
Draft Regional Haze SIP 4-37

US Virgin Islands Tuesday, June 26, 2012

The following graph shows the relative impact of the modeled source categories on visibility at 

the IMPROVE monitor on St. John using meteorology from 2007 - 2010.

Figure 4-5: Modeled Impacts at IMPROVE Monitoring Site on St. John by Emissions 

Grouped Type of Emission
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US Virgin Islands Tuesday, June 26, 2012

Most of the impact on visibility from human emissions is due to dirt lofted into the air by

construction and from motor vehicles kicking up dust from paved and unpaved roads on St. John. 

Most of this dust is made up of coarse particles, which have an effect over relatively short 

distances, but being close to the monitoring site can have a large effect. The modeling does not 

include effects from natural sources, like Saharan Dust or sulfate from phytoplankton in the 

ocean.

4.5 Future Year Emission Control Inventories

Projection-year inventories typically consist of: control of or reduction of emissions from 

sources and, increases or decreases due to growth or contraction of the economy or of source 

emissions.

The future-year emission reductions for the U.S. Virgin Islands Haze Plan are from the 

reductions in HOVENSA due to the consent decree and reductions in emissions from marine 

vessels from implementation of the ECA. 

Emission reductions that we haven’t quantified are likely to occur in the following areas:

 replacement of old motor vehicles with newer, cleaner vehicles would decrease 

emissions; 

 use of cleaner fuels in homes, businesses and vehicles would decrease emissions;

 increases or decreases in population or tourism could increase or decrease 

emissions. 

These changes are more difficult to assess in the Virgin Islands than for most locations because 

of its remote location and lack of direct ties with other states. The Virgin Islands may experience 

a mix of vehicles further from the national averages and have less similar rates of vehicle 

turnover than other states. Federal regulations for new motor vehicles require new models of 

vehicles have reduced emissions, cleaner fuels and additional controls on off-road vehicles may

be take longer to occur in the Virgin Islands than in the continental United States. The fleet of 

vehicles in the Virgin Islands may not change as rapidly due to the isolated location and may

change less predictably due to the small fleet of vehicles.
Draft Regional Haze SIP 5-39

US Virgin Islands Tuesday, June 26, 2012

Thus, this plan does not attempt to quantify emissions changes due to growth or 

decreases due to default emission reductions that other plans use. For the 2018 future case, post 

control, emission inventory, this plan only adjusts emissions to account for control strategies

specifically related to particular sources in the Virgin Islands. 

5.0 EVALUATION OF REASONABLE CONTROL MEASURES

5.1.1 HOVENSA

The emissions from the HOVENSA refinery on St. Croix have a relativity small impact 

on visibility on St. John for a large refinery only 40 miles away. A facility that may have a 

noticeable effect on visibility with a predicted impact of 1.06 dv on visibility in the Class I area 

on St. John must have a review to determine if reasonable controls exist. For HOVENSA, at this 

time, EPA will accept that the reductions negotiated in the Consent Decree are ‘reasonable’ 

controls for this facility. This facility is mostly shutdown at this time of the FIP, so developing 

controls beyond the consent decree is not reasonable at this time. If the facility is going to be 

reopened, before reactivating HOVENSA must prepare and submit to EPA for approval an 

analysis of reasonable emission reductions following EPA’s guidelines for reasonable reductions 

for Regional Haze.

. 

5.1.2 St. John Point Sources -Generators

These sources are power generators, most for backup electric power. The impact of these 

sources, combined, of 0.30 dv, is low enough not to need a full review for reasonable controls.

Most of these sources do not operate all the time. The only full-time source in this category is a 

laundry drier that runs on propane, which has relatively low emissions, and practically no 

emissions of sulfur, so there is no sulfate produced and not much contribution to visibility

obstruction. 
Draft Regional Haze SIP 5-40

US Virgin Islands Tuesday, June 26, 2012

5.1.3 St. John Marine Sources

These sources include ferries, cruise ships, and cargo ships that dock at St. John. The 

Caribbean ECA (Emissions Control Area) emission reductions for ocean vessels are included in 

the future case modeling. Beginning in 2015, fuel used by all vessels operating in these areas 

cannot exceed 0.1 percent fuel sulfur (1,000 ppm). This requirement is expected to reduce PM 

and SOx emissions by more than 85 percent. Beginning in 2016, new engines on vessels 

operating in these areas must use emission controls that achieve an 80 percent reduction in NOx 

emissions. While these reductions are not enforceable as part of this FIP, EPA expects them to 

occur and they will be included in the reductions expected in the period through 2018.

5.1.4 St. John Paved and Unpaved Road Fugitive Sources

Fugitive dust emissions from roadways on St. John contribute to visibility reduction via 

the coarse particulate fraction. Paving dirt roads in the National Park is not reasonable, as it 

would detract from the rustic, primitive nature of the Park. Implementation plans often include 

street sweeping to reduce reentrained dust from roadways. On St. John, based on past experience, 

the road dust is mostly dirt washed onto the roads in heavy, tropical downpours. These 

downpours erode the steep terrain of the island onto the roads and require more than street 

sweeping and pavement wetting to reduce reentraining this dirt. Thus, this source is not 

reasonable for control measures at this time. EPA will discuss with VIDPNR possibilities for 

reducing erosion from hillsides, which would also reduce silt washed into the ocean that may

affect the growth of fragile coral reefs. 

5.1.5 Aggregate St. John Burning

This group covers all sources of fires on St. John, including open burning, forest fires, 

and structure fires. This group has a small effect on modeled visibility, less than half a deciview. 

EPA will review with VIDPNR existing rules for containment of open burning on St. John, but 

we expect that reductions in emissions due to better control of open burning will not be 

significant enough to noticeably improve visibility. 
Draft Regional Haze SIP 5-41

US Virgin Islands Tuesday, June 26, 2012

5.1.6 St. John Residential Boilers

Emissions in this group are from residential heating, mostly for hot water, on St. John. 

Their contribution to modeled haze of 0.01 dv is too small to consider for reasonable controls to 

reduce haze. 

5.1.7 St. John Miscellaneous Industrial Processes -- Construction

This group’s emissions are particulate emissions on St. John from home construction and 

a concrete facility and are predicted by modeling to cause a noticeable reduction in visibility. 

The major controllable source, a concrete facility, has less than four percent of the emissions in 

this category and so controls on concrete production would not improve visibility substantially. 

EPA will review with the VIDPNR its rules for suppression of particulate emissions during 

construction and determine if the existing rules are sufficient or can be modified or if 

enforcement can be increased to reduce emissions from construction on St. John. 

5.1.8 St. John Motor Vehicle Emission Sources

These sources are motor vehicle emissions on St. John, with a 0.08 dv impact on 

visibility on St. John. While cleaner vehicles in the future will reduce mobile source emissions in 

all locations, St. John’s fleet of vehicles is small, the makeup of the present fleet may be different 

from United States national defaults, the rate of vehicle turnover is affected by the remote 

location with no connecting roads to the outside world, and the difficulty of forecasting a future 

rate of increase or decrease in use of motor vehicles on St. John. This all adds up to making the 

uncertainties in projecting future emissions likely to be almost as large as the present estimated 

emissions themselves. Reductions are likely as new vehicles are brought to the island, but the 

small impact of motor vehicle emissions on visibility make any future change small as well.

5.1.9 Sample Puerto Rico Source

We modeled a major power plant on Puerto Rico as if it was on the east coast of Puerto 

Rico, nearer to the Virgin Islands, to see if any major source on Puerto Rico could have an 

impact on visibility on St. John. Modeling predicts a lack of impact of this major source on St. 

John. This is likely to be due to Puerto Rico being downwind of St. John almost all the time. 
Draft Regional Haze SIP 5-42

US Virgin Islands Tuesday, June 26, 2012

Thus, emission reductions from Puerto Rico will not have a quantifiable effect on visibility on 

St. John.

5.1.10 St. Thomas Sources

The emissions from the Virgin Islands Water & Power Authority on St. Thomas are 

downwind of St. John, accounting for VIWAPA’s small (0.04 dv) impact on visibility on St. 

John. Controls would result in small, perhaps too small to quantify, reductions.

5.1.11 Other St. Croix Sources

Emissions from other sources on St. Croix other than HOVENSA have less than a half a 

deciview impact on visibility on St. John. With 170 separate point sources, reductions would 

have to occur at many different locations to quantify even a small improvement in visibility on 

St. John, so controls on these sources are not reasonable.

5.1.12 Aggregate British Virgin Islands Combustion Sources

The impact of oil usage in the British Virgin Islands amounts to only 0.36 dv on St. John. 

Even if the impact of these emissions were larger, emission reductions would need to be 

negotiated with the British Government. International controls are beyond the scope of this FIP. 

5.1.13 Simulated BVI Sources

Because of concerns of the residents of St. John that open burning on Tortula in the 

British Virgin Islands might be reducing visibility, we decided to simulate the effects of open 

burning of Tortula on visibility on St. John. This group represents a hypothetical source of 

emissions from general land clearing via open burning. The impact was too small to contribute to 

visibility impairment on St. John.
Draft Regional Haze SIP 6-43

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5.1.14 St. John Off-Road Sources

These are direct emissions from off-road vehicles on the island of St. John. With a total 

predicted impact of 0.18 dv, these emissions are not contributing to noticeable impairment of 

visibility.

In summary, only emissions from HOVENSA are large enough and have possibilities for 

reasonable control. EPA has determined that the existing consent decree is, by its nature, a 

starting point for reasonable controls for this facility. If the facility reopens, EPA requires that 

HOVENSA perform a complete evaluation to determine what levels of control are reasonable, by 

evaluating all sources at HOVENSA. A useful methodology would be EPA’s multi-factor 

analysis as described in EPA’s Regional Haze Rule.

6.0 BEST AVAILABLE RETROFIT TECHNOLOGY

As required by 40 CFR §51.308(e), the plan evaluates sources within the Virgin Islands 

to determine if they are BART-eligible and if they may reasonably be anticipated to cause or 

contribute to any impairment of visibility in any mandatory Class I Federal area. The BART 

evaluation determines if controls should be implemented on any sources subject to BART within 

in the Virgin Islands. 

BART is an element of EPA’s LTS, as well as a requirement to evaluate controls for 

older sources that affect Class I areas, for the first implementation period. The BART regional 

haze requirement consists of three steps: (a) identification of all the BART-eligible sources; (b) 

an assessment of whether the BART-eligible sources are subject to BART; and (c) the 

determination of the BART controls. 

6.1 The BART Rule

The BART requirements pertain to large facilities in each of 26 source categories that 

meet certain criteria, including industrial boilers, paper and pulp plants, cement kilns, and other 

large stationary sources. The BART program applies to units installed and operated between 
Draft Regional Haze SIP 6-44

US Virgin Islands Tuesday, June 26, 2012

1962 and 1977 with the potential to emit more than 250 tons per year of a visibility impairing 

pollutant. Each potential BART unit must be modeled to determine its impact on the Class I area. 

If a unit is determined to be BART-eligible, the unit must undergo a case-by-case analysis to 

determine if new emission limits are appropriate to limit its impact on Class I areas. The BART 

requirements are intended to reduce emissions specifically from large sources that, due to age, 

were exempted from new source performance standards (NSPS) requirements of the Clean Air 

Act. In June 2005, EPA adopted the final BART rule.

To meet the BART rule, the EPA has developed an inventory of sources within the 

Territory of the Virgin Islands that could be eligible for controls. The rule also includes 

information on:

 Methods to determine if a source is “reasonably anticipated to cause or contribute to 

haze”

 Methodology for conducting BART control analysis

 Presumptive limits for electricity generating units (EGUs) larger than 750 Megawatts

Beyond the specific elements listed above, the final BART rule provides a great deal of 

flexibility in implementing the BART program.

The following sections provide information on how this plan meets the core requirements 

of the BART regulations.

6.2 Potential BART Sources in the Virgin Islands

The first component of a BART evaluation is to identify all the BART eligible sources 

within the United States Virgin Islands (“Virgin Islands” or “Territory”). While the Virgin 

Island’s Department of Planning and Natural Resources (VIDPNR), the Territory’s 

environmental agency, did not submit a SIP, EPA’s evaluation process of identifying BARTeligible sources included a review of Title V permits, a review of Title V applications received 

from VIDPNR, and direct communications with HOVENSA, LLC, one of the BART-eligible 

sources. To establish which facilities are BART-eligible, EPA evaluated eligibility criteria for 

combustion and other process units at the following eight sources throughout the Territory: 

 HOVENSA, LLC (St. Croix)
Draft Regional Haze SIP 6-45

US Virgin Islands Tuesday, June 26, 2012

 Three of the Virgin Islands Water and Power Authority (VI WAPA) facilities – one on 

each of the islands (St. Croix, St. Thomas and St. John)

 St. Croix Renaissance Group, LLLP (St. Croix)

 Wyndham Sugar Bay Beach Club & Resort (St. Thomas)

 Divi Carina Bay Hotel (St. Croix)

 Buccaneer Hotel (St. Croix)

A BART-eligible source is one that meets all of the following criteria. These criteria are in 

section 169A(b)(2)(A) of the Act, codified in 40 CFR Part 51, Appendix Y:

 One or more emissions units at the facility are within one of the 26 categories listed in the 

BART Guidelines (70 FR 39104, 39158-39159 (July 6, 2005));

 The emission unit(s) began operation after August 6, 1962 and were still in existence on 

August 7, 1977

 Potential emissions of SO2, NOx, and PM10 from subject units are 250 tons or more per 

year. 

Table 6-1: BART-eligible Sources in the Virgin Islands:

Facilities Units BART Source

Category 

Location Summary of 

Evaluation

VI WAPA 2 boilers and 

2 combustion turbines

Fossil fuel-fired steam 

electric plant of > 250 

mm BTU/hr 

St. 

Thomas

Impact on visibility

is very small: not 

subject to BART 

VI WAPA 2 boilers Fossil fuel-fired steam 

electric plant of > 250 

mm BTU/hr

St. Croix Impact on visibility

is very small: not 

subject to BART 

HOVENSA 8 boilers Petroleum 

Refinery

St. Croix Sulfur emissions 

control not cost 

effective. Nitrogen 

emissions control 

cost effective, but 

small impact on 

visibility: subject to 

BART analysis

9 combustion turbines

64 process heaters

11 reciprocating gas 

compressors

1 tail gas treatment unit

3 tail gas incinerators

5 flares

water intake pumps and 

desalination water pump
Draft Regional Haze SIP 6-46

US Virgin Islands Tuesday, June 26, 2012

Summary of EPA’s Evaluation

EPA identified three of the eight sources, including multiple combustion or process units 

at each source, as BART-eligible. The three BART-eligible sources identified by EPA as 

potentially impacting the Class I area, are summarized in Table 6-1. None of the remaining five 

sources met these criteria and therefore were removed from consideration for BART review. 

EPA evaluated the three BART-eligible sources to determine if BART controls should be 

required for each of the BART-eligible stacks from these sources. Table 6-1 includes a summary

of the evaluation, which is described in more detail in the following subsections.

6.2.1 Cap-Outs and Shutdowns

Some BART-eligible facilities with relatively small emission but with potential emissions 

that exceeded the statutory threshold of 250 tons per year or more may be exempted from BART 

requirements if the actual emissions of visibility impairing pollutants are well under 250 tons in 

any year. Such facilities may have accepted a permit limitation, restricting their emissions by law 

to less than 250 tons per year. There are no sources in the Virgin Islands that qualified for this 

option.

In January 2012, HOVENSA, LLC announced it would be shutting down its refinery

located on the Virgin Islands. Until the facility revises its Title V permits, the emission 

inventories for the base and future case, and for BART analyses, will still consider the emissions 

from a fully operating HOVENSA refinery, complying with its consent decree, and full 

emissions will be the basis for any BART analysis that may be required. 

6.3 Sources Subject to BART

According to Section III of the 2005 Regional Haze Rule, once the state has compiled its 

list of BART-eligible sources, it needs to determine whether to make BART determinations for 

all of the sources or to consider exempting some of them from BART because they may not 

reasonably be anticipated to cause or contribute to any visibility impairment in a Class I area.
Draft Regional Haze SIP 6-47

US Virgin Islands Tuesday, June 26, 2012

The BART Guidelines recommend addressing SO2, NOx, and PM10 as visibilityimpairment pollutants. The Guidelines note that states can decide whether to evaluate VOC or 

ammonia emissions. EPA is not developing additional strategies for VOC or ammonia emissions 

in its FIP. EPA proposes to determine that the lack of tools available to estimate emissions and 

subsequently model VOC and ammonia effects on visibility inhibits EPA from addressing BART 

for these. 

Furthermore, EPA noted in its proposed rule on BART evaluations (69 FR 25184) that 

EPA determined in the NOx SIP Call notice for the eastern continental United States (63 FR 

57356) that VOCs do not contribute in a large amount to the formation of particulate matter in 

rural areas, as cited by EPA in its proposed BART guidance. While EPA noted in its final 

guidance on BART determinations ( 70 FR 39144) that EPA does not agree that rural VOC 

emissions can be ruled out as a significant contributor to particle formation, and may play a 

significant role where NOx emissions are high, the complicated and rapidly evolving state of 

knowledge of particle formation by VOCs leads EPA to the conclusion that determination of the 

approach to follow in considering whether VOC emissions are precursors to PM2.5 formation is 

a case-by-case approach. In the case of the Virgin Islands, where development of an emission 

inventory for VOC is in its early stages, EPA will defer evaluation of the impact of VOC 

emissions’ contribution to visibility reduction to the next round of visibility plans covering 2018 

to 2028.

6.4 Anticipated Visibility Improvement as a result of BART

The EPA conducted a modeling analysis of BART-eligible sources using CALPUFF in 

order to assess the degree of visibility improvement which could result from installation of 

BART controls. The EPA considered the results of this analysis in its determination of BART for 

individual sources.

Because there are only three BART-eligible sources in the Virgin Islands, which impact 

only one Class I area, so EPA evaluated each source by itself. As shown in Table 6-2, EPA will 

exempt two of the three BART-eligible sources in the Virgin Islands from further review under 

the BART requirements, since their impacts are very small.

This leaves HOVENSA as having the only BART-eligible stacks in the Virgin Islands. 
Draft Regional Haze SIP 6-48

US Virgin Islands Tuesday, June 26, 2012

Table 6-2: Individual BART-Eligible Source Visibility Impacts on Virgin Islands Class I 

Area

Facility and 

Location

Class I Area

And Locations of 

Modeling Receptor

Average 4-year

98th Percentile

Visibility Impact, 

(deciviews)

Subject to BART

Analysis?

VI WAPA

St. Thomas

St. John

Hassel Island,

St Thomas

0.06

0.04

No

VI WAPA

St. Croix

St. John

Hassel Island,

St Thomas

0.09

0.10

No

HOVENSA

St. Croix

St. John

Hassel Island,

St. Thomas

1.88

2.25

Yes

6.4.1 Reasonably Attributable Visibility Impairment

Section 31.302 (c) provides for general plan requirement in cases where the affected 

FLM has notified the State that Reasonably Attributable Visibility Impairment (RAVI) exists in 

a Class I Area in the state. There are no RAVI sources in the Virgin Islands. The FIP

incorporates the provisions of 40 CFR 52.26, 52.29, to address RAVI in the Virgin Islands.

6.5 Determination of BART Requirements for Identified BART-Eligible Sources and 

Analysis of Best System for Each Source

6.5.1 Five Factor Analysis for Each BART Source

The BART cost analysis for each BART-eligible source is included in the EPA 

contractor’s report in an Appendix. The BART analysis includes a modeling analysis to include 

consideration of the degree of improvement in visibility (included in an appendix), cost of 

controls, energy and non-air quality environmental impacts, existing controls at the source, and 

the remaining useful life of the source. The BART-eligible sources in the Virgin Islands are 

shown in Tables 6-2 through 6-4 for each visibility impairing pollutant. These Tables include 

the contractor’s evaluation of possible BART controls. BART is the emission limit for each 

pollutant based on the EPA’s evaluation of degree of reduction achievable through the 

application of the best system of continuous emission reduction, taking into consideration the 

technology available, the costs of compliance, the energy and the non-air quality environmental 
Draft Regional Haze SIP 6-49

US Virgin Islands Tuesday, June 26, 2012

impacts of compliance, any pollution control equipment in use or in existence at the source, the 

remaining useful life of the source, and the degree of improvement in visibility which may

reasonably be anticipated to result from the use of such technology. 

EPA determined BART for each BART-eligible source using the methodology in the 

Guidelines for Best Available Control Retrofit Technology (BART) Determinations under the 

Regional Haze Rules, 40 CFR Part 51, Appendix Y. 

There are no BART-eligible sources on the island of St. John, where the National Park is 

located.
Draft Regional Haze SIP 6-50

US Virgin Islands Tuesday, June 26, 2012

Table 6-3: Sulfur Dioxide Emissions Evaluations for Potential BART Sources

Source and 

Unit ID # Location

Baseline 

Emissions 

(tpy)

Emissions 

at 

Maximum 

Utilization 

Capacity

BART 

Level of 

Control 

(%)

Emissions 

After 

Controls 

(tpy)

Emissions 

Reductions 

(tpy)

Type of 

Control

Hovensa Boiler 

3

B-1153 St Croix 330.1 330.1 55.0 148.5 181.5

DIFF, 

SNCR

Hovensa Boiler 

5

B-1155 St Croix 484.9 484.9 55.0 218.2 266.7

DIFF, 

SNCR

Hovensa Boiler 

6

B-3301 St Croix 330.8 330.8 55.0 148.9 182.0

DIFF, 

SNCR

Hovensa Boiler 

7

B-3302 St Croix 330.8 330.8 55.0 148.9 182.0

DIFF, 

SNCR

Hovensa 

Turbine GT8 G-3408 St Croix 167.6 167.6 55.0 75.4 92.2

DIFF, 

SCR

Hovensa Boiler 

1

B-1151 St Croix 330.1 330.1 55.0 148.5 181.5

DIFF, 

SNCR

Hovensa Boiler 

4

B-1154 St Croix 322.5 322.5 55.0 145.1 177.4

DIFF, 

SNCR

Hovensa Boiler 

8

B-3303 St Croix 640.1 640.1 55.0 288.0 352.1

DIFF, 

SNCR

Hovensa Boiler 

9

B-3304 St Croix 640.1 640.1 55.0 288.0 352.1

DIFF, 

SNCR

Hovensa 

Turbine GT1

G1101E St Croix 135.5 135.5 55.0 61.0 74.5DIFF, 

SCR

Hovensa 

Turbine GT2

G1101F St Croix 135.5 135.5 55.0 61.0 74.5DIFF, 

SCR

Hovensa 

Turbine GT3

G1101G St Croix 135.5 135.5 55.0 61.0 74.5DIFF, 

SCR

Hovensa 

Turbine GT4 G-3404 St Croix 161.0 161.0 55.0 72.4 88.5

DIFF, 

SCR

Hovensa 

Turbine GT5 G-3405 St Croix 161.0 161.0 55.0 72.4 88.5

DIFF, 

SCR

Hovensa 

Turbine GT6 G-3406 St Croix 161.0 161.0 55.0 72.4 88.5

DIFF, 

SCR

Hovensa 

Turbine GT7 G-3407 St Croix 161.0 161.0 55.0 72.4 88.5

DIFF, 

SCR

Hovensa 

Turbine GT9 G-3409 St Croix 52.2 52.2 55.0 23.5 28.7

DIFF, 

SCR

VI WAPA 

Boiler 11 11 St Thomas 646.0 646.0 55.0 290.7 355.3

DIFF, 

SNCR

VI WAPA 

Boiler 13 13 St Thomas 1,116.0 1,116.0 55.0 502.2 613.8

DIFF, 

SNCR

VI WAPA 

Turbine 12 12 St Thomas 381.0 381.0 55.0 171.5 209.6

DIFF,

SCR

VI WAPA 

Turbine 14 14 St Thomas 392.0 392.0 55.0 176.4 215.6

DIFF, 

SCR

VI WAPA 

Boiler 10 10 St Croix 396.0 396.0 55.0 178.2 217.8

DIFF, 

SNCR

VI WAPA 

Boiler 11 11 St Croix 712.0 712.0 55.0 320.4 391.6

DIFF, 

SNCR
Draft Regional Haze SIP 6-51

US Virgin Islands Tuesday, June 26, 2012

Table 6-4: Nitrogen Oxides Emissions Evaluation for Potential BART Sources

Source 

and 

Unit ID # Location

Baseline 

Emissions 

(tpy)

Emissions 

at 

Maximum 

Utilization 

Capacity

BART 

Level 

of 

Control 

(%)

Emissions 

After 

Controls 

(tpy)

Emissions 

Reductions 

(tpy)

Type of 

Control

Hovensa 

Boiler 3

B1153 St Croix 450.6 450.6 65.0 157.7 292.9DIFF, 

SNCR

Hovensa 

Boiler 5

B1155 St Croix 676.9 676.9 65.0 236.9 440.0DIFF, 

SNCR

Hovensa 

Boiler 6

B3301 St Croix 435.3 435.3 65.0 152.3 282.9DIFF, 

SNCR

Hovensa 

Boiler 7

B3302 St Croix 435.3 435.3 65.0 152.3 282.9DIFF, 

SNCR

Hovensa 

Turbine 

GT8

G3408 St Croix

1002.1 1002.1

80.0

200.4 801.7

DIFF, 

SCR

Hovensa 

Boiler 1

B1151 St Croix 450.6 450.6 65.0 157.7 292.9DIFF, 

SNCR

Hovensa 

Boiler 4

B1154 St Croix 443.5 443.5 65.0 155.2 288.3DIFF, 

SNCR

Hovensa 

Boiler 8

B3303 St Croix 559.8 559.8 65.0 195.9 363.9DIFF, 

SNCR

Hovensa 

Boiler 9

B3304 St Croix 559.8 559.8 65.0 195.9 363.9DIFF, 

SNCR

Hovensa 

Turbine 

GT1

G1101E St Croix

805.7 805.7

80.0

161.1 644.6

DIFF, 

SCR

Hovensa 

Turbine 

GT2

G1101F St Croix

805.7 805.7

80.0

161.1 644.6

DIFF, 

SCR

Hovensa 

Turbine 

GT3

G1101G St Croix

805.7 805.7

80.0

161.1 644.6

DIFF, 

SCR

Hovensa 

Turbine 

GT4

G3404 St Croix

809.5 809.5

80.0

161.9 647.6

DIFF, 

SCR

Hovensa 

Turbine 

GT5

G3405 St Croix

766.5 766.5

80.0

153.3 613.2

DIFF, 

SCR

Hovensa 

Turbine 

GT6

G3406 St Croix

766.5 766.5

80.0

153.3 613.2

DIFF, 

SCR

Hovensa 

Turbine 

GT7

G3407 St Croix

766.5 766.5

80.0

153.3 613.2

DIFF, 

SCR

Hovensa 

Turbine 

GT9

G3409 St Croix

150.2 150.2

80.0

30.0 120.2

DIFF, 

SCR

VI 

WAPA 

Boiler 

11

11 St 

Thomas

371.0 371.0

65.0

129.9 241.2

DIFF, 

SNCR

VI 

WAPA 

Boiler 

13

13 St 

Thomas

670.0 670.0

65.0

234.5 435.5

DIFF, 

SNCR

VI 

WAPA 12 St Thomas 1288.0 1288.0 80.0 257.6 1030.4

DIFF, 

SCR
Draft Regional Haze SIP 6-52

US Virgin Islands Tuesday, June 26, 2012

Source 

and 

Unit ID # Location

Baseline 

Emissions 

(tpy)

Emissions 

at 

Maximum 

Utilization 

Capacity

BART 

Level 

of 

Control 

(%)

Emissions 

After 

Controls 

(tpy)

Emissions 

Reductions 

(tpy)

Type of 

Control

Turbine 

12

VI 

WAPA 

Turbine 

14

14 St 

Thomas

1326.0 1326.0

80.0

265.2 1060.8

DIFF, 

SCR

VI 

WAPA 

Boiler 

10

10 St Croix

359.0 359.0

65.0

125.7 233.4

DIFF, 

SNCR

VI 

WAPA 

Boiler 

11

11 St Croix

646.0 646.0

65.0

226.1 419.9

DIFF, 

SNCR

Table 6-5: PM10 Emissions Evaluation for Potential BART Sources

Source and Unit ID # Location

Baseline 

Emissions 

(tpy)

Emissions 

at 

Maximum 

Utilization 

Capacity

BART 

Level 

of 

Control 

(%)

Emissions 

After

Controls 

(tpy)

Emissions 

Reductions 

(tpy)

Type of 

Control

Hovensa Boiler 3 B-1153 St Croix 40.6 40.6 99.0 0.4 40.2

DIFF, 

SNCR

Hovensa Boiler 5 B-1155 St Croix 60.7 60.7 99.0 0.6 60.1

DIFF, 

SNCR

Hovensa Boiler 6 B-3301 St Croix 40.6 40.6 99.0 0.4 40.2

DIFF, 

SNCR

Hovensa Boiler 7 B-3302 St Croix 40.6 40.6 99.0 0.4 40.2

DIFF, 

SNCR

Hovensa Turbine GT8 G-3408 St Croix 15.1 15.1 99.0 0.2 14.9

DIFF, 

SCR

Hovensa Boiler 1 B-1151 St Croix 40.6 40.6 99.0 0.4 40.2

DIFF, 

SNCR

Hovensa Boiler 4 B-1154 St Croix 39.7 39.7 99.0 0.4 39.3

DIFF, 

SNCR

Hovensa Boiler 8 B-3303 St Croix 78.6 78.6 99.0 0.8 77.8

DIFF, 

SNCR

Hovensa Boiler 9 B-3304 St Croix 78.6 78.6 99.0 0.8 77.8

DIFF, 

SNCR

Hovensa Turbine GT1 G-1101E St Croix 12.2 12.2 99.0 0.1 12.0

DIFF, 

SCR

Hovensa Turbine GT2 G-1101F St Croix 12.2 12.2 99.0 0.1 12.0

DIFF, 

SCR

Hovensa Turbine GT3 G-1101G St Croix 12.2 12.2 99.0 0.1 12.0

DIFF, 

SCR

Hovensa Turbine GT4 G-3404 St Croix 12.9 12.9 99.0 0.1 12.8

DIFF, 

SCR

Hovensa Turbine GT5 G-3405 St Croix 12.9 12.9 99.0 0.1 12.8

DIFF, 

SCR

Hovensa Turbine GT6 G-3406 St Croix 12.9 12.9 99.0 0.1 12.8

DIFF, 

SCR

Hovensa Turbine GT7 G-3407 St Croix 12.9 12.9 99.0 0.1 12.8

DIFF, 

SCR
Draft Regional Haze SIP 6-53

US Virgin Islands Tuesday, June 26, 2012

Source and Unit ID # Location

Baseline 

Emissions 

(tpy)

Emissions 

at 

Maximum 

Utilization 

Capacity

BART 

Level 

of 

Control 

(%)

Emissions 

After

Controls 

(tpy)

Emissions 

Reductions 

(tpy)

Type of 

Control

Hovensa Turbine GT9 G-3409 St Croix 14.0 14.0 99.0 0.1 13.9

DIFF, 

SCR

VI WAPA Boiler 11 11 St Thomas 60.0 60.0 99.0 0.6 59.4

DIFF, 

SNCR

VI WAPA Boiler 13 13 St Thomas 28.0 28.0 99.0 0.3 27.7

DIFF, 

SNCR

VI WAPA Turbine 12 12 St Thomas 15.0 15.0 99.0 0.2 14.9

DIFF, 

SCR

VI WAPA Turbine 14 14 St Thomas 16.0 16.0 99.0 0.2 15.8

DIFF, 

SCR

VI WAPA Boiler 10 10 St Croix 45.0 45.0 99.0 0.5 44.6

DIFF, 

SNCR

VI WAPA Boiler 11 11 St Croix 81.0 81.0 99.0 0.8 80.2

DIFF, 

SNCR

Steam Boilers

HOVENSA owns and operates nine steam boilers that are capable of combusting either 

refinery fuel gas (RFG) or No. 6 fuel oil and the heat input to the boilers is in the range of 205 to 

405 mm BTU/hr. 

One of the boilers (Boiler 10) was constructed in 1999 and therefore is not BARTeligible. EPA has determined that the following boilers are subject to BART: Boilers 1 (B1151), 3 (B-1153), 4 (B-1154), 5 (B-1155), 6 (B-3301), 7 (B-3302), 8 (B-3303, and 9 (B-3304). 

HOVENSA has indicated that Boiler 2 is no longer in service. SO2 emissions are controlled by a 

permit limiting the sulfur content of No. 6 fuel oil to 0.50% or 1.0% depending upon wind 

conditions. In addition, the June 2011 consent decree will lower SO2 emissions by requiring that 

the combustion of RFG, containing hydrogen sulfide (H2S), meet the requirements of the New 

Source Performance Standards (NSPS) at Part 60, subparts J and Ja: Boilers 1-5 subject to BART 

must meet subpart Ja requirements that limits the H2S content of RFG to 162 ppmv (3-hour 

rolling average) and 60 ppmv (daily on a 365 day rolling average); Boilers 6-9 subject to BART 

must meet the subpart J requirements that limits the H2S content of RFG to 0.10 grains per dry

standard cubic feet (equivalent to about 162 ppmv). The June 2011 consent decree will also 

lower the sulfur content of No. 6 fuel oil to 0.55% maximum , 0.50% annually, and to a low limit 

0.30% should wind conditions warrant this (as defined in the CD). There are no existing controls 

for NOx and PM emissions from the BART-eligible boilers. 
Draft Regional Haze SIP 6-54

US Virgin Islands Tuesday, June 26, 2012

For control of SO2, NOx and PM emissions, based upon EPA’s analysis, EPA is 

proposing that current operations represent BART for each of the boilers subject to BART. For 

SO2 and PM control, EPA’s contractor evaluated Duct Injection and Fabric Filters (DIFF) using 

lime as the alkaline reagent. DIFF is a semi-wet flue gas desulfurization (FGD) process, with 

additional water added to humidify and cool the gas stream to the desired reaction temperature. 

The fabric filter is the PM control device that would collect the sulfur reactant products and any 

PM formed directly from the combustion process. EPA determined that the cost effectiveness 

for the eight boilers subject to BART varied in the range of about $19,100 to $39,600 per ton of 

SO2 and PM reduced. EPA has determined that for the DIFF controls evaluated for the boilers 

subject to BART, Boilers 1 and 3-9, the cost-effective values are too high to be effective control.

In addition, it is EPA’s opinion that if maximum controls had been evaluated, such as lime or 

limestone wet FGD, the cost effectiveness would be even higher than for the DIFF controls 

evaluated. Therefore, EPA determines that for SO2 and PM controls, current operation is 

considered as BART. 

For control of NOx emissions, EPA’s contractor evaluated selective non-catalytic 

reduction (SNCR) using ammonia as the reagent. EPA has determined that implementation of 

SNCR controls for boilers subject to BART are cost effective. The actual cost effectiveness for 

the boilers is in the range of about $710 to $860 per ton of NOx removed. As summarized in 

Table 8, the visibility impact (98th percentile, 4 year average, see modeling report in the 

Appendix) of all BART-eligible sources at HOVENSA on two receptors in the Class I area, St. 

John and Hassel Island near St. Thomas are 1.91 dv and 2.35 dv, respectively for all pollutants. 

EPA further analyzed the contribution of various chemical species and components on the 

visibility impacts and has established that the contribution of NOx compounds from all potential 

BART sources at HOVENSA is about 5% which would be equivalent to about a 0.09 dv 

visibility impact at St. John and 0.91 for Hassel Island from all HOVENSA units subject to 

BART6. EPA has not analyzed the portion of the NOx contribution specifically from only the 8 

boilers subject to BART since HOVENSA is not currently operating the refinery process units. 

Since HOVENSA is not currently operating as a refinery, EPA proposes to determine that 

 

6 The visibility impact on Hassel Island is larger, but EPA is reviewing the modeling data to determine if this is a 

spurious result. 
Draft Regional Haze SIP 6-55

US Virgin Islands Tuesday, June 26, 2012

HOVENSA is not subject to implementing any new NOx controls at this time and therefore EPA 

proposes to determine that current operation of the boilers subject to BART is considered BART 

for controlling NOx emissions. Regardless, as discussed in the RPG section, EPA is proposing to 

require HOVENSA to do a new reasonable measure analysis (if they resume operations) for 

those units that will be in operation.

Combustion Turbines

HOVENSA owns and operates eleven combustion turbines that are capable of 

combusting two or more of the following fuel combinations: refinery fuel gas (RFG), liquefied 

petroleum gas (LPG) and distillate oil. Two of the turbines (GT 10 and GT 13) were constructed 

in 1993 and 2009 and are therefore not BART-eligible. EPA has determined that the following 

nine turbines are subject to BART: GT1 (G-1101E), GT2 (G-1101F), GT3 (G-1101G), GT4 (G3404), GT5 (G-3405), GT6 (G-3406), GT7 (G-3407), GT8 (G-3408), and GT9 (G-3409). These 

turbines generate electricity for use at the facility, each in the range of 17.5 – 24 MW for a total 

nominal generating capacity of about 169 MW. SO2 emissions are controlled by limiting the fuel 

sulfur content as follows: distillate oil has a permit sulfur limit of 0.20%; LPG does not contain

any sulfur; RFG sulfur content will be limited by the CD that requires the combustion of RFG 

with limits on the H2S content in accordance with the NSPS requirements at subpart J or Ja; 

turbines GT Nos. 1, 2 and 3 must meet subpart Ja requirements limiting the H2S content of the 

RFG to 162 ppmv (3-hour rolling average) and 60 ppmv (daily on a 365 day rolling average); 

turbines GT Nos. 4 through 9 must meet subpart J requirements limiting the H2S content of the 

RFG to 0.10 grains per dry standard cubic feet (equivalent to 162 ppmv). HOVENSA has 

indicated to EPA that turbines GT1 through GT3 typically combusts LPG; turbines GT4 through 

GT 8 typically combusts RFG that is already compliant with Subpart J limits for H2S; and for 

GT9, the permit limits this turbine’s gaseous fuels to propane and butane. For NOx, only turbine 

GT9 has implemented control technology (steam injection). For PM, none of the turbines 

subject to BART have any controls. 

For control of SO2, NOx and PM emissions, based upon EPA’s analysis, EPA is 

proposing that current operations represent BART for each of the nine combustion turbines 

subject to BART. For SO2 and PM control, as with the boilers discussed above, EPA’s 

contractor evaluated Duct Injection and Fabric Filters (DIFF) using lime as the alkaline reagent. 
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US Virgin Islands Tuesday, June 26, 2012

Based upon this analysis, EPA has determined that the DIFF controls evaluated for the nine 

combustion turbines subject to BART are not cost effective because it exceeds a reasonable cost 

effectiveness for this kind of source. EPA determined that the cost effectiveness for the nine 

combustion turbines subject to BART varied in the range of about $122,300 (8 turbines) to 

$359,186 (1 turbine) per ton of SO2 and PM reduced. The cost effectiveness values for the 

combustion turbines are much higher than for the boilers because the SO2 emissions from the 

boilers are much higher (by a factor of 2 to 4 times) than from the turbines. Therefore, EPA 

determines that for SO2 and PM controls, current operation is considered as BART.

For control of NOx emissions, as discussed above for the boilers, EPA’s contractor 

evaluated selective non-catalytic reduction (SNCR) using ammonia as the reagent. EPA has 

determined, except for turbine GT9, that implementation of SNCR controls for eight turbines 

subject to BART, GT1 through GT8, the cost in dollars per ton is low enough to be costeffective. The actual cost effectiveness for the turbines GT1 through GT 8 is in the range of 

about $1750 to $1890 per ton of NOx removed. The actual cost effectiveness for turbine GT9 is 

about $9,500/ton and is too high to be cost effective. The cost effectiveness of turbine GT9 is 

much higher than the other eight turbines because the NOx emissions are much lower due to NOx

controls installed on GT9. 

Even though eight of the nine turbines subject to BART have cost effective values within 

acceptable limits of EPA’s cost benchmark, EPA has determined, for the same reasons discussed 

above for the boilers, that the visibility impact due to NOx emissions is only about 0.09 dv7from 

all HOVENSA units subject to BART, and therefore the implementation of any new NOx 

controls (even SNCR or SCR) on the combustion turbines would not have enough of a 

improvement in visibility on the Class I area in the Virgin Islands. Therefore, EPA is 

determining that current operations of the nine turbines subject to BART are considered BART 

for controlling NOx emissions. 

Process Heaters

 

7 This is the impact of all NOx emissions from BART-eligible stacks at HOVENSA. The impact of 0.16 dv is for the 

IMPROVE monitoring site on St. John. Modeling has calculated an impact for all HOVENSA BART-eligible 

sources of 0.91 dv, but EPA is reviewing that prediction since it may be erroneous. 
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HOVENSA owns seventy process heaters of which twenty-one were shut down in early 

2011. Of the seventy heaters, EPA has determined that sixty-four are subject to BART whereas 

the remaining six heaters were constructed after 1977 and are therefore not BART-eligible. Of 

the sixty-four process heaters subject to BART, fifteen are capable of combusting either RFG or 

No. 6 fuel oil whereas the remaining forty-nine heaters combust only RFG. EPA has determined 

that the following list of sixty-four process heaters are subject to BART: H-101, H-104, H-200, 

H-201, H-202, H-401 A-C, H-1401 A and B, H-1500, H 1501, H-160, H-600 through H-606, H800A and B, H-801, H-2101, H-2102, H-2201A and B, H-2202, H-2400, H-2401, H-2501, H4502 through H-4505, H-3101A and B, H-4101A and B, H-4401, H-4402, H-4451 through H4455, H-4201, H-4202, H-5401, H-5402, H-5451 through H-5455, H-4601A and B, H-4602, H4301A and B, H-4302, H-5301A and B, and H-5302. 

For the fifteen heaters capable of combusting No. 6 fuel oil, SO2 emissions are controlled 

by permit limiting the sulfur content of No. 6 fuel oil to 0.50% or 1.0% depending upon wind 

conditions. The June 2011 CD may lower SO2 emissions by establishing the sulfur content of 

No. 6 fuel oil to 0.55% maximum, 0.50% annually, and to a low limit 0.30% should wind 

conditions warrant this (as defined in the CD). In addition, the CD requires process heaters to 

limit the H2S content of RFG in accordance with the NSPS at Part 60, at either subpart J (about 

162 ppmv H2S) or Ja (162 ppmv H2S on a 3 hour rolling average and 60 ppmv H2S daily on a 

365 day rolling average). Appendix A of the CD identifies which process heaters are subject to 

either subparts J or Ja. None of the process heaters subject to BART have any controls for either 

NOx or PM. 

For control of SO2, NOx and PM emissions, based upon EPA’s analysis, EPA is 

proposing that current operations represent BART for each of the sixty-four process heaters 

subject to BART. Although EPA’s contractor determined cost effectiveness for only the boilers 

and combustion turbines, EPA has concluded that, for control of SO2, NOx and PM, there is 

sufficient information to make a determination that current operation represents BART for each 

of the process heaters subject to BART. For the SO2 and PM BART determination, EPA notes 

that the SO2 emissions, heat input and fuel type for the each of the six largest process heaters is 

similar to that of most of the boilers which EPA’s contractor established cost effectiveness 

values that EPA believes are too high to be cost effective. It is EPA’s judgment from this size 

comparison between the boilers and the six largest heaters that the cost effectiveness for the 
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US Virgin Islands Tuesday, June 26, 2012

process heaters would be less than for the boilers but still excessive. The great majority of the 

remainder of the process heaters combust only RFG, have a smaller heat input (each by a factor 

of about 2.75 average) and have lower SO2 emissions (each by a factor of about 7.8 on average) 

than the six large heaters. Based upon this comparison, EPA would expect that the remaining 

smaller process heaters will also have a cost effectiveness that are sufficiently excessive to make 

these potential controls not cost effective. Therefore, for SO2 and PM control, EPA proposes to 

determine that the process heaters subject to BART are all not cost effective for controlling SO2

and PM emissions and that current operation is considered BART. 

As discussed above for the boilers and combustion turbines, EPA determined that 

implementation of controls on NOx emissions from all BART units at HOVENSA have an 

insignificant visibility impact on the Class I areas in the Virgin Islands and therefore EPA is 

proposing to determine this is also true for the process heaters. Therefore EPA proposes that 

current operation of the process heaters subject to BART is considered as BART for controlling 

NOx emissions. 

Reciprocating gas compressors

HOVENSA owns eleven compressors of which five were shut down in early 2011. EPA 

has determined that the following eleven compressors are subject to BART: C-200A through C, 

C-1500 A through C, C-2400 A and B, and C-4601 A through C. Five of the compressors (C200 A through C and C-2400 A and B) are equipped with catalytic converters (similar to those 

used on cars) for controlling NOx emissions. These eleven compressors combust only liquefied 

petroleum gas (LPG) and therefore there are no emissions of SO2 and PM emissions are small, as 

indicated by emissions data from HOVENSA. 

For control of SO2, NOx and PM emissions, based upon EPA’s analysis EPA is proposing 

that current operations represent BART for each of the eleven reciprocating gas compressors 

subject to BART. Since there are no SO2 emissions and PM emissions are small, EPA is 

proposing that current operation using LPG fuel represents BART for control of SO2 and PM 

emissions from the eleven reciprocating gas compressors subject to BART. NOx reductions will 

not have a useful impact on improving visibility.

Tail Gas Treatment Units
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US Virgin Islands Tuesday, June 26, 2012

HOVENSA owns and operates two Tail Gas Treatment (TGT) units and components of 

each unit combust RFG. EPA has determined that one of the TGT units, No. 2 Beavon (which 

includes H-4761(Reduced Gas Generator) and T-4761 (Stack)), is subject to BART whereas the 

other unit, No. 1 Beavon (which includes H-1061 (Reduced Gas Generator) and T-1061 (Stack)) 

was constructed after 1977 and is therefore not BART-eligible. The TGT units (“Beavons”) are 

control devices for the sulfur recovery plants and the two TGT units process tail gas from the 

four sulfur recovery units (SRU) in order to lower emissions of sulfur compounds and to recover 

additional sulfur. The TGT unit subject to BART (No. 2 Beavon including H-4761 and T-4761) 

processes tail gas from No. 3 SRU and No. 4 SRU and emissions of SO2, NOx and PM are low 

(potential to emit (PTE): 2 tpy SO2 and 4.0 tpy NOx) as compared to other units at this refinery

facility (e.g., Boiler No. 1 PTE: 330 tpy SO2 and 450 tpy NOx). Since the emissions are so low 

for the TGT unit subject to BART, it is EPA’s judgment that any BART analysis for additional 

controls would have resulted in cost effectiveness values too to be cost effective for BART. 

Furthermore, as discussed above for other units subject to BART, any reduction of NOx 

emissions would not have any significant impact on visibility and therefore current operations 

represents BART for control of NOx emissions. Also, it should be noted that the CD requires 

that (1) by the end of 2014, HOVENSA install a second TGT unit to service the No. 3 and No. 4 

SRUs; and (2) by April 1, 2015, the H-4761 section of the TGT unit must be in compliance with 

the NSPS Part 60, subpart Ja concerning the H2S concentration limit of the RFG. 

Therefore, based upon the above analysis, EPA is proposing that current operations 

without any new controls represent BART for the TGT unit subject to BART. 

Tail Gas Incinerators

HOVENSA owns and operates three Tail Gas Incinerators (TGI) and each combusts 

RFG. EPA has determined that all three of the TGI units (H-4745, H-1032 and H-1042) are 

subject to BART. The TGI units are part of the sulfur recovery plants that include the Tail Gas 

Treatment (TGT) units described above as well as for flare units as well as other units that are 

not needed for consideration for this BART determination. It is EPA’s understanding that: (1) 

two incinerators (H-1032 and H-1042) are associated with No.1 and 2 SRUs and these TGIs are 

used during startup, shutdown and malfunction of those SRUs or during a malfunction of the 

associated TGT unit (No. 1 Beavon which includes H-1061 and T-1061); and (2) one incinerator 
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US Virgin Islands Tuesday, June 26, 2012

(H-4745) is associated with No. 3 and 4 SRUs and is used during periods of maintenance or 

malfunction of the associated TGT unit (No. 2 Beavon which includes H-4761 and T-4761) as 

well as during startup, shutdown or malfunction of these SRU units. 

TGI unit H-4745 has much higher annual emissions (PTE: 900 tpy SO2 and 28 tpy NOx; 

actual emissions: 228 tpy SO2 and 7.0 tpy NOx) than each of the other two incinerators. 

However, as discussed above for the TGT unit, the CD requires that, by the end of 2014, 

HOVENSA is to install a second TGT unit to service the No. 3 and No. 4 SRUs. Under this 

scenario there would be two TGT units (No. 2 Beavon which includes H-4761 (Reduced Gas 

Generator) and T-4761 (Stack) and a new TGT unit) servicing No. 3 and 4 SRUs, and because of 

this redundancy in TGT units, the use of incinerator H-4745 might only be used for startup, 

shutdown and malfunction of the associated TGT unit (either the No. 2 Beavon system or the 

new TGT unit). Under this redundancy situation, HOVENSA expects that the PTE for SO2 for 

incinerator H-4745 would be reduced from 900 tpy to a small fraction of this current PTE and, in 

addition, SO2 emissions would meet the NSPS emission limits under Part 60 subparts J or Ja.

Since TGI units H-1032 and H-1042 have very low air pollutant emissions and TGI unit 

H-4745 would also have low air pollutant emissions once in compliance with the CD, it is EPA’s 

judgment that any BART analysis for additional controls would have resulted in high cost 

effectiveness values. Furthermore, as discussed above for other units (boilers, turbines etc) 

subject to BART, any reduction of NOx emissions would not have any significant impact on 

visibility and therefore EPA proposes that current operation represents BART for control of NOx

emissions. Also, it should be noted that the CD requires that each of the three TGI units subject 

to BART must be in compliance with the NSPS Part 60, subpart Ja such that the emissions of 

SO2 are limited to not more than 250 ppmv (at zero percent excess air) – TGI unit H-4745 must 

comply by April 1, 2015 and TGI units H-1032 and H-1042 must comply by December 31, 

2011. 

Therefore, EPA is proposing that current operations without any new controls of SO2, 

NOx and PM emissions represent BART for the three TGI units subject to BART. 

Flares 
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US Virgin Islands Tuesday, June 26, 2012

HOVENSA owns and operates eight flares throughout the refinery. HOVENSA indicates 

that the flares are used primarily as safety devices for purposes of relieving accidental overpressuring. EPA has determined that five of the flares (No 2 (H-1105), No. 3 (H-1104), No. 5 

(H-3351), No. 6 (H-3352), No. 7 (H-3301)), all located within the sulfur recovery plant, are 

subject to BART. Flares 1 and 4 are no longer in service. Each flare subject to BART includes a 

steam injection system at the flare tip for the purpose of improving combustion and thereby

eliminating smoking conditions. HOVENSA reports that the facility PTE for all eight flares is as 

follows: 1200 tpy SO2, 1897 tpy NOx and negligible emissions of PM. For all the flares, 

including those subject to BART, HOVENSA’s best estimate of the PTE for each flare is that 

emissions are divided approximately equally among each flare, as follows: 150 tpy SO2, 237 tpy

NOx and negligible emissions of PM. However, HOVENSA also reports that the PTE emissions 

are much higher than actual emissions which have the following average emissions for the five 

flares subject to BART: 1.46 tpy SO2, 6.7 tpy NOx and 1.0 typ PM. 

The June 2011 CD requires that each of the five BART flares subject to the NSPS Part 60 

subparts J and Ja requirements implement “flare gas recovery” to comply with the CD. Flare gas 

recovery is a system to reduce SO2 emissions by the installation of compressors on the flare line 

to recycle the flare gas back into process units for removal of H2S. Since the CD will further 

reduce SO2 emissions and actual emissions from the flares are very low and EPA is not aware of 

any desulfurization technologies to treat flare gas emissions, EPA is proposing that current 

operations are considered as BART for both SO2 and PM. Furthermore, as discussed above for 

other units (boilers, turbines etc) subject to BART, any reduction of NOx emissions would not 

have any significant impact on visibility and therefore, EPA is proposing that current operations 

are considered as BART for NOx. 

Therefore, EPA is proposing that current operations without any new controls of SO2, 

NOx and PM emissions represent BART for the five flare units subject to BART. 

Water Intake Pumps and Desalination Water Pump

HOVENSA owns and operates four Water Intake Pumps and one Desalination Water 

Pump and each combusts either diesel or No. 2 fuel oil. EPA has determined that each of the 

Water Intake Pumps (PD-1062 through PD-1065) and the Desalination Water Pump (PD-1620) 
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US Virgin Islands Tuesday, June 26, 2012

are subject to BART. HOVENSA has confirmed that each of these pumps is an emergency

standby pump that is used only when there is a complete power failure at the refinery. 

HOVENSA reports that actual emissions are negligible and PTE emissions are small. EPA 

determined that the average PTEs are as follows: 1.8 tpy SO2, 38 tpy NOx, and 2.7 tpy PM. The 

pumps normally in use are electric driven pumps and therefore have no air pollutant emissions. 

Since these five pumps are used very infrequently and actual emissions are negligible it is 

EPA’s judgment that any detailed cost analysis would conclude that implementation of any 

technologies for controlling emissions of SO2, NOx or PM are not cost effective. Therefore, EPA 

is proposing that current operation represents BART for these five pumps subject to BART. 

6.5.2 BART Determinations

In summary, EPA’s BART evaluation of the boilers, turbines, process heaters, and 

several other source categories that are subject to BART at HOVENSA has determined that no 

additional control for SO2, NOx and PM emissions is consistent with BART. Most stacks are not 

amenable to cost effective controls. EPA is proposing that current operations represent BART for 

HOVENSA. As such, EPA’s Federal plan includes the establishment of emission limits for SO2, 

NOx and PM equivalent to the potential to emit (PTE) for each unit subject to BART, as derived 

from HOVENSA's permit limit conditions. EPA’s Federal plan includes these PTE limits in the 

spreadsheets found in the Attachments to the FIP. 

For the stacks that have low cost effectiveness for controls for NOx, EPA further 

analyzed the contribution of various chemical species and components on the visibility impacts.

The contribution of NOx compounds from all potential BART sources at HOVENSA to visibility

impairment on the average 98th percentile day is about a 0.09 dv visibility impact at St. John and 

0.91 dv8for Hassel Island from all HOVENSA units subject to BART. The implementation of 

any new NOx controls (even SNCR or SCR) would not result in sufficient improvements in 

visibility on St. John. Therefore, EPA is determining that current operations of the BART-

 

8 The visibility impact on Hassel Island is larger, but EPA is reviewing the modeling data to determine if this is a 

spurious result. 
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US Virgin Islands Tuesday, June 26, 2012

eligible sources at HOVENSA, including the nine turbines, are considered BART for controlling 

NOx emissions. 

BART Analysis for WAPA Facilities on St. Croix and St. Thomas

WAPA power plants on St. Croix and St. Thomas are potential BART sources, with 

emission sources that are large enough to qualify for BART and were built at during the BARTeligible period. However, the impact of the WAPA power plant on St. Croix and the WAPA 

power plant on St. Thomas have an impact of 0.09 and 0.04 dv, respectively, for the average 98th

percentile metric, on visibility at the IMPROVE monitor on St. John. An analysis of potential 

controls is listed in the accompanying tables. However, the improvement in visibility from these 

reductions would be even less than the less than 0.1 dv total impact of these potential BART 

sources, so EPA has determined that they are not eligible for BART controls, due to how little 

they add to improving visibility at the National Park in St. John.

6.5.3 BART Determinations including Other Types of Standards

As allowed by 40 CFR §51.308(e)(1)(iii) of the Regional Haze Rule the EPA has 

determined in establishing BART that technological or economic limitations on the applicability

of measurement methodology would make the imposition of an emission standard infeasible. A 

design, equipment, work practice, or other operational standard, or combination thereof can be 

prescribed to require the application of BART for each source. These standards, to the degree 

possible, set forth the emission reduction to be achieved by implementation of such design, 

equipment, work practice or operation, and provide for compliance by means that achieve 

equivalent results. 

For this FIP, existing controls were determined to be BART. No other standards were 

needed to determine that BART controls were not feasible.

6.6 Description of BART Alternative for Any Source

In section (e)(2) of the RHR provides that a state may opt to implement an emissions 

trading program or other alternative measure rather than to require sources subject to BART to 

install, operate, and maintain BART. To do so, the State must demonstrate that emissions trading 

program or other alternative measure will achieve greater reasonable progress than would be 
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US Virgin Islands Tuesday, June 26, 2012

achieved through the installation and operation of BART. To make this demonstration, the State 

must submit an implementation plan containing the elements listed in Section (e)(2).

No alternative measures are available for the Virgin Islands FIP, since there are no 

sources in other states that affect the Virgin Islands’ Class I area.

6.7 Schedule for BART Implementation

As provided in 40 CFR §51.308(e)(1)(iv) BART must be in operation for each applicable 

source no later than five years after FIP approval. If these potential BART sources in the Virgin 

Islands were to be subject to BART, each would be required to install and operate BART as 

expeditiously as practicable but in no event later than five years after approval of the FIP or plan 

revision by EPA. 

As provided in 40 CFR §51.308(e)(1)(v), the Title V operating permits for BART sources 

must include a requirement that each source maintain the control equipment and establish 

procedures to ensure such equipment is properly operated and maintained. This requirement 

would have been included in the Title V operating permit for each source subject to BART. 

7.0 LONG-TERM STRATEGY

Section 51.308(d)(3) of 40 CFR part 51 requires the Virgin Islands to submit a long-term 

strategy that addresses regional haze visibility impairment for each mandatory Class I Federal 

area within and outside the Territory that may be affected by emissions from within the 

Territory. The long-term strategy must include enforceable emissions limitations, compliance 

schedules, and other measures necessary to achieve the reasonable progress goals established for 

the Class I. 

This section describes how the FIP for the Virgin Islands meets the long-term strategy

requirements. This long-term strategy addresses visibility impairment for the Virgins Islands 

National Park, which is the only Class I Area that is affected by emissions from within the Virgin 

Islands.

The long-term strategy described below includes enforceable emissions limitations, 

compliance schedules, and other measures necessary to achieve the reasonable progress goals 
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US Virgin Islands Tuesday, June 26, 2012

established for the Class I to the extent that it is reasonable for the Virgin Islands (or EPA on its 

behalf) to adopt them before the date this FIP is finalized. Additional measures may be 

reasonable to adopt at a later date after further consideration and review. In this FIP, EPA is 

using existing measures to address reasonable progress. 

7.1 Overview of the Long-Term Strategy Development Process

Section 51.308(d)(3)(iii) of 40 CFR part 51 requires us to document the technical basis 

for the State’s/Tribe’s apportionment of emission reductions necessary to meet reasonable 

progress goals in each Class I area affected by the Territory’s emissions.

Modeling shows that Puerto Rico, the portion of the United States nearest to the Virgin 

Islands, does not affect visibility in the Class I area of the Virgin Islands National Park on St. 

John. We demonstrated this using dispersion modeling for a representative major source, which 

we located on the closest point on Puerto Rico to simulate the maximum possible impact on 

visibility in the Virgin Islands. The modeling predicts a less than 0.01 DV impact from a 

potential major source on Puerto Rico, so sources or groups of sources in the continental United 

States, which is much further away from the Virgin Islands than Puerto Rico, will not have an 

impact on visibility in the Virgin Islands.

The trajectory and modeling results show that there may be some small effect from 

international sources (e.g., Antigua, St. Martin, British Virgin Islands); reductions from these 

sources would be a matter of international policy. Emissions from natural sources (e.g., Saharan 

Dust, Montserrat Volcano), cannot be controlled. Therefore, the ability of the Virgin Islands to 

coordinate emission reductions from sources on a regionwide scale is limited. 

Because of this limitation, this FIP for the Virgin Islands relies on reductions that will 

occur in the Virgin Islands to achieve reasonable progress toward improving visibility in the 

Virgin Islands National Park. The following sections discuss the pollutants, source regions, and 

types of sources considered in developing this long-term strategy to assure the attainment of 

reasonable progress goals. 

7.2 Emission Reductions Due to Ongoing Air Pollution Programs 

Section 51.308(d)(3)(v)(A) of 40 CFR part 51 requires State/Tribes to consider emission 

reductions from ongoing pollution control programs. In developing its Long Term Strategy, the 
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US Virgin Islands Tuesday, June 26, 2012

Virgin Islands FIP considered emission control programs being implemented between the 

baseline period and 2018, as discussed below. However, the effect of these programs, except for 

the HOVENSA consent decree and emission reductions from ocean vessels, were not included in 

the modeling, since EPA and VIDPNR do not have sufficient information on these source 

categories and how they will change by 2018. In addition, the remoteness of the Virgin Islands, 

especially the island of St. John (which is mostly a National Park), makes it difficult to project 

the effects of vehicle turnover and improvements to diesel engine fleets. Thus, these measures 

are included as possible contributors to improved visibility for the National Park on St. John.

7.2.1 Other Point Source Controls Expected by 2018 Due to Ongoing Air Pollution 

Control Programs

Point source controls applicable to the Virgin Islands include the following:

EPA’s Refinery Enforcement Initiative9. Since March 2000, the EPA has reached 

settlements with 29 U.S. companies responsible for 90 percent of petroleum refining in the 

nation. Through multi-issue, multi-facility settlements or detailed investigations and aggressive 

enforcement, this national initiative addresses the most significant Clean Air Act compliance 

concerns affecting the petroleum refining industry. HOVENSA, LLC was one such company that 

entered into a settlement with the EPA for its refinery on St. Croix. EPA's settlements require 

significant reductions of SO2 and nitrogen oxide, as well as emission reductions of benzene, 

VOCs, and particulate matter.

VOC 2-, 4-, 7-, and 10-year MACT Standards. Various point source MACTs and 

associated emission reductions were implemented in many parts of the United States, but were 

not considered in the development of projection emissions inventory for the Virgin Islands.

Combustion Turbine MACT. The projection inventories do not include the NOx cobenefit effects of the MACT regulations for Gas Turbines or stationary Reciprocating Internal 

Combustion Engines, which the EPA estimates to be small compared to the overall inventory. 

Industrial Boiler/Process Heater/RICE MACTs. The EPA issued final rules to 

substantially reduce emissions of toxic air pollutants from industrial, commercial and 

 

9

 EPA’s Refinery Enforcement Initiative: http://www.epa.gov/compliance/resources/cases/civil/caa/hovensa.html
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US Virgin Islands Tuesday, June 26, 2012

institutional boilers, process heaters and from stationary reciprocating internal combustion 

engines (RICE). These rules reduce emissions of a number of toxic air pollutants, including 

hydrogen chloride, manganese, lead, arsenic and mercury by 2013. This rule also reduces 

emissions of NOx and VOCs in conjunction with the toxic air pollutant reductions 

(http://www.epa.gov/ttn/atw/rice/ricepg.html).

7.2.2 Controls on Non-road Sources Expected by 2018 due to Ongoing Air 

Pollution Control Programs

Non-road source controls that may be applicable to the Virgin Islands include the 

following:

Non-road Diesel Rule. This rule sets standards that will reduce emissions by more than 

90 percent from non-road diesel equipment, and reduce sulfur levels by 99 percent from current 

levels in non-road diesel fuel starting in 2007. This step will apply to most non-road diesel fuel 

in 2010 and to fuel used in locomotives and marine vessels in 2012 

(http://www.epa.gov/nonroad-diesel/). Reductions due to this program may reduce impairment to 

visibility by a small amount, but it was not modeled due to uncertainties in the emissions from 

this source category. 

7.2.3 Mobile Source Controls Expected by 2018 due to Ongoing Air Pollution 

Control Programs

Mobile source controls applicable to the Virgin Islands include the following:

Heavy Duty Diesel (2007) Engine Standard. EPA set a PM emissions standard for new 

heavy-duty engines of 0.01 grams per brake-horsepower-hour (g/bhp-hr), to take full effect for 

diesel engines in the 2007 model year. This rule also includes standards for NOx and nonmethane hydrocarbons (NMHC) of 0.20 g/bhp-hr and 0.14 g/bhp-hr, respectively. These NOx 

and NMHC standards will be phased in together between 2007 and 2010 for diesel engines. 

Sulfur in diesel fuel must be lowered to enable modern pollution-control technology to be 

effective on these trucks and buses. EPA will require a 97 percent reduction in the sulfur content 

of highway diesel fuel from its current level of 500 parts per million (low sulfur diesel, or LSD) 

to 15 parts per million (ultra-low sulfur diesel, or ULSD) (http://www.epa.gov/otaq/highwaydiesel/index.htm).
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Tier 2 Motor Vehicle Standards. Tier 2 is a fleet averaging program, modeled after the 

California LEV II standards. Manufacturers can produce vehicles with emissions ranging from 

relatively high to zero, but the mix of vehicles a manufacturer sells each year must have average 

NOx emissions below a specified value. Tier 2 standards became effective in the 2005 model 

year (http://www.epa.gov/tier2/finalrule.htm).

Large Spark Ignition and Recreational Vehicle Rule. EPA has adopted new standards for 

emissions of NOx, hydrocarbons (HC), and carbon monoxide (CO) from several groups of 

previously unregulated non-road engines. Included in these are large industrial spark-ignition 

engines and recreational vehicles. Non-road spark-ignition engines are those powered by

gasoline, liquid propane, or compressed natural gas rated over 19 kilowatts (kW) (25 

horsepower). These engines are used in commercial and industrial applications, including 

forklifts, electric generators, airport baggage transport vehicles, and a variety of farm and 

construction applications. Non-road recreational vehicles include snowmobiles, off-highway

motorcycles, and all-terrain vehicles. These rules were initially effective in 2004 and should be 

fully phased-in by 2012 (http://epa.gov/nonroad/2002/cleanrec-final.htm).

Reductions from these source categories are not estimated for modeling because of the 

uncertainties in the makeup of the emission inventories for these sources. 

7.2.4 Source Retirement and Replacement Schedules 

Section 51.308(d)(3)(v)(D) of 40 CFR part 51 requires us to consider source retirement 

and replacement schedules in developing reasonable progress goals. In January 2012, it was 

announced that the HOVENSA refinery would be ceasing refinery operations and converting to 

an oil storage terminal by mid-February of 2012. Modeling suggests the emissions from

HOVENSA sources are responsible for 1.06 dv of visibility impairment in the Virgin Islands 

National Park at St. John. The closure of this facility would provide much of the reduction 

needed to meet reasonable progress target for 2018, although this FIP is not using these 

reductions because HOVENSA has not surrendered its emissions permits. So for the long-term 

plan, HOVENSA is modeled as if it continues to operate, but with the emission reductions 

agreed to in the consent decree. 
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US Virgin Islands Tuesday, June 26, 2012

Additional source retirements or replacements are not expected by 2018. Any retirement 

and replacement must comply with existing SIP requirements including those pertaining to PSD 

and New Source Review.

7.3 Additional Reasonable Strategies

Section 51.308(d)(3) of 40 CFR part 51 requires Plans to include enforceable emissions 

limitations, compliance schedules, and other measures as necessary to achieve the reasonable 

progress goals established by States/Tribes with Class I areas. The plan must include reasonable 

measures and identify the visibility improvement that will result from those measures.

Since existing measures and agreements are the reasonable measures for this FIP for the 

Virgin Islands, the Section 51.308(d)(3) compliance schedules are not need for this Plan.

As discussed in the next section, additional controls for this long-term strategy are 

limited, in part, due to the compressed schedule for this FIP. 

7.3.1 Analysis of the Four Statutory Factors

The CAA (Sec. 169A) requires that Haze Plans provide for reasonable progress toward 

attaining the goal of preventing any future, and remedying any existing impairment of visibility

in mandatory Class I Federal areas. In determining reasonable progress, States shall consider the 

four factors listed below:

 Costs of compliance 

 Time necessary for compliance

 Energy and non-air quality environmental impacts of compliance

 Remaining useful life of any potentially affected sources.

Regulations implementing this requirement have been promulgated in 40 CFR Part 51, 

Subpart P – Protection of Visibility. Section 51.308 specifically addresses the regional haze 

program requirements. Guidance on implementing the reasonable progress requirements have 

been developed by the EPA, Guidance for Setting Reasonable Progress Goals under the 

Regional Haze Program, revised June 1, 2007.

In judging the adequacy of visibility improvement, the EPA has considered all current 

regulations and programs, and then determined the amount of additional improvement that may

be necessary to represent reasonable progress. For the Virgin Islands, visibility improvements 
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will not reach the reasonable progress goal, but existing controls are all that can reasonably be 

done to improve visibility in the first period ending in 2018. 

With respect to the four-factor analysis, the implementation of any additional control 

strategies is hampered by the compressed schedule that this FIP was developed under. Sources 

would have only a few years to comply with any additional control programs. Based on 

timeframes presented in regional haze SIPs for other States, this would be a minimum amount of 

time needed for the simplest of additional strategies. It is unreasonable to expect any additional 

control in this period. 

7.3.2 Best Available Retrofit Technology

BART controls at sources potentially subject to BART are identified in Section 6 of this 

FIP. EPA has determined BART to be existing controls, as additional controls are neither cost 

effective nor to have much impact on improving visibility in the National Park.

7.3.3 Changes to Emissions by 2018

The emissions inventory for the Virgin Islands Haze Plan has been completed for the 

island of St. John. Due to the small impact from sources on St. Thomas and St. Croix, except for 

HOVENSA, and the emerging state of the emissions inventory for the Virgin Islands, the official 

emission inventory for regional haze plan will be tabulated for sources on the island of St. John 

and surrounding waters. Emissions change from the 2004 base year to the 2018 inventory for the 

island of St. John due to reduced emissions from marine vessels. While these reductions in 

marine vessel emissions are not part of the enforceable plan for the Virgin Islands Haze Plan, 

they are included as EPA anticipates that the marine vessel controls will be in place before 2018. 

Other emission reductions are possible, such as introduction of newer, cleaner motor vehicles 

and reduced sulfur in fuel and controls on off-road vehicles. But these reductions in vehicle 

emissions are hard to quantify for a remote location like St. John, so emission reductions from 

these sources will not be quantified in the emission inventory for St. John for 2018.

Visibility on St. John will also be improved by the emission reductions from the consent 

decree at HOVENSA. This change in emissions is tabulated separately from the emission 

inventory for St. John, as they occur on the island of St. Croix, not on St. John. Other emissions 

on St. Croix and St. Thomas are not anticipated to change or the change will be too small to 

affect visibility on St. John, so this haze plan will not include them in the emissions summaries. 
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A summary of these changes is in emissions of SO2 is provided in Table 7-1, NOx in Table 7-2, 

and PM in Table 7.3 for the island of St. John. HOVENSA emission changes from the consent 

decree are in Table 7.4.

Table 7-1: Emissions from Point, Area and Mobile Sources on St. John, Virgin Islands 

(SO2 tpy)

Source Sector Baseline 2002 2018 (with measures for RPG)

Point 43.11 43.11

Area 0.05 0.05

Non-Road Mobile 17.89 17.89

On-Road Mobile 1.61 1.61

Marine Vessels 94.06 14.11

Total 156.72 76.77

Table 7-2: Emissions from Point, Area and Mobile Sources on St. John, Virgin Islands 

(NOx tpy)

Source Sector Baseline 2002 2018 (with measures for RPG)

Point 477.66 477.66

Area 3.69 3.69

Non-Road Mobile 2.07 2.07

On-Road Mobile 25.03 25.03

Marine Vessels 318.23 63.65

Total 826.68 572.1

Table 7-3: Emissions from Point, Area and Mobile Sources on St. John, Virgin Islands 

(PM tpy)

Source Sector Baseline 2002 2018 (with measures for RPG)

Point 34.33 34.33

Area 38.32 38.32

Non-Road Mobile 1.93 1.93

On-Road Mobile 0.73 0.73

Marine Vessels 8.57 1.28

Total 83.88 76.59
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Table 7-4: Emissions from HOVENSA (tons per year)

SO2 NOx PM EC*

HOVENSA Base 2002 12,778 26,362 2,207 22.1

HOVENSA Post Control

2018

9,318 21,331 2,192 21.9

* Elemental Carbon emissions were assumed to be 1/100 of total PM emissions.

These emissions are included in the modeling analysis to determine the improvement in visibility

at the Class I area in the Virgin Islands. Other emissions sources are described in the modeling 

analysis in the Appendix.

7.4 Additional Measures Considered

These sources include ferries, cruise ships, and cargo ships that dock at St. John. The 

Caribbean ECA (Emissions Control Area) emission reductions for ocean vessels are included in 

the future case modeling. Beginning in 2015, fuel used by all vessels operating in these areas 

cannot exceed 0.1 percent fuel sulfur (1,000 ppm). This requirement is expected to reduce PM 

and SOx emissions by more than 85 percent. Beginning in 2016, new engines on vessels 

operating in these areas must use emission controls that achieve an 80 percent reduction in NOx 

emissions. While these reductions are not enforceable as part of this FIP, EPA expects them to 

occur and they will be included in the reductions expected in the period through 2018.

7.4.1 Caribbean Emissions Control Area

The Caribbean ECA (Emissions Control Area) emission reductions for ocean vessels are 

included as an improvement in air quality for the future case modeling. Beginning in 2015, fuel 

used by all vessels operating in these areas cannot exceed 0.1 percent fuel sulfur (1,000 ppm). 

This requirement is expected to reduce PM and SOx emissions by more than 85 percent. 

Beginning in 2016, new engines on vessels operating in these areas must use emission controls 

that achieve an 80 percent reduction in NOx emissions. While these emission reductions were 

not developed specifically for this FIP, the use of the proper fuel and emission controls will be 

enforceable by EPA when this program goes into effect. These emission reductions will result in 
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0.03 dv improvement in visibility on the twenty percent worst visibility days at the IMPROVE 

site on St. John. 

7.4.2 Measures to Mitigate the Impacts of Construction Activities

Section 51.308(d)(3)(v)(B) of 40 CFR part 51 requires the Virgin Islands to consider 

measures to mitigate the impacts of construction activities. 

As noted previously, the majority of the soils contribution to visibility impairment on the 

twenty percent worst days is attributable to transport of Saharan dust, and not necessarily local 

sources. In preparation for the next SIP revision in 2018, the EPA will work with VIDPNR to 

determine the effectiveness of better construction practices on St. John and quantify the 

contribution of construction activity to visibility impairment and possible mitigation strategies. 

7.4.3 Agricultural and Forestry Smoke Management

Section 51.308(d)(3)(v)(E) of 40 CFR part 51 requires Haze Plans to consider smoke 

management techniques for the purposes of agricultural and forestry management in developing 

reasonable progress goals. The Virgin Islands has an open burning regulation.

Smoke Management Programs are only required when smoke impacts from fires 

managed for resource benefits contribute significantly to regional haze. The results of the 

emissions inventory on St. John indicate that emissions from agricultural, managed, and 

prescribed burning are small sources of pollution. It is unlikely that fires for agricultural or 

forestry management cause large impacts on visibility in the Virgin Islands National Park. On 

rare occasions, when smoke from major fires degrades the air quality and visibility in the Virgin 

Islands. However, these fires are generally unwanted wildfires that are not subject to smoke 

management programs. 

7.5 Enforceability of Emission Limitations and Control Measures

Section 51.308(d)(3)(v)(F) of 40 CFR part 51 requires Haze Plans to ensure that emission 

limitations and control measures used to meet reasonable progress goals are enforceable. 

BART eligible sources have existing permits that are enforceable by EPA.

Federal measures, such as the Federal Motor Vehicle Control Program, are enforceable 

by EPA. 

The marine vessel emission reductions under ECA are enforceable by EPA.
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EPA will continue to work with the Virgin Islands to evaluate the measures included in 

the long-term strategy, especially if HOVENSA reopens. EPA and the Virgin Islands will 

determine whether controls, particularly at HOVENSA, are reasonable to adopt and implement 

by 2018 and will evaluate these and other potential measures in preparation for the next revision 

of the haze plan in 2018. 

EPA will require that if HOVENSA reopens its refinery, HOVENSA shall evaluate all of 

its emission points to determine if reasonable controls are available for those emission points.

7.6 Consultation on the Long-Term Strategy

Section 51.308(d)(3)(i) 40 CFR part 51 requires consultation with other States/Tribes to 

develop coordinated emission management strategies. This requirement applies both where 

emissions from the Virgin Islands are reasonably anticipated to contribute to visibility

impairment in Class I areas outside the Virgin Islands and when emissions from other 

States/Tribes are reasonably anticipated to contribute to visibility impairment in Class I areas 

within the Virgin Islands.

As noted in Section 3, the Virgin Islands have little impact on visibility impairment in 

other States and other States have little to no impact on visibility impairment in Virgin Islands. 

Therefore, consultation was limited to interaction with EPA Region 2 and the FLMs. The 

coordination with FLMs on long-term strategy development is described in sections 3.3, 8.0 and 

9.2 of this plan.

8.0 REASONABLE PROGRESS GOALS

For each Class I area within the State/Tribe, 40 CFR 51.308 (d)(1) requires the state (in 

this case, EPA for the Virgin Islands) to establish reasonable progress goals (RPG) (expressed in 

deciviews) that provide for reasonable progress towards achieving natural visibility. The EPA 

released guidance on June 7, 2007 to use in setting reasonable progress goals. The goals must 

provide improvement in visibility for the most impaired days, and ensure no degradation in 

visibility for the least impaired days over the SIP period. 

Under 40 CFR 51.308 (d)(1)(iv), consultation is required in developing reasonable 

progress goals. As discussed in Section 3, because of the Virgin Islands’ remote location, there is 
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little to no impact from the Virgin Islands on visibility on other Class I areas or impacts of other 

states on Virgin Islands National Park. As such, the Virgin Islands did not need to be consulted 

during the establishment of reasonable progress goals for other Class I Areas and other States 

were not consulted in the development of the RPG for the Virgin Islands. In lieu of coordination 

with other States, the required discussions about the RPG that occurred between EPA Region 2 

officials, EPA Headquarters and the appropriate FLMs will suffice for consultation.

In developing the RPG, the Class I State must also consider four factors (cost, time 

needed, energy and non-air quality environmental impacts, and remaining useful life). This plan 

discusses the uniform rate of improvement, the improvement in visibility needed to achieve the 

RPG for 2018 and how the effect of the planned measures compare to the RPG for the period 

covered by the implementation plan. 

8.1 Calculation of Uniform Rate of Progress 

As a benchmark to aid in developing reasonable progress goals, EPA Region 2 compared 

the baseline visibility conditions to natural visibility condition in the Class I area and determined 

the uniform rate of visibility improvement (in deciviews) that would need to be maintained 

during each implementation period in order to attain natural visibility condition by 2064. Table 

7-1 presents the baseline visibility, natural visibility, and required uniform rate of progress for 

the Virgin Islands National Park. Additional Class I areas are listed in Table 7-1 for comparison. 

Table 8-1: Uniform Rate of Progress Calculation 

Class I Area

(2000-2004) 

Baseline 

Visibility 

(deciviews)

(20% Worst 

Days)

Natural 

Visibility 

Conditions

(20% Worst 

Days)

Deciview 

Improvement 

Needed by 

2018 (from 

2004)

Total 

Deciview 

Improvement 

Needed by 

2064

Uniform 

Rate of 

Improvement 

Annually

Virgin Island 

National Park 17.02 10.68 1.48 6.34 0.11

Acadia 

National Park 22.9 12.4 2.4 10.5 0.17

Brigantine 

Wilderness 29.0 12.2 3.9 16.8 0.28

Everglades 

National Park 22.3 12.2 2.4 10.2 0.17

Hance Camp 

at Grand 

Canyon 

11.7 7.0 1.1 4.6 0.08
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National Park

Both natural conditions and baseline visibility for the 5-year period from 2000 through 

2004 were calculated in conformance with the alternative, updated method recommended by the 

IMPROVE Steering Committee. Progress toward the 2018 target will be calculated based on 5-

year averages calculated in a nationally consistent manner consistent with EPA’s Guidance for 

Tracking Progress Under the Regional Haze Rule (EPA-454/B-03-004, September 2003) as 

updated by the alternative method for calculating regional haze recommended by the IMPROVE 

Steering Committee.

Based on a base case visibility for the twenty percent worst days of 17.02 DV and a 

natural background calculated for worst twenty percent days of 10.68 DV, the difference is the 

Reasonable Progress Goal for 2064: 6.34 DV. According to EPA’s Regional Haze Rule, a 

reduction of 6.34 DV by 2064 is to be accomplished by reducing visibility impairment by at least 

the rate of uniform reduction in each of the ten-year period covered by the haze plans. The 

reduction needed by 2018 from 2004 (14 years for the first period) is calculated thus: 6.34 dv 

divided by 60 and multiplied by 14 = 1.48dv.

8.2 Reasonable Progress Goals for the Class I Area in the State 

In accordance with the requirements of 40 CFR Section 51.308(d)(1), this Regional Haze 

Plan establishes reasonable progress goals for the Class I area in the Virgin Islands for the period 

of the implementation plan. The RPG for the Virgin Islands for the twenty percent worst days is 

1.48 dv, of which the modeling predicts that visibility will be improved by 0.16 dv for the first

period ending in 2018. 

The Clean Air Act’s plan for reducing regional haze is twofold: 1) Set the natural 

visibility target and insure that every 10 years the Virgin Islands has a plan to reduce emissions 

enough to remain on track to meet the target, and 2) Find all reasonable reductions in emissions 

that reduce visibility in the protected area. There is a tremendous amount of uncertainty in 

estimating how much of the Virgin Islands’ visibility impairment is due to natural sources, and 

this plan has used default natural background concentrations, and not tried to adjust for the 

effects of Saharan Dust or other natural sources. It is likely that the effects of dust from the 
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Sahara Desert overwhelm the effects of local sources on visibility in the Virgin Islands National 

Plan in a way not seen in any other part of the United States, since the Virgin Islands are nearer 

to Africa than any other location in the United States. 

So, this plan determines the amount of emission reductions for the first plan period 

through 2018 based on the application of reasonably available emission reductions from sources 

that affect visibility in the Virgin Islands National Park on St. John. 

In order to be on track to improve visibility to meet the CAA goal of reaching natural 

visibility levels, this plan estimates the amount of progress needed by 2018 based on the 

calculated natural level of visibility. In the case of the Virgin Islands, the emission reductions do 

not improve visibility to meet the reasonable progress goal line for 2018. However, the amount 

of progress estimate for 2018 may be an overestimate due to the underestimation of natural 

visibility conditions. This calculation does not include the full impact of Saharan Dust and other 

natural emissions that interfere with visibility. Therefore, this plan will focus on obtaining the 

maximum amount of reasonable reductions. For the next 10 years’ plan, EPA and the Virgin 

Islands Department of Natural Resources will need to develop better estimates of the natural 

background visibility in the Virgin Islands and adjust the goal accordingly, while still reducing 

emissions as much as reasonably possible in the meantime. 

To determine the RPG in deciviews, EPA Region 2 prepared emissions data and 

conducted modeling before and after certain control measures. The control measures reflected in 

these reasonable progress goals include the Caribbean ECA and the HOVENSA Consent Decree.

8.2.1 Consideration of Other Air Quality Requirements 

40 CFR 51.308(d)(1)(vi) of EPA’s Clean Air Visibility Rules requires that reasonable 

progress goals represent at least the visibility improvement expected from implementation of 

other CAA programs during the applicable planning period.

As documented in the emissions inventory and long-term strategy sections of this FIP, the 

modeling that formed the basis for reasonable progress goals in the Virgin Islands National Park 

could not estimate how other programs required by the CAA reduce emissions. Further 

information can be found in those sections of this FIP.
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8.2.2 Additional Reasonable Controls within Virgin Islands 

A full list of all Federal control measures considered is presented in Section 7. No 

additional measures are determined to be reasonable for the Virgin Islands. Implementation of 

any measures that have not been reviewed would be hampered by the compressed schedule that 

this FIP was developed under. Sources would have little time to comply with any additional 

control programs recommended in this FIP. Based on timeframes presented by States in their 

regional haze SIPs, this is minimum amount of time needed for the simplest of additional 

strategies. It is unreasonable to plan for any additional control in this period.

8.2.3 Visibility Impacts of Additional Reasonable Controls

This section explains assumptions used to model the impact of potential control strategies 

and describes the combined potential visibility benefits of all the strategies based on CALPUFF 

modeling and emissions analysis. As with all modeling, emissions estimates and modeling 

results for 2018 entail uncertainty, and further evaluation may be conducted as part of the SIP 

report required in 5 years under 40 CFR 51.308(g).

8.2.4 Impacts of BART Controls in the Virgin Islands

As discussed in Section 5, the Virgin Islands have three facilities with units that 

potentially could be subject to BART. As explained in this FIP, no BART controls beyond 

existing controls are being proposed or adopted. 

8.2.5 Impacts of other Federal Controls in the Virgin Islands

The implementation of low sulfur fuels in the non-road sector (i.e., marine vessels) under 

the Caribbean ECA will provide an 85 percent reduction in SO2 and an additional 80 percent 

reduction in NOx from this source sector. This represents a 0.03 deciview improvement on the 

twenty percent worst days. 

The settlement reached with HOVENSA, LLC as a result of EPA’s Refinery

Enforcement Initiative will result in an estimated 15 percent reduction in SO2 and a 16 percent 

reduction in NOx from the facility. This represents a 0.13 deciview reduction on the twenty

percent worst days.

Additional controls that will affect the Virgin Islands are noted in Section 6, but were not 

included in the modeling for calculating improvement to visibility in the Class I area because of 

the limited data available on emissions in the Virgin Islands. All of the measures laid out in 
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Section 6 will contribute to reductions in anthropogenic emission that may further improve 

visibility conditions at the Virgin Islands National Park. 

8.2.6 Results of Best and Final Modeling

The starting point for indicating progress achieved by measures included in this FIP is the 

2000-2004 baseline visibility at affected Class I areas. To calculate the baseline visibility for 

affected Class I areas, using 2000-2004 IMPROVE monitoring data, the deciview value for the 

twenty percent best days in each year with adequate data were averaged together, producing a 

single average deciview value for the best days. Similarly, the deciview values for the twenty

percent worst days in each year with adequate data were averaged together, producing a single 

average deciview value for the worst days.

In order to estimate the visibility impacts of the measures discussed above, the EPA 

combined CALPUFF modeling results and emissions scaling analysis to assess the visibility

improvement in the Virgin Islands. Documentation of the CALPUFF modeling is contained in 

Appendix C. Based on currently available information, this analysis provides an estimate of 

visibility improvement that could be achieved by 2018 through reasonable measures described 

above. 

Figure 7-1 illustrates the predicted visibility improvement by 2018 resulting from the 

implementation of the long-term strategy, where quantifiable. This improvement is compared to 

the Uniform Rate of Progress for affected Class I areas. The Virgin Islands are projected to fall 

short of the uniform rate of progress goal for 2018. However, emission reductions from several 

control methods noted in this section could not be quantified due to the limited emissions 

information for the Virgin Islands. EPA has included reasonable measures in this FIP. In 

addition, the emissions are not expected to increase impairment of best day visibility relative to 

the baseline.

In addition to improving visibility on the 20% worst visibility days, states are also 

required to protect visibility on the 20% best days at the Class I areas. EPA’s calculations show 

that visibility on the 20% best days is projected to be protected in this first planning period at the 

Virgin Islands National Park as emission controls will decrease emissions though 2018.
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Figure 8-1: Projected Progress Goals 

8.3 Demonstration that the Goals are 

Section 51.308 (d)(1)(i)(A) of 40 CFR part 51 requires that in establishing reasonable 

progress goals for each Class I area, the 

necessary for compliance, the energy and non

and the remaining useful life of any potentially affected sources, and the SIP must include a 

demonstration showing how these factors were taken into consideration in setting the goal. These 

factors are sometimes termed the “four statutory factors,” since the

the Clean Air Act.

Focus on SO2

Tuesday, June 26, 2012

Progress Goals and Modeled Progress at Virgin Islands National 

Park 

Demonstration that the Goals are based on Reasonable Controls

)(A) of 40 CFR part 51 requires that in establishing reasonable 

progress goals for each Class I area, the Plan must consider the costs of compliance, the time 

necessary for compliance, the energy and non-air quality environmental impacts of compliance, 

the remaining useful life of any potentially affected sources, and the SIP must include a 

demonstration showing how these factors were taken into consideration in setting the goal. These 

factors are sometimes termed the “four statutory factors,” since their consideration is required by 

 8-80

Tuesday, June 26, 2012

in Islands National 

)(A) of 40 CFR part 51 requires that in establishing reasonable 

must consider the costs of compliance, the time 

air quality environmental impacts of compliance, 

the remaining useful life of any potentially affected sources, and the SIP must include a 

demonstration showing how these factors were taken into consideration in setting the goal. These 

ir consideration is required by 
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The conceptual model developed for the Virgin Islands indicated that the dominant 

anthropogenic contributor to visibility impairment in the Virgin Islands National Park was 

particulate sulfate formed from emissions of SO2. While other pollutants will need to be 

addressed in order to achieve the national visibility goals, SO2 is responsible for 19 percent of 

light extinction on the twenty percent worst days. Therefore, it is reasonable that the additional 

measures considered in setting the reasonable progress goals described in Section 9.3 required 

reductions of SO2 emissions. Because of the relative lack of anthropogenic emission sources in 

the Islands, natural interference with visibility, mostly due to Saharan Dust, predominates, but 

can’t be controlled. 

Contributing Sources

As discussed in Section 1, the Virgin Island’s distance from major land areas with major 

sources of pollution limits the number of sources affecting their Class I area. The emission 

inventory in Section 4 shows that point sources on St. Thomas and St. Croix are significant 

sources of SO2 emissions. Evaluation of these sources’ emissions for reasonable controls is in 

section 5. The largest of these sources included potentially BART-eligible sources and the 

evaluation of BART controls is discussed in section 6. Potential BART controls were either not 

reasonable or had little impact on improving visibility in the Virgin Islands.

9.0 CONSULTATION AND COORDINATION

9.1 Regional Planning

In 1999, EPA and affected States/Tribes on the continental United States agreed to create 

five Regional Planning Organizations (RPOs) to facilitate interstate coordination on Regional 

Haze SIP/Tribal Implementation Plans. The RPOs and States/Tribes within each RPO are 

required to consult on the development of emission management strategies directed towards 

visibility improvement in affected Class 1 areas. The RPOs have also allowed States to pool 

resources and collectively develop information, such as emissions inventories and modeling, to 

support regional haze plans. 

Because the Virgin Islands are separated from the continental United States by over a 

thousand miles, they were not included in any RPO. As a result, this plan was developed without 
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the assistance that the multi-state RPOs typically provide. Because the Virgin Islands 

government could not leverage its resources by working with other states to lay the groundwork 

for the their regional haze plan, EPA has opted to work alongside the Virgin Islands’ government 

to prepare this regional haze plan as a Federal Implementation Plan

9.2 State/Tribe and Federal Land Manager Coordination

Section 51.308(i) of 40 CFR requires coordination between States/Tribes and the Federal 

Land Managers (FLMs). EPA Region 2 has discussed the technical documents developed by 

EPA Region 2 and included in this FIP with the FLMs. EPA Region 2 has provided agency

contacts to the FLMs as required. In the development of this plan, the FLMs were consulted in 

accordance with the provisions of 40 CFR 51.308(i)(2). EPA Region 2 has consulted via 

conference call meetings with the FLMs. The National Park Service has expressed their 

understanding of the proposed plan and reserves the opportunity to comment during the 

comment period upon EPA’s proposal of this FIP. EPA, in consultation with the Virgin Islands 

Government, will respond to comments from the FLM in accordance with 40 CFR 51.308(i)(3). 

The FLM’s comments and EPA’s responses will be included in Appendix A of this plan. 

Section 51.308(i)(4) of 40 CFR requires procedures for continuing consultation between 

the State/Tribe and FLMs on the implementation of the visibility protection program. The Virgin 

Islands and EPA Region 2 will consult with the FLM(s) on the status of the following 

implementation items: 

1. Implementation of emissions strategies identified in the FIP as contributing to achieving 

improvement in the worst-day visibility.

2. Summary of major new source permits issued.

3. Status of actions in the Virgin Islands to meet commitments for completing any future 

assessments or rulemakings on sources identified as likely contributors to visibility

impairment, but not directly addressed in the most recent FIP revision. 

4. Any changes to the monitoring strategy or monitoring stations status that may affect 

tracking of reasonable progress. 

5. Work underway for preparing the 5-year review and / or 10-year revision.

6. Items for FLMs to consider or provide support for in preparation for any visibility

protection SIP revisions (based on a 5-year review or the 10-year revision schedule under 

EPA’s RHR) 
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7. Summary of topics discussion (meetings, emails, other records) covered in ongoing 

communications between the Virgin Islands Government, EPA and FLMs regarding 

implementation of the visibility program.

The consultation will be coordinated with the designated visibility protection program 

coordinators for the National Park Service.

EPA Region 2 and the Virgin Islands will continue to coordinate and consult with the 

FLMs during the development of future progress reports and plan revisions, as well as during the 

implementation of programs having the potential to contribute to visibility impairment in the 

mandatory Class I areas.

10.0 COMPREHENSIVE PERIODIC IMPLEMENTATION PLAN REVISIONS 

Pursuant to the requirements of 40 CFR 51.308(a) and (b), EPA Region 2 will implement

this FIP to meet the requirements of EPA’s Regional Haze rules that were adopted to comply

with requirements set forth in the Clean Air Act. Elements of this Plan address the Core 

Requirements pursuant to 40 CFR 51.308(d) and the BART components of 40 CFR 50.308(e). In 

addition, this FIP addresses Regional Planning, State/Tribe and Federal Land Manager 

coordination, and contains a commitment to provide Plan revisions and adequacy determinations.

Section 51.308(f) of 40 CFR requires a State/Tribe to revise its regional haze 

implementation plan and submit a plan revision to EPA by July 31, 2018 and every 10 years 

thereafter. In accordance with the requirements listed in 40 CFR 51.308(f) of the Federal rule for 

regional haze, EPA expects the Virgin Islands government to revise and submit a regional haze 

implementation plan by July 31, 2018 and every 10 years thereafter. 

In addition, 40 CFR 51.308(g) requires periodic reports evaluating progress towards the 

reasonable progress goals established for each mandatory Class I area. In accordance with the 

requirements listed in 40 CFR 51.308(g) of the Federal rule for regional haze, the EPA expects 

the Virgin Islands government to submit a report on reasonable progress every 5 years following 

the initial submittal of this FIP. The report will be in the form of a SIP revision submitted 5 years 

after FIP submission. The reasonable progress report will evaluate the progress made towards the 

reasonable progress goal for the mandatory Class I area located within the Virgin Islands. All 
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requirements listed in 40 CFR 51.308(g) shall be addressed in the FIP revision for reasonable 

progress.

Section 51.308(d)(4)(v) of 40 CFR requires periodic updates of the emission inventory. 

The EPA expects that the Virgin Islands government will update and expand upon the existing 

inventory.

11.0 COMMITMENT TO DETERMINE THE ADEQUACY OF THE EXISTING 

PLAN

As required by 40 CFR 51.308(h), depending on the findings of the 5-year progress 

report, required under 40 CFR 51.308(g), the EPA expects that the Government of the Territory

of the Virgin Islands will take one of the following actions at the same time the 5-year progress 

report is submitted: 

(1) If EPA and the Virgin Islands determine that the existing implementation plan 

requires no further substantive revision in order to achieve established goals for visibility

improvement and emissions reductions, the EPA will make a negative declaration that further 

revision of the existing implementation plan is not needed.

(2) If EPA or the Virgin Islands determine that the implementation plan is or may be 

inadequate to ensure reasonable progress due to emissions from sources in another country, the 

EPA will work with the Virgin Islands to assess the amount of impairment from other counties 

and determine if consultation is needed with the other country or countries. 

(3) If EPA or the Virgin Islands determines that the implementation plan is or may be 

inadequate to ensure reasonable progress due to emissions from sources within the Virgin 

Islands, and if reasonable measures are available, the EPA expects that the Virgin Islands will 

submit a revision to the implementation plan to address the plan's deficiencies within 1 year.

The findings of the 5-year progress report will determine which actions are appropriate 

and necessary.
Draft Regional Haze SIP 12-85

US Virgin Islands Tuesday, June 26, 2012

12.0 SUMMARY OF THE FEDERAL PLAN FOR VISIBILITY IN THE NATIONAL 

PARK ON ST. JOHN IN THE UNITED STATES VIRGIN ISLANDS

EPA is adopting a Regional Haze Federal Implementation Plan to begin the process for 

reducing man-made interference with visibility to meet the Federal Regional Haze Rule’s goal of 

not man-made pollution interfering with visibility by 2064. This FIP also addresses coordination

with the Virgin Islands Government and the National Park Service as Federal Land Manager for 

the Virgin Islands National Park. EPA expects the Virgin Islands Government to determine if 

the Plan is working and to update the plan within five years and when the next plan is due in 

2018. 

The EPA used models to calculate how much local air pollution has affected visibility in 

Virgin Islands National Park, and is implementing this plan to reduce regional haze in the 

National Park using controls already in place and on the way. 

Most of the interference with visibility in the Park is due to the effects of dust from the 

Sahara Desert. However, EPA developed this haze plan by evaluating the reasonableness and 

effectiveness of reducing emissions based on the amount of air quality improvement that would 

occur. Emission controls were not rejected because of their impact compared to the effects of 

natural sources of visibility reduction affecting the Caribbean, but because they would be too 

expensive, not practicable, or not improve visibility. We cannot count the improvement in 

visibility from the shutdown of HOVENSA in this Plan, as HOVENSA must give up their air 

quality permits before we can take credit for up to 1.04 dv in visibility improvement. 

Table 12-1: Virgin Islands National Park Visibility Improvement Due to the FIP

Virgin Islands National Park

IMPROVE Measured 

Visibility Impairment in for 

the 20% worst days

(Deciviews)

Modeled Visibility 

Impairment for 20% worst 

days (Deciviews)

All sources, 4 years

Measured Baseline 17.02 10.14

Calculated Natural Background 10.68 -

Progress Goal for 2064 6.34 -

2018 Goal / Modeled 15.54 9.98

Reduction 2004-2018: 

Needed / Modeled 1.48 0.16
Draft Regional Haze SIP 12-86

US Virgin Islands Tuesday, June 26, 2012

In summary, EPA’s calculated a progress goal of improving visibility by 1.48 dv. The air 

quality improvements from the HOVENSA consent decree and the expected reductions in 

marine vessel emissions are modeled as a reduction of 0.16 dv. A number of measures, mostly 

related to motor vehicle emissions, are not quantifiable and no other measures were cost 

effective on a dollar per ton basis or they did not improve visibility very much. 

EPA expects that the Virgin Islands’ Government will determine if local action can 

reduce impacts of local sources on visibility in the Virgin Islands. In addition, before the 

HOVENSA refining facility on St. Croix reopens, it will first need to reevaluate its emissions to 

determine if reasonable controls should be implemented. The methods in EPA’s Regional Haze 

Rule should be a useful guide to a successful evaluation of reasonable measures.