State ofNew Mexico

Susana Martinez

Governor

June 24, 2011

Dr. Alfredo Armendariz

Regional Administrator (6-A)

U.S. Environmental Protection Agency, Region 6

1445 Ross Avenue, Suite 1200

Dallas, TX 75202-2733

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On behalf of the New Mexico Environment Department, I am pleased to submit to the

Environmental Protection Agency the enclosed revisions to the New Mexico State

Implementation Plan (SIP). These revisions include amendments to New Mexico's Regional

Haze SIP under 40 CFR § 51.309.

The hearing record for all of the SIP revisions is attached, which includes the revised SIP, filed

regulations, transcripts, exhibits, public notices, affidavits of publication, the notice of intent to

present technical testimony, and public comments.

Included with the attached hardcopy of the hearing record is an electronic copy of the record

provided on disk which I certify to be an exact duplicate ofthe hardcopy.

These SIP revisions satisfY the requirements of the Clean Air Act, comply with EPA regulations

and policy, and will result in significant emission reductions while preserving the proper federalstate partnership envisioned under the Clean Air Act. As such, EPA must approve these

revisions. In addition, because the enclosed SIP revisions address two different provisions ofthe

federal Clean Air Act, I believe EPA should address them separately.

First, the enclosed "Interstate Transport SIP" addresses Section 11 0 of the Act, which requires

states to avoid interfering with any other states' implementation plans for visibility. As made

clear in the Interstate Transport SIP submitted in 2007, and further explained in two letters to

EPA Region 6 from the previous New Mexico administration (one from Governor Richardson on

June 12,2009 and another from a member of his staff on May 6, 2010), New Mexico has already

satisfied its Interstate Transport obligations. However, the enclosed Interstate Transport SIP

supplements those previous submittals by confirming that the emissions from New Mexico

sources will not exceed the assumptions utilized in the modeling conducted by the Western

Regional Air Partnership (WRAP), upon which other western states' visibility plans are based.

State Capitol • Room 400 • Santa Fe, New Mexico 87501 • 505-476-2200 • fax: 505-476-2226
EPA has already recognized that "the analysis conducted by the WRAP provides an appropriate

means for designing a [plan] that will ensure that emissions from sources in New Mexico are not

interfering with the visibility programs ofother states." In fact, the enclosed Interstate Transport

SIP confirms that emissions will actually be much lower than the WRAP modeling assumptions.

Second, the enclosed revisions to the 2003 "Regional Haze Section 309 SIP" and the enclosed

"Regional Haze Section 309(g) SIP" (together, the "Regional Haze SIPs") address New

Mexico's obligation to reduce visibility impairment at national parks and wilderness areas

("Class I areas") in accordance with Sections 169A & 169B ofthe Clean Air Act. The Regional

Haze SIPs satisfy New Mexico's regional haze requirements by adopting new sulfur dioxide

(S02) milestones for the Section 309 Backstop Trading Program, establishing reasonable

progress goals and a long-term strategy for New Mexico's nine Class I areas, and adopting a

variety of control measures to address emissions of visibility impairing pollutants from New

Mexico sources. Most notably, the enclosed Regional Haze SIP also includes a Best Available

Retrofit Technology (BART) determination for the San Juan Generating Station, which requires

the installation of a Selective Non-Catalytic Reduction (SNCR) system to meet EPA's

presumptive BART limit for nitrogen oxides (NO,).

I am aware that EPA has proposed a different plan for implementing the Interstate Transport

program and at least a portion of the Regional Haze program in New Mexico through a

combined Federal Implementation Plan (FIP). I am also aware ofEPA's concern that it is bound

by a court order to complete that rulemaking effort by August 5, 20 II. However, the court order

imposing the August 5, 20 II deadline only requires EPA to address Interstate Transport

requirements before that date. In addition, the proposed FIP suffers from a variety of legal and

technical flaws and inappropriately seeks to address only an isolated portion ofthe regional haze

program. Under these circumstances, I believe EPA can and should address the Interstate

Transport program and Regional Haze program separately. Doing so will enable EPA to address

New Mexico's Interstate Transport requirements by the court-ordered deadline, while allowing

additional time for review ofthe more lengthy and complicated Regional Haze SIPs.

One of the fundamental principles expressed in Section !OI of the Clean Air Act is that "air

pollution control at its source is the primary responsibility of States and local governments."

That principle is nowhere better illustrated in the Act than in its visibility provisions, which, as

EPA and the courts have recognized, grant to the states significant discretion in the

implementation of measures to address visibility impairment. In designing the regional haze

program, Congress recognized that the individual states are best-equipped to balance the need for

robust environmental protections with the costs those protections necessarily entail.

Moreover, nothing in the Clean Air Act requires EPA to address Interstate Transport and

Regional Haze requirements together. On the contrary, EPA has generally addressed these

programs separately in the past. As just one example, EPA Region 8 recently proposed to take

separate action on the Interstate Transport and Regional Haze implementation plan revisions

submitted by the state of Colorado. Even EPA's proposed FIP for New Mexico itself

contemplates separate Interstate Transport and Regional Haze plans with regard to S02

emiSSIOns.
Accordingly, EPA should meet its August 5, 2011 deadline by simply approving New Mexico's

prior Interstate Transport submittals, as supplemented by the enclosed Interstate Transport SIP.

Even if EPA does not agree that New Mexico's prior submittals have already satisfied its

Interstate Transport obligations, EPA should be able to act on New Mexico's four-page Interstate

Transport SIP before August 5, 2011.

Since the court order does not require EPA to address New Mexico's Regional Haze program by

August 5, 2011, New Mexico is now, as of this submittal, in the same position as nearly every

other state - awaiting EPA action on its Regional Haze SIP. As with other states, EPA must

determine whether New Mexico's Regional Haze SIPs are complete no more than six months

from this date and, following that completeness determination or the expiration of six months,

EPA must act to approve or disapprove those SIPs within twelve months, including time allowed

for public notice and comment on the proposed action. Because EPA will be required to

consider New Mexico's Regional Haze SIPs regardless of whether it flllalizes the proposed FIP,

EPA should take no action on its proposed FIP, particularly since the August 5, 2011 deadline

does not apply to regional haze. At a minimum, EPA should reopen the docket on the proposed

PIP for at least ninety (90) days to accept further comment in light ofthe submission ofthese SIP

revisions.

I hope you will begin an immediate, expedited review and approval ofthe enclosed SIP revisions

and, as recommended above, take separate action on the separate Interstate Transport and

Regional Haze requirements ofthe Clean Air Act.

If there are any questions concerning this SIP submittal, please contact Raj Solomon at (505)

827-2855.

Sincerely,

Susana Martinez

Governor

Enclosures

cc: Guy Donaldson, EPA Region 6

Dave Martin, NMED Cabinet Secretary

Raj Solomon, NMED Deputy Cabinet Secretary
1

List of Enclosures: 

01 Section 309 Revised State Implementation Plan 

02 Appendix K - Recommendations for Making Attribution Determinations in the 

Context of Reasonably Attributable BART 

03 20.2.73 NMAC Revisions - Notices of Intent and Emissions Inventory 

Requirements 

04 20.2.81 NMAC Revisions - Western Backstop Sulfur Dioxide Trading Program 

05 Section 309(g) State Implementation Plan 

06 Appendix A - Emissions Overview (WRAP, undated) 

07 Appendix B - Air Quality Modeling (WRAP, undated) 

08 Appendix C - Summary of WRAP RMC BART Modeling for New Mexico 

09 Appendix D - New Mexico BART Determination for San Juan Generating 

Station 

10 Appendix E - Supplementary Information for Four Factor Analyses by WRAP 

States, EC/R Incorporated, May 4, 2009 (corrected April 20, 2010) 

11 Appendix F - Supplementary Information for Four-Factor Analyses for 

Selected Individual Facilities in New Mexico, May 5, 2009 

12 NMED Notice of Intent to Present Technical Testimony - May 2, 2011 

13 NMED Ex. 1 Clean Air Act § 169A 

14 NMED Ex. 2 Clean Air Act § 169B 

15 NMED Ex. 3 40 C.F.R. § 51.308 (Regional Haze Rule § 308) 

16 NMED Ex. 4 40 C.F.R. § 51.309 (Regional Haze Rule § 309) 

17 NMED Ex. 5 BART Guidelines – Appendix Y to 40 C.F.R. Part 51 Published 

at 70 Fed. Reg. 39104 

18 NMED Ex. 6 NMED Requests for Information from PNM 

19 NMED Ex. 6a Email - BART Modeling Results from WRAP (11.9.06) 

20 NMED Ex. 6b Email – PNM San Juan Generating BART Modeling (6-26-07) 

21 NMED Ex. 6c Email - Comments on the BART modeling report for the San 

Juan Generating Station (7.30.07) 

22 NMED Ex. 6d Email - SJGS BART Analysis Additional Information Request 

(9.21.07) 

23 NMED Ex. 6e Letter - Department Request (12.21.07) 

24 NMED Ex. 6f Letter PNM-BART-Request (4-25-08) 

25 NMED Ex. 6g Email - PNM NOx Information Review (3.20.08) 

26 NMED Ex. 6h Email - Meeting (6.18.08) 

27 NMED Ex. 6i Letter – Additional Information Request (12.29.08) 
2

28 NMED Ex. 7 PNM Submittals Related to BART 

29 NMED Ex. 7a San Juan BART Modeling Protocol (4.13.07) 

30 NMED Ex. 7b PNM BART Analysis (6.6.07) 

31 NMED Ex. 7c Email Thread with Cost Analysis Attached 

32 NMED Ex. 7d SCR Cost Analysis - (7.11.07) 

33 NMED Ex. 7e SNCR Hybrid Cost Analysis (7.11.07) 

34 NMED Ex. 7f Updated Visibility Cost Effectiveness Data - (8.23.07) 

35 NMED Ex. 7g PNM Response to NMED (9.14.07) - September 14, 2007 

36 NMED Ex. 7h PNM SCR Schematic 

37 NMED Ex. 7i Refined Visibility Results (11.5.07) 

38 NMED Ex. 7j PNM Discussion of OAQPS Cost Manual Method (3.29.08) 

39 NMED Ex. 7k Final BART Modeling Response (3.31.08) 

40 NMED Ex. 7L Final BART SNCR Analysis (5.30.08) 

41 NMED Ex. 7m Discussion of SJGS Coal and Classification 

42 NMED Ex. 7n Final Nalco-MOBOTEC NOx BART Analysis (8.28.08) 

43 NMED Ex. 7o Final PM BART Analysis (8.28.08) 

44 NMED Ex. 7p PNM SO3 Removal Report (3.16.09) 

45 NMED Ex. 7q SNCR Cover Ltr (2.9.11) 

46 NMED Ex. 7r PNM BART SNCR Analysis Update (2.9.11) 

47 NMED Ex. 7s SNCR Cover Ltr (2.11.11) 

48 NMED Ex. 7t Revised SNCR Analysis (2.11.11) 

49 NMED Ex. 7u Rate Impact Analysis (2.11.11) 

50 NMED Ex. 8 Testimony of Mary Uhl 

51 NMED Ex. 8a Testimony on Scientific and Regulatory Background of 

Regional Haze 

52 NMED Ex. 8b Regional Haze Powerpoint Slides 

53 NMED Ex. 8c Testimony Re BART Determination for PNM SJGS 

54 NMED Ex. 9 Testimony of Rita Bates 

55 NMED Ex. 9a Testimony Re Revisions to 2003 § 309 SIP 

56 NMED Ex. 9b Testimony Re Proposed §309(g) SIP 

57 NMED Ex. 10 Additional Proposed Revisions to § 309 SIP (5.2.11) 

58 NMED Ex. 11 Additional Proposed Revisions to § 309(g) SIP (5.2.11) 

59 NMED Ex. 12 Public Notices 
3

60 San Juan Citizens Alliance Comment Letter - May 3, 2011 

61 NMED Response to San Juan Citizens Alliance Comments 

62 Public Service Company of New Mexico Notice of Intent to Present Technical 

Testimony - May 17, 2011 

63 San Juan Coal Company Notice of Intent to Present Technical Testimony - 

May 17, 2011 

64 The Natural Resources Defense Council, San Juan Citizens Alliance, and 

WildEarth Guardians Entry of Appearance - May 17, 2011 

65 NMED Notice of Receipt of Comments - May 16, 2011 (includes U.S. EPA 

Comments) 

66 NMED Supplemental Notice of Intent to Present Technical Testimony - May 

20, 2011 

67 NMED Ex. 13 May 20, 2011 Revisions to § 309(g) SIP in Response to EPA 

Comments 

68 NMED Ex. 14 May 20, 2011 Revisions to 20.2.81 NMAC in Response to EPA 

Comments 

69 NMED Ex. 15 May 13, 2011 Comments from U.S. EPA Region 6 

70 NMED Ex. 16 NMED Responses to EPA Comments of May 13, 2011 

71 NMED Ex. 17 U.S.F.S. Letter of March 30, 2011with Comments 

72 NMED Ex. 18 NMED Response to U.S.F.S Comments of March 30, 2011 

73 NMED Ex. 19 Proposed Statement of Reasons for Adoption and Order 

74 NMED Second Notice of Receipt of Comments - May 26, 2011 (includes 

comments received May 25, 2011 from U.S. Park Service and Fish and Wildlife 

Service) 

75 NMED Exhibits Presented at the June 1, 2011 Hearing 

76 NMED Ex. 20 Compiled Section 309(g) SIP (included herein as Section 309(g) 

SIP) -- was not included in submittal EPA received -- probably the same as 

enclosures 05 to 11. 

77 NMED Ex. 21 Responses to U.S. Park Service and Fish and Wildlife Service 

Comments 

78 Transcript of Hearing - June 1 and 2, 2011 (Volumes 1 and 2) 

79 New Mexico Environmental Improvement Board Statement of Reasons for 

Adoption of SIP Revisions 
REVISION TO THE NEW MEXICO

STATE IMPLEMENTATION PLAN

FOR REGIONAL HAZE

December 31, 2003

(Revisions dated June 2, 2010)

Prepared by staff of the:

Air Quality Bureau

Environmental Protection Division

New Mexico Environment Department

1301 Siler Road

Santa Fe, New Mexico 87507
NM Regional Haze SIP

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i

New Mexico Regional Haze State Implementation Plan

Table of Contents

Executive Summary ..................................................................................................................... iii

Introduction ................................................................................................................................... 1

Background ................................................................................................................................. 1

Public Involvement ..................................................................................................................... 3

State Implementation Plan Requirements .................................................................................. 4

A. Projection of visibility improvement. ................................................................................. 4

B. Treatment of Clean Air Corridors ....................................................................................... 9

C. Stationary Sources ............................................................................................................ 12

D. Mobile Sources ................................................................................................................. 58

E. Programs Related to Fire. ................................................................................................. 60

F. Paved and Unpaved Road Dust......................................................................................... 64

G. Pollution Prevention.......................................................................................................... 65

H. Implementation of Additional Recommendations. ........................................................... 76

I. Periodic implementation plan revisions. ........................................................................... 77

J. State planning and interstate coordination. ....................................................................... 78

K. Geographic Enhancement. ................................................................................................ 79

L. Reasonable Progress for Additional Class I Areas. .......................................................... 81

M. Demonstration That the SO2 Milestones Provide Greater Reasonable Progress Than 

BART ............................................................................................................................ 82

LIST OF APPENDICES

Appendix A: Projection of Visibility Improvement 

Appendix B: Western Regional Air Partnership Policy on Clean Air Corridors 

Appendix C: Stationary Sources 

Appendix C-1: Western Backstop Emissions and Allowance Tracking System and 

Analysis 

Appendix C-2: Stationary Source NOx and PM Emissions in the WRAP Region: An 

Initial Assessment of Emissions, Controls, and Air Quality Impacts 

Appendix C-3: SO2 Emission Monitoring Protocols 

[Appendix D: Reserved] 

Appendix E: Fire Programs 

Appendix E-1: Comparison of Existing NM Smoke Management Program with RHR 

Requirements 

Appendix E-2: Description of Process to Identify and Remove Administrative Barriers to 

the Use of Non-burning Alternatives
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ii

Appendix E-3: Process for Establishing Annual Emission Goals 

Appendix E-4: Western Regional Air Partnership Policy on Enhanced Smoke 

Management Programs for Visibility

Appendix E-5: Western Regional Air Partnership Policy on Annual Emission Goals for 

Fire

Appendix E-6: Western Regional Air Partnership Fire Tracking System Policy

Appendix F: Paved and Unpaved Road Dust 

Appendix G: Pollution Prevention 

[Appendix H: Reserved] 

[Appendix I: Reserved] 

Appendix J: Interstate and Regional Coordination 

[[Appendices K-] 

Appendix K: Recommendations for Making Attribution Determinations in the Context of 

Reasonably Attributable BART, Westar Council, May 2003

Appendix

Appendix M: Monitoring Requirements 

L: Reserved]

Appendix N: WRAP Technical Support Document (on CD-ROM)
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iii

EXECUTIVE SUMMARY

This document comprises the State of New Mexico's State Implementation Plan (SIP) submittal 

to the U.S. Environmental Protection Agency (EPA) under the Regional Haze Rule in Section 

309 of Title 40 of the Code of Federal Regulations, Part 51 (40 CFR 51.309). The first section of 

the SIP includes introductory and background information. Section II includes the SIP 

requirements under Section 309 and how New Mexico is addressing those requirements. Table 

ES-1 is a brief summary of each of the 309 SIP requirements along with New Mexico's approach 

in addressing those requirements.

Table ES-1 Summary of 309 SIP Requirements

Projection of visibility 

improvement

Projected visibility improvement for each of the Class I areas on the 

Colorado Plateau (San Pedro Parks Wilderness in New Mexico)

Clean Air Corridors Emission growth either inside or outside of the Clean Air Corridor are 

not shown to be contributing to impairment within the Clean Air 

Corridor

Stationary Sources of SO2 This section includes milestones for sulfur dioxide emissions along 

with a backstop market cap and trade program for sulfur dioxide 

emissions from specific sources.

Mobile Sources Federal programs (such as low sulfur diesel, vehicle emission 

standards, etc.) lead to decreasing mobile source emissions throughout 

the planning period.

Programs Related to Fire New Mexico has developed a smoke management regulation (20.2.65 

NMAC) that is included as an appendix to this SIP and that is 

responsive to the Western Regional Air Partnership (WRAP) 

Enhanced Smoke Management Programs for Visibility Policy.

Paved and Unpaved Road 

Dust

Dust emissions are not a significant contributor to visibility 

impairment within the Colorado Plateau 16 Class I areas.

Pollution Prevention Programs and policies within New Mexico related to renewable energy 

and energy efficiency are described. New Mexico's anticipated 

contribution to the pollution prevention goals are outlined.

Additional 

Recommendations 

New Mexico has not identified any other recommendations in the 

Grand Canyon Visibility Transport Commission Report to implement 

in New Mexico at this time.

Periodic Revisions New Mexico will submit period revisions to this SIP every five years 

as required by the Regional Haze Rule.

State Planning and 

Interstate Coordination 

New Mexico has participated in the WRAP and will continue to 

participate in the WRAP. In addition, New Mexico participates with 

the Joint Advisory Council on US/Mexico border issues.

Geographic Enhancement [As New Mexico does not have an approved SIP for reasonably 

attributable visibility impairment at this time, New Mexico is deferring 

the geographic enhancement option until a later date.] EPA approval 

of New Mexico's Phase I visibility SIP became effective on March 28, 

2006. New Mexico commits to following the recommendations for 

determining attribution outlined in the report "Recommendations for 

Making Attribution Determinations in the Context of Reasonably 

Attributable BART", Westar Council, May 2003.
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iv

Reasonable Progress for 

Additional Class I Areas

New Mexico [intends to follow] is concurrently submitting a Section 

309(g)(2) SIP for the eight additional Class I areas in New Mexico.
NM Regional Haze SIP

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1

INTRODUCTION

The blue skies and scenic vistas of New Mexico are considered some of the most beautiful in the 

United States. While New Mexico's residents and visitors frequently enjoy good visibility, air 

pollutants interfering with light transmission can impose limitations on aesthetic appreciation of 

scenery. Visibility is the term used to characterize physical limitations in the atmosphere that 

affect our ability to see clearly. Human caused pollution of varied concentrations and sizes in the 

atmosphere can impair or reduce visibility. Widespread visibility impairment caused by 

pollutants from a variety of sources and activities over a broad geographic area is known as 

regional haze. This document is the State of New Mexico's Regional Haze State Implementation 

Plan (SIP), compiled in accordance with the requirements of Title 40 of the Code of Federal 

Regulations, Part 51, Section 309 (40 CFR 51.309). 

Background 

Particles and gases released into the atmosphere either scatter or absorb light. Light scattering 

and absorption reduces the amount of light the human eye receives from a viewed object and 

diminishes resolution and contrast. The effects include degradation of color, flattening or 

blurring of textures, and blocking of landscapes, resulting in the reduction or loss of aesthetic 

value. Visibility impairment can occur across state and international borders and at locations far 

from pollution source(s). 

In 1977, Congress amended the 1970 Clean Air Act (CAA) and declared the national visibility 

goal, which is as follows: 

The prevention of any future, and the remedying of any existing, impairment in visibility 

in mandatory class I areas which impairment results from anthropogenic air pollution. 

In accordance with requirements contained in the CAA, the U.S. Environmental Protection 

Agency (EPA) in 1980 promulgated its first visibility protection regulation [40 CFR 51.300 

through 307]. Known as Phase I visibility protection, states were required to develop plans to 

address visibility impairment in mandatory federal Class I areas that is reasonably attributable to 

single sources or small groups of sources. In response to this regulation, New Mexico developed 

and submitted to EPA a Phase I, Part I visibility SIP in 1986 and a Phase I, Part II visibility SIP 

in 1992. The Phase was divided into two parts as a result of litigation following the promulgation 

of the regulation. EPA's approval of New Mexico's Phase I visibility SIP submittals became 

effective on March 28, 2006. 

[However, New Mexico's Phase I visibility SIPs did not explicitly provide authority and 

obligation to New Mexico for reasonable visibility impairment attributions and Best Available 

Retrofit Technology (BART) determinations for single sources and groups of sources, nor were 

the SIPs given final approval by EPA. Currently, there are Federal Implementation Plans (FIPs) 

in place and EPA continues to hold the authority and obligation for Phase I visibility protection 

in New Mexico. Although New Mexico's two Phase I SIPs were intended to replace the two 

FIPs, they have not done so. The result of these complications is special language addressing 

Geographic Enhancements in New Mexico's Regional Haze SIP, due to the fact that the state 
NM Regional Haze SIP

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2

does not have authority or obligation for reasonable visibility impairment attributions or BART 

determinations.] 

Building on science and technology that was developed since the Phase I requirements, EPA in 

1999 promulgated a Phase II visibility protection regulation [40 CFR 51.308 and 309]. The 

Phase II regulation is commonly known as the Regional Haze Rule. The Regional Haze Rule 

addresses impairment across large geographic areas that impacts visibility in mandatory Federal 

Class I areas (Class I areas), with a goal of returning visibility in Class I areas to natural 

conditions by 2064. The Regional Haze Rule requires that states develop State Implementation 

Plans to control visibility-impairing air pollution.

Class I areas are those designated as areas of special national or regional value from a natural, 

scenic, recreational, and/or historic perspective. These areas are the focus of federal visibility 

protection regulations, including the Regional Haze Rule. Across the country, Class I areas 

include such places as the Grand Canyon, Yosemite, Mt. Rainier, Great Smoky Mountains, 

Yellowstone, and the Everglades. There are a total of 156 mandatory federal Class I areas in the 

U.S. There are nine Class I areas in New Mexico, including Carlsbad Caverns National Park, 

Bandelier National Monument, Bosque del Apache National Wildlife Refuge, and the Gila, 

Pecos, Salt Creek, San Pedro Parks, Wheeler Peak, and White Mountain Wilderness Areas. The 

combination of Phase I and Phase II (Regional Haze) visibility protection is expected to improve 

visibility throughout the United States and attain the national visibility goal. 

Section 309 of the Regional Haze Rule (40 CFR 51.309) is an option available to only the nine 

western states that comprised the Grand Canyon Visibility Transport Commission (GCVTC), an 

organization formed by Congress in 1991 to study scientific and technical information on 

visibility protection for 16 Class I areas located on the Colorado Plateau, including the San Pedro 

Parks Wilderness Area in New Mexico. In 1996, the GCVTC submitted a report to EPA with 

recommendations on how to protect visibility for these areas. The Regional Haze Rule's Section 

309 incorporates the recommendations of the GCVTC, which were developed through a 

consensus-based process that involved states, tribes, EPA, federal land managers, industry, 

citizens and environmental groups from the west. New Mexico was an active participant in the 

process, as were New Mexico tribal governments, industry representatives and environmental 

groups. The State of New Mexico has chosen to pursue the path outlined in Section 309 in 

addressing regional haze. 

The Western Regional Air Partnership (WRAP) is the successor organization to the GCVTC. 

Comprised of western states, tribes, federal agencies, and stakeholders, the WRAP is 

administered by the Western Governors' Association and the National Tribal Environmental 

Council. The WRAP's committees and forums have developed many technical and policy tools 

useful to New Mexico in implementing the requirements of Section 309. These committees and 

forums have membership from the State of New Mexico as well as from New Mexico tribal 

governments, industry, federal land managers and environmental groups. 
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3

Public Involvement

In reaching the decision to develop a SIP in accordance with Section 309, New Mexico held 13 

meetings and numerous conference calls with stakeholders. New Mexico has also been an active 

member and participant in WRAP committees, forums, and work groups. New Mexico 

stakeholders have been active participants in the WRAP process as well. 
NM Regional Haze SIP

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4

STATE IMPLEMENTATION PLAN REQUIREMENTS

A. Projection of visibility improvement.

(a) Applicable Class I areas. This projection of visibility improvement covers the 16 Class I 

areas of the Colorado Plateau, as defined in 40 CFR 51.309(b)(1).

(b) Projected visibility improvement. [Pursuant to 40 CFR 51.309(d)(2), Tables 1 and 2 below 

indicate the projected visibility improvement in deciviews for each of the 16 Class I areas, from 

the years 1997-2001 through December 31, 2018. This projection was made for the 20% worst 

days and 20% best days, and is expressed in deciview (dV). Comparing the modeled data across 

the last three columns of the tables shows the improvement in visibility that would result from 

implementation of all of the 309 control strategies. The base case modeled column shows the 

visibility that would result in the absence of the 309 control strategies. The last two columns 

show the improvements resulting from the control strategies either with or without an optimal 

smoke management program.

The technical work was conducted by the WRAP, which evaluated the visibility improvements 

resulting from the application of the regional haze control strategies and programs described in 

Chapter 2 of the WRAP's Technical Support Document. See Appendix A of this implementation 

plan for the complete description of the control strategies and technical analysis.] 

Pursuant to 40 CFR 51.309(d)(2), Table A-1 below compares the monitored 2000-04 baseline 

visibility conditions in deciviews for the 20% Best and 20% Worst days to the projected 

visibility improvement resulting from the 2018 Base Case (Base 18b) and 2018 Preliminary 

Reasonable Progress (PRP18) modeling scenarios completed to date. These 2018 modeling 

scenarios are defined as follows:

• Base Case (Base 18b) = growth plus all controls “on the books” as of December 2004, no 

BART or SO2 milestones assumptions;

• Preliminary Reasonable Progress Case (PRP18b) = refined growth estimates plus all controls 

“on the books” as of May 2007, includes presumptive limit or known SO2 BART on EGUs; 

and

• [future] Final Reasonable Progress Case (FRP18) = all controls “on the books” as of 2007, 

will include all BART controls in the WRAP region and limits defined in the SO2 milestone 

“better-than-BART” program.

When SO2 and NOx controls for all BART sources have been adopted in the WRAP region, and 

the 309 states re-adopt the SO2 milestone program, a 2018 Final Reasonable Progress (FRP18) 

modeling scenario will then be analyzed and the remaining cells completed in the table below. 

The data in the table below satisfy 40 CFR 51.309(d)(2) of the Regional Haze Rule.

All 16 Colorado Plateau Class I areas show a projected visibility improvement for 2018 using the 

monthly averages on the 20% Worst average visibility days, and no degradation on the 20% Best 

average visibility days for each monitoring site. The monthly average method for projecting 
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5

visibility improvement is an allowed variation of EPA guidance, and the method description is 

found at: http://www.wrapair.org/forums/taf/meetings/070226c/Applying_Monitoring_Metrics_ 

for_Regional_Haze_Planning_%20February_23_2007_finalreviewdraft.pdf. The monthly 

averaging method was chosen because it was the shortest averaging period for making the future 

visibility projections, while avoiding the use of the EPA specific days method that only assesses 

improvements on the Worst and Best days observed during one year (2002) of the 2000-04 

baseline monitoring period. The methodology and current data showing projected visibility 

improvement in 2018 are now available through the WRAP TSS 

(http://vista.cira.colostate.edu/tss).
NM Regional Haze SIP

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6

[Table A-1. Modeling Results of Projected Visibility Improvement at the 16 Colorado Plateau Class I Areas in 2018 on 

the Average 20% Worst Days, resulting from implementation of "All §309 Control Strategies."

Modeling Results (deciviews)

Colorado Plateau

Class I Area State (20% Worst 

Days' Visibility -

deciviews)

1997-2001 

Monitoring Data (20% Worst 

Days' Visibility 

for all controls 

"on the books"

as of 2002)

2018 Base Case (20% Worst Days'

Visibility for all §309 

Control Strategies (SO2

Annex Milestones and 

Pollution Prevention) 

with Base Smoke 

Management)

2018 Scenario 1

(20% Worst Days'

Visibility for all §309 

Control Strategies (SO2

Annex Milestones and 

Pollution Prevention) 

with Optimal Smoke 

Management)

2018 Scenario 2

Grand Canyon NP AZ 12.30 11.62 11.56 11.51

Mount Baldy Wilderness AZ 14.30 12.22 12.02 11.96

Petrified Forest NP AZ 13.00 11.99 11.82 11.74

Sycamore Canyon Wilderness AZ 15.40 11.63 11.51 11.48

Black Canyon of Gunnison NP CO 11.30 10.90 10.76 10.60

Flat Tops Wilderness CO 10.50 11.04 10.91 10.73

Maroon Bells-Snowmass WA CO 10.60 11.15 11.00 10.84

Mesa Verde NP CO 13.10 12.24 12.03 11.84

West Elk Wilderness CO 10.60 11.19 10.99 10.84

Weminuche Wilderness CO 11.30 11.08 10.89 10.72

San Pedro Parks Wilderness NM 10.70 12.33 12.12 11.71

Arches NP UT 12.10 12.41 12.29 12.15

Bryce Canyon NP UT 11.80 12.26 12.24 11.95

Canyonlands NP UT 12.10 12.41 12.31 12.18

Capitol Reef NP UT 12.10 12.51 12.49 12.36

Zion NP UT 13.60 12.13 12.09 12.03
NM Regional Haze SIP

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7

Table A-2. Modeling Results of Projected Visibility Improvement at the 16 Colorado Plateau Class I Areas in 2018, on 

the Average 20% Best Visibility Days, resulting from implementation of "All §309 Control Strategies."

Modeling Results (deciviews)

Colorado Plateau

Class I Area State

1997-2001 

Monitoring Data

(20% Best Days'

Visibility -

deciviews)

(20% Best 

Days' Visibility 

for all controls 

"on the books"

as of 2002)

2018 Base 

Case (20% Best Days'

Visibility for all §309 

Control Strategies 

(SO2 Annex 

Milestones and 

Pollution Prevention) 

with Base Smoke 

Management)

2018 Scenario 1

(20% Best Days' Visibility 

for all §309 Control 

Strategies (SO2 Annex 

Milestones and Pollution 

Prevention) with Optimal 

Smoke Management)

2018 Scenario 2

Grand Canyon NP AZ 4.80 4.76 4.72 4.64

Mount Baldy Wilderness AZ 5.50 5.49 5.46 5.36

Petrified Forest NP AZ 6.50 5.18 5.14 5.10

Sycamore Canyon Wilderness AZ 6.30 4.85 4.82 4.75

Black Canyon of Gunnison NP CO 4.60 3.89 3.83 3.75

Flat Tops Wilderness CO 3.10 3.96 3.90 3.81

Maroon Bells-Snowmass WA CO 3.10 3.90 3.85 3.80

Mesa Verde NP CO 5.50 4.40 4.38 4.33

West Elk Wilderness CO 3.10 3.89 3.83 3.74

Weminuche Wilderness CO 4.60 3.97 3.92 3.82

San Pedro Parks Wilderness NM 4.00 5.59 5.51 5.36

Arches NP UT 5.50 4.85 4.72 4.61

Bryce Canyon NP UT 4.30 3.91 3.92 3.89

Canyonlands NP UT 5.60 4.87 4.76 4.67

Capitol Reef NP UT 5.60 4.85 4.85 4.75

Zion NP UT 5.90 3.81 3.79 3.75]
NM Regional Haze SIP

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8

Table A-1. Visibility Impairment in Deciviews*

Colorado Plateau Class I 

Areas Under §309(d)(2) State

20% Worst Visibility Days 20% Best Visibility Days

2000-2004 

Regional 

Haze Rule 

Baseline 

Monitoring 

Data

Projected Visibility (Monthly Average 

Method) 2000-2004 

Regional 

Haze Rule 

Baseline 

Monitoring 

Data

Projected Visibility (Monthly Average 

Method)

2018 Base 

Case 

(Base 

18b)

2018 

Preliminary 

Reasonable 

Progress 

Case 

(PRP18b)

2018 Final 

Reasonable 

Progress 

Case 

(FRP18)

2018 Base 

Case 

(Base 

18b)

2018 

Preliminary 

Reasonable 

Progress 

Case 

(PRP18b)

2018 Final 

Reasonable 

Progress 

Case 

(FRP18)

Grand Canyon National Park AZ 11.7 11.4 11.1 2.2 2.2 2.1

Mount Baldy Wilderness AZ 11.9 11.5 11.5 3.0 2.9 2.9

Petrified Forest National Park AZ 13.2 12.9 12.8 5.0 4.9 4.7

Sycamore Canyon 

Wilderness AZ 15.3 15.1 15.0 5.6 5.6 5.5

Black Canyon of the 

Gunnison National Park CO 10.3 10.0 9.8 3.1 2.9 2.9

Flat Tops Wilderness CO 9.6 9.2 9.0 0.7 0.6 0.5

Maroon Bells Wilderness CO 9.6 9.2 9.0 0.7 0.6 0.5

Mesa Verde National Park CO 13.0 12.8 12.5 4.3 4.1 4.0

Weminuche Wilderness CO 10.3 10.0 9.8 3.1 2.9 2.9

West Elk Wilderness CO 9.6 9.2 9.0 0.7 0.6 0.5

San Pedro Parks Wilderness NM 10.2 10.0 9.8 1.5 1.3 1.2

Arches National Park UT 11.2 11.0 10.7 3.8 3.6 3.5

Bryce Canyon National Park UT 11.6 11.3 11.1 2.8 2.7 2.6

Canyonlands National Park UT 11.2 11.0 10.7 3.8 3.6 3.5

Capitol Reef National Park UT 10.9 10.6 10.4 4.1 4.0 3.9

Zion National Park UT 13.2 13.0 12.8 5.0 4.7 4.7

* Data are from: http://vista.cira.colostate.edu/TSS/Results/HazePlanning.aspx --> Modeling --> Visibility Projections
NM Regional Haze SIP 9 

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B. Treatment of Clean Air Corridors 

(a) Comprehensive emissions tracking program. Pursuant to 40 CFR 51.309(d)(3), a 

comprehensive emissions tracking system has been established to track emissions within 

portions of Oregon, Idaho, Nevada and Utah, that have been identified as part of the Clean Air 

Corridor, as specified in (b) below, to ensure that visibility is not degraded on the least-impaired 

days in any of the 16 Class I areas of the Colorado Plateau. This comprehensive emissions 

tracking system was developed by the WRAP to assist the above states in meeting this 

requirement. Appendix M-1 of this implementation plan describes the comprehensive emissions 

tracking system, and the process by which the WRAP will summarize annual emission trends in 

order to identify any significant emissions growth that could lead to visibility degradation in the 

16 Class I areas. Included in this summary will be an assessment of whether any significant 

emissions growth has occurred within the Clean Air Corridor, in accordance with (c) below. 

(b) Identification of Clean Air Corridors. Pursuant to 40 CFR 51.309(d)(3)(i), the State of New 

Mexico has identified a Clean Air Corridor, as indicated in the map provided below. This Clean 

Air Corridor was identified using studies conducted by the Meteorological Subcommittee of the 

Grand Canyon Visibility Transport Commission, and then updated by the WRAP based on an 

assessment described in the WRAP Policy Paper on Clean Air Corridors, and related technical 

analysis conducted by the WRAP. The comprehensive emissions tracking system described 

above in (a) shall track emissions within these counties. Appendix B of this implementation plan 

is the WRAP Policy Paper on Clean Air Corridors. Technical work associated with the 

identification of the Clean Air Corridor is included in Appendix N, the WRAP final draft 

Technical Support Document. 

Map of the Clean Air Corridor in the Transport Region
NM Regional Haze SIP 10 

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(c) Patterns of growth within the Clean Air Corridor. Pursuant to 40 CFR 51.309(d)(3)(ii), the 

State of New Mexico has determined, based on the WRAP Policy Paper on Clean Air Corridors

and technical analysis conducted by the WRAP, that inside the Clean Air Corridor identified in 

(b) there is no significant emissions growth occurring at this time that is causing visibility 

impairment in the 16 Class I areas of the Colorado Plateau. See Appendix B of this 

implementation plan for further details of emissions growth assessment conducted by the 

WRAP. Future emissions growth will be tracked in accordance with the comprehensive 

emissions tracking system in (a) above. The WRAP will summarize annual emission trends 

within the corridor and make an assessment of whether any significant emissions growth has 

occurred within the corridor. 

(d) Patterns of growth outside the Clean Air Corridor. Pursuant to 40 CFR 51.309(d)(3)(iii), the 

State of New Mexico has determined, based on the WRAP Policy Paper on Clean Air Corridors

and technical analysis conducted by the WRAP, that outside the Clean Air Corridor identified in 

(b) there is no emissions growth occurring at this time that is impairing air quality within the 

Clean Air Corridor sufficient to cause any visibility impairment in any of the 16 Class I areas of 

the Colorado Plateau. See Appendix B of this implementation plan for further details of 

emissions growth assessment conducted by the WRAP. As part of the WRAP's annual summary 

of emission trends within the corridor, an assessment will be made of emission and monitoring 

data trends outside the Clean Air Corridor, in order to determine if significant emissions growth 

is occurring outside the corridor that could be impairing air quality within the corridor, and 

resulting in visibility impairment in the 16 Class I areas. See Appendix B for additional details 

on this assessment process.

(e) Actions if impairment inside or outside the Clean Air Corridor occurs. The State of New 

Mexico, in coordination with other transport region states and tribes, will review the WRAP's 

annual summary of emission trends within the Clear Air Corridor and whether any significant 

emissions growth was identified within the corridor in accordance with (c) above, or was 

identified outside the corridor, in accordance with (d) above. If significant emissions growth was 

identified, the State of New Mexico in coordination with other transport region states and tribes, 

will conduct or seek WRAP assistance in conducting an analysis of the effects of this emissions 

growth in terms of possible impact on air quality within the corridor and possible degradation of 

the least-impaired days in any of the 16 Class I areas of the Colorado Plateau. Pursuant to 40 

CFR 51.309(d)(3)(iv), if this analysis finds that this growth is causing visibility impairment in 

the 16 Class I areas, the State of New Mexico in coordination with other transport states and 

tribes will evaluate the need for additional emission reduction measures, and identify an 

implementation schedule for such measures, if needed. The implementation of any additional 

emission measures shall be coordinated with all appropriate transport region states and tribes, on 

a mutually agreed upon timetable, and reported to EPA in accordance with the periodic progress 

reports required under 40 CFR 51.309(d)(10)(i). 

(f) Other Clean Air Corridors. Pursuant to 40 CFR 51.309(d)(3)(v), the State of New Mexico 

has concluded that no other Clean Air Corridors can be identified at this time. This finding is 

based on the review of work conducted by the Meteorological Subcommittee of the Grand 

Canyon Visibility Transport Commission on Clean Air Corridors, as described in the WRAP 
NM Regional Haze SIP 11 

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Policy Paper on Clean Air Corridors. See Appendix B of this implementation plan for further 

description of this finding. Although no formal update on this finding is required, the State of 

New Mexico recognizes that future modeling or monitoring data may indicate other possible 

Clean Air Corridors exist. The State of New Mexico will notify EPA if there is evidence to 

support such a finding in the future, and take appropriate action pursuant to this requirement. No 

clean air corridor or portion of a clean air corridor has been identified within New Mexico. 
NM Regional Haze SIP 12 

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C. Stationary Sources 

Sulfur Dioxide Milestone and Backstop Trading Program

Background

The SO2 Milestones and Backstop Trading Program was developed to implement the emissions 

reduction program for major industrial sources of sulfur dioxide described in 40 CFR 51.309(h). 

The program is implemented through the following documents: 

• The New Mexico Regional Haze Implementation Plan describes the overall program, 

and contains New Mexico's commitment to implement all parts of the program as 

outlined in the plan. The plan establishes the regional milestones, SO2 emissions 

tracking requirements, and if the Western Backstop SO2 Trading Program ("WEB 

Trading Program") is triggered, the plan also describes how the Department shall 

determine allocations and manage the allowance tracking system that is needed to 

implement the program. 

• Western Backstop SO2 Trading Program Model Rule 20.2.81 NMAC contains the 

requirements that shall apply to major industrial sources of sulfur dioxide as a 

backstop regulatory program if the SO2 milestones are exceeded. The rule may never 

be implemented if the goal to meet the regional SO2 milestones through voluntary 

means is achieved. If the rule is implemented, it establishes the procedures and 

compliance requirements for sources in the Trading Program. 

• 20.2.73 NMAC requires major industrial sources of SO2 to submit an annual 

emissions inventory in the pre-trigger phase of the program to measure compliance 

with the regional SO2 milestones. If the backstop program is triggered then these 

requirements will eventually be replaced by more rigorous monitoring requirements 

in 20.2.81 NMAC. 

Definitions

The definitions in this part apply only to this Implementation Plan: 

Account Certificate of Representation means for a WEB Source the completed and signed 

submission required to designate an Account Representative for a WEB source who is authorized 

to represent the owners and operators of the WEB source with regard to matters under the WEB 

Trading Program and for a general account, the individual who is authorized to represent the 

persons having an ownership interest with respect to allowances in the general account with 

regard to matters concerning the general account.

Account Representative means the individual who is authorized through an Account Certificate 

of Representation to represent owners and operators of the WEB source with regard to matters 

under the WEB Trading Program (including, for example, to transfer and otherwise manage 
NM Regional Haze SIP 13 

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allowances and certify all submissions to the Allowance Tracking System and the emissions 

tracking database for the purposes of the Rule) or, for a general account, who is authorized 

through an Account Certificate of Representation to represent the persons having an ownership 

interest in allowances in the general account with regard to matters concerning the general 

account. 

Act means the Clean Air Act, as amended, 42 U.S.C. 7401, et seq.

Actual Emissions means total annual sulfur dioxide emissions determined in accordance with 

20.2.81.106 NMAC of the WEB Trading Program Rule, or determined in accordance with 

20.2.73 NMAC for sources that are not subject to 20.2.81 NMAC. 

Allocate means to assign allowances to a WEB source through Section C1 of this SIP. 

Allowance means the limited authorization under the WEB Trading Program to emit one ton of 

SO2 during a specified control period or any control period thereafter subject to the terms and 

conditions for use of unused allowances as established by the 20.2.81 NMAC. 

Allowance limitation means the tonnage of SO2 emissions authorized by the allowances 

available for compliance deduction for a WEB source for a control period under Subsection A of 

20.2.81.109 NMAC on the allowance transfer deadline for that control period.

Allowance Tracking System means the system developed by the Department where allowances 

under the WEB Trading Program are recorded, held, transferred and deducted. 

Allowance Tracking System account means an account in the Allowance Tracking System 

established for purposes of recording, holding, transferring, and deducting allowances. 

Compliance account means an account established in the Allowance Tracking System under 

Subsection A of 20.2.81.105 NMAC for the purpose of recording allowances that a WEB source 

might hold to demonstrate compliance with its allowance limitation. 

Control period means the period beginning January 1 of each year and ending on December 31 

of the same year, inclusive[, during which a WEB source must hold allowances not less than its 

emissions]. 

Department means the New Mexico Environment Department or its successor agency or 

authority, as represented by the Department Secretary or his or her designee. 

Emissions tracking database means the central database where SO2 emissions for WEB sources 

as recorded and reported in accordance with 20.2.81 NMAC are tracked to determine compliance 

with allowance limitations.

Emission unit means any part of a stationary source that emits or would have the potential to 

emit any pollutant submitted to regulations under the Clean Air Act.
NM Regional Haze SIP 14 

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EPA Administrator means the Administrator of the United States Environmental Protection 

Agency or the Administrator's duly authorized representative.

Existing source means a stationary source that commenced operation before the Program 

Trigger Date. 

Floor allocation means the amount of allowances set by the Department in accordance with this 

Plan that represents the minimum necessary for a source to operate under stringent control 

assumptions. 

 

General account means an account established in the Allowance Tracking System under 

20.2.81.105 NMAC for the purpose of recording allowances held by a person that are not to be 

used to show compliance with an allowance limitation. 

Milestone means the maximum level of stationary source regional sulfur dioxide emissions for 

each year from 2003 to 2018, established according to the procedures in Part C, Section A of the 

implementation plan, Milestones and Determination of Program Trigger. 

New WEB Source means a WEB source that commenced operation on or after the Program 

Trigger Date.

New Source Set-aside means a pool of allowances that are available for allocation to new WEB 

sources and modified WEB sources that have increased capacity in accordance with the 

provisions of Section C1.3 (a) of this implementation plan. 

Opt-in means to choose to participate in the WEB Trading Program by following the procedures 

in 20.2.81.101 NMAC and to comply with the terms and conditions of 20.2.81 NMAC. 

Potential to emit means the maximum capacity of a stationary source to emit any air pollutant 

under its physical and operational design. Any physical or operational limitation on the capacity 

of a source to emit an air pollutant, including air pollution control equipment and restrictions on 

hours of operation or on the type or amount of material combusted, stored or processed, shall be 

treated as part of its design if the limitation is enforceable by the EPA Administrator.

Program Trigger Date means the date that the Department determines that the WEB Trading 

Program has been triggered in accordance with the provisions of Section A2 of this Plan. 

Reducible allocation means the amount of allowances set by the Department in accordance with 

Section C1.1(b)(9) of this Plan that represents, for each source, emissions in excess of the floor 

allocation that shall be reduced over time as the regional milestone is decreased.

[Renewable Energy Resource means a resource that generates electricity by non-nuclear and 

non-fossil technologies that results in low or no air emissions. The term includes electricity 

generated by wind energy technologies; solar photovoltaic and solar thermal technologies; 
NM Regional Haze SIP 15 

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geothermal technologies; technologies based on landfill gas and biomass sources, and new lowimpact hydropower that meets the Low-Impact Hydropower Institute criteria. Biomass includes 

agricultural, food and wood wastes. For the purposes of this Plan, a renewable energy resource 

does not include pumped storage or biomass from municipal solid waste, black liquor, or treated 

wood.]

Retired source means a WEB source that has received a retired source exemption as provided in 

Subsection D of 20.2.81.101 NMAC. [Any retired source resuming operations under Paragraph 

(4) of Subsection D of 20.2.81.101 NMAC, must submit its exemption as part of its registration 

materials.] 

Stationary source means any building, structure, facility or installation that emits or may emit 

any air pollutant subject to regulation under the Clean Air Act.

Ton means 2000 pounds and, for any control period, any fraction of a ton equaling 1000 pounds 

or more shall be treated as one ton and any fraction of a ton equaling less than 1000 pounds shall 

be treated as zero tons.

Tracking System Administrator means the person designated by the Department as the 

administrator of the WEB Allowance Tracking System and the emission tracking database.

Tribal Set-Aside means a [20,000] 2,000-ton SO2 WEB allowance allocated to tribes on an 

annual basis. The tribes will decide how to distribute the allowances in the set-aside among tribes 

in the region. The set-side is intended to ensure equitable treatment for tribal economies and to 

prevent barriers to economic development. 

Trigger refers to the activation of the WEB Trading Program for SO2 in accordance with Part C 

Section A.1 of this state implementation plan.

Unit means a stationary boiler, combustion turbine or combined cycle system.

WEB source means a stationary source that meets the applicability requirements of 20.2.81.100 

NMAC.

Western Backstop SO2 Trading Program ("WEB Trading Program") refers to 20.2.81 

NMAC that shall be triggered as a backstop in accordance the provisions in Section C of this 

Plan to ensure that regional SO2 emissions are reduced. 

Western Regional Air Partnership (WRAP) means the collaborative effort of tribal 

governments, state governments, and federal agencies to promote and monitor implementation of 

recommendations from the Grand Canyon Visibility Transport Commission authorized under 

Section 169B(f) of the Act, and to address other common Western regional air quality issues.
NM Regional Haze SIP 16 

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C. Emission Reductions for Stationary Sources 

A1. Regional SO2 Milestones and Determination of Program Trigger

A1.1 Base Milestone Values

The regional sulfur dioxide base milestones for the years [2003] 2008 through 2018 are provided 

in Table C-1. The base milestones shall be adjusted annually as described in paragraphs A1.2 

and A1.3 of the New Mexico State Implementation Plan. 

TABLE C-1. [Base] Sulfur Dioxide Emissions Milestones [(excludes Smelter Set-aside)] 

Column 1 Column 2 Column 3

For the year the base regional sulfur 

dioxide milestone is

and the annual SO2 emissions for these years will 

determine whether emissions are greater than or less 

than the milestone

2003 682,000 tons SO2 2003

2004 682,000 tons SO2 Average of 2003 and 2004

2005 682,000 tons SO2 Average of 2003, 2004 and 2005

2006 682,000 tons SO2 Average of 2004, 2005 and 2006

2007 682,000 tons SO2 Average of 2005, 2006 and 2007

2008 [680,333] 269,083 tons SO2 Average of 2006, 2007 and 2008

2009 [678,667] 234,903 tons SO2 Average of 2007, 2008 and 2009

2010 [677,000] 200,722 tons SO2 Average of 2008, 2009 and 2010

2011 [677,000] 200,722 tons SO2 Average of 2009, 2010 and 2011

2012 [677,000] 200,722 tons SO2 Average of 2010, 2011 and 2012

2013 [659,667] 185,795 tons SO2 Average of 2011, 2012 and 2013

2014 [642,333] 170,868 tons SO2 Average of 2012, 2013 and 2014

2015 [625,000] 155,940 tons SO2 Average of 2013, 2014 and 2015

2016 [625,000] 155,940 tons SO2 Average of 2014, 2015 and 2016

2017 [625,000] 155,940 tons SO2 Average of 2015, 2016 and 2017

2018 [480,000] 141,849 tons SO2 Year 2018 only

2019 forward 

until replaced by 

an approved SIP

[480,000] 141,849 tons SO2 Annual; no multiyear averaging

[A1.2 Adjustments for participation by eligible States and Tribes. 

The amount provided in Table 2 below shall be subtracted from the milestone in Table 1 for each 

state and tribe that does not have an Implementation Plan approved by the EPA Administrator as 

meeting the requirements of 40 CFR 51.309 as of December 31 of the year following the 

milestone year. The first adjustment to the 2003 milestone shall be made no later than March 31, 

2005, and shall be based on all states and tribes that do not have a federally approved 

Implementation Plan as of December 31, 2004.
NM Regional Haze SIP 17 

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TABLE 2a. [Years 2003-2010] Amounts of SO2 tons to be Subtracted from the Base 

Milestones for States and Tribes that do not have an Approved Implementation Plan under 

40 CFR 51.309 (Data includes new source set aside but not smelter set aside.)

State or Tribe 2003 2004 2005 2006 2007 2008 2009 2010

1. Arizona 117,372 117,372 117,372 117,372 117,372 117,941 118,511 119,080

2. California 37,343 37,343 37,343 37,784 37,343 36,363 35,382 34,402

3. Colorado 98,897 98,897 98,897 98,897 98,897 98,443 97,991 97,537

4. Idaho 18,016 18,016 18,016 18,016 18,016 17,482 16,948 16,414

5. Nevada 20,187 20,187 20,187 20,187 20,187 20,282 20,379 20,474

6. New Mexico 84,624 84,624 84,624 84,624 84,624 84,143 83,663 83,182

7. Oregon 26,268 26,268 26,268 26,268 26,268 26,284 26,300 26,316

8. Utah 42,782 42,782 42,782 42,782 42,782 42,795 42,806 42,819

9. Wyoming 155,858 155,858 155,858 155,858 155,858 155,851 155,843 155,836

10. Navajo Nation 53,147 53,147 53,147 53,147 53,147 53,240 53,334 53,427

11. ShoshoneBannock Tribe of 

the Fort Hall 

Reservation

4,994 4,994 4,994 4,994 4,994 4,994 4,994 4,994

12. Ute Indian Tribe 

of the Uintah and 

Ouray Reservation

1,129 1,129 1,129 1,129 1,129 1,131 1,131 1,131

13. Wind River 

Reservation

1,384 1,384 1,384 1,384 1,384 1,384 1,384 1,384
NM Regional Haze SIP 18 

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TABLE 2b. [Years 2011-2018] Amounts of SO2 tons to be Subtracted from the Base 

Milestones for States and Tribes that do not have an Approved Implementation Plan under 

40 CFR 51.309 *

State or Tribe 2011 2012 2013 2014 2015 2016 2017 2018

1. Arizona 119,080 119,080 116,053 113,025 109,998 109,998 109,998 82,302

2. California 34,402 34,402 33,265 32,128 30,991 30,991 30,991 27,491

3. Colorado 97,537 97,537 94,456 91,375 88,294 88,294 88,294 57,675

4. Idaho 16,414 16,414 15,805 15,197 14,588 14,588 14,588 13,227

5. Nevada 20,474 20,474 20,466 20,457 20,449 20,449 20,449 20,232

6. New Mexico 83,182 83,182 81,682 80,182 78,682 78,682 78,682 70,000

7. Oregon 26,316 26,316 24,796 23,277 21,757 21,757 21,757 8,281

8. Utah 42,819 42,819 41,692 40,563 39,436 39,436 39,436 30,746

9. Wyoming 155,836 155,836 151,232 146,629 142,025 142,025 142,025 97,758

10. Navajo 

Nation

53,427 53,427 52,707 51,986 51,266 51,266 51,266 44,772

11. ShoshoneBannock Tribe 

of the Fort Hall 

Reservation

4,994 4,994 4,994 4,994 4,994 4,994 4,994 4,994

12. Ute Indian 

Tribe of the 

Uintah and 

Ouray 

Reservation

1,135 1,135 1,135 1,135 1,135 1,135 1,135 1,135

13. Wind River 

Reservation

1,384 1,384 1,384 1,384 1,384 1,384 1,384 1,384

* These numbers differ from Annex opt-in/-out tables in that the smelter set-aside is excluded 

and the new source set-aside is included.] 

[A1.3 Adjustment for Future Operation of Copper Smelters in Arizona and New Mexico.

If either the BHP San Manuel smelter in Arizona or the Phelps Dodge Hidalgo smelter in New 

Mexico resumes operation, the milestones shall be increased as described below. The adjustment 

shall occur only if the respective state has a State Implementation Plan approved by the EPA 

Administrator under 40 CFR 51.309. Once the adjustments have been made, the milestones shall 

not be changed due to future suspensions or changes in plant operations, except as provided 

below. If Arizona or New Mexico elect not to submit a SIP under 40 CFR 51.309, the emissions 

for the smelters in the state opting-out will be subtracted from the smelter set-aside.

(a) If one or both smelters resume operations under their existing permits, the milestone shall 

automatically be adjusted upward for each smelter respectively by the following amounts:

1. Phelps Dodge Corporation, Hidalgo Smelter: 22,000 tons SO2 

2. BHP, San Manuel Smelter: 16,000 tons SO2

3. For the 2013 through 2018 milestones, the maximum increase shall be 30,000 

tons SO2.
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(b) If New Mexico determines that either smelter will resume operation by operating only a 

portion of the plant, the milestone adjustment in (a) shall be reduced by a percentage to 

reflect current conditions. If the smelter resumes normal operations at a later date, the full 

adjustment described in (a) shall be applied.

(c) If one or both smelters resume operations after going through new source review, the 

milestone adjustment shall be based on the new permitted level for the source, but in no 

instance may the adjustment to the milestones exceed 22,000 tons SO2 per year for the 

Hidalgo Smelter or 16,000 tons SO2 per year for the San Manuel Smelter.

(d) If one or both smelters do not resume operation, the Department will determine, based on 

the calculation procedures in provision A3.4 the amount of facility specific set-aside that will 

be added to the milestone to account for capacity expansion at the remaining smelters. This 

set-aside shall only be available for use if sulfur input and emissions from the copper 

smelters are above the baseline level listed in Table 3 in any particular year, as a result of 

increased capacity. The increase to the milestone will be based on a smelter's proportional 

increase above its baseline sulfur input. The set-aside shall be recalculated every year to 

reflect actual operations of the remaining copper smelters. The set-aside may not be traded.

TABLE 3. Preliminary Smelter-Specific Set Aside

Company / Smelter Baseline

Sulfur input

Baseline 

Allocation

Smelter-specific Setaside

BHP San Manuel 417,200 tons 16,000 tons SO2 1,500 tons SO2

Asarco Hayden 235,000 tons 23,000 tons SO2 3,000 tons SO2 

Phelps Dodge Chino 212,800 tons 16,000 tons SO2 3,000 tons SO2

Phelps Dodge Hidalgo 256,800 tons 22,000 tons SO2 4,000 tons SO2

Phelps Dodge Miami 208,700 tons 8,000 tons SO2 2,000 tons SO2

Kennecott Salt Lake 340,269 tons 1,000 tons SO2 100 tons SO2

TOTAL 1,670,769 tons 86,000 tons SO2 13,600 tons SO2]

A1.4 [Other] Milestone Adjustments.

a)All [other] milestone adjustments shall require a SIP revision. Section A3.3 of this plan 

outlines adjustments to be made to the emissions inventory to ensure a consistent comparison to 

the milestones. These adjustments shall be incorporated into the milestones every five years as 

part of the periodic Implementation Plan revisions required by 40 CFR 51.309(d)(10). The 

Department shall track all adjustments to the milestone pursuant to section A3.3. 
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(b) Within ninety days of the periodic Implementation Plan revision incorporating adjustments 

based on section A3.3, the Department shall provide the date of the SIP revision reflecting the 

milestone adjustment to sources whose records were used as the basis for the milestone 

adjustment and state that the source needs to retain the record at least five years from the date of 

the SIP revision, or ten years from the date of establishing the record, whichever is longer.

(c) Opt-in Provisions for States and Tribes. The regional milestones in Table C-1 were developed 

for a three state and one local jurisdiction region: New Mexico, Utah, and Wyoming, and the 

City of Albuquerque. Other western states and tribes may choose to join this backstop trading 

program in the future. The addition of a state or tribe to the program will require SIP/Tribal 

Implementation Plan (TIP) revision for all participating states and tribes to adjust the regional 

milestones, and will not occur automatically. Any state or tribe that wishes to opt in to the 

program will propose milestone adjustments to the participating states and tribes using the same 

methodology that was used to develop the milestones in Table C-1. A new participant must agree 

to develop a SIP or TIP and backstop trading rule that is consistent with those adopted by the 

other participating states and tribes.

A2. Regional Program Administration

A2.1 Pre-trigger tracking of regional SO2 emissions. 

The Department shall work cooperatively with the states and tribes that are participating in the 

SO2 Milestones and Backstop Trading Program to ensure that an emission tracking system for 

the regional SO2 inventory is developed and maintained. The Western Regional Air Partnership 

(WRAP) compiled the SO2 emission inventories that were used during the development of the 

Annex, and the WRAP continues to refine and improve the overall tracking system for regional 

haze. The WRAP shall maintain the pre-trigger emissions tracking functions outlined in this 

plan for the foreseeable future. If the WRAP is no longer able to fulfill this function, then the 

Department shall ensure that other arrangements are made, either through a different regional 

organization or through a contractor to maintain the SO2 tracking system that is described in this 

plan. The Department is responsible for all regional program administration functions as 

described in this plan. The Department shall perform these functions through the WRAP, as the 

Department's agent. The WRAP shall have no authority to make regulatory determinations. The 

WRAP has limited authority under this plan to perform tracking and accounting functions, 

prepare reports, and perform other administrative functions as directed by the states and tribes. 

The Department shall work expeditiously to correct any problems if the WRAP fails to perform 

any of the functions described in the SIP/TIP in a timely manner. 

A2.2 Designation of the Tracking System Administrator. 

If the backstop trading program is triggered due to an exceedance of the SO2 milestones as 

outlined in section A3 of this plan, New Mexico shall work cooperatively with the other 

participating states and tribes to designate one Tracking System Administrator (TSA). The TSA 

shall be designated as expeditiously as possible, but no later than six months after the program 

trigger date. In addition, before the TSA is designated, the Department shall have entered into a 
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binding contract with the TSA that shall require the TSA to perform all TSA functions described 

in this plan. In addition, the Department must obtain sufficient authority to ensure the functions 

in the Implementation Plan are carried out by the TSA.

A2.3 Information Provided by other States and Tribes. 

New Mexico shall accept the emission inventory and permitting information provided by the 

other participating states and tribes in order to determine the milestone value and program trigger 

if such other states and tribes have provided proper documentation and followed the public 

notification process outlined in A3.6 through A3.8 of this Plan.

A3. Determination of Program Trigger. 

A3.1 [The] Until the program has been triggered and source compliance is required, the

Department shall submit an annual emissions report to the WRAP and all participating states and 

tribes by September 30 of each year. The report shall document actual sulfur dioxide emissions 

during the previous calendar year for all sources required under Subsection F of 20.2.73 NMAC, 

Pre-trigger Emissions Tracking Requirements for Sulfur Dioxide Emissions Inventories, to 

submit emission inventory reports in New Mexico. The first report for calendar year 2003 shall 

be submitted by September 30, 2004. The Department shall prepare the supporting 

documentation that is included with the annual emissions report as noted in provisions A3.2 and 

A3.3 below. 

A3.2 The annual emissions report for New Mexico shall include a source emissions change 

exceptions report that contains the following information: 

(a) identification of any new sources that were not contained in the previous calendar year's 

emissions report, and an explanation of why the source is now included in the program; 

(b) identification of any sources that were included in the previous year's report and are no 

longer included in the program, and an explanation of why this change has occurred; and 

(c) an explanation for emissions variations at any applicable source that exceeds +/- 20 

percent from the previous year. 

A3.3 The annual emissions report for New Mexico shall include a proposed emissions 

adjustment as described in (a) [through (c)] and (b) below to ensure a consistent comparison to 

the milestones.

(a) [Changes in flow rate measurement methods. Actual emission inventories for utilities that 

use EPA's Reference Method 2F, 2G, or 2H to measure stack flow rate will be adjusted to be 

comparable with the flow rate assumptions that were used in 1999, the base year inventory 

for the Annex, except emissions for the year 2018 shall not be adjusted. The adjustment may 

be calculated using any of the following three methods.

1. Directly determine the difference in flow rate through a side-by-side comparison of 

data collected with the new and old flow reference methods during a RATA test.
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2. Compare the annual average heat rate using Acid Rain heat input data (MMBtu) and 

total generation (MWHrs) as reported to the federal Energy Information Administration 

(EIA). Under this approach, the flow adjustment factor shall be calculated using the 

following ratio:

Heat input/MW for first full year of data using new flow rate method

Heat input/MW for last full year of data using old flow rate method.

3. Compare the standard CFM per MW before and after the new flow reference method 

based on CEMs data submitted in the Acid Rain Program, as follows:

SCF/Unit of Generation for first full year of data using new flow rate method

SCF/Unit of Generation for last full year of data using old flow rate method.] 

 (b)] Changes in emission monitoring or calculation methods. Actual emission inventories for 

sources that change the method of monitoring or calculating their emissions shall be adjusted to 

be comparable to the emission monitoring or calculation method that was used in the 2006 base 

year inventory [for the Annex (1999 for utilities and 1998 for all other sources)]. 

 

[(c)] (b) Changes due to enforcement actions 

1. Adjustments due to enforcement settlements. Adjustments to the milestones shall be 

made, as specified in Section [A3.3(c)] A3.3(b) 3 and 4, if: 

(A) an agreement to settle an action, arising from allegations of a failure of an owner 

or operator of an emissions unit at a source in the program to comply with applicable 

regulations which were in effect during the base year, is reached between the parties 

to the action; 

(B) the alleged failure to comply with applicable regulations affects the assumptions 

that were used in calculating the source's base year and forecasted sulfur dioxide 

emissions; and 

(C) the settlement includes or recommends an adjustment to the milestones. 

2. Adjustments due to enforcement actions arising from administrative or judicial orders. 

The milestones shall also be adjusted as directed by any final administrative or judicial 

order, as specified in Section [A3.3(c)] A3.3(b) 3 and 4. Where the final administrative or 

judicial order does not include a reforecast of the source's baseline, the Department shall 

evaluate whether a reforecast of the source's baseline emissions is appropriate. 

3. Adjustment procedures. Based on [A3.3(c)] A3.3(b) 1 and 2, the milestone must be 

decreased by an appropriate amount based on a reforecast of the source's decreased sulfur 

dioxide emissions. The adjustments do not become effective until after the source has 

reduced its sulfur dioxide emissions as required in the settlement agreement, or 

administrative or judicial order. All adjustments based upon enforcement actions must be 

made in the form of an implementation plan revision that complies with the procedural 

requirements of 40 CFR 51.102 and 40 CFR 51.103. 
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4. Documentation of adjustments. In the periodic plan revision required under 40 CFR 

51.309(d)(10), the Department shall include the following documentation of any 

adjustment due to an enforcement action:

(A) identification of each source under New Mexico's jurisdiction which has reduced 

sulfur dioxide emissions pursuant to a settlement agreement, or an administrative or 

judicial order; 

(B) for each source identified, a statement indicating whether the milestones were 

adjusted in response to the enforcement action; 

(C) discussion of the rationale for the Department's decision to adjust or not to adjust 

the milestones; and 

(D) if [extra] SO2 emissions reductions [(] over and above those reductions needed 

for compliance with the applicable regulations [)] were part of an agreement to settle 

an action, a statement indicating whether such reductions resulted in any adjustment 

to the milestones or allowance allocations, and a discussion of the rationale for the 

Department's decision on any such adjustment. 

A3.4 The annual sulfur dioxide milestone and emissions report for New Mexico shall document 

any adjustments that should be made to the milestone for the previous year as described in (a) 

[through (e)] and (b). 

(a) The Department shall document the submittal date of this Implementation Plan to 

implement the regional WEB Trading Program, and the approval date by the EPA 

Administrator, if applicable. 

[(b) New Mexico shall determine the status of Phelps Dodge Hidalgo copper smelter during 

the previous year. If the smelter resumed operation in the milestone year, the report shall 

include:

1. the date the smelter resumed operation;

2. a determination by New Mexico that either,

(i) the smelter resumed production consistent with past operations,

(ii) the smelter was required to go through new source review, in which case New 

Mexico shall include the new permitted limit for sulfur dioxide for the Phelps 

Dodge Hidalgo smelter in the report, or

(iii) the smelter resumed operations in a substantially different manner such that 

emissions will be less than for past operations, in which case New Mexico shall 

determine expected emissions from the operation; and

3. a proposed adjustment to the sulfur dioxide milestone to account for the operation of 

the Phelps Dodge Hidalgo smelter.

(c) Comparison of actual emissions from all smelters in New Mexico to the baseline 

emissions level for that smelter listed in Table 3. If actual emissions and sulfur input are 

greater than the baseline level in Table 3, and either the BHP San Manuel smelter in Arizona 

or the Phelps Dodge smelter in New Mexico have not resumed operation, the Department 

shall determine the milestone by determining the increase in the milestone based on the 
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proportional increase in sulfur input over baseline levels. For each smelter, the adjustment 

shall not exceed the smelter specific set-aside listed in Table 3. 

The following example is for illustrative purposes: 

Asarco's baseline SO2 emissions are 23,000 tons

Asarco's baseline sulfur input is 235,000 tons

For example, in 2005: 

Asarco's S02 emissions were 25,000 tons

Asarco's sulfur input was 250,000 tons. 

Because Asarco's 2005 emissions and sulfur input exceeded it's baseline 

emissions and sulfur input: need to calculate the percent increase in sulfur input in 

the year 2005 

= [(2005 sulfur input) - (baseline sulfur input)] ÷ [baseline sulfur input]

= [250,000 - 235,000] ÷ [235,000]

= [15,000] ÷ [235,000]

= 0.0638

= 6.38%

The adjustment to the milestone based on Asarco's increase in production is to 

increase the milestone by 1,564 tons of SO2 (which is ok, since it is less than the 

maximum of 3,000 tons in Table 3 for Asarco).

adjustment = 6.38% x baseline emissions

adjustment = 6.38% x 23,000 

adjustment = 1,564 tons] 

(b) Changes due to enforcement actions.

1. Adjustments due to settlements arising from enforcement actions. Adjustments to the 

milestones will be made, as specified in subsection (3.) below, if:

(i) an agreement to settle an action, arising from allegations of a failure of an 

owner or operator of an emissions unit at a source in the program to comply with 

applicable regulations which were in effect during the base year, is reached 

between the parties to the action;

(ii) the alleged failure to comply with applicable regulations affects the 

assumptions that were used in calculating the source's base year and forecasted 

sulfur dioxide emissions; and

(iii) the settlement includes or recommends an adjustment to the milestones.

2. Adjustments due to administrative or judicial orders. Adjustments to the milestones 

will be made as directed by any final administrative or judicial order, as specified in (3.) 
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below. Where the final administrative or judicial order does not include a reforecast of 

the source's baseline, the Department will evaluate whether a reforecast of the source's 

baseline emissions is appropriate.

3. Adjustments method and effective dates. The milestone will be decreased by an 

appropriate amount based on a reforecast of the source's decreased sulfur dioxide 

emissions. The adjustments will not be made to the milestone until after the source has 

reduced its sulfur dioxide emissions as required in the settlement agreement, or 

administrative or judicial order.

4. Documentation of adjustments for enforcement actions. The report will include the 

following documentation of any adjustment due to an enforcement action or a settlement 

agreement:

(i) identification of each source in New Mexico that has reduced sulfur dioxide 

emissions pursuant to a settlement agreement or an administrative or judicial 

order;

(ii) for each source identified, a statement indicating whether the milestones were 

adjusted in response to the enforcement action;

(iii) discussion of the rationale for the Department's decision to adjust or not to 

adjust the milestones; and

(iv) if SO2 emissions reductions over and above those reductions needed for 

compliance with the applicable regulations were part of an agreement to settle an 

action, a statement indicating whether such reductions resulted in any adjustment 

to the milestones or allowance allocations, and a discussion of the rationale for the 

Department's decision on any such adjustment.

5. The State of New Mexico will include all accumulated milestone adjustments due to 

enforcement actions or settlement agreements in the periodic SIP revisions required 

under 40 CFR 51.309(d)(10).

A3.5 Compilation of Reports 

(a) The WRAP shall compile the annual emissions reports submitted by all participating 

states and tribes into a draft regional emission report for sulfur dioxide. The WRAP shall 

follow additional quality assurance procedures developed by states and tribes to identify 

possible errors in the emissions data, including screening for missing or added sources, name 

changes, and significant changes in reported emissions. Any questions or anomalies 

regarding New Mexico's report shall be referred back to the Department for resolution prior 

to the submission of the draft regional emission report.
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(b) By December 31 of each year, the WRAP shall submit the draft regional emission and 

milestone report to the Department and shall post the draft report on the WRAP website for 

public review. The report shall include the following information for all states and tribes that 

have an Implementation Plan that has been approved by the EPA Administrator under 40 

CFR 51.309(h). 

1. Actual regional sulfur dioxide emissions (tons/year). 

2. Adjustments to account for: 

(i) [changes in flow rate measurement methods,

(ii)] changes in emission monitoring or calculation methods, or 

[(iii)] (ii) enforcement actions or settlement agreements as a result of enforcement 

actions.

3. Average adjusted emissions for the last three years (if applicable) for comparison to 

the regional milestone.

[4. Regional milestone adjustments to account for participation by eligible states and 

tribes and the future operation of smelters in Arizona and New Mexico.] 

[A separate report that includes additional states and tribes that have submitted 

Implementation Plans that are still under review by the Environmental Protection Agency 

shall also be prepared for information purposes.] 

A3.6 The Department shall evaluate the draft regional emissions report and shall propose a draft 

determination that the sulfur dioxide milestone has either been met in the region, or has been 

exceeded. In the event that the TSA has not submitted to the Department a draft regional 

emissions and milestone report by the December 31 deadline for any year, the Department shall 

prepare its own report for that year based upon the annual emissions reports submitted by all 

participating states and tribes pursuant to A3.5 for that year. The Department shall modify the 

data in these annual emissions reports, or use data where such report(s) have not been submitted, 

based upon direction received from the Environmental Protection Agency. 

A3.7 The Department will publish a notice of the final determination in newspapers of general 

circulation throughout the state of New Mexico. This notice will include the milestone and the 

final annual regional sulfur dioxide emissions for that year. If the milestone has been exceeded, 

the notice will specify the program trigger date and the first year that WEB sources must be in 

compliance with the WEB Trading Program provisions as outlined in 20.2.81.109 NMAC. New 

Mexico shall submit the draft determination to EPA for review and comment. 

A3.8 The Department shall review any comments received during the comment period, and shall 

submit a copy of all comments to the WRAP and to all participating states and tribes along with 

a response to address the comments.

A3.9 The WRAP shall compile the comments and responses from all participating states and 

tribes and prepare a draft final regional emissions report. The report shall be submitted to the 

states and tribes that are participating in the program and, if necessary, the report shall propose a 

common Program Trigger Date. 
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A3.10 The Department shall review and approve the final regional emissions report. The 

Department shall then submit this report to the Environmental Protection Agency along with a 

final determination that the milestone has either been met in the region, or that the milestone has 

been exceeded and the WEB Trading Program has been triggered in New Mexico. This final 

determination shall be submitted to the Environmental Protection Agency by the end of March 

fifteen months following the milestone year. The first final determination shall be due March 31, 

2005 for the 2003 milestone. If the milestone has been exceeded, the common trigger date 

proposed in the regional report shall become the Program Trigger Date for purposes of 

implementing the WEB Trading Program. In the event that the Program Trigger Date must be 

established by the Department in the absence of a regional emissions and milestone report 

prepared by the TSA, the date shall be March 31 of the applicable year. 

A3.11 The Department shall notify the public of the final determination. This notice shall include 

the final calculation of the milestone and the final annual regional emissions. If the milestone has 

been exceeded, the notice shall include the program trigger date and the first year that WEB 

sources must be in compliance with the WEB Trading Program provisions outlined in Subsection 

C of 20.2.81.101 NMAC. 

New Mexico will publish the final annual emissions report in a statewide newspaper's legal 

section and post it on the New Mexico Environment Department's website. 

A4. Year 2013 Assessment. 

A4.1 Initial Assessment in 2013 Periodic SIP/TIP Review. 

(a) The Department shall work cooperatively with the WRAP and other participating states 

and tribes to develop a projected emission inventory for SO2 through the year 2018, using the 

2010 regional inventory as a baseline. This projected inventory shall be included in the 2010 

annual emission and milestone report that shall be completed in March 2012 as outlined in 

Section A3 of this plan. 

(b) [New Mexico] The Department shall evaluate the projected inventory, and based upon 

this information make an assessment of the likelihood of meeting the regional milestone for 

the year 2018.The Department shall include this assessment as part of New Mexico's 

progress report that must be submitted by December 31, 2013, as required by 40 CFR 51.309 

(d)(10).

A4.2 Regional Emissions Report for 2012. 

(a) The Department shall prepare an SO2 emission report for the year 2012 by September 30, 

2013 as described in Section A3.1 of this plan. The Department shall include a list of all 

known projects in New Mexico that are anticipated to affect SO2 emissions in 2018. This 

may include permitted projects, projects that are still in the planning stage, or projections 

from the affected sources of anticipated emissions in 2018. The status of these projects shall 
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be described to provide a better understanding of the degree of certainty that individual 

projects will be completed by 2018. 

(b) The WRAP shall compile the information from all participating states and tribes, prepare 

draft SO2 inventory projections for the year 2018, and estimate the effect of known future 

projects on SO2 emissions. Projected 2018 emissions will be compared to the 2018 milestone.

This information shall be included in the draft regional emissions report that shall be 

submitted to the Department by December 31, 2013, as outlined in Section A3.5 of this plan. 

A4.3 Consensus Decision. 

The Department commits to meet with the participating states and tribes in March 2014 to 

discuss any comments received on the 2018 emission projections in the draft report. The 

participating states and tribes shall decide, through a consensus process, whether an early trigger 

of the WEB Trading Program is necessary to meet the SO2 emission reduction goals in 2018.

A4.4 Official Trigger.

If the participating states and tribes unanimously decide under Section A4.3 that an early trigger 

of the backstop trading program is necessary, the Department shall trigger the WEB Trading 

Program and the timing of various program elements shall be adjusted as follows to ensure that 

the WEB Trading Program is in place in 2018. The date of the consensus decision by the 

participating states and tribes to voluntarily trigger the WEB trading program shall become the 

Program Trigger Date.

(a) Allowances for 2018 shall be distributed to WEB sources by January 1, 2015. 

(b) The first control period shall be the year 2018. WEB sources will need to demonstrate at 

the end of the first control period that they have enough allowances to cover their emissions 

of SO2 in 2018. 

A4.5 Public Notification. 

[New Mexico] The Department shall notify the public of the decision in a newspaper of 

statewide circulation and post the document on the NMED website. If applicable, the notification 

shall include a statement that the WEB Trading Program is in effect and a notification of the 

official program trigger date.

A5. Special Penalty Provisions for the 2018 Milestone

If the WEB Trading Program is triggered as outlined in Section A of the SO2 Milestone and 

Backstop Trading Program Implementation Plan, and the first control period will not occur until 

after the year 2018, a special penalty shall be assessed for the exceedance of the 2018 milestone.
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[The Department shall allocate allowances to all WEB sources as established in the 2013 SIP 

revision described in Section D of this Plan. WEB sources will have the option to buy and sell 

allowances during a two-month allowance transfer period as provided in 20.2.81.110 NMAC.

At the end of this two-month allowance transfer period, compliance with the allowance 

limitation shall be determined as provided in Subsection A of 20.2.81.109 NMAC of the WEB 

Trading Program Model Rule. Penalties shall be assessed for SO2 emissions that are greater than 

the allowance limitation for each WEB source as provided in Subsection C of 20.2.81.109 

NMAC. However, notwithstanding Subsections A and C of 20.2.81.109 NMAC, SO2 emissions 

in the year 2018 for each WEB source shall be determined in accordance with the pre-trigger 

emission tracking requirements in Section B of this plan.] 

Details on the penalty provisions for violation of the 2018 milestone can be found in 20.2.81.110 

NMAC. In general, the penalty involves an assessment of the minimum $5,000 per ton of SO2

emissions in excess of the WEB source's allowance limitation. The source can resolve its excess 

emissions violation by agreeing to a streamline settlement approach outlined in 20.2.81.110 

NMAC.

The amount of the minimum monetary penalty in 20.2.81.110 NMAC shall be evaluated at each 

five-year SIP review, and adjusted to ensure that penalties per ton substantially exceeds the 

expected cost of allowances to ensure that this remains a stringent penalty.

The 2018 special penalty provisions shall continue to be applied each year after 2018 until the 

2018 milestone has been achieved.

B1. SO2 Emission Inventory

Pre-Trigger Emission Tracking Requirements

The State of New Mexico is currently in the process of revising our state regulation for 20.2.73 

NMAC -- Notice of Intent and Emission Inventory Requirements. The regulation revision will 

be submitted for hearing in conjunction with this SIP. Appendix C-2 contains the revised 

regulation language for 20.2.73 NMAC. 

To insure compliance with the emission inventory requirements for pre-trigger tracking 

compliance with the sulfur dioxide milestones set forth under 40 CFR 51.309, the following 

changes will be incorporated into 20.2.73 NMAC. 

(a) All stationary sources with actual emissions of one hundred (100) tons per year or 

more of sulfur dioxide in the year 2000, or in any subsequent year, to submit an annual inventory 

of sulfur dioxide emissions, beginning with the 2003 emission inventory. A source that meets 

these criteria that then emits less than 100 tons per year in a later year must still submit a sulfur 

dioxide inventory for tracking compliance with the regional sulfur dioxide milestones until the 

WEB Trading Program has been fully implemented and emission tracking is occurred under 

20.2.81.106 NMAC - Western Backstop Sulfur Dioxide Trading Program. 
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(b) All WEB Trading Program sources will be subject to the following federally 

enforceable provisions:

 

 (1) submit an annual inventory of sulfur dioxide emissions; 

 

(2) document the emissions monitoring/estimation methodology used, and 

demonstrate that the selected methodology is acceptable under the inventory 

program; 

(3) include emissions from start up, shut down, and upset conditions in the annual 

total inventory;

(4) use methods from 40 CFR Part 75 methodology to report emissions from all 

sources subject to the federal acid rain program;

 (5) smelters must submit an annual report of sulfur input, in tons per year[.];

(6) maintain all records used in the calculation of the emissions, including but not 

limited to the following: 

(i) amount of fuel consumed, 

(ii) percent sulfur content of fuel and how the content was determined, 

(iii) quantity of product produced, 

(iv) emissions monitoring data,

(v) operating data, and 

(vi) how the emissions are calculated; 

(7) maintain records of any physical changes to facility operations or equipment, 

or any other changes (e.g. raw material or feed) that may affect the emissions 

projections. 

(8) retain records for a minimum of ten years from the date of establishment, or if 

the record was the basis for an adjustment to the milestone, 5 years after the date 

of an implementation plan revision, whichever is longer. 

(c) The State of New Mexico shall retain emission inventory records for non-utilities 

[sources from 1996 and 1998] until the year 2018 to ensure that changes in emissions monitoring 

techniques can be tracked.

 [(2) Reporting of emissions for which reporting is required under the Federal Act 

shall not be waived.] 

B2. Development of Emission Tracking System
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The Department shall work cooperatively with the states and tribes that are participating in the 

WEB Trading Program to ensure that an emission tracking system for the regional SO2 inventory 

is developed and maintained. 

B3. Periodic Audit of Pre-Trigger Emission Tracking Database

During the pre-trigger phase when the Department is tracking compliance with the regional SO2 

milestones, the Department shall work cooperatively with the participating states and tribes to 

ensure that an independent audit of the tracking database is conducted to ensure that the WRAP 

is accurately compiling the regional emissions report. The first audit shall occur during the year 

2006 and shall review data collected during the first two years of the program. Subsequent audits 

shall occur in 2011 (which shall cover emissions years 2005-2009) and 2016 (which shall cover 

emissions years 2010-2014). 

The primary focus of the audit will be the process that is used to compile the regional inventory 

from the data provided by each state and tribe, and the tracking of accumulated changes during 

the period between SIP revisions. The audit shall also review the accuracy and integrity of the 

regional reports that are used by the Department to determine compliance with the milestones.

The audit is not intended to be a full review the Department's process for compiling and 

reporting SO2 emissions, but shall include a broad review of the Department's inventory 

management and quality assurance systems (i.e., presence and exercise of systems to assure data 

quality and integrity). 

The audit shall discuss the uncertainty of emissions calculations, and whether this uncertainty is 

likely to affect the annual determination of whether the milestone is exceeded. The audit shall 

identify any recommended changes to emissions monitoring or calculation methods or data 

quality assurance systems. The audit shall also review and recommend any changes to improve 

the administrative process of collecting the annual emissions data at the state and tribal level, 

compiling a regional emission inventory, and making the annual determination of whether the 

WEB Trading Program has been triggered. 

Changes to the WEB trading program, including any changes to the milestones, due to the results 

of these periodic audits shall be submitted to EPA as a SIP revision as part of the five-year 

SIP/TIP review required by 40 CFR 51.309(d)(10). 

The Department shall provide an opportunity for public review and comment on the draft audit 

report following each Department procedure. The Department shall respond to comments and 

provide notice of the final availability of the report. The Department shall submit the final audit 

report to the EPA regional office.
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C WEB Trading Program Requirements

[The proposed revisions to the regional haze rule 40 CFR 51.309 are referenced to reflect the SIP 

requirements for the WEB Trading Program as found in 68 FR 33784.] 

C1. Allowance Allocations

C1.1 Initial Allocation of SO2 Allowances.

(a) Draft Allocation Report from the Department to Tracking System Administrator

Within six months of the program trigger date, as outlined in Section A3.11 of this plan, the 

Department shall submit a draft allocation report to all participating states and tribes and to 

the Tracking System Administrator. This report shall contain the following information:

1. List of all WEB sources in New Mexico as defined in 20.2.81.101 NMAC. The list 

shall group the sources into two categories: 

(i) Category 1: WEB sources that commenced operation prior to January 1, [2003] 

2008. These sources shall receive a floor allocation and shall be eligible for the 

reducible portion of the allocation.

(ii) Category 2: WEB sources that commenced operation on January 1, [2003] 

2008 or a later date. These sources shall receive a floor allocation, but shall not be 

eligible for the reducible allocation. The floor allocation for Category 2 sources 

shall be deducted from the new source set-aside.

WEB sources that have received a retired source exemption under Subsection D 

of 20.2.81.101 NMAC will be included in the allocation process in the same 

manner as WEB sources that are currently operating. However, sources that were 

permanently shut down prior to the program trigger date are not considered WEB 

sources under Subsection A of 20.2.81.101 NMAC and would therefore not be 

included in the allocation process.

2. Floor allocation for all WEB sources in New Mexico. 

(i) For non-utility category 1 WEB sources, the floor allocation shall be as 

established in the E.H. Pechan Report, "Market Trading Forum Non-Utility Sector 

Allocation Final Report from the Allocations Working Group" (November 2002). 

If any additional category 1 sources are identified, the Department shall calculate 

a floor allocation using the methodology outlined in the E.H. Pechan Report. 

(ii) For utility category 1 WEB sources, the floor will be calculated by first 

assigning a "clean unit" emission rate to each unit. The clean unit emission rate 

will then be multiplied by an annual heat input (MMBtu) that represents a realistic 

upper bound for the unit. 
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(iii) For Category 2 WEB sources the floor allocation shall be the lower of the 

permitted SO2 annual emissions for the WEB source, or SO2 annual emissions 

calculated based on a level of control equivalent to BACT and assuming 100% 

utilization of the WEB source.

Note: The floor level approach described above is designed to address equity issues regarding 

the allocation process for utilities. The State of New Mexico is participating in ongoing 

discussions with the other participating states, tribes and regional stakeholders to ensure that all 

equity issues have been addressed. New Mexico will work with the other participating states and 

tribes to ensure that the floor allocation is calculated in a consistent manner for all participants. 

As outlined further in this allocation methodology, the floor for both utilities and non-utilities is 

limited by the utility/non-utility split in Table C-2. The floor allocation methodology will ensure 

that credits are available for early reduction allocations. In addition, the regional number of 

allowances allocated for each year cannot exceed the milestone for that year under any 

circumstances.

Principles

• Each unit will have enough allowances to operate as a clean source and at an 

operating rate (capacity factor) that is a realistic upper bound for the unit.

• There will not be significant winners and losers in this process.

• The focus is on a fair approach that is applied equally to all sources rather than on 

state and tribal budgets.

• The allocation process will use data that reflect current conditions, including current 

monitoring methodologies.

Equity Issues

• Sources that are currently burning very low sulfur coal may see changes in their 

supply in the future. Historic actual emissions may not reflect future operations.

• Sources that are currently operating at a low utilization may not reach full 

capacity in the future. Assumptions about growth that are realistic on the regional 

level may provide a windfall to some sources, and not provide adequate 

allowances for other sources.

• There are some utility units in the region that are not BART-eligible and are 

operating at a low level of control for SO2. The relative responsibility of BARTeligible vs. non-BART-eligible is a consideration in the process.
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• Sources that are operating at a high level of control are already bearing the cost of 

control and this affects their ability to compete in the market.

• Sources that have no SO2 controls are facing a large expense that could affect 

their ability to continue to operate.

• Emission rate disparities exist throughout the region.

3. A list of certified early reductions, expressed as tons of SO2. Early reductions shall be 

calculated and certified as follows:

(i) Any WEB source that installs control technology and accepts new permit 

emissions limits that are, for a non-utility source, below its floor as established in 

this section, or, for a utility source, below BACT, may apply for an early 

reduction credit as outlined in Subsection E of 20.2.81.104 NMAC. The credit 

will be available for reductions that occur between 2008 and the program trigger 

year. The application must show that the floor was calculated in a manner that is 

consistent with the monitoring requirements of Subsections A and C of 

20.2.81.106 NMAC of 20.2.81 NMAC and the new permit must contain 

monitoring requirements that are consistent with Subsections A and C of 

20.2.81.106 NMAC. Emission units that are monitored using the less stringent 

monitoring requirements of Subsections B of 20.2.81.106 NMAC are not eligible 

for early reduction credits. The credits accumulate from the time the new controls 

come on line until the program trigger date and will be allocated to the WEB 

source over a 10 year period. The use of early reduction credits in any control 

period is limited to no more than five percent, systemwide, of the existing 

available allowances, as provided in this plan. 

(ii) The Department will review the application and will certify early reductions 

for each full year between [2003] 2008 and the program trigger year that meet the 

requirements of Subsection E of 20.2.81.104 NMAC [of the WEB Trading Model 

Rule] and this plan. 

(iii) A source's certified early reductions for all years will be added together to 

obtain the total certified early reductions for that source. 

[4. A list of all renewable energy resources in New Mexico that began operation after 

October 1, 2000, and the MW of installed nameplate capacity for each of these resources. 

Renewable energy credits will be granted at a rate of 2.5 tons per MW, and will 

accumulate from the beginning of the facility's operation. Their use in any control period 

is limited to no more than five percent, systemwide, of the existing available allowances, 

as provided in this plan.] 
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[5.] 4. Historical SO2 emissions data for all Category 1 sources for the purposes of 

calculating the reducible allocation.

(i) For utilities, [the average of the years 2000 – 2002] the annual SO2 emissions 

for the year 2006. Another time period may be used for individual emission units, 

if needed, to be representative of normal operating conditions. 

(ii) For non-utilities, the average of annual SO2 emissions for the [years 1996 and 

1998] year 2006. 

[6] 5. Changes due to enforcement actions or settlement agreements as a result of 

enforcement actions. The adjustment shall be determined in accordance with section A3.3 

(c) of this Implementation Plan. The difference between the WEB source's allocations 

prior to enforcement and after the enforcement action shall be removed from the 

allocation pool. 

(b) Compiled Allocation Report [from Tracking System Administrator]

The Tracking System Administrator shall compile the information provided by all 

participating states and tribes into a draft regional allocation report, and shall submit this 

draft regional report to the Department and all participating states and tribes for review and 

comment thirty days after receiving the preliminary allocation reports. The draft regional 

allocation report shall include a proposed budget for each state and tribe and the proposed 

allocation for each WEB source in New Mexico.

The State of New Mexico will work closely with the other participating states and tribes to 

ensure that the regional allocation is distributed consistently and fairly and to address any 

change in status that may affect this process.

The following methodology [for calculating the proposed regional allocation for utilities and 

non-utilities is based on the assumption that the states of Arizona, Oregon, New Mexico, 

Utah and Wyoming are the only participating states in the WEB Trading Program. These 5 

states are actively pursuing a SIP under section 309 of the Regional Haze Rule and it is 

unlikely that any other states will be able to develop a SIP under section 309 by the deadline 

of December 31, 2003. The State of New Mexico will work closely with the other four states 

that are developing 309 SIPs to ensure that the regional allocation is distributed consistently 

and fairly and to address any change in status that may affect this process. Tribal nations 

may participate in the program at a later date under the provisions of the Tribal Authority 

Rule. There are currently four category 1 sources operating on tribal lands under the 

jurisdiction of three tribal nations. The following methodology will remain unchanged if any 

of these tribal nations opt in to the program at a later date because the allocation for any of 

the four existing tribal sources will be covered by the opt-in adjustment for the tribe, and the 

allocation for any new sources will be covered by the regional new-source set-aside] 

distributes the allowances available under the milestone in the following order: tribal setaside, new source set-aside, floor, early reduction credit, reducible allocation. The allocation 

process is limited by the number of allowances available under the milestone. It is not 
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possible under this methodology to distribute more allowances than are available under the 

milestone. New Mexico expects that there will be allowances available for all of the 

categories listed above. However, if at any time in the process there are not enough 

allowances available to fully cover a particular category, then the sources eligible for that 

category will receive a pro-rated allowance, and the process will stop. For example, if the 

early reduction credit allocation is greater than the remaining available allowances under the 

milestone, then each of the early reduction sources would receive a reduced early reduction 

credit allocation, and there would be no reducible allocation. 

1. Table [7] C-2 shows [the calculation of the available allocation for existing 

sources. The base milestone for the 5-state region calculated in accordance with 

section E.1.a(2) of this plan is the starting point. The base milestone does not 

include the smelter set-aside. 20,000 tons of SO2 is then subtracted for a tribal setaside] the major categories that will be used to allocate allowances under the 

milestone. The methodology to calculate the available allocation for existing 

sources is described below. The milestone for the 3-state region is the starting 

point. 

 . 

Table [7] C-2. Utility/Non-utility Split.

Year Milestone

Tribal 

Set-Aside

New Source 

Set-Aside

Remaining 

Allocation

Utility 

Portion

Non-Utility 

Portion

2008 269,083 2,500 6,143 260,440 210,480 49,961

2009 234,903 2,500 6,143 226,260 176,299 49,961

2010 200,722 2,500 6,143 192,079 142,119 49,961

2011 200,722 2,500 6,143 192,079 142,119 49,961

2012 200,722 2,500 6,143 192,079 142,119 49,961

2013 185,795 2,500 12,286 171,009 121,048 49,961

2014 170,868 2,500 12,286 156,082 106,121 49,961

2015 155,940 2,500 12,286 141,154 91,194 49,961

2016 155,940 2,500 12,286 141,154 91,194 49,961

2017 155,940 2,500 12,286 141,154 91,194 49,961

2018 141,849 2,500 12,286 127,063 80,402 46,661

2019* 141,849 2,500 12,286 127,063 80,402 46,661

*2019 and forward, until replaced by an approved SIP.

[2. Table 8 shows the new source set-aside for the 5-state region.

(i) The new source set-aside is calculated by subtracting the new source set-aside 

adjustment listed in Table 8 for all states and tribes that do not have a federally 

approved Implementation Plan for the WEB trading program under 40 CFR 

51.309 as of the program trigger date from the maximum possible set-aside for 

each of the first five years of the trading program. 

Table 8. New Source Set-Aside Adjustment

2003 - 2007 2008 - 2012 2013 - 2018
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Maximum 

Possible SetAside

9,000 18,000 27,000

State or Tribe Adjustment

(tons/yr SO2)

1. Arizona 1,757 3,596 5,437

2. California 559 1,039 1,532

3. Colorado 1,480 2,945 4,364

4. Idaho 270 496 721

5. Nevada 302 618 1,011

6. New Mexico 1,267 2,512 3,889

7. Oregon 393 795 1,075

8. Utah 640 1,293 1,949

9. Wyoming 2,333 4,706 7,020

10. Tribes No 

adjustment

needed

No 

adjustment 

needed

No 

adjustment 

needed

(ii) Subtract the floor allocation for all WEB sources in the region that were 

identified as Category 2 from the new source set-aside for the 5-state region to 

determine the available allocation for new sources that begin operation after the 

program trigger date. The allocation process for these new sources is described in 

section E.3.c of this plan. ] 

2. Subtract the floor allocation for all WEB sources in the region that were 

identified as Category 2 from the new source set-aside to determine the available 

allocation for new sources that begin operation after the program trigger date.

This allocation methodology treats all Category 2 sources as existing sources 

because these sources will be operating on the program trigger date. However, the 

allowances for all Category 2 sources are actually drawn from the new source setaside. If new source growth exceeds the projections used to develop this Plan, it is 

possible that the above calculation will result in a negative number. Therefore, to 

address this problem, Category 2 sources will be ranked based on the date the 

permit is issued for each source. Sources will then be removed from the list of 

Category 2 sources, starting with the most recent permit, until the new source setaside is no longer depleted. The last source on the list will receive a partial 

allocation. The sources that were removed from the list will be considered new 

sources as described in Section C1.3 of this Plan. These sources will need to 

purchase allowances to cover their emissions because the new source set-aside for 

sources that begin operation after the program trigger date will be calculated as 

zero until it is replenished in the next 5-year period. The allocation process for 

these new sources is described in Section C1.3 of this Plan.
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Example calculation of the new source set-aside.

The example uses the following assumptions:

(i) Emissions exceed the milestones based on an average of the years [2003-2005] 

2004-2006. 

(ii) The program trigger date is March 31, [2007] 2008 . 

(iii) The first 5 years of the program are [2011-2015] 2012-2016. 

[(iv) Five states are participating in the program (AZ, NM, OR, UT, WY)]. 

(iv) New sources that commenced operation between January 1, [2003] 2008 and 

the program trigger date have a total floor allocation of [6,000] 600. 

2011 2012 2013 2014 2015

Maximum Possible SetAside18,000 18,000 27,000 27,000 27,000

5-State Adjustment - 5,098 -5,098 -7,628 -7,628 -7,628

Floor for Category 2 

Sources

-6,000 -6,000 -6,000 -6,000 -6,000

Remaining New Source Setaside6,902 6,902 13,372 13,372 13,372

2012 2013 2014 2015 2016

New Source Set-Aside 6,143 12,286 12,286 12,286 12,286

Floor for Category 2 

Sources

600 600 600 600 600

Remaining New Source 

Set-Aside

5,543 11,686 11,686 11,686 11,686

 

3. The remaining allocation shown in Table [7] C-2 is available for distribution to 

category 1 sources. The final two columns in Table [7] C-2 split this remaining allocation 

into a utility allocation and a non-utility allocation. [Apply any milestone adjustments 

due to the smelter set-aside as outlined in section E.1.a(3) to the non-utility allocation 

listed in Table 7. ] 

4. Subtract the floor allocations for all category 1 utility and non-utility sources in the 

region from the utility allocation or the non-utility allocation.

In the unlikely event that the total floor allocation for either utility or non-utility sources 

submitted by the participating states and tribes exceeds the total allocation available for 

that category, the TSA will notify the participating states and tribes of the discrepancy. 

New Mexico commits to work with the participating states and tribes through a 

consensus process to ensure that the floor allocation has been calculated in a consistent 

manner for all participants and to ensure that the floor allocation does not exceed the total 

allocation available for that category. The total number of allowances distributed cannot 

exceed the milestone for any given year.
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5. Calculate the early reduction allocation.

(i) Divide the number of certified early reduction credits for all WEB sources in 

the region by ten. 

(ii) Add the utility allocation for 2018 to the non-utility allocation for 2018 and 

then multiply this total by 0.05. 

(iii) If the product of paragraph (i) is no more than the product of paragraph (ii), 

the product of paragraph (i) is the early reduction allocation, and each source is 

allocated ten percent of its early reduction credits.

(iv) If the product of paragraph (i) is more than the product of paragraph (ii), the 

early reduction allocation for the region is the product of paragraph (ii). To 

determine a source's allocation, divide the product of paragraph (ii) by 0.10 times 

the total number of early reduction credits and apply that ratio to the early 

reduction credits claimed by the source. 

(v) Split the regional early reduction allocation based on the ratio of utility to nonutility allocations in 2018 and subtract the early reduction allocation from the 

utility and non-utility allocation totals.

(vi) The early reduction allocation will be calculated in a similar manner for the 

second five-year allocation period under this program, and will then be 

discontinued for any future allocation periods. 

 [6. Calculate the regional renewable energy allocation.

(i) Add together the reported MW of installed nameplate capacity for renewable 

energy facilities reported by the participating states and tribes, and then multiply 

this number by 2.5. 

(ii) Add the utility allocation for 2018 to the non-utility allocation for 2018 and 

then multiply this total by 0.05.

(iii) If the product of paragraph (i) is no more than the product of paragraph (ii), 

the product of paragraph (i) is the renewable energy allocation.

(iv) If the product of paragraph (i) is greater than or equal to the product of 

paragraph (ii), the renewable energy allocation for the region is the product of 

paragraph (ii). To determine a source's allocation, divide the product of 

paragraph (ii) by the total number of renewable energy credits and apply that 

ratio to the early reduction credits claimed by the source.
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(v) Split the regional renewable energy allocation based on the ratio of utility to 

non-utility allocations in 2018 and subtract the renewable energy allocation from 

the utility and non-utility allocation totals.] 

[7] 6. Any remaining allowances in the utility allocation or the non-utility allocation 

after subtraction of the early reduction allocation [and the renewable energy allocation] is 

considered the reducible allocation and will be assigned to Category 1 sources. 

(i) For non-utility sources, add together the historic SO2 emissions in accordance 

with [section XX.E.3.a(1)(e)] Part C1.1(a)5 of this [plan] section for all Category 

1 non-utility sources in the region to determine an historic emission total. 

Determine a percent contribution of SO2 emissions for each WEB source to the 

historic emission total. Multiply the non-utility reducible allocation calculated in 

paragraph [(h)] (7) by the percent contribution for each WEB source to determine 

a reducible allocation for each WEB source. 

(ii) For utility sources, the reducible allocation will be distributed to sources that 

emitted above their floor in the baseline period [(2000 through 2002)] (2006)

based on their percentage of total floor emissions for sources emitting above the 

floor times the number of reducible allowances available for the first five years of 

the WEB Trading Program. The number of allowances for any source receiving a 

reducible allocation shall not exceed a recent historic emission rate times a heat 

input that represents a realistic upper bound for the unit. 

Note: The approach for distributing the reducible utility allocation described 

above is designed to address equity issues regarding the allocation process for 

utilities. The State of New Mexico is participating in ongoing discussions with the 

other participating states, tribes and regional stakeholders to ensure that all equity 

issues have been addressed. The principles and equity issues that are under 

discussion are listed in Part C1.1(a)2 of this section.

[8] 7. Add together the floor allocation, early reduction allocation [, renewable energy 

resource allocation,] and reducible allocation for each WEB source [and each renewable 

energy source] to determine the proposed allocations for the first five years of the WEB 

Trading Program. 

8. [(i)] Add together the proposed allocations for all of the WEB sources in the 

jurisdiction of each participating state and tribe to determine a draft SO2 allowance 

budget for each state and tribe. 

(c) Public Comment Period.

[New Mexico shall make the draft regional allocation report available for public 

comment. New Mexico shall notify the public of the decision in a newspaper of statewide 

circulation and post the document on the NMED website. The Public will have thirty (30) 

days to comment on the report.] The Department will publish notice of availability of the 
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draft regional allocation report in newspapers of general circulation throughout New 

Mexico. A 30-day public comment period will be established, and a hearing will be held 

during the comment period. The Department will consider the comments, and will revise 

the draft report if the recommended changes are consistent with the allocation process 

outlined in this Plan. The Department will prepare a written response that explains why 

each comment has either been accepted or has been determined to be inconsistent with 

the allocation process outlined in this Plan.

(d) Proposed Changes Submitted to Tracking System Administrator.

[The Department shall submit proposed changes to the budget and source allocations to 

the Tracking System Administrator within sixty days of receipt of the draft regional 

allocation report.] The Department will submit a copy of all comments received, the 

response to those comments, and any proposed changes to the budget and source 

allocations to the TSA within sixty days of receipt of the draft regional allocation report.

(e) Compilation of Changes. 

[The Tracking System Administrator shall compile the proposed changes and shall 

submit a final draft regional allocation report to the participating states and tribes for 

approval within 30 days of receipt of the recommended changes.] The TSA will compile 

the comments, responses, and proposed changes to the report and will submit a final draft 

regional allocation report that is consistent with the allocation methodology outlined in 

this Plan to the Department within 90 days of the receipt of the draft regional allocation 

report.

(f) Final Regional Allocation Report.

The Department shall review the final regional allocation report and shall determine the 

budget for New Mexico and allocations for WEB sources within New Mexico in accordance 

with the [provisions of] allocation methodology outlined in this plan within thirty days of 

receipt of the final draft allocation report. The Department shall submit the budget and 

allocations for all WEB sources in New Mexico to EPA, and shall notify the Tracking 

System Administrator that the WEB source allocations should be recorded in the allowance 

tracking system.

(g) The Department shall notify all WEB sources within New Mexico of the number of 

allowances that have been recorded in their compliance account. The notice shall include a 

warning to the WEB sources that reported annual sulfur dioxide emissions may change due 

to the implementation of new monitoring methodologies as required by 20.2.81.106 NMAC . 

Allocations for the first five years of the program shall not be adjusted to account for changes 

due to the new monitoring methodology. However, allocations during the next five-year 

distribution shall be adjusted as needed to account for paper changes in emissions due to 

changes in monitoring methodology.
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C1.2 Distribution of Allowances for Future Control Periods. 

By December 1 of the year five years after the initial allocation, the Department shall follow the 

process outlined in Section C1.1 to distribute allowances for the next five-year period. This 

process shall continue every five years until allowances have been allocated through the year 

2018. 

C1.3 Distribution of the New Source Allocation.

(a) The new source set-aside shall be available for two categories of sources.

1. New WEB sources are eligible to receive [allowances from the new source setaside in the amount of the annual permitted SO2 emissions for the source] an annual 

floor allocation equal to the lower of the annual permitted sulfur dioxide emissions 

for the source, or sulfur dioxide annual emissions calculated based on a level of 

control equivalent to BACT and assuming 100% utilization of the WEB source, 

beginning with the first full calendar year of operation and in accordance with the 

provisions of Subsection F of 20.2.81.104 NMAC. 

2. Existing sources that increase production are eligible to receive allowances from 

the new source set-aside [for the annual permitted amount of SO2 emissions that is 

attributable to the increase in production over the permitted production level as of 

January 1, 2003.] equal to:

(i) the permitted annual sulfur dioxide emission limit for a new unit; or 

(ii) the permitted annual SO2 emission increase for the WEB source due to 

the replacement of an existing unit with a new unit or the modification of 

an existing unit that increased the production capacity of the WEB source.

Permitted emission increases due to fuel switching or other process changes that are 

not directly related to increased production capacity are not eligible for allocations 

from the new source set-aside. The allocation from the new source set-aside in the 

first year of operation shall be adjusted to account for the number of days that the 

source is operating in that first year.

EXAMPLE. A new unit with a nameplate capacity of 400 MW is constructed 

at a power plant with two existing units with nameplate capacities of 400 MW 

and 300 MW. The two existing units install SO2 controls and reduce 

emissions to meet PSD requirements for the construction of the new unit. In 

this example, the source would continue to receive a floor and a reducible 

allocation for each of the existing units, and would also be eligible to receive 

an allocation from the new source set-aside for the new unit. Even though 

total SO2 emissions will decrease at this plant due to the construction of the 

new unit, the allowances allocated to the source will increase to reflect the 
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increase in production capacity of 400 MW of electricity. If the new unit 

comes on line on July 1 the allocation for the first year shall be reduced by 50 

percent because the unit was operational for half of the year.

(b) Allocations from the new source set-aside shall remain constant for the applicable WEB 

source and shall be made on an annual basis by March 31 of each year for the current control 

period. When the next five-year allocation block is distributed as outlined in Section C1.2 of 

this plan, all sources with an allocation under the new source set-aside shall receive a fiveyear allocation block from the new source set-aside, and shall continue to receive this 

allocation in future five-year allocation blocks. 

(c) Owners or operators of new sources or modified sources that meet the eligibility 

requirements of C1.3(a) may apply for an allocation from the new source set-aside by 

submitting a written request to the Department as outlined in Subsection F of 20.2.81.104 

NMAC. 

(d) The Department shall review the application for an allocation from the new source setaside for accuracy and completeness, and shall notify the source of intent to distribute 

allocations from the regional new source set-aside pending verification that allowances are 

available in the new source set-aside account. The Department shall then forward the request 

to the Tracking System Administrator. 

(e) The Tracking System Administrator shall document the date that the TSA receives the 

request. Requests for allocation of allowances from the new source set-aside shall be 

processed in the order received. The Tracking System Administrator shall deduct the number 

of allowances requested from the regional new source set-aside that was established by the 

participating states and tribes [in accordance with Section C1.1(b)3 of this plan], and shall 

then record an equal number of allowances in the source's compliance account for each 

remaining year of the five-year period. The Tracking System Administrator shall then send 

written notification to the source and to [New Mexico] the Department that the allowances 

have been recorded in the source's compliance account.

(f) If [the new source set-aside is depleted] there are insufficient allowances remaining in the 

new source set-aside to fulfill the request, the source [shall need to] must purchase the 

allowances required to demonstrate compliance. Any eligible WEB source that does not 

receive an allocation from the new source set-aside because the set-aside was depleted shall 

be first in line to receive an allocation when the new source set-aside is increased in the next 

five-year period as outlined in Section C1.1(b)(3) of this Implementation Plan. If there is 

more than one such source, their allocation requests will be processed in the order they were 

received by the TSA.

(g) A source that has received a retired source exemption and continues to receive an 

allocation as a retired WEB source shall not be eligible to receive an allocation from the new 

source set-aside. 
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C1.4 Regional Tribal Set-aside.

(a) Each year after the program is triggered, [20,000] 2,500 allowances will exist as a tribal 

set-aside.

(b) The tribal caucus of the WRAP has stated its intent to determine the means for 

distributing the allowances among the tribes by one year after the program trigger date. The 

Department understands that there will be a process that shall meet the tracking and data 

security requirements of the allowance tracking system by which a tribe shall move its setaside allowances into the trading program for the purposes of trading. 

(c) The state recognizes that the tribal set-aside allowances are bonus allowances for the 

tribes and as such, are separate and additional to any allowances included in a tribal budget 

or the new source set-aside as outlined in the allocation report in C1.1(b)(11). 

C1.5. [Distribution of Allowances for] Opt in Sources. [The WRAP Market Trading Forum has 

recommended including provisions in this plan that would allow smaller sources to opt in to the 

program. Opt-in sources may provide a more cost-effective way to reduce overall regional SO2

emissions, and therefore may strengthen the market incentives of this program. While the 

benefits of allowing sources to opt in to the program are important, the program must also 

provide safeguards to ensure that the integrity of the program is not affected. For example, it 

would be counterproductive to allow sources that were already planning to shut down to opt in to 

the program and then sell allowances to an existing source. In this example, regional emissions 

could slowly creep upward in a manner that is not consistent with the goals of the SO2

milestones.] The Department is deferring inclusion of provisions for opt-in sources until a future 

SIP revision to allow time to thoroughly consider how to provide the flexibility and potential 

benefits to the market by expanding the program while also ensuring that the SO2 emission 

reductions goals are maintained. 

C2. WEB Allowance Tracking System (WEB ATS)

[[Note: Section C1 includes a commitment to distribute the first round of allocations one year 

after the program is triggered. The contract for development of the ATS and ETD specifications 

should address whether this time frame is reasonable.]] 

[51 CFR 309(d)(4)(v) requires the] The Department [to] will provide a centralized system for the 

tracking of allowances and emissions within the framework of the SIP. The centralized system 

will be referred to as the WEB Emissions and Allowance Tracking System (WEB EATS). The 

WEB EATS must provide that all necessary information regarding emissions, allowances, and 

transactions is publicly available in a secure, centralized database. The EATS must ensure that

each allowance is uniquely identified, allow for frequent updates, and include enforceable 

procedures for recording data. 
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The Department shall work cooperatively with other states and tribes participating in the WEB 

Trading Program to designate this system. The Department shall be responsible for ensuring that 

all the EATS provisions are completed as described in this plan. 

The EATS will not exist unless the program is triggered. Prior to the implementation of the WEB 

Trading Program, a separate emissions tracking database will be employed to track the ongoing 

emissions of sources emitting SO2 at amounts equal to or greater than 100 tons per year. The 

emissions tracking database, used to track and measure SO2 emissions against the milestones, 

will still exist once the WEB Trading Program is triggered; If the program is triggered, either the 

emissions tracking database will be incorporated into the SO2 Allowance Tracking System, or a 

similar, parallel one more suitable for enforcement and program specific purposes will be 

developed and incorporated into the SO2 Emissions and Allowance Tracking System. Both the 

emissions tracking database and the EATS shall be centralized systems with data posted in a 

format, including an electronic, Web-based program, and available to anyone.

The participating states and tribes shall contract with a common Tracking System Administrator 

to service and maintain the WEB EATS. It is envisioned that the EATS will require the use of a 

contracted consultant or database design engineer to create a secure, efficient and transparent 

tracking system. Because the EATS shall be utilized by all states and tribes participating in the 

program, the design will require a uniform approach and level of security that will satisfy 

regional needs and concerns as well as meet the electronic, Web-based, access needs and security 

provisions. Due to the dynamic needs of the marketplace, the EATS will require a database that 

will reflect the current status of allowances and allowance transactions. The EATS shall be 

operational within one year after the program trigger date.

Specifications of the WEB EATS such as emissions tracking, the recording of allowance 

transactions, account management, system integrity and transparency are [described in a report 

prepared for the WRAP, titled "Western Emissions Backstop (WEB) Emissions and Allowance 

Tracking System (EATS) Analysis" (July 2003)] WEB Emissions and Allowance Tracking 

System (EATS) Analysis. [A copy of this report is provided in outlined in related Technical 

Support Document (TSD) included in this plan as an appendix in this SIP.] The [report] EATS 

Analysis and related Sections of [the WEB Trading Program Model Rule] 20.2.81 NMAC detail 

how a WEB source will register for the EATS and how the source will, through an account 

representative, establish accounts, transfer allowances, and track unused allowances from a 

previous year. The account representative will also look to the Analysis to determine the 

appropriate interface with the EATS.

Neither the Department nor the TSA shall adjudicate any dispute concerning the authorization of 

any Account Representative with regard to any representation, action, inaction, or submission of 

the Account Representative.

As an example of how the WEB EATS will generally function, once the WEB Trading Program 

is triggered a WEB source will have its allowance allocation determined. On a parallel track, the 

WEB source's account representative will register for the EATS under 20.2.81.103 NMAC , and 

a compliance account will be established under 20.2.81.105 NMAC. Each allowance will be 
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assigned a serial number. The allowance serial number will be used by the WEB EATS to track 

allowance allocations, transfers under 20.2.81.107 NMAC, deductions, and account for any 

unused allowances from a previous year (20.2.81.108 NMAC). The serial number will also be 

assigned each allowance recorded in a general account, an account for allowances that are not 

held to meet program compliance requirements. Furthermore, the EATS will track tribal 

allowance set-asides and new source allowance set-asides not yet assigned to either a compliance 

or general account. 

It is important to note that while an effort has been made in this plan to provide a design for and 

an operational understanding of the EATS, the components of the EATS will need to be 

examined and possibly altered upon each required SIP revision. 

C3. Allowance Transfers.

[40 CFR 51.309(d)(4)(viii) requires the Implementation Plan to include provisions for detailing 

the process for transferring allowances between parties.] [Transfers] Allowance transfers are 

defined as the conveyance from one account to another account (compliance account or general 

account) of one or more allowances by whatever means, including but not limited to purchase, 

trade, or gift in accordance with the procedures established in 20.2.81.107 NMAC. This includes 

transfers of allowances for the purpose of retirement. Once an allowance is retired, it is no longer 

available for transfer to or from any account. Allowances may be purchased by any party for the 

purpose of retirement. 

The Tracking System Administrator shall have specific recording requirements involving 

transfers. These required procedures will be detailed in the service contract but are outlined here 

as well. 

C3.1 Recording of Allowance Transfers. 

Within five business days of receiving an allowance transfer, except when the transfer does not 

meet the requirements of this Section, the Tracking System Administrator shall record an 

allowance transfer by moving each allowance from the transferor account to the transferee 

account as specified by the request, provided that: 

(a) The transfer is correctly submitted; and 

(b) The transferor account includes each allowance identified in the transfer.

Any allowance transfer that is submitted for recording following the allowance transfer deadline 

and that includes any allowances allocated for a control period prior to or the same as the control 

period to which the allowance transfer deadline applies, shall not be recorded until after 

completion of the compliance account reconciliation. 

Where an allowance transfer submitted for allowance transfer recording fails to meet the 

requirements of this Section, the Tracking System Administrator shall not record such transfer.
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C3.2 Notification of the Recording of Allowance Transfers 

The Tracking System Administrator has specific responsibilities involving the notification of the 

recording of any transferred allowances, including the failure to record any transfer of 

allowances. Again, these required procedures will be outlined in the service contract, but will 

include what is outlined here. 

(a) Within five business days of the recording of an allowance transfer, the Tracking System 

Administrator shall notify the Account Representatives of both the transferor and transferee 

accounts, and make the transfer information publicly available on the Internet. 

(b) Within five business days of receipt of an allowance transfer that fails to meet the 

requirements of 20.2.81.107 NMAC, the Tracking System Administrator shall notify the 

Account Representatives of both accounts of the decision not to record the transfer, and the 

reasons for not recording the transfer. 

C4. Use of Allowances from a Previous Year. 

C4.1 Background. 

[51 CFR 309(4)(ix) allows states to include in the Implementation Plan provisions for the 

accounting of unused allowances from a previous year. The unused] Unused allowances may be 

kept for use in future years in accordance with 20.2.81.108 NMAC [and describe the restrictions 

on the use of the allowances in accordance with 20.2.81.108 NMAC]. 

[The federal rule requires that allowances] Allowances kept for use in future years may be used 

in calendar year 2018 only to the extent that the Implementation Plan guarantees that such 

allowances will not interfere with the achievement of the 2018 milestone.

Subsection D of 20.2.81.108 NMAC addresses this requirement by prohibiting the use, after the 

year 2017, of allowances allocated for the years 2003 - 2017. This provision ensures that actual 

emissions will be less than the 2018 milestone because only allowances allocated for the year 

2018 could be used to show compliance in that year. The provision also maintains flexibility by 

resetting the baseline to the year 2018 and then allowing sources to once again use extra 

allowances to show compliance in any future year. This flexibility is important for sources that 

have variable operations because the source may build up a reserve of unused allowances for use 

in a high production year. 

[The Annex explains the benefits of allowing the WEB source to tap the previous year's unused 

allowances, including increased] Increased flexibility and early reduction stimulus are a benefit 

to allowing the WEB source to tap the previous year's unused allowances. [The risk in allowing 

the use of allowances carried from a previous year could be an increase in emissions in later 

years as the unused allowances are withdrawn for compliance.] 
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Because the regional haze SIP is based on reasonable progress requirements related to the 

remedying or prevention of any future visibility impairment, it is important to assure the use of 

these allowances will not interfere with attainment or maintenance of any reasonable progress 

goals. The safeguard employed here to mitigate this type of risk is termed, "flow control" , and is 

described below. 

C4.2 Flow Control Provisions. 

At the end of each control period, WEB sources may transfer allowances in and out of their 

compliance account for a period of 60 days to ensure that the account will contain enough 

allowances to cover sulfur dioxide emissions during the previous year. At the end of the sixtyday transfer period, allowances shall be deducted from the compliance account of each WEB 

sources in an amount equal to the sulfur dioxide emissions of that source during the control 

period. 

After the deductions have been completed, the Tracking System Administrator shall perform the 

following calculations and prepare a report according to Section C7.1(b). 

(a) Determine the total number of allowances remaining in the allowance tracking system 

that were allocated for the just completed control period and all previous control periods. 

(b) If the number calculated in (a) exceeds 10 percent of the milestone for the next control 

period, then the flow control procedures in Subsection C of 20.2.81.108 NMAC shall be 

triggered for that next control period. These flow control provisions will discourage the 

excessive use of allowances that were allocated for an earlier control periods without 

establishing an absolute limit on their use. WEB sources shall maintain the option to use 

allowances allocated for an earlier control period, but will be required to use two allowances 

for each ton of SO2 emissions. Flow control operates as follows:

(1) The flow control ratio shall be calculated by multiplying one tenth multiplied by the 

milestone for the next control period divided by the total number of unused allowances 

remaining in the system.

(2) To calculate the number of prior-year allowances that can be used without restriction 

by a source for the just-completed control period, the TSA shall multiply them by the 

flow control ratio. The resulting number of allowances may be used on a one-to-one ratio 

to show compliance with the source's emission limitation as outlined in 20.2.81.109 

NMAC.

(3) The remaining prior-year allowances may be used on a two-to-one ratio to show 

compliance. Thus, WEB sources will maintain the option to use allowances allocated for 

an earlier control period, but will be required to use two of those allowances for each ton 

of SO2 emissions.
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Example: On March 1, 2010 (the compliance transfer deadline for the 

2009 control period) the Tracking Systems Administrator deducts 

allowances from the compliance account for each WEB source to cover 

2009 SO2 emissions from that source. After completing these deductions, 

the TSA reports the following information:

Total number of allowances still in the system

 for the years 2003 - 2009 = [75,000] 30,000

 2010 milestone [(5-state, no smelter)] = [508,223] 200,722

Percent of milestone = [14.75] 14.94% 

Because the number of allowances not used in previous control periods is greater than 10% of 

the milestone, flow control procedures are triggered. In the annual report required in C7.1 (b) the 

TSA will then calculate the flow control ratio for 2010:

0.1 x 2010 Milestone ÷ prior year allowances = flow control ratio 

20.1 x [508,223] 200,722 ÷ [75,000] 30,000 = [0.67] 0.70

On March 1, 2011 ( the compliance transfer deadline for the 2010 control period) the TSA will 

apply the 2010 flow control ratio before deducting allowances from each WEB source's 

compliance account

WEB Source A 2010 Allowances = 1,000 

 Remaining Prior Year Allowances = [500] 600

 2010 Emissions = [1,400] 1,580

In this example, the TSA would multiply the prior year allowances by [0.67] 0.70 to determine 

the number of prior year allowances that could be used without restriction at a one to one ratio. 

This would equal [335] 420. The remaining prior year allowances would then be used at a 2:1 

ratio. [130] Three hundred sixty allowances would be needed to cover the remaining [65] 180

tons of SO2 emissions. The TSA would therefore deduct a total of [1,465] 1,780 allowances 

(1,000 + [335] 420 + [130] 360) to cover [1,400] 1,580 tons of SO2 emissions. 

C5. Monitoring and Recordkeeping Section

[Recommendations regarding monitoring and recordkeeping and reporting are under 

development by the WRAP. Recommendations will be included in 20.2.81 NMAC, New 

Mexico's Backstop Trading Program Rule, pending their acceptance by the WRAP.] 

C5.1 For WEB sources subject to 40 CFR Part 75, the EPA Administrator shall quality assure 

and finalize the data for submission to the Tracking System Administrator. For WEB sources 

subject to 20.2.81.111 NMAC or 20.2.81.112 NMAC, the Department shall quality assure and 

finalize the data in accordance with these provisions for submission to the Tracking System 

Administrator
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C5.2 The [EPA Administrator and the] Department [, as applicable,] shall verify and submit data 

to the emissions tracking database as soon as reasonably feasible after annual emissions are 

reported by the WEB sources. Note: these timelines will be modified, as necessary, according to 

the monitoring protocols. 

C5.3 Special Reserve Compliance Accounts. The WEB Trading Program requires most WEB 

sources to install continuous emission monitoring systems (CEMS) that meet the monitoring, 

recordkeeping and reporting requirements of 40 CFR part 75. However, there are some emission 

units that are not physically able to install CEMS and there are also emission units that do not 

emit enough sulfur dioxide to justify the expense of installing these systems (see Subsection B of 

20.2.81.106 NMAC. The WEB Trading Program allows these emission units to continue to use 

their pre-trigger monitoring methodology, but does not allow the WEB source to transfer any 

allowances that were allocated to that unit for use by another WEB source. The restriction on 

transferring these allowances is needed to ensure that an emission reduction of sulfur dioxide and 

the corresponding increase in sulfur dioxide are equal. The allowances associated with emission 

units that continue to use their pre-trigger monitoring methodology are placed in a special 

reserve compliance account, while allowances for other emission units are placed in a regular 

compliance account. Allowances may not be traded out of a special reserve compliance account, 

even for use by emission units with CEMS at the same WEB source. However, the WEB source 

may use allowances in the compliance account to demonstrate compliance with the WEB 

source's allowance limitation.

Paragraph 1 of Subsection B of 20.2.81.106 NMAC allows WEB sources with any of the

following emission units to apply to establish a special reserve compliance account:

(a) any smelting operation where all of the emissions from the operation are not ducted to a 

stack; or

(b) any flare, except to the extent such flares are used as a fuel gas combustion device at a 

petroleum refinery; or

(c) any other type of unit without add-on sulfur dioxide control equipment, if the unit belongs to 

one of the following source categories: cement kilns, pulp and paper recovery furnaces, lime 

kilns, or glass manufacturing.

The emission units described in (a) and (b) cannot physically be monitored using a CEM. The 

emission units described in (c) do not typically have add-on controls for sulfur dioxide. These 

units, addressed in Subsection B of 20.2.81.106 NMAC, are expected to operate within their 

floor-level allocation and therefore will not be affected by the market, unless they make a 

process change and wish to sell allowances on the market. Other sources that are meeting the 

more rigorous monitoring requirements of Subsection A of 20.2.81.106 NMAC and emit sulfur 

dioxide above their expected allocation will either need to purchase allowances or install sulfur 

dioxide controls. Therefore, it is important that all emission units that participate in emissions 

trading have an accurate monitoring methodology that is comparable to other sources in the 
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program to ensure that a ton of reductions is the same regardless of where the reductions 

originate.

The Department will review the application to monitor under Paragraph 1 of Subsection B of 

20.2.81.106 NMAC. If the emission units meet the criteria in Paragraph 1 of Subsection B of 

20.2.81.106 NMAC, the Department will determine the portion of the WEB source's allocation 

that is associated with the emission units that will be monitored under Paragraph 1 of Subsection 

B of 20.2.81.106 NMAC and will require the TSA to record that portion of the WEB source's 

allocation in the special reserve compliance account. The Department will use the methodology 

for determining allocations described in Section C1.1 of this Plan to determine the portion of the 

allocation that is associated with emission units monitored under Paragraph 1 of Subsection B of 

20.2.81.106 NMAC. The Department will notify the WEB source that the application has either 

been accepted or rejected, including a notification of the allowances that are to be recorded in the 

WEB source's regular compliance account and the special reserve compliance account.

If an emission unit that is monitored under Paragraph 1 of Subsection B of 20.2.81.106 NMAC is 

permanently retired, the TSA will transfer the portion of allowances that were associated with 

that emission unit from the WEB source's special reserve compliance account to the source's 

compliance account. These allowances will then be available for use or sale by the WEB source. 

The allowances will be transferred after the compliance deduction has taken place for the last 

control period that the unit was in operation.

C6. Compliance and Penalties.

C6.1 Compliance, Excess Emissions, and Penalties

When a WEB source exceeds its allowance limitation in 20.2.81.109 NMAC, the Department 

shall require the Tracking System Administrator to deduct allowances from the following year's 

allocation in an amount equal to [two] three times the WEB source's emissions of SO2 in excess 

of its allowance limitation. This deduction shall be made from the WEB source's compliance 

account after deductions for compliance under 20.2.81.109 NMAC. If sufficient allowances do 

not exist in the compliance account for the next control period to cover this amount, the 

Department shall require the Tracking System Administrator to deduct the required number of 

allowances, regardless of the control period for which they were allocated, whenever the 

allowances are recorded in the account.

Under the rule, sources may also be liable for penalties for each day of violations of the 

program's other requirements.

[C6.2 Penalties

The amount of the penalty shall be evaluated at each five-year SIP review, and adjusted to ensure 

that penalties per ton substantially exceeds the expected cost of allowances to ensure that this 

remains a stringent penalty. The rule establishes a penalty of $5000 per ton for each ton of 

emissions above the source's allowance limitation. Each ton represents a separate violation. In 

addition, two allowances from the next year's allocation will be deducted from the account for 
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each ton of exceedance. Under the rule, sources are also liable for penalties for each day of 

violations of the program's other requirements. More detail on liabilities for different provisions 

can be found in the provisions of 20.2.81 NMAC.] 

C7. Periodic Evaluation of the Trading Program.

C7.1 Annual Report 

(a) [One] Beginning one year after compliance with the trading program is required, the 

Department shall obtain from the Tracking Systems Administrator an annual report that 

contains the following information: 

 (1) The level of compliance program-wide;

 (2) A summary of the use and transfer of allowances, both geographically and 

temporally;

 (3) A source-by source accounting of allocations compared to emissions; 

(4) A report on the use of unused allowances from a previous year [[] in order to 

determine whether these emissions have or have not contributed to the emissions in 

excess to the cap.[]] 

(5) The total number of WEB sources participating in the trading program and 

any changes to eligible sources, such as retired sources, or sources that emit more than 

100 tons of SO2 after the program trigger date. 

(b) Within 10 months after the allowance transfer deadline for each control period when 

compliance with the trading program is required, the Tracking System administrator 

[will] shall prepare a draft report that lists:

 (1) the total number of allowances deducted for the control period. 

(2) the total number of allowances remaining in the Allowance Tracking System 

allocated for that control period for and any earlier control period. 

(3) proposed determination that flow control procedures have either been 

triggered or have not been triggered for the next control period, and 

(4) if flow control procedures have been triggered, a draft flow control ratio 

calculated according to Section C4.2 of the state implementation plan. 

(c)The Department shall evaluate the draft report, and shall propose a determination that 

flow control procedures have been either been triggered or have not been triggered for the 

next control period.

(d) The Department will publish a notice of availability of the draft report, in newspapers 

of general circulation throughout New Mexico, and will hold a 30-day comment period. 

(e) [The] After the comment period, the Department will make a final determination that 

the flow control procedures have either been triggered or have not been triggered for the 

next control period. If the flow control procedures have been triggered, the Department 

will notify all WEB sources in New Mexico that flow control procedures will be in effect 

during the next control period. 

 

C7.2 Five-year Evaluation. 
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(a) The Department will work cooperatively with other participating States and tribes 

[shall] to conduct an audit of the WEB Trading Program no later than three years 

following the first full year of the trading program, and at least every five years 

thereafter. This evaluation does not [supplant] replace the Implementation Plan 

assessments in [2008,] 2013[,] and 2018 as required by the regional haze regulations. The 

evaluation [should] will be conducted by an independent third party and include an 

analysis of: 

1. Whether the total actual emissions could exceed the values in Table C-1 of this 

Implementation Plan of the WEB Trading Program even though sources comply 

with their allowances;

2. Whether the program achieved the overall emission milestone it was intended to 

reach;

3. The effectiveness of the compliance, enforcement and penalty provisions; 

4. A discussion of whether states and tribes have enough resources to implement the 

WEB Trading Program; 

5. Whether the trading program resulted in any unexpected beneficial effects, or any 

unintended detrimental effects;.

6. Whether the actions taken to reduce sulfur dioxide have led to any unintended 

increases in other pollutants;

7. Whether there are any changes needed in emissions monitoring and reporting 

protocols, or in the administrative procedures for program administration and 

tracking; and,

8. The effectiveness of the provisions for interstate trading, and whether there are 

any procedural changes needed to make the interstate nature of the program more 

effective.

9. The integrity of the emissions and allowance tracking system, including whether 

the procedures for recording transactions are adequate, whether the procedures are 

being followed and in a timely manner, whether the information on sources' 

emissions are accurately recorded, whether the emissions and allowance tracking 

system has procedures in place to ensure that the transactions are valid, whether 

back-up systems are in place to account for problems with loss of data. 

(b) The public shall have an opportunity to participate in this trading program 

 evaluation. 
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(c) In the event that any audit results in recommendations for program revisions, the 

Department, in consultation with the WRAP, will make appropriate modifications to this 

plan. The Department will revise this plan if the program is not meeting its emission 

reduction goals. 

(d) The Department shall submit a copy of the report to the EPA regional office. 

C8. Retired Source Exemption

Subsection D of 20.2.81.101 NMAC [Section 4 of the Model Rule] outlines the procedure that a 

WEB source must follow to receive a retired source exemption. The exemption would allow the 

source to continue to receive an allocation, but would exempt the source from monitoring and 

recordkeeping requirements that would serve no useful function for a source that has ceased 

operations. The Department shall notify the source of its obligation to apply for a retired source 

exemption upon the cancellation or relinquishment of a permit. 

In order to receive a retired source exemption, the source must submit a request for the 

exemption to the Department. The Department shall review this request, and within sixty days of 

receipt of the request shall notify the source that the retired source exemption has been granted or 

has been rejected. If the exemption has been rejected, the notification shall contain an 

explanation of the reasons for rejecting the request. 

The TSA shall record an allocation to a WEB source that has received a retired source 

exemption. However, the allowances shall be recorded in a general account rather than a 

compliance account for the source. The TSA will transfer any existing allowances in the retired 

source's compliance account or special reserve compliance account into the general account for 

the retired source, and will close the compliance accounts.

A WEB source that is retired and that does not request a retired source exemption shall forfeit all 

abandoned allowances in that source's compliance account, as outlined in Paragraph (5) of 

Subsection D of 20.2.81.101 NMAC Section 4 of the WEB Trading Program Model Rule. The 

forfeited allowances shall not be redistributed to other sources, and shall be retired from the 

Allowance Tracking System as outlined in 20.2.81.107 NMAC. During the next five-year 

allowance distribution period the retired source shall not receive an allocation, and the 

allowances that would have been distributed to that source shall be added to the new source setaside.

 

C9. Integration into Federally Enforceable Permits

[40 CFR 51.309 requires that the requirements for emissions reporting and for the trading 

program be incorporated into a permit that is enforceable as a practical matter by EPA and by 

citizens to the extent permitted by the Act.] It is expected that all WEB sources will at least 

initially be required to obtain a permit under New Mexico's Title V delegated permitting 

program. Under 20.2.70 NMAC, New Mexico's delegated Title V permitting program, the pre- 
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and post- trigger requirements of the market trading program fall under the definition of 

"applicable requirements", and will be incorporated into each source's Title V permit. 20.2.81 

NMAC requires that any source that for any reason and at any time is not required to have a 

permit under 20.2.70 NMAC must obtain a New Source Review permit pursuant to 20.2.72 

NMAC, 20.2.74 NMAC or 20.2.79 NMAC that incorporates the same requirements, and that the 

source must at all times possess a permit containing the program's requirements. Additionally, in 

order for a source permitted under Title V to become a synthetic minor source, and thus not need 

a Title V permit, a source first must obtain federally enforceable permit limits through a New 

Source Review permit, and thus there will be no gap between the effective Title V permit and the 

new NSR permit which contains the same market trading program requirements. Both types of 

permits are enforceable both federally and by citizens pursuant to New Mexico's Implementation 

Plan.

D 2013 SIP/TIP Revision; Backstop for Beginning of Second Planning 

Period

D1. Requirements of 2013 SIP Revision

In addition to the requirements of 40 CFR 51.309(d)(10), the 2013 SIP [/TIP] shall contain:

1. Source specific allocations for all WEB sources under the jurisdiction of the 

Department for the year 2018; and 

2. Either the provisions of a program designed to achieve reasonable progress for 

stationary sources of SO2 beyond 2018 or a commitment to submit a SIP/TIP revision 

containing the provisions of such a program no later than December 31, 2016. The 

program will ensure that the requirements of 40 CFR 51.309 for the first planning period 

are achieved, including requirements that cannot be measured until after 2018, such as 

the determination of compliance with the 2018 milestone.

[D2] Adjustments in Allocation Calculations

This 2013 SIP revision will provide certainty to sources regarding their potential liability under 

the special penalty provisions for the year 2018 outlined in Section A5 of this Implementation 

Plan. The calculation of these allocations is delayed until 2013 to provide certainty about the 

number of sources that would qualify as WEB sources at that time; the allocations needed for 

new sources in the region; [and the magnitude of renewable energy development] and early 

reductions that would need to be included in the allocation process. It is difficult to estimate the 

impact of these factors in 2003 because many things may change during the next 10 years. 

If the 2018 milestone is not met, the starting point for the next planning period shall be the 2018 

milestones, not actual emissions in 2018. 
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D2. Achievement of 13 percent SO2 emission reduction. 

Pursuant to 40 CFR 51.309(d)(4)(ii), the State of New Mexico has determined that a 13 percent 

reduction in actual stationary source SO2 emissions has occurred between the years 1990 and 

2000. Table [5] C-3 below provides a state-by-state comparison of these emissions, and shows 

that there has been a 25 percent reduction from 1990 to 2000 for all states (from 828,775 tons to 

621,838 tons). [Further information on the emission inventories used for this calculation is 

described in Appendix M-5 of this implementation plan.] The current emissions and modeling 

data and results for stationary sources in the WRAP region are now available through the WRAP 

TSS (http://vista.cira.colostate.edu/tss). The methodology and data for the revised SO2 Milestone 

Program are available at: http://www.wrapair.org/forums/309/docs.html. Tracking pre-trigger 

stationary source SO2 emissions is found in Section 4.3 of Chapter 4 of the WRAP TSD.

Table [5] C-3: State-by-State Comparison of SO2 Emission Reductions, 1990-2000 

(in tons per year) 

States 1990 2000

Arizona 185,398 99,133

California 52,832 38,501

Colorado 95,534 99,161

Idaho 24,652 27,763

Nevada 52,775 53,943

New Mexico 177,994 117,344

Oregon 17,705 23,362

Utah 85,567 38,521

Wyoming 136,318 124,110

Totals 828,775 621,838

D3. [Report on Assessment of NOx / PM Strategies] Provisions for Stationary 

Source NOx and PM

[Provisions for Stationary Source NOx and PM. Pursuant to 40 CFR 51.309 (d)(4)(v), the State 

of New Mexico has included in this SIP a report which assesses emissions control strategies for 

stationary sources of NOx and PM, and the degree of visibility improvement that would result 

from implementation of the identified strategies. The report, Stationary Source NOx and PM 

Emissions in the WRAP region: An Initial Assessment of Emissions, Controls, and Air Quality 

Impacts, was prepared by the WRAP and is included in Appendix C-2. The report represents the 

initial assessment of stationary source NOx and PM strategies for regional haze. The Department 

has determined that NOx and PM strategies are not needed at this time. The State of New 

Mexico will review the need for long term strategies for stationary sources of NOx and PM 

during the SIP revision updates due in 2008, 2013 and 2018.] 

Assessment of need for NOx and PM milestones. Pursuant to 40 CFR 51.309(d)(4)(vii), the State 

of New Mexico has evaluated the need for NOx and PM emission control strategies, the degree 

of visibility improvement expected, and whether such milestones are needed to avoid any net 
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increase in these pollutants. This evaluation was made by the WRAP Market Trading Forum for 

all WRAP states, including the transport region states.

Several conclusions were reached based on WRAP analyses. These include:

(a) That for the vast majority of Mandatory Federal Class I areas throughout the WRAP region 

stationary source NOx and PM emissions are not a major contributor to visibility impairment;

(b) That RAVI remedies are available in cases where particular stationary sources may impact 

particular Class I areas;

(c) Analysis for NOx and PM impacts in the 309(g) SIP submittal has reaffirmed the position 

that the need for milestones to support potential market-based programs is not yet established.

The initial assessment of the need for NOx and PM long-term strategies is provided in the New 

Mexico TSD. The State of New Mexico will continue to work with the WRAP to improve the 

emission inventories and regional modeling to support future policy decisions regarding 

stationary source NOx and PM emissions. The State of New Mexico has made an additional 

preliminary assessment on the need for long-term strategies for stationary sources of PM and 

NOx in the 309(g) SIP. NOx and PM long-term strategies are discussed in the 309(g) SIP 

submittal, with commitments to reassess in SIP updates for 2013 and 2018.

Applicable WRAP Reports and Documents. Chapter 4, Section 4.3 of the TSD Development 

Plan provides a summary of the method for tracking and reporting stationary source emissions

covered in the backstop trading program, through the WRAP emissions data system. The current 

emissions and modeling data and results for stationary sources in the WRAP region are now 

available through the WRAP TSS (http://vista.cira.colostate.edu/tss). The methodology and data 

for the revised SO2 Milestone Program are available at:

http://www.wrapair.org/forums/309/docs.html.

The Western Emissions Backstop Emissions Trading and Allowance Tracking System (EATS) 

Analysis report describes how emissions, allocations, and transactions will occur if the backstop 

trading program is triggered. This report is described further in the New Mexico TSD.

Stationary Source NOx and PM Emissions in the WRAP Region: An Initial Assessment of 

Emissions, Controls and Air Quality Impacts reviews possible emission control strategies for 

stationary sources of NOx and PM, and the degree of visibility improvement that would result 

from such strategies. The report is described further in the New Mexico TSD.
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D. Mobile Sources

(a) Actual and projected statewide inventory for mobile source emissions. Pursuant to 

requirements in 40 CFR 51.309(d)(5)(i), a statewide inventory of baseline and future year mobile 

source emissions has been compiled for the years 2003 to 2018. Table D-1 below summarizes 

these emissions, and indicates the year on-road mobile source emissions are projected to be at 

their lowest level within the state. The following inventory as well as additional information on 

mobile source emissions can be found in Chapter 5 of the Wrap Technical Support Document, 

included in Appendix N of this SIP. 

Table D-1: Statewide On-Road Mobile Source Emissions, Annual Average Day 

(Tons Per Day) 

Year VOC NOx SO2 PM2.5*

1996 194 208 5.7 6.6

2003 137 179 7.6 6.7

2008 95 132 0.8 6.3

2013 70 87 0.9 4.3

2018 59 60 1.0 3.3

Lowest Year 59 60 0.8 3.3

*Includes organic and elemental carbon as a percentage of PM2.5. As a percentage of PM2.5, 

both organic and elemental carbon shows a continuous decline over the 2003-2018 planning 

period 

(b) Contribution to Visibility Impairment Finding. Pursuant to 40 CFR 51.309(d)(5)(i), the State 

of New Mexico, with the assistance of the WRAP, has developed a statewide inventory that 

shows a decline in sulfur dioxide emissions from mobile sources over the 2003-2018 planning 

period. In the 2008 SIP review, New Mexico will reevaluate mobile source emissions to 

determine if long-term strategies are needed. Mobile source emissions are not a significant 

source of visibility impairment in New Mexico. Additional information on the mobile source 

emission inventory as well as significance is included in Chapter 1 of the WRAP Technical 

Support Document, included as Appendix N to this SIP. 

Table D-2 Net emissions change from 2003 to 2018 for total mobile source emissions, 

by pollutant. 

2018 Total Mobile Source Emissions 

(tons per day) Reduction from 2003 (%) 

VOC NOx PM2.5* SO2 VOC NOx PM2.5 SO2

75.8 80.4 6.9 1.4 54% 62% 38% 89%

* Exhaust emissions only, includes elemental and organic carbon as a percentage of PM2.5. As 

a percentage of PM2.5, both organic and elemental carbon shows a continuous decline over the 

2003-2018 planning period. 

.
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(c) Interim Implementation Status Reports. Pursuant to 40 CFR 51.309(d)(5)(iv), the State of 

New Mexico will submit periodic progress reports in 2008, 2013 and 2018 on the status of 

implementation of adopted regional and local strategies recommended by the Commission 

Report to address mobile source emissions.
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E. Programs Related to Fire.

(a) Definition of "fire". The Regional Haze Rule in Section 40 CFR 51.309(b)(4) defines fire as 

"wildfire, wildland fire (including prescribed natural fire), prescribed fire, and agricultural 

burning conducted and occurring on Federal, State, and private wildlands and farmlands." 

Prescribed natural fire has been functionally replaced by wildland fire managed for resource 

benefit (WFU) under the National Fire Plan. Except where "prescribed fire" is noted, the term 

"fire" shall apply to the sources identified herein.

(b) Prescribed Fire Program Evaluation. Pursuant to 40 CFR 51.309(d)(6)(i), the Department 

has evaluated its smoke management program and all Federal, State, and private prescribed fire 

smoke management programs in the state, based on the potential to contribute to visibility 

impairment in the 16 Class I areas of the Colorado Plateau, and how visibility protection from 

smoke is addressed in planning and operation. The Department has also evaluated whether New 

Mexico's smoke management program and these prescribed fire smoke management programs 

contain the following elements: actions to minimize emissions; evaluation of smoke dispersion; 

alternatives to fire; public notification; air quality monitoring; surveillance and enforcement; and 

program evaluation. Appendix E-1 describes the results of these evaluations in detail. 

The Department currently has in place a memorandum of understanding (MOU) with the federal 

land management agencies and the State Forestry Division. This MOU addresses actions to 

minimize emissions; evaluation of smoke dispersion; alternatives to fire; air quality monitoring; 

surveillance and enforcement; and program evaluation. 

As a result of these evaluations, the Department is making the following changes to the smoke 

management programs listed below. 

Program evaluation is part of this smoke management program as required by the Regional Haze 

Rule. The Department will convene an annual meeting after the beginning of the calendar year 

during which the burn community and other interested stakeholders will assess the adequacy of 

the design, impact and implementation of the program. These program evaluations will be used 

to revise and improve the smoke management program and regulation as needed, as well as 

assisting the Department in the preparation of the five-year state implementation plan revision. 

 

The proposed Smoke Management regulation adds requirements for public notice for burn 

projects planned in proximity to populations. For small projects planned within one mile of a 

population, public notice is now required. For larger projects planned within 15 miles of a 

population, or if wind direction is prescribed within 15 miles upwind of a population, public 

notice is required. 

For larger burn projects, the proposed Smoke Management regulation requires burners to either 

review smoke management educational materials provided by the Department, or to complete an 

approved smoke management training program prior to initiating burning. 

 

Surveillance/enforcement is an oversight mechanism that assures adherence to smoke

management efforts as defined by the smoke management program. The New Mexico Air 
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Quality Control Act, NMSA 1978, Chapter 74, Article 2, authorizes enforcement actions and the 

assessment of civil penalties for violations. These actions may include a Warning Letter, Notice 

of Violation, or Compliance Order. An appeal process for enforcement actions is detailed in the 

Act as well. 

The Civil Penalty Policy, a public document available on the Department website, provides 

guidance to the Air Quality Bureau in determining the amount of civil penalties related to 

violations of the Air Quality Control Act. The objectives of the policy include ensuring fair and 

consistent penalty determination, ensuring a level playing field among sources and to impose 

penalties proportional to the gravity of the violation. 

The Department has authority to audit data, records, or weather measurements from previously 

conducted burns, if necessary to verify conformity with, or deviation from, procedures and 

authorizations outlined in the Smoke Management Regulation. On-site inspections of burn sites 

may be conducted to ensure compliance with required elements of the smoke management 

regulation where appropriate. Any field surveillance and enforcement conducted will be 

consistently applied to all burners. 

The Department will respond to and investigate smoke complaints on a case-by-case basis. If the 

burn is in compliance with the Smoke Management Regulation, shut down or mop up activities 

would not be anticipated. The Department will compile data from complaints to assist in future 

planning and program evaluation. The Department will notify individuals or agencies responsible 

for a burn of smoke complaints specific to the burn project. 

In order to ensure that the regional effects on visibility are addressed in this program, the 

Department will coordinate with tribes and other states during the evaluation of airshed impacts. 

For example, should the state become aware of large burns planned or wildfires already 

occurring on lands outside of New Mexico's jurisdiction, the Department will work with burners 

to ensure that airsheds are not overly impacted by smoke emissions. Conversely, the Department 

will coordinate with New Mexico burners to ensure that New Mexico is not adversely impacting 

other jurisdictions. The Department will continue to work with the WRAP and the Western 

States Air Resources Council on issues including smoke management.

All fires of more than 10 acres in size or greater than 1000 cubic feet of pile volume are included 

within the New Mexico Smoke Management Regulation [20.2.65 NMAC]. The proposed Smoke 

Management Regulation addresses actions to minimize emissions; evaluation of smoke 

dispersion; alternatives to fire; public notification; air quality monitoring; burn authorization; and 

fire tracking. 

(c) Emissions Inventory and Tracking System. Pursuant to 40 CFR 51.309(d)(6)(ii), New Mexico 

has established a system for tracking and emissions inventory for VOC, NOx, elemental and 

organic carbon, and particulate for fire sources within the state. The Department has 

implemented an emissions tracking system that follows the WRAP Fire Tracking System Policy, 

which identifies a process for gathering the essential post-burn activity information necessary to 

consistently calculate emissions and uniformly assess fire impact on regional haze on an annual 
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basis. The fire tracking system described in this policy consists of seven components: (1) date of 

burn, (2) burn location, (3) area of burn, (4) fuel type, (5) pre-burn fuel loading, (6) type of burn, 

and (7) "anthropogenic" or "natural" classification or information to support this classification. 

This policy served as the basis for creating a fire emissions inventory within the State of New 

Mexico. See Appendix M-2 of this implementation plan for further information on the fire 

emissions inventory and tracking system in New Mexico. 

The database for New Mexico will be implemented as follows:

1. Information from the registration and tracking forms will be entered into the database.

2. Information from the database will eventually be available to the public through a web 

portal, as that capability is developed within the New Mexico Environment Department. 

3. All sources that burn over 10 acres (or 1000 cubic feet of pile volume) in a day are 

required to track; therefore, all sources will be included in the database.

4. The database will use appropriate emission factors to determine the emissions of VOC, 

NOx, elemental carbon, organic carbon, and PM 2.5. 

(d) Strategy for use of non-burning alternatives. The Department has developed a process with 

key public and private entities, such as the state departments of agriculture and forestry, farming 

and forestry associations, etc. to identify and remove administrative barriers to the use of nonburning alternatives to prescribed fire on federal, state, and private lands, pursuant to 40 CFR 

51.309(d)(6)(iii). The process is collaborative and provides for continuing identification and 

removal of administrative barriers, and considers economic, safety, technical and environmental 

feasibility criteria, and land management objectives. This process is described in Appendix E-2 

of this implementation plan. Included in Appendix E-2 is a summary of the administrative 

barriers currently known to exist in the state. In developing this process, the Department relied 

on two documents: (1) Non-burning Alternatives for Vegetation and Fuel Management, and (2) 

Burning Management Alternatives on Agricultural Lands in the Western United States, prepared 

by the WRAP, that describe a variety of non-burning alternatives and methods of assessing their 

potential applicability. No administrative barriers are known to exist in New Mexico at this time, 

but any barriers identified shall be addressed through the collaborative process in Appendix E-2. 

(e) Enhanced Smoke Management Program. Pursuant to CFR 51.309(d)(6)(iv), all smoke 

management programs within the State of New Mexico are consistent with the WRAP Enhanced 

Smoke Management Programs for Visibility Policy. This policy calls for programs to be based on 

the criteria of efficiency, economics, law, emission reduction opportunities, land management 

objectives, and reduction of visibility impacts. The WRAP policy lists the previously identified 

elements under 40 CFR 51.309(d)(6)(i) as well as adding "burn authorization" and "regional 

coordination" elements to ensure visibility protection and meet the designation of "enhanced." 

The table in Appendix E-1 assesses the current smoke management program in the state, and 

explains how it will meet the Enhanced Smoke Management Program policy and the rule 

requirements.
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The Department has developed a Smoke Management Regulation that address all sources of fire 

over 10 acres or 1,000 cubic feet pile volume. This will add private burns to the federal land 

manager and state agency burns the New Mexico Environment Department currently tracks 

through its Memorandum of Understanding with these agencies. 

New Mexico's new smoke management regulation requires the use of at least one emission 

reduction technique for all burns with emissions of PM-10 greater than one ton per day. These 

burns must also only be conducted during dispersion conditions of good or better. All burners 

with burns greater than 10 acres per day or 1000 cubic feet pile volume per day are required to 

submit prior registration and follow up after the burn with tracking, including the use of emission 

reduction techniques. For burns with emissions of greater than one ton of PM-10 emission per 

day, burners are required to document the reasons for not utilizing alternatives to burning on the 

registration form.

The burn authorization process requires that burners register burn projects, notify the Department 

prior to beginning burning, and, for larger burns, complete smoke management training. Burn 

authorization, regional coordination, and the requirement to utilize at least one ERT all focus on 

ensuring visibility protection.

(f) Annual Emission Goals. Pursuant to 40 CFR 51.309(d)(6)(v), efforts will be made within the 

State of New Mexico to minimize emission increases in fire, excluding wildfire, to the maximum 

extent feasible, through the use of annual emission goals (AEG), in accordance with the WRAP 

Annual Emission Goals for Fire Policy. This policy recognizes that Emission Reduction 

Techniques (ERTs) can be used to minimize emissions from fire. The Department has 

established a collaborative mechanism for setting annual emission goals, and developed a 

process for tracking their attainment on a yearly basis. 

The minimum emission increase from fire is accomplished through the application of emission 

reduction techniques (ERTs). The use of ERTs with the projected annual burn information 

provides the basis for the AEG. Due to the potential impacts from all fire sources, annual 

emission goals will apply to all fire except wildfire (as exempted by the Regional Haze Rule), 

and will be developed for the entire state in cooperation with all burners on a yearly basis. 

The AEG is determined by the New Mexico Environment Department compiling all the 

registration information provided by the burners, specifically the total projected emissions and 

the total projected emission reductions. Information on the statewide use of ERTs from prior 

years' tracking forms will be used to determine if the annual emission goal is being set in a 

realistic manner. Appendix E-3 of this implementation plan describes this process in more detail.
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F. Paved and Unpaved Road Dust. 

(a) Impact of paved and unpaved road dust emissions. Pursuant to 40 CFR 51.309(d)(7), an 

assessment was made by the WRAP of the impact of dust emissions from paved and unpaved 

roads from transport region states on the 16 Class I areas of the Colorado Plateau. A complete 

description of this assessment is provided in Appendix F of this implementation plan. 

(b) Contribution to Visibility Impairment Finding. Pursuant to 40 CFR 51.309(d)(7), the results 

of assessment on the impact of dust emissions described above, the State of New Mexico has 

determined that dust emissions are not a significant contributor to visibility impairment within 

the Colorado Plateau 16 Class I areas. A summary of this impact assessment is provided in 

Appendix F of this implementation plan. Based on these findings, no emission management 

strategies have been identified for inclusion in this SIP submittal. A summary of this impact 

assessment is provided below. See also Appendix F for more information. 

Road dust emission inventories were developed for WRAP states and the significance of road 

dust was then tested using the regional air quality model. Across WRAP states, paved road dust 

emissions increase by about three percent per year from 1996 to 2018, per the increase in vehicle 

miles traveled. Unpaved road dust emissions are projected to decrease between 1996 and 2018, 

by about 0.75% per year, because of reductions in unpaved road mileage over time as more roads 

are paved. As a result, unpaved road dust emissions are about 80% of road dust PM10 emissions 

in 1996, and about 65% of road dust PM10 emissions in 2018. Overall, road dust PM10 emissions 

increase by about 6% from 1996 to 2018. The modeled regional impact of road dust emissions at 

the 16 Colorado Plateau Class I areas ranged from 0.31 deciviews (3.1% of natural conditions to 

be reached by 2064) at the Black Canyon of the Gunnison National Park to 0.08 deciviews (0.8% 

of natural conditions to be reached by 2064) at the Weminuche Wilderness. From these results, 

WRAP determined that the regional impacts of road dust emissions are not significant at the 16 

Colorado Plateau Class I areas at this time.

The state of New Mexico will continue to work with EPA and other entities to research the 

effects of road dust on visibility impairment, and re-evaluate whether or not dust control 

strategies should be developed. 

(c) Tracking of Road Dust Emissions. The State of New Mexico shall track road dust emissions 

with the assistance of the WRAP, and provide an update on paved and unpaved road dust 

emission trends, including any modeling or monitoring information regarding the impact of these 

emissions on visibility in the Colorado Plateau 16 Class I areas. These updates shall include a 

re-evaluation of whether road dust is a significant contributor to visibility impairment. These 

updates shall be part of the periodic implementation plan revisions, pursuant to 40 CFR 

51.309(d)(10). Appendix M-3 of this implementation plan provides a description of the road 

dust emission tracking program. 
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G. Pollution Prevention. 

(a) Summary of P2 programs in the state. Pursuant to 40 CFR 51.309(d)(8)(i), Tables G-1 

through G-3 summarize all P2 programs currently in place in New Mexico. Appendix G 

summarizes all renewable energy generation capacity and production in use or planned as of 

2002, the total energy generation capacity and production in the State, and the percent of the total 

that is renewable. 

Table G-1. Policy Mechanisms to Promote Renewable Energy

Policy Program 

Title

Statutory/Regulatory Citation Program Description

Renewable

Portfolio Standard

Statutory/Regulatory Citation:

New Mexico Public Regulation 

Commission, Utility Case No. 

3619;

Title 17, Chapter 9, Part 573—

Renewable Energy as a Source 

of Electricity, in New Mexico 

Administrative Code 

[http://www.nmcpr.state.nm.us/n

mac/]

Description:

In December 2002, the New Mexico Public 

Regulation Commission adopted a new 

Renewable Energy rule. The purpose of the 

rule is "...to establish a process for promoting 

the use and development of renewable energy 

in New Mexico to assure that electric 

consumers obtain adequate and reliable 

electric services at just and reasonable rates." 

The rule includes a Renewable Portfolio 

Standard (RPS); Section 17.9.573.10.A-C, 

NMAC. The RPS requires public utilities (El 

Paso Electric Company, Public Service 

Company of New Mexico, Southwestern 

Public Service Company, Texas-New Mexico 

Power Company) to develop an energy 

portfolio appropriate to its suppliers and 

customers. The portfolio must include a 

progressively greater percentage of service 

from renewable sources, as follows:

By January 1, 2006, the RPS shall be at least 

five percent (5%) of retail jurisdictional 

energy sales;

By January 1, 2007, the RPS shall be at least 

six percent (6%) of retail energy sales;

By January 1, 2008, the RPS shall be at least 

seven percent (7%) of retail energy sales;

By January 1, 2009, the RPS shall be at least 

eight percent (8%) of retail energy sales;

By January 1, 2010, the RPS shall be at least 

nine percent (9%) of retail jurisdictional 

energy sales;

Upon and after January 1, 2011, the RPS shall 

be at least ten percent (10%) of retail 

jurisdictional energy sales.

Other factors being equal, preference is to be 

given to renewable energy generated in New 
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Policy Program 

Title

Statutory/Regulatory Citation Program Description

Mexico. All transactions are to be 

documented using Renewable Energy 

Certificates (RECs). RECs are to be issued in 

the following values:

1 kilowatt-hour (kwh) WIND or HYDRO = 1 

kwh REC

1 kwh BIOMASS, GEOTHERMAL, 

LANDFILL GAS = 2 kwh REC

1 kwh SOLAR = 3 kilowatt-hours REC

Green Power 

Marketing

Statutory/Regulatory Citation:

New Mexico Public Regulation 

Commission, Utility Case No. 

3619;

Title 17, Chapter 9, Part 573—

Renewable Energy as a Source 

of Electricity, in New Mexico 

Administrative Code 

[http://www.nmcpr.state.nm.us/n

mac/]

Description: 

In December 2002, the New Mexico Public 

Regulation Commission adopted a new 

Renewable Energy rule. The purpose of the 

rule is "...to establish a process for promoting 

the use and development of renewable energy 

in New Mexico to assure that electric 

consumers obtain adequate and reliable 

electric services at just and reasonable rates." 

The rule includes a Green Pricing/Green 

Power Marketing Program facilitated through 

Voluntary Renewable Tariffs filed by public 

utilities and rural electric cooperatives; 

Section 17.9.573.10.D, NMAC. Under this 

section of the Rule, each utility and 

cooperative must offer a voluntary renewable 

energy tariff for those customers who want 

the option to purchase additional renewable 

energy. The tariff is to set out any applicable 

conditions as to price, quantity and term of the 

agreement. Each public utility must also 

develop a corresponding educational program 

on the benefits and availability of its 

voluntary renewable energy program. All 

utilities and cooperatives are required to file a 

proposed tariff by September 1, 2003.

Net Metering New Mexico Public Regulation 

Commission;

Title 17, Chapter 10, Part 571—

Net Metering of CustomerOwned Qualifying Facilities of 

10kW or Smaller, in New 

Mexico Administrative Code 

[http://www.nmcpr.state.nm.us/n

mac/]

Description: The purpose of this rule, 

effective September 30, 1999, is "...to 

simplify the interconnection requirements for 

Qualifying Facilities of 10 kilowatts (kW) or 

smaller and encourage the use of small-scale, 

customer-owned renewable or alternative 

energy resources in recognition of the 

beneficial effects the development of such 

resources will have on the environment of 

New Mexico." If the electricity generated by 

a customer exceeds the electricity supplied by 
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Policy Program 

Title

Statutory/Regulatory Citation Program Description

the grid during a billing period, the utility 

must credit the customer on the next bill for 

the excess kilowatt-hours generated. Unused 

credits are carried forward from month to 

month.

Table G-2. Financial Incentives to Promote Renewable Energy

Policy Program 

Title

Statutory/Regulatory Citation Program Description

Renewable Energy 

Production Tax 

Credit 

Statutory/Regulatory Citation:

New Mexico Statutes Annotated, 

Section 7-2A-19 

[http://www.legis.state.nm.us];

New Mexico Energy, Minerals 

and Natural Resources 

Department, Title 3, Chapter 13, 

Part 19—Renewable Energy 

Production Tax Credit, in New 

Mexico Administrative Code 

[http://www.nmcpr.state.nm.us/n

mac/]

Description: 

This tax incentive was enacted into law during 

the 2002 New Mexico Legislative Session. It 

originally provided a tax incentive in the 

amount of one cent ($0.01) per kilowatt-hour 

for each kilowatt-hour of electricity generated 

from solar or wind energy resources. The 

credit is applied against a company's state 

income tax liability. Qualifying facilities had 

to be at least 20 megawatts in size, with the 

credit available up to a maximum of 400,000 

megawatt-hours per year per company or 

800,000 megawatt-hours per year in the 

aggregate for all companies. The statute was 

amended in 2003 to include biomass as a 

qualifying form of source material. Other 

amendments included lowering the minimum 

megawatt limit for qualifying projects from 

20MW to 10MW to allow smaller wind, solar 

and biomass projects to qualify; and increasing 

the total amount of the credit available each 

year from 800,000 megawatt-hours to 

2,000,000 megawatt-hours. 

Industrial Revenue 

Bond (IRB) 

Financing 

Statutory/Regulatory Citation:

New Mexico Statutes Annotated: 

NM Industrial Revenue Bond 

Act (Section 3-32-1 et seq.); and 

County Industrial Revenue Bond 

Act (Section 4-59-1 et seq.) 

[http://www.legis.state.nm.us]

Description:

The cited laws provide that any county or 

municipality may issue Industrial Revenue 

Bonds (IRBs) for the purpose of financing 

electric generating plants, including those 

fueled by renewable resources. The 

significance of IRB financing is the associated 

tax advantages.

Gross Receipts Tax 

Exemption for Wind 

Equipment

Statutory/Regulatory Citation:

New Mexico Statutes Annotated, 

Section 7-9-54.3 

Description:

This law provides wind developers an 

exemption from the gross receipts tax for 
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Policy Program 

Title

Statutory/Regulatory Citation Program Description

[http://www.legis.state.nm.us]; certain wind equipment, including nacelles and 

rotors, provided the project is financed with 

Industrial Revenue Bonds (Section 7-9-54.3 

NMSA 1978).

Table G-3. Programs to Promote Renewable Energy

Policy Program 

Title

Program Description

State Energy 

Program

State Energy Program

The State Energy Office administers the U.S. Department of Energy State Energy 

Program grant and implements program goals to encourage energy efficiency and 

renewable-energy usage, provide energy education and community outreach, offer 

policy advise to the Executive and Legislative branches, and help New Mexico 

citizens reduce their utility bills and improve their comfort and safety.

The Energy Office is funded through a combination of federal funds and Petroleum 

Violation Escrow funds.

Director: Chris Wentz

(505) 476-3312 

http://www.emnrd.state.nm.us

Special Projects

The State Energy Office administers the State Energy Program – Special Project 

Grants. Each year states submit proposals in response to a DOE solicitation 

identifying how specific technologies could be implemented in their region of the 

country. DOE then selects the projects that best meet national energy goals. The 

Energy Office publicizes grant availability, helps prepare grant applications, 

selects partners for project implementation and administers grants. 

Geothermal 

Development and 

Use Program

Geopowering the West Program

NM Geothermal Energy Working Group

The New Mexico Geothermal Energy Working Group was established in 

December 2000. It is an informal organization of representatives from both the 

public and private sectors, including geothermal developers, leaseholders and 

businesses, federal/state/tribal/local governments, national laboratories, electric 

utilities, universities, and renewable energy advocates. The Energy Conservation 

and Management Division of the New Mexico Energy, Minerals and Natural 

Resources Department coordinates the group, with assistance from Sandia National 

Laboratories-Albuquerque and the U.S. Department of Energy's Geopowering the 

West program. Over 70 individuals are now included on the NM Geothermal 

Working Group e-mail address list. A primary role of the Working Group is to 

function as a stakeholder organization that can act and speak collectively on behalf 

of geothermal interests operating in New Mexico. Key tasks and activities of the 

NM Geothermal Energy Working Group are: serve as a forum for networking, 

communications and coordination among geothermal stakeholders; acquisition and 
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Policy Program 

Title

Program Description

dissemination of information about existing geothermal resources, their 

development and use (both electric generation and thermal applications); 

identification and delineation of the issues that impede expansion of geothermal 

applications; and removal of barriers to geothermal advancement. 

Solar Development 

and Use 

Million Solar Roofs Program

Million Solar Roofs (MSRI) is an initiative to install solar energy systems on one 

million U.S. buildings by 2010. The initiative includes two types of solar 

technology: solar electric systems (or photovoltaics) that produce electricity from 

sunlight and solar thermal systems that produce heat for domestic hot water, space 

heating, or heating swimming pools. The Million Solar Roofs Initiative is helping 

increase the market for solar energy. At the same time, the Initiative is offering 

consumers an affordable, clean-energy option, creating new U.S. high-technology 

jobs, and playing an important role in reducing emissions. Emissions associated 

with power generation are caused mostly by the inefficient burning of fossil fuels. 

By increasing the efficiency of how we use fossil fuels, reducing our use of these 

fuels and switching to alternative, non-polluting fuels, we can significantly reduce 

the emissions we put into the air and the atmosphere thereby reducing their 

harmful effects on human health and the environment. One of the most promising 

non-fossil sources is solar energy.

Schools with Sol Solar Demonstration

The Schools with Sol program is managed by ECMD to implement one of 

Governor Richardson's conservation agenda goals, which is to provide solar power 

to 10 schools each year. Solar energy systems will be installed at New Mexico 

schools, competitively selected, to be used as demonstrations in renewable energy 

education for K-12 students, as well as reduce energy consumption. Both 

photovoltaic and solar domestic water heating systems will be used. A teacher at 

each participating school will "champion" their system through educational 

activities in renewable energy. System installers will be selected from statewide 

price agreements. ECMD is using $100,000 in federal funds to implement the 

current FY2004 cycle of 10 school installations, with an additional $18,000 

provided by Public Service Company of New Mexico and in-kind contributions 

provided by participating schools.

Solar Rights Act

Statutory/Regulatory Citation:

New Mexico Statutes Annotated, Sections 47-3-1 to -5 

[http://www.legis.state.nm.us]

Description: 

The Solar Rights Act declares that the State of New Mexico recognizes that 
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Policy Program 

Title

Program Description

economic benefits can be derived for its citizens from the use of solar energy. It 

goes on to state that the actual construction and installation of solar devises is 

properly a commercial activity which the law should encourage to be carried out, 

whenever practicable, by private enterprise. The Act defines the term "solar right" 

as "...a right to an unobstructed line-of-sight path from a solar collector to the 

sun." Moreover, the Legislature declares in the Act that the right to use the natural 

resource of solar energy is a property right. 

Solar Recordation Act

Statutory/Regulatory Citation:

New Mexico Statutes Annotated, Sections 47-3-6 to -12 

[http://www.legis.state.nm.us]

Description:

The Solar Recordation Act declares that solar energy is a viable energy source in 

New Mexico and, as such, its development should be encouraged. The purpose of 

the Act is to accomplish such encouragement through the protection of solar rights 

necessary for small-scale installations. A solar right is considered an "easement 

appurtenant" and may be claimed by an owner of real property upon which a solar 

collector has been placed. The solar right is claimed and recorded by filing a 

declaration with the county clerk of the applicable county where the property is 

located; a sample declaration is included in the statute as are provisions for 

notification of affected property owners. The statute also provides for the transfer 

of solar rights when a property changes ownership.

Solar Energy Development Act

Statutory/Regulatory Citation:

New Mexico Statutes Annotated, Sections 71-6-1 to -3 

[http://www.legis.state.nm.us]

Description:

The purpose of Solar Energy Development Act is to promote development and use 

of solar energy in New Mexico, by both industry and government, for the benefit 

of New Mexico and United States citizens. It is proposed to accomplish this 

purpose through active measures to encourage the location within New Mexico of 

research to discover practical and feasible methods to harness solar energy, as well 

as development of a vigorous and productive solar energy industrial complex. The 

New Mexico Economic Development Department is charged with various 

responsibilities under the Act, including establishment and operation of a program 

to encourage investment in the research and application of solar energy within 

New Mexico; development of necessary promotional material to be used in the 

process of attracting new investment capital within the solar energy field; 

employing sufficient staff to carry out the purpose of this law; and cooperation 

with private firms and all agencies of the state and federal government in 
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Program Description

furthering research and investment in solar energy use in New Mexico.

Solar Collector Standards Act

Statutory/Regulatory Citation:

New Mexico Statutes Annotated, Sections 71-6-4 to -10 

[http://www.legis.state.nm.us]

Description:

The purpose of the Solar Collector Standards Act is to develop and implement a 

program to promote solar industry and stimulate a demand for high quality solar 

components and systems. The New Mexico Energy, Minerals and Natural 

Resources (EMNRD) is charged with the responsibility under the Act to 

promulgate regulations to define minimum standards for the durability and 

reliability of solar collectors; and to establish criteria for testing the durability, 

reliability and thermal efficiency of solar collectors. The Department is also 

authorized to develop and implement a solar collector certification program. 

EMNRD promulgated appropriate regulations and implemented the specified 

certification program in the mid-1980s until the expiration of federal and state 

solar tax credits. 

Biomass 

Development and 

Use Program 

Western Regional Biomass Program

Biomass Industry Development Working Group

The Energy, Minerals and Natural Resources Department is serving as the 

convener of a Biomass Industry Development Work Group in New Mexico. The 

purpose of this group is to develop a coordination process to encourage and assist 

in the development of a viable biomass industry in New Mexico, resulting in 

improved forest health and increased use of domestic biomass resources to 

stimulate economic development. This process will include assessing 

opportunities, current projects, end products (biofuels, biopower and bioproducts), 

supply, technologies, incentives, barriers, funding and economics.

Wind Development 

and Use Program

Wind Powering America Program

NM Wind Energy Working Group

The New Mexico Wind Energy Working Group was established in December 

2000. It is an informal organization of representatives from both the public and 

private sectors, including wind developers, related businesses, 

federal/state/tribal/local governments, national laboratories, electric utilities, 

universities, and renewable energy advocates. Approximately 80 individuals are 

now included on the NM Wind Working Group e-mail address list. The Energy 

Conservation and Management Division of the New Mexico Energy, Minerals and 

Natural Resources Department coordinates the group, with assistance from Sandia 

National Laboratories-Albuquerque and the U.S. Department of Energy's Wind 

Powering America program. A primary role of the Working Group is to function 

as a stakeholder organization that can act and speak collectively on behalf of 

geothermal interests operating in New Mexico. Key tasks and activities of the NM 

Wind Energy Working Group are: serve as a forum for networking, 
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Program Description

communications and coordination among wind stakeholders; acquisition and 

dissemination of information about existing wind resources, their development and 

use in electric generation; identification and delineation of the issues that impede 

expansion of wind applications; and removal of barriers to geothermal 

advancement. 

Hydrogen 

Development and 

Use Program

Hydrogen Technology Partnership (HyTep)

The Energy Conservation and Management Division is administering the U.S. 

Department of Energy Industries of the Future (IOF) program in New Mexico. The 

Industries of the Future program seeks to bring together industry, academia, and 

state agencies to address industrial energy efficiency and pollution prevention. 

These public-private coalitions facilitate industry solutions locally and enhance 

economic development. New Mexico is currently focusing on the mining and 

forest products industry because of their high energy use, opportunities for 

pollution prevention and important role in New Mexico's economic development

Supplemental 

Environmental 

Projects (SEPs)

The New Mexico Environment Department can utilize supplemental 

environmental projects in enforcement cases for pollution prevention projects.

 Table G-4. Policy Mechanisms to Promote Energy Efficiency/Energy Conservation

Policy Program Title Program Description

Governor's Executive Order: 

Resource Efficiency in State 

Government

Since 1992 New Mexico State Government has been directed through 

Executive orders to reduce energy consumption and costs in state buildings. 

To accomplish the directive the State Energy Office has provided technical 

assistance, financial assistance grants, and worked with state agencies to 

develop and implement energy plans. New Executive Order currently 

being developed.

Public Facility Energy 

Efficiency and Water 

Conservation Act

New Mexico Statutes Annotated, 

Sections 6-23-1 to-10

[http://www.legis.state.nm.us]

This legislation allows state agencies, school districts, and universities to 

enter into 'Performance contracts' whereby private sector energy service 

companies provide the up-front costs of energy saving measures (such as 

installation of more efficient lighting, motors, and heating systems) and 

guarantee energy savings to recoup their investment through the utility cost 

savings over the period of up to 10 years. By statute, the State Energy 

Office is responsible for review of the proposed contracts to ensure that 

savings estimates are accurate and reasonable prior to agencies entering 

into performance contracts. 

Green Purchasing: Energy 

Star Partnership

New Mexico is working with the U.S. Department of Energy and the 

Environmental Protection Agency to become a partner in the Energy Star 

Program to promote the benefits of energy efficient homes, buildings, and 

products. 

According to Energy Star Program if all available opportunities for energy 

efficiency improvements were taken advantage of more than $229 million 

would be saved annually and 2.5 billion pounds of CO2, 6 million pounds 

of NOx, and 5.7 million pounds of SO2 would be prevented each year in 

New Mexico.
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Table G-5. Programs to Promote Energy Efficiency/Energy Conservation 

Policy Program Title Program Description

State Government 

Energy Management 

Program

Electric/Gas Utility Database

Professional engineering staff with the State Energy Office maintains a utility 

database that tracks utility usage by state agencies. 30 utility companies provide 

the data across the state. The database is the sole centralized repository for 

information on the State's $13 million building energy expenditures.

Energy Performance Contracting

Public Schools 

Energy Efficiency 

Program

Construction Plan Review

Professional energy engineers within the State Energy office continue to work with 

school districts throughout New Mexico in an effort to improve their facilities' 

energy efficiency. Under an agreement with the State Department of Education 

the construction plans are reviewed to ensure compliance with applicable building 

energy codes. 

Energy Performance Contracting

New Mexico school districts utilize "performance contracts" to implement energy 

efficiency projects in school buildings that are paid from guaranteed energy 

savings. Private-sector energy service companies provide the up-front investment 

and installation of the energy efficient measures 

Commercial and 

Industrial Sector 

Energy Efficiency 

Program

Building America Program

Building Energy Codes/Standards

The State Energy office has participated in several code technical advisory group 

meetings, provided graphical comparisons between old and new code 

requirements, and has been working with the Construction Industries Commission 

(CIC) to upgrade New Mexico's residential and commercial building energy codes. 

Currently Energy Office efforts on codes are being concentrated in the areas of 1) 

codes adoption, and 2) training provided to the building industry designed to help 

insure that structures designed to code will be more energy efficient

Green Zia Environmental Excellence Program

The Green Zia Environmental Excellence program is a voluntary program 

designed to support and assist all New Mexico businesses to achieve 

environmental excellence through continuous improvement and effective energy 

management. The program encourages integration of environmental excellence 

into business operations and management practices through establishment of a 

prevention-based environmental management system. The Governor of New 

Mexico recognizes and presents awards annually to organizations that successfully 

participate in the program. 

Rebuild America/Rebuild NM Program 

The program provides information, training and technical assistance to private 

commercial building owners and local government participants in the program. 

Over 59 participants, with over 42.4 million square feet of building space, are 

improving their energy efficiency. Energy audits have identified potential savings 

of more than $750,000 per year. 

Industries of the Future Program 

The US Department of Energy Program seeks to broaden the impact of 

investments in advanced industrial technologies and practices for energy efficiency 
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Policy Program Title Program Description

and waste reduction through implementation of nationally developed IOF vision 

and technology roadmaps. New Mexico is currently conducting inventories of 

energy use and pollution prevention within the mining and forest industries in the 

state and will be working on a sustainability plan.

Residential Sector 

Energy Efficiency 

Program

Wind Powering America Program

Weatherization Assistance Program

The New Mexico Mortgage Finance Authority through an Agreement with the 

State of New Mexico administers New Mexico's Weatherization Assistance 

Program (federal and private funds), low-income, weatherization program The 

primary mission of this program is to reduce the energy required for space heating 

and cooling for income eligible households applying for assistance through the 

process sub-grantees, statewide. This program receives its primary funding from 

the U.S. Department of Energy and the U.S. Department of Health and Human 

Services. The program also leverages additional funds through partnership with 

utilities, and other federal and state housing programs. Many aspects of the 

Residential Training and Technical Assistance Programs are now incorporated into 

the training of Weatherization sub-grantees, which assures that savings are 

maximized.

Federal Energy 

Management 

program

The purpose of this program is to advance energy efficiency, water conservation, 

the use of distributed and renewable energy, and improving utility management 

decisions at federal sites. Currently the State Energy office is working with the 

Institute of American Indian Arts (IAIA) to develop and implement a Sustainable 

Energy Initiative on the IAIA campus. 

(b) Summary of the anticipated contribution toward the Renewable Energy Goals for 2005 and 

2015. Pursuant to 40 CFR 51.309(d)(8)(i), Appendix G of this implementation plan summarizes 

the State of New Mexico's anticipated contribution toward meeting the GCVTC renewable 

energy goals for 2005 and 2015. See also section (g) below. 

(c) Incentive programs. Pursuant to 40 CFR 51.309(d)(8)(ii), Table G-6 identifies incentive 

programs in the State of New Mexico that reward efforts to go beyond compliance and/or 

achieve early compliance with air pollution related requirements. 

Table G-6: New Mexico Incentive Program

Green Zia 

Environmental 

Excellence Program

The Green Zia Environmental Excellence program is a voluntary program 

designed to support and assist all New Mexico businesses to achieve 

environmental excellence through continuous improvement and effective energy 

management. The program encourages integration of environmental excellence 

into business operations and management practices through establishment of a 

prevention-based environmental management system. The Governor of New 

Mexico recognizes and presents awards annually to organizations that 

successfully participate in the program. 
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(d) Programs that preserve and expand energy conservation efforts. Pursuant to 40 CFR 

51.309(d)(8)(iii), Tables G-1 through G-5 identify programs in New Mexico that preserve and 

expand energy conservation efforts. 

(e) Potential for renewable energy. Pursuant to 40 CFR 51.309(d)(8)(iv), the State of New 

Mexico has made an assessment of areas where there is the potential for renewable energy to 

supply power in a cost-effective manner. This assessment is described in Appendix G of this 

implementation plan. 

(f) Projections of renewable energy goals, energy efficiency and pollution prevention activities. 

Pursuant to 40 CFR 51.309(d)(8)(v), regional projections have been made by the WRAP of the 

short and long term emissions reductions, visibility improvements, cost savings, and secondary 

benefits associated with "renewable energy goals, energy efficiency and pollution prevention 

activities." Projections of visibility improvements for the 16 Class I areas on the Colorado 

Plateau are provided in Table A-1. These projections include the combined effects of all 

measures in this SIP, including air pollution prevention programs. Although emission reductions 

and visibility improvements from air pollution prevention programs are expected at some level, 

they were not explicitly calculated because the resolution of the regional air quality modeling 

system is not currently sufficient to show any significant visibility changes resulting from the 

marginal nitrogen oxide emission reductions described above for air pollution prevention 

programs. 

(g) Demonstration of progress in achieving the GCVTC renewable energy goal. Pursuant to 40 

CFR 51.309(d)(8)(vi), Appendix G and Tables G-1 through G-5 list the programs relied upon by 

the State of New Mexico to demonstrate progress in achieving the renewable energy goal of the 

GCVTC that renewable energy comprise 10 percent of the regional power needs by 2005 and 20 

percent by 2015. Appendix G of this implementation plan provides additional information on 

how these programs are meeting the 10/20 goals, and a discussion of a regional modeling 

analysis showing progress in meeting these goals. Included in Appendix G is documentation of 

the potential for renewable energy resources, the percentage of renewable energy associated with 

new power generation projects implemented or planned, and the renewable energy generation 

capacity and production in use and planned in the state. 

(h) Future progress reports. Pursuant to 40 CFR 51.309(d)(8)(vi), the State of New Mexico 

shall submit progress reports in 2008, 2013, and 2018, describing the state's contribution toward 

meeting the GCVTC renewable energy goals. This description shall be consistent with section 

(g) above. To the extent that it is not feasible for the state to meet its contribution to these goals, 

the state shall identify what measures were implemented to achieve its contribution, and explain 

why meeting its contribution was not feasible. 
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H. Implementation of Additional Recommendations. 

(a) Evaluation of additional Grand Canyon Visibility Transport Commission recommendations. 

Pursuant to 40 CFR 51.309(d)(9), the State of New Mexico has evaluated the "additional" 

recommendations of the Grand Canyon Visibility Transport Commission, to determine if any of 

these recommendations can be practicably included in this implementation plan. The State of 

New Mexico reviewed the Commissions' 1996 report Recommendations for Improving Western 

Vistas to identify those recommendations that were not incorporated into Section 309 of the 

Regional Haze Rule.

(b) Implementation of Additional Recommendations. Based on the evaluation made by the State 

of New Mexico, no additional recommendations were identified that the state believes are 

practical or necessary for inclusion in this implementation plan at this time. 

(c) Future progress reports. Pursuant to 40 CFR 51.309(d)(9), the State of New Mexico shall 

prepare a progress report in 2008, 2013, and 2018 that contains an evaluation in accordance with 

Section (a) and (b) above. Copies of this report shall be provided to EPA and made available to 

the general public. 
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I. Periodic implementation plan revisions. 

(a) Periodic Progress Reports for demonstrating Reasonable Progress. Pursuant to 40 CFR 

51.309(d)(10)(i), the State of New Mexico shall submit to EPA, as a SIP revision, periodic 

progress reports for the years 2008, 2013, and 2018 for the purpose of demonstrating reasonable 

progress in Class I areas within New Mexico, and Class I areas outside New Mexico that are 

affected by emissions from New Mexico. This demonstration may be conducted by the WRAP, 

with assistance from New Mexico, and shall address the elements listed under 40 CFR 

51.309(d)(10)(i)(A) through (G), as summarized below: 

1. Implementation status of 2003 SIP measures; 

2. Summary of emissions reductions;

3. Assessment of most/least impaired days;

4. Analysis of emission reductions by pollutant; 

5. Significant changes in anthropogenic emissions;

6. Assessment of 2003 SIP sufficiency; and

7. Assessment of visibility monitoring strategy.

(b) Actions to be taken concurrent with Periodic Progress Reports. Pursuant to 40 CFR 

51.309(d)(10)(ii), the State of New Mexico shall take one of the following actions based upon 

information contained in each periodic progress report:

1. Provide a negative declaration statement to EPA saying that no implementation plan 

revision is needed if reasonable progress is being made, in accordance with section (a) 

above; 

2. If the state finds that the implementation plan is inadequate to ensure reasonable progress 

due to emissions from outside the state, New Mexico shall notify EPA and the other 

contributing state(s), and initiate efforts through a regional planning process to address 

the emissions in question. The State of New Mexico shall identify in the next progress 

report the outcome of this regional planning effort, including any additional strategies 

that were developed to address the plan's deficiencies; 

3. If the state finds that the implementation plan is inadequate to ensure reasonable progress 

due to emissions from another country, New Mexico shall notify EPA and provide 

information on the impairment being caused by these emissions; or 

4. If the state finds that the implementation plan is inadequate to ensure reasonable progress 

due to emissions from within New Mexico, New Mexico shall develop additional 

strategies to address the plan deficiencies and revise the implementation plan no later 

than one year from the date that the progress report was due. 
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J. State planning and interstate coordination. 

(a) Participation in Regional Planning and Coordination. Pursuant to 40 CFR 51.309(d)(11), 

the State of New Mexico has participated in regional planning and coordination with other states 

in developing its emission reduction strategies under 40 CFR 51.309, related to protecting the 16 

Class I areas of the Colorado Plateau. This participation was through the Western Regional Air 

Partnership. The State of New Mexico has not participated in any regional planning and/or 

interstate coordination outside our participation with the Western Regional Air Partnership. 

Should this change, Appendix J-1 of this implementation plan will describe any participation in 

regional planning and interstate coordination outside of work with the Western Regional Air 

Partnership. 

(b) Tribal Implementation. Pursuant to 40 CFR 51.309(d)(12), and in accordance with the 

Tribal Authority Rule, no Tribes whose lands are surrounded by the State of New Mexico have 

elected to develop a regional haze TIP at this time to assure reasonable progress in the 16 Class I 

areas of the Colorado Plateau. Should this change, Appendix J-2 of this implementation plan will 

describe the participating Tribes and the emission management strategies in more detail.

(c) Federal Implementation. Pursuant to 40 CFR 49.11(a), the Administrator under sections 

301(a) and 301(d)(4) shall promulgate without unreasonable delay such federal implementation 

provisions as are necessary or appropriate to protect air quality, consistent with the provisions of 

304(a) and 301(d)(4), if a Tribe does not submit a TIP meeting the completeness criteria of 40 

CFR part 51, Appendix V, or does not receive EPA approval of a submitted TIP. 

 
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K. Geographic Enhancement. 

[The purposes of this section of New Mexico's Phase II visibility State Implementation Plan 

(SIP) are as follows: 

 Address the authority and obligation that EPA has for reasonably attributable visibility 

impairment (RAVI) attribution and Best Available Retrofit Technology (BART) 

determination for a source or group of sources, if and when a Federal Land Manager(s) 

certifies RAVI for one or more mandatory federal Class I areas in New Mexico;

 Clarify why the authority and obligation held by EPA are currently not held by the New 

Mexico Environment Department;

 Explain how the authority and obligation held by EPA may be transferred to the New Mexico 

Environment Department. 

The authority and obligation held by EPA for RAVI attributions and BART determinations in 

New Mexico derive from the Federal Implementation Plans (FIPs) that are in place for New 

Mexico for Phase I of the federal visibility protection regulations (40 CFR 51.300 through 40 

CFR 51.307). FIPs are now in place for New Mexico because a SIP was not developed by New 

Mexico and submitted to EPA in accordance with a May 6, 1985 deadline specified in an April 

20, 1984 court-approved settlement between EPA and Environmental Defense Fund (now called 

Environmental Defense). The court-approved settlement divided Phase I of the federal visibility 

protection regulations into two parts (Phase I, Part I and Phase I, Part II) and outlined a schedule 

for EPA to put into place FIPs for New Mexico for each of these two parts. 

New Mexico developed and submitted to EPA a Phase I, Part I visibility SIP in 1986 and a Phase 

I, Part II visibility SIP in 1992. Although submitted after the deadline, the two SIPs were 

intended to replace the two FIPs, and in doing so, provide to New Mexico the authority and 

obligation to undertake RAVI attributions and related BART determinations if and when a 

Federal Land Manager(s) certifies RAVI for one or more mandatory federal Class I area in New 

Mexico. However, EPA never approved New Mexico's Phase I visibility SIPs. Compounding 

the issue is the fact that neither of New Mexico's Phase I visibility SIPs contain language 

explicitly providing to New Mexico the authority and obligation for RAVI attributions and 

BART determinations. 

Geographic enhancement, an optional component of New Mexico's Phase II visibility SIP, is 

meant to address the intersection between a state's existing reasonably attributable BART 

provision and regional haze BART, which may be met through an emissions trading program 

such as the milestone/backstop market trading program. RAVI is different from regional haze, in 

that it addresses visibility impairment in a Class I area that is reasonably attributable to a single 

source or a small group of sources in relatively close proximity to the Class I area. The 

geographic enhancement approach allows a state to use the efficiencies and reduced cost 

provided by the market trading program in the Annex to accommodate situations where RAVI 

needs to be addressed. Since New Mexico's Phase I visibility SIPs did not provide to New 

Mexico authority or obligation to perform RAVI attributions or related BART determinations, 

EPA continues to hold the authority and obligation through the FIPs that are in place for New 
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Mexico's Phase I visibility protection. Accordingly, this Phase II visibility SIP for New Mexico 

does not include geographic enhancement. The authority and obligation needed by New Mexico 

to perform RAVI attributions and related BART determinations, and the geographic 

enhancement that may be necessary with such authority, may be provided to New Mexico by a 

SIP revision completed at a future date.] 

1. Geographic Enhancements Program

The requirements for geographic enhancement are discussed on page 35757 in the Preamble to 

the 1999 regional haze rule. Geographic enhancement is a voluntary approach for addressing 

reasonably attributable visibility impairment (RAVI) for stationary sources, under the provisions 

of 40 CFR 51.302(c). RAVI is different from regional haze in that it addresses "hot spots" or 

situations where visibility impairment in a Class I area is reasonably attributable to a single 

source or small group of sources in relatively close proximity to the Class I area. The geographic 

enhancement approach would allow states or tribes to use the efficiencies and reduced cost 

provided by the market trading program to accommodate situations where RAVI needs to be 

addressed. Additional information is contained in the WESTAR report, Recommendations for 

Making Attribution Determinations in the Context of Reasonably Attributable BART.

Procedure for addressing Reasonably Attributable Visibility Impairment under the Regional 

Haze Rule. If the Federal Land Manager certifies impairment, the State of New Mexico will 

fulfill its obligations to determine attribution and if necessary determine BART for the applicable 

source or group of sources in accordance with New Mexico's SIP for reasonably attributable 

visibility protection approved by EPA through a notice in the Federal Register on January 27, 

2006. The New Mexico SIP for reasonably attributable visibility became effective on March 28, 

2006.

2. Applicable WRAP Reports and Documents

See WESTAR report Recommendations for Making Attribution Determinations in the Context 

of Reasonably Attributable BART (Appendix K). New Mexico commits to following the 

recommendations outlined in this report in making RAVI determinations.
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L. Reasonable Progress for Additional Class I Areas. 

(a) Declaration for other Class I areas. Pursuant to 40 CFR 51.309(g)(1), the State of New 

Mexico declares it will follow Section 309(g)(2) in developing an implementation plan for the 

eight Class I areas not on the Colorado Plateau in the State of New Mexico, to be submitted by 

December 31, 2008. These Class I areas are as follows:

Bandelier National Monument 

 Bosque del Apache National Wildlife Refuge 

Carlsbad Caverns National Park

Gila Wilderness Area

Pecos Wilderness Area

Salt Creek Wilderness Area

Wheeler Peak Wilderness Area

White Mountain Wilderness Area
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M. Demonstration That the SO2 Milestones Provide Greater Reasonable Progress Than 

BART

A. Background

In 1996 the Grand Canyon Visibility Transport Commission (GCVTC) submitted 

recommendations to EPA to improve visibility in the 16 Class I Areas on the Colorado Plateau. 

The GCVTC concluded that a broad-based approach that addressed multiple pollutants and 

source categories was necessary to reduce regional haze. The report recommended a series of 

strategies to address stationary sources, mobile sources, fire, pollution prevention, fugitive dust, 

and clean air corridors. 

On July 1, 1999 the Environmental Protection Agency (EPA) published regulations to address 

regional haze visibility impairment. The regulations required States to address Best Available 

Retrofit Technology (BART) requirements for regional haze visibility impairment, and allowed 

nine western states to develop plans that were based on the GCVTC recommendations for 

stationary sources in lieu of BART. 

In 2000, the Western Regional Air Partnership (WRAP) submitted an Annex to the GCVTC 

recommendations that provided more details regarding the regional SO2 milestones and backstop 

trading program that had been recommended in the GCVTC Report, and included a 

demonstration that the milestones achieved greater reasonable progress than would have been 

achieved by the application of BART in the region. The Annex was approved by EPA in 2003, 

but this approval was later vacated by the DC Circuit Court of Appeals in 2005 due to problems 

with the methodology that was required in the regional haze rule for demonstrating greater 

reasonable progress than BART.1 

On July 6, 2005 EPA revised the regional haze rule in response to the judicial challenges to the 

BART requirements. On October 13, 2006 EPA published additional revisions to address 

alternatives to source-specific BART determinations.

Five western states (Arizona, New Mexico, Oregon, Utah, and Wyoming) and the City of 

Albuquerque had submitted State Implementation Plans (SIPs) in 2003 under 40 CFR §51.309. 

Three of those states (New Mexico, Utah, and Wyoming) and the City of Albuquerque plan to 

update their SIPs to include new milestones that are based on more recent emission inventories 

as well as the revised BART requirements in the regional haze rule. Arizona and Oregon are no 

longer participating in the program. This demonstration shows that the SO2 milestones will 

achieve greater reasonable progress than would have been achieved from the installation and 

operation of BART at all sources subject to BART in the participating states in accordance with 

the revised regional haze rule.

 

1 Center for Energy and Economic Development v. EPA, February 18, 2005; American Corn Growers 

Association v. EPA, May 24, 2002.
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B. RH Rule Requirements

40 CFR 51.309(d)(4) states, “The milestones must be shown to provide for greater reasonable 

progress than would be achieved by application of BART pursuant to §51.308(e)(2).”

40 CFR 51.308(e)

...(2) A State may opt to implement or require participation in an emissions trading program or other 

alternative measure rather than to require sources subject to BART to install, operate, and maintain BART. 

Such an emissions trading program or other alternative measure must achieve greater reasonable progress 

than would be achieved through the installation and operation of BART. For all such emission trading 

programs or other alternative measures, the State must submit an implementation plan containing the 

following plan elements and include documentation for all required analyses:

(i) A demonstration that the emissions trading program or other alternative measure will 

achieve greater reasonable progress than would have resulted from the installation and 

operation of BART at all sources subject to BART in the State and covered by the alternative 

program. This demonstration must be based on the following:

(A) A list of all BART-eligible sources within the State.

(B) A list of all BART-eligible sources and all BART source categories covered by the 

alternative program. The State is not required to include every BART source category or 

every BART-eligible source within a BART source category in an alternative program, 

but each BART-eligible source in the State must be subject to the requirements of the 

alternative program, have a federally enforceable emission limitation determined by the 

State and approved by EPA as meeting BART in accordance with section 302(c) or 

paragraph (e)(1) of this section, or otherwise addressed under paragraphs (e)(1) or 

(e)(4)of this section.

(C) An analysis of the best system of continuous emission control technology available 

and associated emission reductions achievable for each source within the State subject to 

BART and covered by the alternative program. This analysis must be conducted by 

making a determination of BART for each source subject to BART and covered by the 

alternative program as provided for in paragraph (e)(1) of this section, unless the 

emissions trading program or other alternative measure has been designed to meet a 

requirement other than BART (such as the core requirement to have a long-term strategy 

to achieve the reasonable progress goals established by States). In this case, the State may 

determine the best system of continuous emission control technology and associated 

emission reductions for similar types of sources within a source category based on both 

source-specific and category-wide information, as appropriate.

(D) An analysis of the projected emissions reductions achievable through the trading 

program or other alternative measure.

(E) A determination under paragraph (e)(3) of this section or otherwise based on the clear 

weight of evidence that the trading program or other alternative measure achieves greater 

reasonable progress than would be achieved through the installation and operation of 

BART at the covered sources.
NM Regional Haze SIP 84 

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C. Identification of BART-Eligible Sources and Sources Subject to BART.

Establishing BART emission limitations under 40 CFR 51.308(e)(1) is a three step process (70 

FR 39106): 

• States identify sources which meet the definition of BART eligible 

• States determine which BART eligible sources are “subject to BART” 

• For each source subject to BART the State identifies the appropriate control technology. 

 

1. BART-Eligible Sources. 

Pursuant to 40 CFR 51.308(e)(2)(i), States submitting §309 SIPs are required to list all BARTeligible sources covered by the alternative program. BART-eligible sources are identified as 

those sources that fall within one of 26 specific source categories, were built between 1962 and 

1977, and have potential emissions of at least 250 tons per year of any visibility impairing air 

pollutant (40 CFR 51.301). The BART-eligible sources identified by the three §309 States are 

shown in Table M-1.

2. Subject to BART Determination. 

Pursuant to 40 CFR 51.308(e)(2)(i)(B) and (e)(1)(ii), States are required to determine which 

BART-eligible sources are “subject to BART.” BART-eligible sources are subject to BART if 

they emit any air pollutant that may reasonably be anticipated to cause or contribute to any 

impairment of visibility in any mandatory Class I Federal area. §309 States have conducted 

individual source modeling to determine if a BART-eligible source causes or contributes to 

visibility impairment. 

Two of the §309 States (New Mexico and Utah) utilized the technical modeling services of the 

WRAP Regional Modeling Center (RMC). Modeling was performed according to the RMC 

modeling protocols (CALMET/CALPUFF Protocol for BART Exemption Screening Analysis 

for Class I Areas in the Western United States). For the WRAP BART exemption screening 

modeling, the RMC followed the EPA BART Guidelines (EPA, 2005) and the applicable 

CALMET/CALPUFF modeling guidance (e.g., IWAQM, 1998; FLAG, 2000; EPA, 2003c) 

including EPA’s March 16, 2006 memorandum: “Dispersion Coefficients for Regulatory Air 

Quality Modeling in CALPUFF” (Atkinson and Fox, 2006).

The basic assumptions of the WRAP BART CALMET/CALPUFF modeling protocols are as 

follows.

• Three years (2001, 2002 and 2003) were modeled.

• Visibility impacts due to emissions of SO2, NOx and primary PM emissions were 

calculated.

• Visibility was calculated using the original IMPROVE equation and “Annual Average 

Natural Conditions”. 

• The effective range of CALPUFF modeling was set at 300km from the sources.

• According to 40 CFR Part 51, Appendix Y (EPA BART Guidelines; EPA, 2005), a 

BART-eligible source is considered to “contribute” to visibility impairment in a Class I 

area if the modeled 98th percentile change in deciviews is equal to or greater than the 

“contribution threshold.” 
NM Regional Haze SIP 85 

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• The threshold for visibility impact, for a single source, was a 0.5 deciview change or 

more to “contribute” to visibility impairment. This threshold is consistent with the EPA 

BART Guidelines (EPA 2005) that states, “As a general matter, any threshold that you 

use for determining whether a source ‘contributes’ to visibility impairment should not be 

higher than 0.5 deciviews.” This threshold is also consistent with long-standing visibility 

modeling practices. States have the discretion to set a lower threshold, but the three 

participating states have not determined that a lower threshold is needed or justified. 

The State of Wyoming performed modeling in-house that was also based on EPA BART 

Guidelines and the applicable CALMET/CALPUFF guidelines. The basic assumptions were the 

same as used in the RMC modeling with the following exception: meteorological data for 1995, 

1996, and 2001 that were prepared for a previous modeling analysis were used for the southwest 

Wyoming modeling domain. Wyoming’s BART Air Modeling Protocol, September 2006, is 

posted at http://deq.state.wy.us/aqd/BART.asp. 

Table M-1. Subject to BART Status for §309 BART-Eligible Sources 

State Plant Name Unit BART 

Eligible

Subject 

to BART

Modeling 

Entity

BART 

Category

NM Amoco Empire Abo SRU Only Y N WRAP 15

NM SWPS Cunningham Station (Xcel 

Energy)

One Unit Y N WRAP 01

NM Duke Energy Artesia Gas Plant SRU Only Y N WRAP 15

NM Duke Energy Linam Ranch Gas Plant SRU Only Y N WRAP 15

NM Dynegy Saunders SRU Only Y N WRAP 15

NM Giant Refining San Juan Refinery Unit #1 FCCP ESP 

Stack

Y N WRAP 11

NM Giant Refining, Ciniza Refinery 4 B&W CO boiler Y N WRAP 11

NM SWPS Maddox Station (Xcel Energy) One Unit Y N WRAP 01

NM Marathon Indian Basin Gas Plant SRU Only Y N WRAP 15

NM PNM, San Juan Units 1-4 Y Y WRAP 01

NM Rio Grande Station One Unit Y N WRAP 01

NM Western Gas Resources San Juan 

River Gas Plant

SRU Only Y N WRAP 15

UT PACIFICORP – Hunter Power Plant Units 1-2 Y Y WRAP 01

UT PACIFICORP – Huntington Power 

Plant

Units 1-2 Y Y WRAP 01

WY BASIN ELECTRIC POWER COOP –

LARAMIE RIVER

Units 1-3 Y Y WY DEQ 01

WY BLACK HILLS POWER & LIGHT = 

NEIL SIMPSON 1

Unit 1 Y N WY DEQ 01

WY Dyno Nobel (formerly Coastal 

Chemical)

9 Units Y N WY DEQ 10

WY FMC CORP – GREEN RIVER SODA 

ASH PLANT

3 Units Y Y WY DEQ 22

WY FMC WYOMING CORP –

GRANGER SODA ASH PLANT

2 Units Y N WY DEQ 22

WY GENERAL CHEMICAL – GREEN 

RIVER SODA ASH PLANT

2 Units Y Y WY DEQ 22

WY P4 PRODUCTION – ROCK 1 Unit Y N WY DEQ 22
NM Regional Haze SIP 86 

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State Plant Name Unit BART 

Eligible

Subject 

to BART

Modeling 

Entity

BART 

Category

SPRINGS COKING PLANT

WY PACIFICORP – DAVE JOHNSTON Units 3-4 Y Y WY DEQ 01

WY PACIFICORP – JIM BRIDGER Units 1-4 Y Y WY DEQ 01

WY PACIFICORP – NAUGHTON Units 1-3 Y Y WY DEQ 01

WY PACIFICORP –WYODAK Unit 1 (335 MW) Y Y WY DEQ 01

WY SINCLAIR OIL CORP-SINCLAIR 

REFINERY

16 units Y N WY DEQ 11

WY SINCLAIR REFINERY – CASPER 1 unit Y N WY DEQ 11

D. Baseline Inventory for 2018

The Stationary Sources Joint Forum of the WRAP coordinated the development of a baseline 

inventory for 2018 that was used to update the SO2 milestones for the 3-state region. The 

inventory was estimated as described below.

1. Electric Generating Units (EGU’s)

The methodology for projecting existing EGU's into the future involves the following steps:

a) the electricity production (MW's) for each individual unit at a plant was determined 

from the Energy Information Administration [EIA] (data available for 2002-05)

b) the electricity generation design maximum capacity (MW's) was determined for each 

individual unit from EIA data

c) an operating Capacity Factor was determined by dividing the year specific production 

by the design maximum capacity of the each individual plant unit

d) all individual units were assumed to be operating at 85% capacity in 2018 (unless they 

were already operating above this level in 2002)

e) the Growth Ratio necessary to achieve 85% capacity was determined by dividing 0.85 

by the Capacity Factor for each individual plant unit (averaged over four years)

f) a Current Year Emission Factor (lb SO2/MM-Btu) was calculated for the latest year of 

available EIA data (2006), using the actual reported emissions (tons SO2) for each 

individual plant unit divided by the actual reported annual heat generation (MM Btu)

g) the 2018 Emission Factor was assumed to be the same as the current emission factor, 

except for a few sources that had a new permitted emission rate.

h) the 2018 Emission Rate (tons SO2) was calculated by multiplying current year 

emissions by the ratio of the 2018 to current year Emission Factors

i) the Adjusted 2018 Emission Rate (tons SO2) was "grown" to 85% capacity by 

multiplying the 2018 Emission Rate by the Growth Ratio from Step 5

(emissions from units already operating at or higher than the 85% capacity in the 

2002 data year, were not grown, but accepted at face value).

2. Permitted/Future EGU’s

The PRP 18b inventory is documented in the ERG Final Technical Memorandum dated October 

16, 2009. The Memorandum projects the need for 61.99 billion kWh of future coal-fired 

electricity generation between 2002 and 2018. Of this total, 36.37 billion kWh will be met by 

increased utilization of existing plants, and the addition of new plants that are already under 

construction. The remaining 25.62 billion kWh will be met by new coal plants in the WRAP 
NM Regional Haze SIP 87 

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region. The §309 States estimate that 25% of that total will be constructed in the 3-state region, 

with an emission estimate of 2,600 tons SO2 by 2018. 

a) Growth estimates in 2008 SIPs. 

The previous SO2 milestones were finalized by the §309 States in the Spring of 2008 

and were adopted into the SIPs for Albuquerque, Utah, and Wyoming later that year. 

The milestones included a new source growth estimate of 20,000 tons SO2 for 

utilities. This new source growth estimate was drawn from the PRP18a inventory that 

relied on the 2007 EIA projections. As part of the technical demonstration for the 

SIPs, the §309 States identified projects that were under construction or had been 

permitted that would have consumed about 10,000 tons of the new source set-aside.

b) Changes in Underlying Assumptions. 

During the last two years there have been significant changes in the EIA projections 

for future growth of coal-fired electricity generation. The PRP18b inventory that is 

documented in the ERG Final Technical Memorandum dated October 16, 2009 has 

scaled back the projections of growth of coal-fired utilities. EPA has indicated that 

this more recent information calls into question the estimates for future growth in 

coal-fired generation in the current milestones. In addition, the State of Arizona has 

elected to develop a SIP under Section 308 of the Regional Haze rule, further 

reducing the new source set-aside.

c) Updated New Source Growth Estimates. 

The §309 States have reviewed the new Memorandum and have determined that the 

new source growth estimate should be reduced from 20,000 tons SO2 to 6,600 tons 

SO2. Of this total, approximately 4,000 tons SO2 can be attributed to new units in 

Wyoming that are currently operating, or have commenced construction (Wygen 

Units II and III, Dry Fork Station, and Two Elk Unit 1). This leaves a remaining 

estimate of new source growth that has not been attributed to a specific plant of 2,600 

tons SO2. 

This estimate is consistent with the 2009 ERG Final Technical Memorandum. As 

outlined in Table 3 of that Memorandum (summarized below) an additional 61.99 

billion kWh of coal-fired electricity generation will be needed between 2002 and 

2018. 
NM Regional Haze SIP 88 

12/31/03; 12/20/10 Rev.; 05/02/11 Rev.

Future Coal-Fired Electricity Generation (billion kWh)

258.7 2002 Electricity Generation

320.69 2018 Electricity Generation

61.99 Needed Generation

Future Coal-Fired Electricity Generation from existing sources, and those under 

construction (billion kWh)

16.6 Unused capacity at existing 2002 Facilities

5.34 Capacity at post-2002 facilities

14.43 Estimated generation capacity of the 6 EGUs under construction

36.37 Total

25.62 New Source Growth needed in WRAP Region (billion kWh)

As shown above, 36.37 billion kWh can be met by the combination of unused 

capacity from existing sources plus new sources that are in operation or under 

construction (including the three plants in Wyoming that are described above). This 

leaves a remaining 25.62 billion kWh that would be met by new coal plants in the 

region.

The need for new source growth beyond what is already under construction is 

supported by estimates of future electricity demand in the region. For example, the 

Integrated Resource Plan submitted by PacifiCorp to the Utah Public Service 

Commission in May 2009 estimates a capacity deficit of 3,520 MW by 2018. The 

IRP meets that deficit through a combination of new natural gas-fired plants, 

renewable resources, and demand side management and does not include plans for 

new coal-fired generation. This is a change from the 2006 IRP (submitted in 2007), 

that included plans for new coal generation in Utah (340 MW) and Wyoming (527 

MW) by 2018. However, the 2008 IRP also increased the estimated front office 

transactions (power purchased on the open market), from 249 MW in the 2006 IRP to 

800 MW in the 2008 IRP for the year 2018. Because future demand exceeds existing 

capacity as shown in Table 3 of the ERG Final Technical Memorandum, it is 

reasonable to assume that new plants (including potential merchant plants built by 

other entities) will be needed to meet this demand for purchased power in 2018. 

Table 4 in the Final Technical Memorandum identifies 8,880 MW that are being 

permitted in the region. The Memorandum states, “However, if 39% of the new coalfired EGU plant capacity currently in the permitting process is brought on-line, then 

the 2008 coal-fired EIA projection for 2018 will be met.” (see page 7). Therefore, the 

estimate of future coal-fired EGUs in the 12-state region is 3,463 MW. 

Approximately 25% of the MWs listed in Table 4 as “being permitted” are located in 

Utah and Wyoming, therefore it is reasonable to estimate that 900 MWs (conservative 

emission estimate of 2,600 tons SO2) of future coal-fired EGUs be attributed to the 

§309 States. 
NM Regional Haze SIP 89 

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3. Non-EGU's

The Methodology for projecting emissions from "Other Industrial Sources" is described in E.H. 

Pechan's October 2006 Report, 2018 SO2 Emissions Evaluation for Non-Utility Sources- Final. 

The report is posted online at:

http://www.wrapair.org/forums/ssjf/documents/eictts/projections.html.

a) The SO2 emissions for 19 Natural Gas Processing Plants were updated by Environ in 

April 2007, with additional research into future O&G Operations. The September 

2007 Final report with results of that update is posted at:

http://www.wrapair.org/forums/ssjf/documents/eictts/oilgas.html.

b) The 2005 SO2 Milestone Report had some sources which were not picked up in the 

Pechan report. In those cases, the 2005 emissions were used as a placeholder for the 

2018 emission values.

c) The projections do not specifically break out emissions from existing sources vs. new 

sources. For purposes of establishing a new source set-aside, 2006 emissions were 

assumed to be the baseline emissions for existing sources, and the projected increase 

in emissions between 2006 and 2018 is attributed to new source growth.

There have been steady SO2 emission reductions from the non-utility sector since 1990. Several 

major sources were shut down, including two copper smelters (BHP San Manuel and Phelps 

Dodge Chino: 69,491 tons SO2 in 1990) and a steel mill (Geneva Steel: 8,473 tons SO2 in 

1990). Kennecott Utah Copper reduced SO2 emissions by 25,000 tons SO2 during the mid1990s. During this same time period, oil and gas production increased substantially in all three 

states requiring upgrades to processing plants and other facilities to address potential air quality 

problems. These upgrades have largely been completed, and it is anticipated that future 

emissions will reflect growing demand for natural gas in the Western US. As can be seen in 

Figure 1, emissions have leveled off in recent years and are likely to increase as the US emerges 

from a major recession in coming years. The 2006 EH Pechan report describes in detail the 

methodology that was used to project future emissions for each source category. 
NM Regional Haze SIP 90 

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Nonutility SO2 Emission Trends 2000-2008

0

20000

40000

60000

80000

100000

120000

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Nonutility

Figure 1. Non-utility Emission Trends

Table M-2 summarizes the projected 2018 Baseline SO2 emissions for the 3-State region.

Table M-2. 2018 Baseline

Projected 2018 SO2

Emissions

Baseline

Utility 128,409

Non-Utility 49,961

New Source Growth Utility 6,600

New Source Growth Non-Utility 5,686

Total 2018 Baseline 190,656

E. Estimated Emission Reductions Due to BART

The SO2 milestones and backstop trading program were designed primarily to achieve reasonable 

progress towards meeting the long-term visibility goal. As outlined in the regional haze rule, in 

cases where the an alternative program has been designed to meet requirements other than 

BART, States are not required to make BART determinations under 40 CFR 51.308(e) and may 
NM Regional Haze SIP 91 

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use simplifying assumptions in establishing a BART benchmark based on an analyisis of what 

BART is likely to be for similar types of sources within a source category. Emission estimates 

for 2018, assuming the application of BART for SO2 on all subject-to-BART sources in the three 

states, were prepared and are compiled in a spreadsheet named “8-11-10_milestone.xls” (see 

technical support documentation). The 2018 estimates for these sources are estimates of actual 

emissions and therefore reflect greater emission reductions than would be enforceable in a caseby-case BART permit. The methodology that was used to estimate these emission reductions is 

described below.

1. Utilities - Presumptive BART. 

All utilities that were determined to be subject to BART were assumed to be operating at the 

presumptive emission rate established in 40 CFR Part 51, Appendix Y (0.15 lb/MMBtu). Actual 

emissions at this presumptive emission rate were estimated for 2018.

2. Other sources. 

The SO2 milestones were primarily designed to achieve reasonable progress for all sources of 

SO2 in the 3-state region and therefore the regional haze rule allows States to use simplifying 

assumptions in establishing the BART benchmark. EPA has not established presumptive 

emission rates for nonutilities, therefore another approach was needed to estimate emission 

reductions from four boilers located at 2 trona facilities in SW Wyoming. . Recent pollution 

control projects achieved a 63% reduction in SO2 from two of the boilers, and represent 

reasonably stringent controls, considering the age and purpose of the facility. Therefore, the 

emission rate achieved by these projects is used as the BART benchmark for the four boilers. 

I. General Chemical Soda Ash Partners, Green River Plant

C Boiler

Constructed in 1/74

Fuel Analysis for coal: 262,800 tons/year; 534 x 10e6 BTU/hr site rated capacity

Emission limit for SO2 1.2 lb/MMBtu; 640.8 lb/hr; 2806.7 TPY

D Boiler

Constructed in 1/75

Fuel Analysis for coal: 388,000 tons/year; 880 x 10e6BTU/hr site rated capacity

Emission limit for SO2 1.2 lb/MMBtu; 1056.0 lb/hr; 4625.3 TPY

II. FMC Wyoming Corporation Westvaco Facility

NS-1A

Constructed in 1975

Modified 8/2007 (New chevron mist eliminators installed in venturi scrubber)

Fuel Analysis coal: 380,888 tons/year; 887 x 10e6 BTU/hr site rated capacity

Emission limit for SO2 0.54 lb/MMBtu; 
NM Regional Haze SIP 92 

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NS-1B

Constructed in 1975

Modified 7/2008 (New chevron mist eliminators installed in venturi scrubber)

Fuel Analysis coal: 380,888 tons/year; 887 x 10e6 BTU/hr site rated capacity

Emission limit for SO2 0.54 lb/MMBtu

All four boilers were originally constructed in SW Wyoming for purposes of processing trona in 

the mid 1970’s. As process units, these four boilers are subject to greater load swings than would 

be experienced at electric generating units which typically come up to full operating levels and 

stay there. All four boilers were at one time operating under emission limits of 1.2 lb/MMBtu. 

All four boilers are roughly the same size with site rated capacities between 880 MMBtu/hr and 

887 MMBtu/hr except for the oldest boiler, C Boiler at General Chemical at Green River rated at 

534 MMBtu/hr. All four boilers burn primarily coal with oil and gas used as start up fuels. All 

four units have been participating in the SO2 Backstop Trading Program, reporting inventories 

annually as required by Wyoming Air Quality Standards and Regulations. 

Two of the four units, NS1A and NS1B operated by FMC, sought early SO2 reductions in 2007 

and 2008 respectively as participants in the 309 program. These two units reduced SO2

emissions by 55 percent or 5126 tons collectively from both units. New chevron mist 

eliminators were installed on venturi scrubbers to accomplish this reduction. Since that time, 

FMC has reviewed additional reductions resulting in a total reduction from the 2018 baseline of 

5827 tons or an additional 701 tons. Total reduction from the 1.2 lb/MMBtu emission rate is a 

63 percent removal rate. The State of Wyoming has reviewed these additional reductions and has 

determined that they represent reasonably stringent controls, considering the age and purpose of 

the facility.

In a similar fashion, the State has reviewed potential SO2 reductions at the General Chemical 

facility at Green River and had concluded that a 63 percent removal rate is also appropriate for 

the two boilers located at that facility. As was mentioned above, these facilities are similar in 

age, and purpose. General Chemical boilers C and D are currently permitted at 7,432 tons of 

SO2 operating at 1.2 lb/MMBtu. The State would expect that reasonably stringent controls at 

this facility would result in a similar 63 percent reduction from the same starting point of 1.2 

lb/MMBtu. Reviewing reductions from the 2018 milestone baseline, the General Chemical 

boilers would be looking at reducing emissions by 2,669 tons. 

While the 2018 milestone baseline level is not the same for the two companies, the state has 

determined that equitable treatment of like facilities would require similar reductions from the 

two companies prior to the 309 program. Both companies would be reducing emissions from a 

starting point of 1.2 lb/MMBtu down to 0.45 lb/MMBtu. In the case of FMC, who made early 

reductions in the program, an additional 701 ton reduction is expected to be achieved. In the 

case of General Chemical, 2,669 tons will be achieved. The total reduction from both facilities 

has been estimated at 3,370 tons. The State has determined that these are reasonably stringent 

controls and the resulting emissions would serve as an adequate BART benchmark.

 
NM Regional Haze SIP 93 

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3. Summary.

The estimated emission reductions due to the application of BART in the §309 States are 

summarized in Table M-3.

Table M-3. Emission Reduction due to BART

2018 baseline SO2 2018 SO2 with BART Emission Reduction 

due to BART

Utilities 128,409 82,972 45,437

Non-Utilities 49,961 46,661 3,370

Total 48,807

F. 2018 BART Benchmark

2018 Baseline 190,656

Estimated BART Reductions -48,807

Total 141,849

G. Milestones Provide Greater Reasonable Progress than BART

The Regional SO2 milestone of 141,849 equals the BART benchmark, but provides greater 

reasonable progress than BART for the reasons outlined below.

1. Early Reductions.

The GCVTC recommended that the market trading program "contain specific provisions to 

encourage and reward early emission reductions, including reductions achieved before 2000."2 

The GCVTC committed to achieve a 13% reduction in SO2 emissions from stationary sources by 

the year 2000. The GCVTC also recognized that there was a good possibility that actual 

emission reductions would be greater than this 13% goal. A general plan was derived to give 

some early reductions credit to the region and some to the environment. The emission reductions 

that were greater than 13% were to be split, with 1⁄2 going to the environment (through the 

establishment of milestones) and the other 1⁄2 providing headroom.3

Sulfur dioxide emissions decreased by 25% in the 9-state GCVTC region between 1990 and 

2000, and SO2 emissions in the three §309 states 33% in that same time period. 

The regional milestones have been in effect since 2003 when the original five participating states 

submitted regional haze SIPs, as required by section 309 of the regional haze rule. The 2003 SIP 

was designed to provide flexibility so that sources could find the most cost-effective way to 

reduce SO2 emissions, including over-controlling some plants while opting for lower cost 

 2 Recommendations for Improving Western Vistas at 33 (June 1996).

3 Id. at 34.
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controls at other plants. The 2003 SIP was also designed to encourage early reductions by 

providing an extra allocation for sources that made reductions prior to the program trigger year. 

The 2003 SIP influenced the long term planning for sources in the region, and utilities began 

upgrading plants based on the provisions of the SIP years earlier than would have been required 

under a case-by-case BART determination in a §308 SIP. 

Emissions in the 3-state region decreased an additional 31% between 2000 and 2008.4

Figure 2 shows the emission reductions from 1990 baseline emissions in the §309 states that will 

have been achieved by 2018. This total 60% reduction from 1990 emissions is well on the way 

to the GCVTC goal of reducing SO2 emissions by 50% - 70% by the year 2040.

Figure 3 shows the sulfate contribution to visibility at the long-term IMPROVE sites located on 

the Colorado Plateau. As can be seen from these graphs, there has been a steady decrease in the 

visibility impact due to sulfates. The trend is especially apparent on the 20% best days that are 

not affected by the variability of fire emissions in the region.

 4 WRAP 2008 Regional Emissions and Milestone Report, March 31, 2010. 
NM Regional Haze SIP

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95

Figure 2. Emission Trends

§309 SO2 Backstop Cap and Trade Program - 

Emissions, Modeling EI, and Milestone Program Data 

(no tribal sources)

-

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

Tons per year

NM 140,177 79,011 37,918 31,068 31,012 

UT 84,983 37,483 42,183 44,175 35,429 

WY 133,204 122,373 120,991 113,465 96,809 

3-State Total 358,364 238,867 201,092 188,708 200,722 155,940 163,250 141,849 

1990 2000 2002 

(Plan02d)

2006 Milestone 

Report 2008 Milestone 2013 Milestone 2018 (PRP18b) 2018 Milestone
NM Regional Haze SIP 96

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Figure 3. Sulfate Contribution to Light Extinction at Class I Areas on the Colorado Plateau.5 

Series – Aggregation: Best 20%, Worst 20%, Best 20% 2000-2004 Baseline, Worst 20% 2000-2004 Baseline, 

Metadata – Program: IRHR2, Poc: 1, Parameter: ammSO4_bext, Method: RHR Dataset.

 

5 Only those Class I areas on the Colorado Plateau with at least 15 years of data are included in this 

figure.
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NM Regional Haze SIP 98

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NM Regional Haze SIP 99

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2. Additional Sources Included. 

The backstop trading program includes all stationary sources with emissions greater than 100 

tons/year of SO2. The §309 States designed this program as part of an overall strategy to address 

all sources of visibility impairing pollutants, rather than focusing on a subset of stationary 

sources. 

 2006 

Number of Sources Emissions Percentage

Subject to BART 10 121,542 62%

Other Stationary Sources 63 73,038 38%

The inclusion of all major SO2 sources in the program is necessary to create a viable trading 

program, and also serves a broader purpose to ensure that growth in emissions from sources that 

are not subject to BART does not undermine the progress that has been achieved. BART applied 

on a case-by-case basis would not affect these sources, and there would be no limitation on their 

future operations under their existing permit conditions. Because the milestones will cap these 

sources at actual emissions (which are less than current allowable emissions), the overall effect 

of their inclusion is to provide greater reasonable progress than would have been achieved if only 

sources that are subject to BART were included in the program.

3. Cap on New Source Growth. 

When Congress established the visibility program in 1977 it declared as a national goal "the 

prevention of any future, and the remedying of any existing" anthropogenic visibility impairment 

in mandatory class I federal areas.6 BART is an emission limitation established at a specific 

source and is designed as a remedy to impairment at specific mandatory Class I areas. By 

contrast, the SO2 milestones developed by the §309 States serve the dual purpose of remedying 

existing impairment and preventing future impairment by requiring regional SO2 emissions 

reductions and capping emissions for stationary sources. Future impairment is prevented by 

capping emissions growth from sources not eligible under the BART requirements, from sources 

subject to BART that are expected to significantly increase utilization, and from entirely new 

sources in the region.

The milestones include estimates for growth, but then lock these estimates in as an enforceable 

emission cap. The milestone approach is consistent with the statutory goal of preventing any 

future visibility impairment that results from man-made air pollution. The entire region is 

experiencing rapid growth which could erode the progress that has been achieved in the last two 

decades towards improving visibility. BART applied on a case-by-case basis would have no 

impact on future growth, and in the long run would not achieve the regional emission reductions 

that are guaranteed by the program. 

4. Commission Strategies are a Total Package. 

The GCVTC recommendations were developed as a comprehensive strategy includes strategies 

to address mobile sources, prescribed fire, pollution prevention, and Clean Air Corridors. The 

stationary source strategies need to be viewed as part of this overall package. Visibility 

 6

 CAA § 169A(a)(1).
NM Regional Haze SIP 100

12/31/03; 12/20/10 Rev.; 05/02/11 Rev.

impairment in the west is caused by multiple sources and pollutants, and a narrow focus on 

stationary sources may not achieve the same results as a broad-based program. When viewed as 

part of the entire SIP, the milestones achieve much greater reasonable progress than BART.

5. Mass Based Cap has Inherent Advantages over BART 

The baseline emission projections and assumed reductions due to the assumption of BART-level 

emission rates on all sources subject to BART are all based on actual emissions, using 2006 as 

the baseline. The use of actual emissions has an effect in several ways. If the BART process 

was applied on a case-by-case basis to individual sources, emission limitations would typically 

be established as an emission rate (lbs/hr or lbs/MMBtu) that would account for variations in the 

sulfur content of fuel and alternative operating scenarios. The difference between actual 

emissions and allowable emissions is particularly large when a source is permitted to burn two 

different fuel types, such as oil and natural gas, or when the source is part of a cyclical industry 

where production varies from year to year due to the changing demand for their product. A 

mass-based cap that is based on actual emissions is more stringent because it does not allow a 

source to consistently use this difference between current actual and allowable emissions.

Another difference is that mass-based limits will include excess emissions that may occur due to 

malfunctions or during the start-up or shut-down of emission units. A good example of this 

difference is the requirement in the acid rain program that emissions must be assumed to be the 

highest value recorded from the past year during the time period that continuous emission 

monitors are not functioning on a stack. These higher emissions are calculated as part of the 

overall tons/year, and must be accounted for under the mass-based cap for the acid rain program.

6. Tribal Setaside

The GCVTC recommended a market based program to address stationary source emissions of 

SO2. The GCVTC recommended that the market based program include allocations to tribes that 

are of practical benefit.7 This recognized the concern that "tribes, by and large, have not 

contributed to the visibility problem in the region" and that "[t]ribal economies are much less 

developed than those of states, and tribes must have the opportunity to progress to reach some 

degree of parity with states in this regard."8 The tribes specifically recommended that if an 

emission trading strategy is adopted to achieve SO2 reductions from stationary sources that 

allocations be based on considerations of equity rather than historical emissions: 

Credits should not be based on historical emissions, but should be based on equitable 

factors, including the need to preserve opportunities for economic development on tribal 

lands. In general, these lands are currently lacking in economic bases and have not 

contributed to the visibility problems.9

 7 Recommendations for Improving Western Vistas (June 1996). at 35.

8

Id. at 66-67.

9

Id. at 71.
NM Regional Haze SIP 101

12/31/03; 12/20/10 Rev.; 05/02/11 Rev.

Accordingly, the backstop trading program contains a 2,500 allocation to tribes in the GCVTC 

region. Case-by-case BART permits would not provide this practical benefit to tribes that was 

an integral part of the GCVTC recommendations.

7. Other Class I Areas Also Show Improvement in Visibility

In addition to demonstrating successful SO2 emission reductions, §309 states have also relied on 

visibility modeling conducted by the WRAP to demonstrate improvement at Class I areas. The 

complete modeling demonstration showing deciview values was included as part of the visibility 

improvement section in each of the state §309 SIPs, but the SO2 portion of the demonstration has 

been included below as Table M-4 to underscore the improvements associated with 309 SO2

reductions and further demonstrate why the 309 program is better than BART. 40 CFR 

51.309(g)(2)(i) allows states to build upon the strategies implemented in a 309 program and take 

full credit for visibility improvement achieved through these strategies when addressing 

additional Class I areas. This table demonstrates achievements in visibility in these additional 

Class I areas (off the Colorado Plateau) in and surrounding the three states participating in the 

309 program. For the most part, the table shows projected visibility improvement for 2018 with 

respect to SO2 on the worst days and no degradation on the best days.
NM Regional Haze SIP 102

12/31/03; 12/20/10 Rev.; 05/02/11 Rev.

Table M-4. Visibility - Sulfate Extinction Only

Class I Area Monitor

(Class I Areas Represented)

20% Worst Visibility Days

(Monthly Average, Mm-1)

20% Best Visibility Days

(Monthly Average, Mm-1)

2018 1

Base Case

(Base 18b)

2018 2

Preliminary

Reasonable

Progress Case

(PRP18a)

2018 1

Base Case

(Base 18b)

2018 2

Preliminary

Reasonable

Progress Case

(PRP18a)

Bridger, WY

(Bridger WA and Fitzpatrick WA) 5.2 4.3 1.6 1.3

North Absaroka, WY

(North Absaroka WA and Washakie WA) 4.8 4.5 1.1 1.1

Yellowstone, WY

(Yellowstone NP, Grand Teton NP and Teton WA) 4.3 3.9 1.6 1.4

Badlands, SD 17.8 16.0 3.5 3.1

Wind Cave, SD 13.0 12.1 2.7 2.5

Great Sand Dunes NM, CO 5.3 4.9 2.0 1.8

Mount Zirkel, CO

(Mt. Zirkel WA and Rawah WA) 4.6 4.1 1.4 1.3

Rocky Mountain, CO 6.8 6.2 1.3 1.1

Gates of the Mountains, MT 5.3 5.1 1.0 1.0

UL Bend, MT 9.7 9.6 1.8 1.7

Craters of the Moon, ID 5.8 5.5 1.5 1.5

Sawtooth, ID 3.0 2.8 1.2 1.1

Bandelier NM, NM 6.4 5.9 2.4 2.2

Bosque del Apache NWRW, NM 7.0 6.6 2.7 2.5

Gila W, NM 6.2 6.0 1.8 1.7

Salt Creek NWRW, NM 14.4 14.0 3.3 3.1

Wheeler Peak, NM

(Pecos W and Wheeler Peak W) 4.7 4.4 1.1 1.0

White Mountain W, NM 8.9 8.7 1.8 1.7

Great Basin NP, NV 4.1 4.1 1.2 1.2

Jarbidge W, NV 3.8 3.4 1.3 1.2

Chiricahua, AZ

(Chiricahua NM, Chiricahua W, Galiuro W) 7.4 7.4 2.2 2.1

Ike’s Backbone, AZ

(Mazatzal W, Pine Mountain W) 6.1 5.9 2.2 2.1

Queen Valley, AZ 7.5 7.5 3.0 3.0

Saguaro NM, AZ 7.1 6.8 2.6 2.5

Saguaro West, AZ 7.3 7.1 3.2 3.1

Sierra Ancha, AZ 6.0 5.8 2.2 2.1

Superstition, AZ 6.7 6.5 2.7 2.6

Guadalupe Mountains NP, TX

(Carlsbad Caverns NP, NM and Guadalupe 

Mountains NP, TX)

13.7 13.6 3.3 3.2

1 Represents 2018 Base Case growth plus all established controls as of Dec. 2004. No BART or SO2 Milestone assumptions were included. 2 Represents 2018 Preliminary Reasonable Progress growth estimates and established SO2 limits.
NM Regional Haze SIP 103

12/31/03; 12/20/10 Rev.; 05/02/11 Rev.

H. Comparison of Trading vs Command and Control BART Requirements 

During the development of the Annex, the WRAP conducted modeling to determine whether the 

distribution of emissions under the backstop trading program would differ substantially from the 

distribution of emissions assuming installation of BART or would disproportionately impact any 

Class I area due to a geographic concentration of emissions. The results of this modeling are 

included in Tables 2 and 3 of Attachment C to the Annex10. Attachment C, Section G concludes, 

“The results of this analysis showed that the maximum difference between the two scenarios at 

any of the Class I areas was only 0.1 deciviews.11” 

 

10 Voluntary Emissions Reduction Program for Major Industrial Sources of Sulfur Dioxide in Nine 

Western States and A Backstop Market Trading Program, an Annex to the Report of the Grand Canyon 

Visibiltiy Transport Commission (September 2000) at C-15 and 16.

11 Id. at C-21.
Recommendations for Making 

Attribution Determinations 

in the Context of 

Reasonably Attributable BART 

Prepared by: The WESTAR Council 

Prepared for: The Air Managers Committee, Western Regional Air Partnership 

May 2003 

Recommendations for Making 

Attribution Determinations 

in the Context of 

Reasonably Attributable BART 

Prepared by: 

The WESTAR Council RA BART Phase II Working Group: Alice Edwards, Alaska Department 

of Environmental Conservation; Mike Sundblom, Arizona Department of Environmental 

Quality; Deb Wolfe, Montana Department of Environmental Quality; Dana Mount, North 

Dakota Department of Health; Dave DuBois, New Mexico Environment Department; Colleen 

Delaney, Utah Department of Environment Quality; Alan Newman, Washington Department of 

Ecology; Lisa Reiner, Quinalt Indian Nation; Bruce Polkowsky and Kristi Gebhart, National 

Park Service; and Kristin Gaston and Bob Lebens, WESTAR. 

Prepared for: 

The Air Managers Committee of the Western Regional Air Partnership 

in fulfillment of the Western Governors’ Association contract #30203-13 

May 2003 
Acknowledgements 

The recommendations regarding the attribution process, the applicable technical 

approaches and the examples in this report are the product of the RA BART Phase II Working 

Group. The WESTAR Council acknowledges the generous support of all the Working Group 

members. Alice Edwards, Alaska Department of Environmental Conservation; Mike Sundblom, 

Arizona Department of Environmental Quality; Deb Wolfe, Montana Department of 

Environmental Quality; Dana Mount, North Dakota Department of Health; Dave DuBois, New 

Mexico Environment Department; Colleen Delaney, Utah Department of Environment Quality; 

Lisa Reiner, Quinalt Indian Nation; Bruce Polkowsky and Kristi Gebhart, National Park Service; 

and Kristin Gaston and Bob Lebens, WESTAR. 

Authors of the Attribution Techniques (Section VI) are Mike Sundblom (Monitoring); 

Kristi Gebhart (Receptor Modeling); and Dave DuBois (Source Modeling), with assistance from 

Ajith Kaduwela, California Air Resources Board. Bruce Polkowsky and Colleen Delaney 

drafted the certification section and provided liaison between the Western Regional Air 

Partnership Market Trading Forum and the Working Group. Alan Newman, Washington 

Department of Ecology drafted the portion of the report outlining the example process to which 

Dana Mount also contributed. Kristin Gaston drafted the regulatory context section and along 

with Bob Lebens, edited the report. 
EXECUTIVE SUMMARY 

This report recommends a general procedure and applicable technical approaches that may 

be used by states and tribes to assess reasonable attribution in response to a Federal land manager 

(FLM) certification of visibility impairment in a Class I area (Certification). 

WESTAR formed the Reasonably Attributable Best Available Retrofit Technology (RA 

BART) Phase II Working Group with Federal land management agency staff and members of 

state and tribal air quality agencies knowledgeable about RA BART and associated monitoring 

and modeling techniques. To provide the necessary framework, the report provides background 

information about both the certification process and the attribution determination process. 

However, the recommendations focus on the general principles of the attribution assessment 

process and the technical criteria used in the assessment. 

The recommendations are summarized below: 

General Principles: 

 The attribution assessment should be: 

 

 A collaborative process that relies on existing data with minimal additional 

analyses. 

 Technically and legally defensible. 

 Accomplished at a reasonable cost and within a reasonable time frame. 

 No more complex than necessary. 

 Performed by state or tribal agency staff. 

 Adequate to determine whether or not visibility impairment is attributable to an 

existing stationary source potentially subject to BART. 

Technical Criteria: 

 Emissions from BART-eligible sources must “cause or contribute to” visibility 

impairment. Visibility-impairing pollutants of concern must be identified. 

 Factors to consider in assessing impairment include: duration, frequency, 

geographic extent, magnitude, and time of occurrence. 

 Identify distance from source to Class I area to determine appropriate tools for 

characterization of the impairment. 

 Quantitative results are preferable, although qualitative results such as 

photographs may be adequate. 

 Use as many different indicators of impairment as practicable rather than relying 

on a single indicator. 

 Consider level of uncertainty in the assessment.

 Use EPA guideline models whenever practicable. 

Table of Contents 

I. Background....................................................................................................... 1

 A. Introduction and Purpose 

 B. Regulatory Context 

II. Federal Land Manager Certification of Impairment ........................................ 7 

III. The Attribution Determination Process.............................................11 

IV. General Principles and Criteria ...................................................................... 17

 A. General Principles of the Attribution Process 

B. Technical Criteria 

C. Examples of the Attribution Process 

V. Techniques...................................................................................................... 31 

A. Monitoring 

B. Source Modeling 

C. Observational Modeling 

VI. Appendix 

 RA BART Rule (40 CFR 51.300-306) 

I. BACKGROUND 

A. Introduction and Purpose 

Reasonably Attributable Best Available Retrofit Technology (RA BART) is the portion of 

EPA’s visibility rule published in 1980 and codified in 40 CFR 51.302–51.306 that deals with 

visibility impacts from one source or a small groups of sources. RA BART refers to reasonably 

attributable visibility impairment and best available retrofit technology for eligible sources and 

emission limits, and emissions controls as defined by the statute and the rules. Some confusion 

exists regarding the application of RA BART, the process of assessing sources of visibility 

impairment, and the technical tools available for an RA BART attribution determination. RA 

BART is a statutory requirement, although certain of the requirements may no longer be 

applicable when a source complies with BART or installs BART-like controls or after a state 

implements a trading program under 51.308(e)(2) or any trading program under 51.309, and if no 

remaining visibility impacts continue from one source or a small group of sources. 

This report, therefore, addresses the RA BART attribution process and builds upon case 

studies WESTAR developed in 2001 to examine and document how Reasonably Attributable 

Visibility Impairment (RAVI) had been addressed in previous assessments.1 

The Federal land managers (FLMs) advocate maintaining RA BART as a tool because RA 

BART is effective when new monitoring indicates that a previously un-monitored area has 

visibility problems differing from the regional visibility impairment conditions at other areas. In 

addition, RA BART is effective when BART-eligible sources in the vicinity of the protected area 

are causing or contributing to identified visibility impairment.2 

First, this report recommends attribution process principles and assessment techniques a 

state or tribe may consider in an attribution assessment to identify if, and to what degree, an 

existing source or small group of sources causes or contributes to visibility impairment. The 

report focuses on RAVI and does not specifically address impairment due to regional haze. 

Although this report includes references to regional haze, such references serve only to place the 

attribution process in the larger context of the broad regulatory framework that addresses 

visibility impairment, including the regional haze regulations. 

Second, this report includes no recommendations with regard to establishing a threshold 

level at which reasonably attributable impairment exists. Instead, the working group outlined a 

recommended general process and recommended technical procedures that may be used as 

guidelines if an attribution assessment is necessary. Due to the circumstances unique to each 

attribution assessment and the requirement that the assessment be conducted on a case-by-case 

basis, recommending one specific analysis for every situation was not possible. A state or tribe 

should select from the techniques summarized in Section IV. Section IV(C) includes five 

examples of the attribution assessment process, each providing a range of techniques to be used 

 

1

 WESTAR Council, RA BART and RA BART-like Case Studies, June 2001. 2

 This document specifically relates to RA BART and does not address broader issues relating to long-term visibility 

strategies. FLMs generally do not intend to issue Certifications citing specific sources except for situations involving 

BART sources. 

1 
based on available data. The examples also recommend more refined analyses that may require 

additional data. 

Third, this report includes specific information about the current policy of FLM agencies 

regarding certifications of impairment (Certification), but makes no recommendations regarding 

the certification process. This report makes no recommendations regarding state process 

following an attribution determination nor examines options for performing the Best Available 

Retrofit Technology (BART) analysis or the incorporation of BART requirements into State 

Implementation Plans (SIPs). 

Tribal Implementation 

The recommendations in this document are intended to help states assess reasonable 

attribution following Certification by an FLM. Subject to the requirements of the Clean Air Act, 

42 USC 7601(d) and the Tribal Authority Rule, 40 CFR 49.1– 49.11, a tribe may accept 

responsibility for making reasonably attributable determinations in response to a Certification by 

an FLM when a BART-eligible source identified by the FLM in the Certification is on the tribe’s 

land. The regional haze rule also explicitly recognizes the authority of tribes to implement the 

provisions of that rule on tribal lands. Those provisions create the following framework: 

1. Absent special circumstances, reservation lands are not subject to state jurisdiction. 

2. Federally recognized tribes may apply for and receive delegation of federal authority to 

implement CAA programs (including visibility regulation), or “reasonably severable” 

elements of such programs. The mechanism for this delegation is a Tribal 

Implementation Plan (TIP). A reasonably severable element is one that is not integrally 

related to program elements that are not included in the plan submittal, and is consistent 

with applicable statutory and regulatory requirements. 

3. Where a tribe does not seek delegation through a TIP, the Environmental Protection 

Agency (EPA), as necessary and appropriate, will promulgate a Federal Implementation 

Plan (FIP) within a reasonable timeframe to protect air quality on tribal lands. 

 Accordingly, these recommendations also may assist a federally recognized tribe that 

chooses to adopt a TIP to implement the RA BART provisions. In some cases, a tribe may be 

able to utilize the recommendations in much the same way as states. In many other cases, 

however, the recommendations may be modified to meet the unique situation of the tribe and the 

nature of its air program, including its manner of defining “reasonably severable elements” and 

its method of dividing responsibilities between the tribe and EPA. Because of these differences, 

the recommendations that follow do not refer to tribes every time states are referenced. 

B. Regulatory Context 

The national goal for visibility is set forth in the Clean Air Act (CAA) at 42 USC 7491: “the 

prevention of any future, and the remedying of any existing, impairment of visibility in 

mandatory Class I Federal areas which impairment results from manmade air pollution.” The 

requirements apply to 156 designated Class I areas. 

2 
As stated previously, Congress required that states provide a remedy for visibility 

impairment that was “reasonably attributable” to one source or a small group of sources. (42 

USC 7491). Congress directed EPA to ensure that all SIPs contained measures necessary to 

make reasonable progress toward meeting the national goal, including requirements for 

identifying major sources of emissions causing or contributing to visibility impairment, and 

requirements for the application of BART on such sources. EPA promulgated rules pursuant to 

Congress’s directive to provide guidelines to the states on appropriate techniques and methods 

for implementing the SIP requirements. (40 CFR 51.302(c)). (Note: when this report refers to a 

“source” within the meaning of this regulation, the phrase “or a small group of sources” is 

implied.) 

The requirement to install Best Available Retrofit Technology controls on existing sources 

is a key element of the visibility protection provisions in the CAA demonstrating the need to 

focus on pollution emitted from a specific set of existing sources. Sources are potentially subject 

to BART controls if they meet the following criteria: 

1. A major stationary source from 1 of 26 source categories identified in the CAA and 

regulations (see Appendix A); 

2. Potential to Emit (PTE) 250 tons per year of any air pollutant; and, 

3. Not in operation prior to August 7, 1962 and “in existence” on August 7, 1977. 

In the 1980 visibility rule, EPA used the term “existing stationary facility” to define a 

facility that met the above criteria. However, to avoid any confusion about whether that term 

encompassed a larger group of sources, EPA now uses the term “BART-eligible source.” The 

term “BART-eligible source” is used throughout this report for similar reasons, but the reader 

should be aware that some sections of the visibility rule still refer to “existing stationary 

facilities.” For purposes of the attribution discussion in this paper, these terms are 

interchangeable. 

In 1999, EPA added two new sections to the visibility rule to address regional haze (40 CFR 

51.308 and 51.309). Pollutants causing regional haze may be transported hundreds of miles, and 

therefore, regional haze must be addressed as a broader regional issue. The 1980 visibility rule 

focused on direct visibility impacts of an individual source or small group of sources. The 1999 

revisions are commonly referred to as the regional haze rule, although the 1999 rule incorporates 

the earlier requirements for BART as well as the new regional haze provisions. 

To remedy RAVI, the regulations outline a process to identify and control emissions from 

sources that are directly impacting visibility at specific Class I areas (40 CFR 51.302). Three 

primary steps in this process are: 

1. The Federal land manager certifies impairment; 

2. The state identifies existing sources that cause or contribute to the visibility 

impairment; and 

3 
3. The state performs a BART analysis to determine what controls, if any, are required 

on any existing source that meets the BART criteria and has been identified as 

contributing to the impairment. 

Attribution Process 

The language of 40 CFR 51.302(c)(4)(i) provides the basic principle upon which the state 

will rely during the attribution process. That section states that the attribution must indicate each 

[BART-eligible source] “which may reasonably be anticipated to cause or contribute to 

impairment of visibility.” Whether or not the impairment is “reasonably attributable” is 

determined by “visual observation or other technique the state deems appropriate.” (40 CFR 

51.301(s)). Because the state is responsible for identifying sources, this report provides 

recommendations for the state to consider when it undertakes an attribution determination. 

Once visibility impairment is identified, RAVI is addressed on a case-by-case basis. Under 

the 1980 regulation, a state evaluates BART-eligible sources only after an FLM certifies the 

existence of visibility impairment. However, in the context of the current regional haze rule, 

states must also address BART requirements for regional haze (RH BART).3

 Several options 

exist for addressing RH BART. For example, rather than require a source-specific BART 

emission limit, a state may choose to develop a trading program, either regionally or within its 

own jurisdiction, that achieves greater reasonable progress than case-by-case RH BART. 

If a state develops a trading program, the time period to achieve the emissions reductions 

may be extended. As a result, visibility conditions at a specific Class I area initially may remain 

static or even deteriorate during the early implementation period. During this time, FLMs have 

indicated that the RAVI process may be utilized to provide steady and continuing improvement 

in visibility. Within the context of the regional haze rule, this may be an example of a 

“geographic enhancement.” As noted above, the recommendations in this report apply only to 

case-by-case applications of BART and are not intended to apply to the broader regional haze 

rule such as a market-based trading program implemented as part of the 1999 rule. 

A state may find it difficult to determine a source/receptor link for RAVI difficult when 

there are other sources located in the area, including international sources. However, the regional 

haze rule provisions do not alter the requirement to undertake the attribution assessment. 

State determines what controls, if any, are required 

After the attribution determination, the state is required to perform a BART analysis to 

determine what types of controls, if any, should be placed on the source(s) found to be 

contributing to the impairment. The following factors affect the BART determination: 

1. Available technology; 

2. Costs of compliance; 

3. Energy and non air quality environmental impacts of compliance; 

 

3

 The RH BART provision was remanded to EPA by the U.S. Court of Appeals as a result of the ruling in American 

Corn Growers Association v. EPA, No. 9901348 (DC Cir. May 24, 2002) 

4 
4. Remaining useful life of the source; and, 

5. Degree of improvement that can be anticipated to result from the use of the controls. 

As noted above, this report does not provide guidance regarding state process following an 

attribution determination nor does it examine options for implementing the BART requirement. 

5 
 

6 
II. FEDERAL LAND MANAGER CERTIFICATION OF IMPAIRMENT 

The Federal land managers monitor visibility through a nationwide monitoring network, 

known as Interagency Monitoring of PROtected Visual Environments (IMPROVE). The 

IMPROVE network has recently been expanded and the FLMs anticipate reliable trend data for 

the new IMPROVE sites between the years 2006 and 2008. The FLMs plan to evaluate the 

current visibility conditions in Class I areas as well as trends occurring over time to identify 

areas where visibility is not improving. 

 

The FLMs generally will use a screening process to identify Class I areas that may be 

affected by RAVI. This screening process will be influenced by the approach the state relies 

upon to address RH BART in its SIP. There are three approaches that may be used. 

1. Case-by-Case Review of RH BART under 51.308

No distinction exists between emission reductions needed to address RH BART and 

reductions to address RAVI, therefore, the BART process will address both types of visibility 

impairment. 

2. Trading Program under 51.308

The FLMs anticipate that the following screening criteria may be appropriate, but will not 

make a final decision until a 308 trading program has been developed. The screening criteria 

associated with this approach may be similar to the screening criteria associated with the trading 

program option under 51.309. However, the FLMs have indicated that the screening criteria 

ultimately selected for 51.308 will depend on how the trading program is structured, the selected 

emissions cap, and other aspects of the trading program. 

 

Potential Screening Process Criteria: 

(i) Sulfate, nitrate, organic carbon, other fine particulate, etc., levels in the Class I 

area are not decreasing.4

(ii) One or more BART-eligible sources of SO2, NOx, VOC, PM10, etc., are located 

within 100 miles of the mandatory federal Class I area. 

(iii) The BART-eligible sources identified in (ii) are not already well-controlled for 

pollutants that contribute to visibility impairment. 

3. Milestones and Backstop Trading Program under 51.309 

 

The FLMs plan to sign a Memorandum of Understanding (MOU) with the participating 

states to define the screening criteria the FLMs will use to certify impairment. 

 

4

 The decrease of a pollutant (or secondary species of that pollutant) would be measured from the beginning of the 

market or emissions trading program, and such a trading program would take a long time (10 to 15 years) to reach 

the level of reduction that “meets” BART. The decrease would be tested over the first 5 to 10 years. A very quick 

time frame for reductions would negate the need for RA BART criteria. 

7 
Screening Process criteria:5

(i) Sulfate levels in the Class I area are not decreasing. 

(ii) One or more BART-eligible sources of SO2 are located within 100 miles of the 

mandatory federal Class I area. 

(iii) The BART-eligible sources identified in (ii) are not already well-controlled for 

SO2 (85% or better SO2 control for coal-fired utility boilers). 

Goal: For FLMs to complete the certification process between 2006 and 2008.6

These criteria were influenced by the design of the 309 trading program including emission 

reduction estimates, shape of the declining emission cap, inclusion of sources that were not 

BART-eligible, and inclusion of new source growth under the cap. 

Although geographic enhancements do not need to be addressed under the first approach, 

they must be addressed in the two trading programs described above because emission 

reductions may occur more gradually in the context of a trading program. The FLMs do not 

anticipate certifying impairment under these circumstances but do intend to notify the state as 

part of the SIP development process if concerns arise regarding “hot spot” impacts from sources 

that may directly affect specific Class I areas. 

Note: BART for regional haze has been addressed for SO2 under this option. Regional haze 

BART for NOx and PM will be addressed in SIP revisions that are due in 2008.

In all three cases discussed above, if the FLM determines that a certification of visibility 

impairment is necessary, the FLM will send an official Certification to the state. The 

Certification will generally include the following information: 

1. Class I area(s) impacted; 

2. Basis of certification (photographic documentation, monitoring, modeling, etc.); 

3. Type of impairment certified: plume impact, or layered or uniform haze; 

4. Pollutant(s) of interest; and, 

5. Preliminary identification of source(s) believed responsible for impact. 

FLM, State, and EPA roles in RA BART 

 FLMs are responsible for certifying impairment. The Certification demonstrates the FLM’s 

determination that there is evidence of visibility impairment from one source or a small group of 

sources. 

 

5

 Within the context of established regional milestones for SO2 and a backstop trading program, the FLMs have said 

it is appropriate to use the following screening process in making these recommendations as part of the Certification. 

Voluntary Emissions Reduction Program for Major Industrial Sources of Sulfur Dioxide in Nine Western States and 

A Backstop Trading Program. An Annex to the Report of the Grand Canyon Visibility Transport Commission. 

Submitted by the Western Regional Air Partnership to the U.S. Environmental Protection Agency, p. 61, September 

29, 2000. 

6

 This goal will not in any way restrict the ability of the FLMs to certify impairment at a later date if it is necessary 

to fulfill their statutory obligations. ibid. 

8 
Following the Certification, states have the following regulatory obligations: (1) identify 

facilities that “emit an air pollutant which may be reasonably anticipated to cause or contribute to 

any visibility impairment” in that Class I area, and (2) for sources subject to BART, the state 

must identify the BART level of control technology. If the source does not have adequate control 

in place, the state must establish a BART limit in the SIP. 

 EPA has two major responsibilities for the RA BART requirement. First, in the states that do 

not have a SIP in place to address the RA BART requirements, but where the program is 

implemented through a FIP, EPA will conduct the BART analysis and establish any BART 

emission limits. Second, for the states with SIPs that include RA BART regulations, EPA will 

provide federal enforcement of state-established BART emission limits. 

9 
10 
III. THE ATTRIBUTION DETERMINATION PROCESS 

This section recommends a process for the state to follow in order to complete an attribution 

determination after receipt of a Certification from an FLM under 40 CFR 51.302(c)(1).

The Certification focuses on the existence of visibility impairment. While the FLM may 

identify sources or even sources areas that contribute to the Certification, the formal 

identification of sources is a state responsibility. 

The state should make a detailed review of the data supporting the Certification to determine 

which sources or source areas require further evaluation. If the data are insufficient to identify 

specific sources or source areas, the state may request that the FLM perform more detailed 

analyses to further substantiate the impairment set forth in the Certification. 

If the state determines sufficient information exists to proceed, the state should begin the 

process by: (1) evaluating which sources are BART-eligible, and (2) reviewing the impairment 

information provided by the FLM in support of the Certification. 

1. Evaluate which sources are BART-eligible

 

Congress and EPA established criteria to determine which sources are subject to BART. The 

categories of sources subject to BART are listed in 40 CFR 51.301, the definition of “existing 

stationary facility,” and also are included in Appendix A of this report. 

The state must confirm that the potential source or group of sources is subject to the RA 

BART process by examining the potential source emissions and the dates of operation. 

The criteria for determining if a source is BART-eligible may be complicated if a source has 

multiple units that were constructed at different times and a state may be unable to determine if a 

specific source would qualify as BART-eligible. EPA published guidelines in 1980 to aid states 

in implementing the 1980 rule.7

 In addition to the 1980 guidelines for determining BARTeligibility, EPA also has proposed guidelines that include criteria for determining if a source is 

BART-eligible.8 These guidelines are expected to be re-proposed in 2004, promulgated in 2005 

and codified at 40 CFR Part 51 as Appendix Y. The state should refer to both sets of guidelines 

to determine if a source is BART-eligible, although the proposed guidelines are not binding until 

final promulgation occurs. 

When using the applicability criteria in Appendix Y, the state should look for information 

readily available from existing state data such as permitting history, emission inventory, or other 

similar databases. 

 

7

 U.S. Environmental Protection Agency, Guidelines for Determining Best Available Retrofit Technology for Coalfired Power plans and Other Existing Stationary Facilities, EPA-450/3-80-009(b), Office of Air Quality Planning 

and Standards, Research Triangle Park, N.D., November 1980 (1980 BART Guidelines). 8

 66 FR 38108 Proposed Guidelines for Best Available Retrofit Technology (BART) (July 20, 2001). EPA will repropose these guidelines as a result of the remand in American Corn Growers v. EPA. 

11 
1. If a database of Potential To Emit (PTE) is not available, state emission inventories 

can be a useful screening tool to determine whether a source meets the size criteria 

(for example, identify all sources with emissions greater than 100 tons/year of 

visibility impairing pollutants). Operating permit applications may also contain 

information about the PTE of a source, or individual units within a source. 

2. State business records may be useful to determine when the facility was constructed 

or when it commenced operation. Newspaper article searches or a detailed historical 

review of each source may also provide useful information. 

3. The state should require the source to provide information regarding the construction 

dates of individual emission units. 

4. Institutional memory within the air agency can be invaluable if records of 

construction dates of major emission units are not available, although memories will 

not withstand legal challenges like hard documentary data. 

5. New Source Review permitting records may be useful to identify new units that were 

constructed after 1977, determine the PTE of the source, or determine if 

reconstruction has occurred. (Note: the draft guidelines in Appendix Y state that 

modifications at a source do not affect applicability unless the change qualifies as 

reconstruction of the source). 

If the source or group of sources identified in the Certification is not BART-eligible, the 

state should inform the FLM of its finding. The state should look in the vicinity of all the sources 

suspected of causing or contributing to the impairment identified in the Certification. If no 

BART-eligible sources exist, an attribution assessment is unnecessary. 

2. Review Support Information in the FLM Certification 

Initially, the state should acquire all the supporting information the FLM used in the 

Certification and independently evaluate the data. This initial review will help the state 

determine if the information is sufficient to support a reasonable attribution determination. 

The state should consider the type of impairment in the Certification: (a) plume impact 

visibility impairment, (b) uniform haze visibility impairment, or (c) layered haze visibility 

impairment: 

 

(a) Plume impact is the impairment addressed by the original visibility protection 

program under which the state must make a reasonable attribution 

determination before proceeding to the BART analysis (40 CFR 51.301-

51.307). 

(b) In some instances, uniform haze may be thought to be source-specific haze 

from a BART-eligible source. If a state can successfully demonstrate there is a 

source emitting any air pollutant that may reasonably be anticipated to cause or 

contribute to any impairment of visibility, the state should consider that portion 

of the uniform haze to be impact from the identified source(s) and, therefore, 

consider the source to be subject to BART. 

(c) The visibility impairment may also be defined as layered haze, a condition that 

results when aerosols are “trapped” under stagnant air mass conditions. 

12 
 Once the FLM has issued a Certification, the responsibility for the attribution assessment 

shifts to the state. If a state does attribute impairment to a source, the state must be able to defend 

its finding that one or more BART-eligible sources did cause or contribute to visibility 

impairment in the Class I area. However, the Ninth Circuit Court of Appeals established a low 

threshold for unacceptable visibility impairment.9

3. Evaluate Existing Data not included in the Certification 

When analyzing supporting data, the state should determine if additional information exists 

that was not available to the FLM. Examples include special project camera studies or ambient 

monitoring data collected by the state or local air pollution control agency, the potential or actual 

PSD permit applicant,10 or the university. In certain situations, another agency may have 

previously collected information that could be used in an attribution determination.11 These data 

should be reviewed to determine whether they support the FLM Certification. 

To conclude this portion of the attribution process, the state may wish to prepare a report that 

summarizes its initial evaluation of the Certification. The purpose of the report is to carefully 

document the state’s findings and conclusions about its decisions. The report would address two 

questions: 

First, the report would assess whether any BART-eligible source(s) exist that potentially 

contributed to visibility impairment as described in the Certification. The report would contain a 

preliminary determination of whether the sources are BART-eligible and, if possible, analyze 

each source’s relative contribution to the impairment (based on available source/receptor 

information). 

Second, the report would assess the impairment data. This assessment would include the 

state’s evaluation of the supporting data in the Certification and an analysis of any additional 

data used in the attribution assessment. The data gaps found in this review would be identified 

along with any recommendations for strategies to obtain the missing information. The state may 

use these recommendations to determine the next steps in the attribution process. 

If the state believes the Certification is supported by sufficient data, proceeds with an 

attribution assessment and makes a determination that the data does or does not indicate a source 

subject to BART, the attribution process is complete. However, if the state determines the data is 

insufficient to complete an attribution assessment, the evaluation process ends, and the state may 

proceed to the next step—identification of data gaps and the studies necessary to obtain this 

information. 

 

 

9

 See Central Ariz. Water Conservation Dist v. EPA, 990 F.2d 1531 (9th Cir. 1993); See also discussion in RA BART 

and RA BART-like Case Studies. 10 For example, a PSD permit applicant may be required to obtain pre-application ambient air quality information, 

and that information may not have been available to or known to the FLM. 

11 In Washington state, the plume of a defunct copper smelter has been traced by its arsenic deposition. If this were 

an active facility, this ground tracing of the plume could be used to support a source/receptor connection in an 

attribution determination. 

13 
4. Identify data gaps and necessary studies to fill the gaps 

As part of the data review, the state should note gaps or inconsistencies in the available data. 

Examples of data gaps and inconsistencies may include: 

1. Missing photos in a sequence of photos, 

2. Poor resolution of the plume or its source in the photos, 

3. Back trajectory analyses done with a very large grid resolution or poor techniques, 

4. IMPROVE monitor data missing at critical periods, 

5. Lack of association between the source’s emissions and monitored data at the receptor, 

6. Special studies performed during a time when a source that potentially contributed to 

the impairment was not operating, 

7. Contemporaneous studies with contradictory results that cannot be explained, 

8. Ambient studies that use naturally occurring tracers and, when the suspected source(s) 

are tested, the tracers do not exist or exist at levels far below (or above) the level 

indicated by the ambient study results, 

9. Tracer studies where the tracer was not found at the anticipated receptors, 

10. No explicit exploration of whether wildfire or other natural events significantly caused 

or contributed to one or more of the impairment episodes, 

11. Other differences or inconsistencies in the available data. 

Once any data gaps have been identified, the state should decide which studies are necessary 

to obtain the missing information sufficient to complete an attribution assessment. The state 

should design potential studies and determine the resource needs of those studies. The amount of 

work necessary will depend on the availability of the information and how critical the 

information is to the attribution assessment. Section IV provides technical criteria and examples 

of the technical process the state may consider at this point in the process. 

5. Consultation Process 

The WESTAR review of previous RAVI assessments demonstrated the importance of 

including all stakeholders in the design of any data collection plans or modeling protocols. 

Competing studies can be very inefficient, expensive, and time-consuming, and ultimately may 

not help the state make a final decision. 

If stakeholders are involved in the design of any data collection efforts or modeling 

protocols, disagreements may be resolved before the state or source continues with any 

additional studies. The state should consider involving the following stakeholders in the 

consultation process: 

1. Affected sources 

2. Neighboring states and tribes 

3. Environmental Protection Agency 

4. Federal land managers 

5. Local environmental groups 

6. Local permitting agencies 

14 
7. Local government representatives 

6. Completion and Review of Additional Visibility Studies 

When the additional visibility studies, if any, are complete, the state should evaluate the 

resulting data. The technical staff may wish to finalize the report and make recommendations 

based on the scientific aspects of the data. 

7. Final Determination of Reasonably Attributable Visibility Impairment 

The state may reach any one of the following conclusions: 

1. The impairment certified by the FLM is reasonably attributable to the identified BARTeligible source(s) for specific pollutants; 

2. The impairment certified by the FLM is reasonably attributable to the source(s) 

identified by the FLM and additional sources not identified by the FLM for specific 

pollutants; 

3. There is inadequate data to support a determination that the impairment is due to the 

source(s) identified by the FLM; 

4. The impairment is reasonably attributable to other adjacent BART-eligible sources for 

specific pollutants; or 

5. The impairment certified by the FLM is not reasonably attributable to a BART-eligible 

source. 

15 
16 
IV. GENERAL PRINCIPLES AND CRITERIA 

This section provides general principles and technical criteria for the state to consider after 

receipt of an FLM Certification. After receipt of such a Certification, the state must determine 

whether BART-eligible sources “emit any air pollutant which may reasonably be anticipated to 

cause or contribute to any visibility impairment in any” Class I area. While these principles and 

technical criteria should generally be useful and applicable, each state must decide what is 

required to support its individual determination. 

Part A contains general principles to guide the development of a conceptual framework for 

the attribution assessment process. Part B contains evaluation criteria to guide the decisions 

regarding a technical framework for the attribution assessment process. 

Conceptually, the statutory framework for an attribution determination (“may reasonably be 

anticipated to cause or contribute to visibility impairment”) should be the general principle 

guiding the attribution process. EPA maintains, and the Ninth Circuit agreed, that an affirmative 

attribution decision is possible even with considerable uncertainty and a low triggering threshold. 

However, each state should decide individually what is required to support its determination. 

A. General Principles of the Attribution Process

Attribution process criteria address factors likely to influence the performance of the state 

attribution assessment. These criteria provide parameters to define and implement the attribution 

assessment process given resource constraints, legal considerations, administrative 

decisionmaking requirements, and other relevant factors. The general principles include the 

following: 

1. Whenever possible, an attribution assessment should be a collaborative process that 

relies on existing data with a minimum of additional analysis (see section III). If 

supplemental data are needed, field studies should be designed in a collaborative 

process between affected states and tribes, identified sources, Federal land managers, 

EPA, and the general public. Past experience has shown that competing technical 

studies often result in an unnecessarily expensive and unduly complicated process. 

2. Attribution assessments should be technically and legally defensible. 

3. Attribution assessments should be accomplished at a reasonable cost and within a 

reasonable time frame. 

4. Attribution assessments should be no more complex than necessary, recognizing that 

the circumstances surrounding a Certification may vary greatly. State or tribal agency 

staff should be capable of performing the attribution assessment and making the final 

determination, although contractors may be used for certain types of modeling or 

monitoring. 

5. Reasonably attributable visibility impairment can only be identified if a source/receptor 

17 
links a potentially BART-eligible source or small group of sources to a Class I area. 

B. Technical Criteria 

The technical criteria address the appropriateness of available analytical techniques from a 

scientific perspective. The rule defines visibility impairment to mean “any humanly perceptible 

change in visibility (light extinction, visual range, contrast, coloration) from that which would 

have existed under natural conditions.” 

The technical criteria include the following: 

1. The BART source must emit an air pollutant that may reasonably be anticipated to 

cause or contribute to any of the impairment. The visibility-impairing pollutants of 

concern must be identified. 

2. The attribution assessment should address the unique visibility impairment in the FLM 

Certification for the Class I area. Some factors to consider include: 

 a. Duration: source’s length of effect on visibility per episode;12

b. Frequency: how often episodes of impairment occur; 

 

c. Geographic extent: how much of the Class I area is affected by the impairment; 

 d. Magnitude: how much visibility impairment is due to the source’s emissions; and 

 e. Time of occurrence: including time of day and time of year. 

These factors need to be considered together, because they affect each other. An 

infrequent occurrence of a large magnitude episode may meet the criteria. A frequent 

occurrence of a small magnitude episode may also meet the criteria. The FLM may 

provide information about these criteria in the Certification, and the state should review 

this information as a starting point for its assessment. The state may consider other 

factors and data, as appropriate. 

3. The attribution assessment should identify the distance from the source to the Class I 

area. This distance will affect the choice of tools appropriate for characterizing the 

specific source’s impact on visibility impairment. 

4. To the extent possible, the attribution assessment should be quantitative. Under certain 

circumstances, qualitative information, such as photographs or time-lapse video of 

distinct plumes or source-specific haze events, may be adequate. 

5. The state should use as many approaches or indicators of impairment as practicable 

12 Based on previous cases, most impairment episodes are relatively short—lasting one to several hours—which may 

affect monitoring and other assessment techniques. 

18 
rather than relying on a single method. The assessment may rely on air monitoring and 

modeling techniques and other supporting scientific data. Consistency between source 

and observational techniques strengthens the analysis.13 

6. The state should consider the level of uncertainty in the assessment. 

7. EPA guideline models should be used whenever practicable. When other models are 

used, additional technical discussions with EPA may be necessary. 

C. Examples of the Attribution Process

The state should consult this section after evaluation of the FLM Certification. At this point, 

the state will already have decided what gaps need to be filled to complete the attribution 

assessment. 

The recommendations in this report recognize that each attribution determination will be 

unique. Because an attribution determination is a fact-specific and individual determination, it is 

not possible to recommended a single technical approach for a state to follow. A combination of 

monitoring and modeling techniques is usually appropriate, but instead of attempting to cover all 

possible combinations of techniques, this report provides five selected scenarios. The general 

principles and technical criteria identified in sections A and B are incorporated into these 

scenarios. The goal is to provide the state with references for use when it is creating its own 

individualized technical procedure. 

In addition to the scenarios, this report provides detailed tables and narrative descriptions of 

techniques that may be considered and/or substituted for the techniques in the scenarios (see 

Section V). 

Scenario 1: Limited data/one source 

Data input: Small amount of existing data (i.e., one IMPROVE site with data for 2-3 years) 

Evidence of “local” impact. 

Limited meteorological data. 

Where it is likely that one major source contributes to impairment, a combination of the 

following techniques is suggested: 

1. Examine IMPROVE data, including quality assurance 

2. Look at extinction budget to identify visibility-impairing pollutants 

3. Perform some analysis of when the episodes are occurring 

4. Perform a simple back trajectory analysis using a method such as HYSPLIT 

5. Look at relationships between particulate species 

6. Examine source emissions data for correlations with ambient monitoring 

7. Perform dispersion model based on data and capabilities such as VISCREEN or 

CALPUFF Lite 

 

13 WESTAR Council, RA BART and RA BART-like Case Studies, June 2001. 

19 
8. Examine other data such as source owner data, deposition data, or photographic 

evidence 

The results of this initial analysis may not always be conclusive. This level of review may be 

adequate if a source/receptor relationship can be identified. However, if the results are 

inconclusive, more data and/or more refined analyses may be necessary and may help the state 

reach an attribution determination. The state should consider how the available data and choice 

of techniques might affect its ability to assess the effectiveness of the controls in remedying the 

impairment. 

It may be efficient to look ahead to the data and analytical needs of a potential BART 

analysis. For example, the state may wish to use a more refined model that would be useful for 

both attribution and remedy assessment. 

 

Assuming there is a two-year time period14 to collect data and analyze additional information, 

the following techniques also can be considered: 

1. Better source characterization, including measurement of emissions of trace elements 

(source profiles) for use in CMB modeling 

2. Met monitoring or modeling 

3. Camera site, possibly with time-lapse video 

4. Additional aerosol monitoring, episodic or saturation 

5. In plume trajectory by aircraft, if available 

6. Fine time-resolved optical monitoring, such as nephelometer, transmissometer, 

aethelometer combined with pollutant monitoring (e.g., SO2, NOx, real time PM) for 

monitoring of episodes 

7. More refined chemical visibility model, such as CALPUFF 

8. Repeat initial techniques with new data 

The technical criteria are listed below, followed by techniques that may be used to obtain results 

about the criteria. 

1. The impairment must be related to emissions from specific sources. The visibilityimpairing pollutants of concern should be identified. 

Techniques: Back trajectory, species relationships, relationship between source 

emissions and ambient monitoring, dispersion model refined by camera, aerosol, in 

plume, optical monitoring, and refined dispersion models. 

2. The attribution assessment must address the unique visibility impairment certified by 

 

14 The 1999 regional haze rule revised the requirements for general plan requirements for visibility protection. As a 

result, plan revisions are required once every five years, rather than the Long Term Strategy review requirement of 

every three years. If an FLM certifies RAVI at least 6 months prior to a plan revision, section 51.302 requires that 

the State Plan revision address such Certifications. Given this 5-year cycle, we have presumed for this report that an 

attribution analysis should take about two years to complete in order to allow time for the BART engineering 

analysis, if needed. 

20 
the FLM for the Class I area. Some factors to consider include: 

a. Duration: source’s length of effect per episode 

Techniques: Monitoring, dispersion model, back trajectory, camera 

b. Frequency: how often the impairment occurs 

Techniques: Monitoring, dispersion model, back trajectory, camera 

c. Geographic extent: how much of the Class I area is impaired 

Techniques: Monitoring, dispersion model, additional data on deposition and other 

studies 

d. Magnitude: how much impairment is due to the source 

Techniques: Dispersion model, receptor model 

e. Time of occurrence 

Techniques: Monitoring, dispersion model, back trajectory, camera 

3. Uncertainty of results: Each analytical method will have its own level of uncertainty. 

These individual uncertainties should be kept in mind as outputs are compared within 

the overall assessment. If the results of different techniques are the same or similar 

(within the uncertainties of the techniques), then the overall level of uncertainty is likely 

to decrease. 

Scenario 2: Moderate data/multiple sources 

Data input: Moderate amount of existing data (i.e., one IMPROVE site with data for six or 

more years) 

Evidence of an increasing trend in sulfate 

Meteorological data likely from several stations 

Assuming the Certification identifies multiple BART sources of different types within a 100-

mile radius, a combination of the following techniques is suggested: 

1. Examine IMPROVE data, including quality assurance 

2. Look at extinction budget to identify visibility-impairing pollutants 

3. Perform some analysis of when the episodes are occurring 

4. Perform multiple back trajectory analyses using a method such as HYSPLIT 

5. Look at relationships between particulate species 

6. Examine source emissions data for correlations with ambient monitoring 

7. Perform dispersion model based on data and capabilities such as CALMET/CALPUFF 

8. Examine other data such as source owner data, deposition data, or photographic 

evidence 

9. Wind fields/Synoptic analyses 

10. Comparison of different episodes 

11. UNMIX, PMF and/or CMB 

21 
12. Analysis of any regional modeling already conducted, such as CMAQ 

13. Long term visual monitoring, such as camera data or transmissometer data, compared to 

met data to identify quadrants of concern 

The results of this initial analysis may not be conclusive. This level of review may be 

adequate if a source/receptor relationship can be identified. 

However, if the results are inconclusive, more data and/or more refined analyses may be 

necessary and may help the state reach an attribution determination. The state should consider 

how the available data might affect the ability to assess the effectiveness of the controls in 

remedying the impairment. It may be efficient to look ahead to the data and analytical needs of a 

potential BART analysis. For example, the state may wish to use a more refined model that 

would be useful for both attribution and remedy assessment. 

 

Assuming there is a two-year time period to collect data and analyze additional information, the 

following techniques also can be considered: 

1. Emissions inventory 

2. Analysis of a nested domain within the regional model 

3. Source profiles (natural tracers) 

4. Additional source measurements, such as stack testing 

5. Met monitoring or modeling 

6. Camera 

7. Additional aerosol monitoring, episodic or saturation 

8. Monitoring to measure additional parameters, such as precursors, ammonia and 

oxidants 

9. In plume trajectory by aircraft, if available, to characterize plume chemistry 

10. Fine time-resolved optical monitoring, such as nephelometer, transmissometer, 

aethelometer combined with pollutant monitoring (e.g., SO2, NOx, real time PM) for 

monitoring episodes. 

11. Repeat initial techniques with new data 

The technical criteria are listed below, followed by techniques that may be used to obtain results 

about the criteria. 

1. The impairment must be related to emissions from specific sources. The visibilityimpairing pollutants of concern should be identified. 

Techniques: Back trajectory, species relationships, relationship between source 

emissions and ambient monitoring, dispersion model refined by camera, aerosol, in 

plume, optical monitoring, and refined dispersion models. 

2. The attribution assessment must address the unique visibility impairment certified by 

the FLM for the Class I area. Some factors to consider include: 

a. Duration: each source’s length of effect per episode 

22 
Techniques: Monitoring, dispersion model, back trajectory, camera 

b. Frequency: how often the impairment occurs by source 

Techniques: Monitoring, dispersion model, back trajectory, receptor model, camera 

c. Geographic extent: how much of the Class I area is impaired 

Techniques: Monitoring, dispersion model, additional data on deposition and other 

studies 

d. Magnitude: how much impairment is due to each individual source 

Techniques: Dispersion model, receptor model 

e. Time of occurrence 

Techniques: Monitoring, dispersion model, back trajectory, camera 

Scenario 3: No IMPROVE data, Certification by modeling evidence 

Data input: Detailed modeling of a source and specific visibility impairment using a 

CALPUFF run, or detailed (nested) run of regional model. 

Detailed emissions data and meteorological data were input to the model. 

No IMPROVE data available for this specific Class I area (monitoring may be at a 

“representative site”) 

Some optical data, photographic data, and limited aerosol data from other 

networks 

Assuming the Certification points to a specific source, a combination of the following techniques 

is suggested: 

1. Examine IMPROVE data for any nearby Class I areas (especially those included in the 

modeling domain) to better understand the regional conditions and compare with model 

outputs of the unique effect 

2. Review the model’s outputs on “high impact” days and compare with actual 

meteorological data of the area (to confirm transport, inversions, or other aspects of the 

model which may create the unique impact) 

3. Review source emissions data used in the model 

4. Review other monitoring data (optical measurements, deposition data, ozone data, etc.) 

to collaborate model predictions 

5. Examine any photographic evidence 

The results of this initial analysis may not always be conclusive. This level of review may be 

adequate if a source/receptor relationship can be identified. Because no visibility-specific particle 

monitoring is available in this case, the key to attribution is to determine that the source 

emissions are indeed reaching the Class I area on days when impairment exists. If the results are 

inconclusive, more data and/or more refined analyses may be necessary and may help the state 

reach an attribution determination. The state should consider if the available data and modeling 

information supplied with this Certification could be used to determine the effectiveness of the 

23 
controls in remedying the impairment. It may be efficient to look ahead to the data and analytical 

needs of a potential BART analysis if additional or different modeling will be necessary. 

Additional data collection and analyses that might be considered: 

1. Better source profiles or newer emissions information 

2. Met monitoring or modeling 

3. Camera 

4. New aerosol monitoring (episodic or saturation) 

5. In plume trajectory by aircraft, if available 

6. Repeat initial analytical techniques with new data 

The technical criteria are listed below, followed by techniques that may be used to obtain results 

about the criteria. 

1. The impairment must be related to emissions from specific sources. The visibilityimpairing pollutants of concern should be identified. 

Techniques: Confirm model inputs, compare with any new particle monitoring at Class I 

area. Examine performance of the model, and perform uncertainty analyses. 

2. The attribution assessment must address the unique visibility impairment certified by the 

FLM for the Class I area. Some factors to consider include: 

a. Duration: source’s length of effect per episode 

Techniques: Monitoring, dispersion model, back trajectory, camera 

b. Frequency: how often the impairment occurs 

Techniques: Monitoring, dispersion model, back trajectory, camera 

c. Geographic extent: how much of the Class I area is impaired 

Techniques: New monitoring and examination of dispersion model outputs, 

additional data on deposition and other studies 

d. Magnitude: how much impairment is due to the source 

Techniques: Dispersion model 

e. Time of occurrence 

Techniques: Monitoring, dispersion model, back trajectory, camera 

Scenario 4: Direct Photographic Evidence 

Data input: The FLM certified impairment in a wilderness area based on photographic 

evidence. Photographs taken over a period of two years showed a distinct haze 

in a valley located in the wilderness area when the wind is from the east. A 

series of photographs during two episodes showed a distinct plume that 

24 
originates at an existing stationary source constructed in 1965 and located ten 

miles east of the wilderness area. The photographic series showed that the 

plume traveled into the wilderness area. 

Aerial photos during one episode also show a distinct plume that travels into 

the wilderness area. The wilderness area does not have an IMPROVE site. A 

Class I area located 50 miles to the north has an IMPROVE site that was 

representative for the area. This monitoring site does not show decreased 

visibility on the days when haze was photographed in the wilderness valley. 

Assuming the Certification identifies one BART source, the following steps are suggested: 

1. Review the photographic evidence and determine whether the photographs show a clear 

connection between the source and the haze documented in the wilderness area. 

In this example, the photographic evidence showed a clear connection between the 

source and the haze in the wilderness area. Qualitative information, such as 

photographic evidence that establishes a source/receptor link, is allowed under EPA 

regulations that define reasonable attribution as determined by “visual observation or 

other technique the State deems appropriate.” (40 CFR 51.301(s)). 

The results of this initial analysis may not always be conclusive. If the photographic 

evidence is not compelling, the state may reach a different conclusion. The state may determine 

that the impairment, as documented by the FLM, was not reasonably attributable to the source 

identified in the Certification. The FLM would then need to gather additional information to 

support a Certification. Alternatively, if the state determines that the source may be causing the 

haze but the qualitative evidence is not quite sufficient to determine attribution, the state could 

initiate a data collection effort to provide better information regarding visibility impairment at 

the Class I area. Such techniques may include: 

1. Better source characterization, including measurement of emissions of trace elements 

(source profiles) for use in CMB modeling 

2. Met monitoring or modeling 

3. Additional aerosol monitoring (episodic or saturation) 

4. In plume trajectory by aircraft, if available 

5. Fine time-resolved optical monitoring, such as nephelometer, transmissometer, or 

aethelometer combined with pollutant monitoring (e.g., SO2, NOx, real time PM) for 

monitoring of episodes. 

6. More refined chemical visibility model, such as CALPUFF 

The technical criteria are listed below, followed by techniques that may be used to obtain results 

about the criteria. 

1. The impairment must be related to emissions from specific sources. The visibilityimpairing pollutants of concern should be identified. 

Techniques: Back trajectory, species relationships, relationship between source 

emissions and ambient monitoring, dispersion model refined by camera, aerosol, in 

25 
plume, optical monitoring, and refined dispersion models. 

2. The attribution assessment must address the unique visibility impairment certified by 

the FLM for the Class I area. Some factors to consider include: 

a. Duration: source’s length of effect per episode 

Techniques: Monitoring, dispersion model, back trajectory, camera 

b. Frequency: how often the impairment occurs 

Techniques: Monitoring, dispersion model, back trajectory, camera 

c. Geographic extent: how much of the Class I area is impaired 

Techniques: Monitoring, dispersion model, additional data on deposition and other 

studies 

d. Magnitude: how much impairment is due to the source 

Techniques: Dispersion model, receptor model 

e. Time of occurrence 

Techniques: Monitoring, dispersion model, back trajectory, camera 

3. Uncertainty of results: Each analytical method will have its own level of uncertainty. 

These individual uncertainties should be kept in mind as outputs are compared within 

the overall assessment. If the results of different techniques are the same or similar 

(within the uncertainties of the techniques), then the overall level of uncertainty is likely 

to decrease. 

The final step in the attribution process scenario would be to verify that the source was 

operating on the days when the haze was observed in the area. The state should also determine if 

the source was experiencing unusual upset conditions during the times identified. In this 

example, the source was determined to have been operating normally. The state would then issue 

a determination that the visibility impairment at the Class I area was reasonably attributable to 

the existing stationary facility. 

Scenario 5: Data Rich 

Data input: A large special visibility study recently was conducted. 

Four months of data spanning two seasons was collected including: 

1. At one “receptor” site in a Class I area there were multiple meteorological, optical, and 

particulate samplers including extensive measurements of particle compositions, size 

distributions, scattering, absorption, light extinction, ions, oxidants, relative humidity, 

temperature, vertical wind profiles, SO2, photographs, and concentrations of four unique 

tracers released from four different sources of interest. There were co-located samplers 

measuring several parameters in more than one way. There are at least some one, six, 

and twelve-hour particle measurements in addition to twenty-four hour samples. 

26 
2. This receptor site has been an IMPROVE site for several years and these data are also 

available. 

3. At thirty-five other sites in the region, called “satellite” sites there was an IMPROVE 

Module-A sampler taking daily twenty-four hour samples which were analyzed for fine 

mass, S, soil elements, trace metals, and elemental H from which organics can be 

estimated. The unique tracers were also measured at many of these sites. 

4. Aircraft sampling of plumes from source(s) of interest was conducted. 

5. An extensive current emissions inventory was created. 

6. Wind profilers were deployed at two to three sites in addition to the receptor site. 

7. Measurements of the chemical composition of resuspended local dust, smoke from 

burning local fuels, and emissions from local point and area sources of interest were 

collected in order to create “source profiles” to be used in receptor modeling. 

Assuming the certification identifies a BART source within 100 miles of the Class I area 

from which a unique tracer was released, a combination of the following techniques is 

suggested: 

1. Examine fine particle data, including quality assurance. Use the collocated data to 

assess accuracy and precision. The one, six, and twelve-hour data should average up to 

match the twenty-four hour data and if reasonable, be used to examine the diurnal 

cycles in the fine particle concentrations. 

2. Look at the extinction budget to identify visibility-impairing pollutants. Because size 

distributions were measured, the extinction budget can be estimated from Mie scattering 

calculations as well as by using simple techniques that assume bulk scattering and 

absorption efficiencies. Check to see if measured scattering plus absorption add up to 

the measured and reconstructed extinction. 

3. Compare the special study data to historical IMPROVE and archived meteorological 

data to determine the representativeness of the study period. 

4. Perform some analysis of when the episodes are occurring. EOF analysis can be helpful 

to summarize the massive data set. Use the photographs to create a time-lapse 

visualization of the scene at the receptor site. 

5. Perform back trajectory analyses using HYSPLIT, CAPITA Monte Carlo or ATAD. 

Examine whether the trajectories change substantially when the study’s wind-profiler 

data are included. Determine whether trajectories are consistent with tracer 

concentrations. 

6. Look at relationships between particulate species (factor analysis) to see if they identify 

source types. 

7. Look at the spatial and temporal patterns of trace elements and the major constituents of 

the fine mass. This may suggest dominant source areas and transport patterns for 

different source types. Use EOF analysis to determine the patterns that explain most of 

the covariance in the data. Check to see how well these are reconciled with the back 

trajectory modeling and the deterministic modeling. Check to see if the same dominant 

sources were indicated. 

8. Examine source emissions data for correlations with ambient monitoring. 

9. Perform dispersion model such as CALMET/CALPUFF. 

27 
10. Analyze wind fields, synoptic conditions, and satellite photos. Check to see if they were 

consistent with more sophisticated meteorological modeling. Look for unusual 

conditions such as wild fires, hurricanes, stagnation episodes, etc. Look to see if 

modeled and observed cloud patterns were comparable. 

 11. Compare the meteorological and chemical characteristics of different episodes 

12. UNMIX, PMF and CMB can help determine major source types and when they were 

important. 

If, at this point, similar source/receptor relationships have been identified using several 

different techniques, this level of review is adequate. If the results are inconclusive, and there are 

differing points of view about the frequency, duration, or significance of the attribution to the 

BART-eligible source, more analyses may be necessary. Often in a large study, measurements 

are made, but not immediately analyzed in the lab due to cost. If this is the case, more samples 

could be analyzed. It is unlikely that any additional field monitoring would be required. 

The technical criteria are listed below, followed by techniques that may be used to obtain 

results about the criteria. 

1. The impairment must be related to emissions from specific sources. The visibilityimpairing pollutants of concern should be identified. 

Techniques: Reconstructed particle mass and light extinction including examination of 

the reconstructions in different size ranges and at different sites in the region, analysis 

of responses of light scattering to relative humidity, back trajectory analyses, 

examination of inter-species relationships compared to measured source profiles, 

dispersion modeling with sophisticated models such as REMSAD and CMAQ, analysis 

of wind fields and dispersion by comparison to measured tracer concentrations, 

computer animation of spatial patterns of species of interest, use of receptor models 

such as TMBR, DMB, and TAGIT that utilize unique tracer information, or other 

receptor models such as CMB, UNMIX, and PMF that do not require tracer 

information, but can use it. When so many different models can be used, model 

reconciliation is usually a part of a data-rich scenario. 

2. The attribution assessment must address the unique visibility impairment certified by 

the FLM for the Class I area. Some factors to consider include: 

a. Duration: each source’s length of effect per episode 

Techniques: Monitoring, dispersion model, back trajectory, camera 

b. Frequency: how often the impairment occurs by source 

Techniques: Monitoring, dispersion model, back trajectory, receptor model, camera 

c. Geographic extent: how much of the Class I area is impaired 

Techniques: Monitoring, dispersion model, analysis of spatial patterns using data 

from the satellite sites. 

28 
d. Magnitude: how much impairment is due to each individual source 

Techniques: Dispersion model, receptor model 

e. Time of occurrence 

Techniques: Monitoring, dispersion model, back trajectory, camera 

3. Uncertainty of results: In this case, the ability of a model to predict the observed tracer 

concentrations is an indicator of the model’s uncertainty. 

29 
30 
V. TECHNIQUES 

A. Monitoring 

Introduction 

This section describes a variety of ambient air monitoring methods that, if appropriate, 

might be used to support an attribution analysis. The methods described include those most 

commonly used in pollution studies or ambient monitoring programs and should not be 

considered an exhaustive list of potential methods. Methods include, IMPROVE, filter based 

aerosol, continuous aerosol (includes optical methods such as the nephelometer), continuous gas 

and canister sampling, transmissometer, scene (includes film, video, digital), and tracer or 

aircraft methods. 

Several of the methods described are currently in use as a part of national, state, local, tribal, 

or private ambient monitoring networks. These sites are generally located in urban areas, but 

those near the area of study could be used in the attribution analysis thereby reducing the cost of 

monitoring. 

The IMPROVE network is designed to assess visibility in Class I areas and routinely 

measure visibility impairing pollutants. These sites offer value to the attribution analysis if they 

are located in the area of study. 

The RA BART case studies show additional examples of the methods used during source 

attribution studies. The case studies also show that methods, other than ambient monitoring, may 

be used to support the analysis. Existing programs such as CASTNET (dry deposition network), 

surface water deposition studies, or snow deposition studies may provide additional data for the 

attribution analysis. 

Although not specifically listed as a monitoring technique, meteorological monitoring is an 

important element the attribution analysis. Collection of meteorological data can range from 

simple wind, temperature, and relative humidity measurement to an array of acoustic wind 

profilers. The complexity of the meteorological monitoring program depends on data needs and 

the availability of existing data. As with ambient monitoring, meteorological data may be 

available at sites located near the study area and offers reduced monitoring cost. 

1. IMPROVE

Overview: The Interagency Monitoring of PROtected Visual Environments (IMPROVE) 

program is a cooperative measurement effort governed by a steering committee composed of 

representatives from Federal and regional-state organizations. The IMPROVE monitoring 

program was established in 1985 to aid the creation of Federal and State implementation plans 

for the protection of visibility in Class I areas (156 national parks and wilderness areas) as 

stipulated in the 1977 amendments to the Clean Air Act. The objectives of IMPROVE are to: (1) 

establish current visibility and aerosol conditions in mandatory class I areas; (2) identify 

chemical species and emission sources responsible for existing man-made visibility impairment; 

31 
(3) document long-term trends for assessing progress towards the national visibility goal; and (4) 

with the enactment of the regional haze rule, provide regional haze monitoring representing all 

visibility-protected federal class I areas where practical. 

Magnitude: Possible when used in conjunction with appropriate analytical techniques. 

Frequency: Possible when used in conjunction with appropriate analytical techniques; Limited 

by twenty-four hour sample integration, and one-in-three day sampling frequency. 

Duration: Possible when used in conjunction with appropriate analytical techniques; Limited by 

24 hour sample integration, and one-in-three day sampling frequency. 

Principle: Twenty-four hour integrated filter-based ambient monitor; Gravimetric analysis for 

PM2.5 (Module D) and PM10); S from Particle Induced X-ray Emission (PIXE); NO3 from ion 

chromatography (denuded nylon filter from Module C); Organic and elemental carbon from 

Thermal Optical Reflectance (TOR); H from Proton Elastic Scattering (PESA). 

Uncertainty: All elemental S if from sulfate; All sulfate is ammonium sulfate; NO3 (Denuder 

efficiency is close to 100%. All nitrate is from ammonium nitrate); 

Average organic molecule is 70% carbon; Carbon (organic and elemental) is defined by the 

analytical method; Fine soil based on elemental composition; Course mass (PM10 – PM2.5) 

consists only of insoluble soil particles. 

Strengths: Regulatory indicator for regional haze rule; Long term data record in or near many 

federal Class I areas; Extensive network currently in place. 

Limitations: Integrated twenty-four hour sample; one-in-three day sampling interval; Nitrate 

losses due to volatilization from filter; Not capable of distinguishing between primary particulate 

and atmospherically transformed particulate. 

Level of Expertise Required: Standard operating procedures available for routine operation and 

maintenance; Chemical analysis must be conducted by appropriate laboratory. 

Regulatory Context: Regional Haze rule; Included in SIP Visibility Plan 

2. FILTER-BASED AEROSOL

Overview: Filter-based aerosol monitoring is used to identify chemical species and obtain 

concentration measurements of atmospheric constituents that contribute to visibility impairment. 

Primary techniques include filter-based aerosol samplers that collect samples on various 

substrates in various size ranges such as PM2.5 or PM10. Aerosol monitoring can provide fine 

mass concentration, course mass concentration, optical absorption, major and trace elements, 

organic and elemental carbon, and sulfate, nitrate, and chloride ions. A variety of methods are 

available to conduct filter based aerosol monitoring. Many methods are approved as an EPA 

reference method, while some are not, but may offer variability that the reference method does 

not. 

32 
Magnitude: Possible when used in conjunction with appropriate analytical techniques. 

Frequency: Possible when used in conjunction with appropriate analytical techniques; Limited 

by 24-hour sample integration and sampling frequency (daily sampling is possible depending on 

instrument selected). 

Duration: Possible when used in conjunction with appropriate analytical techniques; Limited by 

24-hour sample integration and sampling frequency (daily sampling is possible depending on 

instrument selected). 

Principle: The methods used for analyses of these filter media include gravimetry (electromicrobalance) for mass; X-ray fluorescence (XRF) and particle induced X-ray emission (PIXE) 

for trace elements; Ion chromatography (IC) for anions and selected cations; Controlledcombustion for carbon; Gas chromatography/mass spectroscopy (GC/MS) for semi-volatile 

organic particles; Special measurement needs may include determining particle size and 

morphology through optical and/or electron microscopy. 

Strengths: Large network of urban monitoring available; Filter based sampling allows for a 

variety of chemical/elemental analysis. 

Limitations: Integrated twenty-four hour sample; Generally operated on one-in-three or one-insix day sampling interval (daily sampling is possible depending on instrument selected); Not 

capable of distinguishing between primary particulate and atmospherically transformed 

particulate. 

Level of Expertise Required: Standard operating procedures available for routine operation and 

maintenance; Chemical analysis must be conducted by appropriate laboratory. 

Regulatory Context: Commonly used in NAAQS/SIP compliance monitoring networks. 

3. CONTINUOUS AEROSOL 

Overview: Aerosols can be measured continuously using several different methods. Optical 

measurement of aerosols can be measured using an instrument such as a nephelometer to 

measure light scattering (bscat) or a aethelometer to measure light absorption (babs) by aerosols 

(black carbon). Continuous instruments such as TEOM or BETA can provide PM10 or PM2.5

aerosol concentration. 

Magnitude: Possible when used in conjunction with appropriate analytical techniques. 

Frequency: Possible when used in conjunction with appropriate analytical techniques; Limited 

by twenty-four hour sample integration and sampling frequency (daily sampling is possible 

depending on instrument selected). 

33 
Duration: Possible when used in conjunction with appropriate analytical techniques; Limited by 

twenty-four hour sample integration and sampling frequency (daily sampling is possible 

depending on instrument selected). 

Strengths: Continuous measurement with at least hourly time resolution; Nephelometers and 

Aethelometers are commonly used to support Class I area monitoring programs and an existing 

data record may be available in some areas. 

Limitations: Continuous aerosol measurement with methods such as TEOM and BETA are 

generally made in urban areas to support NAAQS compliance networks; Not capable of 

distinguishing between primary particulate and atmospherically transformed particulate. 

Level of Expertise Required: Standard operating procedures available for routine operation and 

maintenance. 

Regulatory Context: Commonly used in Class I area monitoring networks or urban NAAQS 

compliance networks. 

4. CONTINUOUS GASEOUS 

Overview: A variety of gaseous pollutants, such as Ozone (O3), Carbon Monoxide (CO), 

Nitrogen Dioxide (NOx), nitric oxide (NO), ammonia (NH3), hydrogen peroxide (H2O2), sulfur 

dioxide (SO2), Organics, and HAPS/TOXICS, can be measured continuously. Gaseous 

monitoring is generally conducted with instruments that continuously draw sample air and 

periodically (as frequently as once per second) analyze the sample. Canister systems collect an 

ambient air sample over a specific period of time in clean evacuated canisters. The canisters are 

then subject to subsequent analysis at a laboratory using a method such as GC/FID. This method 

is able to provide time-integrated samples from several hours to twenty-four hours or more. 

Regular checks of the flow rate, stability, reproducibility, precision, and accuracy of these 

instruments must be conducted on a regular schedule in order to ensure data quality. 

Magnitude: Possible when used in conjunction with appropriate analytical techniques. 

Frequency: Possible when used in conjunction with appropriate analytical techniques. 

Duration: Possible when used in conjunction with appropriate analytical techniques. 

Strengths: Continuous measurement with hourly time resolution; Monitors available to identify 

variety of pollutants. 

Weaknesses/Limitations: Generally require conditioned environment and frequent performance 

checks. 

Practical Considerations: Data may be available from established urban area monitoring 

networks and some Class I area monitoring networks; Additional cost ($/year) for new sites. 

34 
Level of Expertise Required: Standard operating procedures available for routine operation and 

maintenance. 

Regulatory Context: Commonly used in urban NAAQS compliance and HAPS/TOXICS 

networks. 

5. TRANSMISSOMETER 

Overview: Transmissometers measure the amount of light transmitted through the atmosphere 

over a known distance (generally between 0.5 km and 10.0 km) between a light source of known 

intensity and a receiver. The transmission measurements are electronically converted to hourly 

averaged light extinction (bext). 

Magnitude: Possible when used in conjunction with appropriate analytical techniques. 

Frequency: Possible when used in conjunction with appropriate analytical techniques. 

Duration: Possible when used in conjunction with appropriate analytical techniques. 

Uncertainties: A transmissometer must be installed in stable locations with a clear and 

unobstructed path to avoid interference with the signal. 

Strengths: Continuous measurement of bext in many Class I areas and some urban areas. 

Limitations: Not capable of identifying pollutants contributing to visibility impairment. 

Level of Expertise Required: Standard operating procedures available for routine operation and 

maintenance; Data processing/quality assurance requires high level of expertise. 

Regulatory Context: Commonly used in Class I area monitoring networks and in some urban 

areas.

6. SCENE

Overview: Scene monitoring refers to the use of still and/or time-lapse photography (including 

digital imagery) to provide a qualitative representation of visual air quality. Scene monitoring 

data quality objective recommendations are to document the appearance of scenes of interest 

under a variety of air quality and illumination conditions at different times of day and different 

seasons. Scene monitoring documents the visual condition observed at a monitoring site. The 

data collection schedule can be tailored to capture the periods when visibility impairment is most 

likely to occur at specific sites. Time-lapse movies (generally time-lapse video or super 8 mm 

film) can be used at monitoring sites and during special studies to document the visual dynamics 

of a scene or source. 

Magnitude: Cannot provide a quantitative measurement of visibility impairment but can 

qualitatively illustrate various levels of visibility impairment. 

35 
Frequency: Possible depending on the method used. Time-lapse video may be able to 

demonstrate the frequency of the impairment. The use of still photography to document 

impairment frequency depends upon the number of images acquired over time. 

Duration: Possible depending on the method used. Time-lapse video may be able to demonstrate 

the impairment frequency. The use of still photography to document impairment frequency 

depends upon the number of images acquired over time. 

Uncertainties: n/a 

Strengths: Provides image/video record 

Limitations: Not capable of identifying pollutants contributing to visibility impairment. 

Level of Expertise Required: Standard operating procedures available for routine operation and 

maintenance. 

Regulatory Context: Commonly used in Class I area monitoring networks and in some urban 

areas. 

7. TRACER METHODS, LIDAR SYSTEMS, AIRCRAFT BASED MEASUREMENTS 

Overview: The methods described in this section are more specialized methods generally 

reserved for special studies as opposed to the previously described methods that are used more 

routinely. Tracer methods, lidar systems and aircraft based measurements will be described 

individually. 

Tracer Methods: 

A tracer element or compound is a substance with unique characteristics that allows positive 

identification at very low concentrations. The tracer compound of choice will vary by source 

type and composition of the plume being tracked. In general, the tracer must have very low 

natural background concentrations and ideally would have the same chemical form and 

properties as the compound being tracked. In ambient applications where use of the ideal tracer 

is not possible due to potential environmental risk, a near-substitute compound may be used. 

When used to determine potential source impacts, the chosen compound is released from a 

source stack and downwind monitors are used to detect the presence of the compound. 

Lidar Methods: 

A lidar transmits short pulses of laser light into the atmosphere. The laser beam loses light to 

scattering as it travels. At each range, some of the light is backscattered into a detector. Because 

the light takes longer to return from the more distant ranges, the time delay of the return pulses 

can be converted to the corresponding distance between the atmospheric scatterer and the lidar. 

The end result is a profile of atmospheric scattering versus distance. Analysis of this signal can 

yield information about the distribution of aerosols in the atmosphere. The amount of backscatter 

indicates the density of the scatters. This can be used to measure cloud base height or track 

36 
plumes of pollution. Other properties of the atmosphere can also be deduced from the lidar return 

signals. A frequency shift in the light because of the Doppler effect permits measurement of 

wind speeds. By detecting the amount of depolarization, one can discriminate between liquid 

droplets and nonspherical ice particles. Differential Absorption Lidar (DIAL) uses absorption, as 

evidenced by reduced backscatter from greater distances, to measure the concentration of 

atmospheric gases. A Raman lidar detects particular atmospheric components (such as water 

vapor) by measuring the wavelength-shifted return from selected molecules (NOAA). 

Aircraft Based Measurements: 

Aircraft based measurement systems utilize specially equipped aircraft to make pollutant and 

meteorological measurements at various elevations throughout the study domain. The aircraft 

can be equipped with a multitude of gaseous, aerosol, optical and meteorological equipment. 

This measurement method provides the advantage of vertical profiles of various parameters, the 

ability to track point source plumes, and the ability to establish boundary conditions for future 

analytical and modeling exercises. 

References:

NOAA, Atmospheric Light Division, Environmental Technology Laboratory, 

http://www2.etl.noaa.gov/DIAL_lidar.html

U.S. Environmental Protection Agency, Visibility Monitoring Guidance (EPA-454/R-99-003), 

June 1999. 

National Research Council, Protecting Visibility in National Parks and Wilderness Areas, 

National Academy Press, Washington D.C., 1993, pp. 315-357. 

37 
38 
Table 1. Monitoring Techniques 

Criteria Monitoring Method 

IMPROVE Filter Based

Aerosol 

Continuous Aerosol Gaseous; 

Continuous 

methods, canister 

sampling, etc. 

Transmissometer Scene 

35mmfilm/8

video, dig

PollutantPM10 Yes Yes Yes No No No PM2.5 Yes Yes Yes Yes No No NOx (Site specific) No No Yes No No SO2 (Site specific) No No Yes No No Sulfate Yes Yes No No No No Nitrate Yes Yes No No No No Carbon Yes Yes No No No No Organics Yes Yes No Yes No No Other Reconstructed 

extinction 

Nephelometer - 

Bscat 

Aethelometer - Babs 

HAPS, TOXICS Total 

Extinction 

Visual 

Paramete

Visibility/Concentration ChangesMagnitude Yes Yes All Possible All Possible All Possible No Frequency Yes Yes Yes Duration Yes Yes Yes Time of Day No No 

All Possible All Possible All Possible 

Yes 

Likely Part of FLM Certification?

Possible 

39 
Monitoring Techniques (continued)

PrincipalQualitative/ Quantitative 

Quantitative Qualitati

Strengths Reconstructed 

extinction calculation, historical record 

various chemical analysis, large network nationwide 

Continuous measurement, nephelometer commonly located in or near Class I areas 

Continuous measurement, variety of possible pollutants 

Continuous measurement, provides light extinction value, historical record 

Relatively inexpensivuncomplicaoperational requiremen

Weaknesses/ Limitations 

Fixed location in or near ClassI areas, also located in several urban areas 

Integrated 24 hour sample generally collected on onein-three schedule, commonly in urban areas 

TEOM, BETA, etc, commonly located in urban areas 

Generally require conditioned environment for proper operation, commonly located in urban areas 

Fixed location in or near ClassI areas 

Number of images limvideo requistorage and routine rev

Distinguish BART Sources? 

Possible with other analysis 

Possible with otheranalysis 

No Possible with other

analysis 

No Possible wi

other analy

Practical ConsiderationsCost Moderate; varies depending on the number of instruments Low 

40 
 B. Source Modeling 

Introduction

Given the complex natural environment, the state must choose the configuration of modeling 

techniques that will provide the most information on the contributing source or sources of 

impairment within the limited resources of current technology, data, budgets, time and staff 

availability. 

1. Physical Models

Physical models are those that simulate the meteorology and air quality over an area. 

Modeling relies on a numerical or analytical model to estimate particulate concentrations in 

space and time. Because of its nature and sources, particulate matter is difficult to model over all 

spatial scales. Many air quality models that are currently available were designed to be applied 

over the regional scale with grid sizes from four to forty kilometers. Modeling requires detailed 

meteorological fields and emissions inventory over the entire domain. The compilation of data 

required to run these models can require much effort and expertise. Efforts are underway by 

government agencies in the U.S. to generate and archive both emissions and estimated activity 

levels of many source types in geographical information systems. 

Numerical source-oriented models are designed to simulate atmospheric diffusion or 

dispersion and estimate concentrations at defined receptors. Numerical source models can be 

grouped as kinematic, first-order closure, or second-order closure models (Bowne and 

Lundergan, 1983). Kinematic models are the simplest both mathematically and conceptually. 

These models simplify the non-linear equations of turbulent motion, thereby permitting a closed 

analytical approximation to describe pollutant concentration (Green et al., 1980). First-order 

closure models are based on the assumption of an isotropic pollutant concentration field. 

Consequently, turbulent eddy fluxes are estimated as being proportional to the local spatial 

gradient of the transport quantities. The Eulerian grid models, Lagrangian particle models, and 

trajectory puff/plume models are included in this category. Second-order closure models involve 

a series of algorithm transformations of the equations of state, mass continuity, momentum, and 

energy by using the Boussinesque approximation and Reynold’s decomposition theory (Holton, 

1992; Stull, 1988). 

2. Spatial Scales 

The model’s applicable spatial scales play a large role meeting the analysis' objectives and 

its ability to accurately assess spatial variability. PM10 and PM2.5 concentrations modeled or 

measured at any receptor result from the complex interaction of meteorology, chemical 

transformations and emissions from nearby and distant sources. For example, a monitor located 

near an operating construction site will be impacted more by the daily construction activity than 

the surrounding area. That site may be classified as representing an area of a few tens of meters 

to no more than one kilometer depending on the size of the construction area and fugitive dust 

control measures. 

The dimensions given below are nominal rather than exact and are presented as defined in 

40 CFR part 58. 

41 
a. Micro-Scale (10 to 100 m): This scale does not apply to scenarios relevant to the attribution 

problem. Modeling at the microscale is usually done by simple Gaussian plume models such as 

ISCST3. Measurements in urban areas can show considerable variations at this scale while those 

in pristine areas would not. Variations often occur when monitors are located close to a low-level 

emissions source, such as a busy roadway, construction site, within a community that uses wood 

stoves, or a short industrial stack. Fortunately, compliance monitoring site exposure criteria 

avoids microscale influences even for source-oriented monitoring sites. 

b. Middle Scale (100 to 500 m): Middle-scale monitors show significant differences between 

locations that are ~0.1 to 0.5 km apart. These differences may occur near large industrial areas 

with many different operations or near large construction sites. Monitors with middle-scale zones 

of representation are often source-oriented, used to determine the contributions from emitting 

activities with multiple, individual sources to nearby community exposure monitors. 

c. Neighborhood Scale (500 m to 4 km): Neighborhood-scale monitors do not show significant 

differences in particulate concentrations with spacing of a few kilometers. This dimension is 

often the size of emissions and modeling grids used in large urban areas for PM source 

assessment, so this zone of representation of a monitor is the only one that should be used to 

evaluate such models. Sources affecting neighborhood-scale sites typically consist of small 

individual emitters, such as clean, paved, curbed roads, uncongested traffic flow without a 

significant fraction of heavy-duty vehicles, or neighborhood use of residential heating devices 

such as fireplaces and wood stoves. 

d. Urban Scale (4 to 100 km): Urban-scale monitors show consistency among measurements 

with monitor separations of tens of kilometers. These monitors represent a mixture of particles 

from many sources within the urban complex, including those from the smaller scales. PM 

measurements at urban-scale locations are not dominated by any particular neighborhood, 

however. Urban-scale sites are often located at higher elevations and away from highly traveled 

roads, industries, and residential heating. 

e. Regional-Scale Background (100 to 1,000 km): Regional-scale background monitors show 

consistency among measurements for monitor separations of a few hundred kilometers. 

Background concentrations are often more consistent for specific chemical compounds, such as 

sulfate or nitrate, than they are for PM mass concentrations. Regional-scale PM is a combination 

of naturally-occurring aerosol from windblown dust and marine aerosol as well as particles 

generated in urban and industrial areas that may be more than 1,000 km distant. Regional-scale 

sites are best located in rural areas away from local sources, and at higher elevations. National 

parks, national wilderness areas, and many state and county parks and reserves are appropriate 

areas for regional-scale sites. Many of the IMPROVE sites characterize PM regional scale 

background in different regions of the United States. 

f. Continental-Scale Background (1,000 to 10,000 km): Continental-scale background 

monitors show little variation even when they are separated by more than 1,000 km. They are 

hundreds of kilometers from the nearest significant emitters. Though these sites measure a 

mixture of natural and diluted manmade source contributions, the manmade component is at its 

minimum expected concentration. The Jarbidge Wilderness IMPROVE site in northern Nevada 

is a good example of a continental-scale background site for particulate matter in North America. 

42 
e. Global-Scale Background (>10,000 km): Global-scale background monitors are intended to 

quantify concentrations transported between different continents as well as naturally-emitted 

particles and precursors from sea spray, volcanoes, and windblown dust. Yellow sand from 

China has been detected at the Mauna Loa, HI, laboratory (Darzi and Winchester, 1982; Braaten 

and Cahill, 1986), as well as on the North American continent. Red dust from Africa’s Sahara 

desert has been detected at Mt. Yunque, Puerto Rico and over the southeastern United States. 

Other global-scale sites include McMurdo, Palmer, and Ahmundson-Scott stations in Antarctica 

(Lowenthal et al., 1996), Pt. Barrow, Alaska, and Mace Head, Ireland. 

3. Chemical Composition 

This section illustrates how the chemical composition of aerosols is an important 

consideration in the choice of particulate matter models. The knowledge of how the aerosol's 

composition varies over an area will play a key role in the attribution study design. 

The relative abundance of chemical components in the atmosphere closely reflect the 

characteristics of emission sources. Major chemical components of PM2.5 and PM10 mass in 

urban and rural areas consist of nitrate, sulfate, ammonium, carbon, geological material, sodium 

chloride, and liquid water. 

Chemical compositions can vary spatially in all scales of the atmosphere and depend on 

sources surrounding the monitoring site. For example, on the continental scale, the eastern U.S. 

fine particulate chemical compositions are different than those of the western states. In the 

eastern portion of the U.S., nonurban PM2.5 is dominated by secondary sulfate, organics and 

elemental carbon (EPA, 1996). The data to support this conclusion are based on the IMPROVE 

and CASTNET networks. These networks provide a background fine-fraction aerosol database 

because the monitoring sites are primarily located in national parks and wilderness areas. 

Analysis of this network shows that the western U.S. nonurban PM2.5 aerosol is predominantly 

carbon in nature. Nitrate also contributes significantly to the fine particle mass budget 

particularly in central and coastal California. Within these generalizations, obvious departures 

will be found especially near sources such as near the ocean and urban areas where the aerosol 

will be primarily influenced by sea salt and combustion particles, respectively. 

The typical PM2.5 chemical compositions vary by season (Chow et al., 1993a; 1996a, 

Watson et al., 1997), and consist of the following major components: 

a. Organic Carbon: Organic carbon is composed of gases and particles containing 

combinations of carbon and hydrogen atoms. Organic compounds found in ambient air may also 

be associated with other elements and compounds, particularly oxygen, nitrogen, sulfur, 

halogens, and metals. Particulate organic carbon consists of hundreds, possibly thousands, of 

separate compounds (Rogge et al., 1993a). The mass concentration of organic carbon can be 

accurately measured, as can carbonate carbon (Chow et al., 1993b), but only about ten percent of 

the specific organic compounds that it contains have been measured. Vehicle exhaust (Rogge et 

al., 1993b), residential and agricultural burning (Rogge et al., 1998), meat cooking (Rogge et al., 

1991), fuel combustion (Rogge et al., 1997), road dust (Rogge et al., 1993c), and particle 

formation from heavy hydrocarbon gases (Pandis et al., 1992), are the major sources of organic 

carbon in PM2.5. 

43 
b. Elemental Carbon: Elemental carbon is black, often called “soot.” Elemental carbon 

contains pure, graphitic carbon, but it also contains high molecular weight, dark-colored, 

nonvolatile organic materials such as tar, biological material (e.g., coffee), and coke. Elemental 

carbon usually accompanies organic carbon in combustion emissions, with diesel exhaust 

(Watson et al., 1994a, 1998) being the largest contributor. 

c. Sulfate: Ammonium sulfate ((NH4SO4), ammonium bisulfate (NH4HSO4), and sulfuric acid 

(H2SO4), are the most common sulfate compounds in PM2.5. These compounds are water-soluble 

and reside almost exclusively in the PM2.5 size fraction. Sodium sulfate (Na2SO4) has been found 

in coastal areas where sulfuric acid has been neutralized by sodium chloride (NaCl) in sea salt. 

Although gypsum (Ca2SO4) and some other geological compounds contain sulfate, these are not 

easily dissolved in water for chemical analysis and are more abundant in the coarse fraction than 

in PM2.5; they are usually classified in the geological fraction. 

d. Nitrate: Ammonium nitrate (NH4NO3) is the most abundant nitrate compound, a large 

fraction of PM2.5 occurs during winter, and a moderate fraction occurs during fall. Sodium nitrate 

(NaNO3) is found in the PM2.5 and coarse fractions near the oceans and salt playas. Small 

quantities of sodium nitrate have been found in summertime particulate matter inland owing to 

transport from the ocean (Chow et al., 1996b). 

e. Ammonium: Ammonium sulfate (NH4SO4) and ammonium nitrate (NH4NO3) are the most 

common compounds containing ammonium from reactions between sulfuric acid, nitric acid, and 

ammonia gases. While most of the sulfur dioxide and oxides of nitrogen originate from fuel 

combustion in stationary and mobile sources, most of the ammonia derives from living things, 

especially animal husbandry practiced in dairies and feedlots. 

f. Geological Material: Suspended dust consists mainly of oxides of aluminum, silicon, 

calcium, titanium, iron, and other metal oxides. In areas surrounded by substantial terrain (i.e., 

mountains), eons of runoff produce mineral compositions in soils that can be fairly 

homogeneous, with the exception of places where dry lake beds exist that have accumulated salt 

deposits. Industrial processes such as steel making, smelting, and mining have distinct geological 

compositions. For instance, cement production and distribution facilities may use alcareous, 

siliceous, argillaceous, and ferriferous minerals that may not be natural to the region, with 

limestone (CaCO3) being the most abundant (Greer et al., 1992). Suspended geological material 

resides mostly in the coarse particle fraction (Houck et al, 1989,1990), and typically constitutes 

~50% of PM10 while only contributing 5 to 15% of PM2.5 (Watson et al., 1994b). 

g. Sodium Chloride: Salt is found in suspended particles near oceans, open playas, and after 

de-icing materials are applied. Bulk sea water contains 57±7% chloride, 32±4% sodium, 8±1% 

sulfate, 1.1±0.1% soluble potassium, and 1.2±0.2% calcium (Pytkowicz and Kester, 1971). As 

noted above, sodium chloride is often neutralized by nitric or sulfuric acid in urban air where it is 

encountered as sodium nitrate or sodium sulfate. 

h. Liquid Water: Soluble nitrates, sulfates, ammonium, sodium, other inorganic ions, and some 

organic material (Saxena and Hildemann, 1997) absorb water vapor from the atmosphere, 

especially when relative humidity exceeds 70% (Tang and Munkelwitz, 1993). Sulfuric acid 

absorbs some water or deliquesces at all humidities. Particles containing these compounds grow 

44 
into the droplet mode as they take on liquid water. Some of this water is retained when particles 

are sampled and weighed for mass concentration. The precise amount of water quantified in a 

PM2.5 depends on its ionic composition and the equilibration relative humidity applied prior to 

laboratory weighing. 

Ambient mass concentrations contain both primary and secondary particles. Primary 

particles are directly emitted by sources and usually undergo few changes between source and 

receptor. Atmospheric concentrations of primary particles are, on average, proportional to the 

quantities that are emitted. 

Secondary particles are those that form in the atmosphere from gases that are directly 

emitted by sources. Sulfur dioxide, ammonia, and oxides of nitrogen are the precursors for 

sulfuric acid, ammonium bisulfate, ammonium sulfate, and ammonium nitrate particles. “Heavy” 

volatile organic compounds or HVOC (those containing more than eight carbon atoms) may also 

change into particles. The majority of these transformations result from intense photochemical 

reactions that also create high ozone levels. Secondary particles usually form over several hours 

or days and attain aerodynamic diameters in the accumulation mode between 0.1 and 1 μm. 

Several of these particles, notably those containing ammonium nitrate, are volatile and transfer 

mass between the gas and particle phase to maintain a chemical equilibrium. This volatility has 

implications for ambient concentration measurements as well as for gas and particle 

concentrations in the atmosphere. 

Ambient concentrations of secondary aerosols are not necessarily proportional to quantities 

of emissions since the rate at which they form may be limited by factors other than the 

concentration of the precursor gases. Secondary particulate ammonium nitrate concentrations 

depend on gaseous ammonia and nitric acid concentrations as well as temperature and relative 

humidity. A nearby source of ammonia may cause a localized increase in PM2.5 concentrations 

by shifting the equilibrium from the gas to the particulate ammonium nitrate phase (Watson et 

al., 1994c). Ammonium sulfate may form rapidly from sulfur dioxide and ammonia gases in the 

presence of clouds and fogs, or slowly in dry air. Because fine particle deposition velocities are 

slower than those of the gaseous precursors, PM2.5 may travel much farther than the precursors, 

and secondary particles precursors are often found far from their emissions sources and may 

extend over scales exceeding 1,000 km. 

4. Particle Formation 

Ammonium nitrate and ammonium sulfate aerosols are the most prevalent secondary 

particles found at urban and non-urban sites throughout the U.S. during the winter. These 

particles can form when gas molecules are attracted to and adhere to existing particles. 

Sulfur dioxide gas changes to particulate sulfate through gas- and aqueous-phase 

transformation pathways. In the gas-phase pathway, ultraviolet sunlight induces photochemical 

reactions creating oxidizing species that react with a wide variety of atmospheric constituents. 

The gas-phase transformation rate appears to be controlled more by the presence or absence of 

the hydroxyl radical and its competing reactions of other gases than by the sulfur dioxide 

concentrations. 

45 
In the presence of fogs or clouds, sulfur dioxide dissolves in droplets where it experiences 

aqueous reactions that are much faster than gas-phase reactions. When ozone and hydrogen 

peroxide are dissolved in the droplet, the sulfur dioxide is quickly oxidized to sulfuric acid. 

When ammonia is dissolved in the droplet, the sulfuric acid is neutralized to ammonium sulfate. 

If the fog or cloud evaporates and relative humidity decreases below 100 percent, the sulfate 

particle exists as a small droplet that includes a portion of liquid water. As the relative humidity 

further decreases below 70 percent, the droplet evaporates and a small, solid sulfate particle 

remains. The reactions within the fog droplet are very fast, and the rate is controlled by the 

solubility of the precursor gases. Aqueous transformation rates of sulfur dioxide to sulfate are 10 

to 100 times as fast as gas-phase rates. These chemical reactions are critical to understanding PM 

concentrations in areas and downwind of areas that emits large amounts of SO2. The location and 

SO2 emissions output of large point sources such as coal and oil fired power plants need to be 

mapped and compared with transport patterns in order to determine the impact of ammonium 

sulfate particles on ambient surface concentrations. 

Fogs serve as an environment for creating particles and as vehicles for particle removal. 

During heavy fogs, particles and precursor gases are scavenged as fog droplets grow to sizes that 

settle rapidly to the surface. The extent and intensity of these fogs is so poorly characterized, 

however, that it is not yet possible to determine where and when particle formation overtakes 

particle deposition, thereby adding to the PM2.5 concentration loading. 

Nitrogen oxide converts to nitrogen dioxide, primarily by reaction with ozone. Nitrogen 

dioxide can: 1) change back to nitrogen oxide in the presence of ultraviolet radiation; 2) change 

to short-lived species which take place in other chemical reactions; 3) form organic nitrates; or 4) 

oxidize to form nitric acid. The major pathway to nitric acid is a reaction with hydroxyl radicals 

that transforms nitrogen dioxide to nitric acid. Nitric acid deposits from the atmosphere fairly 

rapidly but, in the presence of ammonia, it is neutralized to particulate ammonium nitrate. This is 

an important process in secondary particle production because many agricultural areas 

surrounding populated urban areas contain large ammonia sources. Chow and Egami (1997) 

show that San Joaquin Valley ammonia concentrations are large during winter. Conversion rates 

for nitrogen dioxide to nitric acid, ranging from less than one percent per hour to ninety percent 

per hour. These rates are typically five to ten times the conversion rates for sulfate formation. 

Though they vary throughout a twenty-four hour period, these rates are significant during both 

daytime and nighttime hours, in contrast to the gas-phase sulfate chemistry that is most active 

during daylight hours. The important nitric acid-ammonia reaction has implications to network 

design by the need to locate and map possible sources of ammonia. Significant sources of 

ammonia are associated with animal husbandry and fertilizer applications. Locating and 

estimating ammonia emissions will be a difficult task because it is not traditionally tabulated in 

emission inventories and requires further research to refine the methodology to measure the 

emissions. 

While ammonium sulfate is a fairly stable compound, ammonium nitrate is not. Its 

equilibrium with gaseous ammonia and nitric acid is strongly influenced by temperature and 

relative humidity. Atmospheric particle nitrate can occur in atmospheric aerosol particles as solid 

ammonium nitrate or as ionized ammonium nitrate in aerosol particles containing water. In both 

46 
the solid and ionized forms, ammonium nitrate is in equilibrium with gas-phase nitric acid and 

ammonia. 

For fixed relative humidity, increasing temperature decreases the particle nitrate fraction. 

This is a consequence of the direct relation between the equilibrium constants and temperature. 

As temperature increases, the equilibrium constants increase, which means higher gas-phase 

pressures can be supported, thereby reducing the particle nitrate fraction. For fixed humidity, 

decreasing temperature increases the particle nitrate fraction. As temperatures approach 0°C, the 

curves approach limiting values. Particle fractions of one are used for ion ratios greater than or 

equal to one, and particle fractions are determined by the amount of available ammonia for ion 

ratios less than one. For the higher temperatures, increasing relative humidity increases the 

particle nitrate fraction. This is a consequence of liquid water present for the 60% and 80% 

relative humidity cases. When there is sufficient ammonia present with 30% relative humidity, 

more than 90% of the nitrate is in the particle phase for temperatures less than 20°C. More than 

half of the particle nitrate is gone at temperatures above 30°C, and all of it disappears at 

temperatures above 40°C. 

Atmospheric water is another important component of suspended particulate matter. The 

sharp rise in liquid water content at relative humidities between 55% and 75% is known as 

deliquescence. A precise humidity at which soluble particles take on liquid water depends on the 

chemical mixture and temperature. Particles containing these compounds grow into the droplet 

mode as they take on liquid water, so the same concentration of sulfate or nitrate makes a much 

larger contribution to light extinction when humidities are high (>70 percent) than when they are 

low (<30 percent). Excess liquid water is also measured as part of the PM2.5 mass when sampled 

by light scattering continuous monitors or when filters have not been equilibrated at relative 

humidities less than 30% prior to weighing. 

Some of the organic carbon in suspended particles is also of secondary origin. Secondary 

organic compounds in particulate matter include aliphatic acids, alcohols, aromatic acids, nitroaromatics, carbonyls, esters, phenols, and aliphatic nitrates (Grosjean and Seinfeld, 1989; 

Grosjean, 1992, Pandis et al., 1992, 1993; Seinfeld and Pandis, 1998). Normally, primary 

organic carbon particles are more prevalent than secondary organics with exceptions such as 

those found in Los Angeles where conditions of clear skies and high photochemical smog are 

frequent. Although secondary organic aerosol was thought to be minimal during winter in central 

California, recent analyses (Strader et al., 1998) demonstrate that it could be as much as 20% of 

twenty-four hour organic carbon in some samples. This occurs because low wintertime 

temperatures lower the saturation vapor pressure for semi-volatile organic compounds. This is 

probably minor during winter and fall when photochemical reactions are not dominant. 

The exact precursors of secondary organics are not well understood, but they are believed to 

consist of heavy hydrocarbons with more than seven carbon atoms. Odum (1997) identifies 

aromatics as the major group of commonly measured reactive organic gases that affect both 

ozone and secondary aerosol formation. 

47 
5. Source Modeling Techniques 

Before selecting a modeling technique, it is wise to establish a conceptual model. A 

conceptual model describes the relevant physical and chemical processes that affect emissions, 

transport, and transformation specific to the region of interest. It is the starting point for any 

source apportionment process. Conceptual models take advantage of the large body of scientific 

knowledge already acquired. They identify the sources that are likely to be present and eliminate 

those that are not. They examine meteorological conditions that affect concentrations and focus 

further modeling on the conditions conducive to the high concentrations. 

Modeling techniques relevant to attribution are split into several categories depending 

complexity, physical attributes, purpose and cost to execute. The following tables on pages 55 to 

62 provide a matrix of detailed information on specific models grouped in these categories. 

a. Puff Modeling Techniques 

These models are based on a Lagrangian framework where air parcels are tracked spatially 

and temporally. They can include chemical mechanisms as well as deposition effects. The most 

commonly used puff model is the CALMET/CALPUFF (Scire et al., 2000). 

b. Grid Modeling Techniques 

For estimating PM2.5 levels, Eulerian models that include aerosol modules simulating the 

physical and chemical processes governing particulate concentrations in the atmosphere are more 

suitable than Lagrangian models such as plume trajectory models. Eulerian three-dimensional 

models may use either a simplified treatment of atmospheric chemistry (usually used to address 

long-term particulate concentrations at urban sites) or include a more detailed atmospheric 

chemistry treatment (usually used to simulate only a few days of episodes due to their 

compositional cost). 

Commonly used long-term Eulerian models with simplified atmospheric processes include 

(Seigneur et al., 1997): 

• Urban Airshed Model Version V (UAM-V). 

• Urban Airshed Model with version V with Linear Chemistry (UAM-LC) 

• Regulatory Modeling System for Aerosol and Deposition (REMSAD). 

Short-term Eulerian models with complex atmospheric processes include: 

• Urban Airshed Model Version V with Aerosols (UAM-AERO), 

• Urban Airshed Model with Aerosol Inorganic Module (UAM-AIM). 

• SARMAP Air Quality Model with Aerosols (SAQM-AERO). 

• Community Multi-scale Air Quality Model (CMAQ) 

48 
• Comprehensive Air Quality Model with extensions (CAMx) 

All of the above mentioned Eulerian models have been developed by various scientists from 

universities, federal and state agencies, and the private sector. These particulate air quality 

models provide a three-dimensional treatment to simulate the fate and transport of atmospheric 

contaminants. All of these Eulerian models include gas phase chemistry and aerosol dynamics 

and simulate atmospheric inorganics (such as sulfate, nitrate, and ammonium), but some of these 

models do not include the treatment of organics (i.e., REMSAD and UAM-LC). 

c. Lagrangian Trajectory Model Techniques 

The advantages of using Lagrangian models are the ease of use, the ability to perform many 

trajectories and perform back trajectories. Commonly used Lagrangian models include 

HYSPLIT (Draxler and Hess, 1997) and FLEXPART (Stohl and Siebert, 2001). 

d. Meteorological Modeling Techniques 

Meteorological models describe transport, dispersion, vertical mixing, and moisture in time 

and space. Meteorological models consist of straight line, interpolation (termed diagnostic), and 

first principle (termed prognostic) formulations, with increasing levels of complexity and 

requirements for computational and data resources. 

The straight line model is applied to hourly wind directions from a single monitor, assuming 

an air mass travels a distance equal to the wind velocity in the measured direction, regardless of 

the distance from the monitoring site. This model is applicable for a few hours of transport in flat 

terrain, typically for evaluating a single emissions source. 

Interpolation models integrate wind speed and directions from multiple measurement 

locations, including upper air measurements provide by remote sensors or balloon launches. The 

more advanced of these models allow barriers, such as mountains, to be placed between 

monitors. Wind fields, therefore, show different directions and velocities at different horizontal 

and vertical positions. Interpolation wind models are applicable to domains with a large number 

of well-placed monitors and for estimating the movement of air masses from many sources over 

transport times of more than half a day. The number and placement of monitors, especially upper 

air monitors, is especially important in mountainous terrain and in coastal areas where winds are 

unusual. 

First principle models (Stauffer and Seaman, 1994; Seaman et al., 1995; Koracin and Enger, 

1994) embody scientists’ best knowledge of atmospheric physics and thermodynamics, 

employing basic equations for conservation and transfer of energy and momentum. Also known 

as “prognostic models,” first principle models purport to need no data other than values from a 

sparse upper air network for interpolation. They are computationally intensive, often requiring 

supercomputers but have become more practical and cost-effective as workstation and desktop 

computers become more powerful. Modern versions use “four-dimensional data assimilation” or 

FDDA that compare model-calculated wind, humidity, and temperature fields with 

measurements and “nudge” model outputs toward observations. 

49 
A more complex meteorological model is not necessarily a better model for a specific 

application. One of the most widely used first principle model is the Fifth-Generation 

NCAR/Penn State Mesoscale Model or MM5 model (Grell et al., 1995). The MM5 

meteorological model has been adopted as the platform for central California air quality studies 

(Seaman et. al., 1995). MM5 input data consist of wind speed, wind direction, temperature, 

atmospheric pressure, and relative humidity at ground level, within the boundary layer, and 

above the boundary layer. In many cases in valley situations ten-meter vertical resolution is 

needed within the surface layer, 30-50 m resolution is needed in the valley wide layer, and 100 m 

resolution is needed above the valleywide layer up to ~2000 m agl (Watson et al., 1998). Time 

resolution is at least hourly for these measurements. Measurements are needed where large 

differences are expected, although this is largely unknown for winter.

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53 

Source Modeling and Back Trajectory Attribution Techniques 

Table 2. Puff, Visibility and Trajectory Modeling Attribution Techniques 

Air Quality Models 

Visibility Models Lagrangian Trajectory Models Evaluation Criteria 

CALPUFF VISCREEN PLUVUEII HYSPLIT RAPTAD FLEX

Chemical Mechanisms 

Does the model simulate aqueous phase chemistry? (If it does what chemistry mechanism is used and does it include fog/cloud chemistry) 

Yes; reactions for 

SO4 and NO3

NO NO NO NO N

Does the model simulate gas phase chemistry? (if it does, what chemical mechanism is implemented) 

Yes NO NO NO NO N

Simulate secondary organic aerosols 

4 species model NO NO NO NO N

Inorganic PM (i.e. ions, SO4, 

NO3, etc) 

SO4, NO3 NO NO NO NO N

Size distributions (sectional or modal) 

Coarse and fine 

modes 

NO NO Only for deposition NO 

Applicable spatial scales Micro- to regional 

scale 

Neighbor-hood to 

urban scale 

Neighborhood to 

global scale 

Neighborhood to global 

scale 

Neighborhood 

Applicable temporal scales (episodic or long term applications) 

Episodic or Long 

term 

N/A N/A Episodic or Long

term 

Episodic or Long term Episodic o

Does the model have the capability to distinguish BART sources? 

YES YES YES YES YES Y

Does the model have the capability to ingest field measurements (PM, HNO3, 

H2O2, NH3, etc) 

NO; only as 

background values 

NO NO NO NO N

55 
Air Quality Models (continued) 

Visibility Models Lagrangian Trajectory Models Evaluation Criteria 

CALPUFF VISCREEN PLUVUEII HYSPLIT RAPTAD FLEX

Visibility Modeling 

Does the model simulate background regional haze 

NO NO NO NO NO N

Point source treatment (plume rise, plume in grid) 

YES YES YES YES YES Y

Does the model have the capability to calculate wet and dry deposition? 

YES NO NO YES NO Y

Visibility treatment: (extinction, deciview, visual range) 

Extinction (total 

and for SO4, NO3, 

EC, OC, fine, 

coarse), Deciviews 

* * NO NO N

Input Requirements 

Meteorological data required (single site, gridded, number of levels, etc) 

Gridded; able to 

run with single site 

* * Gridded 

(FNL, EDAS, 

MM5) 

 Gridded 

(Use HOTMAC’s 

prediction) 

 Gridded (EC

Emission data required (single stack, multiple point sources, gridded, etc) 

 Multiple point, 

area, volume 

* * Multiple point 

sources, gridded 

inventory 

Single stack or multiple 

point sources 

Allow for initial and boundary conditions (is it required or not applicable) 

YES NO NO NO NO N

Has the model been compared against field program data? Has the model been peer reviewed? 

YES YES YES YES YES N

Does enough data exist now to run the model (Does data exist in a format ready for the model? Are current databases adequate for the model?) 

Use CALMET 

with existing 

stations or MM 

data 

YES YES Gridded met data 

available on NOAA 

ARL ftp site (FNL, 

EDAS); adaptable 

to read in MM5 

Use HOTMAC to obtain 

wind and turbulence data 

56 
Air Quality Models (continued) 

Visibility Models Lagrangian Trajectory Models Evaluation Criteria 

CALPUFF VISCREEN PLUVUEII HYSPLIT RAPTAD FLEX

Practical Considerations

Costs to run (hardware platforms, file storage, operating system) 

Inexpensive; PC, 

Windows, up to 

20GB (with 

CALMET) 

Inexpensive; PC, 

DOS, 1MB 

Inexpensive; 

PC, DOS, 

1MB 

Inexpensive; PC, 

Windows, 20MB 

Inexpensive: Linux PC, 

Redhat 

Inexpensive; Linux compiled on PC 

Have protocols or procedures been developed to run and interpret the model? 

FLAG for Class I 

AQRVs 

FLAG for Class I 

AQRVs 

FLAG for 

Class I 

AQRVs 

NO NO N

Is the source code available? YES YES YES NO YES YAre beginning user training classes available? 

YES; by 

EarthTech, BEELine 

EPA; APTI EPA; APTI NO YES N

Are user support groups available? 

YES; one list-serve YES; through EPA 

SCRAM 

YES; through 

EPA SCRAM 

NO YES N

Level of expertise required to run and interpret results (Level of Linux, UNIX, PC skills required) 

Moderate; able to 

run PC DOS 

programs; 

knowledge of 

atmospheric 

chemistry & 

physics 

Simple; able to run on 

PC DOS and windows 

Simple; able 

to run on PC 

DOS and 

Windows 

Simple; able to run 

on PC running 

Windows 

 Simple to run: GUI 

allows the user to easily 

run the program 

Knowledge is needed to 

interpret results 

Moderate; must com

PC, Linux or UNIX

input 

Output visualization required to interpret output numbers 

YES NO NO YES; has built in 

visualization 

YES; has built in 

visualization 

Y

Other strengths * * * * Applicable from building 

scale to terrain scale. 

Availability EarthTech

www.src.com

EPA EPA NOAA Air

Resource 

Laboratory; 

www.arl.noaa.gov/s

s/models/hysplit.ht

ml 

Yamada Science & Art; 

http://www.ysasoft.com 

http://ww

muenchen.de/EXT/

lexpa

 * No information available at this time

57 
Source Modeling and Back Trajectory Attribution Techniques 

Table 3. Eulerian Grid Based Modeling Attribution Techniques 

Air Quality Models 

Grid Models Evaluation Criteria 

CMAQ REMSAD CAMx UAM-AERO UAM-VPM 

Chemical Mechanisms 

Does the model simulate aqueous phase chemistry? (If it does, what chemistry mechanism is used and does it include fog/cloud chemistry) 

35 equilibria and 99 

reactions for SO4 and 

NO3

1 reaction for SO4 1 reaction for SO4 35 equilibria and 99 

reactions for SO4 and 

NO3

* 2 

Does the model simulate gas phase chemistry? (if it does, what chemical mechanism is implemented) 

CBM-IV (93 

reactions) or RADM2 

(158 reactions) 

CBM-IV 

(93 reactions) or 

RADM2 (158 

reactions) 

CB-IV with enhanced 

isoprene or 

SAPRC97 

SAPRC97 

(185 reactions) 

CB 

(

Simulate secondary organic aerosols Primary from 

emissions; secondary 

from organics 

Primary from 

emissions 

Primary from 

emissions; secondary 

from gas phase 

reactions of organic 

precursors using 

yields 

Secondary from gas 

phase reactions of 

organic precursors 

using yields 

Primary from 

emissions 

e

Inorganic PM (i.e. ions, SO4, NO3, etc) SO4, NO3 and other 

material 

SO4, NO3, NH4, and 

other material 

SO4, NO3, NH4, Cl, 

other ions and 

materials 

SO4, NO3, NH4, Cl, 

other ions and 

materials 

SO4, NO3, NH4, and 

other materials 

Size distributions (sectional or modal) Lognormal; three 

modes: Aitken, 

Accumulation and 

coase 

PM2.5 fraction, coarse 

mode 

Discrete bins, user 

specified up to 10 

Discrete bins, user 

specified up to 10 

Lognormal bins; user 

specified 

Applicable spatial scales Mesoscale Mesoscale Mesoscale Urban scale Urban scale Applicable temporal scales (episodic or long term applications) 

Episodic Long term Episodic Episodic Episodic 

Does the model have the capability to distinguish BART sources? 

YES; using plume in 

grid 

NO YES NO NO 

58 
Air Quality Models (continued) 

Grid Models Evaluation Criteria 

CMAQ REMSAD CAMx UAM-AERO UAM-VPM 

Chemical Mechanisms (continued) 

Does the model have the capability to ingest field measurements (PM,HNO3,H2O2,NH3,etc) 

YES; as initial and 

boundary conditions 

Uses default profiles YES; as initial and 

boundary conditions 

YES; as initial and 

boundary conditions 

YES; as initial and 

boundary conditions 

Visibility Modeling 

Does the model simulate background regional haze 

YES YES YES YES (with

processing) 

YES 

Point source treatment (plume rise, plume in grid) 

Plume in grid NO Plume in grid NO NO 

Does the model have the capability to calculate wet and dry deposition? 

YES YES YES YES YES 

Visibility treatment: (extinction, deciview, visual range) 

Extinction (total and 

for SO4, NO3, EC, 

OC, fine, coarse), 

Deciviews 

Extinction (total and 

for SO4, NO3, EC, 

OC, fine, coarse), 

Deciviews 

NO YES (with 

processing) 

* 

Input Requirements 

Meteorological data required (single site, gridded, number of levels, etc) 

Gridded Gridded Gridded Gridded Gridded 

Emission data required (single stack, multiple point sources, gridded, etc) 

Gridded Gridded Gridded Gridded Gridded 

Allow for initial and boundary conditions (is it required or not applicable) 

YES YES YES YES YES 

Has the model been compared against field program data? Has the model been peer reviewed? 

YES YES YES YES YES 

Does enough data exist now to run the model (Does data exist in a format ready for the model? Are current databases adequate for the model?) 

Extensive need for 

detailed emissions 

and meteorological 

fields 

Extensive need for 

detailed emissions 

and meteorological 

fields 

Extensive need for 

detailed emissions 

and meteorological 

fields 

Extensive need for 

detailed emissions 

and meteorological 

fields 

Extensive need for 

detailed emissions 

and meteorological 

fields 

59 
Air Quality Models (continued) 

Grid Models Evaluation Criteria 

CMAQ REMSAD CAMx UAM-AERO UAM-VPM 

Practical Considerations

Costs to run (hardware platforms, file storage, operating system) 

Can be run 

inexpensively; Linux 

PC, up to 1 TB 

(annual runs) 

Can be run 

inexpensive; Linux 

PC 

Can be run 

inexpensively; Linux 

PC 

Can be run 

inexpensively; Linux 

PC 

Can be run 

inexpensively; Linux 

PC 

i

Has a protocol or procedures been developed to run the model? 

NO; but RPOs have 

regional haze 

protocols 

NO; but RPOs have 

regional haze 

protocols 

NO NO NO 

Is the source code available? YES * YES YES YES Are beginning user training classes available? YES; through EPA 

and RPOs 

NO YES; through SAI 

and RPOs 

NO NO 

Are user support groups available? YES; through EPA 

and RPOs 

NO NO NO NO 

Level of expertise required to run and interpret results (Level of Linux, UNIX, PC skills required) 

Considerable 

expertise in UNIX or 

Linux; knowledge of 

atmospheric 

chemistry & physics 

 * Moderate to 

extensive 

 Moderate to 

extensive 

* 

Output visualization required to interpret output numbers 

YES; use PAVE YES; use PAVE YES YES YES 

Availability EPA; Sharon LeDuc 

919-541-1335 

SAI; Sharon Douglas 

415-507-7108 

ENVIRON; Ralph 

Morris 415-899-0700 

SAI; Sharon Douglas 

415-507-7108 

SAI; Sharon Douglas 

415-507-7108 

R

 * No information available at this time 

60 
Table 4. Meteorological Modeling Attribution Techniques 

Diagnostic Models Mesoscale Prognostic Models 

Evaluation Criteria CALMET Diagnostic Wind Model RAMS MM5 Eta * ARPS 

Applicable spatial scales Urban to regional 

scale 

Urban to regional 

scale 

Urban to global 

scale 

Urban to global 

scale 

Urban to global 

scale 

Urban to global 

scale 

Applicable temporal scales 

Hourly to annual Hourly to annual Hourly to annual Hourly to annual Hourly to annual Hourly to annual H

Does enough data exist in organization now to run the model? Are the existing monitoring networks adequate within the domain? 

Depends on area Depends on area Depends on area Depends on area Depends on area Depends on area D

For the prognostic models: Capable of FDDA? 

N/A N/A Yes Yes Yes Yes 

For the prognostic models: Are files available (archived) from real-time? 

N/A N/A NOAA is running 

the model for the 

east coast 

Several federal 

agencies and 

regional 

consortiums are 

running MM5 

NOAA is running 

the Eta model and 

fields available 

through NCEP ftp 

site 

It can be 

initialized using 

NCEP analyses 

files as well as 

individual 

observations 

Data storage/archival requirements for simulation of episodic and annual events 

Depends on 

modeling domain, 

grid size, number of 

species and length 

of simulation 

Depends on 

modeling domain, 

grid size, number 

of species and 

length of 

simulation 

Depends on 

modeling domain, 

grid size, number 

of species and 

length of 

simulation 

Depends on 

modeling domain, 

grid size, number 

of species and 

length of 

simulation 

Depends on 

modeling domain, 

grid size, number 

of species and 

length of 

simulation 

Depends on 

modeling domain, 

grid size, number 

of species and 

length of 

simulation 

m

g

Simulate clouds/precipitation fields? At what time intervals? 

No No Yes – minutes to 

days 

Yes – minutes to 

days 

Yes – minutes to 

days 

Yes – minutes to 

days 

Y

Has the model been compared against field program data? Has the model been peer reviewed? 

Yes Yes Yes Yes Yes Yes 

61 
Meteorological Modeling Attribution Techniques (continued) 

Diagnostic Models Mesoscale Prognostic Models 

Evaluation Criteria CALMET Diagnostic Wind Model RAMS MM5 Eta * ARPS 

Tools available to visualize output fields? What operating systems? 

Yes – Unix, Linux, 

Windows 

Yes – Unix, 

Linux, Windows 

Yes – Unix, Linux Yes – Unix, Linux Yes – Unix, Linux Yes – Unix, Linux 

G

Are user groups, listservers available when problems arise? 

Yes Yes Yes Yes No Yes 

Cost to run (hardware, software) 

PC Windows, PC 

Linux; Free source 

code 

PC Linux, UNIX; 

Free 

PC Linux; licensed 

source code 

PC Linux, UNIX; 

Free source code 

PC Linux, UNIX; 

Free source code 

PC Linux, UNIX; 

Free source code 

PC 

Level of expertise required to run and interpret results (Level of Linux, UNIX, PC skills required) 

Moderate Moderate High High High High 

Availability of user training 

Yes Yes Yes Yes No Yes 

Is the source code available? 

Yes Yes Yes Yes No Yes 

Has a protocol or procedures been developed to run the model? 

Yes Yes Yes Yes Yes Yes 

Strengths Relatively easy to 

use; little observed 

data needed 

Relatively easy to 

use; little observed 

data needed 

Detailed 3-D, 

complex flow in 

time 

Detailed 3-D, 

complex flow in 

time 

Detailed 3-D, 

complex flow in 

time 

Detailed 3-D, 

complex flow in 

time 

c

Weaknesses/ Limitations 

Parameterization 

depended; may not 

capture various 

flows 

Parameterization 

depended; may not 

capture various 

flows 

Large computer 

time; time 

consuming to 

debug 

Large computer 

time; time 

consuming to 

debug 

Large computer 

time; time 

consuming to 

debug 

Large computer 

time; time 

consuming to 

debug 

N

* While the Eta is not considered a mesoscale model, it has been used to simulate meteorology down to 10 km grid scales. The workstation Eta is ava

 NOAA and used experimentally by some NWS offices. * No information available at this time

62 
C. Observational Modeling Techniques 

Introduction 

Observational or receptor modeling refers to a group of analysis techniques in which 

monitoring data collected at or in the region of a receptor are analyzed in various ways in order 

to infer information about the pollutants and the sources of the pollutants causing visibility 

impairment. 

These types of models often are used as the first technique for source apportionment in order 

to get an initial understanding of the source-receptor relationships in a region. They are also used 

to verify or reconcile deterministic models, and to aid in planning intensive monitoring studies. 

Results of observational models can either be quantitative or qualitative. Quantitative results 

are estimates of the fractions of a measured species that can be attributed to a single source or 

attributed among several sources or source areas. Qualitative results include such information as 

the wind directions and other meteorological conditions most associated with high 

concentrations, or inferences about probable source types based on the relationships between 

trace elements at a single site, or information about source areas based on the spatial and 

temporal patterns in the concentrations of a single species. Often several observational models 

are used together to form hypotheses about the important source areas and source types affecting 

the concentrations at a receptor. 

Advantages of receptor models are that they are generally quick and inexpensive to run and 

require relatively little input data. Disadvantages include the necessity of employing simplifying 

assumptions such as linear relationships and often the results are limited to averages over long 

periods of time or large spatial areas. Subjective user judgment is required to choose appropriate 

input data and/or interpret the results of many receptor models. As an example, suppose the 

UNMIX model data located a source associated with high concentrations of Br, K, elemental 

carbon, and organic carbon, and another source associated with high Se and S. It is the judgment 

of the modeler regarding the relationship of the individual species to a specific source that 

determines that first source is “smoke” and the second is “coal-fired power plants.” 

Receptor models could potentially be grouped in several different ways, based on their 

different attributes. Here they are somewhat arbitrarily put into four categories, with each 

category requiring incrementally more particulate data at the receptor: 1) back-trajectory 

analyses; 2) analyses of interspecies relationships; 3) analyses of spatial and temporal patterns; 

and 4) analyses that require a unique tracer. Some models that fall into each category are listed 

below: 

Category 1. Back-Trajectory Analyses 

a. Residence Time Analyses including residence time, source contribution function, 

conditional probability, and so forth. These give qualitative information about source 

areas and transport patterns. 

63 
b. Trajectory Mass Balance – Regression of residence time of back trajectories in selected 

source areas against concentrations yielding quantitative source attributions. 

Category 2. Analyses of Interspecies Relationships 

a. Chemical Mass Balance (CMB) - Quantitative source attributions are obtained by a 

weighted regression of known source profiles against measured concentrations of several 

species. 

b. UNMIX – By looking for “edges” in the relationships between species, UNMIX 

estimates both the source profiles and the quantitative source contributions from each 

source. 

c. Positive Matrix Factorization (PMF) – PMF, like UNMIX, uses the relationships between 

species to estimate the number and composition of the sources and the quantitative source 

contributions. 

d. Enrichment Factors (EF) – The “enrichment” of certain ratios of trace elements is used to 

qualitatively infer source types impacting a receptor. 

Category 3. Analyses of Spatial and Temporal Patterns 

a. Empirical Orthogonal Function Analysis (EOF) – Analysis of spatial and temporal 

patterns leading to qualitative information about locations of dominant source areas, 

frequency and timing of source impacts and meteorological conditions associated with 

them. 

b. Receptor Model Applied to Patterns in Space (RMAPS) – With additional assumptions 

applied to EOFs, quantitative source attributions are estimated. 

Category 4. Tracer Analyses 

a. Tracer Mass Balance Regression (TMBR) – Tracer concentrations, possibly weighted by 

other factors, are regressed against concentrations of the species of interest to give a 

quantitative estimate of the contribution from the source that emitted the tracer. 

b. Differential Mass Balance (DMB) - The differential ratios of tracer to pollutant between 

source and receptor are adjusted based on simple chemistry and meteorology to give an 

estimate of the contribution of the tracer source to the receptor. 

c. Tracer-Aerosol Gradient Interpretive Technique (TAGIT) – By comparing the ratios of 

tracer to concentration of interest at “background” sites to the ratios at tracer-affected 

sites, a quantitative attribution of the tracer source to the receptor is estimated. 

Following are brief descriptions of each of these models and a few references giving further 

details and examples of their use. 

1a. Qualitative Back Trajectory Residence Time Analyses 

There are several methods of statistically analyzing the relationships between where air 

masses arrived from and the concentrations measured at a receptor. These include, but are not 

limited to: 1) where was air most likely to arrive from when concentrations are high; 2) if air 

arrived from a given area, what is the probability that the concentration at the receptor was high 

when the air mass arrived there; 3) what is the mean (or median or maximum or distribution) of 

64 
concentrations at the receptor when air masses arrived from a given area. Selected References: 

Ashbaugh et al. (1985), Gebhart et al. (2001), Poirot and Wishinski (1986). 

Data Needed: A time series of concentrations of the species of interest. One or more back 

trajectories of three to five days duration corresponding to each concentration. Back trajectories 

can be calculated by any of several methods including ATAD, Hysplit, the CAPITA Monte 

Carlo Model, as well as others. Standard National Weather Service upper air data can be used as 

input, though more detailed meteorological data can be input if available. Dispersion can be 

included in some of these models. 

Model Assumptions: Errors in trajectory placement are random and uncorrelated. Variations 

in deposition, chemistry, emissions, and so forth, have less influence on measured concentrations 

on average than variations in transport directions. 

Biggest Potential Problems: Results of these types of analyses are qualitative rather than 

quantitative. Results are more statistically robust when averaged over long time periods, usually 

a minimum of one season and preferably several years. Nearby sources cannot be resolved. User 

judgment is required to choose trajectories of an appropriate type, height, and length and also to 

choose appropriate definitions of “high” concentrations. Some concentrations that vary 

seasonally may have all “high” concentrations in a single season, necessitating some 

compensation in the analysis. Model results are probably more appropriate for species such as 

particulate sulfate that are relatively uniform over large spatial scales, rather than, for example, 

particulate nitrate, which is more volatile and seems to be more related to local sources than 

long-range transport. 

1b. TrMB (Trajectory Mass Balance) 

This is a multiple linear regression of the frequency of occurrence of trajectory endpoints in 

each of several source areas against the corresponding concentrations at the receptor. The result 

is the average attribution of a single species among up to about 25 source areas over a long time, 

for example, one season or year, or several years. Selected references: Gebhart and Malm (1989), 

Stohl (1998). 

Data Needed: Time series of concentrations of the pollutant of interest at a single site. One 

or more back trajectories associated with each concentration. Input data for these are upper air 

winds, temperatures, and moisture over a large area. Often data are obtained from the standard 

National Weather Service observations, but other data such as higher resolution wind fields, 

wind profiler data specific to a given study, can also be used if available. Emission data can be 

used if available, but must vary in time to be useful. Simple chemistry and/or deposition can be 

used if data are available. The user defines the size and locations of the source areas to be 

considered. 

Model Assumptions: Average contributions of each source area can be written as a linear 

combination of the contributions from several source areas. Average chemistry and deposition 

are adequate to explain average source contributions. Errors in back trajectories are random and 

normally distributed. 

65 
Biggest Potential Problems: No attribution to single sources—only to source areas. 

Attributions must be averaged over long time periods. Nearby sources cannot be modeled 

accurately. Subjectivity in choosing source areas. Violation of assumptions of linear chemistry. 

2a. Chemical Mass Balance (CMB)

CMB is a multiple linear regression of measured concentrations against known source 

profiles. It is used for the attribution of all measured chemical species among several sources for 

each concentration measurement period for a single monitoring site. Regressions are weighted by 

the uncertainties in both the source profiles and the concentrations. Selected References: Watson 

et al. (1984 and 2001). 

Data Needed: Concentrations and measurement uncertainties of both the chemical species of 

interest and of as many trace elements as possible are necessary for each time period and location 

for which attributions are desired. IMPROVE data can be used. A source profile is needed for 

each source. These are the relative amounts of each emitted chemical species and the 

uncertainties in these values. 

Model Assumptions: Compositions of source emissions are constant over the period of 

ambient and source sampling. Chemical species do not react with each other, for example, they 

add linearly. All sources with a potential for significantly contributing to the receptor have been 

identified and have had their emissions characterized. The sources’ compositions are linearly 

independent of each other. The number of sources or source categories is less than or equal to the 

number of chemical species. Measurement uncertainties are random, uncorrelated and normally 

distributed. 

Biggest Potential Problems: The model cannot directly apportion secondary species such as 

sulfates, nitrates, and secondary organics. There are some workarounds for this. The usual tactic 

is to apportion these species between the known primary sources and a source designated as 

“secondary particles.” It is also possible to use “fractionated” or “aged” source profiles where an 

attempt is made to pre-determine the chemical processes that occurred between source and 

receptor and then adjust the source profile accordingly. Obtaining all necessary source profiles 

can be difficult. In some studies, other receptor models have estimated source profiles. 

2b. UNMIX

For a selection of measured species, UNMIX uses singular value decomposition with 

additional non-negativity constraints to estimate the number of sources, the source compositions, 

and the source contributions to each sample at a single monitoring site. UNMIX attempts to find 

the “edges” in the relationships between species and relates these to sources. Selected 

References: Henry (1997a, 1999), Lewis et al. (1998). 

Data Needed: A time series of concentrations of several species measured at a single site. 

IMPROVE data can be used. 

66 
Model Assumptions: Concentrations are linear combinations of an unknown number of 

sources of unknown composition. Contributions from sources are positive. Source compositions 

are approximately constant in time. For each source there are some samples that contain little or 

no contribution from that source. 

Biggest Potential Problems: A maximum of seven sources can be identified. There is some 

subjectivity in choosing fitting species, number of sources, how to deal with missing or below 

detection limit values, and which time periods and species should be analyzed together. Sources 

of secondary species will probably violate the assumption of constant source composition. This 

can cause multiple sources to be identified for a single physical source that impacts the receptor 

under differing conditions. Supplemental analysis may be required to deconvolute these. 

2c. Positive Matrix Factorization (PMF) 

PMF uses an iterative weighted least squares method to decompose a time-by-species matrix 

to estimate the number and composition of the sources and the contributions of each source to 

each measured species. It will also calculate error estimates for these values. Selected 

References: Paatero and Tapper (1994), Paatero (1997); Xie et al. (1999). 

Data Needed: A time series of concentrations and their uncertainties for several species at a 

single monitoring location. IMPROVE data can be used. 

Model Assumptions: Concentrations are linear combinations of an unknown number of 

sources of unknown composition. Contributions from sources are positive. Source compositions 

are approximately constant in time. 

Biggest Potential Problems: Correlations in detection limits or uncertainties as well as in 

concentrations can influence the results. For example, PMF may detect positive correlations 

between species either due to source activity (desirable) or measurement protocol changes 

(undesirable). 

2d. Enrichment Factors (EF) 

The differences in ratios of elemental concentrations between a reference sample and a 

measured sample are used to determine how sources may have “enriched” the concentrations of 

certain species. Some examples include: high Al/Ca has been linked to Saharan dust, high Br/Pb 

may indicate lead is linked to autos rather than industry, high Se is linked to coal burning, heavy 

metals are linked to smelting, V and Ni are linked to residual oil combustion. Selected 

References: Lawson and Winchester (1979), Parekh et al. (1989), Perru (1997), Roshid and 

Griffiths (1993). 

Data Needed: Time series of concentrations of trace elements and the species of interest. 

Some historical information about the “standard” crustal, sea salt, or other ratios for a region. 

Model Assumptions: Elemental ratios depend mostly on enrichment of trace elements by a 

source and have less dependence on meteorology. The reference ratios are constant. 

67 
Biggest Potential Problems: Attributions are generally to source areas, not to single sources. 

3a. Empirical Orthogonal Function Analysis (EOF) 

A few (typically two to six) spatial patterns that explain most of the covariance in the spatial 

and temporal patterns of a measured species are obtained by singular value decomposition. 

Associations between the spatial patterns and source areas and/or transport of air pollutants into 

the study area can often be inferred, but are qualitative. The original data matrix can be 

approximately reconstructed by linearly recombining these few patterns. Selected References: 

Gebhart and Malm (1997), Henry et al. (1991), Malm et al. (1990), Malm and Gebhart (1997). 

Data Needed: Measurements of a single air pollutant of interest at several sites for several 

time periods. Typically used are concentrations measured at fifteen to forty sites for thirty or 

more time periods. There must be more time periods than sites. Data from special studies are 

often analyzed in this way. 

Model Assumptions: Only a few spatial patterns are required to explain a large majority of 

the covariance in the spatial and temporal patterns. These patterns have a physical meaning that 

can be inferred, such as transport of emissions from a source into the study area or local 

stagnation. 

Biggest Potential Problems: Source attributions are qualitative, not quantitative and 

interpretation of the spatial patterns is subjective. The model requires a site by time matrix with 

no missing values, so some method of eliminating or filling in both missing and below detection 

limit values is necessary. 

3b. Receptor Model Applied to Patterns in Space (RMAPS) 

Determines the average attribution of a single species among a few source areas by 

decomposing the time by site matrix of concentrations into a source matrix and a time weighting 

matrix. Similar to UNMIX, the edges in the scatterplots between sources and non-negativity 

requirements are used to constrain the identification of sources. Selected References: Henry 

(1997 b, c, d), White (1999). 

Data Needed: Time series of concentrations of the pollutant of interest at several sites within 

a region. The model previously has been used in special studies such as Project MOHAVE and 

PREVENT where there are fifteen to forty sites within a one or two state region collecting data 

daily for several weeks or months. 

Model Assumptions: Average contributions of each source area can be written as a nonnegative linear combination of the major principal components of the data. The spatial scale of 

the pollutant is large compared to the spacing of the sampling sites. 

Biggest Potential Problems: If the second major assumption is violated, the concentrations 

of the pollutant at each site will have little correlation with the other sites; therefore the model 

would not apply because it relies on the common variations among sites. 

68 
4a. Tracer Mass Balance Regression (TMBR) also called Multiple Linear Regression 

(MLR) on Marker Species 

Estimates the attribution of the aerosol species of interest by a source or source type, which 

emitted or emits a unique tracer. Uncertainty estimates are also generated if included in the 

regression. The model is a regression of the tracer, possibly weighted by other factors against the 

species of interest. Selected References: Malm et al. (1989 a, b, c). 

Data Needed: Time series of ambient concentrations and their uncertainties for the aerosol 

species being apportioned and also the tracer species. 

Model Assumptions: The tracer(s) are uniquely emitted by non-overlapping groups of 

sources. Source emissions are constant over the period of ambient sampling. Deposition and 

conversion are constant for all sampling periods and can be estimated by first-order 

approximations. In the WHITEX application, sulfate oxidation rates were assumed to be related 

to RH, where RH was a surrogate for time the air mass spent in clouds. Measurement errors are 

random, uncorrelated, and normally distributed. 

Biggest Potential Problems: Tracer concentrations are not often available. Source profiles, 

deposition, and conversion all vary in time and space. 

4b. Differential Mass Balance (DMB) 

DMB estimates the fraction of a species of interest attributable to a single source that can be 

tagged with a unique tracer. The ratio of measured tracer to measured sulfate or nitrate is 

assumed to be related to the fractional contribution of the traced source. The ratio is adjusted 

based on the estimated difference between the ratio at the source to the ratio at the receptor. 

Travel times between the source and receptor are estimated based on winds, and then by using 

simple estimates of dispersion, deposition and oxidation, the tracer to secondary species ratio is 

adjusted. Selected References: Malm (1989b, c). 

Data Needed: Time series of tracer concentrations and concentrations and emission rates of 

the species of interest and its precursors, for example, sulfur dioxide and sulfate. Estimates of 

wind speed and direction, mixing heights, deposition and oxidation rates. 

Model Assumptions: Wind direction does not change during transport time. The rates for 

deposition and conversion are first-order and invariant in space and time along the transport path 

between the source and the receptor. The ratio of the emission rates for the species of interest or 

its parent species and the tracer is known. 

Biggest Potential Problems: Simple chemistry and meteorology may not be adequate, 

especially for long transport times, complex terrain, and/or changing chemical regimes. Tracer 

concentrations unique to a single source are often not available. The fraction of attributable 

concentration may only be calculable to within a range based on the reasonable ranges of rate 

coefficients. 

69 
4c. Tracer-Aerosol Gradient Interpretive Technique (TAGIT) 

Results are the attribution of primary or secondary species associated with the source 

“tagged” by a tracer release. TAGIT computes attributions on a sample period-by-sample period 

basis. For each sample period, background concentration of the species of interest is determined 

by averaging the concentrations of the species at nearby sites that do not have tracer 

concentrations and are significantly above background. These sites are presumed to be 

unaffected by the tracer-tagged source and thus represent the average background. This 

background for each sample period is then subtracted from the concentration of the species of 

interest at impacted receptor sites for corresponding sample periods. The difference is the 

concentration attributable to the tagged source. Green (2001), Kuhns et al. (1999), Pitchford et 

al. (2000). 

Data Needed: Concentrations of a unique tracer from a source of interest and simultaneous 

concentrations of a pollutant of interest at several sites in a region. 

Model Assumptions: There is no impact from the tagged source if the tracer concentration is 

less than the level considered to be “significantly” above its’ background. Background 

concentrations of the species of interest do not vary systematically in space. 

Biggest Potential Problems: Assuming no impact from the tagged source when tracer is not 

statistically above background can lead to an underestimation of attribution. Measured tracer 

concentrations often have large uncertainties. Some sampling periods will have a negative 

concentration attributed to the tagged source. 

References: 

Ashbaugh, Lowell L., William C. Malm, Willy Z. Sadeh (1985) “A Residence Time Probability 

Analysis of Sulfur Concentrations at Grand Canyon National Park,” Atmospheric 

Environment, 19, 1263-1270. 

Gebhart, Kristi A., Sonia A. Kreidenweiss, and William C. Malm (2001) “Back-Trajectory 

Analyses of Fine Particulate Matter Measured at Big Bend National Park in the Historical 

Database and the 1996 Scoping Study” Science of the Total Environment, 276, 185-204. 

Gebhart, Kristi A. and William C. Malm (1989) “Source Apportionment of Particulate Sulfate 

Concentrations at Three National Parks in the Eastern United States,” in Transactions of 

the A&WMA/EPA Specialty Conference-Visibility and Fine Particles, Estes Park, CO, 

Oct. 15-19, 1989, pp. 898-913, C.V. Mathai, Ed. 

Gebhart, Kristi A. and William C. Malm (1997) “Spatial and Temporal Patterns in Particle Data 

Measured during the MOHAVE Study,” J. of the Air & Waste Management Assoc., 47, 

119-135 

Green, Mark, 2001 (Informal paper, BRAVO) 

70 
Henry, R.S. (1997a) “History and fundamentals of multivariate air quality receptor models,” 

Chemometrics and Intelligent Laboratory Systems, 37, 37-42. 

Henry, R.C. (1997b) “Receptor Model Applied to Patterns in Space (RMAPS) Part I – Model 

Description” JA&WMA, 47, 216-219. 

Henry, R.C. (1997c) “Receptor Model Applied to Patterns in Space (RMAPS) Part II – 

Apportionment of Airborne Particulate Sulfur from Project MOHAVE” JA&WMA, 47, 

220-225. 

Henry, R.C. (1997d) “Receptor Model Applied to Patterns in Space (RMAPS) Part III – 

Apportionment of Airborne Particulate Sulfur Western Washington State” JA&WMA, 47, 

226-230. 

Henry, R.C. (1999) “Comparing a new algorithm with the classic methods for estimating the 

number of factors,” Chemometrics and Intelligent Laboratory Systems, 48, 91-97. 

Lewis, C.W., R.C. Henry, and J.H. Shreffler (1998) “An Exploratory Look at Hydrocarbon Data 

from the Photochemical Assessment Monitoring Stations Network” J. Air & Waste 

Management Assoc. 48, 71-76. 

Henry, Ronald C., Yi-Jin Wang, and Kristi A. Gebhart (1991) “The Relationship Between 

Empirical Orthogonal Functions and Sources of Air Pollution,” Atmospheric 

Environment, 25A, 503-509. 

Kuhns et al. (1999) 

Lawson, D.R. and J.W. Winchester (1979) “A Standard crustal aerosol as a reference for 

elemental enrichment factors,” Atmospheric Environment, 13, 517-523. 

Malm, William C, Hari K. Iyer, and Kristi Gebhart (1989a) “Application of Tracer Mass Balance 

Regression to WHITEX Data” in Transactions of the A&WMA/EPA Specialty 

Conference: Visibility and Fine Particles, Estes Park, CO, Oct. 15-19, 1989, pp. 806-818, 

C.V. Mathai, Ed. 

Malm, William C., Hari K. Iyer, John Watson, and Douglas A. Latimer (1989b) “Survey of a 

Variety of Receptor Modeling Techniques,” Transactions of the A&WMA/EPA Specialty 

Conference-Visibility & Fine Particles, Estes Park, CO, Oct. 15-19, 1989, pp. 781-805, 

C.V. Mathai, Ed. 

Malm, William, Kristi Gebhart, Douglas Latimer, Thomas Cahill, Robert Eldred, Roger Pielke, 

Roger Stocker, and John Watson (1989) “National Park Service Report On the Winter 

Haze Intensive Tracer Experiment” National Park Service, Air Quality Division, 

Research Branch, Fort Collins, CO, Dec. 4, 1989 

71 
Malm, William C. and Kristi A. Gebhart (1997) “Source apportionment of sulfur and light 

extinction using receptor modeling techniques,” Journal of the Air & Waste Management 

Association, 47, 250-258. 

Malm, William C., Kristi A. Gebhart, and Ronald C. Henry (1990) “An Investigation of the 

Dominant Source Regions of Fine Sulfur in the Western United States and their Areas of 

Influence,” Atmospheric Environment, 24A, 3047-3060. 

Paatero, P. (1997) “Least squares formulation of robust non-negative factor analysis,” 

Chemometrics and Intelligent Laboratory Systems, 37, 15-35. 

Paatero, P. and U. Tapper (1994) “Positive Matrix Factorization – a Nonnegative Factor Model 

with Optimal Utilization of Error-Estimates of Data Values,” Environmetrics, 5, 111-126. 

Parekh, P.P., B. Ghauri, and L. Husain (1989) “Identification of Pollution Sources of 

Anomalously Enriched Elements,” Atmospheric Environment, 23, 1435-1442. 

Perru, K.D., T.A. Cahill, R.A. Eldred, and D.D. Dutcher (1997) “Long-range Transport of North 

African dust to the eastern United States,” J. Geophys. Res., 102, 11,225-11,238. 

Pitchford, Marc, Mark Green, Hampden Kuhns, and Robert J. Farber (2000) “Characterization of 

Regional Transport and Dispersion Using Project MOHAVE Tracer Data” J. Air & 

Waste Manage. Assoc. 50: 733-745. (This is not exactly TAGIT, but the 1999 reference 

may be a conference paper.) 

Poirot, Richard L. and Paul R. Wishinski (1986) “Visibility, Sulfate and Air Mass history 

Associated with the Summertime Aerosol in Northern Vermont,” Atmospheric 

Environment, 20, 1457-1469. 

Roshid, M. and R.F. Griffiths (1993) “Ambient K, S, and Si in fine and coarse aerosols of Kuala 

Lumpur, Malaysia,” Journal of Aerosol Science, 24, 597-601. 

Stohl, A. (1998) “Computation, Accuracy and Applications of Trajectories - A Review and 

Bibliography,” Atmospheric Environment, 32, 947-966. 

Watson, John G., John A. Cooper, and James J. Huntzicker (1984) “The Effective Variance 

Weighting for Least Squares Calculations Applied to the Mass Balance Receptor Model,” 

Atmospheric Environment, 18, 1347-1355. 

Watson, John G., Judith C. Chow and Eric M. Fujita (2001) “Review of volatile organic 

compound source apportionment by chemical mass balance” Atmospheric Environment, 

35, 1567-1584. 

White, Warren H. (1999) “Phantom Spatial Factors: An Example,” J. of the Air & Waste 

Management Assoc., 49, 345-349. 

72 
Xie, Yu-Long, Philip K. Hopke, Pentti Paatero, Leonard A. Barrie, and Shao-Meng Li (1999) 

“Identification of Source Nature and Seasonal Variations of Arctic Aerosol by Positive 

Matrix Factorization,” J. of the Atmospheric Sciences, 56, 249-260. 

73 
74 
Table 5. Observational Modeling Techniques 

Analyses of Back Trajectories 

Criteria Residence Time & Source Contribution 

Function 

Conditional Probability 

Concentration Statistics by Air Mass History (Mean, Max, Median) 

Cluster Analysis 

Hit – No H

Quantitative Source Attribution? No No No No No Number of sources that can be distinguished? Typically only about 

10 or fewer transport patterns are distinguishable 

Maximum of 10-15 1/grid cell, typically 

50x50 (2500), though usually only about 5-20 transport patterns are distinguishable 

2-15 1 

Averaging Time of Result? Weeks to years Weeks to years Weeks to years Weeks to years Daily, 

possibly hourly 

Previous use at Class I Areas? (See Text for References) Yes Yes Yes Yes Yes Magnitude of impacts? No No Yes No No Frequency of impacts? Yes No No Yes Yes Duration of impacts? Yes No No Yes Yes Time of Day of impacts? Depends on particle 

data 

Depends on particle data 

Depends on particle data 

Depends on particle data 

Yes 

Time of Year of impacts? Yes Yes Yes Yes Yes Appropriate for what source-receptor distances? Regional Scale Regional Scale Regional Scale Regional Scale Regional 

Scale 

Attribution of Secondary Species? Yes Yes Yes Yes Yes Cost to run? Minimal Minimal Minimal Minimal Minimal Code Available? No No No No No Equations and/or algorithms available? Yes Yes Yes Yes None needComputer Hardware Needed PC PC PC PC PC Additional software necessary? Any programming 

language or statistical package and graphics and/or mapping software that allows overlay of data on a map 

Any programming language or statistical package and graphics and/or mapping software that allows overlay of data on a map 

Any programming language or statistical package and graphics and/or mapping software that allows overlay of data on a map 

Any programming language or statistical package and graphics and/or mapping software that allows overlay of data on a map 

Graphing mapping software tallows overlay of data on a map 

EPA Approved Model? No No No No No 

75 
Observational Modeling Techniques(continued)

Analyses of inter-species relationships Analyses o

Patterns 

Criteria CMB PMF UNMIX Factor Analysis EOF Quantitative Source Attribution? Yes Yes Yes No No Number of sources that can be distinguished? 

Usually < 10 

Usually < 10 

7 < Number of species 

analyzed 

Usually 4-8 transport patt

Averaging Time of Result? Same as 

monitoring data 

Same as monitoring data 

Same as monitoring data 

Same asmonitoring d

Previous use at Class I Areas? (See Text for References) 

Yes No? No? Yes Yes 

Magnitude of impacts? Yes Yes Yes No No Frequency of impacts? Yes Yes Yes Yes Yes Duration of impacts? Yes Yes Yes No Yes Time of Day of impacts? Depends on 

input data 

Depends on input data 

Depends on input data 

Depends on input data 

Depends on idata 

Time of Year of impacts? Yes Yes Yes Yes Yes Appropriate for what source-receptor distances? 

Urban to regional scales 

Urban to regional scales 

Urban to regional scales 

Urban to regional scales 

Regional Sca

Attribution of Secondary Species? With 

additional information 

With additional information 

With additional information 

Yes Yes 

Cost to run? Free to 

purchase, minimal to run 

$700 to purchase, minimal to run 

Currently free to purchase, minimal to run, $100 (student)-1500 (full) for MATLAB 

Minimal Minimal 

Code Available? Yes Yes Yes No No Equations and/or algorithms available? Yes Yes Yes Yes Yes Computer Hardware Needed PC PC PC PC PC Additional software necessary? No No MATLAB with 

optimization toolbox 

Any statistics package 

Any statistics package with ability to do singular value decompositio

EPA Model? Yes No? Yes? No No 

76 
Observational Modeling Techniques (continued)

Analyses of Unique Tracer Data 

Criteria TMBR DMB TAGITQuantitative Source Attribution? Yes Yes Yes Number of sources that can be distinguished? 

1-3 1-3 1/tracer

Averaging Time of Result? Same as 

particulate data 

Same as particulat

Previous use at Class I Areas? (See Text for References) 

Yes Yes Yes

Magnitude of impacts? Yes Yes Yes Frequency of impacts? Yes Yes Yes Duration of impacts? Yes Yes Yes Time of Day of impacts? Depends on particulate data Depends on 

particulate data 

Depends on partic

Time of Year of impacts? Yes Yes Yes Appropriate for what source-receptor distances? 

Urban to Regional Scale Urban to Regional 

Scale 

Regional Scale 

Attribution of Secondary Species? Yes Yes Yes Cost to run? Minimal Minimal Minimal Code Available? No No No Equations and/or algorithms available? 

Yes Yes Yes

Computer Hardware Needed PC PC PC Additional software necessary? Any programming language, 

spreadsheet, or statistical package 

Any programming language, spreadsheet, or statistical package 

Any programming or statistical packa

EPA Model? No No No 

77 

Appendix A: RA BART Rule (40 CFR 51.300-306) 

Sec. 51.300 Purpose and applicability. 

 Authority: Secs. 110, 114, 121, 160-169, 169A, and 301 of the Clean Air Act, (42 U.S.C. 

7410, 7414, 7421, 7470-7479, and 7601). 

 Source: 45 FR 80089, Dec. 2, 1980, unless otherwise noted. 

 (a) Purpose. The primary purposes of this subpart are to require States to develop programs to 

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

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

impairment results from manmade air pollution; and to establish necessary additional procedures 

for new source permit applicants, States and Federal Land Managers to use in conducting the 

visibility impact analysis required for new sources under Sec. 51.166. This subpart sets forth 

requirements addressing visibility impairment in its two principal forms: ``reasonably 

attributable'' impairment (i.e., impairment attributable to a single source/small group of sources) 

and regional haze (i.e., widespread haze from a multitude of sources which impairs visibility in 

every direction over a large area). 

 (b) Applicability. (1) General Applicability. The provisions of this subpart pertaining to 

implementation plan requirements for assuring reasonable progress in preventing any future and 

remedying any existing visibility impairment are applicable to: 

 (i) Each State which has a mandatory Class I Federal area identified in part 81, subpart D, of 

this title, and Each State in which there is any source the emissions from which may reasonably 

be anticipated to cause or contribute to any impairment of visibility in any such area. 

 (ii)The provisions of this subpart pertaining to implementation plans to address reasonably 

attributable visibility impairment are applicable to the following States: Alabama, Alaska, 

Arizona, Arkansas, California, Colorado, Florida, Georgia, Hawaii, Idaho, Kentucky, Louisiana, 

Maine, Michigan, Minnesota, Missouri, Montana, Nevada, New Hampshire, New Jersey, New 

Mexico, North Carolina, North Dakota, Oklahoma, Oregon, South Carolina, South Dakota, 

Tennessee, Texas, Utah, Vermont, Virginia, Virgin Islands, Washington, West Virginia, 

Wyoming. 

 (3) The provisions of this subpart pertaining to implementation plans to address regional haze 

visibility impairment are applicable to all States as defined in section 302(d) of the Clean Air Act 

(CAA) except Guam, Puerto Rico, American Samoa, and the Northern Mariana Islands. 

[45 FR 80089, Dec. 2, 1980, as amended at 64 FR 35763, July 1, 1999] 

Sec. 51.301 Definitions. 

 For purposes of this subpart: 

 Adverse impact on visibility means, for purposes of section 307, visibility impairment which 

interferes with the management, protection, preservation, or enjoyment of the visitor's visual 

experience of the Federal Class I area. This determination must be made on a case-by-case basis 

taking into account the geographic extent, intensity, duration, frequency and time of visibility 

impairments, and how these factors correlate with (1) times of visitor use of the Federal Class I 
area, and (2) the frequency and timing of natural conditions that reduce visibility. This term does 

not include effects on integral vistas. 

 Agency means the U.S. Environmental Protection Agency. 

 BART-eligible source means an existing stationary facility as defined in this section. Best 

Available Retrofit Technology (BART) means an emission limitation based on the degree of 

reduction achievable through the application of the best system of continuous emission reduction 

for each pollutant which is emitted by an existing stationary facility. The emission limitation 

must be established, on a case-by-case basis, taking into consideration the technology available, 

the costs of compliance, the energy and nonair quality environmental 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. 

 Building, structure, or facility means all of the pollutant-emitting activities which belong to the 

same industrial grouping, are located on one or more contiguous or adjacent properties, and are 

under the control of the same person (or persons under common control). Pollutant-emitting 

activities must be considered as part of the same industrial grouping if they belong to the same 

Major Group (i.e., which have the same two-digit code) as described in the Standard Industrial 

Classification Manual, 1972 as amended by the 1977 Supplement (U.S. Government Printing 

Office stock numbers 4101-0066 and 003-005-00176-0 respectively). 

 Deciview means a measurement of visibility impairment. A deciview is a haze index derived 

from calculated light extinction, such that uniform changes in haziness correspond to uniform 

incremental changes in perception across the entire range of conditions, from pristine to highly 

impaired. The deciview haze index is calculated based on the following equation (for the 

purposes of calculating deciview, the atmospheric light extinction coefficient must be calculated 

from aerosol measurements): 

Deciview haze index = 10 lne (bext/10Mm-1) Where bext = the atmospheric light extinction 

coefficient, expressed in inverse megameters (Mm-1). 

 Existing stationary facility means any of the following stationary sources of air pollutants, 

including any reconstructed source, which was not in operation prior to August 7, 1962, and was 

in existence on August 7, 1977, and has the potential to emit 250 tons per year or more of any air 

pollutant. In determining potential to emit, fugitive emissions, to the extent quantifiable, must be 

counted. 

 Fossil-fuel fired steam electric plants of more than 250 million British thermal units per hour 

heat input, 

 Coal cleaning plants (thermal dryers), 

 Kraft pulp mills, 

 Portland cement plants, 

 Primary zinc smelters, 

 Iron and steel mill plants, 

 Primary aluminum ore reduction plants, 

 Primary copper smelters, 

 Municipal incinerators capable of charging more than 250 tons of refuse per day, 

 Hydrofluoric, sulfuric, and nitric acid plants, 

 Petroleum refineries, 

 Lime plants, 

 Phosphate rock processing plants, 
 Coke oven batteries, 

 Sulfur recovery plants, 

 Carbon black plants (furnace process), 

 Primary lead smelters, 

 Fuel conversion plants, 

 Sintering plants, 

 Secondary metal production facilities, 

 Chemical process plants, 

 Fossil-fuel boilers of more than 250 million British thermal units per hour heat input, 

 Petroleum storage and transfer facilities with a capacity exceeding 300,000 barrels, 

 Taconite ore processing facilities, 

 Glass fiber processing plants, and 

 Charcoal production facilities. 

 Federal Class I area means any Federal land that is classified or reclassified Class I. 

Federal Land Manager means the Secretary of the department with authority over the Federal 

Class I area (or the Secretary's designee) or, with respect to Roosevelt-Campobello International 

Park, the Chairman of the Roosevelt-Campobello International Park Commission. 

 Federally enforceable means all limitations and conditions which are enforceable by the 

Administrator under the Clean Air Act including those requirements developed pursuant to parts 

60 and 61 of this title, requirements within any applicable State Implementation Plan, and any 

permit requirements established pursuant to Sec. 52.21 of this chapter or under regulations 

approved pursuant to part 51, 52, or 60 of this title. 

 Fixed capital cost means the capital needed to provide all of the depreciable components. 

Fugitive Emissions means those emissions which could not reasonably pass through a stack, 

chimney, vent, or other functionally equivalent opening. 

 Geographic enhancement for the purpose of Sec. 51.308 means a method, procedure, or 

process to allow a broad regional strategy, such as an emissions trading program designed to 

achieve greater reasonable progress than BART for regional haze, to accommodate BART for 

reasonably attributable impairment. 

 Implementation plan means, for the purposes of this part, any State Implementation Plan, 

Federal Implementation Plan, or Tribal Implementation Plan. 

 Indian tribe or tribe means any Indian tribe, band, nation, or other organized group or 

community, including any Alaska Native village, which is federally recognized as eligible for the 

special programs and services provided by the United States to Indians because of their status as 

Indians. 

 In existence means that the owner or operator has obtained all necessary preconstruction 

approvals or permits required by Federal, State, or local air pollution emissions and air quality 

laws or regulations and either has (1) begun, or caused to begin, a continuous program of 

physical on-site construction of the facility or (2) entered into binding agreements or contractual 

obligations, which cannot be cancelled or modified without substantial loss to the owner or 

operator, to undertake a program of construction of the facility to be completed in a reasonable 

time. 

 In operation means engaged in activity related to the primary design function of the source. 

 Installation means an identifiable piece of process equipment. 
 Integral vista means a view perceived from within the mandatory Class I Federal area of a 

specific landmark or panorama located outside the boundary of the mandatory Class I Federal 

area. 

 Least impaired days means the average visibility impairment (measured in deciviews) for the 

twenty percent of monitored days in a calendar year with the lowest amount of visibility 

impairment. 

 Major stationary source and major modification mean major stationary source and major 

modification, respectively, as defined in Sec. 51.166. 

 Mandatory Class I Federal Area means any area identified in part 81, subpart D of this title. 

 Most impaired days means the average visibility impairment (measured in deciviews) for the 

twenty percent of monitored days in a calendar year with the highest amount of visibility 

impairment. 

 Natural conditions includes naturally occurring phenomena that reduce visibility as measured 

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

 Potential to emit means the maximum capacity of a stationary source to emit a pollutant under 

its physical and operational design. Any physical or operational limitation on the capacity of the 

source to emit a pollutant including air pollution control equipment and restrictions on hours of 

operation or on the type or amount of material combusted, stored, or processed, shall be treated 

as part of its design if the limitation or the effect it would have on emissions is federally 

enforceable. 

Secondary emissions do not count in determining the potential to emit of a stationary source. 

 Reasonably attributable means attributable by visual observation or any other technique the 

State deems appropriate. Reasonably attributable visibility impairment means visibility 

impairment that is caused by the emission of air pollutants from one, or a small number of 

sources. 

 Reconstruction will be presumed to have taken place where the fixed capital cost of the new 

component exceeds 50 percent of the fixed capital cost of a comparable entirely new source. Any 

final decision as to whether reconstruction has occurred must be made in accordance with the 

provisions of Sec. 60.15 (f) (1) through (3) of this title. 

 Regional haze means visibility impairment that is caused by the emission of air pollutants from 

numerous sources located over a wide geographic area. Such sources include, but are not limited 

to, major and minor stationary sources, mobile sources, and area sources. 

 Secondary emissions means emissions which occur as a result of the construction or operation 

of an existing stationary facility but do not come from the existing stationary facility. Secondary 

emissions may include, but are not limited to, emissions from ships or trains coming to or from 

the existing stationary facility. 

 Significant impairment means, for purposes of Sec. 51.303, visibility impairment which, in the 

judgment of the Administrator, interferes with the management, protection, preservation, or 

enjoyment of the visitor's visual experience of the mandatory Class I Federal area. This 

determination must be made on a case-by-case basis taking into account the geographic extent, 

intensity, duration, frequency and time of the visibility impairment, and how these factors 

correlate with (1) times of visitor use of the mandatory Class I Federal area, and (2) the 

frequency and timing of natural conditions that reduce visibility. 

 State means ``State'' as defined in section 302(d) of the CAA. 

 Stationary Source means any building, structure, facility, or installation which emits or may 

emit any air pollutant. 
 Visibility impairment means any humanly perceptible change in visibility (light extinction, 

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

 Visibility in any mandatory Class I Federal area includes any integral vista associated with 

that area. 

[45 FR 80089, Dec. 2, 1980, as amended at 64 FR 35763, 35774, July 1, 1999] 

Sec. 51.302 Implementation control strategies for reasonably attributable visibility impairment. 

 (a) Plan Revision Procedures. (1) Each State identified in Sec. 51.300(b)(2) must have 

submitted, not later than September 2, 1981, an implementation plan meeting the requirements of 

this subpart pertaining to reasonably attributable visibility impairment. 

 (2)(i) The State, prior to adoption of any implementation plan to address reasonably 

attributable visibility impairment required by this subpart, must conduct one or more public 

hearings on such plan in accordance with Sec. 51.102. 

 (ii) In addition to the requirements in Sec. 51.102, the State must provide written notification 

of such hearings to each affected Federal Land Manager, and other affected States, and must 

state where the public can inspect a summary prepared by the Federal Land Managers of their 

conclusions and recommendations, if any, on the proposed plan revision. 

 (3) Submission of plans as required by this subpart must be conducted in accordance with the 

procedures in Sec. 51.103. 

 (b) State and Federal Land Manager Coordination. (1) The State must identify to the Federal 

Land Managers, in writing and within 30 days of the date of promulgation of these regulations, 

the title of the official to which the Federal Land Manager of any mandatory Class I Federal area 

can submit a recommendation on the implementation of this subpart including, but not limited to: 

 (i) A list of integral vistas that are to be listed by the State for the purpose of implementing 

section 304, 

 (ii) Identification of impairment of visibility in any mandatory Class I Federal area(s), and 

 (iii) Identification of elements for inclusion in the visibility monitoring strategy required by 

section 305. 

 (2) The State must provide opportunity for consultation, in person and at least 60 days prior to 

holding any public hearing on the plan, with the Federal Land Manager on the proposed SIP 

revision required by this subpart. This consultation must include the opportunity for the affected 

Federal Land Managers to discuss their: 

 (i) Assessment of impairment of visibility in any mandatory Class I Federal area, and 

 (ii) Recommendations on the development of the long-term strategy. 

 (3) The plan must provide procedures for continuing consultation between the State and 

Federal Land Manager on the implementation of the visibility protection program required by 

this subpart. 

 (c) General plan requirements for reasonably attributable visibility impairment. (1) The 

affected Federal Land Manager may certify to the State, at any time, that there exists reasonably 

attributable impairment of visibility in any mandatory Class I Federal area. 

 (2) The plan must contain the following to address reasonably attributable impairment: 

 (i) A long-term (10-15 years) strategy, as specified in Sec. 51.305 and Sec. 51.306, including 

such emission limitations, schedules of compliance, and such other measures including schedules 
for the implementation of the elements of the long-term strategy as may be necessary to make 

reasonable progress toward the national goal specified in Sec. 51.300(a). 

 (ii) An assessment of visibility impairment and a discussion of how each element of the plan 

relates to the preventing of future or remedying of existing impairment of visibility in any 

mandatory Class I Federal area within the State. 

 (iii) Emission limitations representing BART and schedules for compliance with BART for 

each existing stationary facility identified according to paragraph (c)(4) of this section. 

 (3) The plan must require each source to maintain control equipment required by this subpart 

and establish procedures to ensure such control equipment is properly operated and maintained. 

 (4) For any existing reasonably attributable visibility impairment the Federal Land Manager 

certifies to the State under paragraph (c)(1) of this section, at least 6 months prior to plan 

submission or revision: 

 (i) The State must identify and analyze for BART each existing stationary facility which may 

reasonably be anticipated to cause or contribute to impairment of visibility in any mandatory 

Class I Federal area where the impairment in the mandatory Class I Federal area is reasonably 

attributable to that existing stationary facility. The State need not consider any integral vista the 

Federal Land Manager did not identify pursuant to Sec. 51.304(b) at least 6 months before plan 

submission. 

 (ii) If the State determines that technologicial or economic limitations on the applicability of 

measurement methodology to a particular existing stationary facility would make the imposition 

of an emission standard infeasible it may instead prescribe a design, equipment, work practice, or 

other operational standard, or combination thereof, to require the application of BART. Such 

standard, to the degree possible, is to set forth the emission reduction to be achieved by 

implementation of such design, equipment, work practice or operation, and must provide for 

compliance by means which achieve equivalent results. 

 (iii) BART must be determined for fossil-fuel fired generating plants having a total generating 

capacity in excess of 750 megawatts pursuant to ``Guidelines for Determining Best Available 

Retrofit Technology for Coal-fired Power Plants and Other Existing Stationary Facilities'' 

(1980), which is incorporated by reference, exclusive of appendix E, which was published in the 

Federal Register on February 6, 1980 (45 FR 8210). It is EPA publication No. 450/3-80-009b 

and is for sale from the U.S. Department of Commerce, National Technical Information Service, 

5285 Port Royal Road, Springfield, Virginia 22161. It is also available for inspection at the 

Office of the Federal Register Information Center, 800 North Capitol NW., suite 700, 

Washington, DC. 

 (iv) The plan must require that each existing stationary facility required to install and operate 

BART do so as expeditiously as practicable but in no case later than five years after plan 

approval. 

 (v) The plan must provide for a BART analysis of any existing stationary facility that might 

cause or contribute to impairment of visibility in any mandatory Class I Federal area identified 

under this paragraph (c)(4) at such times, as determined by the Administrator, as new technology 

for control of the pollutant becomes reasonably available if: 

 (A) The pollutant is emitted by that existing stationary facility, 

 (B) Controls representing BART for the pollutant have not previously been required under this 

subpart, and 

 (C) The impairment of visibility in any mandatory Class I Federal area is reasonably 

attributable to the emissions of that pollutant. 
[45 FR 80089, Dec. 2, 1980, as amended at 57 FR 40042, Sept. 1, 1992; 64 

FR 35764, 35774, July 1, 1999] 

 

Sec. 51.303 Exemptions from control. 

 (a)(1) Any existing stationary facility subject to the requirement under Sec. 51.302 to install, 

operate, and maintain BART may apply to the Administrator for an exemption from that 

requirement. 

 (2) An application under this section must include all available documentation relevant to the 

impact of the source's emissions on 

visibility in any mandatory Class I Federal area and a demonstration by the existing stationary 

facility that it does not or will not, by itself or in combination with other sources, emit any air 

pollutant which may be reasonably anticipated to cause or contribute to a significant impairment 

of visibility in any mandatory Class I Federal area. 

 (b) Any fossil-fuel fired power plant with a total generating capacity of 750 megawatts or 

more may receive an exemption from BART only if the owner or operator of such power plant 

demonstrates to the satisfaction of the Administrator that such power plant is located at such a 

distance from all mandatory Class I Federal areas that such power plant does not or will not, by 

itself or in combination with other sources, emit any air pollutant which may reasonably be 

anticipated to cause or contribute to significant impairment of visibility in any such mandatory 

Class I Federal area. 

 (c) Application under this Sec. 51.303 must be accompanied by a written concurrence from the 

State with regulatory authority over the source. 

 (d) The existing stationary facility must give prior written notice to all affected Federal Land 

Managers of any application for exemption under this Sec. 51.303. 

 (e) The Federal Land Manager may provide an initial recommendation or comment on the 

disposition of such application. Such recommendation, where provided, must be part of the 

exemption application. This recommendation is not to be construed as the concurrence required 

under paragraph (h) of this section. 

 (f) The Administrator, within 90 days of receipt of an application for exemption from control, 

will provide notice of receipt of an exemption application and notice of opportunity for public 

hearing on the application. 

 (g) After notice and opportunity for public hearing, the Administrator may grant or deny the 

exemption. For purposes of judicial review, final EPA action on an application for an exemption 

under this Sec. 51.303 will not occur until EPA approves or disapproves the State 

Implementation Plan revision. 

 (h) An exemption granted by the Administrator under this Sec. 51.303 will be effective only 

upon concurrence by all affected Federal Land Managers with the Administrator's determination. 

[45 FR 80089, Dec. 2, 1980, as amended by 64 FR 35774, July 1, 1999] 

Sec. 51.304 Identification of integral vistas. 

 (a) On or before December 31, 1985 the Federal Land Manager may identify any integral 

vista. The integral vista must be identified according to criteria the Federal Land Manager 
develops. These criteria must include, but are not limited to, whether the integral vista is 

important to the visitor's visual experience of the mandatory Class I Federal area. Adoption of 

criteria must be preceded by reasonable notice and opportunity for public comment on the 

proposed criteria. 

 (b) The Federal Land Manager must notify the State of any integral vistas identified under 

paragraph (a) of this section, and the reasons therefor. 

 (c) The State must list in its implementation plan any integral vista the Federal Land Manager 

identifies at least six months prior to plan submission, and must list in its implementation plan at 

its earliest opportunity, and in no case later than at the time of the periodic review of the SIP 

required by Sec. 51.306(c), any integral vista the Federal Land Manager identifies after that time. 

 (d) The State need not in its implementation plan list any integral vista the identification of 

which was not made in accordance with the criteria in paragraph (a) of this section. In making 

this finding, the State must carefully consider the expertise of the Federal Land Manager in 

making the judgments called for by the criteria for identification. Where the State and the 

Federal Land Manager disagree on the identification of any integral vista, the State must give the 

Federal Land Manager an opportunity to consult with the Governor of the State. 

[45 FR 80089, Dec. 2, 1980, as amended by 64 FR 35774, July 1, 1999] 

 

Sec. 51.305 Monitoring for reasonably attributable visibility impairment. 

 (a) For the purposes of addressing reasonably attributable visibility impairment, each State 

containing a mandatory Class I Federal area must include in the plan a strategy for evaluating 

reasonably attributable visibility impairment in any mandatory Class I Federal area by visual 

observation or other appropriate monitoring techniques. Such strategy must take into account 

current and anticipated visibility monitoring research, the availability of appropriate monitoring 

techniques, and such guidance as is provided by the Agency. 

 (b) The plan must provide for the consideration of available visibility data and must provide a 

mechanism for its use in decisions required by this subpart. 

[45 FR 80089, Dec. 2, 1980, as amended at 64 FR 35764, July 1, 1999] 

Sec. 51.306 Long-term strategy requirements for reasonably attributable visibility impairment. 

 (a)(1) For the purposes of addressing reasonably attributable visibility impairment, each plan 

must include a long-term (10-15 years) strategy for making reasonable progress toward the 

national goal specified in Sec. 51.300(a). This strategy must cover any existing impairment the 

Federal Land Manager certifies to the State at least 6 months prior to plan submission, and any 

integral vista of which the Federal Land Manager notifies the State at least 6 months prior to plan 

submission. 

 (2) A long-term strategy must be developed for each mandatory Class I Federal area located 

within the State and each mandatory Class I Federal area located outside the State which may be 

affected by sources within the State. This does not preclude the development of a single 

comprehensive plan for all such areas. 
 (3) The plan must set forth with reasonable specificity why the long-term strategy is adequate 

for making reasonable progress toward the national visibility goal, including remedying existing 

and preventing future impairment. 

 (b) The State must coordinate its long-term strategy for an area with existing plans and goals, 

including those provided by the affected Federal Land Managers, that may affect impairment of 

visibility in any mandatory Class I Federal area. 

 (c) The plan must provide for periodic review and revision, as appropriate, of the long-term 

strategy for addressing reasonably attributable visibility impairment. The plan must provide for 

such periodic review and revision not less frequently than every 3 years until the date of 

submission of the State's first plan addressing regional haze visibility impairment in accordance 

with Sec. 51.308(b) and (c). On or before this date, the State must revise its plan to provide for 

review and revision of a coordinated long-term strategy for addressing reasonably attributable 

and regional haze visibility impairment, and the State must submit the first such coordinated 

long-term strategy. Future coordinated long-term strategies must be submitted consistent with the 

schedule for periodic progress reports set forth in Sec. 51.308(g). Until the State revises its plan 

to meet this requirement, the State must continue to comply with existing requirements for plan 

review and revision, and with all emission management requirements in the plan to address 

reasonably attributable impairment. This requirement does not affect any preexisting deadlines 

for State submittal of a long-term strategy review (or element thereof) between August 30, 1999, 

and the date required for submission of the State's first regional haze plan. In addition, the plan 

must provide for review of the long-term strategy as it applies to reasonably attributable 

impairment, and revision as appropriate, within 3 years of State receipt of any certification of 

reasonably attributable impairment from a Federal Land Manager. The review process must 

include consultation with the appropriate Federal Land Managers, and the State must provide a 

report to the public and the Administrator on progress toward the national goal. This report must 

include an assessment of: 

 (1) The progress achieved in remedying existing impairment of visibility in any mandatory 

Class I Federal area; 

 (2) The ability of the long-term strategy to prevent future impairment of visibility in any 

mandatory Class I Federal area; 

 (3) Any change in visibility since the last such report, or, in the case of the first report, since 

plan approval; 

 (4) Additional measures, including the need for SIP revisions, that may be necessary to assure 

reasonable progress toward the national visibility goal; 

 (5) The progress achieved in implementing BART and meeting other schedules set forth in the 

long-term strategy; 

 (6) The impact of any exemption granted under Sec. 51.303; 

 (7) The need for BART to remedy existing visibility impairment of any integral vista listed in 

the plan since the last such report, or, in the case of the first report, since plan approval. 

 (d) The long-term strategy must provide for review of the impacts from any new major 

stationary source or major modifications on visibility in any mandatory Class I Federal area. This 

review of major stationary sources or major modifications must be in accordance with Sec. 

51.307, Sec. 51.166, Sec. 51.160, and any other binding guidance provided by the Agency 

insofar as these provisions pertain to protection of visibility in any mandatory Class I Federal 

areas. 
 (e) The State must consider, at a minimum, the following factors during the development of its 

long-term strategy: 

 (1) Emission reductions due to ongoing air pollution control programs, 

 (2) Additional emission limitations and schedules for compliance, 

 (3) Measures to mitigate the impacts of construction activities, 

 (4) Source retirement and replacement schedules, 

 (5) Smoke management techniques for agricultural and forestry management purposes 

including such plans as currently exist within the State for these purposes, and 

 (6) Enforceability of emission limitations and control measures. 

 (f) The plan must discuss the reasons why the above and other reasonable measures considered 

in the development of the long-term strategy were or were not adopted as part of the long-term 

strategy. 

 (g) The State, in developing the long-term strategy, must take into account the effect of new 

sources, and the costs of compliance, the time necessary for compliance, the energy and nonair 

quality environmental impacts of compliance, and the remaining useful life of any affected 

existing source and equipment therein. 

[45 FR 80089, Dec. 2, 1980, as amended at 64 FR 35764, 35774, July 1, 1999] 




20.2.73 NMAC 1

TITLE 20 ENVIRONMENTAL PROTECTION

CHAPTER 2 AIR QUALITY (STATEWIDE)

PART 73 NOTICE OF INTENT AND EMISSIONS INVENTORY REQUIREMENTS

20.2.73.1 ISSUING AGENCY: Environmental Improvement Board.

[11/30/95; 20.2.73.1 NMAC - Rn, 20 NMAC 2.73.100 02/18/02]

20.2.73.2 SCOPE: All persons who own or operate a source or who intend to construct or modify a source.

[11/30/95; 20.2.73.2 NMAC - Rn, 20 NMAC 2.73.101 02/18/02]

20.2.73.3 STATUTORY AUTHORITY: Environmental Improvement Act, NMSA 1978, Section 74-1-

8(A)(4), and Air Quality Control Act, NMSA 1978, Sections 74-2-1 et seq., including specifically, Section 74-2-

7(A)(1) and (B).

[11/30/95; 20.2.73.3 NMAC - Rn, 20 NMAC 2.73.102 02/18/02]

20.2.73.4 DURATION: Permanent.

[11/30/95; 20.2.73.4 NMAC - Rn, 20 NMAC 2.73.103 02/18/02]

20.2.73.5 EFFECTIVE DATE: November 30, 1995 except where a later date is cited at the end of a 

section or paragraph.

[11/30/95, 10/01/97; 20.2.73.5 NMAC - Rn, 20 NMAC 2.73.104 02/18/02]

[The latest effective date of any section in this Part is July 6, 2011.]

20.2.73.6 OBJECTIVE: The objective of this part is to establish requirements for the submission of certain 

relevant information to ensure that the regulations and standards under the Air Quality Control Act and the federal 

act will not be violated, and to facilitate the quantification of greenhouse gas emissions in New Mexico.

[11/30/95; 20.2.73.6 NMAC - Rn, 20 NMAC 2.73.105 02/18/02; A, 01/01/08]

20.2.73.7 DEFINITIONS: In addition to the terms defined in 20.2.2 NMAC (Definitions), as used in this 

part, the following apply.

A. "Air pollution control equipment" means any device, equipment, process or combination 

thereof the operation of which would limit, capture, reduce, confine, or otherwise control air contaminants or 

convert for the purposes of control any air contaminant to another form, another chemical or another physical state.

B. "California climate action registry" means the voluntary registry for greenhouse gas emissions 

established pursuant to California Health & Safety Code D. 26, Pt. 4, Ch. 6 (West 2007).

C. "Commencement" means that an owner or operator has undertaken a continuous program of 

construction or modification.

D. "Construction" means fabrication, erection, installation or relocation of a stationary source, 

including but not limited to temporary installations and portable stationary sources.

E. “Emission report or inventory” means a listing, by source, of the amount of air pollutants 

discharged into the atmosphere of a community.

F. “Fuel carbon content” means the mass of carbon per unit of heat content of a fuel.

G. "Fugitive emissions" are those emissions which could not reasonably pass through a stack, 

chimney, vent, or other functionally-equivalent opening.

H. "Greenhouse gas emissions reporting year” means the calendar year in which greenhouse gas 

emissions required to be reported under this part occurred.

I. "Modification" means any physical change in, or change in the method of operation of, a 

stationary source which results in an increase in the potential emission rate of any regulated air contaminant emitted 

by the source or which results in the emission of any regulated air contaminant not previously emitted, but does not 

include:

 (1) a change in ownership of the source;

 (2) routine maintenance, repair or replacement;

 (3) installation of air pollution control equipment, and all related process equipment and materials 

necessary for its operation, undertaken for the purpose of complying with regulations adopted by the board or 

pursuant to the federal Clean Air Act; or

 (4) unless previously limited by enforceable permit conditions:
20.2.73 NMAC 2

 (a) an increase in the production rate, if such increase does not exceed the operating design 

capacity of the source;

 (b) an increase in the hours of operation; or

 (c) use of an alternative fuel or raw material if, prior to January 6, 1975, the source was capable 

of accommodating such fuel or raw material, or if use of an alternate fuel or raw material is caused by any natural 

gas curtailment or emergency allocation or any other lack of supply of natural gas.

J. "Nonattainment area" means, for any air pollutant, an area which has been designated as a 

nonattainment area under Section 107 of the federal act.

K. "Operator" means the person or persons responsible for the overall operation of a facility.

L. "Owner" means the person or persons who own a facility or part of a facility.

M. "Part" means an air quality control regulation under Title 20, Chapter 2 of the New Mexico 

administrative code, unless otherwise noted; as adopted or amended by the board.

N. "Portable stationary source" means a source which can be relocated to another operating site 

with limited dismantling and reassembly, including for example but not limited to moveable sand and gravel 

processing operations and asphalt plants.

O. "Potential emission rate" means the emission rate of a source at its maximum capacity to emit a 

regulated air contaminant under its physical and operational design, provided any physical or operational limitation 

on the capacity of the source to emit a regulated air contaminant, including air pollution control equipment and 

restrictions on hours of operation or on the type or amount of material combusted, stored or processed, shall be 

treated as part of its physical and operational design only if the limitation or the effect it would have on emissions is 

enforceable by the department pursuant to the Air Quality Control Act or the federal act.

P. "Potential to emit" means the maximum capacity of a stationary source to emit any air pollutant 

under its physical and operational design; any physical or operational limitation on the capacity of a source to emit 

an air pollutant, including air pollution control equipment and restrictions on hours of operation or on the type or 

amount of material combusted, stored, or processed, shall be treated as part of its design if the limitation is federally 

enforceable; the potential to emit for nitrogen dioxide shall be based on total oxides of nitrogen.

Q. "Regulated air contaminant" means any air contaminant, the emission or ambient concentration 

of which is regulated pursuant to the New Mexico Air Quality Control Act or the federal act.

R. "Shutdown" means the cessation of operation of any air pollution control equipment, process 

equipment or process for any purpose, except routine phasing out of batch process units.

S. "Stationary source" or "source" means any building, structure, equipment, facility, installation 

(including temporary installations), operation or portable stationary source which emits or may emit any air 

contaminant; any research facility may group its sources for the purpose of this part at the discretion of the secretary 

of the department.

T. “The climate registry” means the nonprofit corporation by that name incorporated under the 

District of Columbia Nonprofit Corporation Act with a purpose of creating and operating a multi-state greenhouse 

gas emissions registry.

U. “WEB source” means a stationary source that meets the applicability requirements of 20.2.81.101 

NMAC.

V. “Western backstop sulfur dioxide trading program” means 20.2.81 NMAC, triggered as a 

backstop in accordance with the provisions in the sulfur dioxide milestones and backstop trading program 

implementation plan, if necessary, to ensure that regional sulfur dioxide emissions are reduced.

[11/30/95, 10/01/97; 20.2.73.7 NMAC - Rn, 20 NMAC 2.73.107 & A, 02/18/02; A, 12/31/03; A, 01/01/08]

20.2.73.8 to 20.2.73.105 [RESERVED]

20.2.73.106 AMENDMENT AND SUPERSESSION OF PRIOR REGULATIONS: This part amends and 

supersedes Air Quality Control Regulation ("AQCR") 703.1 - Notice of Intent and Emissions Inventory 

Requirements last filed May 29, 1990, as amended ("AQCR 703.1").

A. All references to AQCR 703.1 in any other rule shall be construed as a reference to this part.

B. The amendment and supersession of AQCR 703.1 shall not affect any administrative or judicial 

enforcement action pending on the effective date of such amendment nor the validity of any permit issued pursuant 

to AQCR 703.1.

[11/30/95; 20.2.73.106 NMAC - Rn, 20 NMAC 2.73.106 02/18/02]

20.2.73.107 to 20.2.73.199 [RESERVED]
20.2.73 NMAC 3

20.2.73.200 NOTICE OF INTENT:

A. Applicability:

 (1) Any owner or operator intending to construct a new stationary source which has a potential 

emission rate greater than 10 tons per year of any regulated air contaminant or 1 ton per year of lead shall file a 

notice of intent with the department.

 (2) Any owner or operator intending to modify a stationary source which either prior to or following 

the modification has a potential emission rate greater than 10 tons per year of any regulated air contaminant or 1 ton 

per year of lead shall file a notice of intent with the department.

 (3) The requirements of 20.2.73.200 NMAC do not apply to stationary sources or modifications 

located in Bernalillo county.

 (4) The notice of intent shall be filed prior to the commencement of construction. Construction shall 

not begin prior to issuance of a written determination by the department that a permit is not required, or if a permit is 

required, prior to the issuance of the permit under 20.2.72 NMAC, 20.2.74 NMAC or 20.2.79 NMAC.

B. Contents of Notice: Notices of intent shall be filed on forms furnished by the department, which 

shall be identical to the extent practicable, as those used for 20.2.72 NMAC (Construction Permits) and shall 

include:

 (1) The applicant's name and address, the person to contact regarding the application, and the name 

and address of the new source or modification.

 (2) The date of the application.

 (3) A description of the new facility or modification including all operations affecting air emissions.

 (4) The anticipated operating schedule.

 (5) A map such as a 7.5 minute United States geological survey topographic quadrangle showing the 

location of the stationary source.

 (6) The nature and quantities of any regulated air contaminants the new source or modification will 

emit, including all calculations utilized to estimate emissions.

 (7) A description of any air pollution control device or method to be utilized, including the basis for 

the estimated control efficiency.

 (8) The stack and exhaust gas parameters for all emission points.

 (9) Any other relevant information as the department may reasonably require.

 (10) Be signed under oath or affirmation by the operator, the owner, or an authorized representative, 

certifying to the best of his or her knowledge the truth of all information submitted.

C. Review of Notice: Within thirty days from the date a notice is received, the department shall 

review its content and by certified letter indicate to the applicant:

 (1) the notice is incomplete and indicate specific additional material or clarification required; or

 (2) a permit is not required and construction may commence; or

 (3) a permit is required before construction may commence. For this case, the department will 

indicate whether the application is complete with respect to the requirements of each applicable permit regulation 

and specify additional material or clarification required if it is not complete.

D. Verification: In verifying information submitted in response to the requirements of this part, the 

department may:

 (1) Enter at all reasonable times in or upon any private or public property, except private residences, 

which the department has reasonable cause to believe is or will become a source of air contaminants contributing to 

air pollution; and

 (2) Require the production of information relating to emissions which cause or contribute to air 

pollution, including the sampling of emissions in accordance with methods and at locations and intervals as may be 

prescribed by the department.

E. Notification Requirements:

 (1) The owner or operator of a portable stationary source shall notify the department in writing of the 

date and site of any relocation at least fifteen days prior to its occurrence.

 (2) Any owner or operator of a stationary source which will be shut down for a period of one year or 

more shall notify the department in writing of the actual date of shut down within thirty days after the shut down 

occurs.

 (3) Any new owner or operator of a stationary source shall notify the department within thirty days of 

assuming ownership of his or her name and address.

[11/30/95; 20.20.73.200 NMAC - Rn, 20 NMAC 2.73.200-204 02/18/02]
20.2.73 NMAC 4

20.2.73.201 to 20.2.73.299 [RESERVED]

20.2.73.300 EMISSION INVENTORY REQUIREMENTS:

A. Applicability. The requirements of 20.2.73.300 NMAC apply to the owner or operator of any 

stationary source located outside of Bernalillo county which:

 (1) has been issued a permit under 20.2.72 NMAC (Construction Permits) during any period of time, 

except for toxic air pollutant permits issued under Sections 401 to 499 of 20.2.72 NMAC;

 (2) is required to file a notice of intent under 20.2.73.200 NMAC; or

 (3) emits in excess of 1 ton of lead or 10 tons of total suspended particulate, PM10, PM2.5, sulfur 

dioxide, nitrogen oxides, carbon monoxide, or volatile organic compounds in any calendar year including and 

subsequent to 1990.

B. Reporting requirements.

 (1) Any source which emits, or has the potential to emit, 5 tons per year or more of lead or lead 

compounds, or 100 tons per year or more of PM10, PM2.5, sulfur oxides, nitrogen oxides, carbon monoxide, or 

volatile organic compounds shall submit an emissions report annually.

 (2) Any source defined as a major source of hazardous air pollutants under 20.2.70 NMAC 

(Operating Permits) shall submit an emissions report annually.

 (3) Any source which is located in an ozone nonattainment area and which emits, or has the potential 

to emit, 25 tons per year or more of nitrogen oxides or volatile organic compounds shall submit an emissions report 

annually.

 (4) Any source which is not required by Paragraph (1), (2), or (3) of Subsection B of this section 

(20.2.73.300 NMAC) to submit an emission report shall submit an emissions report under this part upon request by 

the department, but no more frequently than annually.

 (5) Except as provided in Paragraph (8) of Subsection B of this section (20.2.73.300 NMAC), the 

department shall provide to the owner or operator required by this section (20.2.73.300 NMAC) to submit an 

emissions report a complete copy of the most current emissions report for their stationary source which is on file 

with the department. The department shall provide this copy to the owner or operator at least 90 days prior to the 

date when the source is required to submit an emissions report.

 (6) The owner or operator shall submit to the department a complete, correct and current emissions 

report in the format specified by the department which reflects emissions during the previous calendar year.

 (7) Except as provided in Paragraph (8) of Subsection B of this section (20.2.73.300 NMAC) the 

owner or operator shall submit the emission report by April 1 of each year in which the source is required to submit 

an emission report.

 (8) Sources for which a date for submitting an annual emission report is specified in a current 

operating permit issued under 20.2.70 NMAC (Operating Permits) shall submit such report on that date. The 

department shall provide a copy of the previous emissions report upon request by the owner or operator of such 

source. 

 (9) Any source that is requested by the department to submit a report of greenhouse gas emissions 

shall:

 (a) submit such report on the schedule and according to the greenhouse gas emissions reporting 

procedures established by the department, but not more often than annually; or

 (b) report greenhouse gas emissions from the source under 20.2.87 NMAC for the greenhouse 

gas emissions reporting year and the two years following that year; or

 (c) provide the department access to the requested information for the greenhouse gas 

emissions reporting year registered in either the climate registry or the California climate action registry; and

 (d) keep records in support of the report for a minimum of five years.

 (10) In determining the schedule of greenhouse gas emissions reports and reporting procedures, the 

department, subject to Paragraph (11) below, shall provide an opportunity for public comment, and shall consider:

 (a) public comments regarding the schedule of such reports and greenhouse gas emissions 

reporting procedures;

 (b) emissions quantification standards and best practices approved or recommended by federal 

and state agencies, by greenhouse gas emissions registries, and by non-governmental bodies having expertise in 

greenhouse gas emissions quantification;
20.2.73 NMAC 5

 (c) whether greenhouse gases emissions from a particular source or source type, considering 

the amount and chemical composition of the emissions, are expected to be minimal relative to emissions from other 

sources or source types, and

 (d) whether emissions of a particular greenhouse gas from a source or source type, considering 

the amount and chemical composition of the emissions, are expected to be minimal relative to the total greenhouse 

gas emissions from that source or source type.

 (11) The schedule for greenhouse gas emissions reports and reporting procedures pursuant to 

Paragraphs (9) and (10) of Subsection B of 20.2.73.300 NMAC, shall:

 (a) subject to the department’s selection of best available quantification methodologies, include 

a requirement that sources within North American industry classification system codes 211111, 211112, 213111, 

213112, 486210, 221210, 486110, and 486910 subject to this part and permit requirements pursuant to 20.2.70 

NMAC (Operating Permits) report at a minimum emissions of carbon dioxide and methane beginning no later than 

reporting year 2009 and for subsequent reporting years; and

 (b) subject to the department’s selection of best available quantification methodologies, include 

a requirement that sources within North American industry classification system codes 211111, 211112, 213111, 

213112, 486210, 221210, 486110, and 486910 subject to this part pursuant to Paragraphs (1) and (2) of Subsection 

A of 20.2.73.300 NMAC, and not otherwise covered by Subparagraph (a), above, report at a minimum emissions of 

carbon dioxide and methane no later than reporting year 2010 and for subsequent reporting years as requested by the 

department.

C. Content of emissions reports. Emissions report contents for reports made under Paragraphs (1) 

through (8) of Subsection B of 20.2.73.300 NMAC shall include:

 (1) the name, address, if any, and physical location of the stationary source;

 (2) the name and telephone number of the person to contact regarding the emissions report;

 (3) a certification signed by the owner, or operator, or a responsible official as defined in 20.2.70 

NMAC attesting that the statements and information contained in the emissions report are true and accurate to the 

best knowledge and belief of the certifying official, and including the full name, title, signature, date of signature, 

and telephone number of the certifying official; for sources subject to 20.2.70 NMAC, the certification shall be 

made as required under that part;

 (4) smelters shall submit an annual report of sulfur input, in tons/year;

 (5) for each emission point, as required by the department:

 (a) stack and exhaust gas parameters and location information;

 (b) type of control equipment and estimated control efficiency;

 (c) schedule of operation;

 (d) estimated actual emissions, including fugitive emissions and emissions occurring during 

maintenance, start-ups, shutdowns, upsets, and downtime of total suspended particulate, PM10, PM2.5, ammonia, 

sulfur oxides, nitrogen oxides, carbon monoxide, volatile organic compounds, and lead, and, if requested by the 

department, speciated hazardous air pollutants, in tons per year and a description of the methods utilized to make 

such estimates, including calculations;

 (e) the annual process or fuel combustion rates; and

 (f) the fuel heat, sulfur, and ash content; and

 (6) all information required under the federal act.

D. Additional content for emissions reports from sources in ozone nonattainment areas. 

Emissions reports from sources located in ozone nonattainment areas shall include, in addition to the contents 

specified by Subsection C of this section (20.2.73.300 NMAC), the following information:

 (1) typical daily process rate during the peak ozone season, where the peak ozone season is specified 

by the department; and

 (2) estimated actual emissions of nitrogen oxides and volatile organic compounds, which shall be 

reported:

 (a) for each emissions point;

 (b) for each process and fuel type contributing to emissions from each point;

 (c) in units of tons per year for annual emissions; and

 (d) in units of pounds per day for a typical day during the peak ozone season.

E. Waiver of reporting requirements for insignificant emissions. The department may waive the 

requirements of Paragraph (5) of Subsection C of this section (20.2.73.300 NMAC) for emissions which the 

department determines to be insignificant under 20.2.70 NMAC, except that:
20.2.73 NMAC 6

 (1) for sources in nonattainment areas, reporting of emissions of pollutants for which the area is 

nonattainment shall not be waived; and

 (2) reporting of emissions for which reporting is required under the federal act shall not be waived.

F. Emission tracking requirements for sulfur dioxide emission inventories. All stationary 

sources with actual emissions of one hundred (100) tons per year or more of sulfur dioxide in the year 2000, or in 

any subsequent year, shall submit an annual inventory of sulfur dioxide emissions, beginning with the 2003 

emission inventory. A source that meets these criteria that then emits less than 100 tons per year in a later year shall 

submit a sulfur dioxide inventory for tracking compliance with the regional sulfur dioxide milestones until the 

western backstop sulfur dioxide trading program has been fully implemented and emission tracking has occurred 

under 20.2.81.106 NMAC.

 (1) All WEB sources will be subject to the following federally enforceable provisions:

 (a) submit an annual inventory of sulfur dioxide emissions;

 (b) document the emissions monitoring/estimation methodology used, and demonstrate that the 

selected methodology is acceptable under the inventory program;

 (c) include emissions from start up, shut down, and upset conditions in the annual total 

inventory;

 (d) use 40 CFR Part 75 methodology for reporting emissions for all sources subject to the 

federal acid rain program;

 (e) maintain all records used in the calculation of the emissions, including but not limited to the 

following:

 (i) amount of fuel consumed;

(ii) percent sulfur content of fuel and how the content was determined;

 (iii) quantity of product monitoring data;

 (iv) emissions monitoring data;

(v) operating data; and

 (vi) how the emissions are calculated;

 (f) maintain records of any physical changes to facility operations or equipment, or any other 

changes that may affect the emissions projections; and

 (g) retain records for a minimum of ten years from the date of establishment, or if the record 

was the basis for an adjustment to the milestone, five years after the date of an implementation plan revision, 

whichever is longer.

 (2) Changes in emission measurement techniques. Each source subject to this subsection that uses a 

different emission monitoring or calculation method than was used to report sulfur dioxide emissions in 2006 under 

this part or 40 CFR Part 75 shall adjust their reported emissions to be comparable to the emission monitoring or 

calculation method that was used in 2006. The calculations that are used to make this adjustment shall be included 

with the annual emission report.

 (3) The department shall retain emission inventory records for non-utilities for 2006 until the year 

2018 to ensure that changes in emissions monitoring techniques can be tracked.

G. Content of greenhouse gas emissions reports. Greenhouse gas emissions reports shall contain 

the following information, as set out in the greenhouse gas emissions reporting procedures established under 

Subparagraph (a) of Paragraph (9) of Subsection B of 20.2.73.300 NMAC:

 (1) the name, location, and permit or notice of intent number of the stationary source;

 (2) the name and telephone number of the person to contact regarding the greenhouse gas emissions 

report;

 (3) a certification signed by the owner or operator attesting that the statements and information 

contained in the emissions report are true and accurate to the best knowledge and belief of the certifying official, and 

including the full name, title, signature, date of signature, and telephone number of the certifying official;

 (4) for each emission point as required by the department under the greenhouse gas emissions 

reporting procedures, the estimated actual emissions of greenhouse gases, including fugitive emissions and 

emissions occurring during maintenance, start-ups, shutdowns, upsets and downtime; and

 (5) if requested by the department, the fuel type, fuel heat content, and fuel carbon content.

[11/30/95, 10/01/97; 2.20.73.300 NMAC - Rn, 20 NMAC 2.73.300 - 304 02/18/02; A, 12/31/03; A, 12/31/04; A, 

01/01/08; A, 07/06/11] 

HISTORY OF 20.2.73 NMAC:
20.2.73 NMAC 7

Pre-NMAC History: The material in this part was derived from that previously filed with the commission of 

public records - state records center and archives.

EIB/AQCR 703.1, Air Quality Control Regulation 703.1 - Notice of Intent and Emissions Inventory Requirements, 

5/29/90.

History of Repealed Material: [RESERVED]

Other History:

EIB/AQCR 703.1, Air Quality Control Regulation 703.1 - Notice of Intent and Emissions Inventory Requirements, 

filed 5/29/90, was renumbered into first version of the New Mexico Administrative Code as 20 NMAC 2.73, 

Notice of Intent and Emissions Inventory Requirements, filed 10/30/95.

20 NMAC 2.73, Notice of Intent and Emissions Inventory Requirements, filed 10/30/95, was renumbered, 

reformatted, amended and replaced by 20.2.73 NMAC, Notice of Intent and Emissions Inventory Requirements, 

effective 02/18/02.

























20.2.81 NMAC 1

TITLE 20 ENVIRONMENTAL PROTECTION

CHAPTER 2 AIR QUALITY (STATEWIDE)

PART 81 WESTERN BACKSTOP SULFUR DIOXIDE TRADING PROGRAM

20.2.81.1 ISSUING AGENCY: Environmental Improvement Board.

[20.2.81.1 NMAC - N, 12/31/03]

20.2.81.2 SCOPE: All geographic areas within the jurisdiction of the environmental improvement board.

[20.2.81.2 NMAC - N, 12/31/03]

20.2.81.3 STATUTORY AUTHORITY: Environmental Improvement Act, NMSA 1978, Section 74-1-

8(A)(4) and (7), and Air Quality Control Act, NMSA 1978, Sections 74-2-1 et seq., including specifically, Section 

74-2-5 (A), (B) and (C).

[20.2.81.3 NMAC - N, 12/31/03]

20.2.81.4 DURATION: Permanent.

[20.2.81.4 NMAC - N, 12/31/03]

20.2.81.5 EFFECTIVE DATE: December 31, 2003, except where a later date is cited at the end of a 

section.

[20.2.81.5 NMAC - N, 12/31/03]

[The latest effective date of any section in this part is July 6, 2011.]

20.2.81.6 OBJECTIVE:

A. 20.2.81 NMAC implements the western backstop sulfur dioxide trading program ("WEB trading 

program") provisions required under the federal regional haze rule, 40 CFR 51.309, and New Mexico's regional haze 

implementation plan.

B. Nothing in 20.2.81 NMAC waives any requirement otherwise in effect or subsequently required 

under another program, including rules governing new sources.

[20.2.81.6 NMAC - N, 12/31/03]

20.2.81.7 DEFINITIONS: In addition to the terms defined in 20.2.2 NMAC (Definitions), as used in this 

part, the following definitions shall apply.

A. "Account certificate of representation" means the completed and signed submission required to 

designate an account representative for a web source or an account representative for a general account. 

B. "Account representative" means the individual who is authorized through an account certificate 

of representation to represent owners and operators of the WEB source with regard to matters under the web trading 

program or, for a general account, who is authorized through an account certificate of representation to represent the 

persons having an ownership interest in allowances in the general account with regard to matters concerning the 

general account. 

C. "Act " means the federal Clean Air Act, as amended, 42 U.S.C. 7401, et seq. 

D. "Actual emissions" means total annual sulfur dioxide emissions determined in accordance with 

20.2.81.106 NMAC, or determined in accordance with 20.2.73 NMAC for sources that are not subject to 

20.2.81.106 NMAC. 

E. "Allocate" means to assign allowances to a WEB source through Section C1 of the 

implementation plan. 

F. "Allowance" means the limited authorization under the WEB trading program to emit one ton of 

sulfur dioxide during a specified control period or any control period thereafter subject to the terms and conditions 

for use of unused allowances as established by 20.2.81 NMAC. 

G. "Allowance limitation" means the tonnage of sulfur dioxide emissions authorized by the 

allowances available for compliance deduction for a WEB source for a control period under 20.2.81.109 NMAC on 

the allowance transfer deadline for that control period. 

H. "Allowance tracking system" means the system developed by the department where allowances 

under the WEB trading program are recorded, held, transferred and deducted. 

I. "Allowance tracking system account" means an account in the allowance tracking system 

established for purposes of recording, holding, transferring, and deducting allowances. 
20.2.81 NMAC 2

J. "Allowance transfer deadline" means the deadline established in Subsection B of 20.2.81.107 

NMAC when allowances must be submitted for recording in a WEB source's compliance account in order to 

demonstrate compliance for that control period. 

K. "Best available retrofit technology (BART)" means that emission reduction control device, 

facility, method, or system, used to achieve the best continuous emission reduction for each pollutant emitted by an 

existing stationary facility. The emission limitation shall be established on a case-by-case basis taking into 

consideration the technology available, the costs of compliance, the energy and non-air quality environmental 

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.

 L. "Compliance account" means an account established in the allowance tracking system under 

Subsection A of 20.2.81.105 NMAC for the purpose of recording allowances that a WEB source might hold to 

demonstrate compliance with its allowance limitation. 

 M. "Compliance certification" means a submission to the department by the account representative 

as required under Subsection B of 20.2.81.109 NMAC to report a WEB source's compliance or noncompliance with 

20.2.81 NMAC. 

 N. "Control period" means the period beginning January 1 of each year and ending on December 31 

of the same year, inclusive. 

 O. "Emission unit" means any part of a stationary source that emits or would have the potential to 

emit any pollutant subject to regulations under the Clean Air Act. 

 P. "Emissions tracking database" means the central database where sulfur dioxide emissions for 

WEB sources as recorded and reported in accordance with 20.2.81 NMAC are tracked to determine compliance with 

allowance limitations.

 Q. "Existing source" means, a stationary source that commenced operation before the program 

trigger date. 

 R. "Fugitive emissions" are those emissions that could not reasonably pass through a stack, 

chimney, vent, or other functionally equivalent opening. 

 S. "General account" means an account established in the allowance tracking system under 

20.2.81.105 NMAC for the purpose of recording allowances held by a person that are not to be used to show 

compliance with an allowance limitation. 

 T. "Milestone" means the maximum level of stationary source regional sulfur dioxide emissions for 

each year from 2003 to 2018, established according to the procedures in section A of the sulfur dioxide milestones 

and backstop trading program implementation plan. 

 U. "New web source" means a WEB source that commenced operation on or after the program 

trigger date. 

 V. "New source set-aside" means a pool of allowances that are available for allocation to new 

sources in accordance with the provisions of the sulfur dioxide milestones and backstop trading program 

implementation plan. 

 W. "Owner or operator" means any person who is an owner or who operates, controls or supervises 

a WEB source, and includes but is not be limited to any holding company, utility system or plant manager. 

 X. "Part" means an air quality control regulation under Title 20, Chapter 2 of the New Mexico 

administrative code, unless otherwise noted, as adopted or amended by the board. 

 Y. "Potential to emit" means the maximum capacity of a stationary source to emit any air pollutant 

under its physical and operational design. Any physical or operational limitation on the capacity of a source to emit 

an air pollutant, including air pollution control equipment and restrictions on hours of operation or on the type or 

amount of material combusted, stored or processed, shall be treated as part of its design if the limitation is 

enforceable by the EPA administrator. 

 Z. "Program trigger date" means the date that the department determines that the WEB trading 

program has been triggered in accordance with the provisions of section A2 of the sulfur dioxide milestones and 

backstop trading program implementation plan. 

AA. "Program trigger years" means the years shown in table 1, column 3, of the sulfur dioxide 

milestones and backstop trading program implementation plan for the applicable milestone if the WEB trading 

program is triggered as described in section A of the sulfur dioxide milestones and backstop trading program 

implementation plan. 

 AB. "Retired source" means a WEB source that has received a retired source exemption as provided 

in Subsection D of 20.2.81.101 NMAC. Any retired source resuming operations under Subsection D of 20.2.81.101 
20.2.81 NMAC 3

NMAC, must submit its exemption as part of its registration materials. 

 AC. "Serial number" means, when referring to allowances, the unique identification number assigned 

to each allowance by the tracking systems administrator, in accordance with Subsection B of 20.2.81.104 NMAC. 

AD. "Special reserve compliance account" means an account established in the allowance tracking 

system under 20.2.81.105 NMAC for the purpose of recording allowances that a WEB source might hold to 

demonstrate compliance with its allowance limitation for emission units that are monitored for sulfur dioxide in 

accordance with 20.2.81.106 NMAC. 

 AE. "Sulfur dioxide emitting unit" means any equipment that is located at a WEB source and that 

emits sulfur dioxide. 

 AF. "Sulfur dioxide milestones and backstop trading program implementation plan" or 

"implementation plan" means section C of the New Mexico regional haze state implementation plan. 

 AG. "Stationary source" means any building, structure, facility or installation that emits or may emit 

any air pollutant subject to regulation under the Clean Air Act. 

 AH. "Submit" means sent to the appropriate authority under the signature of the account 

representative. For purposes of determining when something is submitted, an official U.S. postal service postmark, 

or equivalent electronic time stamp, shall establish the date of submittal. 

 AI. "Ton" means 2000 pounds and, for any control period, any fraction of a ton equaling 1000 

pounds or more shall be treated as one ton and any fraction of a ton equaling less than 1000 pounds shall be treated 

as zero tons. 

 AJ. "Tracking system administrator" means the person designated by the department as the 

administrator of the allowance tracking system and the emission tracking database. 

 AK. "Web source" means a stationary source that meets the applicability requirements of 20.2.81.101 

NMAC. 

 AL. "Western backstop sulfur dioxide trading program ("WEB trading program")" means 

20.2.81 NMAC, triggered as a backstop in accordance with the provisions in the sulfur dioxide milestones and 

backstop trading program implementation plan, if necessary, to ensure that regional sulfur dioxide emissions are 

reduced.

[20.2.81.7 NMAC - N, 12/31/03; A, 07/06/11] 

20.2.81.8 - 20.2.81.99 [RESERVED]

20.2.81.100 WEB TRADING PROGRAM TRIGGER:

A. Except as provided in Subsection B of this section, the provisions of 20.2.81 NMAC shall apply

on the program trigger date that is established in accordance with the procedures outlined in the sulfur dioxide 

milestones and backstop trading program implementation plan.

B. 20.2.81.110 NMAC, special penalty provisions for 2018 milestone, shall apply on January 1, 2018 

and shall remain effective until the provisions of 20.2.81.110 NMAC have been fully implemented.

C. The department shall report to the environmental improvement board every two years following 

the trigger of this program on the distributions of emissions allowances under the program.

[20.2.81.100 NMAC - N, 12/31/03; A, 07/06/11] 

20.2.81.101 WEB TRADING PROGRAM APPLICABILITY:

A. General applicability. 20.2.81 NMAC applies to any stationary source or group of stationary 

sources that are located on one or more contiguous or adjacent properties and which are under the control of the 

same person or persons under common control, belonging to the same industrial grouping, and that are described in 

Paragraphs 1 through 4 of Subsection B. A stationary source or group of stationary sources shall be considered part 

of a single industrial grouping if all of the pollutant emitting activities at such source or group of sources on 

contiguous or adjacent properties belong to the same major group as described in the North American industry 

classification system (NAICS), 2007. 

B. The following are WEB sources.

 (1) All BART-eligible sources as defined in 40 CFR 51.301 that are BART-eligible due to sulfur 

dioxide emissions.

 (2) All stationary sources not meeting the criteria of Paragraph 1 of Subsection B of 20.2.81.101 

NMAC, that have actual sulfur dioxide emissions of 100 tons or more per year in the program trigger years or any 

subsequent year. The fugitive emissions of a stationary source shall not be considered in determining whether it is a 

WEB source unless the source belongs to one of the following categories of stationary source:
20.2.81 NMAC 4

 (a) coal cleaning plants (with thermal dryers);

 (b) Kraft pulp mills;

 (c) Portland cement plants;

 (d) primary zinc smelters;

 (e) iron and steel mills;

 (f) primary aluminum ore reduction plants;

 (g) primary copper smelters;

 (h) municipal incinerators capable of charging more than 250 tons of refuse per day;

 (i) hydrofluoric, sulfuric, or nitric acid plants;

 (j) petroleum refineries;

 (k) lime plants;

 (l) phosphate rock processing plants;

 (m) coke oven batteries;

 (n) sulfur recovery plants;

 (o) carbon black plants (furnace process);

 (p) primary lead smelters;

 (q) fuel conversion plants;

 (r) sintering plants;

 (s) secondary metal production plants;

 (t) chemical process plants;

 (u) fossil-fuel boilers (or combination thereof) totaling more than 250 million British thermal 

units per hour heat input;

 (v) petroleum storage and transfer units with a total storage capacity exceeding 300,000 

barrels;

 (w) taconite ore processing plants;

 (x) glass fiber processing plants;

 (y) charcoal production plants;

 (z) fossil-fuel-fired steam electric plants of more than 250 million British thermal units per 

hour heat input; or

 (aa) any other stationary source category, which as of August 7, 1980 is being regulated under 

Section 111 or 112 of the Clean Air Act.

 (3) A new source that begins operation after the program trigger date and has the potential to emit 

100 tons or more of sulfur dioxide per year.

 (4) The department may determine on a case-by-case basis, with concurrence from the EPA 

administrator, that a source defined in Paragraph 2 of Subsection B of 20.2.81.101 NMAC is not a WEB source if 

the source: 

 (a) in each of the previous five years had actual sulfur dioxide emissions of less than 100 tons 

per year; and

 (b) had actual sulfur dioxide emissions of 100 tons or more in a single year due to a temporary 

emission increase that was caused by a sudden, infrequent, and not reasonably preventable failure of air pollution 

control equipment, failure of process equipment, or a failure to operate in a normal or usual manner; and

 (c) took timely and reasonable action to minimize the temporary emission increase; and

 (d) has corrected the failure of air pollution control equipment, process equipment, or process 

by the time of the department's determination under this section; or

 (e) had to switch fuels or feedstocks on a temporary basis and as a result of an emergency 

situation or unique and unusual circumstances besides cost of such fuels or feedstocks; and

 (f) a temporary emission increase due to poor maintenance or careless operation does not meet 

the criteria of this section.

C. Duration of program participation. Except as provided for in Subsection D of 20.2.81.101 

NMAC, once a source is subject to the WEB trading program, it will remain in the program every year thereafter.

D. Retired source exemption: application.

 (1) Any WEB that is retired shall apply for a retired source exemption. The WEB source may only be 

considered retired if all sulfur dioxide emitting units at the source are retired. The application shall contain all of the 

following information:

 (a) identification of the WEB source, including plant name and an appropriate identification 

code in a format specified by the department;
20.2.81 NMAC 5

 (b) name of account representative;

 (c) description of the status of the WEB source, including the date that the WEB source was 

retired;

 (d) signed certification that the WEB source is retired and will comply with the requirements of 

Subsection D of 20.2.81.101 NMAC; and

 (e) verification that the WEB source has a general account where any unused allowances or 

future allocations will be recorded.

 (2) Responsibilities of retired sources. The retired source exemption becomes effective when the 

department notifies the source that the retired source exemption has been granted.

 (3) A retired source shall be exempt from 20.2.81.106 NMAC and 20.2.81.109 NMAC, except as 

provided below.

 (a) A retired source shall not emit any sulfur dioxide after the date the retired source exemption 

is effective.

 (b) A WEB source shall submit sulfur dioxide emissions reports, as required by Subsection O 

of 20.2.81.106 NMAC for any time period the source was operating prior to the effective date of the retired source 

exemption. The retired source shall be subject to the compliance provisions of 20.2.81.109 NMAC, including the 

requirement to hold allowances in the source's compliance account to cover all sulfur dioxide emissions prior to the 

date the source was permanently retired.

 (c) A retired source that is still in existence but no longer emitting sulfur dioxide shall, for a 

period of five years from the date the records are created, retain records demonstrating the effective date of the 

retired source exemption for purposes of this part.

 (4) Resumption of operations.

 (a) Should a retired source desire to resume operation, the retired source shall submit 

registration materials as follows:

 (i) if the source is required to obtain a new source review permit or operating permit 

under 20.2.70 NMAC, 20.2.72 NMAC, 20.2.74 NMAC or 20.2.79 NMAC prior to resuming operation, then the 

source shall submit registration information as described in 20.2.81.103 NMAC and a copy of the retired source 

exemption with the application required under 20.2.70 NMAC, 20.2.72 NMAC, 20.2.74 NMAC or 20.2.79 NMAC; 

or

 (ii) if the source is not required to obtain a new source review permit or operating permit 

under 20.2.70 NMAC, 20.2.72 NMAC, 20.2.74 NMAC or 20.2.79 NMAC prior to resuming operation, then the 

source shall submit registration information as described in Subsection A of 20.2.81.103 NMAC and a copy of the 

retired source exemption to the department at least ninety days prior to resumption of operation.

 (b) The retired source exemption shall automatically expire on the day the source resumes 

operation.

 (5) Loss of future allowances. A WEB source that is retired and that does not apply to the 

department for a retired source exemption within ninety days of the date that the source is retired shall forfeit any 

unused and future allowances. The abandoned allowances shall be retired by the tracking system administrator.

[20.2.81.101 NMAC - N, 12/31/03; A, 07/06/11] 

20.2.81.102 ACCOUNT REPRESENTATIVE FOR WEB SOURCES: Each WEB source must identify 

one account representative and may also identify an alternate account representative who may act on behalf of the 

account representative. Any representation, action, inaction or submission by the alternate account representative 

will be deemed to be a representation, action, inaction or submission by the account representative.

A. Identification and certification of an account representative.

 (1) The account representative and any alternate account representative shall be appointed by an 

agreement that makes the representations, actions, inactions or submissions of the account representative and any 

alternate binding on the owners and operators of the WEB source.

 (2) The account representative shall submit to the department and the tracking system administrator a 

signed and dated account certificate of representation (certificate) that contains the following elements:

 (a) identification of the WEB source by plant name, state and an appropriate identification code 

in a format specified by the department;

 (b) the name, address, e-mail (if available), telephone and facsimile number of the account 

representative and any alternate;

 (c) a list of owners and operators of the WEB source; and

 (d) information to be part of the emission tracking system database in accordance with the 
20.2.81 NMAC 6

implementation plan. the specific data elements shall be as specified by the department to be consistent with the data 

system structure, and may include basic facility information that may appear in other reports and notices submitted 

by the WEB source, such as county location, industrial classification codes, and similar general facility information.

 (e) the following certification statement: "I certify that I was selected as the account 

representative or alternate account representative, as applicable, by an agreement binding on the owners and 

operators of the WEB source. I certify that I have all the necessary authority to carry out my duties and 

responsibilities under the WEB trading program on behalf of the owners and operators of the WEB source and that 

each such owner and operator shall be fully bound by my representations, actions, inactions, or submissions and by 

any decision or order issued to me by the department regarding the WEB trading program."

 (3) Upon receipt by the department of the complete certificate, the account representative and any 

alternate account representative represents and, by his or her representations, actions, inactions, or submissions, 

legally binds each owner and operator of the WEB source in all matters pertaining to the WEB trading program. The 

owners and operators shall be bound by any decision or order issued by the department regarding the WEB trading 

program.

 (4) No WEB allowance tracking system account shall be established for the WEB source until the 

tracking system administrator has received a complete certificate. Once the account is established, the account 

representative shall make all submissions concerning the account, including the deduction or transfer of allowances.

B. Requirements and responsibilities.

 (1) The responsibilities of the account representative include, but are not limited to, the transferring 

of allowances, and the submission of monitoring plans, registrations, certification applications, sulfur dioxide 

emissions data and compliance reports as required by 20.2.81 NMAC, and representing the source in all matters 

pertaining to the WEB trading program.

 (2) Each submission under this program shall be signed and certified by the account representative 

for the WEB source. Each submission shall include the following truth and accuracy certification statement by the 

account representative: "I am authorized to make this submission on behalf of the owners and operators of the WEB 

source for which the submission is made. I certify under penalty of law that I have personally examined, and am 

familiar with, the statements and information submitted in this document and all its attachments. Based on my 

inquiry of those individuals with primary responsibility for obtaining the information, I certify that the statements 

and information are to the best of my knowledge and belief true, accurate, and complete. I am aware that there are 

significant penalties for submitting false statements and information or omitting required statements and 

information, including the possibility of fine or imprisonment."

C. Changing the account representative or owners and operators.

 (1) Changes to the account representative or the alternate account representative. The account 

representative or alternate account representative may be changed at any time by sending a complete superseding 

certificate to the department and the tracking system administrator under Paragraph 3 of Subsection A of 

20.2.81.102 NMAC, with the change taking effect upon receipt of such certificate by the department. 

Notwithstanding any such change, all representations, actions, inactions, and submissions by the previous account 

representative or alternate prior to the time and date when the tracking system administrator receives the superseding 

certificate shall be binding on the new account representative and the owners and operators of the WEB source.

 (2) Changes in owners and operators.

 (a) Within thirty days of any change in the owners and operators of the WEB source, including 

the addition of a new owner or operator, the account representative shall submit a revised certificate amending the 

list of owners and operators to include such change.

 (b) In the event a new owner or operator of a WEB source is not included in the list of owners 

and operators submitted in the certificate, such new owner or operator shall be deemed to be subject to and bound by 

the certificate, the representations, actions, inactions, and submissions of the account representative of the WEB 

source, and the decisions, orders, actions, and inactions of the department as if the new owner or operator were 

included in such list.

[20.2.81.102 NMAC - N, 12/31/03]

20.2.81.103 REGISTRATION:

A. Deadlines.

 (1) Each source that is a WEB source on or before the program trigger date shall register by 

submitting the initial certificate required in Subsection A of 20.2.81.102 NMAC to the department no later than 180 

days after the program trigger date.

 (2) Any existing source that becomes a WEB source after the program trigger date shall register by 
20.2.81 NMAC 7

submitting the initial certificate required in Subsection A of 20.2.81.102 NMAC to the department no later than 

September 30 of the year following the inventory year in which the source exceeded the emission threshold.

 (3) Any new WEB source shall register by submitting the initial certificate required in Subsection A 

of 20.2.81.102 NMAC to the department prior to the commencement of operation.

B. Integration into permits.

 (1) Any allocation, transfer or deduction of allowance to or from the compliance account of a WEB 

source shall not require revision of the WEB source's operating permit under 20.2.70 NMAC.

 (2) Any WEB source is not required to have a permit under 20.2.72 NMAC, 20.2.74 NMAC or 

20.2.79 NMAC at any time after this rule becomes effective, must at all times possess a permit that includes the 

requirements of 20.2.81 NMAC. If it does not possess a title V permit under 20.2.70 NMAC , it may satisfy this 

paragraph's requirements by obtaining or modifying a permit under 20.2.72, NMAC, 20.2.74 NMAC or 20.2.79 

NMAC to incorporate the requirements of 20.2.81 NMAC. The source must at all times possess a permit that 

includes these requirements.

[20.2.81.103 NMAC - N, 12/31/03]

20.2.81.104 ALLOWANCE ALLOCATIONS:

A. The tracking system administrator shall record the allowances for each WEB source in the 

compliance account for a WEB source once the allowances are allocated by the department under section C1 of the 

sulfur dioxide milestones and backstop trading program implementation plan. If applicable, the tracking system 

administrator shall record a portion of the sulfur dioxide allowances for a WEB source in a special reserve account 

assigned to the department to account for any allowances to be held by the Department in accordance with 

Subsection B of 20.2.81.106 NMAC.

B. The tracking system administrator shall assign a serial number to each allowance in accordance 

with section C2 of the sulfur dioxide milestones and backstop trading program implementation plan.

C. All allowances shall be allocated, recorded, transferred, or used as whole allowances. To 

determine the number of whole allowances, the number of allowances shall be rounded down for decimals less than 

0.50 and rounded up for decimals of 0.50 or greater.

D. An allowance is not a property right, and is a limited authorization to emit one ton of sulfur 

dioxide valid only for the purpose of meeting the requirements of 20.2.81 NMAC. No provision of this WEB trading 

program or other law should be construed to limit the authority of the United States or the department to terminate 

or limit such authorization.

E. Early reduction bonus allocation. Any WEB source that reduces permitted annual sulfur 

dioxide emissions to a level that is below the floor level allocation established for that source in section C1 of the 

sulfur dioxide milestones and backstop trading program implementation plan between 2003 and the program trigger 

year may apply to the department for an early reduction bonus allocation. The application shall be submitted no later 

than ninety days after the program trigger date. Any WEB source that applies and receives early reduction bonus 

allocations shall retain the records referenced below for a minimum of five years after the early reduction bonus 

allowance is certified in accordance with section C1.1(a) (3) of the implementation plan. The application for an early 

reduction bonus allocation shall contain the following information.

 (1) Copies of all permits or other enforceable documents that include annual sulfur dioxide emissions 

limits for the WEB source during the period the WEB source was generating the early reductions. Such permits or 

enforceable documents shall require monitoring for sulfur dioxide emissions that meets the requirements in 

Subsection A and Subsection C of 20.2.81.106 NMAC and that the monitoring provisions were in effect one year 

prior to the beginning of the credit generating period.

 (2) Copies of emissions monitoring reports, for one year prior to the beginning of the credit 

generating period and for the period the WEB source was generating the early reductions, that documents the actual 

annual sulfur dioxide emissions. The emissions monitoring reports during the credit generating period must 

demonstrate that the actual annual sulfur dioxide emissions were below the floor level allocation established for that 

source in section C1 of the sulfur dioxide milestones and backstop trading program implementation plan.

 (3) Demonstration that the floor level established for the source in accordance with section C1 of the 

sulfur dioxide milestones and backstop trading program implementation plan was calculated using data that are 

consistent with the new monitoring methodology under Subsection A of 20.2.81.106 NMAC. If new monitoring 

techniques change the floor level for the source, then a demonstration of the new floor level based on new 

monitoring techniques shall be included in the application.

F. Request for allowances for new WEB sources or modified WEB sources.

 (1) A new WEB source or an existing WEB source that has increased production capacity through a 
20.2.81 NMAC 8

permitted change in operations under 20.2.72 NMAC, 20.2.74 NMAC or 20.2.79 NMAC may apply to the 

department for an allocation from the new source set-aside, as outlined in section C1.3 of the implementation plan.

 (a) A new WEB source is eligible to apply for an annual allocation equal to the permitted 

annual sulfur dioxide emission limit for that source after the source has commenced operation.

 (b) An existing WEB source is eligible to apply for an annual allocation equal to the permitted 

annual sulfur dioxide emission limit for that source that is attributable to any amount of production capacity that is 

greater than the permitted production capacity for that source as of January 1, 2003.

 (c) A source that has received a retired source exemption under Subsection D of 20.2.81.101 

NMAC is not eligible to apply for an allocation from the new source set-aside.

 (2) The application for an allocation from the new source set-aside shall contain the following 

information:

 (a) for existing WEB sources, documentation that shows the permitted production capacity of 

the source before and after the new permit; or

 (b) for new WEB sources, documentation of the actual date of the commencement of operation 

and a copy of the permit.

[20.2.81.104 NMAC - N, 12/31/03]

20.2.81.105 ESTABLISHMENT OF ACCOUNTS:

A. Allowance tracking system accounts. All WEB sources shall open a compliance account. Any 

person may open a general account for holding and transferring allowances. In addition, if a Web source conducts 

monitoring under Subsection B of 20.2.81.106 NMAC, the WEB source shall open a special reserve compliance 

account for allowances associated with units monitored under those provisions. The WEB source and account 

representative shall have no rights to transfer allowances in or out of such special reserve compliance account. The 

department shall allocate allowances to the account in accordance with Paragraph 5 of Subsection B of 20.2.81.106 

NMAC and all such allowances for each control period shall be retired each year for compliance in accordance with 

20.2.81.109 NMAC. To open either type of account; an application that contains the following information shall be 

submitted:

 (1) the name, mailing address, e-mail address, telephone number, and facsimile number of the 

account representative; for a compliance account, include a copy of the account certificate of representation of the 

account representative and any alternate as required in Paragraph 2 of Subsection A of 20.2.81.102 NMAC; for a 

general account, include the account certificate of representation of the account representative and any alternate as 

required in Paragraph 2 of Subsection C or 20.2.81.105 NMAC;

 (2) the WEB source or organization name;

 (3) the type of account to be opened; and

 (4) a signed certification of truth and accuracy by the account representative according to Paragraph 2 

of Subsection A of 20.2.81.102 for compliance accounts and for general accounts, certification of truth and accuracy 

by the account representative according to Subsection D of 20.2.81.105 NMAC.

B. Account representative for general accounts. For a general account, one account representative 

shall be identified and an alternate account representative may be identified and may act on behalf of the account 

representative. Any representation, action, inaction or submission by the alternate account representative shall be 

deemed to be a representation, action, inaction or submission by the account representative.

C. Identification and certification of an account representative for general accounts.

 (1) The account representative shall be appointed by an agreement that makes the representations, 

actions, inactions or submissions of the account representative binding on all persons who have an ownership 

interest with respect to allowances held in the general account.

 (2) The account representative shall submit to the department and the tracking system administrator a 

signed and dated account certificate of representation (certificate) that contains the following elements:

 (a) the name, address, e-mail (if available), telephone and facsimile number of the account 

representative and any alternate;

 (b) the organization name; and

 (c) the following certification statement: "I certify that I was selected as the account 

representative or alternate account representative, as applicable, by an agreement binding on all persons who have 

an ownership interest in allowances in the general account with regard to matters concerning the general account. I 

certify that I have all the necessary authority to carry out my duties and responsibilities under the WEB trading 

program on behalf of said persons and that each such person shall be fully bound by my representations, actions, 

inactions, or submissions and by any decision or order issued to me by the department regarding the general 
20.2.81 NMAC 9

account."

 (3) Upon receipt by the department of the complete certificate, the account representative represents 

and, by his or her representations, actions, inactions, or submissions, legally binds each person who has an 

ownership interest in allowances held in the general account with regard to all matters concerning the general 

account. Such persons shall be bound by any decision or order issued by the department.

 (4) No WEB allowance tracking system general account shall be established until the tracking system 

administrator has received a complete certificate. Once the account is established, the account representative shall 

make all submissions concerning the account, including the deduction or transfer of allowances.

D. Requirements and responsibilities. Each submission for the general account shall be signed and 

certified by the account representative for the general account. Each submission shall include the following truth and 

accuracy certification statement by the account representative: "I am authorized to make this submission on behalf 

of all person who have an ownership interest in allowances held in the general account. I certify under penalty of 

law that I have personally examined, and am familiar with, the statements and information submitted in this 

document and all its attachments. Based on my inquiry of those individuals with primary responsibility for obtaining 

the information, I certify that the statements and information are to the best of my knowledge and belief true, 

accurate, and complete. I am aware that there are significant penalties for submitting false statements and 

information or omitting required statements and information, including the possibility of fine or imprisonment."

E. Changing the account representative. The account representative or alternate account 

representative may be changed at any time by sending a complete superseding certificate to the department and the 

tracking system administrator under Paragraph 2 of Subsection C of 20.2.81.105 NMAC, with the change taking 

effect upon receipt of such certificate by the department. Notwithstanding any such change, all representations, 

actions, inactions, and submissions by the previous account representative or alternate prior to the time and date 

when the department receives the superseding certificate shall be binding on the new account representative and all 

persons having ownership interest with respect to allowances held in the general account.

F. Changes to the account. Any change to the information required in the application for an existing 

account under Subsection A of 20.2.81.105 NMAC shall require a revision of the application.

[20.2.81.105 NMAC - N, 12/31/03]

20.2.81.106 MONITORING, RECORDKEEPING AND REPORTING - GENERAL REQUIREMENTS 

ON MONITORING METHODS:

A. For each sulfur dioxide emitting unit at a WEB source shall comply with the following, as 

applicable, to monitor and record sulfur dioxide mass emissions.

 (1) If a unit is subject to 40 CFR Part 75 under a requirement separate from the WEB trading 

program, the unit shall meet the requirements contained in Part 75 with respect to monitoring, recording and 

reporting sulfur dioxide mass emissions.

 (2) If a unit is not subject to 40 CFR Part 75 under a requirement separate from the WEB trading 

program, a unit shall use one of the following monitoring methods, as applicable:

 (a) a continuous emission monitoring system (CEMS) for sulfur dioxide and flow that 

complies with all applicable monitoring provisions in 40 CFR Part 75;

 (b) if the unit is a gas- or oil-fired combustion device, the excepted monitoring methodology in 

Appendix D to 40 CFR Part 75, or, if applicable, the low mass emissions (LME) provisions (with respect to sulfur 

dioxide mass emissions only) of Section 75.19 of 40 CFR Part 75;

 (c) one of the optional WEB protocols, if applicable, in 20.2.81.111 NMAC or 20.2.81.112 

NMAC; or

 (d) a petition for site-specific monitoring that the source submits for approval by the 

department, and approval by the U.S. environmental protection agency in accordance with Paragraph 5 of 

Subsection O of 20.2.81.106 NMAC.

 (3) A permanently retired unit shall not be required to monitor under this section if such unit was 

permanently retired and had no emissions for the entire period for which the WEB source implements this Paragraph 

3 and the account representative certifies in accordance with Subsection B of 20.2.81.109 NMAC that these 

conditions were met. In the event that a permanently retired unit recommences operation, the WEB source shall 

meet the requirements of this Section 20.2.81.106 NMAC in the same manner as if the unit was a new unit.

B. Notwithstanding Subsection A of this section, the WEB source with a unit that meets one of the 

conditions of Paragraph 1 of Subsection B of 20.2.81.106 NMAC may elect to have the provisions of this Paragraph 

1 apply to that unit.

 (1) Any of the following units may implement Subsection B of 20.2.81.106 NMAC:
20.2.81 NMAC 10

 (a) any smelting operation where all of the emissions from the operation are not ducted to a 

stack;

 (b) any flare, except to the extent such flares are used as a fuel gas combustion device at a 

petroleum refinery; or

 (c) any other type of unit without add-on sulfur dioxide control equipment, if no control level 

was assumed for the WEB source in establishing the floor level (and reducible allocation) provided in section C1 of 

the implementation plan.

 (2) For each unit covered by Subsection B of 20.2.81.106 NMAC , the account representative shall 

submit a notice to request that Subsection B of 20.2.81.106 NMAC apply to one or more sulfur dioxide emitting 

units at a WEB source. The notice shall be submitted in accordance with the compliance dates specified in 

Paragraph 1 of Subsection M of 20.2.81.106 NMAC, and shall include the following information (in a format 

specified by the department with such additional, related information as may be requested):

 (a) a notice of all units at the applicable source, specifying which of the units are to be covered 

by Subsection B of 20.2.81.106 NMAC;

 (b) consistent with the emission estimation methodology used to determine the floor level (and 

reducible allocation) for the source in accordance with section C1 of the implementation plan, the portion of the 

WEB source's overall allowance allocation that is attributable to any unit(s) covered by this paragraph; and

 (c) an identification of any such units that are permanently retired.

 (3) For each new unit at an existing WEB source for which the WEB source seeks to comply with 

this Subsection B of 20.2.81.106 NMAC; and for which the account representative applies for an allocation under 

the new source set-aside provisions of Subsection F of 20.2.81.104 NMAC, the account representative shall submit a 

modified notice under Paragraph 2 of Subsection B of 20.2.81.106 NMAC, that includes such new sulfur dioxide 

emitting unit(s). The modified notice shall be submitted in accordance with the compliance dates in Paragraph 1 of 

Subsection M of 20.2.81.106 NMAC, but no later than the date on which a request is submitted under Paragraph 1 

of Subsection F of 20.2.81.104 NMAC for allocations from the set-aside.

 (4) The department shall evaluate the information submitted by the WEB source in Paragraphs 2 and 

3 of Subsection B of 20.2.81.106 NMAC, and may issue a notice to the source to exclude any units that do not 

qualify under this Subsection B of 20.2.81.106 NMAC or to adjust the portion of allowances attributable to units 

that do qualify to be consistent with the emission estimation methodology used to establish the floor level (and 

reducible allocation) for the source.

 (5) The department shall allocate allowances equal to the adjusted portion of the WEB source's 

allowances under Paragraphs 2, 3, and 4 of Subsection B of 20.2.81.106 NMAC in a special reserve compliance 

account provided that no such treatment of the WEB source's allocation will be required for any unit that is 

permanently retired and had no emissions for the entire period for which the WEB source implements this 

Subsection B and the account representative certifies in accordance with 20.2.81.109 NMAC that these conditions 

are met. In the event that a permanently retired unit recommences operation, the WEB source shall meet the 

requirements of this Section 20.2.81.106 NMAC in the same manner as if the unit was a new unit.

 (6) The account representative for a WEB source shall submit an annual emissions statement for each 

unit under this Subsection B of 20.2.81.106 NMAC in accordance with Subsection O of 20.2.81.106 NMAC. The 

WEB source shall maintain operating records sufficient to estimate annual emissions in a manner consistent with the 

emission estimation methodology used to establish the floor level (and reducible allocation) for the source. In 

addition, if the estimated emissions from all such units at the WEB source are greater than the allowances for the 

current control year held in the special reserve compliance account under Paragraph 5 of Subsection B of 

20.2.81.106 NMAC for the WEB source, the account representative shall report the excess amount as part of the 

annual report for the WEB source under 20.2.81.109 NMAC and be required to use other allowances in the standard 

compliance account for the WEB source to account for such emissions, in accordance with 20.2.81.109 NMAC.

 (7) The remaining provisions of this section shall not apply to units covered by Subsection B of 

20.2.81.106 NMAC except where otherwise noted.

 (8) A WEB source may opt to modify the monitoring for an sulfur dioxide emitting unit to use 

monitoring under Subsection A of 20.2.81.106 NMAC, but any such monitoring change shall take effect on January 

1 of the next compliance year. In addition, the account representative shall submit an initial monitoring plan at least 

180 days prior to the date on which the new monitoring will take effect and a detailed monitoring plan in accordance 

with Subsection D of 20.2.81.106 NMAC. The account representative shall also submit a revised notice under 

Subsection B of 20.2.81.106 NMAC at the same time that the initial monitoring plan is submitted.

C. For any monitoring that the WEB source uses under this section (including Paragraph 1), the WEB 

source (and, as applicable, the account representative) shall implement, certify, and use such monitoring in 
20.2.81 NMAC 11

accordance with this section, and shall record and report the data from such monitoring as required in this section. In 

addition, the WEB source (and, as applicable, the account representative) shall not:

 (1) except for an alternative approved by the U.S. EPA administrator for a WEB source that 

implements monitoring under Paragraph 1 of Subsection A of 20.2.81.106 NMAC, use an alternative monitoring 

system, alternative reference method or another alternative for the required monitoring method without having 

obtained prior written approval in accordance with Paragraph 5 of Subsection O of 20.2.81.106 NMAC;

 (2) operate an sulfur dioxide emitting unit so as to discharge, or allow to be discharged, sulfur dioxide 

emissions to the atmosphere without accounting for these emissions in accordance with the applicable provisions of 

this section;

 (3) disrupt the approved monitoring method or any portion thereof, and thereby avoid monitoring and 

recording sulfur dioxide mass emissions discharged into the atmosphere, except for periods of recertification or 

periods when calibration, quality assurance testing or maintenance is performed in accordance with the applicable 

provisions of this section; or

 (4) retire or permanently discontinue use of an approved monitoring method, except under one of the 

following circumstances:

 (a) during a period when the unit is exempt from the requirements of this section, including 

retirement of a unit as addressed in Paragraph 3 of Subsection A of 20.2.81.106 NMAC;

 (b) the WEB source is monitoring emissions from the unit with another certified monitoring 

method approved under this section for use at the unit that provides data for the same parameter as the retired or 

discontinued monitoring method; or

 (c) the account representative submits notification of the date of certification testing of a 

replacement monitoring system in accordance with this section, and the WEB source recertifies thereafter a 

replacement monitoring system in accordance with the applicable provisions of this section.

D. Monitoring plan general provisions. The WEB source of a sulfur dioxide emitting unit that uses 

a monitoring method under Paragraph 2 of Subsection A of 20.2.81.106 NMAC shall meet the following 

requirements:

 (1) prepare and submit to the department an initial monitoring plan for each monitoring method that 

the WEB source uses to comply with this section; in accordance with Subsection F of 20.2.81.106 NMAC, the plan 

shall contain sufficient information on the units involved, the applicable method, and the use of data derived from 

that method to demonstrate that all unit sulfur dioxide emissions are monitored and reported; the plan shall be 

submitted in accordance with the compliance deadlines specified in Subsection M of 20.2.81.106 NMAC;

 (2) prepare, maintain and submit to the department a detailed monitoring plan prior to the first day of 

certification testing in accordance with the compliance deadline specified in Subsection M of 20.2.81.106 NMAC; 

the plan shall contain the applicable information required by Subsection D of 20.2.81.106 NMAC; the department 

may require that the monitoring plan (or portions thereof) be submitted electronically; the department also may 

require that the plan be submitted on an ongoing basis in electronic format as part of the quarterly report submitted 

under Paragraph 1 of Subsection O of 20.2.81.106 NMAC or resubmitted separately within after any change is made 

to the plan in accordance with the following Paragraph 3 of Subsection D of 20.2.81.106 NMAC; and

 (3) whenever the WEB source makes a replacement, modification, or change in one of the systems or 

methodologies provided for in Paragraph 2 of Subsection A of 20.2.81.106 NMAC, including a change in the 

automated data acquisition and handling system or in the flue gas handling system, that affects information reported 

in the monitoring plan (e.g., a change to serial number for a component of a monitoring system), then the WEB 

source shall update the monitoring plan in accordance with the compliance deadline specified in Subsection M of 

20.2.81.106 NMAC. 

E. A WEB source with a sulfur dioxide emitting unit that uses a method under Paragraph 1 of 

Subsection A of 20.2.81.106 NMAC (a unit subject to 40 CFR Part 75 under a program other than this WEB trading 

program) shall meet the requirements of Subsections D-I of 20.2.81.106 NMAC by preparing, maintaining and 

submitting a monitoring plan in accordance with the requirements of 40 CFR Part 75, provided that the WEB source 

also shall submit the entire monitoring plan to the department upon request.

F. Initial monitoring plan. The account representative shall submit an initial monitoring plan for 

each sulfur dioxide emitting unit (or group of units sharing a common methodology) that, except as otherwise 

specified in an applicable provision in 20.2.81.111 NMAC, contains the following information.

 (1) For all sulfur dioxide emitting units involved in the monitoring plan:

 (a) plant name and location; 

 (b) plant and unit identification numbers assigned by the department;

 (c) type of unit (or units for a group of units using a common monitoring methodology);
20.2.81 NMAC 12

 (d) identification of all stacks or pipes associated with the monitoring plan;

 (e) types of fuel(s) fired (or sulfur containing process materials used in the sulfur dioxide 

emitting unit), and the fuel classification of the unit if combusting more than one type of fuel and using a 40 CFR 

Part 75 methodology;

 (f) type(s) of emissions controls for sulfur dioxide installed or to be installed, including 

specifications of whether such controls are pre-combustion, post-combustion, or integral to the combustion process;

 (g) maximum hourly heat input capacity, or process throughput capacity, if applicable;

 (h) identification of all units using a common stack; and

 (i) indicator of whether any stack identified in the plan is a bypass stack.

 (2) For each unit and parameter required to be monitored, identification of monitoring methodology 

information, consisting of monitoring methodology, monitor locations, substitute data approach for the 

methodology, and general identification of quality assurance procedures. If the proposed methodology is a sitespecific methodology submitted pursuant to Subparagraph d of Paragraph 2 of Subsection A of 20.2.81.106 NMAC, 

the description under this paragraph shall describe fully all aspects of the monitoring equipment, installation 

locations, operating characteristics, certification testing, ongoing quality assurance and maintenance procedures, and 

substitute data procedures.

 (3) If the WEB source intends to petition for a change to any specific monitoring requirement 

otherwise required under this section, such petition may be submitted as part of the initial monitoring plan.

 (4) The department may issue a notice of approval or disapproval of the initial monitoring plan based 

on the compliance of the proposed methodology with the requirements for monitoring in this section.

G. Detailed monitoring plan. The account representative shall submit a detailed monitoring plan 

that, except as otherwise specified in an applicable provisions in 20.2.81.111 NMAC or 20.2.81.112 NMAC, shall 

contain the following information.

 (1) Identification and description of each monitoring component (including each monitor and its 

identifiable components, such as analyzer or probe) in a CEMS (e.g., sulfur dioxide pollutant concentration monitor, 

flow monitor, moisture monitor), a 40 CFR Part 75, Appendix D monitoring system (e.g., fuel flowmeter, data 

acquisition and handling system), or a protocol in 20.2.81.111 NMAC or 20.2.81.112 NMAC , including:

 (a) manufacturer, model number and serial number;

 (b) component or system identification code assigned by the facility to each identifiable 

monitoring component, such as the analyzer or probe;

 (c) designation of the component type and method of sample acquisition or operation (e.g., in 

situ pollutant concentration monitor or thermal flow monitor);

 (d) designation of the system as a primary or backup system;

 (e) first and last dates the system reported data;

 (f) status of the monitoring component; and

 (g) parameter monitored.

 (2) Identification and description of all major hardware and software components of the automated 

data acquisition and handling system, including:

 (a) hardware components that perform emission calculations or store data for quarterly 

reporting purposes (provide the manufacturer and model number); and

 (b) software components (provide the identification of the provider and model or version 

number).

 (3) Explicit formulas for each measured emissions parameter, using component or system 

identification codes for the monitoring system used to measure the parameter that links the system observations with 

the reported concentrations and mass emissions. The formulas shall contain all constants and factors required to 

derive mass emissions from component or system code observations and an indication of whether the formula is 

being added, corrected, deleted, or is unchanged. The WEB source with a low mass emissions unit for which the 

WEB source is using the optional low mass emissions excepted methodology in Section 75.19(c) of 40 CFR Part 75 

is not required to report such formulas.

 (4) Inside cross-sectional area (square feet) at flow monitoring location (for units with flow monitors, 

only).

 (5) If using CEMS for sulfur dioxide and flow, for each parameter monitored: scale, maximum

potential concentration (and method of calculation), maximum expected concentration (if applicable) (and method 

of calculation), maximum potential flow rate (and method of calculations), span value, full-scale range, daily 

calibration units of measure, span effective date and hour, span inactivation date and hour, indication of whether 

dual spans are required, default high range value, flow rate span, and flow rate span value and full scale value in 
20.2.81 NMAC 13

standard cubic feet per hour (scfh) for each unit or stack using sulfur dioxide or flow component monitors.

 (6) If the monitoring system or excepted methodology provides for use of a constant, assumed, or 

default value for a parameter under specific circumstances, then the following information for each value of such 

parameter shall be included:

 (a) identification of the parameter;

 (b) default, maximum, minimum, or constant value, and units of measure for the value;

 (c) purpose of the value;

 (d) indicator of use during controlled and uncontrolled hours;

 (e) types of fuel;

 (f) source of the value;

 (g) value effective date and hour;

 (h) date and hour value is no longer effective (if applicable); and

 (i) for units using the excepted methodology under Section 75.19 of 40 CFR Part 75, the 

applicable sulfur dioxide emission factor.

 (7) Unless otherwise specified in Section 6.5.2.1 of Appendix A to 40 CFR Part 75, for each unit or 

common stack on which hardware CEMS are installed:

 (a) the upper and lower boundaries of the range of operation (as defined in Section 6.5.2.1 of 

Appendix A to 40 CFR Part 75), or thousand of lb/hr of steam, or ft/sec (as applicable);

 (b) the load or operating level(s) designated as normal in Section 6.5.2.1 of Appendix A to 40 

CFR Part 75, or thousands of pounds per hour lb/hr of steam, or feet per second ft/sec (as applicable);

 (c) the two load or operating levels (i.e., low, mid, or high) identified in Section 6.5.2.1 of 

Appendix A to 40 CFR Part 75 as the most frequently used;

 (d) the date of the data analysis used to determine the normal load (or operating) level(s) and 

the two most frequently-used load (or operating) levels; and

 (e) activation and deactivation dates when the normal load or operating level(s) change and are 

updated. 

 (8) For each unit that is complying with 40 CFR Part 75 for which the optional fuel flow-to-load test 

in Section 2.1.7 of Appendix D to 40 CFR Part 75 is used:

 (a) the upper and lower boundaries of the range of operation (as defined in Section 6.5.2.1 of 

Appendix A to 40 CFR Part 75), expressed in thousand of lb/hr of steam;

 (b) the load level designated as normal, pursuant to Section 6.5.2.1 of Appendix A to 40 CFR 

Part 75, expressed in thousands of lb/hr of steam; and

 (c) the date of the load analysis used to determine the normal load level.

 (9) Information related to quality assurance testing, including (as applicable): identification of the 

test strategy; protocol for the relative accuracy test audit; other relevant test information; calibration gas levels 

(percent of span) for the calibration error test and linearity check; calculations for determining maximum potential 

concentration, maximum expected concentration (if applicable), maximum potential flow rate, and span. 

 (10) If applicable, apportionment strategies under Sections 75.10 through 75.18 of 40 CFR Part 75.

 (11) Description of site locations for each monitoring component in a monitoring system, including 

schematic diagrams and engineering drawings and any other documentation that demonstrates each monitor location 

meets the appropriate siting criteria. For units monitored by a continuous emission monitoring system, diagrams 

shall include:

 (a) a schematic diagram identifying entire gas handling system from unit to stack for all units, 

using identification numbers for units, monitor components, and stacks corresponding to the identification numbers 

provided in the initial monitoring plan and Paragraphs 1 and 3 of Subsection G of 20.2.81.106 NMAC; the 

schematic diagram must depict the height of any monitor locations; comprehensive or separate schematic diagrams 

shall be used to describe groups of units using a common stack; and

 (b) stack and duct engineering diagrams showing the dimensions and locations of fans, turning 

vanes, air preheaters, monitor components, probes, reference method sampling ports, and other equipment that 

affects the monitoring system location, performance, or quality control checks.

 (12) A data flow diagram denoting the complete information handling path from output signals of 

CEMS components to final reports.

H. In addition to supplying the information in Subsections F and G above, the WEB source with an 

sulfur dioxide emitting unit using either of the methodologies in Subparagraph b of Paragraph 2 of Subsection A of 

20.2.81.106 NMAC shall include the following information in its monitoring plan for the specific situations 

described. 
20.2.81 NMAC 14

 (1) For each gas-fired or oil-fired sulfur dioxide emitting unit for which the WEB source uses the 

optional protocol in Appendix D to 40 CFR Part 75 for sulfur dioxide mass emissions, the WEB source shall include 

the following information in the monitoring plan:

 (a) parameter monitored;

 (b) type of fuel measured, maximum fuel flow rate, units of measure, and basis of maximum 

fuel flow rate (i.e., upper range value or unit maximum) for each fuel flowmeter;

 (c) test method used to check the accuracy of each fuel flowmeter;

 (d) submission status of the data;

 (e) monitoring system identification code;

 (f) the method used to demonstrate that the unit qualifies for monthly gross calorific value 

(GCV) sampling or for daily or annual fuel sampling for sulfur content, as applicable;

 (g) a schematic diagram identifying the relationship between the unit, all fuel supply lines, the 

fuel flowmeter(s), and the stack(s); the schematic diagram must depict the installation location of each fuel 

flowmeter and the fuel sampling location(s); comprehensive and separate schematic diagrams shall be used to 

describe groups of units using a common pipe;

 (h) for units using the optional default sulfur dioxide emission rate for "pipeline natural gas" or 

"natural gas" in Appendix D to 40 CFR Part 75, the information on the sulfur content of the gaseous fuel used to 

demonstrate compliance with either Section 2.3.1.4 or 2.3.2.4 of Appendix D to 40 CFR Part 75;

 (i) for units using the 720 hour test under Section 2.3.6 of Appendix D to 40 CFR Part 75 to 

determine the required sulfur sampling requirements, report the procedures and results of the test; and

 (j) for units using the 720 hour test under Section 2.3.5 of Appendix D to 40 CFR Part 75 to 

determine the appropriate fuel GCV sampling frequency, report the procedures used and the results of the test.

 (2) For each sulfur dioxide emitting unit for which the WEB source uses the low mass emission 

excepted methodology of Section 75.19 to 40 CFR Part 75, the WEB source shall include the following information 

in the monitoring plan that accompanies the initial certification application:

 (a) the results of the analysis performed to qualify as a low mass emissions unit under Section 

75.19(c) to 40 CFR Part 75; this report shall include either the previous three years actual or projected emissions; the 

following items shall be included: a) current calendar year of application; b) type of qualification; c) years one, two, 

and three; d) annual measured, estimated or projected sulfur dioxide mass emissions for years one, two, and three; 

and e) annual operating hours for years one, two, and three;

 (b) a schematic diagram identifying the relationship between the unit, all fuel supply lines and 

tanks, any fuel flowmeter(s), and the stack(s); comprehensive or separate schematic diagrams shall be used to 

describe groups of units using a common pipe;

 (c) for units which use the long term fuel flow methodology under Section 75.19(c)(3) to 40 

CFR Part 75, a diagram of the fuel flow to each unit or group of units and a detailed description of the procedures 

used to determine the long term fuel flow for a unit or group of units for each fuel combusted by the unit or group of 

units;

 (d) a statement that the unit burns only gaseous fuel(s) and/or fuel oil and a list of the fuels that 

are burned or a statement that the unit is projected to burn only gaseous fuel(s) and/or fuel oil and a list of the fuels 

that are projected to be burned;

 (e) a statement that the unit meets the applicability requirements in Sections 75.19(a) and (b) to 

40 CFR Part 75 with respect to sulfur dioxide emissions; and

 (f) any unit historical actual, estimated and projected sulfur dioxide emissions data and 

calculated sulfur dioxide emissions data demonstrating that the unit qualifies as a low mass emissions unit under 

Sections 75.19(a) and (b) to 40 CFR Part 75.

 (3) For each gas-fired unit the WEB source shall include the following in the monitoring plan: 

current calendar year, fuel usage data as specified in the definition of gas-fired in Section 72.2 of 40 CFR Part 72, 

and an indication of whether the data are actual or projected data. 

I. The specific elements of a monitoring plan under Subsection D of 20.2.81.106 NMAC shall not be 

part of an operating permit for a WEB source issued in accordance with the title V of the Clean Air Act, and 

modifications to the elements of the plan shall not require a permit modification.

J. Certification and recertification.

 (1) All monitoring systems are subject to initial certification and recertification testing as specified in 

40 CFR Part 75, 20.2.81.111 NMAC or ; 20.2.81.112 NMAC. Certification or recertification of a monitoring 

system by the U.S. environmental protection agency for a WEB source that is subject to 40 CFR Part 75 under a 

requirement separate from 20.2.81 NMAC shall constitute certification under the WEB trading program.
20.2.81 NMAC 15

 (2) The WEB source with a sulfur dioxide emitting unit not otherwise subject to 40 CFR Part 75 that 

monitors sulfur dioxide mass emissions in accordance with 40 CFR Part 75 to satisfy the requirements of this 

section shall perform all of the tests required by that regulation and shall submit the following:

 (a) a test notice, not later than 21 days before the certification testing of the monitoring system, 

provided that the department may establish additional requirements for adjusting test dates after this notice as part of 

the approval of the initial monitoring plan under Subsection F of 20.2.81.106 NMAC; 

 (b) an initial certification application within 45 days after testing is complete;

 (c) a monitoring system shall be considered provisionally certified while the application is 

pending, and the system shall be deemed certified if the department does not approve or disapprove the system 

within six months after the date on which the application is submitted; and

 (d) whenever an audit of any monitoring certified under 20.2.81 NMAC, and a review of the 

initial certification or recertification application, reveal that any system or component should not have been certified 

or recertified because it did not meet a particular performance specification or other requirement of 20.2.81 NMAC, 

both at the time of the initial certification or recertification application submission and at the time of the audit, the 

department will issue a notice of disapproval of the certification status of such system or component; for the 

purposes of this paragraph, an audit shall be either a field audit of the facility or an audit of any information 

submitted to the department regarding the facility; by issuing the notice of disapproval, the certification status is 

revoked prospectively, and the data measured and recorded shall not be considered valid quality-assured data from 

the date of issuance of the notification of the revoked certification status until the date and time that the WEB source 

completes subsequently approved initial certification or recertification tests in accordance with the procedures in 

Subsection J of 20.2.81.106 NMAC; the WEB source shall apply the substitute data procedures in Paragraph 2 of 

Subsection L of 20.2.81.106 NMAC to replace, prospectively, all of the invalid, non-quality-assured data for each 

disapproved system or component.

K. Ongoing quality assurance and quality control. The WEB source shall satisfy the applicable 

quality assurance and quality control requirements of Part 75 or, if the WEB source is subject to a WEB protocol in 

20.2.81.111 NMAC , the applicable quality assurance and quality control requirements in 20.2.81.111 NMAC on 

and after the date that certification testing commences.

L. Substitute data procedures.

 (1) For any period after certification testing is complete in which quality assured, valid data are not 

being recorded by a monitoring system certified and operating in accordance with 20.2.81 NMAC, missing or 

invalid data shall be replaced with substitute data in accordance with 40 CFR Part 75 or, if the WEB source is 

subject to a WEB protocol in 20.2.81.111 NMAC or 20.2.81.112 NMAC , with substitute data in accordance with 

20.2.81.111 NMAC.

 (2) For a sulfur dioxide emitting unit that does not have a certified or provisionally certified 

monitoring system in place as of the beginning of the first control period for which the unit is subject to the WEB 

trading program, the WEB source shall:

 (a) if the WEB source will use a CEMS to comply with this section, substitute the maximum 

potential concentration of sulfur dioxide for the unit and the maximum potential flow rate, as determined in 

accordance with 40 CFR Part 75; the procedures for conditional data validation under Section 75.20(b)(3) may be 

used for any monitoring system under 20.2.81 NMAC that uses these 40 CFR Part 75 procedures, as applicable;

 (b) if the WEB source will use the 40 CFR Part 75 Appendix D methodology, substitute the 

maximum potential sulfur content, density or gross calorific value for the fuel and the maximum potential fuel flow 

rate, in accordance with Section 2.4 of Appendix D to 40 CFR Part 75;

 (c) if the WEB source will use the 40 CFR Part 75 methodology for low mass emissions units, 

substitute the sulfur dioxide emission factor required for the unit as specified in 40 CFR 75.19 and the maximum 

rated hourly heat input, as defined in 40 CFR 72.2; or 

 (d) if using a protocol in 20.2.81.111 NMAC or 20.2.81.112 NMAC, follow the procedures in 

the applicable protocol.

M. Compliance deadline.

 (1) The initial monitoring plan shall be submitted by the following dates.

 (a) For each source that is a WEB source on or before the program trigger date, the monitoring 

plan shall be submitted 180 days after such program trigger date.

 (b) For any existing source that becomes a WEB source after the program trigger date, the 

monitoring plan shall be submitted by September 30 of the year following the inventory year in which the source 

exceeded the emissions threshold.

 (c) For any new WEB source, the monitoring plan shall be included with the permit application 
20.2.81 NMAC 16

under 20.2.70 NMAC, 20.2.72 NMAC, 20.2.74 NMAC or 20.2.79 NMAC.

 (2) A detailed monitoring plan under Subsection E of 20.2.81.106 NMAC shall be submitted no later 

than 45 days prior to commencing certification with the following Paragraph 3.

 (3) Emission monitoring systems shall be installed, operational and shall have met all of the 

certification testing requirements of this 20.2.81.106 NMAC (including any referenced in 20.2.81.111 NMAC or 

20.2.81.112 NMAC ) by the following dates.

 (a) For each source that is a WEB source on or before the program trigger date, two years prior 

to the start of the first control period as described in 20.2.81.109 NMAC.

 (b) For any existing source that becomes a WEB source after the program trigger date, one year 

after the due date for the monitoring plan under Subparagraph b of Paragraph 2 of Subsection M of 20.2.81.106 

NMAC.

 (c) For any new WEB source, (or any new unit at a WEB source under Paragraph 3 

Subparagraph a or b, the earlier of 90 unit operating days or 180 calendar days after the date the new source 

commences operation.

 (4) The WEB source shall submit test notices and certification applications in accordance with the 

deadlines set forth in Paragraph 2 of Subsection J of 20.2.81.106 NMAC.

 (5) For each applicable control period, the WEB source shall submit each quarterly report under 

Subsection O of 20.2.81.106 NMAC by no later than 30 days after the end of each calendar quarter and shall submit 

the annual report under Subsection O of 20.2.81.106 NMAC no later than 60 days after the end of each calendar 

year.

N. Recordkeeping.

 (1) The WEB source shall keep copies of all reports, registration materials, compliance certifications, 

sulfur dioxide emissions data, quality assurance data, and other submissions under 20.2.81 NMAC for a period of 

five years. In addition, the WEB source shall keep a copy of all account certificates of representation. Unless 

otherwise requested by the WEB source and approved by the department, the copies shall be kept on site at the 

source.

 (2) The WEB source shall keep records of all operating hours, quality assurance activities, fuel 

sampling measurements, hourly averages for sulfur dioxide, stack flow, fuel flow, or other continuous 

measurements, as applicable, and any other applicable data elements specified in this section , 20.2.81.111 NMAC 

or in 20.2.81.112 NMAC. The WEB source shall maintain the applicable records specified in 40 CFR Part 75 for 

any sulfur dioxide emitting unit that uses a Part 75 monitoring method to meet the requirements of this section.

O. Reporting.

 (1) Quarterly reports. For each sulfur dioxide emitting unit, the account representative shall submit a 

quarterly report within thirty days after the end of each calendar quarter. The report shall be in a format specified by 

the department to include hourly and quality assurance activity information and shall be submitted in a manner 

compatible with the emissions tracking database designed for the WEB trading program. If the WEB source 

submits a quarterly report under 40 CFR Part 75 to the U.S. EPA administrator, no additional report under this 

paragraph shall be required, provided, however, that the department may require that a copy of that report (or a 

separate statement of quarterly and cumulative annual sulfur dioxide mass emissions) be submitted separately to the 

department.

 (2) Annual report. Based on the quarterly reports, each WEB source shall submit an annual statement 

of total annual sulfur dioxide emissions for all sulfur dioxide emitting units at the source. The annual report shall 

identify the total emissions for all units monitored in accordance with Subsection A of 20.2.81.106 NMAC and the 

total emissions for all units with emissions estimated in accordance with Subsection B of 20.2.81.106 NMAC. The 

annual report shall be submitted within 60 days after the end of a control period.

 (3) If the department so directs that any monitoring plan, report, certification, recertification, or 

emissions data required to be submitted under this section be submitted to the tracking system administrator.

 (4) The department may review and reject any report submitted under this Subsection O of 

20.2.81.106 NMAC that contains errors or fails to satisfy the requirements of this section, and the account 

representative shall resubmit the report to correct any deficiencies.

 (5) A WEB source may petition for an alternative to any requirement specified in Paragraph 2 of 

Subsection A of 20.2.81.106 NMAC. The petition shall require approval of the department and the U.S. EPA 

administrator. Any petition submitted under this paragraph shall include sufficient information for the evaluation of 

the petition, including, at a minimum, the following information:

 (a) identification of the WEB source and applicable sulfur dioxide emitting unit(s);

 (b) a detailed explanation of why the proposed alternative is being suggested in lieu of the 
20.2.81 NMAC 17

requirement;

 (c) a description and diagram of any equipment and procedures used in the proposed 

alternative, if applicable;

 (d) a demonstration that the proposed alternative is consistent with the purposes of the 

requirement for which the alternative is proposed and is consistent with the purposes of 20.2.81 NMAC and that any 

adverse effect of approving such alternative will be de minimis; and

 (e) any other relevant information that the department may require.

 (6) For any monitoring plans, reports, or other information submitted under 20.2.81.106 NMAC, the 

WEB source shall ensure that, where applicable, identifying information is consistent with the identifying 

information provided in the most recent certificate of representation for the WEB source submitted under 

20.2.81.102 NMAC.

[20.2.81.106 NMAC - N, 12/31/03; A, 07/06/11] 

20.2.81.107 ALLOWANCE TRANSFERS:

A. Procedure. To transfer allowances, the account representative shall submit the following 

information to the tracking system administrator:

 (1) the transfer account number(s) identifying the transferor account;

 (2) the transfer account number(s) identifying the transferee account;

 (3) the serial number of each allowance to be transferred; and

 (4) the transferor's account representative's name and signature and date of submission.

B. Deadline. The allowance transfer deadline is midnight Pacific standard time March 1 of each year 

(or if this date is not a business day, midnight of the first business day thereafter) following the end of the control 

period. By this time, the transfer of the allowances into the WEB source's compliance account must be correctly 

submitted to the tracking system administrator in order to demonstrate compliance under Subsection A of 

20.2.81.109 NMAC for that control period.

C. Retirement of Allowances. To transfer allowances for the purpose of retirement, the account 

representative shall submit the following information to the tracking system administrator:

 (1) the transfer account number(s) identifying the transferor account;

 (2) the serial number of each allowance to be retired; and

 (3) the transferor's account representative's name and signature and date of submission accompanied 

by a signed statement acknowledging that each retired allowance as no longer available for future transfers from or 

to any account.

[20.2.81.107 NMAC - N, 12/31/03]

20.2.81.108 USE OF ALLOWANCES FROM A PREVIOUS YEAR:

A. Any allowance that is held in a compliance account or general account shall remain in such an 

account unless and until the allowance is deducted in conjunction with the compliance process, or transferred to 

another account.

B. In order to demonstrate compliance under Subsection A of 20.2.81.109 NMAC for a control 

period, WEB sources shall only use allowances allocated for that current control period or any previous year. 

Because all allowances held in a special reserve compliance account for a WEB source that monitors certain units in 

accordance with Subsection B of 20.2.81.106 NMAC will be deducted for compliance for each control period, no 

banking of such allowances for use in a subsequent year is permitted by 20.2.81 NMAC.

C. If flow control procedures for the current control period have been triggered as outlined in section 

C4.2 of the sulfur dioxide milestones and backstop trading program implementation plan, then the use of allowances 

that were allocated for any previous year shall be limited as follows.

 (1) The number of allowances that are held in each compliance account and general account as of the 

allowance transfer deadline for the immediately previous year and that were allocated for any previous year shall be 

determined.

 (2) The number determined in Paragraph 1 shall be multiplied by the flow control ratio established in 

accordance with section C4.2 of the sulfur dioxide milestones and backstop trading program implementation plan to 

determine the number of allowances that were allocated for a previous year that can be used without restriction for 

the current control period.

 (3) Allowances that were allocated for a previous year in excess of the number determined in 

Paragraph 2 may also be used for the current control period. If such allowances are used to make a deduction, three

allowances shall be deducted for each deduction of one allowance required under 20.2.81.109 NMAC.
20.2.81 NMAC 18

D. Special provisions for the year 2018. After compliance with the 2017 allowance limitation has 

been determined in accordance with Subsection A of 20.2.81.109 NMAC, allowances allocated for any year prior to 

2018 shall not be used for determining compliance with the 2018 allowance limitation or any future allowance 

limitation.

[20.2.81.108 NMAC - N, 12/31/03; A, 07/06/11] 

20.2.81.109 COMPLIANCE:

A. Compliance with allowance limitations.

 (1) The WEB source shall hold allowances, in accordance with Paragraph 2 of Subsection A of 

20.2.81.109 NMAC and 20.2.81.108 NMAC, as of the allowance transfer deadline in the WEB source's compliance 

account (together with any current control year allowances held in the WEB source's special reserve compliance 

account under Subsection B of 20.2.81.106 NMAC in an amount not less than the total sulfur dioxide emissions for 

the control period from the WEB source, as determined under the monitoring and reporting requirements of 

20.2.81.106 NMAC.

 (a) For each source that is a WEB source on or before the program trigger date, the first control 

period is the calendar year that is six years following the calendar year for which sulfur dioxide emissions exceeded 

the milestone in accordance with procedures in section A of the sulfur dioxide milestones and backstop trading 

program implementation plan.

 (b) For any existing source that becomes a WEB source after the program trigger date, the first 

control period is the calendar year that is four years following the inventory year in which the source exceeded the 

sulfur dioxide emissions threshold.

 (c) For any new WEB source after the program trigger date the first control period is the first 

full calendar year that the source is in operation.

 (d) If the WEB trading program is triggered in accordance with the 2013 review procedures in 

section A4 of the sulfur dioxide milestones and backstop trading program implementation plan, the first control 

period for each source that is a WEB source on or before the program trigger date is the year 2018.

 (2) Allowance transfer deadline. An allowance may only be deducted from the WEB source's 

compliance account if:

 (a) the allowance was allocated for the current control period or meets the requirements in 

20.2.81.108 NMAC for use of allowances from a previous control period; and

 (b) the allowance was held in the WEB source's compliance account as of the allowance 

transfer deadline for the current control period, or was transferred into the compliance account by an allowance 

transfer correctly submitted for recording by the allowance transfer deadline for the current control period.

 (3) Compliance with allowance limitations shall be determined as follows.

 (a) The total annual sulfur dioxide emissions for all sulfur dioxide emitting units at the source 

that are monitored under Subsection B of 20.2.81.106 NMAC, as reported by the source in Paragraph 2 or 4 of 

Subsection O of 20.2.81.106 NMAC, and recorded in the emissions tracking database shall be compared to the 

allowances held in the source's special reserve compliance account as of the allowance transfer deadline for the 

current control period, adjusted in accordance with 20.2.81.108 NMAC. If the emissions are equal to or less than 

the allowances in such account, all such allowances shall be retired to satisfy the obligation to hold allowances for 

such emissions. If the total emissions from such units exceeds the allowances in such special reserve account, the 

WEB source shall account for such excess emissions in Subparagraph b of this paragraph. 

 (b) The total annual sulfur dioxide emissions for all sulfur dioxide emitting units at the source 

that are monitored under Subsection A of 20.2.81.106 NMAC, as reported by the source in Paragraph 2 or 4 of 

Subsection O of 20.2.81.106 NMAC, and recorded in the emissions tracking database, together with any excess 

emissions as calculated in the preceding Subparagraph a, shall be compared to the allowances held in the source's 

compliance account as of the allowance transfer deadline for the current control period, adjusted in accordance with 

20.2.81.108 NMAC.

 (c) If the comparison in Subparagraph b of this paragraph results in emissions that exceed the 

allowances held in the source's compliance account, the source has exceeded its allowance limitation and the excess 

emissions are subject to the allowance deduction penalty in Subsection C of this section.

 (4) Other than allowances in a special reserve compliance account for units monitored under

Subsection B of 20.2.81.106 NMAC, to the extent consistent with 20.2.81.108 NMAC, allowances shall be deducted 

for a WEB source for compliance with the allowance limitation as directed by the WEB source's account 

representative. Deduction of any other allowances as necessary for compliance with the allowance limitation shall 

be on a first-in, first-out accounting basis in the order of the date and time of their recording in the WEB source's 
20.2.81 NMAC 19

compliance account, beginning with the allowances allocated to the WEB source and continuing with the allowances 

transferred to the WEB source's compliance account from another compliance account or general account. The 

allowances held in a special reserve compliance account pursuant to Subsection B of 20.2.81.106 NMAC shall be 

deducted as specified in Subparagraph a of Paragraph 3 of Subsection A of 20.2.81.109 NMAC.

B. Certification of compliance.

 (1) For each control period in which a WEB source is subject to the allowance limitation, the account 

representative of the source shall submit to the department a compliance certification report for the source.

 (2) The compliance certification report shall be submitted no later than the allowance transfer 

deadline of each control period, and shall contain the following:

 (a) identification of each WEB source;

 (b) at the account representative's option, the serial numbers of the allowances that are to be 

deducted from a source's compliance account for compliance with the allowance limitation; and

 (c) the compliance certification report according to Paragraph 3 of this section.

 (3) In the compliance certification report, the account representative shall certify, based on reasonable 

inquiry of those persons with primary responsibility for operating the WEB source in compliance with the WEB 

trading program, whether the WEB source for which the compliance certification is submitted was operated during 

the control period covered by the report in compliance with the requirements of the WEB trading program 

applicable to the source including:

 (a) whether the WEB source operated in compliance with the sulfur dioxide allowance 

limitation;

 (b) whether sulfur dioxide emissions data has been submitted to the department in accordance 

with Subsection A of 20.2.81.106 NMAC and other applicable guidance, for review, revision as necessary, and 

finalization for forwarding to the sulfur dioxide allowance tracking system for recording;

 (c) whether the monitoring plan that governs the WEB source has been maintained to reflect 

the actual operation and monitoring of the source, and contains all information necessary to attribute sulfur dioxide 

emissions to the source, in accordance with Subsection A of 20.2.81.106 NMAC;

 (d) whether all the sulfur dioxide emissions from the WEB source if applicable, were 

monitored or accounted for either through the applicable monitoring or through application of the appropriate 

missing data procedures; 

 (e) if applicable, whether any sulfur dioxide emitting unit for which the WEB source is not 

required to monitor in accordance with Paragraph 3 of Subsection A of 20.2.81.106 NMAC remained permanently 

retired and had no emissions for the entire applicable period; and

 (f) whether there were any changes in the method of operating or monitoring the WEB source 

that required monitor recertification; if there were any such changes, the report shall specify the nature, reason, and 

date of the change, the method to determine compliance status subsequent to the change, and specifically, the 

method to determine sulfur dioxide emissions.

C. Allowance deduction penalty for any WEB source exceeding its allowance limitations.

 (1) If emissions from a WEB source exceed the allowance limitation for a control period, as 

determined in accordance with Subsection A of 20.2.81.109 NMAC, the source's allowance held in its compliance 

account will be reduced by an amount equal to three times the source's tons of excess emissions. If the compliance 

account does not have sufficient allowances allocated for that control period, the required number of allowances 

shall be deducted from the WEB source's compliance account regardless of the control period for which they were 

allocated, once allowances are recorded in the account.

 (2) Any allowance deduction required under this section shall not affect the liability of the owners 

and operators of the WEB source for any fine, penalty or assessment or their obligation to comply with any other 

remedy, for the same violation, as ordered under the Clean Air Act, implementing regulations or applicable state or 

tribal law. Accordingly, a violation can be assessed each day of the control period for each ton of sulfur dioxide

emissions in excess of its allowance limitation if the department so chooses.

D. Liability.

 (1) WEB source liability for non-compliance. Separate and regardless of any allowance deduction 

penalty, a WEB source that violates any requirement of 20.2.81 NMAC is subject to civil and criminal penalties 

under the Air Quality Control Act and the Clean Air Act. Each day of the control period is a separate violation, and 

each ton of sulfur dioxide emissions in excess of a source's allowance limitation is a separate violation.

 (2) General liability.

 (a) Any provision of the WEB trading program that applies to a source or an account 

representative shall apply also to the owners and operators of such source.
20.2.81 NMAC 20

 (b) Any person who violates any requirement or prohibition of the WEB trading program shall 

be subject to enforcement pursuant to applicable state, tribal or federal law.

 (c) Any person who knowingly makes a false material statement in any record, submission, or 

report under this WEB trading program shall be subject to criminal enforcement pursuant to the applicable state, 

tribal or federal law.

[20.2.81.109 NMAC - N, 12/31/03; A, 07/06/11] 

20.2.81.110 SPECIAL PENALTY PROVISIONS FOR THE 2018 MILESTONE:

A. If the WEB trading program is triggered as outlined in section A of the sulfur dioxide milestones 

and backstop trading program implementation plan, and the first control period will not occur until after the year 

2018, the following provisions shall apply for the 2018 emissions year.

 (1) All WEB sources shall register, and open a compliance account within 180 days after the program 

trigger date, in accordance with Subsection A of 20.2.81.103 NMAC and 20.2.81.105 NMAC.

 (2) The tracking system administrator shall record the allowances for the 2018 control period for each 

WEB source in the source's compliance account once the department allocates the 2018 allowances under section C1 

and D1 of the sulfur dioxide milestones and backstop trading program implementation plan.

 (3) The allowance transfer deadline is midnight Pacific standard time on May 31, 2021 (or if this date 

is not a business day, midnight of the first business day thereafter). WEB sources may transfer allowances as 

provided in Subsection A of 20.2.81.107 NMAC until the allowance transfer deadline. For each control period after 

2018 that the special penalty provisions are assessed, the dates for the 2019 control period will be adjusted forward 

by one year.

 (4) A WEB source shall hold allowances allocated for 2018 including those transferred into the 

compliance account by an allowance transfer correctly submitted by the allowance transfer deadline, in an amount 

not less than the WEB source's total sulfur dioxide emissions for 2018. Emissions shall be determined using the pretrigger monitoring provisions in section B of the sulfur dioxide milestones and backstop trading program 

implementation plan, and 20.2.73 NMAC.

 (5) In accordance with Subsection D of 20.2.81.108 NMAC and Paragraph 4 of Subsection A of 

20.2.81.110 NMAC, the department shall seek at least the minimum financial penalty of $5,000 per ton of sulfur 

dioxide emissions in excess of the WEB source’s allowance limitation.

 (a) Any source may resolve its excess emissions violation by agreeing to a streamline 

settlement approach where the source pays a penalty of $5,000 per ton or partial ton of excess emissions, and 

payment is received within 90 calendar days after the issuance of a notice of violation.

 (b) Any source that does not resolve its excess emissions violation in accordance with the 

streamlined settlement approach in Subparagraph a of this paragraph will be subject to civil enforcement action, in 

which the department shall seek a financial penalty for the excess emissions based on the state's statutory maximum 

civil penalties.

 (6) Each ton of sulfur dioxide emissions in excess of a source's allowance limitation is a separate 

violation and each day of a control period is a separate violation.

B. The provisions in 20.2.81.110 NMAC shall continue to apply for each year after the 2018 

emission year until:

 (1) the first control period under the WEB trading program under Paragraph 1 of Subsection A of 

20.2.81.109 NMAC; or

 (2) the department determines, in accordance with section A3.10 of the implementation plan, that the 

2018 sulfur dioxide milestone has been met.

C. If 20.2.81.110 NMAC was implemented, the following shall apply to each emissions year after the 

2018 emissions year.

 (1) The tracking system administrator will record the allowances for the control period for the 

specific year for each WEB source in the source's compliance account once the department allocates the allowances 

under section C1 of the sulfur dioxide milestones and backstop trading program implementation plan.

 (2) The allowance transfer deadline for the 2019 emissions year shall be midnight Pacific standard 

time on May 31, 2021 (or if this date is not a business day, midnight of the first business day thereafter); and for 

each control period after 2018 that the special penalty provisions are assessed, the May 31, 2021 allowance transfer 

deadline for the 2019 control period will be adjusted forward by one year.

 (3) A WEB source must hold allowances allocated for that specific emissions year, or any year after 

2018, including those transferred into the compliance account by an allowance transfer correctly submitted by the 

allowance transfer deadline, in an amount not less than the WEB source's total sulfur dioxide emissions for the 
20.2.81 NMAC 21

specific emissions year. Emissions are determined using the pre-trigger monitoring provisions in section B of the 

sulfur dioxide milestones and backstop trading program implementation plan, and 20.2.73 NMAC.

 (4) An allowance deduction penalty and financial penalty shall be assessed and levied in accordance 

with Subsection D of 20.2.81.108 NMAC, Paragraph 4 of Subsection A of 20.2.81.109 NMAC, and Subsection C 

of 20.2.81.109 NMAC, except that sulfur dioxide emissions shall be determined under Paragraph 3 of Subsection C 

of 20.2.81.110 NMAC.

[20.2.81.110 NMAC - N, 12/31/03; A, 07/06/11] 

20.2.81.111 NMAC SULFUR DIOXIDE MONITORING OF FUEL GAS COMBUSTION DEVICES:

A. Applicability.

 (1) The provisions of this protocol are applicable to fuel gas combustion devices at petroleum 

refineries.

 (2) Fuel gas combustion devices include boilers, process heaters, and flares used to burn fuel gas 

generated at a petroleum refinery.

 (3) Fuel gas means any gas which is generated and combusted at a petroleum refinery. Fuel gas does 

not include:

 (a) natural gas, unless combined with other gases generated at a petroleum refinery;

 (b) gases generated by a catalytic cracking unit catalyst regenerator;

 (c) gases generated by fluid coking burners;

 (d) gases combusted to produce sulfur or sulfuric acid; or 

 (e) process upset gases generated due to startup, shutdown, or malfunctions.

B. Monitoring Requirements.

 (1) Except as provided in Paragraphs 2 and 3 of 20.2.81.111 NMAC, fuel gas combustion devices 

shall use a continuous fuel gas monitoring system (CFGMS) to determine the total sulfur content (reported as H2S) 

of the fuel gas mixture prior to combustion, and continuous fuel flow meters to determine the amount of fuel gas 

burned.

 (a) Fuel gas combustion devices having a common source of fuel gas may be monitored for 

sulfur content at one location, if monitoring at that location is representative of the sulfur content of the fuel gas 

being burned in any fuel gas combustion device.

 (b) The CFGMS shall meet the performance requirements in Performance Specification 2 in 

Appendix B to 40 CFR Part 60, and the following.

 (i) Continuously monitor and record the concentration by volume of total sulfur 

compounds in the gaseous fuel reported as ppmv H2S.

 (ii) Have the span value set so that the majority of readings fall between 10 and 95 

percent of the range.

 (iii) Record negative values of zero drift, for initial certification and daily calibration 

error tests.

 (iv) Calibration drift shall be 5.0 percent of the span. 

(v) Methods 15A, 16, or approved alternatives for total sulfur, are the reference methods 

for the relative accuracy test. The relative accuracy test shall include a bias test in accordance with Paragraph 3 of 

Subsection D of 20.2.81.111 NMAC.

 (c) All continuous fuel flow meters shall comply with the provisions of Section 2.1.5 of 

Appendix D to 40 CFR Part 75.

 (d) The hourly mass sulfur dioxide emissions rate for all the fuel combustion devices 

monitored by this approach shall be calculated using the following equation:

Et = (CS)(Qf)(K)

where: Et = Total sulfur dioxide emissions in lb/hr from applicable fuel gas combustion devices

CS = Sulfur content of the fuel gas as H2S(ppmv)

Qf = Fuel gas flow rate to the applicable fuel gas combustion devices (scf/hr) 

K = 1.660 x 10-7 (lb/scf)/ppmv

 (2) In place of a CFGMS in Paragraph 1 of Subsection B of 20.2.81.111 NMAC, fuel gas combustion 

devices having a common source of fuel gas may be monitored with an sulfur dioxide CEMS flow CEMS and (if 

necessary) a moisture monitoring system at only one location, if the CEMS monitoring at that location is 

representative of the sulfur dioxide emission rate (lb sulfur dioxide/scf fuel gas burned) of all applicable fuel gas 

combustion devices. Continuous fuel flow meters shall be used in accordance with Paragraph 2 of Subsection B of 

20.2.81.111 NMAC, and the fuel gas combustion device monitored by a CEMS shall have separate fuel metering.
20.2.81 NMAC 22

 (a) Each CEMS for sulfur dioxide and flow, and (if applicable) moisture, shall comply with the 

operating requirements, performance specifications, and quality assurance requirements of 40 CFR Part 75. 

 (b) All continuous fuel flow meters shall comply with the provisions of Section 2.1.5 of 

Appendix D to 40 CFR Part 75.

 (c) The sulfur dioxide hourly mass emissions rate for all the fuel gas combustion devices 

monitored by this approach shall be determined by the ratio of the amount of fuel gas burned by the CEMSmonitored fuel gas combustion device to the total fuel gas burned by all applicable fuel gas combustion devices 

using the following equation:

Et = (Em)(Qt)/(Qm) 

where: Et = Total sulfur dioxide emissions in lb/hr from applicable fuel gas combustion devices.

Em = sulfur dioxide emissions in lb/hr from the CEMS-monitored fuel gas combustion device, calculated using 

Equation F-1 or (if applicable) F-2 in Appendix F to 40 CFR Part 75

Qt = Fuel gas flow rate (scf/hr) from applicable fuel gas combustion devices.

Qm = Fuel gas flow rate (scf/hr) to the CEMS-monitored fuel gas combustion device.

 (3) In place of a CFGMS in Paragraph 1 of Subsection B of 20.2.81.111 NMAC, fuel gas combustion 

devices having a common source of fuel gas may be monitored with an sulfur dioxide - diluent CEMS at only one 

location, if the CEMS monitoring at that location is representative of the sulfur dioxide emission rate (lb sulfur 

dioxide/mmBtu) of all applicable fuel gas combustion devices. If this option is selected, the owner or operator shall 

conduct fuel gas sampling and analysis for gross calorific value (GCV), and shall use continuous fuel flow metering 

in accordance with Paragraph 1 of Subsection B of 20.2.81.111 NMAC, with separate fuel metering for the CEMSmonitored fuel gas combustion device.

 (a) Each sulfur dioxide - diluent CEMS shall comply with the applicable provisions for sulfur 

dioxide monitors and diluent monitors in 40 CFR Part 75, and shall use the procedures in Section 3 of Appendix F to 

Part 75 for determining sulfur dioxide emission rate (lb/mmBtu) by substituting the term sulfur dioxide for nox in 

that section, and using a K factor of 1.660 x 10 - 7 (lb/scf) ppmv instead of the NOx K factor.

 (b) All continuous fuel flow meters and fuel gas sampling and analysis for GCV to determine 

the heat input ratio shall comply with the applicable provisions of Section 2.1.5 and 2.3.4 of Appendix D to 40 

CFR Part 75. 

 (c) The sulfur dioxide hourly mass emissions rate for all the fuel gas combustion devices 

monitored by this approach shall be determined by the ratio of the fuel gas heat input to the CEMS-monitored fuel 

gas combustion device to the total fuel gas heat input to all applicable fuel gas combustion devices using the 

following equation:

Et = (Em)(Qt)/(GCV) / 106

where: Et = Total sulfur dioxide emissions in lbs/hr from applicable fuel gas combustion devices.

Em = sulfur dioxide emissions in lb/mmBtu from the CEMS - monitored fuel gas combustion device.

Qt = Fuel gas flow rate (scf/hr) to the applicable fuel gas combustion devices.

GCV = Fuel Gross Calorific Value (Btu/scf)

106 = Conversion from Btu to million Btu

 (d) The owner or operator shall calculate total sulfur dioxide mass emissions for each calendar 

quarter and each calendar year based on the emissions in lb/hr and equations F-3 and F-4 in Appendix F to 40 CFR 

Part 75, Appendix F.

C. Certification and recertification requirements. All monitoring systems are subject to initial 

certification and recertification testing as follows.

 (1) The owner or operator shall comply with the initial testing and calibration requirements in 

performance specification 2 in Appendix B of 40 CFR Part 60 and Subparagraph b of Paragraph 1 of Subsection B 

of 20.2.81.111 NMAC for each CFGMS.

 (2) Each CEMS for sulfur dioxide and flow or each sulfur dioxide-diluent CEMS shall comply with 

the testing and calibration requirements specified in 40 CFR Part 75, Section 75.20 and appendices A and B, except 

that each sulfur dioxide-diluent CEMS shall meet the relative accuracy requirements for a NOx-diluent CEMS 

(lb/mmBtu).

 (3) A continuous fuel flow meter shall comply with certification requirements in Section 2.1.5 of 

Appendix D of 40 CFR Part 75.

D. Quality assurance/quality control requirements.

 (1) A quality assurance and quality control (QA/QC) plan shall be developed and implemented for 

each CEMS for sulfur dioxide and flow or the sulfur dioxide-diluent CEMS in compliance with Sections 1, 1.1, and 

1.2 of Appendix B of 40 CFR Part 75.
20.2.81 NMAC 23

 (2) A quality assurance and quality control plan shall be developed and implemented for each 

continuous fuel flow meter and fuel sampling and analysis in compliance with Sections 1, 1.1, and 1.3 Appendix B 

of 40 CFR Part 75. The owner or operator shall meet the requirements in Section 2.1.6 of Appendix D to 40 CFR 

Part 75, and may use the procedures set forth in Section 2.1.7 of that appendix.

 (3) A quality assurance and quality control plan shall be developed and implemented for each 

CFGMS in compliance with Sections 1 and 1.1 of Appendix B to 40 CFR Part 75, and the following.

 (a) Perform a daily calibration error test of each CFGMS at two gas concentrations, one low 

level and one high level. Calculate the calibration error as described in Appendix A to 40 CFR Part 75. An out of 

control period occurs whenever the error is greater than 5.0 percent of the span value.

 (b) In addition to the daily calibration error test, an additional calibration error test shall be 

performed whenever a daily calibration error test is failed, whenever a monitoring system is returned to service 

following repairs or corrective actions that may affect the monitor measurements, or after making manual calibration 

adjustments. 

 (c) Perform a linearity test once every operating quarter. Calculate the linearity as described in 

Appendix A to 40 CFR Part 75. An out of control period occurs whenever the linearity error is greater than 5.0 

percent of a reference value, and the absolute value of the difference between average monitor response values and a 

reference value is greater than 5.0 ppm.

 (d) Perform a relative accuracy test audit once every four operating quarters. Calculate the 

relative accuracy as described in Appendix A to 40 CFR Part 75. An out of control period occurs whenever the 

relative accuracy is greater than 20.0 percent of the mean value of the reference method measurements.

 (e) Using the results of the relative accuracy test audit, conduct a bias test in accordance with 

Appendix A to 40 CFR Part 75, and calculate and apply a bias adjustment factor if required.

E. Missing data procedures.

 (1) For any period in which valid data are not being recorded by an sulfur dioxide CEMS or flow 

CEMS specified in this section, missing or invalid data shall be replaced with substitute data in accordance with the 

requirements in subpart D of 40 CFR Part 75.

 (2) For any period in which valid data are not being recorded by an sulfur dioxide-diluent CEMS 

specified in this section, missing or invalid data shall be replaced with substitute data on a rate basis (lb/mmBtu) in 

accordance with the requirements for sulfur dioxide monitors in subpart D of 40 CFR Part 75.

 (3) For any period in which valid data are not being recorded by a continuous fuel flow meter or for 

fuel gas GCV sampling and analysis specified in this section, missing or invalid data shall be replaced with 

substitute data in accordance with missing data requirements in Section 2.4 of Appendix D to 40 CFR Part 75.

 (4) For any period in which valid data are not being recorded by the CFGMS specified in this section, 

hourly missing or invalid data shall be replaced with substitute data in accordance with the missing data 

requirements for units performing hourly gaseous fuel sulfur sampling in Section 2.4 of Appendix D to 40 CFR Part 

75.

F. Monitoring plan and reporting requirements. In addition to the general monitoring plan and 

reporting requirements of 20.2.81.106 NMAC, the owner or operator shall meet the following additional 

requirements.

 (1) The monitoring plan shall identify each group of units that are monitored by a single monitoring 

system under this 20.2.81.111 NMAC, and the plan shall designate an identifier for the group of units for emissions 

reporting purposes. For purpose of submitting emissions reports, no apportionment of emissions to the individual 

units within the group is required.

 (2) If the provisions of Paragraph 2 or 3 of Subsection B of 20.2.81.111 NMAC are used, provide 

documentation and an explanation to demonstrate that the sulfur dioxide emission rate from the monitored unit is 

representative of the rate from non-monitored units.

[20.2.81.111 NMAC - N, 12/31/03]

20.2.81.112 NMAC PREDICTIVE FLOW MONITORING SYSTEMS FOR KILNS WITH POSITIVE 

PRESSURE FABRIC FILTER:

A. Applicability. The provisions of this protocol are applicable to cement kilns or lime kilns that:

 (1) are controlled by a positive pressure fabric filter;

 (2) combust only a single fuel, no fuel blends; and

 (3) have operating conditions upstream of the fabric filter that the WEB source documents would 

reasonably prevent reliable flow monitor measurements; this protocol does not modify the sulfur dioxide monitoring 

requirements in 20.2.81.106 NMAC.
20.2.81 NMAC 24

B. Monitoring requirements.

 (1) A cement or lime kiln with a positive pressure fabric filter shall use a predictive flow monitoring 

system (PFMS) to determine the hourly kiln exhaust gas flow.

 (2) A PFMS is the total equipment necessary for the determination of exhaust gas flow using process 

or control device operating parameter measurements and a conversion equation, a graph, or computer program to 

produce results in cubic feet per hour.

 (3) The PFMS shall meet the following performance specifications.

 (a) Sensors readings and conversion of sensor data to flow in cubic feet per hour must be 

automated.

 (b) The PFMS must allow for the automatic or manual determination of failed monitors. At a 

minimum a daily determination must be performed.

 (c) The PFMS shall have provisions to check the calibration error of each parameter that is 

individually measured. The owner or operator shall propose appropriate performance specifications in the initial 

monitoring plan for all parameters used in the PFMS comparable to the degree of accuracy required for other 

monitoring systems used to comply with 20.2.81 NMAC. The parameters shall be tested at two levels, low: 0 to 20 

percent of full scale, and high: 50 to 100 percent of full scale. The reference value need not be certified.

 (d) The relative accuracy of the PFMS must be < 10.0 percent of the reference method average 

value, and include a bias test in accordance with Paragraph 3 of Subsection D of 20.2.81.112 NMAC.

C. Certification Requirements. The PFMS is subject to initial certification testing. The source 

owner or operator shall:

 (1) demonstrate the ability of the PFMS to identify automatically or manually a failed monitor;

 (2) provide evidence of calibration testing of all monitoring equipment. Any tests conducted within 

the previous 12 months of operation that are consistent with the QA/QC plan for the PFMS are acceptable for initial 

certification purposes; and

 (3) perform an relative accuracy test audit and accompanying bias test once every four operating 

quarters. Calculate the relative accuracy (and bias adjustment factor) as described in Appendix A to 40 CFR Part 75. 

An out of control period occurs whenever the flow relative accuracy is greater than 10.0 percent of the mean value 

of the reference method.

D. Quality assurance and quality control requirements. A quality assurance and quality control 

plan shall be developed and implemented for each PFMS in compliance with Sections 1 and 1.1 of Appendix B of 

40 CFR Part 75, and the following:

 (1) perform a daily monitor failure check;

 (2) perform calibration tests of all monitors for each parameter included in the PFMS. At a minimum, 

calibrations shall be conducted prior to each relative accuracy test audit; and

 (3) perform a relative accuracy test audit and accompanying bias test once every four operating 

quarters. Calculate the relative accuracy (and bias adjustment factor) as described in Appendix A to 40 CFR Part 

75. An out of control period occurs whenever the flow relative accuracy is greater than 10.0 percent of the mean 

value of the reference method.

E. Missing data. For any period in which valid data are not being recorded by the PFMS specified 

in this section, hourly missing or invalid data shall be replaced with substitute data in accordance with the flow 

monitor missing data requirements for non-load based units in subpart D of 40 CFR Part 75.

F. Monitoring plan requirements. In addition to the general monitoring plan requirements of 

20.2.81.106 NMAC, the owner or operator shall meet the following additional requirements.

 (1) The monitoring plan shall document the reasons why stack flow measurements upstream of the 

fabric filter are unlikely to provide reliable flow measurements over time.

 (2) The initial monitoring plan shall explain the relationship of the proposed parameters and stack 

flow, and discuss other parameters considered and the reasons for not using those parameters in the PFMS. The 

department may require that the subsequent monitoring plan include additional explanation and documentation for 

the reasonableness of the proposed PFMS.

[20.2.81.112 NMAC - N, 12/31/03]

HISTORY OF 20.2.81 NMAC:

Pre-NMAC History: None.

History of Repealed Material: [RESERVED]
20.2.81 NMAC 25

Other History: [RESERVED]