United States
Environmental Protection
Agency
Office;of Air Quality
Planning and Standards
Research' Triangle Park, NC 27/11
EPA-452/R-93-015
January, 1994
Air
GUIDANCE ON T POST-1996
&EPA RATE.QF,PROGRESS PLAN AND
THE ATTAINMEN1
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Corrected Version as of February 18, 1994
Guidance on the Post-1996 Rate-of-Progress
Plan and the Attainment Demonstration
Ozone/Carbon Monoxide Programs Branch
U.S. Environmental Protection Agency
Office of Air Quality Planning and
Standards
Research Triangle Park, NC 27711
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CONTENTS
Page
LIST OF TABLES v
LIST OF FIGURES vi
ACRONYMS . vii
EXECUTIVE SUMMARY 1
1.0 INTRODUCTION 3
1.1 Purpose 5
2.0 CALCULATION OF POST-1996 TARGET LEVELS 7
2.1 Calculation of Post-1996 Target Level(s) of Emissions 7
2.2 Example Calculation of Post-1996 Target Level(s) 13
Calculation of 1999 Target Level of Emissions 13
2.3 Conditions Permitting Less than a 3 Percent VOC Emission Reduction 16
3.0 ATTAINMENT DEMONSTRATION REQUIREMENTS 17
3.1 Modeling Requirements for Attainment Demonstrations 17
3.2 Special Air Quality Situations 18
Areas Requiring Emission Reductions in Addition to 3 Percent per Year 18
Multi-State Nonattainment Areas 18
States Included in More than One Modeling Domain 19
International Border Areas 19
Areas with Differing Required Attainment Dates 19
Exceedances Monitored within a Modeling Domain Due Primarily to
Emissions in Another Domain 20
4.0 NOX EMISSION REDUCTIONS 21
4.1 Substitution of NOX Emission Reductions for Post-1996 VOC Emission
Reductions 21
4.2 Calculation of Post-1996 NOX and VOC Target Levels of Emissions 21
4.3 Creditability of Pre-1996 VOC and NOX Reductions 29
4.4 Example Calculation of Post-1996 VOC and NOX Target Levels 30
Calculation of 1999 Target Levels of Emissions 30
5.0 CONTROL STRATEGIES 35
5.1 Mandatory Requirements .'....... 35
Serious Nonattainment Area Requirements 35
Severe Nonattainment Area Requirements 40
Extreme Nonattainment Area Requirements . . . 40
5.2 Additional Control Measures 41
5.3 Emission Projections . . 42
Growth Factors 43
111
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5.4 Relationship Between the Post-1996 Rate-of-Progress Plans and Other
Provisions of the Act 47
Multiple Projection System 48
5.5 Economic Incentive Programs 49
5.6 Contingency Measures 49
5.7 Long-Term Control Measures 51
5.8 New Technologies for Extreme Ozone Nonattainment Areas 53
6.0 POST-1996 RATE-OF-PROGRESS PLAN AND ATTAINMENT-
DEMONSTRATION SUBMTTTALS AND DOCUMENTATION 55
6.1 Post-1996 Rate-of-Progress and Attainment Demonstration Requirements 55
1990 Adjusted Base Year Inventory 55
56
Target Level(s) of Emissions 56
Control Measure and Growth Factor Information 56
Milestone Year Projected Inventories 57
6.2 Multi-State Submittal Information 57
6.3 Mid-Course Corrections 57
6.4 Suggested Submittal Tables 58
REFERENCES 63
APPENDIX A: DEFINITIONS OF TERMS . . A-l
APPENDIX B: GENERAL IMPLICATIONS OF MILESTONE AND ATTAINMENT
FAILURES B-l
APPENDIX C: CHECKLISTS C-l
APPENDIX D: COMPILATION OF GUIDANCE MEMORANDA ON THE 15 PERCENT
RATE-OF-PROGRESS REQUIREMENT D-l
IV
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LIST OF TABLES
Number Page
1. SERIOUS AND ABOVE OZONE NONATTAINMENT AREA POST-1996 MILESTONE
AND ATTAINMENT DATES 7
2. SIP SUBMITTAL REQUIREMENTS FOR MODERATE AND ABOVE OZONE
NONATTAINMENT AREAS 36
3. BEA PROJECTION CATEGORIES FOR METROPOLITAN STATISTICAL AREAS
(MSA'S) AND STATES 45
5. SUGGESTED FORMAT FOR POST-1996 RATE-OF-PROGRESS CONTROL
STRATEGY SUMMARY SUBMITTAL 59
6. SUGGESTED FORMAT FOR ATTAINMENT CONTROL STRATEGY SUMMARY
SUBMITTAL 60
7. SUGGESTED FORMAT FOR CONTINGENCY MEASURE SUBMITTAL 61
8. SUGGESTED FORMAT FOR SUBMITTAL OF RULE EFFECTIVENESS (RE)
IMPROVEMENT MEASURES 62
9. SUGGESTED FORMAT FOR SUBMITTAL OF STATIONARY SOURCE CONTROL
MEASURES FOR THE POST-1996 RATE-OF-PROGRESS PLAN 62
10. SUGGESTED FORMAT FOR SUBMITTAL OF STATIONARY SOURCE CONTROL
MEASURES FOR THE ATTAINMENT DEMONSTRATION 62
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LIST OF FIGURES
Number Page
Figure 1. Flowchart for generic post-1996 rate-of-progress VOC target level calculation 8
Figure 2. Flowchart of hypothetical example 1999 rate-of-progress VOC target level
calculation 14
Figure 3. Flowchart for generic post-1996 rate-of-progress VOC calculations (with NOX
substitution) 22
Figure 4. Flowchart for rate-of-progress NOX calculation for 1999 23
Figure 4a. Flowchart for generic post-1999 rate-of-progress NOX calculations 24
Figure 5. Flowchart for hypothetical example 1999 rate-of-progress VOC calculations (with
NOX substitution) ; . . 31
Figure 6. Flowchart for hypothetical example 1999 rate-of-progress NOX calculations 32
VI
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ACRONYMS
Act
ACT
AEERL
AFS
AIRS
AMS
ASC
BEA
CFR
CO
CTG
E-GAS
EIP
EPA
EPS
FIP
FIPS
FMVCP
FR
I/M
Ib
LEV
MPO
MPS
MSA
NAAQS
NESHAP
NO2
NO,
NSPS
NSR
OAQPS
ppb
ppm
psi
RACT
RE
REMI
ROM
RVP
SAS
SCC
SIC
SIP
STAPPA/ALAPCO
Clean Air Act
Alternative Control Technology
Air and Energy Engineering Research Laboratory
AIRS Facility Subsystem
Aerometric Information Retrieval System
AIRS Area and Mobile Source Subsystem
Area Source Category code
Bureau of Economic Analysis
Code of Federal Regulations
carbon monoxide
Control Techniques Guideline
Economic Growth Analysis System
Economic Incentive Program
U.S. Environmental Protection Agency
Emissions Preprocessor System
Federal Implementation Plan
Federal Information Processing Standards
Federal Motor Vehicle Control Program
Federal Register
Inspection and Maintenance
pound(s)
Low-Emitting Vehicle
Metropolitan Planning Organization
Multiple Projection System
Metropolitan Statistical Area
National Ambient Air Quality Standard(s)
National Emission Standard for Hazardous Air Pollutants
nitrogen dioxide
nitrogen oxides
New Source Performance Standards
New Source Review
Office of Air Quality Planning and Standards
parts per billion
parts per million
pounds per square inch
Reasonably Available Control Technology
rule effectiveness
Regional Economic Models, Inc.
regional oxidant modeling
Reid vapor pressure
Statistical Analysis System
Source Classification Code
Standard Industrial Classification
State implementation plan
State and Territorial Air Pollution Program Administrators and
Association of Local Air Pollution Control Officials
vn
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TCM transportation control measures
TIP Transportation Improvement Program
tpy tons per year
TSD Technical Support Documentation.)
UAM Urban Airshed Model
VMT vehicle miles traveled
VOC volatile organic compound(s)
via
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EXECUTIVE SUMMARY
Section 182(c)(2) of the Clean Air Act (Act) requires each serious and above ozone
nonattainment area to submit a State implementation plan (SIP) revision by November 15, 1994,
which describes, in part, how the area will achieve an actual volatile organic compound (VOC)
emission reduction of at least 3 percent per year averaged over each consecutive 3-year period
beginning 6 years after enactment (i.e., November 15, 1996) until the area's attainment date. The
attainment dates prescribed by section 181 (a) of the Act are as follows:
November 15, 1999 for serious ozone nonattainment areas.
November 15, 2005 for severe ozone nonattainment areas.
November 15, 2007 for severe ozone nonattainment areas with a 1986-1988 ozone
design value of 0.190 parts per million (ppm) up to, but not including, 0.280 ppm.
November 15, 2010 for extreme ozone nonattainment areas.
This SIP revision must also describe how any growth in emissions over each applicable post-
1996 period will be offset. The portion of the SIP revision that illustrates the plan for the
achievement of these emission reductions is subsequently defined in this document as the "post-1996
rate-of-progress plan."
The Act permits less than a 3 percent per year VOC emission reduction averaged over each
consecutive 3-year period for serious and severe ozone nonattainment areas if the State demonstrates
that the plan includes all measures that, given technological achievability, can feasibly be implemented
in the given area. Additionally, the State must demonstrate that its plan includes measures that are
achieved in practice by sources in the same source category in nonattainment areas of the next higher
classification [section 182(c)(2)(B)(ii) of the Act]. The 3 percent requirement cannot be waived in
areas classified as extreme. The Act also provides for crediting of VOC emission reductions achieved
in the 1990-1996 period to the post-1996 rate-of-progress plan, if they are in excess of the 15 percent
VOC reductions (net of growth) required between 1990 and 1996 [section 182(c)(2)(B)(ii)], and
substitution of nitrogen oxides (NOJ emission reductions (net of growth) occurring in the post-1990
period for the post-1996 VOC emission reduction requirements [section 182(c)(2)(C) of the Act].
In addition to the 3 percent VOC emission reduction requirement, section 182(c)(2) also
requires the SIP for serious and above ozone nonattainment areas to provide "a demonstration that the
plan, as revised, will provide for attainment of the ozone national ambient air quality standard
(NAAQS) by the applicable date." Furthermore, section 182(c)(2) requires that the demonstration be
based on photochemical grid modeling or an equivalent analytical method as determined by the U.S.
Environmental Protection Agency (EPA). All serious and above ozone nonattainment areas and all
multi-State moderate ozone nonattainment areas are required to submit their attainment
demonstrations, based on the use of a photochemical grid model such as the Urban Airshed Model
(UAM), to EPA by November 15, 1994. It is important to note that the underlying requirement of
the SIP is that nonattainment areas achieve attainment of the ozone NAAQS by their attainment date.
That is, additional reductions beyond the required 3 percent per year VOC emission reductions may
be needed for the nonattainment area to attain the NAAQS by its applicable date.
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This document focuses on the calculation of post-1996 target levels, the required submittals
and submittal schedules for each element of the post-1996 rate-of-progress plan and attainment
demonstration, and the development of control strategies to achieve the required emission reductions.
This document also provides States with information on acceptable data sources and procedures for
projecting emissions.
Significant overlap occurs between concepts relating to the 15 percent rate-of-progress plan
and concepts relating to the post-1996 plan. Where such overlap occurs, the applicable guidance
documents developed for the 15 percent rate-of-progress plan are referenced. One significant
difference between the two plans is that unlike the 15 percent plan, NOX emission reductions can be
substituted for the required VOC emission reductions in the post-1996 plan. Guidance is provided on
how States can calculate the amount of NO, emission reductions that can be substituted for VOC
emission reductions.
This document'also describes the EPA requirements for an attainment demonstration based on
photochemical grid modeling and discusses the role of NOX reductions in attainment demonstrations.
Additionally, this document discusses the general implications of milestone and attainment failures for
serious and above ozone nonattainment areas. Specific requirements for milestone compliance
demonstrations and consequences of failure to meet a milestone will be addressed in future
rulemaking. This document also provides a sample checklist to aid States in a step-by-step review of
their rate-of-progress plans to ensure diat they contain all of the necessary components required for
approval by EPA. Finally, this document provides blank forms that States are encouraged to use to
document and submit their post-1996 rate-of-progress plans.
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1.0 INTRODUCTION
Section 182(c)(2) of the Act requires each serious and above ozone nonattainment area to
submit a SIP revision by November 15, 1994, which provides for an actual VOC emission reduction
of at least 3 percent per year averaged over each consecutive 3-year period beginning 6 years after
enactment of the Act (i.e., up to November 15, 1996) until the area attains the ozone standard. The
attainment dates prescribed by section 181(a) of the Act are as follows:
November 15, 1999 for serious ozone nonattainment areas.
November 15, 2005 for severe ozone nonattainment areas.
November 15, 2007 for severe ozone nonattainment areas with a 1986-1988 ozone
design values of 0.190 ppm up to, but not including, 0.280 ppm.
November 15, 2010 for extreme ozone nonattainment areas.
If an area's attainment demonstration shows that the area will attain before the statutory attainment
date, the post-1996 rate-of-progress plan is only required to extend to the demonstrated attainment
date.
The portion of the SIP revision that illustrates the plan for the achievement of the post-1996
emission reductions is subsequently defined in this document as the "post-1996 rate-of-progress plan.'r
The SIP must also describe how any growth in emissions over each applicable period will be offset.
The Act also mandates a 15 percent VOC emission reduction, net of growth, between 1990
and 1996. The SIP revision describing how this requirement will be met was due by November 15,
1993. The plan for these 1990-1996 reductions is termed the "15 percent rate-of-progress plan." The
EPA has published guidance documents describing the procedures to follow in developing the
15 percent rate-of-progress plans. Because many of the issues discussed in these documents are also
associated with concerns relating to the development of the post-1996 rate-of-progress plan, States
should review the following documents pertaining to the 15 percent rate-of-progress plans:
Guidance on the Adjusted Base Year Emissions Inventory and the 1996 Target for the
15 Percent Rate-of-Progress Plans. EPA-452/R-92-005, U.S. Environmental
Protection Agency, Office of Air Quality Planning and Standards, Research Triangle
Park, NC. October 1992.
Guidance on the Relationship Between the 15 Percent Rate-of-Progress Plans and
Other Provisions of the Clean Air Act. EPA-452/R-93-007, U.S. Environmental
Protection Agency, Office of Air Quality Planning and Standards, Research Triangle
Park, NC. May 1993.
Guidance for Growth Factors. Projections, and Control Strategies for the 15 Percent
Rate-of-Progress Plans. EPA-452/R-93-002, U.S. Environmental Protection Agency,
Office of Air Quality Planning and Standards, Research Triangle Park, NC. March
1993.
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Guidance on Preparing Enforceable Regulations and Compliance Programs for the
15 Percent Rate-of-Progress Plans. EPA-452/R-93-005, U.S. Environmental
Protection Agency, Office of Air Quality Planning and Standards, Research Triangle
Park, NC. June 1993.
The SIP for serious and above ozone nonattainment areas due by November 15, 1994 must
also include "a demonstration that the plan, as revised, will provide for attainment of the ozone
NAAQS by the applicable date" [section 182(c)(2)(A)]. This demonstration must be based on
photochemical grid modeling, such as UAM, or an equivalent analytical method as determined by
EPA. This requirement also applies to all multi-State moderate ozone nonattainment areas.
Additionally, those intrastate moderate nonattainment areas that opt to use photochemical grid
modeling for their attainment demonstrations must also submit their demonstrations by November 15,
1994. It is important to note that the underlying requirement of the SIP is that nonattainment areas
attain the NAAQS by their attainment date. That is, achievement of the 3 percent per year VOC
emission reduction requirement may not provide all of an area's mandated emission reductions.
Section 182(c)(2)(B)(ii) permits less than a 3 percent per year VOC emission reduction
averaged over each consecutive 3-year period for serious and severe ozone nonattainment areas if the
State demonstrates that the plan includes all measures that, given technological achievability, can
feasibly be implemented in the given area. Additionally, the State must demonstrate that its plan
includes measures that are achieved in practice by sources in the same source category in
nonattainment areas of the next higher classification. The 3 percent requirement cannot be waived in
areas classified as extreme. The Act also provides for crediting of VOC emission reductions achieved
in the 1990-1996 period to the post-1996 rate-of-progress plan, if they are in excess of the 15 percent
VOC reductions (net of growth) required between 1990 and 1996 [section 182(c)(2)(B)(ii)], and
substitution of NOX emission reductions (net of growth) occurring in the post-1990 period for the
post-1996 VOC emission reduction requirements [section 182(c)(2)(C)].
Demonstrating achievement of the 15 percent VOC emission reductions by November 15,
1996, and then subsequently demonstrating achievement of the 3 percent per year VOC emission
reductions averaged over each consecutive 3-year period from November 15, 1996 until the
attainment date, are termed milestone demonstrations. Achievement of the milestones must be
demonstrated within 90 days of the milestone date (e.g., the 9 percent reduction required by
November 15, 1999 must be demonstrated by February 13, 2000). Moderate areas are not required
to submit such a demonstration. Serious and above nonattainment areas will not be required to
demonstrate achievement of the milestone if the milestone date and attainment date are the same, and
the standard has been attained. The EPA will instead determine whether the nonattainment area has
attained the ozone NAAQS based on the nonattainment area's air quality data for the previous
3 years. However, to comply with the rate-of-progress requirements, nonattainment areas are
required to develop a plan for milestone emission reductions (i.e., a post-1996 rate-of-progress plan)
up through their attainment date.
The EPA expects to promulgate in late 1994 a milestone compliance demonstration rule that
will address this requirement. The rule will also address summary data needs, detailed reporting
requirements, and the consequences of submitting an inadequate demonstration (in terms of
documentation) as well as consequences of failure to demonstrate the 15 percent and 3 percent per
year emission reduction requirements.
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1.1 Purpose
This document provides guidance on the procedures that States should follow in calculating
target levels of emissions, projecting emission inventories and creditable emission reductions, and
developing and presenting control measures which serious and above ozone nonattainment areas must
include in their post-1996 rate-of-progress plans. Fully-adopted post-1996 rate-of-progress plans are
due to EPA by November 15, 1994.
The post-1996 rate-of-progress plan must account for the effects of emissions growth
projected to occur in a nonattainment area. This document provides information and references on
acceptable data sources and procedures for projecting emissions using growth factors.
Attainment demonstration requirements are described for those nonattainment areas that are
required or choose to use photochemical grid modeling. This section also discusses special air quality
situations involving attainment demonstrations.
Unlike the 15 percent rate-of-progress plan, NOX reductions, net of growth, can be substituted
for the required post-1996 VOC reductions. This document explains how to calculate the amount of
NO,, reductions available to an ozone nonattainment area to meet the post-1996 rate-of-progress
requirements and the role of NOX reductions in attainment demonstrations based on photochemical
grid modeling .
A key component of the post-1996 rate-of-progress plan is the control measures that the States
adopt and implement to reduce VOC and or NOX emissions to meet the 3 percent per year reduction
requirements. States are referenced to further documentation of stationary and mobile source control
measures and economic incentive programs (EIP's) if they wish to employ a particular control
measure toward the post-1996 rate-of-progress plan and/or attainment demonstration. The regulatory
concepts of long-term measures (for serious and above nonattainment areas) and new technologies (for
extreme nonattainment areas) are discussed as ways for States to obtain additional time to plan for and
adopt certain control measures that require complex analyses or other time consuming activities. The
purpose of this discussion is to guide States as to how EPA intends to administer these two concepts
in the context of the rate-of-progress plan requirements.
The Act requires that States with ozone nonattainment areas include contingency measures in
their SIP's [sections 172(c)(9) and 182(c)(9)]. The contingency measures are the additional controls
to be implemented in the event of a milestone or attainment failure. This document discusses
contingency measures to provide States with guidance on how to comply with the contingency
measure requirements for serious and above ozone nonattainment areas.
A final purpose of this document is to provide the States with a suggested format for their
post-1996 rate-of-progress control strategy submittals and describe the documentation requirements for
attainment demonstrations based on photochemical grid modeling.
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2.0 CALCULATION OF POST-1996 TARGET LEVELS
To determine their control strategies for achieving the post-1996 VOC emission reductions,
States will need to calculate the target level of emissions for each milestone and attainment year. This
section explains the procedures for calculating the target level of emissions for each milestone and
attainment date to which serious and above ozone nonattainment areas are subject.
Emissions and emission reductions for the post-1996 plan are calculated on a typical
weekday basis for the "peak" 3-month ozone period (generally June through August). States will
need to document how they calculated the targets for each of their applicable milestone and attainment
dates. The documentation will need to show the 3 percent per year .emission reduction levels
averaged over each period between consecutive milestone dates and the target level of emissions for
each milestone.
Table 1 presents the post-1996 milestone and attainment dates for serious and above ozone
nonattainment areas.
TABLE 1. SERIOUS AND ABOVE OZONE NONATTAINMENT AREA POST-1996
MILESTONE AND ATTAINMENT DATES
Serious
Severe1
Severe2
Extreme
Milestone Date(s)
Nov. 15, 1999
Nov. 15, 1999, 2002, & 2005
Nov. 15, 1999, 2002, 2005, & 2007
Nov. 15, 1999, 2002, 2005, 2008, & 2010
Primary NAAQS
...Attainment Date
Nov. 15, 1999
Nov. 15, 2005
Nov. 15, 2007
Nov. 15, 2010
1 With an ozone design value of less than 0.190 ppm.
2 With a 1986-1988 ozone design value of 0.190 ppm up to, but not including, 0.280 ppm.
If an area's attainment demonstration shows that the area will attain before the statutory attainment
date, the post-1996 rate-of-progress plan is only required to extend to the demonstrated attainment
date.
2.1 Calculation of Post-1996 Target Level(s) of Emissions
The target level(s) of emissions represents the maximum amount of emissions that a
nonattainment area can emit for a given target year while complying with the post-1996 rate-of-
progress plan requirements. Figure 1 outlines the general approach to calculating the target level of
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FINAL BASE YEAR
C1990^
INVENTORY*
T
1990
RATE-OF-PROGRESS
BASE YEAR
INVENTORY
SUBTRACT
BIOGENICS,
EMISSIONS OUTSIDE
NONATTAINMENT
AREA
TARGET LEVEL FOR
YEAR y
CTLyD
TARGET LEVEL FOR
YEAH x
CTLy - BGr CFTX)
"> <-^
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VOC emissions. Two equations are presented in the General Preamble to describe the calculation of
the post-1996 target levels. These equations can be generalized into the following single equation:
Target level = (previous milestone's target level) - (reductions required to meet the rate-
of-progress requirement) - (fleet turnover correction term).
or
TLX = TLy-BGr-FTx
where:
x = Current milestone or attainment year
y = Year of previous milestone
TLX = Target level of emissions for year x (in pounds (lb)/day)
TLy = Target level of emissions for year y (in Ib/day)
BGr = Emission reduction requirement for year x (in Ib/day)
FTX = Fleet turnover correction term for year x (in Ib/day).
This equation can be used to calculate the target level of emissions for each post-1996 milestone year.
The target level for each milestone year (TL^) is calculated by subtracting the 3 percent per year rate-
of-progress emission reduction (BGr) and the fleet turnover correction term (FTJ from the previous
milestone year (TLy). The specific steps needed to calculate the target are discussed below.
There are six major steps in calculating a post-1996 target level of emissions. The first four
steps are needed to calculate the 3 percent per year rate-of-progress emission reductions. Steps 1 and
2, developing the 1990 base year inventory and the 1990 rate-of-progress inventory, were required to
have been submitted by States in the 15 percent rate-of-progress plan. The EPA document entitled
Guidance on the Adjusted Base Year Emissions Inventory and the 1996 Target for the 15 Percent
Rate-of-Progress Plans (see reference 1), describes these two inventories in more detail.
Step 1: Develop the 1990 base year inventory
The total 1990 base year emissions from the four emission source types (point, area, mobile,
and biogenic) are compiled. It should be noted that the base year inventory used for the post-1996
rate-of-progress plan must be consistent with the base year inventory used for attainment
demonstration purposes. Any changes that were made to the inventory between submittal of the
15 percent rate-of-progress plan and the post-1996 rate-of progress plan should be reflected.
Step 2: Develop the 1990 rate-of-progress base year inventory
Biogenic source emissions and other emissions from sources located outside the nonattainment
area, but included in step 1, are removed from the 1990 base year inventory.
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Step 3: Calculate the 1990 adjusted base year inventory
The Act specifies the emissions "baseline" from which each emission reduction milestone is
calculated. Section 182(c)(2)(B) states that the reductions must be achieved "from the baseline
emissions described in subsection (b)(l)(B)." This baseline value is termed the 1990 adjusted base
year inventory. Section 182(b)(l)(B) defines baseline emissions (for purposes of calculating each
milestone VOC/NOX emission reduction) as "the total amount of actual VOC or NOX emissions from
all anthropogenic sources in the area during the calendar year of enactment." This section excludes
from the baseline the emissions that would be eliminated by Federal motor vehicle control program
(FMVCP) regulations promulgated by January 1, 1990, and Reid vapor pressure (RVP) regulations
promulgated by the time of enactment (55 FR 23666, June 11, 1990), which require maximum RVP
limits for gasoline to be sold in nonattainment areas during the peak ozone season.
The 1990 adjusted base year inventory must be recalculated relative to each milestone and
attainment date because the emission reductions associated with the FMVCP increase each year due to
fleet turnover. Thus, a severe ozone nonattainment area with an ozone design value of less than
0.190 ppm would need to calculate the 1990 adjusted base year inventory relative to 1999, 2002, and
2005. The only adjustment that must be made to the inventory in each case is to recalculate mobile
source emissions, including emissions from vehicle refueling, using MOBILESa. This adjustment is
made by calculating a separate mobile source emission factor for each applicable milestone year. The
emission factors are then multiplied by 1990 vehicle miles traveled (VMT), or gallons of gasoline for
refueling emissions, to yield the mobile source emissions that must be subtracted from the 1990 rate-
of-progress base year inventory to calculate the 1990 adjusted base year inventory for each
milestone/attainment date. These reductions are calculated as follows:
FMVCP'/RVP Reductions Between 1990 and Current Target Year (x)
Subtract
Adjusted 1990 mobile source emissions = (1990 VMT)(MOBILE5a emission factors from B)
from
Actual 1990 mobile source emissions = (1990 VMT)(MOBILE5a emission factors from A)
A) MOBILESa run from the 1990 base year inventory. Emission factors from this run will be
used with actual 1990 VMT to calculate actual 1990 emissions. If the refueling emission
factor is calculated in MOBILESa as a grams per gallon of gasoline factor, that factor should
be multiplied by actual 1990 gasoline throughput and those emissions should be included in
the 1990 actual mobile source emissions.
B) MOBILESa run as in the 1990 base year inventory, except that year "x" will be used as the
evaluation year (this will change the vehicle mix to account for fleet turnover). Emission
factors from this run will be used with actual 1990 VMT to calculate adjusted 1990 emissions
relative to year "x." If the refueling emission factor is calculated in MOBILESa as a grams
per gallon of gasoline factor, that factor should be multiplied by actual 1990 gasoline
throughput and those emissions should be included in the 1990 adjusted mobile source
emissions.
10
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A detailed description of the procedure for calculating the 1990 adjusted base year inventory is
provided in an EPA document entitled Guidance on the Adjusted Base Year Emissions Inventory and
the 1996 Target for the 15 Percent Rate-of-Progress Plans. (See reference 1.) The adjusted base year
inventory can be calculated the same way for each post-1996 milestone/attainment year. After this
inventory has been calculated for each applicable milestone and attainment year, the next step is to
determine the required creditable emission reductions.
Step 4: Calculate 3 percent per year reductions
In general, to compute the required emission reductions, the number of years between
successive milestone dates (or in some cases between a milestone date and the attainment date) should
be multiplied by 0.03. If an area plans to substitute NOX for VOC, however, the percent reduction
will have to be adjusted. This is discussed in more detail in section 4 of this document.
Percentage reduction = r = [0.03 * (x-y)]
where:
(x-y) = Number of years between current (x) and previous (y) target dates.
For example, an extreme area would multiply 0.03 by 2 to calculate that it will need a 6 percent
emission reduction between 2008 and 2010. Next, this percentage figure is multiplied by the adjusted
base year inventory calculated relative to the current milestone/attainment date to yield the required
emission reduction.
BGr = BEx*r
where:
BGr = Emission reduction requirement for milestone or attainment date (in Ib/day)
BEX = 1990 adjusted base year inventory calculated relative to
year x
r = Percent reduction needed to meet the rate-of-progress requirement.
The fifth step is to calculate the fleet turnover correction term.
Step 5: Calculate fleet turnover correction term
In the absence of any new requirements of the Act, there would still be some decrease in
motor vehicle emission factors for many years as a result of fleet turnover, the gradual replacement of
older pre-control vehicles with newer vehicles with controls. The Act does not allow States to take
credit for these reductions for rate-of-progress purposes. During the calculation of the 1996 milestone
target, these "FMVCP reductions" (along with non-creditable RVP reductions) that would occur
between 1990 and 1996 were subtracted from the 1990 rate-of-progress base year inventory to
calculate the 1990 adjusted base year inventory. This 1990 adjusted base year inventory was then
used to calculate the required reductions and the 1996 target.
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Because nonattainment areas are required to meet their 1996 targets, the calculation of the
1999 target must be based, in part, on the 1996 target. Likewise, the calculation of each subsequent
target will depend, in part, on the level of the previous target. In the previous step (step 4), the
adjusted base year inventory was multiplied by the total percent required reduction in order to
determine the reductions required in the target year. This emission reduction requirement must then
be subtracted from the emission target in the previous milestone year to calculate the new milestone
target. However, one additional correction term, the fleet turnover correction, is needed to properly
calculate the target.
The fleet turnover correction is needed to account for the mobile source emission reductions
that would have occurred under the preenactment FMVCP and RVP requirements (under 55 FR
23666), between consecutive milestone years. For example, assume that a nonattainment area has
met the milestone target for 1996. The further creditable reduction required to meet the post-1996
rate-of-progress requirements was calculated in step 4. However, between 1996 and 1999, there will
be some additional reductions in emissions due to fleet turnover of older vehicles that are not
creditable. These reductions must also be subtracted from the 1996 target to determine the 1999
target. These additional, non-creditable, reductions are referred to here as the fleet turnover
correction term.
The calculation of the fleet turnover correction term is simple and does not require any
additional MOBILE runs beyond what has been required in previous steps of this calculation. For the
general case, the fleet turnover correction term is calculated as follows:
Fleet Turnover Correction (FTJ = 1990yFMVCP/RVP - 1990.FMVCP/RVP
where:
x = current target year
y = previous target year
1990yFMVCP/RVP = Adjusted 1990 mobile source emissions for the previous target
year
1990XFMVCP/RVP = Adjusted 1990 mobile source emissions for the current target
year.
The adjusted 1990 mobile source emissions for the current target year were calculated earlier
in step 3 as 1990 VMT times MOBILE5a emission factors for the current target year with all new
Clean Air Act measures disabled and RVP set to the Phase 2 limit required in Summer 1992. The
adjusted 1990 mobile source emissions for the previous target year were calculated in the same way
as part of the target level calculation for the previous year. For example, the fleet turnover
correction for the 1999 target is equal to the adjusted mobile source emissions calculated for the 1996
rate-of-progress requirement minus the adjusted mobile source emissions calculated in step 3 of the
current calculation.
Step 6: Calculate post-1996 target level of emissions
To calculate each target level of emissions, the required emission reductions calculated in step
4 and the fleet turnover correction term from step 5 are subtracted from the previous milestone's
target level. For the purposes of calculating the 1999 target, it may be necessary to recalculate the
12
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1996 target if the base year inventory was significantly revised after submittal of the 15 percent rate-
of-progress plan.
Target level = (previous milestone's target level) - (reductions required to meet the rate-
of-progress requirement, calculated in step 4) - (fleet turnover correction
term, calculated in step 5).
This target represents the level of emissions that must be achieved in order for a
nonattainment area to demonstrate that the rate-of-progress requirement will be met.
2.2 Example Calculation of Post-1996 Target Level(s)
This section presents a hypothetical example that calculates a target level for 1999. This
example builds on the example contained in the EPA document entitled Guidance on the Adjusted
Base Year Emissions Inventory and the 1996 Target for the 15 Percent Rate-of-Progress Plans (see
reference 1), and assumes that no changes have been made to the base year emission inventory.
Figure 2 outlines the procedure to follow to calculate the target.
Calculation of 1999 Target Level of Emissions
Step 1: Develop 1990 base year VOC emission inventory (Ib/day)
Point Sources 1,000
Area Sources 2,500
Mobile Sources 3,500
Biogenic Sources + 5,000
Total 12,000
Step 2: Develop 1990 rate-of-progress base year inventory (Ib/day)
1990 base year inventory = 12,000
Point Sources (outside nonattainment area) ' -200
Area Sources (outside nonattainment area) -500
Mobile Sources (outside nonattainment area) -500
Biogenic Sources -5,000
Total 5,800
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FINAL BASE YEAR
C19903
INVENTORY*
12,000 Ib/day
T
1990
RATE-OF-PROGRESS
BASE YEAR
INVENTORY
5,300 Ib/day
1990 ADJUSTED BASE YEAR
INVENTORY CALCULATED
RELATIVE TO YEAR x
CBExO
5,200 Ib/day
B
mu11 iply
by r=O.D9
EMISSIONS REDUCTION
REQUIRED BETWEEN
YEAR y AND YEAR x
468 Ib/day
SUBTRACT
BIOGENICS C5,QOO Ib/day},
EMISSIONS OUTSIDE
NONATTAINMENT AREA C1,200 Ib/day}
SUBTRACT
FMVCP/RVP REDUCTIONS
BETWEEN 1990 AND YEAR x
C6QO Ib/day}
TARGET LEVEL FOR
YEAR y
4,000 Ib/day
TARGET LEVEL FOR
YEAR x
CTLx} =
CTLy - BGr -
3,432 Ib/day
x = current target year = 1999
y = previous target year = 1996
FLEET TURNOVER CORRECTION
CFTx} = a - b
100 Ib/day
a = 1990y FMVCP/RVP
REDUCTIONS C600 Ib/day}
b = 1990x FMVCP/RVP
REDUCTIONS C^OO Ib/day}
* - Does not include preenactment banked emissions reduction credits
Figure 2. Flowchart of hypothetical example 1999 rate-of-progress VOC target level calculation
14
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c
Step 3: Calculate the 1990 adjusted base year inventory for 1999
The only adjustment that must be made to the rate-of-progress inventory is to calculate mobile
source emission reductions using MOBILESa. This adjustment is made by calculating a mobile
source emission factor for 1999, multiplying the emission factor by 1990 VMT, and subtracting that
total from the 1990 actual mobile source emissions to yield the FMVCP and RVP reductions between
1990 and 1999. For this example, the State calculates that there will be a reduction of 600 Ib/day of
VOC due to fleet turnover up through 1999 and the RVP limit specified for the nonattainment area in
55 FR 23666. The following is the adjusted base year inventory developed for the hypothetical
nonattainment area:
1990 Adjusted Base Year Inventory (Ib/day)
= 1990 rate-of-progress inventory - (FMVCP and RVP reductions between 1990 and
1999)
= 5,800 Ib/day - 600 Ib/day = 5,200 Ib/day.
Step 4: Calculate 3 percent per year reductions
The 1990 adjusted base year inventory calculated relative to the 1999 milestone year is
multiplied by 0.09 to calculate the required emission reductions from 1996 to 1999.
9 percent reduction = 5,200 x 0.09 = 468 Ib/day
Step 5: Calculate fleet turnover correction term
The fleet turnover correction term is the difference between the FMVCP/RVP emission
reductions calculated in step 3 and the previous milestone year's FMVCP/RVP emission reductions. -
In this hypothetical example, the FMVCP/RVP reductions calculated relative to 1996 are assumed to
be 500 Ib/day. Therefore, the fleet turnover correction term for 1999 is 100 Ib/day (i.e., 600 Ib/day -
500 Ib/day).
Step 6: Calculate target level of emissions for 1999
To calculate the target level of emissions for 1999, the required emission reductions calculated
in step 4 and the fleet turnover correction term are subtracted from the 1996 milestone target level.
The 1996 target level was calculated to be 4,000 Ib/day in the EPA document Guidance on the
Adjusted Base Year Emissions Inventory and the 1996 Target for the 15 Percent Rate-of-Progress
Plan (see reference 1).
15
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Target level = (1996 milestone target level) - (reductions calculated in step 4) - (fleet
turnover correction term calculated in step 5)
= 1996 target level - (5,200 Ib/day * 0.09) - (600 Ib/day - 500 Ib/day)
= 4,000 Ib/day - 468 Ib/day - 100 Ib/day
= 3,432 Ib/day
This area's plan must therefore demonstrate that the projected emissions for 1999, reflecting
the adopted control strategy, will be less than or equal to 3,432 Ib/day.
2.3 Conditions Permitting Less than a 3 Percent VOC Emission Reduction
A State may be permitted to achieve VOC emission reductions less than 3 percent if it
demonstrates that the plan includes all measures that, given technological achievability, can feasibly
be implemented in the given area. In addition, the State must demonstrate that its plan includes
measures that are achieved in practice by sources in the same source category in nonattainment areas
of the next higher classification. The measures necessary to meet this requirement will be determined
on a case-by-case basis. Any determination to lessen the 3 percent requirement will be reviewed at
each milestone demonstration, and revised to include any new measures achieved in practice by
sources in the same source category in any State, allowing a reasonable time to implement such
measures [section 182(c)(2)(B)(ii)].
It is important to note that the waiver provision does not apply to extreme ozone
nonattainment areas. Furthermore, States must understand that the attainment of the ozone NAAQS is
the underlying requirement of the Act. Although less than a 3 percent VOC emission reduction may
be permitted for the purposes of satisfying the rate-of-progress requirements, a State must have
sufficient emission reductions in its SIP to attain the ozone NAAQS by its applicable attainment date.
Although it is not necessary to demonstrate attainment to obtain a waiver, the waiver does not relieve
serious and severe areas from the obligation to demonstrate attainment.
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3.0 ATTAINMENT DEMONSTRATION REQUIREMENTS
This section of the document describes the attainment demonstration requirements for those
nonattainment areas that are required or choose to use photochemical grid modeling, and describes
special air quality situations involving attainment demonstrations.
3.1 Modeling Requirements for Attainment Demonstrations
The UAM is described in the EPA document entitled User's Guide for the Urban Airshed
Model (see reference 2). In addition, the General Preamble (57 FR 13510) should be consulted
regarding the attainment demonstration implications of using UAM or other photochemical grid
models.
Procedures to follow in applying photochemical grid models to support the attainment
demonstration are described in Guideline for Regulatory Application of the Urban Airshed Model (see
reference 3). Chapters 1 and 2 of the Guideline identify establishment of a modeling protocol. The
protocol identifies Technical Committees whose responsibilities are to: (1) define the geographic
location and specific meteorological episodes to be modeled (note that the modeling domain will
generally be larger than the nonattainment area); (2) develop compatible inputs for the model
application such as episode specific air quality, wind fields, and emissions; (3) apply the model and
troubleshoot results so that performance is acceptable; (4) develop projected emissions for the
required attainment date; and (5) apply the model using projected emissions to see whether predicted
ozone concentrations are 120 parts per billion (ppb) or less throughout the modeling domain (i.e., the
model demonstrates attainment). If the model does not demonstrate attainment, additional control
measures must be developed and their effectiveness evaluated. This is an iterative process until
attainment is demonstrated.
It should be noted that both biogenic and anthropogenic emissions are included in the
modeling. Also, for consistency the projected emissions should reflect the control measures used to
obtain the 15 percent VOC emission reduction required between 1990 and 1996, additional annual 3
percent reductions thereafter, and where necessary, additional control measures to achieve attainment.
The required modeling protocol should also identify a Policy Oversight Committee. This
group provides input on the strategies to be tested and is responsible for reaching consensus on the
strategy to implement in the 1994 SIP revision.
The modeling demonstration supporting the 1994 SIP revision should be submitted to the
appropriate U.S. EPA Regional Office(s) by November 15, 1994. The Regional Office will then
evaluate the plan and prepare a technical support document (TSD) assessing the adequacy of the
documentation of the analysis. The following should be provided by States to support preparation of
this document: (1) the modeling protocol with episode dates and the modeling domain defined;
(2) the emissions input preparation for the base case inventory, emission projections and emission
estimates derived for the attainment demonstration to be implemented in the 1994 SIP revision; (3) air
quality and meteorological input preparations for the selected episodes; (4) diagnostic analyses used to
troubleshoot model performance, including the rationale for revisions to inputs which resulted;
(5) results of the model performance evaluation; (6) air quality predictions corresponding with the
attainment demonstration to be implemented in the SIP; and (7) procedures which .the EPA or other
interested parties can follow to gain access to all relevant input and output files so as to replicate
17
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results, if desired. Each of these seven required components is described in greater detail in
Guidance on Urban Airshed Model (UAM) Reporting Requirements for Attainment Demonstration
(see reference 4). Regional Offices are encouraging States to submit these items as soon as possible
to receive early feedback.
States should plan to achieve emission reductions as early in the process as possible, since
section 181(b)(2) requires EPA to make a determination as to whether an area has attained the ozone
NAAQS within 6 months following an applicable attainment date. This requirement dictates the use
of the most recent 3 years of air quality data in determining whether a nonattainment area has attained
the ozone NAAQS. For example, for a serious area with an attainment date of November 1999, EPA
will use air quality data for 1997 - 1999 to determine if the nonattainment area has attained the ozone
NAAQS. [See the General Preamble (57 FR 13509).]
3.2 Special Air Quality Situations
Areas Requiring Emission Reductions in Addition to 3 Percent per Year
There may be circumstances under which a nonattainment area in order to demonstrate
attainment of the NAAQS will require additional VOC and/or NOX reductions in excess of the
3 percent per year reduction mandated in section 182(c)(2)(B)(i). The underlying requirement of the
SIP is that nonattainment areas must achieve attainment of the NAAQS by their attainment date, not
solely the achievement of the 3 percent per year reduction requirement.
Multi-State Nonattainment Areas
Section 182(j) defines and establishes requirements for ozone nonattainment areas covering
areas in more than one State called multi-State nonattainment areas. Beyond the requirements in
section 182 for the different nonattainment area classifications, section 182(j)(l) requires States in
these areas to coordinate the revisions and implementation of the SIP's applicable to the nonattainment
areas and to use photochemical grid modeling (or another method determined by EPA) as part of the
SIP-preparation process.
A joint modeling demonstration must be submitted by all States in the modeling domain. The
EPA will not to approve any attainment demonstration unless all of the affected States have agreed to
a strategy. This demonstration should identify the strategy to be used for attainment and should
identify the emission reduction necessary in each State. The demonstration should reference the
applicable modeling protocol and include a schedule for developing control measures and the
attainment demonstration for the entire multi-State area. Where all of the States are in the same
Region, only one modeling demonstration must be submitted. If the States are in different Regions,
the demonstration should be sent to each Region. In addition, each State must individually submit
regulations to achieve the necessary reductions for that State.
Section 182(j)(2) recognizes that if any State in which there is located a portion of a multi-
State nonattainment area fails to provide a demonstration of attainment within the required period, the
State may petition EPA to make a finding that the State(s) would have been able to make such a
demonstration "but for the failure of one or more other States, in which other portions of the area are
located, to commit to the implementation .of all measures required by section 182...." If the EPA
Administrator makes a finding that this situation is occurring, the sanctions of section 179 shall not
18
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apply to the petitioning State(s). Section III.A.9 of the General Preamble provides the primary
guidance for these nonattainment area SIP's (57 FR 13529).
States Included in More than One Modeling Domain
There are a number of cases where a State is included in more than one modeling domain. In
this situation, the State must ensure that control measures are applied consistently in all model
applications.
International Border Areas
Section 179B applies to nonattainment areas that are affected by emissions emanating from
outside the United States. This section provides relief for nonattainment areas along international
borders analogous to what is provided to States within multi-State nonattainment areas by section
182(j): EPA shall approve the SIP if it meets all the requirements in the Act and if the State
establishes that the implementation of the plan would be adequate to attain and maintain the relevant
NAAQS "but for emissions emanating from outside the United States." Section 179B (created by
Title Vin, section 818 of the Act) and section V.C of the General Preamble provide SIP guidance for
areas on international border areas.
Areas with Differing Required Attainment Dates
There are several situations in which areas with later statutory attainment dates can affect
areas with earlier attainment dates. In some cases, a modeling domain may include several designated
nonattainment areas of varying severity. A common example is a domain containing a moderate
nonattainment area(s) (required attainment date of 1996) and a serious (1999) or severe (2005 or
2007) nonattainment area. In other cases, an area may be impacted by another area outside the
modeling domain.
Each ozone nonattainment area is still subject to the applicable requirements for a
demonstration of attainment under section 182(b)(l)(A) and (c)(2). For example, a moderate area
located within the transport region is still subject to the 6-year attainment deadline and the 15 percent
reduction requirement. However, this area is (at least, presumptively) being affected by transport
from another area(s) and is possibly affecting other areas, as well. If the areas that are affecting air
quality levels in this moderate area have a higher classification, that moderate area may be receiving
transported ozone concentrations exceeding the NAAQS well after its own mandatory attainment date.
In general, two situations exist in which an area might be subject to additional emission
reduction requirements related to the demonstration of attainment. In the first, an area might be
receiving such high levels of transport that even if it reduced its own emissions dramatically (e.g.,
totally eliminated its own emissions), the incoming ozone and precursors would be high enough to
continue to cause violations of the standard beyond the applicable attainment date. In the second
situation, the area might be able to achieve additional reductions (beyond those required under section
182), but even where those additional reductions could be achieved to demonstrate attainment, the
question arises whether it is equitable to require those reductions or to allow more time for the
reductions in the "upwind" area to take place. The Act provides no express relief for these situations.
Thus, where the demonstration of attainment is complicated by transport between two areas of
different classifications, the State is still responsible for developing and submitting demonstrations
19
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which show that the standard will be attained by the applicable date. In other words, the State must
provide for sufficient emission reductions on a schedule that will ensure attainment by the deadline
prescribed in the Act (e.g., by 1996 for moderate areas). The area does have the option of requesting
to be reclassifled to the next higher classification.
When such areas develop the demonstration of attainment due in November 1994, they should
provide a comprehensive assessment of the impacts of all control measures being implemented in both
the local and upwind areas. States should clearly show the extent to which the downwind area is
dependent on upwind strategies while fully meeting its own requirements associated with its
classification. The EPA will continue working with States facing this situation to resolve these issues.
Exceedances Monitored within a Modeling Domain Due Primarily to Emissions in Another Domain
Generally, episodes in which emissions included within a modeling domain do not play a
significant role in contributing to monitored exceedances within that domain should not be modeled in
an attainment demonstration. Guidance on "overwhelming transport" contained in sections 3.1 and
3.2 of Criteria for Assessing the Role of Transported Ozone/Precursors in Ozone Nonattainment
Areas (see reference 5) may be used to identify unsuitable episodes. Alternatively, diagnostic tests
described in section 4.3 of Guideline for Regulatory Application of the Urban Airshed Model (see
reference 3) may be used to identify unsuitable episodes. Note that this guidance is not saying that
episodes in which transported ozone/precursors play an important role are unsuitable for modeling.
This guidance is singling out cases in which drastic changes in emissions within the domain are likely
to result in minor or negligible differences in predicted daily maximum ozone concentrations due to
large amounts of extraneous ozone/precursors.
An episode which is otherwise consistent with requirements in section 3.1 of Guideline for
Regulatory Application of the Urban Airshed Model may bfe rejected due to overwhelming transport.
In this case, evidence should be presented as part of the documentation that (a) those undertaking
modeling for the upwind domain(s) identified as likely sources of the transport have been contacted;
and (b) agreement has been reached that the upwind area(s) will consider at least one episode with the
appropriate transport pattern to ensure that predicted concentrations within the upwind grid or at the
upwind boundary of the downwind grid are at or below 120 ppb. Sections 176A(b) and 184(a)-(c) of
the Clean Air Act provide one means for facilitating such interdomain coordination. Other ad hoc
arrangements may be acceptable if evidence of a good faith effort to implement resulting agreements
is demonstrated.
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4.0 NOx EMISSION REDUCTIONS
Section 182(c)(2)(C) of the Act allows States to substitute actual NOX emission reductions
which occur after 1990 to meet post-1996 VOC emission reduction requirements. This section of the
document describes the procedure for calculating NOX emission reductions which can be used to meet
post-1996 VOC emission reduction requirements.
4.1 Substitution of NO, Emission Reductions for Post-1996 VOC Emission Reductions
Section 182(c)(2)(C) states that actual NOX emission reductions which occur after 1990 can be
used to meet post-1996 emission reduction requirements, provided that such reductions meet the
criteria outlined in EPA's December 15, 1993 NOX Substitution Guidance. The condition for meeting
the rate-of-progress requirement is that the sum of all creditable VOC and NOX emission reductions
must equal 3 percent per year averaged over each applicable milestone period. The percent VOC
reduction is determined from the VOC rate-of-progress inventory and the percent NOX reduction is
determined from the NOX rate-of-progress inventory. In addition, the overall VOC and NOX
reductions must be consistent with the area's modeled attainment demonstration. In other words, the
NOX emission reductions creditable toward the rate-of-progress plan cannot be greater than the
cumulative reductions dictated by the modeled attainment demonstration. This is necessary because
there may be a number of different control strategies that could be used to show attainment, and the
rate-of-progress plan must be consistent with the strategy selected by the State as its attainment
strategy. It should be noted, however, that if a State chooses to make mid-course corrections to its
attainment demonstration, it can also make corresponding changes to the rate-of-progress plan.
Although the NOX supplement to the General Preamble does not specify that photochemical
grid modeling must be used for this demonstration, this modeling is generally necessary to determine
the extent to which NOX can be substituted for VOC. In addition, use of photochemical grid
modeling for NOX substitution demonstrations would be consistent with requirements that
photochemical modeling be used to justify exempting the area from NOX controls or lessening the
amount of NOX controls required.
If a State plans to substitute NOX reductions for VOC reductions, separate target level(s) of
emissions will have to be calculated for both NOX and VOC. Figure 3 provides an overview of the
procedure for calculating the VOC target level and Figures 4 and 4a provides an overview of the
procedure for calculating the NOX target level. The target levels are calculated as discussed in section
2 of this document with some exceptions.
4.2 Calculation of Post-1996 NO, and VOC Target Levels of Emissions
The target levels of emissions represent the maximum amount of emissions allowed in each
post-1996 milestone year given the 3 percent per year rate-of-progress requirement. The target
level(s) of VOC emissions can be calculated using the following equation:
21
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FINAL BASE YEAR
C 19900
INVENTORY*
1990
RATE-OF-PROGRESS
BASE YEAR
INVENTORY
SUBTRACT
BIOGENICS,
EMISSIONS OUTSIDE
NONATTAINMENT
AREA
TARGET LEVEL FOR
YEAR y
CTLy)
T
TARGET LEVEL FOR
YEAR x
CTLx) =
CTLy - BGr - FTx}
1990 ADJUSTED BASE YEAR
INVENTORY CALCULATED
RELATIVE TO YEAR x
CBEx}
B
mu11 i pIy
by rVOC
EMISSIONS REDUCTION
REQUIRED BETWEEN
YEAR y AND YEAR x
CBQO
SUBTRACT
FMVCP/RVP REDUCTIONS
BETWEEN 1990 AND YEAR x
x = current target year
y = previous target year
FLEET TURNOVER CORRECTION
CFTx} = a - b
a = 1990y FMVCP/HVP
EMISSIONS
b = 1990x FMVCP/RVP
EMISSIONS
* - Does not include preenactment banked emissions reduction credits
Figure 3. Flowchart for generic post-1996 rate-of-progress VOC calculations (with NOX sub'stitution)
22
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FINAL BASE YEAR
C1990D
INVENTORY*
T
-1990
RATE-OF-PROGRESS
BASE YEAR
INVENTORY
SUBTRACT
EMISSIONS OUTSIDE
NONATTAINMENT
AREA
1990 ADJUSTED BASE YEAR
INVENTORY CALCULATED
RELATIVE TO YEAR x
CBEx}
SUBTRACT
FMVCP/RVP REDUCTIONS
BETWEEN 1990 AND YEAR x
B
mu11 i pIy
by n
EMISSIONS REDUCTION
REQUIRED BETWEEN
1990 AND YEAR x
x = current target year
TARGET LEVEL FOR
YEAR x
CA - CD
TOTAL EXPECTED REDUCTIONS
BY YEAR x
ADD
REDUCTIONS FROM:
FMVCP/RVP
* - Does not include preenactment banked emissions reduction credits
Figure 4. Flowchart for rate-of-progress NOX calculation for 1999
23
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FINAL BASE YEAR
C199CO
INVENTORY*
1990
RATE-OF-PHOGRESS
BASE YEAR
INVENTORY
SUBTRACT
BIOGENICS,
EMISSIONS OUTSIDE
NONATTAINMENT
AREA
TARGET LEVEL FOR
YEAR y
TARGET LEVEL FOR
YEAR x
CTLx) =
CTLy - BGr - FTx}
1990 ADJUSTED BASE YEAR
INVENTORY CALCULATED
RELATIVE TO YEAR x
CBEx}
B
EMISSIONS REDUCTION
REQUIRED BETWEEN
YEAR y AND YEAR x
CBGO
SUBTRACT
FMVCP/HVP REDUCTIONS
BETWEEN 1990 AND YEAR x
x = current target year
y = previous target year
FLEET TURNOVER CORRECTION
CFTx} = a - b
a = 1990y FMVCP/HVP
EMISSIONS
b = 1990X FMVCP/RVP
EMISSIONS'
- Does not include preenactment banked emissions reduction credits
Figure 4a. Flowchart for generic post-1999 rate-of-progress NOX calculations
24
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~ TLyrvOC
where:
x = Current milestone or attainment year
y = Year of previous milestone
TLx,voc = Target level of VOC emissions for year x (Ib/day)
TLy.voc = Target level of VOC emissions for year y (in Ib/day)
BGr.voc Emission reduction requirement for VOC for year x (in Ib/day)
FTx,voc = Fleet turnover correction term for VOC for year x (in Ib/day).
* »
The target level of NOX emissions for 1999 can be calculated using the following equation:
TL1999 = 1990 ROP - BGr>NOx - FMVCP/RVP1999
where:
1990 ROP = 1990 rate-of-progress NOX inventory
BGr,NOx = NOX emission reduction requirement for 1999 (in Ib/day)
FMVCP/RVP19,» = FMVCP/RVP NOX reductions calculated relative to 1999 (in Ib/day)
The target level of NOX emissions for years after 1999 can be calculated using the following equation:
TL^r^ = TLy>NOx - BGr>NOx - FTXiNOx
where:
x = Current milestone or attainment year
y = Year of previous milestone
TL^nox = Target level of NOX emissions for year x (Ib/day)
TLy.NOx = Target level of NOX emissions for year y (in Ib/day)
BGrtNOx = Emission reduction requirement for NOX for year x (in Ib/day)
= Fleet turnover correction term for NOX for year x (in Ib/day).
These equations can be used to calculate the target level of emissions for each post-1996 milestone
year. The reason that the 1999 NOX target is calculated differently is that there is not a 1996 NOX
target that can be used to calculate the 1999 target. Once the 1999 NOX target is established it can be
used to calculate the next target. The specific steps needed to calculate each target are discussed
below.
There are six major steps in calculating a post-1996 target level of emissions. The first four
steps are needed to calculate the 3 percent per year rate-of-progress emission reduction. The first
three of these steps, developing the 1990 base year inventory, developing the 1990 rate-of-progress
inventory, and developing the adjusted base year inventory were discussed in detail for VOC in
section 2 of this document. The following describes how the post-1996 target levels should be
calculated when NOX substitution for VOC will occur. .
Step 1: Develop the 1990 base year inventory
The total 1990 base year VOC and NOX emissions from the five major emission source
categories (point, area, on-road and off-road mobile, and biogenic) are compiled. It should be noted
25
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that the base year inventory used for the post-1996 rate-of-progress plan must be consistent with the
base year inventory used for attainment demonstration purposes. Any changes that were made to the
inventory between submittal of the 15 percent rate-of-progress plan and the post-1996 rate-of progress
plan should be reflected.
Step 2: Develop the 1990 rate-of-progress base year inventory for nonattainment area
Biogenic source emissions1 and other emissions from sources located outside the
nonattainment area, but included in step 1, are removed from the 1990 base year inventory.
Step 3: Calculate the 1990 adjusted base year inventories
The Act specifies the emissions "baseline" from which each emission reduction milestone is
calculated. Section 182(c)(2)(B) states that the reductions must be achieved "from the baseline
emissions described in subsection (b)(l)(B).n This-baseline value is termed the 1990 adjusted base
year inventory. The baseline excludes the VOC and NOX emissions that would be eliminated by
FMVCP regulations promulgated by January 1, 1990, and by RVP regulations promulgated by the
time of enactment (55 FR 23666, June 11, 1990), which require maximum RVP limits for gasoline to
be sold in nonattainment areas during the peak ozone season.
The 1990 adjusted base year inventories must be calculated relative to each milestone and
attainment year because the emission reductions associated with the FMVCP increase each year due to
fleet turnover. The only adjustment that must be made to the inventories in each case is to recalculate
mobile source emissions, including VOC emissions from vehicle refueling, using MOBDLESa. This
adjustment is made by calculating a separate mobile source emission factor for each applicable
milestone year. The emission factors are then multiplied by 1990 VMT, or gallons of gasoline for
refueling emissions, to yield the mobile source emissions that must be subtracted from the 1990 rate-
of-progress base year inventories to calculate the 1990 adjusted base year inventories for each
milestone/attainment year. These reductions are calculated as follows:
FMVCP/RVP Reductions Between 1990 and Current Target Year (x):
Subtract
Adjusted 1990 mobile source emissions = (1990 VMT)(MOBILE5a emission factors from B)
from
Actual 1990 mobile source emissions = (1990 VMT)(MOBILE5a emission factors from A)
1 Most emission inventories do not contain biogenic NOX emissions. If these emissions are
included, they must be subtracted in developing the rate-of-progress inventory.
26
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A) MOBILESa run from the 1990 base year inventory. Emission factors from this run will be
used with actual 1990 VMT to calculate actual 1990 emissions. If the refueling emission
factor for VOC is calculated in MOBILESa as a grams per gallon of gasoline factor, that
factor should be multiplied by actual 1990 gasoline throughput and those emissions should be
included in the 1990 actual mobile source emissions.
B) MOBILESa run as in the 1990 base year inventory, except that year "x" will be used as the
evaluation year (this will change the vehicle mix to account for fleet turnover). Emission
factors from this run will be used with actual 1990 VMT to calculate adjusted 1990 emissions
relative to year "x." if the refueling emission factor for VOC is calculated hi MOBILESa as
a grams per gallon of gasoline factor, that factor should be multiplied by actual 1990 gasoline
throughput and those emissions should be included in the 1990 adjusted mobile source
emissions.
A detailed description of the procedure for calculating the 1990 adjusted base year inventory is
provided in an EPA document entitled Guidance on the Adjusted Base Year Emissions Inventory and
the 1996 Target for the 15 Percent Rate-of-Progress Plans (see reference 1). The adjusted base year
inventory must be calculated the same way for each post- 1996 milestone/attainment year.
*
Step 4: Calculate required creditable reductions
The percent reduction required is calculated separately for VOC and NOX. The sum of the
percent VOC reduction and the percent NOX reduction must equal the 3 percent per year required
reduction. The VOC reduction is equal to the number of years between milestone dates (usually 3)
multiplied by 0.03 minus the percent (n) that will be achieved through NOX reductions.
Percentage VOC reduction = rvoc = [0.03 * (x-y)] - n
where:
TVOC = percent VOC reduction needed to meet the rate-of-progress requirement.
(x-y) = Number of years between current (x)
and previous (y) target dates.
n = percent of reductions that will be achieved through NOX reductions
Next, these percentage figures are multiplied by the adjusted base year inventories calculated
relative to the current milestone/attainment date to yield the required VOC and NOX emission
reductions.
rvoc
and
27
-------
where:
BGr>VOc = VOC emission reduction requirement for milestone date (in Ib/day)
- NOX emission reduction requirement for milestone date (in Ib/day)
= 1990 adjusted base year VOC inventory calculated relative to year x
= 1990 adjusted base year NOX inventory calculated relative to year x
= percent VOC reduction needed to meet the rate-of-progress requirement.
n = percent NO, reduction needed to meet the rate-of-progress requirement.
Step 5: Calculate fleet turnover correction term
For VOC and for the post-1999 NOX target, the fleet turnover correction is needed to account
for the mobile source emission reductions that would have occurred under the preenactment FMVCP
and RVP requirements (under 55 FR 23666), between consecutive milestone years. The calculation
of this correction for VOC is described in detail in section 2 of this document. This term is
calculated the same way for NOX.
For the 1999 NOX target, different adjustments need to be made because there is not a target
from a previous year that accounts for reductions between 1990 and 1996. Adjustments must be
made to account for emission reductions associated with FMVCP and RVP because these emission
reductions are not creditable for substitution. Unlike the adjustments made to the VOC rate-of-
progress base year emission inventory, the effects of reasonably available control technology (RACT)
fix-ups do not need to be included in the adjustment calculation because they do not affect NOX
emissions. Due to the lack of a NOX performance standard for I/M programs prior to enactment of
the 1990 amendments to the Act and the negligible impact of corrections to I/M programs on NOX
emissions, the NOX target does not need to be adjusted to account for I/M program corrections.
The NOX adjustment for FMVCP for the 1999 target is calculated as follows:
FMVCP/RVP NO, Reductions Between 1990 and 1999:
Subtract
Adjusted 1990 mobile source emissions = (1990 VMT)(MOBILE5a emission factors from B)
from
Actual 1990 mobile source emissions = (1990 VMT)(MOBILE5a emission factors from A)
A) MOBILESa run from the 1990 base year inventory. Emission factors from this run will be
used with actual 1990 VMT to calculate actual 1990 emissions.
B) MOBILESa run as in the 1990 base year inventory, except that 1999 will be used as the
evaluation year (this will change the vehicle mix to account for fleet turnover). Emission
factors from this run will be used with actual 1990 VMT to calculate adjusted 1990 emissions
relative to 1999.
28
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Step 6: Calculate post-1996 target levels of emissions
To calculate the target level VOC emissions, the required emission reductions calculated in
step 4 and the fleet turnover correction term from step 5 are subtracted from the previous milestone's
target level. For the purposes of calculating the 1999 VOC target, it may be necessary to recalculate
the 1996 target if the base year inventory was significantly revised after submittal of the 15 percent
rate-of-progress plan.
VOC target level = (previous milestone's target level) - (reductions required to meet the
rate-of-progress requirement, calculated in step 4) - (fleet turnover
correction term, calculated in step 5).
The 1999 NOX target is calculated by adding the required emission reductions calculated in
step 4 to the expected reductions from the FMVCP and RVP and subtracting this total from the 1990
NO, rate-of-progress inventory.
NOX target level = (1990 NOX rate-of-progress inventory) - [(reductions required to meet
the rate-of-progress requirement, calculated in step 4) + (reductions
from 1990 to target year from FMVCP and RVP, calculated in step
5)].
To calculate the post-1999 target level NOX emissions, the required emission reductions
calculated in step 4 and the fleet turnover correction term from step 5 are subtracted from the
previous milestone's target level.
Post-1999 NOX target level = (previous milestone's target level) - (reductions required to
meet the rate-of-progress requirement, calculated in step 4) -
(fleet turnover correction term, calculated in step 5).
These targets represent the level of VOC and NO, emissions that must be achieved hi order
for a nonattainment area to demonstrate that the rate-of-progress requirement will be met. Once these
targets have been calculated, the overall emission levels should be compared to the area's attainment
demonstration to ensure that the rate-of-progress plan is consistent with the strategy selected for the
area's attainment demonstration.
4.3 Creditability of Pre-1996 VOC and NOX Reductions
Under section 182(c)(2)(B)(ii) of the Act, States can credit VOC emission reductions achieved
in the 1990-1996 period to the post-1996 rate-of-progress plan, if they are in excess of the 15 percent
VOC reductions (net of growth) required between 1990 and 1996. In addition, section 182(c)(2)(C)
of the Act provides for substitution of NOX emission reductions (net of growth) for required post-1996
VOC emission reductions. As discussed in the "General Preamble for the Implementation of Title I
of the Clean Air Act Amendments of 1^90," (57 FR 13517), this includes NOX reductions occurring
in the post-1990 period such as NOX reductions achieved as a result of the NOX RACT requirements
of the Act. Because some NOX RACT provisions may allow 30-day averaging, States will need to
convert emissions from any source subject to such rules to a typical summer day level of emissions.
29
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4.4 Example Calculation of Post-1996 VOC and NOT Target Levels
.This section presents a hypothetical example that describes target levels for 1999. Figures 5
and 6 show the calculation procedure for this example for VOC and NOX, respectively.
Calculation of 1999 Target Levels of Emissions
Developing the 1990 base year inventory and the 1990 rate-of-progress inventory are the first
two steps in calculating the post-1996 target levels. These inventories, which are briefly presented
below, were to have been submitted by the States hi their 15 percent rate-of-progress plans. The
EPA document entitled Guidance on the Adjusted Base Year Emissions Inventory and the 1996 Target
for the 15 Percent Rate-of-Progress Plans (see reference 1) describes these two inventories in more
detail.
Step 1: Develop the 1990 base year inventory (Ib/day)
VOC NOX
Point Sources - 1^300 ' 5,000
Area Sources 2,500 2,000
Mobile Sources 3,500 + 3,000
Biogenic Sources + 5,000 -
Total 12,000 10,000
Step 2: Develop 1990 rate-of-progress base year inventory (Ib/day)
VOC NOX
1990 base year inventory 12,000 10,000
Point Sources 3DU-1,000
Area Sources -500 -500
Mobile Sources -500 -700
Biogenic Sources -5,000
Total 57S0157,800
30
-------
FINAL BASE YEAR
C199CO
I NVENTORY*
12,000 Ib/day
SUBT
Q t nncM i re- f c
A
r
3ACT
1990
HATE-OF- PROGRESS
BASE YEAR
INVENTORY
5,800 Ib/day
r
^1990 ADJUSTED
1 NVENTORY CA
RELATIVE TO
CBEx}
5,200 Ib/
BASE YEAR
.CULATED
1999
day
by
rVOC=0.05
EMISSIONS REDUCTION
REQUIRED BETWEEN
1996 AND 1999
CBGr}
260 Ib/day
SUBTRACT
.,-. FMVCP/RVP REDUCTIONS
EMISSIONS OUTSIDE
NONATTAINMENT AREA C1,200 Ib/day}
BETWEEN 1990 AND 1999
C600 Ib/day}
TARGET LEVEL FOR
1996
CTLy}
4,000 Ib/day
TARGET LEVEL FOR
1999
CTLx} =
CTLy - BGr - FTx)
3,640 Ib/day
x = 1999
y = 1996
FLEET TURNOVER CORRECTION
CFTx} = a - b
100 Ib/day
a = 1990y FMVCP/RVP
REDUCTIONS C600 Ib/day}
b = 1990x FMVCP/RVP
REDUCTIONS £500 Ib/day}
* - Does not Include preenactment banked emissions reduction credits
Figure 5. Flowchart for hypothetical example 1999 rate-of-progress VOC calculations (with NO, substitution)
31
-------
FINAL BASE YEAR
C1990^
INVENTORY*
10.000 Ib/day
1990
RATE-OF-PROGRESS
BASE YEAR
INVENTORY
7,800 Ib/day
SUBTRACT
EM ISSIONS OUTS IDE
NONATTAINMENT
AREA
C2,200 Ib/day 3
1990 ADJUSTED BASE YEAR
INVENTORY CALCULATED
RELATIVE TO 1999
CBEx)
7,600 Ib/day
mult iply
by n=0.04
SUBTRACT
FMVCP/RVP REDUCTIONS
BETWEEN 1990 AND 1999
C200 Ib/day)
i
TARGET LEVEL FOR
1999
CA - C}
7,296 Ib/day
EMISSIONS REDUCTION
REQUIRED BETWEEN
1990 AND 1999
CBGrD
304 Ib/day
TOTAL EXPECTED REDUCTIONS
BY 1999
504 Ib/day
ADD
REDUCTIONS FROM:
FMVCP/RVP C200 Ib/dayD
* - Does not include preenactment banked emissions reduction credits
Figure 6. Flowchart for hypothetical example 1999 rate-of-progress NO, calculations
32
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Step 3: Calculate the 1990 adjusted base year inventory for 1999
The only adjustment that must be made to the rate-of-progress inventory is to calculate mobile
source emission reductions using MOBILESa. This adjustment is made by calculating a mobile
source emission factor for 1999, and multiplying the emission factor by 1990 VMT to. yield mobile
source emissions for the 1990 adjusted base year inventory. For this example, the State estimates that
there will be a reduction of 600 Ib/day of VOC due to fleet turnover up through 1999 and the RVP
limit specified for the nonattainment area in 55 FR 23666, and a NOX reduction of 200 Ib/day for the
FMVCP and RVP. The following is the adjusted base year inventory developed for the hypothetical
nonattainment area:
1990 adjusted VOC base year inventory
1990 adjusted NO^ base year inventory
1990 VOC rate-of-progress inventory
FMVCP/RVP reductions
5,800 Ib/day - 600 Ib/day
5,200 Ib/day.
1990 NOX rate-of-progress inventory -
FMVCP/RVP reductions
7,800 Ib/day - 200 Ib/day
7,600 Ib/day.
Step 4: Calculate required creditable reductions
For 1999, the total percentage required reduction is 9 percent (3 percent per year x 3 years).
In this example, VOC emission reductions will account for 5 percent of the reductions needed by
1999 and NOX reductions will account for the remaining 4 percent. This example assumes that these
percent reductions are consistent with the area's attainment demonstration. The required VOC and
NOT emission reductions from 1996 to 1999 are calculated as follows:
Percent NO* reduction
Percent VOC reduction
= n = 4%.
= rvoc = [0.03 * (x-y)] - n
= [0.03 * (1999-1996)] - 0.04 = 0.05 = 5%
Next, these percentage figures are multiplied by the adjusted base year inventories calculated
relative to the current milestone/attainment date to yield the required VOC and NOX emission
reductions.
33
-------
BGrtvoc BE^voc * rvoc
= 5,200 * 0.05 = 260 Ib/day
and
BGr.NOx = BE^o^n
= 7,600*0.04 = 3041b/day.
Severe and extreme nonattainment areas must also calculate the post-1996 rate-of-progress emission
reductions for each of their milestone/attainment dates.
Step 5: Calculate fleet turnover correction term
As noted previously, this terra is calculated differently for VOC and NOX for the 1999
example. For VOC, the fleet turnover correction term is the difference between the FMVCP/RVP
emission reductions calculated in step 3 and the previous milestone year's FMVCP/RVP emission
reductions. In this hypothetical example, the FMVCP/RVP reductions calculated relative to 1996 are
assumed to be 500 Ib/day of VOC. Therefore, the fleet turnover correction term for 1999 is 100
Ib/day of VOC (i.e., 600 Ib/day - 500 Ib/day). The NOX correction factor is the reductions from the
FMVCP and RVP. In this example, the FMVCP/RVP NOX reductions are 200 Ib/day.
Step 6: Calculate target level of emissions for 1999
To calculate the target level of emissions for VOC for 1999, the required emission reductions
calculated in step 4 and the fleet turnover correction term are subtracted from the 1996 milestone
target level. The 1996 target level was calculated to be 4,000 Ib/day in the EPA document Guidance
on the Adjusted Base Year Emissions Inventory and the 1996 Target for the 15 Percent Rate-of-
Progress Plan (see reference 1).
VOC target level = (1996 milestone target level) - (reductions calculated in step 4) - (fleet
turnover correction term)
= 1996 target level - (5,200 Ib/day * 0.05) - (600 Ib/day - 500 Ib/day)
= 4,000 Ib/day - 260 Ib/day -100 Ib/day
= 3,640 Ib/day.
The target for NOX is calculated by subtracting the sum of the NOX reduction required and
FMVCP/RVP reductions between 1990 and 1999 from the 1990 rate-of-progress inventory.
34
-------
NOX target level = (1990 NOX rate-of-progress inventory) - [(required reductions for 1999
calculated in step 4) + (FMVCP/RVP reductions)]
= 7,800 Ib/day - (7,600 Ib/day * 0.04) - (200 Ib/day)
= 7,296 Ib/day.
This area's plan must therefore demonstrate that the projected 1999 VOC inventory will be
less than or equal to 3,640 Ib/day and the projected 1999 NOX inventory will be less than or equal to
7,296 Ib/day.
34a
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5.0 CONTROL STRATEGIES
States will need to include control strategies in their post-1996 rate-of-progress plans to
demonstrate how emissions will be controlled to achieve their milestone target level(s) of emissions
and to demonstrate attainment of the ozone NAAQS by their attainment date. States may demonstrate
emission reductions by developing, adopting, and implementing Federally enforceable" control
measures for stationary and mobile sources or by documenting improvements in rule effectiveness
(RE). Existing and future Federal regulatory programs for VOC and NOX sources have been
discussed in detail in the following two documents:
Guidance for Growth Factors. Projections, and Control Strategies for the 15 Percent
Rate-of-Progress Plans (see reference 6).
Guidance on the Relationship Between the 15 Percent Rate-of-Progress Plans and
Other Provisions of the Clean Air Act (see reference 7).
5.1 Mandatory Requirements
This section identifies the specific measures required by the Act for each classification of
ozone nonattainment area. In addition, Table 2 lists the SIP submittal requirements for moderate and
above nonattainment areas in chronological order.
Serious Nonattainment Area Requirements
Under section 182(c) of the Act, serious nonattainment areas are subject to the control
measures required for moderate areas (i.e., RACT rule fix-ups, RACT catch-ups, I/M program
corrections, basic I/M, stage n vapor recovery) as well as the following additional control measures:
Enhanced I/M program.
A major stationary source cut-off for RACT of 50 tons per year (tpy) VOC or NOX.
Clean-fuel vehicle program in areas with a population greater than or equal to
250,000.
Emission offset ratio of 1.2:1.
Emission reductions associated with stage II vapor recovery, RACT catch-ups, basic I/M, and
the first three of the four control measures listed above are creditable toward the post-1996 VOC
emission reduction requirement to the extent that they occur between 1990 and 1999; represent
emission reductions that are real, permanent, and enforceable; and are not needed to meet the 15
percent rate-of-progress requirement. Due to uncertainties in projecting new source growth and
determining the level of emission reductions needed to offset minor source growth, EPA will not
allow States to take credit in their post-1996 rate-of-progress plan for projected emission reductions
resulting from emission offsets. However, any additional, actual, permanent, and enforceable
emission reductions from an offset that are not used to offset minor source growth will be creditable
in the milestone compliance demonstrations required for serious areas.
35
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TABLE 2. SIP SUBMITTAL REQUIREMENTS FOR MODERATE AND ABOVE OZONE
NONATTAINMENT AREAS
Nov. 15
1993
Nov. 15
Moderate and above ozone nonattainmerit areas must submit the following items for their 15 percent
rate-of-progress plans:
Final 1990 base year inventory for VOC, NO,, and CO.
1990 rate-of-progress base year inventory for VOC, NO,, and CO.
Initial 1990 adjusted base year inventory for VOC.
Documentation of how the 15 percent VOC reduction and 1996 target level of emissions
were calculated.
Growth factors for developing projected rate-of-progress and modeling inventories.
Doeumentation of Act mandated control measures and associated control efficiencies.
Moderate and above ozone nonattainment areas must submit:
New source review (NSR) rules for VOC and NO,.
VOC and NO, RACT rules (committal SIP acceptable for NO, for 1993 under certain
circumstances).
Stage n vapor recovery programs.
Requirements for emission statement program (major sources of VOC and NO,).
Serious and above ozone nonattainment areas must submit:
Enhanced I/M programs and begin implementation (committal SIP acceptable for 1993
implementation).
Optional clean fuel fleet substitute
Severe and extreme ozone nonattainment areas must submit:
Employer trip reduction programs.
Measures for reducing VMT.
Transportation control measures (TCM's).
Moderate ozone nonattainment areas not using the UAM must submit an attainment demonstration.
Moderate and above ozone nonattainment areas must submit their final 15 percent rate-of-progress plans
including:
Final 1996 projected emission inventory for VOC, NO, and CO.
Control measures that will achieve emission reductions needed to meet their 15 percent
VOC emission reduction requirement.
Contingency measures for failures to meet their 1996 target level of emissions or failure
to attain the ozone NAAQS.
36
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TABLE 2. SIP SUBMITTAL REQUIREMENTS FOR MODERATE AND ABOVE OZONE
NONATTAINMENT AREAS (Continued)
Serious ozone nonattainment areas with a population greater than or equal to 250,000, and all severe
and above ozone nonattainment areas must submit a clean fuel fleet vehicle program.
Moderate ozone nonattainment areas using UAM must submit an attainment demonstration.
- Serious and above ozone nonattainment areas must submit the following items for their post-1996 rate-
1990 adjusted VOC base year inventory calculated for each applicable milestone and
attainment year.
Projected inventory for applicable post-1996 milestone and attainment dates (e.g.,
projected 1999 inventory for serious ozone nonattainment areas) .
Documentation of how the 3 percent per year VOC emission reduction and target level
of emissions were calculated for each applicable milestone date.
Growth factors used in developing projected rate-of-progress and modeling inventories.
Final Technical Support Documentation (TSD) of mandated control measures and
associated control efficiencies, plus discretionary controls needed for attainment.
Serious and above ozone nonattainment areas and interstate moderate nonattainment areas must submit
an attainment demonstration based on UAM modeling, including control measures.
^A^":,:,
May 15
NOT. 15
1995
NOT. 15
', swe'*.:---;
NOT. 15
1997
Feb. 15
. 1998
NOT. 15
Serious c
and abov
Moderate
Serious a
of-progre
Serious a
an attaim
Moderate
emission
Attainme
an extens
Mileston
emission
Serious a
showing
Moderate
emission:
Moderate and above ozone nonattainment areas must submit a periodic inventory of VOC, NO,, and CO
Attainment date for moderate ozone nonattainment areas unless the area has requested and been granted
Milestone date for moderate and above ozone nonattainment areas to achieve the 15 percent VOC
Serious and above ozone nonattainment areas must submit a milestone compliance demonstration
showing compliance with the 15 percent VOC emission reduction requirement.
Moderate and above ozone nonattainment areas must submit periodic inventory of VOC, NO,, and CO
3
EPA is currently considering the possibility of requiring the submittal of this periodic inventory by November 15,1994.
EPA is currently considering the possibility of requiring the submittal of this periodic inventory by November 15, 1997.
37
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TABLE 2. SIP SUBMITTAL REQUIREMENTS FOR MODERATE AND ABOVE OZONE
NONATTAINMENT AREAS (Continued)
Attainment date for serious ozone nonattainment areas, unless the area has requested and been granted
Milestone date for serious, severe, and extreme ozone nonattainment areas to achieve the 3 percent per
year VOC emission reduction requirement.
Severe and extreme ozone nonattainment areas must submit a milestone compliance demonstration
showing compliance with the 3 percent per year VOC emission reduction requirement.
Serious and above ozone nonattainment areas must submit periodic inventory of VOC, NOX, and CO
*
Milestone date for severe and extreme ozone nonattainment areas to achieve the 3 percent per year VOC
Severe and extreme ozone nonattainment areas must submit a milestone compliance demonstration
showing compliance with the 3 percent per year VOC emission reduction requirement.
ffi$^:%
Nov. 15
H3;?:,.i>o|i;':r: %
Feb. 15
'. ".' ?$&:. /
Nov. 15
;:;:r|;;;J)02|::!43:
Nov. 15
A -l:^1-!. ;;"v
Feb. 15
;::- .;' .2004.. ':
Nov. 15
t^>fi&'-.ly
Nov. 15
2006
Feb. 15
2007 . :.
Nov. 15
Attainme
an extens
Milestone
year VCK
Severe ai
showing
Serious a
emission.
Milestone
emission
Severe ai
showing
Severe ai
emission.
Attainme
between
Milestone
emission
Severe o:
extreme <
complian
For sevei
Severe ai
emission:
Severe and extreme ozone nonattainment areas must submit periodic inventory of VOC, NO,, and CO
Attainment date for severe ozone nonattainment areas (except those with a 1986-1988 design value
between 0.190 and 0.280 ppm) unless the area has requested and been granted an extension.
Milestone date for severe and extreme ozone nonattainment areas to achieve the 3 percent per year VOC
Severe ozone nonattainment areas wife a 1986-1988 design value between 0.190 and 0.280 ppm and
extreme ozone nonattainment areas mast submit a milestone compliance demonstration showing
compliance with the 3 percent per year VOC emission reduction requirement.
For severe ozone nonattainment areas with a 1986-1988 design value between 0.190 and 0.280 ppm:
Milestone date.
Attainment date unless the area has requested and been granted an extension.
Severe and extreme ozone nonattainment areas must submit periodic inventory of VOC, NOI( and CO
EPA is currently considering the possibility of requiring the submittal of this periodic inventory by November 15, 2000.
EPA is currently considering the possibility of requiring the submittal of this periodic inventory by November 15, 2003.
-------
TABLE 2. SIP SUBM1TTAL REQUIREMENTS FOR MODERATE AND ABOVE OZONE
NONATTAINMENT AREAS (Continued)
Milestone date for extreme ozone nonattainment areas to achieve the 3 percent per year VOC emission
Extreme ozone nonattainment areas must submit a milestone compliance demonstration showing
compliance with the 3 percent per year VOC emission reduction requirement.
^''J3ti&A
Nov. 15
Kifl?«fe?*5
Feb. 15
'.; :": *&*'.***
Nov. 15
Milestom
. reduction
Extreme
complian
For extre
For extreme ozone nonattainment areas:
Milestone date.
Attainment date unless the area has requested and been granted an extension.
Submit periodic inventory for VOC, NO,, and CO emissions in 2008 7
EPA is currently considering the possibility of requiring the submittal of this periodic inventory by November 15, 2006.
7 EPA is currently considering the possibility of requiring the submittal of this periodic inventory by November 15, 2009.
39
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In addition, the Federally implemented program for reformulated gasoline is required in the
nine nonattainment areas with the highest ozone design values during the 1987-1989 period and
populations over 250,000. Emission reductions from the use of reformulated gasoline are also
creditable toward the post-1996 rate-of-progress plan.
Because certain measures are expected to require significant levels of effort to develop,
including large amounts of coordination between government agencies, States may have difficulty
adopting all control measures in their final form by the required 1994 rate-of-progress plan deadline.
The EPA will allow States to take credit for expected reductions from "long-term" measures in their
post-1996 rate-of-progress plans only if: backstop measures of at least equivalent reductions have
been adopted in the State's 1994 SIP, and such backstop measures will automatically go into effect if
the long-term measures are not ready in time for their projected implementation date. Further
discussion of long-term control measures is provided in section 5.7.
Severe Nonattainment Area Requirements
Under section 182(d) of the Act, severe nonattainment areas are subject to the control
measures required for serious areas (except for emission offset requirements) as well as the following
additional control measures.
Measures to offset VMT growth.
Employer trip reduction program.
A major stationary source cut-off for RACT of 25 tpy VOC or NOX.
Emission offset ratio of 1.3 to 1 (or 1.2 to 1 if the State's plan requires all existing
major sources hi the nonattainment area to use the best available control technology
for the control of VOC emissions).
As with serious nonattainment areas, EPA will not allow States with severe nonattainment areas to
take credit for projected emission reductions resulting from emission offsets hi their post-1996 rate-of-
progress plans. However, any additional, actual, permanent, and enforceable emission reductions
from an offset that are not used to offset minor source growth will be creditable in the milestone
compliance demonstrations required for severe areas (i.e., in 1999, 2002, and for severe areas with a
1986-1988 ozone design value of 0.190 ppm up to, but not including, 0.280 ppm, 2005). All other
post-1996 emission reductions that are real, permanent, and enforceable are creditable hi the post-
1996 rate-of-progress plan.
Extreme Nonattainment Area Requirements
Under section 182(e) of the Act, extreme ozone nonattainment areas are subject to the control
measures required for severe areas (except for emission offset requirements) as well as the following
additional control measures.
40
-------
» Clean fuels or advanced control technology for specified boilers.
A major stationary source cut-off for RACT of 10 tpy VOC or NOX.
Emission offset ratio of 1.5 to 1 (or 1.2 to 1 in the case where the State's plan
requires all existing major sources in the nonattainment area to use the best available
control technology to control VOC emissions).
As with severe nonattainment areas, EPA will not allow States with extreme nonattainment areas to
take credit in their post-1996 rate-of-progress plans for projected emission reductions resulting from
emission offsets. However, any additional, actual, permanent, and enforceable emission reductions
resulting from an offset that is not used to offset minor source growth will be creditable in the
milestone compliance demonstrations required for such areas (i.e., in 1999, 2002, 2005, and 2008).
All other post-1996 emission reductions that are real, permanent, and enforceable are creditable in the
post-1996 rate-of-progress plan.
5.2 Additional Control Measures
Reference 6 provides information with respect to stationary source controls including control
technique guideline (CTG) and alternative control technique (ACT) documents, new source
performance standards (NSPS), and national emission standards for hazardous air pollutants
(NESHAP). The appendices of Reference 6 also provide references for and summarize the
information contained in draft and final CTG and ACT documents, provide references for background
information documents developed to support the technical basis for NSPS and NESHAP, and present
other information sources that provide technical and cost information for alternative control
technologies for VOC and NOX source categories. Additionally, the State and Territorial Air
Pollution Program Administrators and Association of Local Air Pollution Control Officials
(STAPPA/ALAPCO) has developed a document titled Meeting the 15-Percent Rate-of-Progress
Requirement Under the Clean Air Act. September 1993, that contains a comprehensive catalogue of
control measures for VOC emission sources.
Sections 5.5 and 5.6 of Reference 6 discuss RE improvements and the quantification of RE
improvement programs, respectively. The criteria for determining creditable emission reductions
associated with RE improvements for the 15 percent VOC emission reduction requirement are also
applicable for determining the credibility of emission reductions toward the post-1996 emission
reduction requirement so long as emission reductions were not credited towards meeting the
15 percent VOC emission reduction requirement. State and local agencies should review the
information in Reference 6 for determining the credibility of emission reductions associated with RE
improvements in their post-1996 rate-of-progress plans. EPA has issued a new guideline on RE
improvements (see reference 8).
Motor vehicle controls can be classified into measures that reduce per vehicle emissions or
measures that reduce VMT, and thus overall emissions. The latter group of control measures are
commonly classified as TCM's. The Act mandates a mix of national and area-specific motor vehicle
control measures to reduce per vehicle emissions. National measures include the FMVCP and RVP
limits for gasoline. The FMVCP includes evaporative/running loss controls and tailpipe/extended
useful life standards. Area-specific measures include Stage II (service station vehicle refueling)
controls, clean fuel fleet programs, the California general clean fuels program, reformulated gasoline,
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and enhanced I/M. The TCM's attempt to decrease traffic congestion, especially during peak
commuting hours, by providing alternatives to single-occupant vehicle use. Note that if the TCM's
are not adopted measures a statement must be included in the plan that the State, local government, or
regional agency enters into a commitment (enforceable to the extent allowed under enforcement
provisions of the Act and applicable State law) to do the following: (a) implement and enforce the
plan elements for which the State, local government, or regional agency is responsible under the SIP;
(b) use, insofar as necessary, the resources identified in the SIP for carrying out those SIP elements;
and (c) on the schedule specified in the SIP, apply for resources and legislative authority that are not
yet available to the State, local government, or regional agency. The Office of Mobile Sources is
currently developing additional guidance which will provide more detail on including TCM's in a SIP
submittal.
Section 5 of Reference 6 provides an overview of all of these control measures and provides
references for further information on the control measures. Reference 6 also discusses EPA's plans
for controlling emissions from nonroad engines [e.g., heavy-duty nonroad (farm and construction)
equipment, recreational boats, small farm and garden equipment, railroad engines, and construction
equipment.]
It should be noted that the final post-1996 rate-of-progress plans must contain fully adopted
measures in the control strategy submitted by November 15, 1994. However, after the November 15,
1994 post-1996 rate-of-progress plan submittal date, a State may choose to revise its SIP to replace
existing control measures in its control strategy with newly promulgated Federal control measures.
Any control measures implemented in a nonattainment area that are the result of a pre-1990
Federal implementation plan are not creditable in the post-1996 rate-of-progress plan.
5.3 Emission Projections
States must include control measures in their post-1996 rate-of-progress plans to offset the
emissions growth projected to occur after 1996. States will therefore need to project their emission
inventories to estimate emissions growth for each milestone and attainment year. The projected
inventories must reflect expected growth in activity, as well as regulatory actions which will affect
emission levels. These projected inventories will be used to determine whether a control strategy is
adequate to meet the rate-of-progress and attainment demonstration requirements.
Projections of emissions require consideration of several factors:
Changes in activity at sources included in the base year inventory.
Changes in the number of controlled sources and the levels of control for sources
included in the base year inventory.
Changes in the level of effectiveness of control measures [(RE)].
Retirement of sources in the base year inventory.
Addition of new sources and their levels of control (where known).
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The EPA document entitled Guidance for Growth Factors. Projections and Control Strategies for the
15 Percent Rate-of- Progress Plan (see reference 6) provides guidance on how these concepts should
be incorporated in projecting emissions for rate-of-progress and attainment demonstration purposes.
The following provides additional details on the selection of appropriate growth factors for estimating
emissions growth.
Growth Factors
Emission projections for point sources can be based on information obtained directly from
facilities and/or permit applications; area and mobile source emission projections may be developed
from information from local planning agencies. The EPA suggests that under the following
circumstances, surveys of individual point sources be performed: (1) the industry is a dominant one in
the region; (2) the industry's growth may not be captured in regional projections; or (3) it is expected
that the industry will experience significant growth or decline in production (see reference 9). When
information on a specific facility is not available and there are survey data on growth trends for other
facilities in the same category, it may be possible to apply these trends to the facilities which were not
surveyed (see reference 10). When information is not available from plants, permit applications, or
local planning agencies, survey data can be extrapolated to all sources or forecasts. Source-specific
information on expected future emissions-producing activity is rare for point sources and not available
for area or mobile sources. In the absence of source-specific data, credible growth factors must be
developed from accurate forecasts of economic variables and the activities associated with the
variables.
When survey data are not available or it is not appropriate to extrapolate survey results to a
source, economic variables may be used to project activity. Economic variables that may be used as
indicators of activity growth are product output, value added, earnings, and employment. Product
output is a measure of physical units of output by an industry, value added is the difference between
the value of inputs to the production process and the values of the outputs of the process, earnings
data capture wage earnings in an industry, and employment measures the number of persons
employed in an industry. Emission projections guidance developed by EPA suggests that product
output is the best indicator of activity growth and that its use is "preferable to any of the (other)
indicators, if it is available" (see reference 3).
Economic data and models which provide acceptable growth factors for emission projections
include the Bureau of Economic Analysis (BEA) forecasts for States and metropolitan statistical areas
(MSA's); the Economic Growth Analysis System (E-GAS), which models economic growth and
estimates corresponding increases in emissions-producing activity; and the Emissions Preprocessor
System (EPS) for UAM, which produces spatially- and temporally-resolved emission inventories for
input to UAM.
BEA Data
If emissions growth estimates are not available from individual plants or other local sources,
use a surrogate growth indicator unless one of the previously stated circumstances exists. One EPA-
approved source of economic data for projecting stationary sources is the U.S. Department of
Commerce's BEA. Every 5 years, BEA publishes economic forecasts for MSA's, States, and regions
in hard copy and disk format. The most recent economic forecasts released by BEA are summarized
in the Bureau of Economic Analysis Regional Projections to 2040: Volumes I. II. and III (see
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references 11, 12, 13) which contain forecasts of personal income, earnings, and employment
data for the MSA's, States, regions, and the entire United States. The forecasts of interest for ozone -
modeling are the MSA- and State-level forecasts. The BEA economic forecast variables available for
MSA's and States are presented in Table 3. For these data to be used to project source classification
code (SCC)- and area source category code (ASC)-level activity, some type of matching, or
Crosswalk, between economic categories and point and area sources, must be used. The E-GAS
model and the EPS both contain Crosswalks. The EPS allows the user to enter BEA (or other)
forecasts and uses this information to develop projected emission inventories for use by UAM; E-GAS
develops economic growth factors internally and sends these factors to its Crosswalk, which produces
SCC- and ASC-level growth factors. These growth factors can be used in rate-of-progress
calculations or, with the addition of control measures, in UAM modeling.
As the information in Table 3 indicates, there is a trade-off between geographic and industrial
disaggregation in the BEA data. The state-level forecasts are disaggregated into 65 categories,
including over 20 industrial categories. The MSA-level forecasts are for 16 categories, and only
three general industrial categories: total manufacturing, durable goods manufacturing, and nondurable
goods manufacturing. The MSA-level data, however, are specific to each urban area and therefore
should provide a better estimate of expected activity in the UAM modeling domains.
Economic Growth Analysis System (E-GAS}
The EPA's Air and Energy Engineering Research Laboratory (AEERL) developed E-GAS as an
additional tool for use in projecting emission inventories. The E-GAS model provides activity growth
for each SCC for each serious and above ozone nonattainment area in the United States. In addition,
E-GAS provides SCC-level growth factors for multi-State moderate nonattainment areas, as well as
the attainment portion of each State in the continental United States. The outputs from E-GAS
provide one set of growth estimates that could be used by States for the 15 percent rate-of-progress
plans, the post-1996 rate-of-progress plans, and as inputs to UAM.
The E-GAS model comprises three linked tiers. The first tier contains a national economic model
developed by Regional Economic Models, Inc. (REMI) and national economic forecasts from the
U.S. Bureau of Labor Statistics and Wharton Econometrics Forecasting Associates. Outputs from the
first tier are used by the second tier, which houses REMI economic models of the multi-State
moderate and serious and above nonattainment areas, as well as the attainment portions of States.
The regional economic models produce forecasts of economic and demographic activity for each of
the modeled areas. These forecasts are input to the third tier of E-GAS, which includes energy
models for the residential, commercial, industrial, and utility sectors, as well as an industrial physical
output module and a VMT forecasting module.
Outputs from the third tier include forecasts of various measures of emissions-producing
activity including fossil fuel and electricity consumption, physical output for 210 sectors, and VMT.
These forecasts of emissions-producing activity are sent to the E-GAS Crosswalk where each SCC in
the aerometric information retrieval system (AIRS) is matched to the appropriate forecast. The
E-GAS model produces forecasts of value added and, for some of the major VOC-producing
categories, physical output.
Although the REMI models in E-GAS interact at the 1-digit SIC level, the models are able to
estimate economic activity for 3- and 4-digit SIC's for both urban areas and the surrounding States.
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TABLE 3. BEA PROJECTION CATEGORIES FOR METROPOLITAN STATISTICAL
AREAS (MSA'S) AND STATES
MSA's
Farm
Agricultural services, forestry, fisheries, and other
Mining
Construction
Manufacturing
Nondurable goods manufacturing
Durable goods manufacturing
Transportation and public utilities
Wholesale trade
Retail trade
Finance, insurance, and real estate
Services
Government and government enterprises
States
Farm
Agricultural services, forestry, fisheries, and other
Agricultural services, forestry, and fisheries
Other
Mining
Coal mining
Oil and gas extraction
Metal mining
Nonmetallic minerals, except fuels
Construction
Manufacturing
Nondurable goods manufacturing
Food and kindred products
Tobacco manufacturers
Textile mill products
Apparel and other finished textile products
Paper and allied products
Printing and publishing
Chemical and allied products
Petroleum and coal products
Rubber and miscellaneous plastic products
Leather and leather products
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TABLE 3. BEA PROJECTION CATEGORIES FOR METROPOLITAN STATISTICAL
AREAS (MSA's) AND STATES (continued)
States
Manufacturing
Durable goods manufacturing
Lumber and wood products (except furniture and fixtures)
Furniture and fixtures
Stone, clay, and glass products
Primary metal industries
Fabricated metal products
Machinery, except electrical
Electric and electronic equipment
Transportation equipment, except motor vehicles
Motor vehicles and equipment
Instruments and related products
Miscellaneous manufacturing
Transportation and public utilities
Railroad transportation
Trucking and warehousing
Local, suburban, and highway passenger transportation
Air transportation
Pipeline transportation
Transportation services
Water transportation
Communication
Electric, gas, and sanitary services
Wholesale trade
Retail trade
Finance, insurance, and real estate
Banking
Other credit and securities agencies
Insurance
Real estate and combination offices
Services
Hotels and other lodging places
Personal, business, and miscellaneous repair services
Automotive repair, services, and garages
Amusement and recreation services
Motion pictures
Private households
Health services
Private education services
Nonprofit organizations
Miscellaneous professional services
Government and government enterprises
Federal, civilian
Federal, military
State and local
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In addition, the REMI moueis are updated yearly, which allows the forecasts to be based on recent information
on the economic structure and activity of the U.S. and its regional .economies.
The EPA is not preferring or requiring the use of E-GAS. States are encouraged to
incorporate the most accurate growth factors available into their projected inventories. E-GAS is
another tool that can be used in this process. Documentation of the system was released in April
1993. (See references 14, 15.) Copies of the model software can be obtained from the Global
Emissions and Control Division of AEERL.
EPA's Emissions Preprocessor System (EPS)
While the BEA data and E-GAS are tools that assist in the development of projection factors, the
EPS is a tool that can be used to take those economic projections and calculate projection year
emissions. If a State uses a preprocessor system other than EPS, it should be documented in its SIP.
These projections can be for the post-1996 rate-df-progress requirement and also for the UAM
modeling required for the attainment demonstrations. In order to run the UAM, an emission
inventory which corresponds to a specific episode (defined by the day of the week, time of day, and
meteorological conditions) must be developed. This inventory must be disaggregated spatially,
temporally, and chemically as UAM develops estimates of ozone concentrations using hourly emission
data, by chemical species, for each grid cell in the modeling domain. The inventories required by the
Act include typical peak ozone day, county-level VOC, NOX, and carbon monoxide (CO) emissions
for 1990. The EPS serves to develop hourly emission rates from annual or daily emissions; emissions
by grid cell from county emissions; nitrogen oxide (NO) and nitrogen dioxide (NOj) emissions from
NOX inventories and speciated hydrocarbon emissions from VOC inventories. The EPS can be used
to develop these inventories for 1990 or, using forecasts of various economic indicators such as
population, VMT, and industrial sector activity, for a future year. Pre-1990 estimates can be
developed in a similar fashion using backcasts of these economic indicators.
Based on the population, VMT, and industrial activity forecasts, EPS can develop a gridded,
speciated, hourly emission inventory for a future episode for use by UAM. This inventory will
reflect expected growth in activity, but will not account for changes in emissions due to controls,
process changes, or other factors which would change the amount of emissions produced per unit
activity. These changes can be identified by the user and input to EPS to run control scenario
forecasts. These scenarios can be developed to examine potential or expected reductions in emissions
from specific SCC's or more general source categories (e.g., fuel combustion, degreasing, dry
cleaning, etc.).
5.4 Relationship Between the Post-1996 Rate-of-Progress Plans and Other Provisions of the
Act
Reference 7 summarizes the regulatory programs required by the Act for controlling VOC and
NOX emissions. This guidance document also provides guidelines on the types of emission reductions
that can be credited towards meeting the emission reduction requirements for the rate-of-progress
plans. The criteria for determining creditable emission reductions for the 15 percent VOC emission
reduction requirement are also applicable for determining the creditability of emission reductions
toward the post-1996 rate-of-progress plan requirements so long as emission reductions were not
credited towards meeting the 15 percent VOC emission reduction requirement. State and local
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agencies should review the information in Reference 7 for determining the creditability of emission
reductions in their post-1996 rate-of-progress plans.
Multiple Projection System (MPS)
The MPS is designed to facilitate the projection of future emissions of ozone precursors,
specifically CO, VOCs, and NOX, in any given geographic area. The MPS gives state/local air
agencies a computer system capable of performing "what if scenario analysis" and reporting the final
results (i.e., their rate-of-progress inventory) to EPA.
The system is capable of projecting emissions out to the year 2008 at intervals of 3 years. In
addition to projecting emissions, the system can make projections in the form of percent reduction
relative to base year emissions. The system is designed to accept input data from either the AIRS
Facility Subsystem (AFS) or the Area and Mobile Source Subsystem (AMS). Output from the system
is in the form of tables or graphs, which can be directed to the computer screen or to a printer.
Tabular results can also be output to an ASCII file, allowing the user to subsequently import the
reported information into other software for further analysis (either numeric or graphic). Data
contained in the output file can also be exported to Lotus 123, dBaselll, or Excel. As indicated
above, the principal output types are batch transactions in AIRS FS and AMS format.
As was stated earlier, the purpose of the MPS is to facilitate the projection of future emissions
of CO, VOC, and NOX. To this end, the interactive mode of the MPS was created with the following
basic capabilities:
: import emission data for 1990 and control efficiency, RE, rule penetration, and growth factor
data for 1990 and later years;
: import 1990 activity level data, projected growth factors, and projected emission factor data
for on-road mobile sources;
: accept user-specified criteria for selecting imported records;
: allow editing of imported control efficiency, RE, rule penetration, and growth factor data
prior to projection of future emissions;
: project future emissions for the selected records based on these data;
: export projected emission data as DBaselll, Lotus, and Excel files;
generate tabular reports of projected emissions out to the year 2008;
: generate graphs depicting projected emissions out to the year 2008; and
: generate batch transaction files of projected emission data for import into AFS or AMS.
Necessary input from the user to the MPS may be apparent from this list. The user must
provide files containing the 1990 emission data and the control efficiency, RE, rule penetration and
growth factor data for future years. The projected growth factor file is generated by the E-GAS.
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5.5 Economic Incentive Programs (EIP)
Section 182(g)(4)(B) of the Act requires EPA to promulgate rules for EIP's. A State with an
extreme ozone nonattainment area must submit an EIP when it fails to submit a milestone compliance
demonstration or to meet an applicable rate-of-progress milestone. Such programs are also identified
as an explicit option upon such failures in serious and severe ozone nonattainment areas.
Additionally, the Act explicitly allows the use of EIP's in the general SIP requirements [section
110(a)(2)], the general provisions for nonattainment area SIP's [section 172(c)(6)], and in the system
of regulations for controlling emissions from consumer or commercial products [section 183(e)(4)].
On February 23, 1993, EPA proposed a rule for implementing EIP's (58 FR 11110). The
proposed EIP rule serves as interim guidance for both mandated (statutory) and discretionary EIP's
and addresses some of the general issues associated with the design and implementation of EIP's.
Reference 7 presents EPA's interim guidance on the relationship between the 15 percent rate-of-
progress plans and EIP's. Because the discussion provided in reference 7 is also relevant to the post-
1996 plan, States should review the guidance provided in that document.
5.6 Contingency Measures
The Act requires that States with ozone nonattainment areas classified as moderate and above
include contingency measures in their SIP's [sections 172(c)(9) and 182(c)(9)]. The contingency
measures are the additional controls to be implemented in the event of a milestone or attainment
failure. Section 172(c)(9) of the Act specifies the general requirements for nonattainment area SIP's
to contain contingency measures that will take effect without further action by the State or EPA if an
area either fails to make reasonable further progress or fails to attain the NAAQS by the applicable
attainment date. Section 182(c)(9) requires SIP contingency measures for failure of serious and above
areas to meet milestones. Plans to meet the 1996 milestone date are required as part of the 15 percent
rate-of-progress submittal, due by November 15, 1993. Reference 6 presents background information
on the development of contingency measures for the 15 percent rate-of-progress plan, which is also
applicable to the post-1996 rate-or-progress plan.
All contingency measures must be fully adopted rules or measures but do not have to be
implemented unless and until they are triggered by a failure to either meet a milestone or attain the
NAAQS. EPA recognizes that many States are not accustomed to adopting rules that are not
implemented immediately so the triggering of measures to be implemented at a later date may be a
novel concept. The SIP should clearly state the trigger mechanisms, a schedule of the implementation
of the measures, and an indication that the measures will be implemented with no further action by
the State or EPA (e.g., a public hearing should take place before the SIP is submitted). Appendix B
discusses the milestone and attainment failure process. Additional information specific to the
development or implementation of contingency measures in the post-1996 timeframe is discussed
below.
If a moderate or above nonattainment area receives a 1-year or two 1-year extensions of its
attainment date, the contingency measures will not be required until the nonattainment area fails to
attain the new attainment date. If a milestone compliance demonstration is required for a
nonattainment area and the area fails to meet the milestone, then the contingency measures would be
required to be implemented even if the nonattainment area were receiving an attainment date
extension.
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For the post-1996 rate-of-progress plan, some areas will be able to meet the contingency
measures requirement by referencing the contingency measures identified in 15 percent rate-of-
progress plan. The policy for States to include NOX contingency measures hi their 15 percent rate-of-
progress plan that was due November 15, 1993 is outlined in "Guidance on Issues Related to the
15 Percent Rate-of-Progress Plans/' Memorandum from Michael H. Shapiro, Acting Assistant
Administrator for Air and Radiation to the Regional Division Directors, August 23, 1993.
Contingency measures for the post-1996 rate-of-progress plan must not be inconsistent with the area's
attainment demonstration. If a serious or above area fails to meet the 15 percent f equirement and
uses their contingency measures or a portion thereof, then the State can backfill those measures with
all VOC, NOX, or a combination of VOC and NOX measures based upon the modeling analysis in that
area. EPA finds this acceptable due to the fact that NOX substitution for the 3 percent per year VOC
reduction requirement is permitted for under the Act.
Additionally, areas that have implemented control measures from their overall SIP control -
strategy as a contingency measure or that have implemented any of their contingency measures listed
in their 15 percent rate-of-progress plan must develop new measures to backfill the contingency plan
and/or the control strategy. Within 1 year of the triggering of a contingency requiring the early
implementation of control measures, the State must submit a SIP revision containing whatever
additional provisions are needed to backfill the SIP to remedy any eventual shortfall that may occur as
the result of the early use of the control measures. The EPA expects any control measures that are
implemented early as part of a contingency plan will remain in place (or be superseded by
replacement control measures) until the next milestone. At the next milestone, the State can
demonstrate whether or not these control measures are needed to stay on track.
The EPA encourages the early implementation of required control measures and of
contingency measures as a means of guarding against failures to meet a milestone or to attain. Any
implemented measures (that are not needed for the rate-of-progress requirements or for the attainment
demonstration) would need to be backfilled only to the extent they are used to meet a milestone. For
purposes of an attainment failure, it would be impractical to require States to backfill the contingency
measures when they have already fulfilled the contingency measure requirement for their
classification. The State would be required to adopt new contingency measures as part of the process
of developing their new SIP for their new classification. See "Early Implementation of Contingency
Measures for Ozone and Carbon Monoxide (CO) Nonattainment Areas," Memorandum from
G.T. Helms, Chief, Ozone/Carbon Monoxide Programs Branch, August 13, 1993.
For milestone failures, EPA only requires that contingency measures be implemented to
compensate for the degree of failure. For example, a shortfall of 2 percent requires implementation
of sufficient measures to make up for the 2 percent, and does not require that all contingency
measures be implemented. General information on milestone and attainment failures is contained in
Appendix B of this document. Additional information on the milestone compliance demonstration
submittals and implications will be provided in a forthcoming rulemaking to be proposed in the spring
of 1994. For an attainment failure, EPA will require that all contingency measures in the SIP be
implemented.
States could adopt measures that are required for the next higher classification to fulfill their
contingency measure requirement. The cutpoints for stationary or area sources could also be lowered
for already-adopted measures in the control strategy. States should be aware that any rule or measure
that meets the creditability requirements of section 182(b)(l)(C) and (D), that would achieve real,
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permanent, enforceable reductions, and that is not already required, can be adopted as a contingency
measure. In addition, please refer to "Clarification of Issues Regarding the Contingency Measures
that are due November 15, 1993 for Moderate and Above Ozone Nonattainment Areas,"
Memorandum from D. Kent Berry, Acting director, Air Quality Management Division,
November 8, 1993, for more information.
5.7 Long-Term Control Measures
It is anticipated that some serious and above ozone nonattainment areas will need significantly
large emission reductions to achieve attainment by their attainment date. The EPA recognizes that it
may be an unreasonable burden for such areas to identify, develop, and adopt hi final form all of the
control measures needed to demonstrate attainment in their post-1996 rate-of-progress plans, which
must be submitted to EPA by November 15, 1994. The General Preamble for the Implementation of
Title I of the Clean Air Act Amendments of 1990 (57 FR 13498) sets forth the requirements for the
areas that may need additional time to fully develop and adopt certain "long-term" control measures
that would be the preferred method to achieve attainment. The long-term control measures would
include those that require complex analyses, decision making, and coordination among a number of
governmental agencies. It is important to note that no measure that is specifically required by the Act
(e.g., NOX RACT controls) can be considered a "long-term" control measure.
The EPA intends to allow such areas reasonable time to complete full development and
adoption of long-term control measures under the following conditions:
The portion of the post-1996 rate-of-progress plan that contains the demonstration of
attainment must identify each control measure for which additional time would be
needed for full development and adoption.
The plan must show that the long-term control measures cannot be fully developed
and adopted by the submittal date for the attainment demonstration,
The plan must contain an enforceable commitment (i.e., a commitment that has been
subjected to hearing as part of the SIP) by the relevant agency that development and
adoption will occur on an expeditious schedule to achieve specified emission
reductions from each long-term control measure for each year through the attainment
year.
The plan must contain a "backstop" control measure for each long-term control
measure that would be implemented to achieve equivalent emission reductions unless
the long-term control measure is adopted and implemented on schedule.
The long-term control measures must not be needed to meet any emission reduction
requirements during the first 6 years after enactment (i.e., from November 15, 1990
through November 15, 1996).
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States must have enabling legislation adopted by November 15, 1994 that provides
States with the authority to adopt any measures under consideration for the post-1996
rate-of-progress plan.
The backstop control measures must be fully adopted and included in the post-1996 rate-of-
progress plan submittal and are in addition to the contingency measures that are required to address
milestone and attainment failure. The backstop control measures must be designed to go into effect
automatically on a schedule (which should be defined in the SIP submittal) sufficient to achieve all of
the emission reductions associated with each long-term control measure for each year through the
attainment year. The backstop control measures may represent broad, across-the-board emission
reductions rather than thoroughly analyzed and developed control measures. For example, a declining
emission cap (e.g., Ibs/day, tpy) for all stationary sources above a certain size could be an appropriate
backstop control measure.
Several States have expressed concern about the backstop measure requirement. However,
EPA's legal counsel has advised that the only remedy to allow a State to include long-term measures
in their post-1996 rate-of-progress plan is to require the backstop measures. The requirement for
backstop control measures is set forth in the General Preamble for the Implementation of Title I of the
Clean Air Act Amendments of 1990 (57 FR 13498). The rationale for this requirement is that the
wording in the Act requires that States submit SIP measures to achieve emission targets and
attainment within a certain timeframe. The adoption of backstop control measures helps to ensure
that these will be achieved.
When each long-term control measure is fully developed and adopted, it must be submitted to
EPA as a SIP revision. The revision would also propose deletion of the corresponding backstop
control measure. The EPA's approval of each long-term control measure would also rescind each
corresponding backstop control measure from the SIP. For this reason, EPA does not anticipate the
actual implementation of backstop control measures in most cases because States will have ample
opportunity to submit SIP revisions to incorporate fully developed and adopted long-term control
measures and to delete the backstop control measures from the SIP. In addition, if a long-term
control measure cannot be developed, then a State has the option of submitting a SIP revision to add a
fully developed and adopted alternative control measure to replace the original long-term control
measure prior to any necessary implementation of a backstop control measure.
Thus, a State may find that progress can be achieved with control measures that are fully
developed, adopted, and included in its post-1996 rate-or-progress plan by November 15, 1994.
However, the State may determine that expeditious attainment of the NAAQS is impossible unless its
SIP also includes control measures which cannot be fully developed until after the November 15,
1994 submittal deadline. In its post-1996 rate-of-progress plan submittal, the State must clearly
describe each of the long-term control measures and show that each measure cannot be fully
developed and adopted until a specified future date, despite expeditious implementation efforts. The
post-1996 rate-of-progress plan must include with each long-term control measure an enforceable
schedule binding responsible agencies to achieve the identified emission reductions associated with
implementation of each long-term control measure. Please note that the intention of long-term control
measures are for aiding in attaining the NAAQS. EPA realizes, however, that in some circumstances
long-term measures may be needed for the rate-of-progress requirements as well. Therefore, these
measures (if all above requirements are followed) are creditable to the post-1996 rate-of-progress plan
requirements as long as the appropriate amount of reductions are achieved by the milestone date.
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5.8 New Technologies for Extreme Ozone Nonattainment Areas
In addition to the long-term measures option discussed in section 5.7 above, section 182(e)(5)
of the Act permits the EPA to approve SIP's and attainment demonstrations for extreme ozone
nonattainment areas which include control measures that anticipate the development of new control
techniques or the improvement of existing technologies. In order to receive EPA approval, the State
cannot use such measures to achieve the necessary emission reductions required during the 1990-2000
period and the State must submit enforceable commitments to develop and adopt contingency
measures in case the anticipated technologies either were not developed or do not achieve the planned
reductions. These contingency measures must be submitted to EPA no later than 3 years before the
proposed implementation of the new technology measures, and must be approved by EPA in
accordance with the requirements of section 110 of the Act. These contingency measures are in
addition to the contingency measures required for the post-1996 rate-of-progress plan.
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6.0 POST-1996 RATE-OF-PROGRESS PLAN AND ATTAINMENT DEMONSTRATION
SUBMITTALS AND DOCUMENTATION
6.1 Post-1996 Rate-of-Progress and Attainment Demonstration Requirements
This section identifies the information and documentation that must be included in the
November 15, 1994 rate-of-progress and attainment demonstration submittal. It also includes
suggested formats for these submittals. The November 15, 1994 SIP submittals must include the
following elements and documentation:
1990 adjusted base year inventory(ies).8
-9
VOC (and NOX, where applicable) target level(s) for each milestone year and
supporting calculations.
Growth factors for developing projected rate-of-progress and attainment modeling
inventories.
Control measures and their associated control efficiencies.
Projected milestone and attainment year inventories reflecting the adopted control
strategy.
Fully adopted post-1996 rate-of-progress plan, including attainment demonstration and
any control measures needed to meet rate-of-progress or attainment demonstration
requirements.9
Modeling Documentation (see reference 4).
1990 Adjusted Base Year Inventory
Documentation of the adjusted base year inventory for each milestone year will take two
distinct forms. The written documentation must include the expected emission reductions from the
FMVCP and RVP program, as well as both actual 1990 motor vehicle emissions using 1990 VMT
and MOBILESa emission factors, and the adjusted emissions using 1990 VMT and the MOBILESa
emission factors calculated for each milestone/attainment year with the appropriate RVP for the
8 Both the 1990 base year inventory and 1990 rate-of-progress base year inventories were
calculated for the 15 percent rate-of-progress plan. If any adjustments are made to these inventories
since they were submitted for the 15 percent plan, then these revised inventories will need to be
submitted as part of the post-1996 rate-of-progress plan, with a full explanation of the changes and
why they were made. If no changes were made, then the State should reference the previous
inventories in the post-1996 rate-of-progress plan.
9 See CFR Part 51.281 on adopted measures. See section 5.2 of this document for information
on using TCM's that are not adopted measures for the rate-of-progress plan.
55
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nonattainment area as mandated by EPA. States must provide EPA with the inputs to the MOBILESa
model used in calculating the expected emission reductions from the FMVCP and RVP program.
For purposes of the AIRS Area and Mobile Source Subsystem (AMS) adjusted base year
submittal, States must provide the RVP inputs as required under the Act for the nonattainment area,
and run the MOBILESa model for 1999 and each subsequent milestone/attainment year vehicle mix
(e.g., extreme areas run the model for 1999, 2002, 2005, 2008, and 2010). Because the calculation
of the FMVCP and RVP program emission reductions requires separate runs of the MOBILESa
model, States will not submit the emission reductions from these programs directly into AIRS.
Other requirements for documentation and submittal of the adjusted base year inventory to
AIRS are the same as those for the 1990 base year inventory. Requirements and guidance for
documentation of the base year inventory are presented in Emission Inventory Requirements for
Ozone State Implementation Plans (see reference 16), and Example Documentation Report for 1990
Base Year Ozone and Carbon Monoxide State Implementation Plan Emission Inventories (see
reference 17.) States should realize that there will be no submittal of an "adjusted" point-source
inventory for the AIRS facility subsystem (AFS) because point-source emissions are not altered in the
calculation of the adjusted inventory from the rate-of-progress base year inventory. The point-source
emissions for both the rate-of-progress and adjusted base year inventories can, therefore, be directly
retrieved from the 1990 base year inventory. Stationary area-source emissions are not altered either.
All adjustments apply to mobile source emissions. Base year and adjusted base year point source
emissions are different because the base year inventory includes sources located outside of the
nonattainment area boundaries. The AIRS has a flag to indicate which sources are within the
designated nonattainment area boundaries and, therefore, can separate the point source emissions to
develop these two different inventories.
Target Level (s) of Emissions
The target level(s) of emissions for each milestone and attainment year is the maximum
amount of anthropogenic emissions within the nonattainment area that are permitted to occur in that
year in order to comply with the rate-of-progress requirements. The EPA expects the States to
document the target emission level(s) as well as the calculations made in determining the target
level(s).
Control Measure and Growth Factor Information
Documentation for all of the control measures and their associated control efficiencies and RE
factors for both the post-1996 rate-of-progress plan and the attainment demonstration must be
submitted. See Table 1 in the EPA document entitled Guidance on the Adjusted Base Year Emissions
Inventory and the 1996 Target for the 15 Percent Rate-of-Progress Plans (see reference 1) for a
suggested computerized format. Table I also provides an example of growth factor documentation.
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The control measure information consists primarily of a list of control measures and
associated control efficiencies on a computer diskette file formatted as discussed above. For control
measures that will be applied during modeling of attainment, control information must be reported for
the entire modeling domain unless measures are specifically limited to the nonattainment area.
Supplied control information for attainment year strategies will be used as input to the upcoming
regional oxidant modeling (ROM) exercises to improve consistency between ROM and IT AM results.
Also included should be the rule penetration (percentage of rule coverage) associated with new
area-source control measures and any expected changes in RE for point or area sources. In addition
to the data on spreadsheet, paper documentation should be provided describing the control measures,
their implementation dates, assumptions made, and any further explanation needed for the information
listed on the spreadsheet.
Milestone Year Projected Inventories
«
The milestone year projected inventories should reflect the adopted control strategy. All of
the assumptions used to calculate these inventories (e.g., growth factors, control efficiencies) must be
documented.
6.2 Multi-State Submittal Information
The officials in each State that are formally delegated the authority to submit SIP revisions to
EPA should send, as part of their post-1996 rate-of-progress plan, a letter to the.appropriate EPA
Regional Administrators) stating that each State in the multi-State nonattainment area is submitting a
multi-State post-1996 rate-of-progress plan. The letter should include the calculation of the original
target for each State, percent reduction required for each State, and the new target level to achieve the
total 3 percent per year YOG/NO^ emission reductions required for the nonattainment area. The
original targets are calculated assuming that each State will meet the 3 percent per year requirement
on its own. The sum of. the new targets must equal the sum of the original targets.
Each State will be responsible for adopting and implementing control measures to meet its
new target. No State will be responsible for the failure of another State meeting their target.
6.3 Mid-Course Corrections
The EPA recognizes that there are some uncertainties associated with the tools used to
generate base year and projected emission inventories and to model the relationship between future
VOC and NOX emissions and ozone air quality. It is expected that, over the next few years,
additional experience in running the current version of UAM and improved air quality monitoring
systems will be available. In addition, anticipated improvements in emission inventory preparation
methodologies will result in improved input to UAM.
For these reasons, States are encouraged to consider making mid-course corrections to their
attainment demonstrations and rate-of-progress plans around 1997. This will allow States to take
advantage of improved modeling techniques, air quality monitoring systems and emission inventories
to refine their attainment strategies.
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6.4 Suggested Submittal Tables
The following tables are the suggested submittal forms for a summary of the post-1996 rate-
of-progress plan and the attainment demonstration. Table 5 is the recommended format for control
strategy submittal. Table 6 contains information for all of the controls needed for the attainment
demonstration. Table 7 suggests a format for the contingency measure submittal. Table 8 provides a
format for explaining RE improvement measures. Tables 9 and 10 recommend a format for giving
further details on all of the stationary source control measures.
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TABLE 5. SUGGESTED FORMAT FOR POST-1996 RATE-OF-PROGRESS CONTROL
STRATEGY SUMMARY SUBMITTAL
Control Measure
STATIONARY SOURCE CONTROLS:
TOTAL STATIONARY
MOBILE SOURCE CONTROLS:
TOTAL MOBILE:
TOTAL
Creditable/
Noncreditable
Noncreditable"
Creditable"1
Creditable"
Implementation
Date
Expected VOC
Emissions
Reductions
(Ib/day)
Expected NO,
Emissions
Reductions
Ob/day)
15
17
All noncreditable mobile source measures should be listed individually but may be calculated
in a single MOBILESa run.
All creditable mobile source measures that are calculated through MOBILESa should be listed
individually but may be calculated in a single run.
Emission reductions from mobile source measures that are not calculated in MOBILESa
should be calculated and listed individually.
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TABLE 6. SUGGESTED FORMAT FOR ATTAINMENT CONTROL STRATEGY
SUMMARY SUBMTTTAL
Expected VOC Expected NO,
T , Emissions Emissions
Implementation _ _ ,
Reductions Reductions
Control Measure * (Ib/day) (Ib/day)
STATIONARY SOURCE CONTROLS:
TOTAL STATIONARY
MOBILE SOURCE CONTROLS:
TOTAL MOBILE:
TOTAL
60
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TABLE 7. SUGGESTED FORMAT FOR CONTINGENCY MEASURE SUBMTTTAL
1990 VOC adjusted base year inventory: 5.200 Ib/day
1990 NOX adjusted base year inventory: 7.600 Ib/day
IMPLEMENTATION
ORDER
1
2
3
DESCRIPTION OF
CONTROL MEASURE
Automobile emission tax
NOX RACT w/ lower major
stationary source cutoff (25
tpy for serious area)
Stage II vapor recovery for
boats
TOTAL
EXPECTED
VOC
EMISSION
REDUCTION
(Ib/day)
80
25
105
EXPECTED
NOX
EMISSION
REDUCTION
(Ib/day)
105
30
135
EMISSION
REDUCTION
ASA
PERCENTAGE
OF 1990 VOC
ADJUSTED
BASE YEAR
INVENTORY
1.54
0.48
2.02
EMISSION
REDUCTION
ASA
PERCENTAGE
OF 1990 NOX
ADJUSTED
BASE YEAR
INVENTORY
1.38
0.39
1.77
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TABLE 8. SUGGESTED FORMAT FOR SUBMTTTAL OF RULE EFFECTIVENESS (RE)
IMPROVEMENT MEASURES
RE
IMPROVEMENT
MEASURE
1990
RE
(percent)
NEW
RE
(percent)
IMPLEMENTATION
DATE
TOTAL:
EXPECTED
EMISSIONS
REDUCTIONS
(Ib/day)
TABLE 9. SUGGESTED FORMAT FOR SUBMITTAL OF STATIONARY SOURCE
CONTROL MEASURES FOR THE POST-1996 RATE-OF-PROGRESS PLAN
CONTROL
MEASURE
IMPLEMENTATION
DATE
1990
CONTROL
EFFICIENCY
(percent)
NEW
CONTROL
EFFICIENCY
(percent)
TOTAL:
EXPECTED
EMISSIONS
REDUCTIONS
Ob/day)
TABLE 10. SUGGESTED FORMAT FOR SUBMITTAL OF STATIONARY SOURCE
CONTROL MEASURES FOR THE ATTAINMENT DEMONSTRATION
CONTROL
MEASURE
IMPLEMENTATION
DATE
1990
CONTROL
EFFICIENCY
(percent)
NEW
CONTROL
EFFICIENCY
(percent)
TOTAL:
EXPECTED
EMISSIONS
REDUCTIONS
(Ib/day)
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REFERENCES
1. Guidance on the Adjusted Base Year Emissions Inventory and the 1996 Target for the 15
Percent Rate-of-Progress Plans. EPA-452/R-92-005, U.S. Environmental Protection Agency,
OAQPS, Research Triangle Park, NC. October 1992.
2. User's Guide for the Urban Airshed Model. EPA-450/4-90-007 A-C, D(R), E-F, U.S.
Environmental Protection Agency, OAQPS, Research Triangle Park, NC. 1990.
3. Guideline for Regulatory Application of the Urban Airshed Model. EPA-450/4-91-01, U.S.
Environmental Protection Agency, OAQPS, Research Triangle Park, NC. 1991.
4. Guidance on Urban Airshed Model (UAM) Reporting Requirements for Attainment
Demonstration. EPA-454/R-93-056, U.S. Environmental Protection Agency, OAQPS,
Research Triangle Park, NC. January 1994.
5. Criteria for Assessing the Role of Transported Ozone/Precursors in Ozone Nonattainment
Areas. EPA-450/4-91-015, U.S. Environmental Protection Agency, OAQPS, Research
Triangle Park, NC. May 1991.
6. Guidance for Growth Factors. Projections, and Control Strategies for the 15 Percent Rate-of-
Progress Plans. EPA-452/R-93-007. U.S. Environmental Protection Agency, OAQPS,
Research Triangle Park, NC. March 1993.
7. Guidance on the Relationship Between the 15 Percent Rate-of-Progress Plans and Other
Provisions of the Clean Air Act. EPA-452/R-93-007, U.S. Environmental Protection Agency,
OAQPS, Research Triangle Park, NC. May 1993.
8. Rule' Effectiveness Guidance: Integration of Inventory. Compliance, and Assessment
Applications. EPA-454/4-94-001, U.S. Environmental Protection Agency, OAQPS, Research
Triangle Park, NC. January 1994.
9. Procedures for Preparing Emissions Projections. EPA-450/4-91-019, U.S. Environmental
Protection Agency, OAQPS, Research Triangle Park, NC. July 1991.
10. Procedures for the Preparation of Emission Inventories for Carbon Monoxide and Precursors
of Ozone. Volume II: Emission Inventory Requirements for Photochemical Air Quality
Simulation Models. EPA-450/4-91-014, U.S. Environmental Protection Agency, OAQPS,
Research Triangle Park, NC. May 1991.
11. BEA Regional Projections to 2040. Volume I: States. U.S. Department of Commerce,
Bureau of Economic Analysis, Washington, DC, U.S. Government Printing Office. October
1990.
12. BEA Regional Projections to 2040. Volume II: Metropolitan Statistical Areas. U.S.
Department of Commerce, Bureau of Economic Analysis, Washington, DC, U.S. Government
Printing Office. October 1990.
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13. BEA Regional Projections to 2040. Volume III: BEA Economic Areas. U.S. Department of
Commerce, Bureau of Economic Analysis, Washington, DC, U.S. Government Printing
Office. October 1990.
14. Economic Growth Analysis System: Reference Manual. EPA-600/R-93-067a, U.S.
Environmental Protection Agency, Office of Research and Development, Washington, DC.
April 1993.
15. Economic Growth Analysis System: User's Guide. EPA-600/R-93-067b, U.S. Environmental
Protection Agency, Office of Research and Development, Washington, DC. April 1993.
16. Emission Inventory Requirements for Ozone State Implementation Plans. EPA-450/4-91-010,
U.S. Environmental Protection Agency, OAQPS, Research Triangle Park, NC. March 1991.
17. Example Documentation Report for 1990 Base Year Ozone and Carbon Monoxide State
Implementation Plan Emission Inventories. EPA 450/4-92-007, U.S. Environmental
Protection Agency, OAQPS, Research Triangle Park, NC. March 1992.
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APPENDIX A: DEFINITIONS OF TERMS
This appendix provides the specific definitions of EPA terms that are used in this guidance
document. Different EPA programs sometimes use different definitions of the same term (e.g., major
source). The following definitions are presented for the purposes of this guidance document only; the
reader is advised to refer to specific regulations, policies, and sections of the Act to obtain complete
definitions for the program or title of interest.
The following terms are defined in Appendix A of the EPA document entitled Guidance for
Growth Factors. Projections, and Control Strategies for the 15 Percent Rate-of-Progress Plans (see
reference 6):
Area Source.
Attainment Demonstration.
Attainment Determination.
Basic Inspection and Maintenance.
Major Stationary Source.
Milestone Compliance Demonstration.
1990 Adjusted Base Year Inventory.
1990 Base Year Inventory.
1990 Rate-of-Progress Base Year Inventory.
1996 Target Level of Emissions.
Peak Ozone Season.
Point Source.
Post-1996 Rate-of-Progress Plan.
RACT "Catch-ups."
RACT "Fix-ups."
Rate-of-Progress Plan.
Rule Effectiveness.
Volatile Organic Compound.
The following terms are defined in Appendix A of the EPA document entitled Guidance on
the Relationship Between the 15 Percent Rate-of-Progress Plans and Other Provisions of the Clean Air
Act (see reference 7):
Reclassification.
Reformulated Gasoline.
Reid Vapor Pressure.
Stage II.
Transportation Control Measures.
Backstop Measure Fully adopted control measure that achieves an annual emission reduction
equivalent to those that would be achieved by the implementation of long-term control measures.
Economic Growth Analysis System (E-GAS) An EPA model for projecting emissions growth based
on value-added and physical output data.
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Economic Incentive Program A program which may include State established emission fees or a
system of marketable permits, or a system of State fees based on the sale or manufacture of products
the use of which contributes to ozone formation, or any combination of the foregoing or other similar
measures, as well as incentives and requirements to reduce vehicle emissions and VMT in an area.
Emissions Preprocessor System (EPS) An EPA model for developing hourly emission rates from
annual emissions, emissions by grid cell from county emissions, NO and NO2 emissions from NOX
inventories, and speciated hydrocarbon emissions from VOC inventories.
Fleet Turnover Correction An adjustment made to the adjusted base year inventory in calculating the
target level of emissions. This adjustment is computed for each milestone and attainment year to
reflect the emission reductions associated with the pre-1990 FMVCP and RVP program as defined in
55 FR 23666, June 11, 1990.
Long-Term Control Measure A measure for controlling VOC and/or NOX emissions that requires
more time to develop and adopt than provided by the deadline for submittal of the post-1996 rate-of-
progress plans (i.e., November 15, 1994). Each long-term measure requires a "backstop" control
measure that will achieve equivalent emission reductions unless the long-term control measure is
adopted and implemented on schedule.
New Technologies Control measures for extreme ozone nonattainment areas based on the
development of new control techniques or the improvement of existing technologies for controlling
VOC and/or NOX emissions that require more time to develop than provided by the deadline for
submittal of the post-1996 rate-of-progress plans (i.e., by November 15, 1994).
Projected Milestone Inventory An inventory of projected emissions that includes the effect of future
control measures. A nonattainment area computes this inventory in its post-1996 rate-of-progress plan
for each target year.
Target Year A year in which a nonattainment area must recalculate its adjusted base year inventory
for the post-1996 rate-of-progress plan (e.g., target years for extreme areas are 1999, 2002, 2005,
2008, and 2010).
Target Level of Emissions The maximum amount of emissions that a nonattainment area can emit for
a given target year while complying with the post-1996 rate-of-progress plan requirements.
Urban Airshed Model (DAM) An EPA-approved photochemical grid model for use in developing
attainment demonstrations for nonattainment areas.
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APPENDIX B: GENERAL IMPLICATIONS OF MILESTONE AND ATTAINMENT
FAILURES
This appendix provides an overview of the implications of post-1996 milestone and attainment
failures for serious, severe, and extreme ozone nonattainment areas. The specific requirements for
milestone demonstrations and the consequences of failure to meet a milestone will be addressed in
future rulemaking. Marginal and moderate ozone nonattainment areas are not discussed since they are
required to attain by 1993 and 1996, respectively.18 However, in the event that a moderate area
does not attain by 1996, it may be reclassified to serious nonattainment status, and will be subject to
the requirements for this higher classification. These requirements include the development of a plan
to achieve the 1999 milestone emission reductions required for serious and above ozone nonattainment
areas.
Serious Areas
Milestone Failures
Serious areas are required to demonstrate one milestone, the 1990-1996 15 percent VOC
emission reduction requirement unless they apply for and receive at least one of the two available 1-
year attainment date extensions under section 181(a)(5). Plans for this reduction must be outlined in
the rate-of-progress plan, due by November 15, 1993. Serious areas must submit a milestone
compliance demonstration within 90 days after the milestone date (i.e., by February 15, 1997). EPA
will determine within 90 days whether or not the demonstration was adequate. If not, section
182(c)(9) requires that contingency measures go into effect automatically. In addition, States are
required to elect one of three additional measures to implement if these contingency measures are not
adequate to correct the failure. The elective options are:
Bumping up to the next higher classification.
Implementing additional contingency measures.
Adopting an EIP that meets the requirements of section 182(g)(4).
This election must occur within 90 days of the milestone failure determination by EPA. If the
State fails to make the election within the 90 days or 6 months thereafter, the area will be reclassified
to the next higher classification by operation of law. Within 12 months after the date by which the
State is required to elect an option, the State must submit a SIP revision that corrects the failure. The
EPA has 9 months after the submittal date to review and approve or disapprove the revised SIP.
Because the timeframe involved in making a State election, revising the SIP to reflect the election,
and EPA approval of the SIP revision may take as long as 2.5 years, States with serious areas are
strongly encouraged to implement control measures as soon as a milestone failure is deemed likely.
18 Appendix H of the document entitled Guidance for Growth Factors. Projections, and Control
Strategies for the 15 Percent Rate-of-Progress Plan. EPA-452/R-93-002, March 1993, describes the
attainment failure implications for marginal and moderate areas.
B-l
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area must implement contingency measures required under section 172(c)(9) and individual sources
must pay the fees authorized by section 185.
"Bump-up" refers to the reclassification process that a marginal, moderate, or serious area
automatically undergoes if it fails to attain the NAAQS. The term bump-up also applies to optional
reclassification of a serious or severe nonattainment area as a result of milestone failure. Serious and
severe nonattainment areas that fail to meet a milestone are required to make an election, under
section 182(g)(3) of the Act, from three given measures identified on page B-l. One explicit option
is reclassification of the area to the next higher classification.
Upon bump-up, the attainment date specified for the higher classification applies to the area
that has been bumped-up. Section 182(i) of the Act allows EPA to establish due dates for the
required submittals associated with the new classification, but does not allow EPA to adjust the
attainment date. An early voluntary bump-up will allow the State more flexibility and time in
planning for and achieving the new requirements of the higher classification. Since failure to submit
approvable SIP revisions can result in sanctions or Federal implementation plan (FIP) measures, it
will be in the best interests of areas to attempt to assess whether attainment is improbable as soon as
possible.
Attainment Date Extensions
If a moderate or above nonattainment area receives a 1-year extension or two 1-year
extensions of their attainment date, no additional rate-of-progress requirements are required during the
tune of the extension^). Contingency measures are not required to be implemented during this time
unless the nonattainment area failed to meet a required milestone. For purposes of section 172(c)(9),
contingency measures would be required to be implemented when the area failed to attain the new
attainment date. However, if a nonattainment area receives an extension, the area is required to
perform a milestone compliance demonstration for the original attainment date year. Since the area is
asking for an-extension, the nonattainment area has not attained and therefore is required to do the
milestone compliance demonstration.
Fee Provisions
Section 185 of the Act mandates that States with severe or extreme areas include provisions in
their SIP's for the imposition of fees upon attainment failure. These provisions must require that each
major stationary source of VOC emissions within the area pay a fee to the State as a penalty for
failure to attain during the applicable attainment year, and must continue to pay a fee each calendar
year until the area attains. These fees apply to sources of NOX emissions as well if NOX controls are
used in the attainment demonstration.
The Act requires that these fees equal $5,000 per ton of VOC or NOX emitted by a major
stationary source during the calendar year in excess of 80 percent of the baseline amount. The fee
will also be adjusted for inflation over time as specified in section 502(b)(3)(B)(v) of the Act. The
baseline level of emissions for a source is determined as the lower of:
The actual VOC or NOX emissions.
The emissions allowed according to the applicable permit or SIP.
B-4
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If EPA determines that the fee provisions of a SIP do not meet the requirements in section
185, or the State is not administering the fee program as required in that section, EPA will collect the
unpaid fees, including any interest computed in accordance with section 6621(a)(2) of the Internal
Revenue Code of 1986.
Additionally, section 185 provides a fee exemption for areas with a population below 200,000
that can demonstrate that their failure to attain is due to ozone or precursors of ozone transported
from other areas.
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APPENDIX C: CHECKLISTS
The following checklists address required components of a State's post-1996 rate-of-progress
plan. Questions in the checklist are stated in a way such that an affirmative answer to a yes-or-no
question requires no further action or comment on behalf of the reviewer. A negative response does
not necessarily invalidate the plan but usually will require an explanation by the State or,
occasionally, will require a SIP revision.
These checklists are designed to assist States in preparing complete post-1996 rate-of-progress
plans, and also to assist EPA in reviewing SIP's. States should not assume that these checklists are
all-inclusive, however.
REVIEWING PROCEDURES
This section outlines the required steps to be taken by State agencies and Regional Offices in
reviewing post-1996 rate-of-progress plans. The completeness criteria established for SIP's19 and the
timeframes allotted for revisions to the plans are discussed. The basic requirements for SIP's can be
found in 40 CFR 51 Requirements for Preparation. Adoption, and Submittal of Implementation Plans.
The specific requirements for post-1996 rate-of-progress plans are contained within this document.
State Agencies
State agencies have the responsibility of compiling the post- 1996 rate-of-progress plan and to
ensure that the plan meets the minimum completeness criteria (40 CFR Part 51, Appendix V). Once
a plan has been adopted by a State, five copies of the plan are to be submitted by the Governor (or
his/her designee) to the Regional Office of the EPA for review.
A State may want to submit a draft copy of the post-1996 rate-of-progress plan to EPA for
comments prior to the November 15, 1994 deadline. This will provide an early opportunity for
feedback on the plan. The EPA will not consider submission of requests for parallel processing of
draft plans as official plans in order to meet statutory deadlines. The EPA interprets the Act as
requiring rules that are acceptable under the approval options of section 110(k).
The EPA is presently amending the completeness criteria to remove the exception for parallel
processing and to add an exception for the submission of commitments as allowed under section
Regional Offices
The first step in the review process for Regional Offices will be to determine if the post- 1996
rate-of-progress plan meets the completeness criteria outlined in 40 CFR Part 51, Appendix V. The
completeness criteria require that within 60 days of EPA's receipt of a plan or plan revision, but not
later than 6 months after the date by which a State was required to submit the plan or plan revision,
the EPA shall determine whether the completeness criteria have been met. If EPA has not made a
19 56 FR 42216, "State Implementation Plan Completeness Criteria; Final Rule."
August 26, 1991.
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completeness determination by 6 months after receipt of the submission, that submission shall on that
date be considered to meet the completeness criteria. The completeness criteria require that EPA
inform the submitting official by letter if the plan meets the requirements of Appendix V. If a
submittal is deemed incomplete, EPA shall notify the State by letter that the submittal is incomplete.
In the letter EPA will request corrective action and identify the components absent or insufficient to
perform a review.
When it has been determined that the State's plan meets the minimum completeness criteria,
EPA is required to approve, partially approve, or disapprove the submission within 12 months of the
completeness determination.
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ADJUSTED BASE YEAR INVENTORY(IES) AND TARGET LEVEL(S)
1. Was the MOBLLESa model used to estimate the noncreditable emission reductions from
FMVCP and RVP?
_Yes _No
Comments: '.
2. Does the plan include information on how the MOBILESa model was run for calculating the
noncreditable emission reductions from FMVCP and RVP?
_Yes _No
Comments:
3. Was the 1990 adjusted base year inventory calculated for each applicable milestone and
attainment year to reflect the effects of FMVCP and RVP due to fleet turnover (i.e., were
noncreditable emission reductions from FMVCP and RVP excluded from each of the
applicable adjusted base year inventories)?
_Yes _No
Comments:
4. Does the adjusted base year emission inventory include only anthropogenic emissions
emanating from within the designated nonattainment area boundaries?
_Yes _No
Comments:
5. Does the plan document the target level(s) as well as the calculations made in determining the
target level(s)?
_Yes _No
Comments:
C-3
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REQUIRED TOTAL EMISSION REDUCTIONS
1. Does the plan demonstrate that it will achieve a 3 percent per year VOC emission reduction
for each applicable milestone and attainment date?20
_Yes _No
Comments:
2. Is the required 3 percent per year VOC emission reduction calculated from the appropriate
adjusted base year emission inventory?
_Yes _No
Comments: :
3. If NOX emission reductions are used in place of VOC emission reductions for the 3 percent
per year requirement, is the substitution consistent with EPA's NOX substitution guidance?
_Yes _No
Comments:
4. If the plan outlined a less than 3 percent per year VOC emission reduction, does the plan
include all measures that can feasibly be implemented in the area in light of technological
achievability (including measures that are achieved in practice by sources in the same source
category in nonattainment areas of the next higher classification)? Yes No
Comments: ;
5. Does the plan include a summary of projected VOC (and NOX where appropriate) emission
levels' for each applicable milestone and attainment date?
_Yes _No
Comments:
6. Is the EPA guidance document entitled Procedures for Preparing Emissions Projections
followed in calculating projected emissions?21
_Yes _No
Comments: .
20 The 3 percent per year emissions reduction is averaged over each 3 year period between
consecutive milestone dates or the last milestone date and the attainment date.
21 Procedures for Preparing Emissions Projections. EPA-450/4-019, U.S. Environmental
Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC. July
1991.
C-4
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7. Does the control strategy contain the necessary control measures to achieve the target level of
emissions for each applicable milestone and attainment year (i.e., does the overall control
strategy provide for a 3 percent per year VOC emission reduction, account for noncreditable
emission reductions, and fully offset any anticipated growth)?
_Yes _No
Comments:
8. Were emission reductions from RACT and I/M corrections accounted for in the calculation of
the target levels (this is not necessary for VOC if the reductions were accounted for in the 15
percent rate-of-progress plan)?
_Yes _No
Comments:
9. If a State plans to use preenactment banked emission reduction credits in the post-1996
period, are the use of such banked credits considered as growth in the post-1996 plan?
_Yes _No
Comments:
10. If emission reductions achieved in the 1990-1996 period are credited to the post-1996 plan,
are they documented to be in excess of the emission reductions (net of growth) required for
the 15 percent rate-of-progress plan?
_Yes _No
Comments:
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STATE IMPLEMENTATION PLAN ATTAINMENT DEMONSTRATION CHECKLIST FOR
AREAS USING UAM
1. Was an approved modeling protocol completed and delivered to EPA prior to use of the
model?
_Yes _No
Comments:
2. Are attainment year emission estimates projected from an EPA approved 1990 base year
inventory?
_Yes _No
Comments:
3. Were allowable emissions used as the basis for future year projections?
_Yes _No
Comments:
4. Was the MOBILESa model used for projecting mobile source emissions?
_Yes _No
Comments:
5. Have all MOBILESa model inputs for the projection emission inventory been incorporated?
_Yes _No
Comments:
6. Were the assumptions used to simulate the effects of control measures (e.g., emission
reductions and implementation dates) in the modeling analysis consistent with the assumptions
used for the control measures specified in the 15 percent and post-1996 rate-of-progress plans
to meet the target level of emissions for each applicable milestone date?
_Yes _No
Comments:
7. Was EPS2.0 used to process (including projection and control) the emission estimates for the
attainment year?
_Yes _No
Comments: '.
C-6
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8. Were the meteorology and air quality data preprocessed in accordance with EPA guidelines?
_Yes _No
Comments:
9. Are emissions for the entire UAM modeling domain included (including biogenic emissions)?
_Yes _No
Comments:
10. Are EPA-supplied numbers for background VOC and NOX levels included in UAM to account
for emissions from the surrounding area?
_Yes _No
Comments:
11. Was the most recent regulatory version of the UAM used in the attainment demonstration and
was it applied in accordance with EPA guideline procedures including the model evaluation
specified in the document entitled Guideline for Regulatory Application of the Urban Airshed
Model?22
_Yes _No
Comments: :
12. Was a modeling demonstration package prepared containing the required information as
documented in EPA guidance?
_Yes _No
Comments:
22 Guideline for Regulatory Application of the Urban Airshed Model. EPA-450/4-91-01, U.S.
Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle
Park, NC. 1991.
C-7
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CONTROL MEASURES AND CONTROL STRATEGIES
1. Does the plan describe the control measures to be implemented?
_Yes _No
Comments: : _
2. Are all control measures required by the Act included in the plan?
Stationary Source Controls;
Serious and above ozone nonattainment areas:
a) RACT rule fix-ups (for those areas with RACT rule deficiencies):
b) RACT rule catch-ups:
Serious ozone nonattainment areas:
a) Major stationary source threshold of 50 tpy:
VOC
NQX
b) New source review (NSR) offset ratio of 1.2 to 1:
VOC
NQX
Severe ozone nonattainment areas:
a) Major stationary source threshold of 25 tpy:
VOC
NQ,
b) NSR offset ratio of 1.3 to 1:
VOC
NQX
_Yes _No
Yes No
_Yes
Yes
_No
No
_Yes
Yes
_No
No
_Yes
_Yes
_Yes
Yes
_No
_No
_No
No
-------
Extreme ozone nonattainment areas:
a) Major stationary source threshold of 10 tpy:
VOC _Yes _No
NQX _Yes _No
b) NSR offset ratio of 1.5 to 1:
VOC _Yes _No
NO,, _Yes _No
c) Clean fuels or advanced control technology for specified boilers: Yes No
Ozone transport region:
a) Additional requirements deemed by the transport commission as appropriate:
Yes No
Comments:
Mobile Source Controls
Serious and above ozone nonattainment areas:
a) FMVCP and RVP program: _Yes _No
b) Stage II vapor recovery program: Yes No
c) Enhanced I/M program: Yes No
d) Clean fuel fleet vehicle program (in areas
with a population of 250,000 or greater) or: Yes No
Optional clean fuel fleet vehicle program substitute: Yes No
C-9
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Severe and above ozone nonattainment areas:
a) TCM's to offset VMT growth: _Yes _No
b) Employer trip reduction program:
_Yes _No
Ozone transport region:
a) Enhanced I/M program for any metropolitan statistical area with a population of
100,000 or more:
Yes No
Comments:
3. "Did" the State identify the appropriate MOBILESa model inputs?
_Yes _No
Comments: .
4. Does the plan present a control strategy implementation schedule?
_Yes _No
Comments: j ;
5. Will all control measures that are specified in the post-1996 rate-of-progress plan be
implemented by the appropriate target year?
_Yes _No
Comments:
6. Is the implementation schedule consistent with the requirements of the Act?
_Yes _No
Comments:
7. Is the agency that will have enforcement authority specified for each control measure?
_Yes _No
Comments:
8. Are the measures adopted and copies of the rules submitted?
_Yes _No . '
Comments: '.
C-10
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9. Does the plan describe the. methods used to calculate the emission reductions attributed to
each control measure? At a minimum, the methods should adhere to the four principles
described in the General Preamble (57 FR 13567) for documenting emission reductions. The
four principles are as follows: (1) baseline emissions from the source and the control
measures must be quantifiable, (2) control measures must be enforceable, (3) interpretation of
the control measures must be replicable, and (4) control measures must be accountable. See
the General Preamble for further discussion of these principles.
_Yes _No
Comments: :
10. Are all major non-CTG stationary sources identified?
_Yes _No
Comments:
11. Does the plan include RACT rules for major non-CTG stationary VOC sources for which
CTG documents are not available?
_Yes _No
Comments:
12. Is RE (and for area sources, rule penetration) factored into the calculation of expected
emission reductions associated with new control measures?
_Yes _No
Comments: _
13. Is the 80 percent default RE used?
_Yes _No
Comments:
«
14. Is the EPA guidance followed in calculating the expected emission reductions from any RE
improvements?
_Yes _No
Comments:
15. In estimating expected emission reductions associated with new control measures, is the
compliance period (e.g., daily compliance) factored into the calculation consistent with EPA
guidance?
_Yes _No
Comments:
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MILESTONE AND ATTAINMENT FAILURE CONTINGENCY MEASURES
Does the post-1996 rate-of-progress plan include contingency measures that will be
automatically implemented in the event of a post-1996 milestone or attainment failure?
_Yes _No
Comments:
2. Will the contingency measures achieve a 3 percent per year VOC/NOX emission reductions in
addition to the emission reductions in the control strategy?
_Yes _No
Comments:
3. Are the contingency measures consistent with the attainment demonstration?
_Yes _No
Comments:
4. Do the contingency measures meet the minimum requirements for control measures set forth
in the General Preamble (56 FR 13498)?
_Yes _No
Comments:
5. Does the post-1996 rate-of-progress plan ensure that contingency measures will be
implemented with no additional rulemaking actions such as public hearings or legislative
review by the State?
_Yes _No
Comments:
C-12
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APPENDIX D: COMPILATION OF GUIDANCE MEMORANDA ON THE 15 PERCENT
RATE-OF-PROGRESS REQUIREMENT
This appendix contains unsigned copies of the guidance memoranda that were issued
concerning the 15 percent rate-of-progress requirement. Many of these are also relevant to the post-
1996 requirements.
D-l
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3/2/93
MEMORANDUM
SUBJECT: Correction to "Guidance on the Adjusted Base Year
Emissions Inventory and the 1996 Target for the 15
Percent Rate of Progress Plans"
FROM: G.T. Helms, Chief
Ozone and Carbon Monoxide Programs Branch (MD-15)
TO: Air Branch Chief, Regions I-X
This memorandum corrects an error in the document entitled,
"Guidance on the Adjusted Base Year Emissions Inventory and the
1996 Target for the 15 Percent Rate of Progress Plans" (EPA
452/R-92-005), which was released in October 1992, Section 2.3
of this document, Requirements of Section 182(b)(1)(A)(ii),
states the following on page 17:
Nonattainment areas can achieve less than the 15
percent required reductions under the following
restrictive circumstances. The State must demonstrate
that the area has a new source review program
equivalent to the requirements in extreme areas
[section 182(e)], except that "major source" must
include any source that emits, or has the potential to
emit, 5 tons per year (tpy) of VOC or NOx.
Additionally, all major sources of VOC and NOx (down to
5 tpy) in the area must be required to have RACT-level
controls.
The correction removes the references to NOx from this
discussion for consistency with the Clean Air Act. Therefore,
the corrected portion of the paragraph now reads "... potential
to emit, 5 tons per year (tpy) of VOC. Additionally, all major
sources of VOC (down to 5 tpy) . . . ."
Please share this information with your State and
appropriate local air pollution control agencies. Any questions
about this correction may be addressed to Kimber Scavo at (919)
541-3354.
D-2
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3/11/93
MEMORANDUM
SUBJECT: 15 Percent Rate-of-Progress Plans
FROM: G.T. Helms, Chief
Ozone/Carbon Monoxide Programs Branch (MD-15)
TO: Air Branch Chief, Regions I-X
The purpose of this memorandum is to clarify an issue
related to the 15 percent rate-of-progress plans. At least one
Region has interpreted the statement that moderate areas are not
required to demonstrate in 1997 that the 15 percent reduction in
volatile organic compounds (VOC) has been achieved to mean that
these areas do not have to submit a rate-of-progress plan by
November 15, 1993. This interpretation is erroneous.
All areas classified as at least moderate must submit a plan
demonstrating how a 15 percent reduction in VOC emissions (net of
growth) will be achieved by 1996 unless the waiver provisions of
section 182(b)(1)(A)(ii) are met. Section 182(g)(l), however,
requires that "the State shall determine whether each
nonattainment area (other than an area classified as marginal or
moderate) has achieved a reduction in emissions- during the
preceding intervals equivalent to the total emission reductions
required to be achieved by the end of such interval . . . ." In
other words, moderate areas must submit a plan by November 15>
1993 showing how the 15 percent will be achieved, but will not be
required to demonstrate in 1997 that the 15 percent was actually
achieved.
The test for moderate areas will be whether they attained
the standard because the attainment date for moderate areas
coincides with the milestone demonstration date. Failure to
attain will cause an area to be required to implement its
contingency measures, and may cause the area to be bumped up to a
higher classification. Also, failure of a moderate area to
implement its 15 percent plan may result in a finding that the
State failed to implement its State implementation plan, which
would result in the imposition of sanctions.
Please make this information available to the appropriate
State and local agencies in your Region. If you have any
D-3
-------
questions concerning this issue, please contact Laurel Schultz at
(919) 541-5511.
D-4
-------
5/6/93
MEMORANDUM
SUBJECT:
FROM:
TO:
Credit Toward the 15 Percent Rate-of-Progress
Reductions from Federal Measures
G.T. Helms, Chief
Ozone/Carbon Monoxide Programs Branch (MD-15)
Susan Wyatt, Chief
Chemicals and Petroleum Branch (MD-13)
Air Branch Chief, Regions I-X
As you know, many States have been asking whether they will
be able to take credit in their 15 percent rate-of-progress plans
for reductions of volatile organic compounds (VQC) from federal
measures and imminent control techniques guidelines. We have
identified several categories for which we believe reductions
will be achieved by 1996. The attached table lists these
categories along with the amount of reductions for which states
can take credit in the plans. Please share this information with
the appropriate State and local agencies in your Region. If you
have any questions, please contact Laurel Schultz at (919) 541-
5511.
Attachment
D-5
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New VOC Related Requirements
Category
CTG's
SOCMI Distillation
SOCMI Reactor Vents
National Rules
TSDF Phase II
NESHAP's
Hazardous Organic NESHAP for SOCMI
Ethylene Oxide Commercial Sterilizers
Percent Reduction23
98% from each controlled vent
98% from each controlled vent
93% from 1990 baseline
5% from 1990 baseline
97% from each major source24
23
The number in this column represents the percent reduction that EPA will allow States to
assume for the purposes of the 15% plans only.
24 The term "major source" is defined for hazardous air pollutants in section 112(a)(l) of the
Clean Air Act.
D-6
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6/14/93
MEMORANDUM
SUBJECT: Correction to "Guidance on the Adjusted Base Year
Emissions Inventory and the 1996 Target for the 15
Percent Rate of Progress Plans"
FROM: G.T. Helms, Chief
Ozone and Carbon Monoxide Programs Branch (MD-15)
TO: Air Branch Chief, Regions I-X
This memorandum corrects an error in the document entitled
"Guidance on the Adjusted Base Year Emissions Inventory and the
1996 Target for the 15 Percent Rate of Progress Plans" (EPA
452/R-92-005), which was released in October 1992. Appendix B of
this document explains how to calculate the emissions reductions
achieved through the correction of existing reasonably available
control technology (RACT) rules. Two of the examples in this
appendix incorrectly use growth factors in determining the
reductions from rule corrections. As with the inspection and
maintenance corrections and reductions from the Federal motor
vehicle control plan and Reid vapor pressure, the RACT
corrections should not include growth. A cor-rected version of
Appendix B is attached. Because the adjustment for RACT
corrections is relatively small, this correction should not have
a significant impact on States1 calculations.
Please share this information with your State and
appropriate local air pollution control agencies. Any questions
about this correction may be addressed to Laurel Schultz of my
staff at (919) 541-5511.
Attachment
D-7
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APPENDIX B:
CALCULATION OP EMISSIONS REDUCTIONS PROM RACT RULE CORRECTIONS
Section 4.1 of this document discusses cases where RACT rule
corrections do not directly result in quantifiable emissions
reductions. Any incidental reductions that occur in these cases
may be handled as part of a rule effectiveness improvement.
Corrections to RACT rules that may result in additional,
enforceable, and quantifiable emissions reductions include
situations where:
A rule was missing [i.e., a State committed to
develop a rule as part of its 1977 State
implementation plan (SIP), or post-1982 SIP, but
never carried through on the commitment prior to
the Clean Air Act Amendments of 1990.
The limit was wrong.
A capture system is now required to ensure meeting
a RACT limit.
For the case where a rule was missing, the State should first
calculate the uncontrolled emissions in 1990. Next, the State
must evaluate the expected emissions reduction in 1996 by
calculating 1996 emissions (including controls) and subtracting
this number from 1990 emissions. This total expected emissions
reduction should be added to the total reductions in step 5 in
the example in section 2.1 of this document. These reductions
are not creditable toward the 15 percent volatile organic
compounds (VOC) emissions reduction requirement.
For the second case, the State should first evaluate the
pound (Ib) VOC/gallon (gal) solids for each limit.
1990 limit = 3.5 Ib VOC/gal coating
1) 1990 Ib VOC/gal solids =
3.5 Ib VOC x 1 gal coating = 0.476 gal VOC
gal coating 7.36 Ib VOC gal coating
2) Calculate solids in 1 gal coating:
I - 0.476 = 0.524 gal solids
3) Calculate gallons of coating needed to get gallon of Solids:
1 cral coating = 1.908 gal coating
0.524 gal solids gal solids
D-8
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4) Convert 3.5 Ib/gal coating to Ib VOC/gal solids:
3.5 Ib VOC x 1.908 aal coating = 6.678 Ib VOC
gal coating gal solids gal solids
The 1996 limit will be 2.9 Ib/gal.
Similarly, convert 2.9 Ib VOC/gal coating to Ib VOC/gal
solids.
5) 2.9 Ib VOC X 1 aal VOC = 0.394 gal VOC
gal coating 7.36 Ib VOC gal coating
6) Volume of solids in 1 gal coating:
1 - 0.394 = 0.606 gal solids
7) Calculate gallons of coating needed to get 1 gallon of solids:
1 gal coating = 1.650 gal coating
0.606 gal solids gal solids
8) Convert 2.9 Ib VOC gal coating to Ib VOC/gal solids:
2.9 Ib VOC x 1.650 aal coating = 4.785 Ib VOC
gal coating gal solids gal solids
The facility uses 100 gal solids in 1990
day
9) Compare 1990 and 1996 Emissions:
1990 = 6.678 Ibs VOC x 100 gal solids = 667.8 Ibs VOC
gal solids day day
1996 = 4.785 Ib VOC X 100 gal solids = 478.5 Ib VOC
gal solids day day
1990 Emissions - 1996 Emissions = 667.8 - 478.5 = 189.3 Ib VOC
day
Therefore, 189.3 Ib VOC/day are noncreditable.
For the third case where a capture system is required,
expected emissions reductions should be calculated in the
following way. First, uncontrolled emissions should be
determined.
1990 Paper Coaters:
* Eighty percent of emissions coming out of the oven
and vented to an incinerator of 98 percent
demonstrated destruction efficiency.
D-9
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Twenty percent of emissions are fugitive from
uncontrolled flash-off area.
Total uncontrolled emissions in 1990 =
1,000 Ib/day if total is uncontrolled,
however, when system is controlled, 80
percent of this is captured, and 98 percent
of captured emissions are destroyed.
Therefore, emissions from the incinerator after control
are 1,000 Ib/day x (1-(0.80)) x (l-(0.98)) =
(1,000 Ib/day) x (0.20) x (0.02) = 4 Ib/day
controlled. Total Emissions from incinerator
+ fugitives = 4 Ib/day + (1,000 Ib/day x
(0.20)) = 204 Ib/day
1996 Emissions:
New State rule now requires permanent total enclosure,
so the controlled emissions are:
1,000 Ib day (1.0) (0.02) = 20 Ib/day
Noncreditable Emissions Reductions =
1990 Emissions - 1996 Emissions = 204 Ib/day - 20 Ib/day
184 Ib/day
The preceding examples are not intended to be fully
inclusive. States should evaluate all RACT rule corrections to
determine if such measures result in real, enforceable, and
permanent emissions reductions. If so, such reductions must be
quantified and considered in the SIP development process when
preparing the 1996 target level of emissions. If a State is
unclear on how to calculate such reductions, then the State
should consult with the Regional Office and Headquarters for
guidance.
D-10
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7/28/93
MEMORANDUM
SUBJECT: Correction Errata to the 15 Percent Rate-of-Progress
Plan Guidance Series
FROM: G.T. Helms, Chief
Ozone and Carbon Monoxide Programs Branch (MD-15)
»
TO: Air Branch Chief, Regions I-X
This memorandum corrects several errors in the 15 percent
rate-of-progress plan guidance series.
1. There is an error in the Table entitled, "Major Source
Thresholds and Minimum Emissions Offset Ratio Requirements for
Ozone Nonattainment Area Classifications," in the following 15
percent guidance documents:
« "Guidance on the Adjusted Base Year Emissions Inventory
and the 1996 Target for the 15 Percent Rate of Progress
Plans" (EPA-452/R-92-005), p. A-3.
» "Guidance for Growth Factors, Projections, and Control
Strategies for the 15 Percent Rate-of-Progress Plans"
(EPA-452/R-93-002), p. A-3.
« "Guidance on the Relationship Between the 15 Percent
Rate-of-Progress Plans and Other Provisions of the
Clean Air Act" (EPA-452/R-93-007), p. 12.
« "Guidance on Preparing Enforceable Regulations and
Compliance Programs for the 15 Percent Rate-of-Progress
Plans" (EPA-452/R-93-005), p. A-4.
The error is in the item, "All Other Nonattainment Areas, in an
Ozone Transport Region." The volatile organic compounds tons per
year (tpy) should be 50 tpy rather than 100 tpy.
2. The document entitled "Guidance on the Relationship
Between the 15 Percent Rate-of-Progress Plans and Other
Provisions of the Clean Air Act" (EPA-452/R-93-007), has an error
concerning the creditability of certain transportation control
D-ll
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measures. Section 5.8 of this document states the following on
page 39:
Emissions reductions resulting from TCM's are
creditable if the TCM is not already
federally mandated (e.g., the employee trip
reduction program required under section
182(d)(l)(B) for severe and extreme ozone
nonattainment areas), or is not part of an
already existing SIP. As with all other
emissions reductions, emissions reductions
associated with TCM's are only creditable to
the 15 percent rate-of-progress plan if they
are quantifiable, real, enforceable,
replicable, accountable, and occur by
November 15, 1996.
The correction revises the first sentence of the preceding
paragraph:
Emissions reductions resulting from TCM's are
creditable if the TCM was not a pre-1990
control measure in an already existing SIP.
As with all other emissions reductions,
emissions reductions associated with TCM's
are only creditable to the 15 percent rate-
of-progress plan if they are quantifiable,
real, enforceable, replicable, accountable,
and occur by November 15, 1996.
3. In the.document, "Guidance for Growth Factors,
Projections, and Control Strategies for the 15 Percent Rate-of-
Progress Plans" (EPA-452/R-93-002, March 1993), there are several
errors in Chapter 6.
a. On page 55, the text under the table, last sentence,
"The [ (200-REPY)/100] factor is not valid for low RE values"
is incorrect and should be deleted.
b. On page 57, the sentence before the heading, "Equation 5
- Projection calculated from permitted emissions rates,"
("The [(200 - RE)/100] factor is not valid for low RE
values") is incorrect and should be deleted.
c. On page 57, the second and third paragraphs under the
heading, "Equation 5 - Projection calculated from permitted
emissions rates," should read as follows:
D-12
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EMISpy = ERpy *
(200 - REY)
PY
100
(200 - REBY)
100
(5)
= 30 *
(200 - 80)
100
(200 - 80)
100
* [0'°75] = 0.098 tons/day = 196 lb/da}
23 J
Please share this information with your State and local air
pollution control agencies. Any questions about these
corrections may be addressed to Kimber Scavo at (919) 541-3354 or
Laurel Schultz at (919) 541-5511.
D-14
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8/23/93
MEMORANDUM
SUBJECT
FROM:
TO:
Guidance on Issues Related to 15 Percent Rate-of-
Progress Plans
Michael H. Shapiro
Acting Assistant Administrator
for Air and Radiation (ANR-443)
Director, Air Pesticides and Toxics
Management Division, Regions I and IV
Director, Air and Waste Management Division,
Region II
Director, Air, Radiation and Toxics Division,
Region III
Director, Air and Radiation Division,
Region V
Director, Air, Pesticides and Toxics Division,
Region VI
Director, Air and Toxics Division,
Regions VII, VIII, IX, and X
As you know, section 182(b)(l) of the Clean Air Act (Act)
requires States to submit, by November 15, 1993 for all ozone
nonattainment areas classified as moderate and above, a State
implementation plan (SIP) that provides for a 15 percent
reduction in emissions of volatile organic compounds (VOC) by
November 15, 1996. The purpose of this memorandum is to provide
guidance related to these SIP submissions.
Committal SIPVs for 15Percent Plan ControI^Measures
Several States asked to what extent will the Environmental
Protection Agency (EPA) accept committal SIP's for the measures
necessary to achieve the 15 percent reduction. Under section
110(k)(4) of the Act, EPA has the authority to conditionally
approve a SIP submittal based on a commitment by the state to
adopt specific enforceable measures by a date certain. A
previous memorandum identified specific cases in which EPA would
accept commitments for submittals which were due by November 15,
1992. For the 15 percent rate-of-progress plans, EPA will not
accept commitments to adopt the measures needed to meet the 15
D-15
-------
percent reduction requirement and any such plans would not be
considered approvable. In fact, EPA may determine such
submittals to be incomplete, which would trigger a findings
letter starting the clock for mandatory sanctions. The only
exception would be for the State of Texas where EPA Headquarters,
based on initial views at the time, indicated a commitment would
be acceptable.
NOx Substitution for Contingency Measures
Section 172(c)(9) of the Act requires moderate and above
ozone nonattainment areas to adopt contingency measures by
November 15, 1993. These measures would have to be implemented
if the area fails to make reasonable further progress (RFP) or to
attain the national ambient air quality standards (NAAQS) by the
applicable attainment date. In addition, section 182(c)(9) of
the Act requires serious and above areas to adopt contingency
measures which would be implemented if the area fails to meet any
applicable milestone. When triggered, the contingency measures
must be implemented without further action by the State or the
EPA.
The "General Preamble for the Implementation of Title I of
the Clean Air Act Amendments of 1990" (57 FR 13498, April 16,
1992) requires that the contingency measures generally must
provide reductions of 3 percent of the emissions from the
adjusted base year inventory. The reductions must be achieved in
the year following that in which the failure has been identified.
Three percent represents 1 year's worth of reductions under the
post-1996 rate-of-progress requirement.
The contingency measures that are required to be adopted by
November 15, 1993 are for both failure to achieve RFP and failure
to attain. While the contingency measures to address failure to
achieve RFP must be for VOC, the contingency measures for failure
to attain may be for VOC and/or NOx. Since these measures will
be implemented after 1996, and because these measures serve two
purposes (i.e., failure to achieve RFP and failure to attain),
the contingency measures could provide for less than 3 percent in
VOC reductions as long as some of the measures are for VOC and
the area would have the difference (up to 3 percent) in NOx
reductions. Based on discussions with EPA's Office of General
Counsel, we have determined that States must adopt a minimum of
0.3 percent in VOC measures of the 3 percent contingency measure
requirement to be legally defensible. Therefore, in an area that
has demonstrated that NOx controls are needed for attainment, 2.7
percent of the required 3 percent could be NOx contingency
measures; at least 0.3 percent must still be VOC to cover the
contingency requirement for meeting RFP. Note that this applies
to moderate areas as well; moderate areas must submit an
approvable plan that shows how they will achieve the 15 percent
D-16
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requirement but are not required to submit a demonstration that
the milestone was achieved. Moderate areas, of course, must
demonstrate that they have attained the NAAQS for ozone by
November 15, 1996.
In order for NOx contingency measures to be acceptable, the
State must adhere to EPA's forthcoming guidance on NOx
substitution. In addition, States must show with modeling
evidence that NOx reductions are needed in a particular
nonattainment area. Therefore, in order to give States enough
time to consult EPA's guidance on NOx substitution and to
determine if NOx reductions are needed, EPA will accept
committals for contingency measures that are due November 15,
1993. If the contingency measures themselves are not included
with the November 15, 1993 submittal, that submittal must include
a commitment, with schedule, for contingency measures to be
adopted by November 15, 1994.
We believe that this is acceptable due to the fact that the
earliest a contingency measure would be implemented would be in
1997. The first attainment date and milestone date for areas
that are required to adopt contingency measures is November 15,
1996. The EPA will expect all actions needed to make the
measures fully effective to occur within 60 days after EPA
notifies the State of its milestone failure or within 6 months of
its attainment failure. Therefore, the State would not need to
implement the contingency measures until 1997 and EPA could
accept measures that could not be implemented until 1997.
Upon activation of the contingency measures, reductions of
up to 3 percent (or such lesser percentage that will cure the
identified failure) must be achieved 1 year following the date on
which the failure had been identified. The State must achieve
these reductions while conducting additional control measure
development and implementation as necessary to correct the
shortfall if it is beyond the 3 percent the State would have
already adopted. In determining what measures should be
implemented if less than 3 percent reduction is needed to cure
the failure, all VOC contingency measures should be required
first followed by the appropriate percentage of NOx measures that
will correct the shortfall.
15 Percent Waiver Provision
Under section 182(b)(1)(A)(ii), areas can submit plans
demonstrating less than a 15 percent emission reduction if 1»he
following conditions are met. First, the State must demonstrate
that the area has a new source review program equivalent to the
requirement in extreme areas [section 182(e)], except that a
"major source" must include any source that emits, or has the
potential to emit, 5 tons per year (tpy) of VOC. Second, all
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major sources (down to those with emissions of 5 tpy of VOC or
greater) in the area must be required to have RACT-level
controls. Third, the State must demonstrate that the SIP
includes all measures (both stationary and mobile) that are
achieved in practice by sources in the same source category in
nonattainment areas of the next higher classification. Fourth,
the plan must include all measures that can be feasibly
implemented in the area, in light of technological achievability
and cost.
If an area chooses to"meet the requirements of section
182(b)(1)(A)(ii) to get a-waiver of the 15 percent provision, EPA
interprets title ₯ to require operating permits for all VOC
sources in that area that emit or have the potential to emit 5
tpy of VOC. This is because the definition of "major source" in
title V expressly refers to "major stationary source" as defined
in part D of title I. Since; under the waiver provision, "major
stationary source" would be defined as having the potential to
emit 5 tpy for the purposes of title I, this would become the
definition of major source for the purposes of title V.
I suggest that you provide a copy of this memo to your
affected State and local agencies. Inquiries may be directed to
John Silvasi at (919) 541-5666.
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9/20/93
MEMORANDUM
SUBJECT: Reclassification of Areas to Nonattainmervt and 15
Percent Rate-of-Progress Plans
FROM: John S. Seitz, Director
Office of Air Quality Planning and Standards (MD-10)
TO: Winston A, Smith, Director
Air, Pesticides and Toxics Management Division,
Region IV
This is in response to your August 20, 1993 memorandum
requesting guidance on the reclassification of areas to
nonattainment and the 15 percent rate-of-progress plans. Your
specific questions are addressed as follows:
1. If an attainment area becomes a moderate nonattainment
area, what is the year of the baseline inventory? Will it be
1990 or some other year? If it is a year other than 1990, how
will it be determined?
Answer: Section 181(b)(l) of the Clean Air Act (Act) covers
areas that were attainment after enactment and that are
redesignated to nonattainment. These areas are subject to the
requirements under section 110 upon classification, except that
any absolute, fixed date applicable in connection with any such
requirement is extended by operation of law by a period equal to
the length of time between the date of the enactment of the Act
and the date the area is classified. Therefore, the base-year
inventory year would be the year in which the area was
redesignated to nonattainment.
2. Are there any regulatory programs that if adopted for
nonattainment areas would be creditable toward the 15 percent
requirement but if adopted prior to the nonattainment designation
would not be creditable?
Answer: A regulatory program adopted for a nonattainment
area that would be creditable toward the 15 percent requirement
could be considered noncreditable for an area that was
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redesignated to nonattainment if the regulatory program was
adopted and implemented prior to the base-year inventory year in
the redesignated area. Thus, the base-year inventory must
reflect actual emissions including the effect of reductions
occurring prior to that year. Only reductions that occur after
the base year are creditable toward the 15 percent requirement
[assuming that they meet the other creditability requirements of
section 182(b)(1)(D)]. Also, if a regulatory program that met
the creditability provisions was adopted and implemented prior to
the base year but continued to result in emissions reductions
after the base year, then those emissions reductions occurring
after the base year would be creditable to the 15 percent
requirement.
3. If a State implements nonregulatory/voluntary programs
and is subsequently designated nonattainment for ozone, can the
State use these programs to meet the 15 percent requirement by
passing legislation and submitting a State implementation plan
(SIP) revision?
Answer: The program would be creditable only if the
reductions occur after the base year.
4. Can a State pass legislation lowering the Reid vapor
pressure (RVP) of gasoline below the 9.0 allowed in attainment
areas for purposes of- maintaining the standard? If they can,
what are the procedures that must be followed?
Answer: States are generally preempted under section
211(c)(4)(A) from establishing controls on the RVP of gasoline
for purposes of motor vehicle emissions control unless the State
RVP control is identical to the Federal requirement.1 A State
may, however, adopt and enforce a nonidentical RVP control if an
applicable SIP so provides. The EPA may approve such a SIP
provision only if the State RVP control is "necessary to achieve"
the national ambient air quality standards (NAAQS) that the SIP
implements.
The EPA has previously approved several State RVP controls
where the State was able to show that an RVP control more
stringent than the Federal requirement was necessary to achieve
attainment for designated ozone nonattainment areas in that State
[see, e.g., EPA's approval of a Maryland State RVP control
'The Federal RVP standards were promulgated under both section
211(c) and 211(h) of the Act. States are generally preempted
under section 211{c)(4)(A) from establishing State fuel standards
that are not identical to those established under section 211(c).
California is not subject to this preemption pursuant to section
211(0) (4) (B).-
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published at 56 FR 23804 (May 24, 1991)]. That decision
describes the criteria used by EPA in determining whether such a
SIP revision is necessary to achieve the NAAQS.
For an area that is currently designated attainment, a State
would generally have to demonstrate that the RVP measure is
needed in the attainment area in order to achieve the standard in
another area that is not in attainment. The EPA approved a SIP
revision for statewide RVP controls in the State of New York
based on such a showing. However, it is questionable whether EPA
would have authority to approve a State RVP control adopted
solely to maintain compliance with the NAAQS in attainment areas.
If a State would like to pursue this latter issue, then we would
work with the Office of General Counsel to determine under what
conditions EPA could approve such a SIP submittal.
The process for obtaining a waiver of Federal preemption for
State RVP controls involves submission by the State of a SIP
revision in section 110 of the Act. The Federal Register notice
referred to above provides detailed information on the criteria
used by EPA in acting on such a SIP revision.
If you have any further questions or concerns, please give
me a call.
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10/6/93
MEMORANDUM
SUBJECT: Clarification of "Guidance for Growth Factors,
Projections and Control Strategies for the 15 Percent
Rate of Progress Plans"
FROM: G. T. Helms, Chief
Ozone/Carbon Monoxide Programs Branch (MD-15)
TO: Air Branch Chief, Regions I-X
This memorandum clarifies the document entitled, "Guidance
for Growth Factors, Projections and Control Strategies for the 15
Percent Rate of Progress Plans," (EPA-452/R-93-002) which was
released in March 1993. Section 6.5 of this document discusses
the effects of equipment replacement and new source requirements
on the 15 percent plans. However, this discussion, as it relates
to new source review, is inconsistent with the document entitled,
"Guidance on the Relationship Between the 15 Percent Rate-of-
Progress Plans and Other Provisions of the Clean Air Act," (EPA-
452/R-93-007) which was released in May 1993. As discussed in
this document, emissions reductions projected to occur from the
part D new source review offset requirements are not creditable
toward the 15 percent rate-of-progress plan requirements.
However, at the time of reconciliation, any additional, actual,
permanent, and enforceable emissions occurring after 1990
resulting from offsets that are not used to offset minor source
growth will be creditable in the milestone compliance
demonstration due in February 1997 for serious and above areas.
The EPA's Office of General Counsel concurs with this position.
A corrected version of section 6.5 of the growth factors
document, which is consistent with the relationship document, is
attached.
Please share this information with your State and
appropriate local air pollution control agencies. Any questions
about this correction may be addressed to Laurel Schultz of my
staff at (919) 541-5511, or me at (919) 541-5527.
Attachment
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6.5 Effects of Equipment Replacement
Failure to consider the effects of equipment replacement and
NSPS requirements for an affected facility's existing capital
stock, may result in development of a SIP which requires more
emissions reductions than necessary to meet rate-of-progress
milestones or NAAQS attainment dates.
As an existing facility wears out and is replaced with newer
equipment, it may become subject to a NSPS. To the extent NSPS
requirements are more restrictive than present requirements on
the existing (not modified or reconstructed) facility, future
emissions will be reduced. The implications of such emissions
reductions can be assessed using the following formula:
Ext = [(Eb -En) * (1 + .r) exp t]
where: Ert = Emissions reductions in year t
Eb = Emissions in the base year
En = NSPS emissions
r = Annual replacement rate for worn out capital
stock
t = Years from the base year
Consequently, zero net growth emissions need not be the same
as baseline; they might actually be less.
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10/29/93
MEMORANDUM
SUBJECT: Rate-of-Progress Plan Guidance on the 15 Percent
Calculations
FROM: D. Kent Berry, Acting Director
Air Quality Management Division (MD-15)
TO: Director, Air, Pesticides and Toxics
Management Division, Regions I and IV
Director, Air and Waste Management Division,
Region II
Director, Air, Radiation and Toxics Division,
Region III
Director, Air and Radiation Division,
Region V
Director, Air, 'Pesticides and Toxics Division,
Region VI
Director, Air and Toxics Division,
Regions VII, VIII, IX, and X
The Clean Air Act (Act) requires a specified rate of
emissions reductions for all ozone areas classified as moderate
and above. Moderate and above areas must submit a State
implementation plan (SIP) revision detailing how the area will
achieve a reduction in volatile organic compounds emissions of at
least 15 percent between November 15, 1990 and November 15, 1996
(hereafter called the rate-of-progress plan). The rate-of-
progress requirement is based on the 1990 base-year emissions
inventory. The rate-of-progress plan revision is part of the
full SIP (including an attainment demonstration based on
modeling) for most moderate areas, and a separate submittal for
serious and above areas (due November 15, 1993).
The Ozone/Carbon Monoxide Programs Branch coordinated the
development of a series of guidance documents to guide States as
they develop their SIP's to meet the new rate-of-progress
requirements of section 182(b)(l). These documents were released
between October 1992 and June 1993. In addition, Office of Air
Quality Planning and Standards staff presented a satellite
training workshop on the 15 percent rate-of-progress plans and
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the attainment demonstrations in the spring of 1993. The
guidance documents and the workshop explained the procedures for
calculating the 15 percent requirement that was first put forth
in the "General Preamble for the Implementation of Title I of the
Clean Air Act Amendments of 1990," (57 FR 13498, April 16, 1992).
Several variations have been suggested for the calculation
procedures of this requirement. One suggestion would allow
States to offset only 15 percent of the growth rather than all of
the growth. Another suggestion would take credit for the Federal
motor vehicle control program as a means to achieve the total
reductions necessary to meet the 15 percent requirement and
offset growth.
Regarding the requirement to account for growth, the
Environmental Protection Agency's (EPA's) interpretation of" the
Act ensures that actual reductions will occur if an area is to
meet the 15 percent reduction requirement. Some of the
alternative interpretation suggested could lead to a situation
where, due to significant growth, an area's projected emissions
even after applying a 15 percent reductioncould be higher in
1996 than in 1990, but the area would still be considered as
meeting the progress requirement. We do not believe this
reflects the intent of the Act. States should, therefore, follow
the guidance documents issued by EPA when developing their 15
percent rate-of-progress plans that are due November 15, 1993.
Thus, we do not foresee allowing the variations such as those
discussed above.
A second issue arises as a result of some confusion
concerning the above-cited EPA guidance on 15 percent plans. The
EPA intends to determine the approvability of the 15 percent
rate-of-progress plans using four basic criteria: (1) the base-
year inventory and associated projections must be appropriately
justified; (2) the target level of emissions is properly
calculated; (3) the target level of emissions will be achieved if
the strategies adopted and identified in the plan are shown to
successfully achieve the necessary level of reductions by the end
of 1996; and (4) contingency measures of 3 percent (or a
commitment to adopt such measures) are included. Some of the
confusion associated with the guidance may come from the
discussion of total required reductions. The best test of
whether a 15 percent rate-of-progress plan will be acceptable is
not whether a certain amount of reductions is achieved, but
whether the projected emissions in 1996 will be at or below the
target. The attachment to this memorandum explains specifically
how these calculations are to be done.
Finally, there is apparently some confusion concerning the
creditability of reductions due to the Federal motor vehicle
control program (FMVCP). The Act states that emission reductions
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from "[a]ny measures relating to motor vehicle exhaust or
evaporative emissions promulgated by the Administrator by
January 1, 1990" are not creditable toward the 15 percent
requirement. This means that reductions due to the pre-1990
FMVCP standards are not creditable but that reductions due to any
new standards promulgated after January 1,1990 are creditable.
We suggest that you forward this information to your State
and local agencies. If you have questions or comments, please
contact Kimber Scavo at (919) 541-3354 or Laurel Schultz at (919)
541-5511.
Attachment
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ATTACHMENT
A specific question that has been raised is whether the 1996
projected emissions that are used to calculate the total required
reductions (box "C" in the attached flowchart) should reflect the
effects of the noncreditable Federal motor vehicle control
program (FMVCP) and Reid vapor pressure (RVP) requirements.
There are at least three approaches to this. All three
approaches will result in the same answer if followed carefully.
However, some may be easier than others depending on what work
has already been done. Method 3 may be the simplest of the three
because it does not require individual calculation of reductions
associated with each mobile source measure. In all cases
(including method 3), full documentation must be provided,
including information on MOBILESa input and vehicle miles
travelled (VMT) used in the calculations.
States should also note that the test of the plan will be to
determine whether the reductions from the measures listed below
are greater than or equal to the "Reductions Needs by 1996 to
Achieve 15 Percent Net of Growth" (box C, - box D). Because of
the possibility for errors in these reduction calculations,
States should double-check their calculations by looking at
whether the projected emissions for 1996, including growth and
all of the controls expected to be in place, will be at or below
the calculated 1996 target. If there is a discrepancy between
the results calculated by comparing the projected 1996 inventory
to the target and the results calculated above, it is likely that
some of the reductions have been double-counted. The EPA intends
to compare the 1996 projected inventory (that should be submitted
with the documentation of the 15 percent rate-of-progress plan)
to the target as the primary test of whether a State's plan
demonstrates the required reduction.
1. Growth Projections without Control Projections
(a) The State can project the 1996 emissions as if the
reductions from FMVCP and RVP will not occur. In other words,
the "1996 Estimated Emissions (Anthropogenic)" is the "1990 Rate-
of-Progress Base-Year Inventory" (box A) multiplied by the
appropriate growth factors. The on-road mobile portion of this
1996 inventory is determined by multiplying the 1990 emission
factors by the 1996 VMT. The "Reductions Needs by 1996 to
Achieve 15 Percent Net of Growth" (box C - box D) will represent
all of the reductions needed by 1996, including pre-enactment
FMVCP and RVP that will occur anyway.
(b) The reductions that will count toward this total are as
follows:
Pre-enactment FMVCP and RVP
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I/M corrections
Tier 1 (post-1990 vehicle emission standards)
Enhanced I/M
Reformulated gasoline
RACT corrections
Reductions from any other stationary or mobile source
measures
States should take care that the reductions are properly
calculated. For example, the reductions associated with the pre-
enactment FMVCP and RVP in this case are calculated as the
difference between the product of box A times growth factors
(i.e., 1990 emission factors times 1996 VMT) and 1996 projected
emissions with no new Clean Air Act (Act) measures (1996 emission
factors with NEWFLG=5 and Phase II RVP times 1996 VMT). Note
that this is different than the calculation used to adjust the
1990 base-year inventory.
The reductions associated with Tier 1 standards are then
calculated as the difference between 1996 emissions with no new
Act measures (calculated in the previous step) and 1996 projected
emissions with NEWFLG=1 and Phase II RVP. Reductions for other
measures can then be calculated sequentially in the same manner
(i.e., compare 1996 projected emissions with the new control
measure in place to 1996 emissions without the new control
measure in place but with all the previously calculated control
measures in place).
2. Growth Prelections with Federal Mobile Source Control
Projections
(a) The State can project the 1996 emissions as if the
reductions from FMVCP and RVP will occur, but no additional
mobile or stationary source controls will be in effect. In this
case, the "1996 Estimated Emissions (Anthropogenic)" is
essentially the "1990 Adjusted Base-Year Inventory" multiplied by
the appropriate growth factors. The on-road mobile portion of
this 1996 inventory is determined by multiplying the 1996
emission factors (with NEWFLG-5, Tier 1 turned off, Phase II RVP
on) by the 1996 VMT.
(b) The "Reductions Needs by 1996 to Achieve 15 Percent Net
of Growth" (box C - box D) will represent all of the reductions
needed by 1996, in addition to pre-enactment FMVCP and RVP that
will occur anyway. The reductions that will count toward this
total are as follows:
Tier 1 (post-1990 vehicle emission standards)
Enhanced I/M
Reformulated gasoline
I/M corrections
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RACT corrections
Reductions from any other stationary or mobile source
measures
3. Growth Projections with all Current Control Projections
(a) The State can project the 1996 emissions as if the
reductions from FMVCP and RVP and any other mobile and stationary
source controls, planned or in effect, will occur. In this case,
the "1996 Estimated Emissions (Anthropogenic)" is essentially the
"1990 late-of-Progress Base-Year Inventory" with the appropriate
growth factors and controls applied. The on-road mobile portion
of this 1996 inventory is determined by multiplying the 1996
emission factors (with NEWFLG=1, enhanced I/M, reform, and any
other controls turned on) by the 1996 VMT.
(b) The "Reductions Needs by 1996 to Achieve 15 Percent Net
of Growth" (box C - box D) will represent all of the additional
reductions needed by 1996. The reductions that will count toward
this total are as follows:
Reductions from any other stationary or mobile source
measures.
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11/8/93
MEMORANDUM
SUBJECT: Clarification of issues Regarding the contingency
Measures that are due November 15, 1993 for Moderate
and Above Ozone Nonattainment Areas
FROM: D. Kent Berry, Acting Director
Air Quality Management Division (MD-15)
TO: Director, Air Pesticides and Toxics
Management Division, Regions I and IV
Director, Air and Waste Management Division,
Region II
Director, Air, Radiation and Toxics Division,
Region III
Director, Air and Radiation Division,
Region V
Director, Air, Pesticides and Toxics Division,
Region VI
Director, Air and Toxics Division,
Regions VII, VIII, IX, and X
The August 23, 1993 memorandum "Guidance on Issues Related
to 15 Percent Rate-of-Progress Plans," from Michael H. Shapiro,
Acting Assistant Administrator for Air and Radiation, to you, set
forth the policy on accepting nitrogen oxide (NOx) measures for a
portion of the contingency measures that are due November 15,
1993, and for allowing committal State implementation plans
(SIP's) for the contingency measure submittal. This memorandum
provides additional clarification on a number of related issues
that were raised after issuance of the August 23 memo.
NOxReasonably Available Control Technology CRACT)
Section 172(c)(9) of the Clean Air Act (Act) states that
moderate and above ozone nonattainment areas "'. . . shall provide
for the implementation of specific measures to be undertaken if
the area fails to make reasonable further progress, or to attain
the national ambient air quality standard,"
In addition, section 182(c)(9) of the Act states that
serious and above areas "... shall provide for the
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implementation of specific measures to be undertaken if the area
fails to meet any applicable milestone."
Because the Act says that specific measures must be
undertaken if the area fails to meet a milestone, any measures
that are already required in any ozone nonattainment area would
not be creditable for the 3 percent contingency measure
requirement.1 Therefore, since NOx RACT is already a
requirement, it would not be accepted as a contingency measure.
The only exception would be the early implementation of required
measures scheduled for implementation at a later date in the SIP.
In this case, if an area then failed to meet a milestone which
triggered the implementation of the contingency measures, the
State would have 1 year to backfill the shortfall.
Note that measures that provide for emissions reductions
beyond RACT would be creditable as contingency measures.
Controjl Techniques Guidelines (CTGJs)
States may adopt, as a contingency measure, rules for
categories where the Environmental Protection Agency (EPA) plans
to issue a CTG. When EPA finally issues the CTG, however, the
State will have to revise its SIP to ensure implementation of the
RACT rule by a date certain* In other words, the rule can no
longer be a "contingency measure" that is triggered by failure to
attain or failure to meet reasonable further progress. The rule
would thtis have to be replaced with another contingency measure
after EPA issues the CTG because of the rationale stated above.
When a CTG is issued by EPA, States can consider moving a rule or
measure from its 15 percent plan to its contingency plan and
replacing the 15 percent, rule or measure with the CTG rule. This
type of transaction would require a SIP revision.
Maximum Available Control Technology (MACT), and Other Federal
Rules
Any reductions that occur because of implementing MACT or
any Federal rule are not creditable toward the contingency
measure requirement because of the rationale stated above.
States may, however, use as contingency measures rules for
categories for which EPA plans in the future to issue Federal
rules. Note that such contingency measures must be replaced when
EPA finally issues the rule. As stated in the discussion of
CTG's, a SIP revision would be required when a State replaces
*Note that an area may use as a contingency measure a rule or
measure that is required for another pollutant (such as carbon
monoxide) as long as it would provide reductions in volatile
organic compounds (VOC) or NOx.
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rules or measures in their 15 percent plan with the new MACT
standard or Federal rule and moves the replaced rule or measure
to its contingency plan.
Episodic Strategies
Section 123 of the Act states that an emissions limitation
may not be affected by any dispersion technique, which includes
"any intermittent or supplemental control of air pollutants
varying with atmospheric conditions." According to EPA guidance
documents,2 by November 15, 1993, EPA expects the regulations or
measures that are adopted for the 15 percent rate-of-progress
plan to be fully adopted, real, permanent, quantifiable, and
enforceable. Therefore, since episodic strategies do not result
in real, permanent, quantifiable, and enforceable emission
reductions, they will not be approvable for the contingency
measure requirement, as-well as the 15 percent plan requirement.
The EPA's policy was set forth in, "Stack Height Regulation;
Final Rule," 50 FR 27892, July 8, 1985.
Committal SIP's
If a State elects to submit in its SIP a commitment for the
contingency measure requirement, it must include a commitment to
adopt, by November 15, 1994, the measures or rules for the entire
3 percent required. The commitment must provide as much
information as possible, but we recognize that in some cases it
may be difficult to list the measures that an area is considering
with a schedule because the area's modeling may not yet be
complete. Completion of modeling may be necessary in cases where
a State is considering NOx controls as part of the contingency
measures. Therefore, EPA will accept such commitments without a
list of specific measures, but the commitment should at least
note the possible kinds of measures under consideration for NOx
and VOC.
Please forward this information to your State and local
agencies. Your staff may contact Kimber Scavo at (919) 541-3354
with questions.
*Two of which are: "General Preamble for the Implementation of Title I of the Clean Air Act
Amendments of 1990," 57 FR 13498, April 16, 1992, and "Guidance for Growth Factors,
Projections, and Control Strategies for the 15 Percent Rate-of-Progress Plans," EPA-452/R-93-002,
March 1993.
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