Document ID: EPA-HQ-OAR-2003-0090-0266
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2004-04-07T04:00Z

Attainment
Demonstration
for
the
San
Antonio
Early
Action
Compact
Region
Proposed
Local
Revision
to
the
State
Implementation
Plan
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
2
List
of
Appendices
Appendix
A
Conceptual
Model
and
Episode
Selection
for
the
San
Antonio
EAC
Region
Appendix
B
Development
of
the
Meteorological
Model
Appendix
C
On­
Road
Mobile
Emissions
Inventory
Development
(
TTI
Report)

Appendix
D
1999
Base
Case
Modeling
Emissions
Inventory
Development
Appendix
E
1999
Base
Case
Development
and
Performance
Analyses
Appendix
F
2007
Future
Base
Modeling
Emissions
Inventory
Development
Appendix
G
2007
Base
Case
and
Sensitivity
Analyses
Appendix
H
Modeled
Attainment
Test
Appendix
I
Clean
Air
Strategy
Development
Appendix
J
Modeling
Protocol
Appendix
K
Additional
Evidence
Appendix
L
Maintenance
for
Growth
Appendix
M
Impact
of
Transport
Appendix
N
Resolutions
from
Early
Action
Compact
Signatory
Local
Governments
in
Support
of
the
Proposed
Local
Revisions
to
the
State
Implementation
Plan
and
the
Local
Clean
Air
Strategies
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
3
LIST
OF
ACRONYMS
AACOG
Alamo
Area
Council
of
Governments
AFV
Alternative
Fuel
Vehicle
AIR
Air
Improvement
Resources
Committee
AQTF
Air
Quality
Task
Force
ARPDB
Acid
Rain
Program
Data
Base
CAPCO
Capital
Area
Planning
Council
CAMS
Continuous
Air
Monitoring
Stations
CAMx
Comprehensive
Air
Quality
Model
with
Extensions
CO
Carbon
Monoxide
COSA
City
of
San
Antonio
CPS
City
Public
Service
DFW
Dallas/
Fort
Worth
EAC
Early
Action
Compact
EGU
Electric
Generating
Unit
EI
Emissions
Inventory
EPA
U.
S.
Environmental
Protection
Agency
FAR
Flexible
Attainment
Region
FCAA
Federal
Clean
Air
Act
HC
Hydrocarbon
HDDV
Heavy
Duty
Diesel
Vehicles
HGA
Houston/
Galveston
Area
HPMS
Highway
Performance
Monitoring
System
ITS
Intelligent
Transportation
System
LED
Low
Emission
Diesel
NAAQS
National
Ambient
Air
Quality
Standards
NEGU
Non­
electric
Generating
Unit
NOx
Nitrogen
Oxides
NNA
Near
Non­
attainment
Areas
PPB
Parts
per
Billion
PPM
Parts
per
Million
RRF
Relative
Reduction
Factor
RVP
Reid
Vapor
Pressure
SA­
BC
MPO
San
Antonio­
Bexar
County
Metropolitan
Planning
Organization
SAER
San
Antonio
Early
Action
Compact
Region
SB
Senate
Bill
SIP
State
Implementation
Plan
SOS
Southern
Oxidants
Study
TCEQ
Texas
Commission
on
Environmental
Quality
TDM
Travel
Demand
Management
TERM
Transportation
Emission
Reduction
Measures
TIP
Transportation
Improvement
Plan
TPY
Tons
per
Year
TTI
Texas
Transportation
Institute
VMT
Vehicle
Miles
Traveled
VOC
Volatile
Organic
Compounds
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
4
Table
of
Contents
Page
List
of
Tables
                           
6
List
of
Figures
                           
8
Chapter
1:
General
                         .
10
1.1
Introduction
                       ..
10
1.2
Background
                       ..
10
1.2.1
History
of
Air
Quality
Planning
in
the
San
Antonio
Region 
11
1.2.2
The
Clean
Air
Plan
                 ..
12
1.3
Public
Involvement
Program                 
12
Chapter
2:
Emissions
Inventory
                    
18
2.1
Overview
                         
18
2.2
Point
Sources                       .
18
2.3
Area
Sources
                       
19
2.4
On­
Road
Mobile
Sources
                  
19
2.5
Non­
Road
Mobile
Sources
                 .
19
2.6
Biogenic
Sources
                     .
20
2.7
Emissions
Summary
                    .
20
Chapter
3:
Photochemical
Modeling
                  .
23
3.1
Introduction
                        
23
3.2
Episode
Selection
                     
23
3.3
Modeling/
Analysis
Protocol
                 .
26
3.4
1999
Meteorological
Model
                 .
28
3.5
1999
Modeling
Emissions
Inventory
             .
29
3.5.1
Local
Emissions
Inventory
               .
30
3.5.2
Texas
and
Regional
Emissions
Inventories
        
31
3.5.3
QA/
QC
Methodology
and
Preparation
of
EI
Data
for
Photochemical
Modeling
                
32
3.6
1999
Photochemical
Model
Base
Case
and
Performance
Evaluation                         
33
3.6.1
Evaluation
Methodology
                
33
3.6.2
Ozone
Metrics
                    .
35
3.6.3
Predictions
of
Precursor
Concentrations         .
40
3.6.4
Precursor
Sensitivity
Studies
              
41
3.7
2007
Future
Case
Modeling
Emissions
Inventory
       ..
43
3.8
2007
Photochemical
Model
Base
Case
and
Sensitivity
Analyses
 
45
3.9
Attainment
Demonstration
Process
             ..
50
3.9.1
Design
Values
and
Relative
Reduction
Factors      .
50
3.9.2
Modeled
Attainment
Test
               ..
51
3.9.3
Screening
Test
                    
52
3.10
Summary
and
Recommendations
              .
53
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
5
Table
of
Contents
(
continued)
Page
Chapter
4:
Data
Analysis
                       
55
4.1
Introduction
                        
55
4.2
Levels
and
Trends
in
Ozone
Concentrations          
55
4.3
Analysis
of
Meteorological
Data
               .
59
4.4
Transport
and
Local
Contributions
to
Ozone
Concentrations
   
62
4.5
Conclusion
                        .
62
Chapter
5:
Clean
Air
Strategies
                    .
64
5.1
Introduction
                        
64
5.1.1
Challenges
to
Local
Clean
Air
Strategies
        .
66
5.1.2
Challenges:
Degreasing
Equipment
Controls
      ..
68
5.1.3
Conclusion
                     .
70
5.2
Federal
and
State
Reduction
Strategies
           ..
71
5.3
Local
Clean
Air
Strategies
                 ..
72
5.4
Strategy
Testing
                      
73
5.5
Additional
Evidence
                    .
74
5.5.1
Evidence
Supporting
Attainment
Demonstration
     
74
5.5.2
Degreasing
Emissions
                
74
5.5.3
Pollution
Transport
                 ..
75
5.5.4
Alternative
Fuel
Vehicles
               
75
5.5.5
Energy
Efficiency
/
Renewable
Energy
Projects     .
75
5.5.6
Lawnmower
Recycling
Program            ..
76
5.5.7
Lower
Reid
Vapor
Pressure              
76
5.5.8
Windshield
Wiper
Fluid
                
77
5.5.9
Gas­
fired
Water
Heaters,
Small
Boilers,
and
Process
Heaters
                      ..
77
5.5.10
Transportation
Demand
Management
         ..
78
5.5.11
Transportation
Emission
Reduction
Measures
     ..
78
5.5.12
TransGuide
                     
79
5.5.13
Public
Education
                  ..
79
5.6
Summary
and
Recommendations
              .
79
Chapter
6:
Maintenance
for
Growth
                  ..
82
6.1
Background
                        
82
6.2
Maintenance
Analysis                    
82
6.3
Updating
the
Planning
Process
               .
88
6.3.1
Modeling
Updates
and
Modeling
Assumption
Verification
 .
88
6.3.2
Transportation
Patterns
                
89
6.4
New
Strategy
Requirements
                ..
89
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
6
List
of
Tables
Page
Table
1­
1
Public
Reporting
of
EAC
Milestones
             .
13
Table
3­
1
Comparisons
of
Mean
Daily
Statistics
with
Performance
Benchmarks
for
Selected
Urban
Regions
           .
29
Table
3­
2
Average
Weekday
(
Wednesday)
Anthropogenic
VOC
Emissions
in
the
Four­
county
SAER
Calculated
for
the
September
1999
Episode
                         ..
30
Table
3­
3
Average
Weekday
(
Wednesday)
Anthropogenic
NOx
Emissions
in
the
Four­
county
SAER
Calculated
for
the
September
1999
Episode
                         ..
30
Table
3­
4
Statistical
Metrics
(%),
Based
on
the
Predicted
Daily
Maximum
Ozone
Concentration
within
a
7x7
Array
of
Grid
Cells
Near
Each
Monitor,
used
to
Assess
8­
hour
Performance
of
the
September
13­
20,
1999
Photochemical
Model
in
Central
Texas
      ..
37
Table
3­
5
Statistical
Metrics
(%),
Based
on
the
Predicted
Daily
Maximum
Ozone
Concentration
within
a
7x7
Array
of
Grid
Cells
Near
Each
Monitor
that
is
Closest
in
Magnitude
to
the
Observed
Daily
Maximum,
used
to
Assess
8­
hour
Performance
of
the
September
13­
20,
1999
Photochemical
Model
in
Central
Texas
      ..
37
Table
3­
6
Statistical
Metrics
(%),
Based
on
a
Bilinear
Interpolation
of
Predicted
Daily
Maximum
Ozone
Concentration,
used
to
Assess
8­
hour
Performance
of
the
September
13­
20,
1999
Photochemical
Model
in
Central
Texas
                   
37
Table
3­
7
Estimated
2007
Average
Weekday
(
Wednesday)
VOC
Emissions
from
Anthropogenic
Sources
in
the
Four­
county
SAER
     .
44
Table
3­
8
Estimated
2007
Average
Weekday
(
Wednesday)
NOx
Emissions
from
Anthropogenic
Sources
in
the
Four­
county
SAER
     .
44
Table
3­
9
Percent
Difference
between
Estimated
Weekday
VOC
Emissions
for
1999
and
2007
in
the
Four­
county
SAER          
44
Table
3­
10
Percent
Difference
between
Estimated
Weekday
NOx
Emissions
for
1999
and
2007
in
the
Four­
county
SAER          
45
Table
3­
11
Comparison
of
1999
and
2007
Predicted
Ozone
Concentrations
by
Monitor
                        ..
45
Table
3­
12
Results
of
Sensitivity
Runs
Conducted
at
CAMS
23
(
San
Antonio
Northwest
 
Marshall
High
School)
              
48
Table
3­
13
Results
of
Sensitivity
Runs
Conducted
at
CAMS
58
(
Camp
Bullis)
..
49
Table
3­
14
Results
of
Sensitivity
Runs
Conducted
at
CAMS
59
(
Calaveras
Lake)
                          ..
49
Table
3­
15
Results
of
Sensitivity
Runs
Conducted
at
CAMS
678
(
CPS
Pecan
Valley)
                          .
50
Table
3­
16
Selection
of
Current
Monitored
Design
Values
based
on
Comparison
of
1998
 
2000
Values
with
2001
 
2003
Values
  .
51
Table
3­
17
Modeled
Attainment
Test
Results
at
SAER
Monitors
      .
51
Table
3­
18
Modeled
Attainment
Test
Results
that
Account
for
Implementation
of
Stage
I
Vapor
Recovery
                 ..
52
Table
3­
19
Screening
Cell
Design
Value
Scaling
Results
         .
53
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
7
List
of
Tables
(
continued)
Page
Table
5­
1
SAER
VOC
Emission
Reduction
Estimates
for
an
Average
Weekday
(
Wednesday)
                   
64
Table
5­
2
SAER
NOx
Emission
Reduction
Estimates
for
an
Average
Weekday
(
Wednesday)
                   
64
Table
5­
3
State
and
Federal
Issued
Rules
               .
71
Table
5­
4
Locally
Issued
Rules
                    
73
Table
5­
5
Comparison
of
1999
and
2007
Base
Cases
&
Adopted
Control
Strategies
                        ..
73
Table
5­
6
Projected
Ozone
Reductions
by
Local
Reduction
Strategies
   
74
Table
5­
7
Reduced
Emissions
from
"
Mow
Down
Smog"
Recycling
Program 
76
Table
5­
8
Reductions
for
SAER
Counties
with
RVP
7.2
Gasoline,
Compared
with
RVP
7.8
                       ..
77
Table
6­
1
Point
Source
VOC
&
NOx
Emissions
of
New
Point
Source
Projects
                         ..
84
Table
6­
2
Airport/
Military
Emissions
for
the
San
Antonio
EAC
Region
   ..
85
Table
6­
3
Biogenic
Emissions
for
the
San
Antonio
EAC
Region
      
85
Table
6­
4
Anthropogenic
Emissions
within
the
San
Antonio
Early
Action
Compact
Region
                     ..
86
Table
6­
5
Anthropogenic
Emissions
within
the
SAER,
2007­
2012
     
87
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
8
List
of
Figures
Page
Figure
2­
1
September
15,
1999
(
Wednesday)
VOC
Emissions
Inventory
for
the
San
Antonio
EAC
Counties
              
21
Figure
2­
2
September
15,
1999
(
Wednesday)
NOx
Emissions
Inventory
for
the
San
Antonio
EAC
Counties
              
21
Figure
2­
3
Estimated
Wednesday,
September
2007
VOC
Emissions
Inventory
for
the
San
Antonio
EAC
Counties
              .
22
Figure
2­
4
Estimated
Wednesday,
September
2007
NOx
Emissions
Inventory
for
the
San
Antonio
EAC
Counties
              
22
Figure
3­
1
Eight­
hour
Average
Daily
Maxima
during
the
Ramp­
up
Period
and
Modeling
Episode,
September
13
­
20,
1999,
Recorded
by
Monitors
in
the
San
Antonio
Region
             .
25
Figure
3­
2
Modeling
Domain
used
to
Simulate
the
September
13
 
20,
1999
High
Ozone
Episode
                    .
27
Figure
3­
3
Locations
of
Central
Texas
Air
Quality
Monitors
in
the
Model's
4­
km
Grid
System
                     .
35
Figure
3­
4
Observed
and
Predicted
(
within
7x7
array
of
grid
cells
near
each
monitor)
Daily
Maximum
8­
hour
Ozone
Concentrations
at
Central
Texas
Monitors
                      .
38
Figure
3­
5
Observed
and
Predicted
(
within
7x7
array
of
grid
cells
near
each
monitor
that
is
closest
in
magnitude
to
the
observed
daily
maximum)
Daily
Maximum
8­
hour
Ozone
Concentrations
at
Central
Texas
Monitors
                   
39
Figure
3­
6
Observed
and
Predicted
(
based
on
a
bilinear
interpolation
of
daily
maximum
ozone
concentrations
around
each
monitor)
Daily
Maximum
8­
hour
Ozone
Concentrations
at
Central
Texas
Monitors
                      .
39
Figure
3­
7
Comparison
of
Observed
and
Predicted
(
Run
18)
NOx
Concentrations
at
CAMS
27
during
the
September
13­
20,
1999
Episode
                         ..
40
Figure
3­
8
Comparison
of
Observed
and
Predicted
(
Run
18)
NOx
Concentrations
at
CAMS
59
during
the
September
13­
20,
1999
Episode
                         ..
41
Figure
3­
9
Comparison
of
Observed
and
Predicted
(
Run
18)
NOx
Concentrations
at
CAMS
62
during
the
September
13­
20,
1999
Episode
                         ..
41
Figure
3­
10
Predicted
Ozone
Concentrations
at
CAMS
23
after
Removing
Local
(
4­
county
SAER)
NOx
and
VOC
Emissions,
average
from
September
15
 
20,
1999
                  
42
Figure
3­
11
Predicted
Ozone
Concentrations
at
CAMS
58
after
Removing
Local
(
4­
county
SAER)
NOx
and
VOC
Emissions,
average
from
September
15
 
20,
1999
                  
43
Figure
3­
12
Comparison
of
1999
and
2007
Predicted
Daily
Maximum
8­
hour
Ozone
Concentrations
within
the
4­
km
Subdomain
for
a
Typical
Weekday
(
Wednesday,
September
15th)
           .
46
Figure
4­
1
Annual
Peak
1­
hour
and
8­
hour
Ozone
Measurements
within
SAER
                          .
55
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
9
List
of
Figures
(
continued)
Page
Figure
4­
2
San
Antonio
Eight­
hour
Ozone
Design
Value
Trends
by
Site
  ..
57
Figure
4­
3
Annual
Number
of
Days
in
which
Measured
8­
hour
Averages
Met
or
Exceeded
85
ppb
at
SAER
Monitors
          
58
Figure
4­
4
High
Ozone
Readings
by
Two­
week
Period
for
San
Antonio
Region
                          .
58
Figure
4­
5
High
Ozone
Readings
by
Two­
week
Period
for
Major
Texas
Urban
Areas
                          ..
59
Figure
4­
6
Daily
8­
hour
Ozone
Maxima
Measured
at
CAMS
23
v.
Peak
Temperature,
1998
 
2002                  
61
Figure
4­
7
Daily
8­
hour
Ozone
Maxima
v.
Average
Wind
Speeds,
1997
 
2002
                           
61
Figure
4­
8
Comparison
of
Daily
8­
hr
Maxima
&
Daily
Solar
Radiation
Maxima,
1999­
2002
                    .
61
Figure
6­
1
Trend
of
VOC
and
NOx
Emissions
in
the
SAER,
1996,
1999,
2007,
2012
                        .
87
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
10
CHAPTER
1:
GENERAL
1.1
INTRODUCTION
The
Clean
Air
Act
is
the
comprehensive
federal
law
that
regulates
airborne
emissions
from
area,
mobile,
and
stationary
sources
across
the
United
States.
This
law
authorizes
the
U.
S.
Environmental
Protection
Agency
(
EPA)
to
establish
National
Ambient
Air
Quality
Standards
(
NAAQS)
to
protect
public
health
and
the
environment.

Of
the
many
air
pollutants
commonly
found
throughout
the
country,
the
EPA
has
recognized
six
"
criteria"
pollutants
that
can
injure
health,
harm
the
environment,
and
cause
property
damage.
EPA
refers
to
these
pollutants
as
"
criteria"
air
pollutants
because
the
agency
has
regulated
them
by
first
developing
health­
based
criteria
(
science­
based
guidelines)
as
the
basis
for
setting
permissible
levels.
The
NAAQS
are
a
listing
of
the
threshold
levels,
the
concentration
values
above
which
human
health
is
put
at
risk,
for
these
criteria
pollutants.

During
the
past
several
years,
air
quality
planning
in
the
San
Antonio
region
has
intensified
since
ozone
concentrations
have
exceeded
the
values
permitted
in
the
8­
hour
ozone
NAAQS.
Due
to
legal
challenges
to
the
NAAQS
and
ensuing
litigation,
the
EPA
has
not
formally
designated
any
areas
of
the
United
States
in
violation
of
the
8­
hour
ozone
NAAQS.
However,
that
designation
process
is
expected
to
begin
as
early
as
2004.
Areas
formally
designated
in
violation
of
the
NAAQS
and
contributing
to
a
violation
are
called
"
non­
attainment
areas,"
a
term
frequently
used
in
this
and
many
other
air
quality
documents.

Local
elected
officials,
concerned
leaders
in
business
and
industry,
and
other
citizens
committed
to
air
quality
planning
have
worked
together
for
years
to
create
an
air
quality
plan
for
the
citizens
of
the
San
Antonio
region.
This
group,
meeting
as
the
Air
Improvement
Resources
(
AIR)
Committee
of
the
Alamo
Area
Council
of
Governments
(
AACOG),
has
proactively
created
an
air
quality
plan
that
is
comprehensive,
flexible,
and
relies
on
EPA­
approved
technical
analysis
for
its
control
strategy
recommendations.

1.2
BACKGROUND
During
the
ozone
seasons
of
1997
through
2000,
local
air
quality
monitors
recorded
ozone
levels
above
the
concentrations
allowed
under
the
8­
hour
ozone
NAAQS.
Moreover,
in
June
of
2002,
area
monitors
recorded
some
of
the
highest
8­
hour
and
1­
hour
ozone
values
on
record
since
19981.
In
December
2003,
the
EPA
indicated
its
intent,
barring
review
of
compelling
evidence
from
the
State
to
the
contrary,
to
designate
the
counties
of
Bexar,
Comal,
Guadalupe,
and
Wilson
as
non­
attainment
of
the
8­
hour
ozone
NAAQS.
These
counties
constituted
the
San
Antonio
Metropolitan
Statistical
Area
at
the
time
an
Early
Action
Compact,
a
major
component
of
the
area's
Clean
Air
Plan,
was
developed
and
submitted
to
the
EPA.
Since
EPA
guidance
suggests
that
Metropolitan
Statistical
Areas
be
considered
for
establishing
the
boundaries
of
new
8­

1
On
June
24,
2002,
the
CAMS
23
monitor,
located
near
Marshall
High
School
in
San
Antonio,
recorded
a
1­
hour
average
ozone
value
of
126
parts
per
billion,
an
exceedance
of
the
1­
hour
ozone
NAAQS.
The
most
recent
exceedance
of
the
1­
hour
standard
prior
to
this
date
was
141
ppb
recorded
September
4,
1998
at
CAMS
58
in
Camp
Bullis.
Also
on
June
24,
2002,
the
CAMS
23
monitor
recorded
an
8­
hour
average
ozone
reading
of
110
ppb,
an
exceedance
of
the
8­
hour
average
ozone
NAAQS.
The
most
recent
8­
hour
reading
prior
to
this
date
above
100
ppb
was
a
reading
of
110
ppb
recorded
September
4,
1998
at
CAMS
58
in
Camp
Bullis.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
11
hour
ozone
non­
attainment
areas,
air
quality
planning
focused
on
Bexar,
Comal,
Guadalupe
and
Wilson
Counties.

1.2.1
History
of
Air
Quality
Planning
in
the
San
Antonio
Region
As
early
as
1995,
the
Air
Quality
Committee
of
the
Alamo
Area
Council
of
Governments,
chaired
by
Senator
Jeff
Wentworth,
first
met
to
address
air
quality
issues
in
the
San
Antonio
region.
This
committee
requested
the
first
emissions
inventory,
for
inventory
year
1994.

In
January
1996,
the
San
Antonio
Mayor's
Blue
Ribbon
Committee
on
Air
Quality
merged
with
the
Air
Quality
Committee
of
the
Alamo
Area
Council
of
Governments
(
AACOG)
to
form
the
Air
Quality
Task
Force
(
AQTF).
The
charge
of
the
AQTF
was
to
develop
public
education
and
provide
advice
to
elected
officials
on
air
quality
issues.
The
major
accomplishment
of
the
early
AQTF
was
the
establishment
of
the
Ozone
Action
Day
program.
During
FY
1996
­
1997,
the
AQTF
provided
input
on
the
first
Near
Non­
Attainment
grant,
authorized
by
the
1997
Texas
Legislature.

However,
when,
in
the
summer
of
1996,
the
EPA
proposed
the
new
eight­
hour
ozone
NAAQS,
the
focus
of
the
AQTF
began
to
shift,
first
by
providing
comments
and
guidance
on
the
impact
of
the
new
eight­
hour
ozone
NAAQS.
In
the
summer
of
1998
a
local
contingency
met
with
EPA's
Region
6
to
begin
discussion
on
the
development
of
a
Flexible
Attainment
Region
(
FAR)
agreement.

The
AACOG
developed
its
first
photochemical
model
in
1997
along
with
sponsoring
air
quality
monitoring
efforts
at
St.
Hedwig
(
southeast
Bexar
County)
during
the
1997
ozone
season.
Monitoring
results
indicated
that
on
high
ozone
level
days,
background
levels
coming
into
Bexar
County
were
at
or
near
ozone
NAAQS
threshold
levels.
Later
that
year
when
EPA
finalized
the
eight­
hour
NAAQS
it
became
apparent
that,
based
on
historical
data,
the
SAER
could
well
be
designated
non­
attainment
when
the
EPA
made
the
first
eight­
hour
non­
attainment
designations
initially
scheduled
for
July
2000.

During
July
1998,
the
City
of
San
Antonio
(
COSA),
San
Antonio­
Bexar
County
Metropolitan
Planning
Organization
(
MPO),
Bexar
County,
and
AACOG
staff
recommended
to
elected
officials
that
the
AQTF
be
revised
to
fit
the
structure
advised
by
the
Texas
Commission
on
Environmental
Quality
(
TCEQ),
then
known
as
the
Texas
Natural
Resource
Conservation
Commission
(
TNRCC).
During
January
­
February
1999,
the
Boards
of
Directors
and
other
responsible
parties
representing
COSA,
Bexar
County,
MPO,
and
AACOG
approved
the
formation
of
the
Air
Improvement
Resources
(
AIR)
Committee
consortium
including
the
Executive/
Advisory,
Technical,
and
Public
Education
Committees
and
member
appointments.
The
AIR
Committee
conducted
its
first
official
meeting
during
April
1999
with
the
goal
to
establish
an
organized,
comprehensive,
and
aggressive
plan
of
action
to
keep
the
SAER
from
slipping
into
nonattainment
of
the
ozone
standard.

Working
with
partners
in
the
near
non­
attainment
areas
across
Texas,
the
AACOG
has
developed
a
second
photochemical
model
for
September
1999.
This
episode
models
ozone
formation
for
four
of
the
five
near
non­
attainment
areas
of
the
state,
Corpus
Christi,
Austin,
Victoria
and
San
Antonio.
AACOG
is
now
expanding
the
network
of
ozone
and
meteorological
monitoring
stations
in
the
San
Antonio
region.
The
TCEQ
is
responsible
for
maintaining
monitors
upon
which
official
air
quality
data
depends.
Better
monitoring
allows
for
refined
technical
analysis
of
human
exposure
to
ozone,
a
greater
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
12
understanding
of
the
formation
and
movement
of
ozone
in
the
region,
and
provides
a
database
for
verification
of
the
performance
of
future
photochemical
models.

1.2.2
The
Clean
Air
Plan
On
December
9,
2002
the
Clean
Air
Plan
for
the
San
Antonio
Region
was
signed
by
elected
officials
representing
the
SAER.
The
Clean
Air
Plan
was
designed
to
enable
a
local
approach
to
ozone
attainment
and
to
encourage
early
emission
reductions
that
will
help
keep
the
SAER
in
attainment
of
the
1­
hour
ozone
NAAQS
and
ensure
attainment
of
the
8­
hour
ozone
NAAQS,
and
so
protect
human
health.

This
Clean
Air
Plan
also
incorporates
the
Early
Action
Compact
for
the
San
Antonio
area.
The
Early
Action
Compact
protocol
was
endorsed
by
EPA
Region
6
on
June
19,
2002,
and
is
designed
to
develop
and
implement
control
strategies,
account
for
growth,
and
achieve
and
maintain
the
8­
hour
ozone
standard.
As
such,
it
represents
a
key
component
to
finalizing
this
area's
Clean
Air
Plan.

Since
its
first
meeting,
the
AIR
Committee
has
worked
to
transform
the
results
of
its
planning
effort
into
a
protocol
able
to
address
air
quality
planning
requirements
originating
with
the
Clean
Air
Act.
The
AIR
Committee
recognizes
that
the
Clean
Air
Plan
provides
the
means
to
sustain
the
region's
air
quality
by
proactively
seeking
local
solutions
within
a
suitable
state
and
federally
approved
protocol.

The
Clean
Air
Plan
is
designed
to
be
a
working
document
providing
comprehensive
planning
for
the
ozone
challenge
faced
by
the
citizens
of
the
entire
SAER.
Adoption
of
this
Clean
Air
Plan
requires
development
of
control
strategies,
or
methodologies
for
lowering
ozone
concentrations
to
acceptable
levels,
which
are
designed
to
meet
the
region's
clean
air
challenge.
The
technical
analysis
of
the
photochemical
modeling,
used
to
demonstrate
the
effectiveness
of
the
control
strategies,
is
performed
by
the
staff
of
AACOG
and
is
reviewed
and
approved
by
the
AIR
Committee,
the
staff
of
AACOG,
the
TCEQ,
and
the
EPA.

1.3
PUBLIC
INVOLVEMENT
PROGRAM
The
EAC
for
the
San
Antonio
region
requires
that
the
AIR
Committee
be
responsible
for
the
assessment
and
reporting
of
the
region's
progress
against
milestones
with
deliverables
sent
to
TCEQ
and
the
EPA
and
reported
in
a
regular,
public
process
at
least
every
six
months.
Public
reporting
of
assessment
and
progress
against
milestones
occurs
at
least
once
every
six
months
during
the
regularly
scheduled,
public
meetings
(
scheduled
on
a
monthly
basis),
of
the
joined
AIR
Executive/
Advisory
Committees
of
the
AACOG.
Every
regularly
scheduled
meeting
of
the
AIR
Executive
and
Advisory
Committees
is
a
public
meeting,
with
notification
of
the
meeting
time
and
location
published
by
AACOG
according
to
the
Texas
Open
Meetings
Act.

EAC
milestones
were
discussed
during
the
AIR
Executive/
Advisory
Committee
meetings
conducted
at
the
Alamo
Area
Council
of
Governments,
8700
Tesoro
Drive,
Suite
100,
San
Antonio,
Texas
on
the
dates
provided
in
table
1­
1.

In
addition
to
the
meetings
listed
in
table
1­
1,
AACOG
conducted
public
workshops
in
all
four
SAER
counties
to
discuss
elements
of
the
Clean
Air
Plan
and
obtain
citizen
feedback.
Meeting
topics
and
meeting
dates
for
these
public
workshops
are
provided
in
appendix
J,
"
Modeling/
Analysis
Protocol."
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
13
Table
1­
1.
Public
Reporting
of
EAC
Milestones.

Milestone
Date
of
Air
Improvement
Resources
(
AIR)
Public
Meeting
in
which
Progress
was
Assessed/
Reported
Emissions
Inventory
Milestones
Development
of
a
1999
or
later
episode
emissions
inventory
4­
23­
03
Agenda
Item:
Clean
Air
Plan
Update
 
MOBILE6
On­

Road
Update
Incorporation
of
MOBILE6
data
with
link­
based
Travel
Demand
Model
data
4­
23­
03
Agenda
Item:
Clean
Air
Plan
Update
 
MOBILE6
On­

Road
Update
10­
1­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
Attainment
Demonstration
Model
Status
Development
of
additional
emission
inventory
episode
data
based
on
local
Conceptual
Model
update.
Development
of
other
episode
inventories,
if
required,
made
in
concert
with
EPA,
TCEQ,
and
local
entities
4­
23­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Conceptual
Model
Development
of
NONROAD
model
data
adjusted
for
local
equipment
populations
and
usage
rates
and
development
of
area
source
data
based,
when
possible,
on
local
survey
data
8­
27­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
2007
Projection
in
the
Photochemical
Model
Completion
of
an
Emissions
Trend
Analysis
Report
utilizing
the
National
Emissions
Trends
Emissions
Inventories
8­
27­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
Trend
Analysis
10­
1­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
Final
Approval
of
the
Trend
Analysis
Modeling
Milestones
Development
of
SIP­
quality
modeling
episodes
that
perform
within
the
EPA's
accepted
margin
of
accuracy
by
completion
of
the
following
modeling­
related
tasks:

Develop
base
case
on
or
before
December
31,
2007

Develop
future
case
on
or
before
December
31,
2007

Provide
documentation
to
TCEQ
and
EPA

Evaluate
quantifiable
emission
reduction
measures
in
the
future
case
to
produce
one
or
more
control
cases

Evaluate
control
strategies
against
control
case
model.
4­
23­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Photochemical
Model
Update
7­
23­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Photochemical
Modeling
Update
8­
27­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
2007
Projection
in
the
Photochemical
Model
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
14
Milestone
Date
of
Air
Improvement
Resources
(
AIR)
Public
Meeting
in
which
Progress
was
Assessed/
Reported
Modeling
Milestones
(
continued)
10­
1­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
Attainment
Demonstration
Model
Status
10­
1­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
Final
Approval
of
the
2007
Photochemical
Model
Projection
10­
29­
03
Agenda
Item:
AIR
Technical
Committee
Reports
 
Attainment
Demonstration
Model
Status
Development
of
other
episodes,
as
necessary,
to
fully
represent
the
variety
of
situations
that
typically
contribute
to
local
ozone
production
4­
23­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Conceptual
Model
Note:
Based
on
current
Conceptual
Model
analyses,
no
other
photochemical
model
episodes
are
planned
at
this
time
Control
Strategy
Development
Milestones
Identify
additional
local
controls,
as
necessary,
to
demonstrate
2007
attainment
of
the
8­
hour
standard.

Implement
controls
by
December
31,
2005,
with
full
local
stakeholder
participation.
2­
26­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Review
of
Control
Strategy
Matrix
3­
26­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Review
of
Control
Strategy
Matrix
4­
23­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Submission
of
Draft
Clean
Air
Strategies
5­
28­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Submission
of
Draft
Clean
Air
Strategies
8­
27­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
Update
to
the
Clean
Air
Strategies
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
15
Milestone
Date
of
Air
Improvement
Resources
(
AIR)
Public
Meeting
in
which
Progress
was
Assessed/
Reported
Control
Strategy
Development
Milestones
(
continued)
10­
1­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
Update
to
the
Clean
Air
Strategies
10­
29­
03
Agenda
Item:
AIR
Technical
Committee
Reports
 
Update
to
the
Clean
Air
Strategies
12­
22­
03
Agenda
Item:
Technical
Updates
­
Further
Modeling
of
Clean
Air
Strategies
for
the
EAC
Provide
control
measures
to
TCEQ
for
incorporation
into
the
State
Implementation
Plan
1­
28­
04
Agenda
Item:
Clean
Air
Plan
 
Action
Item:
Approve
Clean
Air
Strategies
List
Recommended
by
the
AIR
Technical
Committee
for
the
State
Implementation
Plan
3­
3­
04
Agenda
Item:
Clean
Air
Plan
 
Clean
Air
Strategies
Update
3­
24­
04
Agenda
Item:
Clean
Air
Plan
 
Clean
Air
Strategies
Update
and
Action
Item:
Approval
of
finalized
Clean
Air
Plan
and
Signed
Letter
of
Submission
addressed
to
TCEQ/
EPA
Maintenance
for
Growth
Milestones
Address
emissions
growth
at
least
5
years
beyond
December
31,
2007
to
ensure
the
area
will
remain
in
attainment
of
the
8­
hour
standard
during
that
period
8­
27­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
Trend
Line
Analysis
Continue
the
planning
process
by
including
updates
to
modeling
and
verification
of
modeling
assumptions
(
particularly
growth
assumptions)
4­
23­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Photochemical
Model
Update
7­
23­
03
Agenda
Item:
AIR
Technical
Committee
Reports
 
Photochemical
Modeling
Update
8­
27­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
air
Plan
 
2007
Projection
in
the
Photochemical
Model
SIP
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San
Antonio
EAC
Region
16
Milestone
Date
of
Air
Improvement
Resources
(
AIR)
Public
Meeting
in
which
Progress
was
Assessed/
Reported
Incorporate
additional
measures
to
the
plan
if
the
review
of
growth
demonstrates
that
adopted
control
measures
are
inadequate
to
address
increases
in
emissions
10­
1­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
Final
Approval
of
September
30
EAC
Milestones
Action
Item:
Final
Approval:
Trend
Analysis
Public
Involvement
Milestones
Encourage
public
involvement
in
all
stages
of
the
planning
and
implementation
process.
Involve
stakeholders
in
the
planning
process
as
early
as
possible.

Conduct
public
education
programs
to
raise
awareness
regarding
issues,
opportunities
for
involvement
in
the
planning
process,
and
implementation
of
control
strategies.

Make
draft
plans
publicly
available
and
allow
sufficient
opportunities
for
comment
from
all
interested
stakeholders.

Present
and
make
publicly
available
semi­
annual
reports
detailing,
at
a
minimum,
progress
toward
milestones
1­
29­
03
Agenda
Item:
Citizen
Comments
at
First
Public
Meeting
on
the
Clean
Air
Plan
Conducted
January
22,
2003
2­
26­
03
Agenda
Item:
Citizen
Comments
at
Second
Public
Meeting
on
the
Clean
Air
Plan
Conducted
February
22,
2003
3­
26­
03
Agenda
Item:
Citizen
Comments
at
Third
Public
Meeting
on
the
Clean
Air
Plan
Conducted
March
19,
2003
3­
26­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Business
and
Industry
Outreach
4­
23­
03
Agenda
Item:
Citizen
Comments
at
the
Fourth
Public
Meeting
on
the
Clean
Air
Plan
Conducted
April
12,
2003
4­
23­
03
Agenda
Item:
Discussion
of
Issues
of
Public
Participation
and
the
Early
Action
Compact
4­
23­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Biannual
Progress
Report
5­
28­
03
Agenda
Item:
Citizen
Comments
at
the
Fifth
Public
Meeting
on
the
Clean
Air
Plan
Conducted
May
20,
2003
5­
28­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Review
of
First
Biannual
Progress
Report
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
17
Milestone
Date
of
Air
Improvement
Resources
(
AIR)
Public
Meeting
in
which
Progress
was
Assessed/
Reported
Public
Involvement
Milestones
(
continued)
6­
18­
03
Agenda
Item:
Citizen
Comments
at
the
Sixth
Clean
Air
Plan
Workshop
of
2003
Conducted
on
June
14,
2003
6­
18­
03
Agenda
Item:
Clean
Air
Plan
Update
 
Approval
of
First
Biannual
Progress
Report
7­
23­
03
Agenda
Item:
Citizen
Comments
at
the
Seventh
Clean
Air
Plan
Workshop
of
2003
Conducted
July
16,
2003
8­
27­
03
Agenda
Item:
Milestones
and
Timelines
in
the
Clean
Air
Plan
 
Ongoing
Local
Efforts
10­
1­
03
Agenda
Item:
Other
Issues
For
Discussion
 
Public
Presentation
of
Clean
Air
Strategies
10­
29­
03
Agenda
Item:
Other
Issues
 
Clean
Air
for
Central
Texas
Public
Presentation/
Workshop
for
Clean
Air
Strategies
Scheduled
for
November
5,
2003
12­
22­
03
Agenda
Item:
Clean
Air
Plan
 
Action
Item
EAC
Milestone
Approval:
2nd
Biannual
Progress
Report
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
18
CHAPTER
2:
EMISSIONS
INVENTORY
2.1
OVERVIEW
The
1990
Amendments
to
the
federal
Clean
Air
Act
(
FCAA)
and
40
CFR,
§
51.322
require
that
emissions
inventories
(
EI)
be
prepared
statewide,
particularly
for
ozone
nonattainment
areas.
The
chemical
species
that
form
ozone
include
volatile
organic
compounds
(
VOC),
nitrogen
oxides
(
NOx),
and
to
a
more
limited
degree,
carbon
monoxide
(
CO).
Because
ground­
level
ozone
forms
photochemically
(
i.
e.,
in
the
presence
of
sunlight)
as
the
result
of
VOC,
NOx
and
CO
chemical
reactions,
it
is
critical
that
planners
identify
and
quantify
these
precursor
pollutants.
The
EI
describes
sources
of
precursors
within
a
region
as
well
as
the
amount
of
each
pollutant
emitted
and
any
processes
and
control
devices
in
use.

EI
data
are
used
in
support
of
a
variety
of
air
quality
planning
tasks,
including
establishing
baseline
emission
levels,
calculating
reduction
targets,
developing
control
strategies,
developing
emission
inputs
for
air
quality
simulation
models,
and
tracking
actual
emission
reductions
against
the
established
emissions
growth
and
control
budgets.
This
chapter
focuses
on
the
development
of
EI
data
used
in
the
development
of
a
photochemical
model
that
simulates
an
elevated
ozone
episode
that
occurred
in
September
1999.
This
San
Antonio
area
base
case
EI
includes
VOC,
NOx,
and
CO
emissions
for
the
September
1999
episode
for
five
general
categories
of
emissions
sources,
as
described
below.

2.2
POINT
SOURCES
Major
point
sources
include
industrial,
commercial,
or
institutional
sources
that
emit
criteria
pollutants
at
or
above
thresholds
established
by
the
FCAA.
For
nonattainment
areas,
this
threshold
varies
from
10
tons
per
year
(
tpy)
to
100
tpy
depending
on
the
pollutant
in
question
and
the
seriousness
of
the
nonattainment
problem.
For
the
attainment
areas
of
the
state,
any
source
that
emits
a
minimum
of
100
tpy
of
a
regulated
pollutant
must
complete
an
inventory.
Additionally,
any
source
that
generates
or
has
the
potential
to
generate
at
least
10
tpy
of
any
single
hazardous
air
pollutant
(
HAP)
or
25
tpy
of
aggregate
HAPs
is
also
required
to
report
emissions
to
the
Texas
Commission
on
Environmental
Quality
(
TCEQ).

To
collect
emissions
and
industrial
process
operating
data
for
these
plants,
the
TCEQ
mails
Emissions
Inventory
questionnaires
(
EIQ)
to
all
sources
identified
as
having
emissions
that
trigger
the
reporting
requirements.
Companies
must
report
the
type
of
emissions
from
all
emission­
generating
units
and
emission
points,
as
well
as
the
amount
of
materials
used
in
the
processes
that
result
in
emissions.
The
EIQ
also
requests
information
on
process
equipment,
operation
schedules,
emissions
control
devices,
abatement
device
control
efficiency,
and
stack
parameters
such
as
location,
height,
and
exhaust
gas
flow
rate.
All
data
submitted
via
the
EIQ
are
subjected
to
rigorous
quality
assurance
procedures
by
the
technical
staff
of
the
Industrial
Emissions
Assessment
Section,
and
are
then
entered
into
the
Point
Source
Data
Base
(
PSDB)
by
the
Data
Services
Section.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
19
2.3
AREA
SOURCES
Area
sources
are
defined
as
emission
sources
that
fall
below
the
point
source
reporting
levels,
and
are
too
numerous
or
too
small
to
identify
individually.
Area
sources
include
commercial,
small­
scale
industrial,
and
residential
sources
that
use
materials
or
operate
processes
generating
VOC,
NOx,
or
CO
emissions.
Area
sources
can
be
divided
into
two
groups
 
hydrocarbon
evaporative
emissions
or
fuel
combustion
emissions
 
depending
on
the
emission
mechanism.
Examples
of
activities
that
generate
evaporative
losses
include
printing,
application
of
industrial
coatings,
use
of
degreasing
solvents,
house
painting,
leaking
underground
storage
tanks,
gasoline
service
station
underground
tank
filling,
and
vehicle
refueling
operations.
Fuel
combustion
sources
include
stationary
source
fossil
fuel
combustion
at
residences
and
businesses,
as
well
as
outdoor
burning,
structural
fires,
and
wildfires.
These
emissions,
with
some
exceptions,
may
be
calculated
by
multiplication
of
an
established
emission
factor
(
emissions
per
unit
of
activity)
times
the
appropriate
activity.
If
the
activity
level
is
difficult
to
obtain
or
measure,
surrogate
data
may
be
used
to
develop
emissions
estimates.
Population
is
the
most
commonly
used
surrogate
for
many
area
source
categories,
while
other
activity
data
include
amount
of
gasoline
sold
in
an
area,
employment
by
industry
type,
and
acres
of
cropland.

2.4
ON­
ROAD
MOBILE
SOURCES
On­
road
mobile
sources
consist
of
automobiles,
trucks,
motorcycles,
and
other
motor
vehicles
traveling
a
region's
roadways.
Combustion­
related
emissions
are
estimated
for
vehicle
engine
exhaust,
and
evaporative
hydrocarbon
emissions
are
estimated
for
the
fuel
tank
and
other
sources
of
leaks
from
vehicles.
Emission
factors
were
developed
using
the
EPA's
mobile
emission
factor
model,
MOBILE6.
Model
inputs
were
developed
specifically
for
the
San
Antonio
area.
These
inputs
include
such
parameters
as
vehicle
speeds
by
roadway
type,
vehicle
registration
by
vehicle
type
and
age,
percentage
of
miles
traveled
by
vehicle
type,
and
gasoline
vapor
pressure.
All
of
these
inputs
have
an
impact
on
the
emission
factor
calculated
by
the
MOBILE
model,
and
every
effort
is
made
to
use
parameters
reflecting
local
conditions.
To
complete
the
emissions
estimate,
the
emission
factors
calculated
by
the
MOBILE
model
must
be
multiplied
by
a
measure
of
vehicle
activity:
vehicle
miles
traveled
(
VMT).
The
level
of
vehicle
travel
activity
is
developed
from
the
federal
Highway
Performance
Monitoring
System
(
HPMS)
data
compiled
by
the
Texas
Department
of
Transportation
for
each
county.
Finally,
roadway
speeds,
which
are
required
for
the
MOBILE
model's
input,
are
obtained
from
an
analysis
for
several
roadway
types
performed
by
the
Texas
Transportation
Institute
(
TTI).

2.5
NON­
ROAD
MOBILE
SOURCES
Non­
road
mobile
sources
include
aircraft
operations,
recreational
boats,
residential
and
commercial
lawn
maintenance
equipment,
railroad
locomotives,
and
a
wide
range
of
offhighway
equipment.
Methods
for
calculating
emissions
from
non­
road
engine
sources
are
based
on
information
about
equipment
populations,
engine
horsepower,
load
factor,
emission
factor,
and
annual
usage.
With
the
exception
of
aircraft
and
locomotives,
nonroad
emissions
were
estimated
using
EPA's
NONROAD
model.
Aircraft
emissions
were
estimated
using
the
Emissions
and
Dispersion
Modeling
System
(
EDMS)
aircraft
emissions
model.
Model
inputs
were
obtained
from
airport
documents
containing
landing
and
takeoff
data.
Locomotive
emissions
were
developed
from
fuel
usage
and
track
mileage
data
obtained
from
individual
railroads.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
20
2.6
BIOGENIC
SOURCES
Biogenics
refers
to
natural
sources
of
emissions,
primarily
vegetation
(
e.
g.,
crops,
lawn,
and
forests).
Vegetation
emits
VOCs
such
as
isoprenes,
monoterpenes,
and
alphapinenes
Natural
processes
in
soil
also
contribute
to
ozone
by
emitting
a
small
amount
of
NOx.
The
biogenic
emission
inventory
for
the
San
Antonio
region
was
developed
by
ENVIRON
International
Corporation,
under
contract
with
the
TCEQ,
using
version
2.2
of
the
GloBEIS
biogenic
emissions
model.
Emissions
were
calculated
at
the
county
level
for
an
ozone
season
day
in
1999
by
using
weather
conditions
typical
of
the
September
1999
timeframe
as
model
input.
The
model
was
further
enhanced
through
the
use
of
the
TCEQ's
landuse/
landcover
(
LULC)
database.

Emissions
from
biogenic
sources
are
natural;
therefore
controls
on
biogenic
sources
are
not
appropriate.
Nevertheless,
biogenic
emissions
are
part
of
the
ozone
chemistry
and
must
be
included
in
both
the
base
and
future
case
photochemical
modeling
to
ensure
that
the
overall
chemical
profile
is
correct.
Only
anthropogenic
emissions
are
included
in
control
strategy
testing,
however.

2.7
EMISSIONS
SUMMARY
The
base
case
EI
for
the
four
SAER
counties
are
summarized
in
figures
2­
1
(
VOC)
and
2­
2
(
NOx).
These
numbers
represent
emission
estimations
for
September
15,
1999
(
Wednesday),
chosen
to
represent
an
average
weekday.

The
percent
contributions
from
VOC
sources
in
the
September
15,
1999
base
case
inventory
include
the
following:
53.8%
from
biogenic,
26.6%
from
area/
non­
road,
18.2%
from
on­
road,
and
1.5%
from
point
sources.
The
percent
contributions
from
NOx
sources
for
the
September
15,
1999
EI
include:
45.7%
from
on­
road,
32.3%
from
point
sources,
15.3%
from
area/
non­
road,
and
6.7%
from
biogenic.

Natural
sources
(
biogenics)
are
included
in
the
summary.
However,
control
strategies
are
limited
to
the
reduction
of
anthropogenic
emissions.

In
addition
to
creating
a
1999
base
case
EI,
a
2007
future
base
EI
was
developed
to
facilitate
attainment
demonstration
modeling.
The
2007
EI
was
projected
from
1999
emissions
using
growth
factors
and
control
factors.
Figures
2­
3
(
VOC)
and
2­
4
(
NOx)
summarize
the
2007
future
base
EI
for
the
four
San
Antonio
EAC
counties.
The
percent
contributions
from
VOC
sources
in
the
September
2007
(
Wednesday)
future
case
inventory
include
the
following:
59.5%
from
biogenic,
26.0%
from
area/
non­
road,
11.5%
from
on­
road,
and
3.1%
from
point
sources.
The
percent
contributions
from
NOx
sources
for
the
September
2007
EI
include:
36.5%
from
on­
road
category,
33.3%
from
point
sources,
21.0%
from
area/
non­
road,
and
9.3%
from
biogenic.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
21
Figure
2­
1.
September
15,
1999
(
Wednesday)
VOC
Emissions
Inventory
for
the
San
Antonio
EAC
Counties.

Figure
2­
2.
September
15,
1999
(
Wednesday)
NOx
Emissions
Inventory
for
the
San
Antonio
EAC
Counties.
On­
road
18.2%

Area/
Non­
road
26.6%
Point
1.5%
Biogenic
53.8%
Tons/
Day
Percent
On­
road
88.8
18.2%
Area/
Non­
road
130.2
26.6%
Point
7.2
1.5%
Biogenic
263.0
53.8%

Total
489.2
100.0%

On­
road
45.7%

Area/
Non­
road
15.3%
Point
32.3%
Biogenic
6.7%
Tons/
Day
Percent
On­
road
143.6
45.7%

Area/
Non­
road
48.1
15.3%
Point
101.3
32.3%
Biogenic
21.0
6.7%

Total
314.0
100.0%
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
22
Figure
2­
3.
Estimated
Wednesday,
September
2007
VOC
Emissions
Inventory
for
the
San
Antonio
EAC
Counties.

Figure
2­
4.
Estimated
Wednesday,
September
2007
NOx
Emissions
Inventory
for
the
San
Antonio
EAC
Counties.
On­
road
11.5%

Area/
Non­
road
26.0%

Point
3.1%
Biogenic
59.5%
Tons/
Day
Percent
On­
road
50.7
11.5%
Area/
Non­
road
114.8
26.0%
Point
13.5
3.1%
Biogenic
263.0
59.5%

Total
441.9
100.0%

On­
road
36.5%

Area/
Non­
road
21.0%
Point
33.3%
Biogenic
9.3%
Tons/
Day
Percent
On­
road
82.3
36.5%
Area/
Non­
road
47.3
21.0%
Point
75.1
33.3%
Biogenic
21.0
9.3%

Total
225.7
100.0%
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
23
CHAPTER
3:
PHOTOCHEMICAL
MODELING
3.1
INTRODUCTION
The
Natural
Resources
staff
of
the
Alamo
Area
Council
of
Governments
has
supported
the
development
of
and
made
refinements
to
two
discrete
photochemical
models
suitable
for
attainment
demonstrations
in
the
San
Antonio
EAC
region.
The
first
was
a
1995
episode
simulation
developed
to
establish
a
base
case
for
an
attainment
demonstration
in
the
region's
Early
Implementation
Plan
and
O3
Flex
Plan.
These
plans
were
forerunners
to
the
current
Clean
Air
Plan
developed
under
the
TCEQ's
and
EPA's
Early
Action
Compact
protocol.
The
1995
model
simulation
was
presented
to
EPA
Region
6
and
TCEQ
representatives
in
2002
and
was
found
adequate
for
attainment
work.

AACOG
staff
also
refined,
with
the
assistance
of
other
agencies2,
a
1999
episode
that
is
used
to
demonstrate
attainment
in
the
SAER's
Early
Action
Compact
SIP.
Development
of
the
September
15th
through
20th,
1999
episode
model
was
sponsored
by
four
Southcentral
Texas
near
nonattainment
areas3
(
NNA)
and
TCEQ.
During
this
time
span,
monitors
in
the
San
Antonio
region
recorded
8­
hour
ambient
ozone
levels
as
high
as
96
parts
per
billion
(
ppb)
4
as
shown
in
figure
3­
1.
This
exceeds
the
85­
ppb
threshold
established
by
the
"
eight­
hour
average
ozone
standard"
in
the
1997
amendments
to
the
Clean
Air
Act.
Similarly,
other
urban
areas
of
South
and
Central
Texas
also
experienced
elevated
ozone
concentrations.

The
intent
of
developing
the
1999
simulation
was
to
provide
a
base
case
as
the
first
step
in
projecting
air
quality
conditions
to
the
year
2007
so
that
clean
air
measures
could
be
modeled
and
analyzed
for
their
effectiveness
in
that
future
time
period.
The
year
2007
was
chosen
because
it
coincides
with
the
attainment
dates
for
the
largest
metropolitan
areas
of
Texas
including
Dallas­
Fort
Worth
and
Houston.
By
that
date,
three
of
the
four
Texas
nonattainment
areas
should
have
control
strategies
in
place.
Since
ambient
ozone
levels
in
San
Antonio
can
be
affected
by
transport
of
pollution
from
Houston
and
other
areas,
selecting
a
date
in
which
control
strategies
are
in
place
for
other
large
urban
areas
is
an
important
modeling
consideration.
Furthermore,
the
Early
Action
Compacts
for
two
Texas
regions
(
Austin
and
San
Antonio)
require
attainment
by
2007.
As
a
result,
the
Texas
non­
attainment
and
EAC
areas
benefit
from
the
use
of
coordinated
timelines
and
coordinated
planning
of
control
strategy
programs.

3.2
EPISODE
SELECTION
An
initial
step
in
the
attainment
demonstration
model
process
entailed
developing
a
conceptual
description
of
the
SA
area's
ozone
problem.
The
conceptual
model
of
ozone
formation
provided
a
basis
for
determining
subsequent
steps
in
the
model
development
process
including
those
related
to
episode
selection.
One
of
the
intents
of
the
conceptual
model
was
to
summarize
both
the
local
meteorological
conditions
and
associated
synoptic
weather
patterns
typically
experienced
during
periods
of
elevated
ozone
concentrations.
This
process
was
facilitated
by
assembling
and
reviewing
all
available
ambient
air
quality
data,
meteorological
data,
and
previous
photochemical
2
Other
entities
involved
in
refining
the
1999
base
case
included
the
TCEQ,
The
University
of
Texas
at
Austin,
and
ENVIRON
International
Corporation.
3
The
regions
of
Austin,
Corpus
Christi,
San
Antonio
and
Victoria.
4
Measured
at
the
Camp
Bullis
monitor
on
September
18,
1999.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
24
modeling
efforts.
Appendix
A
provides
a
description
of
the
conceptual
model
developed
for
the
San
Antonio
region.

Ozone
formation
in
the
San
Antonio
region
is
influenced
by
many
of
the
same
factors
as
in
other
areas
of
Texas.
These
factors
include
sunny
skies,
high
pressure,
and
low
wind
speeds.
Ozone
formation
peaks
during
the
warm
weather
that
predominates
in
the
San
Antonio
region
from
April
through
October.

In
their
draft
guidance
(
1999),
EPA
recommends
using
four
criteria,
at
a
minimum,
to
select
episodes
appropriate
for
modeling.
The
minimum
criteria
include:
1)
reviewing
a
mix
of
episodes
that
represent
a
variety
of
meteorological
conditions
associated
with
observed
8­
hour
daily
maxima
in
excess
of
84
ppb;
2)
selecting
periods
in
which
observed
8­
hour
daily
maxima
approximate
the
average
fourth
highest
8­
hour
ozone
concentrations;
3)
reviewing
periods
for
which
extensive
air
quality/
meteorological
data
exist;
and
4)
modeling
a
sufficient
number
of
days
to
represent
a
complete
ozone
cycle.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
25
Figure
3­
1.
Eight­
hour
Average
Daily
Maxima
during
the
Ramp­
up
Period
and
Modeling
Episode,
September
13
­
20,
1999,
Recorded
by
Monitors
in
the
San
Antonio
Region.

Monitoring
Site
13
14
15
16
17
18
19
20
San
Antonio
Northwest
C23
57
66
82
85
75
92
89
84
Camp
Bullis
C58
57
63
79
78
74
96
91
81
CPS
Pecan
Valley
C678
56
57
74
74
64
76
84
86
Calaveras
Lake
C59
64
64
81
81
76
80
89
84
Numbers
in
red
represent
exceedances
of
the
8­
hour
average
threshold.

Work
conducted
during
the
summer
of
2000
on
the
Conceptual
Model
helped
staff
identify
five
candidate
episodes
for
modeling
purposes:
June
21­
23,
1995,
August
28
 
September
3,
1998,
August
16
 
21,
1999,
August
30
 
September
1,
1999,
and
September
16
 
20,
1999.
However,
the
June
21­
23,
1995,
August
16­
21,
1999,
and
August
30
 
September
1,
1999
episodes
were
eliminated
from
consideration
because
of
a
lack
of
meteorological
data
(
8/
30
 
9/
1/
99
episode),
an
insufficient
number
of
exceedance
days
(
8/
16
 
8/
21/
99
episode),
or
because
the
episode
occurred
prior
to
the
design
value
period
(
6/
21
 
6/
23/
95
episode)
 
a
secondary
criterion.

Ultimately,
the
September
13
 
20,
1999
high
ozone
episode
was
chosen
for
the
most
recent
modeling
effort.
Both
the
August­
September
1998
and
September
1999
episodes
met
the
primary
selection
criteria
recommended
by
the
EPA.
In
addition,
both
episodes
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
26
met
some
secondary
criteria,
such
as
inclusion
of
weekend
days
and
correspondence
with
the
current
(
as
of
Conceptual
Model
development
in
September
2000)
design
value.
However,
the
decision
to
model
the
September
1999
episode
was
based
on
another
secondary
selection
criterion;
i.
e.,
the
1999
time
period
represented
an
elevated
ozone
episode
for
multiple
regions
of
Texas.
The
benefits
of
developing
a
regional
model
covering
four
near
non­
attainment
areas
included
cost­
sharing
and
a
consistent,
Central
Texas
base
case
on
which
to
model
clean
air
strategies.

The
September
episode
consists
of
two
model
initialization
days,
September
13th
and
14th,
and
five
primary
episode
days,
September
15
 
20,
1999.
Although
these
days
(
15th­
20th)
were
chosen
because
they
represent
a
period
in
which
elevated
ozone
levels
occurred
in
South­
central
Texas,
the
modeling
domain
covers
a
much
larger
geographical
area
than
South­
central
Texas
alone.
The
larger
domain
is
necessary
to
simulate
the
effects
of
meteorological
and
atmospheric
processes
including
transport
of
precursors
and
background
concentrations
of
ozone
to
the
San
Antonio
region.
The
32­
hour
back
trajectories
for
the
1999
episode
originated
in
southeastern
Missouri.
Consequently,
the
36­
km
coarse
grid
used
in
the
model
simulation
extends
throughout
much
of
the
South
and
Central
U.
S.
including
the
Ohio
River
Valley
to
the
north
and
Atlanta
to
the
east,
as
shown
in
Figure
3­
2.
Furthermore,
this
matches
the
TCEQ
standard
modeling
domain.
The
grid
formulation
includes
two
nested
grids:
a
12­
km
grid
domain
that
incorporates
eastern
Texas
including
the
nonattainment
areas
of
Dallas/
Fort
Worth,
Houston/
Galveston,
and
Beaumont/
Port
Arthur,
and
an
urban
scale
4­
km
grid
that
covers
the
four
NNAs
in
South­
central
Texas.

The
EAC
requires
development
of
other
episodes,
as
necessary,
to
fully
represent
the
variety
of
situations
that
typically
contribute
to
local
ozone
production.
The
San
Antonio
region
agreed
in
the
Early
Action
Compact
signed
December
2002,
to
investigate
further
episode
development
based
on
Conceptual
Model
updates.
Updates
are
scheduled
for
completion
by
AACOG
by
April
30,
2003
and
April
30,
2005.
Based
on
the
April
2003
update
of
the
Conceptual
Model,
in
an
analysis
agreed
upon
by
TCEQ,
no
candidate
episodes
were
revealed.

The
2003
Conceptual
Model
update
was
comprehensive
of
all
potential
episodes
from
1995
through
2002.
Although
there
was
one
candidate
episode
in
2002,
the
meteorological
conditions
resemble
the
meteorological
patterns
in
the
September
1999
episode.
Also,
this
2002
episode
was
potentially
useful
to
Austin
and
San
Antonio;
whereas
the
1999
episode
was
useful
to
Austin,
Corpus
Christi,
San
Antonio,
and
Victoria.
As
a
consequence,
the
2002
episode
is
not
a
particularly
strong
candidate.
However,
if
the
region
is
required
to
perform
2002
modeling,
as
is
currently
the
case
for
traditional
8­
hour
non­
attainment
areas,
then
this
episode
may
be
revisited
and
developed.
Ongoing
research
will
attempt
to
identify
new,
viable
episodes.

3.3
MODELING/
ANALYSIS
PROTOCOL
Many
stakeholders
were
involved
in
the
modeling/
analysis
protocol
process.
Decisions
as
to
which
modeling
episode,
air
quality
simulation
model,
and
modeling
consultant(
s)
to
use
were
made
by
staff
of
the
TCEQ
and
representatives
of
four
Texas
NNAs:
Austin
(
Capital
Area
Planning
Council
and
Central
Texas
Clean
Air
Force),
Corpus
Christi
(
City
of
Corpus
Christi),
San
Antonio
(
Alamo
Area
Council
of
Governments),
and
Victoria
(
City
of
Victoria).
Modeling
decisions
were
reviewed
within
the
SAER
by
the
Air
Improvement
Resources
Technical
Committee
which
is
composed
of
technical
staff
representing
local
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
27
governments.
Recommendations
from
the
Technical
Committee
were
forwarded
to
the
Air
Improvement
Resources
(
AIR)
Executive/
Advisory
Committee
during
regularlyscheduled
public
meetings
for
final
approval
at
the
local
level.
For
example,
the
decision
to
use
the
September
13
 
20,
1999
episode
for
modeling
purposes
was
approved
during
the
August
23,
2000
AIR
Executive/
Advisory
Committee
meeting
by
voting
members
of
the
AIR
Committee.

Voting
members
(
Executive
members)
of
the
AIR
Committee
include
one
representative
each
from
Bexar
County,
Comal
County,
City
of
Floresville,
Guadalupe
County,
City
of
New
Braunfels,
City
of
San
Antonio,
City
of
Seguin,
Wilson
County,
The
Alamo
Area
Council
of
Governments
Board
of
Directors,
Greater
Bexar
County
Council
of
Cities
(
GBCCC)
and
the
San
Antonio­
Bexar
County
Metropolitan
Planning
Organization
(
MPO).

The
Advisory
committee,
although
not
consisting
of
voting
members,
includes
representatives
of
other
governmental
entities,
numerous
industries,
and
private
citizens.
Appendix
J
provides
additional
information
regarding
the
modeling/
analysis
protocol
for
the
SAER.

Figure
3­
2.
Modeling
Domain
used
to
Simulate
the
September
13
 
20,
1999
High
Ozone
Episode.
Source:
ENVIRON
International
Corporation.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
28
3.4
1999
METEOROLOGICAL
MODEL
The
September
1999
ozone
model
was
developed
using
the
Mesoscale
Model
(
MM5),
the
standard
meteorological
model
used
by
TCEQ
and
recommended
by
EPA.
The
original
September
13
 
20,
1999
meteorological
model
was
developed
using
version
3.4
of
the
MM5
model.
However,
statistical
summaries
of
modeling
results
indicated
certain
performance
problems.
These
included
consistent
over
prediction
of
wind
speed
at
night
and
under
predictions
during
the
daytime;
over
prediction
of
early
morning
temperatures;
and
marginal
performance
for
both
humidity
and
the
overall
pressure
pattern
covering
the
south­
central
U.
S.

It
was
assumed
that
the
deficiencies
in
performance
were
the
result
of
a
combination
of
errors
associated
with
model
inputs
and
the
choice
of
internal
model
algorithms.
Based
on
results
of
sensitivity
tests,
numerous
additional
iterations
of
the
model
were
conducted
to
incorporate
new
information
and
improve
known
deficiencies.
These
subsequent
runs
were
conducted
on
the
newly­
released
version
3.5
of
MM5;
and
so,
took
advantage
of
the
additional
modeling
capabilities
of
the
refined
meteorological
model.
The
new
runs
also
incorporated
improvements
to
the
boundary
layer
scheme,
radiation
scheme,
soil
moisture
scheme,
and
observational
analyses
and
FDDA
techniques.

The
final
MM5
configuration,
referred
to
as
"
Met
Run
5g,"
exhibited
improved
simulation
capabilities
of
surface
temperature
and
pressure
gradients
over
Texas,
and
improved
temperature
and
humidity
performance
at
the
surface.
In
addition,
the
EDAS
analysis
field
utilized
for
large­
scale
grid
nudging
on
Met
Run
5g
more
closely
resembled
observations
than
the
EDAS
initialization
package
used
for
other
meteorological
runs.
As
a
result,
the
Met
Run
5g
configuration
is
the
basis
for
the
meteorological
fields
used
in
development
of
the
September
13
 
20,
1999
photochemical
model
for
the
San
Antonio,
area,
as
well
as
three
other
NNA
regions.
Met
Run
5g
incorporates
the
following
model
physics
and
options
(
CAPCO
2004):

28
sigma
levels

Two­
way
interactive
108/
36/
12/
4­
km
grids

Three­
dimensional
analysis
nudging
 
MM5
was
lightly
nudged
toward
3
hourly
gridded
EDAS
analysis
of
winds
(
in
the
boundary
layer
and
aloft)
and
temperature
and
humidity
(
only
above
the
boundary
layer),
which
were
improved
by
the
blending
of
routine
surface
and
upper­
air
observational
data

Two­
dimensional
surface
analysis
nudging
 
MM5
was
lightly
nudged
toward
3
hourly
gridded
surface
analyses
of
winds,
temperature
and
humidity

Observation
nudging
on
the
12/
4­
km
grids
 
MM5
was
strongly
nudged
toward
discrete
hourly
wind
observations
from
routine
and
special
measurement
networks
operating
in
Texas
during
the
episode

Medium
Range
Forecast
(
MRF)
planetary
boundary
layer
scheme

Simple
ice
cloud
microphysics

Kain­
Fritsch
cumulus
parameterization,
except
on
4­
km
grid

Five­
layer
soil
model

RRTM
radiation
scheme

Reduced
soil
moisture
and
thermal
inertia
to
account
for
drier
conditions
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
29
Table
3­
1
provides
Met
Run
5g
performance
statistics
for
several
regions
within
the
4­
km
domain.
These
4­
km
grid
subdomains
include
Austin
/
San
Antonio,
Corpus
Christi
/
Victoria,
and
Houston
/
Galveston
/
Beaumont
/
Port
Arthur.
A
fourth
column
lists
performance
benchmarks
for
comparison
purposes.
The
benchmarks
represent
performance
goals
that
were
established
as
the
result
of
comparing
statistical
summaries
of
nearly
thirty
regional
meteorological
models
developed
for
various
areas
of
the
country.
The
goals
reflect
the
results
of
meteorological
models
that
were
accepted
and
used
in
support
of
regulatory
air
quality
photochemical
modeling
efforts
(
CAPCO,
2004).

The
subdomain
performance
statistics
listed
in
table
3­
1are
based
on
comparisons
between
observations
obtained
from
ground­
level
monitoring
stations
and
Met
Run
5g
predictions.
As
indicated
by
the
results,
Met
Run
5g
demonstrated
excellent
performance
for
wind
speed
and
direction
and
good
performance
for
temperature
and
humidity
within
the
4­
km
domain.
Since
the
most
important
variables
passed
to
the
ozone
model
are
wind
speed
and
direction,
MM5
performance
on
other
variables
is
secondary.

Table
3­
1.
Comparisons
of
Mean
Daily
Statistics
with
Performance
Benchmarks
for
Selected
Urban
Regions.
Values
in
red
denote
statistics
outside
the
performance
goals
(
CAPCO,
January
2004).
Episode
Mean
Parameter
Benchmark
Austin/
San
Antonio
Corpus
Christi/
Victoria
Houston/
Galveston/
Beaumont/
Port
Arthur
Wind
Speed
RMSE*
<
2.0
m/
s
1.2
1.3
1.3
Wind
Speed
Bias
±
0.5
m/
s
0.0
0.5
0.4
Wind
Speed
IOA**
>
0.60
0.68
0.81
0.63
Wind
Direction
Gross
Error
<
30
deg
36
23
30
Wind
Direction
Bias
±
10
deg
­
6
­
5
2
Temperature
Gross
Error
<
2.0
K
2.1
1.3
1.5
Temperature
Bias
±
0.5
K
­
1.3
0.4
­
0.6
Temperature
IOA**
>
0.80
0.92
0.92
0.95
Humidity
Gross
Error
<
2.0
g/
kg
1.4
2.4
1.1
Humidity
Bias
±
1.0
g/
kg
­
0.3
­
1.6
­
0.3
Humidity
IOA**
>
0.60
0.47
0.53
0.61
*
RMSE:
root
mean
square
error
**
IOA:
index
of
agreement
Development,
analysis,
and
subsequent
refinement
of
the
September
13­
20,
1999
meteorological
model
are
explained
in
more
detail
in
appendix
B.
Appendix
B
also
provides
descriptions
of
the
statistical
measurements
used
to
evaluate
the
meteorological
model's
performance.

3.5
1999
MODELING
EMISSIONS
INVENTORY
In
addition
to
meteorological
inputs,
photochemical
models
require
emissions
inputs
that
are
day­
and
hour­
specific
to
the
modeled
time
period.
For
the
September
1999
ozone
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
30
episode,
this
required
identifying
and
quantifying
sources
of
VOC,
NOx
and
CO
emissions,
as
ozone
forms
as
the
result
of
chemical
reactions
between
these
chemical
precursors.
In
order
to
prepare
emissions
for
use
in
an
air
quality
model,
the
emissions
were
temporally
allocated
to
account
for
seasonal
differences
in
emission
rates
or
activity
and
to
apportion
emissions
to
a
particular
day
or
hour,
in
accordance
with
EPA
policy
(
EPA
April
1999).
Furthermore,
the
emissions
were
spatially
allocated
among
each
grid
cell
in
the
modeling
domain,
both
horizontally
and
vertically.

As
described
previously,
the
original
September
1999
photochemical
simulation
failed
to
meet
certain
EPA­
established
acceptance
criteria
for
photochemical
simulations.
Efforts
to
improve
model
performance
focused
on
refining
the
meteorological
inputs
(
see
section
3.3)
and
the
emissions
inputs.
As
a
result,
the
emission
inventory
for
the
September
13­
20,
1999
episode
underwent
extensive
scrutiny
and
refinement
since
development
of
the
original
1999
model
simulation.
The
final
mobile
on­
road,
area/
nonroad
and
point
source
(
anthropogenic)
VOC
and
NOx
emission
inventories
developed
for
the
four­
county
SAER
are
summarized
in
tables
3­
2
and
3­
3,
respectively.

Table
3­
2.
Average
Weekday
(
Wednesday)
Anthropogenic
VOC
Emissions
in
the
Fourcounty
SAER
Calculated
for
the
September
1999
Episode.

County
On­
Road
(
tpd)
Area
/
Non­
road
(
tpd)
Point
(
tpd)
Total
(
tpd)
Bexar
75.52
111.98
6.30
193.80
Comal
6.15
6.70
0.34
13.20
Guadalupe
5.57
7.77
0.45
13.78
Wilson
1.57
3.73
0.07
5.37
Total
(
tpd)
88.81
130.18
7.17
226.15
Table
3­
3.
Average
Weekday
(
Wednesday)
Anthropogenic
NOx
Emissions
in
the
Fourcounty
SAER
Calculated
for
the
September
1999
Episode.

County
On­
Road
(
tpd)
Area
/
Non­
road
(
tpd)
Point
(
tpd)
Total
(
tpd)
Bexar
119.57
39.39
88.59
247.55
Comal
11.64
3.57
12.16
27.38
Guadalupe
10.47
4.24
0.51
15.21
Wilson
1.89
0.93
0.00
2.82
Total
(
tpd)
143.58
48.12
101.26
292.96
3.5.1
Local
Emissions
Inventory
TCEQ
provided
staff
with
local
biogenic
and
point
source
emissions
inventories
for
the
12­
county
AACOG
region.
Area
and
non­
road
inventories
were
developed
by
staff
using
guidance
from
such
documents
as
EPA's
Air
Chief
and
AP­
42.
Whenever
possible,
emission
calculation
methodologies
were
supplemented
with
data
obtained
from
surveys.
Specific
sources
that
were
surveyed
in
development
of
the
local
1999
EI
included
quarry
operations;
power
plants;
operators
of
construction,
commercial,
industrial,
railroad,
and
agricultural
equipment;
bakeries;
wineries;
breweries;
wastewater
treatment
plants;
and
asphalt
paving
operations.

One
of
the
most
significant
refinements
made
to
the
modeling
EI
was
the
use
of
traffic
demand
modeling
and
EPA's
MOBILE6
model
to
develop
link­
based
on­
road
inventories
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
31
for
some
urban
areas
of
Texas
including
the
4­
county
SAER.
The
original
1999
SAER
on­
road
EI
was
created
using
a
previous
version
of
the
model,
MOBILE5a_
h.
Texas
Transportation
Institute,
under
contract
with
the
TCEQ,
developed
MOBILE6
on­
road
emission
estimates
for
18
Texas
NNA
counties.
This
MOBILE6
EI
file,
labeled
version
1,
continued
to
undergo
review
during
the
QA/
QC
process.

As
a
product
of
their
review,
an
enhanced
MOBILE6
on­
road
file,
version
2,
was
developed
by
TTI
to
account
for
an
improved
methodology
for
allocating
vehicle
miles
traveled
(
VMT)
for
heavy­
duty
diesel
vehicles
(
HDDV).
The
Bexar
County
MOBILE6
version
2
on­
road
file
was
provided
to
AACOG
by
TCEQ
modeling
staff
on
August
29,
2003
and
incorporated
into
the
September
1999
photochemical
model
labeled
"
CAMx
Run
18."
Although
AACOG
eventually
received
MOBILE6
on­
road
inventories
for
surrounding
SAER
counties
(
Comal,
Guadalupe,
and
Wilson),
the
file
was
not
received
in
time
to
incorporate
into
the
photochemical
model.

To
account
for
the
anticipated
difference
between
MOBILE5a_
h
and
MOBILE6
emission
estimations
in
Comal,
Guadalupe,
and
Wilson
counties,
an
emissions
factor
was
applied
to
the
counties'
on­
road
emission
data
using
a
software
adjustment.
This
"
cntlem"
software
program
was
provided
to
staff
by
UT
Austin.

The
on­
road
inventories
were
developed
by
TTI
for
a
September
17
 
20,
1999
timeframe.
TTI's
documentation
on
development
of
NNA
on­
road
emission
inventories
is
included
as
appendix
C
of
this
SIP.
The
process
of
converting
TTI's
emissions
inventory
from
an
abbreviated
episode,
September
17­
20,
1999,
to
the
complete
episode
including
ramp­
up
period
(
September
13
 
20,
1999),
is
presented
in
appendix
D.

3.5.2
Texas
and
Regional
Emissions
Inventories
September
1999
area
and
non­
road
modeling
EIs
were
developed
for
three
other
urban
areas
within
the
4­
km
subdomain
(
the
NNA
partners
participating
in
the
joint
modeling
project
­
Austin,
Corpus
Christi,
and
Victoria)
for
inclusion
in
the
photochemical
model.
Area/
non­
road
files
for
the
remainder
of
Texas
were
obtained
from
the
TCEQ
and
based
on
the
TEXAQS
2000
data
set.
In
order
to
use
this
data
set
for
modeling
a
September
1999
ozone
episode,
the
data
were
backcast
to
1999
using
the
ratio
of
1999/
2000
emissions
as
determined
by
the
Economic
Growth
Analysis
System
(
EGAS)
4.0
and
NONROAD
2000
models.

Non­
electric
generating
unit
(
NEGU)
point
source
emissions
were
obtained
from
the
TCEQ's
point
source
database
(
PSDB).
Electric
generating
unit
(
EGU)
point
source
emissions
were
provided
by
the
TCEQ
from
a
September
1999
TCEQ
emissions
package
that
was
updated
with
data
from
the
1999
Acid
Rain
Program
Data
Base
(
ARPDB).
This
data
set
applied
to
all
of
Texas
with
the
exception
of
Houston.
The
11­
county
Houston
point
source
file
was
based
on
a
2000
NEGU
and
EGU
emissions
inventory.

On­
road
mobile
EI
data
for
Texas
were
developed
by
TTI
and
provided
to
staff
by
TCEQ.
MOBILE6,
version
1
was
used
to
develop
on­
road
emissions
for
the
Houston
area,
Gregg
County
and
Smith
County.
On­
road
EI
files
for
the
remainder
of
the
state
were
developed
using
MOBILE5a_
h.

In
some
cases
the
Texas
area,
non­
road,
and
mobile
EI
data
provided
by
the
TCEQ
required
additional
refinement.
The
modeling
EI
for
the
Houston
area,
for
example,
was
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
32
developed
for
an
August
2000
ozone
episode.
Therefore,
the
emissions
data
were
backcast
from
August
2000
to
September
1999
using
appropriate
modeling
software
such
as
the
EGAS,
MOBILE6
and
NONROAD
models.

Regional
EI
data
for
states
outside
of
Texas
were
provided
by
the
TCEQ.
Other
than
point
sources
for
the
State
of
Louisiana,
the
TCEQ
based
the
emission
rates
on
EPA's
1999
National
Emission
Inventory
(
NEI
v.
2).
The
point
source
EI
for
Louisiana
was
obtained
from
the
Louisiana
Department
of
Environmental
Quality,
quality
assured
by
the
TCEQ,
and
updated
with
September
data
from
the
ARPDB.

3.5.3
QA/
QC
Methodology
and
Preparation
of
EI
Data
for
Photochemical
Modeling
Several
quality
assurance/
quality
control
methodologies
were
used
to
assess
the
reliability
of
the
EI
calculations.
These
included
"
reality
checks"
in
which
calculations
were
evaluated
for
reasonableness,
peer
review
of
the
EI
by
TCEQ,
replication
of
calculations
for
some
emissions
sources,
statistical
checks,
and
computerized
checks.
To
conduct
computerized
checks,
staff
evaluated
computer­
generated
graphics
using
PAVE
software
to
identify
possible
problems
and
make
comparisons
(
1999
EI
versus
2007
EI
for
example).
This
type
of
check
provided
an
additional
benefit;
i.
e.,
it
allowed
analysts
to
evaluate
the
spatial
allocation
of
emissions.
Examples
of
these
types
of
comparisons
can
be
found
in
figures
G­
1
through
G­
6
of
appendix
G.

In
addition
to
checking
data
for
accuracy
in
terms
of
calculation
methodologies
and
geographical
allocation,
data
were
also
evaluated
in
terms
of
temporal
allocation.
This
step
involved
reviewing
data
distribution
by
hour
of
the
day,
day
of
the
week,
and
season.

Although
the
original
September
1999
model
was
developed
by
ENVIRON
and
further
refined
by
collaboration
between
ENVIRON
and
UT
Austin
(
meteorological
model
and
air
quality
input
refinements),
the
model
was
eventually
provided
to
the
NNA
partners
(
or
their
contractors)
for
further
modifications.
These
modifications
included
refinement
of
the
emissions
inventory
inputs,
development
of
the
future
case,
and
clean
air
strategy
analyses.
Because
the
model
was
modified
by
more
than
one
agency
during
this
process,
there
was
a
concern
that
the
various
agencies'
models
would
be
dissimilar
and
provide
different
predictions
for
the
base
case,
future
case,
and
control
strategy
runs.

As
part
of
the
QA/
QC
process,
a
great
amount
of
effort
was
spent
ensuring
that
the
Austin
and
San
Antonio
base
and
future
cases
contained
identical
input.
Often
this
involved
discussions
between
the
two
agencies,
as
well
as
TCEQ,
regarding
the
most
appropriate
model
procedures
and
EI
data
for
local
and
regional
areas.
Discrepancies
in
emissions
inputs
were
corrected
prior
to
the
final
AACOG
and
UT
Austin
runs.

As
a
result
of
this
effort,
the
base
and
future
cases
refined/
developed
by
AACOG
and
UT
are
nearly
identical.
An
analysis
of
predictions
made
by
the
two
models
reveals
that
there
is
an
insignificant
difference
in
the
models'
predictions
at
the
two
Austin
monitors.
The
average
differences,
during
the
six­
day
episode,
between
peak
predictions
at
the
Murchison
and
Audubon
monitors
when
comparing
the
AACOG
and
UT
base
cases
were
0.00
ppb
and
0.05
ppb,
respectively.
For
the
2007
future
cases,
the
average
differences
in
peak
concentrations
were
 
0.06
ppb
(
Murchison)
and
 
0.04
ppb
(
Audubon).
Daily
differences
in
peak
predictions
by
the
two
models
are
provided
in
the
Summary
of
appendix
E.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
33
Upon
completion
of
the
QA/
QC
process,
the
emissions
were
formatted
for
the
CAMx
photochemical
model
using
EPA's
Emissions
Preprocessor
System
2.0
(
EPS2).
The
EPS2
computer
program
performs
the
data
manipulations
required
to
incorporate
spatial,
temporal,
and
chemical
resolution
into
the
emissions
inventory
used
by
photochemical
models.
At
the
end
of
the
spatial
and
temporal
allocation
process,
data
totals
were
checked
to
ensure
no
emissions
were
lost
during
the
allocation
process.

3.6
1999
PHOTOCHEMICAL
MODEL
BASE
CASE
AND
PERFORMANCE
EVALUATION
In
addition
to
extensive
refinement
of
the
meteorological
and
emissions
inputs,
other
model
configurations
were
reviewed
for
suitability
during
an
on­
going
test
and
evaluation
process.
This
step
entailed
performing
sensitivity
analyses
on
various
model
parameters
including
dry
deposition
algorithms,
chemistry
data,
and
boundary/
initial
conditions.
As
a
result
of
these
studies,
changes
were
made
to
some
model
settings
including
dry
deposition
algorithms
(
to
account
for
mild
drought
conditions
occurring
in
eastern
Texas
during
September
1999)
and
boundary
condition
data.
Sources
of
refined
boundary/
initial
condition
data
included
U.
S.
EPA's
guidance
on
UAM
modeling,
measurements
of
rural
oxidants
collected
during
the
Southern
Oxidants
Study
(
SOS),
and
data
collected
during
the
Gulf
of
Mexico
Air
Quality
Study
sponsored
by
the
Minerals
Management
Service.
Appendix
E
provides
a
more
extensive
description
of
1999
photochemical
model
development
including
the
modifications
made
to
the
dry
deposition
algorithms,
chemistry
data,
and
boundary/
initial
conditions.

3.6.1
Evaluation
Methodology
In
accordance
with
EPA's
draft
8­
hour
guidance
(
May
1999),
the
September
1999
photochemical
simulation
was
subjected
to
a
variety
of
1­
hour
and
8­
hour
performance
analyses.
Many
of
the
tests
conducted,
including
scatter
plots,
Q­
Q
plots,
and
ozone
metrics,
were
used
to
measure
the
differences
between
predictions
and
their
paired
observations.
Due
to
some
uncertainty
as
to
the
most
appropriate
method
of
implementing
the
EPA's
8­
hour
statistics,
and
in
recognition
that
model
performance
for
8­
hour
averaged
ozone
attainment
demonstrations
is
currently
being
applied
for
the
first
time,
statistical
metrics
were
calculated
using
three
different
methodologies.
These
included:
1)
The
predicted
daily
maximum
ozone
concentration
within
grid
cells
near
a
monitor;
2)
The
predicted
daily
maximum
ozone
concentration
within
grid
cells
near
a
monitor
that
is
closest
in
magnitude
to
the
observed
daily
maximum
at
the
monitor;
and
3)
A
bilinear
interpolation
of
predicted
daily
maximum
ozone
concentration
around
the
monitor
location.

EPA's
draft
guidance
provides
default
recommendations
for
delineating
the
area
"
near
a
monitor."
The
defaults
are
based
on
the
size
of
the
grid
cells
used
in
the
photochemical
model.
Since
the
1999
episode
was
modeled
using
a
4­
km
grid,
"
near
a
monitor"
was
determined
to
be
the
7
x
7
array
of
cells
surrounding
each
monitor.
The
7
x
7
arrays
surrounding
the
Central
Texas
monitors
are
represented
by
dashed
red
lines
in
figure
3­
3.
The
Central
Texas
monitors
include
four
CAMS
sites
located
in
the
10­
county
Capital
Area
Planning
Council
(
CAPCO)
region
and
four
monitors
located
in
the
12­
county
AACOG
region.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
34
The
1999
base
case
was
also
evaluated
using
a
second
type
of
performance
analysis:
sensitivity
tests.
These
tests
were
used
to
determine
how
accurately
the
model
responds
to
changes
in
emissions.
Diagnostic,
or
sensitivity,
tests
were
conducted
throughout
the
model
development
process.
The
type
of
sensitivity
test
applied
to
the
model
depended
on
the
stage
of
model
development.
During
the
performance
evaluation
stage,
sensitivity
analysis
efforts
focused
on
testing
the
impacts
of
precursor
species
on
ozone
concentrations.
These
tests
and
test
results
are
provided
in
Section
3.5.2.
SIP
Revision
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EAC
Region
35
Figure
3­
3.
Locations
of
Central
Texas
Air
Quality
Monitors
in
the
Model's
4­
km
Grid
System.
Dashed
red
lines
represent
the
7
x
7
array
of
cells
surrounding
each
monitor.

3.6.2
Ozone
Metrics
EPA
recommends
calculating
ozone
metrics
to
produce
numerical
comparisons
between
observed
(
measured)
ozone
concentrations
and
the
model's
predicted
concentrations.
The
recommended
metrics
include
calculations
of
bias,
error,
and
correlation
coefficients.

In
addition
to
conducting
the
metrics
calculations
for
individual
monitors,
the
EPA
recommends
"
pooling"
data
by
monitor
location,
i.
e.,
developing
average
statistics
for
downwind,
city
center,
and
upwind
groups
of
monitors.
Both
the
San
Antonio
and
Austin
areas
have
relatively
sparse
monitoring
networks.
Although,
bias,
error,
and
other
metrics
were
calculated
for
monitoring
groups
when
possible,
the
two
EAC
regions,
based
on
recommendations
from
the
TCEQ
and
U.
S.
EPA
Region
6,
evaluated
performance
based
on
the
averaged
statistics
for
all
stations
in
Central
Texas.
The
ozone
metrics
calculated
for
the
pooled
eight
Central
Texas
monitors
are
provided
in
this
section.
Metrics
for
individual
monitors
and
monitor
groups
are
provided
in
appendix
E.

In
their
draft
guidance
(
EPA,
May
1999),
the
EPA
recommends
specific
goals
for
each
of
the
ozone
metrics
tests.
These
goals
include
the
following:
SIP
Revision
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San
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EAC
Region
36
Test
Goal
Bias
between
predicted/
observed
mean
8­
hour
(
and
1­
hour)
daily
maxima
near
each
monitor
20%
most
monitors
(
8­
hr
comparisons
only)

Fractional
bias
between
predicted/
Observed
mean
8­
hour
(
and
1­
hour)
daily
maxima
near
each
monitor
20%
most
monitors
(
8­
hr
comparisons
only)

Correlation
coefficients,
all
data,
temporally
paired
means,
spatially
paired
means
Moderate
to
large
positive
correlation
Bias
(
8­
hour
daily
maxima
and
1­
hour
observed/
predicted),
all
monitors
5
 
15%

Gross
error
(
8­
hour
daily
maxima
and
1­
hour
observed/
predicted),
all
monitors
30
 
35%

Statistical
metrics
averaged
for
the
eight
Central
Texas
monitors,
using
each
of
the
three
methodologies
described
in
Section
3.5.1,
are
presented
in
tables
3­
4
through
3­
6.
Likewise,
scatter
plots
with
correlation
coefficients
and
Q­
Q
results,
using
each
of
the
three
methodologies,
are
provided
in
figures
3­
4
through
3­
6.
These
statistical
and
graphical
metrics
were
performed
on
the
final
photochemical
model
run,
CAMx
Run
18,
which
incorporated
the
refined
meteorological
model
(
Met
Run
5g),
refined
emissions
inventories,
modified
dry
deposition
algorithms
to
account
for
vegetation
moisture
stress,
and
the
modified
boundary/
initial
conditions
described
in
appendix
E.

Although
EPA
does
not
require
calculating
performance
statistics
for
the
model
initialization
period,
these
metrics
are
included
in
tables
3­
4
through
3­
6
for
comparison
purposes.
Metrics
for
the
initialization
days
are
highlighted
in
yellow.

As
demonstrated,
all
bias
and
error
metrics
averaged
for
the
eight
Central
Texas
monitors
fall
within
the
goals
established
for
the
EPA.
Furthermore,
the
goals
are
not
only
met
on
primary
episode
days
(
September
15
 
20,
1999),
but
also
on
the
initialization
days.
SIP
Revision
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the
San
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EAC
Region
37
Table
3­
4.
Statistical
Metrics
(%),
Based
on
the
Predicted
Daily
Maximum
Ozone
Concentration
within
a
7x7
Array
of
Grid
Cells
Near
Each
Monitor,
used
to
Assess
8­
hour
Performance
of
the
September
13­
20,
1999
Photochemical
Model
in
Central
Texas.

Date
Maximum
Observed
8­
Hour
Ozone
Concentration
(
ppb)
Maximum
Predicted
8­
Hour
Ozone
Concentration
(
ppb)
Average
Normalized
Bias
(
±
15%)
Average
Fractional
Bias
(
±
15%)
Average
Normalized
Error
(
35%)
Average
Fractional
Error
(
35%)

9/
13/
99
55.74
52.87
­
4.54
­
5.01
8.63
8.94
9/
14/
99
60.03
59.56
­
0.13
­
0.70
7.51
7.39
9/
15/
99
75.41
74.09
­
1.28
­
1.67
6.80
6.92
9/
16/
99
76.19
75.04
­
0.80
­
1.13
7.46
7.50
9/
17/
99
82.12
80.75
­
0.79
­
1.16
7.66
7.74
9/
18/
99
85.53
83.59
­
2.13
­
2.40
5.96
6.15
9/
19/
99
88.76
89.58
1.16
0.82
7.07
7.01
9/
20/
99
82.24
86.20
4.68
4.43
6.40
6.21
Table
3­
5.
Statistical
Metrics
(%),
Based
on
the
Predicted
Daily
Maximum
Ozone
Concentration
within
a
7x7
Array
of
Grid
Cells
Near
Each
Monitor
that
is
Closest
in
Magnitude
to
the
Observed
Daily
Maximum,
used
to
Assess
8­
hour
Performance
of
the
September
13­
20,
1999
Photochemical
Model
in
Central
Texas.

Date
Maximum
Observed
8­
hour
Ozone
Concentration
(
ppb)
Maximum
Predicted
8­
hour
Ozone
Concentration
(
ppb)
Average
Normalized
Bias
(
±
15%)
Average
Fractional
Bias
(
±
15%)
Average
Normalized
Error
(
35%)
Average
Fractional
Error
(
35%)

9/
13/
99
55.74
51.92
­
6.45
­
6.84
6.74
7.13
9/
14/
99
60.03
57.59
­
3.84
­
4.07
3.84
4.07
9/
15/
99
75.41
72.15
­
4.09
­
4.34
4.11
4.36
9/
1699
76.19
72.77
­
4.13
­
4.32
4.13
4.32
9/
17/
99
82.12
78.25
­
4.24
­
4.47
4.32
4.55
9/
18/
99
85.53
81.83
­
4.20
­
4.43
4.26
4.49
9/
19/
99
88.76
86.02
­
2.88
­
3.02
3.15
3.30
9/
20/
99
82.24
81.61
­
0.85
­
0.88
1.01
1.04
Table
3­
6.
Statistical
Metrics
(%),
Based
on
a
Bilinear
Interpolation
of
Predicted
Daily
Maximum
Ozone
Concentration,
used
to
Assess
8­
hour
Performance
of
the
September
13­
20,
1999
Photochemical
Model
in
Central
Texas.

Date
Maximum
Observed
8­
hour
Ozone
Concentration
(
ppb)
Maximum
Predicted
8­
hour
Ozone
Concentration
(
ppb)
Average
Normalized
Bias
(
±
15%)
Average
Fractional
Bias
(
±
15%)
Average
Normalized
Error
(
35%)
Average
Fractional
Error
(
35%)

9/
13/
99
55.74
50.49
­
8.82
­
9.61
9.87
10.65
9/
14/
99
60.03
55.17
­
7.55
­
8.17
9.23
9.81
9/
15/
99
75.41
68.04
­
9.37
­
10.07
9.73
10.43
9/
16/
99
76.19
70.04
­
7.43
­
8.07
9.37
9.96
9/
17/
99
82.12
73.97
­
9.22
­
9.92
10.22
10.90
9/
18/
99
85.53
76.44
­
10.52
­
11.34
10.52
11.34
9/
19/
99
88.76
82.97
­
6.30
­
6.82
8.41
8.85
9/
20/
99
82.24
78.36
­
4.69
­
5.20
6.68
7.16
SIP
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Region
38
Observed
and
predicted
8­
hour
maxima
were
compared
graphically
using
scatter
plots
and
Q­
Q
plots.
5
Figures
3­
4
through
3­
6
provide
combined
scatter/
Q­
Q
data
pairs
determined
for
the
pooled
Central
Texas
monitors
using
the
three
methodologies
described
previously.
Only
the
third
methodology
(
figure
3­
6)
yields
observed/
predicted
data
pairs
(
indicated
by
blue
"+"
signs)
outside
the
±
20
indicator
lines.
Q­
Q
points,
designated
by
magenta
circles,
follow
the
1:
1
reference
line
closely
in
each
graph,
particularly
for
methods
1
and
2.
Furthermore,
each
methodology
yields
moderate
to
high
correlation
coefficients.
Therefore
the
graphics
tests
indicate
a
high
degree
of
correlation
between
peak
8­
hour
ozone
concentrations
measured
during
the
September
1999
episode
and
the
predicted
8­
hour
maximums
predicted
by
the
model
for
the
same
period.

Figure
3­
4.
Observed
and
Predicted
(
within
7x7
array
of
grid
cells
near
each
monitor)
Daily
Maximum
8­
hour
Ozone
Concentrations
at
Central
Texas
Monitors.

5
Q­
Q
plots
are
used
to
determine
whether
two
data
sets,
observed
and
predicted
values
in
this
case,
come
from
populations
with
a
common
distribution.
A
quantile
is
the
percentage
of
points
below
a
given
value;
thus
the
60%
quantile
is
the
point
at
which
60%
of
the
data
are
below
and
40%
are
above
that
value.
The
closer
the
Q­
Q
points
follow
the
1:
1
reference
line,
the
greater
the
evidence
that
the
two
data
sets
come
from
populations
with
similar
distributions.
Daily
maximum
8­
Hour
ozone
near
monitor.
All
sites
and
all
days.
Subregion
=
Central
Texas
Monitors
0
20
40
60
80
100
120
0
20
40
60
80
100
120
Observed
Ozone
(
ppb)
Predicted
Ozone
(
ppb)
r2=
0.7741
O
­
­
O
shows
quantiles
SIP
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EAC
Region
39
Figure
3­
5.
Observed
and
Predicted
(
within
7x7
array
of
grid
cells
near
each
monitor
that
is
closest
in
magnitude
to
the
observed
daily
maximum)
Daily
Maximum
8­
hour
Ozone
Concentrations
at
Central
Texas
Monitors.

Figure
3­
6.
Observed
and
Predicted
(
based
on
a
bilinear
interpolation
of
daily
maximum
ozone
concentrations
around
each
monitor)
Daily
Maximum
8­
hour
Ozone
Concentrations
at
Central
Texas
Monitors.

Daily
maximum
8­
Hour
ozone
at
monitor.
All
sites
and
all
days.
Subregion
=
Central
Texas
Monitors
0
20
40
60
80
100
120
0
20
40
60
80
100
120
Observed
Ozone
(
ppb)
Predicted
Ozone
(
ppb)
r2=
0.773
O
­
­
O
shows
quantiles
Nearest
daily
maximum
8­
Hour
ozone.
All
sites
and
all
days.
Subregion
=
Central
Texas
Monitors
0
20
40
60
80
100
120
0
20
40
60
80
100
120
Observed
Ozone
(
ppb)
Predicted
Ozone
(
ppb)
r2=
0.9042
O
­
­
O
shows
quantiles
SIP
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Attainment
Demonstration
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the
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EAC
Region
40
Regardless
of
the
methodology
used
to
determine
the
predicted
maximum
concentration
within
Central
Texas,
the
results
of
applying
metrics
tests
to
Run
18
for
each
day
of
the
September
13
 
20,
1999
episode
fell
well
within
EPA's
guidelines.
In
addition,
1­
hour
metrics
and
8­
hour
metrics
conducted
on
individual
monitors
and
groups
of
monitors
yielded
excellent
results.
These
tests
and
test
results
are
described
in
appendix
E.

3.6.3
Predictions
of
Precursor
Concentrations
Models
may
also
be
assessed
by
how
well
the
simulation
replicates
observed
VOC,
CO,
NOy
and
NO2,
whenever
data
permits.
There
are
no
criteria
for
evaluating
precursor
concentrations,
but
comparing
the
modeled
results
to
monitored
data
where
precursor
data
exists
can
assist
in
resolving
performance
issues.
When
the
two
data
sets
track
closely,
the
comparison
provides
additional
assurance
that
the
model
is
performing
well
and
"
getting
the
right
answer
for
the
right
reasons."

Currently,
the
sole
ozone
precursor
monitored
by
San
Antonio
area
CAMS
stations
is
NOx.
Figures
3­
7
through
3­
9
provide
a
comparison
of
observed
and
predicted
NOx
concentrations
at
three
monitoring
sites:
CAMS
27
located
in
downtown
San
Antonio,
CAMS
59
located
at
Calaveras
Lake
in
southeastern
Bexar
County,
and
CAMS
62
located
northeast
of
San
Antonio
in
Caldwell
County.

The
predicted/
observed
NOx
comparisons
were
particularly
important
for
evaluating
earlier
versions
of
the
model,
as
the
earlier
base
case
runs
tended
to
predict
moderate
to
severe
NOx
reduction
disbenefits
on
some
episode
days.
Refinements
to
subsequent
runs
attenuated
much
of
the
NOx
disbenefit
problem.
These
graphs
depicting
CAMx
Run
18
results
indicate
a
high
degree
of
correlation
between
paired
predicted
and
observed
data.
A
notable
exception
occurs
on
September
20th
when
predicted
NOx
concentrations
are
significantly
higher
than
observed
data
at
all
three
monitors.

Figure
3­
7.
Comparison
of
Observed
and
Predicted
(
Run
18)
NOx
Concentrations
at
CAMS
27
(
San
Antonio­
downtown)
during
the
September
13­
20,
1999
Episode.
NOx
values
represent
maximum
concentrations
within
the
3x3
grid
surrounding
the
monitor.

0
50
100
150
200
250
300
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
Predicted
Observed
SIP
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41
Figure
3­
8.
Comparison
of
Observed
and
Predicted
(
Run
18)
NOx
Concentrations
at
CAMS
59
(
Calaveras
Lake)
during
the
September
13­
20,
1999
Episode.
NOx
values
represent
maximum
concentrations
within
the
3x3
grid
surrounding
the
monitor.

Figure
3­
9.
Comparison
of
Observed
and
Predicted
(
Run
18)
NOx
Concentrations
at
CAMS
62
(
San
Marcos)
during
the
September
13­
20,
1999
Episode.
NOx
values
represent
maximum
concentrations
within
the
3x3
grid
surrounding
the
monitor.

3.6.4
Precursor
Sensitivity
Studies
During
the
base
case
performance
evaluation
process,
two
types
of
analyses
were
conducted
on
the
model:
(
1)
the
metrics
tests
described
above
that
measure
how
accurately
the
model
predicts
observed
concentrations,
and
(
2)
sensitivity
analyses
that
are
useful
for
diagnostic
or
predictive
purposes
depending
on
how
and
when
the
tests
are
applied.
Sensitivity
tests
were
conducted
throughout
the
model
development
process
to
identify
sources
of
uncertainty
and
opportunities
for
model
improvement.
The
sensitivity
tests
applied
during
the
base
case
evaluation
phase
of
model
development
involved
reducing
VOC,
NOx,
and
combinations
of
VOC
and
NOx
to
determine
the
model's
sensitivity
to
precursor
emissions.
Precursor
sensitivity
studies
are
useful
for
identifying
the
types
of
emissions
and
sources
of
emissions
on
which
to
focus
strategy
analyses.
CAMS
59
NOx
­
run18
(
3
x
3
Grid)

0
25
50
75
100
125
150
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
0
0
PM
12:
00
AM
4:
00
AM
8:
00
AM
1
2:
00
PM
4:
00
PM
8:
00
PM
12:
0
0
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
0
0
AM
8:
00
AM
12:
00
PM
4:
00
PM
8
:
00
PM
12:
00
AM
4:
00
A
M
8:
0
0
AM
12:
00
PM
4:
00
PM
8:
00
PM
12
:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
Predicted
Observed
0
25
50
75
100
125
150
12:
00
AM
4
:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
0
0
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
0
0
AM
4:
00
AM
8:
00
AM
12:
0
0
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
12:
00
AM
4:
00
AM
8:
00
AM
12:
00
PM
4:
00
PM
8:
00
PM
Predicted
Observed
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
42
Across­
the­
board
sensitivity
runs
were
conducted
by
removing
25%,
50%,
75%,
and
100%
of
the
local
(
4­
county
SAER)
NOx
emissions,
VOC
emissions,
and
combinations
of
the
two,
from
the
CAMx
Run
17b
model.
Figures
3­
10
and
3­
11
provide
the
results
of
the
across­
the­
board
reduction
runs
for
CAMS
23
and
CAMS
58,
averaged
over
the
six
day
modeling
period.
In
general,
VOC
reductions
were
more
effective
than
NOx
reductions
over
the
range
of
controls
required
to
demonstrate
attainment.

Due
to
time
constraints,
VOC/
NOx
reduction
analyses
were
not
conducted
on
CAMx
Run
18.
However,
several
precursor
sensitivity
runs
were
conducted
on
a
prior
version
of
the
September
1999
model,
CAMx
Run
17b.
The
primary
difference
between
CAMx
Run
17b
and
CAMx
Run
18,
for
the
1999
base
cases,
6
was
the
use
of
a
refined
MOBILE6
on­
road
EI
in
the
latter
model,
as
described
in
section
3.4.
Rerunning
all
the
sensitivity
tests
again
on
Run
18
would
have
added
an
enormous
amount
of
work.
Based
upon
experience,
it
was
assumed
that
the
general
findings
and
directional
guidance
determined
from
previous
runs
would
remain
stable
with
relatively
small
emissions
adjustments.

Figure
3­
10.
Predicted
Ozone
Concentrations
at
CAMS
23
after
Removing
Local
(
4­
county
SAER)
NOx
and
VOC
Emissions,
average
from
September
15
 
20,
1999.

6
The
2007
projection
developed
from
CAMx
Run
18
incorporates
a
refined
regional
EI
(
described
in
Section
3.6);
however,
the
regional
EIs
for
Runs
17b
and
18
1999
base
cases
are
identical.
60
65
70
75
80
85
90
0%
25%
50%
75%
100%

Anthropogenic
Emission
Reductions
(
percentage)
Ozone
Concentration
(
ppb)

NOx
Reduction
VOC
Reduction
NOx
&
VOC
Reduction
8
hour
standard
­
85
ppb
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
43
Figure
3­
11.
Predicted
Ozone
Concentrations
at
CAMS
58
after
Removing
Local
(
4­
county
SAER)
NOx
and
VOC
Emissions,
average
from
September
15
 
20,
1999.

3.7
2007
FUTURE
CASE
MODELING
EMISSIONS
INVENTORY
Based
on
the
positive
outcome
of
performance
evaluations
conducted
on
the
September
1999
episode
simulation
(
Run
18),
the
model
was
subjected
to
a
subsequent
step
in
the
attainment
demonstration
process:
development
of
an
attainment
year
base
case.
In
order
to
create
a
future
base
case
for
the
SAER,
emissions
inventory
inputs
were
developed
for
the
attainment
year
of
2007.
This
step
required
adjusting
the
modeling
EI
calculated
for
the
1999
base
case
to
the
projection
year
using
both
control
and
growth
factors.
Growth
factors
accounted
for
anticipated
increases
or
decreases
in
emissiongenerating
activities
as
the
result
of
growth
/
decline
in
employment,
population,
and
transportation.
Control
factors
were
applied
to
emission
projections
to
account
for
state
and
federal
control
regulations
that
are
already
mandated
and
expected
to
be
in
place
by
the
attainment
year.
Such
control
factors
are
expected
to
impact
local
emissions
through
changes
in
technology,
fuel
formulations,
fuel
use,
energy
efficiency,
and
other
emission
reduction
programs.

One
exception
to
"
growing"
emissions
to
a
projection
year
was
the
estimation
of
future
biogenic
emissions.
In
accordance
with
EPA
recommendations,
the
biogenic
inventory
for
2007
was
identical
to
that
used
in
the
1999
base
case.
Biogenic
sources
were
estimated
to
release
263
tons
per
day
(
tpd)
of
VOC
and
21
tpd
of
NOx
in
the
SAER
during
the
September
1999
episode.
Therefore,
the
2007
biogenic
emission
input
file
contains
these
same
values.
Likewise,
the
biogenic
EI
for
the
remainder
for
the
modeling
domain
remains
consistent
between
base
and
future
cases.

Emission
projection
procedures
are
specific
to
the
source
category
 
on­
road
mobile,
area/
non­
road,
and
point
 
and
are
discussed
in
more
detail
in
appendix
F.
As
part
of
the
on­
road
emission
estimation
project
referenced
in
section
3.4,
TTI
also
developed
2007
attainment
year
mobile
emissions
for
the
NNA
regions.
The
methodology
TTI
used
to
project
on­
road
emissions
for
the
San
Antonio
area
is
described
in
their
report,
San
Antonio
Metropolitan
Statistical
Area
On­
Road
Mobile
Source
Modeling
Emissions
60
65
70
75
80
85
90
0%
25%
50%
75%
100%

Anthropogenic
Emission
Reductions
(
percentage)
Ozone
Concentration
(
ppb)

NOx
Reduction
VOC
Reduction
NOx
&
VOC
Reduction
8
hour
standard
­
85
ppb
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
44
Inventories:
1999,
2007,
and
2012
(
TTI,
2003),
included
as
appendix
C.
The
results
of
projecting
the
VOC
and
NOx
EI
to
2007
for
all
anthropogenic
sources
in
the
four­
county
SAER
are
summarized
in
tables
3­
7
and
3­
8,
respectively.

Table
3­
7.
Estimated
2007
Average
Weekday
(
Wednesday)
VOC
Emissions
from
Anthropogenic
Sources
in
the
Four­
county
SAER.

County
On­
Road
(
tpd)
Area
/
Non­
road
(
tpd)
Point
(
tpd)
Total
(
tpd)
Bexar
42.42
98.55
11.82
152.79
Comal
3.85
5.53
0.52
9.90
Guadalupe
3.42
6.98
1.10
11.50
Wilson
0.98
3.68
0.07
4.74
Total
(
tpd)
50.67
114.75
13.50
178.93
Table
3­
8.
Estimated
2007
Average
Weekday
(
Wednesday)
NOx
Emissions
from
Anthropogenic
Sources
in
the
Four­
county
SAER.

County
On­
Road
(
tpd)
Area
/
Non­
road
(
tpd)
Point
(
tpd)
Total
(
tpd)
Bexar
67.45
39.18
53.24
159.86
Comal
7.07
3.70
13.77
24.53
Guadalupe
6.47
3.40
8.07
17.95
Wilson
1.34
1.04
0.00
2.39
Total
(
tpd)
82.34
47.32
75.08
204.74
For
most
anthropogenic
source
categories,
the
emission
estimates
decreased
between
1999
and
2007,
as
shown
in
tables
3­
9
and
3­
10.
Exceptions
include
an
estimated
increase
in
VOC
emissions
from
point
sources
in
Bexar,
Comal,
and
Guadalupe
counties.
The
increases
in
Bexar
and
Guadalupe
counties
are
primarily
attributed
to
a
new
Toyota
manufacturing
plant
scheduled
for
completion
by
2006
in
Bexar
County
and
two
gas­
fired
power
plants
(
online
between
1999
and
2007)
in
Guadalupe
County.
The
increase
in
NOx
emissions
in
Guadalupe
County
for
2007
is
based
on
projected
effluent
from
the
new
power
plants
as
well.
In
addition,
area/
non­
road
NOx
emissions
are
estimated
to
increase
in
Comal
and
Wilson
Counties
by
2007.
Overall,
VOC
emissions
are
expected
to
decrease
by
20.88%
between
1999
and
2007
in
the
four­
county
SAER
and
NOx
emissions
are
expected
to
decrease
by
30.11%
during
the
same
timeframe.

Table
3­
9.
Percent
Difference
between
Estimated
Weekday
VOC
Emissions
for
1999
and
2007
in
the
Four­
county
SAER.

County
On­
Road
(
tpd)
Area
/
Non­
road
(
tpd)
Point
(
tpd)
Total
(
tpd)
Bexar
­
43.83%
­
11.99%
87.47%
­
21.16%
Comal
­
37.42%
­
17.45%
50.94%
­
24.98%
Guadalupe
­
38.63%
­
10.08%
145.00%
­
16.58%
Wilson
­
37.42%
­
1.31%
0.00%
­
11.82%
Total
(
tpd)
­
42.95%
­
11.85%
88.44%
­
20.88%
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
45
Table
3­
10.
Percent
Difference
between
Estimated
Weekday
NOx
Emissions
for
1999
and
2007
in
the
Four­
county
SAER.

County
On­
Road
(
tpd)
Area
/
Non­
road
(
tpd)
Point
(
tpd)
Total
(
tpd)
Bexar
­
43.59%
­
0.53%
­
39.90%
­
35.42%
Comal
­
39.30%
3.46%
13.22%
­
10.39%
Guadalupe
­
38.15%
­
19.65%
1492.19%
17.99%
Wilson
­
29.00%
12.17%
0.00%
­
15.44%
Total
(
tpd)
­
42.65%
­
1.67%
­
25.85%
­
30.11%

3.8
2007
PHOTOCHEMICAL
MODEL
BASE
CASE
AND
SENSITIVITY
ANALYSES
The
effects
of
modifying
emissions
inputs
to
the
model
in
order
to
develop
a
2007
future
base
are
provided
in
table
3­
11.
This
table
lists
the
average
daily
(
September
15
 
20)
maximum
8­
hour
ozone
concentrations
within
the
7x7
array
of
cells
surrounding
the
SAER
monitors,
as
predicted
by
the
2007
future
case,
and
compares
those
values
to
those
predicted
for
1999.
For
each
monitoring
site,
ozone
concentrations
are
predicted
to
decrease
between
1999
and
2007.
The
difference
in
the
1999
and
2007
predictions
ranges
from
­
3.3%
at
CAMS
678
to
­
5.7%
at
CAMS
59.
Both
CAMS
59
and
CAMS
678
are
upwind
monitors
located
southeast
of
downtown
San
Antonio.

Table
3­
11.
Comparison
of
1999
and
2007
Predicted
Ozone
Concentrations
by
Monitor.

CAMS
Station
1999
Predicted
8­
hr
Max.
Ozone
2007
Predicted
8­
hr
Max.
Ozone
1999­
2007
Percent
Change
CAMS
23
89.0
ppb
84.5
ppb
­
5.0%
CAMS
58
87.8
ppb
82.8
ppb
­
5.6%
CAMS
59
78.1
ppb
73.6
ppb
­
5.7%
CAMS
678
80.1
ppb
77.4
ppb
­
3.3%

The
1999­
2007
predicted
ozone
concentration
results
are
compared
graphically
in
figure
3­
12.
This
comparison
represents
the
maximum
8­
hour
concentrations
within
the
entire
4­
km
subdomain
for
a
typical
episode
weekday
 
Wednesday,
September
15th.
As
shown,
predicted
ozone
levels
fell
significantly
between
1999
and
2007
throughout
the
4­
km
subdomain
and
the
area
with
exceedances
was
completely
eliminated.
Moreover,
the
peak
predicted
8­
hour
maximum
concentration
for
the
domain
decreased
from
90
ppb
to
81
ppb
in
the
September
15th
simulation.
Comparisons
of
1999
and
2007
peak
ozone
concentration
predictions
for
each
episode
day
are
provided
in
appendix
G,
2007
Base
Case
and
Sensitivity
Analyses.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
46
Figure
3­
12.
Comparison
of
1999
and
2007
Predicted
Daily
Maximum
8­
hour
Ozone
Concentrations
within
the
4­
km
Subdomain
for
a
Typical
Weekday
(
Wednesday,
September
15th).

1999
2007
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
47
Once
the
photochemical
model
was
modified
using
the
projected
2007
EI,
several
additional
sensitivity
runs
were
conducted
on
the
simulation
to
assess
the
robustness
of
the
2007
base
case
simulation.
The
2007
base
case
included
an
updated
2007
regional
EI
that
was
originally
used
by
ENVIRON
to
model
an
ozone
episode
for
northeast
Texas.
Much
of
the
regional
emission
rate
file
was
based
on
an
EPA
study
which
analyzed
the
impacts
of
implementing
federal
rules
pertaining
to
heavy­
duty
diesel
engines
and
fuels
in
the
on­
road
and
off­
road
source
categories.
The
study
was
documented
in
the
federal
agency's
report
Procedures
for
Developing
Base
Year
and
Future
Year
Mass
and
Modeling
Inventories
for
the
Heavy­
Duty
Engine
and
Vehicle
Standards
and
Highway
Diesel
Fuel
(
HDD)
Rulemaking.
7
After
the
sensitivity
tests
were
completed
on
the
CAMx
Run
18
base
case
(
or
1999
base
case
A),
AACOG
received
additional
EI
data
and
performed
other
modifications
to
incorporate
into
the
1999
base
and
2007
future
cases.
Modifications
incorporated
into
the
1999
base
case
included:

refined
1999
VOC
emission
rates
from
a
San
Antonio­
based
water
utility
for
wastewater
treatment
plants

EI
data
file
from
ENVIRON
International
Corporation
(
via
TCEQ)
for
states
outside
of
Texas

updated
area
and
non­
road
source
temporal
profiles
for
regional
Texas
that
matches
2007
temporal
profiles

updated
point
source
cut
off
point
from
20m
to
50m
for
the
4km
grid

updated
Victoria's
mobile
EI

updated
chemical
and
temporal
profiles
for
Texas
area
and
non­
road
emissions

updated
Victoria's
point
sources

updated
Texas
NEGU
and
EGU
point
sources
outside
of
Houston

updated
Louisiana
point
source
emissions

updated
San
Antonio
asphalt
emissions

updated
tanker
truck
unloading
emissions

updated
tanker
trucks
in
transit
emissions

updated
emissions
for
other
gasoline
distribution
activities
Additional
modifications
incorporated
into
the
2007
base
case
included:

updated
regional
EI
non­
road
HDD
provided
by
TCEQ

updated
Austin
Point
Source
Control
database
(
several
revisions)

new
wastewater
estimates

new
regional
temporal
profile
for
point
sources

updated
Austin
CO
on­
road
EI
(
3
County)

stage1
(
125k)
file

removed
tank
truck
unloading
on
Sunday

updated
area
source
temporal
profiles

updated
Texas
regional
area
and
non­
road
emissions

updated
Texas
point
sources
(
besides
CPS),

new
Lehigh
cement
kiln
controls

updated
point
source
cut
off
point
from
20m
to
50m
for
the
4km
grid

updated
Victoria's
emissions

updated
chemical
and
temporal
profiles
for
Texas
area
and
non­
road
emissions

updated
San
Antonio
asphalt
emissions
7
The
report
,
dated
October
2000,
was
prepared
for
EPA
by
E.
H.
Pechan
&
Associates,
Inc.
and
is
available
on­
line
at:
http://
www.
epa.
gov/
otaq/
models/
hd2007/
r00020.
pdf
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
48

updated
tanker
truck
unloading
emissions

updated
tanker
trucks
in
transit
emissions

updated
emissions
for
other
gasoline
distribution
activities

updated
emissions
for
rate
of
progress
controls
As
a
consequence
of
receiving
and
incorporating
revised
local
and
regional
EI
data
files
for
the
base
case
and
future
case,
additional
sensitivity
runs
were
conducted
on
the
refined
base
runs.
The
final
run,
1999
Base
Case
G
(
CAMX
Run
18.
f)
incorporates
all
refinements
listed
above.
Tables
3­
12
through
3­
15
list
the
results
(
by
ppb)
of
sensitivity
runs
conducted
for
2007
based
on
predictions
of
ozone
concentrations
within
the
7
x
7
grids
surrounding
each
of
four
CAMS
stations
in
the
San
Antonio
area.
The
tables
also
provide
comparisons
between
1999
and
2007
predicted
average
ozone
concentrations
and
between
1999
and
2007
design
values
for
both
A
and
G
versions
of
the
CAMx
Run
18
simulations.

As
demonstrated
in
these
tables,
the
future
case
"
zero
out"
runs
(
removal
of
power
plants
and
other
sources),
show
that
SAER
sources
will
contribute
from
~
12
 
21%
of
the
ambient
ozone,
depending
on
the
CAMS
station
being
evaluated.
These
sensitivity
runs
also
indicate
that
emissions
added
by
the
Toyota
plant
and
the
various
power
plants
make
small
changes
in
total
ozone
concentrations
in
the
SAER.
Furthermore,
the
predicted
2007
design
values
(
see
section
3.9
for
methodology
used
to
calculate
design
values)
at
each
CAMS
location
in
the
San
Antonio
region
are
reduced
below
the
85
ppb
threshold
for
both
A
and
G
versions
of
the
future
cases.
This
holds
true
even
for
CAMS
23,
which
has
the
highest
current
design
value:
89
ppb.

Table
3­
12.
Results
of
Sensitivity
Runs
Conducted
at
CAMS
23
(
San
Antonio
Northwest
 
Marshall
High
School).

Sensitivity
Run
Year
Design
Value
(
ppb)
Change
(
ppb)
Base
Case
A
1999
89
­­­
Base
Case
G
1999
89
­­­

No
City
Public
Service
Plants
2007
83.32
­
1.21
No
Spruce
Power
Plant
(
5.93
tons/
day
NOx)
2007
84.42
­
0.10
No
Toyota
Manufacturing
Plant
2007
84.51
­
0.01
No
San
Antonio
(
4­
county
area
)
2007
2007
63.09
­
21.43
Base
Case
A
2007
84.56
­­­
Base
Case
G
2007
84.52
­­­
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
49
Table
3­
13.
Results
of
Sensitivity
Runs
Conducted
at
CAMS
58
(
Camp
Bullis)

Sensitivity
Run
Year
Design
Value
(
ppb)
Change
(
ppb)
Base
Case
A
1999
87
­­­
Base
Case
G
1999
87
­­­

No
City
Public
Service
Plants
2007
81.15
­
0.97
No
Spruce
Power
Plant
2007
82.04
­
0.08
No
Toyota
Manufacturing
Plant
2007
82.11
­
0.01
No
San
Antonio
(
4­
county
area
)
2007
2007
63.42
­
18.69
Base
Case
A
2007
82.19
­­­
Base
Case
G
2007
82.12
­­­

Table
3­
14.
Results
of
Sensitivity
Runs
Conducted
at
CAMS
59
(
Calaveras
Lake)

Sensitivity
Run
Year
Design
Value
(
ppb)
Change
(
ppb)
Base
Case
A
1999
79
­­­
Base
Case
G
1999
79
­­­

No
City
Public
Service
Plants
2007
71.07
­
3.42
No
Spruce
Power
Plant
2007
74.46
0.03
No
Toyota
Manufacturing
Plant
2007
74.46
­
0.02
No
San
Antonio
(
4­
county
area
)
2007
2007
64.51
­
9.97
Base
Case
A
2007
74.96*
­­­
Base
Case
G
2007
74.48
­­­
*
averaged
over
one
more
day
(
Sept
17th)
because
the
value
was
above
70
ppb
requirement
(
EPA
1999
,
p.
41)
to
be
included
in
the
RRF
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
50
Table
3­
15.
Results
of
Sensitivity
Runs
Conducted
at
CAMS
678
(
CPS
Pecan
Valley)

Sensitivity
Run
Year
Design
Value
(
ppb)
Change
(
ppb)

Base
Case
A
1999
77
­­­
Base
Case
G
(
includes
refined
wastewater
VOCs)
1999
77
­­­

No
City
Public
Service
Plants
2007
72.17
­
2.29
No
Spruce
Power
Plant
2007
74.35
­
0.11
No
Toyota
Manufacturing
Plant
2007
74.48
­
0.02
No
San
Antonio
(
4­
county
area)
2007
2007
61.29
­
13.17
Base
Case
A*
2007
74.71
­­­
Base
Case
G
2007
74.46
­­­

*
averaged
over
one
more
day
(
Sept
17th)
because
the
value
was
above
the
70
ppb
requirement
(
EPA
1999
,
p.
41)
to
be
included
in
the
RRF
3.9
ATTAINMENT
DEMONSTRATION
PROCESS
An
attainment
demonstration
compares
predicted
ozone
concentrations
with
the
thresholds
established
by
the
ozone
NAAQS.
The
NAAQS
are
met
if
the
fourth
highest
8­
hour
daily
maximum
ozone
concentration
averaged
over
three
consecutive
years
is
less
than
or
equal
to
0.08
ppm.
Therefore,
the
modeled
attainment
test
is
passed
when
the
predicted
future
design
values
near
all
monitoring
sites
are
less
than
or
equal
to
84
ppb.
The
EPA
has
specified
a
procedure
for
calculating
the
future
design
values.
In
order
to
determine
the
level
of
reductions
needed
to
reach
attainment
by
2007,
staff
calculated
the
future
design
values
for
the
San
Antonio
region
in
accordance
with
EPA
guidance.

3.9.1
Design
Values
and
Relative
Reduction
Factors
As
recommended
by
the
EPA,
attainment
demonstrations
for
the
8­
hour
ozone
NAAQS
should
be
based
on
the
results
of
modeled
attainment
tests,
screening
tests,
and,
when
appropriate,
weight­
of­
evidence
determinations.
Key
components
of
these
tests
are
the
predicted
and
observed
design
values.

The
"
current"
design
value
for
the
SAER
was
determined
using
EPA
guidelines.
This
step
entailed
reviewing
the
three­
year
period
straddling
the
year
represented
by
the
most
recently
available
emissions
inventory
(
1998
 
2000)
and
the
three­
year
period
that
is
anticipated
to
be
used
to
designate
the
area
nonattainment
(
2001
 
2003).
The
current
monitored
design
values
were
selected
based
on
the
higher
of
the
two
estimates
at
each
monitor,
as
shown
in
table3­
16.
Based
on
this
procedure,
the
area­
wide
"
current"
design
value
for
the
San
Antonio
area
is
89
ppb
at
CAMS
23.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
51
Table
3­
16.
Selection
of
Current
Monitored
Design
Values
based
on
Comparison
of
1998
 
2000
Values
with
2001
 
2003
Values.

Monitor
1998­
2000
Design
Value
2001­
2003
Design
Value
Current
Monitored
Design
Value
Used
in
the
Modeled
Attainment
Test
CAMS
23
85
ppb
89
ppb
89
ppb
CAMS
58
84
ppb
87
ppb
87
ppb
CAMS
59
79
ppb
78
ppb
79
ppb
CAMS
678
77
ppb
76
ppb
77
ppb
3.9.2
Modeled
Attainment
Test
The
modeled
attainment
test
predicts
whether
or
not
all
observed
future
design
values
will
be
less
than
or
equal
to
the
8­
hour
ozone
NAAQS
under
the
same
meteorological
conditions
as
those
simulated
for
the
base
case
(
EPA,
May
1999).
The
future
design
value
is
calculated
by
multiplying
the
"
current"
design
value
by
a
"
Relative
Reduction
Factor,"
which
is
the
relative
change
in
modeled
values
between
the
base
and
future
case.
The
test
was
performed
by
solving
the
following
equation
for
each
monitoring
site
within
the
San
Antonio
region.

(
DVF)
I
=
(
RRF)
I(
DVC)
I
where
(
DVC)
I
=
the
current
design
value
at
monitoring
site
I
(
RRF)
I
=
the
relative
reduction
calculated
near
site
I
(
ratio
of
the
future
8­
hour
daily
maximum
concentration
predicted
near
a
monitor
(
within
the
7
x
7
grid)
to
the
current
8­
hour
daily
maximum
concentration
predicted
near
a
monitor
(
DVF)
I
=
the
estimated
future
design
value
for
the
time
attainment
is
required
The
modeled
attainment
test
is
passed
if
all
resulting
predicted
future
design
values
are
 
84
ppb.
Table
3­
17
provides
the
results
of
the
modeled
attainment
test
at
each
SAER
monitor.
As
indicated,
the
test
was
passed
at
all
the
monitors
used
to
determine
attainment.

Table
3­
17.
Modeled
Attainment
Test
Results
at
SAER
Monitors.

Monitor
Modeled
Average
Daily
Maximum
Ozone
Concentration
 
1999
Modeled
Average
Daily
Maximum
Ozone
Concentration
­
2007
RRF
Current
Design
Value
Future
Design
Value
Pass
/
Fail
Status
CAMS
23
88
ppb
84
ppb
0.95
89
ppb
84
ppb
Pass
CAMS
58
87
ppb
82
ppb
0.94
87
ppb
82
ppb
Pass
CAMS
59
78
ppb
73
ppb
0.95
79
ppb
74
ppb
Pass
CAMS
678
80
ppb
77
ppb
0.97
77
ppb
74
ppb
Pass
While
the
future
design
values
listed
in
table
3­
17
indicate
the
region
would
be
in
compliance
with
the
8­
hour
ozone
NAAQS
by
the
attainment
year
without
implementing
local
clean
air
controls,
the
results
for
CAMS
23
are
very
close
to
the
85­
ppb
threshold.
Chapter
5
describes
additional
local
controls
that
were
evaluated
as
a
means
of
further
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
52
reducing
ozone
concentrations
in
the
SAER
by
the
attainment
year.
One
strategy,
Stage
I
vapor
recovery,
is
creditable,
enforceable,
and
permanent
in
terms
required
for
credit
taken
in
the
SIP.

Table
3­
18
provides
the
future
design
values,
by
monitor,
calculated
from
a
2007
control
strategy
run
that
incorporated
the
impacts
of
Stage
I
vapor
recovery
technology
in
the
SAER.
The
table
provides
a
comparison
between
these
values
and
the
future
design
values
calculated
from
the
2007
future
case
(
without
local
controls).
Although
EPA
guidance
(
May
1999)
suggests
truncating
design
value
calculations,
decimal
places
are
provided
in
table
3­
18
to
allow
for
comparisons.
These
results
indicate
that
implementation
of
Stage
I
vapor
recovery
systems
in
the
SAER
is
expected
to
reduce
ozone
concentrations
at
all
SAER
monitors.
More
information
on
clean
air
strategies
and
calculation
of
design
values
is
provided
in
chapter
5
of
this
attainment
document
and
appendix
H.

Table
3­
18.
Modeled
Attainment
Test
Results
that
Account
for
Implementation
of
Stage
I
Vapor
Recovery.

Monitor
Future
Design
Value
(
ppb)
RRF
Future
Design
Value
with
Stage
I
(
ppb)
Pass/
Fail
Status
CAMS
23
84.52
0.950
84.40
Pass
CAMS
58
82.12
0.944
82.03
Pass
CAMS
59
74.48
0.943
74.44
Pass
CAMS
678
74.46
0.967
74.39
Pass
3.9.3
Screening
Test
Since
the
modeled
attainment
test
provides
no
indication
of
future
ozone
concentrations
at
locations
without
monitors,
the
EPA
recommends
a
supplementary
screening
analysis
to
support
an
attainment
demonstration.
The
screening
test
is
particularly
important
in
areas
such
as
Central
Texas
where
monitoring
networks
are
relatively
sparse.
The
screening
test
requires
identifying
areas
in
the
domain
where
absolute
predicted
8­
hour
daily
maximum
ozone
concentrations
are
consistently
greater
than
any
predicted
in
the
vicinity
of
a
monitoring
site.
The
final
step
in
the
screening
test
requires
estimating
the
future
design
value
for
each
identified
area.

The
default
criterion
recommended
by
EPA
for
defining
areas
with
consistently
high
predictions
of
8­
hour
daily
maximum
ozone
concentrations
requires
identifying
8­
hour
concentration
predictions
that
are
>
5%
higher
than
any
near
a
monitored
location
on
50%
or
more
of
the
modeled
days.
Table
3­
19
provides
a
list
of
the
daily
maximum
8­
hour
concentrations
predicted
within
the
San
Antonio
region
for
the
September
episode
model
and
compares
the
data
to
daily
maximum
8­
hour
concentrations
in
the
vicinity
of
a
monitoring
site.
As
shown,
the
predicted
8­
hour
daily
maximum
for
the
SA
region
exceeded
the
highest
predicted
8­
hour
daily
maximum
near
a
monitor
by
more
than
5%
on
only
two
day
of
the
episode
(
16th
and
17th).
Since
the
5%
threshold
was
not
exceeded
on
"
50%
or
more
modeled
days,"
a
screening
test
is
unnecessary
for
demonstration
purposes.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
53
Table
3­
19.
Screening
Cell
Design
Value
Scaling
Results*

8­
hr
Daily
Maximum
Date
CAMS
23
CAMS
58
CAMS
59
CAMS
679
Maximum
Screened
Cell
Value
Percent
difference
compared
to
Peak
CAMS
Value
15th
81.14
75.59
66.89
70.16
83.22
2.56%
16th
78.08
77.26
72.38
71.51
84.67
8.43%
17th
81.36
82.01
69.90
69.90
86.13
5.03%
18th
98.57
98.57
72.12
79.63
98.57
0.00%
19th
101.40
101.83
81.75
91.49
101.83
0.00%
20th
93.20
91.30
86.26
87.65
93.20
0.00%
*
Bold
type
indicates
>
5%
of
modeled
daily
maximum
value
3.10
SUMMARY
AND
RECOMMENDATIONS
The
extensive
QA/
QC
process
performed
on
and
subsequent
refinements
made
to
the
September
1999
photochemical
simulation
have
produced
a
model
that
replicates
observed
trends
very
well.
A
variety
of
performance
tests,
including
1­
hour
and
8­
hour
metrics,
precursor
observations,
and
diagnostic
tests,
were
conducted
on
the
simulation
with
encouraging
results.
In
particular,
the
final
iteration
labeled
Run
18,
replicated
observations
quite
accurately
and
passed
all
performance
tests.
Extensive
model
analyses,
testing,
and
performance
evaluation
provided
all
four
South
and
Central
Texas
urban
areas
with
the
confidence
to
use
the
simulation
for
modeling
purposes.
Furthermore,
model
performance
lent
credence
for
basing
attainment
demonstrations
for
two
cities
on
the
September
episode
simulation:
the
SAER
attainment
demonstration
described
here
and
the
Austin
/
Round
Rock
MSA
Clean
Air
Plan.

Following
EPA
guidance,
modeled
attainment
tests
and
screening
tests
were
conducted
on
the
model
to
determine
the
reductions
necessary
to
meet
NAAQS
thresholds
by
the
attainment
year.
Although
these
tests
indicated
the
San
Antonio
region
would
reach
attainment
by
2007
with
no
additional
local
controls,
it
was
recognized
that
the
attainment
tests
were
passed
with
very
little
margin
for
error.
Therefore,
it
was
deemed
prudent
to
proceed
with
modeling
the
effects
of
controlling
local
sources
of
emissions.

Results
of
the
precursor
sensitivity
analyses
described
in
Section
3.5.3
indicate
that,
at
the
25%
reduction
level,
decreases
in
either
VOC
or
NOx
effectively
reduce
ozone
levels
in
the
San
Antonio
region.
However,
VOC
reductions
were
generally
more
effective
at
lowering
ozone
concentrations
at
the
25%
reduction
level
than
comparable
reductions
of
NOx.
Based
on
these
precursor
tests,
it
was
recommended
that
a
variety
of
local
controls
be
modeled
that
target
reductions
of
NOx,
VOC,
or
both
NOx
and
VOC.

References
Capital
Area
Planning
Council
(
January
2004).
Development
of
the
September
13­
20,
1999
Base
Case
Photochemical
Model
for
Austin's
Early
Action
Compact,
Report
submitted
to
the
U.
S.
EPA
and
TCEQ
by
CAPCO
with
contractors
from
The
University
of
Texas
at
Austin
and
ENVIRON
International
Corporation.
Austin,
TX.

Environmental
Protection
Agency
(
April
1999).
Emissions
Inventory
Guidance
for
Implementation
of
Ozone
and
Particulate
Matter
National
Ambient
Air
Quality
Standards
(
NAAQS)
and
Regional
Haze
Regulations
(
EPA­
454/
R­
99­
006).
Research
Triangle
Park,
NC:
Office
of
Air
Quality
Planning
and
Standards.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
54
Environmental
Protection
Agency
(
May
1999).
Draft
Guidance
on
the
Use
of
Models
and
Other
Analyses
in
Attainment
Demonstrations
for
the
8­
Hour
Ozone
NAAQS
(
EPA­
454/
R­
99­
004).
Research
Triangle
Park,
NC:
Office
of
Air
Quality
Planning
and
Standards.

Texas
Transportation
Institute
(
June
2003).
San
Antonio
Metropolitan
Statistical
Area
On­
Road
Mobile
Source
Modeling
Emissions
Inventories:
1999,
2007,
and
2012.
College
Station,
TX:
TTI
 
The
Texas
A&
M
University
System
SIP
Revision
Attainment
Demonstration
for
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Antonio
EAC
Region
55
CHAPTER
4:
DATA
ANALYSIS
4.1
INTRODUCTION
A
great
amount
of
data
must
be
accumulated
and
reviewed
in
preparation
for
photochemical
modeling.
This
not
only
includes
the
data
used
to
develop
meteorological,
precursor
emissions,
and
air
quality
inputs
to
the
model,
but
data
used
to
understand
and
define
the
conditions
that
contribute
to
elevated
ozone
concentrations
in
a
region.
Data
analysis
entails
assessing
and
characterizing
these
environmental
conditions
to
develop
an
understanding
of
their
impact
on
ozone
formation,
transport,
and
deposition.
Further,
these
analyses
enhance
the
decision­
making
process
for
clean
air
strategy
selection.

Ozone
data
analysis
focuses
on
the
underlying
causes
of
ozone
level
exceedances.
Such
studies
include
a
review
of
ozone
trends
to
identify
patterns
of
peak
ozone
formation;
meteorological
conditions
that
are
conducive
to
exceedances;
and
the
impacts
of
transport,
as
well
as
contribution
of
local
sources,
on
ozone
levels.
The
following
sections
summarize
the
results
and
conclusions
of
these
analyses.
Detailed
information
on
these
topics
is
provided
in
appendices
A
and
M.

4.2
LEVELS
AND
TRENDS
IN
OZONE
CONCENTRATIONS
The
SAER
region
continues
to
meet
the
1­
hour
ozone
NAAQS.
However,
since
promulgation
of
the
8­
hour
ozone
standard
in
1997,
the
region
has
exceeded
the
8­
hour
standard
during
several
averaging
periods.

Figure
4­
1
identifies
the
annual
peak
1­
hour
and
8­
hour
ozone
concentrations
measured
by
any
SAER
monitor
between
1995
and
2002.
Of
note
is
the
relative
rarity
of
1­
hour
ozone
exceedances
in
the
region.
From
1995­
2003,
the
region
has
recorded
a
total
of
five
one­
hour
ozone
readings
at
or
above
125
ppb.
One
of
these,
May
7,
1998,
was
associated
with
a
Mexican
smoke
event
and
is
not
a
regulatory
reading.
This
graph
also
indicates
the
highest
8­
hour
average
measured
in
the
region
varies
from
year
to
year.
Due
to
the
limited
information
this
graph
provides
(
annual
peak
values),
and
the
relatively
short
(
8
years)
study
period,
no
conclusions
are
drawn
regarding
ozone
concentration
trends.

Figure
4­
1.
Annual
Peak
1­
hour
and
8­
hour
Ozone
Measurements
within
SAER.

0
20
40
60
80
100
120
140
160
1995
1996
1997
1998
1999
2000
2001
2002
ppb
1­
hr
8­
hr
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Figure
4­
2
displays
the
eight­
hour
ozone
design
value
trends,
by
site,
between
the
years
1980
and
2003.
Although
this
graph
provides
a
much
wider
data
range
than
figure
4­
1,
there
is
little
indication
of
ozone
trends
in
this
graph,
as
the
values
tend
to
vary
from
year
to
year.
The
lowest
8­
hour
design
values
generally
occurred
during
the
early
1990s.
However,
beginning
in
1995,
the
design
values
began
to
rise
and
the
85­
ppb
design
was
exceeded
multiple
times.
Only
the
design
values
for
CAMS
59
(
Calaveras
Lake)
and
CAMS
678
(
CPS
Pecan
Valley)
consistently
remained
below
85
ppb.
During
the
ozone
season,
these
monitors
are
historically
upwind.
Since
CAMS
59
and
678
typically
measure
background
concentrations,
these
monitors
are
expected
to
have
lower
design
values
than
San
Antonio's
downwind
monitors,
CAMS
23
and
58.
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57
Figure
4­
2.
San
Antonio
Eight­
hour
Ozone
Design
Value
Trends
by
Site.*

*
Each
plotted
value
covers
a
3­
year
period
ending
with
the
year
indicated.

70
75
80
85
90
95
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
Year
Design
Value
(

ppb)
Northwest
C23
North
C07
Camp
Bullis
C58
Calaveras
C59
CPS/
Trinity
C678
8­
Hour
O3
Exceedance
C58
Level
to
Exceed
the
8­
Hour
Ozone
Standard
C23
C23
C23
C07
C07
C07
C59
C678
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Figure
4­
3
provides
an
indication
of
the
frequency
of
8­
hour
threshold
exceedances.
This
graph
identifies,
on
an
annual
basis,
the
number
of
days
the
85­
ppb
threshold
was
exceeded
between
1995
and
2002.
The
annual
values
range
from
one
exceedance
day
in
2001
to
17
exceedance
days
the
following
year,
2002.
As
with
annual
peak
concentrations,
this
comparison
shows
a
great
deal
of
variability
between
1995
and
2002,
with
no
obvious
conclusions
regarding
trends.

Figure
4­
3.
Annual
Number
of
Days
in
which
Measured
8­
hour
Averages
Met
or
Exceeded
85
ppb
at
SAER
Monitors.

Figure
4­
4.
High
Ozone
Readings
by
Two­
week
Period
for
San
Antonio
Region.
(
Source:
TCEQ).
14
2
3
8
11
3
1
17
0
2
4
6
8
10
12
14
16
18
1995
1996
1997
1998
1999
2000
2001
2002
#
of
Days
per
Year
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59
While
few
conclusions
can
be
drawn
regarding
annual
trends
in
ozone
data
as
demonstrated
above,
aggregated
annual
data
may
be
more
useful.
The
previous
graph
(
figure
4­
4)
shows
ozone
exceedance
counts
by
two­
week
bin
for
San
Antonio.
The
following
graph
(
figure
4­
5)
provided
by
TCEQ
compares
high
ozone
measurements,
by
two­
week
period,
for
the
combined
years
of
2000­
2002.
The
curve
for
the
SAER
is
similar
to
several
other
Texas
urban
areas
(
also
displayed)
in
which
peak
measurements
are
typically
recorded
in
June,
August,
and
September.
These
peaks
indicate
the
influence
of
seasonal
weather
patterns
on
regional
ozone
concentrations,
given
that
exceedance
frequency
occurs
in
patterns
when
averaged.

Figure
4­
5.
High
Ozone
Readings
by
Two­
week
Period
for
Major
Texas
Urban
Areas.
(
Source:
TCEQ).

4.3
ANALYSIS
OF
METEOROLOGICAL
DATA
The
TCEQ
conducts
periodic
studies
to
determine
air
quality/
meteorological
conditions,
both
at
the
surface
and
aloft,
throughout
Texas.
Several
of
these
studies
have
involved
the
use
of
aircraft
for
collecting
air
samples.
For
example,
the
Baylor
University
Aviation
Sciences
Department,
under
contract
with
the
TCEQ,
has
been
collecting
airborne
air
quality
data
in
Texas
for
several
years.
Sonoma
Technology,
Inc.
analyzed
air
quality
data
collected
by
the
Baylor
Airborne
sampling
program
during
the
years
1997
and
1998
and
concluded
that,
in
the
San
Antonio
region,
elevated
ozone
levels
were
associated
0
5
10
15
20
25
Early
Jan.

Late
Jan.

Early
Feb.

Late
Feb.

Early
Mar.

Lat
e
Mar,

Early
Apr.

Late
Apr.

Early
May
Late
May
Early
Jun.

Late
Jun.

Earl
y
Jul
.

Late
Jul.

Early
Aug.

Late
Aug.

Early
Sep.

Late
Sep.

Early
Oct.

Late
Oct.

Early
Nov.

Late
Nov.

Early
Dec.

Late
Dec.

Coverage
Years:
2000­
2002
Total
#
of
Days
over
0.08/
8
Hr.
Dallas/
Fort
Worth
Tyler/
Longview
El
Paso
Beaumont/
Port
Arthur
Austin
Houston/
Galveston
San
Antonio
Corpus
Christi/
Victoria
McAllen/
Rio
Grande
Valley
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with
high
pressure
systems,
clear
skies,
light
flow
aloft,
and
peak
mixing
heights
at
approximately
1500
meters
(
MacDonald
et
al.,
1999).

Additional
meteorological
analyses
have
been
conducted
by
AACOG.
Staff
analyzed
the
relationship
of
regional
ozone
concentrations
to
several
meteorological
parameters:
temperature,
wind
speed,
and
solar
radiation.
Results
of
these
analyses
are
provided
in
figures
4­
6
through
4­
8.

The
average
daily
peak
temperature
on
ozone
exceedance
days
(
8­
hour
average
 
85
ppb)
during
the
study
period
of
1998­
2002
was
91.2o
F.
As
shown
in
figure
4­
6,
95%
of
the
exceedances
occurred
on
days
when
peak
daily
temperatures
were
greater
than
84o
F.
Although
8­
hour
ozone
exceedances
in
the
SAER
typically
occur
when
peak
temperatures
are
>
84o
F.,
the
figure
also
makes
it
clear
that
peak
temperatures
do
not
necessarily
produce
ozone
exceedances.
The
majority
of
high
temperature
days
are
associated
with
ozone
levels
below
the
85
ppb
threshold.
The
temperature
data
indicate
that
other
factors,
or
combinations
of
factors,
are
of
greater
influence
on
concentrations
than
temperature
alone.

Analysis
of
1997
 
2002
wind
speed
data
indicate
no
exceedances
occurred
on
days
when
wind
speeds
surpassed
6
mph.
In
addition,
only
15%
of
the
exceedance
days
occurred
on
days
when
wind
speeds
were
between
5­
6
mph.
Therefore,
stagnation
is
an
important
factor
in
ozone
exceedances.
Figure
4­
7
also
indicates
that
on
the
majority
of
days
with
little
or
no
wind,
there
were
no
exceedances
of
the
85­
ppb
threshold.

Since
ozone
forms
as
the
result
of
photochemical
reactions
between
precursor
emissions,
the
amount
of
solar
radiation
reaching
the
lower
atmosphere
is
another
meteorological
condition
that
influences
the
chemical's
formation.
Figure
4­
8
shows
that
below
1
langley/
minute,
there
were
only
two
days
between
1999
and
2002
in
which
8­
hour
ozone
levels
exceeded
85
ppb.
Below
0.9
langleys/
minute
there
were
no
exceedances.
As
with
temperature
and
wind
speed
however,
certain
solar
radiation
levels
may
be
conducive
to,
but
by
no
means
guarantee,
ozone
exceedances.

Local
ozone
exceedances
are
typically
associated
with
certain
meteorological
conditions:
high
pressure
systems
and
stagnation,
high
ambient
temperatures,
and
low
wind
speeds.
As
demonstrated,
these
conditions
do
not
always
produce
excessive
ozone
concentrations
in
SAER.
Other
factors
also
influence
ozone
buildup.
Such
conditions
include
background
ozone
concentrations
and
transport.
These
issues
are
discussed
in
more
detail
in
the
following
section.
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Figure
4­
6.
Daily
8­
hour
Ozone
Maxima
Measured
at
CAMS
23
v.

Peak
Temperature,
1998
 
2002
0
20
40
60
80
100
120
2
4
6
8
10
12
14
Average
Daily
Wind
Speed
(
mph)

Daily
Ozone
8­

Hour
Maximum
(

ppb)
8­
hr
Ozone
Standard
15%
of
exceedance
days
had
average
wind­
speeds
>
5mph
&
0%
>
6mph
0
20
40
60
80
100
120
40
60
80
100
Daily
Peak
Temperatures
in
Degrees
F
Daily
Ozone
8
­

Hour
Maximums
95%
of
exceedance
days
had
temps
>
84
F
8­
hr
Ozone
Standard
0
20
40
60
80
100
120
0
0.25
0.5
0.75
1
1.25
1.5
Daily
Solar
Radiation
Maximums
(
langleys/
min.)

Daily
Ozone
8­

Hour
Maximums
(

ppb)
8­
hr
Ozone
Standard
95%
of
exceedance
days
had
Solar
Radiation
>
1.0
&
100%
had
>
0.9
Figure
4­
7.
Daily
8­
hour
Ozone
Maxima
v.
Average
Wind
Speeds,

1997
­
2002
Figure
4­
8.
Comparison
of
Daily
8­
hr
Maxima
&
Daily
Solar
Radiation
Maxima,
1999­
2002
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4.4
TRANSPORT
AND
LOCAL
CONTRIBUTIONS
TO
OZONE
CONCENTRATIONS
It
is
generally
recognized
that
transport
is
a
more
significant
issue
under
the
8­
hour
ozone
standard
than
under
the
1­
hour
standard.
Since
transport
is
a
primary
contributor
to
the
local
ozone
problem,
the
SAER
has
less
control
over
local
ambient
air
quality.

As
is
shown
extensively
in
Appendix
M,
photochemical
modeling
runs
in
which
the
entire
anthropogenic
emissions
inventory
for
the
four­
county
San
Antonio
region
is
removed
lowers
the
peak
ozone
levels
by
less
than
25%
in
the
1999
base
case.
This
result
intimates
that
transport
and
background
ozone
levels
heavily
influence
the
ozone
levels
recorded
on
area
ozone
monitors.
Clearly,
local
governments
in
the
San
Antonio
region
have
no
jurisdiction
over
the
background
concentrations
or
the
external
sources
giving
rise
to
transport.

Based
on
the
modeled
results
of
implementing
clean
air
measures
locally,
it
is
predicted
that
many
strategies
which
significantly
reduce
ambient
ozone
concentrations
in
onehour
nonattainment
areas
would
be
considerably
less
effective
in
the
SA
region.
(
See
Chapter
5
for
results
of
modeled
clean
air
strategies
in
the
SAER).
As
a
consequence,
the
San
Antonio
regional
Early
Action
Compact
signatories
must
rely
on
state
and
federal
partners
to
ensure
that
the
clean
air
strategies
and
controls
they
have
proposed
and
promulgated
are
installed
and
effective.

In
specific
terms,
the
future
case
model
assumes
that
the
Houston
SIP
controls
will
be
in
place
and
effective
by
2007,
the
attainment
year
for
the
San
Antonio
area.
If
the
controls
are
not
in
place
early
enough,
Houston's
emissions
will
continue
to
affect
San
Antonio
during
2005,
2006
and
2007,
the
three
years
that
will
be
used
to
calculate
the
attainment
year
design
value.
Since
attainment
year
modeling
predicts
that
San
Antonio
will
be
below
the
8­
hour
ozone
standard
by
less
than
one
part
per
billion,
any
weakening
or
delay
in
the
implementation
of
Houston
controls
will
affect
San
Antonio,
as
well
as
Austin
and
the
rest
of
Central
Texas.

Nevertheless,
the
San
Antonio
region
is
going
beyond
the
attainment
analysis
requirements
and
is
petitioning
the
state
and
federal
partners
to
enact
further
local
clean
air
strategies
to
control
its
own
sources
and
lower
ozone
levels
still
further.
These
actions
are
consistent
with
the
goals
and
letter
of
the
Early
Action
Compact
protocol.

Some
of
the
transport
determinations
described
in
Appendix
M
are
based
strictly
on
modeling
results
for
a
specific
time
period;
however,
there
is
a
variety
of
additional
evidence
that
indicates
SAER
ozone
levels
are
significantly
impacted
by
transport.
These
include
smoke
and
haze
events
tracked
by
the
Navy
Aerosol
Analysis
and
Prediction
System
and
other
agencies'
monitoring
programs,
as
described
in
appendix
M.

4.5
CONCLUSION
1­
hour
average
ozone
readings
at
or
above
125
ppb
are
relatively
rare,
at
five
since
1995.
One
of
these
was
disqualified
for
regulatory
purposes
as
associated
with
the
May
1998
Mexican
smoke
event.
The
eight­
hour
design
value,
from
1980
to
2003,
has
exceed
the
8­
hour
average
ozone
standard
seventeen
times,
yet
this
design
value
has
only
exceeded
88
ppb
once
(
1982).
SIP
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63
These
ozone
average
values,
while
relatively
mild,
are
frequently
at
or
above
the
8­
hour
average
ozone
standard.
Many
of
the
factors
conducive
to
ozone
production,
including
daily
temperatures
above
95
º
F,
low
wind
speeds,
high
solar
radiation,
and
wind
patterns
conducive
to
transport
(
see
Appendices
A
and
M)
are
present
in
San
Antonio
during
the
ozone
season.

In
all,
San
Antonio
is
a
region
that
has
typical
conditions
for
moderate
to
high
ambient
ozone
levels.
The
trend
indicated
by
the
1980­
2003
design
value
is
simply
one
of
sustained
levels
as
read
on
this
graph.
The
data
analysis
contained
throughout
this
document
reinforces
the
predictability
of
these
readings.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
64
CHAPTER
5:
CLEAN
AIR
STRATEGIES
Table
5­
1.
SAER
VOC
Emission
Reduction
Estimates
for
an
Average
Weekday
(
Wednesday).

September
1999
Base
Case
Emissions
Inventory
1999
Base
Case
(
tpd)
Percent
of
1999
Total
2007
Future
Base
2007
Future
Control
Strategy
(
tpd)
Percent
of
2007
Total
Area
and
Non­
road
sources
130
27%
115
109
26%

Point
sources
7
1%
13
14
3%

On­
road
mobile
sources
89
18%
51
52
11%

Biogenic
sources
263
54%
263
263
60%

TOTALS
489
100%
442
437
100%

Table
5­
2.
SAER
NOx
Emission
Reduction
Estimates
for
an
Average
Weekday
(
Wednesday).

September
1999
Base
Case
Emissions
Inventory
1999
Base
Case
(
tpd)
Percent
of
1999
Total
2007
Future
Base
2007
Future
Control
Strategy
(
tpd)
Percent
of
2007
Total
Area
and
Non­
road
sources
48
15%
47
47
21%

Point
sources
101
32%
75
75
33%

On­
road
mobile
sources
144
46%
82
82
37%

Biogenic
sources
21
7%
21
21
9%

TOTALS
314
100%
225
225
100%

5.1
INTRODUCTION
The
Clean
Air
Plan,
which
incorporates
the
Early
Action
Compact,
was
designed
to
develop
and
implement
control
strategies,
account
for
growth,
and
achieve
and
maintain
the
8­
hour
ozone
standard.
The
EAC
requires
that
clean
air
strategies,
or
methodologies
for
lowering
ozone
concentrations
to
acceptable
levels,
be
developed
to
meet
the
region's
clean
air
challenge.
The
technical
analysis
of
the
photochemical
modeling
used
to
demonstrate
the
effectiveness
of
the
control
strategies
is
performed
by
the
staff
of
AACOG
and
has
been
reviewed
and
approved
by
the
AIR
Committee,
the
staff
of
AACOG,
the
TCEQ,
and
the
EPA.
(
AACOG,
2002
pgs.
3,
6)

Section
d)
of
Chapter
4
in
the
Clean
Air
Plan
for
the
San
Antonio
region
lists
the
requirements
for
clean
air
strategies
development
once
the
base
case
and
future
case
modeling
is
complete.
The
future
and
base
case
accounts
for
all
Federal,
State,
and
local
controls
that
have
been
or
will
be
adopted
by
2007.
The
base
and
future
case
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
65
modeling
has
been
developed
based
on
AACOG's
September
1999
photochemical
model.
Tables
5­
1
and
5­
2
detail
VOC
and
NOx
emissions
that
are
inputs
in
the
base
case
and
future
case.
The
tables
also
contain
the
emission
reductions
by
the
selected
clean
air
measures.

The
requirements
for
clean
air
strategy
development
and
selection
are
listed
below:
 
After
all
adopted
Federal
and
State
controls
that
have
been
or
will
be
implemented
by
the
attainment
date
of
December
31,
2007,
are
accounted
for
in
the
modeling,
the
area
will
identify
additional
local
controls,
as
necessary,
to
demonstrate
attainment
of
the
8­
hour
standard
on
or
before
December
31,
2007.
These
local
controls
will
be
specific,
quantified,
permanent,
and
enforceable
control
strategies.
All
controls
will
include
specific
implementation
dates,
as
well
as
detailed
documentation
and
reporting
processes.
 
Controls
will
be
implemented
as
soon
as
practicable,
but
not
later
than
December
31,
2005.
 
Controls
will
be
designed
and
implemented
by
the
community
with
full
stakeholder
participation.
 
All
control
measures
will
be
incorporated
by
the
state
into
the
State
Implementation
Plan,
which
will
be
submitted
to
the
EPA
for
review
and
approval.
In
the
event
that
areas
wish
to
add
or
substitute
measures
after
SIP
submittal,
plan
modifications
will
be
treated
as
SIP
revisions
and
facilitated
by
the
state.
(
AACOG,
2002
pg.
18)

Following
the
guidance
provided
by
the
EAC
assures
that
the
selection
of
the
Clean
Air
Strategies
are
EPA
and
TCEQ
compliant.
This
chapter
will
detail
the
strategies
implemented
on
the
federal,
state,
and
local
level
as
well
as
the
emission
reductions
and
effects
the
strategies
will
have
on
regional
ozone
levels.

The
AIR
Committee
recommended
three
Clean
Air
Strategies
for
inclusion
in
the
Clean
Air
Plan
to
local
Early
Action
Compact
signatory
governments
for
their
final
approval.
The
strategies
were:
 
Reid
Vapor
Pressure
lowered
to
7.2
pounds
per
square
inch
during
the
ozone
season
for
the
San
Antonio
region;
 
Degreasing
Equipment
Operation
Controls,
described
in
TAC,
Title
30,
Ch.
115;
and
 
Stage
I
Vapor
Recovery
required
of
service
stations
of
25,000
gallons
throughput
of
gasoline
or
more
per
month.
The
eight
local
governments
which
are
signatories
to
the
Early
Action
Compact
for
the
San
Antonio
region
deliberated
these
strategies
during
regularly
scheduled
meetings
of
their
representatives
(
i.
e.,
during
City
Council
meetings
or
during
Commissioners'
Court
sessions).
These
meetings
are
open
to
the
public
and
have
meeting
schedules
published
according
to
the
Texas
Open
Meetings
Act.
All
eight
governments
approved
each
of
the
three
strategies
specified
above.
Copies
of
their
signed
resolutions
to
this
effect
are
attached
to
this
Clean
Air
Plan
document
set.

The
San
Antonio
EAC
Region,
acting
through
the
AIR
Committee,
has
incorporated
these
three
strategies
into
the
Clean
Air
Plan
and
requests
that
the
Texas
Commission
on
Environmental
Quality
take
the
necessary
actions,
including
development
of
enforcement
provisions,
to
implement
these
Clean
Air
Strategies.
However,
challenges
to
promulgation
of
these
strategies
have
changed
the
amount
and
manner
that
credit
can
be
taken
for
these
strategies.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
66
5.1.1
Challenges
to
Local
Clean
Air
Strategies
During
the
Clean
Air
Strategy
ratification
phase,
TCEQ
and
EPA
notified
AACOG
staff
of
possible
"
challenges"
to
several
of
the
clean
air
strategies
that
were
under
consideration
by
the
EAC
signatory
governments.
The
challenges
concerned
the
Clean
Air
Strategies
requesting
seasonal
RVP
7.2
gasoline
as
well
as
the
strategy
requiring
Degreasing
Equipment
controls.

Understanding
a
brief
history
of
these
challenges
is
important
since
the
credit
for
these
two
locally
enacted
Clean
Air
Strategies
was
originally
envisioned
as
SIP
creditable.

Challenges:
RVP
Mayor
Howard
Peak
of
San
Antonio
requested
a
lower
RVP
level
for
all
gasoline
shipped
into
the
San
Antonio
metropolitan
region
for
the
ozone
season
of
1999.
His
success
brought
seasonal
7.8
RVP
gasoline
to
the
area
before
that
requirement
became
a
regional
law
enacted
by
the
state
in
the
following
year.
8
Lowering
RVP
from
7.8
to
7.2
has
consistently
been
considered
a
potential
new
Clean
Air
Strategy
for
the
San
Antonio
region
since
that
success.
It
has
remained
under
review
by
the
AIR
Technical
Committee
during
the
Early
Action
Compact
strategy
refinement
process.
Consideration
of
lower
RVP
received
special
prominence
after
AACOG
staff
announced,
in
December
2003,9
tentative
agreement
by
EPA,
AACOG
and
TCEQ
technical
staff
that
the
2007
design
value
for
the
San
Antonio
region
was
below
85
parts
per
billion.
This
was
one
of
the
results
of
a
long
process
of
review
and
verification
regarding
the
performance
of
the
September
13­
10,
1999
photochemical
model
episode
and
its
corresponding
2007
projection.

On
the
one
hand,
the
determination
that
the
2007
design
value
for
the
region
was
below
85
ppb
was
a
simple
technical
result
that
followed
from
the
refinement
of
the
photochemical
model.
On
the
other,
the
fact
that
the
2007
design
value
is
below
85
ppb
means,
as
a
straightforward
corollary,
that
no
additional
local
controls
(
beyond
all
adopted
Federal
and
State
controls
that
have
been
or
will
be
implemented
by
the
attainment
date
of
December
31,
2007)
are
required
to
model
attainment.

Despite
the
fact
that
the
model
showed
attainment
in
2007
without
recourse
to
enactment
of
further
Clean
Air
Strategies,
the
AIR
Committee
continued
to
support
lower
RVP
as
a
locally
enacted
Clean
Air
Strategy.

On
January
27,
2004,
AACOG
received
communication
from
EPA's
Region
6
office
regarding
Section
211
of
the
Clean
Air
Act.
At
that
time,
it
was
not
clear
whether
Section
211
would
apply
to
a
lower
RVP
request
by
a
region
acting
under
the
Early
Action
Compact.
This
was
the
first
notification
to
AACOG
that
there
might
perhaps
be
existing
law
affecting
some
conditions
of
the
request
by
the
San
Antonio
area
for
lower
RVP.

8
The
current
Texas
State
Regional
Low
RVP
Gasoline
program
began
May
1,
2000.
It
requires
that
all
gasoline
sold
in
95
central
and
eastern
Texas
counties,
including
the
San
Antonio
EAC
region,
have
a
maximum
RVP
of
7.8
psi
from
June
1
through
October
1
of
each
year.
http://
www.
tnrcc.
state.
tx.
us/
air/
ms/
fuelprograms.
html
9
Modeled
attainment
in
2007
was
first
publicly
announced
during
the
December
15,
2003
meeting
of
the
AIR
Technical
Committee.
See
the
AIR
Technical
Committee
meeting
minutes
of
Dec.
15,
2003:
<
http://
www.
aacog.
com/
board/
comm_
agendas/
12­
15­
03_
AIR_
TechMin_
Approved.
pdf>
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
67
During
a
regularly
scheduled
meeting
of
the
AIR
Executive/
Advisory
Committees
the
following
day,
January
28,
lower
RVP
received
the
formal
endorsement
by
the
committee
as
a
strategy
selected
for
ratification
by
the
local
EAC
signatory
governments.
Prior
to
that
endorsement,
Cindy
Morphew,
Vice­
President
for
Environmental
Affairs
with
the
Texas
Oil
&
Gas
Association
(
TxOGA)
spoke
before
the
AIR
Executive/
Advisory
Committees
during
the
same
meeting.
10
In
effect,
the
general
TxOGA
membership
was
not
supportive
of
developing
further
new
fuel
blends
in
our
area,
according
to
Ms.
Morphew.
11
The
eight
local
Early
Action
Compact
signatory
governments
took
up
the
formal
endorsement
of
RVP
as
one
of
three
Clean
Air
Strategies
for
their
approval.
The
first
government
to
consider
this
Clean
Air
Strategy
set
was
the
City
of
Seguin
on
February
3,
2004.
The
final
government
to
consider
them
was
Guadalupe
Commissioners'
Court
on
February
24,
2004.
All
eight
local
governments
approved
resolutions
requesting
the
three
strategies
during
that
February
3
­
24
period.

On
February
13,
2004,
TCEQ
provided
AACOG
some
clarification12
regarding
the
circumstances
allowing
such
a
measure
to
be
implemented
in
the
local
EAC
SIP.
According
to
EPA
and
TCEQ
preliminary
investigations,
Section
211(
c)(
4)(
A)
of
the
federal
CAA
prohibits
state
and
federal
governments
from
enforcing
RVP
as
it
was
being
requested.
Such
a
measure
can
only
be
implemented
in
an
EAC
SIP
if
there
are
special
circumstances.
Detailed
descriptions
regarding
Section
211
and
its
effect
on
the
promulgation
of
lower
RVP
rules
are
provided
in
Appendix
K.
On
February
17,
2004,
an
EPA
Working
Group
confirmed
their
earlier
interpretation
of
this
provision,
supporting
TCEQ's
opinion.

Resolution
of
Challenges:
RVP
 
Given
the
formal
approval
of
the
EAC
signatory
governments,
the
San
Antonio
EAC
region
is
committed
to
requesting
that
the
state
implement
a
4­
county
EAC
regional
rule
requiring
gasoline
stations
to
dispense
gasoline
with
an
RVP
7.2
during
the
months
of
March
to
October.
 
Given
also
the
apparent
enforcement
prohibitions
described
above,
the
emissions
reduction
credits
which
would
be
expected
through
such
a
rule
are
not
being
placed
in
the
SIP­
creditable
section
of
this
document,
nor
in
the
Attainment
Demonstration
model.
 
Specifically,
the
credits
which
would
be
available
due
to
seasonal
7.2
RVP
and
the
technical
details
of
such
credit
estimation
methodology
are
relegated
to
Appendix
K,
which
is
the
Analysis
of
Additional
Evidence
appendix
of
this
document
set.
The
credits
are
also
listed
in
the
Additional
Evidence
section
of
this
chapter
(
Chapter
5.5).
 
If
a
resolution
is
reached
such
that
lower
RVP
is
supplied
to
the
San
Antonio
region
as
approved
by
local
governments
on
a
permanent,
enforceable
basis,
appropriate
SIP
credit
will
be
taken
for
the
measure
as
a
successful
local
Clean
Air
Strategy.

10
Email
from
Ms.
Morphew
on
this
subject
and
voicing
the
same
opinion,
received
by
AACOG
on
January
12,
was
circulated
to
the
AIR
Technical
Committee
on
January
18
th.
11
The
Austin
region
has
also
asked
their
elected
officials
to
support
a
reduced
RVP
strategy
as
well.
They
asked
for
an
ozone
season
RVP
level
of
7.0
pounds
per
square
inch,
a
lower
level
than
requested
in
the
San
Antonio
area.
12
Email
from
Candy
Garrett,
dated
February
13,
2004
to
Peter
Bella
of
AACOG.
Ms.
Garrett
is
Director,
Environmental
Planning
and
Implementation
for
TCEQ.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
68
5.1.2
Challenges:
Degreasing
Equipment
Controls
On
October
14,
2003,
Eastern
Research
Group
(
ERG)
completed
a
technical
memorandum
under
a
consultant
contract
with
the
Capital
Area
Planning
Council
(
CAPCO)
13.
In
their
memorandum,
ERG
identified
Degreasing/
Solvent
Surface
Cleaning
as
a
strategy
for
the
Austin
region.
They
noted14
as
a
potential
control
option
that
the
region
could
"
establish
an
equipment
based
VOC
standard,
such
as
the
one
in
effect
in
the
Beaumont/
Port
Arthur,
Dallas/
Fort
Worth,
El
Paso,
and
Houston/
Galveston
areas
of
Texas."

Since
that
time,
both
Austin15
and
San
Antonio
proposed
the
Chapter
11516
(
Texas
Administrative
Code,
or
TAC)
application
of
the
Degreasing
Equipment
Control
Standard
noted
as
a
candidate
Clean
Air
Strategy.
Both
regions
estimated
reductions
based
on
the
methodologies
noted
in
the
memorandum.
Degreasing
Equipment
controls,
as
prescribed
in
Chapter
115,
were
projected
to
provide
VOC
emission
reductions
of
12.83
tons
per
day
in
the
San
Antonio
region.
This
reduction
total
assumes
no
existing
state
degreasing
controls
of
this
type.
This
reduction
total
was
presented
to
the
elected
officials
and
technical
staff
as
the
reductions
available
through
local
enactment
of
a
Chapter
115
Degreasing
Controls
rule
as
identified
in
the
ERG
report.

The
eight
local
Early
Action
Compact
signatory
governments
took
up
the
formal
endorsement
of
Degreasing
Controls
as
one
of
three
Clean
Air
Strategies
for
their
approval.
The
first
government
to
consider
this
Clean
Air
Strategy
set
was
the
City
of
Seguin
on
February
3,
2004.
The
final
government
to
consider
them
was
Guadalupe
Commissioners'
Court
on
February
24,
2004.
All
eight
local
governments
approved
resolutions
requesting
the
three
strategies
during
that
February
3
­
24
period.

In
early
February
2004,
TCEQ
staff
from
the
Region
13
office
informed
AACOG
staff
that
Chapter
106
of
the
TAC
contained
a
requirement
to
implement
Chapter
115­
compliant
degreasing
controls
statewide.
Subsequent
investigations
revealed
that
subchapter
T
of
Chapter
106
requires
Permit
By
Rule
degreasing
units,
regardless
of
the
county
in
which
they
are
located,
to
meet
the
requirements
of
§
115.412
and
§
115.415.
Following
the
realization
that
much
of
the
credit
previously
calculated
for
degreasing
controls
as
a
voluntary
Clean
Air
Strategy
might
no
longer
be
available
due
to
Chapter
106,
AACOG
staff
proceeded
to
analyze
Chapter
106
and
Chapter
115
and
assess
how
emission
reductions
should
be
properly
determined
and
allocated.

13
CAPCO
is
the
council
of
governments
for
the
Austin
region
and
is
responsible
for
the
technical
planning
for
that
area's
Early
Action
Compact,
much
as
AACOG
is
responsible
for
the
technical
planning
in
the
San
Antonio
region.
14
ERG
Technical
Memorandum
dated
October
14,
2003,
to
CAPCO.
Subject:
Area
Source
VOC
Control
Options.
15
The
Austin
region's
Clean
Air
Action
Plan
was
written
to
fulfill
their
requirements
under
their
Early
Action
Compact.
The
Degreasing
Control
strategy
proposed
in
their
Clean
Air
Action
Plan
is
available
online.
Visit
page
38
of
<
http://
www.
cleanairforce.
org/
Draft
CAAP
1­
04.
pdf>.
16
The
Degreasing
Processes
strategy
in
the
TAC
advised
by
the
AIR
Committee
is
available
through
http://
www.
tnrcc.
state.
tx.
us/
oprd/
rules/
index.
html.
Click
on
the
"
30
TAC
Administrative
Code
in
HTML
Format"
hotlink
on
that
page
and
then
click
on
the
following
series
of
hotlinks:
Title
30;
Part
I;
Chapter
115;
Subchapter
E
(
Solvent­
Using
Processes);
Division
I
(
Degreasing
Processes).
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
69
The
Chapter
115
degreaser
requirements
have
been
in
place
since
early
in
the
1980'
s
for
certain
other
regions
of
the
state.
Permit
by
rule
(
PBR)
stipulations
in
Chapter
106
(
§
106.454)
require
compliance
with
the
Chapter
115
degreaser
requirements,
regardless
of
location.
Such
compliance
with
Chapter
115
through
106
regardless
of
location
has
only
been
in
place
since
May
1994.17
Hence,
the
initial
2007
degreasing
emission
reductions
estimated
through
local
Chapter
115
promulgation,
which
assumed
that
no
such
state
rule
was
in
place,
were
clearly
overestimated.
On
the
other
hand,
since
promulgation
of
Chapter
106
predates
1999,
then
both
the
1999
and
2007
"
uncontrolled"
degreasing
emissions
inventories,
which
heretofore
had
also
assumed
no
effective
degreasing
controls
of
this
type,
were
also
likely
to
be
too
large.

Note
that
Chapters
106/
115
as
existing
state
rules
guarantee
that
reduction
credits
are
available,
not
as
voluntary
credits
available
to
the
region
as
Local
Clean
Air
Strategy
enactment,
but
in
both
the
1999
and
2007
base
case
as
is
true
for
other
existing
state
and
federal
rules.

Reductions
in
degreasing
emissions
due
to
both
local
implementation
of
Chapter
115
in
the
Clean
Air
Plan
and
due
to
Chapter
106
are
described
in
two
categories.
1.
Reductions
in
emissions
based
on
the
growth
of
degreasing
emission
between
1999
and
2007,
and
2.
Reductions
in
degreasing
emissions
in
the
1999
(
and
hence,
in
the
2007)
base
case.

As
reported
in
Appendix
F,
area
source
emission
projections
were
generally
calculated
for
2007
using
the
Economic
Growth
Analysis
System
(
E­
GAS)
model.
The
EGAS
model
supplied
growth
factors
for
projecting
of
all
area
source
emissions18.
Thus
growth
in
degreasing
emissions
to
2007
was
calculated
based
on
the
1999
emissions
inventory
for
this
category.

Because
Chapter
106
was
in
effect
from
1999
to
2007,
the
growth
in
degreasing
emissions
during
that
period
was
in
fact
limited
by
the
same
factor
as
promulgation
of
the
effective
rule
limited
emissions
in
the
degreasing
operations
themselves.
That
is,
reduction
credits
due
to
the
effective
state
rule
can
be
taken
on
earlier
calculations
for
growth
in
the
degreasing
emissions
category
from
1999­
2007.
This
is
both
a
first
approximation
correction
to
the
2007
base
case
degreasing
emissions
inventory
and
a
source
of
modeling
credit
identified
under
applicable
state
and
federal
rules.
As
mentioned
earlier,
these
reductions
are
not
categorized
as
voluntary
credits
available
to
the
region
as
Local
Clean
Air
Strategy
enactment.

Correcting
the
1999
EI
to
account
for
the
promulgation
of
Chapter
106,
which
was
effective
in
1994
and
hence
prior
to
1999,
is
challenging.
The
1999
EI
should
be
corrected
to
account
for
the
effects
of
Chapter
106,
just
as
the
1999­
2007
growth
has
been
corrected.
The
preferred
approach
in
taking
credit
for
Chapter
106/
115
emission
reductions
for
1999
involves
using
available
information
and
data
regarding
compliance
to
the
rules
in
1999.
Information
regarding
Safety­
Kleen,
a
Texas
based
company
which
provides
various
environmental
services
throughout
the
nation,
was
utilized
in
this
approach.

17
Email
from
Eddie
Mack,
TCEQ,
February
13,
2004.
18
With
the
exception
of
Architectural
Surface
Coatings
and
Consumer/
Commercial
Solvents
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
70
Documentation
provided
by
TCEQ
shows
that
Safety­
Kleen
1)
provides
degreasing
equipment
and
solvents
for
approximately
50%
of
the
San
Antonio
market;
2)
Safety­
Kleen
products
are
Chapter
115
compliant;
3)
Safety­
Kleen
provided
these
products
to
their
customers
in
the
San
Antonio
region
consistent
with
the
promulgation
of
Chapter
106.
Hence,
the
85%
reduction
effective
through
Chapter
106/
115
should
act
as
a
first
approximation
correction
to
50%
of
the
degreasing
emissions
in
the
1999
EI.
Since
these
emission
reductions
are
tentative,
they
are
not
reflected
in
the
1999
base
case,
but
are
treated
as
potential
credit
and
are
documented
in
Appendix
K,
Additional
Evidence.

Resolution
of
Challenges:
Degreasing
Equipment
Controls
 
Given
the
formal
approval
of
the
EAC
signatory
governments,
the
San
Antonio
EAC
region
is
committed
to
requesting
that
the
state
implement
a
4­
county
EAC
regional
rule
requiring
compliance
with
Degreasing
Equipment
Operation
Controls,
described
in
TAC,
Title
30,
Ch.
115.
 
Given
Chapter
106,
reductions
in
earlier
estimates
of
the
growth
of
degreasing
emissions
between
1999
and
2007
have
been
approximated
and
are
treated
uniquely
as
creditable
reductions
achieved
through
current
State
rule.
These
credits
are
listed
in
this
chapter
in
the
Federal
and
State
reductions
strategies
section
(
Chapter
5.2),
and
treated
in
greater
depth
in
Appendix
I,
Federal
and
State
reductions.
 
Reductions
in
the
1999
(
and
2007)
base
case
degreasing
emissions
inventories
have
been
calculated
based
on
Safety­
Kleen's
participation
in
the
regional
market.
These
reductions
are
treated
as
tentative
and
unconfirmed.
An
overview
of
these
reductions
is
given
in
this
chapter
in
the
Additional
Evidence
section
(
Chapter
5.5).
These
reductions
are
discussed
in
greater
depth
in
Appendix
K,
Additional
Evidence.
 
Chapter
106
of
the
TAC
was
adopted
in
1994,
thus
applying
to
degreasing
facilities
that
were
constructed
or
scheduled
to
be
constructed
on
and
after
1994.
This
potentially
leaves
degreasing
facilities
that
were
in
existence
prior
to
1994
exempt
from
Chapter
106.
Such
uncontrolled
facilities
would
be
subject
to
Chapter
115
due
to
the
passage
of
the
rule
requested
by
local
governments.
In
this
case,
enactment
of
Chapter
115
as
a
local
Clean
Air
Strategy
would
be
a
source
of
additional
emission
reductions.
This
potential
reduction
source
is
discussed
in
Appendix
K.

5.1.3
Conclusion
The
San
Antonio
EAC
Region
has
committed
to
pursue
three
Clean
Air
Strategies
requested
by
the
local
governments.
The
EAC
signatory
governments
passed
resolutions
requesting
the
clean
air
measures
in
table
5.4
be
implemented
in
the
SAER.
These
commitments
involve
requesting
lower
RVP
gasoline
implementation,
Stage
I
Vapor
recovery
systems,
and
Degreasing
Equipment
Controls.
Details
regarding
emission
reductions
due
to
gasoline
having
an
RVP
of
7.2
can
be
found
in
Appendix
K,
Additional
Evidence.
Stage
I
Vapor
Recovery
for
retailers
that
dispense
no
less
than
25,000
gallons
per
month
is
SIP
creditable
and
is
discussed
in
Appendix
I.
Degreasing
controls,
through
consideration
of
Chapter
106
and
Chapter
115,
have
various
degrees
of
creditability.
Emission
reductions
achieved
by
Chapter
106
on
growth
in
degreasing
emission
between
1999
and
2007
are
accounted
for
as
emission
reductions
due
to
state
rule
and
discussed
in
Appendix
I.
Reductions
in
the
1999
base
case
due
to
Chapter
106
are
treated
as
additional
evidence
and
discussed
in
Appendix
K.
Additional
reductions
to
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
71
degreasing
units
that
were
in
existence
prior
to
1999,
possibly
achieved
through
local
implementation
of
Chapter
115,
are
described
in
Appendix
K.

5.2
FEDERAL
AND
STATE
REDUCTION
STRATEGIES
Various
state
and
federal
strategies
are
scheduled
to
be
promulgated
and
enforced
by
the
TCEQ
and
EPA
by
2007.
These
strategies
will
provide
emission
reductions
in
the
SAER
in
future
years.
Detailed
descriptions
of
the
federal
and
state
reduction
strategies
can
be
found
in
Appendix
I
­
Clean
Air
Strategy
Development.
The
reduction
estimations
listed
in
the
table
below
are
calculated
for
the
four
county
Early
Action
Compact
region
of
Bexar,
Comal,
Guadalupe
and
Wilson
Counties.

Table
5­
3.
State
and
Federal
Issued
Rules
FEDERAL
ISSUED
RULES
Estimated
NOx
Reductions
in
2007
(
tpd)
Estimated
VOC
Reductions
in
2007
(
tpd)
Federal
area
measures:
On­
board
Refueling
Vapor
Recovery
0.00
8.20
Federal
on­
road
measures:
Federal
Phase
II
Reformulated
Gasoline
National
Low
Emission
Vehicle
(
NLEV)
Program
Tier
II
Vehicle
Emission
Standards
Federal
Regulation
of
On­
road
Diesel
Engines
22.39
12.43
Federal
non
road
measures:
Standards
for
Compression­
ignition
Vehicles
and
Equipment
Standards
for
Spark­
ignition
Off­
road
Vehicles
and
Equipment
Tier
III
Heavy
Diesel
Equipment
Lawn
and
Garden
Equipment
Recreational
Marine
Standards
Locomotives
1.10
10.97
STATE
ISSUED
RULES
Estimated
NOx
Reductions
in
2007
(
tpd)
Estimated
VOC
Reductions
in
2007
(
tpd)
State
area
measures:
Stage
I
Vapor
Recovery
(
throughput
 
125,000
gal
/
month)
19
TAC
Chapter
106
Degreasing
Controls
0.00
7.61
State
point
measures:
Senate
Bill
766
 
Grandfathered
Power
Plants
Senate
Bill
7
 
Grandfathered
Power
Plants
39.51
1.06
19
Gasoline
stations
that
dispense
more
than
125,000
gallons
per
month
are
subject
to
stage
I
vapor
recovery
requirements:
TAC
Chapter
115.227.
Available
online:
http://
www.
tnrcc.
state.
tx.
us/
oprd/
rules/
pdflib/
115c.
pdf
SIP
Revision
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the
San
Antonio
EAC
Region
72
5.3
LOCAL
CLEAN
AIR
STRATEGIES
Signatories
of
the
Clean
Air
Plan
for
the
San
Antonio
region
are
committed
to
early
planning
and
early
actions
that
will
benefit
the
region's
air
quality.
These
actions
were
accomplished
through
cooperative
relations
between
the
representatives
of
the
affected
region,
state
and
federal
officials
in
assessing
the
region's
air
quality
situation
and
in
developing
the
best
available
approach
to
reach
and
maintain
the
8­
hour
ozone
NAAQS.
Since
the
EAC
was
created
to
enable
early
local
actions,
it
is
pertinent
to
implement
strategies
locally
that
will
improve
air
quality
most
effectively.

Lower
Reid
Vapor
Pressure
(
RVP)
 
Reid
Vapor
Pressure
lowered
to
7.2
pounds
per
square
inch
during
the
ozone
season
for
the
San
Antonio
region.
The
requested
rule,
as
approved
by
the
AIR
Committee
and
all
Early
Action
Compact
signatory
governments,
would
lower
the
ozone
seasonal
RVP
to
7.2.

Stage
I
Vapor
Recovery
at
Stations
Dispensing
>
25,000
gallons/
month
 
Stage
I
Vapor
Recovery
required
of
service
stations
of
25,000
gallons
throughput
of
gasoline
or
more
per
month.
Stage
I
Vapor
Recovery
systems
are
designed
to
control
the
escape
of
gasoline
vapors
from
gasoline
storage
tanks.
The
uncontrolled
vapors
escape
from
storage
tanks
when
displaced
by
liquid
gasoline
unloaded
from
refueling
trucks.
With
installation
of
Stage
I
equipment,
the
storage
tank
vapors
are
captured
by
a
vapor
return
hose
and
are
returned
to
the
refueling
truck.
Texas
currently
enforces
the
requirement
of
Stage
I
Vapor
Recovery
systems
at
gasoline
stations
that
dispense
no
less
than
125,000
gallons
of
gasoline
per
month.
This
strategy
proposes
Stage
I
Vapor
Recovery
systems
at
gasoline
stations
that
dispense
no
less
than
25,000
gallons
per
month.

Stage
I
Vapor
Recovery
for
service
stations
of
25,000
gallons
throughput
of
gasoline
or
more
per
month
will
be
implemented
and
operational
no
later
than
December
31,
2005.
Implementation
of
this
control
strategy
comes
as
a
formal
request
of
the
eight
local
governments
who
are
signatories
to
the
Early
Action
Compact.
Their
support
for
Stage
I
Vapor
Recovery
as
a
local
clean
air
strategy,
and
their
approval
of
this
proposed
local
State
Implementation
Plan
Revision,
are
attached
as
appendix
N.

Reduction
Calculations
Methodology
Overview
Evaluation
of
this
strategy
involved
quantification
of
emission
reductions
resulting
from
potential
strategy
implementation.
The
estimated
2007
VOC
tonnage
from
Source
Classification
Code
2501060053
(
Tanker
Truck
Unloading)
was
multiplied
by
an
emission
factor
provided
by
TCEQ.
(
TCEQ,
2004c)
Further
details
regarding
emission
reduction
calculations
can
be
found
in
Appendix
I.

Degreasing
 
Degreasing
Equipment
Operation
Controls,
described
in
TAC,
Title
30,
Ch.
115.
The
requested
rule,
as
approved
by
the
AIR
Committee
and
all
Early
Action
Compact
signatory
governments,
would
lower
VOC
emissions
on
degreasing
operations.

The
following
table
lists
the
strategies
were
formally
approved
for
implementation
by
the
EAC
signatory
governments
along
with
their
estimated
emission
reduction
when
implemented
in
the
SAER.
SIP
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Attainment
Demonstration
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the
San
Antonio
EAC
Region
73
Table
5­
4.
Locally
Issued
Rules
Local
Clean
Air
Strategies
Estimated
NOx
Reductions
in
2007
(
tpd)
Estimated
VOC
Reductions
in
2007
(
tpd)
Reid
Vapor
Pressure
(
RVP)
lowered
from
7.8
to
7.2
psi
*
*

Stage
I
Vapor
Recovery
for
gas
stations
dispensing
25,000
to
125,000
gallons/
month
0.00
tpd
5.81
tpd
See
State
Rules;
thru
Ch.
106
See
State
Rules;
thru
Ch.
106
Degreasing
Controls
*
*

*
Potential
Emissions
Reductions
are
listed
in
Additional
Evidence,
Appendix
K
5.4
STRATEGY
TESTING
Various
emission
reducing
strategies
were
scrutinized
and
analyzed
for
their
effectiveness
in
reducing
ozone
precursors
as
well
as
reducing
ambient
ozone
levels
in
the
photochemical
model.
Local
entities
that
were
involved
in
the
strategy
selection
were
provided
numerous
control
strategies
that
would
have
an
effect
on
the
ambient
air
quality.
AACOG
technical
staff
presented
a
preliminary
list
that
detailed
over
100
clean
air
strategies.
The
strategies
on
the
list
were
then
analyzed
based
on
criteria
that
would
be
acceptable
to
the
TCEQ
and
EPA.
The
criteria
consisted
of
emission
reducing
strategies
that
were
quantifiable
(
emissions
can
be
quantified
from
such
a
strategy),
enforceable
(
local
or
state
jurisdiction
can
be
applied
to
enforce
the
strategy),
and
permanent.
Once
the
strategies
that
did
not
meet
the
criteria
had
been
eliminated,
the
potential
clean
air
strategies
were
analyzed
based
on
feasibility,
cost
effectiveness,
and
emission
reducing
capacity.
The
strategies
that
met
these
criteria
were
then
incorporated
into
the
photochemical
model
so
that
their
effect
on
ambient
ozone
levels
could
be
observed.
The
strategies
listed
in
Table
5­
4
were
selected
as
local
initiatives
that
will
assist
the
SAER
reach
8­
hour
attainment
standards.
Table
5­
5
lists
the
design
values
for
the
CAMs
stations
in
the
SAER.
Table
5­
6
depicts
the
emission
reductions
the
selected
strategies
are
projected
to
provide
by
2007.

Table
5­
5.
Comparison
of
1999
and
2007
Base
Cases
&
Adopted
Control
Strategies
Model
Run
Design
Value
at
CAMS
23
Design
Value
at
CAMS
58
Design
Value
at
CAMS
59
Design
Value
at
CAMS
678
1999
Base
Case
89
87
79
77
2007
Base
case
84.52
82.12
74.48
74.46
Control
Strategies
Included
84.40
82.03
74.44
74.39
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
74
Table
5­
6.
Projected
Ozone
Reductions
by
Local
Reduction
Strategies
Strategy
Reduction
in
Ground­
Level
Ozone
(
ppb)
Implementing
Entity
Degreasing
Solvent
*
State
Stage
I
VR
(
25K)
0.12
State
RVP
7.2
*
Fuel
distribution
through
local
agreement
 
Potential
Emissions
Reductions
are
listed
in
Additional
Evidence,
Appendix
K
5.5
ADDITIONAL
EVIDENCE
This
section
describes
additional
analyses
performed,
key
assumptions
and
outcomes
of
each
analysis,
and
justifies
the
conclusion
that,
viewed
as
a
whole,
the
area
will
attain
the
NAAQS.
In
the
following
pages
we
introduce
further
local
projects
as
well
as
additional
studies
and
indicators
supporting
the
likelihood
of
the
results
of
our
photochemical
modeling
in
regard
to
the
attainment
of
NAAQS
ozone
level
by
the
year
2007.
For
some
of
the
strategies
presented
in
this
chapter,
additional
comments
and
calculations
are
available
beyond
those
given
here.
These
comments
and
calculations
are
given
in
Appendix
K
 
Additional
Evidence.

5.5.1
Evidence
Supporting
Attainment
Demonstration
The
argument
presented
here
consists
of
several
corroboratory
analyses,
which
together
form
a
compelling
argument
that
by
the
year
2007
attainment
will
be
achieved.
Table
5.6
shows
the
1999
base
case,
the
2007
base
case,
and
the
impacts
of
adopted
control
strategies
on
design
values
for
CAMS
23,
59,
678,
and
58
where
ozone
levels
are
being
recorded.

5.5.2
Degreasing
Emissions
As
described
in
section
5.1.1
Resolution
of
Challenges:
Degreasing
Equipment
Controls,
degreasers
in
the
SAER
are
subject
to
adherence
of
Chapter
115
controls
through
reference
in
Chapter
106.
Chapter
106
of
the
TAC
was
adopted
in
1994,
thus
applying
to
degreasing
facilities
that
were
constructed
or
scheduled
to
be
constructed
on
and
after
1994.
This
leaves
degreasing
facilities
that
were
in
existence
prior
to
1994
exempt
from
Chapter
106
rule.
These
uncontrolled
facilities
would
be
subjected
to
the
regulations
of
Chapter
115
due
to
the
passage
of
the
rule
by
local
governments,
therefore
be
a
source
of
additional
emission
reductions.
Additional
details
regarding
the
emission
reductions
can
be
found
in
Appendix
K.

Reduction
Calculations
Methodology
Overview
TAC
Chapter
115
addresses
controlling
emissions
from
degreasing
facilities
and
providing
a
reduction
in
emissions
by
85%.
Documentation
provided
by
TCEQ
shows
that
Safety­
Kleen
1)
provides
degreasing
equipment
and
solvents
for
approximately
50%
of
the
San
Antonio
market;
2)
Safety­
Kleen
products
are
Chapter
115
compliant;
3)
Safety­
Kleen
provided
these
products
to
their
customers
in
the
San
Antonio
region
consistent
with
the
promulgation
of
Chapter
106.
Hence,
the
85%
reduction
effective
through
Chapter
106/
115
should
act
as
a
first
approximation
correction
to
50%
of
the
degreasing
emissions
in
the
1999
EI.
Projecting
degreasing
emission
reductions
for
2007
was
calculated
as
follows:
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
75
1999
Degreasing
Emissions
Inventory
x
0.85
emission
factor
x
0.5
market
share
=
Emission
Reduction
Further
details
regarding
emission
reduction
calculations
can
be
found
in
Appendix
I.

5.5.3
Pollution
Transport
The
evidence
for
transport
can
be
demonstrated
by
conducting
a
series
of
special
modeling
runs
in
which
all
of
the
anthropogenic
emissions
from
selected
adjacent
metropolitan
areas
are
removed
from
the
CAMx
emission
inventory
for
the
modeled
episode.
Using
the
graphic
capabilities
of
the
CAMx
model
and
applying
some
post
processing
techniques,
attempts
have
been
made
to
depict
the
results
of
this
analysis
at
regional
level,
as
well
as
at
various
CAMS
in
San
Antonio
area.
These
results,
which
are
discussed
in
the
Appendix
M,
specifically
show
the
impacts
of
removing
the
anthropogenic
emissions
on
the
design
value
of
the
modeled
episode
at
various
CAMS.

The
highest
8­
hour
ozone
concentrations
near
this
monitor,
for
each
day
of
the
6
modeling
days
in
the
episode,
were
dependent
on
local
(
i.
e.,
within
Bexar,
Comal,
Guadalupe
or
Wilson
Counties)
ozone
precursor
production
sources,
on
average,
for
less
than
25%
of
the
total
ozone
concentrations
predicted.
In
addition,
while
the
amount
of
emissions
attributed
to
the
San
Antonio
region
is
predicted
to
increase
in
2007,
this
region's
contribution
to
its
design
value
for
the
Sept.
1999
episode
will
remain
as
25%
of
the
total
design
value,
or
21.86
parts
per
billion
of
ozone.
(
AACOG,
2003a)
Additional
details
regarding
the
effect
of
transport
on
San
Antonio's
air
quality
can
be
located
in
Appendix
M.

5.5.4
Alternative
Fuel
Vehicles
A
local
alternative
fuel
survey
was
conducted
in
2001,
which
inventoried
the
AFV
fleet
in
the
SA
MSA.
The
survey
provided
information
on
the
number
of
AFVs,
specific
fuel
type,
the
percentage
of
time
that
they
operate
on
alternative
fuel,
the
number
of
days
per
week
they
typically
operate,
and
an
estimate
on
how
many
vehicle
miles
traveled
(
VMT)
were
accumulated
by
each
vehicle
for
2001.

The
results
indicated
that
there
were
2,050
AFVs
in
the
San
Antonio
region,
and
this
number
is
expected
to
increase
to
2,442
AFVs
by
2006.
Of
the
reported
fleet,
1,755
vehicles
were
modeled
as
the
September
2001
fleet
and
2,147
vehicles
modeled
for
the
September
2007
fleet.
Analysis
of
fleet
indicated
that
this
fleet
is
generated
emission
reductions
of
62
lbs./
day
of
VOC,
45
lbs./
day
of
CO,
and
689
lbs./
day
of
NOx.
By
2007,
it
is
projected
that
this
fleet
could
contribute
emissions
reductions
of
72
lbs./
day
of
VOCs,
45
lbs./
day
of
CO,
and
858
lbs./
day
of
NOx
for
the
year
2007.

5.5.5
Energy
Efficiency
/
Renewable
Energy
Projects
The
TCEQ
revised
the
Houston­
Galveston
(
HGA)
SIP
and
the
Dallas/
Ft.
Worth
(
DFW)
SIP
to
include
a
protocol
for
implementing
and
calculating
emission
reductions
from
energy
saving
resulting
from
Senate
Bill
5
(
SB5)
and
Senate
Bill
7
(
SB7)
measures.
The
revisions
relied
on
assumptions
about
the
level
of
commitment
by
political
subdivisions
to
implement
the
5%
per
year
reduction
within
their
facilities.
SB5
only
requires
that
a
target
of
5%
reduction
in
energy
usage
per
year
be
set,
it
remains
the
responsibility
of
each
individual
political
subdivision
to
adopt
ordinances,
resolutions,
procedures
or
plans
to
demonstrate
its
commitment.
Since
passing
the
bills,
efforts
have
been
underway
both
to
implement
the
energy
reductions
required
by
the
state
and
to
quantify
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
76
the
associated
ozone
precursor
reductions.
Air
quality
planners
in
the
San
Antonio
region
currently
benefit
from
a
partnership
created
by
the
TCEQ
between
AACOG,
the
Energy
Systems
Laboratory
(
ESL)
of
Texas
A&
M
University,
the
local
Metropolitan
Partnership
for
Energy,
and
the
Brooks
Energy
Sustainability
Laboratory
(
BESL)
of
the
Texas
Engineering
Experiment
Station.

5.5.6
Lawnmower
Recycling
Program
Gasoline­
powered
lawnmowers
contribute
a
significant
amount
of
NOx,
VOCs,
and
particulate
matter
to
the
atmosphere.
Not
surprisingly,
carbon
dioxide
(
CO2)
emissions,
the
major
greenhouse
gas,
are
spewed
out
in
large
quantities
from
gas­
powered
mowers
too.

In
San
Antonio,
City
Public
Service
(
CPS)
initiated
the
"
buy
back"
program
in
1998.
The
City
of
San
Antonio
and
the
Alamo
Area
Council
of
Governments
later
partnered
in
promoting
CPS'
"
buy
back"
events.
Their
first
trade­
in
event
was
held
on
March
31,
2001
and
is
scheduled
to
start
in
2004
on
March
20
continuing
through
August
31.
(
CPS,
2004)

Since
its
inception,
CPS's
"
Mow
Down
Smog"
lawn
mower
rebate
program
has
removed
over
3,200
pieces
of
operating
gasoline­
powered
lawn
equipment
and
replaced
them
with
virtually
pollution­
free
electric
lawn
equipment.
The
emissions
reductions
attributed
to
this
program
have
not
been
taken
into
account
in
the
process
of
photochemical
modeling
task
for
the
attainment
forecast.
The
reductions
for
all
VOC,
CO,
and
NOx
categories
have
been
calculated
for
Bexar
County
and
the
procedure
for
calculation
of
these
reductions
is
presented
in
the
Appendix
K
of
this
document.
The
followings
show
the
amount
of
these
reductions.

Table
5­
7.
Reduced
Emissions
from
"
Mow
Down
Smog"
Recycling
Program
5.5.7
Lower
Reid
Vapor
Pressure
Fuel
control
measures
are
effective
strategies
for
states
to
use
to
reduce
ozone
pollution.
Such
measures
reduce
volatile
organic
compounds
but
may
differ
on
methods
the
state
or
federal
government
administers
them,
and
the
statutory
provisions
governing
their
adoption.
Gasoline
with
an
RVP
of
7.2
was
proposed
for
the
San
Antonio
region
after
in
depth
modeling,
cost­
benefit
analysis,
and
consideration
of
sentiments
of
the
local
communities
and
their
elected
officials.
If
allowed,
adoption
of
this
fuel
during
the
ozone
season
is
expected
to
help
reduce
emissions
of
VOCs
and
NOx
by
2.1
and
0.05
Emission
Exhuast
Crank
Diurnal
Displ.
Spillage
Total
VOC
90.62
3.60
5.84
1.50
12.70
114.24
NOx
4.78
4.78
CO
1145.39
1145.39
*
Ozone
season
in
1999
EI
report
consists
196
days
2003
Emission
Reduction
due
to
City
Public
Service
"
Mow
Down
Smog"
Program
pound
per
ozone
season
day*
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
77
tons/
day
respectively.
The
requirement
for
gasoline
refineries
to
provide
such
gasoline
will
only
be
during
the
months
of
March
through
October,
which
is
usually
the
time
of
the
year
ozone
levels
exceed
the
national
standard
in
San
Antonio
region.

Modeling
scenarios
with
the
MOBILE6
model20
indicated
that
lowering
the
RVP
in
gasoline
to
7.2
from
7.8
would
reduce
emissions
from
the
on­
road
mobile
fleet
in
the
SAER
counties.
Table
5­_
lists
the
emission
reduction
percentages
for
each
of
the
SAER
counties.
(
AACOG,
2003b)

Table
5­
8.
Reductions
for
SAER
Counties
with
RVP
7.2
Gasoline,
Compared
with
RVP
7.8.

County
VOC
%
Reduction,
2007
On­
Road
Mobile
Fleet
NOx
%
Reduction,
2007
On­
Road
Mobile
Fleet
Bexar
County
4.18
0.06
Comal
County
3.73
0.05
Guadalupe
County
3.69
0.05
Wilson
County
3.14
0.06
The
percentage
reduction
of
precursor
emissions
was
used
to
calculate
actual
reductions.
The
actual
reduction
was
estimated
by
multiplying
the
2007
daily
on
road
emissions
total
for
each
county
with
the
emission
reduction
percentage.
The
resulting
number
was
then
divided
by
100
to
provide
the
emission
reduction
total
in
tons
per
day.

(
2007
tons/
day
VOC
x
emission
reduction
%)
/
100
=
2007
tons/
day
of
VOC
reduced)
Further
details
regarding
emission
reduction
calculations
can
be
found
in
Appendix
I.

5.5.8
Windshield
Wiper
Fluid
In
1998,
the
EPA
promulgated
rules
pertaining
to
the
VOC
emission
standards
for
certain
consumer
solvents.
One
solvent,
windshield
wiper
fluid,
is
limited
35
weight­%
VOC.
EPA
calculated
VOC
reductions
from
this
national
consumer
products
rule
to
be
20%
and
allowed
states
to
take
this
emission
reduction
credit
in
their
SIPs.
Prior
to
EPA's
issuance
of
its
national
rule,
Texas
adopted
a
consumer
products
rule
that
limits
automotive
windshield
washer
fluid
to
23.5
weight­%
VOC.
Due
to
the
difference
between
EPA's
35%
requirement,
the
EPA
allows
Texas
to
take
credit
for
the
difference
Due
to
this
limited
reduction
and
that
the
photochemical
model
shows
attainment
in
the
2007
base
case,
this
reduction
credit
has
not
been
fully
estimated
and
included
in
the
photochemical
model
since
a
VMT­
based
estimate
of
VOCs
allowed
in
the
San
Antonio
region
is
60
lbs­
per­
day
for
this
category.
(
TCEQ,
1999)

5.5.9
Gas­
fired
Water
Heaters,
Small
Boilers,
and
Process
Heaters
This
statewide
rule
would
reduce
NOx
emissions
from
new
natural
gas­
fired
water
heaters,
small
boilers,
and
process
heaters
sold
and
installed
in
Texas
beginning
in
2002.
It
is
estimated
that
this
rule
would
help
reduce
area
source
NOx
emissions
by
5%

20
MOBILE6
Vehicle
Emissions
Modeling
Software
developed
by
the
USEPA.
Available
online:
http://
www.
epa.
gov/
otaq/
m6.
htm
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
78
to
10%.
The
rules
would
apply
to
each
new
water
heater,
boiler,
or
process
heater
with
a
maximum
rated
capacity
of
up
to
2.0
MMBtu/
hr.
(
TCEQ,
2004)

5.5.10
Transportation
Demand
Management
Transportation
Demand
Management
(
TDM)
projects
are
transportation­
related
projects
that
attempt
to
reduce
vehicle
use,
change
traffic
flow,
or
reduce
congestion
conditions..
Due
to
a
survey
conducted
by
AACOG
in
2002,
results
indicated
that
TDMs
are
or
will
be
implemented
by
government
agencies
and
companies
in
the
San
Antonio
area.
These
TDMs
included:
rideshare,
telecommuting,
flex
time,
compressed
workweek,
and
staggered
hours.
Study
results
revealed
that
during
the
weekday
peak
hours,
TDMs
could
help
reduce
on­
road
source
emissions
of
VOC's
and
NOx
by
3.3%
and
2.4%
respectively
for
the
year
2007.
(
AACOG,
2002)
These
reduction
rates
however,
have
not
been
included
in
the
photochemical
modeling
efforts
for
the
year
2007
attainment
demonstration.

5.5.11
Transportation
Emission
Reduction
Measures
Transportation
Emission
Reduction
Measures
(
TERMs)
are
strategies
or
actions
that
can
be
employed
to
offset
increases
in
nitrogen
oxide
(
NOx)
and
volatile
organic
compound
emissions
from
mobile
sources
by
reducing
either
the
number
of
vehicle
trips,
vehicle
miles
traveled,
or
both.
These
strategies
may
include
ridesharing,
telecommuting
programs,
clean
fuel
vehicle
programs,
improved
transit/
bicycling
facilities,
or
other
possible
actions
such
as
intersection
improvement
and
signalization.

It
is
important
to
note
that
many
of
projects
included
in
the
San
Antonio­
Bexar
County
Metropolitan
Planning
Organization
(
SA­
BC
MPO)
Transportation
Improvement
Programs
(
TIP)
21
can
be
quantified
as
creditable
reductions.
They
are
listed
n
the
Appendix
K
as
TERM
projects
since
the
projects
target
vehicle
trip
reduction
and
improvement
of
air
quality.
AACOG
photochemical
modeling
for
the
attainment
demonstration
does
not
take
into
account
any
emission
reductions
due
to
the
implementation
of
these
projects.

While
the
quantity
of
available
and
appropriate
reductions
have
not
been
calculated
and
included
in
the
attainment
demonstration
of
the
San
Antonio
proposed
revisions
to
the
State
Implementation
Plan,
local
air
quality
planners
are
now
researching
measures
to
make
the
appropriate
TERMS
enforceable.
The
region
is
intent
on
making
them
enforceable
and
calculating
SIP
credit
for
them
in
coordination
with
the
state
and
the
SABC
MPO.
Even
if
credit
is
not
taken
here
for
the
TERMS
projects
in
the
region,
the
benefits
of
the
reductions
accrue
as
Additional
Evidence
that
the
San
Antonio
region
will
reach
attainment.

Intersection
Improvement
and
Signalization
Traffic
signalization
projects
can
reduce
carbon
monoxide
(
CO)
and
hydrocarbon
(
HC)
by
reducing
the
number
of
vehicular
stops
and
idling,
which
would
reduce
travel
times
and
traffic
delays.
Reductions
in
fuel
consumption
have
also
been
observed
through
traffic
signal
re­
timing.
Traffic
flow
at
intersections
can
be
improved
in
interconnection
and
coordination
of
signals.

21
Available
online:
http://
www.
co.
bexar.
tx.
us/
mpo/
pages/
futureprojects/
short/
main.
html
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
79
Of
many
projects
shown
in
the
MPO's
TIP
in
Appendix
K,
certain
traffic
signals
for
various
intersections
in
the
Bexar
County
were
separately
evaluated
for
their
impacts
on
air
quality.
(
AACOG,
2003b)
The
results
can
be
considered
as
additional
evidence
indicating
future
lower
ozone
levels
for
the
San
Antonio
area.

5.5.12
TransGuide
ITS
projects
have
shown
to
be
a
crucial
ingredient
of
traffic
management
in
metropolitan
areas
throughout
the
nation.
Studies
have
proved
that
ITS
have
a
significant
impact
on
reducing
the
delays
due
to
accidents
and
congestion
on
freeway
systems
in
metropolitan
areas.
(
Henk,
R.,
et.
al.,
1996),
(
Carter,
M.,
et.
al.,
2000)
Results
indicate
that
the
most
effective
stand­
alone
implementation
is
incident
management,
recording
improvements
in
all
impact
measures
assessed.
VMS
and
arterial
traffic
signal
control
can
provide
additional
improvement
under
many
of
these
areas.
For
the
particular
corridor
modeled
during
this
study,
optimum
implementation
of
the
integrated
VMS
and
incident
management
result
in
a
5.7%
decrease
in
delay,
a
2.8%
decrease
in
crashes,
and
a
1.2%
decrease
in
fuel
consumption
annually.
Integrated
use
of
incident
management,
VMS
and
arterial
traffic
control
can
achieve
an
annual
benefit
of
a
5.9%
reduction
in
delay,
a
2.0%
decrease
in
crashes,
and
a
1.4%
decrease
in
fuel
consumption
for
travelers
in
the
corridor.

AACOG
staff,
neither
in
the
photochemical
modeling
process
nor
in
applications
of
MOBILE6
for
the
analysis
of
control
strategies,
has
taken
the
air
quality
impacts
of
TransGuide
into
account.
Techniques
could
be
developed
to
translate
reductions
in
fuel
consumption,
due
to
the
impacts
of
TransGuide,
into
reductions
of
ozone
precursor
emissions.

5.5.13
Public
Education
A
detailed
description
of
the
public
outreach
and
education
projects
undertaken
by
AACOG
staff,
for
the
purpose
of
disseminating
information
on
air
quality
and
informing
the
public
of
seriousness
of
air
pollution
problem
in
the
San
Antonio
area,
is
presented
in
the
Appendix
K.

The
main
goal
is
to
familiarize
the
public
with
actions
they
can
take
to
improve
the
air
quality.
There
has
been
no
attempt
to
quantify
the
air
quality
impacts
of
these
public
outreach
projects.

5.6
SUMMARY
AND
RECOMMENDATIONS
Clean
air
strategy
selection
required
various
technical
analyses.
These
analyses
provided
by
local
air
quality
planners
enabled
elected
officials
to
select
applicable
and
effective
clean
air
measures
that
would
best
improve
the
region's
air
quality.
The
number
of
strategies
was
reduced
by
elimination
based
on
creditability.
Creditable
strategies
are
strategies
that
are
quantifiable,
enforceable,
and
permanent.
Strategies
that
did
not
reflect
these
qualities
were
eliminated
from
the
list.
The
remaining
creditable
strategies
were
then
analyzed
for
emission
reducing
capacity
and
cost
effectiveness.

The
strategies
that
were
then
deemed
cost
effective
and
reduced
emissions
sufficiently
were
then
subject
to
additional
analysis
by
way
of
ozone
reductions
in
the
photochemical
model.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
80
Since
the
attainment
demonstration
predicted
8­
hour
ozone
levels
below
the
NAAQS,
it
was
deemed
that
the
addition
of
three
strategies
would
be
enough
to
maintain
attainment.
These
strategies
are
gasoline
with
an
RVP
of
7.2,
stage
I
vapor
recovery
implementation
on
service
stations
that
throughput
at
least
25,000
gallons,
and
degreasing
controls
on
manufacturing
equipment.
The
San
Antonio
Early
Action
Compact
Region
will
comply
with
attainment
standards
by
2007
with
the
federal
and
state
issued
rules,
the
strategies
selected
by
local
officials,
and
the
strategies
presented
in
the
additional
evidence
section.

References:

Texas
Administrative
Code
(
TAC),
2004.
Chapter
106,
Subchapter
T:
Surface
Preparation:
§
106.454.
Available
online:
http://
www.
tnrcc.
state.
tx.
us/
oprd/
rules/
pdflib/
106_
ind.
pdf
Alamo
Area
Council
of
Governments
(
AACOG),
2003.
Conceptual
Model
for
Ozone
Analysis
of
the
San
Antonio
Region,
San
Antonio,
TX.

City
Public
Service
(
CPS),
2004.
Mow
Down
Smog.
Available
online:
http://
www.
citypublicservice.
com/
for%
5Fhome/
rebates/
lawn_
mower_
rebates.
asp
Texas
Commission
on
Environmental
Quality
(
TCEQ),
1999.
Revisions
to
the
State
Implementation
Plan
for
the
Control
of
Ozone
Air
Pollution.
Available
online:
http://
www.
tnrcc.
state.
tx.
us/
oprd/
rule_
lib/
4dfwrop.
pdf
Texas
Commission
on
Environmental
Quality
(
TCEQ),
2004.
Chapter
117
Control
of
Air
Pollution
From
Nitrogen
Compounds.
Available
online:
http://
www.
tnrcc.
state.
tx.
us/
oprd/
rules/
pdflib/
117_
ind.
pdf
Alamo
Area
Council
of
Governments
(
AACOG),
2002.
Analyses
of
TCMs,
AFVs,
and
Control
Strategies
for
the
September
13­
20,
1999
Photochemical
Modeling
Episode.
San
Antonio,
TX.

Alamo
Area
Council
of
Governments
(
AACOG),
2003.
Refinements
to
the
1999
San
Antonio
Region
Photochemical
Model
using
MOBILE6
and
Enhanced
Meteorological
Data.
San
Antonio,
TX.

Henk,
R.,
et.
al.,
1996.
Before­
and­
After
Analysis
of
the
San
Antonio
TransGuide
System.
San
Antonio
Texas.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
81
Carter,
M.,
et.
al.,
2000.
Metropolitan
Model
Deployment
Initiative:
San
Antonio
Evaluation
Report.
McLean,
VA.

Texas
Commission
on
Environmental
Quality
(
TCEQ),
2004.
Emission
Reduction
from
Stage
I
Vapor
Recovery
System
in
the
95­
county
Region.
Austin,
TX.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
82
CHAPTER
6:
MAINTENANCE
FOR
GROWTH
6.1
BACKGROUND
The
general
elements
required
for
the
development
of
the
Maintenance
for
Growth
were
stated
in
the
Protocol
for
Early
Action
Compacts
Designed
to
Achieve
and
Maintain
the
8­
Hour
Ozone
Standard.
22
The
protocol
states
that
the
Maintenance
for
Growth
plan
must
address
emissions
growth
at
least
5
years
beyond
December
31,
2007
to
ensure
the
area
will
remain
in
attainment
of
the
8­
hour
standard.
The
component
may
include
modeling
analyses,
annual
review
of
growth,
or
the
identification
and
quantification
of
federal,
state,
and
local
control
measures
that
indicate
sufficient
emission
reduction.
A
continuing
planning
process
that
includes
modeling
updates
and
modeling
assumption
verification
must
also
be
included.
The
modeling
must
consider
and
evaluate
relevant
new
point
sources,
impacts
from
potential
new
source
growth,
and
future
transportation
patterns.

If
the
review
of
growth
indicates
that
the
adopted
control
measures
are
inadequate
to
address
growth
in
emissions,
additional
measures
will
be
added
to
the
plan.

6.2
MAINTENANCE
ANALYSIS
The
Clean
Air
Plan
for
the
SAER
is
directed
to
achieve
the
8­
hour
standard
by
December
2007.
Maintaining
the
8­
hour
standard
five
years
beyond
the
attainment
date
will
be
achieved
through
an
annual
review
of
growth
as
required
in
the
EAC
protocol.

The
Maintenance
for
Growth
analysis
performed
by
AACOG
has
several
stages
or
components.
 
Current
Analysis:
The
current
Maintenance
for
Growth
analysis
is
an
updated
and
expanded
Trend
Analysis,
first
published
September
30,
2003
as
an
EAC
milestone.
The
Maintenance
for
Growth
section
(
Appendix
L)
analyzes
the
emissions
inventories
from
1996
and
1999
and
projects
emissions
to
2007
and
2012.
These
future
year
projections
encompass
all
relevant
changes
affecting
future
emissions,
including
revised
or
new
federal,
state,
and
local
rules
and
any
new
practices
that
would
result
in
changes
to
future
year
emissions
inventories.
As
a
separate
document,
the
Trend
Analysis
itself
is
updated
once
more,
and
is
due
as
an
updated
milestone
/
deliverable
in
the
EAC
by
September
30,
2005.
 
Continuing
Planning
Process:
The
assumptions
underlying
this
analysis
will
be
reviewed
annually
throughout
the
term
of
the
EAC
(
through
2007).
Changes
in
assumptions
will
be
incorporated
annually
into
an
updated
Maintenance
for
Growth
analysis
and
reported
as
a
component
of
the
Semi­
Annual
Updates.
The
current
analysis
reported
in
this
document
set
(
Appendix
L)
will
next
be
updated
and
reported
in
the
December
2004
Semi­
Annual
Update.
 
New
Strategy
Requirements:
In
the
event
the
annual
analysis
of
emission
trends
and
control
strategies
fails
to
maintain
attainment
standards,
appropriate
planning
and
implementation
of
additional
clean
air
measures
will
result.

Current
Analysis
As
part
of
the
initial
analysis
of
the
region's
air
quality,
emission
projections
were
developed.
These
projections
provided
insight
to
future
air
quality
scenarios
with
increases
in
population
and
emission
sources
along
with
control
strategies
that
will
be
implemented
by
state
and
federal
agencies
in
the
years
to
come.
In
summary,
table
6­
4
lists
emissions
from
various
anthropogenic
sources
for
1996,
1999,
2007,
and
2012.

22
Available
online:
http://
www.
epa.
gov/
ttn/
naaqs/
ozone/
eac/
20020619_
eac_
protocol.
pdf
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
83
Methodologies:
2012
projections
The
2012
emission
projections
were
developed
using
the
same
methodologies
in
the
development
of
2007
emissions,
which
are
described
in
Appendix
F,
Future
Year
Modeling
Emissions
Inventory
Development.
However,
there
are
some
components
in
the
methodologies,
such
as
emission
factors,
that
were
altered
to
reflect
predicted
changes
for
2012
different
from
2007.
These
alterations
are
described
in
Appendix
L,
Maintenance
for
Growth.

New
Point
Sources,
2007­
2012
The
following
section
describes
new
point
sources
that
are
expected
to
come
into
existence
between
2007
to
2012.
Detailed
descriptions
of
the
new
point
sources
in
methods
used
to
determine
their
projected
emissions
can
be
found
in
Appendix
L
 
Maintenance
for
Growth.

Guadalupe
County
Power
Plants
Two
natural
gas
powered
electrical
generating
facilities
are
slated
for
completion
and
operation
prior
to
2007.
Both
facilities
are
under
construction
in
Guadalupe
County.
Two
facilities
are
currently
being
constructed,
each
facility
is
projected
to
emit
3.79
tons
of
NOx
and
0.24
tons
of
VOC
per
day.

Tessman
Road
Landfill
Gas
Power
Station
The
proposed
Tessman
Road
power
station
is
located
in
Bexar
County
near
Converse,
TX.
The
station
will
feature
six
Deutz
TBG
620
V16
engines,
producing
electricity
from
methane
and
other
landfill
gases.
According
to
our
calculation,
this
project
will
release
0.179
ton
of
NOx
and
0.049
ton
of
VOC
in
the
air
on
a
daily
basis.

City
Public
Service
Power
Plant
City
Public
Service
is
currently
developing
plans
to
build
an
additional
coal
burning
power
plant
in
our
study
area.
City
Public
Service
plans
estimate
that
the
plant
will
emit
5.92
tons
of
NOx
in
the
air
by
2012
when
the
plant
is
fully
operational.
Also,
CPS
plans
to
have
a
natural
gas
plant
on­
line
by
September
2012
and
its
projected
NOx
emissions
are
estimated
at
0.72
tons
per
day.

Toyota
Motor
Manufacturer
North
America
Toyota
Motor
Manufacturer
North
America
(
TMMNA)
is
currently
negotiating
the
building
of
an
auto­
production
assembly
plant
in
south
Bexar
County.
Toyota
provided
emissions
estimates
of
the
anticipated
pollutants
produced
by
this
plant
at
the
start
of
production.
Detailed
emission
data
can
be
found
in
Appendix
L.
Table
6­
1
lists
total
emissions
projected
to
be
emitted
from
plant
production
along
with
the
other
point
source
projected
emissions.
These
figures
do
not
include
emissions
produced
during
the
building
of
this
plant;
they
contain
only
those
emitted
during
operation
of
the
plant,
after
the
building
is
completed.
Plant
construction
will
be
completed
prior
to
2012.

New
Point
Source
Emission
Total
Table
6­
1
displays
the
accumulative
VOC
and
NOx
emissions
due
to
the
introduction
new
point
source
related
emissions
to
San
Antonio
region.

Table
6­
1.
Point
Source
VOC
&
NOx
Emissions
of
New
Point
Source
Projects
(
tons/
weekday)
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
84
1999
2007
2012
Point
Source
VOC
NOx
VOC
NOx
VOC
NOx
Emissions
without
new
sources
7.3
96.6
8.0
67.1
8.3
49.8
CPS
­
New
Coal
Plant
0.0
0.0
0.0
0.0
0.0
5.9
CPS
 
New
Gas
Plant
0.0
0.0
0.0
0.0
0.0
0.7
Guadalupe
Power
Plants
0.0
0.0
0.4
7.5
0.4
7.5
Toyota
0.0
0.0
5.0
0.3
10.0
0.7
Tessman
Road
Power
Station
0.0
0.0
0.0
0.2
0.0
0.2
Total
7.3
96.6
13.5
75.1
18.7
64.9
The
VOC
emissions
will
increase
due
to
the
contribution
of
the
Toyota
Manufacturing
Plant
to
the
2007
emissions
projection
as
well
as
the
2012
emissions
projection.
The
remaining
new
point
source
projects
such
as
the
CPS
power
plant,
the
Tessman
LFG
Power
Station,
and
the
Guadalupe
Power
Plant
are
not
expected
to
contribute
as
significant
amount
of
VOC
emissions
as
the
Toyota
Manufacturing
Plant.
NOx
emissions
decrease
in
the
2007
and
2012
projections.

Comparison
of
2007­
2012
Emissions
by
Major
Category
Point
VOC
emissions
from
point
source
are
estimated
to
increase
approximately
38.5%
(
13.5
TPD 
18.7
TPD)
from
2007
to
2012.
The
rise
is
attributed
to
the
emergence
of
new
point
sources
within
the
region.
NOx
emissions
are
expected
to
decrease
by
13.6%
(
75.1
TPD 
64.9
TPD).
The
drop
in
NOx
is
anticipated
due
to
use
of
improved
emission
reducing
technologies
employed
at
the
City
Public
Service
power
production
facilities.

Non
Road
The
17.6%
drop
in
VOC
(
30
TPD 
24.7
TPD)
and
the
8.2%
drop
in
NOx
emissions
(
44
TPD 
40.4
TPD)
across
the
four
counties
between
2007
and
2012
for
this
source
category
are
based
on
various
state
and
federal
control
strategies,
which
are
reflected
in
input
files
for
the
photochemical
model.
These
files
are
described
in
Appendix
F.

Area
From
2007
to
2012,
area
source
VOC
emissions
are
projected
to
increase
3.2%
(
80.5
TPD 
83.1
TPD)
and
NOx
emissions
by
5.6%
(
9
TPD 
9.5
TPD).
This
can
be
attributed
to
various
growth
assumptions,
such
as
population
growth.

On
Road
On
road
VOCs
decreased
by
25.5%
(
53.8
TPD 
40.1
TPD)
and
NOx
emissions
dropped
by
40%
(
84
TPD 
50.4
TPD)
from
2007
to
2012.
State
and
federal
control
strategies
that
will
be
implemented
by
2007
are
reasons
for
the
decrease
in
both
ozone
precursors
and
can
be
found
in
Appendix
C
 
On­
Road
Mobile
Emissions
Inventory
Development.

Airport
Airport
and
military
emission
data
were
compiled
by
AACOG
staff.
These
emissions
cannot
be
projected
due
to
the
uncertainty
of
future
of
airport
and
military
bases
in
the
region.
Political
influence
or
unusual
circumstances,
such
as
wartime
situation,
may
increase
emissions
levels.
In
times
of
peace
or
poor
economy,
the
military
may
cut
back,
causing
a
decrease
in
emissions.
Thus,
emissions
for
this
category
remain
the
same
for
1999,
2007,
and
2012.
Table
6­
2
details
the
emissions
from
airport
and
military
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
85
sources.
These
emissions
are
accounted
for
in
the
non­
road
source
emissions
listed
in
Table
6­
4.

Table
6­
2.
Airport/
Military
Emissions
for
the
San
Antonio
EAC
Region
1996
1999
2007
2012
VOC
NOx
VOC
NOx
VOC
NOx
VOC
NOx
Bexar
2.7
6.8
3.0
9.9
3.0
9.9
3.0
9.9
Comal
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Guadalupe
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Wilson
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Airport
Sources
Total
2.7
6.8
3.0
9.9
3.0
9.9
3.0
9.9
Biogenic
Biogenic
emissions
emissions
were
unchanged
from
1999
for
2007
and
2012.
Table
6­
3
lists
the
biogenic
emissions
for
the
SAER
region.
Biogenic
emissions
were
not
included
in
table
6­
4.

Table
6­
3.
Biogenic
Emissions
for
the
San
Antonio
EAC
Region
1996
1999
2007
2012
VOC
NOx
VOC
NOx
VOC
NOx
VOC
NOx
Bexar
60.1
5.0
60.1
5.0
60.1
5.0
60.1
5.0
Comal
56.5
1.5
56.5
1.5
56.5
1.5
56.5
1.5
Guadalupe
83.6
7.5
83.6
7.5
83.6
7.5
83.6
7.5
Wilson
62.8
6.5
62.8
6.5
62.8
6.5
62.8
6.5
Biogenic
Sources
Total
263.0
20.6
263.0
20.6
263.0
20.6
263.0
20.6
Figure
6­
3
illustrates
the
predicted
emission
trend
from
1996
to
2012.
This
illustration
further
supports
the
SAER's
projected
maintenance
of
attainment
of
the
NAAQS
8­
hour
ozone
standard.
Between
1999
and
2007,
an
overall
reduction
of
28%
of
NOx
emissions
and
a
23%
reduction
in
VOC
emissions
are
predicted.
Between
2007
and
2012,
an
additional
22%
reduction
in
NOx
emissions
and
7%
reduction
in
VOC
emissions
can
be
expected.
These
reductions
are
a
result
of
the
positive
actions
enforced
by
the
USEPA
and
TCEQ
and
indicate
improved
air
quality
is
in
the
future
of
the
San
Antonio
EAC
region.
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
86
Tons
per
Day
Emission
1996
1999
2007
2012
San
Antonio
Early
Action
Compact
Region
VOC
NOx
VOC
NOx
VOC
NOx
VOC
NOx
Bexar
78.3
2.4
73.4
4.7
69.2
5.0
71.4
5.2
Comal
4.4
0.1
3.7
0.3
3.4
0.5
3.6
0.5
Guadalupe
6.1
0.3
5.4
0.9
5.2
1.7
5.4
1.8
Wilson
2.6
0.4
2.7
0.9
2.7
1.8
2.7
2.0
Area
Sources
Total
91.4
3.3
85.2
6.8
80.5
9.0
83.1
9.5
Bexar
7.0
64.3
6.3
83.9
11.8
53.2
17.0
43.0
Comal
0.4
8.2
0.5
12.2
0.5
13.8
0.5
13.8
Guadalupe
0.4
0.3
0.5
0.5
1.1
8.1
1.1
8.1
Wilson
0.0
0.0
0.01
0.004
0.1
0.004
0.1
0.004
Point
Sources
Total
7.8
72.8
7.3
96.6
13.5
75.1
18.7
64.9
Bexar
106.6
122.39
82.1
121.87
45.5
69.1
33.7
41.4
Comal
6.8
10.4
6.2
11.7
3.9
7.1
3
4.3
Guadalupe
6.6
10
5.6
10.5
3.4
6.5
2.6
3.9
Wilson
1.9
1.9
1.6
1.9
1
1.3
0.8
0.8
On
Road
Sources
Total
121.9
144.69
95.5
145.97
53.8
84
40.1
50.4
Bexar
54.3
55.2
36.3
36.4
25.6
36.3
21.0
32.9
Comal
9.8
3.5
3.4
2.6
2.1
3.4
1.8
3.3
Guadalupe
4.3
4.4
4.1
2.3
1.7
3.3
1.4
3.3
Wilson
1.4
4.1
1.0
0.7
0.6
1.0
0.5
0.9
Non
Road
Sources
Total
69.9
67.2
45.7
42.0
30.0
44.0
24.7
40.4
Table
6­
4.
Anthropogenic
Emissions
within
the
San
Antonio
Early
Action
Compact
Region
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
87
SA
Early
Action
Compact
Region
Change
VOC
2007 
2012
(
TPD)
Change
VOC
2007 
2012
(%)
Change
NOx
2007 
2012
(
TPD)
Change
NOx
2007 
2012
(%)
Area
Sources
80.5 
83.1
+
2.6
+
17.6%
9 
9.5
+
0.5
+
5.6%

Point
Sources
13.5 
18.7
+
5.2
+
38.5%
75.1 
64.9
­
10.2
­
13.6%

On­
Road
Sources
53.8 
40.1
­
13.7
­
25.5%
84 
50.4
­
23.6
­
40%

Non­
Road
Sources
30 
24.7
­
5.3
­
17.7%
44 
40.4
­
3.6
­
8.2%

Total
177.8 
166.6
­
11.2
­
6.3%
212.1 
165.2
­
46.9
­
22.1%

Table
6­
5
is
a
synopsis
of
table
6­
4.
The
trend
in
emissions
changes
between
2007
and
2012
shown
is
a
downward
trend,
most
significantly
in
NOx.
The
claim
that
the
San
Antonio
region
will
be
in
attainment
by
2007
is
based
on
the
results
of
the
modeled
attainment
demonstration
(
Appendix
H).
The
claim
that
the
region
will
stay
in
attainment
through
2012
is
based
centrally
on
this
downward
trend
in
locally
produced
precursors
between
attainment
year
2007
and
maintenance
year
2012.
Once
the
standard
is
achieved,
the
region
should
remain
in
attainment.

Figure
6­
1
Trend
of
VOC
and
NOx
Emissions
in
the
SAER,
1996,
1999,
2007,
2012
*
note
1996
estimates
include
version
two
of
the
1995
Mobile6
inventory
Table
6­
5.
Anthropogenic
Emissions
within
the
SAER,
2007­
2012
0
50
100
150
200
250
300
350
1996*
1999
2007
2012
Emission
Inventory
Years
Tons/
Day
Anthropgenic
NOx
Anthropgenic
VOC
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
88
Emission
reductions
achieved
through
state
and
federal
control
measures
will
be
further
complemented
by
local
clean
air
strategies
enacted
through
the
EAC,
which
are
not
shown
in
the
2007
baseline
projections
in
table
6­
4.
Periodic
trend
analyses
updates,
which
will
take
into
account
the
clean
air
strategies
enacted
through
the
EAC
and
their
schedules,
will
ensure
that
the
reductions
achieved
through
all
measures
are
adequate
to
maintain
attainment
through
2012.

6.3
UPDATING
THE
PLANNING
PROCESS
Various
stages
of
planning
and
verification
must
be
performed
on
a
continual
basis
to
ensure
timely
emission
reductions
for
the
region
to
maintain
air
quality
standards.
The
impacts
of
new
point
source
related
emissions,
economic
and
population
growth,
and
the
implementation
of
new
control
strategies
are
evaluated
during
the
air
quality
modeling
process.
The
modeling
output
allows
for
the
air
quality
planners
to
identify
the
impacts
of
the
new
emission
sources
or
control
strategies
on
the
air
pollutants
in
the
region.
In
the
development
of
the
State
Implementation
Plan
for
the
San
Antonio
Early
Action
Compact
Region,
projected
growth
of
emission
sources
in
the
area
was
integral
in
the
air
quality
planning
process.
This
preliminary
trend
analysis
indicated
that
emissions
for
some
sources
were
projected
to
increase
while
other
sources
would
have
a
decrease
in
emissions.
Besides
the
emission
sources
projected
for
their
effect
in
2012
using
projected
population
statistics,
models,
or
other
methodologies,
new
point
source
emissions
that
come
into
existence
between
1999
and
2012
will
be
accounted
for
in
the
analysis
of
emission
growth.
Analyzing
their
effect
on
ambient
ozone
levels
will
be
essential
in
ensuring
the
maintenance
of
attainment.

6.3.1
Modeling
Updates
and
Modeling
Assumption
Verification
AACOG
staff
will
analyze
air
quality
and
related
data
and
perform
necessary
modeling
updates
and
modeling
assumption
verification
annually.
In
the
event
that
updated
emission
inventories,
updates
in
any
photochemical
model
inputs,
or
corrections
to
earlier
modeling
assumptions
are
created
and
available,
the
modeling
scenarios
used
to
demonstrate
attainment
for
the
SAER
will
be
brought
up
to
date.
Modeling
updates
will
be
performed
in
accordance
with
state
and
federal
guidelines.

Ongoing
Updates
Gathering,
updating,
and
verifying
data
is
part
of
an
ongoing
process
between
the
Texas
Commission
on
Environmental
Quality,
the
US
Environmental
Protection
Agency,
and
the
Alamo
Area
Council
of
Governments.
The
updating
and
verification
process
will
continue
to
occur
in
the
context
of
the
Joint
Near
Nonattainment
Area
meetings
held
by
air
quality
planning
technical
staff
representing
TCEQ,
and
the
San
Antonio,
Victoria,
Corpus
Christi,
Austin
and
the
Tyler­
Longview
areas,
or
other
appropriate
venue
(
technical
meetings
with
TCEQ
and
/
or
EPA,
etc.).
Joint
Near
Nonattainment
Area
meetings
are
held
at
least
as
often
as
every
three
months.
They
were
established
as
a
forum
for
discussion
of
new
technology,
new
program
and
planning
requirements
under
state
programs,
progress
on
and
cooperation
in
attainment
of
air
quality
goals,
as
well
as
discussion
of
updates
to
modeling
input
and
modeling
technique.
AACOG
frequently
attends
other
technical
modeling
meetings
hosted
by
the
TCEQ,
EPA
and
other
agencies,
which
provides
greater
opportunity
for
information
update
exchanges.
In
addition,
AACOG
staff
attends
regularly
scheduled
monthly
technical
meetings
of
the
local
San
Antonio
/
Bexar
County
Metropolitan
Planning
Organization
(
MPO),
allowing
AACOG
staff
the
most
recent
transportation
planning
information.
AACOG
provides
all
air
quality
analysis
for
the
local
MPO
transportation
projects.
All
local
transportation
SIP
Revision
Attainment
Demonstration
for
the
San
Antonio
EAC
Region
89
planning
updates
to
the
modeling
inputs
will
be
incorporated
as
they
occur,
and
their
impacts
analyzed.

Reporting
of
modeling
updates
and
modeling
assumption
verification
will
be
reported
in
the
Semi­
Annual
Reports
written
by
the
AACOG.
These
reports
are
due
on
an
ongoing
six­
month
cycle
ending
December
31
and
June
30
of
each
year
of
the
Early
Action
Compact,
ending
December
31,
2007.
These
reports
will
specifically
address,
at
a
minimum,
 
all
relevant
actual
new
point
sources;
 
impacts
from
potential
new
source
growth;
and
 
future
transportation
patterns
and
their
impact
on
air
quality
in
a
manner
that
is
consistent
with
the
most
current
adopted
Long
Term
Transportation
Plan
and
most
current
trend
and
projections
of
local
motor
vehicle
emissions.

6.3.2
Transportation
Patterns
The
development
of
transportation
patterns
is
influenced
by
many
such
as
land
use
and
urban
planning.
Transportation
patterns
directly
effect
emissions
originating
from
onroad
sources,
therefore
they
must
be
evaluated
for
their
impact
on
ozone
levels.
Onroad
emissions,
as
detailed
in
table
6­
4,
are
projected
to
decrease
by
maintenance
year
2012.

Throughout
the
continuing
planning
process,
the
air
quality
impact
on
the
region's
ozone
levels
imposed
by
transportation
patterns
will
be
evaluated
and
assessed
by
technical
staff
of
various
local,
regional,
state,
and
federal
offices.
As
specified
in
6.3.2,
the
ongoing
technical
collaboration
between
AACOG
and
the
local
MPO
is
the
central
conduit
such
that
updated
transportation
planning
becomes
integrated
in
air
quality
planning.
These
cooperative
relations
will
assist
in
maintaining
the
8­
hour
ozone
standard
by
the
technical
assistance
provided
by
each
agency
and
in
the
event
additional
planning
is
necessary.

6.4
NEW
STRATEGY
REQUIREMENTS
The
annual
reviews
of
growth,
including
the
updates
and
the
continuing
planning
processes
reported
in
the
Semi­
Annual
Updates
will
provide
air
quality
planners
the
insight
necessary
to
ensure
attainment
of
the
8­
hour
standard
up
to
2012.
The
extensive
clean
air
strategy
modeling
performed
by
AACOG
staff
will
facilitate
the
planning
if
the
continuous
review
process
indicates
additional
measures
should
be
considered.

If
at
any
time
the
review
of
growth
demonstrates
that
adopted
control
measures
are
inadequate
to
address
growth
in
emissions,
additional
measures
will
be
added
to
the
plan.
If
additional
control
measures
for
2007
attainment
are
suggested
as
being
necessary
through
a
review
of
growth,
they
will
be
verified
using
the
current
attainment
demonstration
photochemical
model
and
adopted
according
to
the
public
review
process
overseen
by
the
Air
Improvement
Resources
Committee.
If
additional
control
measures
for
2012
attainment
are
suggested
as
being
necessary
through
a
review
of
growth,
AACOG
staff
will
work
with
the
TCEQ
and
EPA
to
analyze
control
strategies
based
on
then­
currently
available
photochemical
models.
Appropriate
control
strategies
will
be
adopted
according
to
the
public
review
process
overseen
by
the
Air
Improvement
Resources
Committee.