Document ID: EPA-HQ-OAR-2002-0060-0658
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2004-03-17T05:00Z

Revision
to
"
Response
to
Public
Comments
on
Proposed
Stationary
Combustion
Turbines
NESHAP"

The
"
Response
to
Public
Comments
on
Proposed
Stationary
Combustion
Turbines
NESHAP"
memorandum
(
Edocket
document
ID
number
OAR­
2002­
0060­
0655)
was
placed
in
the
docket
for
the
Stationary
Combustion
Turbines
NESHAP
at
the
time
that
the
final
NESHAP
was
signed
by
the
EPA
Administrator
on
8/
29/
03.
Several
of
the
commenters
requested
that
the
final
rule
allow
ASTM
Method
D6348­
98
as
equivalent
to
Method
320.
The
response
to
comments
document
that
was
placed
in
the
docket
at
the
time
the
final
NESHAP
was
signed
indicated
that
EPA
would
consider
allowing
ASTM
Method
D6348­
98
upon
successful
ASTM
balloting
of
changes
to
the
method.
This
is
discussed
in
comment
VII.
A.
5.1.
After
the
final
package
was
signed
but
before
it
was
published
in
the
Federal
Register,
EPA
became
aware
that
ASTM
had
revised
ASTM
D6348­
98.
The
revised
method,
ASTM
D6348­
03,
was
reviewed
and
approved
by
EPA
as
an
alternative
to
Method
320
in
the
final
rule.
Therefore,
the
response
to
comments
document
was
revised
to
indicate
that
ASTM
D6348­
03
would
be
an
acceptable
alternative
to
Method
320
in
the
final
rule.
The
revised
"
Response
to
Public
Comments
on
Proposed
Stationary
Combustion
Turbines
NESHAP"
is
attached.
1
MEMORANDUM
Subject:
Response
to
Public
Comments
on
Proposed
Stationary
Combustion
Turbines
NESHAP
­
REVISED
From:
Sims
Roy,
ESD
Combustion
Group
To:
Robert
Wayland,
ESD
Combustion
Group
On
January
14,
2003,
the
EPA
proposed
national
emission
standards
for
hazardous
air
pollutants
(
NESHAP)
for
stationary
combustion
turbines
(
68
FR
1888).
The
proposed
rule
fulfills
the
requirements
of
section
112(
d)
of
the
Clean
Air
Act
(
CAA).
The
purpose
of
this
document
is
to
present
a
summary
of
the
public
comments
that
EPA
received
on
the
proposed
standards
and
the
responses
developed
by
EPA.
This
summary
of
comments
and
responses
serves
as
the
basis
for
revisions
made
to
the
standards
between
proposal
and
promulgation.

The
EPA
received
75
public
comments
on
the
proposed
rule.
A
listing
of
all
persons
submitting
comments,
their
affiliation,
and
the
document
number
for
their
comments
is
presented
in
Table
1.
The
comments
can
be
obtained
online
from
the
EPA's
Edocket
website
(
http://
www.
epa.
gov/
edocket).
The
Edocket
number
for
this
rulemaking
is
OAR­
2002­
0060.
The
comments
can
also
be
obtained
from
the
paper
docket,
docket
number
A­
95­
51.
Each
commenter
has
two
document
numbers,
one
number
is
the
Edocket
Document
ID,
and
the
other
document
number
is
for
the
paper
(
legacy)
document
numbering
system.
In
this
document,
commenters
are
identified
by
the
last
three
digits
of
the
Edocket
Document
ID
of
their
comments.

On
January
29,
2003,
a
public
hearing
on
the
proposed
NESHAP
for
stationary
combustion
turbines
(
CTs)
was
held
at
the
EPA
facility
in
Research
Triangle
Park,
NC.
Six
speakers
presented
comments
on
the
proposed
rule
and
are
listed
at
the
end
of
Table
1.
All
of
the
commenters
except
one
supplemented
their
comments
at
the
public
hearing
with
written
comments
submitted
to
the
docket.
Any
comments
from
the
public
hearing
that
were
not
included
in
the
written
comments
submitted
to
the
docket
are
also
summarized
in
this
document.
A
transcript
of
the
public
hearing
is
available
from
the
Edocket
website
(
document
ID
OAR­
2002­
0060­
0541).
2
Table
1.
List
of
Commenters
on
the
Proposed
NESHAP
for
Stationary
Combustion
Turbines
EDocket
ID
Number
Legacy
Document
Number
Commenter,
Addressee,
Title
or
Description,
etc.
Date
of
Document
OAR­
2002­
0060­
0385
IV­
D­
01
J.
Bardi,
Administrative
Assistant,
ASTM
International,
W.
Conshohocken,
PA.
01/
21/
2003
OAR­
2002­
0060­
0386
IV­
D­
02
S.
Clowney,
El
Paso
Pipeline
Group.
12/
19/
2002
OAR­
2002­
0060­
0387
IV­
D­
03
L.
Eagan,
Chair,
STAPPA
Air
Toxics
Committee
and
R.
Colby,
Chair,
ALAPCO
Air
Toxics
Committee,
Washington,
DC.
01/
29/
2003
OAR­
2002­
0060­
0412
IV­
D­
06
G.
M.
Adams,
Assistant
Departmental
Engineer,
Office
Engineering
Department,
The
Los
Angeles
County
Sanitation
Districts
(
LACSD),
Whittier,
CA.
02/
12/
2003
OAR­
2002­
0060­
0413
IV­
D­
52
W.
E.
Corbin,
Private
Citizen,
Saylorsburg,
PA.
Undated
OAR­
2002­
0060­
0414
IV­
D­
04
D.
M.
Anthony,
Air
Quality
Engineer,
Alyeska
Pipeline
Service
Company,
Fairbanks,
AK.
02/
08/
2003
OAR­
2002­
0060­
0415
jeanpublic@
yahoo.
com
Undated
OAR­
2002­
0060­
0416
IV­
D­
53
D.
R.
Schregardus,
Deputy
Assistant
Secretary
of
the
Navy
(
Environment),
Washington,
DC.
02/
19/
2003
OAR­
2002­
0060­
0417
IV­
D­
54
J.
C.
Solt,
Lindh
&
Assoc.,
Comments
on
behalf
of
Catalytica
Energy
Systems,
Antelope,
CA.
02/
10/
2003
OAR­
2002­
0060­
0418
IV­
D­
55
N.
Popa,
Senior
Environmental
Planner,
CMS
Energy/
Consumers
Energy,
Jackson,
MI.
02/
27/
2003
OAR­
2002­
0060­
0419
IV­
D­
56
M.
Murray,
Director
Environmental
&
Safety
Policy,
Sempra
Energy,
San
Diego,
CA.
02/
28/
2003
EDocket
ID
Number
Legacy
Document
Number
Commenter,
Addressee,
Title
or
Description,
etc.
Date
of
Document
3
OAR­
2002­
0060­
0420
IV­
D­
25
J.
Shefchek,
Managing
Director
and
Chief
Environmental
Officer,
Wisconsin,
Power
and
Light
Company,
Alliant
Energy,
Madison,
WI.
02/
27/
2003
OAR­
2002­
0060­
0421
IV­
D­
31
B.
Rising,
Regulatory
Affairs
Manager,
Siemens
Westinghouse
Power
Corp.,
Orlando,
FL.
02/
27/
2003
OAR­
2002­
0060­
0422
IV­
D­
23
R.
J.
Morehouse,
ExxonMobil,
Houston,
TX.
02/
27/
2003
OAR­
2002­
0060­
0423
IV­
D­
57
M.
C.
Frank,
Director
of
Regulatory
Affairs,
The
Boeing
Company,
VA.
02/
28/
2003
OAR­
2002­
0060­
0424
IV­
D­
58
J.
M.
Vaught,
Chair,
Subcommittee
on
Environment
&
Fuels
and
L.
Witherspoon,
Chair,
Environmental
&
Regulatory
Affairs,
ASME
Gas
Turbine
Procurement
Subcommittee
on
Environment
and
Fuels
and
IGTI
Environmental
and
Regulatory
Affairs
Technical
Committee.
02/
28/
2003
OAR­
2002­
0060­
0425
IV­
D­
46
C.
Van
Atten,
The
Clean
Energy
Group,
Concord,
MA.
02/
28/
2003
OAR­
2002­
0060­
0426
IV­
D­
48
M.
S.
Brownstein,
Director
Environmental
Strategy
&
Policy,
Public
Service
Enterprise
Group,
Newark,
NJ.
02/
28/
2003
OAR­
2002­
0060­
0427
IV­
D­
59
L.
Witherspoon,
Solar
Turbines
Inc.,
San
Diego,
CA.
02/
27/
2003
OAR­
2002­
0060­
0428
IV­
D­
60
D.
M.
Chari,
Senior
Environmental
Manager,
Rohm
and
Haas
Company,
Philadelphia,
PA.
02/
28/
2003
OAR­
2002­
0060­
0429
IV­
D­
61
J.
P.
LaCosse,
President
and
Principal
Scientist,
Spectral
Insights
LLC,
Durham,
NC.
02/
28/
2003
EDocket
ID
Number
Legacy
Document
Number
Commenter,
Addressee,
Title
or
Description,
etc.
Date
of
Document
4
OAR­
2002­
0060­
0430
IV­
D­
49
D.
J.
Jezouit,
Counsel
to
the
Class
of
`
85
Regulatory
Response
Group,
Baker
Botts
LLP,
Washington,
DC.
02/
28/
2003
OAR­
2002­
0060­
0431
IV­
D­
62
J.
C.
deRuyter,
Principal
Consultant,
DuPont
Engineering
Technology,
Wilmington,
DE.
02/
28/
2003
OAR­
2002­
0060­
0433
IV­
D­
44
D.
Kolaz,
Chief,
Bureau
of
Air,
Illinois
Environmental
Protection
Agency,
Springfield,
IL.
02/
27/
2003
OAR­
2002­
0060­
0435
IV­
D­
26
S.
D.
Meyers,
Counsel­
Environment,
Health
&
Safety,
GE
Power
Systems,
Schenectady,
NY.
02/
28/
2003
OAR­
2002­
0060­
0436
IV­
D­
40
M.
Klassen,
Vice
President/
Principal
Research
Engineer,
Combustion
Science
&
Engineering
Inc.,
Columbia,
MD.
02/
28/
2003
OAR­
2002­
0060­
0437
IV­
D­
63
T.
Steichen,
American
Petroleum
Institute,
Washington,
DC.
02/
28/
2003
OAR­
2002­
0060­
0438
IV­
D­
47
T.
R.
Weeks,
Chief,
Engineering,
San
Diego
County
Air
Pollution
Control
District,
Air
Pollution
Control
Board,
San
Diego,
CA.
02/
28/
2003
OAR­
2002­
0060­
0439
IV­
D­
64
S.
E.
Woock,
Federal
Regulatory
Affairs
Manager,
Weyerhaeuser,
New
Bern,
NC.
02/
28/
2003
OAR­
2002­
0060­
0440
IV­
D­
66
J.
Michael
Geers,
Cinergy
Corp,
Cincinnati,
OH.
02/
28/
2003
OAR­
2002­
0060­
0442
IV­
D­
65
J.
Dreyer,
Director
of
Industry
Affairs,
Gas
Processors
Association,
Tulsa,
OK.
02/
28/
2003
OAR­
2002­
0060­
0443
IV­
D­
72
G.
Calvo,
Hunton
&
Williams,
Comments
of
the
Utility
Air
Regulatory
Group,
Washington,
DC.
02/
28/
2003
EDocket
ID
Number
Legacy
Document
Number
Commenter,
Addressee,
Title
or
Description,
etc.
Date
of
Document
5
OAR­
2002­
0060­
0444
IV­
D­
67
C.
Levesque,
Supervisor
Permits
Section,
City
Public
Service,
San
Antonio,
TX.
02/
28/
2003
OAR­
2002­
0060­
0445
IV­
D­
68
J.
Whynot,
Planning
and
Rules
Manager,
South
Coast
Air
Quality
Management
District,
Diamond
Bar,
CA.
02/
28/
2003
OAR­
2002­
0060­
0446
IV­
D­
69
E.
H.
McMeekin,
Environmental
Manager,
PPG
Industries,
Allison
Park,
PA.
02/
28/
2003
OAR­
2002­
0060­
0447
&
OAR­
2002­
0060­
0448
IV­
D­
70
G.
S.
Lipka,
Earth
Tech.
02/
28/
2003
OAR­
2002­
0060­
0449
IV­
D­
41
L.
Beal,
Director,
Environmental
Affairs,
The
Interstate
Natural
Gas
Association
of
America,
Washington,
DC.
02/
28/
2003
OAR­
2002­
0060­
0460
IV­
D­
21
J.
Abboud,
Executive
Director,
Gas
Turbine
Association,
Great
Falls,
VA.
02/
28/
2003
OAR­
2002­
0060­
0463
IV­
D­
16
P.
Chu,
EPRI,
Palo
Alto,
CA.
02/
26/
2003
OAR­
2002­
0060­
0464
IV­
D­
18
P.
T.
Cavanaugh,
Vice
President
Federal
and
International
Government
Relations,
ChevronTexaco,
Washington,
DC.
02/
28/
2003
OAR­
2002­
0060­
0465
IV­
D­
17
J.
T.
Higgins,
Director,
Bureau
of
Stationary
Sources,
Division
of
Air
Resources,
New
York
State
Department
of
Environmental
Conservation,
Albany,
NY.
02/
27/
2003
OAR­
2002­
0060­
0469
IV­
D­
20
C.
Waxman,
Senior
Environmental
Scientist,
Environmental
Engineering
and
Compliance,
KeySpan,
Hicksville,
NY.
02/
28/
2003
EDocket
ID
Number
Legacy
Document
Number
Commenter,
Addressee,
Title
or
Description,
etc.
Date
of
Document
6
OAR­
2002­
0060­
0470
IV­
D­
08
R.
R.
Scott,
Chief
Air
Programs
Manager,
Air
Resources
Division,
New
Hampshire
Department
of
Environmental
Services,
Concord,
NH.
02/
12/
2003
OAR­
2002­
0060­
0471
IV­
D­
11
N.
L.
Pospisil,
Director,
Safety,
Health
&
Environment,
Calpine
Corp.,
Folsom,
CA.
02/
13/
2003
OAR­
2002­
0060­
0472
IV­
D­
12
J.
Pew,
EarthJustice,
Washington,
DC.
02/
13/
2003
OAR­
2002­
0060­
0473
IV­
D­
19
D.
M.
Shea,
ENSR
International,
Westford,
MA.
02/
28/
2003
OAR­
2002­
0060­
0474
IV­
D­
27
B.
H.
Spooner,
Senior
Engineer,
Environmental
Services,
Municipal
Electric
Authority
of
Georgia
(
MEAG
Power),
Atlanta,
GA.
02/
27/
2003
OAR­
2002­
0060­
0475
IV­
D­
28
D.
R.
Adams,
Air
Quality
Specialist,
WE
Energies,
Milwaukee,
WI.
02/
27/
2003
OAR­
2002­
0060­
0476
IV­
D­
22
R.
J.
Barkanic,
Manager­
Environmental,
PPL
Services
Corp.,
Allentown,
PA.
02/
28/
2003
OAR­
2002­
0060­
0477
IV­
D­
32
S.
A.
Knis
and
G.
G.
Gaetke,
The
Dow
Chemical
Company,
Freeport,
TX.
02/
24/
2003
OAR­
2002­
0060­
0478
IV­
D­
29
L.
Murphy,
Vice
President
Safety
&
the
Environment,
Manufacturing
Division,
Merck
&
Co.
Inc.,
Whitehouse
Station,
NJ.
02/
27/
2003
OAR­
2002­
0060­
0479
IV­
D­
30
P.
F.
Faggert,
Vice
President
and
Chief
Environmental
Officer,
Dominion
Generation,
Glen
Allen,
VA.
02/
28/
2003
OAR­
2002­
0060­
0481
IV­
D­
37
A.
Wright,
Director,
Environmental
Management,
Dayton
Power
and
Light
Company
(
DPL),
Dayton,
OH.
02/
28/
2003
OAR­
2002­
0060­
0482
IV­
D­
39
C.
R.
Wakild,
Progress
Energy,
Raleigh,
NC.
02/
28/
2003
EDocket
ID
Number
Legacy
Document
Number
Commenter,
Addressee,
Title
or
Description,
etc.
Date
of
Document
7
OAR­
2002­
0060­
0483
IV­
D­
35
A.
R.
Newman,
Washington
State
Department
of
Ecology,
Olympia,
WA.
02/
28/
2003
OAR­
2002­
0060­
0484
IV­
D­
36
R.
Bessette,
President,
Council
of
Industrial
Boiler
Owners,
Washington,
DC.
02/
28/
2003
OAR­
2002­
0060­
0485
IV­
D­
38
R.
Poteet,
ConocoPhillips
Alaska
Inc.
02/
28/
2003
OAR­
2002­
0060­
0486
IV­
D­
34
B.
Machaver,
Private
Citizen.
02/
28/
2003
OAR­
2002­
0060­
0487
IV­
D­
71
A.
E.
Smith
Jr.,
Senior
Vice
President
&
Environmental
Counsel,
Portside
Energy
Corp.
(
PEC),
Merrilville,
IN.
02/
28/
2003
OAR­
2002­
0060­
0488
IV­
D­
42
D.
T.
Riley,
Vice
President,
Government
Community
and
Industrial
Relations,
Tesoro
Petroleum
Companies,
Auburn,
WA.
02/
28/
2003
OAR­
2002­
0060­
0489
IV­
D­
33
M.
M.
Round,
Senior
Air
Toxics
Program
Analyst,
Northeast
States
for
Coordinated
Air
Use
Management
(
NESCAUM),
Boston,
MA.
02/
27/
2003
OAR­
2002­
0060­
0501
IV­
D­
45
D.
L.
Kraisinger,
Vice
President,
Health
Safety
&
Environment,
BP
America
Inc.,
Los
Angeles,
CA.
02/
27/
2003
OAR­
2002­
0060­
0502
IV­
D­
50
J.
J.
Mayhew,
Vice
President
Regulatory
&
Technical
Affairs,
The
American
Chemistry
Council,
Arlington,
VA.
02/
28/
2003
OAR­
2002­
0060­
0504
IV­
D­
43
R.
S.
Bahnick,
Vice
President,
Operations
and
Technical
Support,
Southern
Star
Central
Gas
Pipeline
Inc.,
Owensboro,
KY.
02/
26/
2003
OAR­
2002­
0060­
0505
IV­
D­
51
M.
G.
Helm,
Environmental
Consultant,
Conectiv
Energy,
Newark,
DE.
02/
28/
2003
EDocket
ID
Number
Legacy
Document
Number
Commenter,
Addressee,
Title
or
Description,
etc.
Date
of
Document
8
OAR­
2002­
0060­
0508
IV­
G­
01
T.
Pugh,
Manager
Environmental
Services,
American
Public
Power
Association,
03/
04/
2003
OAR­
2002­
0060­
0509
IV­
D­
73
R.
Meyer,
Manager
of
Environmental
Affairs,
American
Municipal
Power­
Ohio
(
AMP­
Ohio),
Columbus,
OH.
02/
27/
2003
OAR­
2002­
0060­
0513
IV­
D­
05
O.
M.
Dominguez,
Director,
Environmental
Management
Division,
National
Aeronautics
and
Space
Administration,
Headquarters,
Washington,
DC.
02/
06/
2003
OAR­
2002­
0060­
0514
IV­
D­
07
J.
A.
Paul,
Supervisor,
Regional
Air
Pollution
Control
Agency,
Dayton,
OH.
02/
11/
2003
OAR­
2002­
0060­
0515
IV­
D­
09
L.
Eagan,
Director,
Bureau
of
Air
Management,
State
of
Wisconsin,
Department
of
Natural
Resources,
Madison,
WI.
01/
07/
2003
OAR­
2002­
0060­
0516
IV­
D­
10
J.
F.
Metzger,
Sr.
Environmental
Specialist,
3M
Environmental
Technology
and
Safety
Services,
St.
Paul,
MN.
02/
12/
2003
OAR­
2002­
0060­
0517
IV­
D­
13
E.
W.
Repa,
Director
Environmental
Programs,
National
Solid
Wastes
Management
Association,
Washington,
DC.
02/
12/
2003
OAR­
2002­
0060­
0518
IV­
D­
14
W.
O'Sullivan,
Acting
Director,
State
of
New
Jersey
Department
of
Environmental
Protection,
Trenton,
NJ.
02/
14/
2003
OAR­
2002­
0060­
0519
IV­
D­
15
N.
Dee,
Director
of
Environment
and
Safety,
National
Petrochemical
&
Refiners
Association,
Washington,
DC.
02/
26/
2003
OAR­
2002­
0060­
0520
IV­
D­
24
P.
A.
Lacey,
Senior
Managing
Counsel,
American
Gas
Association,
Washington,
DC.
02/
28/
2003
EDocket
ID
Number
Legacy
Document
Number
Commenter,
Addressee,
Title
or
Description,
etc.
Date
of
Document
9
OAR­
2002­
0060­
0541
(
transcript
of
public
hearing)
Speakers
were:
(
A)
W.
F.
Priebe,
representing
Alaska
North
Slope
Oil
and
Gas
Production
and
Transmission
Operators.

(
B)
C.
Wait,
Panhandle
Pipe
Line
Companies,
on
behalf
of
the
Interstate
Natural
Gas
Association
of
America.

(
C)
S.
Clowney,
El
Paso
Pipeline
Group,
on
behalf
of
the
Interstate
Natural
Gas
Association
of
America.

(
D)
L.
Witherspoon,
Manager,
Environmental
Programs,
Solar
Turbines
Inc.,
San
Diego,
CA.

(
E)
B.
Nicholson,
Chief
of
the
Planning
Section,
NC
Division
of
Air
Quality,
on
behalf
of
the
State
and
Territorial
Air
Pollution
Program
Administrators
and
the
Association
of
Local
Air
Pollution
Control
Officials.

F)
S.
Lanier,
American
Petroleum
Institute.

Many
commenters
expressed
support
for
the
comments
submitted
by
other
commenters.
Table
2
shows
those
commenters
and
the
comments
that
they
supported.

Table
2.
List
of
Commenters
Expressing
Support
for
Other
Comments
Commenter
Supports
Comments
of:

OAR­
2002­
0060­
0501
OAR­
2002­
0060­
0437,
OAR­
2002­
0060­
0502
OAR­
2002­
0060­
0464
OAR­
2002­
0060­
0437,
OAR­
2002­
0060­
0502
OAR­
2002­
0060­
0484
OAR­
2002­
0060­
0431,
OAR­
2002­
0060­
0502
Commenter
Supports
Comments
of:

10
OAR­
2002­
0060­
0482
OAR­
2002­
0060­
0443
OAR­
2002­
0060­
0481
OAR­
2002­
0060­
0430,
OAR­
2002­
0060­
0443
OAR­
2002­
0060­
0479
OAR­
2002­
0060­
0443,
OAR­
2002­
0060­
0449
OAR­
2002­
0060­
0478
OAR­
2002­
0060­
0502
OAR­
2002­
0060­
0477
OAR­
2002­
0060­
0502
OAR­
2002­
0060­
0475
OAR­
2002­
0060­
0443
OAR­
2002­
0060­
0474
OAR­
2002­
0060­
0443,
OAR­
2002­
0060­
0508
OAR­
2002­
0060­
0428
OAR­
2002­
0060­
0484,
OAR­
2002­
0060­
0502,
National
Association
of
Manufacturers
OAR­
2002­
0060­
0446
OAR­
2002­
0060­
0502
OAR­
2002­
0060­
0442
OAR­
2002­
0060­
0449
OAR­
2002­
0060­
0431
OAR­
2002­
0060­
0502
OAR­
2002­
0060­
0444
OAR­
2002­
0060­
0508
OAR­
2002­
0060­
0427
OAR­
2002­
0060­
0449
OAR­
2002­
0060­
0418
OAR­
2002­
0060­
0443,
OAR­
2002­
0060­
0449
OAR­
2002­
0060­
0508
OAR­
2002­
0060­
0443
OAR­
2002­
0060­
0509
OAR­
2002­
0060­
0443,
OAR­
2002­
0060­
0508
OAR­
2002­
0060­
0422
OAR­
2002­
0060­
0437,
OAR­
2002­
0060­
0502
OAR­
2002­
0060­
0440
OAR­
2002­
0060­
0443
OAR­
2002­
0060­
0519
incorporates
by
reference
OAR­
2002­
0060­
0502'
s
comments
supporting
EPA's
Flexibility
in
promulgating
NESHAPs.
Those
comments
appear
in
Section
I
of
OAR­
2002­
0060­
0502.

OAR­
2002­
0060­
0520
OAR­
2002­
0060­
0449
The
summary
of
public
comments
and
responses
is
organized
as
follows:

I.
Applicability
A.
Applicability
Cutoff
11
B.
Emission
Factors
C.
Subcategories
with
Limited
Requirements
1.
Limited
Use
2.
Digester
Gas,
Landfill
Gas,
and
Other
Gaseous
Fuels
3.
Other
D.
Delisting
E.
Other
II.
Definitions
A.
Lean
Premix
Stationary
Combustion
Turbine
B.
Emergency
Stationary
Combustion
Turbine
C.
Stationary
Combustion
Turbine
D.
Major
Source
E.
Other
III.
Dates
IV.
MACT
A.
MACT
Floor
and
MACT
for
Diffusion
Flame
Units
B.
MACT
Floor
and
MACT
for
Lean
Premix
Units
C.
MACT
Floor
and
MACT
for
Other
Subcategories
D.
Other
V.
Emission
Limitations
A.
Formaldehyde
B.
CO
C.
Duct
Burners
D.
Other
VI.
Monitoring,
Recordkeeping,
Reporting
A.
CO
CEMS
B.
Performance
Testing
C.
Other
VII.
Test
Methods
A.
Formaldehyde
1.
CARB
430
2.
FTIR/
EPA
Method
320
3.
EPA
SW­
846
Method
0011
4.
EPA
Method
323
5.
Other
B.
CO
1.
CEMS
2.
EPA
Method
10
VIII.
Cost/
Impacts
IX.
Risk
X.
Other
A.
Startup/
Shutdown
B.
Dual
Fuel
Units
12
C.
Oil
Firing
D.
Duct
Burners
E.
Other
I.
APPLICABILITY
A.
Applicability
Cutoff
I.
A.
1
Comment:
Eight
commenters
(
420,
425,
426,
428,
430,
431,
433,
502)
expressed
support
for
the
subcategory
for
turbines
with
a
rated
peak
power
output
of
less
than
1
megawatt
(
MW).

Response:
The
EPA
acknowledges
the
commenters'
support.
A
subcategory
for
these
units
has
been
retained
in
the
final
rule.

I.
A.
2
Comment:
Nine
commenters
(
414,
437,
442,
444,
449,
479,
485,
501,
508,
509)
believed
that
the
EPA
should
increase
the
1
MW
capacity
threshold.
Three
commenters
(
501,
485,
437)
said
that
EPA
should
exclude
from
regulation
all
turbines
rated
less
than
10
MW.
Three
commenters
(
444,
508,
509)
recommended
that
EPA
create
a
subcategory
for
units
with
a
capacity
of
25
MW
or
less
and
set
no
maximum
achievable
control
technology
(
MACT)
standard
for
such
units.
Three
commenters
(
437,
449,
442)
said
that
the
size
applicability
criteria
should
be
adjusted
to
be
consistent
with
the
MACT
floor.

Response:
The
EPA
is
aware
of
stationary
combustion
turbines
as
small
as
3
MW
that
are
equipped
with
add­
on
HAP
control
devices.
Therefore,
EPA
does
not
have
the
discretion
to
create
a
subcategory
for
units
with
a
capacity
of
25
MW
or
less
(
or
10
MW
or
less)
and
set
no
maximum
achievable
control
technology
(
MACT)
standard
for
such
units.
Although
3
MW
is
the
smallest
size
unit
that
is
known
to
have
add­
on
HAP
control,
EPA
feels
it
is
appropriate
to
set
the
cutoff
for
inclusion
in
the
less
than
1
MW
rated
peak
power
subcategory
at
1
MW
because
it
is
believed
that
the
control
technology
used
for
3
MW
units
can
be
transferred
to
units
as
small
as
1
MW
in
size.

I.
A.
3
Comment:
One
commenter
(
438)
said
that
the
rule
should
be
explicit
as
to
whether
the
1
MW
capacity
level
for
inclusion
in
the
less
than
1
MW
rated
peak
power
subcategory
applies
to
an
individual
CT
or
applies
to
the
aggregate
capacity
of
a
group
of
CTs,
including
two
or
more
CTs
that
have
a
common
add­
on
air
pollution
control
device.

Response:
The
EPA
intended
for
the
1
MW
capacity
level
to
apply
to
an
individual
CT,
not
the
aggregate
capacity
of
a
group
of
CTs.
This
clarification
has
been
made
in
the
final
rule.

I.
A.
4
Comment:
Nine
commenters
(
418,
424,
427,
437,
442,
449,
487,
501,
502)
recommended
that
EPA
provide
an
emission
threshold
as
an
alternative
applicability
cutoff.
Eight
13
(
418,
424,
427,
437,
442,
449,
501,
502)
of
those
commenters
recommended
that
the
emission
threshold
should
be
set
at
less
than
1
ton
per
year
of
formaldehyde
emissions.
One
commenter
(
487)
suggested
that
EPA
should
include
a
greater
than
2
tons
per
year
formaldehyde
applicability
requirement.

Response:
The
basis
for
this
comment
is
the
Oil
and
Natural
Gas
Production
and
Natural
Gas
Transmission
and
Storage
NESHAP
(
promulgated
on
June
17,
1999).
In
that
rule,
HAP
emissions
from
process
vents
at
glycol
dehydration
units
that
are
located
at
major
HAP
sources
and
from
process
vents
at
certain
area
source
glycol
dehydration
units
are
required
to
be
controlled
unless
the
actual
flowrate
of
natural
gas
in
the
unit
is
less
than
85,000
m3/
day
(
3.0
MMSCF/
D),
on
an
annual
average
basis,
or
the
benzene
emissions
from
the
unit
are
less
than
0.9
Mg/
yr
(
1
tpy).
The
1
ton
per
year
emission
threshold
in
the
Oil
and
Natural
Gas
Production
and
Natural
Gas
Transmission
and
Storage
MACT
is
equivalent
to
the
smallest
size
glycol
dehydration
unit
with
control
of
HAP
emissions
and
is
therefore
based
on
equivalence,
not
risk.
EPA
does
not
have
the
discretion
to
provide
an
alternative
applicability
cutoff
based
on
risk.

I.
A.
5
Comment:
One
commenter
(
502)
expressed
the
view
that
despite
the
National
Lime
II
and
CKRC
cases,
EPA
has
not
lost
any
of
its
discretion
to
establish
applicability
criteria
that
define
the
source
category
and
the
units
subject
to
a
MACT
standard.
The
commenter
felt
that
EPA
should
revisit
its
decision
that
it
does
not
have
de
minimis
authority,
and
EPA's
interpretation,
discussed
in
National
Lime
II,
that
it
lost
its
inherent
authority
to
relieve
burdens
of
regulation
where
they
yield
trivial
or
no
value
is
based
on
an
incorrect
analysis
of
the
wrong
provision
of
the
statute.
The
commenter
suggested
that
EPA
should
not
take
such
a
restrictive
position
on
its
de
minimis
authority.

Response:
It
is
not
necessary
for
EPA
to
assert
the
de
minimis
authority
which
the
commenter
claims
EPA
possesses.
The
EPA's
discretion
to
establish
appropriate
subcategories
based
on
the
characteristics
of
sources
within
the
source
category
is
sufficient
to
provide
relief
from
the
burdens
of
regulation.

B.
Emission
Factors
I.
B.
1
Comment:
Eleven
commenters
(
414,
420,
422,
427,
430,
437,
442,
449,
474,
485,
501)
expressed
the
view
that
the
emission
factors
presented
in
Table
1
of
the
preamble
should
be
removed,
or
wording
should
be
added
to
acknowledge
the
use
of
factors
from
other
sources.
Three
of
those
commenters
(
427,
442,
449)
said
that
EPA
should
not
dictate
emission
factors
for
major
source
determination;
owner/
operators
should
be
allowed
to
determine
appropriate
emission
factors
for
their
facility.

Two
commenters
(
427,
449)
expressed
concern
with
the
quality
of
the
emissions
data
and
methodology
used
to
develop
the
emission
factors
presented
in
Table
1
of
the
preamble.
Those
commenters
also
stated
that
the
emission
factors
for
all
loads
in
Table
1
of
the
preamble
do
not
accurately
reflect
the
emission
profiles
for
turbines
in
variable
load
applications.
One
commenter
14
(
412)
stated
that
all
existing
turbines
do
not
fit
the
emissions
mold
projected
in
Table
1.

Response:
The
EPA
agrees
and
has
removed
Table
1
from
the
preamble.
Table
1
was
intended
to
simplify
major
source
determination,
e.
g.,
facilities
would
not
have
to
develop
their
own
emission
factors.
The
EPA
agrees
that
all
turbines
may
not
fit
the
emissions
mold
projected
in
Table
1.
The
use
of
the
emission
factors
in
Table
1
was
intended
to
be
optional;
EPA
did
not
intend
to
dictate
the
use
of
these
emission
factors.

The
emission
factors
in
Table
1
of
the
preamble
to
the
proposed
rule
were
based
on
emissions
data
from
test
reports
that
were
reviewed
and
accepted
by
EPA
according
to
a
common
set
of
acceptance
criteria.
However,
EPA
received
several
comments
regarding
the
quality
of
its
emissions
data
and
as
a
result,
performed
an
extensive
review
of
tests
used
at
proposal
and
new
tests
received
during
the
comment
period.
This
review
is
discussed
in
greater
detail
in
the
response
to
comment
V.
A.
1.
As
a
result
of
this
review,
revised
emission
factors
for
stationary
combustion
turbines
were
calculated
and
are
presented
in
the
memorandum
"
HAP
Emission
Factors
for
Stationary
Combustion
Turbines,"
which
can
be
found
in
the
rule
docket.
This
memo
has
emission
factors
for
both
high
load
and
all
load
conditions;
the
emission
standards
in
this
rule
are
based
on
data
for
high
loads.

Many
public
comments
were
received
demonstrating
that
formaldehyde
emissions
measured
using
CARB
Method
430
or
EPA
Method
0011
were
biased
low
compared
to
FTIR
measurements.
Caution
should
therefore
be
used
when
using
data
collected
using
CARB
430
or
EPA
Method
0011
in
determining
applicability.
The
EPA
believes
that
the
emission
factors
presented
in
the
"
HAP
Emission
Factors
for
Stationary
Combustion
Turbines"
memorandum
provide
the
most
accurate
information
on
stationary
combustion
turbine
emission
factors.

I.
B.
2
Comment:
One
commenter
(
412)
stated
that
the
emission
factors
in
Table
1
of
the
preamble
do
not
account
for
diesel
particulate
toxicity.

Response:
The
commenter
is
correct,
the
emission
factors
in
Table
1
of
the
preamble
are
not
adjusted
for
toxicity.
The
emission
factors
in
Table
1
were
on
a
mass
per
heat
input
basis.
The
emission
factors
in
Table
1
have
not
been
included
in
the
final
rule,
therefore,
the
comment
is
moot.
However,
as
discussed
in
the
reply
to
comment
I.
B.
1,
revised
emission
factors
are
presented
in
a
memorandum
which
can
be
found
in
the
rule
docket.

I.
B.
3
Comment:
Four
commenters
(
420,
430,
471,
474)
requested
that
EPA
clarify
that
the
factors
are
applicable
for
the
total
aggregate
hazardous
air
pollutants
(
HAPs)
that
can
be
expected
from
a
single
CT.
Two
of
those
commenters
(
420,
430)
suggested
that
EPA
should
provide
emission
factors
for
individual
HAPs
so
that
sources
can
determine
whether
they
will
be
a
major
source
based
on
the
threshold
of
10
tons
per
year
of
a
single
HAP.

Response:
The
emission
factors
have
not
been
included
in
the
final
rule,
therefore,
the
first
comment
is
moot.
Emission
factors
for
individual
HAPs
can
be
found
in
a
memorandum
15
available
from
the
rulemaking
docket,
as
discussed
in
the
reply
to
comment
I.
B.
1.
This
document
can
be
obtained
from
the
EPA's
Edocket
website.

I.
B.
4
Comment:
One
commenter
(
471)
asserted
that
EPA
should
include
the
emission
factors
in
Table
1
of
the
preamble
in
the
definitions
under
§
63.6085
if
EPA
intends
to
require
the
use
of
these
factors
as
the
basis
of
determining
applicability
to
a
particular
source.

Response:
The
emission
factors
in
Table
1
have
not
been
included
in
the
final
rule,
therefore,
the
comment
is
moot.

I.
B.
5
Comment:
One
commenter
(
474)
stated
that
the
final
rule
should
clarify
whether
the
emission
factors
in
Table
1
of
the
preamble
can
also
be
used
to
determine
HAP
emissions
from
associated
duct
burners.

Response:
The
emission
factors
in
Table
1
did
not
include
emissions
from
duct
burners;
therefore
they
should
not
be
used
to
determine
HAP
emissions
from
duct
burners.
The
emission
factors
in
Table
1
have
not
been
included
in
the
final
rule,
therefore,
the
comment
is
moot.

C.
Subcategories
with
Limited
Requirements
1.
Limited
Use
I.
C.
1.1
Comment:
Twenty­
four
commenters
(
414,
416,
420,
422,
423,
430,
431,
437,
440,
442,
443,
444,
449,
474,
475,
476,
479,
482,
485,
501,
502,
508,
509,
519)
supported
the
creation
of
a
subcategory
for
limited
use
CTs
with
a
capacity
utilization
of
10
percent
or
less.
One
commenter
(
416)
expressed
the
view
that
the
limited
use
subcategory
should
apply
to
all
limited
use
CTs,
not
just
electric
power
peak
shaving
units.

One
commenter
(
414)
requested
that
EPA
define
what
is
meant
by
a
capacity
utilization
of
10
percent
or
less.
Two
commenters
(
440,
475)
stated
that
the
basis
should
be
no
more
than
10
percent
utilization
during
the
previous
three
calendar
years
and
no
more
than
20
percent
in
each
of
those
years.
Two
commenters
(
443,
482)
said
that
the
10
percent
capacity
utilization
should
be
based
on
a
three­
year
average.
One
of
those
commenters
(
443)
believed
that
a
CT
should
only
trigger
MACT
if
it
exceeds
2,628
hours
in
any
three
year
period,
and
that
EPA
should
consider
creating
a
sliding
scale
in
which
the
limited
use
cutoff
could
exceed
876
hours
if
a
unit's
formaldehyde
emissions
are
below
a
certain
level.

Six
commenters
(
414,
421,
433,
479,
484,
519)
requested
that
EPA
increase
the
allowable
operating
time
for
limited
use
turbines.
Commenter
414
recommended
that
the
50
hour
allowance
for
limited
use
be
increased
to
200
hours
to
allow
for
maintenance
checks.
Commenters
421
and
433
stated
that
a
more
appropriate
cut­
off
is
500
hours
per
year,
which
Commenter
433
said
is
consistent
with
EPA
policy
for
designating
emergency
engines
for
Title
V
permits
and
is
also
appropriate
because
year­
to­
year
variability
in
the
utilization
does
not
result
in
routine
changes
in
16
a
unit's
status.
Commenter
433
also
suggested
that
EPA
could
develop
a
more
refined
approach;
for
example,
the
cutoff
for
turbines
greater
than
10
MW
could
be
200
hours
per
year.

Commenter
519
said
that
if
a
10
percent
utilization
is
not
implemented,
the
testing
of
CTs
to
assure
the
unit
will
be
operational
when
needed
should
be
excluded
from
the
operating
limit,
because
these
testing
operations
can
range
from
weekly
testing
for
more
than
one
hour
to
several
times
each
month.

One
commenter
(
481)
said
that
EPA
should
consider
an
expanded
limited
use
category
for
simple
cycle
CTs
that
are
permitted
as
synthetic
minors,
because
the
cost
of
control
per
ton
of
HAP
reduced
for
simple
cycle
units
would
be
very
high.
One
commenter
(
430)
said
that
EPA
should
create
an
expanded
limited
use
subcategory
for
simple
cycle
CTs
operated
at
capacity
factors
of
up
to
30
percent.

Two
commenters
(
465,
470)
contended
that
the
subcategorization
of
limited
use
CTs
without
controls
is
not
protective
of
public
health,
because
these
CTs
operate
mostly
in
the
summer
months
when
the
public
is
more
likely
to
be
exposed
to
the
emissions.

Two
commenters
(
465,
470)
remarked
that
any
subcategorization
of
limited
use
CTs
should
include
a
permit
requirement
that
these
units
operate
less
than
876
hours
per
year.
To
lower
costs
for
these
units,
less
onerous
monitoring
requirements
such
as
periodic
stack
tests
with
a
temperature
sensor
on
the
catalyst
could
be
required.

Three
commenters
(
426,
431,
502)
supported
the
subcategory
for
limited
use
units
and
EPA's
finding
that
no
emission
reduction
should
be
required
for
these
units.

One
commenter
(
423)
said
that
if
EPA
does
not
increase
the
allowable
operating
hours
for
a
limited
use
unit
to
876,
EPA
should
subcategorize
and
delist
the
special
limited
use
activity
of
a
turbine
that
is
a
stationary
mounted
aircraft
engine
to
provide
motive
force
for
a
wind
tunnel.

One
commenter
(
518)
expressed
the
view
that
existing
limited
use
CTs
might
be
exempted
from
the
MACT
emission
limits,
but
new
limited
use
CTs
should
not
be
exempted.
The
commenter
observed
that
in
New
Jersey,
limited
use
units
generally
operate
for
less
than
250
hours
per
year.

Response:
The
preamble
for
the
proposed
rule
proposed
a
subcategory
for
limited
use
stationary
CTs
and
defined
them
as
operating
50
hours
or
less
per
calendar
year.
The
EPA
solicited
comments
on
creating
a
subcategory
of
limited
use
stationary
CTs
with
capacity
utilization
of
10
percent
or
less
and
used
for
electric
power
peak
shaving;
numerous
commenters
supported
the
creation
of
such
a
subcategory.
Comments
were
received
both
for
and
against
the
limited
use
subcategory.
After
considering
all
of
the
comments,
EPA
has
decided
not
to
include
a
subcategory
for
limited
use
stationary
CTs
in
the
final
rule.
Several
commenters
indicated
that
a
limit
of
50
hours
was
so
low
that
most
turbines
would
exceed
the
operating
limit
through
the
17
operation
of
the
turbine
for
routine
testing
and
maintenance.
Therefore,
it
is
believed
that
no
turbines
would
utilize
the
limit
of
50
hours.
A
subcategory
of
limited
use
stationary
CTs
with
capacity
utilization
of
10
percent
or
less
and
used
for
electric
power
peak
shaving
was
not
created
because
these
sources
are
similar
sources
to
units
equipped
with
add­
on
oxidation
catalyst
control
and
their
operation
only
during
peak
periods
does
not
preclude
them
from
being
equipped
with
add­
on
oxidation
catalyst
control.

Our
objective
in
subcategorizing
is
not
to
protect
public
health,
but
to
establish
groups
of
sources
which
share
common
characteristics
that
are
related
to
the
availability
of
potential
emission
control
strategies.
In
any
case,
EPA
has
not
adopted
a
limited
use
subcategory,
because
EPA
determined
that
creation
of
such
a
subcategory
would
not
change
the
nature
of
the
required
controls.

2.
Digester
Gas,
Landfill
Gas,
and
Other
Gaseous
Fuels
I.
C.
2.1
Comment:
Seven
commenters
(
420,
426,
430,
431,
433,
502,
517)
expressed
support
for
the
subcategory
for
turbines
firing
landfill
gas
or
digester
gas.

Response:
The
EPA
acknowledges
the
commenters'
support;
this
subcategory
has
been
retained
in
the
final
rule.

I.
C.
2.2
Comment:
One
commenter
(
517)
noted
that
EPA
should
not
develop
NESHAP
for
landfill
gas
fired
CTs
because
turbines
are
one
of
the
control
technologies
mandated
by
the
Municipal
Solid
Waste
Landfill
NESHAP
(
68
FR
2227).
As
such,
EPA
should
not
be
regulating
control
devices
with
control
devices.

Response:
The
EPA
does
not
believe
that
control
devices
utilized
to
reduce
HAP
emissions
should
by
themselves
be
deemed
to
be
an
affected
source
for
the
purpose
of
MACT
standard
development.
However,
the
EPA
also
does
not
believe
that
the
mere
fact
that
a
source
which
emits
HAP
may
also
be
utilized
to
address
other
environmental
problems
is
a
sufficient
basis
to
exempt
that
source
entirely
from
inclusion
in
a
standard.

I.
C.
2.3
Comment:
One
commenter
(
413)
remarked
that
primary
fuel
is
not
defined
in
the
rule.
The
commenter
noted
that
applying
the
subcategory
only
to
turbines
using
landfill
or
digester
gas
as
primary
fuel
is
overly
restrictive.
The
commenter
suggested
that
the
subcategory
should
be
for
turbines
with
annual
landfill
and
digester
gas
consumption
10
percent
or
more
of
the
total
fuel
consumption
on
an
annual
basis
based
on
gross
heat
input
(
similar
to
the
boiler
NSPS
in
40
CFR
60
Subpart
Db).

Response:
The
EPA
agrees
that
it
is
appropriate
to
provide
guidelines
for
the
usage
of
landfill
and
digester
gas,
and
is
incorporating
the
commenter's
suggestion
that
the
subcategory
should
be
for
turbines
with
annual
landfill
and
digester
gas
consumption
10
percent
or
more
of
the
gross
heat
input
on
an
annual
basis.
The
EPA
believes
that
firing
greater
than
10
percent
landfill
18
or
digester
gas
will
cause
fouling
that
will
render
an
oxidation
catalyst
inoperable
within
a
short
period
of
time.
This
belief
is
based
on
information
gathered
from
catalyst
vendors
and
sanitation
districts
indicating
that
the
presence
of
siloxanes
in
landfill
or
digester
gas
will
lead
to
immediate
catalyst
fouling.
One
Sanitation
District
in
California
indicated
that
fouling
of
the
catalyst
starts
immediately
and
rapidly
gets
worse.
In
their
experience,
catalyst
fouling
was
noticed
after
about
two
weeks
of
operation,
and
the
catalyst
became
practically
ineffective
after
three
months
of
operation.
All
of
the
catalyst
vendors
contacted
by
EPA
indicated
that
there
would
be
problems
with
catalyst
deactivation
with
the
use
of
landfill
or
digester
gas.

I.
C.
2.4
Comment:
Two
commenters
(
421,
435)
requested
that
the
subcategory
for
CTs
firing
landfill
or
digester
gas
be
expanded
to
included
CTs
used
at
gasification
plants.

Response:
The
EPA
agrees
that
if
municipal
solid
waste
(
MSW)
is
used
as
fuel
in
a
turbine,
problems
with
catalyst
fouling
similar
to
those
found
for
digester
and
landfill
gas
units
may
occur.
Therefore,
in
the
final
rule,
the
subcategory
for
CTs
firing
landfill
or
digester
gas
has
been
expanded
to
include
units
where
gasified
MSW
is
used
to
generate
10
percent
or
more
of
the
gross
heat
input
to
the
stationary
combustion
turbine
on
an
annual
basis.

I.
C.
2.5
Comment:
One
commenter
(
427)
stated
that
the
subcategory
for
CTs
firing
landfill
or
digester
gas
should
be
expanded
to
other
non
natural
gas
fuels
that
would
result
in
technical
issues
with
catalyst
operation
similar
to
the
issues
for
units
firing
landfill
or
digester
gas.
Examples
of
other
fuels
include
biogas,
refinery
gas,
and
other
low,
medium,
and
high
BTU
gases.

Response:
The
commenter
has
not
provided
any
data
to
support
their
comment
that
there
would
be
technical
issues
with
catalyst
operation.
Therefore,
EPA
does
not
have
any
evidence
to
suggest
that
turbines
firing
other
non
natural
gas
fuels
would
not
be
able
to
meet
the
emission
limitations,
and
is
not
expanding
the
subcategory
to
other
non
natural
gas
fuels
(
other
than
fuels
containing
MSW).

3.
Other
I.
C.
3.1
Comment:
Six
commenters
(
420,
425,
426,
430,
431,
502)
expressed
support
for
the
subcategory
for
emergency
stationary
CTs.

Response:
The
EPA
acknowledges
the
commenters'
support.
This
subcategory
has
been
retained
in
the
final
rule.

I.
C.
3.2
Comment:
Six
commenters
(
414,
422,
437,
485,
501,
541(
F))
urged
EPA
to
add
a
subcategory
to
cover
turbines
installed
north
of
the
Arctic
Circle
and
to
specify
no
additional
control
requirements
for
the
subcategory.
The
commenters
stated
that
technologies
identified
for
controlling
HAP
emissions
from
stationary
combustion
turbines
are
unproven
or
have
met
with
limited
success
in
northern
Alaska
above
the
Arctic
Circle.
Lean
premix
combustion
(
LPC)
turbines
have
met
with
limited
success
on
the
Alaska's
North
Slope.
The
annual
average
19
temperature
above
the
Arctic
Circle
is
approximately
10

F,
with
winter
temperatures
that
can
drop
below
­
50

F.
Turbine
manufacturers
have
been
required
to
"
de­
tune"
the
lean
premix
systems
to
ensure
the
integrity
of
the
equipment
at
these
cold
ambient
temperatures.

The
commenters
stated
that
one
of
the
technical
issues
with
LPC
at
the
North
Slope
is
the
very
wide
range
of
ambient
temperatures
that
the
turbine
must
operate
over.
A
range
of
­
50

F
to
80

F
(
130

F
range)
is
a
very
challenging
requirement
for
turbine
manufacturers.
They
have
to
employ
various
air
bleed,
inlet
guide
vane
control,
or
fuel
staging
to
allow
them
to
operate
at
the
cold
extremes.
Sites
in
Canada
have
reported
having
to
tune
their
Dry
Low
Emissions
engines
differently
for
the
summer
and
winter
months.
Even
when
temperatures
drop
to
extremely
low
levels
in
the
lower
48
states,
the
duration
of
those
low
temperatures
is
normally
measured
in
hours;
on
the
North
Slope
it
is
not
uncommon
for
equipment
to
have
to
endure
months
of
severe
cold.
In
addition
to
this
large
range,
at
the
colder
end
of
the
range
the
airflow
on
some
turbine
models
can
be
40
percent
higher
that
at
the
standard
ISO
design
conditions
of
60

F
creating
an
especially
acute
problem
in
LPC
units.
For
these
reasons
turbines
manufactures
with
experience
in
the
Arctic
do
no
guarantee
NO
x
and
CO
levels
at
cold
ambient
temperatures
(
below
0

F).
Therefore,
lean
premix
systems
that
can
achieve
low
NO
x
emissions
typical
of
lower
48
applications
have
not
been
demonstrated
to
be
achievable
north
of
the
Arctic
Circle.
On
the
North
Slope,
<
0

F
represents
about
one
half
of
the
year.
Some
of
the
turbine
models
with
LPC
do
not
even
operate
in
a
LPC
mode
at
cold
ambient
temperatures
because
of
their
inability
to
maintain
a
stable
flame
at
these
conditions.

The
commenters
noted
that
lean
premix
systems
require
that
combustion
occur
at
the
very
lean
edge
of
combustion.
On
the
North
Slope,
unique
environmental
conditions
make
the
application
of
lean
premix
particularly
challenging.
Such
flames
are
inherently
unstable
and
the
manufacturer,
to
successfully
employ
this
technology,
must
include
extremely
tight
control
on
the
excess
air.
The
design
operating
point
for
LPC
is
closer
to
the
lean
extinction
limit
of
the
flame
and,
therefore,
this
type
of
combustor
has
an
inherently
limited
range
of
operation.
To
address
this
limitation,
manufacturers
utilize
either
some
type
of
variable
air
of
fuel
control
or
some
type
of
air
bleed
arrangement.
This
complexity
greatly
adds
to
the
inherent
instability
of
these
systems.
The
very
lean
flame
can
lead
to
acoustic
disturbances
in
the
combustor
at
certain
operating
conditions
such
as
low
loads
and
low
ambient
temperature.
These
acoustic
patterns
have
led
to
mechanical
failure
of
components
and
in
the
extreme
have
led
to
flameout.
All
of
the
North
Slope
operators
have
experienced
this
phenomenon,
and
thus
far
there
has
not
been
an
universal
solution.
All
nine
of
the
LPC
oil
and
gas
production
turbines
on
the
North
Slope
have
had
some
form
of
mechanical
problems
associated
with
the
combustion
system
due
to
combustion
acoustics
or
bleed
system
dynamics.

According
to
the
commenters,
vendors
of
CO
oxidation
catalysts
have
indicated
that
their
products
will
perform
adequately
on
the
North
Slope,
but
the
technology
has
never
been
tried.
To
date,
no
CO
oxidation
catalyst
has
ever
been
installed
on
a
turbine
on
the
North
Slope.
It
is
unknown
what
impacts
the
extreme
thermal
conditions
of
North
Slope
operation
will
have
on
CO
oxidation
catalysts.
There
is
no
data
on
the
effect
the
wider
temperature
range
and
rapid
cool
20
down
might
have
on
the
ceramic
or
metal
support
for
the
catalyst.
Gas
turbines
that
must
operate
at
low
ambient
conditions
and
at
varying
loads
operate
closer
to
their
weak
extinction
limit
than
do
base
loaded
turbines
in
the
Lower
48.
As
a
result
the
North
Slope
turbines
could
experience
flameout
conditions
more
frequently
than
Lower
48
turbines,
particularly
if
the
LPC
design
is
utilized.
The
commenters
are
concerned
that
flameouts
may
result
in
damage
to
an
oxidation
catalyst
due
to
the
sudden
introduction
or
a
large
amount
of
natural
gas
to
the
catalyst
at
high
temperature.

In
addition
to
emissions,
the
commenters
stated
that
the
requirement
for
a
CO
oxidation
catalyst
may
have
other
adverse
environmental
impacts
unique
to
the
North
Slope.
To
reduce
environmental
impacts,
the
North
Slope
Operators
have
strived
to
reduce
the
facility
"
footprint."
The
"
footprint"
is
the
required
amount
of
surface
area
required
for
the
equipment
site.
This
has
a
whole
host
of
benefits
in
reducing
impacts
on
tundra
and
wildlife.
The
commenters
estimate
that
the
addition
of
a
catalyst
system
on
the
exhaust
of
gas
turbines
could
double
the
footprint
for
the
turbine
itself.

Response:
The
EPA
agrees
with
the
commenters
that
a
subcategory
should
be
created
for
turbines
installed
north
of
the
Arctic
Circle
to
recognize
their
distinct
differences.
There
is
a
substantial
difference
in
temperature
between
the
North
Slope
of
Alaska
and
even
the
coldest
areas
in
the
lower
48
states.
As
noted
by
the
commenters,
turbine
operators
on
the
North
Slope
of
Alaska
have
experienced
problems
with
operation
of
the
turbines
in
lean
premix
mode,
and
turbine
manufacturers
do
not
guarantee
the
performance
of
their
turbines
at
the
ambient
temperatures
typically
found
north
of
the
Arctic
Circle.
In
addition,
no
turbines
on
the
North
Slope
are
equipped
with
oxidation
catalyst
control.
Therefore,
a
subcategory
for
turbines
north
of
the
Arctic
Circle
has
been
established.
A
MACT
floor
and
MACT
analysis
has
determined
that
MACT
is
no
emission
reduction
requirement
for
these
units.

I.
C.
3.3
Comment:
One
commenter
(
435)
requested
that
EPA
exempt
transportable
CTs
from
the
rule
or
create
a
new
subcategory
for
those
units.

Response:
Transportable
CTs
are
considered
stationary
and
therefore
are
not
exempt
from
the
rule.
The
EPA
has
evaluated
the
information
provided
by
the
commenter
and
does
not
believe
a
subcategory
is
necessary.

I.
C.
3.4
Comment:
One
commenter
(
516)
said
that
EPA
should
add
an
exemption
for
stationary
CTs
that
are
specifically
used
to
destroy
or
otherwise
control
volatile
organic
compound
(
VOC)
emissions.
The
commenter
felt
that
without
such
an
exemption,
the
proposed
NESHAP
will
create
disincentives
for
further
use
and
development
of
this
method
of
controlling
VOC
emissions.

Response:
The
EPA
does
not
agree
that
such
an
exemption
is
warranted.
The
commenter
did
not
provide
any
information
about
turbines
used
to
destroy
or
control
VOC
emissions.
The
EPA
does
not
agree
that
the
proposed
NESHAP
will
create
disincentives
for
this
method
of
21
controlling
VOC
emissions.

I.
C.
3.5
Comment:
Two
commenters
(
513,
516)
recommended
that
to
be
consistent
with
most
other
NESHAPs,
EPA
should
add
an
exemption
for
research
and
development
(
R&
D)
to
the
applicability
section
of
the
proposed
rule.
Commenter
516
also
requested
that
a
definition
of
R&
D
be
added
to
the
proposed
rule.

Response:
The
final
rule
provides
that
stationary
CTs
located
at
a
research
or
laboratory
facility
are
not
subject
to
the
NESHAP,
if
research
is
conducted
on
the
turbine
itself
and
the
turbine
is
not
being
used
to
power
other
applications
at
the
research
or
laboratory
facility.
A
definition
of
research
or
laboratory
facility
is
included
in
the
final
rule.

I.
C.
3.6
Comment:
One
commenter
(
487)
contended
that
EPA
should
provide
an
exclusion
for
natural
gas
fired
combined
heat
and
power
CTs
to
promote
the
generation
of
highly
efficient,
low
emitting
energy
solutions
at
host
facilities.
The
commenter
had
the
opinion
that
the
proposed
rule
economically
disadvantages
these
types
of
projects.

Response:
The
commenter
did
not
provide
any
details
about
how
these
facilities
will
be
economically
disadvantaged.
Without
such
information,
EPA
is
unable
to
address
the
concern
directly.
As
a
result,
EPA
is
not
changing
the
NESHAP
in
response
to
this
comment.

I.
C.
3.7
Comment:
One
commenter
(
438)
stated
that
turbines
associated
with
military
tactical
support
equipment
are
not
addressed.
The
commenter
believed
that
such
turbines
often
have
unique
requirements
for
deployability
that
may
preclude
the
use
of
add­
on
air
pollution
equipment,
and
the
feasibility
of
applying
controls
to
these
turbines
and
the
associated
costs
and
cost
effectiveness
and
environmental
benefits
should
be
evaluated
and
an
exception
or
separate
category
for
these
turbines
should
be
established
if
warranted.

Response:
The
EPA
contacted
the
commenter
to
obtain
more
information
about
turbines
associated
with
military
tactical
support
equipment.
The
commenter
indicated
that
they
did
not
have
any
existing
or
planned
military
tactical
support
equipment
with
turbines
greater
than
1
MW.
Therefore,
no
exemption
or
separate
category
is
needed
for
these
turbines.

I.
C.
3.8
Comment:
One
commenter
(
416)
requested
that
§
63.6090(
b)(
4)
be
removed
because
stationary
combustion
engine
test
cells/
stands
are
excluded
from
this
source
category.

Response:
Section
63.6090(
b)(
4)
has
not
been
removed
from
the
final
rule.
The
section
is
necessary
because
it
clarifies
that
CT
engine
test
cells/
stands
do
not
have
to
meet
the
requirements
of
this
subpart.

I.
C.
3.9
Comment:
One
commenter
(
416)
asked
that
EPA
clarify
§
63.6090(
b)
to
identify
which
excepted
sources
are
not
required
to
comply
with
the
initial
notification
requirements
of
§
63.6145(
d).
22
Response:
Section
63.6090(
b)
has
been
clarified
to
clearly
indicate
which
excepted
sources
are
not
required
to
comply
with
the
initial
notification
requirements
of
§
63.6145(
d).

I.
C.
3.10
Comment:
Two
commenters
(
442,
449)
urged
EPA
to
clarify
that
no
initial
notification
is
required
for
existing
diffusion
flame
combustor
(
DFC)
units,
even
if
they
are
used
in
emergency
service.

Response:
The
rule
has
been
revised
to
clarify
that
no
initial
notification
is
required
for
any
existing
units,
even
if
they
are
used
in
emergency
service.

I.
C.
3.11
Comment:
Three
commenters
(
430,
443,
482)
expressed
support
for
EPA's
subcategorization
approach
in
the
proposed
NESHAP.

Response:
The
EPA
acknowledges
the
commenters'
support.

I.
C.
3.12
Comment:
Two
commenters
(
428,
502)
expressed
support
for
the
exemptions
for
duct
burners
and
stationary
combustion
engine
test
cells/
stands.

Response:
The
EPA
acknowledges
the
commenters'
support.
These
exemptions
have
been
retained
in
the
final
rule.

I.
C.
3.13
Comment:
One
commenter
(
502)
expressed
support
for
EPA's
proposal
to
only
require
notification
for
emergency
power
units,
limited
use
units,
and
units
that
combust
digester
gas
or
landfill
gas.

Response:
The
commenter's
support
is
acknowledged.
This
approach
has
been
retained
in
the
final
rule.

D.
Delisting
I.
D.
1
Comment:
Commenter
460
submitted
a
revised
petition
to
delist
two
subcategories
of
stationary
combustion
turbines:
lean
premix
stationary
combustion
turbines
firing
natural
gas
as
a
primary
fuel,
and
other
turbines
demonstrated
to
qualify
for
a
low
risk
subcategory.
An
earlier
version
of
the
delisting
petition
was
provided
to
EPA
in
August
2002;
the
revised
petition
was
submitted
to
respond
to
EPA's
request
for
additional
information
and
to
focus
on
the
specific
subcategories
to
be
delisted.
The
commenter
claimed
the
petition
demonstrates
that
the
stationary
and
lean
pre­
mix
combustion
turbines
which
fire
natural
gas
as
a
primary
fuel
meet
the
statutory
criteria
for
delisting
because
they
do
not
pose
a
cancer
risk
greater
than
one
in
one
million
and
noncarcinogens
have
a
hazard
index
well
below
1.0.
The
petition
also
indicates
there
will
be
no
adverse
environmental
effects
from
this
group
of
sources.
The
commenter's
analysis
showed
that
the
vast
majority
of
stationary
combustion
turbine
installations
would
meet
the
delisting
criteria,
but
due
to
the
multiple
turbine
configurations
and
varying
amounts
of
oil
used
as
backup
fuel,
it
was
not
possible
to
address
all
sources
in
the
category.
Therefore,
the
commenter
suggested
that
23
each
individual
source
that
is
not
a
lean
premix
turbine
firing
primarily
natural
gas
be
required
to
demonstrate
that
it
qualifies
for
the
low­
risk
subcategory.
The
commenter
requested
that
EPA
create
a
subcategory
of
stationary
lean
premix
combustion
turbines
which
fire
natural
gas
as
a
primary
fuel,
create
a
low
risk
subcategory
of
stationary
combustion
turbines,
and
delist
both
of
these
subcategories
at
the
same
time
that
it
issues
any
final
MACT
standard.

Twenty­
one
commenters
(
414,
421,
422,
424,
427,
431,
435,
437,
440,
443,
460,
464,
479,
482,
484,
485,
488,
501,
502,
508,
509)
expressed
support
for
the
delisting
petition.

Commenter
421
stated
that
based
on
a
study
conducted
by
the
GTA,
there
is
no
health
risk
related
to
formaldehyde
emissions
from
gas
turbines
at
any
level
of
aldehydes
reported
in
the
ICCR
database.
The
GTA
provided
EPA
with
an
analysis
as
part
of
its
delisting
petition
that
showed
that
formaldehyde
levels
from
gas
turbines
would
have
to
reach
several
hundred
ppb
to
even
approach
a
one­
in­
a­
million
risk
level
to
an
individual
exposed
over
70
years.
The
commenter
supported
GTA's
delisting
petition
since
there
is
no
risk
to
the
most
exposed
individual,
and
stated
that
an
emission
standard
at
the
levels
proposed
in
the
CT
MACT
offers
no
benefit.

Commenter
422
believes
that
the
health
risk
evaluations
necessary
for
EPA
to
delist
combustion
turbines
as
a
source
category
will
result
in
a
finding
of
insignificant
public
health
impact.
The
commenter
believes
that,
consistent
with
the
GTA
delisting
petition,
EPA
should
delist
gas­
fired
turbines
as
well
as
gas­
fired
with
oil
backup
turbines.

Commenter
435
stated
that
the
GTA
petition
demonstrates
that
natural
gas­
fired
CTs
(
with
limited
oil
backup)
do
not
present
a
risk
to
human
health
or
the
environment
above
statutory
delisting
thresholds
established
in
section
112(
c)(
9)
of
the
CAA.

Commenter
440
believes
that,
as
petitioned
by
the
GTA,
EPA
may
properly
delist
natural
gas­
fueled
CTs
from
the
source
category
list
pursuant
to
section
112(
c)
of
the
CAA.
The
GTA
included
in
its
petition
a
study
indicating
that
HAP
emissions
from
gas­
fueled
turbines
will
not
result
in
a
lifetime
cancer
risk
greater
than
one
in
one
million
to
the
individual
in
the
population
most
exposed
to
emissions,
thus
satisfying
the
criteria
for
delisting.
The
commenter
also
noted
that
GTA
will
submit
to
EPA
an
addition
to
its
petition
that
addresses
deficiencies
cited
by
EPA.
The
commenter
added
that
they
have
modeled
emissions
from
two
of
their
facilities
that
demonstrate
the
highest
predicted
offsite
receptor
concentration
of
exposure
to
formaldehyde.
The
results
showed
concentrations
of
0.507

g/
m3
and
0.86

g/
m3,
values
which
are
far
lower
than
those
required
to
protect
human
health
and
the
environment.

Commenter
443
supported
GTA's
petition
to
delist
gas
turbines.
The
commenter
cited
the
GTA
study
that
showed
that
HAP
emissions
from
gas­
fueled
turbines
will
not
result
in
a
lifetime
cancer
risk
greater
than
one
in
one
million
to
the
individual
in
the
population
most
exposed
to
emissions.
In
addition
to
the
technical
reasons
for
delisting,
the
commenter
cited
the
following
policy­
related
reasons
for
delisting:
(
1)
gas
turbines
are
clean
and
efficient,
and
delisting
24
them
will
create
an
incentive
for
their
use;
(
2)
delisting
gas
turbines
will
create
energy
and
economic
benefits
(
resulting
from
creating
the
incentive
for
this
efficient
technology
and
the
cost
savings
associated
with
delisting);
and
(
3)
delisting
has
administrative
benefits
for
EPA
by
reducing
the
number
of
listed
source
categories
for
which
EPA
must
promulgate
final
MACT
standards.

Based
on
the
emissions
data
evaluated
by
EPA
in
the
combustion
turbine
rulemaking
(
Combustion
Turbine
Emissions
Database
v.
5),
Commenter
437
stated
that
gas­
fired
combustion
turbines
do
not
pose
a
significant
health
risk
and
should
be
delisted
as
allowed
under
112(
c)(
9)(
b).
The
commenter
stated
that
natural
gas
and
process
gas
fuels
should
be
considered
equivalent,
and
referenced
EPA's
statement
in
the
preamble,
"
The
summation
of
emission
factors
for
various
HAP
when
using
natural
gas...
diesel
fuel,
or
digester
gas
were
comparable..."
The
commenter
submitted
data
to
demonstrate
that
tests
on
external
combustion
sources
show
no
difference
in
HAP
emissions
among
gaseous
fuels.
Therefore
the
commenter
requested
that
EPA
consider
the
petition
by
the
GTA
to
delist
at
least
the
gas­
fired
(
including
natural
gas
and
process
gas
fuels)
combustion
turbine
source
category
from
section
112(
c).

Commenter
431
believes
it
is
within
EPA's
authority
(
under
112(
c)(
9)(
b))
to
provide
a
delisting
such
as
that
advocated
by
the
GTA
petition.
The
commenter
urged
EPA
to
fully
consider
this
approach
with
recognition
of
the
very
low
emitting
nature
of
combustion
turbine
sources.

Commenters
501
and
485
believe
EPA
should
delist
the
stationary
combustion
turbine
source
category
as
provided
by
section
112(
c)(
9)
of
the
CAA.
The
commenters
urged
EPA
to
consider
undertaking
steps
to
fully
evaluate
exposure
and
public
health
impacts
from
stationary
source
combustion
turbines,
as
the
commenters
believe
these
sources
do
not
pose
a
significant
health
risk.
The
commenters
believe
that
the
proposed
regulation
will
not
result
in
significant
environmental
benefits.
The
commenters
noted
that
the
majority
of
combustion
turbines
currently
in
operation
will
not
be
regulated
since
the
MACT
floor
for
diffusion
flame
turbines
is
no
emission
reduction,
and
above­
the­
floor
options
were
deemed
cost
prohibitive.
In
addition,
the
commenters
noted
that
EPA
expects
the
majority
of
new
combustion
turbines
installed
to
be
LPM
units,
which
will
have
reduced
CO
and
HAP
emissions.
Therefore
the
net
benefit
of
reduced
HAP
emissions
from
combustion
turbines
will
ultimately
be
realized
without
regulation
under
Part
63,
and
the
source
category
should
be
delisted.

Commenter
464
urged
EPA
to
give
serious
consideration
to
the
petitions
to
delist.
The
commenter
believes
the
data
EPA
gathered
for
the
rulemaking
demonstrates
that
stationary
combustion
turbines
are
relatively
small
sources
of
HAP
emissions.

Commenter
474
believes
EPA
should
reconsider
the
need
for
a
MACT
standard
for
combustion
turbines
based
on
significant
additional
information
that
has
become
available
on
health
and
environmental
risks
related
to
this
source
category.
The
commenter
cited
the
GTA
petition
to
delist
gas
turbines
from
the
MACT
source
category
list
and
the
November
20,
2002
25
Air
Daily
publication
which
reports
that
formaldehyde
emissions
pose
such
a
minimal
risk
that
they
do
not
warrant
rulemaking.

Commenter
488
strongly
supported
the
efforts
of
the
GTA
to
delist
lean
pre­
mix
combustion
turbines
and
natural
gas
fired
turbines
from
the
rule
under
section
112(
c)(
9).
In
addition,
the
commenter
supported
an
expansion
of
the
delisting
category
to
include
other
gaseous
fuel
forms
with
similar
properties
to
natural
gas
such
as
refinery
fuel
gas.
The
commenter
noted
that
petroleum
refineries
are
inherently
major
sources
of
HAP
emissions
that
potentially
could
have
to
install
expensive
controls
on
insignificant
sources
of
HAP
emissions
like
turbines
simply
because
they
are
located
at
a
major
facility.
The
commenter
considered
this
potentially
inequitable
as
significantly
larger
turbines
with
higher
HAP
emissions
could
be
exempt
simply
because
they
are
not
located
at
a
major
facility.

Response:
The
EPA
acknowledges
the
support
expressed
by
the
commenters
but
notes
that
the
delisting
petition
is
on
a
separate
schedule
and
not
associated
with
this
rule.

I.
D.
2
Comment:
One
commenter
(
488)
recommended
that
the
delisting
category
include
other
gaseous
fuel
forms
with
similar
properties
to
natural
gas,
such
as
refinery
fuel
gas.

Response:
The
delisting
petition
submitted
by
the
Gas
Turbine
Association
did
not
request
that
turbines
firing
other
gaseous
fuel
forms
be
delisted.
The
EPA
will
only
consider
delisting
the
sources
indicated
in
the
delisting
petition.

I.
D.
3
Comment:
One
commenter
(
460)
recommended
that
EPA
seek
a
modification
of
the
consent
decree
agreement
with
the
Sierra
Club
to
allow
sufficient
time
to
act
on
the
delisting
petition.

Response:
The
EPA
would
only
seek
a
modification
of
the
consent
decree
deadline
in
circumstances
where
EPA
has
concluded
that
the
MACT
standard
itself
could
not
be
promulgated
in
the
agreed
time
frame.

E.
Other
I.
E.
1
Comment:
Two
commenters
(
485,
501)
expressed
the
view
that
the
routine
exchange
of
aeroderivative
turbines
for
routine
overhaul
should
not
result
in
a
facility
becoming
a
new
source.
Commenter
439
stated
that
EPA
should
provide
(
a)
an
exemption
for
temporary
replacement
engines
during
routine
rebuilds
and
(
b)
a
mechanism
to
reduce
the
likelihood
a
source
would
suddenly
trigger
new
source
preconstruction
review/
approval
and
MACT
requirements
arising
from
an
unexpected
repair
or
replacement
of
a
stationary
CT.
One
way
to
accomplish
(
b)
is
to
provide
a
definition
of
"
reconstruction"
exclusively
for
Subpart
YYYY.
EPA
could
define
the
term
"
comparable
new
source"
to
include
the
affected
unit
and
"
all
physically
and
functionally
integrated
ancillary
equipment."
26
One
commenter
(
421)
suggested
that
the
definition
of
"
reconstructed
turbine"
be
clarified
and
at
a
minimum
exclude
any
gas
turbine
that
undergoes
a
repair
or
maintenance
operation.
One
commenter
(
422)
recommended
that
the
following
language
be
added
to
§
63.6090(
b):

(
5)
Removal
and
replacement
of
an
entire
turbine
or
turbine
subsection
(
e.
g.,
gas
producer
section,
power
turbine
section),
with
a
functionally
equivalent
turbine
or
subsection,
which
does
not
result
in
an
increase
in
HAP
emissions,
shall
not
be
considered
construction
of
a
new
affected
source
or
reconstruction
of
an
existing
affected
source.

Response:
The
definition
of
reconstructed
turbine
in
the
proposed
rule
is
consistent
with
the
General
Provisions
of
Part
63.
If
an
existing
CT
is
refurbished
to
the
extent
that
it
meets
the
definition
of
reconstruction,
then
it
should
be
considered
a
reconstructed
source.
The
EPA
is
not
aware
of
any
routine
refurbishment
for
which
the
fixed
capital
cost
of
the
new
components
exceeds
50
percent
of
the
fixed
capital
cost
that
would
be
required
to
construct
a
comparable
new
source.

I.
E.
2
Comment:
Seven
commenters
(
422,
431,
437,
440,
484,
502,
519)
said
that
the
definition
of
affected
source
should
be
modified
to
be
consistent
with
the
definition
found
in
§
63.2
of
the
General
Provisions.

Response:
Although
40
CFR
63.2
of
the
General
Provisions
provides
that
EPA
will
generally
adopt
a
broad
definition
of
affected
source,
which
includes
all
emission
units
within
each
subcategory
which
are
located
within
the
same
contiguous
area,
this
section
also
provides
that
EPA
may
adopt
a
narrower
definition
of
affected
source
in
instances
where
EPA
determines
that
the
broader
definition
would
"
create
significant
administrative,
practical,
or
implementation
problems"
and
"
the
different
definition
would
resolve
those
problems."
This
is
such
an
instance.
Because
of
the
way
that
the
subcategories
of
combustion
turbines
are
defined,
individual
turbines
can
switch
between
subcategories
based
on
the
fuel
they
are
burning.
The
EPA
has
taken
some
steps
in
the
definition
of
subcategories
to
limit
the
frequency
of
such
switching
between
subcategories,
because
EPA
believes
it
could
create
confusion
and
complicate
compliance
determinations.
However,
fuel
specific
subcategories
are
necessary
to
derive
a
MACT
floor
which
appropriately
considers
the
difference
in
the
composition
of
the
HAPs
emitted
based
on
the
fuel
used.
Thus,
EPA
cannot
eliminate
the
possibility
that
individual
turbines
will
switch
subcategories.
Use
of
the
broader
definition
of
affected
source
specified
by
the
General
Provisions
would
require
very
complex
aggregate
compliance
determinations,
because
an
individual
turbine
could
be
part
of
one
affected
source
at
one
time
and
part
of
a
different
affected
source
at
another
time.
This
would
require
that
the
contribution
of
each
turbine
to
total
emissions
for
all
emission
units
within
each
subcategory
be
adjusted
to
reflect
the
proportionate
time
the
unit
was
operating
within
that
subcategory.
The
EPA
believes
such
complicated
compliance
determinations
to
be
impractical,
and
therefore
has
decided
to
adopt
a
definition
which
establishes
each
individual
combustion
turbine
as
the
affected
source.

I.
E.
3
Comment:
One
commenter
(
437)
stated
that
emission
sources
on
offshore
27
platforms
located
in
the
Central
and
Western
planning
areas
of
the
Gulf
of
Mexico
are
not
subject
to
EPA
jurisdiction
pursuant
to
42
U.
S.
C.
section
7627.
The
Department
of
Interior
has
exclusive
authority
to
regulate
air
emissions
in
these
areas.
The
EPA
should
include
a
statement
in
either
§
63.6590
or
the
preamble
to
the
final
rule
that
the
rule
does
not
apply
to
sources
in
the
Central
or
Western
planning
areas
of
the
Gulf
of
Mexico.

Response:
The
EPA
does
not
construe
CAA
section
328
in
the
same
manner
as
the
commenter.
That
section
requires
EPA
to
regulate
sources
on
the
Outer
Continental
Shelf
to
attain
and
maintain
ambient
air
quality
standards
and
to
prevent
significant
deterioration
of
air
quality.
Requirements
established
pursuant
to
that
section
are
considered
to
be
standards
issued
pursuant
to
CAA
section
111.
Since
the
definition
of
a
stationary
source
in
CAA
section
112(
a)(
3)
is
the
same
as
in
CAA
section
111(
a)(
3),
EPA
finds
no
basis
in
the
cited
section
for
excluding
combustion
turbines
located
on
the
Outer
Continental
Shelf
in
the
Gulf
of
Mexico
from
this
standard.

I.
E.
4
Comment:
Two
commenters
(
427,
487)
remarked
that
a
CT
that
is
co­
located
at
a
major
source
(
but
would
not
be
a
major
source
by
itself)
would
be
put
at
an
economic
disadvantage
merely
because
of
location,
without
regard
to
CT
emissions.

Response:
The
CAA
requires
EPA
to
regulate
all
major
sources
of
HAP.
The
definition
of
major
source
includes
all
HAP­
emitting
units
which
are
located
within
a
contiguous
area
and
under
common
control.
Thus,
the
claimed
discriminatory
impact
on
combustion
turbines
which
are
co­
located
with
other
sources
that
emit
HAP
is
intrinsic
to
the
statutory
scheme.

I.
E.
5
Comment:
One
commenter
(
437)
felt
that
EPA
should
add
a
new
§
63.6095(
b)(
2)
(
with
the
existing
§
63.6095(
b)
becoming
(
b)(
1))
stating
that
existing
CTs
at
area
sources
that
become
major
sources
are
not
affected.

Response:
Combustion
turbines
which
are
located
at
area
sources
that
subsequently
become
major
sources
would
be
subject
to
the
rule.
However,
such
turbines
would
be
existing
sources,
and
EPA
has
not
adopted
emission
control
requirements
for
existing
sources.

I.
E.
6
Comment:
Two
commenters
(
442,
449)
requested
that
the
final
rule
include
the
non­
aggregation
provisions
for
transmission
and
storage
facilities
from
the
Natural
Gas
Transmission
and
Storage
MACT.

Response:
The
EPA
has
incorporated
this
comment
in
the
final
rule.
The
nonaggregation
provisions
for
transmission
and
storage
facilities
from
the
Natural
Gas
Transmission
and
Storage
MACT
(
40
CFR
part
63
subpart
HHH),
which
are
found
in
the
definition
of
major
source
in
that
subpart,
are
as
follows:

(
1)
Emissions
from
any
pipeline
compressor
station
or
pump
station
shall
not
be
aggregated
with
emissions
from
other
similar
units,
whether
or
not
such
units
are
in
a
contiguous
area
or
under
28
common
control;
and
(
2)
Emissions
from
processes,
operations,
and
equipment
that
are
not
part
of
the
same
natural
gas
transmission
and
storage
facility,
as
defined
in
this
section,
shall
not
be
aggregated.

The
non­
aggregation
provisions
in
(
1)
above
were
already
included
in
the
proposed
definition
of
major
source
for
the
CT
NESHAP
and
have
been
retained
in
the
final
rule.
The
nonaggregation
provisions
in
(
2)
above
have
also
been
added
to
the
definition
of
major
source
for
the
CT
NESHAP.

I.
E.
7
Comment:
One
commenter
(
518)
stated
that
the
proposed
emission
limits
should
be
applied
to
all
CTs
(
both
new
and
existing,
at
major
and
non­
major
facilities),
not
just
to
CTs
at
major
HAP
facilities.

Response:
This
rule
will
not
cover
area
sources.
In
developing
the
Urban
Air
Toxics
Strategy,
EPA
identified
area
sources
that
EPA
believes
warrant
regulation
to
protect
the
environment
and
the
public
health
and
satisfy
the
statutory
requirements
in
section
112
of
the
CAA
pertaining
to
area
sources.
Stationary
CTs
located
at
area
sources
were
not
included
on
that
list.
As
a
result,
the
final
rule
does
not
apply
to
stationary
CTs
located
at
area
sources.

I.
E.
8
Comment:
Five
commenters
(
418,
427,
442,
449,
520)
urged
EPA
to
establish
at
least
two
size
subcategories
of
LPC
CTs
to
account
for
the
differences
between
large
and
small
LPC
units.
Two
of
those
commenters
(
427,
429)
recommended
that
at
least
one
subcategory
be
created
to
represent
stationary
CTs
less
than
25
MW
in
size.

Response:
The
commenters
noted
that
large
utility
(
heavy
duty)
LPC
units
have
inherent
technical
characteristics
that
make
them
different
from
small
industrial
and
aeroderivative
LPC
turbines,
including
multiple­
combustion
chamber
assemblies,
higher
firing
temperatures,
advanced
airflow
and
cooling
techniques,
dimensional
scaling
benefits,
and
advanced
combustion
systems
and
controls.
The
combustors
for
small
CTs
are
smaller,
therefore
there
is
not
enough
room
do
to
the
same
amount
of
mixing
as
for
larger
units.
Due
to
these
technical
distinctions,
emission
profiles
for
large
LPC
units
have
historically
been
different
from
those
of
small
industrial
and
aeroderivative
turbines.
Manufacturers
of
large
LPC
units
offer
NOx
and
CO
guarantees
below
25
ppm
and
as
low
as
9
ppm.
Manufacturer
guarantees
for
small
industrial
and
aeroderivative
turbines
are
on
the
order
of
25
to
42
ppm
for
NOx
and
50
ppm
for
CO.

The
EPA
agrees
with
the
commenters
that
emission
profiles
are
different
for
large
and
small
units.
Due
to
the
limited
amount
of
emissions
data
EPA
had
at
proposal,
EPA
requested
HAP
emissions
test
data
from
stationary
combustion
turbines
in
the
proposed
rule.
As
a
result
of
this
request,
EPA
received
new
data
in
the
form
of
several
test
reports
during
the
comment
period.
The
data
set
demonstrates
that
on
average,
when
comparing
formaldehyde
emissions
from
turbines
of
the
same
combustor
and
fuel
type,
the
uncontrolled
emissions
are
higher
for
smaller
units.
The
analysis
of
the
MACT
floor
showed
that
both
large
and
small
units
are
equipped
with
add­
on
HAP
emission
control.
However,
EPA
has
a
limited
data
set
that
does
not
29
include
testing
of
either
a
large
diffusion
flame
or
small
lean
premix
turbine
with
add­
on
HAP
emission
control.
Consequently,
EPA
would
have
to
set
the
same
limit
for
small
and
large
units.
Therefore,
EPA
did
not
see
any
reason
to
subcategorize
by
size
and
has
not
done
so.

II.
DEFINITIONS
A.
Lean
Premix
Stationary
Combustion
Turbine
II.
A.
1
Comment:
One
commenter
(
478)
requested
that
the
definition
of
lean
premix
stationary
combustion
turbine
be
modified
to
recognize
that
fuel
and
air
mixing
may
be
occurring
in
the
combustor
of
some
LPC
CTs.
The
definition
should
be
modified
to
include
these
types
of
stationary
CTs
that
burn
a
lean
mixture
and
thoroughly
mix
their
fuel
prior
to
combustion
in
the
combustor.

One
commenter
(
430)
asked
for
clarification
of
the
definition
of
lean
premix
stationary
combustion
turbine
as
it
applies
to
CTs
that
meet
the
definition
while
burning
one
fuel,
but
fail
to
meet
the
definition
while
burning
another
fuel.

Response:
The
EPA
has
revised
the
definition
of
lean
premix
technology
to
recognize
that
fuel
and
air
mixing
may
be
occurring
in
the
combustor
of
some
LPC
CTs.
In
the
final
rule,
lean
premix
gas­
fired
units
that
fire
oil
will
still
remain
in
the
lean
premix
gas­
fired
units
subcategory
if
the
turbine
is
located
at
a
major
source
where
all
new
and
existing
stationary
combustion
turbines
fire
oil
no
more
than
an
aggregate
total
of
1000
hours
during
the
calendar
year.
This
allowance
will
limit
the
frequency
of
switching
between
subcategories,
and
it
is
believed
the
1000
hour
allowance
will
be
sufficient
to
accommodate
those
situations
where
distillate
oil
is
used
as
a
backup.

B.
Emergency
Stationary
Combustion
Turbine
II.
B.
1
Comment:
Nine
commenters
(
414,
422,
425,
426,
438,
485,
501,
502,
519)
said
the
definition
of
emergency
stationary
combustion
turbine
should
include
operational
allowances
for
the
periodic
operation/
testing
to
verify
operational
readiness.
Commenter
438
stated
that
it
is
not
clear
if
testing
and
maintenance
operations
are
included
in
the
limit
of
50
hours
for
nonemergency
operations;
the
definition
should
be
clarified
in
this
respect,
and
the
number
of
hours
allowed
for
nonemergency
operations
should
also
reflect
the
testing
and
maintenance
needs
for
emergency
CTs
for
certain
types
of
operations
(
example
­
airport
operations).
Commenter
519
recommended
that
the
following
should
be
added
to
the
definition:
"
Required
testing
of
such
units
should
be
minimized,
but
there
is
no
time
limit
on
the
use
of
emergency
stationary
sources."

Three
commenters
(
420,
442,
449)
felt
that
EPA
should
raise
the
threshold
to
100
hours
of
non­
emergency
operation
in
order
to
provide
sufficient
time
for
maintenance,
training,
and
reliability
testing/
early­
on
operation.
30
Response:
The
EPA
agrees
with
the
commenters
that
routine
testing
and
maintenance
to
ensure
operational
readiness
should
be
included
in
the
definition
of
emergency
turbine
and
has
made
this
revision
in
the
final
rule.
The
routine
testing
and
maintenance
must
be
within
limits
recommended
by
the
turbine
manufacturer
or
other
entity
such
as
an
insurance
company.

II.
B.
2
Comment:
One
commenter
(
438)
requested
that
the
definition
be
clarified,
or
extended,
to
allow
for
operations
in
anticipation
of
an
emergency
situation.

Response:
The
EPA
does
not
agree
that
operation
in
anticipation
of
an
emergency
situation
should
be
included
in
the
definition
of
emergency
turbine
and
has
not
made
this
change.

II.
B.
3
Comment:
Four
commenters
(
422,
438,
502,
519)
asked
for
clarification
as
to
whether
loss
power
that
constitutes
an
emergency
is
limited
to
power
supplied
to
the
facility
as
a
whole
or
includes
power
supplied
to
portions
of
a
facility.

Response:
The
definition
of
emergency
turbine
has
been
revised
to
indicate
that
loss
of
power
that
constitutes
an
emergency
can
include
power
supplied
to
portions
of
a
facility.

II.
B.
4
Comment:
Three
commenters
(
422,
431,
502)
recommended
that
operation
not
be
limited
to
only
those
times
when
the
primary
power
source
has
been
interrupted.
They
commented
that
operation
should
not
be
restricted
at
all,
providing
the
primary
design
purpose
of
the
unit
is
to
provide
emergency
services,
fire
water,
etc.

Response:
The
EPA
intended
that
the
definition
of
emergency
turbine
include
operation
during
emergency
situations,
including
times
when
the
primary
power
source
has
been
interrupted
as
well
as
other
situations
such
as
pumping
water
in
the
case
of
fire
or
flood,
which
was
given
as
an
example
of
emergency
operation
in
the
definition
in
the
proposed
rule.
The
definition
has
been
clarified
to
clearly
indicate
that
operation
is
not
limited
to
only
times
when
the
primary
power
source
has
been
interrupted.

II.
B.
5
Comment:
Three
commenters
(
416,
485,
501)
recommended
that
the
definitions
of
emergency
CT
and
limited
use
CT
be
combined
into
a
single
definition.

Response:
The
EPA
has
not
included
a
separate
subcategory
for
limited
use
CTs
in
the
final
rule.
Thus,
the
comment
is
moot.

II.
B.
6
Comment:
One
commenter
(
502)
suggested
that
EPA
should
include
more
examples
of
emergency
operation
in
the
definition.
These
might
include
fuel
and
raw
material
curtailments
that
require
the
operation
of
a
standby
stationary
CT.

Response:
The
EPA
contacted
the
commenter
for
more
information
about
what
types
of
curtailments
they
were
concerned
with.
The
commenter
provided
only
one
example,
which
was
shutdown
of
offshore
wells
during
a
hurricane.
The
EPA
believes
that
the
definition
of
emergency
31
stationary
combustion
turbine
is
sufficient
to
cover
this
particular
scenario
and
it
is
not
necessary
to
include
more
examples
of
emergency
operation.
It
would
be
nearly
impossible
to
provide
examples
of
every
potential
type
of
emergency
situation.

II.
B.
7
Comment:
One
commenter
(
437)
advised
that
the
50
hours
per
year
definition
should
be
changed
to
mean
a
CT
whose
operation
is
restricted
by
federally
enforceable
limits
to
less
than
876
hours
per
year.
Their
rationale
is
that
876
hours
is
enough
time
over
a
period
of
one
year
to
cover
a
wide
range
of
potential
needs
for
the
CT,
including
emergency
power,
stand­
by
compression,
peaking,
testing
and
maintenance,
and
compensation
for
"
brownouts"
or
power
interruptions.
The
commenter
noted
that
some
units
in
critical
emergency
service
such
as
backup
power
may
required
testing
on
a
frequent
basis
to
ensure
reliability.

Response:
The
operation
of
emergency
turbines
for
emergency
use
is
not
limited
to
a
specific
number
of
hours,
and
routine
testing
and
maintenance
to
ensure
operational
readiness
have
been
included
in
the
definition
of
emergency
turbine.
This
is
discussed
in
greater
detail
in
the
response
to
comment
II.
B.
1.
As
discussed
in
the
response
to
comment
II.
C.
1.1,
the
final
rule
does
not
include
an
subcategory
for
limited
use
units,
therefore
the
suggestion
to
increase
the
operating
limit
to
876
hours
per
year
is
moot.

II.
B.
8
Comment:
One
commenter
(
412)
said
that
the
use
of
emergency
equipment
is
being
severely
limited
because
it
appears
in
the
preamble
that
emergency
stationary
CTs
have
been
made
a
subset
of
the
limited
use
category.

Response:
Emergency
stationary
CTs
are
not
a
subset
of
the
limited
use
category.
The
final
rule
does
not
have
a
category
for
limited
use
units.
Thus,
the
use
of
emergency
equipment
is
not
being
severely
limited.

C.
Stationary
Combustion
Turbine
II.
C.
1
Comment:
Two
commenters
(
485,
501)
proposed
that
the
definition
of
"
stationary
combustion
turbine"
include
all
appropriate
associated
equipment.
Two
commenters
(
422,
502)
recommended
that
stationary
combustion
turbine
should
be
defined
as
follows:

"
A
stationary
combustion
turbine
includes
all
equipment,
including
but
not
limited
to
the
turbine,
the
fuel,
air,
lubrication
and
exhaust
gas
systems,
control
systems,
and
any
ancillary
components
and
sub­
components
comprising
any
simple
cycle
stationary
combustion
turbine,
any
regenerative/
recuperative
cycle
stationary
combustion
turbine,
the
combustion
turbine
portion
of
any
stationary
cogeneration
cycle
combustion
system,
or
the
combustion
turbine
portion
of
any
stationary
combined
cycle
steam/
electric
generating
system.
Stationary
means
that
the
combustion
turbine
is
not
self
propelled
or
intended
to
be
propelled
while
performing
its
function."

Response:
The
EPA
has
adopted
the
commenters
suggested
modification
to
the
definition
32
of
stationary
combustion
turbine
but
has
clarified
the
definition
to
indicate
that
emissions
control
equipment
are
not
considered
part
of
the
stationary
combustion
turbine.

II.
C.
2
Comment:
One
commenter
(
435)
expressed
the
opinion
that
EPA
should
employ
consistent
definitions
of
"
mobile"
and
"
stationary"
from
MACT
standard
to
MACT
standard.
One
commenter
(
422)
remarked
that
the
definition
should
be
modified
to
exclude
portable/
transportable
turbines.

Response:
The
EPA
does
not
agree
that
it
is
necessary
to
employ
consistent
definitions
of
"
mobile"
and
"
stationary"
from
MACT
standard
to
MACT
standard.
The
commenter
cited
the
definition
of
"
stationary"
in
the
proposed
MACT
standard
for
stationary
reciprocating
internal
combustion
engines
(
RICE).
The
definition
from
this
rule
cannot
be
compared
to
the
RICE
rule;
the
RICE
rule
does
not
cover
stationary
RICE
that
are
portable
or
transportable
because
those
engines
are
already
covered
by
the
rule
for
mobile
RICE
sources.

II.
C.
3
Comment:
One
commenter
(
438)
requested
that
the
definition
of
stationary
combustion
turbine
be
moved
to
the
definitions
section
instead
of
being
defined
in
§
63.6085(
a).

Response:
The
EPA
agrees
that
stationary
combustion
turbine
should
also
be
defined
in
the
definitions
section.
This
change
has
been
made
in
the
final
rule.

D.
Major
Source
II.
D.
1
Comment:
One
commenter
(
437)
expressed
support
for
the
definition
of
major
source,
except
as
follows:

The
phrase
"
except
when
they
are
on
the
same
surface
site"
should
be
removed
from
the
end
of
part
(
1)
of
the
Combustion
Turbine
major
source
definition.
This
phrase
is
not
present
in
the
40
CFR
Part
63
Subpart
HH
major
source
definition
that
is
the
template
for
the
Combustion
Turbine
MACT
major
source
definition.
Section
112(
n)(
4)
of
the
CAA
of
1990
requires
that
wells
and
associated
equipment
not
be
aggregated
even
within
the
same
surface
site
except
as
provided
in
part
(
3)
of
the
Combustion
Turbine
MACT
major
source
definition.

In
part
(
3)
of
the
Combustion
Turbine
MACT
major
source
definition,
the
phrase
"
storage
vessel
with
flash
emissions
potential"
should
be
changed
to
"
storage
vessel
with
the
potential
for
flash
emissions"
to
conform
to
the
40
CFR
Part
63
Subpart
HH
definition.

The
General
Provision
major
source
definition
presented
in
the
Combustion
Turbine
MACT
is
different
from
those
found
in
the
definition
of
major
source
in
the
National
Emission
Standards
for
Hazardous
Air
Pollutants
From
Oil
and
Natural
Gas
Production
Facilities
(
40
CFR
63.761).
The
significance
of
this
difference
is
that
sources
that
are
area
sources
under
Subpart
HH
could
possibly
be
rendered
"
Major
Sources"
under
Combustion
Turbine
MACT.
EPA
should
acknowledge
this
possibility
in
the
preamble
to
the
final
rule
and
clearly
state
that
this
does
not
33
change
the
source's
status
under
Subpart
HH
or
any
other
MACT.
Similarly,
one
commenter
(
422)
recommended
that
the
preamble
clarify
that
the
definition
of
major
source
in
the
CT
MACT
does
not
alter
the
definition
of
major
source
in
Subpart
HH,
and
therefore
does
not
affect
Subpart
HH
applicability.

Response:
The
EPA
agrees
that
the
phrase
"
except
when
they
are
on
the
same
surface
site"
should
be
removed
from
the
end
of
part
(
1)
of
the
Combustion
Turbine
major
source
definition
and
the
phrase
"
storage
tanks
with
flash
emissions
potential"
in
part
(
3)
of
the
Combustion
Turbine
MACT
major
source
definition
should
be
changed
to
"
storage
vessel
with
the
potential
for
flash
emissions;"
these
changes
have
been
made
in
the
final
rule.

The
EPA
recognizes
the
commenters'
concern
regarding
the
definition
of
major
source
in
the
CT
NESHAP
and
its
difference
from
the
definition
of
major
source
in
Subpart
HH.
The
preamble
to
the
final
rule
clarifies
that
the
definition
of
major
source
in
the
CT
MACT
does
not
alter
the
definition
of
major
source
in
Subpart
HH,
and
therefore
does
not
affect
Subpart
HH
applicability.

E.
Other
II.
E.
1
Comment:
Two
commenters
(
428,
502)
suggested
that
the
definition
of
diffusion
flame
stationary
combustion
turbine
should
be
modified
to
recognize
that
swirl
cups,
nozzles
or
orifice
mixers
are
used
to
provide
fuel
and
air
mixing
in
some
diffusion
flame
combustors.
The
definition
should
be
modified
to
read
"
diffusion
flame
stationary
combustion
turbine
means
any
stationary
combustion
turbine
where
fuel
and
air
are
injected
at
the
combustor
and
are
mixed
by
diffusion,
swirl
cups,
nozzles
or
orifices
prior
to
ignition."

Response:
The
EPA
believes
that
the
definition
of
diffusion
flame
stationary
combustion
turbine
is
adequate.
Diffusion
is
the
means
by
which
the
gas
is
mixed.
The
identified
devices
are
parts
of
the
combustor
used
to
mix
the
gas
and
do
not
affect
how
the
combustor
is
classified.

II.
E.
2
Comment:
One
commenter
(
438)
observed
that
in
the
proposed
rule
landfill
and
digester
gas
are
defined
as
being
formed
through
anaerobic
decomposition,
which
is
usually
but
not
always
the
case.

Response:
The
definitions
of
landfill
gas
and
digester
gas
were
modified
to
indicate
that
they
are
typically
formed
through
anaerobic
decomposition.

II.
E.
3
Comment:
One
commenter
(
502)
stated
that
the
definition
of
"
deviation"
should
be
changed
to
"
excursion"
to
avoid
confusion
with
Title
V
operating
permit
requirements
and
for
consistency
with
other
MACTs
(
e.
g.
HON).

Response:
The
EPA
does
not
agree
with
the
commenter
that
the
definition
of
deviation
should
be
changed
to
excursion.
The
term
"
deviation"
has
been
commonly
been
used
in
other
34
MACT
standards.

II.
E.
4
Comment:
One
commenter
(
437)
recommended
that
the
definitions
from
40
CFR
Subpart
HH
and
HHH
for
glycol
dehydration
unit,
storage
vessel
with
the
potential
for
flash
emissions,
and
production
well
should
be
included.

Response:
The
EPA
agrees
with
the
commenter
that
the
definitions
should
be
included
in
the
CT
NESHAP.
The
definitions
from
40
CFR
Subpart
HH
and
HHH
for
glycol
dehydration
unit,
storage
vessel
with
the
potential
for
flash
emissions,
and
production
well
have
been
added
to
the
final
CT
NESHAP.

II.
E.
5
Comment:
Three
commenters
(
437,
442,
449)
requested
that
EPA
acknowledge
that
the
special
potential
to
emit
(
PTE)
provisions
in
40
CFR
Part
63
Subpart
HH
are
also
applicable
to
the
CT
PTE
determination
by
referencing
these
provisions
in
the
CT
PTE
definition.
Commenters
449
and
442
recommended
that
the
following
provisions
from
the
Natural
Gas
Transmission
and
Storage
MACT
should
be
incorporated
in
the
CT
rule:

1)
40
CFR
63.1270(
a)(
1)
­
maximum
annual
facility
natural
gas
throughput
for
storage
facilities
2)
40
CFR
63.1270(
a)(
2)
­
maximum
annual
throughput
for
transmission
facilities
Response:
The
EPA
has
incorporated
these
comments
in
the
final
rule
by
modifying
the
definition
of
PTE
in
the
final
rule
to
include
the
following:

"
For
oil
and
natural
gas
production
facilities
subject
to
subpart
HH
of
this
part,
the
potential
to
emit
provisions
in
§
63.760(
a)
may
be
used.
For
natural
gas
transmission
and
storage
facilities
subject
to
subpart
HHH
of
this
part,
the
maximum
annual
facility
gas
throughput
for
storage
facilities
may
be
determined
according
to
§
63.1270(
a)(
1)
and
the
maximum
annual
throughput
for
transmission
facilities
may
be
may
be
determined
according
to
§
63.1270(
a)(
2)."

II.
E.
6
Comment:
One
commenter
(
449)
recommended
that
the
following
definitions
from
the
T&
S
MACT
(
40
CFR
63.1271)
should
be
incorporated
into
the
final
rule
to
address
the
non­
aggregation
provisions
for
transmission
and
storage
facilities:
compressor
station,
custody
transfer,
facility,
major
source,
natural
gas
transmission,
surface
site.

Response:
The
proposed
CT
NESHAP
included
definitions
for
custody
transfer
and
surface
site
that
were
consistent
with
the
definitions
in
the
T&
S
MACT;
the
definitions
have
been
retained
in
the
final
rule.
The
proposed
rule
also
had
a
definition
of
major
source,
which
has
been
modified
in
the
final
rule
to
include
the
language
from
the
T&
S
MACT
major
source
definition.
The
definitions
from
the
T&
S
MACT
for
compressor
station,
natural
gas
transmission
and
storage
facility,
and
natural
gas
transmission
have
been
added
to
the
final
CT
rule.
35
III.
DATES
III.
1
Comment:
Two
commenters
(
412,
541(
C))
indicated
that
the
45
day
comment
period
was
insufficient.

Response:
The
EPA
believes
the
comment
period
was
sufficient.
The
shorter
comment
period
was
necessary
due
to
the
August
30,
2003
promulgation
period.
Additionally,
the
rule
was
posted
on
the
EPA
website
prior
to
publication
in
the
Federal
Register.
A
notice
was
published
in
the
Federal
Register
on
January
3,
2003
indicating
that
a
copy
of
the
rule
was
available
on
the
EPA's
website.

III.
2
Comment:
One
commenter
(
386)
contended
that
the
August
30,
2003
promulgation
date
does
not
provide
enough
time
for
EPA
to
receive
and
fully
consider
public
comments,
resolve
significant
testing/
monitoring
issues,
and
consider
risk­
based
alternatives
and
the
delisting
petition.
The
October
10,
2003
deadline
for
Part
2
112(
j)
permit
applications
is
also
not
reasonable.

Response:
The
EPA
does
not
agree
with
the
commenter
and
believes
that
the
August
30,
2003
promulgation
date
provides
sufficient
time
for
EPA
to
evaluate
all
necessary
considerations
prior
to
promulgation
of
the
final
rule.

III.
3
Comment:
Two
commenters
(
412,
443)
stated
that
immediate
compliance
is
unrealistic
for
new
or
reconstructed
turbines,
and
recommended
a
one
year
compliance
timeframe.

Response:
The
EPA
believes
that
immediate
compliance
is
appropriate
for
new
or
reconstructed
turbines
and
is
consistent
with
the
General
Provisions
of
Part
63.
Sources
are
required
to
install
the
proper
equipment
and
meet
the
applicable
emission
limitations
on
startup;
however,
EPA
allows
sources
180
days
to
demonstrate
compliance.

III.
4
Comment:
Three
commenters
(
418,
442,
449)
recommended
that
the
final
rule
allow
one
year
to
conduct
the
initial
performance
test,
rather
than
the
180
days
provided
by
the
Part
63
General
Provisions.

Response:
The
EPA
feels
that
180
days
is
sufficient
time
to
conduct
the
initial
performance
test,
even
for
turbines
that
are
used
in
load
following
operations.
The
180
day
time
period
is
consistent
with
the
General
Provisions
of
Part
63.
Sources
have
the
option
to
petition
for
additional
time
on
a
case­
by­
case
basis
if
necessary.

III.
5
Comment:
Three
commenters
(
412,
478,
502)
remarked
that
immediate
compliance
is
unrealistic
for
area
sources
that
become
major
sources.
Commenter
412
recommended
a
one
year
compliance
timeframe
for
those
sources,
while
commenters
478
and
502
suggested
that
area
sources
that
become
major
sources
be
given
three
years
to
comply,
consistent
with
40
CFR
Part
63,
Subpart
A,
in
which
EPA
recognizes
that
existing
area
sources
that
become
major
sources
36
need
some
time
to
come
into
compliance
with
the
relevant
MACT
standards.
See
§
63.6(
c)(
5).

One
commenter
(
443)
proposed
that
sources
that
are
unable
to
meet
the
formaldehyde
standard
or
that
are
no
longer
in
compliance
with
the
limited
use
provision
be
granted
at
least
18
months
to
install
catalysts.
One
commenter
(
449)
requested
that
limited
use
units
be
allowed
one
year
to
implement
MACT
if
utilization
increases
beyond
the
10
percent
utilization
factor.

Response:
The
EPA
does
not
agree
with
the
comments
that
immediate
compliance
is
unrealistic
for
area
sources
that
become
major
sources.
These
sources
are
aware
in
advance
of
their
change
in
status
from
area
source
to
major
source
and
therefore
should
have
sufficient
time
to
plan
for
immediate
compliance
with
this
rule.
As
mentioned
in
the
response
to
comment
III.
3,
a
period
of
180
days
is
allowed
to
demonstrate
compliance.
The
proposed
subcategory
for
limited
use
units
has
not
been
retained
in
the
final
rule,
thus,
that
comment
is
moot.

III.
6
Comment:
One
commenter
(
417)
requested
that
§
63.6110
be
revised
to
read
"
within
180
calendar
days
after
the
compliance
date
that
is
specified
for
your
stationary
combustion
turbine
in
§
63.6095
and
according
to
the
provisions
in
§
63.7(
a)(
2),
unless
the
testing
is
delayed
pending
the
resolution
of
a
petition
to
the
Administrator
under
§
63.6120(
f)."
Another
way
to
resolve
this
issue
is
word
changes
in
§
63.6095(
a)(
2).

Response:
The
EPA
does
not
feel
that
this
change
is
necessary.
If
a
source
has
petitioned
the
Administrator
under
§
63.6120(
f),
the
petition
could
include
a
request
to
delay
the
testing.

III.
7
Comment:
One
commenter
(
420)
advised
that
EPA
should
ensure
timely
finalization
of
the
proposed
rule
prior
to
the
relevant
Sierra
Club
settlement
trigger
date
because
submittal
of
Part
2
case­
by­
case
MACT
applications
will
be
overly
burdensome
for
both
affected
sources
and
state
regulatory
agencies.

Response:
EPA
intends
to
finalize
this
rule
on
schedule.

III.
8
Comment:
Two
commenters
(
442,
449)
requested
that
the
rule
provide
one
year
for
initial
notification
of
MACT
applicability,
as
in
the
T&
S
MACT
and
the
Oil
and
Natural
Gas
Production
MACT,
instead
of
120
days.

Response:
The
EPA
does
not
agree
that
one
year
is
necessary
for
initial
notification
of
MACT
applicability.
An
initial
notification
is
not
a
time
consuming
activity.

IV.
MACT
A.
MACT
Floor
and
MACT
for
Diffusion
Flame
Units
IV.
A.
1
Comment:
Two
commenters
(
428,
440)
expressed
support
for
EPA's
37
determination
of
the
MACT
floor
for
DFC
units.
Commenter
428
remarked
that
EPA
is
justified
in
relying
on
the
data
it
had;
since
fewer
than
3
percent
of
sources
have
oxidation
catalysts,
the
floor
is
no
control.
Commenter
440
said
that
the
determination
that
MACT
floor
is
no
emission
reduction
is
lawful
because
EPA
determined
that
the
best­
performing
source
was
not
achieving
emissions
reduction
through
the
use
of
an
emission
control
system
and
there
were
no
other
methods
by
which
CTs
could
reduce
HAP
emissions.

Response:
The
EPA
acknowledges
the
commenters'
support.
This
approach
has
been
preserved
in
the
final
rule.

IV.
A.
2
Comment:
Three
commenters
(
485,
488,
501)
took
issue
with
the
MACT
floor
for
new
DFC
turbines.
The
commenters
stated
that
no
formaldehyde
emissions
data
or
oxidation
catalyst
control
efficiency
data
were
available
to
EPA
to
support
setting
the
MACT
floor
for
new
DFC
turbines;
newer
models
of
turbines
in
the
DFC
category
should
be
evaluated
to
identify
the
best­
performing
unit.

Response:
At
proposal,
EPA
had
limited
emissions
data
for
stationary
combustion
turbines,
including
one
test
for
a
DFC
turbine
with
add­
on
HAP
emission
control.
Due
to
the
limited
amount
of
emissions
data
EPA
had
at
proposal,
EPA
requested
HAP
emissions
test
data
from
stationary
combustion
turbines
in
the
proposed
rule.
As
a
result
of
this
request,
EPA
received
new
emissions
data
for
DFC
turbines
during
the
comment
period,
including
an
additional
formaldehyde
test
on
a
DFC
unit
equipped
with
add­
on
HAP
emissions
control.
The
new
data
also
includes
several
tests
conducted
using
FTIR,
which
is
regarded
as
the
most
accurate
measurement
method
for
formaldehyde
for
stationary
CTs.
Thus,
the
data
set
has
been
significantly
improved,
both
quantitatively
and
qualitatively,
and
EPA
believes
that
the
data
set
is
sufficient
to
identify
the
best­
performing
unit.

Based
on
comments
and
information
received
during
the
public
comment
period,
the
DFC
subcategory
was
divided
further
into
subcategories
for
DFC
CTs
when
firing
gas
and
when
firing
oil
at
sites
where
all
turbines
fire
oil
for
no
more
than
1000
hours
annually
("
DFC
gas­
fired
turbines")
and
for
DFC
CTs
when
firing
oil
at
sites
where
all
turbines
fire
oil
more
than
1000
hours
annually
("
diffusion
flame
oil­
fired
turbines").
The
rationale
for
this
subcategorization
is
discussed
in
the
response
to
comment
IV.
A.
8.

To
determine
the
MACT
Floor
for
new
DFC
gas­
fired
turbines,
the
best
performing
unit
was
identified
from
the
new
data
set.
The
best
performing
unit
in
this
subcategory
is
equipped
with
an
oxidation
catalyst.
The
outlet
formaldehyde
concentration
of
this
turbine
was
15
ppb.
This
number
was
measured
using
the
method
CARB
430
and
a
bias
factor
was
applied
to
the
reported
results;
this
is
discussed
in
greater
detail
in
the
response
to
comment
V.
A.
1
and
in
memoranda
available
in
the
rulemaking
docket.
Two
tests
on
the
best
controlled
LPC
unit
(
also
equipped
with
an
oxidation
catalyst)
showed
a
variability
of
approximately
a
factor
of
five.
It
is
expected
that
similar
variability
would
be
associated
with
DFC
turbines
as
is
associated
with
the
LPC
turbine.
Therefore,
applying
a
factor
of
five
to
the
formaldehyde
concentration
measured
at
38
the
outlet
of
the
turbine
is
appropriate
to
account
for
the
variability
of
the
best
performing
unit.
This
results
in
a
formaldehyde
emission
limit
of
75
ppb,
however,
with
a
similar
control
system,
the
emission
limit
should
be
no
lower
than
the
emission
limit
for
LPC
units
since
DFC
CTs
on
average
emit
more
HAP.
Therefore,
it
is
appropriate
to
establish
the
MACT
Floor
for
new
DFC
gas­
fired
units
at
the
same
level
as
the
MACT
Floor
for
new
LPC
gas­
fired
units,
91
ppb.

To
determine
the
MACT
Floor
for
new
DFC
oil­
fired
turbines,
the
best
performing
unit
in
this
subcategory
was
identified
from
the
new
data
sat.
This
turbine
is
equipped
with
an
oxidation
catalyst.
The
outlet
formaldehyde
concentration
of
this
turbine
was
44
ppb.
This
number
was
measured
using
EPA
Method
0011
and
a
bias
factor
was
applied
to
the
reported
results;
this
is
discussed
in
greater
detail
in
the
response
to
comment
V.
A.
1
and
in
memoranda
available
in
the
rulemaking
docket.
Only
one
test
was
available
for
this
turbine,
but
some
variability
as
has
been
shown
for
other
turbines
is
expected.
However,
since
formaldehyde
emissions
from
distillate
oil
fired
units
are
lower
on
average
by
a
factor
of
1.4,
EPA
does
not
believe
that
the
MACT
emission
limit
should
be
set
higher
than
the
emission
limit
for
new
stationary
DFC
gas­
fired
CTs.
The
MACT
Floor
for
new
DFC
oil­
fired
CTs
is
therefore
an
emission
limit
of
91
ppb.

The
EPA
examined
the
inventory
database
to
identify
any
operating
practices
which
could
affect
metal
emissions
and
was
unable
to
identify
any
such
practices.
The
EPA
also
determined
that
no
existing
DFC
CTs
firing
distillate
oil
are
equipped
with
emission
control
devices
for
the
reduction
of
PM
which
could
also
reduce
metal
emissions.
The
EPA
examined
the
inventory
database
in
an
attempt
to
identify
any
operating
practices
which
could
affect
metal
emissions,
however,
EPA
was
unable
to
identify
any
such
practices.

IV.
A.
3
Comment:
Twelve
commenters
(
420,
422,
426,
430,
431,
437,
443,
446,
476,
479,
502,
519)
expressed
support
for
EPA's
determination
that
MACT
for
existing
DFC
turbines
should
be
set
at
the
MACT
floor,
no
controls/
no
emission
reductions.

Response:
The
EPA
acknowledges
the
commenters'
support.
This
approach
has
been
preserved
in
the
final
rule.

IV.
A.
4
Comment:
Three
commenters
(
431,
440,
476)
stated
that
EPA
is
correct
in
determining
that
use
of
oxidation
catalyst
as
a
beyond
the
floor
MACT
is
cost
prohibitive
for
existing
DFC
units.
Commenter
440
also
said
that
EPA
correctly
concluded
that
fuel
switching
is
not
a
viable
beyond
the
floor
option
for
MACT.

Response:
The
commenters'
support
is
acknowledged.

IV.
A.
5
Comment:
One
commenter
(
472)
contended
that
the
MACT
Floor
for
existing
DFC
is
unlawful
because
EPA
did
not
identify
the
best
performing
sources
or
determined
the
emission
levels
they
are
achieving;
EPA
merely
considered
whether
or
not
they
are
equipped
with
a
catalyst.
The
commenter
stated
that
whether
or
not
the
relevant
best
sources
are
equipped
with
control
equipment,
they
are
achieving
some
emission
level,
and
EPA
must
determine
the
average
39
emission
level
they
are
achieving
and
set
floors
at
that
level.

Response:
The
EPA
agrees
with
the
commenter
that
all
factors
which
might
control
HAP
emissions
must
be
considered
in
making
a
floor
determination
for
each
subcategory,
and
that
this
analysis
cannot
be
properly
limited
to
add­
on
controls.
However,
EPA
disagrees
that
it
must
express
the
floor
as
a
quantitative
emission
level
in
those
instances
where
the
source
on
which
the
floor
determination
is
based
has
not
adopted
or
implemented
any
measure
that
would
reduce
emissions.
In
this
instance,
EPA
decided
to
subcategorize
within
diffusion
flame
combustion
turbines
based
on
the
fuel
which
is
used,
because
the
composition
of
HAP
emissions
differs
materially
based
on
whether
gas
or
oil
is
used.
The
EPA
then
determined
for
each
subcategory
of
diffusion
flame
combustion
turbines
that
emissions
of
each
HAP
are
relatively
homogenous
across
that
subcategory,
and
that
there
are
not
any
adjustments
of
the
turbines
or
other
operational
modifications
except
for
the
use
of
add­
on
controls
which
would
be
effective
in
reducing
HAP
emissions.
Since
the
source
on
which
the
floor
for
existing
sources
in
each
subcategory
of
diffusion
flame
turbines
is
based
has
not
installed
such
add­
on
controls,
EPA
determined
that
the
MACT
floor
for
each
such
subcategory
requires
no
emission
reductions.
The
EPA
has
also
established
fuel­
based
subcategories
within
lean
premix
combustion
turbines,
and
has
made
a
comparable
determination
that
the
MACT
floor
for
existing
sources
within
each
of
these
subcategories
requires
no
emission
reductions.

IV.
A.
6
Comment:
One
commenter
(
472)
said
that
the
MACT
Floor
for
new
DFC
is
unlawful
because
EPA
did
not
identify
the
best­
performing
DFC
CT
and
the
floor
does
not
reflect
what
that
source
achieved
in
practice.
According
to
the
commenter,
EPA
ignored
other
factors
that
affect
source's
performance
(
fuel,
design,
age,
maintenance,
operator
training,
skill
and
care,
differences
in
effectiveness
of
catalysts).
The
performance
of
all
sources
using
an
oxidation
catalyst
is
not
the
same
and
cannot
possibly
reflect
the
performance
of
the
single
best
source.

Response:
The
EPA
agrees
with
the
commenter
that
the
standard
for
new
sources
within
each
subcategory
must
be
based
on
the
emission
levels
achieved
in
practice
by
the
best
controlled
similar
source.
However,
EPA
thinks
that
the
performance
in
reducing
emissions
by
the
best
controlled
source
will
not
be
uniform,
and
that
it
would
be
inappropriate
to
establish
a
standard
which
could
not
be
consistently
met
even
by
the
source
upon
which
the
standard
is
based.
The
EPA
therefore
believes
that
there
must
be
some
allowance
made
for
the
intrinsic
variability
in
the
effectiveness
of
controls
in
the
standard
EPA
establishes.
The
EPA
does
not
think
that
the
performance
of
oxidation
catalysts
differs
as
much
from
one
turbine
to
the
next
as
suggested
by
the
commenter,
and
EPA
believes
that
the
emission
control
levels
achieved
in
practice
by
catalysts
on
differing
turbines
is
one
factor
EPA
may
appropriately
consider
in
evaluating
the
variability
in
emission
control
levels
which
is
intrinsic
to
catalyst
operation.

IV.
A.
7
Comment:
One
commenter
(
472)
remarked
that
EPA
did
not
say
what
the
cost
per
ton
would
be
for
beyond
the
floor
standards
or
why
it
is
viewed
as
excessive.
Therefore,
EPA's
rejection
of
beyond
the
floor
standards
is
arbitrary
and
capricious.
40
Response:
Information
on
the
cost
of
oxidation
catalyst
control
per
ton
of
HAP
removed
is
available
from
the
docket
for
this
rulemaking.
This
information
is
in
a
memorandum
that
can
be
obtained
from
the
EPA's
Edocket
website.
The
Edocket
Document
ID
for
the
memorandum
is
OAR­
2002­
0060­
0044
(
A­
95­
51
II­
B­
30).

IV.
A.
8
Comment:
One
commenter
(
472)
observed
that
EPA
stated
that
it
considered
fuel
switching
but
could
not
find
a
less
HAP
emitting
fuel.
The
EPA's
own
data
show
that
CTs
burning
fuel
oil
have
higher
benzene
and
xylene
emissions
than
CTs
firing
natural
gas
or
landfill
gas.
Had
EPA
tested
other
HAPs,
it
would
likely
have
found
that
fuel
oil
produces
higher
levels
of
those
HAPs
as
well.
The
EPA
has
already
found
the
entire
diesel
exhaust
stream
to
be
hazardous.

Response:
The
EPA
agrees
with
the
commenter
that
the
composition
of
HAP
emissions
are
different
for
CTs
firing
natural
gas
and
CTs
firing
oil.
The
EPA
has
evaluated
both
the
data
it
had
prior
to
proposal
and
the
data
received
since
proposal;
the
test
data
supports
the
conclusion
that
HAP
emissions
are
different
for
different
fuels
for
stationary
DFC
units.
Uncontrolled
formaldehyde
emissions
are
in
general
lower
as
a
result
of
the
combustion
of
distillate
oil
than
for
natural
gas.
Other
differences
in
emissions
between
natural
gas
and
distillate
oil
include
higher
levels
of
pollutants
such
as
PAH
and
metals
for
stationary
CTs
burning
distillate
oil.

The
EPA
proposed
one
subcategory
for
combustion
turbines
using
lean
premix
technology
and
another
subcategory
for
combustion
turbines
using
diffusion
flame
technology.
However,
in
recognition
of
the
clear
differences
EPA
found
in
the
composition
of
HAP
emissions
depending
on
the
fuel
that
is
used,
EPA
has
determined
that
it
is
appropriate
to
subcategorize
further
based
on
fuel
use.
In
devising
appropriate
subcategories
based
on
fuel
use,
EPA
needs
to
consider
that
many
combustion
turbines
are
configured
both
to
use
natural
gas
and
distillate
oil.
These
dual
fuel
units
typically
burn
natural
gas
as
their
primary
fuel,
and
only
utilize
distillate
oil
as
a
backup.
To
limit
the
frequency
of
switching
between
subcategories
caused
by
limited
usage
of
a
backup
fuel,
EPA
has
defined
the
gas
subcategories
in
a
manner
which
permits
combustion
turbines
that
fire
gas
to
remain
in
the
gas
subcategory
if
all
turbines
at
the
site
in
question
fire
oil
no
more
than
a
total
of
1000
hours
during
the
calendar
year.
The
following
subcategories
have
therefore
been
established:

°
Lean
Premix
Gas­
Fired
Turbines.
This
subcategory
includes
(
a)
each
stationary
combustion
turbine
which
is
equipped
only
to
fire
gas
using
lean
premix
technology,
(
b)
each
stationary
combustion
turbine
which
is
equipped
both
to
fire
gas
using
lean
premix
technology
and
to
fire
oil,
during
any
period
when
it
is
firing
gas,
and
(
c)
each
stationary
combustion
turbine
which
is
equipped
both
to
fire
gas
using
lean
premix
technology
and
to
fire
oil,
and
is
located
at
a
major
source
where
all
stationary
combustion
turbines
fire
oil
no
more
than
an
aggregate
total
of
1000
hours
during
the
calendar
year.

°
Lean
Premix
Oil­
Fired
Turbines.
This
subcategory
includes
(
a)
each
stationary
combustion
turbine
which
is
equipped
only
to
fire
oil
using
lean
premix
technology,
and
41
(
b)
each
stationary
combustion
turbine
which
is
equipped
both
to
fire
oil
using
lean
premix
technology
and
to
fire
gas,
and
is
located
at
a
major
source
where
all
stationary
combustion
turbines
fire
oil
more
than
an
aggregate
total
of
1000
during
the
calendar
year,
during
any
period
when
it
is
firing
oil.

°
Diffusion
Flame
Gas­
Fired
Turbines.
This
subcategory
includes
(
a)
each
stationary
combustion
turbine
which
is
equipped
only
to
fire
gas
using
diffusion
flame
technology,
(
b)
each
stationary
combustion
turbine
which
is
equipped
both
to
fire
gas
using
diffusion
flame
technology
and
to
fire
oil,
during
any
period
when
it
is
firing
gas,
and
(
c)
each
stationary
combustion
turbine
which
is
equipped
both
to
fire
gas
using
diffusion
flame
technology
and
to
fire
oil,
and
is
located
at
a
major
source
where
all
stationary
combustion
turbines
fire
oil
no
more
than
an
aggregate
total
of
1000
hours
during
the
calendar
year.

°
Diffusion
Flame
Oil­
Fired
Turbines.
This
subcategory
includes
(
a)
each
stationary
combustion
turbine
which
is
equipped
only
to
fire
oil
using
diffusion
flame
technology,
and
(
b)
each
stationary
combustion
turbine
which
is
equipped
both
to
fire
oil
using
diffusion
flame
technology
and
to
fire
gas,
and
is
located
at
a
major
source
where
all
stationary
combustion
turbines
fire
oil
more
than
an
aggregate
total
of
1000
hours
during
the
calendar
year,
during
any
period
when
it
is
firing
oil.

The
EPA
expects
that
the
majority
of
distillate
oil
burned
in
stationary
combustion
turbines
will
be
fuel
oil
number
2.
The
EPA
recognizes
that
stationary
combustion
turbine
owners
and
operators
may
burn
different
varieties
of
distillate
oil,
however
it
is
believed
that
any
other
distillate
oil
combusted
will
be
of
similar
quality
and
composition
to
fuel
oil
number
2.
The
EPA
does
not
anticipate
that
owners
and
operators
will
burn
any
other
liquid
based
fuel
that
is
more
contaminated
with
metals
than
fuel
oil
number
2
and
expects
that
most
available
liquid
fuels
that
may
be
used
in
stationary
combustion
turbines
will
be
similar
and
fairly
consistent.

B.
MACT
Floor
and
MACT
for
Lean
Premix
Units
IV.
B.
1
Comment:
Several
commenters
took
issue
with
the
methodology
and
data
used
to
set
the
MACT
Floor
for
LPC
units.
Two
commenters
(
427,
460)
contended
that
EPA's
determination
of
the
floor
for
existing
LPC
is
fundamentally
flawed.
Reliance
on
a
single
data
point
and
the
assumptions
made
to
compensate
for
the
inherent
error
and
variability
are
arbitrary
and
capricious,
therefore
EPA
must
obtain
additional
information
before
it
can
set
a
floor.

Two
commenters
(
430,
440)
stated
that
data
from
all
five
CTs
should
be
used
to
set
the
MACT
floor
for
existing
LPC
turbines.
Commenter
440
determined
that
the
formaldehyde
limit
should
be
219
ppb
(
this
option
is
recommended
only
if
EPA
declines
to
set
the
floor
as
no
emission
reduction).

Six
commenters
(
424,
431,
484,
485,
488,
501)
remarked
that
the
MACT
floor
for
new
and
existing
LPC
turbines
does
not
reflect
a
reasonable
estimate
of
formaldehyde
emissions
42
achieved
in
practice
by
the
best­
performing
source;
EPA
should
adjust
the
MACT
floor
to
reflect
formaldehyde
emissions
reasonably
expected
over
the
operating
range
of
the
best­
performing
LPC
turbine.
One
commenter
(
519)
observed
that
EPA's
use
of
the
performance
test
of
one
"
best"
LPC
unit
is
not
statistically
viable
and
does
not
meet
the
statutory
requirement
for
setting
the
MACT
floor.

Two
commenters
(
437,
502)
said
that
EPA's
emission
standard
for
LPC
CTs
is
unlawful
and
EPA
should
establish
a
"
no
control"
emission
limitation.
The
EPA
did
not
determine
that
the
best
performers
in
the
subcategory
were
"
controlling"
their
emissions
in
a
duplicable
manner.
The
EPA
improperly
set
the
floor
for
the
existing
LPC
subcategory;
EPA
based
the
floor
on
the
performance
of
the
best
source
for
which
it
had
data,
instead
of
basing
it
on
the
average
emission
limitation
of
the
5
sources
for
which
it
had
data.
Also,
EPA
has
not
considered
all
of
the
variability
that
either
the
best
performers
will
experience
or
that
will
affect
the
attainability
of
emissions.
The
EPA
should
consider
the
normal
turbine
variations
based
on
time,
fuel,
location,
and
weather.
The
EPA
should
also
consider
the
repeatability
of
testing
and
monitoring
methods.
It
is
improper
to
set
an
emission
standard
based
on
the
testing
of
one
unit
when
there
is
no
acceptable
test
method
to
assure
that
the
existing
test
data
is
reasonable
and
that
it
may
not
be
possible
to
demonstrate
compliance.

Response:
As
discussed
in
the
response
to
comment
IV.
A.
2,
EPA
had
limited
emissions
data
at
proposal
for
stationary
combustion
turbines.
The
EPA
had
five
tests
for
formaldehyde
emissions
for
LPC
CTs,
none
of
which
were
on
LPC
units
with
add­
on
HAP
emission
control.
As
a
result
of
EPA's
request
for
HAP
emissions
test
data
in
the
proposal,
EPA
received
new
emissions
data
for
LPC
turbines
during
the
comment
period,
including
two
formaldehyde
tests
on
a
LPC
unit
equipped
with
add­
on
HAP
emissions
control.
The
new
data
also
include
several
tests
conducted
using
FTIR,
which
is
regarded
as
the
most
accurate
measurement
method
for
formaldehyde
for
stationary
CTs.
Thus,
the
data
set
has
been
significantly
improved,
both
quantitatively
and
qualitatively,
and
EPA
believes
that
the
data
set
is
sufficient
to
identify
the
bestperforming
unit.

Also,
as
discussed
in
the
response
to
comment
IV.
A.
2,
the
EPA
decided
that
it
is
appropriate
to
subcategorize
based
on
fuel
within
the
subcategories
for
DFC
and
LPC
CTs.

As
a
result
of
comments
and
the
new
data
submitted
post­
proposal,
EPA
reevaluated
the
MACT
Floor
for
both
existing
and
new
LPC
gas­
fired
units
and
existing
and
new
LPC
oil­
fired
units.
For
existing
units
in
both
fuel
subcategories,
it
was
determined
that
the
average
of
the
best
performing
12
percent
of
existing
units
is
no
HAP
emission
reduction.
To
determine
the
MACT
Floor
for
new
LPC
gas­
fired
units,
the
performance
of
the
best
turbine
for
which
EPA
has
emissions
information
for
was
selected.
The
best
performing
turbine
is
equipped
with
an
oxidation
catalyst
and
was
tested
twice,
separated
by
a
period
of
2
years,
under
the
same
conditions.
The
formaldehyde
was
measured
to
be
19
ppb
and
91
ppb
during
the
testing.
These
tests
were
conducted
using
CARB
430
and
a
bias
factor
was
applied
to
the
reported
results;
this
is
discussed
in
greater
detail
in
the
response
to
comment
V.
A.
1
and
in
memoranda
available
in
the
43
rulemaking
docket.
The
MACT
Floor
was
set
at
the
higher
measurement
of
91
ppb
to
account
for
the
variability
of
the
best
performing
unit.

For
new
LPC
oil­
fired
units,
EPA
does
not
have
any
formaldehyde
emissions
data.
However,
it
is
expected
that
the
level
of
control
achieved
by
the
application
of
oxidation
catalyst
control
to
LPC
gas­
fired
units
would
be
equivalent
to
the
level
of
control
achieved
by
applying
an
oxidation
catalyst
to
a
LPC
oil­
fired
unit.
Based
on
data
that
show
that
for
DFC
units,
formaldehyde
emissions
are
lower
for
distillate
oil,
it
is
also
expected
that
the
formaldehyde
emissions
from
LPC
oil­
fired
units
would
be
equal
to
or
less
than
the
formaldehyde
emissions
from
LPC
gas­
fired
units.
As
a
result,
the
MACT
Floor
for
new
LPC
oil­
fired
CTs
is
the
same
as
the
MACT
Floor
for
new
LPC
gas­
fired
CTs,
a
formaldehyde
emission
limitation
of
91
ppb.

The
EPA
examined
the
inventory
database
to
identify
any
operating
practices
which
could
affect
metal
emissions
and
was
unable
to
identify
any
such
practices.
The
EPA
also
referred
to
the
inventory
database
to
determine
if
any
existing
lean
premix
stationary
combustion
turbines
firing
distillate
oil
were
equipped
with
emission
controls
for
the
reduction
of
PM
which
would
also
reduce
metal
emissions.
No
such
units
were
found
in
the
inventory
database
and
none
were
identified
by
commenters
during
the
public
comment
period.

IV.
B.
2
Comment:
Three
commenters
(
422,
440,
479)
believed
that
the
MACT
floor
for
existing
LPC
units
should
be
no
emissions
reductions,
while
one
commenter
(
427)
said
that
existing
LPC
units
should
be
exempted
from
the
standard.

Response:
The
EPA
agrees
with
the
commenters
that
the
MACT
floor
for
existing
LPC
units
should
be
no
emissions
reductions.
The
EPA
does
not
agree
that
existing
LPC
units
should
be
exempted
from
the
standard
but
notes
that
these
units
have
no
emission
limitations
or
operating
limitations
in
the
final
rule.

IV.
B.
3
Comment:
One
commenter
(
426)
observed
that
EPA
did
not
undertake
any
MACT
floor
analysis
for
existing
LPC
CTs
related
to
the
use
of
oxidation
catalysts.
The
commenter
said
that
EPA
should
determine
the
MACT
floor,
and
it
should
not
be
95
percent
reduction
because
the
level
of
control
achieved
by
the
average
of
the
best
performing
12
percent
of
existing
sources
would
be
significantly
less
than
95
percent.

Response:
For
existing
sources,
EPA
is
required
to
set
the
MACT
floor
at
the
emission
level
achieved
by
the
average
of
the
best
performing
12
percent
of
existing
sources.
As
discussed
in
the
response
to
comment
IV.
B.
1,
EPA
has
re­
analyzed
its
data
set
and
determined
that
the
MACT
floor
for
existing
gas­
fired
and
oil­
fired
LPC
units
is
no
emission
reduction.

IV.
B.
4
Comment:
One
commenter
(
424)
asserted
that
the
low
concentrations
of
formaldehyde
used
to
set
the
MACT
floor
are
suspect
and
should
have
been
observed
on
more
than
five
representative
turbines.
Detection
levels
for
measurement
methods
are
closer
to
100
ppb.
44
Response:
The
EPA
does
not
agree
with
the
commenter.
After
proposal
of
the
CT
NESHAP,
EPA
received
additional
source
test
reports
that
included
testing
of
formaldehyde
emissions
from
LPC
CTs.
These
tests
showed
that
the
measurement
methods
are
capable
of
detecting
levels
of
formaldehyde
lower
than
100
ppb.
The
EPA
consulted
with
several
experts
in
the
measurement
of
formaldehyde
using
FTIR
and
they
indicated
that
detection
levels
of
as
low
as
10
ppb
were
possible.
This
is
discussed
in
much
more
detail
in
the
response
to
comment
VII.
A.
2.1.

IV.
B.
5
Comment:
One
commenter
(
472)
said
that
the
MACT
Floor
for
existing
LPC
CTs
is
unlawful.
The
floor
(
formaldehyde)
is
at
a
level
far
worse
than
the
emission
levels
achieved
by
the
best
source.
The
95
percent
reduction
standard
is
unlawful
because
it
does
not
even
purport
to
reflect
the
actual
emission
levels
achieved
by
the
relevant
best
sources.
Also
CO
is
not
a
valid
surrogate.

Response:
As
discussed
in
the
response
to
comment
IV.
B.
1,
EPA
reevaluated
the
MACT
Floor
for
existing
gas­
fired
and
oil­
fired
LPC
units
as
a
result
of
comments
and
the
new
data
submitted
post­
proposal.
The
EPA
does
not
agree
that
CO
reduction
is
not
a
valid
surrogate
for
HAP
reduction.
As
stated
in
the
response
to
comment
VI.
A.
1,
the
alternative
CO
emission
limitation
has
been
removed
from
the
final
rule
due
to
CO
measurement
difficulties.
Thus,
the
commenters'
concerns
are
moot.
The
EPA
has
determined
that
formaldehyde
is
an
appropriate
and
valid
surrogate
for
each
of
the
organic
HAP
that
can
be
controlled
by
a
catalyst,
and
that
the
standard
for
such
organic
HAP
can
be
reasonably
expressed
in
terms
of
formaldehyde
emissions
measured
after
exiting
any
control
device.

IV.
B.
6
Comment:
One
commenter
(
472)
stated
that
the
MACT
Floor
for
new
LPC
units
does
not
reflect
the
actual
performance
of
the
single
best
source
and
is
therefore
unlawful,
arbitrary,
and
capricious.

Response:
As
explained
in
the
response
to
comment
IV.
A.
6,
EPA
believes
that
it
must
accommodate
intrinsic
variability
in
performance
when
setting
a
standard
which
is
based
on
the
performance
of
the
best
controlled
similar
source.
It
would
make
no
sense
to
adopt
a
standard
based
on
the
best
controlled
source
which
could
not
be
consistently
met
even
by
that
source.

IV.
B.
7
Comment:
One
commenter
(
504)
recommended
that
the
standard
for
LPC
CTs
should
be
technology
based:
the
use
of
lean
premix
combustion.

Response:
The
EPA
thinks
it
is
inappropriate
to
base
the
standard
for
a
subcategory
on
a
characteristic
which
is
intrinsic
to
all
sources
in
that
subcategory.
Rather,
EPA
must
consider
additional
characteristics
of
the
sources
within
the
subcategory
which
would
be
associated
with
reduced
HAP
emissions.
In
this
instance,
for
each
of
the
fuel
specific
subcategories
within
lean
premix
turbines,
EPA
has
determined
that
the
only
measure
which
would
materially
reduce
HAP
emissions
is
the
installation
of
an
oxidation
catalyst.
This
technology
is
not
utilized
by
the
average
source
for
the
existing
source
MACT
floor
determination,
but
it
is
utilized
by
the
best
controlled
45
similar
source.
Even
if
EPA
was
to
determine
that
the
use
of
lean
premix
technology
alone
was
a
valid
basis
for
a
standard,
the
standard
must
still
be
expressed
in
quantitative
terms
(
as
a
percentage
of
control
or
a
level
of
emissions)
rather
than
as
a
type
of
technology,
unless
EPA
makes
the
determination
required
for
a
design,
equipment,
work
practice,
or
operational
standard
under
CAA
section
112(
h).

IV.
B.
8
Comment:
One
commenter
(
472)
remarked
that
for
MACT,
EPA's
rejection
of
potential
control
technologies
that
might
be
applied,
including
wet
scrubbers,
dry
scrubbers,
and
activated
carbon,
without
even
considering
them
is
arbitrary,
capricious,
and
unlawful.
The
EPA's
argument
that
a
greater
degree
of
reduction
could
not
be
achieved
through
the
use
of
clean
fuels
is
unlawful,
arbitrary,
and
capricious.

Response:
The
EPA
agrees
with
the
commenter
that
the
effect
of
the
choice
of
natural
gas
or
fuel
oil
on
the
composition
of
HAP
emissions
is
significant,
and
EPA
has
therefore
subcategorized
further
within
both
lean
premix
and
diffusion
flame
turbines
based
on
which
of
these
fuels
is
used.
The
EPA
is
not
aware
of
any
data
indicating
that
HAP
emissions
could
be
consistently
reduced
by
selection
of
particular
clean
fuels
within
these
general
fuel
groups.
As
for
the
other
novel
emission
control
technologies
to
which
the
commenter
refers,
EPA
does
not
believe
that
these
technologies
are
in
use
on
any
combustion
turbine
and
EPA
does
not
consider
any
sources
utilizing
such
controls
to
be
similar
sources.
Moreover,
EPA
is
unable
based
on
available
information
to
determine
that
these
technologies
would
be
both
efficacious
and
cost
effective
in
reducing
HAP
emissions
from
combustion
turbines.

IV.
B.
9
Comment:
One
commenter
(
440)
expressed
the
view
that
EPA's
decision
not
to
set
"
beyond­
the­
floor"
emission
limitations
is
permissible.

Response:
The
EPA
agrees
with
the
commenter
that
its
decision
not
to
set
"
beyond­
thefloor
emission
limitations
is
permissible.

C.
MACT
Floor
and
MACT
for
Other
Subcategories
IV.
C.
1
Comment:
One
commenter
(
472)
remarked
that
for
existing
emergency,
limited
use,
landfill
or
digester
gas
fired,
and
less
than
1
MW
units,
EPA
did
not
set
a
floor
that
reflects
the
emission
levels
that
the
best
performing
sources
actually
achieved.
The
EPA
has
not
identified
the
relevant
best
performing
sources
and
has
not
determined
the
average
emission
limitation
achieved
by
such
sources,
therefore
EPA's
floors
for
these
sources
is
unlawful.

Response:
As
noted
in
the
response
to
comment
I.
C.
1.1,
EPA
has
not
decided
to
establish
a
limited
use
subcategory.
For
the
emergency,
landfill
or
digester
gas
fired,
and
less
than
1
MW
subcategories,
EPA
has
not
identified
any
adjustments
or
other
operational
modifications
that
would
materially
reduce
emissions
by
these
units
and
EPA
has
determined
that
no
add­
on
controls
are
presently
in
use.
In
these
circumstances,
EPA
believes
that
it
has
appropriately
established
the
floors
for
these
sources
as
no
emission
reduction.
46
IV.
C.
2
Comment:
One
commenter
(
472)
said
that
for
new
emergency,
limited
use,
landfill
or
digester
gas
fired,
and
less
than
1
MW
units,
the
floor
is
unlawful
because
EPA
did
not
identify
the
single
best
controlled
source
in
any
of
these
subcategories
and
did
not
set
floors
reflecting
such
source's
actual
performance.
The
floors
are
arbitrary
and
capricious
because
EPA
did
not
explain
how
its
"
no
emissions
reductions"
floor
satisfies
the
CAA.

Response:
As
noted
in
the
response
to
comment
I.
C.
1.1,
EPA
has
not
decided
to
establish
a
limited
use
subcategory.
For
the
emergency,
landfill
or
digester
gas
fired,
and
less
than
1
MW
subcategories,
EPA
has
not
identified
any
adjustments
or
operational
modifications
that
would
materially
reduce
emissions
by
these
units
and
EPA
has
determined
that
no
add­
on
controls
are
presently
in
use.
The
EPA
also
has
determined
because
of
the
specific
characteristics
of
turbines
in
these
subcategories
that
the
turbines
in
other
subcategories
that
utilize
add­
on
controls
are
not
similar
sources.
In
these
circumstances,
EPA
believes
that
it
has
appropriately
determined
that
the
new
source
MACT
floor
for
these
subcategories
should
also
be
no
emission
reduction.

IV.
C.
3
Comment:
One
commenter
(
472)
contended
that
EPA's
rejection
of
beyond
the
floor
standards
for
new
emergency,
limited
use,
landfill
or
digester
gas
fired,
and
less
than
1
MW
units
is
arbitrary
and
capricious.
The
EPA
does
not
state
the
cost
of
applying
any
control
technology
or
indicate
the
quantity
of
the
HAPs
that
would
be
reduced.

Response:
The
EPA
believes
that
the
record
includes
analysis
demonstrating
that
it
is
not
cost
effective
to
require
HAP
controls
for
turbines
in
instances
where
no
similar
source
has
installed
such
controls.

IV.
C.
4
Comment:
One
commenter
(
440)
noted
that
for
emergency
and
limited
use
units,
the
determination
that
MACT
floor
is
no
emission
reduction
is
lawful
because
EPA
determined
that
the
best­
performing
source
were
not
achieving
emissions
reduction
through
the
use
of
an
emission
control
system
and
there
were
no
other
methods
by
which
CTs
could
reduce
HAP
emissions.

Response:
The
commenter's
support
is
acknowledged
by
EPA.

IV.
C.
5
Comment:
One
commenter
(
440)
said
that
EPA's
decision
not
to
set
"
beyondthe
floor"
emission
limitations
is
permissible
for
stationary
CTs
combusting
digester
or
landfill
gas.

Response:
The
commenter's
support
is
acknowledged
by
EPA.

D.
Other
IV.
D.
1
Comment:
One
commenter
(
421)
urged
EPA
not
to
impose
limits
and/
or
controls
on
existing
or
new
stationary
gas
CTs
if
EPA
does
not
delist
them.
47
Response:
The
commenter
did
not
give
any
rationale
for
this
suggestion.
The
EPA
is
required
by
the
CAA
to
set
MACT
standards
for
these
units.

IV.
D.
2
Comment:
One
commenter
(
472)
said
that
EPA's
proposal
is
unlawful
because
EPA
must
set
standards
for
each
listed
HAP.
Oxidation
catalyst
control
devices
do
not
control
many
of
the
HAPs
that
CT
emit,
for
example
metals.

Response:
The
EPA
does
not
agree
that
it
is
required
to
establish
a
discrete
standard
for
each
listed
HAP.
However,
EPA
does
agree
that
each
listed
HAP
must
be
separately
considered
by
EPA,
both
in
determining
the
MACT
floors
and
in
establishing
the
emission
standards
for
each
subcategory.
If
emissions
of
a
particular
HAP
are
relatively
homogenous
for
a
particular
subcategory,
and
there
are
no
adjustments
or
operational
modifications
except
for
add­
on
controls
which
would
reduce
emissions
of
that
HAP,
the
MACT
floor
and
the
emission
standard
for
that
HAP
may
be
expressed
as
a
level
of
emission
reduction
corresponding
to
the
efficacy
of
add­
on
controls.
Moreover,
if
the
data
demonstrate
that
control
of
emissions
of
a
particular
HAP
is
a
suitable
surrogate
for
control
of
emissions
of
a
group
of
listed
HAP,
EPA
may
appropriately
set
the
standard
in
terms
of
a
level
of
emission
reduction
or
an
emission
level
for
that
particular
HAP.

In
establishing
new
source
standards
for
certain
subcategories,
EPA
determined
that
formaldehyde
is
an
appropriate
surrogate
for
the
other
organic
HAP
which
are
also
controlled
by
an
oxidation
catalyst.
While
use
of
an
oxidation
catalyst
does
not
control
the
metallic
HAP
which
are
emitted
by
turbines
burning
distillate
oil,
there
are
no
combustion
turbines
or
similar
sources
utilizing
other
technologies
to
control
metallic
HAP.
Moreover,
EPA
does
not
believe
it
would
be
practical
or
cost
effective
to
require
control
of
these
metallic
HAP,
and
therefore
the
floor
and
the
standard
for
each
metallic
HAP
was
appropriately
set
at
no
emission
reduction.

IV.
D.
3
Comment:
One
commenter
(
502)
stated
that
EPA
should
interpret
National
Lime
II
as
requiring
it
to
set
emission
standards
only
for
those
HAPs
emitted,
or
at
most,
reasonably
expected
to
be
emitted
by
units
in
the
source
category.

Response:
The
EPA
agrees
with
the
commenter.

IV.
D.
4
Comment:
One
commenter
(
472)
noted
that
EPA's
floors
must
reflect
the
average
emission
levels
achieved
by
the
relevant
best
sources.
Thus,
even
if
some
of
the
relevant
best
sources
are
not
using
any
control
device,
the
agency
must
average
their
performance
with
that
of
the
relevant
best
sources
that
are
using
a
control
device.
That
some
of
the
relevant
best
performers
are
not
using
an
end­
of­
stack
control
technology
does
not
allow
EPA
to
discount
the
performance
of
other
best
performers
that
are
using
such
technology.

Response:
The
EPA
does
not
agree
with
the
premise
of
this
commenter
that
the
existing
source
MACT
floor
(
the
average
emission
limitation
achieved
by
the
best
performing
12
percent
of
existing
sources
or
the
best
performing
5
existing
sources
in
subcategories
with
fewer
than
30
sources)
must
be
calculated
by
determining
the
arithmetic
average
of
the
emission
limitations
48
achieved
individually
by
each
of
these
sources.
The
EPA
has
consistently
construed
the
statute
to
permit
EPA
to
determine
the
average
emission
limitation
by
selecting
the
median
facility
among
the
best
performing
12
percent
or
5
existing
sources.
The
EPA
thinks
this
well­
established
construction
of
the
statute
is
reasonable,
because
an
arithmetic
average
will
quite
often
not
coincide
with
the
level
of
emission
reduction
that
has
been
achieved
in
practice
by
any
real
facility.
The
EPA
does
not
think
it
is
appropriate
to
establish
an
existing
source
MACT
floor
which
may
not
be
achievable
by
most
of
the
sources
from
which
it
was
derived.
Nor
does
EPA
think
it
is
required
to
set
a
standard
which
is
less
stringent
than
most
of
the
sources
from
which
it
is
derived
are
achieving.
Use
of
the
emission
limitation
achieved
by
the
median
facility
avoids
these
problems.

IV.
D.
5
Comment:
One
commenter
(
502)
expressed
the
view
that
EPA
is
on
firm
ground
controlling
and
measuring
a
surrogate
for
HAPs
as
long
as
it
can
show
the
barest
of
correlation.
The
EPA
can
require
direct
control
and
measurement
of
a
HAP
or
use
surrogate
control.

Response:
The
commenter's
support
is
acknowledged
by
EPA.

IV.
D.
6
Comment:
One
commenter
(
502)
had
the
opinion
that
EPA
still
retains
the
authority
to
discover
what
the
best
performers
achieve
and
how
they
achieve
it
as
part
of
their
floor
analysis.
If
that
methodology
is
reproducible
by
others,
then
it
is
a
legitimate
basis
for
the
MACT
floor
standards.
The
EPA
is
not
required
to
use
an
"
emissions­
based"
approach.

Response:
The
commenter's
support
is
acknowledged
by
EPA.

IV.
D.
7
Comment:
One
commenter
(
502)
noted
that
EPA
has
the
authority
to
determine
that
the
floor
is
no
control.
Section
112(
d)
requires
EPA
to
discover
what
the
best
performers
achieve
and
how
they
achieve
it
as
part
of
their
floor
analysis.
If
the
methodology
is
not
reproducible
by
others
then
the
emissions
achieved
by
the
least
HAP
emitting
source
is
subject
to
the
same
variability
as
any
other
source
in
the
category.
Consequently
there
is
no
activity
that
the
"
best
performers"
are
conducting
that
can
be
duplicated
by
the
other
"
lesser"
performers
in
the
category
to
achieve
a
specified
limit.
Therefore
a
floor
based
on
what
the
best
performers
achieve
is
impossible
to
set,
and
a
"
no
control"
floor
is
appropriate.

Response:
The
commenter's
support
is
acknowledged
by
EPA.

IV.
D.
8
Comment:
One
commenter
(
502)
observed
that
in
the
CKRC
case,
the
court
did
not
address
EPA's
duty
to
consider
reproducibility
by
others
in
the
source
category.
If
another
source
is
physically
unable
to
replicate
what
the
best
performers
do,
EPA
could
consider
the
floor
determination
inapplicable
because
it
is
not
representative
of
that
category
and
therefore
not
a
"
similar
source."

Response:
The
EPA
agrees
with
the
commenter.
49
IV.
D.
9
Comment:
One
commenter
(
502)
stated
that
EPA
can
establish
the
MACT
floor
based
on
work
practice
standards.

Response:
The
EPA
agrees
that
work
practice
standards
can
be
established,
but
is
usually
only
done
when
it
is
not
possible
to
set
an
emission
limitation,
which
is
not
the
case
for
this
rule.

V.
EMISSION
LIMITATIONS
A.
Formaldehyde
V.
A.
1
Comment:
Twenty­
three
commenters
(
418,
421,
422,
424,
425,
426,
427,
430,
431,
435,
436,
437,
442,
443,
449,
460,
475,
479,
482,
505,
508,
509,
519)
took
issue
with
the
data
used
to
set
the
formaldehyde
emission
limitation.
The
commenters
noted
that
the
test
reports
used
to
set
the
limit
used
two
different
test
methods
and
that
the
limit
was
based
on
only
five
data
points
and
therefore
does
not
reflect
a
level
of
performance
that
is
achievable
for
all
sources.
Commenter
443
said
that
EPA
has
not
provided
enough
data
to
know
definitively
what
the
standard
should
be.
Commenter
460
stated
that
EPA
must
obtain
additional
information
before
it
can
set
a
floor.

The
commenters
also
had
concerns
about
possible
errors
in
the
test
reports
that
are
the
source
of
the
emissions
data
used
to
set
the
formaldehyde
emission
limitation.
Commenter
437
said
that
close
examination
of
the
five
reports
uncovers
questions
regarding
the
actual
test
procedures,
comparability,
data
reduction
and
data
reporting
that
should
be
revisited
before
finalizing
the
formaldehyde
concentration
limit.
All
five
reports
appear
to
have
calculation
errors
and/
or
other
data
quality
issues
that
significantly
affect
the
reported
formaldehyde
concentration,
the
comparability
of
the
results
because
different
test
methods
were
used,
and/
or
uncertainty
associated
with
the
average
result.
Commenter
449
also
reviewed
the
five
tests
used
to
set
the
standard
and
found
that
all
of
the
five
tests
used
do
not
present
valid
quantitative
results;
therefore,
data
from
these
tests
may
not
be
used
to
establish
a
quantitative
emission
standard
for
formaldehyde
emissions
from
LPC
CTs.

One
commenter
(
430)
said
that
CARB
430
may
report
anomalously
low
formaldehyde
emissions;
therefore,
the
standard
may
be
too
stringent
and
unachievable
in
practice.
Two
commenters
(
435,
460)
questioned
whether
the
CARB
430
data
used
to
develop
the
standard
followed
CARB
method
requirements.
One
commenter
(
437)
believed
that
the
results
from
all
tests
used
to
determine
the
MACT
floor
should
be
recalculated
using
CARB
430
procedures
so
the
data
can
be
justifiably
compared.
The
results
should
also
be
recalculated
using
the
American
Society
of
Mechanical
Engineers
measurement
uncertainty
analysis
procedure.
The
EPA
should
then
use
these
results
for
establishing
the
formaldehyde
concentration
limit.
The
commenter
estimated
that
an
enforceable
formaldehyde
concentration
limit
should
be
in
the
range
of
approximately
100
to
500
ppb.
50
One
commenter
(
449)
said
that
a
single
emission
test
does
not
fully
reflect
the
variability
that
will
be
seen
by
the
best
performing
source
employing
any
technology.
The
EPA
should
properly
assess
variability
that
may
be
experienced
by
the
best
performing
sources
under
the
worst
foreseeable
conditions
that
are
expected
to
recur.
Emission
testing
conducted
by
the
commenter
in
conjunction
with
the
Gas
Turbine
Institute
indicates
that
43
ppb
is
not
achievable
for
small
industrial
and
aeroderivative
turbines.
This
is
also
demonstrated
by
emission
testing
that
the
Wyoming
Department
of
Environmental
Quality
intends
to
submit
to
EPA.
The
commenter
also
contended
that
pooling
the
emissions
data
for
large
General
Electric
LPC
units
with
emission
data
for
small
industrial
and
aeroderivative
turbines
fails
to
recognize
the
inherent
technical
differences
between
these
two
classes
of
LPC
CTs.
The
EPA
should
consider
a
MACT
floor
analysis
for
small
units
based
on
emission
test
data
that
properly
represents
the
best
performing
sources
within
that
subcategory.
Preliminary
analysis
for
small
industrial/
aeroderivative
units
demonstrates
that
emissions
from
70
­
500
ppb
have
been
reported.

Several
commenters
suggested
a
revised
level
for
the
emission
limitation.
One
commenter
(
479)
said
that
EPA
must
revise
the
limit
upward
to
at
least
63
ppb.
Two
commenters
(
443,
475)
stated
that
additional
formaldehyde
data
suggests
that
EPA
should
consider
setting
the
emission
standard
to
90
ppbvd
given
the
tremendous
variability
in
the
few
measurements
that
are
available.
One
commenter
(
505)
submitted
a
summary
table
of
data
for
nine
tests
conducted
on
LPC
CTs;
the
test
results
show
a
variability
between
high
and
low
loads
of
34
percent,
also
six
out
of
nine
tests
were
above
43
ppb.

One
commenter
(
421)
said
that
EPA
should
consider
postponing
promulgation
until
issues
related
to
the
data
quality
are
fully
resolved.

Response:
As
stated
in
the
response
to
comment
IV.
A.
2,
EPA
had
limited
emissions
data
for
stationary
combustion
turbines
at
proposal.
Due
to
the
limited
amount
of
emissions
data
EPA
had
at
proposal,
EPA
requested
HAP
emissions
test
data
from
stationary
combustion
turbines
in
the
proposed
rule.
As
a
result
of
this
request,
EPA
received
new
data
in
the
form
of
several
test
reports
during
the
comment
period
and
has
more
than
doubled
its
total
data
set.
Data
were
received
for
both
diffusion
flame
and
lean
premix
turbines.
New
test
reports
received
included
many
tests
conducted
using
FTIR;
at
proposal
EPA
did
not
have
any
emissions
data
conducted
using
FTIR.
Therefore,
EPA's
data
set
has
been
significantly
improved,
both
quantitatively
and
qualitatively.

As
a
result
of
comments
received
during
the
comment
period,
EPA
performed
an
extensive
review
of
tests
used
at
proposal
and
new
tests
received
during
the
comment
period.
A
screening
analysis
of
the
formaldehyde
test
data
for
diffusion
flame
combustor
turbines
was
conducted.
Tests
conducted
using
CARB
430
were
evaluated
due
to
the
CARB
advisory
issued
April
28,
2000,
which
stated
that
formaldehyde
data
measured
by
CARB
430
where
the
NOx
emissions
were
greater
than
50
ppm
should
be
flagged
as
non­
quantitative.
Tests
where
the
NOx
emissions
were
greater
than
50
ppm
or
tests
where
the
NOx
levels
were
unknown
were
excluded
from
EPA's
analysis.
Most
of
the
diffusion
flame
tests
in
the
Emissions
Database
were
unable
to
51
pass
the
screening.
The
tests
unable
to
pass
the
screening
were
not
equipped
with
add­
on
control
for
the
reduction
of
HAPs.

The
remaining
test
reports
were
further
analyzed
and
reviewed
to
ensure
the
methods
were
used
correctly
in
calculating
and
reporting
formaldehyde
concentrations
and
to
check
that
proper
QA/
QC
procedures
were
followed.
A
number
of
errors
were
found
in
the
test
reports
where
CARB
430
was
used
to
quantify
formaldehyde
concentrations.
In
several
instances
the
CARB
430
reporting
protocol
was
not
followed.
If
the
analytical
concentration
is
less
than
five
times
the
average
field
blank,
then
CARB
430
uses
five
times
the
field
blank
as
the
reported
result
to
correct
for
interferences
or
contaminants
that
can
react
with
the
formaldehyde
or
dinitrophenylhydrazine
to
yield
negative
bias.
However,
many
test
reports
did
not
report
formaldehyde
concentrations
in
this
fashion.
The
formaldehyde
concentrations
were
therefore
recalculated
where
the
CARB
430
reporting
protocol
was
not
followed
correctly.
General
Electric
(
GE)
proposed
a
method
for
blank
correcting
in
their
comments
on
the
proposed
NESHAP
for
stationary
combustion
turbines.
A
copy
of
GE's
comments
can
be
obtained
from
EPA's
Edocket
Website
as
Document
ID
Number
OAR­
2002­
0060­
0435.
The
EPA
evaluated
formaldehyde
emissions
estimated
using
both
blank
correction
procedures
(
CARB
430
reporting
protocol
and
proposed
GE
method),
however,
EPA
chose
the
CARB
430
protocol
because
its
results
are
closer
to
FTIR
(
considered
the
most
accurate
method)
and
the
correlations
to
FTIR
for
both
protocols
were
similar.

No
errors
were
found
in
test
reports
which
used
FTIR
to
measure
formaldehyde
concentrations
in
the
stationary
combustion
turbine
exhaust.
The
reported
formaldehyde
concentrations
were
representative
of
stationary
combustion
turbines
and
the
measured
QA/
QC
parameters
were
within
acceptable
limits
as
set
in
the
method.

The
EPA
agrees
that
CARB
430
generally
understates
the
formaldehyde
concentration
in
the
exhaust
gas
from
stationary
combustion
turbines.
Since
EPA
Method
0011
is
a
similar
method
to
CARB
430,
it
is
believed
that
Method
0011
also
understates
the
emissions
of
formaldehyde.
The
EPA
feels
that
FTIR
is
a
more
accurate
and
reliable
method.
Several
test
reports
were
received
during
the
comment
period
on
recent
testing
on
small
lean
premix
combustion
turbines
which
used
both
CARB
430
and
FTIR
to
measure
formaldehyde
emissions.
An
analysis
was
conducted
to
correlate
formaldehyde
concentrations
measured
by
CARB
430
and
formaldehyde
concentrations
measured
by
FTIR.
A
linear
regression
was
performed
on
the
CARB
430
and
FTIR
formaldehyde
data
from
these
tests
which
gave
a
slope
of
1.667
with
a
correlation
coefficient
of
0.561.
Therefore,
EPA
concluded
that
CARB
430
formaldehyde
results
are
on
average
1.7
times
lower
than
FTIR
formaldehyde
results.
To
account
for
the
differences
in
the
methods,
a
bias
factor
of
1.7
was
applied
to
the
CARB
430
and
Method
0011
formaldehyde
emissions
data
to
make
these
data
comparable
to
FTIR.

As
a
result
of
a
complete
data
review
including
emissions
data
EPA
had
at
proposal
and
new
emissions
data
EPA
received
during
the
comment
period,
EPA
currently
has
a
very
different
data
set
as
compared
to
what
it
had
at
proposal.
For
example,
the
amount
of
data
for
LPC
units
52
increased,
while
the
amount
of
data
for
DFC
units
decreased.
The
new
data
set
includes
more
emissions
data
on
smaller
units
as
compared
to
the
data
set
at
proposal.
As
discussed
in
the
responses
to
comments
IV.
A.
2
and
IV.
B.
1,
the
new
data
set
was
used
to
determine
the
MACT
Floors.
For
new
LPC
gas­
fired
units
and
new
LPC
oil­
fired
units,
a
formaldehyde
emission
limitation
of
91
ppb
was
established
for
the
MACT
Floor.
It
is
believed
that
this
emission
limitation
will
be
achievable
for
both
small
and
large
size
CTs.
The
EPA
considered
establishing
separate
subcategories
by
size
but
found
that
there
was
little
difference
among
the
best
performing
small
and
large
units.
The
best
performing
large
LPC
unit
was
controlled
by
an
oxidation
catalyst
and
had
formaldehyde
emissions
of
19
and
91
ppb.
The
best
performing
small
LPC
unit
(<
25
MW)
had
uncontrolled
formaldehyde
emissions
of
68
ppb,
which
is
within
the
range
of
emissions
for
the
large
LPC
unit.

The
EPA
believes
that
it
has
adequately
considered
the
variability
in
emissions
by
the
best
performing
source.
The
EPA
has
emissions
data
for
two
tests
for
the
best
performing
turbine
in
the
LPC
gas­
fired
turbines
subcategory;
the
formaldehyde
emissions
varied
by
a
factor
of
4.8
between
the
two
tests.
Since
both
tests
were
performed
under
similar
conditions
but
at
different
times,
they
represent
the
variability
of
the
best
performing
unit.
The
MACT
floor
for
this
subcategory
was
set
based
on
the
higher
formaldehyde
measurement,
thus
the
variability
of
the
best
performing
unit
has
been
accounted
for.
Similar
variability
factors
were
applied
for
the
other
subcategories.

V.
A.
2
Comment:
One
commenter
(
488)
requested
that
a
mass
based
emission
limit
be
included
as
an
alternative
to
the
concentration
based
standard
for
LPC
CTs.
Two
commenters
(
424,
427)
recommended
that
EPA
add
a
formaldehyde
ton
per
year
emission
limit
alternative.

Response:
The
EPA
does
not
agree
with
the
commenters.
As
stated
in
the
preamble,
a
volume
concentration
was
chosen
for
the
emission
limitation
because
it
can
be
measured
directly
and
is
clearly
related
to
the
performance
of
the
HAP
reduction
technology.

V.
A.
3
Comment:
One
commenter
(
443)
stated
that
LPC
units
that
do
not
meet
the
formaldehyde
standard
but
are
in
compliance
with
the
NO
x
limit
should
not
be
required
to
install
additional
controls.

Response:
The
EPA
does
not
agree
that
units
that
are
not
meeting
the
formaldehyde
emission
limitation
should
not
be
required
to
install
additional
controls.
Our
analysis
of
the
MACT
Floor
shows
that
the
best
performing
LPC
unit
is
equipped
with
add­
on
HAP
emission
control.

V.
A.
4
Comment:
Three
commenters
(
421,
424,
502)
contended
that
a
contradiction
exists
between
the
proposed
formaldehyde
standards
of
17,000
ppb
for
RICE
and
43
ppb
for
CTs.
Commenter
421
stated
that
the
CT
rule
would
discourage
owners
to
acquire
clean
burning
turbines,
promoting
reduced
air
quality.
53
Response:
The
EPA
is
required
to
regulate
stationary
combustion
turbines
and
to
set
MACT
according
to
the
provisions
set
forth
in
the
CAA.
The
emission
standards
for
other
MACT
rules
do
not
have
any
relevance
when
setting
MACT
for
stationary
combustion
turbines.

V.
A.
5
Comment:
One
commenter
(
424)
requested
that
the
standard
value
be
stated
in
the
same
units
of
measurement
of
similar
formaldehyde
combustion
source
standards,
e.
g.
RICE,
for
ease
of
comparison.
The
commenter
asked
that
any
formaldehyde
emission
level
in
the
final
rule
be
denoted
in
ppm
units
rather
than
ppb.

Response:
The
EPA
believes
that
it
is
not
necessary
to
state
the
emission
limitation
in
the
same
units
of
measurement
as
other
combustion
source
standards.
The
EPA
believes
that
ppb
is
the
most
appropriate
unit
for
this
standard;
units
are
not
selected
on
the
basis
of
ease
of
comparison
with
other
standards.

V.
A.
6
Comment:
One
commenter
(
436)
expressed
the
opinion
that
the
formaldehyde
emission
limitation
could
increase
the
use
of
diffusion­
flame
turbines
and
RICE,
resulting
in
substantial
increase
in
emissions.

Response:
The
EPA
does
not
agree
that
the
formaldehyde
emission
limitation
would
increase
the
use
of
DFC
CTs
and
RICE.
The
commenter
did
not
provide
any
clarifying
information
to
explain
why
the
use
of
DFC
CTs
would
be
increased.
New
DFC
units
are
subject
to
this
rule
and
have
emission
limitations;
the
EPA
has
also
proposed
a
NESHAP
for
stationary
RICE
which
includes
similar
requirements
to
this
rule,
i.
e.
formaldehyde
limits.
Therefore
there
would
be
no
incentive
to
use
these
units
instead
of
LPC
units.
In
addition,
limitations
for
other
pollutants,
such
as
NOx,
are
also
a
factor.

V.
A.
7
Comment:
One
commenter
(
436)
observed
that
variations
in
atmospheric
methane
can
result
in
variation
in
formaldehyde
levels
that
exceed
the
proposed
level
of
43
ppbvd.

Response:
The
EPA
agrees
with
the
commenter
that
atmospheric
levels
of
formaldehyde
could
be
as
high
as
43
ppbvd.
However,
EPA
believes
that
any
ambient
formaldehyde
would
be
combusted
in
the
turbine
and
would
have
little
effect
on
the
stack
levels
of
formaldehyde.

V.
A.
8
Comment:
One
commenter
(
417)
stated
that
the
43
ppbvd
limit
should
be
changed
to
25
ppbvd
because
EPA
did
not
consider
data
provided
to
the
CT
MACT
Work
Group
on
tests
performed
on
CTs
using
two
different
emission
control
technologies
that
resulted
in
substantially
lower
formaldehyde
and
HAP
emissions.
According
to
the
commenter,
both
technologies
demonstrated
the
ability
to
guarantee
formaldehyde
emissions
of
less
than
25
ppbvd.
Therefore,
EPA
should
consider
the
HAP
advantages
provided
by
these
control
technologies
when
determining
the
formaldehyde
limit.

Response:
The
commenter
did
not
provide
any
details
about
whether
these
technologies
are
commercially
available
and
if
they
can
be
retrofit
on
existing
units.
Without
any
information
54
regarding
the
feasibility
and
availability
of
these
control
technologies,
EPA
is
unable
to
address
the
concern
directly.
As
a
result,
EPA
is
not
changing
the
NESHAP
in
response
to
this
comment.

V.
A.
9
Comment:
One
commenter
(
502)
remarked
that
the
formaldehyde
limit
is
not
justified
considering
the
relatively
small
risks
associated
with
the
HAPs
being
emitted
by
the
CT
category.

Response:
Risk
is
not
a
consideration
in
establishing
emission
standards
under
CAA
section
112,
except
in
those
limited
instances
where
an
alternate
standard
for
a
threshold
pollutant
can
be
established
pursuant
to
CAA
section
112(
d)(
4).

V.
A.
10
Comment:
One
commenter
(
435)
requested
that
the
rule
allow
the
EPA
Administrator
to
enter
into
agreements
with
a
manufacturer
of
lean
pre­
mix
combustion
turbines
to
certify
as
compliant
with
the
43
ppb
formaldehyde
standard
each
model
or
other
class
of
turbine
that
its
testing
demonstrates
meets
the
standard.
Notice
of
each
proposed
agreement
could
be
published
in
the
Federal
Register,
with
an
opportunity
for
public
comment
prior
to
finalization
of
the
agreement.

Response:
The
EPA
believes
that
performance
testing
and
continuous
parametric
monitoring
is
a
better
method
to
determine
continuous
compliance
than
a
one­
time
factory
test.
The
EPA
therefore
does
not
agree
with
the
commenter.

B.
CO
V.
B.
1
Comment:
Twenty­
seven
commenters
(
412,
418,
419,
420,
421,
422,
424,
425,
426,
427,
430,
431,
437,
440,
442,
443,
444,
445,
446,
449,
460,
475,
479,
484,
502,
508,
509)
urged
EPA
to
revise
the
CO
emission
limitation
of
95
percent
reduction
because
it
does
not
represent
actual
emission
reductions
achievable
by
oxidation
catalysts
since
it
is
based
solely
on
two
tests
from
a
catalyst
vendor,
and
it
does
not
account
for
variability
in
catalyst
performance.
The
commenters
also
noted
that
catalysts
may
not
achieve
the
same
level
of
CO
reduction
for
multiple
years
and
recommended
that
the
rule
provides
for
potential
long­
term
degradation
of
catalyst
performance
in
practical
turbine
applications.

Three
commenters
(
424,
427,
449)
said
that
it
is
inappropriate
for
EPA
to
rely
on
emissions
data
for
the
SCONO
x
(
EM
x
GT)
system
to
establish
the
emission
performance
achieved
by
traditional,
passive
oxidation
catalysts.
One
commenter
(
430)
questioned
whether
the
reductions
reported
by
the
catalyst
vendor
have
been
achieved
in
practice
by
an
operating
CT
owned
and
operated
independent
of
the
vendor.
Two
commenters
(
430,
449)
observed
that
the
SCONO
x
catalyst
operates
in
temperature
range
of
300
­
700

F,
consequently
a
heat
exchanger
may
be
required
to
lower
the
exhaust
gas
temperature,
at
significant
additional
cost.
One
commenter
(
449)
remarked
that
the
emission
testing
conducted
for
the
SCONO
x
system
represents
inflated
performance
in
terms
of
CO
percent
reduction
due
to
the
high
CO
levels
at
the
inlet
to
the
SCONO
x
system.
55
Eight
commenters
(
420,
422,
443,
446,
460,
475,
479,
502)
stated
that
90
percent
reduction
of
CO
is
a
more
appropriate
emission
limitation.
One
commenter
(
419)
stated
that
they
have
catalysts
that
have
been
achieving
about
90
percent
reduction,
not
95
percent.
One
commenter
(
430)
noted
that
they
have
found
it
impossible
to
achieve
95
percent
reduction,
and
that
EPA
has
not
shown
95
percent
is
achievable
in
practice.
One
commenter
(
437)
recommended
that
the
limit
be
set
at
75
percent
reduction.
Two
commenters
(
442,
449)
advised
that
the
reduction
should
be
set
at
88
percent.
The
basis
for
a
limit
of
88
percent
is
review
of
recent
permitted
emission
limits
for
turbines
with
catalysts
and
confirmed
by
two
recent
CARB
BACT
assessments.
Two
commenters
(
424,
427)
felt
that
80­
90
percent
reduction
is
more
appropriate
for
new
CTs;
for
existing
CTs,
insufficient
data
exists
to
set
a
percent
reduction
level
for
retrofit
applications
as
the
temperature
window
available
for
the
retrofit
catalyst
may
not
be
within
the
optimum
temperature
range
for
the
catalyst.
Two
commenters
(
426,
430)
noted
that
in
the
preamble
to
the
proposed
rule,
EPA
reviewed
design
data
from
catalyst
vendors
and
determined
that
the
typical
emission
reduction
for
CTs
is
90
percent
CO
reduction,
with
only
a
few
systems
designed
to
meet
greater
than
95
percent.
One
commenter
(
430)
stated
that
the
MACT
floor
should
be
as
required
by
section
112(
d)(
3)(
A)
of
the
CAA,
the
level
of
control
achieved
by
the
average
of
the
best
performing
12
percent
of
existing
sources,
and
therefore
would
likely
be
significantly
less
than
95
percent
reduction.

Also,
two
commenters
(
431,
484)
requested
that
the
CO
reduction
requirement
be
reduced
for
retrofit
installations
of
oxidation
catalyst
on
existing
LPC
turbines.

Response:
The
EPA
believes
that
95
percent
reduction
of
CO
is
achievable
through
the
use
of
oxidation
catalyst
control.
The
percent
reduction
is
a
design
parameter
of
the
oxidation
catalyst
control
system.
The
costs
for
proper
design
and
operation
of
such
a
system
were
included
in
our
analysis.
The
EPA
does
not
agree
with
the
commenters'
statements
that
95
percent
reduction
is
not
achievable,
however,
as
discussed
in
the
response
to
comment
VI.
A.
1,
the
alternative
CO
emission
limitation
has
been
removed
from
the
final
rule
due
to
CO
measurement
difficulties.
Thus,
the
commenters'
concerns
are
moot.

V.
B.
2
Comment:
Twenty­
seven
commenters
(
412,
419,
420,
422,
424,
425,
426,
427,
430,
431,
435,
437,
442,
446,
449,
465,
469,
470,
475,
482,
484,
485,
488,
501,
502,
505,
518)
requested
that
a
CO
outlet
concentration
limit
option
be
added.
Five
commenters
(
435,
437,
446,
475,
505)
recommended
that
EPA
specify
a
CO
emission
limitation
of
5
ppm.
Two
commenters
(
485,
501)
recommended
a
CO
limitation
of
1
ppm.
Two
commenters
(
424,
427)
suggested
that
EPA
provide
that
CTs
emitting
less
than
50
ppm
CO
at
full
load
would
comply
with
the
MACT
standard.
One
commenter
(
449)
recommended
an
outlet
standard
of
6
ppm,
based
on
the
BACT
recommendation
by
CARB
for
turbines
rated
3
MW
to
50+
MW.
One
commenter
(
425)
stated
that
EPA
could
set
the
standard
based
on
review
of
recent
BACT/
LAER
determinations.
One
commenter
(
426)
recommended
an
outlet
standard
of
3
ppmvd
at
15
percent
O
2
for
CTs
equipped
with
catalyst
and
new
LPC
CTs.
A
separate
rate
should
be
set
for
CTs
not
equipped
with
catalyst
(
limit
would
be
greater
than
3
ppmvd).
A
CO
limit
of
5­
10
ppmvd
is
reasonable
for
new
DFC
CTs.
One
commenter
(
518)
said
that
EPA
should
review
the
existing
data
correlating
CO
56
emissions
with
formaldehyde
emissions
(
and
collect
additional
data
if
necessary)
to
determine
the
limit.
The
commenter
believed
the
limit
would
be
in
the
2
to
5
ppm
range
(
New
Jersey
has
recently
permitted
LPC
CTs
with
oxidation
catalysts
with
allowable
CO
emissions
in
the
range
of
2
to
5
ppmvd
at
7
percent
O
2).

Commenter
505
noted
that
a
single
emission
limit
for
CO
would
reduce
the
costs
of
compliance
and
negate
the
need
to
use
inadequate
test
methods
to
determine
compliance
with
the
formaldehyde
limit.
Two
commenters
(
465,
470)
remarked
that
a
single
CO
concentration
limit
would
lessen
the
amount
of
record
keeping
for
affected
facilities
by
not
having
to
collect
two
CO
concentrations
and
calculate
the
percent
reduction.

Response:
The
emissions
data
at
the
time
of
proposal
showed
that
CO
reduction
across
an
oxidation
catalyst
was
strongly
correlated
to
HAP
reduction,
while
the
CO
concentration
and
HAP
concentration
was
not.
Thus,
it
would
not
have
been
appropriate
to
have
a
CO
outlet
concentration
limit.

V.
B.
3
Comment:
One
commenter
(
424)
said
that
the
addition
of
a
catalyst
to
reduce
CO
emissions
will
result
in
CO
being
subject
to
regulation
as
a
HAP.

Response:
The
concern
raised
by
the
commenter
is
moot
because
this
rule
does
not
have
any
requirements
for
CO.
However,
as
discussed
in
the
response
to
comment
VI.
A.
1,
the
alternative
CO
emission
limitation
has
been
removed
from
the
final
rule
due
to
CO
measurement
difficulties.
Therefore
the
EPA
does
not
feel
that
it
is
appropriate
to
establish
a
CO
outlet
concentration
limit.

V.
B.
4
Comment:
One
commenter
(
472)
asserted
that
EPA's
claim
that
a
CO
standard
will
result
in
some
unspecified
degree
of
reduction
in
some
unidentified
HAP
falls
far
short
of
establishing
an
adequate
surrogacy
relationship
between
CO
and
the
other
HAPs.
Furthermore,
one
commenter
(
436)
stated
that
no
correlation
between
CO
and
formaldehyde
emissions
at
subppm
levels
has
been
demonstrated.
The
role
of
atmospheric
CO
levels
on
the
development
of
a
CO­
formaldehyde
correlation
must
be
examined.
The
CO
in
the
exhaust
may
bear
no
relationship
to
the
HAPs
generated
by
the
turbine
if
a
significant
percentage
of
air
used
in
the
CT
bypasses
the
combustion
zone.
Likewise,
commenter
424
said
that
a
correlation
between
CO
and
formaldehyde
emissions
should
exist,
yet
this
correlation
is
hard
to
establish
due
to
current
measurement
problems.
To
provide
an
acceptable
surrogate
for
formaldehyde
measurement,
a
precise,
repeatable
correlation
must
be
established.

Similarly,
one
commenter
(
445)
did
not
agree
that
there
is
a
relationship
between
CO
reduction
and
HAP
reduction.
Instead,
the
commenter
believed
a
relationship
exists
between
VOC
and
HAP.
EPA's
proposal
to
use
CO
reduction
as
a
surrogate
for
HAP
reduction
will
not
accurately
reflect
a
like
reduction.

Response:
As
stated
in
the
response
to
comment
VI.
A.
1,
the
alternative
CO
emission
57
limitation
has
been
removed
from
the
final
rule
due
to
CO
measurement
difficulties.
Thus,
the
commenters'
concerns
are
moot.

C.
Duct
Burners
V.
C.
1
Comment:
Three
commenters
(
422,
431,
484)
sought
an
allowance
for
site
specific
emission
limits
where
duct
burners
are
utilized
and
the
formaldehyde
limit
applies.
Three
commenters
(
422,
431,
502)
recommended
that
facilities
should
be
allowed
to
either
accept
the
formaldehyde
limit
at
the
stack
with
the
duct
burner
in
operation,
or
be
allowed
to
petition
the
EPA
for
an
alternate
(
higher)
formaldehyde
limit
for
the
combined
turbine/
duct
burner
co­
firing.

Response:
The
EPA
has
incorporated
the
commenters'
suggestions
that
facilities
be
allowed
to
accept
the
formaldehyde
limit
at
the
stack
with
the
duct
burner
in
operation.
The
EPA
does
not
believe
it
is
necessary
to
specify
in
the
rule
that
affected
sources
are
allowed
to
petition
EPA
for
an
alternate
formaldehyde
limit.

V.
C.
2
Comment:
Two
commenters
(
443,
486)
observed
that
in
some
cases
there
is
no
means
to
separately
monitor
CO/
HAPs
from
the
turbine
and
duct
burner,
because
the
catalyst
may
be
after
the
duct
burner.
Two
commenters
(
508,
509)
remarked
that
EPA
should
address
and
resolve
compliance
and
monitoring
issues
for
combined
cycle
units
using
duct
burners.

Response:
The
EPA
acknowledges
that
in
some
cases
it
may
not
be
possible
to
separately
monitor
emissions
from
the
turbine
and
duct
burner.
The
final
rule
has
been
revised
to
allow
sources
to
meet
the
limit
with
their
duct
burner
in
operation
if
they
choose
to
do
so.

D.
Other
V.
D.
1
Comment:
One
commenter
(
431)
recommended
that
sources
be
able
to
choose
to
meet
either
a
CO
percent
reduction,
CO
outlet
concentration
limit,
or
a
formaldehyde
concentration
limit.

Thirteen
commenters
(
418,
420,
425,
426,
430,
431,
440,
442,
443,
449,
469,
471,
475)
requested
that
CTs
with
oxidation
catalysts
be
allowed
to
comply
with
the
formaldehyde
emission
limit.
Commenter
469
noted
that
uncontrolled
CO
emissions
from
a
LPC
turbine
are
inherently
low,
making
it
difficult
to
achieve
compliance
with
a
95
percent
reduction
limit.

Response:
As
stated
in
the
response
to
comment
VI.
A.
1,
the
alternative
CO
emission
limitation
has
been
removed
from
the
final
rule
due
to
CO
measurement
difficulties.
Thus,
the
comment
is
moot.

V.
D.
2
Comment:
Eight
commenters
(
418,
420,
424,
425,
427,
430,
442,
449)
stated
that
the
rule
should
only
apply
emission
standards
to
the
load
range
represented
by
the
emissions
data
used
to
determine
emission
limitations.
Commenters
430
and
424
said
that
the
emission
standard
58
should
apply
only
at
full
load.
Commenter
420
said
the
emission
standards
should
only
apply
within
a
60
to
100
percent
base
load
range.
Commenter
449
advised
that
EPA
should
specify
in
the
final
rule
that
the
performance
test
should
be
conducted
at
full­
load
conditions.
Full
load
should
be
defined
as
100
percent
±
10
percent
and
owner/
operators
should
be
allowed
to
conduct
the
performance
test
at
any
load
condition
within
that
range.

Response:
The
emission
standards
are
based
on
data
from
testing
at
high
loads
(
90
percent
and
greater).
To
address
the
concerns
expressed
by
the
commenters
about
the
emission
standards
being
applicable
at
full
load
only,
the
final
rule
specifies
that
the
performance
test
must
be
conducted
at
high
load
conditions,
defined
as
100
percent
±
10
percent.

V.
D.
3
Comment:
Two
commenters
(
442,
449)
contended
that
the
emission
standards
should
only
apply
for
ambient
temperatures
ranging
from
0

F
to
100

F
(
this
is
the
range
typically
guaranteed
by
the
manufacturer).
One
commenter
(
427)
said
that
firing
temperature
was
not
considered
in
the
rationale
for
setting
the
emission
limitations.

Response:
The
EPA
does
not
have
any
information
to
indicate
that
there
would
be
a
significant
technological
problem
to
operate
turbines
at
ambient
temperatures
below
0

F
and
above
100

F
and
the
commenters
did
not
provide
any
information
to
support
their
comment.
Information
provided
by
operators
of
turbines
on
Alaska's
North
Slope
indicated
that
they
have
experienced
problems
with
turbine
operation
during
cold
temperatures
but
the
temperatures
on
the
North
Slope
are
well
below
0

F
for
sustained
periods
(
they
provided
the
supporting
temperature
data).
The
information
provided
by
the
North
Slope
turbine
operators
was
based
on
actual
operating
experience,
not
manufacturer
guarantees.
In
the
absence
of
any
information
to
support
the
request
to
apply
the
emission
standards
only
at
ambient
temperatures
between
0

F
and
100

F,
EPA
does
not
agree
with
this
comment.

V.
D.
4
Comment:
One
commenter
(
412)
expressed
support
for
the
development
and
potential
use
of
alternative
control
technologies
to
reduce
HAP
emissions.

Response:
The
commenter's
support
is
acknowledged
by
EPA.

V.
D.
5
Comment:
One
commenter
(
443)
stated
that
EPA's
suggestion
that
the
CO
CEMS
requirement
could
be
replaced
with
a
requirement
to
demonstrate
a
percent
reduction
in
formaldehyde
is
unreasonable.

Response:
The
EPA
does
not
agree
that
a
requirement
to
demonstrate
a
percent
reduction
in
formaldehyde
is
unreasonable,
however,
the
final
rule
does
not
contain
such
a
requirement.

V.
D.
6
Comment:
One
commenter
(
505)
remarked
that
in
the
first
paragraph
under
section
II.
D
of
the
proposal
preamble
("
What
Are
the
Emission
Limitations
and
Operating
Limitations"),
the
phrase
"
new
or
reconstructed"
should
be
removed
from
item
(
2).
59
Response:
The
EPA
is
in
agreement
that
phrase
"
new
and
reconstructed"
should
not
have
been
in
item
(
2).
The
phrase
should
also
not
have
been
in
item
(
1).

V.
D.
7
Comment:
Three
commenters
(
421,
437,
460)
argued
that
EPA's
data
demonstrate
that
there
is
no
substantive
difference
in
formaldehyde
emissions
between
DFC
and
LPC
CTs.
A
no
control
standard
should
therefore
be
issued
for
both
the
DFC
and
LPC
combustion
system
design,
i.
e.
all
gas
turbines.
The
commenters
cited
data
from
ICCR
database
­
11
non­
DLN
turbines
were
reported
with
emission
concentrations
to
be
less
than
44
ppb.
The
commenters
questioned
the
accuracy
of
test
methods.
Also
cited
was
a
GRI/
EPRI
report
that
shows
that
installation
of
a
DLN
combustor
configuration
on
a
gas
turbine,
all
other
components
being
equal,
does
not
result
in
a
reduced
emission
level
of
formaldehyde
and
based
on
questionable
measurement
accuracy
any
differences
on
a
ppb
level
are
negligible.

Response:
The
EPA
does
not
agree
with
the
commenters'
contention
that
there
is
no
substantive
difference
in
formaldehyde
emissions
between
DFC
and
LPC
CTs.
Emissions
data
at
the
time
of
proposal
showed
a
difference
in
HAP
emissions
between
DFC
and
LPC
units;
the
data
received
since
proposal
continues
to
support
this
conclusion.
An
examination
of
formaldehyde
test
data
for
both
DFC
and
LPC
CTs
shows
that
uncontrolled
formaldehyde
emissions
for
stationary
LPC
units
are
significantly
lower
than
those
of
stationary
DFC
units.
The
difference
varies,
but
uncontrolled
DFC
CTs
emit
on
average
about
five
times
more
HAP
as
compared
to
uncontrolled
LPC
CTs.

V.
D.
8
Comment:
One
commenter
(
415)
said
that
the
standards
should
be
cut
by
50
percent.

Response:
The
commenter
did
not
provide
any
details
or
supporting
details
about
why
the
standards
should
be
cut
by
50
percent.
Thus,
EPA
is
unable
to
address
the
comment
directly.

V.
D.
9
Comment:
One
commenter
(
421)
believed
that
there
are
significant
data
quality
issues
with
the
Emissions
Database.
The
commenter
recommended
that
the
National
Academy
of
Sciences
or
the
National
Academy
of
Engineering
review
the
database
for
data
quality.

Response:
As
stated
in
the
response
to
comment
IV.
A.
2,
EPA
had
limited
emissions
data
for
stationary
combustion
turbines
at
proposal.
Due
to
the
limited
amount
of
emissions
data
EPA
had
at
proposal,
EPA
requested
HAP
emissions
test
data
from
stationary
combustion
turbines
in
the
proposed
rule.
As
a
result
of
this
request,
EPA
received
new
data
in
the
form
of
several
test
reports
during
the
comment
period
and
has
more
than
doubled
its
total
data
set.
Data
were
received
for
both
diffusion
flame
and
lean
premix
turbines.
New
test
reports
received
included
many
tests
conducted
using
FTIR;
at
proposal
EPA
did
not
have
any
emissions
data
conducted
using
FTIR.
Therefore,
EPA's
data
set
has
been
significantly
improved,
both
quantitatively
and
qualitatively.

As
a
result
of
comments
received
during
the
comment
period,
EPA
performed
an
60
extensive
review
of
tests
used
at
proposal
and
new
tests
received
during
the
comment
period.
A
screening
analysis
of
the
formaldehyde
test
data
for
diffusion
flame
combustor
turbines
was
conducted.
Tests
conducted
using
CARB
430
were
evaluated
due
to
the
CARB
advisory
issued
April
28,
2000,
which
stated
that
formaldehyde
data
measured
by
CARB
430
where
the
NOx
emissions
were
greater
than
50
ppm
should
be
flagged
as
non­
quantitative.
Tests
where
the
NOx
emissions
were
greater
than
50
ppm
or
tests
where
the
NOx
levels
were
unknown
were
excluded
from
EPA's
analysis.
Most
of
the
diffusion
flame
tests
in
the
Emissions
Database
were
unable
to
pass
the
screening.
The
tests
unable
to
pass
the
screening
were
not
equipped
with
add­
on
control
for
the
reduction
of
HAPs.

The
remaining
test
reports
were
further
analyzed
and
reviewed
to
ensure
the
methods
were
used
correctly
in
calculating
and
reporting
formaldehyde
concentrations
and
to
check
that
proper
QA/
QC
procedures
were
followed.
A
number
of
errors
were
found
in
the
test
reports
where
CARB
430
was
used
to
quantify
formaldehyde
concentrations.
In
several
instances
the
CARB
430
reporting
protocol
was
not
followed.
If
the
analytical
concentration
is
less
than
five
times
the
average
field
blank,
then
CARB
430
uses
five
times
the
field
blank
as
the
reported
result
to
correct
for
interferences
or
contaminants
that
can
react
with
the
formaldehyde
or
dinitrophenylhydrazine
to
yield
negative
bias.
However,
many
test
reports
did
not
report
formaldehyde
concentrations
in
this
fashion.
The
formaldehyde
concentrations
were
therefore
recalculated
where
the
CARB
430
reporting
protocol
was
not
followed
correctly.
General
Electric
(
GE)
proposed
a
method
for
blank
correcting
in
their
comments
on
the
proposed
NESHAP
for
stationary
combustion
turbines.
A
copy
of
GE's
comments
can
be
obtained
from
EPA's
Edocket
Website
as
Document
ID
Number
OAR­
2002­
0060­
0435.
The
EPA
evaluated
formaldehyde
emissions
estimated
using
both
blank
correction
procedures
(
CARB
430
reporting
protocol
and
proposed
GE
method),
however,
EPA
chose
the
CARB
430
protocol
because
its
results
are
closer
to
FTIR
(
considered
the
most
accurate
method).

No
errors
were
found
in
test
reports
which
used
FTIR
to
measure
formaldehyde
concentrations
in
the
stationary
combustion
turbine
exhaust.
The
reported
formaldehyde
concentrations
were
representative
of
stationary
combustion
turbines
and
the
measured
QA/
QC
parameters
were
within
acceptable
limits
as
set
in
the
method.

Due
to
the
extensive
review
of
the
data
and
also
the
acquisition
of
new
data,
EPA
feels
that
it
has
addressed
the
commenters
concerns
regarding
the
data
quality
issues
with
the
Emissions
Database.

V.
D.
10
Comment:
One
commenter
(
425)
expressed
the
view
that
the
rule
discourages
any
control
option
other
than
an
oxidation
catalyst.
Requiring
a
source
to
petition
for
approval
of
operating
limitations
creates
a
high
degree
of
uncertainty
for
a
company
and
shifts
the
burden
of
rulemaking
from
EPA
to
the
regulated
source.

Response:
The
EPA
does
not
agree
with
the
commenter.
The
proposed
rule
required
sources
equipped
with
oxidation
catalyst
control
to
meet
a
CO
emission
reduction
limitation
and
61
other
sources
were
required
to
meet
a
formaldehyde
emission
limitation.
In
the
final
rule,
the
CO
emission
reduction
limitation
has
been
eliminated
and
sources
are
not
restricted
to
using
oxidation
catalyst
control
to
meet
the
formaldehyde
emission
limitation.
The
final
rule
requires
turbines
complying
with
the
emission
limitation
using
oxidation
catalyst
control
to
monitor
catalyst
inlet
temperature
as
an
operating
limitation.
Sources
that
are
not
using
oxidation
catalyst
control
must
petition
the
Administrator
for
approval
of
operating
limitations
(
or
approval
of
no
operating
limitations).
The
EPA
is
not
aware
of
any
add­
on
HAP
control
other
than
oxidation
catalyst
systems
but
would
like
to
allow
the
use
of
other
controls
as
they
become
available.
Since
there
is
no
information
on
other
types
of
controls
that
may
be
utilized
in
the
future,
the
EPA
is
not
able
to
specify
appropriate
operating
limitations
at
this
time.
Therefore,
the
final
rule
requires
sources
that
are
using
other
controls
to
petition
the
Administrator
for
approval
of
appropriate
operating
limitations.

V.
D.
11
Comment:
One
commenter
(
437)
said
that
EPA
should
make
provisions
for
CTs
that
are
designed
as
LPC
but
may
operate
as
DFC
because
of
either
ambient
temperature
or
load
variations.
EPA
should
require
that
the
CT
meet
MACT
standards
for
LPC
CTs
only
when
in
the
LPC
operating
mode.
If
the
turbine
shifts
from
LPC
to
DFC
(
or
a
hybrid
between
LPC
and
DFC),
EPA
can
require
operation
of
all
pollution
control
equipment
(
which
will
be
required
as
a
permit
condition
anyway),
but
not
require
the
CT
meet
any
emission
limitations.

Response:
In
the
final
rule,
the
requirements
for
LPC
units
are
the
same
as
for
DFC
units.
Therefore,
EPA
does
not
feel
that
it
is
necessary
to
make
provisions
for
CTs
that
are
designed
as
LPC
but
may
operate
as
DFC,
since
the
requirements
for
both
types
of
units
are
not
different.

V.
D.
12
Comment:
One
commenter
(
520)
remarked
that
they
were
pleased
that
EPA
is
proposing
no
emission
requirements
for
new
turbines,
reconstructed
turbines,
and
existing
diffusion
flame
turbines.

Response:
The
commenter
is
correct
in
stating
that
existing
DFC
turbines
had
no
requirements
in
the
proposed
rule;
this
is
also
the
case
in
the
final
rule.
The
EPA
believes
the
commenter
misread
the
requirements
in
the
proposed
rule
for
new
and
reconstructed
turbines,
because
their
statement
is
not
correct,
there
were
emission
requirements
for
new
and
reconstructed
turbines.
The
final
rule
also
has
emission
requirements
for
new
and
reconstructed
turbines.

VI.
MONITORING,
RECORDKEEPING,
REPORTING
A.
CO
CEMS
VI.
A.
1
Comment:
Twenty
commenters
(
412,
418,
419,
424,
427,
433,
435,
437,
440,
442,
443,
449,
465,
470,
479,
485,
486,
488,
501,
502)
requested
that
the
CO
CEMS
requirement
be
removed
and
periodic
testing/
parametric
monitoring
be
adopted.
Six
commenters
62
(
412,
427,
449,
465,
470,
479)
cited
the
cost
burden
of
a
CEMS,
with
five
of
those
commenters
(
412,
427,
449,
465,
470)
noting
that
a
requirement
for
CO
CEMS
imposes
an
excessive
cost
burden
for
smaller
turbines.
Commenter
449
also
noted
that
CEMS
have
typically
not
been
required
on
small
turbines
and
personnel
would
not
be
familiar
with
CEMS
operation
and
maintenance,
resulting
in
increased
capital
and
operating
costs.
Furthermore,
commenter
449
felt
that
there
would
not
be
significant
emissions
reductions
for
the
use
of
CEMS
compared
to
the
use
of
inlet
temperature
monitoring
and
periodic
emission
testing;
the
requirement
is
inconsistent
with
previous
EPA
decisions
on
monitoring,
and
there
are
deficiencies
in
the
test
methods
and
performance
protocols.
Commenter
419
questioned
whether
the
low
measurements
can
be
made
accurately
and
reliably
on
a
continuous
basis
without
jeopardizing
the
flexibility
of
facility
operations.

Many
commenters
recommended
alternatives
to
the
CO
CEMS
requirement.
One
commenter
(
475)
suggested
the
option
of
monitoring
compliance
with
a
one­
time
performance
test
for
CO.
One
commenter
(
443)
said
that
an
option
could
be
reliance
on
a
federal
CO
permit
limit
combined
with
periodic
CO
stack
testing.
If
the
permitted
CO
limit
is
relatively
high,
compliance
with
the
formaldehyde
limit
at
that
level
could
first
be
determined
using
an
initial
formaldehyde
test.
If
the
CO
limits/
concentration
are
low,
initial
formaldehyde
testing
should
not
be
necessary.
The
commenter
recommended
that
EPA
establish
a
default
minimum
compliance
demonstration
at
5
ppm.
One
commenter
(
433)
recommended
that
EPA
evaluate
periodic
stack
tests,
conducted
on
the
same
schedule
as
relative
accuracy
test
audit
(
RATA)
testing
as
an
alternative
to
CEMS.
At
a
minimum,
this
approach
should
be
pursued
for
units
with
oxidation
catalyst
systems
that
would
qualify
as
peaking
units
under
the
Acid
Rain
Program
and
are
not
otherwise
required
to
conduct
emissions
monitoring
for
CO
or
other
pollutants.

One
commenter
(
419)
said
that
a
more
workable
solution
would
be
to
measure
downstream
CO,
but
only
if
a
CEMS
is
already
required
for
NO
x.
A
catalyst
efficiency
test
could
be
performed
periodically
to
confirm
continued
reduction
efficiency
(
should
include
option
to
perform
this
check
with
portable
analyzer).
One
commenter
(
440)
said
that
if
EPA
includes
an
option
to
monitor
CO
emissions
using
CPMS
rather
than
CO
CEMS,
a
requirement
to
replace
a
catalyst
bed
when
the
pressure
drop
increases
by
more
than
2
inches
of
water
from
the
drop
measured
during
the
initial
performance
test
may
not
be
appropriate.
Particular
vendors
are
better
able
to
specify
the
conditions
under
which
catalyst
replacement
is
warranted.

Response:
In
the
preamble
for
the
proposed
rule,
EPA
solicited
comments
on
the
performance
capabilities
of
a
state­
of­
the­
art
carbon
monoxide
(
CO)
continuous
emission
monitoring
system
(
CEMS)
and
its
ability
to
measure
the
low
concentrations
of
CO
in
the
exhaust
of
a
stationary
combustion
turbine
following
an
oxidation
catalyst
control
device.
In
general
commenters
did
not
support
CO
CEMS,
stating
that
existing
CO
CEMS
technology
and
EPA
performance
criteria
are
not
adequate
to
reliably
and
accurately
measure
trace
levels
of
CO.
Due
to
the
CO
measurement
difficulties,
EPA
has
decided
to
remove
the
CO
emission
reduction
limitation
from
the
rule.
Therefore,
while
EPA
recognizes
the
concerns
expressed
by
the
commenters,
measurement
of
CO
using
a
CO
CEMS
or
any
other
means
will
not
be
required,
and
63
the
comments
are
moot.

VI.
A.
2
Comment:
One
commenter
(
518)
favored
the
option
of
CO
CEMS
to
measure
CO
emissions
at
the
exhaust
from
a
stationary
CT
or
following
an
oxidation
catalyst
emission
control
device
(
i.
e.
CO
outlet
concentration
limit
monitored
with
CEMS).

Response:
As
stated
in
the
response
to
comment
VI.
A.
1,
EPA
does
not
feel
that
an
outlet
concentration
limit
is
appropriate.
Due
to
the
CO
measurement
difficulties,
EPA
has
decided
to
remove
the
CO
emission
reduction
limitation
from
the
rule.
Therefore,
the
comment
is
moot.

VI.
A.
3
Comment:
Two
commenters
(
444,
475)
requested
that
EPA
provide
justification
for
the
4­
hour
averaging
period
or
use
an
averaging
period
that
is
justified.
Four
commenters
(
422,
431,
437,
502)
said
that
the
averaging
time
for
CO
emissions
should
be
extended
to
24
hours
to
be
consistent
with
the
Boiler/
Process
Heater
MACT.

Response:
As
discussed
in
the
response
to
comment
VI.
A.
1,
the
emission
limitation
for
CO
reduction
has
been
removed
in
the
final
rule,
thus
this
comment
is
moot.
However,
the
EPA
does
not
agree
that
the
4­
hour
averaging
period
is
not
justified.
Gas­
fired
units
have
less
variability
in
the
feed
stream
than
other
sources
such
as
coal­
fired
boilers;
therefore
a
shorter
averaging
time
is
appropriate
for
those
units.

VI.
A.
4
Comment:
One
commenter
(
488)
recommended
that
the
final
rule
contain
provisions
for
using
one
set
of
CEMS
that
would
sequentially
monitor
both
the
inlet
and
outlet.

Response:
The
EPA
is
amenable
to
using
one
CEMS
to
sequentially
monitor
both
the
inlet
and
outlet,
however,
as
discussed
in
the
response
to
comment
VI.
A.
1,
EPA
has
decided
to
remove
the
CO
emission
reduction
limitation
from
the
rule
due
to
the
CO
measurement
difficulties.
Therefore,
the
comment
is
moot.

VI.
A.
5
Comment:
Three
commenters
(
465,
470,
471)
stated
that
it
is
doubtful
that
representative
samples
can
be
easily
and
reliably
obtained
prior
to
the
CO
catalyst.
Commenter
471
said
that
EPA
should
provide
additional
support
and/
or
guidance
regarding
the
most
appropriate
method
for
accurately
measuring
upstream
CO
emissions.

Response:
The
EPA
recognizes
the
commenters'
concern
that
there
could
be
difficulties
in
measuring
prior
to
the
CO
catalyst.
However,
as
discussed
in
the
response
to
comment
VI.
A.
1,
EPA
has
decided
to
remove
the
CO
emission
reduction
limitation
from
the
rule
due
to
the
CO
measurement
difficulties.
Therefore,
the
comment
is
moot.

VI.
A.
6
Comment:
Three
commenters
(
422,
431,
502)
felt
that
there
is
no
justification
for
O
2
and
CO
2
CEM
at
both
inlet
and
outlet
of
catalyst;
use
of
the
outlet
O
2
or
CO
2
concentration
is
more
than
adequate
to
correct
the
CO
concentration
at
both
the
inlet
and
outlet.
64
Response:
The
EPA
agrees
that
use
of
the
outlet
O
2
or
CO
2
concentration
is
more
than
adequate
to
correct
the
CO
concentration
at
both
the
inlet
and
outlet.
However,
as
discussed
in
the
response
to
comment
VI.
A.
1,
EPA
has
decided
to
remove
the
CO
emission
reduction
limitation
from
the
rule
due
to
the
CO
measurement
difficulties.
Therefore,
the
comment
is
moot.

B.
Performance
Testing
VI.
B.
1
Comment:
Three
commenters
(
443,
447/
448,
460)
requested
that
EPA
clarify
that
performance
testing
is
only
required
at
full
load.
One
commenter
(
443)
said
that
the
rule
should
allow
sources
the
option
to
conduct
tests
at
other
loads
as
necessary
to
avoid
interfering
with
sources'
operating
flexibility.
One
commenter
(
460)
recommended
that
compliance
testing
requirements
in
the
rule
account
for
the
possibility
that
in
some
CT
applications,
full
load
may
not
be
achievable
during
a
scheduled
compliance
test.

One
commenter
(
420)
suggested
that
performance
testing
should
be
conducted
within
a
60
to
100
percent
base
load
operating
range,
taking
into
account
operating
conditions
used
to
establish
applicable
vendor
guarantees
for
oxidation
catalyst
efficiency
as
well
as
design
criteria
used
to
develop
permitted
outlet
CO
or
formaldehyde
emissions
limitations.

Response:
As
stated
in
the
response
to
comment
V.
D.
2,
the
emissions
standards
are
based
on
emissions
data
from
testing
conducted
at
high
loads
(
90
percent
and
greater).
The
EPA
has
addressed
the
commenters'
concerns
by
clarifying
in
the
final
rule
that
the
performance
testing
should
be
conducted
at
high
load
conditions,
defined
as
100
percent
±
10
percent.

VI.
B.
2
Comment:
One
commenter
(
465)
remarked
that
subsequent
performance
testing
(
suggest
no
more
frequent
than
annually)
is
needed
for
units
meeting
the
formaldehyde
limit.
There
should
also
be
some
methodology
for
the
demonstration
of
continuous
compliance.

Response:
The
EPA
agrees
with
the
commenter
that
subsequent
performance
testing
is
needed
for
units
meeting
the
formaldehyde
limit.
As
a
result
of
this
comment,
the
final
rule
includes
a
requirement
for
annual
performance
testing
for
formaldehyde
for
these
units.
The
EPA
also
agrees
that
there
should
be
some
methodology
for
the
demonstration
of
continuous
compliance
and
has
designated
requirements
for
continuous
compliance
in
the
final
rule.
For
sources
equipped
with
oxidation
catalyst
control,
continuous
compliance
will
be
demonstrated
by
continuously
monitoring
the
inlet
temperature
to
the
catalyst
and
maintaining
the
inlet
temperature
within
the
range
suggested
by
the
catalyst
manufacturer.
Sources
that
are
not
equipped
with
oxidation
catalyst
control
must
petition
the
Administrator
for
approval
of
operating
limitations
or
approval
of
no
operating
limitations.

VI.
B.
3
Comment:
One
commenter
(
504)
stated
that
the
LPC
subcategory
should
not
have
an
initial
compliance
demonstration
for
the
emission
limit.
No
demonstration
is
needed
if
the
unit
has
an
initial
compliance
demonstration
for
its
respective
NO
x
limit.
65
Response:
An
initial
compliance
demonstration
that
includes
both
formaldehyde
and
NOx
would
be
necessary
to
establish
that
the
formaldehyde
emission
limit
is
being
achieved
at
the
same
time
the
NOx
limit
is
being
achieved.
However,
as
discussed
in
the
response
to
comment
VI.
B.
2,
the
final
rule
does
not
allow
continuous
compliance
to
be
demonstrated
by
meeting
low
NOx
emission
levels
required
by
a
federally
enforceable
permit,
so
this
comment
is
moot.

VI.
B.
4
Comment:
One
commenter
(
502)
said
that
EPA
should
allow
facilities
to
use
existing
test
data
to
demonstrate
compliance
with
the
emission
limitation
if
the
test
was
conducted
using
the
same
methods
specified
in
the
rule
and
no
process
changes
have
been
made
since
the
test,
or
it
can
be
demonstrated
that
the
results
of
the
performance
test
reliably
demonstrate
compliance
despite
process
changes.
The
commenter
recommended
that
EPA
revise
the
proposed
40
CFR
§
63.6110
by
adding
the
following
paragraph:

"
An
owner
or
operator
is
not
required
to
conduct
a
performance
test
to
determine
outlet
formaldehyde
concentration
on
units
for
which
a
performance
test
was
previously
conducted
for
determining
compliance
with
a
regulation
promulgated
by
the
EPA
and
the
test
was
conducted
using
the
same
methods
specified
in
this
subpart
and
either
no
process
or
equipment
changes
have
been
made
since
the
test,
or
the
owner
or
operator
can
demonstrate
that
the
results
of
the
performance
test,
with
or
without
adjustments,
reliably
demonstrate
compliance
despite
process
or
equipment
changes."

Response:
Since
there
are
no
emission
limitation
requirements
for
existing
sources
in
the
final
rule,
EPA
expects
that
few
facilities
will
have
existing
test
data
to
demonstrate
compliance
with.
Facilities
that
came
online
after
the
proposal
would
be
the
only
sources
that
may
have
conducted
emissions
testing
prior
to
the
stack
testing
requirements
of
the
final
rule
and
EPA
will
allow
facilities
to
use
existing
test
data
to
demonstrate
initial
compliance
with
the
emission
limitation
if
the
data
is
of
good
quality
and
is
no
older
than
two
years.
The
facility
must
petition
the
Administrator
for
approval,
and
demonstrate
that
the
tests
were
conducted
using
the
same
test
methods
specified
in
the
subpart,
the
test
method
procedures
were
correctly
followed,
no
process
or
equipment
changes
have
been
made
since
the
test,
and
the
data
is
of
good
quality
and
is
less
than
two
years
old.
Existing
test
data
can
only
be
used
to
demonstrate
initial
compliance;
after
the
initial
compliance
demonstration,
facilities
must
then
begin
to
follow
the
annual
compliance
test
schedule.

VI.
B.
5
Comment:
One
commenter
(
502)
requested
that
EPA
allow
a
facility
with
identical
CTs
to
conduct
performance
tests
on
only
one
of
the
units
to
demonstrate
compliance
with
the
emission
limits
for
all
of
the
identical
units.

Response:
The
EPA
does
not
agree
that
it
is
appropriate
to
allow
a
facility
with
identical
CTs
to
conduct
performance
tests
on
only
one
of
the
units
to
demonstrate
compliance
with
the
emission
limits
for
all
of
the
identical
units.
It
is
our
experience
that
emissions
from
identical
units
can
vary
significantly.
66
VI.
B.
6
Comment:
One
commenter
(
437)
recommended
that
the
initial
performance
test
period
for
demonstration
of
CO
reductions
be
increased
from
4
to
24
hours
or
longer
to
obtain
results
representative
of
the
normal
duty
cycle.

Response:
The
EPA
does
not
agree
with
this
comment;
it
is
believed
that
4
hours
is
sufficient
time
to
conduct
the
initial
performance
test.

VI.
B.
7
Comment:
One
commenter
(
483)
advised
EPA
to
consider
an
exemption
from
further
MACT
performance
testing
for
oxidation
catalyst
equipped
lean
premix
turbine
combined
cycle
units.

Response:
The
EPA
does
not
agree
that
there
should
be
an
exemption
from
further
MACT
performance
testing
for
lean
premix
turbine
combined
cycle
units
equipped
with
oxidation
catalyst
control.
Subsequent
performance
testing
is
necessary
to
demonstrate
that
the
emission
limitations
continue
to
be
met.

VI.
B.
8
Comment:
One
commenter
(
443)
did
not
support
EPA's
suggestion
that
if
it
required
compliance
with
the
formaldehyde
limit
and
not
a
percent
reduction
of
formaldehyde
it
might
require
"
more
frequent
emission
testing"
(
alternative
to
CO
CEMS).

Response:
The
commenter
did
not
identify
the
frequency
of
testing
that
they
do
not
support.
Thus,
EPA
is
not
able
to
respond
to
this
comment.

C.
Other
VI.
C.
1
Comment:
One
commenter
(
486)
requested
that
the
rule
clarify
that
LPC
CTs
with
oxidation
catalysts
will
not
be
required
to
use
CEMS.
The
rule
should
also
clarify
if
CO
CEMS
for
DFC
units
is
an
alternative
or
if
it
is
always
required.
The
commenter
noted
that
all
the
utility
size
CTs
constructed
in
Massachusetts
over
the
last
several
years
are
LPC
units
and
incorporate
CO
catalysts.

Response:
As
discussed
in
the
response
to
comment
VI.
A.
1,
CO
CEMS
are
not
required
in
the
final
rule.
Thus,
the
clarifications
requested
by
the
commenter
are
not
necessary.

VI.
C.
2
Comment:
Eight
commenters
(
433,
443,
447/
448,
471,
475,
483,
486,
505)
recommended
that
CTs
equipped
with
oxidation
catalysts
be
given
the
option
to
meet
the
formaldehyde
emission
limitation.
Commenter
471
said
that
requiring
CO
CEMS
for
units
with
oxidation
catalysts
places
an
unfair
additional
burden
on
those
facilities
that
are
among
the
best
controlled
and
have
the
lowest
emissions.
Commenter
483
contended
that
LPC,
combined
cycle
units
with
selective
catalytic
reduction
(
SCR)
and
oxidation
catalyst
systems
should
be
recognized
as
cleaner,
and
the
final
rule
should
be
amended
to
not
conflict
with
new
source
review
(
NSR)
permit
monitoring
requirements.
The
commenter
recommended
that
EPA
not
require
additional
monitoring
before
the
control
units.
If
unit's
initial
test
is
below
the
43
ppbvd
limit,
continuous
67
compliance
could
be
assured
through
continuing
to
meet
the
permitted
CO
or
NO
x
limit
after
the
catalyst
unit.
Commenter
486
had
a
similar
comment
for
LPC
units
equipped
with
oxidation
catalysts.

Commenter
475
recommended
that
EPA
provide
the
option
to
demonstrate
compliance
with
the
formaldehyde
emission
limit
based
on
a
one­
time
performance
test
conducted
at
the
inlet
to
the
oxidation
catalyst.
Commenter
443
proposed
that
EPA
allow
units
installing
catalysts
to
make
a
demonstration
of
compliance
with
the
formaldehyde
limit
through
periodic
formaldehyde
tests
performed
at
the
stack
(
annual
testing
should
be
more
than
sufficient).
Commenter
433
stated
that
testing
for
formaldehyde
emissions
should
be
required
even
when
an
oxidation
catalyst
system
is
present,
especially
for
larger
CTs
(
greater
than
10
or
50
MW).

Response:
These
commenters
all
were
concerned
that
CTs
equipped
with
oxidation
catalyst
control
were
restricted
to
meeting
the
CO
reduction
limitation
and
installing
CO
CEMS.
The
commenters
felt
that
these
turbines
should
be
given
the
option
to
meet
the
formaldehyde
limitation.
As
discussed
in
the
response
to
comment
VI.
A.
1,
the
CO
reduction
emission
limitation
and
CO
CEMS
requirement
has
been
dropped
from
the
final
rule
and
turbines
equipped
with
oxidation
catalyst
control
can
meet
a
formaldehyde
emission
limitation.
Thus
the
concerns
expressed
by
the
commenters
have
been
adequately
addressed.

VI.
C.
3
Comment:
Four
commenters
(
420,
443,
444,
475)
endorsed
EPA's
proposal
to
allow
LPC
CTs
to
rely
upon
low
NO
x
levels
to
demonstrate
continuous
compliance
following
initial
testing.
Commenter
444
requested
that
it
be
extended
to
all
types
of
turbines
that
have
low
NO
x
levels
permitted
by
an
enforcement
agency.
Two
of
the
commenters
(
443,
475)
recommended
that
EPA
establish
a
minimum
NO
x
emission
limitation
of
15
ppm.
There
would
be
no
requirements
for
additional
emission
testing
or
monitoring
to
demonstrate
MACT
compliance
if
a
given
LPC
CT
is
operating
at
or
below
15
ppm
NO
x
concentration
in
the
exhaust
gas
stream.

Response:
The
EPA
acknowledges
the
support
expressed
by
the
commenters.
However,
as
discussed
in
the
response
to
comment
VI.
B.
2,
comments
received
during
the
comment
period
led
us
to
establish
requirements
for
annual
stack
testing
and
continuous
parametric
monitoring
in
the
final
rule.
The
option
to
rely
upon
low
NOx
levels
is
not
in
the
final
rule.

VI.
C.
4
Comment:
Two
commenters
(
465,
470)
stated
that
CO
is
likely
a
more
reliable
indicator
of
HAP
emissions
than
NO
x
since
NO
x
formation
is
inversely
related
to
the
emission
of
CO
and
HAPs.
A
protocol
needs
to
be
developed
on
how
to
correlate
the
formaldehyde
emission
rate
with
the
surrogate
emission
rate.
One
commenter
(
470)
said
that
EPA
should
use
CO
emissions
as
a
surrogate
for
formaldehyde
for
LPC
units.
Likewise,
two
commenters
(
420,
430)
recommended
that
EPA
allow
testing
and
monitoring
of
a
surrogate
for
formaldehyde,
such
as
VOCs
or
CO.

Response:
As
discussed
in
the
response
to
comment
VI.
A.
1,
there
are
difficulties
in
measuring
CO
at
the
outlet
of
combustion
turbines
equipped
with
oxidation
catalyst
control.
68
Therefore,
using
a
surrogate
CO
emission
rate
is
not
a
viable
option.
The
commenter
did
not
provide
any
supporting
data
to
indicate
a
surrogate
relationship
between
VOC
and
HAP,
thus,
EPA
is
unable
to
address
their
comment.

VI.
C.
5
Comment:
One
commenter
(
429)
expressed
the
view
that
a
combination
of
periodic
Method
320
measurements
and
frequent
or
continuous
surrogate
measurements
would
give
a
high
level
of
confidence
to
the
actual
performance
and
HAP
emissions
at
a
low
cost.
Initial
emission
measurements
and
periodic
(
every
3­
5
years)
should
be
conducted
and
can
provide
a
calibration
of
the
CO
surrogate
to
the
actual
aldehyde
level
to
facilitate
monitoring
in
the
interim
periods
between
Method
320
tests.
Another
option
is
FTIR
CEMS,
however,
the
commenter
believes
CT
emissions
can
be
adequately
monitored
by
periodic
Method
320
testing
with
Method
320
calibrated
CO
surrogate
measurements
in
between
formal
emission
tests.

Response:
As
discussed
in
the
response
to
comment
VI.
A.
1,
the
option
to
use
CO
as
a
surrogate
has
been
removed
from
the
final
rule,
therefore,
some
of
the
comments
expressed
are
moot.
The
EPA
agrees
with
the
commenter
that
periodic
Method
320
measurements
are
appropriate
for
formaldehyde
and
that
method
is
allowed
in
the
final
rule.

VI.
C.
6
Comment:
Two
commenters
(
435,
502)
requested
that
the
proposed
rule
provide
that
emissions
from
CTs
are
to
be
determined
on
a
net
basis,
subtracting
ambient
formaldehyde.
One
commenter
(
424)
suggested
that
sources
should
balance
measurement
of
trace
emissions
(
aldehydes,
HC,
CO)
by
also
measuring
ambient
or
background
levels.
Similarly,
one
commenter
(
423)
recommended
that
EPA
provide
an
option
to
allow
simultaneous
testing
of
exhaust
gases
and
incoming
air.
Those
who
fail
the
stack
test
due
to
high
ambient
formaldehyde
in
the
bypass
air
could
normalize
the
emission
test
by
testing
intake
air
as
well.
An
additional
standard
could
be
based
on
the
difference
in
measured
formaldehyde
between
exhaust
and
intake
air.
A
differential
formaldehyde
option
would
need
to
be
placed
in
several
locations
in
the
final
rule,
including
Tables
1,
3,
and
4.
Suggested
language
is
given
in
the
comment.
Commenter
423
cited
a
study
of
ambient
air
in
St.
Louis
that
showed
formaldehyde
levels
that
would
exceed
the
proposed
43
ppb
emission
limit
as
rationale.

Response:
The
EPA
does
not
believe
that
ambient
formaldehyde
will
have
a
significant
effect
on
stack
levels
of
formaldehyde,
due
to
the
extremely
high
combustion
temperatures
of
CTs,
which
results
in
the
formaldehyde
being
destroyed
in
the
combustion
air.

VI.
C.
7
Comment:
One
commenter
(
420)
requested
that
in
addition
to
proposed
requirements
for
CEMS
for
CO
and
performance
testing,
EPA
should
include
alternatives
for
monitoring
utilizing
protocols
developed
based
on
EPA's
final
CAM
rule.

Response:
As
discussed
in
the
response
to
comment
VI.
A.
1,
the
final
rule
does
not
have
a
requirement
for
CO
CEMS
and
CO
performance
testing
due
to
public
comments
indicating
that
the
CO
stack
testing
methods
and
CO
CEMS
could
not
measure
the
low
CO
levels
that
are
achieved
particularly
by
LPC
units
with
oxidation
catalyst
controls.
Therefore,
the
comment
is
69
moot.

VI.
C.
8
Comment:
One
commenter
(
443)
said
that
EPA
should
not
require
petitions
for
additional
operating
parameters.

Response:
The
EPA
does
not
agree
with
the
commenter.
The
petitions
for
additional
operating
parameters
are
intended
for
HAP
control
systems
that
have
not
been
demonstrated
yet.
The
response
to
comment
V.
D.
10
provides
detailed
rationale
supporting
the
requirement
to
petition
for
additional
operating
parameters.

VI.
C.
9
Comment:
One
commenter
(
502)
recommended
that
the
wording
of
§
63.6120(
f)
should
be
changed
to
ensure
that
some
new,
arbitrary
formaldehyde
limit
would
not
be
imposed.
For
example,
the
following
words
could
be
added
to
(
f):
"
to
assure
that
the
formaldehyde
emission
limit
of
43
ppb
will
be
met."

One
commenter
(
417)
suggested
that
the
wording
of
§
63.6120(
f)
should
be
modified
from
".
.
.
additional
operating
limitations
to
be
established
during
the
initial
performance
test
and
continuously
monitored
thereafter"
to
"
operating
limits
to
demonstrate
compliance
with
the
formaldehyde
emission
concentration
limitation
during
the
initial
performance
test
and
continuously
monitored
thereafter."

Response:
The
EPA
is
amenable
to
clarifying
the
wording
of
§
63.6120(
f)
to
make
it
clear
that
the
operating
limits
are
for
the
formaldehyde
limit
in
the
rule.
The
EPA
has
incorporated
these
suggestions
in
the
final
rule
by
adding
clarifying
language
to
§
63.6120(
f).

VI.
C.
10
Comment:
One
commenter
(
417)
said
that
the
wording
of
§
63.6120(
f)
should
be
revised
from
"
.
.
.
your
stationary
combustion
turbine
is
not
diffusion
flame
or
lean
premix,
you
must
petition
the
Administrator
.
.
."
to
read
"
.
.
.
the
stationary
combustion
model
is
not
diffusion
flame
or
lean
premix,
the
manufacturer
must
petition
the
Administrator
.
.
.
."
The
rationale
for
the
change
is
that
this
only
needs
to
be
done
once
for
each
model.

Response:
The
EPA
does
not
agree
with
the
commenter
that
this
should
only
be
done
once
for
each
model.
The
option
to
petition
the
Administrator
should
be
utilized
on
a
site­
specific
basis,
not
for
an
entire
model
line
of
a
turbine.

VI.
C.
11
Comment:
One
commenter
(
417)
recommended
that
the
wording
of
§
63.6120(
g)(
3)
be
revised
to
read
"
The
limits
proposed
for
the
model
turbine
with
a
discussion
of
how
these
limits
were
developed
and
why
the
applicant
feels
they
will
assure
compliance
with
the
limitations.
If
data
is
not
available
to
determine
the
limitations
at
the
time
the
petition
is
submitted,
the
petition
must
include
a
discussion
of
how
you
will
establish
the
upper
and/
or
lower
values
for
the
parameters
which
will
be
establish
the
limits
on
these
parameters
in
the
operating
limitations:"
70
Response:
The
EPA
does
not
agree
that
this
change
is
necessary.
The
EPA
feels
that
the
language
in
the
section
is
adequate
as
written.

VI.
C.
12
Comment:
One
commenter
(
417)
recommended
that
in
§
63.6120(
h)(
7),
EPA
should
change
".
.
.
infeasible
or
unreasonable.
.
.
"
to
".
.
.
infeasible,
unreasonable
or
unnecessary.
.
.
"

Response:
The
EPA
has
accepted
the
commenter's
recommendation
and
made
this
change
to
§
63.6120(
h)(
7).

VI.
C.
13
Comment:
One
commenter
(
417)
requested
that
EPA
change
the
title
of
Table
6
to
read
"
Other
than
Diffusion
flame
or
Lean
Pre­
mix"
and
also
change
the
table
to
reflect
that
if
the
Administrator
concurs
that
§
63.6120(
h)
applies,
no
monitoring
is
required.

Response:
As
a
result
of
new
information
received
since
proposal,
the
requirements
in
Table
6
no
longer
apply
only
for
turbines
that
are
not
DFC
or
LPC.
Thus,
the
comment
is
moot.

VI.
C.
14
Comment:
One
commenter
(
502)
contended
that
the
requirement
that
deviations
must
be
accounted
for
in
addition
to
exceedances
is
overly
burdensome
(
§
63.6150(
d)(
4)).
Reporting
should
only
require
identification
of
start,
stop,
and
malfunction
periods.

Response:
The
requirements
in
§
63.6150(
d)(
4)
were
for
CTs
using
CEMS
to
comply
with
an
emission
limitation.
The
requirement
to
use
CEMS
has
been
removed
in
the
final
rule,
thus
this
comment
is
moot.

VI.
C.
15
Comment:
One
commenter
(
437)
asked
that
EPA
clarify
in
§
63.6150(
a)
that
only
those
units
subject
to
an
emission
limitation
must
comply
with
the
reporting
requirements.

Response:
The
EPA
agrees
with
the
commenter
that
the
rule
should
clarify
which
units
must
comply
with
reporting
requirements.
This
has
been
clarified
in
the
final
rule.

VII.
TEST
METHODS
A.
Formaldehyde
1.
CARB
430
VII.
A.
1.1
Comment:
Four
commenters
(
412,
421,
436,
449)
urged
EPA
to
re­
review
all
emission
tests
using
CARB
430.
Commenter
412
noted
that
CARB
had
issued
an
advisory
about
the
use
of
CARB
430.
Commenter
449
stated
that
any
historical
data
from
DFC
units
using
this
method
should
be
considered
suspect,
including
data
from
the
CT
Emissions
Database
and
AP­
42
71
emission
factors.
Unless
proven
otherwise,
the
DFC
CT
test
data
should
be
designated
"
nonquantitative
based
on
the
Method
430
advisory
from
CARB.
Commenter
436
said
that
a
study
of
the
accuracy
and
precision
of
CARB
430
at
low
ppb
levels
is
needed
to
determine
the
significance
of
the
test
data
on
which
the
standard
is
based.

Response:
The
EPA
reviewed
the
CARB
advisory
issued
on
April
28,
2000
and
additional
background
material
in
the
GRI
Topical
Report
entitled
"
Investigation
of
Interferences
with
Aqueous
2,4­
DNPH
Based
Methods
for
Measurement
of
Aldehydes
in
Natural
Gas
Combustion
Exhaust"
submitted
by
Commenter
449.
As
a
result
of
comments
received
during
the
comment
period,
EPA
performed
an
extensive
review
of
tests
used
at
proposal
and
new
tests
received
during
the
comment
period.
A
screening
analysis
of
the
formaldehyde
test
data
for
diffusion
flame
combustor
turbines
was
conducted.
Tests
conducted
using
CARB
430
were
evaluated
due
to
the
CARB
advisory,
which
stated
that
formaldehyde
data
measured
by
CARB
430
where
the
NOx
emissions
were
greater
than
50
ppm
should
be
flagged
as
non­
quantitative.
Tests
where
the
NOx
emissions
were
greater
than
50
ppm
or
tests
where
the
NOx
levels
were
unknown
were
excluded
from
EPA's
analysis.

EPA
further
analyzed
and
reviewed
the
remaining
test
reports
to
ensure
the
methods
were
used
correctly
in
calculating
and
reporting
formaldehyde
concentrations
and
to
check
that
proper
QA/
QC
procedures
were
followed.
A
number
of
errors
were
found
in
the
test
reports
where
CARB
430
was
used
to
quantify
formaldehyde
concentrations.
In
several
instances
the
CARB
430
reporting
protocol
was
not
followed.
If
the
concentration
is
less
than
five
times
the
field
blank,
CARB
430
uses
five
times
the
field
blank
as
the
reported
result
to
correct
for
interferences
or
contaminants
that
can
react
with
the
formaldehyde
or
dinitrophenylhydrazine
to
yield
negative
bias.
However,
many
test
reports
did
not
report
formaldehyde
concentrations
in
this
fashion.
EPA
therefore
recalculated
the
formaldehyde
concentrations
where
the
CARB
430
reporting
protocol
was
not
followed
correctly.

VII.
A.
1.2
Comment:
Nine
commenters
(
424,
430,
435,
436,
442,
449,
460,
479,
502)
expressed
concerns
regarding
the
accuracy
and
precision
at
levels
commensurate
with
the
proposed
standard.
Two
of
the
commenters
(
424,
479)
noted
that
CARB
430
is
susceptible
to
interferences.
One
commenter
(
436)
said
that
sample
loss
and
measurement
uncertainties
can
contribute
to
large
measurement
variability.
One
commenter
(
449)
asserted
that
CARB
430
should
not
be
included
as
an
appropriate
method
for
DFC
CTs.

One
commenter
(
429)
contended
that
CARB
430
is
an
indirect
measurement
method
and
is
inferior
to
Method
320.
CARB
430
cannot
give
realistic
results
due
to
the
following:
formaldehyde
results
tend
to
be
negatively
biased
with
high
scatter,
especially
at
low
concentrations;
there
are
other
problems
with
high
field
and
analyte
blanks;
the
tester
must
know
the
NO
2
concentration
prior
to
testing,
introducing
another
uncertainty
into
the
measurement;
the
method
can
give
false
acetaldehyde
detections;
data
cited
showing
inconsistencies
with
CARB
430;
and
the
high
level
of
variations
and
biases
observed
may
lead
to
future
compliance
problems
or
public
lawsuits
over
falsely
detected
species
or
negative
catalyst
performance.
72
Two
commenters
(
485,
501)
observed
that
the
minimum
detection
limits
are
higher
than
the
MACT
Floor.
Standard
procedures
for
handling
blank
corrections
and
non­
detects
should
be
added
to
the
promulgated
test
methods.
The
method
should
be
validated
for
combustion
sources
and
revised
to
provide
for
longer
sampling
runs
necessary
to
achieve
the
detection
levels
needed
to
reliably
and
routinely
measure
ppb
level
formaldehyde.
Longer
sample
runs
are
problematic.

Two
commenters
(
435,
437)
recommended
modifications
to
CARB
430
and
guidelines
to
enhance
the
measurement
reliability
for
CARB
430.
Commenter
435
stated
that
with
the
modifications,
CARB
430
can
achieve
a
detection
level
less
than
43
ppb.
Similarly,
commenter
437
said
that
the
use
of
CARB
430
is
conditionally
supported,
but
additional
guidance
and
deviations
from
the
method
as
currently
published
should
be
provided.
Field
validation
of
the
method
performance
for
CT
applications
according
to
EPA
Method
301
is
recommended.
That
commenter
also
recommended
that
EPA
should
require
use
of
paired
sampling
trains
for
every
test
run.
If
the
precision
of
any
one
test
run
with
paired
sampling
trains
is
poor
due
to
apparent
random
contamination,
it
should
be
explicitly
permitted
to
disregard
the
suspect
sample
results.

One
commenter
(
435)
recommended
that
the
CARB
430
reporting
protocol
be
revised
to
reflect
the
actual
emissions
from
the
CT.
The
rule
should
indicate
that
when
using
CARB
430
to
demonstrate
compliance
with
the
proposed
standard,
the
reporting
criteria
should
not
be
as
indicated
in
CARB
430
but
should
be
the
stack
measurement
minus
the
average
field
blank
measurement.
Conversely,
one
commenter
(
437)
recommended
that
EPA
should
retain
the
CARB
430
reporting
limit
procedures,
or
a
valid
statistical
measure
of
uncertainty
such
as
the
95
percent
upper
confidence
bound,
to
reflect
data
quality.
Since
the
method
was
developed
for
much
higher
in­
stack
formaldehyde
concentrations,
and
hence
much
higher
blank
contamination
levels,
EPA
should
develop
an
alternative
calculation
procedure
to
account
for
increased
likelihood
of
very
low­
level
blank
contamination.

Response:
The
EPA
agrees
with
the
nine
commenters'
concerns
regarding
the
accuracy
of
CARB
430
levels
commensurate
with
the
proposed
standard.
EPA
agrees
with
the
commenters
who
noted
that
CARB
430
is
susceptible
to
interferences
or
who
said
that
sample
loss
and
measurement
uncertainties
contribute
to
large
measurement
variability.
EPA
agrees
with
Commenter
429
that
the
method
is
an
indirect
measurement
method,
however,
EPA
disagrees
that
CARB
430
cannot
give
realistic
results;
in
some
cases
EPA
believes
that
CARB
430
can
provide
realistic
data.
However,
EPA
also
agrees
that
Method
320
would
be
the
better
compliance
method.
Therefore
EPA
has
specified
either
Method
320
or
ASTM
D6348­
03
as
the
compliance
procedure.
As
discussed
in
the
response
to
comment
VII.
A.
5.1,
ASTM
D6348­
03
is
an
acceptable
alternative
to
Method
320.

VII.
A.
1.3
Comment:
One
commenter
(
443)
remarked
that
EPA
does
not
explain
how
it
calculated
the
2­
3
ppb
detection
limit
cited
in
the
preamble
for
CARB
430;
EPA
should
explain
the
procedure
used
to
calculate
the
detection
limit
and
to
review
the
calculation
results.
The
commenter
also
said
that
EPA's
method
for
determining
the
detection
limit
of
CARB
430
significantly
overstates
the
practical
source
measurement
capabilities
of
this
method.
73
Response:
The
EPA
used
reported
responses
from
low
level
standards
or
blanks
to
calculate
standard
deviation
of
the
responses
and
then
multiplied
that
by
three
to
estimate
a
detection
limit
potentially
attainable.

VII.
A.
1.4
Comment:
One
commenter
(
443)
expressed
the
view
that
ambient
formaldehyde
may
affect
CARB
430
test
results.
The
commenter
requested
that
EPA
conduct
ambient
tests
and
develop
ways
to
correct
for
ambient
contributions/
contamination
in
the
results.
The
EPA
should
design
its
standard
and
compliance
methods
to
ensure
that
sources'
compliance
status
is
not
susceptible
to
fluctuations
in
ambient
formaldehyde
concentrations.

Response:
The
EPA
agrees
that
ambient
formaldehyde
may
affect
CARB
430
results;
Method
320
and
ASTM
D6348­
03
results
will
be
less
affected.
However,
since
Method
320
and
ASTM
D6348­
03
are
the
only
test
methods
allowed
in
the
final
rule
to
demonstrate
compliance,
this
comment
is
moot.

2.
FTIR/
EPA
Method
320
VII.
A.
2.1
Comment:
Nine
commenters
(
420,
424,
435,
436,
443,
449,
460,
479,
502)
expressed
concerns
regarding
the
accuracy,
precision,
and
reliability
at
levels
commensurate
with
the
proposed
standard.
Three
commenters
(
435,
460,
502)
said
that
the
method
is
not
acceptable
for
demonstrating
compliance
without
extensive
modifications.
One
commenter
(
502)
noted
that
there
is
little,
if
any,
FTIR
data
at
low
ppb
levels.
One
commenter
(
443)
stated
that
the
method's
lenient
performance
specifications
allow
significant
measurement
error
in
reportable
results.
One
commenter
(
420)
noted
that
FTIR
testing
is
only
offered
by
a
limited
number
of
providers,
requires
special
expertise
and
significant
capital
investment,
and
is
still
a
relatively
immature
field
of
endeavor.
One
commenter
(
424)
said
that
many
stakeholders
are
not
supportive
of
FTIR
because
of
the
attendant
costs,
sensitivity
and
interference
problems,
and
need
for
considerable
operator
expertise.

Two
commenters
(
443,
479)
noted
that
the
method
is
susceptible
to
interferences
from
water
vapor,
NO
2,
and
hydrocarbons.
Likewise,
one
commenter
(
436)
said
the
method
is
susceptible
to
interferences
from
water
vapor
and
carbon
dioxide,
and
the
method
cannot
be
the
preferred
measurement
technique
without
a
field
demonstration
of
the
feasibility
of
measuring
formaldehyde
at
low
ppb
in
LPC
exhaust.

One
commenter
(
479)
said
that
an
instrument
with
a
pathlength
of
200
meters
(
m)
would
be
needed
(
possible
but
would
have
to
be
set
up
at
an
off­
site
facility).
Samples
would
have
to
be
transported
for
sampling
very
quickly.
Contamination
of
samples
during
transport
is
also
a
concern.
One
commenter
(
443)
contended
that
there
are
not
enough
testing
companies
with
instruments
of
sufficient
path
length
to
measure
at
that
low
levels.
The
commenter
estimated
that
path
lengths
higher
than
100
to
125
m
will
be
needed.
The
commenter
is
aware
of
only
two
FTIRs
equipped
with
a
100­
125
m
path
length
cell
and
neither
have
been
tested
and
validated
in
the
field
for
compliance
testing
purposes.
The
commenter
said
that
EPA
has
not
provided
any
74
data
to
assess
what
effect
the
extended
path
length
required
for
low
level
formaldehyde
measurement
will
have
on
instrument
precision,
accuracy,
signal
strength,
or
potential
interferences.

One
commenter
(
443)
stated
that
the
method's
minimum
detection
limit
is
too
high
to
provide
any
confidence
in
measurements
at
the
43
ppb
level.
The
FTIRs
currently
being
used
to
some
degree
in
the
field
with
modified
procedures
have
formaldehyde
detection
limits
of
approximately
50­
60
ppb.
One
commenter
(
449)
expressed
support
for
the
use
of
extractive
FTIR
but
had
reservations
about
EPA's
statement
that
the
method
is
capable
of
achieving
below
43
ppb.
The
commenter
believed
that
this
level
of
detection
is
not
achievable
in
practice
and
that
EPA
should
consider
that
the
test
method
must
be
achievable
in
practice
by
professionals
with
a
level
of
expertise,
and
a
required
capital
investment,
commensurate
with
the
current
standards
in
the
emission
source
test
community.

Two
commenters
(
485,
501)
stated
that
FTIR
can
achieve
the
detection
limits
necessary
to
quantify
sub­
ppm
formaldehyde
emissions,
but
at
high
costs
and
only
with
pre­
concentrating
measures
to
remove
water
vapor
and/
or
CO
2,
specialized
equipment
(
long
path
length)
and
extremely
rigorous
quantitative
analysis.
The
FTIR
test
method
must
be
revised
to
incorporate
approved
methods
and
procedures
for
selecting
path
length,
pre­
concentrating
emissions
or
otherwise
reducing
routinely
achievable
detection
levels.

One
commenter
(
437)
expressed
conditional
support
for
the
use
of
FTIR
but
said
that
additional
field
studies
are
needed
to
demonstrate
minimum
detection
limits
and
practical
quantitation
limits.
Field
validation
of
the
method
performance
for
CT
applications
according
to
EPA
Method
301
is
recommended.

Response:
The
FTIR
technology
is
rapidly
improving
and
this
trend
will
continue.
As
a
result,
EPA
received
a
divergence
of
opinions
reflecting
this
rapidly
changing
trend.
Method
320
is
a
self­
validated
performance­
based
method
that
will
allow
the
use
of
this
improved
technology
and
not
suppress
it.
Current
state­
of­
the­
art
methodology
can
identify
and
measure
formaldehyde
concentrations
well
below
the
current
emission
limitation
with
a
path
length
of
10
meters
or
less.
Some
of
the
older
technology
may
require
100
or
even
200
meter
path
length.
The
method
has
a
pretest
preparation
and
evaluation
procedure
to
determine
the
optimum
sampling
system
configuration
for
measuring
formaldehyde
customized
to
the
technology
the
tester
is
using.
Detection
levels
in
FTIRs
are
limited
either
by
noise
or
by
interference
from
other
gases.
Measurement
of
formaldehyde
has
very
little
interference
so
one
can
get
close
to
the
noise
limited
detection
with
state­
of­
the­
art
technology.
EPA
agrees
with
Commenter
443
that
some
of
the
performance
criteria
may
be
more
lenient
than
needed
by
current
state­
of­
the­
art
technology,
but
it
is
sufficient.
The
cost
to
conduct
a
test
is
not
the
primary
concern
of
EPA,
however,
as
indicated
by
Commenter
429,
the
cost
appears
to
be
decreasing,
as
would
be
expected
in
the
free
market
system.
Water
vapor
(
and
other)
interferences
are
taken
into
consideration
in
the
pretest
planning.
75
VII.
A.
2.2
Comment:
One
commenter
(
429)
expressed
the
view
that
Method
320
is
the
most
accurate,
precise,
and
cost
effective
method
for
formaldehyde
measurements.
It
does
not
have
the
physical
or
chemical
limitations
of
the
other
formaldehyde
methods.
The
commenter
said
that
in
1998,
FTIR
detection
limits
of
10
ppbv
were
obtained
with
a
80
meter
pathlength
cell.
With
subsequent
advances
in
instrumentation
hardware
and
software,
8
ppbv
with
a
10
meter
pathlength
cell
is
now
achievable
and
demonstrated
in
the
field.
Recent
field
data
shows
further
improvement
of
the
detection
limit
to
6
ppb.
An
eventual
reduction
of
detection
limit
to
near
the
3
ppbv
theoretical
limit
obtainable
with
current
instrumentation
at
10
meters
pathlength
is
foreseen.
It
is
possible
to
achieve
this
over
a
1­
hour
measurement
period.

According
to
the
commenter,
the
current
cost
of
Method
320
measurements
is
extremely
competitive
to
that
of
other
methods.
Data
were
cited
that
shows
that
for
two
turbines,
the
cost
for
testing
is
virtually
identical
to
that
for
other
methods.
At
three
turbines
and
more,
the
Method
320
per
turbine
cost
drops
below
that
of
the
other
methods.
The
cost
for
one
turbine
test
on­
site
is
$
11,765.

The
commenter
also
said
that
Method
320
requires
a
few
changes
to
optimize
its
usage
for
turbine
measurements.
They
are
as
follows:
Method
320
should
be
a
performance­
based
method;
"
tweaking"
Method
320
will
not
have
any
effect
on
detection
limits;
Method
320
should
be
classified
as
a
"
stand
alone"
method
in
a
MACT
rule
instead
of
promulgating
other
inferior
methods
as
alternates;
Method
320
should
not
require
revealing
of
spectral
analysis
details,
reference
spectra
or
sample
spectra.

One
commenter
(
437)
recommended
that
in
addition
to
the
formaldehyde
spike
procedure
and
recovery
criteria
already
contained
in
EPA
Method
320,
the
absence
of
significant
sampling
system
bias
be
demonstrated
by
injecting
ultra­
high
purity
nitrogen
calibration
gas
at
a
flow
rate
exceeding
total
sampling
flow
rate
at
two
locations
in
the
sampling
system.
One
location
is
directly
at
the
inlet
of
the
FTIR
sampling
cell,
and
the
other
is
at
the
back
of
the
sampling
probe
as
close
to
the
probe
as
practical
but
upstream
of
any
sample
conditioning
(
e.
g.,
heated
filters).
The
total
absolute
difference
in
measured
formaldehyde
concentrations
at
these
two
locations
(
defined
as
sampling
system
bias)
should
be
less
than
10
percent
of
the
formaldehyde
concentration
limit,
otherwise
corrective
action
to
the
sampling
system
must
be
implemented.

Response:
The
EPA
appreciates
the
suggestions
for
improving
Method
320
and
will
consider
these
as
well
as
any
others
during
periodic
reviews.
However,
the
improvement
suggestions
do
not
appear
to
be
in
the
critical
path
of
the
standard­
setting
process.

3.
EPA
SW­
846
Method
0011
VII.
A.
3.1
Comment:
One
commenter
(
437)
did
not
support
the
use
of
EPA
Method
0011
for
turbines
because:
there
is
no
need
for
isokinetic
sampling
in
CT
stacks;
compared
to
CARB
430,
the
field
procedure
is
more
complex,
the
potential
for
chronic
field
contamination
is
much
greater,
the
QA/
QC
procedures
are
vastly
inferior,
and
the
data
reporting
procedures
76
especially
with
respect
to
blanks
are
more
vague;
and
the
method
does
not
have
sufficient
sensitivity
for
demonstrating
compliance
with
the
proposed
formaldehyde
limit.
One
commenter
(
449)
remarked
that
the
method
should
be
excluded
from
the
list
of
acceptable
test
methods
because
it
uses
a
similar
analytical
approach
to
CARB
430,
has
not
been
validated
for
application
to
CTs,
and
has
QA
requirements
considered
less
than
CARB
430.
Commenter
443
also
noted
that
this
method
is
similar
to
CARB
430
and
thus
will
present
similar
measurement
issues.

Six
commenters
(
435,
437,
460,
485,
501,
502)
noted
that
the
method
states
that
detection
limit
may
be
as
low
as
90
ppb;
therefore
method
does
not
have
demonstrated
capability
for
43
ppb
limit.
One
commenter
(
429)
said
that
the
method
is
inferior
to
EPA
Method
320.

Two
commenters
(
485,
501)
recommended
that
the
method
should
be
validated
for
combustion
sources
and
revised
to
provide
for
longer
sampling
runs
necessary
to
achieve
the
detection
levels
needed
to
reliably
and
routinely
measure
ppb
level
formaldehyde.
Longer
sample
runs
are
problematic.
Standard
procedures
for
handling
blank
corrections
and
non­
detects
should
be
added
to
the
promulgated
test
methods.
More
stringent
QA/
QC
measures
are
needed.

Response:
The
EPA
agrees
with
the
commenters
that
the
method
has
many
shortcomings
and
limited
application
opportunities
for
use
in
measuring
formaldehyde
emissions
from
combustion
turbines.
Accordingly,
EPA
is
not
including
EPA
Method
0011
in
the
final
rule.
Both
EPA
Method
0011
and
CARB
430
can
be
requested
on
a
case­
by­
case
basis
as
part
of
EPA's
alternative
method
review
process.

4.
EPA
Method
323
VII.
A.
4.1
Comment:
Nine
commenters
(
435,
437,
442,
443,
449,
460,
485,
501,
502)
said
that
EPA
Method
323
should
not
be
used
for
measuring
very
low
concentrations
of
formaldehyde.
The
minimum
detection
levels
of
the
method
are
not
suitable
for
the
emission
standard.
One
commenter
(
443)
noted
that
the
method
could
not
be
modified
to
measure
such
low
concentrations
without
significantly
affecting
its
accuracy
and
precision
and
calling
into
question
the
entire
validity
of
the
method.
Two
commenters
(
435,
502)
also
noted
that
the
method
has
not
been
validated
or
demonstrated
for
use
on
CTs
with
low
ppb
range
formaldehyde
emissions.
One
commenter
(
420)
also
noted
that
the
method
is
difficult
and
costly.

One
commenter
(
429)
stated
that
Method
323
is
inferior
to
Method
320.
In
the
commenter's
opinion,
total
water
soluble
aldehyde
methods
such
as
Method
323
are
not
useful,
especially
when
attempting
to
calculate
total
aldehyde
emissions.
Formaldehyde
cannot
be
differentiated
from
acetaldehyde,
etc.
which
prevents
accurate
calculation
of
total
mass
of
HAPs
emitted
from
the
source
measured.
The
commenter
has
also
observed
formaldehyde
positive
biases
as
high
as
300
percent
with
Method
323
in
natural
gas­
fired
combustion
sources
as
compared
to
Method
320.
The
high
level
of
variations
and
biases
observed
may
lead
to
future
compliance
problems
or
public
lawsuits
over
falsely
detected
species
or
negative
catalyst
performance.
77
Response:
The
EPA
agrees
with
the
commenters
that
EPA
Method
323
should
not
be
used
for
measuring
low
concentrations
of
formaldehyde
from
combustion
turbines
and
has
therefore
not
included
it
in
the
final
rule.

VII.
A.
4.2
Comment:
One
commenter
(
440)
requested
that
EPA
include
an
option
to
add
a
cooling
coil
to
the
formaldehyde
test
apparatus.
The
concern
is
that
CT
exhaust
will
melt
the
Teflon
tubing
on
the
proposed
apparatus.

Response:
The
EPA
agrees
with
the
commenter
that
melting
Teflon
is
a
concern.

VII.
A.
4.3
Comment:
One
commenter
(
515)
recommended
that
the
proposed
Method
323
be
clarified
to
indicate
the
sampling
time
required
per
run.

Response:
The
EPA
agrees
that
minimum
sampling
time
should
have
been
specified.
However,
in
the
final
rule
EPA
is
not
allowing
Method
323
for
demonstrating
compliance.

5.
Other
VII.
A.
5.1
Comment:
Four
commenters
(
420,
437,
442,
449)
requested
that
the
final
rule
allow
ASTM
Method
D6348
as
equivalent
to
Method
320.

Response:
The
ASTM
made
a
few
changes
to
ASTM
D6348­
98.
These
were
successfully
balloted.
The
EPA
accepts
the
new
version
as
an
alternative
to
Method
320,
40
CFR
part
63,
appendix
A
for
formaldehyde
measurement
provided
in
ASTM
D6348­
03,
Annex
A5
(
Analyte
Spiking
Technique),
the
percent
R
must
be
greater
than
or
equal
to
70
and
less
than
or
equal
to
130.

VII.
A.
5.2
Comment:
One
commenter
(
449)
said
that
EPA
Method
316
may
be
a
viable
formaldehyde
test
method
for
CTs.
The
final
rule
should
include
provisions
to
use
other
approved
methods,
and
to
incorporate
new
methods
for
formaldehyde
measurement
as
they
are
developed.

Response:
The
EPA
agrees
that
EPA
Method
316
may
be
an
acceptable
alternative
in
limited
cases,
provided
it
is
modified
to
prevent
a
potential
negative
SO
2
interference
as
described
in
the
literature.
However,
additional
study
and
validation
would
be
needed.
If
there
is
interest,
EPA
would
be
willing
to
work
with
interested
users
to
develop
an
acceptable
validation
plan.

VII.
A.
5.3
Comment:
One
commenter
(
385)
informed
EPA
that
three
ASTM
standards
have
been
updated:
E
337­
84
(
1996)
is
now
E
337­
02;
D
3154­
91
is
now
D
3154­
00;
and
D
5835­
95
is
now
D
5835­
95
(
2001).

Response:
The
EPA
appreciates
the
comment;
however,
these
particular
ASTM
standards
are
not
referenced
in
the
preamble
to
the
final
rule,
therefore,
it
was
not
necessary
to
update
the
78
standards..

VII.
A.
5.4
Comment:
Nine
commenters
(
418,
421,
435,
443,
444,
449,
481,
502,
519)
remarked
that
there
is
a
lack
of
repeatable
and
reliable
formaldehyde
test
methodology
that
is
capable
of
detection
at
low
levels.
Commenter
443
observed
that
assuming
a
realistic
detection
limit
of
50
ppb
for
several
of
the
methods,
EPA
would
need
to
set
the
standard
at
250
ppb
or
higher
(
5
x
DL)
to
ensure
that
measurement
issues
would
not
lead
to
a
significant
number
of
failures.
Commenter
443
also
suggested
that
EPA
should
give
additional
consideration
to
its
determination
of
the
MDLs
for
the
proposed
methods
when
it
establishes
the
final
formaldehyde
emission
limit.
Furthermore,
given
the
uncertainty
in
the
methods,
EPA
must
provide
sources
the
opportunity
to
perform
additional
tests
before
a
required
"
performance
test"
would
be
deemed
failed.
Also,
EPA
must
ensure
in
the
final
rule
that
no
source
could
be
required
to
use
one
of
the
methods
to
conduct
performance
testing.

Commenter
421
questioned
the
validity
of
EPA
Method
0011,
CARB
430,
and
EPA
Method
320
or
FTIR
for
measuring
extremely
low
levels
of
formaldehyde
emissions.
Commenter
444
said
that
EPA
should
reevaluate
the
data
on
which
the
proposed
standard
is
based
and
whether
or
not
a
formaldehyde
level
that
may
be
set
in
the
final
rule
can
be
reliably
measured.

Response:
The
EPA
agrees
with
the
commenters
that
EPA
Method
0011
and
CARB
430
may
not
be
valid
for
measuring
extremely
low
levels
of
formaldehyde
emissions.
Therefore
some
of
the
comments
are
moot.
The
EPA
does
not
agree
that
EPA
Method
320
should
not
be
used.
Several
EPA
Method
320/
FTIR
experts
were
consulted
and
they
indicated
that
detection
limits
as
low
as
10
ppb
were
possible.
The
EPA
agrees
that
the
data
on
which
the
proposed
standard
should
be
reevaluated.
An
extensive
review
of
the
data
was
conducted.
This
review
is
discussed
in
great
detail
in
the
response
to
comment
V.
A.
1.

VII.
A.
5.5
Comment:
Two
commenters
(
435,
460)
said
that
there
are
several
ambient
methods
available
for
measurement
of
formaldehyde,
but
the
matrix
of
turbine
combustion
gases
makes
these
methods
unsuitable
for
consideration
as
valid
procedures
to
document
compliance
with
CT
emissions
limits.

Response:
The
EPA
acknowledges
the
comment.

VII.
A.
5.6
Comment:
One
commenter
(
424)
recommended
that
a
joint
industrygovernment
task
force
for
the
measurement
of
aldehydes
from
gas
turbine
exhaust
be
formed.

Response:
The
EPA
would
be
willing
to
participate
in
the
task
force.

VII.
A.
5.7
Comment:
One
commenter
(
424)
contended
that
CEMS
requirements
cannot
be
supported
by
the
current
formaldehyde
monitoring
technology.
Formaldehyde
testing
should
be
performed
on
a
periodic
(
annual)
basis
or
replaced
by
surrogate
CO
measurement
practices.
79
Response:
The
rule
does
not
have
a
CEMS
requirement
for
monitoring
formaldehyde.

VII.
A.
5.8
Comment:
One
commenter
(
463)
submitted
a
test
report
that
compared
FTIR
and
CARB
430.
The
testing
was
conducted
on
a
Siemens
Westinghouse
501F
gas­
fired
CT
with
LPC,
SCR,
and
CO
catalyst.
Formaldehyde
was
measured
using
CARB
430
and
FTIR.
The
CARB
430
results
did
not
compare
well
with
the
FTIR
results.
The
formaldehyde
emissions
using
CARB
430
averaged
9
ppb
in
the
turbine
exhaust
and
5
ppb
at
the
stack.
The
FTIR
results
were
47
ppb
at
the
turbine
exhaust
and
42
ppb
at
the
stack.

Response:
The
EPA
thanks
the
commenter
for
submitting
the
information.
The
EPA
agrees
that
CARB
430
understates
the
formaldehyde
concentration
in
the
exhaust
gas
from
stationary
CTs.

B.
CO
1.
CEMS
VII.
B.
1.1
Comment:
Twenty­
three
commenters
(
421,
422,
424,
426,
427,
430,
435,
436,
437,
442,
443,
444,
447/
448,
449,
460,
479,
482,
485,
486,
501,
502,
508,
509)
said
that
CO
CEMS
cannot
reliably
measure
trace
level
CO
concentrations
and
95
percent
CO
reduction.
Commenter
449
remarked
that
EPA
provides
no
information
to
show
that
CEMS
are
available
to
accurately
measure
low
CO
concentrations,
and
the
use
of
CO
CEMS
for
low
CO
levels
is
well
beyond
the
scope
of
current
40
CFR
60
CEMS
standards.
Revisions
will
be
needed
to
the
standards.
Also,
vendor
claims
for
CO
CEMS
and
CO
instrumental
analyzers,
unless
accompanied
by
emissions
test
data
obtained
under
known
and
controlled
conditions
applicable
to
the
subject
source
type,
should
not
be
considered
adequate
proof
of
availability
and
performance.

Two
commenters
(
485,
501)
observed
that
in
cases
where
CO
is
very
low,
specifications
for
calibration
drift
and
relative
accuracy
set
out
in
PS­
4A
may
be
unattainable;
for
a
trace­
level
CO
analyzer,
alternatives
to
PS­
4A
may
be
necessary.
One
commenter
(
505)
recommended
that
PS
4
and
4A
should
be
revised
to
reflect
the
measurement
of
CO
in
the
range
of
0­
10
ppm
and
0­
1
ppm
and
also
should
be
harmonized
with
40
CFR
Part
75
CEMS
requirements.
Methods
for
determining
the
relative
accuracy
of
the
CEMS
should
be
developed
with
the
low
CO
ppm
measurement
in
mind.

Response:
The
EPA
agrees
that
existing
CO
CEMS
technology
and
EPA
performance
criteria
are
not
adequate
to
reliably
and
accurately
measure
trace
levels
of
CO.
The
ASTM
is
currently
trying
to
address
this
issue
and
EPA
is
participating.

VII.
B.
1.2
Comment:
One
commenter
(
486)
suggested
that
EPA
allow
data
validation
to
be
performed
in
accordance
with
40
CFR
§
75.10(
d)
provisions
as
an
alternative
to
the
two
quadrant
methodology
specified
in
§
63.6125(
a)(
3).
The
commenter
noted
that
Subparts
Da
and
Db
of
40
CFR
part
60
allow
use
of
40
CFR
part
75
data
validation
procedures
as
an
alternative
to
80
application
of
part
60
procedures.

Response:
The
use
of
current
40
CFR
Part
75
data
validation
would
not
be
suitable
for
this
Part
63
application.
However,
CO
CEMS
are
not
being
required
so
the
suggestion
is
moot.

VII.
B.
1.3
Comment:
One
commenter
(
419)
requested
that
the
40
CFR
part
60
Appendix
B,
Specification
2
requirements
regarding
measurement
range
should
be
waived,
and
perhaps
even
the
RATA
requirements.

Response:
Carbon
monoxide
CEMS
are
not
being
required
so
the
suggestion
is
moot.

VII.
B.
1.4
Comment:
One
commenter
(
484)
recommended
that
EPA
revise
the
CO
CEMS
requirement
to
extend
the
averaging
time
and
utilize
O
2
or
CO
2
measurements
at
only
the
outlet
of
the
oxidation
catalyst.

Response:
Based
on
this
comment
and
other
similar
comments
received
during
the
public
comment
period,
EPA
has
decided
that
the
CO
CEMS
systems
are
not
accurate
enough
to
measure
the
outlet
CO
concentrations
of
lean
premix
combustor
turbines
with
oxidation
catalyst
systems,
which
are
expected
to
comprise
most
of
the
affected
sources.
Therefore
EPA
has
decided
to
not
use
CO
CEMS
units
for
monitoring
or
compliance
and
a
reply
to
the
comments
are
moot.
However,
EPA
believes
that
the
4
hour
rolling
average
is
appropriate
for
combustion
turbines
burning
natural
gas
and
number
2
distillate
oil
since
the
fuel
composition
does
not
vary
significantly.
Regarding
the
comment
on
measurement
of
O
2/
CO
2
only
at
the
outlet
rather
than
at
the
inlet
and
outlet
presumably
for
indexing
purposes,
that
comment
is
also
moot
now
but
since
the
O
2/
CO
2
concentration
will
change
only
slightly
going
across
the
catalyst,
one
measurement
at
the
outlet
could
have
been
used
to
index
both
the
inlet
and
outlet
concentrations.

VII.
B.
1.5
Comment:
One
commenter
(
443)
remarked
that
the
absence
of
any
specific
proposals
for
revision
of
PS
4A,
Method
10,
and
Procedure
1
of
Appendix
F,
or
any
data
upon
which
to
develop
suggestions
for
revision,
make
it
impossible
to
comment
on
necessary
revisions.
EPA
must
promulgate
some
alternative
that
does
not
require
use
of
CO
CEMS.

Response:
Based
on
this
comment
and
other
similar
comments
received
during
the
public
comment
period,
EPA
has
decided
that
the
CO
CEMS
systems
are
not
accurate
enough
to
measure
the
outlet
CO
concentrations
of
lean
premix
combustor
turbines
with
oxidation
catalyst
systems,
which
are
expected
to
comprise
most
of
the
affected
sources.
Therefore
EPA
has
decided
to
not
use
CO
CEMS
units
for
monitoring
or
compliance.
Consequently,
the
comment
regarding
the
use
of
PS
4A,
Method
10,
and
Procedure
1
of
Appendix
1
as
they
were
to
be
used
to
support
the
CO
CEMS
are
moot.
However,
EPA
still
plans
to
revise
PS
4,
Method
10,
and
Procedure
I
of
Appendix
A
to
improve
their
accuracy.

VII.
B.
1.6
Comment:
One
commenter
(
485)
requested
that
EPA
eliminate
the
annual
RATA
requirement
for
CO
CEMS
for
the
Alaska
North
Slope.
81
Response:
Stationary
turbines
located
north
of
the
Arctic
Circle
(
and
therefore
the
Alaska
North
Slope)
are
not
being
required
to
install
and
operate
CO
CEMS
in
the
final
rule,
so
the
suggestion
is
moot.

VII.
B.
1.7
Comment:
One
commenter
(
419)
suggested
that
the
CO
range
should
be
set
to
accurately
indicate
CO
breakthrough
rather
than
continuous
measurement.

Response:
The
EPA
understands
the
commenters
position,
i.
e.,
to
intermittently
measure
CO
levels
and
take
action
only
when
the
CO
levels
are
high,
indicating
CO
catalyst
breakthrough,
indicating
that
the
catalyst
system
should
be
replaced.
The
EPA's
preferred
position
is
to
use
continuous
pollutant
emissions
monitoring
whenever
the
continuous
monitoring
system
is
proven
to
accurately
measure
the
pollutant
concentrations
and
the
costs
are
reasonable.
A
continuous
monitoring
system
more
clearly
indicates
continuing
compliance
with
the
emission
limitation,
will
instantaneously
indicate
if
a
process
malfunction
or
control
device
malfunction
is
occurring,
will
result
in
a
quicker
response
to
malfunctions
thereby
reducing
emissions
during
malfunction,
and
will
clearly
indicate
when
a
pollutant
breakthrough
is
occurring.
Based
on
information
received
during
public
comments,
EPA
has
decided
not
to
use
the
CO
CEMS
and
CO
stack
testing
methods
since
the
levels
of
CO
expected
to
be
emitted
by
CTs
would
be
too
low
to
be
accurately
measured.
Therefore
the
final
rule
does
not
have
a
CO
emission
limitation
and
this
comment
is
now
moot.

VII.
B.
1.8
Comment:
One
commenter
(
430)
recommended
that
for
units
complying
with
the
MACT
standard
using
an
oxidation
catalyst,
the
initial
performance
evaluation
for
removal
efficiency
of
CO
should
take
into
account
the
operating
conditions
used
by
the
catalyst
vendor
to
determine
design
removal
efficiency.

Response:
The
commenter
did
not
indicate
how
the
operating
conditions
used
by
the
catalyst
vendor
to
determine
design
removal
efficiency
was
to
be
obtained
and
used.
Also
the
commenter
did
not
indicate
the
relevance
of
this
information
to
the
compliance
determination
of
the
oxidation
catalyst
system.
The
EPA
called
the
commenter
to
clarify
the
commenter's
intent.
The
commenter
intended
that
the
EPA
required
removal
efficiency
should
be
consistent
with
the
vendor's
design
and
take
into
account
operating
load.
An
oxidation
catalyst
system
is
normally
designed
by
the
vendor
based
on
information
provided
by
the
owner/
operator,
including
load
and
other
operating
parameters
and
the
removal
efficiency.
Therefore
the
owner/
operator
should
already
have
knowledge
of
the
load,
design
removal
efficiency,
and
other
parameters.
Some
commenters
indicated
that
EPA
should
explicitly
state
in
the
regulation
that
testing
at
any
load
is
allowed
to
avoid
any
confusion.
The
emission
limitations
established
in
the
final
rule
were
based
on
test
results
measured
when
the
turbines
were
being
operated
at
high
loads
(
between
90
and
110
percent).
Therefore
EPA
has
indicated
in
the
final
rule
that
performance
testing
should
be
conducted
at
high
load;
alternatively,
sources
may
choose
to
conduct
testing
at
lower
loads
but
failure
to
demonstrate
compliance
at
less
than
high
load
is
considered
a
deviation
from
the
emission
limitation.
82
VII.
B.
1.9.
Comment:
One
commenter
(
419)
noted
that
operating
an
upstream
and
downstream
CEMS
is
complicated,
even
if
you
timeshare.
The
commenter
questioned
whether
a
dual
range
analyzer
would
be
needed.

Response:
Carbon
monoxide
CEMS
are
not
being
required
so
the
suggestion
is
moot.

VII.
B.
1.10
Comment:
One
commenter
(
443)
stated
that
measurement
of
CO
directly
at
the
outlet
of
any
CT
(
whether
simple
or
combined
cycle)
would
be
difficult
because
of
the
unrepresentative
nature
of
the
CT
outlet
sampling
location.
One
commenter
(
430)
said
that
for
the
inlet
of
an
oxidation
catalyst,
sampling
is
physically
and
technologically
difficult.

Two
commenters
(
465,
470)
expressed
the
view
that
existing
monitoring
methodology
and
technology
should
be
able
to
accurately
measure
the
CO
emissions
after
control
technology.

Response:
The
EPA
agrees
with
the
commenters.
However,
CO
CEMS
are
not
being
required
so
the
comments
are
moot.

2.
EPA
Method
10
VII.
B.
2.1
Comment:
Two
commenters
(
485,
501)
observed
that
in
cases
where
the
uncontrolled
exhaust
CO
is
already
very
low,
it
will
be
difficult
to
show
compliance
with
the
95
percent
reduction
standard
based
on
Method
10
measurements
Response:
The
EPA
agrees
with
the
commenters.
However,
CO
CEMS
are
not
being
required
so
the
comments
are
moot.

VIII.
COST/
IMPACTS
VII.
1
Comment:
Four
commenters
(
421,
479,
481,
482)
said
that
EPA
has
substantially
underestimated
the
cost
of
the
proposed
standard.
Commenter
482
observed
that
several
of
the
estimates
used
to
calculate
the
impacts
are
not
accurate.
The
following
estimates
are
too
low:
only
20
percent
of
turbines
will
be
located
at
major
sources;
only
5
percent
of
new
turbines
will
have
to
install
oxidation
catalyst
control;
and
only
10
existing
lean
premix
turbines
will
have
to
install
oxidation
catalysts.
Also,
the
assumption
that
turbines
operate
8760
hours
per
year,
used
to
calculate
the
emission
reduction,
is
unrealistic.
More
realistic
figures
are
20
percent
for
simple
cycle
and
60
percent
for
combined
cycle.
Commenter
481
said
that
a
more
realistic
figure
for
simple
cycle
is
30
percent.
Commenter
479
said
that
actual
2002
capacity
factors
for
their
LPC
turbines
averaged
about
4
percent.
The
capacity
factors
for
their
DFC
turbines
were
even
much
lower.
Approximately
80
percent
of
all
gas­
fired
CTs
currently
in
operation
in
the
U.
S.
are
operated
at
annual
capacity
factors
of
10
percent
or
less.
Approximately
65
percent
of
the
CTs
are
operated
at
capacity
factors
of
less
than
6
percent
per
year.
83
Response:
The
EPA
acknowledges
that
the
costs
of
the
proposed
CT
MACT
standard
could
be
higher
than
estimated.
For
example,
the
commenter
took
issue
with
the
percentage
of
new
LPC
turbines
that
may
have
to
put
on
controls
to
achieve
the
emission
limitation.
The
information
that
was
available
to
us
at
proposal
was
that
only
a
small
fraction
of
turbines
(~
5
percent)
would
find
it
necessary
to
install
add­
on
controls.
In
actual
practice
possibly
more
owners/
operators
would
choose
to
put
on
controls
to
assure
that
the
emission
limit
would
be
met
with
a
higher
margin
of
safety.
Since
proposal,
new
information
was
obtained
which
indicates
that
some
LPC
turbines
have
oxidation
catalyst
systems
installed,
which
establishes
the
MACT
floor
for
new
LPC
turbines
in
the
final
rule
to
be
the
level
of
performance
for
a
LPC
turbine
with
an
oxidation
catalyst
control
system
installed.
Therefore
for
purposes
of
costing,
all
new
turbines,
both
DFC
turbines
and
LPC
turbines,
are
assumed
to
have
to
install
oxidation
catalyst
controls.
Therefore
the
costs
of
complying
with
the
final
standards
are
not
underestimated.

The
EPA
also
agrees
that
8,760
hours
per
year
of
operation
is
unrealistic
to
estimate
HAP
emissions
and
agrees
with
the
commenters
that
stated
that
20
percent
average
capacity
factor
for
simple
cycle
turbines
and
60
percent
average
capacity
factor
for
combined
cycle
turbines
are
more
realistic
for
estimating
HAP
emissions.
The
emission
reductions
are
now
based
on
those
assumptions.
Capacity
factors
of
less
than
4
percent
to
6
percent
were
not
felt
to
be
representative
of
all
combustion
turbines.

The
EPA
believes
that
the
estimate
that
only
20
percent
of
turbines
will
be
located
at
major
sources
is
the
most
accurate
estimate
that
could
be
made
based
on
the
information
the
EPA
has.

VII.
2
Comment:
Two
commenters
(
424,
427)
stated
that
EPA
has
significantly
underestimated
the
impact
on
existing
LPC
turbines.
Most
existing
LPC
turbines
will
require
a
CO
catalyst
and
CO
CEMS
because
the
proposed
formaldehyde
level
is
not
representative.
Commenter
427
estimated
that
over
120
of
their
existing
fleet
of
LPC
CTs
will
be
affected.
Both
commenters
recommended
that
existing
LPC
CTs
receive
the
same
treatment
as
existing
DFC,
e.
g.
no
control.

Response:
As
a
result
of
comments,
the
MACT
Floor
for
existing
gas­
fired
and
oil­
fired
LPC
units
was
reevaluated
and
found
to
be
no
emission
reduction.
The
final
rule
therefore
does
not
require
existing
LPC
units
to
meet
an
emission
limitation,
and
these
units
will
not
be
impacted
by
the
rule.
Thus,
the
concerns
expressed
by
the
commenters
are
moot.

VII.
3
Comment:
Two
commenters
(
424,
427)
expressed
the
view
that
most
new
LPC
turbines
will
require
a
CO
catalyst
and
CO
CEMS
(
because
the
proposed
formaldehyde
level
is
not
representative).
The
proposed
rule
will
result
in
very
minor
reduction
of
HAP
with
significant
expense.

Response:
As
discussed
in
the
response
to
comment
IV.
B.
1,
EPA
requested
and
received
new
emissions
data
for
LPC
units
which
led
to
further
subcategorization
by
fuel
and
a
revised
84
formaldehyde
emission
limitation
for
gas­
fired
and
oil­
fired
LPC
turbines.
The
rule
no
longer
requires
units
equipped
with
a
CO
catalyst
to
install
a
CO
CEMS.
Thus,
this
concern
is
moot.
The
EPA
does
not
agree
with
the
comment
that
the
proposed
formaldehyde
level
is
not
representative.
It
is
believed
that
the
data
set
is
adequately
representative
and
that
the
formaldehyde
limit
has
been
set
correctly
according
to
the
requirements
in
the
CAA.

VII.
4
Comment:
One
commenter
(
446)
questioned
whether
EPA
has
factored
the
disposal
or
regeneration
of
the
spent
catalyst
into
their
Environmental,
Energy,
and
Economic
Impacts
evaluation.

Response:
The
disposal
or
regeneration
of
the
spent
catalyst
has
not
been
factored
into
the
Impacts
evaluation.
According
to
catalyst
vendors,
the
catalyst
can
be
washed
and
restored
for
ten
years
or
more
of
continuous
operation.
Spent
catalysts
can
be
returned
to
the
vendor
for
recycling
or
disposal.
The
owner/
operator
can
receive
credits
toward
a
new
catalyst
for
the
return
of
the
old
one,
in
the
form
of
cash,
metal,
or
metal
account.

IX.
RISK
Note:
All
of
the
comments
pertaining
to
risk
are
summarized
below.
There
is
a
single
response
given
at
the
end
of
this
section
for
all
of
the
risk
comments.

IX.
1
Comment:
Commenter
484
recommended
that
EPA
consider
implementation
of
a
risk­
based
approach
to
setting
the
MACT
floor.
IX.
2
Comment:
Commenters
428
and
519
supported
the
use
of
risk­
based
applicability
criteria
to
remove
sources
that
do
not
pose
significant
risk.
Commenter
422
believes
that
EPA
has
an
opportunity,
in
the
CT
rule,
to
significantly
reduce
the
costs
to
the
regulated
community
due
to
the
low
risks
associated
with
emissions
from
turbines.
IX.
3
Comment:
Commenter
502
stated
that
allowing
the
use
of
the
section
112(
d)(
4)
provision
within
the
source
category
could
provide
substantial
cost­
effectiveness
benefits
while,
at
the
same
time,
providing
protection
to
human
health
and
the
environment.
However,
the
commenter
believes
that
EPA
must
clarify
in
the
final
rule
exactly
how
the
provisions
will
be
implemented.
Commenter
502
believes
that
the
risk­
based
approach
is
particularly
viable
for
the
CT
source
category.
The
commenter
noted
that
because
the
authority
Congress
gave
EPA
to
set
risk­
based
standards
during
the
MACT
process
in
CAA
section
112(
d)(
4)
is
limited
to
threshold
HAP
and
some
of
the
HAP
emitted
by
the
CT
source
category
are
non­
threshold
HAP,
EPA
will
have
to
rely
on
both
its
authority
under
112(
d)(
4)
and
its
inherent
de
minimis
authority
to
not
regulate
trivial
matters
that
will
not
foster
the
goals
of
the
statute,
i.
e.,
protecting
public
health
and
the
environment.
IX.
4
Comment:
Commenter
476
believes
that
there
are
ways
to
structure
the
rule
to
focus
on
facilities
that
pose
significant
risks
and
avoid
imposition
of
high
costs
on
facilities
that
85
pose
little
risk.
An
appropriate
approach
would
be
to
allow
individual
facilities
to
conduct
a
risk
assessment
to
show
that
it
poses
insignificant
risks
to
the
public.
Commenter
476
stated
that
such
an
approach
would
involve
air
quality
modeling
and
the
use
of
RfCs.
IX.
5
Comment:
Commenter
440
agreed
with
and
adopted
the
rationales
of
the
referenced
AF&
PA
white
papers,
and
believes
that
EPA
has
the
legal
and
statutory
authority
to
implement
a
risk­
based
approach
in
the
final
rule
pursuant
to
CAA
section
112(
d)(
4)
and
the
Agency's
inherent
de
minimis
authority.
IX.
6
Comment:
Commenter
439
stated
that,
to
the
extent
that
risk­
based
mechanisms
become
available,
they
would
consider
their
use
in
alleviating
non­
cost­
effective
controls
on
their
stationary
CTs.
The
commenter
added
that
if
risk­
based
options
are
not
available
or
workable
at
a
specific
site,
EPA
should
consider
bubbling
and
emissions
averaging.
For
the
low­
HAP
emitting
stationary
CTs,
especially
where
only
one
or
two
units
exist
and
do
not
constitute
a
major
source
designation
themselves,
EPA
should
explicitly
make
available
bubbling
with
other
process
unit
controls.
IX.
7
Comment:
Commenter
431
believes
that
considering
the
very
low
emission
rate
for
combustion
turbines,
it
is
appropriate
for
EPA
to
consider
and
implement
a
risk
based
approach
to
setting
the
MACT
floor
for
combustion
turbines.
The
commenter
believes
that
simplified,
more
flexible,
and
less
onerous
requirements
that
can
meet
the
risk
criteria
set
out
in
the
CAA
would
provide
a
much
more
cost
effective
rule
while
providing
adequate
health
and
environmental
protection.
IX.
8
Comment:
Commenter
487
supported
the
use
of
112(
d)(
4)
to
provide
relief
for
small,
low­
emitting,
co­
located,
natural
gas
fired
combustion
turbines,
since
the
installation
of
additional
controls
would
provide
limited
to
inconsequential
benefit.
The
commenter
referred
to
a
study
conducted
by
the
GTA
in
August
2002
which
included
human
health
risk
modeling
for
natural
gas
fired
GE
Frame
6B
turbines
and
showed
the
health
risk
for
formaldehyde
to
be
well
below
the
cancer
risk
threshold
of
one
in
one
million.
IX.
9
Comment:
Commenter
460
believes
that
the
source­
by­
source
approach
under
section
112(
d)(
4)
may
be
too
cumbersome
for
the
CT
source
category
and
that
the
more
streamlined
approach
of
delisting
a
low
risk
subcategory
is
more
appropriate.
The
commenter
believes
a
"
low
risk
subcategory"
approach
is
authorized
under
section
112(
c)(
9)
and
is
appropriate
for
the
stationary
combustion
turbine
category.
It
is
likely
that
all
diffusion
flame
units
firing
natural
gas
and
many
stationary
combustion
turbines
using
oil
for
periods
longer
than
authorized
in
the
delisting
petition
would
in
fact
meet
the
statutory
delisting
criteria.
However,
due
to
variability
in
locations
and
configuration,
it
can
not
be
categorically
concluded
that
this
is
the
case
for
every
existing
source.
Therefore
the
commenter
believes
it
is
critical
that
sources
have
the
ability
to
opt
into
a
low
risk
subcategory
and
achieve
a
"
delisted"
status.
The
commenter
urged
EPA
to
adopt
this
approach
and
implement
it
in
issuing
the
final
rule.
IX.
10
Comment:
Commenter
479
stated
that
EPA
should
consider
delisting
stationary
combustion
turbines
as
a
source
category
under
section
112(
c)(
9)
of
the
CAA
and
40
CFR
63
subpart
C.
Commenter
479
stated
that
combustion
turbines
are
already
among
the
cleanest­
burning
sources
of
power
in
operation
today.
New
turbines
are
subject
to
permit
restrictions
that
require
best
available
control
technology
for
many
pollutants
including
NOx.
EPA
must
carefully
86
consider
its
cost­
effectiveness
conclusions
in
the
CT
MACT,
especially
in
light
of
comments
provided.
Recent
studies
conducted
by
TRC
indicate
that
HAP
emissions
from
all
gas
turbines
in
the
U.
S.
represent
a
cancer
risk
or
well
below
one
in
one
million
and
the
non­
cancer
risks
are
well
below
levels
EPA
considers
to
protect
public
health
with
an
adequate
margin
of
safety.
The
commenter
added
that
there
are
a
number
of
benefits
of
delisting
the
source
category.
The
most
important
benefit
of
delisting
is
the
encouragement
of
further
use
of
this
clean
and
efficient
source
of
power
generation.
IX.
11
Comment:
Commenter
440
stated
that
sources
wishing
to
take
advantage
of
the
risk­
based
compliance
option
would
take
a
federally­
enforceable
permit
limit
that
would
guarantee
that
their
emissions
remain
below
the
risk­
based
emission
standard.
This
would
constitute
an
"
emission
limitation"
­
within
the
statutory
definition
of
the
term
­
and
it
would
allow
sources
to
forego
the
installation
of
incinerators
where
they
are
not
warranted
by
public
health
and
environmental
considerations.
IX.
12
Comment:
Multiple
commenters
are
opposed
to
the
risk­
based
exemptions
(
472,
387,
489,
514,
518,
470,
and
483).
Commenter
472
believes
that
the
proposed
§
112(
d)(
4)
applicability
cutoffs
are
flatly
unlawful.
However,
the
commenter
provided
additional
comments
on
several
issues
for
which
EPA
solicited
comment.
Commenters
387
and
470
noted
that
the
proposal
to
include
risk­
based
exemptions
is
critically
flawed
and
opposes
adoption
of
the
risk­
based
exemptions
into
MACT.
Commenter
489
stated
that
the
inclusion
of
case­
by­
case
risk­
based
exemptions
into
the
first
phase
of
the
MACT
program
will
negate
the
legislative
mandate
and
jeopardize
the
effectiveness
of
the
national
air
toxics
program
to
adequately
protect
public
health
and
the
environment
and
to
establish
a
level
playing
field.
Therefore,
the
commenter
strongly
disagrees
with
inclusion
of
risk­
based
exemptions
in
the
MACT
standard
process.
The
commenter
was
very
concerned
that
EPA
referenced
a
fundamentally
flawed
interpretation
of
§
112(
d)(
4)
written
by
an
industry
(
AF&
PA)
subject
to
regulation.
Of
particular
concern
was
AF&
PA's
unprecedented
proposal
to
include
"
de
minimis
exemptions"
and
"
cost"
in
the
MACT
standard
process.
Commenter
518
is
extremely
concerned
about
the
policy
and
technical
implications
of
the
risk­
based
exemption
proposal.
Because
of
the
flaws
with
the
proposal,
the
commenter
is
opposed
to
the
adoption
of
the
risk­
based
exemptions
to
MACT.
Commenter
515
stated
the
belief
that
the
use
of
risk­
based
concepts
to
evade
MACT
applicability
is
contrary
to
the
intent
of
the
CAA
and
is
based
on
a
flawed
interpretation
of
section
112(
d)(
4)
of
the
CAA.
The
commenter
added
that
the
CAA
requires
a
technology­
based
floor
level
of
control
and
does
not
provide
exclusions
for
risk
or
secondary
impacts
from
applying
the
MACT
floor.
Commenter
515
stated
that
from
a
practical
standpoint,
the
approaches
(
to
riskbased
exemptions)
in
the
preamble
are
not
appropriate.
IX.
13
Comment:
Commenter
470
stated
that,
under
the
MACT
floor
approach,
processes
which
are
technologically
too
expensive
to
control
would,
in
most
cases,
have
a
MACT
floor
of
no
control,
which
could
be
reevaluated
when
EPA
conducts
the
residual
risk
assessment
required
by
section
112(
f).
Congress
intended
that
this
process
be
used
to
reduce
the
initial
cost
of
the
MACT
program.
IX.
14
Comment:
Commenter
465
is
opposed
to
the
risk­
based
exemptions
and
called
87
upon
EPA
to
promulgate
the
remaining
technology­
based
MACT
standards
without
the
riskbased
exemptions.
IX.
15
Comment:
Multiple
commenters
(
514,
387,
518,
433,
470,
and
465)
believe
that
the
preambles
of
individual
rule
proposals
were
an
inappropriate
forum
for
introducing
significant
changes
in
the
way
that
MACT
standards
are
established.
Precedent­
setting
change
of
the
magnitude
that
EPA
has
raised
should
be
discussed
openly
and
carefully
with
all
affected
parties
instead
of
being
buried
in
the
preambles
of
individual
standards.
Commenter
515
stated
the
concern
that
other
parties
may
miss
commenting
on
the
riskbased
exemptions
because
they
are
contained
within
six
separate
proposals.
The
commenter
added
that
to
give
the
issue
full
consideration,
the
risk
provisions
should
not
be
adopted
within
any
of
the
final
rules
but
should
be
addressed
in
one
place,
such
as
in
revisions
to
the
general
provisions
of
40
CFR
63
subpart
A.
Commenter
489
stated
that
for
many
years,
they
have
coordinated
with
OAQPS
on
development
of
MACT
standards
for
the
national
air
toxics
program,
and
there
has
been
no
indication
of
any
kind
regarding
inclusion
of
risk­
based
exemptions
in
the
first
phase
of
the
MACT
program.
The
commenter
thought
it
was
unprecedented
and
alarming
that
EPA
is
proposing
such
a
radical
change
at
the
end
of
Phase
1
of
the
MACT
standard
process.
Commenter
489
believes
that
allowing
risk­
based
exemptions
requires
changes
to
existing
law
and
that
such
a
debate
should
take
place
within
the
democratic
legislative
process
and
not
in
the
MACT
standard
process.
IX.
16
Comment:
Commenter
518
stated
that
the
preamble
discussion
of
the
risk­
based
approaches
is
not
sufficient
to
allow
for
complete
public
comment
and,
therefore,
it
would
not
be
appropriate
for
EPA
to
go
directly
to
a
final
rule
(
without
reproposal)
with
any
of
the
approaches
outlined
in
the
proposal.
The
commenter
recommended
that
the
risk­
based
exemption
proposal
be
dropped
because
it
is
unacceptable.
Commenters
465
and
470
stated
that
the
use
of
sub­
categorization
and
source
category
deletions
under
section
112(
c)
have
been
implemented
several
times
since
the
MACT
program
began.
The
commenters
have
been
unable
to
comment
on
the
technical
merit
of
the
risk
analysis
employed
by
the
EPA.
Until
the
residual
risk
analysis
procedures
have
been
implemented
via
the
section
112(
f)
process,
risk
analysis
should
not
been
used
in
making
MACT
determinations
pursuant
to
section
112(
d)(
4)
and,
could
never
be
used
to
establish
a
MACT
floor.
IX.
17
Comment:
Commenters
514,
387,
518,
433,
489,
465,
470,
and
483
stated
that
the
proposal
to
include
risk­
based
exemptions
is
contrary
to
the
1990
CAA
Amendments
(
CAAA)
which
calls
for
MACT
standards
based
on
technology
rather
than
risk
as
a
first
step.
Congress
incorporated
the
residual
risk
program
under
§
112(
f)
to
follow
the
MACT
standards
(
not
to
replace
them).
The
need
for
the
technology­
based
approach
has
been
recently
reinforced
by
the
results
of
the
National
Air
Toxics
Assessment
(
NATA),
which
indicates
that
exposure
to
air
toxics
is
very
high
throughout
the
country
in
urban
and
remote
areas.
Commenters
518,
387,
433,
470,
and
483
added
that
risk­
based
approaches
will
be
used
separately
to
augment
and
improve
technology­
based
standards
that
do
not
adequately
provide
protection
to
the
public.
Commenter
489
believes
that
section
112(
b)(
4)
of
the
CAA
and
the
regulatory
precedent
established
in
over
80
MACT
standards
rejects
the
inclusion
of
risk
in
the
first
phase
of
the
MACT
standards
process.
Commenter
514
added
that
section
112(
f)
of
the
CAA
was
developed
88
to
address
residual
risks
remaining
after
implementation
of
technology­
based
MACT
standards
and
was
intended
to
provide
additional
protection,
not
replace
technology
controls.
Commenter
489
added
that
they
have
been
unable
to
substantiate
the
basis
for
EPA's
support
of
the
regulatory
relief
sought
by
industry
through
risk­
based
exemptions.
In
fact,
the
use
of
risk
assessment
at
this
stage
of
the
MACT
program
is
directly
opposed
to
Title
III
of
the
CAA.
Commenter
489
attached
an
EPA
fact
sheet
and
testimony
by
two
individuals
that
supports
this
position.
IX.
18
Comment:
Commenters
514,
387,
465,
518,
433,
and
470
stated
that
the
proposal
to
allow
risk­
based
exemptions
would
divert
back
to
the
time­
consuming
NESHAP
development
process
that
existed
prior
to
the
CAAA.
Under
this
process,
which
began
with
a
risk
assessment
step,
only
eight
NESHAP
were
promulgated
during
a
20­
year
period.
If
the
proposed
approaches
are
inserted
into
upcoming
standards,
the
commenters
fear
the
MACT
program
(
which
is
already
far
behind
schedule)
would
be
further
delayed.
IX.
19
Comment:
Commenters
387,
465,
518,
433,
489,
and
470
stated
that
the
riskbased
exemption
proposal
removes
the
"
level­
playing
field"
that
would
result
from
the
proper
implementation
of
technology­
based
MACT
standards.
Establishing
a
baseline
level
of
control
is
essential
to
prevent
industry
from
moving
to
areas
of
the
country
that
have
the
least
stringent
air
toxics
programs,
which
was
one
of
the
primary
goals
of
developing
a
uniform
national
air
toxics
program
under
section
112
of
the
1990
CAA
amendments.
The
risk­
based
approaches
would
jeopardize
future
reductions
of
HAPs
in
a
uniform
and
consistent
manner
across
the
nation.
Commenters
387
and
470
stated
that
the
NATA
data
show
that
virtually
no
area
of
the
country
has
escaped
measurable
concentrations
of
toxic
air
pollution.
The
NATA
information
indicates
that
exposure
to
air
toxics
is
high
in
both
densely
populated
and
remote
rural
areas.
IX.
20
Comment:
Multiple
commenters
(
443,
502,
440,
and
460)
believe
that
section
112(
d)(
4)
provides
EPA
with
authority
to
exclude
sources
that
emit
threshold
pollutants
from
regulation.
The
commenters
indicated
that
section
112(
d)(
4)
allows
for
discretion
in
developing
MACT
standards
for
HAP
with
health
thresholds.
This
is
consistent
with
the
plain
language
of
the
statute,
which
states
that:
"
With
respect
to
pollutants
for
which
a
health
threshold
has
been
established,
the
Administrator
may
consider
such
threshold
level,
with
an
ample
margin
of
safety,
when
establishing
emission
standards
under
this
subsection."
The
use
of
section
112(
d)(
4)
authority
also
is
supported
by
CAA's
legislative
history,
which
emphasizes
that
Congress
included
§
112(
d)(
4)
in
the
CAA
to
prevent
unnecessary
regulation
of
source
categories.
Multiple
commenters
(
443
and
440)
referenced
Sen
Rep.
101­
228,
at
176
(
1989),
reprinted
in
1990
U.
S.
C.
C.
A.
N.
3385,
3560:
"[
W]
here
some
sources
do
emit
more
than
the
threshold
amount,
the
Administrator
is
authorized
by
section
112(
d)(
4)
to
use
the
no
observable
effects
level
or
NOEL
(
again
with
an
ample
margin
of
safety)
as
the
emission
limitation
in
lieu
of
more
stringent
"
best
technology"
requirements.
Following
this
scenario,
only
those
sources
in
the
category
which
present
a
risk
to
public
health
(
those
emitting
in
amounts
greater
than
the
safety
threshold)
would
be
required
to
install
controls,
even
though
the
general
policy
is
"
maximum
achievable
technology
89
everywhere."
Again,
there
is
a
means
to
avoid
regulatory
costs
which
would
be
without
public
health
benefit."
Commenter
440
pointed
out
that
EPA
has
exercised
such
authority
and
cited
the
Pulp
and
Paper
MACT.
In
addition,
in
the
Pulp
and
Paper
MACT,
EPA
identified
circumstances
in
which
they
would
decline
to
exercise
112(
d)(
4)
authority
 
where
significant
or
widespread
environmental
harm
would
occur
as
a
result
of
emissions
from
the
category
and
the
estimated
health
thresholds
are
subject
to
substantial
scientific
uncertainty.
EPA
determined
that
these
considerations
were
not
relevant
to
emissions
from
the
pulp
and
paper
source
category,
and
the
commenter
believes
that
the
same
is
true
for
their
source
category
and
that
the
same
treatment
is
warranted
for
many
facilities
within
the
source
category.
The
commenter
noted
that
facilities
that
cannot
meet
the
risk
criteria
would
remain
subject
to
the
MACT
requirements.
IX.
21
Comment:
Commenter
CT­
440
stated
that
EPA
invoked
§
112(
d)(
4)
authority
in
choosing
not
to
impose
control
requirements
on
HCl
emissions
from
chemical
recovery
furnaces
at
pulp
mills
(
40
CFR
part
63,
subpart
MM).
See
63
Fed.
Reg.
18754,
18765
(
April
15,
1998).
IX.
22
Comment:
Commenter
440
stated
that
the
risk­
based
approaches
can
be
implemented
as
an
"
emission
standard"
within
the
statutory
definition
of
the
term.
The
commenter
stated
that
the
risk­
based
approaches
being
considered
by
EPA
can,
and
should,
be
implemented
as
compliance
options,
rather
than
outright
exemptions
from
MACT
standard
applicability.
This
approach
fits
with
the
statutory
definition
of
"
emission
standard"
and
"
emission
limitation"
as
used
in
§
112.
Nothing
in
the
definition
equates
"
emission
standard"
with
the
requirement
to
install
control
technology.
If
the
risk­
based
approach
is
implemented
as
a
compliance
option,
then
the
"
emission
standard"
set
by
EPA
would
be
the
emission
rate
that
corresponds
with
the
concentration
of
HAP
at
the
property
line
that
is
below
the
health
benchmark
for
threshold
HAPs,
and
below
the
one
in
a
million
risk
level
for
non­
threshold
carcinogens.
Commenter
440
stated
that
EPA's
implementation
of
the
risk­
based
approach
as
a
compliance
option
clearly
would
meet
the
statutory
definitions
of
"
emission
limitation"
and
"
emission
standard"
(
defined
identically
by
CAA
§
302(
k))
by
placing
federally­
enforceable
limitations
on
facility
HAP
emissions.
That
this
cap
would
be
based
on
correlations
with
risk­
based
property
line
concentrations
does
nothing
to
detract
from
this
conclusion.
IX.
23
Comment:
Commenters
443
and
430
supported
the
use
of
§
112(
d)(
4)
applicability
cutoffs
for
both
threshold
and
non­
threshold
pollutants.
Commenters
443
and
487
stated
that
the
plain
language
of
112(
d)(
4)
does
not
distinguish
between
carcinogens
and
non­
carcinogens.
Commenter
443
stated
that
advances
in
risk
assessment
science
indicate
that
some
carcinogens
may
be
threshold
pollutants.
Commenter
430
believes
that
a
health
threshold
of
one
in
one
million
cancer
risk
is
appropriate
for
non­
threshold
pollutants.
IX.
24
Comment:
Commenter
502
believes
that
EPA
could
implement
a
section
112(
d)(
4)
emissions
limitation
under
both
the
first
and
third
scenarios
discussed
in
the
preamble
(
scenario
1:
exempt
low
risk
facilities
emitting
only
threshold
pollutants,
scenario
3:
exempt
emission
points
at
facilities
that
emit
only
threshold
pollutants).
However,
the
commenter
believes
that
the
use
of
a
section
112(
d)(
4)
emissions
limit
as
described
under
the
third
scenario
in
the
preamble
would
90
provide
the
maximum
benefit
of
the
section
112(
d)(
4)
provision.
Under
this
scenario,
facilities
that
emit
both
threshold
and
nonthreshold
pollutants
could
achieve
exemption
from
MACT
controls
for
threshold
HAP
emission
points
based
on
their
ability
to
meet
the
associated
health
threshold
for
those
HAP.
Another
possible
use
of
the
section
112(
d)(
4)
emissions
limitation
that
EPA
discussed
would
apply
to
both
threshold
and
nonthreshold
pollutants.
IX.
25
Comment:
Several
commenters
(
515,
425,
and
489)
disagreed
that
§
112(
d)(
4)
can
be
interpreted
to
allow
exemptions
for
individual
sources.
The
commenters
believe
that
§
112(
d)(
4)
applies
to
categories
of
sources.
Commenter
425
understood
section
112(
d)(
4)
to
allow
the
Agency
to
reduce
the
stringency
of
a
MACT
standard
applicable
to
an
entire
category
or
subcategory
based
on
a
health
threshold
for
a
particular
pollutant.
IX.
26
Comment:
Multiple
commenters
(
472,
465,
and
470)
stated
that
the
plain
meaning
of
§
112(
d)(
4)
does
not
allow
EPA
to
make
MACT
standard
exemptions
for
individual
sources.
Commenter
472
stated
that
the
CAA
does
not
allow
EPA
to
"
exempt
individual
facilities
that
can
demonstrate
that
their
emissions
will
not
result
in
air
concentrations
above
the
threshold
levels
with
an
ample
margin
of
safety
even
if
the
category
is
otherwise
subject
to
MACT."
The
CAA
provides
only
that
"
with
respect
to
pollutants
for
which
a
health
threshold
has
been
established,
the
Administrator
may
consider
such
threshold
level,
with
ample
margin
of
safety,
when
establishing
emission
standards
under
this
subsection."
Had
Congress
intended
to
give
EPA
discretion
to
consider
threshold
levels
in
exemption
of
facilities
from
compliance,
the
CAA
would
have
said
so.
The
applicability
cutoffs
on
which
EPA
requests
comment
are
unlawful.
Commenters
465
and
470
believe
that
EPA
has
misinterpreted
the
provision
in
112(
d)(
4).
Section
112(
d)(
4)
does
not
state
that
EPA
can
use
applicability
thresholds
"
in
lieu
of"
the
section
112(
d)(
3)
MACT
floor
requirements.
The
commenters
interpreted
section
112(
d)(
4)
to
state
that
health
based
thresholds
can
be
considered
when
establishing
the
degree
of
the
MACT
floor
requirements,
but
it
should
not
be
used
to
supplant
the
requirements
established
pursuant
to
Section
112(
d)(
3).
IX.
27
Comment:
Commenter
472
stated
that
the
legislative
history
of
§
112(
d)(
4)
clearly
rejects
EPA's
proposed
facility­
by­
facility
MACT
exemptions.
The
commenter
noted
that
Congress
considered
and
rejected
the
applicability
cutoffs
upon
which
EPA
now
solicits
comment.
The
House
version
of
the
1990
Amendments
allowed
States
to
issue
permits
that
exempted
a
source
from
compliance
with
MACT
rules
if
the
source
presented
sufficient
evidence
to
demonstrate
negligible
risk.
The
Senate
version
of
the
1990
Amendments
contained
no
such
provision.
In
conference,
Congress
considered
both
the
House
and
Senate
versions
and
rejected
the
House
bill's
exemption
for
specific
facilities
in
favor
of
the
Senate
bill's
language.
IX.
28
Comment:
Several
commenters
(
515,
489,
and
472)
stated
that
section
112(
d)(
4)
does
not
apply
for
source
categories
that
emit
carcinogens.
Commenter
472
stated
that
even
if
the
§
112(
d)(
4)
applicability
cutoffs
were
not
unlawful,
they
would
be
unlawful
for
the
SCALDT
and
CT
source
categories
because
these
categories
emit
carcinogens
(
e.
g.,
SCALDT
emits
benzene,
formaldehyde,
EGBE,
and
nickel
compounds;
CT
emits
benzene,
formaldehyde,
1,3­
butadiene,
acetaldehyde,
arsenic,
beryllium,
cadmium,
chromium,
nickel,
and
lead).
IX.
29
Comment:
Commenter
472
stated
that
legislative
history
makes
it
clear
the
§
112(
d)(
4)
is
only
to
be
use
when
a
there
is
a
well­
established
health
threshold.
Commenter
472
91
cited
legislative
history
that
makes
it
clear
that
Congress
did
not
intend
EPA
to
establish
and
carcinogens
as
"
threshold"
pollutants
under
§
112(
d)(
4).
IX.
30
Comment:
Commenter
518
stated
that
the
concept
of
cancer
exposure
below
a
threshold
is
untried,
and
Congress
clearly
intended
that
carcinogens
be
considered
non­
threshold
pollutants.
IX.
31
Comment:
Commenter
502
believes
that
EPA
could
accomplish
the
same
outcome
as
a
section
112(
d)(
4)
emissions
limitation
if
it
applied
an
emissions
limitation
on
nonthreshold
pollutants
using
its
inherent
de
minimis
authority
instead
of
a
limit
based
on
section
112(
d)(
4).
IX.
32
Comment:
Commenter
440
stated
that
a
risk­
based
compliance
option
for
both
threshold
and
non­
threshold
HAPs
is
well
within
EPA's
authority
under
the
CAA
and
the
de
minimis
doctrine
articulated
by
appellate
courts.
The
commenter
stated
that
appellate
caselaw
makes
clear
that
EPA
may
lawfully
exempt
de
minimis
sources
of
risk
from
MACT­
level
controls
because
the
legislative
mandate
of
CAA
§
112
is
not
"
extraordinarily
rigid"
and
the
exemption
is
consistent
with
the
CAA's
health­
protective
purpose.
CAA
§
§
112(
c)(
9)
and
112(
f)(
2)
clearly
indicate
that
Congress
considered
a
cancer
risk
below
one
in
a
million
to
be
de
minimis
and
therefore
insufficient
to
justify
regulation
under
CAA
§
112.
Under
this
approach,
EPA
would
specify
an
emission
standard
as
a
de
minimis
level
of
cancer
risk,
and
sources
would
have
the
option
to
comply
with
the
NESHAP
by
demonstrating
that
their
emissions
result
in
exposures
below
this
risk
level.
Commenter
440
argued
that
EPA's
de
minimis
authority
properly
is
evaluated
vis­
à­
vis
the
statutory
design.
Appellate
caselaw
establishes
EPA's
authority
to
exempt
de
minimis
sources
as
long
as
the
legislative
mandate
is
not
"
extraordinarily
rigid"
and
the
exemption
is
consistent
with
the
legislative
purpose
­
in
this
case,
the
"
health
protective
purpose
of
the
statute."
Commenter
440
cited
Alabama
Power
Co.
v.
Costle,
636
F.
2D
323
(
D.
C.
Cir.
1979)
where
the
court
explained
that
categorical
exemptions
from
the
requirements
of
a
statute
may
be
permissible:
[
A]
s
an
exercise
of
agency
power,
inherent
in
most
statutory
schemes,
to
overlook
circumstances
that
in
context
may
fairly
be
considered
de
minimis.
It
is
commonplace,
of
course,
that
the
law
does
not
concern
itself
with
trifling
matters,
and
this
principle
has
often
found
application
in
the
administrative
context.
Courts
should
be
reluctant
to
apply
the
literal
terms
of
a
statute
to
mandate
pointless
expenditure
of
effort.
636
F.
2D
at
360.
The
commenter
also
cited
the
more
recent
D.
C.
Circuit
decision
that:
As
long
as
the
Congress
has
not
been
extraordinarily
rigid
in
drafting
the
statute,
however,
there
is
likely
a
basis
for
an
implication
of
de
minimis
authority
to
provide
an
exemption
when
the
burdens
of
regulation
yield
a
gain
of
trivial
or
no
value.
Environmental
Def.
Fund
v.
EPA,
82
F.
3D
451,
466
(
D.
C.
Cir.
1996)
Commenter
440
stated
that
EPA's
frequent
exercise
of
its
de
minimis
authority
has
withstood
judicial
challenge.
The
Agency's
application
of
this
authority,
as
well
as
its
treatment
by
reviewing
courts,
uniformly
has
turned
on
the
degree
of
risk
at
issue,
not
on
the
mass
of
emissions
to
be
regulated.
The
commenter
stated
that
appellate
courts
consistently
have
upheld
EPA's
application
of
its
de
minimis
authority
in
a
line
of
cases
that,
according
to
the
D.
C.
Circuit,
have
established
"
virtually
a
presumption
in
its
favor."
Public
Citizen
v.
Young,
831
F.
2D
at
1113.
These
decisions
include
the
following:
92
­
EDF
v.
EPA,
82
F.
3D
451,
466,
469
(
D.
C.
Cir.
1996)
{
This
case
deals
with
EPA's
transportation
conformity
regulations
promulgated
under
CAA
section
176}
­
Public
Citizen,
831
F.
2D
at
1112
­
Ohio
v.
EPA,
997
F.
2D
1520
(
D.
C.
Cir.
1993)
{
This
case
deals
with
de
minimis
exemptions
from
CERCLA
requirements
on
the
basis
of
no
appreciable
health
risk}
­
Alabama
Power
Co.,
636
F.
2D
at
360
­
Ober
v.
Whitman,
243
F.
3D
1190
(
9th
Cir.
2001)
{
This
case
deals
with
exemption
of
de
minimis
sources
of
PM
10
under
a
FIP}
­
Industrial
Union
Dept.,
AFL­
CIO
v.
American
Petroleum
Inst.,
448
U.
S.
607,
663­
64
(
1980).
Commenter
440
stated
that
the
D.
C.
Circuit
has
invalidated
EPA's
de
minimis
authority
only
where
it
was
applied
under
statutory
designs
that
are
"
extraordinarily
rigid."
In
Public
Citizen,
the
D.
C.
Circuit
refused
to
allow
a
de
minimis
exception
to
the
"
Delaney
Clause"
in
the
Pure
Food
and
Drug
Act,
which
provided
that
a
color
additive
will
be
deemed
unsafe
if
it
is
found
to
induce
cancer
in
man
or
animal.
831
F.
2D
at
1108.
In
distinguishing
its
own
precedent,
the
D.
C.
Circuit
later
noted
that
"[
t]
he
Public
Citizen
court
relied
heavily
on
the
almost
inescapable
terms
of
the
Delaney
Clause
and
the
substantial
legislative
history
supporting
an
absolutist
application
of
the
language."
Ohio,
997
F.
2D
at
1534
(
emphasis
added,
quotations
omitted).
As
discussed
below,
CAA
§
112
contains
no
such
absolutist
language
so
as
to
preclude
EPA's
application
of
its
de
minimis
authority.
IX.
33
Comment:
Commenter
440
stated
that
the
statutory
design
and
legislative
purpose
expressed
in
CAA
§
112
fully
justify
emission
standards
based
on
de
minimis
levels
of
cancer
risk.
The
roots
of
de
minimis
authority
exist
in
the
language
of
CAA
§
112,
and
CAA
§
112
itself
provides
clear
indication
of
congressional
intent
as
to
what
constitutes
a
de
minimis
cancer
risk
for
purposes
of
MACT.
Congress
expressly
included
de
minimis
provisions
in
the
Title
III
program.
Despite
its
initial
emphasis
on
MACT­
based
control
technology,
the
overall
structure
of
CAA
§
112
is
overwhelmingly
risk­
based.
This
emphasis
on
risk
renders
de
minimis
considerations
especially
appropriate.
Unlike,
e.
g.,
the
Delaney
Clause,
CAA
§
112'
s
mandates
are
not
absolute.
For
example,
CAA
§
112(
c)(
9)(
B)(
i)
authorizes
source
category
delisting
if
the
category
(
or
subcategory)
creates
less
than
a
10­
6
cancer
risk;
CAA
§
112(
c)(
9)(
B)(
ii)
allows
delisting
if
non­
carcinogenic
HAP
emissions
do
not
exceed
levels
adequate
to
protect
public
health
with
an
ample
margin
of
safety.
Congress
included
de
minimis
principles
in
§
112(
g)(
1).
In
addition,
Congress
included
other
provisions
in
CAA
§
112
that
demonstrate
that
the
statutory
design
is
not
"
extraordinarily
rigid."
See,
e.
g.,
CAA
§
§
112(
a)(
2)
and
(
c)(
3);
112(
a)(
7);
112(
c)(
7);
112(
f)(
2)(
C);
112(
d)(
5)
and
(
f)(
5);
and
112(
i)(
5)(
E).
Commenter
440
stated
that
CAA
§
112
provides
clear
indication
of
Congressional
intent
as
to
the
degree
of
risk
that
properly
is
to
be
considered
de
minimis.
A
cancer
risk
of
one
in
a
million
is
the
touchstone
for
further
review
under
the
"
residual"
risk
provision
of
CAA
§
112(
f).
(
The
residual
risk
provisions
thus
call
for
additional
controls
if
and
only
if
the
remaining
risk
from
affected
sources
exceeds
one
in
a
million,
but
do
not
call
for
a
reduction
of
risk
to
the
MEI
below
93
this
level.
Rather,
the
provisions
generally
call
for
reduction
of
MEI
risk
to
a
level
no
higher
than
1
in
10,000,
although
in
some
cases,
risks
greater
than
1
in
10,000
may
be
allowable.)
Similarly,
a
one
in
a
million
cancer
risk
is
the
threshold
below
which
EPA
is
authorized
under
CAA
§
112(
c)(
9)(
B)
to
remove
entire
source
categories
from
the
purview
of
MACT
regulation.
Where
Congress
has
authorized
the
wholesale
removal
of
entire
source
categories
on
the
basis
of
a
cancer
risk
below
one
in
a
million,
EPA
is
certainly
warranted
in
exercising
its
de
minimis
authority
to
provide
a
significantly
more
limited
emission
standard
premised
on
the
same
level
of
risk.
IX.
34
Comment:
Commenter
440
cited
EPA's
brief
in
National
Lime
Association
v.
EPA,
233
F.
3D
625
(
D.
C.
Cir.
2000)
and
noted
that
the
D.
C.
Circuit
held
that
EPA
reasonably
declined
to
provide
a
de
minimis
exemption
on
the
basis
of
cost
for
the
Portland
Cement
NESHAP,
but
the
court
did
not
limit
EPA's
de
minimis
authority
under
CAA
§
112
in
any
other
way.
IX.
35
Comment:
Commenter
440
contended
that
use
of
the
phrase
"
de
minimis"
in
CAA
§
112(
g)(
1)
does
not
limit
EPA's
exercise
of
its
de
minimis
authority
in
the
MACT
context.
Although
the
phrase
"
de
minimis"
is
only
used
in
CAA
§
112(
g)(
1),
there
is
no
legal
or
policy
basis
for
assuming
that
Congress
intended
to
preclude
EPA's
exercise
of
its
de
minimis
authority
in
every
other
regulatory
context
affecting
HAPs.
Federal
agencies,
including
EPA,
are
presumed
to
have
de
minimis
authority
regardless
of
whether
such
authority
is
expressly
granted
by
statute.
Appellate
caselaw
recognizes
that
federal
agencies
have
an
inherent
authority
to
exempt
de
minimis
sources
of
risk
from
even
highly
prescriptive
statutory
requirements,
so
long
as
the
legislative
mandate
is
not
"
extraordinarily
rigid"
(
EDF,
82
F.
3D
at
466)
and
the
exemption
is
consistent
with
the
legislative
purpose
(
here,
the
health­
protective
purpose
of
the
CAA).
The
commenter
argued
that
CAA
§
112
is
not
"
extraordinarily
rigid"
and
that
Congress
had
ample
opportunity
to
make
§
112
"
extraordinarily
rigid"
when
it
developed
the
1990
CAAA.
The
commenter
stated
that
EPA's
exercise
of
its
de
minimis
authority
under
CAA
§
112
is
consistent
with
traditional
canons
of
statutory
interpretation.
The
argument
that
the
isolated
use
of
the
term
"
de
minimis"
in
CAA
§
112(
g)(
1)
somehow
precludes
the
exercise
of
EPA's
de
minimis
authority
in
setting
the
MACT
floor
does
not
withstand
scrutiny
under
principles
of
statutory
interpretation
for
three
reasons:
(
1)
the
use
of
a
term
in
one
statutory
provision
is,
at
most,
a
weak
indicator
of
congressional
intent
to
foreclose
the
term's
application
in
other
statutory
provisions
(
See,
e.
g.,
Mourning
v.
Family
Publications
Serv.,
Inc.,
411
U.
S.
356
(
1973)
and
also
United
States
v.
Vonn,
535
U.
S.
55
(
2002)
summarized
on
pp.
43­
44
of
440);
(
2)
the
preclusive
effect
of
the
isolated
use
of
a
term
is
even
more
attenuated
where,
as
here,
the
provision
in
which
the
term
appears
has
little
in
common
with
the
provision
in
which
its
absence
would
be
interpreted
(
see
City
of
Columbus
v.
Ours
Garage
&
Wrecker
Serv.,
536
U.
S.
424
(
2002));
and
(
3)
any
purported
preclusive
effect
is
weakened
further
in
the
context
of
agency
rulemaking,
such
as
the
process
of
MACT
standard
setting.
IX.
36
Comment:
Commenter
472
stated
that
EPA
refers
to,
but
does
not
discuss,
a
third
"
deregulatory"
option
that
"
would
involve
the
use
of
a
concentration­
based
applicability
threshold.
Given
that
EPA
did
not
explain
the
approach,
it
is
impossible
to
comment
on
it
and
it
has
not
been
proposed
sufficiently
to
include
it
in
a
final
rule.
The
commenter
added
that,
in
general,
EPA
needs
to
remember
that
the
CAA
requires
it
to
"
promulgate
regulations
establishing
94
emission
standards
for
each
category
or
subcategory
of
major
sources
or
area
sources
of
hazardous
air
pollutants
listed
for
regulation
pursuant
to
subsection
(
c)..."
The
commenter
also
provided
a
definition
of
"
major
source"
and
"
stationary
source"
and
stated
that
based
on
those
EPA
definitions,
EPA's
112(
d)
standards
must
apply
to
each
emission
point
at
each
source,
and
the
agency
cannot
exempt
any
emission
point
based
on
the
belief
that
its
emissions
have
a
low
concentration
of
HAP.
IX.
37
Comment:
Regarding
the
use
of
a
concentration­
based
applicability
threshold,
commenters
465
and
470
stated
that
this
is
not
what
Congress
intended
in
the
CAAA
of
1990.
Congress
mandated
that
the
MACT
floor
be
established
as
initial
level
of
control.
IX.
38
Comment:
Commenter
502
stated
that
in
the
preambles,
EPA
expresses
uncertainty
over
whether
it
has
the
authority
to
subcategorize
source
categories
based
on
risk.
The
commenter
believes
that
EPA
has
ample
authority,
based
on
sections
112(
c)(
1)
and
112(
d)(
1),
to
subcategorize
based
on
risk.
Section
112(
c)(
1)
states:
"
Nothing
in
the
preceding
sentence
[
relating
to
following
the
NSPS
program
categories
and
subcategories]
limits
the
Administrator's
authority
to
establish
subcategories
under
this
section
as
appropriate."
Thus,
Congress
allowed
EPA
discretion
to
subcategorize
previously
created
categories,
regardless
of
the
criteria
that
EPA
used
to
create
the
category
in
the
first
place,
and
to
do
so
at
any
time.
Section
112(
d)(
1)
provides
that
EPA
"
may
distinguish
among
classes,
types
and
sizes
of
sources"
when
establishing
MACT
standards.
The
broad
terms
"
classes,"
"
types,"
and
"
sizes"
indicate
that
Congress
intended
that
EPA
have
broad
discretion
in
establishing
subcategories
and
do
not
preclude
EPA
from
subcategorizing
based
on
risk,
since
low­
risk
sources
could
be
considered
a
"
class"
or
"
type"
of
source.
The
commenter
added
that
the
only
case
to
clarify
this
statutory
language
recognized
the
broad
discretion
it
confers
on
EPA
to
create
subcategories
with
different
emission
standards.
Sierra
Club
v.
Costle,
657
F.
2D
298
(
D.
C.
Cir.
1981).
The
Court
noted,
"[
t]
he
required
finding
that
must
underlie
a
variable
standard
is
much
broader
than
a
mere
determination
that
uniformity
is
not
achievable."
Id.
at
321.
On
this
basis,
the
Court
expressly
upheld
EPA's
subcategorization
of
coal­
fired
power
plants
based
on
the
sulfur
content
of
fuel.
More
generally,
the
Sierra
Club
decision
confirms
EPA's
discretion
to
set
differentiated
emissions
standards
for
subcategories
of
sources,
even
in
instances
where
the
strictest
standard
may
be
achievable
by
all
sources.
IX.
39
Comment:
Commenter
472
stated
that
subcategory
delisting
under
§
112(
c)(
9)(
B)
is
flatly
unlawful.
Section
112(
c)(
9)(
B)
provides
that
EPA
"
may
delete
any
source
category"
from
the
§
112(
c)
list
upon
making
certain
determinations.
Congress
was
well
aware
of
the
difference
between
a
"
category"
and
a
"
subcategory"
when
it
enacted
§
112(
c).
When
Congress
wished
to
refer
to
both
subcategories
and
subcategories,
it
did
so
expressly.
By
referring
only
to
"
category,"
Congress
made
plain
that
§
112(
c)(
9)(
B)
does
not
allow
EPA
to
delist
a
"
subcategory"
for
any
reason.
Commenter
425
did
not
see
legal
basis
for
creating
a
subcategory
based
on
risk
alone.
IX.
40
Comment:
Commenter
472
stated
that
even
if
EPA
could
delist
a
subcategory,
it
could
not
do
so
based
on
risk.
Section
112(
c)
states
that
"[
t]
o
the
extent
practicable,
categories
and
subcategories
listed
under
this
subsection
shall
be
consistent
with
the
list
of
source
categories
established
pursuant
to
section
111
and
part
C,"
and
the
commenter
stated
that
subcategories
based
on
risk
would
not
be
consistent
with
either
the
section
111
list
or
part
C.
The
commenter
added
that
EPA
has
interpreted
the
statement
regarding
subcategorizing
by
"
classes,
types,
and
95
sizes"
in
section
112(
d)
to
mean
that
subcategories
must
share
physical
characteristics
relevant
to
the
degree
of
pollution
control
that
can
be
achieved.
Because
risk
is
not
such
a
characteristic,
EPA
may
not
subcategorize
based
on
risk.
The
commenter
also
added
that
risk­
based
subcategories
would
be
at
odds
with
Congress's
purpose
in
enacting
section
112
 
i.
e.,
requiring
technology­
based
standards
with
a
performance­
based
floor
 
which
was
intended
to
overcome
the
difficulties
EPA
encountered
in
completing
health­
based
standards.
In
addition,
the
commenter
added
that
EPA
has
not
provided
a
reason
for
departing
from
its
current
interpretation
of
the
guidelines
for
establishing
subcategories
other
than
to
avoid
setting
emission
standards.
Thus,
subcategorization
based
on
risk,
including
under
the
pretense
of
subcategorization
by
technology
(
which
EPA
admits
to
considering),
would
be
unlawful.
IX.
41
Comment:
Commenter
472
stated
that
EPA
did
not
propose
any
subcategories
for
delisting,
and
if
EPA
wanted
to
delist
a
subcategory,
the
would
have
to
propose
the
delisting
and
allow
the
public
to
comment.
The
commenter
added
that
instead
of
creating
further
delays
with
such
a
process,
EPA
should
consider
that
its
standards
are
already
late
and
should
focus
its
resources
on
completing
the
overdue
standards
instead
of
providing
unlawful
exemptions
for
industry
groups
that
wish
to
avoid
cleaning
up
their
hazardous
air
pollution.
IX.
42
Comment:
Commenter
515
stated
that
the
only
option
that
appears
consistent
with
the
CAA,
does
not
create
excessive
work
for
State
and
local
agencies,
and
may
be
able
to
be
based
on
science,
is
the
subcategorization
and
delisting
approach.
However,
the
commenter
added
that
the
subcategories
should
be
based
on
equipment
or
fuel
use,
not
risk.
The
commenter
added
that
a
subcategory
based
on
site­
specific
risk
creates
a
circular
definition
and
does
not
make
sense.
The
commenter
also
stated
that
subcategory
de­
listing
should
occur
before
the
compliance
date
so
that
facilities
don't
put
off
compliance
in
the
hope
or
anticipation
of
de­
listing.
Commenter
515
supported
identifying
and
excluding
technology­
based
subcategories
(
that
include
low
risk
facilities)
and
long
as
the
112(
c)(
9)(
B)
concepts
are
met
(
i.
e.,
less
than
10­
6
cancer
risk,
and
no
source
exceeds
ample
margin
of
safety
level).
IX.
43
Comment:
Commenter
425
urged
caution
in
the
effort
to
define
a
permissible
subcategory
based
upon
technological
differences
that
would
then
be
susceptible
to
delisting
under
the
extremely
stringent
delisting
requirements
of
section
112.
IX.
44
Comment:
Commenter
449
suggested
an
alternative
applicability
criteria
of
1
tpy
formaldehyde
in
order
to
focus
the
rule
on
higher­
emitting
units
and
relieve
low­
emitting
units
of
the
burden
of
MACT
regulation,
given
that
nearly
all
turbines
will
be
subject
to
the
turbine
MACT
as
a
result
of
co­
location
with
other
emission
sources.
The
commenter
stated
that
applicability
based
solely
on
power
output
does
not
address
the
variability
of
formaldehyde
emissions
for
various
turbine
models,
and
provides
little
incentive
for
turbine
manufacturers
or
owner/
operators
to
reduce
emissions
since
all
units
rated
more
than
1
MW
would
be
regulated.
Commenter
422
suggested
that
EPA
add
an
additional
risk­
based
threshold
(
a
mass­
based
threshold)
for
well
operated/
controlled
turbines
with
emissions
less
than
1
tpy
of
formaldehyde.
The
commenter
cited
a
precedent
in
subpart
HH,
Oil
and
Natural
Gas
Production
MACT,
in
which
glycol
units
with
benzene
emissions
less
than
1
tpy
were
exempt
because
"
the
EPA's
analysis
indicated
that
control
of
HAP
emissions
below
these
cutoff
levels
was
not
cost­
effective
for
area
source
glycol
dehydration
units."
IX.
45
Comment:
Commenter
515
stated
that
the
preamble
discussion
of
a
low­
risk
96
subcategory
on
the
MACT
floors
for
the
entire
category
sounds
like
another
valid
reason
not
to
mix
the
risk­
based
and
technology­
based
standards
development.
The
commenter
added
that
EPA
does
not
address
how
the
"
once
in,
always
in"
policy
would
apply.
IX.
46
Comment:
Commenter
502
supported
the
concept
described
in
the
preambles
regarding
the
establishment
of
the
MACT
floor
based
on
the
controls
for
the
entire
source
category.
The
commenter
agreed
that
considering
controls
for
low­
risk
subcategories
could
maintain
the
appropriate
stringency
of
the
MACT
floor.
Once
the
floor
is
established,
facilities
could
demonstrate
their
inclusion
in
the
low­
risk
category
that
is
subsequently
listed.
IX.
47
Comment:
Commenter
445
agreed
that
the
MACT
floor
could
be
established
for
the
entire
source
category
and
then
facilities
could
be
allowed
to
become
part
of
a
low­
risk
subcategory
in
the
future,
after
MACT
standards
are
established.
This
would
allow
low
risk
facilities
to
use
section
112
(
c)(
9)
without
affecting
the
MACT
floor.
IX.
48
Comment:
Commenter
440
stated
that
EPA
cannot
rely
solely
on
the
health
benchmarks
in
the
IRIS
database.
The
commenter
stated
that
EPA's
Integrated
Risk
Information
System
(
IRIS)
database
is
a
useful
tool
for
obtaining
information
about
the
health
effects
of
concern
for
individual
chemicals.
However,
IRIS
is
far
from
definitive,
as
Agency
resource
constraints
have
resulted
in
many
chemical
summaries
that
are
significantly
outdated
and
do
not
reflect
the
most
recent
scientific
developments.
Moreover,
the
IRIS
database
is
a
non­
statutory,
in­
house
Agency
activity,
and
IRIS
entries
are
not
subject
to
formal
notice
and
comment.
Not
surprisingly,
therefore,
EPA
management
has
repeatedly
emphasized
that
the
Agency
is
required
to
consider
other
information,
in
addition
to
the
IRIS
database,
when
evaluating
the
health
effects
of
chemicals
in
a
regulatory
context.
The
commenter
referenced
several
EPA
directives
regarding
use
of
IRIS.
The
commenter
concluded
based
on
these
directives
that
when
evaluating
chemicals
in
a
regulatory
context,
EPA
must
use
a
scientifically
appropriate
health
benchmark,
and
when
determining
that
health
benchmark,
EPA
must
consider
all
relevant
information
to
ensure
that
the
health
benchmark
is
up­
to­
date
and
scientifically
credible
­
even
if
that
means
departing
from
the
value
in
IRIS.
IX.
49
Comment:
Commenter
489
stated
that
the
proposals
inappropriately
use
draft
guidelines
and
toxicity
profiles
that
have
not
been
subject
to
public
review
and/
or
are
not
publicly
available.
The
commenter
was
particularly
concerned
with
the
reference
to
the
use
of
non­
linear
carcinogenic
risk
values
and
toxicity
profiles
(
for
HAP)
that
have
not
been
finalized
and
are
not
available
for
review
by
the
public.
IX.
50
Comment:
Commenter
465
agreed
with
EPA's
choice
to
derive
their
data
from
IRIS,
CAL­
EPA
and
ATSDR
for
its
documentation
for
establishing
risk
based
threshold
and
nonthreshold
values.
The
commenter
added
that
almost
all
HAP
are
being
reviewed
and
reevaluated
on
a
regular
basis,
and
it
would
be
inappropriate
to
single
out
formaldehyde
and
acetaldehyde
at
this
time.
EPA
can
only
rely
on
what
is
currently
published
and
underwent
either
peer
review
or
agency
review.
The
issue
of
changing
health­
based
guideline
values
will
always
be
a
concern
once
health­
based
regulations
are
promulgated.
IX.
51
Comment:
Commenter
445
encouraged
EPA
to
allow
local
agencies
and
states
to
use
more
stringent
risk
factors
in
instances
where
the
California
Office
of
Environmental
health
hazard
assessment
has
more
stringent
risk
values
than
EPA.
The
commenter
also
requested
that
EPA
to
recognize
state
or
local
programs
that
require
more
stringent
toxic
control
strategies
or
97
technologies
than
federal
guidelines.
IX.
52
Comment:
Commenter
440
pointed
out
that
EPA's
initial
IRIS
entry
was
completed
in
1987
and
the
Agency's
core
conclusions
and
analysis
have
remained
untouched
for
more
than
15
years.
The
science,
however,
has
not
remained
stagnant;
in
fact,
the
weight
of
scientific
evidence
should
now
preclude
the
use
of
the
IRIS
unit
risk
factor
for
formaldehyde.
As
a
result,
the
commenter
believes
that
EPA
should
base
its
unit
risk
factor
of
the
CIIT
study
(
described
in
detail
on
pages
48­
52
of
comment
440),
and
conclude
that
formaldehyde
exposures
at
or
below
0.6
ppm
pose
less
than
one
in
one
million
risk
of
respiratory
tract
cancer.
As
an
alternative,
EPA
could
rely
on
recent
work
of
Health
Canada
and
Environment
Canada
in
identifying
a
fenceline
concentration
for
formaldehyde
that
amply
protects
human
health.
The
commenter
noted
that
the
CIIT
report
underwent
extensive
peer
review
by
CIIT,
U.
S.
EPA,
Health
Canada,
and
other
peer
reviewers.
The
commenter
also
noted
that
EPA
should
calculate
a
unit
risk
factor
for
formaldehyde,
whether
through
the
IRIS
process
or
simply
as
part
of
the
CT
rulemaking.
IX.
53
Comment:
Commenter
440
stated
that
acetaldehyde
is
similar
to
formaldehyde
structurally
and
toxicologically,
and
is
expected
to
be
similar
mechanistically.
As
with
formaldehyde,
the
current
state
of
the
science
suggests
that
it
would
be
inappropriate
to
rely
on
the
unit
risk
factor
in
the
IRIS
database.
The
commenter
supported
EPA's
ongoing
efforts
to
revise
the
IRIS
value
for
acetaldehyde
(
and
formaldehyde)
and
believes
that
the
updated
value
should
be
used
for
establishing
fenceline
concentration
thresholds
in
the
CT
MACT.
However,
if
EPA
is
unable
to
complete
the
reassessment
for
acetaldehyde,
the
current
IRIS
value
should
not
be
used.
Based
on
a
peer­
reviewed
Health
Canada
study
(
details
provided
on
pages
55
and
56
of
440),
the
available
data
on
acetaldehyde
suggest
that
the
non­
cancer
health
benchmark
will
be
at
least
as
conservative,
if
not
more,
as
the
health
benchmark
to
protect
against
carcinogenic
effects.
Accordingly,
EPA
should
use
a
non­
cancer
health
benchmark.
Health
Canada's
health
benchmarks
cannot
be
compared
directly
to
the
one
in
a
million
risk
level
calculated
from
EPA's
unit
risk
factor,
because
of
the
non­
linear
nature
of
the
acetaldehyde
dose­
response
curve.
As
stated
in
the
TERA­
ITER
database,
"[
i]
t
would
not
be
appropriate
to
use
linear
extrapolation
procedures
to
aid
in
the
comparison
of
Health
Canada's
tumerogenic
concentration
with
5%
response
(
TC05)
with
U.
S.
EPA's
cancer
assessment
because
the
risk
below
the
TC05
will
fall
off
dramatically
because
of
the
highly
nonlinear
dose­
response
relationship
for
acetaldehyde."
Nonetheless,
it
is
clear
that
a
one
in
a
million
risk
level
based
on
Health
Canada's
extrapolation
approach
would
be
much
higher
than
U.
S.
EPA's
cancer
risk
value
of
0.5

g/
m3.
A
rough
extrapolation
of
the
one
in
a
million
risk
level
for
acetaldehyde
(
assuming
the
mode
of
action
is
similar
to
formaldehyde
and,
therefore,
changing
the
acetaldehyde
cancer
slope
factor
to
reflect
non­
linearity
and
differences
between
rat
and
human
nasal
anatomy)
shows
that
the
acetaldehyde
dose
is
134
times
higher
than
the
formaldehyde
dose.
Applying
this
ratio
to
the
0.6
ppm
level
for
formaldehyde
(
based
on
the
CIIT
formaldehyde
study)
results
in
a
one
in
a
million
risk
level
of
80.4
ppm
(
144,000

g/
m3)
for
acetaldehyde
 
a
value
that
is
quite
close
to
the
TC05
calculated
by
Health
Canada
(
86,000

g/
m3).
While
the
calculation
may
not
necessarily
be
accurate,
the
value
does
illustrate
that
the
non­
cancer
benchmark
almost
certainly
will
be
more
conservative
than
the
one
in
a
million
cancer
risk
for
acetaldehyde.
Therefore,
the
commenter
recommended
establishing
fenceline
concentration
levels
for
acetaldehyde
based
on
protection
against
non­
98
cancer
health
effects,
and
believes
that
a
benchmark
between
27
and
390

g/
m3
is
the
most
scientifically
appropriate.
At
a
minimum,
EPA
should
based
its
fenceline
concentrations
for
acetaldehyde
on
the
existing
IRIS
RfC
of
9

g/
m3,
rather
than
extrapolating
to
a
one
in
a
million
risk
level
using
the
IRIS
unit
risk
factor.
IX.
54
Comment:
Commenter
440
stated
that
EPA
may
properly
treat
formaldehyde
and
acetaldehyde
as
threshold
pollutants.
Based
on
their
specific
comments
regarding
the
need
to
update
the
health
benchmarks
for
formaldehyde
and
acetaldehyde,
the
commenter
believes
that
there
is
a
concentration
of
these
pollutants
which
reasonably
can
be
considered
a
NOEL.
The
legislative
history
of
the
CAA
clearly
establishes
that
Congress
considered
threshold
pollutants
to
be
those
for
which
a
NOEL
can
be
identified.
The
commenter
added
that
the
historic
assumption
that
all
carcinogens
are
non­
threshold
pollutants
that
may
trigger
a
carcinogenic
effect
at
any
dose
level
is
incorrect
because
at
low
levels,
the
carcinogenic
risk
from
formaldehyde
and
acetaldehyde
is
so
small
as
to
be
unmeasurable.
Commenter
515
stated
that
EPA
should
consider
formaldehyde
and
acetaldehyde
as
carcinogens
unless
a
reassessment
classifies
them
as
threshold
pollutants.
IX.
55
Comment:
Commenter
440
stated
that
consideration
of
background
and
multipathway
exposures
is
not
required
by
law
and
is
not
necessary
for
sound
policy.
The
commenter
explained
that
the
exclusive
focus
on
the
emissions
from
a
source
in
making
regulatory
decisions
under
CAA
§
112
is
evident
in
all
of
the
statutory
provisions
on
which
EPA
would
rely
to
implement
the
risk­
based
mechanisms
(
i.
e.,
112(
d)(
4),
112(
c)(
9)(
B),
or
EPA's
de
minimis
authority).
As
a
result,
EPA
has
no
legal
obligation
to
consider
background
or
multi­
pathway
exposures.
Moreover,
the
statutory
focus
on
the
MACT­
regulated
source
further
means
that
there
is
no
legal
obligation
to
model
risks
from
the
entire
facility,
but
rather
only
the
MACT­
regulated
portion
of
the
facility.
Commenter
440
also
noted
that
EPA
has
existing
regulatory
programs
(
e.
g.,
for
mobile
and
area
sources
[
Urban
Air
Toxics
Strategy])
in
place
to
address
HAP
emissions
from
other
sources.
Commenter
440
stated
that
government
surveys
and
EPA's
regulatory
actions
demonstrate
that
non­
inhalation
exposures
to
the
primary
HAP
emitted
by
CTs
are
insignificant
and
should
not
be
considered
in
the
risk
analyses.
IX.
56
Comment:
Commenter
502
stated
that
making
an
allowance
for
other
exposures
under
Section
112
is
not
necessary
to
protect
public
health.
The
commenter
added
that
consideration
of
exposures
from
other
sources
places
a
disproportionate
burden
on
major
sources.
Legislative
history
does
not
support
the
consideration
of
exposures
from
other
source
types
when
setting
risk­
based
criteria.
The
commenter
stated
that
multi­
pathway
risk
assessment
should
be
required
only
for
those
HAP
that
have
the
potential
for
causing
significant
multi­
pathway
exposure.
IX.
57
Comment:
Commenter
502
stated
that
uncertainty
is
already
considered
in
the
establishment
of
reference
concentrations
from
which
the
HI
is
derived.
The
commenter
stated
that
the
uncertainty
factors
used
in
the
NATA
are
large,
and
because
of
the
considerable
uncertainty
adjustments
that
are
already
applied,
it
is
highly
unlikely
that
an
ample
margin
of
safety
would
ever
have
to
include
more
uncertainties
than
are
already
incorporated
in
the
RfCs.
In
some
cases,
the
uncertainty
corrections
are
too
conservative.
IX.
58
Comment:
Commenter
443
stated
that
EPA
should
use
reference
concentrations
99
(
RfCs)
and
reference
doses
(
RfDs)
as
the
threshold
for
deciding
whether
a
MACT
standard
for
a
specific
pollutant
is
warranted.
The
RfCs
and
RfDs
are
set
conservatively
by
first
determining
a
NOEL
and
then
reducing
that
level
by
an
uncertainty
factor.
This
method
of
setting
RfCs
and
RfDs
assures
that
public
health
is
protected
by
"
an
ample
margin
of
safety."
Commenter
443
added
that,
as
EPA
suggests,
the
ample
margin
of
safety
for
nonthreshold
pollutants
is
a
cancer
risk
that
does
not
exceed
one
in
one
million.
IX.
59
Comment:
Commenter
502
stated
that
EPA
should
clarify
that
sources
wishing
to
use
the
section
112(
d)(
4)
emissions
limit
must
only
demonstrate
compliance
with
risk­
based
thresholds
for
those
four
HAP
that
"
account
for
essentially
all
of
the
mass
of
HAP
emissions"
for
the
CT
source
category:
formaldehyde,
toluene,
benzene,
and
acetaldehyde.
Commenter
502
stated,
for
example,
that
a
CT
MACT
facility
would
demonstrate
risk­
based
compliance
with
(
d)(
4)
emissions
limitations
for
threshold
pollutants
(
toluene)
and/
or
compliance
with
de
minimis
emissions
limitations
for
non­
threshold
pollutants
(
formaldehyde,
benzene,
and
acetaldehyde).
IX.
60
Comment:
Commenter
502
stated
that
hazard
quotients
for
chemical
mixes
should
not
be
summed
to
determine
the
hazard
index
(
HI)
unless
the
primary
effects
are
on
the
same
organ
by
the
same
mechanism;
otherwise
the
risk
will
be
overestimated.
IX.
61
Comment:
Commenter
502
stated
that
all
risk­
related
provisions
of
Section
112
should
be
guided
by
the
purpose
of
the
ample
margin
of
safety
determination
­
namely,
to
account
for
uncertainty
in
the
underlying
health
value.
A
hazard
index
equal
to
or
greater
than
1
should
account
for
uncertainty
and
provide
an
ample
margin
a
safety.
Commenter
502
stated
that
The
Report
of
the
Commission
on
Risk
Assessment
and
Risk
Management
provides
further
guidance
and
supports
the
commenter's
contention
that
a
HI
equal
to
or
greater
than
1
should
provide
an
ample
margin
of
safety
for
a
threshold
HAP.
IX.
62
Comment:
Commenter
502
stated
that
adoption
of
the
Drinking
Water
Program's
concept
of
a
HI
of
0.2
is
not
supportable.
The
commenter
added
that,
at
a
minimum,
before
EPA
could
import
the
drinking
water
policy
into
air
programs,
the
agency
would
need
to
evaluate
the
available
scientific
data
 
for
the
HAP
of
concern
in
each
individual
rulemaking
 
to
determine
wether
the
data
justify
a
conclusion
that
80
percent
of
the
exposures
to
those
pollutants
come
from
sources
outside
the
source
category.
IX.
63
Comment:
Commenter
515
stated
that
the
hazard
index
is
useful
in
evaluating
sitespecific
impacts,
but
choosing
a
generic
HI
(
some
multiple
of
1)
for
application
to
a
wide
range
of
sites
is
inappropriate.
The
commenter
added
that
selection
of
an
arbitrary
multiple
of
1
is
not
science,
does
not
conform
with
CAA
section
112(
d)(
4)
and
does
not
protect
public
health.
The
commenter
added
that
using
background
concentrations
from
NATA
and
a
HI
of
1
is
inappropriate
because
NATA
information
includes
warnings
that
the
information
is
useful
for
large­
scale
planning
purposes
and
not
for
local
area
assessment.
IX.
64
Comment:
Commenters
465
and
470
evaluated
the
four
potential
options
that
EPA
proposed
to
ensure
that
a
risk
analysis
under
section
112(
d)(
4)
considers
the
total
ambient
air
concentrations
of
all
the
HAPs
to
which
the
public
is
exposed.
Option
1,
which
requires
that
the
HI
for
all
pollutants
be
no
greater
than
1,
does
not
consider
additional
sources
or
background
and
is
unacceptable.
Option
3,
which
uses
existing
data
such
as
the
National
Scale
Air
Toxics
Assessment
(
NATA)
to
determine
background
and
requires
that
the
HI
be
no
greater
than
1,
is
also
unacceptable.
EPA
has
clearly
stated
at
public
meetings
that
the
NATA
is
not
to
be
used
to
100
make
regulatory
decisions.
The
NATA
relies
on
data
submitted
to
EPA
voluntarily
and
has
been
reported
to
consistently
underestimate
measured
concentrations.
Until
EPA
requires
that
HAP
inventories
be
submitted
as
proposed
in
the
CERR,
and
the
NATA
conducts
refined
modeling
around
stationary
sources,
the
NATA
should
not
be
considered
for
estimating
background
concentrations.
Option
4,
which
allows
individual
facilities
to
monitoring
the
HAP
backgrounds
for
use
in
their
own
analysis,
will
require
oversight
and
evaluation
by
the
States
to
ensure
proper
site
selections
and
analytical
methods
and
should
not
be
considered.
The
commenters
believe
Option
2,
which
requires
that
the
HI
be
no
greater
than
0.2,
would
be
the
only
viable
option
at
this
time
using
a
conservative
risk
screening
analysis.
However,
the
commenters
did
not
endorse
using
any
of
the
proposed
threshold
limit
applicability
methods
to
exempt
process
sources
from
NESHAP
requirements.
IX.
65
Comment:
Commenter
518
referenced
the
greater
than
10­
6
risk
associated
with
formaldehyde
and
benzene
concentrations
predicted
by
NATA
and
stated
that
uniformly
applied
NESHAP
are
needed
to
control
these
pollutants.
IX.
66
Comment:
Commenter
515
stated
that
the
selection
of
a
0.2
hazard
index
as
a
rough
screening
tool
seems
reasonable,
although
it
is
unsupported
by
any
analysis.
The
commenter
added
that
if
a
default
hazard
index
is
used,
EPA
should
include
a
provision
that
would
disallow
the
use
to
exclude
a
facility
from
MACT,
now
or
in
the
future,
if
better
background
information
is
available
that
suggests
that
the
default
does
not
protect
public
health.
The
commenter,
however,
believes
that
the
interpretation
that
includes
the
use
of
such
a
default
to
allow
exemptions
for
individual
sources
is
not
supported
by
the
CAA,
and
the
expansion
of
the
interpretation
to
include
non­
threshold
pollutants
is
in
direct
conflict
with
section
112(
d)(
4)
of
the
CAA.
IX.
67
Comment:
Commenter
489
stated
that
EPA
has
not
discussed
the
need
to
assess
cumulative
risks,
aggregate
exposures,
and
health
impacts
associated
with
exposure
to
chemical
mixtures
emitted
from
facilities
within
the
source
categories.
The
commenter
referred
EPA
to
the
extensive
progress
that
has
been
made
in
more
completely
addressing
risks
from
exposure
to
air
pollution
and
integrated
decisionmaking
in
such
areas
as
children's
risk
issues,
cumulative
exposure
("
Framework
for
Cumulative
Risk
Assessment"
(
EPA/
630/
P­
02/
001A,
April
23,
2002),
and
chemical
mixtures
(
EPA/
630/
R­
00/
002).
The
commenter
requested
that
the
recent
advancements
be
incorporated
into
the
risk
assessment
methods
and
overall
cost
estimates
associated
with
risk­
based
exemptions
in
the
proposed
rules.
Commenter
465
stated
that
the
use
of
NATA
to
determine
background
concentrations
is
unacceptable.
EPA
has
clearly
stated
at
a
number
of
public
meetings
that
NATA
is
not
to
be
used
to
make
regulatory
decisions.
IX.
68
Comment:
Commenter
518
stated
that
the
proposal
is
critically
flawed
because
risk­
based
exemptions
ignore
the
cumulative
risk
that
comes
from
exposure
to
multiple
air
toxics
sources
(
e.
g.,
hundreds
of
combustion
engines
and
boilers
within
a
city)
and
do
not
protect
public
health.
Although
many
individual
sources
may
pose
a
risk
below
a
designated
threshold,
the
accumulation
of
these
pollutants
can
be
hazardous.
Addressing
this
problem
will
require
a
general
reduction
in
air
toxics
emissions
across
large
and
small
sources,
not
just
those
sources
for
which
a
high
local
risk
can
be
demonstrated.
The
commenter
stated
that
NATA
indicates
that
air
toxics
exposures
are
already
high
throughout
the
country.
101
Commenter
518
stated
that,
because
background
risk
is
already
too
high,
the
inhalation
margin
allowed
for
an
individual
source
would
be
zero,
which
leads
back
to
Congress'
decision
that
all
HAP
sources
should
take
reasonable
(
i.
e.,
MACT)
steps
to
reduce
emissions.
IX.
69
Comment:
Commenter
472
stated
that
EPA
must
consider
all
ways
that
a
HAP
could
harm
public
health
or
the
environment.
With
regard
to
EPA's
request
for
comment
on
the
"
appropriateness
and
necessity"
of
accounting
for
non­
inhalation
exposures,
the
commenter
stated
that
§
112(
d)(
4)
refers
to
pollutants
"
for
which
a
health
threshold
has
been
established."
As
this
language
and
the
legislative
history
make
clear,
it
refers
to
pollutants
that
have
no
adverse
health
or
environmental
effects.
See
5
Legislative
History
at
8511.
Thus,
§
112(
d)(
4)
necessarily
requires
EPA
to
consider
all
possible
ways
that
a
pollutant
could
affect
human
health
or
the
environment.
As
EPA
has
recognized
repeatedly
in
the
past,
many
of
the
pollutants
emitted
by
the
source
category
are
re­
deposited
from
the
atmosphere,
and
then
contaminate
soil
and
water
for
long
periods
of
time.
Moreover
they
bioaccumulate
in
wildlife
and
food
sources,
poisoning
people
and
animals
alike.
See,
e.
g.,
64
Fed.
Reg.
52828,
53014
(
September
30,
1999);
64
Fed.
Reg.
31898,
31908­
31909
(
June
14,
1999);
63
Fed.
Reg.
14182,
14193
(
March
28,
1998);
61
Fed.
Reg.
17358,
17478
(
April
19,
1996)
(
due
to
bioaccumulation,
mercury
levels
may
be
10,000,000
times
higher
in
fish
than
in
water
those
fish
inhabit).
To
evaluate
whether
a
pollutant
is
a
threshold
pollutant
and
what
its
health
threshold
and
ample
margin
of
safety
must
be,
therefore,
EPA
must
consider
all
the
potential
health
and
environmental
effects
of
deposition,
persistence
and
bioaccumulation
of
that
pollutant.
EPA
would
contravene
§
112(
d)(
4)
by
considering
only
health
effects
caused
by
inhalation.
IX.
70
Comment:
Commenter
515
stated
that
when
persistent
biological
toxicant
or
metal
emissions
are
significant,
ingestion
and
other
pathways
should
be
considered
in
the
risk
screening.
IX.
71
Comment:
Commenter
465
stated
that
analyses
like
the
concentration­
based
applicability
threshold
approach
do
not
address
non­
inhalation
exposures
or
adverse
effects
on
the
environment.
Commenter
465
stated
that
allowing
individual
facilities
to
monitor
the
HAP
backgrounds
for
use
in
their
own
analysis
would
require
oversight
and
evaluation
by
State
and
local
agencies
to
insure
proper
site
selections
and
analytical
methods
and
would
be
costly
to
administer
and,
therefore,
not
acceptable.
IX.
72
Comment:
Commenter
465
stated
that
the
proposal
did
not
threshold
limitation
guideline
values
for
short­
term
exposure.
Commenter
465
stated
that
formaldehyde
has
a
shortterm
guideline
value
established
by
CAL­
EPA.
IX.
73
Comment:
Commenters
470
and
518
stated
that
the
proposal
does
not
address
ecological
risk
that
may
result
from
uncontrolled
HAP
emissions,
especially
in
those
areas
with
sensitive
habitats
but
few
people
nearby
to
be
exposed.
Commenter
518
stated
that
metals
and
hydrogen
fluoride
have
significant
ecotoxicity.
Commenter
489
stated
that
EPA
provided
inadequate
discussion
of
how
environmental
risks
will
be
evaluated.
The
commenter
added
that
the
CAA
requires
that
EPA
consider
the
environment
as
well
as
public
health,
and
at
a
minimum,
a
facility
would
be
required
to
conduct
an
assessment
based
on
EPA's
Guidelines
for
Ecosystem
Assessment
(
1998).
The
commenter
referred
EPA
to
Appendix
A
of
"
Generic
Assessment
for
Endpoints
for
Ecological
Risk
Assessment"
for
a
detailed
discussion
on
the
legal
basis
from
"
such
statutes
as
the
CAA...
that
require
EPA
to
consider
and
protect
organism­
level
attributes
or
various
taxa
including
fish,
birds,
102
and
plants
and
more
generally,
animals,
wildlife,
aquatic
life,
and
living
things."
IX.
74
Comment:
Commenter
502
supports
EPA's
proposed
tiered
modeling
approach,
which
begins
with
simple
"
look­
up
tables"
and
progresses
to
more
refined
facility­
specific
risk
assessments.
Commenter
502
stated
that
an
initial
simplified
tier
of
risk
assessment,
such
as
look­
up
table,
nomograph,
or
equivalent,
should
be
embedded
in
individual
rulemakings.
The
commenter
added
that
a
guidance
document
should
address
two
additional
tiers
of
assessment:
a
conservative
screening
approach,
and
a
flexible
refined
approach.
Commenter
502
stated
that
a
risk
assessment
guidance
document
should
not
attempt
to
address
policy
and
regulatory
decisions.
Rather,
regulatory
goals
and
policies
should
be
put
forth
within
individual
notice
and
rulemakings.
Appropriate
risk
assessment
endpoints
of
concern
will
also
be
established
within
these
rulemakings.
Commenter
502
stated
that
refined
risk
assessments
(
3rd
tier)
should
allow
for
more
accurate
estimates
of
maximum
individual
risk,
and
could
accomplish
this
through:
(
1)
modeling
ambient
exposures
to
an
actual
human
receptor
location;
(
2)
use
of
exposure
factors
or
models;
(
3)
use
of
realistic
exposure
assumptions
based
on
site­
specific
data
(
residential
tenure,
etc.);
and,
(
4)
use
of
probabilistic
analysis
of
uncertainty
and
variability.
Commenter
502
stated
that
rulemakings
that
use
source­
conducted
risk
assessment
should
appropriately
focus
the
initial
scope
of
the
assessment
on
the
HAP,
sources,
and
other
parameters
of
concern
through
applicability
criteria
specified
with
the
individual
rulemakings.
IX.
75
Comment:
Commenter
515
stated
that
the
State
of
Wisconsin
uses
a
tiered
approach
that
first
allows
sources
to
demonstrate
compliance
if
their
potential
emissions,
stack
height,
and
exhaust
direction
are
within
the
ranges
provided
in
conservative
lookup
tables.
The
second
tier
allows
facilities
to
provide
site­
specific
modeling
to
demonstrate
compliance
with
ambient
air
standards
at
the
property
line.
In
general,
the
tiered
approach
has
worked
well
in
Wisconsin.
IX.
76
Comment:
Commenters
465
and
470
stated
that
if
EPA
decides
to
pursue
an
up
front
risk
analysis
approach,
it
should
not
be
a
tiered
approach.
The
development
of
generic
risk
screening
approach
under
the
Section
112(
d)(
4)
framework
will
need
to
be
conservative,
and
the
use
of
a
(
non­
tiered)
conservative
approach
would
represent
the
least
cost
to
the
regulated
community
and
would
be
the
least
time
consuming
for
States
reviewing
the
facility's
application.
IX.
77
Comment:
Commenter
489
stated
that
EPA's
proposal
for
risk­
based
exemptions
effectively
misinterprets
not
only
the
CAA
but
also
the
guidelines
and
science
policies
established
by
EPA
to
ensure
adequate
protection
of
public
health
and
the
environment.
EPA
proposes
a
disorganized
and
cursory
approach
to
implement
risk­
based
exemptions,
which
falls
far
below
the
quality
of
risk
analysis
typically
required
by
EPA
across
other
Agency
programs.
The
proposal
does
not
adhere
to
EPA's
established
guidelines
for
characterizing
human
health
and
ecological
risks.
The
proposal
does
not
incorporate
risk
assessment
guidelines
for
conducting
multi­
pathway
risk
assessments.
The
proposal
does
not
reference
EPA
guidelines
for
cumulative
risk
assessment
that
specifically
require
consideration
of
non­
inhalation
pathways.
The
goals
of
EPA's
March
1995
Risk
Characterization
Policy
of
transparency,
clarity,
consistency,
and
reasonableness
in
Agency
risk
assessments
apply
to
risk
assessment
practices
across
the
Agency.
The
inconsistencies
between
EPA's
proposal
to
provide
risk­
based
exemptions
in
the
MACT
standard
103
process
and
risk
assessment
guidelines
undermine
many
regulatory
programs
throughout
the
Agency.
(
The
commenter
listed
numerous
programs).
Commenter
489
stated
that
the
critical
deficiency
in
the
[
risk­
based]
scheme
reflects
a
fundamental
misunderstanding
of
the
use
of
public
health
and
ecological
risk
assessments
in
the
regulatory
process.
The
commenter
added
that
the
hallmark
of
the
federal
risk
assessment
guidelines
is
a
series
of
policy
memos
that
require
EPA
programs
to
conduct
risk
assessments
consistently
across
all
federal
environmental
programs.
The
approaches
outlined
by
AP&
PA's
white
papers
neglect
to
include
risk
characterization,
which
provides
needed
and
appropriate
information
to
decision
makers.
The
approaches
also
do
not
incorporate
the
critical
recommendation
of
the
Commission
of
Risk
Assessment
and
Risk
Management
to
establish
a
framework
for
stakeholder­
based
risk
management
decision
making.
These
omissions
in
the
proposals
will
prevent
regulatory
agencies
from
demonstrating
to
the
public
that
public
health
and
the
environment
are
adequately
protected.
IX.
78
Comment:
Commenters
422,
502,
and
428
stated
that
any
risk­
based
approaches
should
be
consistent
with
the
policies
in
development
for
the
residual
risk
rules.
Commenter
502
stated
that
EPA
should
specify
many
of
the
procedures
for
facility­
specific
risk
assessments
in
guidelines
rather
than
in
the
rules,
because
procedures
set
in
rules
could
be
seen
as
precedent
setting
and
could
impact
the
residual
risk
program.
For
example,
the
commenter
believes
that
EPA
should
specify
the
threshold
levels
by
which
a
source
would
be
excluded
from
a
rule,
as
well
as
any
tier
1
lookup
tables,
in
each
individual
rule.
In
contrast,
the
specifics
for
how
sources
should
carry
out
tier
2
and
tier
3
risk
assessments
should
be
left
flexible
in
guidelines
now
under
development
by
EPA
for
the
residual
risk
program.
Commenters
428
and
502
stated
that
decisions
regarding
the
risk­
based
approaches
in
the
CT
rule
have
implications
for
risk­
based
approaches
in
other
MACT
standards.
The
commenters
urged
EPA
to
identify
any
generic
issues
that
may
impact
other
MACT
standards
and
EPA
programs
(
i.
e.,
residual
risk)
and
set
aside
enough
time
and
resources
prior
to
promulgation
of
the
rules
to
adequately
address
these
important
and
potentially
precedent­
setting
issues.
IX.
79
Comment:
Commenters
518,
387,
and
470
stated
that
the
tools
needed
to
identify
sources
eligible
for
the
risk­
based
exemption
would
be
the
same
tools
necessary
for
a
Section
112(
f)
residual
risk
assessment.
It
is
the
commenters'
understanding
that
these
tools
are
not
yet
ready
for
general
use.
Commenter
489
stated
that
the
cancer
risk
guidelines
are
currently
undergoing
public
review.
Commenters
465
and
470
have
serious
reservations
with
EPA's
apparent
attempt
to
conduct
an
ad­
hoc
risk
analysis
for
specific
source
categories
by
seeking
comments
on
the
specific
elements
to
be
included
in
the
risk
analysis
and
do
not
believe
these
rulemakings
are
an
adequate
forum
to
develop
this
risk
analysis
process.
The
commenters
believe
that
any
risk
analysis
conducted
by
the
EPA
must
adhere
to
the
risk
assessment
principles
outlined
in
the
Residual
Risk
Report
to
Congress.
IX.
80
Comment:
Commenters
387
and
470
stated
that
the
proposal
will
place
a
very
intensive
resource
demand
on
state
and
local
agencies
to
review
source's
risk
assessments.
State/
local
agencies
may
not
have
expertise
in
risk
assessment
methodology
or
the
resources
needed
to
verify
information
(
e.
g.,
emissions
data
and
stack
parameters)
submitted
with
each
risk
104
assessment.
IX.
81
Comment:
Commenter
489
pointed
out
that
the
proposal
only
considers
cost
for
the
regulated
source
category,
and
not
for
regulatory
agencies.
The
EPA
did
not
consider
the
costs
and
resources
associated
with:
(
1)
the
public
process
required
in
reviewing/
approving
the
proposed
approaches
and,
if
approved,
making
substantial
changes
to
existing
regulations;
(
2)
the
development
of
methods
and
guidance
for
human
health
and
ecological
risk
assessments
of
affected
sources;
(
3)
the
review
by
already
budgetarily
constrained
state
agencies
of
the
assessments
and
assurance
of
adequate
public
participation
in
the
process;
and
(
4)
the
collection/
verification
of
source­
specific
data
needed
for
conducting
risk
assessments.
IX.
82
Comment:
Commenter
515
stated
that
they
are
concerned
about
the
potential
cost
and
workload
that
risk
provisions
would
place
on
permitting
authorities.
The
commenter
added
that
the
permitting
authorities
would
need
to
either
perform
or
verify
the
risk
analyses,
and
that
diverting
State
and
local
resources
to
focus
on
presumably
insignificant
sources
would
detract
from
efforts
associated
with
significant
sources.
The
commenter
pointed
out
some
of
the
specific
items
that
would
add
burden
to
the
State
and
local
agencies,
including
data
verification
for
background
concentrations
and
ongoing
assurance
that
low­
risk
facilities
remain
low­
risk.
IX.
83
Comment:
Because
EPA
understands
the
difficulty
with
risk
assessments,
commenter
514
found
it
perplexing
that
EPA
believes
such
analyses
at
the
State
and
local
levels
would
be
an
efficient
way
to
protect
public
health.
IX.
84
Comment:
Commenters
465
and
470
noted
that
for
EPA
to
conduct
an
up­
front
risk
analysis,
the
procedure
would
need
to
be
conducted
using
the
most
conservative
stack
parameters,
with
a
hypothetical
facility
fence
line
to
satisfy
the
many
impact
scenarios
that
could
occur.
If
EPA
intends
to
have
the
affected
industries
conduct
the
analysis,
then
EPA
must
consider
the
cost
incurred
by
States
which
may
lack
the
necessary
expertise
to
evaluate
and
review
these
analyses.
The
current
proposal
is
silent
on
these
implementation
and
cost
issues.
IX.
85
Comment:
Commenters
518
and
433
stated
that
the
proposal
is
critically
flawed
because
implementing
the
exemption
program
will
require
significant
State
resources
to
review
risk
assessments
prepared
by
sources
trying
to
exempt
themselves
from
MACT.
This
review
will
require
expertise
in
risk
assessment
methodology
lacking
in
many
States
positioned
to
implement
MACT
standards
through
the
title
V
permit
program.
It
will
also
be
necessary
for
States
to
verify
extensive
emissions
and
stack
information
used
in
the
risk
assessment
to
ensure
that
the
assessment
has
been
done
properly.
Because
the
procedures
for
preparing
these
risk
assessments
on
a
large
scale
basis
and
for
assessing
the
potential
adverse
effects
of
the
pollutants
emitted
(
e.
g.
taking
into
account
existing
background
and
looking
for
a
threshold
level
for
carcinogens)
are
untried
and
will
require
extensive
debate
and
review
to
launch,
even
more
time
and
resources
will
be
needed.
Commenter
518
expressed
concern
about
exempting
a
facility
based
on
limited
emission
data
if
EPA
established
a
subcategory
listing
low­
risk
sources.
IX.
86
Comment:
Commenter
445
expressed
concern
that
the
risk­
based
delisting
would
be
resource
intensive.
IX.
87
Comment:
Commenters
465
and
470
stated
that
if
EPA
intends
to
have
the
affected
industries
conduct
the
analysis,
then
EPA
must
consider
the
additional
cost
incurred
by
smaller
sources
to
do
the
analysis.
IX.
88
Comment:
Commenter
515
stated
that
title
V
permits
seem
to
be
the
obvious
105
implementation
tool,
and
that
title
V
permits
could
provide
enforceable
limitations,
appropriate
recordkeeping
requirements,
and
periodic
review
upon
renewal.
The
commenter
added
that
since
the
rule
would
apply
only
to
major
sources,
title
V
permits
already
are
required
and
would
not
be
an
added
burden.
The
commenter
added
that
title
V
could
be
used
to
implement
applicability
cutoffs,
but
that
the
workload
involved
with
the
options
requiring
modeling,
ambient
monitoring,
or
other
means
to
establish
background
concentrations
would
be
a
hindrance
to
any
implementation
mechanism.
The
commenter
stated
that
with
respect
to
potential
risk­
based
provisions,
monitoring
is
more
useful
for
demonstrating
non­
compliance
than
compliance
because
the
regulation
would
apply
to
potential
emissions
under
any
weather
conditions,
whereas
monitoring
reflects
current
weather
and
emission
conditions.
IX.
89
Comment:
Commenter
489
stated
that
risk­
based
exemptions
are
such
an
implausible
interpretation
of
the
CAA
that
states
do
not
even
have
the
authority
to
grant
them
under
their
title
V
permit
programs.
Therefore,
the
commenter
is
not
aware
of
any
approach
to
ensure
that
emissions
remain
below
specified
levels.
MACT
standard
applicability
is
the
gatekeeper
for
being
subject
to
a
Title
V
operating
permit.
Once
a
source
is
exempt
from
a
MACT
standard,
it
would
be
exempt
from
the
monitoring,
reporting
and
recordkeeping
requirements
needed
to
demonstrate
compliance.
IX.
90
Comment:
Commenters
387
and
470
stated
that
it
is
evident
that
the
proposed
approach
to
risk­
based
exemptions
would
require
extensive
debate
and
review
in
order
to
launch,
which
will
further
delay
promulgation
of
the
remaining
MACT
standards.
Commenters
387
and
470
stated
that
delays
could
be
exacerbated
by
litigation
following
legal
challenges
to
the
rules,
and
such
delays
would
trigger
the
MACT
hammer,
which
would
unnecessarily
burden
the
State
and
local
agencies
and
the
industries.
The
commenters
concluded
that,
obviously,
further
delay
is
unacceptable.
IX.
91
Comment:
Commenter
489
noted
that
the
Inspector
General
recently
found
that
EPA
is
nearly
two
years
behind
in
fulfilling
its
statutory
responsibilities
for
implementing
Phase
1
MACT
standards.
This
delay
potentially
harms
the
public
and
environment.
The
inclusion
of
risk­
based
exemptions
in
10­
year
MACT
standards
will
only
further
delay
this
process.
IX.
92
Comment:
Commenter
518
stated
that
the
risk
assessment
exemption
could
significantly
delay
compliance
with
MACT
for
sources
trying
unsuccessfully
to
opt
out
using
the
exemption.
IX.
93
Comment:
Commenter
425
supported
efforts
to
lower
the
costs
to
industry
but
expressed
concern
about
the
legal
viability
of
the
risk­
based
approaches
discussed
in
the
proposal.
The
concerns
are
practical
and
acute,
in
that
if
the
rules
are
invalidated
the
MACT
"
hammer"
could
fall,
subjecting
sources
to
case­
by­
case
MACT
determinations.
Such
a
result
would
not
serve
the
interests
of
industry
or
any
other
stakeholders.
IX.
94
Comment:
Commenter
386
stated
that
EPA
should
have
sufficient
time
to
fully
consider
both
the
risk­
based
approaches
for
the
CT
source
category
and
the
GTA
petition
for
delisting
the
source
category.
The
target
date
for
promulgation
(
August
30,
2003)
and
the
deadline
for
Part
2
112(
j)
permit
applications
for
the
CT
source
category
do
not
afford
EPA
sufficient
time
to
consider
these
issues.
The
commenter
noted
that
the
MACT
source
categories
included
in
the
April
28,
2004,
bin
include
the
risk
alternatives
(
like
the
CT
MACT),
and
the
106
commenter
requested
that
EPA
adopt
the
April
28,
2004
deadline
for
the
Part
2
112(
j)
permit
applications
for
the
CT
source
category.
IX.
95
Comment:
Commenter
470
stated
that
the
proposed
approaches
will
jeopardize
expeditious
promulgation
of
remaining
MACT
standards.
The
commenter
noted
that
according
to
a
recently
proposed
EPA
rule
regarding
section
112(
j),
the
regulated
community
and
State
and
local
agencies
would
have
to
proceed
with
Part
2
permit
applications,
followed
by
case­
by­
case
MACT,
if
EPA
misses
the
newly
agreed­
upon
MACT
deadlines
by
as
little
as
two
months.
This
would
be
time
consuming,
costly,
and
burdensome
for
both
regulators
and
the
regulated
community.
IX.
96
Comment:
Commenters
489
and
465
endorsed
the
comments
submitted
by
STAPPA/
ALAPCO.
Commenter
483
supported
the
comments
presented
by
STAPPA/
ALAPCO
at
the
January
29,
2003
public
hearing
on
the
combustion
turbines
rule.
IX.
97
Comment:
Commenter
489
included
multiple
attachments,
including
the
following:
Attachment
1­­
Congressional
Record,
E2383,
November
11,
1999
Attachment
2­­
EPA
Science
Policy
Council,
Policy
on
Evaluating
Health
Risks
to
Children
Attachment
3­­
EPA
Science
Policy
Council,
Memorandum
on
EPA
Risk
Characterization
Program,
March
21,
1995
Attachment
4­­
EPA
Science
Policy
Council,
Elements
to
Consider
When
Drafting
EPA
Risk
Characterizations,
March
1995
Attachment
5­­
EPA
Science
Policy
Council,
Policy
for
Risk
Characterization,
February
1995
Attachment
6­­
EPA
Science
Policy
Council,
Policy
for
Risk
Characterization,
March
1995
Attachment
7­­
EPA
Science
Policy
Council,
Memorandum
on
New
EPA
Policy
on
Evaluating
Health
Risks
to
Children,
October
20,
1995
Attachment
8
 
Fact
Sheet,
Report
to
Congress
on
Residual
Risk
Attachment
9
 
Statement
of
John
D.
Graham,
Ph.
D.,
Director,
Center
for
Risk
Analysis,
Harvard
School
of
Public
Health,
October
14,
1999
Attachment
10
 
Statement
of
Lee
P.
Hughes,
Vice
President,
Corporate
Environmental
Control,
Bayer
Corporation,
on
behalf
of
the
American
Chemistry
Council,
before
the
Senate
Environment
and
Public
Works
Committee
on
Clean
Air
Act
Residual
Risk,
October
3,
2000.
IX.
98
Comment:
Commenter
489
stated
that
EPA
provided
inadequate
information
on
the
selection
of
HAP
of
concern
from
combustion
turbines
based
on
mass
of
emissions.
For
example,
the
proposal
does
not
provide
information
on
why
dioxin,
numerous
metals,
and
other
HAP
were
not
considered.
For
metals,
the
commenter
recommended
that
EPA
refer
to
their
June
2002
Guidance
for
Characterizing
and
Ranking
Metals
(
EPA/
630/
P­
02/
003A)
to
determine
whether
they
should
or
should
not
be
considered
in
the
risk
assessment.
IX.
99
Comment:
Commenter
470
stated
that
the
proposed
case­
by­
case,
risk­
based
approach
is
unnecessary
because
EPA
has
already
proposed
to
limit
applicability
to
CTs
located
at
major
sources
of
HAP
and
has
also
proposed
size­
based
applicability
limits.
The
size­
based
applicability
limits
should
be
adequate
for
addressing
both
the
size
of
the
HAP
source
and
the
1See
68
FR
1276
(
January
9,
2003)
(
Plywood
and
Composite
Wood
Products
Proposed
NESHAP)
and
docket
number
A­
98­
44,
Item
No.
II­
D­
525
(
White
papers
submitted
to
EPA
outlining
the
risk­
based
approaches).

107
cost­
effectiveness
of
the
requirements.

Response:
The
preamble
to
the
proposed
rule
requested
comment
on
whether
there
might
be
further
ways
to
structure
the
rule
to
focus
on
the
facilities
which
pose
significant
risks
and
avoid
the
imposition
of
high
costs
on
facilities
that
pose
little
risk
to
public
health
and
the
environment.
Specifically,
EPA
requested
comment
on
the
technical
and
legal
viability
of
three
risk­
based
approaches:
(
1)
an
applicability
cutoff
for
threshold
pollutants
under
the
authority
of
CAA
section
112(
d)(
4);
(
2)
subcategorization
and
delisting
under
the
2­
190
authority
of
CAA
sections
112(
c)(
l)
and
112(
c)(
9),
);
and
(
3)
a
concentration­
based
applicability
threshold.
1
The
EPA
indicated
that
it
would
evaluate
all
comments
before
determining
whether
either
approach
would
be
included
in
the
final
rule.
As
presented
above,
numerous
commenters
submitted
detailed
comments
on
these
risk­
based
approaches.

Based
on
EPA's
consideration
of
the
comments
received
and
other
factors,
EPA
has
decided
not
to
include
the
risk­
based
approaches
in
the
final
rule.
The
risk­
based
approaches
described
in
the
proposed
rule
and
addressed
in
the
comments
EPA
received
raise
a
number
of
complex
issues.
In
addition,
EPA
must
issue
the
final
rule
expeditiously,
because
the
statutory
deadline
for
promulgation
has
passed
and
EPA
has
agreed
to
a
binding
schedule
in
a
consent
decree
entered
in
Sierra
Club
v.
Whitman,
Civil
Action
No.
1:
01CVO1537
(
D.
D.
C.).
Given
the
range
of
issues
raised
by
the
risk­
based
approaches
and
the
need
to
promulgate
a
final
rule
expeditiously,
EPA
believes
that
it
is
appropriate
not
to
include
any
risk­
based
approaches
in
the
final
rule.
Nonetheless,
EPA
expects
to
continue
to
consider
risk­
based
approaches
in
connection
with
other
proposed
NESHAP
where
EPA
has
described
and
solicited
comment
on
such
approaches.
Finally,
while
EPA
is
not
including
risk­
based
approaches
in
the
final
rule,
EPA
has
included
a
number
of
other
measures
that
it
expects
will
reduce
the
costs
and
burdens
on
the
affected
sources.

X.
OTHER
A.
Startup/
Shutdown
X.
A.
1
Comment:
One
commenter
(
438)
stated
that
a
maximum
period
for
startup
and
shutdowns
should
be
defined
in
the
proposed
rule,
with
the
possibility
of
the
Administrator
allowing
a
longer
period
on
a
case­
by­
case
basis.

Response:
It
is
believed
that
this
comment
was
made
because
the
proposed
rule
did
not
have
a
requirement
for
a
startup,
shutdown,
and
malfunction
plan
(
SSMP).
The
final
rule
clarifies
that
a
SSMP
is
required
and
the
EPA
believes
that
this
satisfies
the
commenters
concern.
108
X.
A.
2
Comment:
Four
commenters
(
422,
437,
438,
519)
noted
that
facilities
are
not
required
to
prepare
a
SSMP
as
specified
in
the
Part
63
General
Provisions.
Commenters
422
and
519
recommended
that
EPA
modify
the
General
Provision
references
to
be
consistent
with
the
fact
that
the
proposed
rule
does
not
require
SSMP.
Table
8
should
be
revised
as
follows:

°
40
CFR
63.6(
e)(
1)(
i):
should
clarify
that
emission
limitations
and
operating
limitations
do
not
apply
during
SSM
periods.
°
40
CFR
63.6(
e)(
1)(
ii):
eliminate
the
reference
to
the
SSM
plan
°
40
CFR
63.10(
c)(
15):
eliminate
reference
to
SSM
plan
by
noting
"
No"
under
applicability.
Note:
references
for
63.10(
c)(
2­
15)
were
excluded
from
the
General
Provisions
Table
8.

Response:
The
EPA
agrees
with
the
commenters
that
the
rule
had
conflicting
requirements
for
startup,
shutdown,
and
malfunction.
As
stated
in
the
response
to
comment
X.
A.
1,
the
final
rule
clarifies
that
sources
have
a
plan
for
minimizing
emissions
during
startup,
shutdown,
and
malfunctions.
The
General
Provision
references
in
final
rule
have
been
revised
accordingly.

X.
A.
3
Comment:
One
commenter
(
440)
advised
that
EPA
should
make
clear
that
the
MACT
standards
do
not
apply
during
startup,
shutdown,
or
malfunction.
The
commenter
is
concerned
that
EPA's
general
MACT
provision
for
operations
and
maintenance
incorporated
by
reference
in
the
Proposed
Rule
is
phrased
in
a
manner
that
could
be
misconstrued
for
limited
use,
limited
capacity
LPC
CTs
operated
as
peaking
units.
The
general
MACT
provision
for
operations
and
maintenance
requires
that:

"
At
all
times,
including
periods
of
startup,
shutdown
and
malfunction,
owners
or
operators
shall
operate
and
maintain
any
affected
source,
including
associated
air
pollution
control
equipment,
in
a
manner
consistent
with
good
air
pollution
control
practices
for
minimizing
emissions
at
least
to
the
levels
required
by
the
standards."

The
EPA
is
urged
to
clarify
in
the
preamble
to
the
current
rulemaking
that
the
provisions
"
minimizing
emissions
to
at
least
to
the
levels
required
by
the
standards"
does
not
impose
the
new
standards
proposed
in
this
rulemaking
upon
LPC
CT
peaking
units,
as
well
as
other
types
of
machines,
during
SSM.

Response:
The
EPA
believes
that
§
63.6105(
a),
which
states
that
"
you
must
be
in
compliance
with
the
emission
limitations
and
operating
limitation
which
apply
to
you
at
all
times
except
during
startup,
shutdown,
and
malfunctions,"
adequately
addresses
the
commenters
concern.
Thus,
EPA
is
not
changing
the
NESHAP
in
response
to
this
comment.

B.
Dual
Fuel
Units
109
X.
B.
1
Comment:
Four
commenters
(
422,
431,
484,
502)
stated
that
EPA
should
consider
dual
fuel
combustion
turbine
operation
and
the
impacts
of
byproduct
fuel
use
in
the
process
of
establishing
MACT
limitations.
One
commenter
(
431)
recommended
that
EPA
provide
a
similar
subcategory
as
provided
for
digester
and
landfill
gas
for
units
firing
process
gaseous
and
liquid
byproduct
fuels.
If
the
byproduct
fuel
would
not
impact
catalyst
performance,
EPA
should
allow
the
owner/
operator
to
petition
for
a
site­
specific
CO
reduction
or
specific
emission
rate
for
either
CO
or
formaldehyde,
taking
into
account
the
impact
of
the
byproduct
fuel
on
CT
and
catalyst
emissions
and
performance.

Response:
The
commenters
did
not
provide
any
supporting
information
to
indicate
that
turbines
would
not
be
able
to
meet
the
emission
limitations
while
firing
byproduct
fuels.
In
the
absence
of
any
supporting
detail,
EPA
is
not
changing
the
NESHAP
in
response
to
this
comment.

X.
B.
2
Comment:
Five
commenters
(
443,
460,
475,
482,
484)
disagreed
with
EPA's
assumption
that
companies
will
take
a
50
hour
limit
to
avoid
cost
of
installing
CO
catalysts.
Commenter
443
recommended
that
EPA
increase
the
limit
for
limited
use
to
876
hours.
Commenter
460
noted
that
most
dual
fuels
commonly
permitted
for
operation
of
30
days
(
720
hours)
of
liquid
fuel
operation,
while
some
are
permitted
for
120
days
or
more.
Two
commenters
(
460,
482)
said
that
EPA
should
not
require
any
controls
on
dual­
fueled
units.
Commenter
484
observed
that
a
much
greater
percentage
of
fuel
burned
is
diesel
than
EPA's
estimate
of
5
percent.
The
natural
gas
supply
is
limited
in
some
areas.

Commenter
475
stated
that
EPA's
assumption
that
natural
gas
supply
will
be
adequate
and
cost
competitive
with
diesel
fuel
is
incorrect
when
in
fact
natural
gas
curtailments
can
be
expected
to
occur
often
in
a
volatile
fuel
market.
The
commenter
recommended
that
EPA
provide
a
10
percent
annual
capacity
factor
exclusion
for
dual
fuel
units
when
operating
in
the
diffusion
flame
mode
to
allow
for
the
use
of
fuel
oil
as
backup
fuel.
The
commenter
also
recommended
EPA
exempt
operating
hours
while
firing
a
backup
fuel
that
are
attributed
to
compliance
testing
and
performance
testing
from
the
calculation
of
annual
capacity
factor
exclusion.
The
commenter
also
suggested
that
EPA
address
dual
fuel
CTs
by
not
requiring
emission
limitation
for
new
dual­
fuel
CTs
while
operating
in
the
diffusion
flame
mode
and
require
only
a
one­
time
performance
test
for
such
CTs
while
operating
in
the
lean
premix
mode
to
demonstrate
compliance
with
a
5
ppm
CO
limit.
The
commenter
believed
that
EPA
needs
to
be
consistent
in
its
treatment
of
new
and
existing
DFC
CTs
in
this
rule.

Two
commenters
(
508,
509)
agreed
that
EPA
should
address
and
resolve
compliance
and
monitoring
issues
for
dual
fuel
CTs.

Response:
The
subcategory
for
limited
use
units
is
not
included
in
the
final
rule,
thus,
the
50
hour
exemption
for
backup
fuel
firing
is
not
available.
The
rationale
for
not
including
a
subcategory
for
limited
use
units
is
given
in
the
response
to
comment
I.
C.
1.1.
As
discussed
in
the
response
to
comment
IV.
A.
8,
new
subcategories
were
created
for
natural
gas
fired
units
with
limited
oil
backup
and
oil­
fired
units.
The
formaldehyde
emission
limitation
and
operating
110
limitations
are
the
same
for
both
natural
gas
and
distillate
oil
fired
units,
thus
the
type
of
fuel
being
burned
in
the
turbine
should
not
present
any
compliance
monitoring
issues.
Therefore,
the
commenters'
concerns
regarding
compliance
and
monitoring
issues
for
dual
fuel
units
have
been
addressed.

The
EPA
does
not
agree
with
the
comment
that
it
should
not
require
any
controls
on
dualfueled
units.
There
are
existing
dual­
fuel
units
equipped
with
oxidation
catalyst
control
and
therefore
the
MACT
Floor
for
those
units
is
the
level
of
emission
control
achieved
through
the
use
of
oxidation
catalyst
control.

X.
B.
3
Comment:
Four
commenters
(
431,
474,
508,
509)
said
that
the
limited
use
subcategory
should
cover
periods
of
time
when
a
limited
use
backup
or
secondary
fuel
is
being
utilized.

One
commenter
(
443)
agreed
with
EPA's
statement
of
nonapplicability
for
diffusion
mode
of
existing
dual
fuel
units
and
stated
that
this
should
be
made
more
clear
in
the
rule.
The
commenter
also
requested
clarification
in
the
rule
that
there
is
no
emission
limit
for
any
mode
in
which
a
unit
operates
for
less
than
the
period
defined
in
the
limited
use
definition.

Response:
The
EPA
has
evaluated
the
comments
received
on
the
limited
use
subcategory
and
has
decided
to
not
develop
a
limited
use
subcategory.
The
final
rule
does
not
have
emission
limitation
requirements
for
existing
turbines,
reducing
the
burden
on
existing
turbines
with
low
capacity
factors,
which
was
a
major
concern
of
the
commenters.

X.
B.
4
Comment:
Two
commenters
(
427,
460)
remarked
that
EPA's
declaration
that
diesel
fired
turbines
cannot
be
operated
in
the
lean
premix
mode
is
a
misstatement.
While
some
manufacturers,
on
some
models,
only
offer
liquid
fuel
capability
in
diffusion
flame
mode,
other
manufacturers
have
offered
the
dual
fuel
option
on
LPC
turbines
since
the
mid­
1990'
s.
Commenter
427
stated
that
the
standard
should
be
modified
because
of
the
dual
fuel
capability
of
CTs.
The
commenter
noted
that
EPA
has
no
data
to
represent
LPC
liquid
fuel
operation
and
therefore
cannot
determine
an
appropriate
standard.

Response:
At
the
time
the
NESHAP
was
proposed,
EPA
was
not
aware
of
the
availability
of
diesel
fired
turbines
that
operated
in
the
lean
premix
mode.
The
EPA
has
since
contacted
several
turbine
manufacturers
in
an
attempt
to
obtain
more
information
about
these
units,
and
two
manufacturers
confirmed
that
they
do
offer
diesel
firing
while
operating
in
lean
premix
mode.
The
commenter
is
correct
that
EPA
has
no
emissions
test
data
for
LPC
oil­
fired
units,
however,
information
provided
by
the
manufacturers
indicated
that
their
emission
guarantees
for
CO
and
hydrocarbons
were
similar
for
both
natural
gas
and
diesel.
Also,
testing
on
dual
fuel
diffusion
flame
units
shows
that
formaldehyde
emissions
are
actually
lower
for
distillate
oil
firing.
Therefore,
EPA
has
established
an
emission
standard
for
LPC
oil­
fired
units
in
the
final
rule.

X.
B.
5
Comment:
Three
commenters
(
422,
431,
502)
said
that
the
impact
of
firing
diesel
111
fuel
on
catalyst
activity
should
be
considered
and
a
lower
percent
removal
requirement
established
for
that
fuel.

Response:
Catalyst
vendors
indicate
that
catalysts
installed
on
turbines
that
burn
distillate
oil
can
achieve
the
same
CO
and
HAP
percent
reduction
as
those
installed
on
natural
gas
fired
turbines.
The
typical
vendor
guarantee
period
is
the
same
for
either
fuel.
Therefore,
the
EPA
does
not
believe
it
is
appropriate
to
establish
a
lower
percent
removal
requirement
for
oil­
fired
turbines.

C.
Oil
Firing
X.
C.
1
Comment:
One
commenter
(
473)
said
that
EPA
should
establish
a
separate
MACT
category
for
CTs
that
burn
only
oil,
should
identify
a
MACT
floor,
and
consider
collateral
emission
increases
of
PM,
SO
3,
and
H
2
SO
4.

Response:
The
EPA
agrees
that
a
separate
MACT
category
should
be
established
for
CTs
that
burn
only
oil.
The
EPA
has
created
subcategories
for
DFC
units
burning
distillate
oil
and
LPC
units
burning
distillate
oil
in
the
final
rule
and
identified
the
MACT
Floor
for
those
subcategories.
Catalyst
vendors
were
consulted
and
they
indicated
that
collateral
emission
increases
of
PM,
SO
3,
and
H
2
SO
4
from
oil
fired
units
equipped
with
oxidation
catalyst
control
would
be
small.
According
to
the
vendors,
SO
2
emissions
from
both
natural
gas
and
distillate
oil
fired
turbines
are
very
low,
therefore
the
impact
on
PM
emissions
would
be
very
low.
In
addition,
the
catalyst
can
be
installed
at
a
location
where
the
temperature
and
the
residence
time
would
help
to
minimize
the
potential
for
SO
3
formation.

X.
C.
2
Comment:
One
commenter
(
460)
expressed
the
view
that
there
should
be
no
controls
required
for
oil
operation,
based
on
the
fact
that
formaldehyde
emissions
are
lower
on
oil
operation
compared
to
natural
gas
operation.

Response:
The
EPA
does
not
agree
with
the
commenter
that
there
should
be
no
controls
required
for
oil
operation,
because
formaldehyde
is
not
the
only
HAP
of
concern.
It
may
be
lower
for
oil
operation
but
other
HAPs
are
higher
(
metals
for
example).

X.
C.
3
Comment:
Three
commenters
(
421,
460,
473)
observed
that
EPA
did
not
consider
the
ability
of
the
oxidation
catalyst
to
convert
fuel
bound
sulfur
into
sulfuric
acid
mist.
The
formation
of
sulfuric
acid
over
the
catalyst
will
result
in
the
release
of
a
new
air
toxic.
Commenter
473
stated
that
an
oxidation
catalyst
would
reduce
emissions
of
formaldehyde,
CO,
and
VOCs,
but
would
increase
emissions
of
PM
10,
PM
2.5,
SO
3,
and
H
2
SO
4.
The
commenter
provided
an
estimate
from
a
catalyst
vendor
that
12
percent
of
SO
2
will
be
oxidized
to
SO
3
across
the
catalyst
and
ultimately
to
H
2
SO
4.

Two
commenters
(
421,
460)
stated
that
in
a
facility
already
equipped
with
SCR,
the
inclusion
of
an
oxidation
catalyst
would
very
likely
increase
the
PM
emissions.
112
Response:
The
EPA
consulted
catalyst
vendors
and
they
say
the
oxidation
of
SO
2
to
acid
mist
can
occur
over
a
catalyst.
However,
SO
2
emissions
from
both
natural
gas
and
distillate
oil
fired
turbines
are
very
low,
therefore
the
impact
on
PM
emissions
would
be
very
low.
In
addition,
the
catalyst
can
be
installed
at
a
location
where
the
temperature
and
the
residence
time
would
help
to
minimize
the
potential
for
SO
3
formation.

D.
Duct
Burners
X.
D.
1
Comment:
One
commenter
(
477)
said
that
waste
heat
recovery
units
should
be
considered
emission
control
for
gas
fired
CTs.
The
commenter
suggested
the
creation
of
"
operating
scenarios"
for
CTs
with
duct
burners.
If
a
turbine
is
equipped
with
a
duct
burner
but
the
owner
chooses
not
to
operate
the
duct
burner
because
of
reduced
demand
for
boiler
or
process
heater
output,
the
compliance
requirements
would
be
as
stated
in
CT
MACT.
However,
when
duct
burner
is
in
operation,
the
owner/
operator
should
be
allowed
to
meet
the
control
requirements
of
this
MACT
by
meeting
the
requirements
of
the
proposed
Boiler
and
Process
Heater
MACT
or
by
meeting
the
requirements
of
40
CFR
part
63
subpart
SS
(
Standard
for
Closed
Vent
Systems,
Control
Devices,
Recovery
Devices,
and
Routing
to
a
Fuel
Gas
System
or
Process).

Two
commenters
(
437,
519)
also
said
that
routing
a
turbine
exhaust
stream
to
a
boiler
or
process
heater
should
be
considered
an
acceptable
control
technology.
No
additional
control,
monitoring,
or
reporting
requirements
should
apply
to
the
boiler
or
process
heater.

Response:
The
EPA
does
not
agree
that
routing
a
turbine
exhaust
stream
to
a
boiler
or
process
heater
should
be
considered
an
acceptable
control
technology.
The
commenters
have
not
provided
any
supporting
information
to
indicate
that
routing
the
turbine
exhaust
stream
to
a
boiler,
process
heater,
or
other
waste
heat
recovery
unit
would
control
HAP
emissions.

E.
Other
X.
E.
1
Comment:
One
commenter
(
474)
stated
that
EPA
should
reconsider
the
need
for
MACT
standards
for
stationary
CTs.
According
to
the
commenter,
the
GTA
study
confirms
HAP
emissions
from
virtually
all
gas
turbines
present
health
risks
well
below
the
statutory
delisting
criteria.
A
November
20,
2002
Air
Daily
publication
reported
that
formaldehyde
emissions
pose
such
a
minimal
risk
that
they
do
not
warrant
a
rulemaking.
EPA
has
begun
reviewing
a
possible
reduction
in
the
formaldehyde
toxicity
value.
Based
on
preamble,
relatively
few
CTs
will
actually
have
to
install
MACT­
specific
controls.
The
national
benefit
(
tpy
reduction
in
HAP
emissions)
may
be
significantly
overstated.
The
8,760
hr/
yr
assumption
is
unrealistically
conservative.
The
95
percent
CO
reduction
may
also
be
unachievable.

Response:
The
commenters'
main
points
are
based
on
the
fact
that
CTs
pose
little
risk
and
therefore
should
not
be
established.
The
MACT
standards
are
based
on
the
application
of
maximum
achievable
control
technology
without
the
consideration
of
risk.
Risk
based
standards
113
will
be
developed
for
CTs
at
a
later
date
under
the
residual
risk
program.
Therefore
EPA
will
continue
to
develop
and
promulgate
the
CT
MACT
standards.

The
EPA
agrees
with
the
commenter
regarding
the
8,760
hours/
yr
used
to
calculate
emissions
reductions
and
will
use
a
20
percent
capacity
factor
for
simple
cycle
turbines
and
a
60
percent
capacity
factor
for
combined
cycle
turbines
for
the
final
rule.

The
EPA
continues
to
believe
that
95
percent
CO
emission
reduction
is
achievable
if
the
system
is
adequately
designed.
However,
since
the
final
rule
does
not
the
95
percent
CO
emission
reduction
emission
limitation,
the
point
is
now
moot.

X.
E.
2
Comment:
Four
commenters
(
421,
431,
487,
502)
remarked
that
EPA
did
not
adequately
address
the
feasibility
of
retrofit
controls
on
certain
units.
One
commenter
(
487)
cited
the
example
of
a
once
through
steam
generator
(
OTSG)
that
has
no
space
for
CO
oxidation
catalyst
bed;
therefore,
addition
of
CO
oxidation
catalyst
control
would
mean
replacement
of
OTSG
with
a
new
HRSG.
Commenter
421
stated
that
the
addition
of
a
catalyst
system
would
impact
efficiency,
due
to
increased
backpressure,
resulting
in
potentially
increased
emissions
to
obtain
the
same
power
output.

Commenter
502
recommended
that
when
a
CT
subject
to
the
control
requirements
of
the
rule
fails
to
meet
the
43
ppb
formaldehyde
level,
and
an
existing
HRSG
cannot
be
retrofit
with
an
oxidation
catalyst
due
to
physical
or
design
constraints,
the
catalyst
installation
should
not
be
required
until
the
existing
HRSG
is
replaced
or
reconstructed.
In
the
alternative,
EPA
should
offer
a
petition
process
for
these
sources
to
receive
an
alternative
emission
limitation.

Commenter
431
also
observed
that
retrofit
of
catalysts
into
existing
HRSGs
could
pose
significant
and
costly
problems
which
could
result
in
a
lesser
performance
than
for
a
new
design.
EPA
should
reduce
the
CO
reduction
requirement
for
retrofit
installations
on
existing
LPC
CTs.
There
should
also
be
an
option
for
the
affected
source
to
petition
the
EPA
for
a
site
specific
alternative
emission
limitation
based
on
the
attainable
emissions
rate
or
CO
reduction
achievable
on
a
long
term
basis
for
retrofit
installations
on
existing
sources.
The
option
to
petition
for
a
site
specific
alternative
emission
limit
should
also
be
provided
for
those
cases
where
retrofit
installation
of
an
oxidation
catalyst
into
existing
equipment
is
technically
infeasible.

Response:
The
EPA
agrees
with
the
commenter
that
there
may
be
some
issues
with
the
feasibility
of
retrofit
controls
on
certain
units.
However,
as
discussed
in
the
response
to
comment
IV.
B.
1,
the
final
rule
does
not
have
any
emission
limitations
for
existing
units;
thus,
these
comments
are
moot.

X.
E.
3
Comment:
One
commenter
(
472)
observed
that
HAP
emissions
from
sources
burning
natural
gas
are
enormously
different
from
sources
burning
other
fuels
such
as
diesel.
The
commenter
questioned
EPA's
argument
that
the
summation
of
emission
factors
for
various
HAP
for
different
fuels
is
comparable.
The
commenter
also
said
that
EPA
does
not
explain
what
the
114
summation
of
emission
factors
means
or
how
it
might
be
relevant
to
EPA's
floors
for
any
HAP.

Response:
The
EPA
agrees
with
the
commenter
that
the
composition
of
HAP
emissions
from
sources
burning
natural
gas
are
different
than
from
sources
burning
diesel
fuel.
Uncontrolled
formaldehyde
emissions
are
in
general
lower
as
a
result
of
the
combustion
of
distillate
oil
than
for
natural
gas.
Other
differences
in
emissions
between
natural
gas
and
distillate
oil
include
higher
levels
of
pollutants
such
as
PAH
and
metals
for
stationary
CTs
burning
distillate
oil.
The
EPA
agrees
that
the
summation
of
emission
factors
for
various
HAP
for
different
fuels
may
be
different.
As
discussed
in
the
response
to
comment
IV.
A.
8,
due
to
the
differences
in
HAP
emissions,
subcategories
based
on
fuel
were
established
for
both
DFC
and
LPC
turbines.

X.
E.
4
Comment:
One
commenter
(
425)
encouraged
EPA
to
supplement
its
Emissions
Database
to
the
extent
possible
with
additional
data,
assuming
that
it
can
do
so
without
jeopardizing
its
ability
to
meet
the
strict
deadline
it
is
under
to
finalize
the
rule.

Response:
At
proposal,
EPA
had
limited
emissions
data
for
stationary
combustion
turbines.
In
the
preamble
to
the
proposed
rule,
EPA
requested
HAP
emissions
test
data
from
stationary
combustion
turbines.
As
a
result
of
this
request,
EPA
received
new
data
in
the
form
of
several
test
reports
during
the
comment
period
and
has
more
than
doubled
its
total
data
set.

X.
E.
5
Comment:
One
commenter
(
439)
suggested
that
EPA
provide
a
mechanism
to
allow
facilities
to
make
other,
more
cost
and/
or
energy
effective
HAP
reductions
on
processes
other
than
the
turbine
system
at
facilities
where
one
or
more
turbines
are
subject
to
the
rule
simply
because
the
facility
is
a
major
source
due
to
unrelated
processes.

Response:
The
EPA
does
not
agree
with
the
commenter.
The
CAA
does
not
allow
HAP
emission
trading
across
all
categories
at
a
site.
Therefore
this
suggestion
was
not
implemented
in
the
final
rule.

X.
E.
6
Comment:
One
commenter
(
429)
disagreed
with
EPA's
statement
in
the
proposed
rule
that
acetaldehyde
is
present
in
natural
gas
fired
turbine
exhaust.

Response:
Emissions
data
collected
by
EPA
show
that
several
HAPs
are
present
in
the
stationary
CT
exhaust,
including
acetaldehyde.

X.
E.
7
Comment:
One
commenter
(
421)
asserted
that
EPA,
without
rationale,
has
established
an
arbitrary
and
unwarranted
distinction
between
gas
turbines
and
RICE,
with
the
potential
to
disenfranchise
an
entire
industry
as
well
as
technologies
that
are
among
the
most
environmentally
benign
for
power
generation.
The
commenter
urged
EPA
to
reconsider
its
rulemaking.

Response:
The
EPA
is
required
by
the
CAA
to
regulate
stationary
gas
turbines.
115
X.
E.
8
Comment:
One
commenter
(
460)
requested
that
the
word
"
transients"
be
added
to
the
periods
in
which
compliance
is
not
required
as
follows:
"
.
.
.
except
during
startup,
transients,
shutdown,
and
malfunction."
Similarly,
one
commenter
(
427)
said
that
§
63.6105(
a),
should
read
"
except
during
startup,
shutdown,
transient/
off­
load,
and
malfunction."

Response:
The
commenter
did
not
provide
any
clarifying
information
explaining
why
compliance
should
not
be
required
during
transient
operation
of
the
turbine.
The
EPA
knows
of
no
reason
why
compliance
should
not
be
required
during
transient
operation.
As
a
result,
EPA
is
unable
to
address
the
concern
directly
and
is
not
changing
the
NESHAP
in
response
to
this
comment.

X.
E.
9
Comment:
Three
commenters
(
422,
437,
519)
recommended
that
the
following
modifications/
corrections
should
be
made
to
Table
8
General
Provision
applicability
references:

°
In
Table
8
EPA
indicates
that
for
40
CFR
63.6(
b)(
3)
that
this
doesn't
apply
to
Subpart
YYYY
and
notes
that
compliance
is
required
by
startup
or
effective
date.
EPA
should
change
the
"
No"
to
"
Yes."
Section
63.6(
b)(
3)
is
important
because
in
the
case
that
the
final
rule
is
more
stringent
than
the
proposed
rule,
the
regulated
entity
will
have
three
years
to
comply
with
the
more
stringent
regulation
but
still
must
be
in
compliance
with
the
proposed
rule
during
the
three
year
period
immediately
after
the
effective
date.
This
is
a
practical
necessity.
If
the
final
rule
is
more
stringent
than
the
proposed
rule
the
regulated
entity
may
not
have
sufficient
time
to
add
additional
facilities
and
execute
additional
projects
if
the
final
rule
is
significantly
more
stringent
than
the
proposed
rule.

°
For
63.8(
c)(
1)(
ii)
EPA
should
note
"
Yes,"
not
"
No,"
in
the
applicability
column.
This
refers
to
compliance
with
operation
and
maintenance
requirements;
EPA
incorrectly
describes
this
citation
as
"
SSM
not
in
SSMP."
In
addition,
63.8(
c)(
1)(
iii)
should
be
noted
as
"
No,"
not
"
Yes,"
in
the
applicability
column.
This
refers
to
the
SSM
plan.
Apparently
EPA
switched
the
subject
and
applicability
notations
for
these
two
citations.

°
The
Agency
notes
"
No"
for
63.9(
c)
on
allowing
a
request
for
a
compliance
extension
and
notes
"
compliance
extensions
do
not
apply
to
new
or
reconstructed
sources."
The
actual
regulatory
reference
doesn't
limit
the
compliance
extension
to
new
or
reconstructed
sources
so
it
is
unclear
why
the
Agency
would
not
allow
for
a
request
for
an
extension
of
compliance.
Table
8
should
note
"
Yes"
for
applicability.
Consistent
with
this
the
Agency
should
note
"
Yes"
for
applicability
of
63.10(
d)(
4)
relating
to
progress
reports
on
compliance
extensions.

Response:
The
EPA
agrees
with
the
first
and
third
change
suggested
by
the
commenter
and
has
made
the
changes
to
the
final
rule.
The
second
change
was
not
made
because
sources
are
required
to
have
a
SSMP.

X.
E.
10
Comment:
One
commenter
(
502)
said
that
there
are
inconsistencies
in
indication
of
applicable
requirements
between
the
proposal
and
General
Provisions.
Numerous
changes
to
116
Table
8
were
suggested.
See
attachment
B
of
comment
#
502
for
a
complete
list
of
the
changes.

Response:
As
a
result
of
this
comment,
EPA
reviewed
all
of
Table
7
and
corrected
any
inconsistencies
in
the
indication
of
applicable
requirements
between
the
rule
and
the
General
Provisions.