Approval and Promulgation of Air Quality Implementation Plans; Louisiana: Reasonable-Further-Progress Plan for the 1996-1999 Period, Attainment Demonstration, Contingency Plan, Motor Vehicle Emission Budgets, and 1990 Emission Inventory for the Baton Rouge Ozone Nonattainment Area; Louisiana Point Source Banking Regulations

Related Material

Other Related Documents

[Federal Register: August 18, 1998 (Volume 63, Number 159)]
[Proposed Rules]
[Page 44192-44208]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18au98-29]

=======================================================================
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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[LA-29-1-7181; FRL-6144-9]

Approval and Promulgation of Air Quality Implementation Plans;
Louisiana: Reasonable-Further-Progress Plan for the 1996-1999 Period,
Attainment Demonstration, Contingency Plan, Motor Vehicle Emission
Budgets, and 1990 Emission Inventory for the Baton Rouge Ozone
Nonattainment Area; Louisiana Point Source Banking Regulations

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: In this action, the EPA is proposing to approve revisions to
the Louisiana State Implementation Plan (SIP) for the Baton Rouge ozone
nonattainment area submitted by the State of Louisiana for the purpose
of satisfying the Post-1996 Rate-of-Progress (ROP), Attainment
Demonstration, and Contingency Plan requirements of the Federal Clean
Air Act (the Act), which will aid in ensuring the attainment of the
National Ambient Air Quality Standard (NAAQS) for ozone. The EPA is
also proposing approval of the associated 1999 Motor Vehicle Emissions
Budgets (MVEBs) for the area.
The EPA proposes to take action on additional SIP revisions
submitted by Louisiana including codifying revisions that were made to
the 1990 base year emission inventory and submitted to the EPA as part
of the Baton Rouge 15 Percent Rate-of-Progress Plan approved on October
22, 1996. Furthermore, the EPA proposes to approve additional revisions
to the 1990 base year emissions inventory submitted as part of the
Post-1996 Rate-of-Progress Plan. The EPA is also proposing approval of
the State's point source banking regulations. This rulemaking action is
being taken under sections 110, 301 and part D of the Act.

DATES: Comments must be received on or before October 19, 1998.

ADDRESSES: Written comments on this action should be addressed to Mr.
Thomas H. Diggs, Chief, Air Planning Section, at the EPA Regional
Office listed below. Copies of the documents relevant to this action
are available for public inspection during normal business hours at the
following locations. Persons interested in examining these documents
should make an appointment with the appropriate office at least 24
hours before the visiting day.

Environmental Protection Agency, Region 6, Air Planning Section (6PD-
L), 1445 Ross Avenue, Suite 700, Dallas, Texas 75202-2733.
Louisiana Department of Environmental Quality, Office of Air Quality
and Radiation Protection, H. B. Garlock Building, 7290 Bluebonnet
Blvd., Baton Rouge, Louisiana, 70810.

FOR FURTHER INFORMATION CONTACT: Ms. Jeanne Schulze, Air Planning
Section (6PD-L), Environmental Protection Agency, Region 6, 1445 Ross
Avenue, Dallas, Texas 75202-2733, telephone (214) 665-7254.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background
A. Clean Air Act Requirements
1. Reasonable Further Progress Requirements
2. Contingency Measures Requirements
3. Motor Vehicle Emissions Budgets
4. Attainment Demonstration Requirements
B. Related SIP Approvals
C. Current SIP Submittals
II. Analysis of the Submittals
A. Post-1996 Rate-of-Progress Plan
1. Introduction
2. Base Year Emissions Inventory
3. Adjusted Base Year Inventory
4. Required Rate-of-Progress Reductions
5. Fleet Turnover Correction Term
6. Calculation of Target Level of Emissions
7. Growth Calculations
a. Introduction
b. Point Sources
c. Area Sources
d. On-road Mobile Sources
e. Non-road Mobile Sources
8. Total Required Reductions
9. Measures to Achieve the Required Reductions
a. Surplus Reductions in the 15 Percent ROP Plan
b. Tier I FMVCP
c. Federal Non-road Small Engine Standards

[[Page 44193]]

d. Architectural and Industrial Maintenance (AIM) Coatings
e. Autobody Refinishing National Rule
f. Consumer Products National Rule
g. Glycol Dehydrator Controls
h. Vents to Flare
i. Barge Cleaner (Permit Modification)
j. Acetylene Plant (Agreed To Order)
k. Summary of Reductions in the Plan
l. EPA Action
B. Motor Vehicle Emissions Budgets
1. Introduction
2. EPA Action
C. Contingency Measures
1. Introduction
a. Point Source Emissions Banking
b. EPA Action
D. Additional Rule Submitted
E. Attainment Demonstration
1. Introduction
2. Uncertainty and Model Performance
3. Episodes Modeled
4. Attainment Tests
5. Photochemical Grid Model Used
a. Modeling Inputs
i. Meteorological and Air Quality Inputs
ii. Base Case Emissions Inventories
iii. Projection Inventories
iv. Future Boundary Conditions
b. Base Case Model Performance
6. Attainment Demonstration
7. Modeling Evaluation Summary
8. Control Strategy Evaluation
9. Modeling Attainment Without I/M
10. EPA Action
III. Proposed Rulemaking Action
A. Post-1996 ROP Plan
B. Contingency Plan
C. Motor Vehicle Emissions Budgets
D. Attainment Demonstration
E. Emission Inventory Revisions
F. Revision to 1996 Target Level of Emissions
V. Administrative Requirements
A. Executive Orders 12866 and 13045
B. Regulatory Flexibility Act
C. Unfunded Mandates

I. Background

A. Clean Air Act Requirements

1. Reasonable Further Progress Requirements
Section 182(c)(2)(B) of the Act requires each State having one or
more ozone nonattainment areas classified as serious or worse to
develop a plan by November 15, 1994, that provides for additional
actual volatile organic compound (VOC) reductions of at least three
percent per year, averaged over each consecutive three year period,
beginning six years after enactment of the Act, until such time as
these areas have attained the NAAQS for ozone. These plans are referred
to hereafter as Post-1996 ROP Plans. These plans were due to be
submitted to the EPA as a SIP revision by November 15, 1994.
Section 182(b)(1) of the Act mandates a 15 percent VOC emission
reduction, net of growth, between 1990 and 1996 for each State having
one or more ozone nonattainment areas classified as moderate or worse.
That SIP revision was due to the EPA by November 15, 1993. The plan for
these reductions occurring between 1990-1996 is hereafter referred to
as the 15% ROP Plan.
Sections 182(b)(1)(C), 182(b)(1)(D) and 182(c)(2)(B) of the Act
limit the creditability of certain control measures toward the ROP
requirements. Specifically, States cannot take credit for reductions
achieved by Federal Motor Vehicle Control Program (FMVCP) measures
(e.g., new car emissions standards) promulgated prior to 1990, or for
reductions stemming from regulations promulgated prior to 1990 to lower
the volatility (i.e., Reid Vapor Pressure) of gasoline. Furthermore,
the Act does not allow credit toward ROP requirements for post-1990
corrections to existing motor vehicle Inspection and Maintenance (I/M)
Programs or corrections to Reasonably Available Control Technology
(RACT) rules, since these programs were required to be in place prior
to 1990. Emissions and emissions reductions shall be calculated on a
typical weekday basis for the ``peak'' 3-month ozone period (generally
June through August).
2. Contingency Measures Requirements
Sections 172(c)(9) and 182(c)(9) of the Act require contingency
measures to be included in the ROP and attainment plans. These measures
are required to be implemented immediately if reasonable further
progress has not been achieved, or if the NAAQS is not met by the
deadline set forth in the Act.
3. Motor Vehicle Emissions Budgets
Section 176(c) of the Act, and 40 CFR 51.452(b) of the Federal
transportation conformity rule require States to establish motor
vehicle emissions budgets in any control strategy SIP that is submitted
for attainment and maintenance of the NAAQS.
4. Attainment Demonstration Requirements
Under section 182(c)(2)(A) of the Act, States required to submit
Post-1996 ROP Plans, by November 15, 1994, for serious or worse ozone
nonattaiment areas, must also submit for those areas an attainment
demonstration to provide for achievement of the ozone NAAQS by the
statutory deadline. This demonstration is to be based on photochemical
grid modeling, such as the Urban Airshed Model (UAM), or an equivalent
analytical method. In a March 2, 1995, memorandum from Mary Nichols,
Assistant Administrator for the EPA's Office of Air and Radiation, the
EPA set forth a phased approach to satisfy the attainment demonstration
requirements under section 182(c)(2)(A) of the Act. Under this
approach, Louisiana was required to submit a ROP Plan to cover the
three year Post-1996 ROP period (i.e., 1996-1999) as part of its
``Phase I'' submittal by December 31, 1995. Pursuant to a December 29,
1997, memorandum from Richard D. Wilson, Acting Assistant Administrator
for Air and Radiation, an attainment plan was then due by April 1998,
showing how Baton Rouge would attain by its statutory attainment date.
As reflected in the following discussion entitled, ``Current SIP
Submittals,'' Louisiana made its Post-1996 ROP Plan and Attainment
Demonstration submittals ahead of the schedules outlined in the policy
memoranda.
The Baton Rouge ozone nonattainment area is classified as
``serious'' and is subject to the section 182(b)(1) 15% ROP
requirements, section 182(c)(2)(B) Post-1996 ROP requirements, and
section 182(c)(2)(A) attainment demonstration requirements. The Baton
Rouge ozone nonattainment area is comprised of the following parishes:
East Baton Rouge, West Baton Rouge, Ascension, Livingston, and
Iberville. As a serious ozone nonattainment area, Baton Rouge has a
statutory attainment date of November 15, 1999. Therefore, the area's
Post-1996 ROP requirement is to achieve an overall 9 percent reduction
in actual VOCs (net of growth) during the period 1996-1999 pursuant to
section 182(c)(2)(B) of the Act.

B. Related SIP Approvals

As stated previously, section 182(b)(1) of the Act requires that
moderate and above ozone nonattainment areas reduce their 1990
emissions of VOCs by 15 percent (net of growth) on or before November
15, 1996. The 15% ROP Plan submittals were required to be submitted to
the EPA by November 15, 1993. The EPA approved Louisiana's 15% ROP Plan
on October 22, 1996 (61 FR 54737). The rulemaking and associated
technical support document (TSD), which provide detailed information on
the chronology of the 15% ROP Plan submissions, control measures, etc.,
are available from the EPA Region 6 Office listed above.
The following is a summary of the emissions reductions in the 15%
ROP Plan:

[[Page 44194]]

------------------------------------------------------------------------
Louisiana 15 percent ROP plan required reductions
(excluding RVP/FMVCP) (Tons/Day)
------------------------------------------------------------------------
15% ROP Reduction....................................... 29.7
I/M Correction.......................................... 1.3
RACT Correction......................................... 0.0
Growth.................................................. 3.8
---------------
Total............................................... 34.8
Reductions In the Plan:
Stage II Vapor Recovery............................. 3.4
Vents to Flares..................................... 3.7
Marine Vapor Recovery............................... 8.6
Tank Fitting Controls............................... 7.9
Fugitive Emission Controls.......................... 10.4
Federal Rules (Wastewater NESHAP, VOL Storage NSPS). 1.5
Compliance Orders/Permits........................... 1.0
Other (Tank Vent Recovery, Secondary Roof Seal on
Tank).............................................. .9
---------------
Total........................................... 37.4
Surplus Reductions (To Be Carried Over to Post-1996 Rate-
of-Progress Plan)...................................... 2.6
------------------------------------------------------------------------

Louisiana subsequently submitted a site-specific revision to the
approved 15% ROP Plan on December 20, 1997. On May 11, 1998, the EPA
approved the 15% ROP Plan revision (63 FR 25773). The rulemaking and
SIP submittal are available at the EPA Region 6 Office listed above.
In another rulemaking action, the EPA redesignated Pointe Coupee
Parish, which was formerly part of the six-parish Baton Rouge
nonattainment area, to attainment for the ozone NAAQS (62 FR 648, dated
January 6, 1997). The Baton Rouge area was designated nonattainment for
ozone and classified as serious pursuant to sections 107(d)(4) and
181(a) of the Act (56 FR 56694, dated November 6, 1991). (Note that the
EPA is not reopening or requesting comment on the approval actions
described in this section.)

C. Current SIP Submittals

In a letter from the Governor dated November 10, 1994, the State of
Louisiana submitted to the EPA the Post-1996 ROP Plan and Attainment
Demonstration according to section 182(c)(2). The combined plan
submittal addressed both the 9 percent VOC emissions reduction
requirement and the requirement to demonstrate attainment of the ozone
NAAQS by the area's statutory attainment date, November 15, 1999. The
SIP submittal was deemed administratively complete on May 15, 1995, by
operation of law pursuant to section 110(k)(1)(B) of the Clean Air Act.
Subsequently, on December 22, 1995, the Governor of Louisiana
submitted revisions to the November 10, 1994, submittal. The EPA
determined that, in effect, this revised Post-1996 ROP Plan and
Attainment Demonstration superseded the previous submittal.1
The plan was determined to be administratively complete on March 22,
1996. The revisions Louisiana made to the plan substantially modified
the mix of control measures utilized to satisfy the 9% ROP requirement,
and also made changes to the attainment demonstration based on the
EPA's draft guidance document on attainment modeling entitled,
``Guidance on Use of Modeled Results to Demonstrate Attainment of the
Ozone NAAQS.'' As provided for by the draft guidance document on
modeling, the submittal included a weight-of-evidence determination in
support of the urban airshed modeling results.
---------------------------------------------------------------------------

\1\ In this submittal, the State deleted several of the
appendices found in the previous submittal and substantially revised
the remaining portion of the plan (i.e., control strategy, modeling
demonstration, etc.). The December 22, 1995, submittal is capable of
standing alone and does not rely on the November 10, 1994, submittal
to be a complete plan. As such, the EPA's legal obligation to act on
the State's original Post-1996 ROP Plan/Attainment Demonstration
submittal, dated November 10, 1994, is rendered moot.
---------------------------------------------------------------------------

Finally, on January 2, 1997, the Governor of Louisiana submitted a
revision to the December 22, 1995, submittal. The 1997 submittal
included significant changes to the 1990 base year emissions inventory
(and associated 15% and 9% ROP reductions) to account for the impending
redesignation of Pointe Coupee Parish to ozone attainment. Also, the
1997 submittal incorporated into the 1990 base year emissions inventory
previously unreported emissions from several point sources. In
addition, the 1997 submittal removed the emission reduction credits
taken for the vehicle inspection and maintenance control measure in the
December 22, 1995, submittal, and replaced them with additional point
source emission reductions. The submittal also incorporated enhanced
mobile modeling required by Federal conformity regulations. The
submittal also included an analysis of how removal of the I/M
reductions would impact the attainment modeling results submitted in
the December 22, 1995, Attainment Demonstration. The 1997 submittal was
determined to be administratively complete on June 20, 1997.
In addition, Louisiana submitted its contingency measure, point
source emissions reduction banking regulations, as part of the December
15, 1995, 15% ROP Plan pursuant to sections 172(c)(9) and section
182(c)(9) of the Act. The State subsequently submitted the same
contingency measure in both the December 22, 1995, and January 2, 1997,
Post-1996 ROP/Attainment Demonstration submittals. The EPA deferred
taking action on the regulations in the context of the 15% ROP Plan
approval until its rulemaking action on the Post-1996 ROP Plan/
Attainment Demonstration SIP. (The rationale is explained in more
detail in the rulemaking action and associated TSD for the 15% ROP
Plan.)

II. Analysis of the Submittals

The EPA has reviewed the State's submittals for consistency with
the Act, and applicable EPA regulations and policy. A summary of the
EPA's analysis is provided below. More detailed support and technical
discussion is contained in the July 1998 ``TSD for Proposed Clean Air
Act Approval and Promulgation of the Post-1996 Rate-of-Progress Plan
and Attainment Demonstration for the Baton Rouge Ozone Nonattainment
Area.'' This TSD is available from the EPA's Region 6 Office listed
above.

[[Page 44195]]

A. Post-1996 Rate-of-Progress Plan

1. Introduction
Section 182(c)(2)(B) of the Act requires each serious and above
ozone nonattainment area to submit a SIP revision by November 15, 1994,
which provides for an actual reduction in VOC emissions of at least 3
percent per year averaged over each consecutive 3-year period,
beginning 6 years after enactment of the Clean Air Act Amendments of
1990 (CAAA), until the area attains the ozone standard.
2. Base Year Emissions Inventory
Under section 182(b)(1)(B), the baseline from which States
determine the required reductions for ROP planning is the 1990 base
year emissions inventory. The inventory is broken down into several
emissions source categories: stationary, area, on-road mobile, and off-
road mobile. The EPA originally approved the Louisiana 1990 base year
emissions inventory on March 15, 1995 (60 FR 13911).
Louisiana's December 15, 1995, submittal made a number of
adjustments to the base year inventory. The EPA acted upon the revised
1990 base year inventory as part of its rulemaking on the 15% ROP Plan.
In that rulemaking, however, the EPA failed to codify its approval of
the revised base year inventory in the Code of Federal Regulations
(specifically, 40 CFR part 52). The EPA proposes to codify its approval
of the revised base year inventory (in the context of the rulemaking on
the 15% ROP Plan) in this action. (Note that EPA is not reopening or
asking for comment on its March 15, 1995, approval of the base year
inventory.)
Louisiana's January 2, 1997, submittal made a number of revisions
to the 1990 base year emissions inventory. The following table compares
the revised 1990 base year VOC emissions cited in the January 2, 1997,
submittal, with those cited in the approved 15% Plan rulemaking. (It
should be noted that the inventory cited in the December 22, 1995,
submittal is identical to the base year inventory cited in the EPA's
approval of Louisiana's 15% ROP Plan.)

Baton Rouge, Louisiana, 1990 Base Year Inventory
[Ozone Seasonal VOC Emissions (Tons/Day)]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Point source Area source Onroad mobile Nonroad mobile Biogenic
Plan submittal emissions emissions emissions emissions emissions Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
12/15/95................................................ 115.40 26.30 55.50 23.20 120.91 341.31
1/2/97.................................................. 115.00 25.40 53.40 21.80 99.60 315.20
Difference.............................................. .40 .90 2.10 1.40 21.31 26.11
--------------------------------------------------------------------------------------------------------------------------------------------------------

The changes to the inventory in Louisiana's January 2, 1997,
submittal were the result of the following:
1. Removal of Pointe Coupee emissions from the 1990 base year
inventory (due to redesignation to attainment):

Point sources........................ Reduced................................... 5.1 tons/day.
Area sources......................... Reduced................................... .9 tons/day.
Mobile sources....................... Reduced................................... 2.1 tons/day.
Nonroad sources...................... Reduced................................... 1.4 tons/day.
Biogenic sources..................... Reduced................................... 21.3 tons/day.
------------------------------
Total Reduced.................... ........................................ 30.8 tons/day.

2. The VOC emissions of 1.0 tons/day from JN Oil and Gas facility
were added to the inventory. This facility was not included in the
previously approved 1990 inventory.
3. Borden Chemicals reported an increase in VOC emissions of 3.7
tons/day from its acetylene plant. The adjustment was based on recent
studies indicating that the prior inventory reported was understated.
The EPA is proposing to approve the revised 1990 base year
emissions inventory submitted on January 2, 1997. (It should be noted
that in the January 2, 1997, submittal, these revised 1990 base year
numbers have been rounded to the nearest 10th of a decimal place and
the non-road and area source emissions have been combined.)
Overall, these revisions to the 1990 base year inventory decrease
the ``1990 ROP inventory,'' which is the 1990 base year inventory less
the biogenic emissions, for the Baton Rouge nonattainment area from
220.4 tons/day to 215.6 tons/day. The decrease of 4.8 tons/day in the
1990 ROP inventory reduces the 15% ROP Plan reductions requirement by
.6 tons/day. Since the reductions in the approved 15% ROP Plan have
remained unchanged, Louisiana added the .6 tons/day differential to the
15% Plan surplus reductions resulting in a total surplus of 3.2 tons/
day available to be carried over to the Post-1996 ROP Plan. The EPA is
proposing to find this revised surplus acceptable for use in the Post-
1996 ROP Plan.
3. Adjusted Base Year Inventory
Section 182(c)(2)(B) states that the rate-of-progress reductions
must be achieved ``from the baseline emissions described in subsection
182(b)(1)(B).'' This baseline value is termed the 1990 adjusted base
year inventory. Section 182(b)(1)(B) defines baseline emissions (for
the purposes of calculating each milestone VOC/nitrogen oxides
(NO_X) emissions reduction) as ``the total amount of actual
VOC or NO_X emissions from all anthropogenic sources in the
area during the calendar year of enactment. This section excludes from
the baseline the emissions that would be eliminated by FMVCP
regulations promulgated by January 1, 1990, and the Reid Vapor Pressure
(RVP) regulations promulgated by the time of enactment (at 55 FR 23666,
June 11, 1990), which require maximum RVP limits for gasoline to be
sold in nonattainment areas during the peak ozone season.
The FMVCP/RVP reduction between 1990 and the target year of 1999 is
obtained by subtracting a mobile emission inventory based on projected
1999 fleet emission factors and 1990 vehicle miles travelled (VMT) from
the 1990 mobile emission inventory. The EPA is proposing to accept the
State's FMVCP/RVP adjustment of 24.4 tons/day. Thus, the 1990 adjusted
base year inventory relative to 1999 of 191.2 tons/day (215.6--24.4) is
proposed to be

[[Page 44196]]

acceptable for the Baton Rouge Post-1996 ROP Plan.
Provided below is a tabular summary of the emissions inventories
calculated above.

------------------------------------------------------------------------
Emissions inventory Tons/day
------------------------------------------------------------------------
A. 1990 Base Year Emissions Inventory................... 315.2
B. 1990 Rate-of-Progress Inventory (Base Year--
Biogenics)............................................. 215.6
C. Emissions Reductions from the Pre-1990 FMVCP and
Phase II RVP Expected by 1999.......................... 24.4
D. 1990 Adjusted Base Year Inventory (B-C).............. 191.2
------------------------------------------------------------------------

4. Required Rate-of-Progress Reductions
The next step is then to calculate the Post-1996 ROP reductions
requirement. In order to do so, the 1990 adjusted base year VOC
inventory is multiplied by 9 percent. Thus, the Post-1996 ROP reduction
requirement is 17.2 tons/day (.09 x 191.2). The EPA is proposing to
find this Post-1996 ROP reduction (i.e., the 9% ROP reduction)
acceptable.
5. Fleet Turnover Correction Term
In the absence of any new requirements of the CAAA, some decrease
in motor vehicle emissions will occur automatically due to fleet
turnover. States are not allowed to take credit for these reductions
for ROP purposes. During the State's calculation of the 1996 target
level of emissions, these FMVCP reductions, along with non-creditable
RVP reductions that would occur between 1990 and 1996, were subtracted
from the 1990 ROP inventory to calculate the 1990 adjusted base year
inventory. This 1990 adjusted base year inventory was then used to
calculate the required reductions and the 1996 target level of
emissions.
Between 1996 and 1999, there will be some additional reductions in
emissions due to fleet turnover that are not creditable. These
additional, non-creditable reductions are referred to as the fleet
turnover correction term. The FMVCP/RVP mobile source reductions for
1999 are calculated above (24.4 tons/day). The FMVCP/RVP mobile source
reductions for 1996 (21.4 tons/day) were calculated in the same way.
The fleet turnover correction term is the difference between the 1999
and 1996 reductions, or 3.0 tons/day. The EPA is proposing to accept
the State's fleet turnover correction term in the Baton Rouge Post-1996
ROP Plan.
6. Calculation of Target Level of Emissions
For the purpose of calculating the 1999 target, the 1996 target
inventory (obtained from the 15% ROP Plan calculations) is used. The
1996 target inventory used by the State in this calculation was revised
from the target inventory approved as part of the 15% ROP Plan
rulemaking in order to account for the changes made to the 1990 base
year inventory described above. The EPA is proposing to approve the
State's revised 1996 target level of emissions of 163.8 tons/day in
this rulemaking.
The 1999 target level of emissions is the amount of VOC emissions
that must be achieved in order for the nonattainment area to
demonstrate that the 9% ROP requirement has been met. The 1999 target
level used by the State in the Post-1996 ROP Plan is the revised 1996
target level (163.8 tons/day), less the 9% ROP reductions (17.2 tons/
day), less the fleet turnover correction term (3.0 tons/day), or 143.6
tons/day. The EPA is proposing to approve the State's 1999 target level
of emissions of 143.6 tons/day in this rulemaking.
7. Growth Calculations
a. Introduction. The EPA has interpreted the Act to require that
States must provide for sufficient control measures in their ROP Plans
to offset any emissions growth expected to occur after 1996. Therefore,
to meet the ROP requirement, a State must provide for sufficient
emissions reductions to offset projected growth in emissions in
addition to the 3 percent annual average reduction of VOC emissions.
Thus, an estimate of growth in emissions from 1996 to 1999 is required
for determining the total amount of required reductions in the Post-
1996 ROP Plan. The estimate is made by taking the 1990 base year
inventory for each of the various source categories and multiplying it
by a factor which estimates growth from 1990 to 1999. The growth of
each source is calculated separately since the sources typically grow
at different rates. The following is a discussion of the State of
Louisiana's growth projections for 1996-1999.
b. Point Sources. Growth factors from the EPA's Economic Growth
Analysis System (EGAS) were used to estimate 1990-1999 growth for point
sources. The EGAS is a computer software package that provides growth
factors by Source Category Codes for each specific emissions point at a
facility. The 1999 point source inventory was calculated by projecting
the 1990 base year emissions inventory by the EGAS growth factors. The
1990-1999 point source growth is a negative 1.6 tons per day (TPD).
The growth estimate for 1990-1996 calculated in the 15% ROP Plan
was a negative 1.8 tons/day. As stated earlier, the State is required
to offset the emissions growth expected in 1996-1999. Therefore, the
growth projection for 1996-1999 is a positive .2 tons/day (from
negative 1.8 to negative 1.6 tons/day).
The State noted in its Post-1996 ROP plan that the point source
emissions reductions reflected in the 15% ROP Plan, 34.0 tons/day, had
been adjusted for projected growth through 1996. Growing the point
source reductions out to 1999 increases the point source reductions to
34.2 tons/day. The .2 tons/day difference in projected reductions is
shown in the plan as a reduction in the total amount of growth that
must be offset. The EPA is proposing to find the State's point source
growth projections for 1996-1999 acceptable.
c. Area Sources. The EGAS growth factors were used for area
sources, other than gasoline distribution and leaking underground
storage tanks (USTs). (Gasoline distribution growth was based on 1996
and 1999 fleet gasoline fuel efficiencies (miles/gallon) determined
from the MOBILE5a model and used with 1996 and 1999 VMT to estimate gas
consumption. Leaking USTs were based on an actual count.) The area
source growth for 1996-1999 is .2 tons/day. The EPA is proposing to
find the State's area source growth projections for 1996-1999
acceptable.
d. On-road Mobile Sources. Highway mobile source growth was
determined through projections using the MOBILE5a computer model and
projected growth in VMT. The VMT growth projections were developed by
the Louisiana Department of Transportation, in cooperation with the
Metropolitan Planning Organization, Capitol Regional Planning
Commission, and Louisiana Department of Environmental Quality. The
projected on-road mobile source emissions growth for the Baton Rouge
area (1996-1999) is 2.4 tons/day. The EPA is proposing to

[[Page 44197]]

find acceptable the State's on-road mobile source growth projections
for 1996-1999.
e. Non-road Mobile Sources. The EGAS growth factors were used for
projecting growth in non-road mobile sources. The non-road mobile
growth (1996-1999) is .2 TPD. The EPA is proposing to find acceptable
the State's non-road mobile growth projections for 1996-1999
acceptable.
The following Table summarizes the emissions growth by source
category from the nonattainment area:

Baton Rouge Growth, 1996-1999
------------------------------------------------------------------------
Source category Tons/day
------------------------------------------------------------------------
Point................................................... 0.2
Area.................................................... 0.2
On-road Mobile.......................................... 2.4
Non-road Mobile......................................... 0.2
Subtotal................................................ 3.0
Offset from Growth of 15% Plan Point Source Reductions.. (0.2)
Total Growth in 9% Plan............................. 2.8
------------------------------------------------------------------------

In summary, the EPA proposes that the State's methodology for
selecting growth factors and applying them to the 1990 base year
emissions inventory to estimate growth in emissions from 1996-1999 is
acceptable.
8. Total Required Reductions
The total required reductions in the plan include the 9% ROP
reductions, reductions to offset projected growth (1996-1999), and the
FMVCP/RVP turnover correction reductions (1996-1999). The total
required reductions are 23.0 tons/day. The State's ``share'' of these
reductions consists of the 9 percent reductions (17.2 tons/day) plus
the growth offset (2.8 tons/day), or 20.0 tons/day. The FMVCP/RVP
turnover correction reductions (3.0 tons/day) are the Federal
reductions that are not creditable towards meeting the ROP/growth
offset requirements.
9. Measures to Achieve the Required Reductions
a. Surplus Reductions in the 15 Percent ROP Plan. As stated
previously, the surplus reductions in the 15% ROP Plan total 3.2 tons/
day. The State has carried these reductions over to the Post-1996 ROP
Plan, which the EPA is proposing to find acceptable. A detailed
description of the control measures are included in the TSD to this
proposed rulemaking, as well as in the 15% ROP Plan rulemaking and its
associated TSD.
b. Tier I FMVCP. Section 202 of the Act sets new Tier 1 emission
standards for motor vehicles. The EPA promulgated Tier 1 standards for
1994 and later model year light-duty vehicles and light-duty trucks on
June 5, 1991 (56 FR 25724). The Tier 1 standards are approximately
twice as stringent as prior (pre-1990 CAAA) motor vehicle emissions
standards. The State employed the MOBILE5a emission factor model to
estimate the amount of VOC emissions reductions from this control
measure. The State has calculated that the Tier I FMVCP reductions will
achieve a total of 1.0 tons/day in emissions reductions in 1996-1999.
The EPA is proposing that the State's emission reduction estimates are
adequately documented and acceptable for credit towards the Post-1996
ROP Plan.
c. Federal Non-road Small Engine Standards. The Federal standards
for non-road engines (25 horsepower and below) were promulgated on July
3, 1995 (60 FR 34582). The standards primarily affect two stroke and
four stroke lawn and garden equipment and light commercial,
construction, and logging equipment. States are allowed to take credit
for this measure in their ROP Plans pursuant to EPA's policy memoranda,
``Guidance on Projection of Nonroad Inventories to Future Years,''
dated February 4, 1994, and ``Future Nonroad Emission Reduction Credits
for Court-Ordered Nonroad Standards,'' dated November 28, 1994. Based
on this policy, Louisiana took credit in its Post-1996 ROP Plan for the
reductions expected to result by 1999 from the Federal non-road small
engine standards (22.9 percent from 1990 levels). The EPA is proposing
that the 22.9 percent emissions reduction figure is adequately
documented, follows EPA guidance, and is therefore, acceptable. Thus,
the reductions claimed, 1.1 tons/day (5.0 tons/day projected 1999
uncontrolled emissions x 22.9 percent) are proposed by the EPA to be
creditable towards the Post-1996 ROP Plan.
d. Architectural and Industrial Maintenance (AIM) Coatings. The
State has chosen to rely on the Federal AIM rule for emission
reductions in the Post-1996 ROP Plan. The EPA proposed this national
rule on June 25, 1996 (61 FR 32729). The rule is expected to be
finalized in the August 1998 time frame. The State has followed the
EPA's policy memoranda entitled, ``Credit for the 15 Percent Rate-of-
Progress Plans for Reductions from the Architectural and Industrial
Maintenance Coating Rule,'' dated March 22, 1995, and ``Update on the
Credit for the 15% Rate-of-Progress Plans for Reductions from
Architectural and Industrial Maintenance Coatings Rule,'' dated March
7, 1996, in estimating the amount of creditable emission reductions
that will result from the final rule when promulgated. The guidance
allow States to assume a 20 percent emission reduction from this source
category. The State's projected uncontrolled AIM emissions in 1999 are
5.4 tons/day. Applying the 20 percent reduction credit results in a
reduction of 1.1 tons/day. The EPA is proposing that the State has
properly estimated the emissions reductions that will result from the
Federal AIM rule, and the reductions, therefore, are creditable towards
the Post-1996 ROP Plan. It should be noted, however, that if the final
rule does not provide the amount of credit indicated in the memorandum
that States can claim in their ROP plans, Louisiana is responsible for
developing measures to make up the shortfall.
e. Autobody Refinishing National Rule. Autobody shop emissions come
from the painting of damaged vehicles or the reconditioning of old
vehicles typically done in an industrial or small business shop. The
coatings used emit VOCs in significant amounts and the EPA is in the
process of developing a national rule to address the VOC content in
those coatings. The EPA intends to finalize the rule in the August 1998
time frame. In a November 29, 1994, memorandum, ``Credit for the 15
Percent Rate-of-Progress Plans for Reductions from the Architectural
and Industrial Maintenance Coatings Rule and Autobody Refinishing
Rule,'' the EPA set forth policy on the creditable reductions from the
final autobody refinishing rule. That memorandum allowed for a 37
percent reduction from

[[Page 44198]]

1990 base year emissions. Louisiana is claiming a 37 percent emissions
reduction from projected 1999 uncontrolled emissions. Louisiana's
January 2, 1997, submittal, states the inventory is 1.5 tons/day;
however, based on the supporting documentation submitted, the EPA has
recalculated the projected emissions to actually be 1.68 tons/day
(based on a 1990 uncontrolled inventory of 1.4 multiplied by a 1999
EGAS growth factor of 1.2013). The submittal takes credit for a
reduction of only .5 tons/day (1.5 x 37%). However, the EPA has found
this figure to be incorrectly computed. The reductions should actually
be .62 tons/day (1.68 x 37%). The EPA is proposing that .62 tons/day
of reductions be creditable towards the Post-1996 ROP reduction
requirement. It should be noted, however, that if the final rule does
not provide the amount of credit indicated in the memorandum that
States can claim in their ROP plans, Louisiana is responsible for
developing measures to make up the shortfall.
f. Consumer Products National Rule. Section 183(e) of the Act
required the EPA to conduct a study of VOC emissions from consumer and
commercial products. The EPA was then required to list (and eventually)
to regulate those product categories that account for 80 percent of the
consumer products emissions in the ozone nonattainment area. Group I of
the EPA's regulatory schedule lists 24 categories of consumer products
to be regulated by national rule--including personal, household, and
automotive products. The EPA intends to issue a final rule covering
these products in the August 1998 time frame.
In a June 22, 1995, memorandum entitled, ``Regulatory Schedule for
Consumer and Commercial Products under Section 183(e) of the Clean Air
Act,'' the EPA set forth policy regarding the amount of emissions
reductions credit States could take from the Federal consumer products
rule. The policy allows areas to take a 20 percent reduction from 1990
baseline levels.
The consumer products portion of the State's 1999 uncontrolled
inventory is 4.71 tons/day. However, the January 2, 1997, submittal
inaccurately states that the inventory is 5.1 tons/day. This figure is
actually the uncontrolled 1990 base year inventory figure. When a 1999
EGAS growth factor of .9227 is applied to the 1990 uncontrolled
inventory, 5.1 tons/day, the projected 1999 inventory is 4.71 tons/day.
Applying a 20 percent reduction from 4.71 tons/day (per the EPA's
guidance) results in reductions of .94 tons/day that are creditable
toward the Post-1996 ROP Plan requirement. The .06 tons/day difference
between the amount of reductions creditable (.94 tons/day) and those
claimed in the plan (5.1 tons/day x 20% = 1.0 tons/day) are more than
offset by the additional .12 tons/day reductions creditable to the
Post-1996 ROP Plan from the autobody refinishing regulation (above).
The EPA is proposing that .94 tons/day, versus 1.0 tons/day, be
creditable towards the Post-1996 ROP reduction requirement. It should
be noted, however, that if the final rule does not provide the amount
of credit that the memorandum indicates States can claim in their ROP
plans, Louisiana is responsible for developing measures to make up the
shortfall.
g. Glycol Dehydrator Controls. Controls have been installed on
glycol dehydrators in Louisiana to comply with the State's waste gas
regulations (LAC 33:III.2115). Section 2115 was SIP-approved as part of
the EPA's Louisiana RACT ``Catch-up'' rulemaking (59 FR 17078, dated
April 11, 1994). The natural gas industry had been unaware of the
amount of VOC emissions from this source until several years ago. As a
result, the glycol dehydrator VOC emissions from several facilities
were not included in the original base year inventory. The emissions
were subsequently reported by the facilities for the 1993 Periodic
Emissions Inventory. The State has added these glycol dehydrator
emissions (totalling 9.31 tons/day) back to the 1990 base year
inventory. (As noted previously in the base year emissions inventory
section, the EPA is proposing to approve these revisions to the 1990
base year inventory.) The vent streams have been controlled by routing
them to control devices (incinerators). The EPA is proposing that the
control efficiency and rule effectiveness rates are acceptable. The
State has taken 8.4 tons/day of emissions reduction credit in the Post-
1996 ROP Plan for six facilities that have installed controls on glycol
dehydrators to comply with the State's waste gas regulations. The EPA
is, therefore, proposing the emissions reductions from the glycol
dehydrator controls have been properly quantified and are creditable
towards the Post-1996 ROP Plan requirements.
h. Vents to Flare. A flare system was installed at a carbon black
plant, Sid Richardson, to control vent streams containing VOCs. The
controls were installed to comply with the State's waste gas regulation
(LAC 33:III.2115). As stated above, section 2115 has been Federally
approved into the Louisiana SIP. The 1999 projected emissions
(uncontrolled) were 412 tons/year. Installation of the control device
has resulted in emissions reductions of 400 tons/year or 1.1 tons per
day. The EPA is proposing that the control efficiency and rule
effectiveness rates are acceptable, and the emissions reductions
claimed, 1.1 tons/day, are creditable towards the Post-1996 ROP
reductions requirements.
i. Barge Cleaner (Permit Modification). Trinity, Inc., is a barge
cleaning facility in East Baton Rouge Parish whose uncontrolled VOC
emissions were determined to be .9 tons/day. The State issued a permit
modification (#0840-00065-04) limiting emissions from the facility to
no more than .1 tons/day of VOCs. The State submitted the permit
modification as part of the January 2, 1997, Post-1996 ROP Plan
submittal. The permit modification was issued under a SIP-approved
nonattainment new source review permitting program and is, therefore,
Federally enforceable. The modification has been reviewed to verify
that the emissions limits in the permit are enforceable, the emissions
reductions are properly quantified, and the permit contains acceptable
recordkeeping, reporting, and monitoring requirements. The EPA is
proposing that the amount of emissions reductions claimed, .8 tons/day,
is creditable towards the Post-1996 ROP reductions requirement.
j. Acetylene Plant (Agreed To Order). Borden Chemicals and
Plastics, located in Ascension Parish, discovered that emissions from
two sources in the acetylene plant, the quench water system and a
barometric leg vent, were understated. The State issued a Reasonable
Further Progress Agreed To Order to control these two sources by
November 1, 1999. The order was included in the January 2, 1997, Post-
1996 ROP Plan submittal. Reducing emissions from the barometric
condenser system will involve modification of the barometric condenser
system and the addition of a non-contact cooling tower and heat
exchanger system. The emissions reduction project from the quench water
system involves handling quench water from the soot decanters. Water
exiting the soot decanters is presently cooled via a contact cooling
tower. A closed loop design is planned whereby water returning to the
quench will be cooled by heat exchanger. The exchanger cooling water
will be recycled through a non-contact cooling tower similar to that
described for the barometric condenser system.
As stated previously (in the discussion of the 1990 base year
inventory), the understated emissions

[[Page 44199]]

have been added back to the 1990 base year point source inventory.
The emissions reductions anticipated from controlling the quench
water system and the barometric leg vent are 1.8 and 1.4 tons/day,
respectively. The EPA has reviewed the Agreed To Order to verify that
the emissions limits in the order are enforceable, and that the
reductions have been properly quantified. In addition, the EPA verified
that the order contains acceptable recordkeeping, reporting, and
monitoring requirements. The EPA is proposing to approve the Agreed To
Order as part of the Post-1996 ROP plan and the associated emissions
reductions, 3.2 tons/day, as creditable towards the 9% ROP Plan.
k. Summary of Reductions in the Plan. The following is a summary of
the emissions reductions claimed in the 9% ROP Plan:

------------------------------------------------------------------------
Louisiana 9 percent plan required reductions (excluding
RVP/FMVCP): (Tons/day)
------------------------------------------------------------------------
9% ROP Reduction........................................ 17.2
Growth.................................................. 2.8
Total............................................... 20.0
---------------
Reductions in Plan:
Federal Measures:
FMVCP Tier 1 Standards.......................... 1.0
Small Engines Rule.............................. 1.1
AIM Rule........................................ 1.1
Autobody Refinishing Rule....................... 0.6
Consumer Products Rule.......................... 0.9
Other Sources:
Surplus Reductions in 15% Plan.................. 3.2
Barge Cleaner (Permit Modification)............. 0.8
Acetylene Plant (Agreed Order).................. 3.2
Glycol Dehydrator Controls...................... 8.4
Vents to Flares................................. 1.1
---------------
Total Reductions............................ 21.4
===============
SURPLUS REDUCTIONS.......................... 1.4
------------------------------------------------------------------------

l. EPA Action. The EPA is proposing that the control measures'
associated emissions reductions claimed in the January 2, 1997, Post-
1996 ROP Plan are creditable towards the 9% ROP requirements of section
182(C)(2)(B) of the Act. The EPA is also proposing to approve the
Borden Chemical and Plastics Reasonable Further Progress Agreed To
Order as part of the Baton Rouge Post-1996 ROP Plan.

B. Motor Vehicle Emissions Budgets

1. Introduction
As stated previously, section 176(c) of the Act, and the Federal
Transportation Conformity Rule require States to establish motor
vehicle emissions budgets in any control strategy SIP that is submitted
for attainment and maintenance of the NAAQS. Louisiana submitted, in
the January 2, 1997, Post-1996 ROP Plan, 1999 projected motor vehicle
emissions budgets for VOC and NO_X for the 5-parish Baton
Rouge ozone nonattainment area.
In developing the projections, the State followed the requirements
of section 51.452(b)(1) of the then-effective Federal Transportation
Conformity Rule, which stipulate refined modeling requirements to be
used for the areas classified as serious and above for ozone
nonattainment for conformity determinations made after January 1, 1995.
These enhanced transportation modeling requirements are aimed at
improving the accuracy with which mobile source emissions are
estimated. The modeling requirements are discussed in detail in the
document, ``1999 Mobile Source Emissions Budget for East Baton Rouge
Parish Utilizing Post-Processor for Air Quality,'' prepared by the
Capital Region Planning Commission, dated October 1996. (The document
is available from the EPA Region 6 Office listed above.)
2. EPA Action
For the 5-parish serious ozone nonattainment area, the State
established VOC/NO_X mobile vehicle emissions budgets as
follows:

Baton Rouge, LA 1999 Motor Vehicle Emissions Budgets
------------------------------------------------------------------------
Budget
Pollutant (tons/day)
------------------------------------------------------------------------
VOC........................................................ 33.93
NO<INF>X........................................................ 58.03
------------------------------------------------------------------------

These totals are the official mobile emissions budgets to be used
for transportation conformity determinations. The EPA is proposing to
approve the MVEBs in the table above.

C. Contingency Measures

1. Introduction
Under section 172(c)(9) of the Act, ozone nonattainment areas
classified as moderate or above must submit contingency measures to be
implemented if reasonable further progress (RFP) is not achieved or if
the standard is not attained by the applicable attainment date. The
``General Preamble for the Implementation of Title I of the Clean Air
Act Amendments of 1990'' (57 FR 13498, April 16, 1992) states that the
contingency measures should, at a minimum, ensure that an appropriate
level of emissions reduction progress continues to be made if
attainment or RFP is not achieved in a timely manner and additional
planning by the State is needed.
In the General Preamble, the EPA interpreted the Act to require
States with moderate and above ozone nonattainment areas to include
sufficient contingency measures in their November 1993 submittals so
that, upon implementation of such measures, additional emissions
reductions of up to 3 percent of the emissions in the adjusted base
year inventory (or a lesser percentage that will cure the identified
failure) would be achieved in the year following the year in which the
failure has been identified. States must show that their contingency
measures can be

[[Page 44200]]

implemented with minimal further action on their part and with no
additional rulemaking actions such as public hearings or legislative
review.
Additional contingency provisions are included in section 182(c)(9)
for serious ozone nonattainment areas. These latter provisions are
similar to the section 172(c)(9) requirements except that the focus in
section 182 (``Ozone Areas'') is on meeting emissions reductions
milestones (section 182(g)).
a. Point Source Emissions Banking. Louisiana identified, in both
its 15% and Post-1996 ROP Plans submittals, the State's point source
banking regulations (LAC 33:III sections 601, 613, 617, 619, and 621)
as the 3 percent contingency measure. The banking regulations are
intended to meet the contingency measure requirements of both section
172(c)(9) and section 182(c)(9) of the Act. The adopted point source
banking regulations were initially submitted to the EPA for approval in
the December 15, 1995, 15% ROP Plan submittal. The EPA deferred taking
action on the regulations in the context of the 15% ROP Plan approval
until its rulemaking action on the Post-1996 ROP Plan/Attainment
Demonstration SIP. (The rationale for ``carving out'' the contingency
measures is explained in more detail in the the TSD to this proposed
rulemaking as well as the TSD to the 15% ROP Plan rulemaking.)
These banking regulations enable point sources of VOC and
NO_X emissions in Federally designated ozone nonattainment
areas to identify and preserve emissions reductions for offsetting or
netting purposes. Emission reduction credits which are established in
the bank are also available to the State for confiscation if needed to
meet a reasonable further progress milestone. The banking regulations
prohibit sources from withdrawing reduction credits below the minimum
balance needed to meet the 3 percent contingency requirement. Sources
were allowed six months from the date the regulation was promulgated to
apply for banking their surplus emissions reduction credits which had
occurred prior to enactment of the regulations. If an application for
the credits was not received within the six-month period, the credits
were subject to confiscation by the State. The banking regulations
require that all emission reductions must be surplus and Federally
enforceable for approval by the State as emission reduction credits in
the bank.2
---------------------------------------------------------------------------

\2\ Although the regulations are clear that, at the time of
deposit, emission reductions credits must be surplus, the rules do
not expressly state that they must be surplus at the time they are
used. However, the rules do state that sources must comply with new
source review requirements and preconstruction permit regulations in
accordance with 40 CFR 51.18, 51.24, 51.307, 52.21, 52.24, 52.27,
and 52.28. (Please see the EPA's restructuring of 40 CFR part 51 at
51 FR 40660 to 40661 (November 7, 1986).)
40 CFR 51.165(a)(3)(i) (formerly 40 CFR 51.18(j)), in
particular, specifically requires that the baseline be tied to
allowable (or actual in some cases) emissions at the time a permit
application is filed. Hence, the EPA believes the requirement that
the emission reductions be surplus when actually used is adequately
addressed by the regulations.
---------------------------------------------------------------------------

In the December 22, 1995, Post-1996 ROP Plan submittal, the State
provided a table of the emissions reductions that had been banked by
industry to date pursuant to the regulations. The State's contingency
measure requirement is 5.7 tons/day (3 percent times the adjusted base
year inventory of 191.2 tons/day). The VOC reductions ``on deposit,''
13.0 tons/day, are well in excess of the 3 percent requirement. The
table also identified the amount of NO_X credits ``on
deposit'' in the bank (5.65 tons/day) as of the date of the submittal.
Sections 172(c)(9) and 182(c)(9) specify that the contingency
measures shall ``take effect without further action by the State or the
Administrator.'' In the ``General Preamble for the Implementation of
Title I of the Clean Air Act Amendments of 1990,'' the EPA interpreted
this requirement to be that no further rulemaking activities by the
State or the EPA would be needed to implement the contingency measures.
The EPA recognized that certain actions, such as notification of
sources, modification of permits, etc., would probably be needed before
a measure could be implemented effectively. States would need to show
that their contingency measures could be implemented with minimal
further action on their part and with no additional rulemaking actions
such as public hearings or legislative review. In general, the EPA
expected all actions needed to effect full implementation of the
measures to occur within 60 days after the EPA notified the State of
its failure.
The EPA is proposing that the State has met these contingency
measures requirements by having adopted and submitted the point source
banking regulations and demonstrating the bank has sufficient VOC
credits ``on deposit'' and available for confiscation in the event of a
missed milestone/failure to attain. To ensure that sufficient credits
remain in the bank to cover the contingency requirement, the
regulations stipulate that emission reduction credits may not be drawn
down below the amount claimed by the State in its three percent
contingency measure. The State has discretion in determining which
credits should actually be confiscated (i.e., pro-rata, last-in/first-
out, etc.).
As a result of the confiscation, the credits would no longer be
available to facilities for either offsetting new source growth or
netting out of nonattainment new source review. As such, the banking
regulations stipulate that the State shall provide written notice to
the affected facility(ies) of its intention to confiscate credits to
meet the contingency measures. A 30-day comment period is then allowed
for the affected facility(ies) to respond to the confiscation or submit
an alternative emissions reduction proposal. The EPA is proposing to
find that the banking rules provide for expeditious implementation of
the contingency measures consistent with the time frames identified in
the General Preamble.
Louisiana also submitted to the EPA, in the January 2, 1997, Post-
1996 ROP Plan submittal, a correction to a typographical error in
section 615, ``Schedule for Submitting Applications.'' The EPA is,
therefore, proposing to act upon both the correction and the base rule
in this rulemaking.
b. EPA Action. The EPA is proposing to approve only the already-
banked point source VOC emissions reductions credits of 5.7 tons/day
towards meeting the 3 percent contingency measure requirement.
Although, the EPA's ``NO_X Substitution Guidance'' permits
serious and above ozone nonattainment areas to use both NO_X
and VOC reductions, rather than VOC reductions alone, to meet RFP
requirements after 1996, the policy requires that the cumulative VOC/
NO_X RFP reductions be consistent with the emissions
reductions in the modeled attainment demonstration or comparable
modeling analysis. Consistent with the NO_X substitution
policy, the EPA issued guidance allowing States to substitute up to 2.7
percent NO_X reductions for the 3 percent contingency measure
(which would be implemented after 1996) in their 15% ROP Plans.
On January 16, 1996, however, the EPA approved a section 182(f)
NO_X exemption for the Baton Rouge ozone nonattainment area
(see 61 FR 2438, dated January 26, 1996). The exemption was based on an
urban airshed modeling analysis that showed additional NO_X
reductions would not contribute toward attainment. Like the section
182(f) modeling analysis, the Attainment Demonstration submittal of
December 22, 1995, also did not model any additional NO_X
reductions beyond

[[Page 44201]]

some early (1990-1994) voluntary NO_X reductions. Therefore,
the EPA believes that allowing banked NO_X reductions to be
used toward the 3 percent contingency measure would be inconsistent
with the NO_X waiver already approved for the area, as well
as the Attainment Demonstration SIP.
The EPA has determined that the point source banking regulations,
which generated the 5.7 tons/day of banked VOC reductions, are
generally consistent with the Act, EPA policy/guidance and Federal
regulations. The EPA bases its decision on the following: (1) The rules
mandate that major sources bank their surplus emission reductions
credits (2) the State is vested with the authority to confiscate the
necessary reductions to cover the 3 percent contingency measure (if
triggered following a failure to meet an RFP milestone and/or attain
the NAAQS); (3) the regulations prohibit drawing down credits below the
3 percent requirement; and (4) the State has demonstrated that it has
sufficient credits currently ``on account'' to cover the contingency
measure requirement of 5.7 tons/day of VOCs. Thus, EPA is proposing to
approve 5.7 tons/day of the banked point source VOC reductions (which
total 13.0 tons/day), towards meeting the 3 percent contingency measure
requirement required pursuant to sections 172(c)(9) and 182(c)(9) of
the Act.
In addition, the EPA is proposing to approve the point source VOC/
NO_X emissions reductions banking regulations as meeting the
requirements for SIP approval under part D and section 110 of the Act.
A detailed analysis of the banking regulation is provided in the
TSD to this proposed rulemaking.
It should be noted that the scope of this proposed rulemaking is to
approve the banked VOC emissions reductions as creditable towards the
contingency measures pursuant to sections 172(c)(9) and 182(c)(9) of
the Act, and to approve all of the point source banking regulations as
an acceptable SIP revision pursuant to part D and section 110 of the
Act. The EPA is not approving the banking regulations as an economic
incentive program (EIP) pursuant to the EPA's Economic Incentives
Program Rules (59 FR 16690) and section 182(g) of the Act.
Under section 182(g)(3), if a State fails to submit a milestone
compliance demonstration for any serious or severe area as required by
section 182(g)(2), the State must choose from three options: to bump-up
to the next higher classification, to implement additional measures
(beyond those in the contingency plan which will already be triggered
and implemented) to achieve the next milestone, or to adopt an economic
incentive program (as described in section 182(g)(4)). Under section
182(g)(5), if a State fails to submit a compliance demonstration for
any extreme area as required by section 182(g)(2), or if the area has
not met an applicable milestone as required by section 182(g)(1), the
State must submit a plan revision to implement an economic incentive
program (as described in section 182(g)(4)) within 9 months of such
failure.
An EIP is not required for the Baton Rouge serious ozone
nonattainment area. The EPA encourages the adoption of
``discretionary'' EIPs by States, as allowed for in the Act (section
110(a)(2)(A)), as a means of stimulating the adoption of incentive-
based, innovative programs, where appropriate, that will assist States
in meeting air quality management goals. However, since the State has
not expressly submitted the point source banking regulations as a
section 182(g) SIP revision, the EPA believes it beyond the scope of
this rulemaking to act upon the banking regulations as an EIP.

D. Additional Rule Submitted

The State elected to include regulation LAC 33:III.611, ``Mobile
Sources Emissions Reductions,'' in the January 2, 1997, submittal for
the EPA's approval as part of the overall emissions banking program.
However, the State is not taking any reduction credit in the
contingency plan from this voluntary mobile source emissions reduction
program. In fact, no vehicles have actually been scrapped to date under
the program and, hence, no mobile emission reduction credits have been
banked statewide as part of the vehicle scrappage program.
Since the State's submission of section 611, certain national
policy issues have arisen surrounding the use of mobile source-
generated emissions reductions credits for use by point sources.
Pending resolution of these issues, the EPA is deferring action on the
regulation at this time. Deferring action on this rule will have no
effect on either the Post-1996 ROP Plan or the Attainment Demonstration
since the State is not relying on reductions from the vehicle scrappage
program to meet the reductions target or demonstrate attainment. A more
in-depth discussion of the EPA's rationale for deferring action on the
rule is provided in the TSD to this proposed rulemaking.

E. Attainment Demonstration

1. Introduction
According to section 182(c)(2)(A) of the Act, serious and above
ozone nonattainment areas must submit a revision to the SIP that
includes a demonstration that the plan, as revised, will provide for
attainment of the NAAQS for ozone by November 15, 1999. In addition to
the 15% and 9% (net of growth) ROP reductions requirements, if the
mandatory emission reductions are not sufficient to demonstrate
attainment of the ozone NAAQS by November 15, 1999, emissions (VOCs
and/or NO_X) must be further reduced until attainment is
demonstrated through photochemical grid modeling.
For ozone nonattainment areas classified as serious or above,
section 182(c)(2)(A) of the Act requires an attainment demonstration
based on photochemical grid modeling, for which the Urban Airshed Model
(UAM) is the EPA-approved model. See appendix W of 40 CFR part 51.
The modeling portion of the SIP submittal was reviewed in terms of
technical accuracy and for consistency with EPA modeling guidelines.
The following guidance documents establish the acceptable techniques
for application of UAM demonstrating attainment of the ozone NAAQS:
EPA's Guideline on Air Quality Models (Revised) (July 1986);
EPA's Guideline for Regulatory Application of the UAM (July 1991);
and
EPA's final Guidance on use of Modeled Results to Demonstrate
Attainment of the Ozone NAAQS (June 1996).
Thus, the review covered the appropriateness of data sources,
appropriateness of technical judgements and procedures followed in
input preparation, performance of quality assurance and diagnostic
procedures, adequacy of model base case performance, consistency of
control measure simulation inputs with the submitted control measures,
adequacy of the demonstration of attainment of the NAAQS, and
consistency and completeness of documentation.
The UAM model uses an inventory of pollutant emissions, together
with air quality and meteorological data, as input to a system of
algorithms incorporating chemistry and dispersion, in order to simulate
an observed pollution episode. Once a ``base case'' is developed that
meets the minimum performance criteria, projected future emissions are
used as input to simulate air quality in the attainment deadline year.
Various combinations of

[[Page 44202]]

geographically uniform emission reductions are simulated to determine
approximate attainment reduction targets. Planners design a control
strategy to meet these targets, and then simulate it with UAM,
including the spatially and temporally varying effects of the selected
controls. Attainment is demonstrated when the modeled air quality with
emission controls in effect is below the NAAQS throughout the
geographical modeling domain.
2. Uncertainty and Model Performance
A modeling attainment demonstration is subject to several
uncertainties. The meteorological and air quality inputs have their own
associated uncertainties, both in measurement and in
representativeness. In addition, not all variables can be measured for
all hours, so default and interpolated values must be used. Processes
such as chemical reaction and advection necessarily appear in the model
in simplified form. The selected episodes may not represent all
conditions conducive to high pollutant levels. Finally, base case and
projected emissions are uncertain. Biogenic emission methodologies are
also in a state of flux. In spite of these sources of uncertainty,
photochemical grid modeling is the best tool that is available for
determining the emission reductions that are needed for NAAQS
attainment. The Guideline procedures are meant to ensure that inputs
are set in a scientifically sound manner, and to uncover compensating
errors that can be present even when the model predicts ozone well.
In recognition of these uncertainties, the EPA's Guidance on Use of
Modeled Results to Demonstrate Attainment of the Ozone NAAQS was
developed to better reflect experience gained in model applications
since 1991. The guidance was intended to assist States' efforts to
develop their ``Phase II'' SIP revisions demonstrating attainment of
the ozone NAAQS pursuant to the March 2, 1995, EPA memorandum from
Assistant Administrator Mary Nichols entitled, ``Ozone Attainment
Demonstrations.'' The guidance allows States to use a ``weight-of-
evidence'' determination if the modeled attainment test is not fully
passed, showing that attainment of the NAAQS is still likely. (An
explanation of the attainment tests is provided below.)
As explained in the Guideline, episodes are chosen for modeling
based on their high ozone levels, data availability, and other
criteria. Generally, episodes should be chosen that are approximately
as severe as the area's design value, which is based on the historical
ozone highs. During a particular episode, the observed ozone peak may
be higher or lower than the design value; but as long as it is
relatively close, that episode can be accepted for use in an attainment
demonstration. (See also the discussion of the attainment test below.)
Once an episode is chosen, modelers attempt to simulate it with
UAM. Various performance statistics and diagnostic tests are available
to gauge their success. (A discussion of the statistical and diagnostic
tests employed in the evaluation of the Baton Rouge modeling
demonstration is provided below.) The most commonly stated one is the
peak accuracy, since it is the ozone peak that is ultimately to be
reduced to the NAAQS level. However, it uses only one place and time
out of all those simulated. In judging model performance to be
acceptable, predictions at many places and times are examined. Also the
overall pattern of ozone and other chemical species are evaluated, in
light of the changing emissions and meteorology occuring during the
episode. Sometimes a lengthy process of diagnostic testing and
refinement of inputs is required. Thus, the finally accepted base case
may show some bias (e.g., simulated ozone peak not matching the
observed), and yet be fully adequate as a simulation of the episode,
and for use in an attainment demonstration. The EPA is proposing to
find that the Baton Rouge episodes had acceptable performance and met
EPA's Guideline criteria.
3. Episodes Modeled
The Guideline calls for a minimum of 3 primary episode days to be
modeled. The EPA may allow areas to use just two if they are based on a
field study, since this provides substantially more complete data, and,
hence, more confidence in model development procedures and results. The
tradeoff of higher quality modeling for fewer episodes is deemed by EPA
to be a reasonable one. In the case of the Baton Rouge demonstration,
however, the State modeled all three primary episode days.
The following three episodes were selected for use in the December
22, 1995, Baton Rouge Attainment Demonstration SIP submittal: August
15-16, 1989; May 24-25, 1990; and August 18-19, 1993.
4. Attainment Tests
The Guidance on use of Modeled Results to Demonstrate Attainment of
the Ozone NAAQS (June 1996) identifies two approaches that the State
can use for demonstrating attainment of the ozone NAAQS. One of the
acceptable approaches is called the ``Deterministic Approach,'' which
consists of a deterministic test and an optional weight-of-evidence
determination. The deterministic test is passed if predicted maximum
ozone concentrations are less than or equal to 124 parts per billion
(ppb) in all surface grid cells on all modeled primary episode days. If
the test is not passed, a weight-of-evidence determination may be used
to show that attainment of the NAAQS is still likely.
Meanwhile, the second acceptable approach is called the
``Statistical Approach.'' This approach consists of two parts: a
``Statistical Test,'' and a weight-of-evidence determination. The
``Statistical Test'' includes three benchmarks. The first of these
limits the number of allowed exceedances. The second restricts the
magnitude of an allowed exceedance. The third benchmark requires a
minimum level of improvement in air quality to be exceeded. If one or
more of the benchmarks is failed, a weight-of-evidence determination
may also be performed using corroborative information. If the
corroborative information is consistent with the likelihood that a
proposed strategy will lead to attainment of the ozone NAAQS by
statutory dates, attainment has been demonstrated.
As discussed below, the State has met these requirements by
demonstrating attainment of the ozone NAAQS through UAM modeling
consistent with the EPA's guidance using the ``Statistical Approach.''
5. Photochemical Grid Model Used
The State used UAM version IV, an EPA-approved photochemical grid
model, to develop the attainment demonstration for the Baton Rouge
area. The State's modeling activities were performed as outlined in the
UAM modeling protocols and according to the EPA's ``Guideline for
Regulatory Application of the Urban Airshed Model.'' (A specific
modeling protocol was developed by the State for its modeling
activities. The State's modeling protocol was reviewed and approved by
the EPA.)
The Baton Rouge modeling domain covers all or part of 20 parishes
in Louisiana, including the Baton Rouge serious ozone nonattainment
area consisting of East Baton Rouge, West Baton Rouge, Livingston,
Iberville, and Ascension Parishes.
a. Modeling Inputs. i. Meteorological and Air Quality Inputs. In
performing the base case analyses, meteorological models were employed
to simulate the weather patterns characteristic of each

[[Page 44203]]

episode. Concurrently, models of emissions of NO_X, VOCs, and
carbon monoxide (CO) were developed to characterize the spatial and
temporal distributions of these ozone precursors.
The meteorological data and air quality data used in this modeling
study were obtained from a variety of sources including the Aerometric
Information Retrieval System, the National Climatic Data Center, and
the Louisiana Department of Environmental Quality. Land-use data were
obtained from the U.S. Geological Survey (USGS). The meteorological
data were collected from various surface meteorological monitoring
sites. These were supplemented with aircraft data. The State followed
the EPA's UAM guidance to develop domain-wide hourly wind field data,
mixing heights, temperature, and meteorological scalars for Baton
Rouge.
The State used the air quality data (i.e., ambient ozone, nitric
oxide, nitrogen dioxide and CO concentrations) measured at monitoring
stations throughout the domains to construct initial conditions. In
addition, EPA-recommended background concentration values were used
where measurements were unavailable.
ii. Base Case Emissions Inventories. The State followed the EPA's
procedures for developing episode-specific base case emissions
inventories. The Baton Rouge modeling exercises were conducted using
emissions inventories compiled by survey and direct measurement by the
State. The modeling emissions inventories are composed of point source,
area, on-road mobile, non-road mobile, and biogenic emissions. Where
applicable, emissions were adjusted for pertinent conditions related to
the episode day to be modeled, thus producing day-specific emissions.
Adjustments were related to meteorology, operating conditions at major
point sources, and upset conditions or other unusual events that may
have affected the emissions.
In the Baton Rouge modeling exercises, the State developed separate
modeling inventories for all the episodes primarily based on the 1990
and 1993 base year emissions inventories. The State employed the EPA's
UAM Emissions Preprocessor System (EPS), Version 2.0, to facilitate
developing detailed emission inventories.
For the point source modeling inventory, the State compiled and
used the 1990 base year and 1993 periodic point source inventories for
the entire modeling domain. These annual emissions were adjusted to
reflect seasonal and day-of-week variations in activity levels. The
episode-specific hourly NO_X emissions rates of several major
electric utilities in the area (i.e., Big Cajun #1, Big Cajun #2) were
also taken into account in the modeling. This information was then
processed through EPS 2.0.
For area sources, the State developed the episodic inventory for
the Baton Rouge ozone nonattainment area based on the ``top-down''
approach, wherein parish emissions are spatially allocated using
surrogate parameters. The area source emissions estimates were
developed for all parishes in the modeling domain except Avoyelles
Parish. Area source emissions for Avoyelles Parish were extracted from
the EPA's 1990 Interim Inventory. In addition, emissions from autobody
refinishing were only provided for the then-six nonattainment parishes,
so the emissions for this source category from the 1990 Interim
Inventory were extracted and added to the area source inventory for the
remaining parishes in the modeling domain. The State used EPS 2.0 to
process these area source emissions.
On-road mobile source episode-specific emissions were developed
based on the top-down approach, also. This top-down approach employed
the output of the EPA's mobile emissions factor model, MOBILE5a,
coupled with the LADOTd vehicle miles traveled (VMT) estimates. The VMT
was estimated for each parish in the domain. A seasonal adjustment was
applied to the VMT estimates by LADOTd to reflect peak ozone seasonal
levels before calculating the parish-level onroad motor vehicle
emissions. The final inventories produced by EPS 2.0 for each episode
day accurately reflect episodic daily diurnal temperature variations.
For the non-road mobile source emissions estimates (for the then-
six nonattainment parishes), the State used 1990 county level estimates
of emissions assembled by Energy and Environmental Analysis, Inc., for
the EPA's Office of Mobile Sources (1992). For the remaining parishes
in the modeling domain, the State used emissions data from the EPA's
1990 Interim Inventory to develop the non-road mobile modeling
inventory.
The State developed biogenic emissions estimates for the Baton
Rouge modeling domain based on information provided by the Georgia
Institute of Technology (GIT). The biogenic emissions data provided by
GIT represented biogenic emission rates for one hour, calculated at 30
degrees Celsius and full solar intensity, for each grid cell. In
addition, biogenic emission estimates provided by GIT were adjusted for
specific episodes based on hourly variations in temperature and solar
intensity.
iii. Projection Inventories. The State used the EPS 2.0 utility
program (i.e., Bureau of Economic Analysis Factors (BEAFAC)) to
generate state-level projection factors from to 1999 for area, non-road
mobile, and point sources. The factors produced by BEAFAC are based on
the Bureau of Economic Analysis' ``Regional Projections to 2040,''
which contains the state data related to population, personal income,
employment and earnings for 57 industrial groupings. For this
application, the BEAFAC cross-reference glossary was modified to use
the employment projections rather than earnings, since the State
considered the employment factors as more representative of anticipated
growth in the Baton Rouge area. Meanwhile, the 1999 mobile source
emission inventories for the Baton Rouge modeling domain were based on
MOBILE5a emission factors and LADOTd's VMT projections. (LADOTd's VMT
projection was the 1999 VMT estimates by parish and functional
classification for only the Baton Rouge then-six parish ozone
nonattainment area.) Future year VMT estimates for other parishes were
not available and, therefore, were kept at the 1990 level. (The EPA
believes this is acceptable because the parishes, which are outside of
the Baton Rouge nonattainment area, are, for the most part, rural in
nature and have not experienced significant population growth since
1990.)
The future year (1999) baseline emissions inventories are
summarized in Appendix E to the ``Final Technical Support Document:
Application of the Urban Airshed Model to the Baton Rouge, Louisiana
Ozone Nonattainment Area (December 1995),'' which was included in the
December 22, 1995, attainment demonstration submittal. The 1999
baseline emission estimates account for the effects of growth and
mobile-source emission reductions due to fleet turnover. The federally
mandated 15 percent reduction in VOC emissions between 1990 and 1996,
and additional 9 percent (1996-1999) reduction required for serious
ozone nonattainment areas are accounted for in the 1999 baseline
modeling inventories as well. The controls affect point, area, onroad
and nonroad mobile sources. The industrial-source NO_X
reductions between 1990 and 1994 resulting from several facilities'
participation in a voluntary early NO_X reduction program
were also incorporated into the modeling

[[Page 44204]]

inventory. Other control programs in effect, such as the existing
vehicle anti-tampering inspections required for attainment areas as
well as for nonattainment parishes were taken into account in the
projected modeling inventory.
iv. Future Boundary Conditions. Improvements in air quality in the
Baton Rouge area are anticipated by 1999, and these are reflected in
the boundary condition estimates. For determining future-year boundary
conditions for the three episodes, the State took into account the
emission reductions that would take place between the base and future
years.
b. Base Case Model Performance. In the Baton Rouge model
performance evaluation, both graphical and statistical performance
measures were implemented for all meteorological episodes and
monitoring networks. The graphical measures include time series plots
of the observed and simulated pollutant concentrations, and contour
plots showing isopleths of simulated pollutant concentrations, and,
where available, observed surface-layer concentrations. The statistical
performance measures consisted of the mathematical calculation of a
number of statistical measures of bias including the unpaired highest-
prediction accuracy, the normalized bias test, and the gross error of
all pairs greater than 60 ppb. A sensitivity analysis was also
conducted to assess the stability of the models across a range of
possible input parameters. In the Baton Rouge base case simulations,
the model performance for the August 15-16, 1989, and August 18-19,
1993, episodes was good. The model performance for the May 24-25, 1990,
episode was very good. The TSD to this proposed rulemaking provides a
detailed analysis of the base case model performance.
6. Attainment Demonstration
The EPA's Guideline for the Regulatory Application of the Urban
Airshed Model stipulates that, for the primary episode days modeled,
there should be no predicted daily maximum ozone concentrations greater
than 0.124 ppm anywhere in the modeling domain for each primary episode
day modeled. However, as stated previously, The EPA has revised the
model test for demonstrating attainment of ozone NAAQS. The revisions
purposely make the modeled attainment test more closely reflect the
form of the NAAQS. The revised tests are laid out in the EPA's guidance
document entitled, Guidance on Use of Modeled Results to Demonstrate
Attainment of the Ozone NAAQS (June 1996). In the guidance, the EPA
recommends either a Statistical Approach or Deterministic Approach
should be used for the attainment demonstration of the ozone NAAQS.
Briefly, the Statistical Approach consists of a test and an
optional weight-of-evidence determination. The statistical test
includes the application of three benchmark tests which examine: (1)
the number of simulated exceedances within defined subregions of the
modeling domain, (2) the magnitude of the simulated exceedances
compared to calculated limits, and (3) the simulated reduction in areal
ozone coverage relative to the base case simulation. A weight-of-
evidence determination entails use of supplementary analyses to
determine whether attainment is likely, despite the model results which
do not pass the statistical test.
Meanwhile, the Deterministic Approach consists of a deterministic
test plus an optional weight-of-evidence determination. The
deterministic test is passed if daily maximum concentrations predicted
in every surface grid cell are less than or equal to 124 ppb for all
primary episode days. Again, a weight-of-evidence determination may be
undertaken to demonstrate attainment despite results which do not pass
the deterministic test.
To be consistent with the EPA guidance, the State used the three
episodes, all having good to very good model performance, for
demonstrating attainment of the ozone NAAQS. These episodes were
modeled using the projected 1999 emission inventory, which includes the
emission controls to be implemented through 1999. As a result, for the
August 15-16, 1989 episode, the maximum simulated (peak) concentration
is reduced from 15.9 to 12.2 parts per hundred million (pphm) on the
first day of the episode and from 16.0 to 12.7 pphm on the second day.
For the May 24-25, 1990, episode, the maximum simulated ozone
concentration is reduced from 13.8 to 12.6 pphm on the first day of the
episode and from 16.4 to 13.8 pphm on the second day. For the August
18-19, 1993 episode, the maximum predicted concentration is reduced
from 15.9 to 15.0 pphm on the first day of the episode and from 14.8 to
14.2 pphm on the second day. (These results are provided in the TSD to
this rulemaking at Figures 7.1a, 7.1b, 7.3a, 7.3b, 7.5a, 7.5b, and
Tables 7-4 through 7-6).
These future year simulation results were then reviewed in
accordance with the updated EPA guidance on the use of modeled results
to demonstrate attainment of the ozone standard. The State elected to
use the Statistical Approach along with weight-of-evidence
determination to demonstrate attainment of the ozone NAAQS.
As stated previously, Benchmark Test #1 examines the number of
simulated exceedances within defined subregions of the modeling domain.
For the test, the State used the Classification and Regression Tree
analysis software to classify the three episodes based on the
meteorological and air quality conditions. For Baton Rouge, the test
limits the number of projected exceedance days per subregion in the
modeling domain to 2. The maximum number of days for which an
exceedence occurs within any subregion is 2. Hence, Benchmark Test #1
is passed. (A more detailed explanation of this statistical test is
provided in the TSD to this proposed rulemaking.)
Benchmark Test #2 requires that the predicted daily maxima
corresponding with each allowed modeled exceedance may not be greater
than concentration derived from a distribution of observed daily maxima
at sites currently just attaining the ozone NAAQS. This was defined as
the site having 1 to 3 exceedances within this time frame, and the
fourth highest maximum ozone concentration was less than 12.4 pphm but
greater than or equal to 11.5 pphm. The State used the data collected
at Louisiana monitoring sites for the period 1984-1994 to determine a
distribution of maximum ozone concentrations for monitoring sites just
satisfying the ozone NAAQS. Thus, the State calculated the resultant
maximum allowed concentration for each meteorological episode by
determining the concentration obtained from the distribution which
would correspond to a day with the same likelihood of being exceeded as
the day in question. As a result, the exceedance limits for the August
16, 1989, May 25, 1990, and August 19, 1993, primary episode days are
12.4 pphm, 13.7 pphm and 12.4 pphm, respectively. Meanwhile, the
simulated maximum ozone concentrations for the August 16, 1989, May 25,
1990, and August 19, 1993, primary episode days are 12.7 pphm, 13.8
pphm, and 14.2 pphm, respectively. Thus, the August 16, 1989, and May
25, 1990, primary episode days came very close to meeting the
benchmark, while the August 19, 1993, episode did not.
Benchmark Test #3 requires that, for a composite of all primary
episode days, areal ozone coverage for a cutoff concentration of 12.4
pphm is reduced by at least 80 percent compared to that for the base
case simulation. This test is only required if ozone concentrations are
underestimated in the base case

[[Page 44205]]

simulation. In the base case simulations for Baton Rouge, the
fractional bias, a measure of over/underestimation, for the simulation
of the August 16, 1989, and August 19, 1993, episodes are within plus
or minus 5 percent, and the May 25, 1990, episode value is 7.3 percent
(the positive value indicates overestimation). Therefore, Benchmark
Test #3 did not apply because the model over predicted for the
composite of the three episodes.
7. Modeling Evaluation Summary
The EPA believes that the State's attainment demonstration for the
Baton Rouge ozone nonattainment area fulfills the requirements of
section 182(c)(2)(A) of the Act. The State has adequately followed the
EPA's guidance on the application of the UAM for demonstrating
attainment of the ozone NAAQS. Following the Statistical Approach, it
was demonstrated that two of the three episodes met or nearly met all
the specified benchmark criteria. However, supplementary information
(i.e., mid-course review, severity of selected episodes, uncertainty in
the boundary condition estimates, etc.) provided by the State for
consideration in the weight-of-evidence has supported the State's
attainment demonstration.
In addition, the ``Guidance on the Use of Modeled Results to
Demonstrate Attainment of the Ozone NAAQS,'' allows the use of
normalized trend data, results from observational models and or other
models and consideration of incremental cost/benefit estimates, etc.,
in a weight-of-evidence determination. In determining whether the
State's statistical approach and weight-of-evidence determination was
adequate, EPA considered trend data, in particular, which reflect
significant reductions in monitored ozone values, precurser emissions,
etc. since 1990.
For example, air quality in the Baton Rouge ozone nonattainment
area has shown a steady improvement toward attaining the ozone NAAQS.
The ozone design value has dropped significantly from the 1990 design
level of 168 ppb. The current design value (based on 1995-1997 air
quality data) is 139 ppb. (A historical account of the design values
since 1990 is provided in the TSD to this proposed rulemaking.)
This position is further strengthened by the results of a recent
analysis of precursor emissions in the area conducted by EPA Region
6.3 A review of the total non-methane organic compound trend
data (1985-1996) in Baton Rouge shows a 61 percent decrease at the
Capitol Site of the summer mean concentrations--from 795 parts per
billion carbon (ppbC) in 1985 to 307 ppbC in 1996.
---------------------------------------------------------------------------

\3\ U.S. Environmental Protection Agency Region 6, Initial
Analysis of 1996 Photochemical Assessment Monitoring Stations (PAMS)
Data from Baton Rouge, El Paso, Dallas, and Houston, December 3,
1997.
---------------------------------------------------------------------------

Furthermore, the number of exceedence days has also been on a
generally downward trend. A historical account of the exceedences days
is provided in the TSD to this proposed rulemaking.
In summary, based on the results of the Statistical Approach, along
with the weight-of-evidence determination, EPA is proposing that the
modeled control strategy will provide for attainment of the ozone NAAQS
by the statutory attainment date.
8. Control Strategy Evaluation
Tables 7-1 through 7-3 of the December 22, 1995, submittal compare
the 1999 projected VOC and NO_X inventories with the base
case inventories for the modeling domain. For the August 16, 1989,
primary episode day, the total anthropogenic VOC emissions for 1999 are
29.7 percent lower than the 1989 emissions estimates and the total 1999
anthropogenic NO_X emissions are 9.0 percent lower than the
1989 emissions. For the May 25, 1990 primary episode day, the total
anthropogenic VOC emissions for 1999 are 28.2 percent lower than the
1990 emissions estimates and the total 1999 anthropogenic
NO_X emissions are 8.3 percent lower than the 1990 emissions.
For the August 1993 primary episode day, these percentages are 14.9
percent (lower) for VOC and 2.7 percent (higher) for NO_X.
(The smaller reductions for the 1993 episode reflect the following: (1)
the projection period (1993-1999) is shorter, and (2) the actual
baseline inventories include the VOC reductions and the voluntary early
NO_X reductions that occurred between 1990 and 1993.)
Although the EPA believes that reducing NO_X emissions
can have positive effects on ozone levels, particularly in terms of
lowering the background concentrations in downwind areas, the modeling
demonstrations submitted by the State to EPA to date have not
demonstrated conclusively that the voluntary early NO_X
emissions reductions are essential for attaining the ozone standard
throughout the modeling domain. As such, at this time, the EPA is not
requiring the State to establish permanent and enforceable limits for
those sources at the levels resulting from voluntary early
NO_X reductions. The EPA bases its decision on the following:
First, additional UAM modeling results submitted to EPA have been
inconclusive with regards to the benefits of the early NO_X
reductions on projected ozone levels. In its November 17, 1994, section
182(f) NO_X waiver, the State included a three-episode UAM
demonstration showing that additional NO_X reductions (beyond
the ``early'' NO_X reductions achieved to date) would not
contribute to attainment in the area. For the demonstration, the State
modeled three emission reduction scenarios (i.e., substantial VOC
reductions, substantial NO_X reductions; and VOC and
NO_X reductions) for all three episodes using a 1999
projected emissions inventory that included the early point source
NO_X reductions and the 15% ROP reductions. The State modeled
the scenarios using across-the-board reductions in the projected VOC
4 and NO_X point source emission inventories. For
all three episodes, the controlling day showed that the domain-wide
predicted maximum ozone concentrations were lowest when only VOC
reductions were modeled. In contrast, further NO_X reductions
increased the domain-wide maximum ozone concentrations. The modeling
results are explained in detail in the EPA's TSD to the section 182(f)
rulemaking. The EPA's approval of the State's section 182(f) petition
was published on January 26, 1996 (61 FR 2438).
---------------------------------------------------------------------------

\4\ It should be noted that, for the purposes of the section
182(f) demonstration, the State did not model the post-1996 ROP (9%)
emission reduction strategy since a specific control strategy had
not been developed at the time of submitting the section 182(f)
demonstration. However, the point source reductions scenarios that
were modeled represent equal or greater VOC reductions than those
required to meet the Post-1996 ROP emissions reduction target.
---------------------------------------------------------------------------

In the section 182(f) modeling demonstration, the State plotted the
effect of the 15% ROP, early NO_X, and across-the-board VOC/
NO_X reductions on predicted maximum ozone values. These
plots were also included in the TSD to the proposed rulemaking on the
section 182(f) petition in Figures 7, 9, and 11. Most noteworthy was
the inconclusiveness of the effect of the early NO_X
reductions on predicted peak ozone concentrations. In the case of the
July 28, 1989, episode, the early NO_X reductions resulted in
a slight increase in peak concentrations (from 138 ppb to 139). In the
August 16, 1989, episode, peak concentrations remained unchanged (138
ppb). Lastly, in the May 25, 1990, episode, peak concentrations were
decreased slightly from the early NO_X reductions (145 to
144).
In addition, in the case of the August 19, 1993, episode, the early
NO_X

[[Page 44206]]

reductions are included in the actual emissions (the majority of the
reductions having occurred by 1993). From that baseline level, areawide
point source NO_X emissions are projected to 1999. In 1999,
the projected point source NO_X emissions are 2.7 percent
greater in 1999 than in the base case (i.e., 1993). In spite of the
growth in point source NO_X emissions from 1993-1999,
however, the peak modeled ozone concentration was reduced from 148 ppm
in the base case to 142 ppm. (See Table 7-6 in the TSD to this proposed
rulemaking).
In summary, the EPA proposes that the modeling results for Baton
Rouge adequately demonstrate that the area could attain the ozone
standard by 1999 through the implementation of a VOC-only control
strategy consisting of the Federally enforceable 15 percent and Post-
1996 ROP reductions (net of growth) from the 1990 base year levels, and
without the voluntary early NO_X reductions.
9. Modeling Attainment Without I/M
As mentioned previously, the UAM analyses in the December 22, 1995,
submittal modeled on-road mobile emissions reductions that were
expected to result, by November 15, 1999, from a decentralized, low
enhanced vehicle I/M program. The I/M program, which was scheduled to
begin January 1, 1999, consisted of a biennial two-speed idle test in
East Baton Rouge Parish, with remote sensing in all of the (then six)
ozone nonattainment parishes. The program's authorizing legislation
included a sunset clause requiring reauthorization of the program by
the Legislature every two years. Ultimately, the Louisiana Legislature
did not approve the reauthorization of the program, and the EPA was
required to disapprove the Baton Rouge low enhanced I/M SIP.
In light of this, the State opted to remove the I/M reductions from
the Post-1996 ROP Plan and replace them with additional point source
emissions reductions in the January 2, 1997, Post-1996 ROP Plan
revision. However, in order for the State to replace the I/M reductions
in the plan submittal with point source reductions, the EPA required
the State, in the January 2, 1997, submittal, to provide an analysis of
the impact that removing the reductions from I/M would have on the
modeling results. (In the December 22, 1995, submittal, the State
claimed 2.1 tons/day of reduction credits from implementing the low
enhanced I/M program in the nonattainment area.)
In the January 2, 1997, submittal, Louisiana described observed
impacts on modeling results resulting from increases in the projected
on-road mobile emissions inventory. First, the State noted that, in the
case of the August 1989 and May 1990 episodes, the State initially
modeled a domain-wide projected on-road mobile VOC emissions inventory
of 39.5 tons/day. This represented the projected mobile inventory
assuming a full enhanced (I/M 240) vehicle inspection/maintenance
program that was initially proposed by the State. Subsequently, the EPA
revised the Federal I/M regulations to allow for a low enhanced I/M
program. Under the low enhanced I/M program, the domain-wide projected
on-road mobile emissions were 42.2 tons/day (for the August 1989
episode) and 42.0 tons/day (for the May 90 episode). The projected
increase in VOCs, 2.8 tons/day for the August 89 episode and 2.6 tons/
day for the May 90 episode, had no discernable effect on the maximum
simulated ozone or the areal ozone coverage above 124 ppb for the
modeled attainment demonstration.
The lack of sensitivity to changes in the onroad mobile VOC
emissions was also demonstrated with the August 1993 modeling episode.
Due to a mobile inventory processing error, domain-wide on-road mobile
VOC projected emissions of 56.5 tons/day were initially modeled, which
corresponded to a maximum simulated ozone value of 145 ppb. Correcting
the mobile processing error produced a projected on-road mobile VOC
inventory of 45.3 tons/day (under the low enhanced I/M program). When
the UAM modeling simulation was rerun using the corrected inventory,
the maximum simulated ozone was 142 ppb. The 13.6 tons/day decrease in
mobile VOCs accounted for only a 3 ppb reduction in the maximum
simulated ozone. This further exemplified the lack of response in
maximum simulated ozone levels to changes in projected mobile VOC
emissions.
The EPA is proposing that the analysis has adequately demonstrated
that this increase in projected (1999) mobile source VOC emissions
(resulting from the removal of the low enhanced I/M program from the
control strategy) would have no discernable effect on the maximum
simulated ozone or the areal ozone coverage above 124 ppb for the
modeled attainment demonstration.
It should be noted that the EPA did not request that the State
provide a commensurate analysis of the effect that substituting
additional point source VOC emissions reductions (2.1 tons/day) for the
I/M reductions would have on the modeled results. The EPA considered
this type of analysis unnecessary for the following reasons:
First, as a percentage of the domain-wide VOC point source
emissions reductions modeled, the additional 2.1 tons/day of point
source emissions reductions are not significant and, thus, are not
expected to influence the modeling results. For instance, in the case
of the August 16, 1989, episode, base case point source emissions were
reduced by 48.3 percent in the projection (1999) year. Reducing the
projected point source emissions by 2.1 tons/day constitutes an
additional reduction of only 2.0 percent from the base case levels
(from 48.3 to 50.3 percent). In the case of the May 25, 1990, episode,
base case point source emissions were reduced by 48.7 percent in the
projection year. Reducing the projected point source emissions by 2.1
tons/day also constitutes an additional reduction of only 2.0 percent
from the base case levels (from 48.7 to 50.7 percent). Lastly, in the
case of the August 19, 1993, episode, base case point source emissions
were reduced by 22.4 percent in the projection year. Reducing the
projected point source emissions by 2.1 tons/day constitutes an
additional reduction of only 3.0 percent from the base case levels
(from 22.4 to 25.4 percent).
Second, EPA expects that further reducing the point source VOC
emissions would only contribute to attainment of the NAAQS. This is
consistent with the control strategy being modeled for attainment
(which relies on significant emissions reductions from point sources)
and other directional modeling submitted by the State to date, namely,
the modeling submitted in the section 182(f) NO_X waiver
request. As stated previously, in the section 182(f) UAM demonstration,
the State modeled across-the-board point source VOC reduction scenarios
in addition to the 15% ROP reductions (namely 25, 50, 75, and 100
percent across-the-board reductions in point source VOC emissions). For
all three episodes, the controlling day modeling results showed that
domain-wide predicted maximum ozone concentrations were lowest when the
across-the-board point source VOC reductions were modeled. A more
detailed discussion of the across-the-board VOC reductions scenarios
modeled is provided in the TSD to the EPA's rulemaking action approving
the Baton Rouge section 182(f) NO_X exemption.
10. EPA Action
The EPA is proposing to approve Louisiana's Attainment
Demonstration SIP submittals, dated December 22, 1995, and January 2,
1997, as meeting

[[Page 44207]]

the requirements of section 182(c)(2)(A) of the Act for demonstrating
attainment of the NAAQS for ozone by November 1999. Through
photochemical grid modeling, the State has demonstrated to the EPA's
satisfaction that the VOC reductions in the 15% and Post-1996 ROP Plans
(34.8 tons/day and 21.4 5 tons/day, respectfully) are
sufficient to demonstrate attainment of the ozone NAAQS by the
statutory deadline and that further reductions in VOC and/or nitrogen
oxides (NO_X)) are not necessary to attain.
---------------------------------------------------------------------------

\5\ The 21.4 tons/day in emissions reductions includes the 3.2
tons/day surplus reductions from the 15% ROP Plan carried over to
the Post-1996 ROP Plan.
---------------------------------------------------------------------------

III. Proposed Rulemaking Action

The EPA has reviewed the SIP submittals for consistency with the
Act, applicable EPA regulations and EPA policy, and is proposing to
approve the following under sections 110(k)(3), 301(a), and Part D of
the Act:

A. Post-1996 ROP Plan

The Baton Rouge, Louisiana, Post-1996 Rate-of-Progress Plan as
originally submitted December 22, 1995, and revised January 2, 1997, as
meeting the requirements of section 182(c)(2)(B) of the Act to achieve
a reduction in VOC emissions (net of growth) of 9 percent between 1996
and 1999.

B. Contingency Plan

The Baton Rouge, Louisiana, contingency plan, initially submitted
as part of the 15% ROP Plan on December 15, 1995, and, subsequently, as
part of the Post-1996 Rate-of-Progress Plan submitted December 22,
1995, and revised January 2, 1997. The EPA is proposing approval of the
contingency plan as meeting the requirements of sections 172(c)(9) and
182(c)(9) of the Act that moderate and above ozone nonattainment areas
include contingency measures in their ROP Plan submittals.
Specifically, the EPA is proposing to approve the contingency-reserved
VOC banked emissions reductions of 5.7 tons/day (achieved through the
State's banking regulations), identified in a table in Appendix T of
the December 22, 1995, submittal, as creditable towards the 3 percent
contingency requirements of sections 172(c)(9) and 182(c)(9) of the
Act. In addition, the EPA is proposing to approve the point source VOC
and NO_X emissions reductions banking regulations (LAC 33:III
sections 601, 613, 617, 619, and 621), submitted December 15, 1995, and
revised January 2, 1997, as meeting the requirements for SIP approval
under part D and section 110 of the CAAA.

C. Motor Vehicle Emissions Budgets

The 1999 Motor Vehicle Emissions Budgets for on-road mobile VOC and
NO_X emissions for the Baton Rouge 5-parish ozone
nonattainment area submitted January 2, 1997, as meeting the
requirements of section 176(c) of the Act and 40 CFR 51.452(b) of the
Federal Transportation Conformity Rule.

D. Attainment Demonstration

The Baton Rouge, Louisiana Attainment Demonstration submitted
December 22, 1995, and revised January 2, 1997, including the modeling
analyses, as meeting the requirements of section 182(c)(2)(A) of the
CAAA to provide for attainment of the ozone NAAQS by the applicable
November 15, 1999, attainment date.

E. Emission Inventory Revisions

Revisions to the 1990 base year VOC emissions inventory submitted
January 2, 1997 as meeting the requirements of section 182(a)(1) of the
Act. In addition, the EPA is proposing to codify the revisions to the
1990 base year emissions inventory submitted as part of the 15% ROP
Plan approved October 22, 1996 (61 FR 54737).

F. Revisions to 1996 Target Level of Emissions

The revision to the 1996 target level of VOC emissions submitted
January 2, 1997, as meeting the requirements of part D and EPA
guidance.
The EPA is deferring taking any action at this time on the State's
accelerated vehicle retirement regulation (LAC 33:III.611) entitled,
``Mobile Sources Emission Reductions,'' which was submitted to the EPA
on January 2, 1997. Deferred action on this regulation has no effect on
either the Baton Rouge Post-1996 ROP Plan or on the Baton Rouge
Attainment Demonstration since the State took no credit in these plans
for reductions from vehicle scrappage.
Nothing in this action should be construed as permitting or
allowing or establishing a precedent for any future request for
revision to any SIP. Each request for revision to the SIP shall be
considered separately in light of specific technical, economic, and
environmental factors and in relation to relevant statutory and
regulatory requirements.

IV. Administrative Requirements

A. Executive Orders (E.O.) 12866 and 13045

The Office of Management and Budget has exempted this regulatory
action from E.O. 12866, entitled ``Regulatory Planning and Review,''
review.
The proposed rule is not subject to E.O. 13045, entitled
``Protection of Children from Environmental Health Risks and Safety
Risks,'' because it is not an ``economically significant'' action under
E.O. 12866.

B. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA), 5 U.S.C. 600 et seq.,
generally requires an agency to conduct a regulatory flexibility
analysis of any rule subject to notice and comment rulemaking
requirements unless the agency certifies that the rule will not have a
significant economic impact on a substantial number of small entities.
Small entities include small businesses, small not-for-profit
enterprises, and small governmental jurisdictions. This proposed rule
will not have a significant impact on a substantial number of small
entities because SIP approvals under section 110 and subchapter I, part
D of the Act do not create any new requirements but simply approve
requirements that the State is already imposing. Therefore, because the
Federal SIP approval does not create any new requirements, I certify
that this action will not have a significant economic impact on a
substantial number of small entities. Moreover, due to the nature of
the Federal-State relationship under the Act, preparation of
flexibility analysis would constitute Federal inquiry into the economic
reasonableness of state action. The Act forbids the EPA to base its
actions concerning SIPs on such grounds. Union Electric Co., v. U.S.
EPA, 427 U.S. 246, 255-66 (1976); 42 U.S.C. 7410(a)(2).

C. Unfunded Mandates

Under section 202 of the Unfunded Mandates Reform Act of 1995,
signed into law on March 22, 1995, the EPA must prepare a budgetary
impact statement to accompany any proposed or final rule that includes
a Federal mandate that may result in estimated costs to State, local,
or tribal governments in the aggregate; or to the private sector, of
$100 million or more. Under section 205, the EPA must select the most
cost-effective and least burdensome alternative that achieves the
objectives of the rule and is consistent with statutory requirements.
Section 203 requires the EPA to establish a plan for informing and
advising any small governments that may be significantly or uniquely
impacted by the rule.
The EPA has determined that the approval action proposed does not

[[Page 44208]]

include a Federal mandate that may result in estimated costs of $100
million or more to either State, local, or tribal governments in the
aggregate, or to the private sector. This Federal action approves
preexisting requirements under State or local law, and imposes no new
requirements. Accordingly, no additional costs to State, local or
tribal governments, or to the private sector, result from this action.

List of Subjects in 40 CFR Part 52

Environmental protection, Air pollution control, Hydrocarbons,
Incorporation by reference, Intergovernmental relations, Nitrogen
dioxide, Ozone, Reporting and recordkeeping requirements, Volatile
organic compounds.

Authority: 42 U.S.C. 7401 et seq.

Dated: August 3, 1998
Gregg A. Cooke,
Regional Administrator, Region 6.
[FR Doc. 98-22062 Filed 8-17-98; 8:45 am]
BILLING CODE 6560-50-P

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