UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103-2029

	October 19, 2007



 ADVANCE \x15 SUBJECT:

	Technical Support Document—110(a)(1) 8-Hour Ozone Maintenance Plan
for the White Top Mountain, Smyth County, VA 1-Hour Ozone Nonattainment
Area 



 ADVANCE \x15 FROM:

	Irene Shandruk, Environmental Scientist

         /s/        

 ADVANCE \x15 TO:

	VA-214; Docket No. EPA-R03-OAR-2007-1068

 ADVANCE \x15 THRU:

	Cristina Fernandez, Branch Chief     /s/      

Air Quality Planning Branch



Background

The White Top Mountain 1-hour ozone nonattainment area, located in Smyth
County, Virginia, is that portion of Smyth County that is above 4,500
feet in elevation.  It lies entirely within the Jefferson National
Forest, is no more than a few square miles in area, and has no sources
of anthropogenic ozone precursor emissions.  This area was originally
designated nonattainment under the 1-hour ozone standard on November 6,
1991 (56 FR 56704), and classified as a rural transport area (marginal).
 

In a July 18, 1997 (62 FR 38856) final rule, EPA promulgated a
regulation that replaced the 1-hour ozone NAAQS with an 8-hour standard
at a level of 0.08 parts per million (ppm).  The new standard became
effective on September 16, 1997, and provided increased protection to
the public, especially children and other at-risk populations.  On July
18, 1997, EPA announced that revocation of the 1-hour NAAQS would be
delayed until areas achieved attainment of the 1-hour NAAQS. This was
done in order to facilitate continuity in public health protection
during the transition to the new NAAQS.  In a June 5, 1998 final rule
(63 FR 31014), EPA identified ozone areas where the 1-hour standard was
no longer applicable because these areas had not measured a current
violation of the 1-hour standard.  For all other areas, the 1-hour
standard continued to apply.  The June 5, 1998 final rule was
promulgated to assist in the phasing-out of the 1-hour standard since
the then newly promulgated 8-hour standard was in effect and was more
protective of public health than the 1-hour ozone standard.  All of
Smyth County, Virginia, including the White Top Mountain Area, was one
of the areas where the 1-hour standard was no longer applicable (63 FR
31087, June 5, 1998).  On January 1, 1999, Virginia amended 9 VA
5-20-204.1(b) to remove the White Top Mountain area from the areas
regulated as ozone nonattainment areas and amended 9 VAC 5-20-205.A.4(a)
to remove the exemption of the White Top Mountain area from the areas
subject to regulations as a PSD area.  The August 19, 2005 SIP revision
submittal reflected this change.

On May 14, 1999, the U.S. Court of Appeals for the District of Columbia
remanded the 8-hour NAAQS for ozone and curtailed EPA’s authority to
enforce it, and thereby undermined the basis for EPA’s previous
determinations on the applicability of the 1-hour ozone standard.  The
effectiveness of the 8-hour standard served as the underlying basis for
EPA’s regulations governing the June 1998 applicability
determinations, and thus for EPA’s finding that the 1-hour standard no
longer applied in areas that EPA determined were attaining the 1-hour
standard.  As a result, on October 25, 1999 (64 FR 57424), EPA proposed
the 1-hour ozone standard would be reinstated in areas where it had
previously been revoked and the associated designations and
classifications that previously applied in such areas with respect to
the 1-hour NAAQS would also be reinstated.

On July 20, 2000 (65 FR 451822), EPA issued a final rule rescinding the
prior findings in the June 1998 final rule that the 1-hour ozone NAAQS,
and, the accompanying designations and classifications no longer applied
in certain areas.  EPA reinstated the 1-hour ozone NAAQS because the
public health protection afforded by the 8-hour ozone standard was being
delayed due to continued litigation regarding the 8-hour ozone standard.
 The 1-hour ozone NAAQS again became applicable and the designations and
classifications that previously applied in areas with respect to the
1-hour standard were also reinstated.  The July 20, 2000 final rule
reinstated the White Top Mountain Area as a rural transport (marginal)
ozone nonattainment area under the 1-hour ozone NAAQS.  The effective
date for the reinstatement of the 1-hour ozone NAAQS in the White Top
Mountain area was January 16, 2001.  See 65 FR 45182 at 45182 (effective
date under “DATES” and 65 FR 45190 (Table 1), July 20, 2000.

On April 30, 2004 (69 FR 23951), EPA published the first phase of its
final rule to implement the 8-hour ozone NAAQS (Phase I Rule).  Also on
April 30, 2004 (69 FR 23858), EPA published 8-hour ozone designations
for all areas of the country.  For most areas, including the White Top
Mountain area, the designations under the 8-hour ozone NAAQS became
effective on June 15, 2004.  The Phase I Rule provided that the 1-hour
ozone NAAQS would no longer apply for an area one year following the
effective date of the area’s designation for the 8-hour ozone NAAQS. 
On August 3, 2005 (70 FR 44470), EPA issued a final rule that codified
the revocation of the 1-hour standard for those areas with effective
8-hour ozone designations.  On June 15, 2005, all of Smyth County,
Virginia was no longer subject to the 1-hour ozone NAAQS and was
designated attainment of the 8-hour ozone NAAQS.

Section 110(a)(1) of the Clean Air Act (CAA or Act) requires that areas
that were either nonattainment or attainment/unclassifiable with an
approved 175A maintenance plan for the 1-hour ozone NAAQS, and
attainment for the 8-hour ozone NAAQS submit a plan to demonstrate the
continued maintenance of the 8-hour ozone NAAQS.  These plans were due
to EPA on June 15, 2007, three years after the effective date of the
initial 8-hour ozone designations.

On August 9, 2007, the EPA received a request from the Virginia
Department of Environmental Quality (VDEQ) for approval of the section
110(a)(1) 8-hour ozone maintenance plan for White Top Mountain, Smyth
County, Virginia as a revision to the State Implementation Plan (SIP).
This plan demonstrates how the state intends to maintain the 8-hour
NAAQS for ozone.  Virginia’s SIP submittal meets the CAA requirements
for SIP submittals under Section 110(a)(1).

What are the components of a Section 110(a)(1) 8-hour ozone maintenance
plan?

On May 20, 2005, EPA issued guidance (Maintenance Plan Guidance Document
for Certain 8-hour Ozone Areas Under Section 110(a)(1) of Clean Air Act)
that applies to areas that are designated attainment/unclassifiable for
the 8-hour ozone standard.  The purpose of this guidance, referred to as
section 110(a)(1) guidance, is to assist the states in the development
of a SIP which addresses the maintenance requirements found in section
110(a)(1) of the CAA.  The components of the section 110(a)(1)
maintenance plan include:

Emissions Inventory - The inventory should be based on actual typical
summer day anthropogenic emissions of volatile organic compounds (VOCs)
and nitrogen oxides (NOx) for a 10-year period from a base year as
chosen by the state. The guidance recommends for most areas the use of
emissions year 2002 for developing these inventories.  A key aspect to
the plan is demonstration that the area will comply with the ozone
standard for a 10-year period following the effective date of
designation.  Additionally, the guidance document further states that
projecting emissions and demonstrating maintenance for 10 years is not
required for areas where there are essentially no anthropogenic
emissions.

Maintenance Demonstration - The demonstration should show how the area
will remain in compliance with the 8-hour ozone standard for 10 years
following the base year following the effective date of designation
(June 15, 2004).  This is usually accomplished by a demonstration that
the area will have emissions that are equal to or below the emissions
inventories of VOC and NOx for this 10 year period.

Ambient Air Quality Monitoring - The state should continue to operate
air quality monitors in accordance with 40 CFR Part 58 to verify
maintenance of the 8-hour ozone standard.  

Contingency Plan – Most areas must develop a contingency plan that
will ensure that a violation of the 8-hour ozone NAAQS is promptly
addressed.  

Verification of Continued Attainment – The guidance indicates that the
state should indicate how the state will track the progress of the
maintenance plan.  This is due to the fact that emissions projections
depend on assumptions of point, area, and mobile sources emissions.

How has the state addressed the components of a Section 110(a)(1) 8-hour
ozone maintenance plan?

Emissions Inventory – Since White Top Mountain has no anthropogenic
emissions, the guidance indicates that emissions projections are not
necessary for this submittal.  

Maintenance Demonstration – Since White Top Mountain has no
anthropogenic emissions, the guidance indicates that a maintenance
demonstration is not necessary for this submittal.  

Ambient Air Quality Monitoring – Virginia has never operated monitors
on White Top Mountain.  All of the monitors at this site were part of
studies either managed by the Tennessee Valley Authority or EPA’s
Office of Research and Development, but these monitoring studies have
ceased since 1999.  Virginia does not have any monitors in place to
operate nor does the Commonwealth plan on establishing a monitoring
site.  This is so for reasons which include the following: (1) there are
no anthropogenic emissions at this site, (2) the very remote location of
this nonattainment area, and (3) establishing a monitoring site would be
cost-prohibitive.

Contingency Plan – The guidance indicates that most areas must develop
a contingency plan that will ensure any violation of the 8-hour ozone
NAAQS is promptly corrected.  The guidance also states that for areas
that have essentially no anthropogenic emissions, having a maintenance
plan with contingency measures would be an “absurd” outcome.

Verification of Continued Attainment – Since the guidance specifically
notes that emissions inventories and contingency measures are not
necessary for areas where there are essentially no anthropogenic
emissions, verification of these requirements is also not necessary, and
therefore, not included in the maintenance plan.

Recommendation

The state has met the requirements to submit a section 110(a)(1)
maintenance plan and has adequately addressed the components of a
section 110(a)(1) plan.  Therefore, approval of Virginia’s 8-hour
ozone maintenance plan is recommended. 

 The Phase I Rule was amended on May 26, 2005 (70 FR 30592).  This
amendment addressed two issues raised in a petition for reconsideration
of the Phase I Rule and clarified two aspects of that implementation
rule.  On July 8, 2005 (70 FR 39413), another final rule addressed other
issues raised in a petition for reconsideration of the April 30, 2004,
Phase I Rule.

 This designation for White Top Mountain was based on data collected by
several programs, namely the Tennessee Valley Authority, EPA’s Office
of Research and Development (EPA ORD), and the Mountain Acid Deposition
Program (MADPro).  These monitored ozone data were collected as part of
other studies taking place.  Virginia, itself, has never operated ozone
monitors on this mountain top, nor are any ozone monitors currently in
place on White Top  Mountain.

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