 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103-2029



DATE:                               

	

August 11, 2009



SUBJECT:

	Approval and Promulgation of Air Quality Implementation Plans;
Virginia; Opacity Variance for Rocket Testing Operations Atlantic
Research Corporation’s Orange County Facility

Technical Support Document	 	 

FROM:

	Gregory Becoat, Environmental Scientist /s/

Air Quality Planning Branch (3AP21)

TO:

REVIEWED BY:	SIP Docket File

                  /s/                     

Cristina Fernandez, Branch Chief

Air Quality Planning Branch (3AP21)



I.	Affected Regulation

In accordance with §10.1-1307 of the Virginia Air Pollution Control
Law, 40 CFR Part 51 (Requirements for Preparation, Adoption, and
Submittal of Implementation Plans), and the requirements of section 110
of the federal Clean Air Act (CAA), the Commonwealth of Virginia
requested approval of a revision to the State Implementation Plan (SIP).
 This revision to the Commonwealth of Virginia’s SIP consists of a
variance (9 VAC 5 Chapter 220) for the rocket motor test operations at
Atlantic Research Corporation’s Orange County Facility from the
standard for visible emissions in 9 VAC 5-50-80. 

II.	 Background

  SEQ CHAPTER \h \r 1 On January 26, 2004, the Commonwealth of Virginia
submitted to EPA a regulation revision CV-1, which consisted of an
opacity variance for the rocket motor test operations at Aerojet
Corporation’s Orange County facility.  The variance is included in
Title 9 of the Virginia Administrative Code (9 VAC Chapter 220) and was
effective on December 1, 2002.  Virginia adopted, in lieu of opacity
limits established in 9 VAC 5-50-80, a variance that requires the
facility to limit total particulate matter (PM) emissions from its
rocket motor test operations to 714 pounds per hour (9 VAC 5-220-30.B). 
Along with regulation revision CV-1, the Commonwealth of Virginia
included in their submittal, proposed and final regulations,
certification of public participation activities and compliance with
state administrative procedures, a record of hearing, summary of
testimony, and a technical support document (TSD).

Upon administrative and technical review of regulation revision CV-1,
the U.S. Environmental Protection Agency (EPA) determined that the
dispersion modeling submitted in the TSD was inadequate.  On April 20,
2005, the company provided a more comprehensive TSD to provide
additional modeling information to the EPA.  However, the EPA had
additional comments and questions concerning the submittal.  EPA
determined that the Open Burn/Open Detonation (OB/OD) dispersion model
used to estimate the PM emissions from the rocket motor testing
operations was not an EPA-approved model and therefore, Virginia must
request written approval from the EPA Regional Administrator for the use
of the OB/OD model and provide public notice of the use of an
alternative model.  See 40 CFR 51.112(a)(2).  

On February 27, 2006, EPA received a letter dated February 21, 2006,
officially requesting withdrawal of the Commonwealth of Virginia’s
January 28, 2004 submittal.  Pursuant to Virginia’s withdrawal letter,
EPA returned the January 28, 2004 SIP revision to the Commonwealth of
Virginia for further review.  

On May 5, 2008, the Virginia Department of Environmental Quality (VADEQ)
requested EPA’s approval to allow the use of the OB/OD dispersion
model for a variance from Virginia’s standard for visible emissions, 9
VAC 5-50-80.  EPA reviewed VADEQ rationale for allowing Aerojet
Corporation to use the OB/OD dispersion model for the air quality
analyses for the facility in Orange County.  On July 24, 2008, EPA
approved that the detailed discussion of the criteria under section
3.2.2(e) of the Guideline on Air Quality Models fulfilled the criteria
for selecting OB/OD as an alternative to the generally preferred
American Meteorological Society/EPA Regulatory Model. See Appendix W to
40 CFR Part 51.  

On February 19, 2009, VADEQ resubmitted a request for approval of a
revision to the Commonwealth of Virginia’s SIP.  The revision consists
of information in support of a variance (9 VAC 5 Chapter 220) for the
rocket motor test operations at Aerojet Corporation’s Orange County
Facility from the standard for visible emissions in 9 VAC 5-50-80.  The
submittal contains a comprehensive TSD with additional air dispersion
modeling information requested by EPA, as well as EPA’s approval of
the OB/OD dispersion model.

III.	Summary of Action

  SEQ CHAPTER \h \r 1 On January 26, 2004, the Commonwealth of Virginia
submitted a revision to its SIP designated as revision CV-1.   As part
of the rulemaking for revision CV-1, Virginia submitted an opacity
variance for the rocket motor test operations at Aerojet Corporation’s
Orange County facility.  The variance, adopted on September 30, 2002, is
included in Title 9 of the Virginia Administrative Code (9 VAC Chapter
220) and was effective on December 1, 2002.  Virginia, in lieu of
opacity limits established in 9 VAC 5-50-80, a variance that requires
the facility to limit total PM emissions from its rocket motor test
operations to 714 pounds per hour (9 VAC 5-220-30.B).  The following
provisions are affected by this revision:

9 VAC 5-220-10 - Applicability and designation of affected facility.
(added)

9 VAC 5-220-20 - Definitions.  (added)

9 VAC 5-220-30 - Applicability of standard for visible emissions and
standard for particulate matter.  (added)

9 VAC 5-220-40 - Compliance determination, monitoring, recordkeeping,
and reporting.  (added)

9 VAC 5-220-50 - Transfer of ownership.  (added)

9 VAC 5-220-60 - Applicability of future regulations.  (added)

On February 19, 2009, VADEQ submitted additional information to support
the variance for the rocket motor test operations, which included a
comprehensive TSD that provides additional air dispersion modeling
information requested by EPA for approval of the addition of 9 VAC
5-220-30.

 IV.  Evaluation

EPA recommends approval of the “Variance for Rocket Motor Test
Operations at Atlantic Research Corporation Orange County Facility” (9
VAC 5 Chapter 220) in order to add regulations 9 VAC 5-220-10, 9 VAC
5-220-20, 9 VAC 5-220-30, 9 VAC 5-220-40, 9 VAC 5-220-50, and 9 VAC
5-220-60.  EPA recommends approval of this revision to the SIP because
the additions pertain to Atlantic Research Corporation Orange County
Facility in terms of applicability and designation, definitions,
applicability of standard for visible emissions and standard for PM,
compliance determination, monitoring, recordkeeping, and recording,
transfer of ownership, and applicability of future regulation
amendments.  This revision does not change the substance of the SIP, and
consequently, does not interfere with the timely attainment or progress
towards attainment of a national ambient air quality standard (NAAQS),
nor interfere with any other provision of the CAA, 42 U.S.C. 7401 et
seq.

EPA recommends approval of the addition of 9 VAC 5-220-30,
“Applicability of standard for visible emissions and standard for
particulate matter” in order to establish PM emission limits for
Aerojet Corporation’s rocket test operations in lieu of opacity
standards established in 9 VAC 5-50-80.  EPA approves this revision
because the modeling analysis included in Virginia’s “Technical
Support Documentation for Opacity Variance for Rocket Test Facility”
appears to show that emissions from Aerojet Corporation’s Orange
County Facility will not cause or significantly contribute to violations
of the PM NAAQS.  Further details of EPA’s modeling analysis can be
found in a TSD prepared by Timothy A. Leon Guerrero.

V.   Conclusion

This SIP revision request satisfies all requirements for an acceptable
SIP revision.

VI.  Recommended Agency Action

The SIP revision request should be approved. 

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