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Virginia Regulatory Town Hall
Department of Environmental Quality
Air Pollution Control Board

General Notice
Public Comment Period - Proposed Request for U.S. Environmental Protection Agency (EPA) Approval of an Alternative Air Quality Model Request
Date Posted: 4/1/2008
Expiration Date: 5/1/2008
Submitted to Registrar for publication: YES
No comment forum defined for this notice.


Notice of action: The Department of Environmental Quality (DEQ) is announcing an opportunity for public comment on a proposed request for U.S. Environmental Protection Agency (EPA) approval of an alternative air quality model.
Purpose of notice: DEQ is seeking comment on the issue of whether a request for approval of an alternative model to assess the air quality impact of a variance to control opacity emissions from the Aerojet Orange County Facility should be submitted to EPA.
Public comment period: April 1 to May 1, 2008.
Public hearing:  A public hearing may be conducted if a request is made in writing to the contact listed below. In order to be considered, the request must include the full name, address and telephone number of the person requesting the hearing and be received by DEQ by 5:00 p.m. on the last day of the comment periodNotice of the date, time, and location of any requested public hearing will be announced in a separate notice, and another 30-day comment period will be conducted.
Description of proposal: On September 30, 2002, the State Air Pollution Control Board adopted an opacity 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. In lieu of compliance with this standard, the variance required the facility to limit total particulate matter emissions from its rocket motor test operations to 714 pounds per hour. This variance was submitted to EPA as a revision to the Virginia state implementation plan (SIP) on January 26, 2004. Subsequently, the facility was purchased by Aerojet Corporation.
The January 2004 SIP submittal contained a technical support document that provided a basis for proposed hourly limit for particulate matter emissions from the rocket motor testing operations. Aerojet’s air quality analysis included, in lieu of an EPA-approved model, the Open Burn/Open Detonation (OB/OD) dispersion model.  40 CFR 51.112(a)(2) requires that a modification or substitution of an air quality model specified in the Guideline on Air Quality Models may be allowed on a case-by-case basis if approved in writing by EPA.  In addition, use of a modified or substituted model must be subject to notice and opportunity for public comment under procedures set forth in 40 CFR 51.102.
The Commonwealth therefore intends to request, in accordance with 40 CFR 51.112(a)(2), that the Open Burn/Open Detonation (OB/OD) dispersion model (version 01.3.0021) be used in the dispersion modeling protocol.
How to comment: DEQ accepts written comments by e-mail, facsimile transmission and postal mail.  In order to be considered, comments must include the full name, address and telephone number of the person commenting and be received by DEQ by 5:00 p.m. on the last day of the comment period.  Due to problems with the quality of facsimile transmissions, commenters are encouraged to provide the signed original by postal mail within one week. All testimony, exhibits and documents received are part of the public record.
To review regulation documents: The proposal and any supporting documents are available on the DEQ Air Public Notices for Plans web site ( The documents may also be obtained by contacting the DEQ representative named below.  The public may review the documents between 8:30 a.m. and 4:30 p.m. of each business day until the close of the public comment period at the following locations: 1) DEQ Main Street Office, 8th Floor, 629 E. Main Street, Richmond, Virginia, 804-698-4070, and 2) DEQ Fredericksburg Satellite Office, 806 Westwood Office Park, Fredericksburg, Virginia, 540-899-4600.

Contact Information
Name / Title: Mike Kiss  / Coordinator, Air Quality Assessments Group
Address: 629 East Main Street
P.O. Box 1105
Richmond, 23218
Email Address:
Telephone: (804)698-4426    FAX: (804)698-4510