			UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

						REGION III

					      1650 Arch Street

				   Philadelphia, Pennsylvania 19103-2029			

 ADVANCE \x 0 

DATE:	 January 5, 2011

SUBJECT:	Technical Support Document 

Approval of Pennsylvania State Implementation Plan (SIP) Revisions

to Allegheny County Health Department Regulations incorporating Modeling
Requirements for Major Sources Locating In or Impacting A Nonattainment
Area 

	

				

 ADVANCE \x 0 FROM:         	Paul T. Wentworth, P.E.

Office of Permits and Air Toxics (3AP10)

 ADVANCE \x 0 TO:               	Kathleen Cox, Chief

                      	Office of Permits and Air Toxics (3AP10)

TECHNICAL SUPPORT DOCUMENT

EPA-R03-OAR-2009-0881

APPROVAL

REVISIONS TO ALLEGHENY COUNTY RULES AND REGULATIONS FOR MAJOR SOURCES
LOCATING IN OR IMPACTING A NONATTAINMENT AREA 

I.	 	BACKGROUND

 

	On November 16, 2006, The Pennsylvania Department of Environmental
Protection (PADEP) submitted a revision to Allegheny County’s portion
of the Pennsylvania State Implementation Plan (SIP) consisting of
changes to Allegheny County's Article XXI Air Pollution Control Rules
and Regulations.  The revision incorporates requirements of 40 CFR
51.160(f), “Modeling Requirements” into new subsection 2102.06(g),
“Requirements for Modeling” under Section 2102.06, “Major Sources
Locating in or Impacting a Non-attainment Area”.

 

40 CFR Part 51 Subpart I, “Review of New Sources and Modifications”
requires that each SIP contain legally enforceable procedures that
enable the State or local agency to determine whether the construction
or modification of a facility, building or structure or installation, or
combination of these will result in a violation of applicable portions
of the control strategy; or interference with attainment or maintenance
of a national standard in the state in which the proposed source (or
modification) is located or in a neighboring State.  40 CFR 51.160(f)
states that these procedures must discuss the air quality data and the
dispersion or other air quality modeling used to meet the requirements
of this subpart.  It further stipulates that all applications of air
quality modeling involved in this subpart shall be based on the
applicable models, data bases, and other requirements specified in
appendix W of this part,  Federal Guideline on Air Quality Models
(Guideline). The Guideline provides model users with a common basis for
estimating pollution concentrations, assessing control strategies and
specifying emission limits.  The modeling requirements under 40 CFR
51.160 (f)(2) specify that where an air quality model specified in
appendix W of this part is inappropriate, the model may be modified or
another model substituted on a case-by-case basis or, where appropriate,
on a generic basis for a specific State program provided that written
approval is obtained from the Administrator.  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 modeling
requirements of 40 CFR 51.160 (f)(2) must be incorporated as a new
Subsection, 2102.06(g), under Allegheny County’s Regulation to make
Allegheny’s regulation 2102.06 consistent with 40 CFR 51 Subpart I.

II.	SUMMARY OF ACTION

	EPA is approving, via direct final rulemaking action, amendments to
Allegheny County’s Regulations, section 2102.06 entitled
“Requirements for Modeling”, submitted on November 16, 2006.  These
amendments consist of a new subsection, 2102.06(g), ‘‘Major Sources
Locating in or Impacting a Nonattainment Area’’.  PADEP is
incorporating these amendments into the Pennsylvania SIP. This approval
action will revise the previously approved versions of these rules
approved on November 14, 2002 (67 FR 38935) into the Pennsylvania SIP. 

III.	PROGRAM REVIEW

	This section outlines the changes the State of Pennsylvania has made to
the existing SIP for the purposes of updating their regulations so that
they are consistent with the Federal rules as of the CFR edition dated
July 1, 2008.  There were no public comments made regarding the proposed
adoption of the changes to Article XXI Section 2102.06 at the public
hearing held on January 7, 2005.

Section 2102.06, “Major Sources Locating in or Impacting a
Nonattainment Area 

Section	Status	Description

Regulation

2102.06	Added Subsection 2102.06(g) to Regulation	Updated ACHD
Regulation to include modeling requirements to be consistent with
Federal Requirements

In 40 CFR 51 Subpart I



IV.	CONCLUSION	

EPA concludes that the result of this SIP revision enables Allegheny
County’s program  to meet all of the program element requirements
contained in 40 CFR 51 Subpart I.

V.	RECOMMENDED AGENCY ACTION

	I recommend that the amended Allegheny County regulation 2102.06 be
approved as revisions to strengthen the current Pennsylvania State
Implementation Plan.

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