UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

	1650 Arch Street

	Philadelphia, Pennsylvania  19103

DATE:	February 22, 2012

SUBJECT:	     Technical Support Document - Delaware; Attainment Plan for
the Delaware Portion of the Philadelphia-Wilmington, Pennsylvania-New
Jersey-Delaware 

                        (PA-NJ-DE) 1997 Fine Particulate Matter
Nonattainment Area

				/s/

FROM:	Rose Quinto, Environmental Engineer

Office of Air Program Planning 

TO:		File

			           /s/	

THRU: 	Cristina Fernandez, Associate Director

		Office of Air Program Planning

This document provides a technical review of a revision to the Delaware
State Implementation Plan (SIP) submitted by the Delaware Department of
Natural Resources and the Environmental Control (DNREC) on April 3,
2008.  This SIP revision addresses the attainment plan of the 1997
annual fine particulate matter (PM2.5) national ambient air quality
standard (NAAQS) for the Delaware portion of the
Philadelphia-Wilmington, Pennsylvania-New Jersey-Delaware (PA-NJ-DE)
nonattainment area (Philadelphia area).  The attainment plan includes
the Delaware portion of Philadelphia area’s attainment demonstration,
motor vehicle emission budgets (MVEBs) used for transportation
conformity purposes, an analysis of reasonably available control
measures (RACM) and reasonably available control technology (RACT), base
year emissions inventory, and contingency measures. 

This document also provides a technical review of a supplement to the
April 3, 2008 submittal, submitted by DNREC on November 17, 2011.  This
supplement submittal 1) replaces the onroad emissions budget in the
April 3, 2008 submittal with a budget that is based on a new onroad
mobile emissions model – Motor Vehicle Emissions Simulator (MOVES)
model;  2) demonstrates that the MOVES based mobile source budget is
consistent with attainment of the PM2.5 NAAQS by 2010;  and 3)
demonstrates that the contingency requirements of the CAA are met.  This
SIP revision only impacts PM2.5 and nitrogen oxides (NOx) emissions and
calculations.  DNREC requested EPA to process this supplemental
submittal in parallel with the April 3, 2008 submittal, while DNREC
completes the public procedures necessary to submit the amended PM2.5
attainment demonstration as a formal supplement to the April 3, 2008
submittal.  If the proposed SIP revision is changed in areas other than
those identified in the notice of proposed rulemaking action, EPA will
evaluate those changes and may publish another notice of proposed
rulemaking.  If no changes are made, EPA will publish a final rulemaking
notice on the revisions.  The final rulemaking action by EPA will occur
only after the SIP revision has been adopted by Delaware and submitted
formally to EPA for incorporation into the Delaware SIP.

A.  BACKGROUND

I.  Designation History

g/m3) based on a 3-year average of annual mean PM2.5 concentrations
and a 24-hour (or daily) standard of 65 g/m3 based on a 3-year
average of the 98th percentile of 24-hour concentrations.  EPA
established the standards based on significant evidence and numerous
health studies demonstrating that serious health effects are associated
with exposures to PM2.5. 

	

Following promulgation of a new or revised NAAQS, EPA is required by the
Clean Air Act (CAA) to designate areas throughout the United States as
attaining or not attaining the NAAQS; this designation process is
described in section 107(d)(1) of the CAA.  In 1999, EPA and State Air
Quality Agencies initiated the monitoring process for the 1997 PM2.5
NAAQS and by January 2001, established a complete set of air quality
monitors.  On January 5, 2005 (70 FR 944), EPA promulgated initial air
quality designations for the 1997 PM2.5 NAAQS based on air quality
monitoring data for calendar years 2001-2003.

On April 14, 2005 (70 FR 19844), EPA promulgated a supplemental rule
amending EPA’s initial designations, with the same effective date
(April 15, 2005) as 70 FR 944.  As a result of this supplemental rule,
PM2.5 nonattainment designations are in effect for 39 areas, comprising
208 counties within 20 states (and the District of Columbia) nationwide,
with a combined population of about 88 million.  The Delaware portion of
the Philadelphia area is included in the list of areas not attaining the
1997 PM2.5 NAAQS.  The Delaware portion of the Philadelphia area
consists of New Castle County.

	It should be noted that on November 13, 2009 (74 FR 58688), EPA
relabeled the existing designation tables in 40 CFR 81.308 to clarify
the 1997 designations for the 24-hour PM2.5 NAAQS.   The designation for
New Castle County was clarified as unclassifiable/attainment for the
1997 24-hour PM2.5 NAAQS.

	

II.  Clean Air Fine Particle Implementation Rule

	On April 25, 2007 (72 FR 20586), EPA issued the Clean Air Fine Particle
Implementation Rule for the 1997 PM2.5 NAAQS.  The “PM2.5
Implementation Rule” describes the CAA framework and requirements for
developing SIPs for areas designated nonattainment for the 1997 PM2.5
NAAQS.  An attainment plan must include a demonstration that a
nonattainment area will meet the applicable NAAQS within the time
provided in the statute.  This demonstration must include modeling (40
CFR 51.1007) that is performed in accordance with EPA modeling guidance
(EPA-454/B-07-002, April 2007).  It must also include supporting
technical analyses and descriptions of all relevant adopted Federal,
state, and local regulations and control measures that have been adopted
in order to provide attainment by the proposed attainment date.  

	For the 1997 PM2.5 NAAQS, an attainment plan must show that a
nonattainment area will attain the 1997 PM2.5 NAAQS as expeditiously as
practicable, but within five years of designation (i.e. attainment date
of April 2010 based on air quality data for 2007-2009).  If the area is
not expected to meet the NAAQS by April 2010, a state may request to
extent the attainment date by one to five years based upon the severity
of the nonattainment problem or the feasibility of implementing control
measures (section 172(a)(2) of the CAA) in the specific area. For EPA to
approve an extension of the attainment date beyond 2010, the state must
provide an analysis to support the request and demonstrate that the
attainment date is as expeditious as practicable for the area given the
facts and circumstances of the area and consistent with the statutory
criteria for an extension.

	For each nonattainment area, the state must demonstrate that it has
adopted all RACM, including all RACT as needed to provide for attainment
of the PM2.5 standards in the area “as expeditiously as
practicable.”  The PM2.5 Implementation Rule provides guidance for
making these RACM and RACT determinations.  Any measures that are
necessary to meet these requirements that are not already Federally
promulgated or in an EPA-approved part of the state’s SIP must be
submitted as part of the state’s attainment plan.  Any state measures
must meet the applicable statutory and regulatory requirements, and in
particular, must be Federally enforceable.

	The PM2.5 Implementation Rule also includes guidance on pollutants that
states must address in their attainment plans.  Section 302(g) of the
CAA authorizes EPA to regulate criteria pollutants and their precursors.
 In the case of PM2.5, the main chemical precursors are sulfur dioxide
(SO2), NOx, ammonia (NH3), and volatile organic compounds (VOCs). The
effect of reducing emissions of precursor pollutants that contribute to
PM2.5 concentrations varies by area, however, depending on PM2.5
composition, emission levels, and other area-specific factors.  For this
reason, the PM2.5 Implementation Rule provided guidance recommending
that states elect to control direct PM2.5 emissions and the precursor or
precursors that would be most effective for attaining the NAAQS within
the specific area, based upon an appropriate technical demonstration.

	In accordance with the PM2.5 Implementation Rule, direct PM2.5
emissions means “solid particles emitted directly from an air
emissions source or activity, or gaseous emissions or liquid droplets
from an air emissions source or activity which condense to form
particulate matter at ambient temperatures.  Direct PM2.5 emissions
include elemental carbon, directly emitted organic 

carbon (OC), directly emitted sulfate (SO4), directly emitted nitrate
(NO3), and other inorganic particles (including but not limited to
crustal material, metals, and sea salt).”

The PM2.5 Implementation Rule requires all states to address SO2 as a
PM2.5 attainment plan precursor and to evaluate SO2 for possible control
measures in all PM2.5 nonattainment areas.  States are also required to
address NOx as a PM2.5 attainment plan precursor and evaluate reasonable
controls for NOx in PM2.5 attainment plans, unless the state and EPA
make a finding that NOx emissions from sources in the state do not
significantly contribute to PM2.5 concentrations in the relevant
nonattainment area.

Although current scientific information shows that certain VOC emissions
are precursors to the formation of secondary organic aerosol, and
significant progress has been made in understanding the role of gaseous
organic material in the formation of organic particular matter (PM),
this relationship remains complex.  Further research and technical tools
are needed to better characterize emissions inventories for specific VOC
compounds and to determine the extent of the contribution of specific
VOC compounds to organic PM mass.  Because of these factors, the PM2.5
Implementation Rule did not require states to address VOCs as PM2.5
attainment plan precursors and evaluate them for control measures,
unless the state or EPA makes a finding that VOCs significantly
contribute to a PM2.5 nonattainment problem in the state or to other
downwind air quality concerns.

The PM2.5 Implementation Rule describes the formation of particles
related to NH3 emissions, which is a complex, nonlinear process.  Though
recent studies have improved our understanding of the role of NH3 in
aerosol formation, ongoing research is needed to better describe the
relationships between NH3 emissions, particulate matter concentrations,
and related impacts.  Also, area specific data is needed to evaluate the
effectiveness of reducing NH3 emissions on reducing PM2.5 concentrations
in different areas, and to determine where NH3 decreases may increase
the acidity of particles and precipitation.  For these reasons, in the
PM2.5 Implementation Rule, NH3 is presumed not to be a PM2.5 attainment
plan precursor, meaning that the state is not required to address NH3 in
its attainment plan or evaluate sources of NH3 emissions for reduction
measures, unless the state or EPA makes a finding that NH3 significantly
contributes to a PM2.5 nonattainment problem in the area or to other
downwind air quality concerns.

The presumptive inclusion of NOx and the presumptive exclusion of VOC
and NH3 as attainment plan precursors can be reversed based on an
acceptable technical demonstration for a particular nonattainment area
by the state or EPA.  Such a demonstration should include information
from multiple sources, including results of speciation data analyses,
air quality modeling studies, chemical tracer studies, emission
inventories, or special intensive measurement studies to evaluate
specific atmospheric chemistry in an area.  See PM2.5 Implementation
Rule for more information.

The PM2.5 Implementation Rule also provided guidance on other elements
of a state’s attainment plan, including, but not limited to,
consideration of emission inventories, contingency measures, and MVEBs
used for transportation conformity purposes.

There are, however, three aspects of the PM2.5 Implementation Rule for
which EPA received petitions requesting reconsideration.  These pertain
to the presumption or advance determination that compliance with the
requirements of the Clean Air Interstate Rule (CAIR) automatically
satisfies the requirements for RACT or RACM for NOx or SO2 emissions
from electric generating unit (EGU) sources participating in regional
cap and trade programs; the suggestion in the preamble that the economic
feasibility element of a RACT determination for EGUs should include
consideration of  whether the cost of a measure is reasonable in light
of the benefits; and the policy described in the preamble of allowing
certain emissions reductions from outside the nonattainment area to be
credited as meeting the RFP requirement.  EPA has granted these
petitions.  The attainment plan for the Delaware portion of the
Philadelphia area did not rely on any of these aspects of the rule.

	CAIR, as originally promulgated, requires significant reductions in
emissions of SO2 and NOx to limit the interstate transport of these
pollutants.  In 2008, however, the D.C. Circuit remanded CAIR back to
EPA.  See North Carolina v. EPA, 550 F.3d 1176.  The Court found CAIR to
be inconsistent with the requirements of the CAA, North Carolina v. EPA,
531 F.3d 896 (D.C. Cir. 2008), but ultimately remanded the rule to EPA
without vacatur because it found that “allowing CAIR to remain in
effect until it is replaced by a rule consistent with [the court’s]
opinion would at least temporarily preserve the environmental values
covered by CAIR,” North Carolina v. EPA, 550 F.3d at 1178.  In
response to the court’s decision, EPA has issued a new rule to address
interstate transport of NOx and SO2 in the eastern United States (i.e.,
the Transport Rule, also known as the Cross-State Air Pollution Rule). 
See 76 FR 48208, August 8, 2011.  In the Transport Rule, EPA finalized
regulatory changes to sunset CAIR and the CAIR Federal Implementation
Plans (FIPs) for control periods in 2012 and beyond.  See 76 FR 48322.  

 

 	On December 30, 2011, the D.C. Circuit issued an order addressing the
status of the Transport Rule and CAIR in response to motions filed by
numerous parties seeking a stay of the Transport Rule pending judicial
review.  In that order, the D.C. Circuit stayed the Transport Rule
pending the court’s resolution of the petitions for review of that
rule in EME Homer Generation, L.P. v. EPA (No. 11-1302 and consolidated
cases).  The court also indicated that EPA is expected to continue to
administer the CAIR in the interim until the court rules on the
petitions for review of the Transport Rule.   

Under the circumstances set forth above, EPA believes it is appropriate
to finalize its proposed approval of the Delaware portion of the
Philadelphia area attainment plan demonstration.  Although the Court has
stayed the implementation of the Transport Rule at this time, EPA
believes that the rule has a strong legal basis.  To the extent that the
current status of CAIR and the Transport Rule affect any of the criteria
for approval of this area’s attainment plan, we believe that the
ongoing implementation of CAIR during the period of the stay, coupled
with the promulgation of the Transport Rule, provide adequate assurance
of the components of the attainment plan.  Thus, for purposes of this
proposed approval, EPA believes that the state may rely on the
combination of CAIR, which remains in place temporarily during the
period of the stay, and the Transport Rule which has been promulgated to
replace the CAIR.  When the court issues its ruling on the merits of the
Transport Rule, EPA will re-evaluate its position as necessary and take
such further action as is appropriate.

III.  Determinations of Attainment

The data in Table 1 indicates that the Delaware portion of the
Philadelphia area is meeting the 1997 annual PM2.5 NAAQS.  In addition,
Table 2 shows that the Delaware portion of the Philadelphia area
continues to attain the 1997 annual PM2.5 NAAQS by 2010.  However, this
action does not determine that the Delaware portion of the Philadelphia
area has attained the 1997 annual PM2.5 NAAQS and the information is
included here only to support Delaware’s demonstration that the
Delaware portion of the Philadelphia area could meet the attainment date
of April 5, 2010, and continues to attain based on the most recent data
available.  EPA is taking action to formally determine the Delaware
portion of the Philadelphia area’s attainment of the 1997 annual PM2.5
NAAQS in a separate action.

Table 1.  2009 Annual Averaged PM2.5 Design Value

County	Site Name	Site Number	Design Value (µg/m3)

New Castle	Bellefonte	100031003	12.3

New Castle 	Lums Pond	100031007	11.4

New Castle	Newark 	100031012	12.5

New Castle	MLK	100032004	13.3



Table 2.  2008-2010 Monitored Annual Design Values

County	Site Name	Site Number	Design Value (µg/m3)



	2008	2009	2010

New Castle	Bellefonte	100031003	12.9	12.2	11.1

New Castle	Lums Pond	100031007	11.8	11.3	10.5

New Castle	Newark	100031012	12.9	12.2	11.2

New Castle	MLK	100032004	14.2	13.0	11.7



B.  COMPONENTS OF DELAWARE’S ATTAINMENT PLAN

	In accordance with section 172(c) of the CAA and the PM2.5
Implementation Rule, the attainment plan submitted on April 3, 2008 by
DNREC for the Delaware portion of the Philadelphia area included:  (1)
an emissions inventory for the plan’s base year (2002);  (2) an
attainment demonstration;  and (3) MVEBs for the attainment year.  The
attainment demonstration includes:  (a) technical analyses that locate,
identify, and quantify sources of emissions contributing to violations
of the 1997 annual PM2.5 NAAQS;  (b) analyses of future year emissions
reductions and air quality improvements expected to result from national
and local programs from new measures to meet RACM/RACT requirements; 
(c) adopted emission reduction measures with schedules for
implementation;  and (d) contingency measures for NOx, SO2 and direct
PM2.5 to be implemented if the area did not meet RFP or did not attain
the standard by the attainment date.  

	

	On November 17, 2011, DNREC submitted a supplement to the April 3, 2008
submittal.  This supplement submittal 1) replaces the onroad emissions
budget in the April 3, 2008 submittal with a budget that is based on a
new onroad mobile emissions model – MOVES model;  2) demonstrates that
the MOVES based mobile source budget is consistent with attainment of
the PM2.5 NAAQS by 2010;  and 3) demonstrates that the contingency
requirements of the CAA are met.  This SIP revision only impacts PM2.5
and NOx emissions and calculations.  

	To analyze future year emissions reductions and air quality
improvements, Delaware used local, regional, and national modeling
analyses that have been developed to support Federal and local emission
reduction programs.  This modeling was performed in accordance with
EPA’s “Guidance on the Use of Models and Other Analyses for
Determining Attainment of Air Quality Goals for Ozone, PM2.5, and
Regional Haze,” (EPA-454/B-07-002, April 2007).  

C.  EPA’S REVIEW AND TECHNICAL INFORMATION

The following EPA analysis of the PM2.5 attainment plan for the Delaware
portion of the Philadelphia area addresses all required elements of a
PM2.5 attainment plan as described in the PM2.5 Implementation Rule (72
FR 20586). 

  

I.  Pollutants Addressed 

In accordance with policies described in the PM2.5 Implementation Rule,
Delaware’s PM2.5 attainment plan evaluates emissions of direct PM2.5,
SO2, and NOx in the Delaware portion of the Philadelphia area.  With
regard to evaluation of PM2.5 precursors, the PM2.5 Implementation Rule
requires that SO2 be evaluated for controls in all nonattainment areas,
and describes general presumptive policies for NOx, NH3, and VOCs.  For
NOx, states are required to address NOx as a PM2.5 attainment plan
precursor and evaluate reasonable controls for NOx in PM2.5 attainment
plans, unless the state makes a finding that NOx emissions in the state
do not significantly contribute to PM2.5 concentrations in the area. 
For NH3, because of uncertainties regarding NH3 emission inventories and
the efficacy of ammonia control technologies, the final rule sets forth
the presumption that NH3 is not a PM2.5 precursor and that states are
not required to address NH3 in their attainment plan.  Similarly, VOC
emissions are presumed not to be an attainment plan precursor because of
uncertainties regarding the role of VOC in secondary organic aerosol
formation.  Delaware’s attainment plan does not reverse any of these
presumptions.

II.  Emissions Inventory Requirements

Section 172(c)(3) of the CAA requires states to develop emissions
inventories of point, area, onroad mobile, and nonroad mobile sources
for their attainment demonstrations.  These inventories provide a
detailed accounting of all emissions and emissions sources by precursor
or pollutant.  In addition, inventories are used to model air quality to
demonstrate that attainment of the 1997 PM2.5 NAAQS as expeditiously as
practicable, and if an attainment extension beyond 2010 is needed to
support the need for such an extension.  Emissions inventory guidance
was provided in the April 1999 document “Emissions Inventory Guidance
for Implementation of Ozone and Particulate Matter NAAQS and Regional
Haze Regulations,” (EPA–454/R–99–006), which was updated in
November 2005 (EPA–454/R–05–001).  Emissions reporting
requirements were provided in the 2002 Consolidated Emissions Reporting
Rule (CERR) (67 FR 39602).  On December 17, 2008 (73 FR 76539), EPA
promulgated the Air Emissions Reporting Requirements (AERR) to update
emissions reporting requirements in the CERR, and to harmonize,
consolidate and simplify data reporting by states.

In accordance with the AERR and the November 2005 guidance, the PM2.5
Implementation Rule required states to submit inventory information on
directly emitted PM2.5 and PM2.5 precursors and any additional inventory
information needed to support an attainment demonstration.

PM2.5 is comprised of filterable and condensable emissions.  Condensable
particulate matter (CPM) can comprise a significant percentage of direct
PM2.5 emissions from certain sources, and are required to be included in
national emission inventories based on emission factors.  Test Methods
201A and 202 are available for source-specific measurement of
condensable emissions.  However, the PM2.5 Implementation Rule
acknowledged that there were issues and concerns related to availability
and implementation of these test methods as well as uncertainties in
existing data for condensable PM2.5.  In recognition of these concerns,
EPA established a transition period during which EPA could assess
possible revisions to available test methods and to allow time for
states to update emissions inventories as needed to address direct
PM2.5, including condensable emissions.  Because of the time required
for this assessment, EPA recognized that states would be limited in how
to effectively address CPM emissions, and established a period of
transition, up to January 1, 2011, during which state submissions for
PM2.5 were not required to address CPM emissions.  Amendments to these
test methods were proposed on March 25, 2009 (74 FR 12969), and
finalized on December 21, 2010 (75 FR 80118).  The amendments to Method
201A added a particle-sizing device for PM2.5 sampling, and the
amendments to Method 202 revised the sample collection and recovery
procedures of the method to reduce the formation of reaction artifacts
that could lead to inaccurate measurements of CPM emissions.   

	The period of transition for establishing emissions limits for
condensable direct PM2.5 ended on January 1, 2011.  PM2.5 submissions
made during the transition period are not required to address CPM
emissions; however, states must address the control of direct PM2.5
emissions, including condensable emissions, with any new action taken
after this January 1, 2011.  Delaware submitted the Delaware portion of
the Philadelphia area attainment plan prior to January 1, 2011 and did
not consider condensables. 

In July 2008, EarthJustice filed a petition requesting reconsideration
of EPA’s transition period for CPM emissions provided in the PM2.5
Implementation Rule.  In January 2009, EPA decided to allow states that
have not previously addressed CPM to continue to exclude CPM for PSD
permitting during the transition period.   This TSD reflects a review of
Delaware’s submittal based on current EPA guidance as described in the
PM2.5 Implementation Rule.  More information and the review and
evaluation of the methods used for the emissions inventory submitted by
Delaware are found in section 3 of Delaware’s attainment plan
submittal and a TSD entitled, “Technical Support Document for
Emissions Inventories for the Delaware Nonattainment Area PM2.5 SIP Base
Year Inventory,” dated June 16, 2010.

2002 Base Year Emission Inventories

An emission inventory is an estimate of the emissions from sources in a
particular area.  DNREC developed an emission inventory for 2002, which
is the base year for attainment planning purposes with respect to 8-hour
ozone and PM2.5 SIPs and for planning purposes with respect to the
regional haze SIPs.  The 2002 base year inventory includes the
pollutants PM10, PM2.5, SO2, NOx, VOC, and NH3.  The inventory consists
of four sectors:  stationary point sources, stationary area sources,
highway vehicle sources and nonroad sources.  The Mid-Atlantic/Northeast
Visibility Union (MANE-VU) compiled a regional inventory from the
emission inventories of the Northeastern and Mid-Atlantic states.  This
regional inventory was used to perform the regional modeling analysis
used in the Delaware’s air quality management effort to attain the
8-hour ozone NAAQS and the PM2.5 NAAQS, and to prepare the regional haze
plan.

Stationary point source inventory represents facility-specific data for
Delaware’s larger stationary sources.  Point sources typically include
large industrial, commercial and institutional facilities. 
Manufacturing facilities, within the industrial sector, comprise the
majority of all reporting point sources.  The institutional sector
includes hospitals, universities, prisons, military bases, landfills and
wastewater treatment plants.  Point source emissions data are submitted
to Air Quality Management Section (AQMS) by the facilities using
Terminal Server Satellite i-STEPS software.   i-STEPS are the point
source emission inventory electronic data management system.

Area sources represent a large and diverse set of individual emission
source categories.  An area source category is either represented by
small facilities too numerous to individually inventories, such as
restaurants (commercial cooking), or is a common activity, such as
fugitive dust from construction and agricultural production.  Emissions
from area sources were estimated at the county level.  For the area
sources, DNREC provided an inventory that contained estimations of
emissions by multiplying an emission factor by some known indicator or
activity level for each category at the county level.  These emissions
are calculated on an annual basis.  Various sources of emission factors
or methodologies were used, including EPA’s AP-42, the Factor
Information Retrieval System (FIRE), EPA’s Emissions Inventory
Improvement Program, Volume III, documented projects performed by the
California Air Resource Board, and projects performed by the
Mid-Atlantic Regional Air Management Association (MARAMA).  Area source
estimates were provided by source classification code (SCC).

Highway vehicles, which include passenger cars and light-duty trucks,
other trucks, buses, and motorcycles, are onroad mobile source emissions
inventory that was developed using the most current version of EPA’s
highway mobile source emissions model MOBILE6.2 and link-level vehicle
miles traveled (VMT) data for each county from the Delaware Department
of Transportation (DelDOT).  The emission factors developed using
MOBILE6.2, were by month, using monthly temperature and fuel property
data.  DNREC provided MOBILE6.2 input and output files for review. 
DNREC provided annual mobile emissions values in tons per year (tpy) and
were provided by SCC.

Nonroad sources, which encompass a diverse collection of engines,
including, but not limited to, outdoor power equipment, recreational
vehicles, farm and construction machinery, lawn and garden equipment,
industrial equipment, recreational marine vessels, commercial marine
vessels, locomotives, ships, and aircraft were estimated using the EPA
NONROAD 2005 model.

The emissions inventory for the base year, 2002, was developed in
accordance with EPA guidance, “Emissions Inventory Guidance for
Implementation of Ozone and Particulate Matter National Ambient Air
Quality Standards and Regional Haze Regulations, EPA-454/R-05-001,
August 2005, updated November 2005.”  Tables 3, 4 and 5 summarize the
emissions for 2002.

Table 3.  2002 Annual Emissions by County (tpy)

County	PM10	PM2.5	SO2	NOx	NH3	VOC

Kent	  3991	 1097	  4062	10314	  2841	  5296

New Castle	  8604	 3430	50237	30748	  1384	18062

Sussex	  6758	 2575	25552	16060	10057	10251

Total	19353	 7102	79852	57122	14284	33610

 

Table 4.  2002 Statewide Annual Emissions (tpy)

Source Sector	PM10	PM2.5	SO2	NOx	NH3	VOC

Point 	  3859	 3161	73708	16372	    179	  4773

Area 	13870	 2580	  1330	  2427	13194	10254

Onroad	    581	   415	    584	21341	    903	10564

Nonroad 	  1043	   946	  4230	16982	        8	  8019

Total	19353	 7102	79852	57122	14284	33610



Table 5.  2002 New Castle County Annual Emissions (tpy)

Source Sector	PM10	PM2.5	SO2	NOx	NH3	VOC

Point 	2168	1733	47070	  9157	  118	  2687

Area 	5674	1073	    780	  1513	  710	  6198

Onroad	  304	  209	    326	11799	  552	  5762

Nonroad 	  458	  415	  2061	  8279	      4	  3415

Total	8604	3430	50237	30748	1384	18062

	

The review and evaluation of the methods used for the emissions
inventory submitted by Delaware are found in the attainment plan
submittal (section 3) and a TSD entitled “Technical Support Document
for Emissions Inventories for the Delaware Nonattainment Area PM2.5 SIP
Base Year Inventory,” dated June 16, 2010.

2009 Projected Emission Inventories	

Tables 6 and 7 summarize the emissions expected in 2009.  These
emissions take activity and emissions growth and/or controls from 2002
into account.  Section 4 and Appendix 4-3 of the Delaware’s attainment
plan, relating to emissions projections, contains documents that
describe the methodologies used to project the 2002 baseline emissions
to 2009.

 Table 6.  2009 Projected Emissions (tpy), i.e., Control Strategy
Emissions

County	NH3	NOx	PM10	PM2.5	SO2	VOC

Kent	   2887	   7799	  3253	   989	  3664	  4230

New Castle	   1466	 21807	  6039	 3015	14135	13887

Sussex	 10106	 11591	  5731	 2571	11724	  7558

Totals	 14459	 41197	15023	 6575	29523	25675



Table 7.  CMAQ Modeled 2009 Emissions (tpy), i.e., Attainment Targets

County	NH3	NOx	PM10	PM2.5	SO2	VOC

Kent	   2887	   7799	  3253	   989	  3664	  4230

New Castle	   1466	 21807	  6039	 3015	14135	13887

Sussex	 10106	 11591	  5731	 2571	11724	  7558

Totals	 14459	 41197	15023	 6575	29523	25675



Growth Projections Methodologies

Growth projections methodologies describe the data, methods and
assumptions utilize in developing estimates of emissions changes between
2002 and the milestone year 2009.  Appendix 4-1 of the Delaware’s
attainment plan contains the technical support document entitled,
“Development of Emission Projections for 2009, 2012, and 2018 for
Non-EGU Point, Area, and Nonroad Sources in the MANE-VU Region,”
developed by MARAMA.  This document provides detail on the specific
factors, control assumptions, and implementation schedules used in the
emission projection calculations for each source category.

III.  Modeling

All attainment demonstrations must include modeling that is performed in
accordance with EPA’s “Guidance on the Use of Models and Other
Analyses for Demonstrating Attainment of Air Quality Goals for Ozone,
PM2.5, and Regional Haze” (EPA-454/B-07-002, April 2007).  Modeling
may be based on national (e.g., EPA), regional (e.g., Ozone Transport
Commission), local modeling, or a combination thereof, if appropriate. 
A description of modeling used to support Delaware’s attainment
demonstration follows.  More detailed information on the modeling is
discussed in a TSD entitled, “Technical Support Document for the
Modeling and Weight of Evidence Portions of the Delaware’s State
Implementation Plan for Attainment of the PM2.5 Annual NAAQS,” dated
June 15, 2010 and section 6 of the Delaware’s attainment plan.

Conceptual Model Description

A conceptual model describes how weather patterns affect the formation
and transport of PM2.5, accounting for emissions and photochemistry.

The conceptual model for Delaware’s attainment plan is described in a
document prepared by the Northeast States for Coordinated Air-Use
Management (NESCAUM) final report entitled, “The Nature of the Fine
Particle and Regional Haze Air Quality Problems in the MANE-VU Region: 
A Conceptual Description (2006),” for the use by the Ozone Transport
Commission (OTC) member states which provides the conceptual description
of PM2.5 issues in the OTC states and is consistent with EPA’s
guidance.

The NESCAUM document contains a conceptual description that explains how
elevated regional PM2.5 peak concentrations in the summer differ
significantly from the largely urban peak concentrations observed during
winter.  On average, summertime concentrations of sulfate in the
northeastern United States are more than twice that of the next most
important fine particle constituent, organic carbon (OC), and more than
four times the combined concentration of nitrate and black carbon (BC)
constituents.  Episodes of high summertime sulfate concentrations are
consistent with stagnant meteorological flow conditions upwind of the
Delaware portion of the Philadelphia area and the accumulation of
airborne sulfate (via atmospheric oxidation of SO2) followed by
long-range transport of sulfur emissions from industrialized areas
within and outside the area.  National assessments have indicated that
in the winter, sulfate levels in urban areas are higher than background
sulfate levels across the eastern U.S., indicating that the local urban
contribution to wintertime sulfate levels is significant relative to the
regional sulfate contribution from long-range transport.  A network
analysis for the winter of 2002 suggests that the local enhancement of
sulfate in urban areas of the MANE-VU region ranges from 25 to 40% and
that the long-range transport component of PM2.5 sulfate is still the
dominant contributor in most eastern cities.

In the winter, urban OC and sulfate each account for about a third of
the overall PM2.5 mass concentration observed in Philadelphia and New
York City areas.  Nitrate also makes a significant contribution to urban
PM2.5 levels observed in the northeastern United States during the
winter months.  Wintertime concentrations of OC and nitrate in urban
areas can be twice the average regional concentrations of these
pollutants, indicating the importance of local source contributions. 
This is likely because winter conditions are more conducive to the
formation of local inversion layers which prevent vertical mixing. 
Under these conditions, emissions from tailpipe, industrial and other
local sources become concentrated near the Earth’s surface, adding to
background pollution levels associated with regionally transported
emissions. 

The Model Used in the Attainment Demonstration  

By agreement of OTC, the New York State Department of Environmental
Conservation (NYSDEC) ran the Community Multi-scale Air Quality Model
(CMAQ) for the states in the northeast ozone transport region that
includes Delaware.  EPA agrees CMAQ is appropriate for this modeling
demonstration.  The inputs to the model are described in section 6 of
the attainment plan submittal.  

Meteorological Time Periods Used in the Modeling

Since the Delaware portion of the Philadelphia area’s attainment
demonstration used a resource intensive photochemical grid model, EPA
accepts the use of single, recent representative year to be used for an
annual simulation.  Two factors were used in selecting 2002 as the
representative year:  the observed annual mean concentrations of PM2.5
are close to the 

3-year observed design value at all, or most monitoring sites, and the
pattern of quarterly mean values is similar to the pattern of quarterly
mean concentrations averaged over 3 years.

Meteorological Data Used in the Air Quality Model  

The OTC modeling committee decided to use a prognostic meteorological
model that provides life-like meteorological inputs to the photochemical
grid model.  The Pennsylvania State University/National Center for
Atmospheric Research Mesoscale Meteorological Model (MM5) version 3.6
was chosen for the modeling analysis.  The MM5 model provides a
reasonable representation of weather conditions at the surface and
aloft. 

Domain of the Model, Horizontal/Vertical Resolution and the Initial and
Boundary Conditions  

The modeling domain extends from Maine to Florida and out in the
Atlantic Ocean on the east and west to the Mississippi River.  The size
of the modeling domain was made large enough to include all emission
sources that affect PM2.5 concentration in the northeastern United
States.  Even this boundary is defined by a larger photochemical
modeling domain that covers much of North America.  Over the
northeastern United States, the model used 12 kilometer grid cells.  The
Philadelphia area is included in the 12 kilometer grid cell area.  The
OTC Modeling Committee used a 12-kilometer grid size for the areas in
and near its states to provide a fine enough grid resolution to
adequately capture the PM patterns experienced in the ozone transport
region (OTR).  Outside the local areas the grid resolution used in the
modeling is 36 kilometers.  The selection of model domains and
horizontal grid resolution was deemed acceptable to EPA.  

Vertical resolution is the number of layers and the size of each layer
in the model.  The layers in the photochemical grid model were set up to
be compatible with the model that produced weather conditions for the
photochemical grid model.  The vertical resolution used in the modeling
exercise followed EPA’s modeling guidance and therefore adequately
represents the atmosphere where PM2.5 is emitted, forms and is
transported.  

Emissions Used in the Air Quality Model  

The emissions data for 2002 were generated by individual states within
the OTR and assembled and processed through MANE-VU, a Regional Planning
Organization (RPO).  These emissions were then processed by NYSDEC using
the sparse matrix operator kernel emissions (SMOKE) emissions processor
to provide CMAQ compatible inputs.  The 2002 emissions for the non-OTR
areas within the modeling domain were obtained from the corresponding
RPOs and were processed using SMOKE, in manner similar to that of the
OTR emissions.  The OTR states, through MANE-VU, contracted MACTEC
Federal Programs (called Contractor) to develop 2009, 2012, and 2018
inventories based on 2002 inventories that the states had previously
developed for the base-year model work.  The Contractor, in consultation
with the states, developed the necessary growth and control factors and
applied to the 2002 inventory.  

Base Case Run Model Performance Evaluation  

NYSDEC performed a model evaluation for the OTC to determine how well
CMAQ reproduced the 2002 PM2.5 concentrations.  CMAQ was employed to
simulate PM2.5 for the calendar year 2002.  A review of PM2.5 and its
individual species was conducted for the study domain.  Several
observations were made with respect to model performance:  1)
approximately 80 – 90 percent of organic mass (OM) is in the primary
fraction;  2) CMAQ captures seasonal variation in SO4 well;  3) CMAQ
appears to overestimate primary PM2.5 components, especially during
colder months;  and 4) CMAQ appears to underestimate secondary OM during
the summer.

These issues are not of great regulatory concern since attainment tests
are based on the application of relative response factors.  Therefore,
the regional and local model performance is acceptable for PM2.5.  While
there are some differences between the spatial data between sub-regions,
there is nothing to suggest a tendency for the model to respond in a
systematically different manner between regions.  Examination of the
statistical metrics by sub-region confirms the absence of significant
performance problems arising in one area but not in another, building
confidence that the CMAQ modeling system is operating consistently
across the full OTC domain.  This confidence in the modeling results
allows for the modeling system to be used to support the attainment plan
to meet the 1997 annual PM2.5 NAAQS.

2009 Control Case Modeling and Modeled Attainment Test  

As previously mentioned, the Delaware portion of the Philadelphia area
has an attainment date of April 5, 2010.  The PM2.5 NAAQS include an
annual standard of 15 μg/m3 based on the 3-year average of annual mean
PM2.5 concentrations.

The purpose of a modeling assessment is to determine if control
strategies currently being implemented (“on the books”) will lead to
attainment of the annual average NAAQS for PM2.5 by 2009.  The modeling
is applied in a relative sense, similar to the 8-hour ozone attainment
test.  However, the PM2.5 attainment test is more complicated and
reflects the fact that PM2.5 is a mixture.  In the test, ambient PM2.5
is divided into major components, with a separate relative response
factor (RRF) and future design value (DVF) calculated for each of the
PM2.5 components.  Since the attainment test is calculated on a per
species basis, the attainment test for PM2.5 is referred to as the
Speciated Modeled Attainment Test (SMAT).

Annual SMAT Results

.  Specifically, all calculations are less than15 μg/m3.   Table 8
presents the results of the annual SMAT results for a suite of regional
modeling runs conducted by OTC each representing OTB/OTW – “On the
Books, On the Way” control measures.  All runs demonstrate compliance
with the annual PM2.5 NAAQS.

Table 8.  Annual SMAT Results for Philadelphia-Wilmington, PA-NJ-DE
PM2.5 Nonattainment Area On-The-Books-On-The-Way Control Measures

AIRS ID	Site Name	County	State	2000-2004 Baseline Design Value	2009





Q1	Q2	Q3	Q4	DVF

420170012	Bristol	Bucks	PA	14.14	13.69	14.73	13.85	12.1

420290100	New Garden	Chester	PA	14.39	14.73	16.36	13.76	12.4

420450002	Chester	Delaware	PA	15.07	15.96	16.34	13.74	13.3

420910013	Norristown	Montgomery	PA	12.68	13.62	13.96	12.34	11.3

421010004	AMS Lab	Philadelphia	PA	15.99	14.01	15.95	13.82	12.9

421010024	NE Airport	Philadelphia	PA	13.58	13.63	14.95	12.96	11.9

421010047	Broad Street	Philadelphia	PA	16.59	16.45	15.80	15.37	13.5

421010136	Elmwood	Philadelphia	PA	15.70	14.20	15.27	12.99	12.7

100031003	Bellefonte	New Castle	DE	14.87	15.16	15.50	13.13	12.6

100031007	Lums Pond	New Castle	DE	13.16	14.37	16.05	10.66	11.3

100031012	Newark	New Castle	DE	15.27	14.91	16.53	13.14	12.6

100032004	MLK	New Castle	DE	16.41	15.40	17.61	14.04	13.3

340070003	Camden	Camden	NJ	13.99	14.54	15.76	12.47	12.3

340071007	Pennsauken	Camden	NJ	13.99	14.00	14.75	13.59	12.3

40155001	Gibbstown	Gloucester	NJ	13.92	13.43	15.08	11.39	11.7



μg/m3 in the Philadelphia area.  Therefore, based on EPA’s modeled
attainment test, the Philadelphia area reached attainment of the annual
average PM2.5 standard in 2009 before the attainment date of April 5,
2010. 	

Supplemental Analyses and Weight of Evidence (WOE) Determination

EPA’s modeling guidance states that additional analyses are
recommended to determine if attainment will be likely, even if the
modeled attainment test is “passed.”  The guidance recommends
supplementary analyses in all cases.  EPA’s modeling guidance
describes how to use a photochemical grid model and additional
analytical methods to complete a WOE analysis to estimate if emissions
control strategies will lead to attainment.  A WOE analysis is a
supporting analysis that helps to determine if the results of the
photochemical modeling system are correctly (or not correctly)
predicting future air quality. 

	

	All models, including the CMAQ, model have inherent uncertainties. 
Over or under prediction may result from uncertainties associated with
emission inventories, meteorological data, and representation of PM2.5
chemistry in the model.  Therefore, EPA modeling guidance provides for
other evidence to address these model uncertainties so that proper
assessment of the probability to attain the applicable standards can be
made.  EPA modeling guidance states that those modeling analyses that
show that attainment with the NAAQS will be reached in the future with
some margin of safety (i.e., estimated concentrations below 14.5 μg/m3
for annual PM2.5 and 62 μg/m3 for 24-hour PM2.5) need more limited
supporting material. 

Due to the fact that the modeling results presented in Table 8, fall
below the aforementioned “weight of evidence” thresholds established
by EPA, a limited supplemental analysis was deemed necessary to support
the 2009 attainment demonstration.  DNREC’s supporting evidence
includes a brief summary of the modeling demonstration, recent trends in
the Philadelphia area’s monitoring data and a brief analysis of some
of the largest SO2 sources within the nonattainment area (section 6 of
Delaware’s attainment plan). 

IV.  Reasonably Available Control Measures/Reasonably Available Control
Technology

1.  Requirements for RACM/RACT

CAA section 172(c)(1) requires that each attainment plan “provide for
the implementation of all RACM as expeditiously as practicable,
including such reductions in emissions from the existing sources in the
area as may be obtained through the adoption, at a minimum, of RACT, and
shall provide for attainment of the national primary ambient air quality
standards.”  EPA interprets RACM including RACT under section 172 as
measures that a state finds are both reasonably available and contribute
to attainment as expeditiously are practicable in the nonattainment
area.  Thus, what constitutes RACM or RACT in a PM2.5 nonattainment area
is closely tied to the expeditious attainment demonstration of the plan
(40 CFR 51.1010; 

72 FR 20586 at 20612).  

States are required to evaluate RACM/RACT for direct PM2.5 emissions and
all of the area’s attainment plan precursors (40 CFR 51.1002(c); 72 FR
20586 at 20589 – 97).  Consistent with the guidance provided for the
PM2.5 Implementation Rule, a state initially must evaluate RACM/RACT for
sources that emit direct PM2.5, SO2, and NOx.  A state may establish
with an appropriate demonstration that it should not regulate NOx in the
specific nonattainment area, so it could thereby forgo evaluation of
RACM/RACT for NOx.  Because EPA concluded that VOC and NH3 are
presumptively not regulatory precursors for PM2.5, unless the state or
EPA determines that it is necessary to regulate them in a specific
nonattainment area, the state is not required to evaluate RACM/RACT for
sources of VOC or NH3 unless there is a determination supported by an
appropriate demonstration that such emissions need to be regulated for
expeditious attainment of the NAAQS in the specific area.

For PM2.5 attainment plans, the PM2.5 Implementation Rule requires a
combined approach to RACM and RACT under subpart 1 of part D of the CAA.
 Subpart 1, unlike subparts 2 and 4, does not identify specific source
categories for which EPA must issue control technique documents or
guidelines, or identify specific source categories for state and EPA
evaluation during attainment plan development (72 FR 20586 at 20610). 
Rather, under subpart 1, EPA considers RACT to be part of an area’s
overall RACM obligation consistent with the section 172 definition. 
Because of the variable nature of the PM2.5 problem in different
nonattainment areas which may require states to develop attainment plans
that address widely disparate circumstances, EPA determined not only
that states should have flexibility with respect to RACM/RACT controls
but also that in areas needing significant emission reductions,
RACM/RACT controls on smaller sources may be necessary to reach
attainment as expeditiously as practicable (72 FR 20586 at 20612,
20615).  Thus, under the PM2.5 Implementation Rule, RACM and RACT are
those reasonably available measures that contribute to attainment as
expeditiously as practicable in the specific nonattainment area (40 CFR
51.1010; 72 FR 20586 at 20612).

Specifically, the PM2.5 Implementation Rule requires that attainment
plans include the list of measures that a state considered and
information sufficient to show that the state met all requirements for
the determination of what constitutes RACM/RACT in a specific
nonattainment area (40 CFR 51.1010(a)).  In addition, the PM2.5
Implementation Rule requires that the state, in determining whether a
particular emissions reduction measure or set of measures must be
adopted as RACM/RACT, consider the cumulative impact of implementing the
available measures and to adopt as RACM/RACT any potential measures that
are reasonably available considering technological and economic
feasibility if, considered collectively, they would advance the
attainment date by one year or more.  If a measure or measures is not
necessary for expeditious attainment of the NAAQS in the area, then by
definition that measure is not RACM/RACT for purposes of the 1997 PM2.5
NAAQS in that area.  Any measures that are necessary to meet these
requirements which are not already either Federally promulgated, part of
the state’s SIP, or otherwise creditable in SIPs must be submitted in
enforceable form as part of a state’s attainment plan for the area (72
FR 20586 at 20614).  

Guidance provided in the PM2.5 Implementation Rule for evaluating
RACM/RACT level controls for an area also indicated that there could be
flexibility with respect to those areas that were predicted to attain
the 1997 PM2.5 NAAQS within five years of designation as a result of
existing national or local measures (72 FR 20586 at 20612).  In such
circumstances, EPA indicated that the state may conduct a more limited
RACM/RACT analysis that does not involve additional air quality
modeling.  Moreover, the RACM/RACT analysis for such area would focus on
a review of reasonably available measures, the estimation of potential
emissions reductions, and the evaluation of the time needed to implement
the measures.  Thus, the PM2.5 Implementation Rule guidance recommended
that not all areas would need to conduct as rigorous an analysis, and
suggested that a less rigorous analysis would be needed for those areas
expected to attain within the initial five years from designation as a
nonattainment area for the 1997 PM2.5 NAAQS.  A more comprehensive
discussion of the RACM/RACT requirement for PM2.5 attainment plans and
EPA’s guidance for it can be found in the PM2.5 Implementation Rule
preamble (72 FR 20586 at 20609 – 20633).

2.  Delaware’s Analysis of Pollutants and Sources Delaware Portion of
the Philadelphia Area.

Based upon the emissions inventory for the area, Delaware determined
that it would be appropriate to evaluate sources of PM2.5, SO2, and NOx
located in the nonattainment area for potential control as RACM/RACT. 
Delaware did not determine that controls of sources of VOC or NH3 would
be necessary for expeditious attainment of the NAAQS in this area, nor
does EPA believe that there is a need to do so.  Delaware’s
determination with respect to which pollutants the plan should evaluate
is at section 1.4 of the attainment plan submittal. 

After evaluating which pollutants should be addressed in the attainment
plan, Delaware identified all source categories of those emissions
located within the nonattainment area to determine available controls
that could bring the area into attainment as expeditiously as possible
(section 7 of the attainment plan submittal).  For the primary PM2.5
RACM, DNREC evaluated measures that are limited to the boundaries of the
nonattainment area, i.e. New Castle County.  However, because SO2 and
NOx can be transported over considerable distances to form PM2.5, they
were assessed on a statewide basis (Appendix 7-1 of Delaware’s
attainment plan for “EPA’s List of Potential Control Measures”). 
Although VOC is not a regulated PM2.5 precursor for the Delaware portion
of the Philadelphia area, VOC control measures approved by EPA were
included in the modeling associated with this attainment plan. 

In accordance with 40 CFR 51.1010, a SIP revision for a PM2.5
nonattainment area is required to demonstrate that all RACM, including
RACT stationary sources necessary to demonstrate attainment as
expeditiously as practicable have been adopted.  The cumulative impact
of implementing available measures must be considered in determining
whether a particular emission reduction measure or set of measures is
required to be adopted as RACM.  Potential measures that are reasonably
available considering technical and economic feasibility must be adopted
as RACM if, considered collectively, they would advance the attainment
date by one year or more.  Since the Delaware portion of the
Philadelphia area attained at the end of 2009, any RACM measures need to
be in effect in 2008.  Delaware determined that there are no additional
control measures that could be adopted by January 1, 2008.  In addition,
existing measures and measures planned for implementation by 2009
enabled the Delaware portion of the Philadelphia area to attain the 1997
PM2.5 NAAQS.  Therefore, no further actions on RACM or RACT are
warranted.

3.  Delaware’s evaluation of RACM/RACT control measures for the
Delaware Portion of the Philadelphia Area.

In accordance with section 172 of the CAA, the Delaware portion of the
Philadelphia area has adopted all RACM, including RACT, needed to attain
the standards “as expeditiously as practicable.”  Delaware’s
demonstration for attaining the 1997 annual PM2.5 NAAQS in the Delaware
portion of the Philadelphia area is based on enforceable measures.

 STATIONARY POINT SOURCES

Consent Decree, Premcor Refinery in New Castle County – control of SO2
and NOx emissions from boilers and heaters

Regulation 1146 – Electric Generating Unit Multi-Pollutant Regulation
– SO2 and NOx emission control

Regulation 1148 – Control of Stationary Combustion Turbine Electric
Generating Unit Emissions – NOx emission control

Regulation 1144 – Control of Stationary Generator Emissions – SO2,
PM, VOC and NOx emission control

Regulation 1142 – Section 1 – Control of NOx Emissions from
Industrial Boilers

Regulation 1142 – Section 2 – Control of NOx Emissions from
Industrial Boilers and Process Heaters at Petroleum Refineries in New
Castle County

Regulation 24 – Section 46 – Crude Oil Lightering Operations – VOC
emission control

Facility and unit shutdowns

AREA SOURCES 

Regulation 24 – Section 33 – Solvent Cleaning and Drying, VOC
emission control

Regulation 24 – Section 11 – Mobile Equipment Repair and
Refinishing, VOC emission control

Regulation 41 – Section 3 – Portable Fuel Containers, VOC emission
control

Regulation 41 – Section 3 – Consumer Products, VOC emission control

Regulation 41 – Section 1 – Architectural and Industrial Maintenance
Coatings, VOC emission control

Regulation 24 – Section 36 – Stage II Vapor Recovery, VOC emission
control

Residential Woodstoves, 40 CFR Part 60 Subpart AAA – New Source
Performance Standards (NSPS) for PM, VOC and NOx emission control

Regulation 1113 – Open Burning – PM, VOC and NOx control

HIGHWAY VEHICLES

Regulation 31 – Low Enhanced inspection and Maintenance Program

Regulation 1132 – Transportation Conformity Regulation

40 CFR Parts 80, 85 and 86 – Control of Air Pollution from New Motor
Vehicles – Tier 2 Motor Vehicle Emissions Standards and Gasoline
Sulfur Control Requirements

40 CFR Parts 69, 85 and 86 – Control of Air Pollution from New Motor
Vehicles – Heavy- Duty Engines and Vehicle Standards and Highway
Diesel Fuel Sulfur Control Requirements 

Regulation 1145 – Excessive Idling of Heavy Duty Vehicles

Regulation 40 – National Low Emission Vehicle (NLEV) Program

NONROAD SOURCES

Phase I and Phase II Emissions Standards for Gasoline-Powered Nonroad
Utility Engines, Federal Rule

Emissions Standards for Diesel-Powered Nonroad Utility Engines of 50 or
More Horsepower, Federal Rule

Emissions Standards for Spark Ignition (SI) Marine Engines, Federal Rule

Emissions Standards for Large Spark Ignition Engines, Federal Rule

Reformulated Gasoline Use in Nonroad Motor Vehicles and Equipment,
Federal Rule

OTHER MEASURES

Regulation 1124 – Section 36 – Mandatory episodic prohibition of
lightering on ozone action days

Regulations 1146 and 1148 – Reduction of emissions from high electric
demand day electric generations

Voluntary measures effective in 2010 include:  Brandywine School
District bus retrofits;  Delaware ride share;  ozone action days;  use
biodiesel in state-run equipment;  best workplaces for commuters and
SmartWay transport programs;  implement an anti-idling outreach programs
for school and school districts;  clean state program;  installation of
E85 station;  and continue to identify and implement efficiency programs
for the residential and commercial sectors.

4.  RACM/RACT Demonstration and Control Strategy

Delaware’s evaluation of RACM/RACT control measures for the Delaware
portion of the Philadelphia area is approvable.  The most current
monitoring data for this area indicates that it is attaining the 1997
PM2.5 NAAQS.  EPA’s guidance for the PM2.5 Implementation Rule
recommended that if an area was predicted through the attainment plan to
attain the standards within five years after designation, then the state
could submit a more limited RACM/RACT analysis and the state could elect
not to do additional modeling.  

In light of the fact that the Delaware portion of the Philadelphia area
is now attaining the standards, the attainment plan meets the RACM/RACT
requirements of the PM2.5 Implementation Rule, and that the level of
control in Delaware’s attainment plan constitutes RACM/RACT for
purposes of the 1997 PM2.5 NAAQS.  Because the PM2.5 Implementation Rule
defines RACM/RACT as that level of control that is necessary to bring
the area into attainment, the current level of federally enforceable
controls on sources located within the Philadelphia area is by
definition RACM/RACT for this area for this purpose.  

V.  Reasonable Further Progress

	Section 172(c)(2) of the CAA requires that attainment plans include RFP
to achieve steady progress toward meeting air quality standards by
showing generally linear progress toward attainment.  The PM2.5
Implementation Rule set forth that an area that demonstrates attainment
by 2010 will be considered to have satisfied the RFP requirement and
need not submit any additional material to satisfy the RFP requirement. 
EPA views the attainment demonstration as also demonstrating that the
area is making reasonable further progress toward attainment.  A state
is required to submit a separate RFP plan for any area for which the
state seeks an extension of the attainment date beyond 2010.  The RFP
plan is required to provide emission reductions such that emissions in
2009 represent generally linear progress from the 2002 baseline year to
the attainment year.  The Delaware portion of the Philadelphia area
attained by 2010, and has therefore met the RFP requirements.  For
similar reasons, such areas are not subject to a requirement for a
mid-course review.

VI. Contingency Measures

In accordance with section 172(c)(9) of the CAA, the PM2.5
Implementation Rule requires that PM2.5 attainment demonstrations
include contingency measures (40 CFR 51.1012 and 72 FR at 20642 –
20646, April 25, 2007).  Contingency measures are additional measures to
be implemented in the event that an area fails to meet RFP or fails to
attain a standard by its attainment date.  These measures must be fully
adopted rules or control measures that can be implemented quickly and
without significant further EPA or state action if the area fails to
meet RFP or fails to attain by its attainment date, and should contain
trigger mechanisms and an implementation schedule.  In addition, they
should be measures not already included in the SIP control strategy and
should provide for emission reductions equivalent to one year of RFP.  

 	Delaware submitted contingency measures as required by the PM2.5
Implementation Rule, composed of:  electric generating unit
multi-pollutant regulation controlling NOx and SO2 emissions; and a
consent decree with Premcor Refinery controlling NOx emissions from
boilers and heaters.  In accordance with section 110(k)(2) of the CAA,
EPA must take action on the contingency measures that were submitted by
Delaware.  However, as noted in section A.III. of this document, the
Delaware portion of the Philadelphia area, which consists of New Castle
County, has attained the 1997 annual PM2.5 NAAQS, meets the attainment
date of April 5, 2010, and continues to attain based on the most recent
data available.  Because EPA has determined that the area attained by
its required attainment date, in accordance with section 179(c)(9), no
contingency measures for failure to attain by this date need be
implemented, and further EPA action is unnecessary.  Furthermore, as set
forth in the PM2.5 Implementation Rule, areas that attained the NAAQS by
the attainment date are considered to have satisfied the requirement to
show RFP, and as such do not need to implement contingency measures to
make further progress to attainment.  EPA has determined that the area
has attained by the attainment date, therefore the contingency measures
submitted by Delaware are no longer necessary for the Delaware portion
of the Philadelphia area to meet RFP requirements or attain the annual
PM2.5 NAAQS by the attainment date.

The PM2.5 Implementation Rule requires that quantity of emission
reductions needed to satisfy contingency requirements is an amount equal
to one’s year worth of required reductions.  Required reductions are
the amount of reductions needed to attain compliance with the PM2.5
NAAQS.  2002 emissions are the base year emissions and the CMAQ modeled
2009 emissions are the emission levels necessary for attainment.
Therefore, the difference between these emission levels is the total
quantity of reductions required for attainment.  Since there are seven
years between 2002 and 2009, the total quantity of reductions required
for attainment is divided by seven to determine one-year’s worth of
required reductions (i.e., the contingency requirement).

Table 9 displays the 2002 base year emissions and the 2009 emission
reductions (i.e., attainment targets) accounted for in the CMAQ model
which showed attainment in 2010 for the Philadelphia area.  

Table 9.  2002 Base Year and CMAQ Modeled 2009 Emissions (tpy) 

Year	County	NOx 	PM2.5 	SO2 

2002	New Castle	30748	3430	50237

2009	New Castle	23048	3249	12001



Table 10 shows one year’s worth of required emission reductions (i.e.,
the amount require for contingency).  This was calculated by subtracting
the attainment targets from the 2002 base year and dividing the
difference by 7 years.

Table 10.  Contingency Requirement (tpy)

County	NOx 	PM2.5  	SO2 

New Castle	1100	26	5462



Table 11 shows that Delaware has met the contingency requirements
relative to the pollutants NOx and PM2.5, since the projected 2009
emission levels are lower than those needed for attainment by at least
the amount of the contingency requirement.

Table 11.   Calculation of Required Contingency Plan Reductions

New Castle County	NOx  (tpy)	PM2.5 (tpy)

Target Reductions for Attainment	23048	3249

Calculated Excess Reductions	1241	234

Contingency Requirement	1100	26

Excess Reductions Satisfy Contingency Requirement	Yes	Yes

 

VIII.  Motor Vehicle Emission Budgets

Section 176(c) of the CAA requires Federal actions in nonattainment and
maintenance areas to “conform to” the goals of SIPs.  This means
that such actions will not cause or contribute to violations of a NAAQS,
worsen the severity of an existing violation, or delay timely attainment
of any NAAQS or any interim milestone.  Actions involving Federal
Highway Administration (FHWA) or Federal Transit Administration (FTA)
funding or approval are subject to the transportation conformity rule
(40 CFR 93, subpart A).  Under this rule, metropolitan planning
organizations (MPOs) in nonattainment and maintenance areas coordinate
with State Air Quality and Transportation Agencies, EPA, and the FHWA
and FTA to demonstrate that their long range transportation plans
(“plans”) and transportation improvement programs (TIP) conform to
applicable SIPs.  This is typically determined by showing that estimated
emissions from existing and planned highway and transit projects are
less than or equal to the MVEBs contained in the SIP.

The MVEBs for the 2009 attainment year are based on the projected 2009
onroad motor vehicle source emissions, accounting for the emission
reductions from on-road vehicle source control measures, including
transportation control measures and vehicle technology, fuel or
maintenance-based measures.  MVEBs for 2009 attainment year for the
Delaware portion of the Philadelphia area, submitted on April 3. 2008
were 87 tpy for PM2.5-direct and 4,904 tpy for NOx.  More detailed
information can be found in the TSD entitled, “Adequacy Findings for
Motor Vehicle Emissions Budgets in the 2009 Attainment Plan for the
Delaware Portion of the Philadelphia 1997 PM2.5 NAAQS Nonattainment
Area,” January 7, 2010.  

The budgets that Delaware submitted on April 3, 2008 were calculated
using the MOBILE6.2 motor vehicle emissions model because this model was
the most current model available at the time Delaware was performing its
analysis.  EPA has issued an updated motor vehicle emissions model known
as the Motor Vehicle Emission Simulator or MOVES.  In its announcement
of this model, EPA established a grace period for continued use of
MOBILE6.2 in transportation conformity determinations for transportation
plans and TIPs, after which states and MPOs (other than California) must
use MOVES for transportation plan and TIP conformity determinations. 
This grace period will expire in March 2012 (or March 2013 once the
extension becomes official). 

Additional information on the use of MOVES in SIPs and conformity
determinations can be found in the December 2009, “Policy Guidance on
the Use of MOVES2010 for State Implementation Plan Development,
Transportation Conformity, and Other Purposes.”  This guidance
document is available at:   HYPERLINK
"http://www.epa.gov/otaq/models/moves/420b09046.pdf" 
http://www.epa.gov/otaq/models/moves/420b09046.pdf .

During the conformity grace period, the state and MPO(s) should use the
interagency consultation process to examine how MOVES2010 will impact
their future transportation plan and TIP conformity determinations,
including regional emissions analyses.  For example, an increase in
emission estimates due to the use of MOVES2010 may affect an area’s
ability to demonstrate conformity for its transportation plan and/or
TIP.  Therefore, state and local planners should carefully consider
whether the SIP and motor vehicle emissions budget(s) should be revised
with MOVES2010 or if transportation plans and TIPs should be revised
before the end of the conformity grace period, since doing so may be
necessary to ensure conformity determinations in the future.

We would expect that states and MPOs would work closely with EPA and the
local FHWA and FTA offices to determine an appropriate course of action
to address this type of situation if it is expected to occur.  If
Delaware chooses to revise its PM2.5 attainment plan, it should consult
Question 7 of the December 2009, “Policy Guidance on the Use of
MOVES2010 for State Implementation Plan Development, Transportation
Conformity, and Other Purposes,” for information on requirements
related to such revisions.

On November 17, 2011, DNREC submitted a SIP revision that is related to
the PM2.5 and NOx onroad mobile source budgets that were established in
the April 3, 2008 submittal.  The budgets in the April 3, 2008 submittal
were established using EPA’s MOBILE6.2 model.  However, effective
March 2012 (or March 2013 once the extension becomes official), the
MOVES model is required to be used in all planning and transportation
conformity determinations.  The purpose of the supplemental SIP revision
submitted on November 17, 2011, is to 1) replace the onroad emissions
budget in the April 3, 2008 submittal with a budget that is based on the
MOVES model;  2) demonstrate that the MOVES based mobile source budget
is consistent with attainment of the PM2.5 NAAQS by 2010;  and 3)
demonstrate that the contingency requirements of the CAA are met.  This
SIP revision only impacts PM2.5 and NOx emissions and calculations. 
More detailed information can be found in the TSD entitled, “Adequacy
Findings for Motor Vehicle Emissions Budgets in the Attainment
Demonstration for the Delaware Portion of the
Philadelphia-Wilmington-New Jersey 1997 PM2.5 NAAQS Nonattainment
Area,” January 11, 2012.  

EPA MOVES model was used to quantify PM2.5 and NOx emission from onroad
mobile sources.  The emission levels for the onroad mobile emissions
budget for New Castle County are shown in Table 12.  See Appendix A of
the November 17, 2011 submittal for the associated 2012 MOVES input and
output files.

Table 12.  Revised Onroad Mobile Emission Budget (tpy)

County	Emissions Budget

New Castle	NOx	PM2.5

	6273	199



Delaware demonstrated attainment of the annual PM2.5 NAAQS in its April
3, 2008 submittal by showing that the projected 2009 emissions (i.e. the
2009 emission levels after the implementation of all state and Federal
control requirements) were less than the attainment targets (i.e. the
emissions levels needed for attainment based on modeling).  The same
methodology is used to demonstrate that the MOVES based mobile budgets
are consistent with attainment of the PM2.5 NAAQS.  See Appendix B of
the November 17, 2011submittal for the associated 2009 MOBILE6.2 and
MOVES input and output files.

CMAQ modeling was conducted in the April 3, 2008 submittal to
demonstrate that Delaware and the entire Philadelphia area would attain
the PM2.5 NAAQS in 2010 (attainment date).  See section 6 of the April
3, 2008 submittal.  CMAQ modeling demonstrated that the Delaware
emission levels, referred to as attainment target, shown in Table 13 are
consistent with attainment of the annual PM2.5 NAAQS.  

Table 13.  2009 Attainment Target (tpy)

County	NOx	PM2.5

Kent	 8554	1185

New Castle	23048	3249

Sussex	18001	3581

Statewide Total	49603	8015

	Attainment year (i.e. 2009) emission levels were projected in the April
3, 2008 submittal based on the final and enforceable state and Federal
emission requirements.  These projected 2009 emission levels, referred
to as projected 2009 emissions are shown in Table 14.

Table 14.  Projected 2009 Emissions (tpy)

County	NOx	PM2.5

Kent	  7799	  989

New Castle	21807	3015

Sussex	11591	2571

Statewide Total	41197	6575



	Table 15 compares the 2009 mobile emissions calculated using MOBILE6.2
and MOVES.  See Appendix B of the submittal for the associated 2009
MOBILE6.2 and MOVES input and output files.  

Table 15.  2009 MOBILE6.2 and MOVES (tpy)

	2009 MOBILE6.2	2009 MOVES	MOVES Increase

County	NOx	PM2.5	NOx	PM2.5	NOx	PM2.5

Kent	1922	  32	 3488	109	1566	  77

New Castle	4904	  87	 8448	257	3544	170

Sussex	2707	  41	 4764	147	2057	106

Totals	9533	160	16700	513	7167	353



Table 16 reflects the revised projected 2009 emissions using the MOVES
model instead of MOBILE6.2, i.e. adding the MOVES increase and the
projected 2009 emissions.

Table 16.  Revised Projected 2009 Emissions (tpy)

County	NOx	PM2.5

Kent	  9365	1066

New Castle	25351	3185

Sussex	13648	2677

Statewide Total	48364	6928



The revised projected 2009 emissions are demonstrated to be consistent
with attainment if they are equal or lower than the 2009 attainment
target.  The revised projected 2009 emissions are compared to the
attainment target in Table 17.  This comparison shows that there is a
surplus of 64 tons per year PM2.5 in New Castle County.  This
demonstrates that relative to direct PM2.5, the MOVES based mobile
budgets are consistent with attainment.

Table 17.  Shortfall and Surplus by County and Statewide (tpy)

	Attainment Target	Revised Projected 2009 Emissions	Surplus/Shortfall

County	NOx	PM2.5	NOx	PM2.5	NOx	PM2.5

Kent	  8554	1185	  9365	1066	 -811	 119

New Castle	23048	3249	24351	3185	-2303	   64

Sussex	18001	3581	13648	2677	 4353	  904

Statewide	49603	8015	48364	6928	 1239	1087



In addition, since 64 tpy PM2.5 emissions show that it is greater than
the contingency requirement of 26 tpy, the contingency requirement is
demonstrated relative to PM2.5.  See section 9 of the April 3, 2008
submittal for the contingency requirements.

	Because of the regional nature of secondarily-formed sulfate and
nitrate, and the broad modeling domain of the CMAQ modeling, which
included all of Delaware, emission reductions from Kent and Sussex
counties, will contribute to attainment within New Castle County and the
Philadelphia area.  Kent and Sussex Counties are within the State of
Delaware, contiguous to New Castle County, and are less than 200
kilometers away.  EPA’s PM2.5 Implementation Rule specifically
provides for the consideration of in-state NOX and SO2 reductions in
their SIPs from sources up to 200 kilometers away from the
non-attainment area boundaries.  See PM2.5 Implementation Rule, 72 FR
20586 at 20636.  While there is a 2009 NOx shortfall in New Castle
County, there is a statewide NOx surplus of 1,239 tpy.  Therefore, the
2009 MOVES based emissions do not impair Delaware’s ability to meet
the PM2.5 NAAQS.  

In addition, since the 2009 NOx emissions of 1,239 tpy show that it is
greater than the contingency requirement of 1,100 tpy NOx, the
contingency requirement is demonstrated relative to NOx.  See section 9
of the April 3, 2008 submittal for the contingency requirements.

 

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+ comment period for the NPR.  In this case, EPA is concurrently
processing the action on the attainment plan and the adequacy process
for the MVEBs contained therein.  In the NPR, EPA is proposing to find
the MVEBs adequate, and also proposing to approve the MVEBs as part of
the attainment plan.  The MVEBs cannot be used for transportation
conformity until the attainment plan and associated MVEBs are approved
in a final Federal Register notice, or EPA otherwise finds the budgets
adequate in a separate action following the comment period.  Our action
on the Delaware portion of the Philadelphia area MVEBs will also be
announced on EPA’s conformity website:    HYPERLINK
"http://www.epa.gov/otaq/stateresources/transconf/index.htm" 
http://www.epa.gov/otaq/stateresources/transconf/index.htm , (once
there, click on “Adequacy Review of SIP Submissions).

 D.  SUMMARY AND RECOMMENDATIONS:

	The PM2.5 attainment plan for the Delaware portion of the Philadelphia
area meets the requirements of the CAA as described in the Clean Air
Fine Particle Implementation Rule (April 25, 2007, 72 FR 20586).  The
attainment plan supports a determination that the Delaware portion of
the Philadelphia area attains the 1997 annual PM2.5 NAAQS.  The
attainment plan includes an attainment demonstration, MVEBs used for
transportation conformity purposes, RACM/RACT analysis, contingency
measures, and the 2002 base year emission inventories.  Therefore, we
recommend approval of the PM2.5 attainment plan for the Delaware portion
of the Philadelphia area.

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