Document ID: EPA-R03-OAR-2012-0954-0004
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2013-02-20T05:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                                  REGION III
	1650 Arch Street
	Philadelphia, Pennsylvania  19103

DATE:	February 6, 2013

SUBJECT:	Technical Support Document for the Motor Vehicle Emissions Budgets for the Pennsylvania Counties in the Philadelphia-Wilmington, PA-NJ-DE 1997 Fine Particulate Matter Nonattainment Area 

FROM:	Asrah Khadr, Environmental Engineer /s/ 
            Office of Air Program Planning 

TO:	File
			
THRU: 	Cristina Fernandez, Associate Director /s/ 
            Office of Air Program Planning
 

A.  BACKGROUND:  

On November 6, 2012, the Pennsylvania Department of Environmental Protection (DEP) submitted for parallel processing a revision to the Commonwealth of Pennsylvania's (Pennsylvania) State Implementation Plan (SIP).  On January 31, 2013, Pennsylvania DEP submitted its formal, final SIP revision to update the SIP-approved Motor Vehicle Emissions Budgets (MVEBs) for the Philadelphia Area.  The Region is now acting on the final SIP revision.  The SIP revision consists of updated MVEBs for nitrogen oxides (NOx) and fine particulate matter (PM2.5) for the 1997 PM2.5 National Ambient Air Quality Standard (NAAQS).  The updated budgets were calculated using the Environmental Protection Agency's (EPA) Motor Vehicle Emission Simulator model (MOVES2010a).  The intention of the revised SIP is to replace the approved MOBILE6.2-based MVEBs with budgets based on MOVES2010a and to ensure that the SIP revision still provides for attainment of the 1997 PM2.5 NAAQS.   

On July 18, 1997, EPA established the 1997 PM2.5 NAAQS.  On January 5, 2005 (70 FR 943), Philadelphia, Bucks, Delaware, Chester and Montgomery Counties were designated as nonattainment for the 1997 PM2.5 NAAQS as a part of the Philadelphia Area.  On November 29, 2009 (74 FR 62251), EPA published a finding of failure to submit a SIP that demonstrates attainment of the 1997 PM2.5 NAAQS for the Philadelphia Area.  On April 12, 2010, Pennsylvania submitted a SIP that demonstrates attainment of the 1997 PM2.5 NAAQS.  Pennsylvania submitted an amendment to its April 12, 2010 submittal relating to Reasonably Available Control Technology (RACT) on August 3, 2012.  On August 28, 2012 (77 FR 51930), EPA published a final rulemaking notice (FRN) approving the April 12, 2010 SIP revision, as amended on August 3, 2012.  Included in the April 12, 2010 SIP revision as revised August 3, 2012, are the MVEBs for NOx and PM2.5 for the Philadelphia Area. 

The MVEBs are a mobile source inventory to which an area's transportation improvement program (TIP) and long range transportation plan must conform.  Conformity to MVEBs in a SIP means that transportation activities will not produce new air quality violations, worsen existing violations, or delay timely attainment of the NAAQS or any required interim milestones.  This January 31, 2013 SIP revision submittal provides updated MVEBs for NOx and PM2.5.  The budgets were developed utilizing MOVES2010a.  On March 2, 2010 (75 FR 9411), EPA published a notice of availability for the MOVES2010 model for use in SIP submissions and started a two year grace period for the use of MOVES2010 for transportation conformity purposes.  The two year grace period was scheduled to end on March 2, 2012.  On February 27, 2012 (77 FR 11394), EPA published a final rule extending the grace period another year to March 2, 2013 to ensure adequate time for affected parties to adopt the model.  On September 8, 2010, EPA released MOVES2010a, which is a minor update to MOVES2010.  Pennsylvania utilized MOVES2010a in its January 31, 2013 SIP revision.  MOVES2010a was used in order to ensure that the nonattainment area can demonstrate transportation conformity using MOVES2010a once the 3-year conformity grace period expires.  Pennsylvania updated their 2002 base year inventory and 2009 MVEBs that were approved on August 28, 2012 with the use of MOVES2010a.  The budgets were previously developed with the use of the Highway Mobile Source Emission Factor Model (MOBILE6.2).   

MOBILE6.2 is a motor vehicle emissions factor model that was utilized for SIPs and transportation conformity for PM2.5 and course particulate matter (PM10) standards.  MOBILE6.2 was made available for use in SIPs and transportation conformity purposes on May 19, 2004 (69 FR 28830).  MOBILE6.2 was merely an update to MOBILE6 that added the ability for the program to estimate direct exhaust and brake and tire wear particulate matter emission factors as well as exhaust emission factors for particulate matter precursors. 

MOVES2010 improves upon MOBILE6.2 in many aspects.  MOVES2010 utilizes a plethora of vehicle data that has been made available since the release of MOBILE6.2; this vehicle data includes emissions data for different kinds of vehicles.  The new data has allowed EPA to better understand on-road mobile source emissions and their contribution to emissions inventories as well as how effective different control strategies are.  The MOVES2010 model offers more flexibility because the program has a database design that allows easier organization of input and output files and data.  The database design of the MOVES2010 model allows much easier update of input data upon the release of new data.  MOVES2010 also accounts for temperature and speed variations and allows the model to run at a higher resolution which allows for the input of more activity data. 

Under Section 176(c) of the Clean Air Act (CAA), any federal action is required to conform to the applicable SIP.  A part of this requirement for conformity is transportation conformity.  Transportation conformity requires that any federally funded transportation plan, program or project conform to the applicable SIP for the transportation-related criteria pollutants (ozone, carbon monoxide, PM2.5, PM10, and nitrogen dioxide).  The transportation conformity rules can be found at 40 CFR 93, Subpart A.  One of the requirements found under 40 CFR 93, Subpart A is that any transportation plan, TIP or project not in a conforming TIP must conform to the MVEBs in the applicable SIP.  In order for the MVEBs in a SIP to be used to determine conformity of a transportation plan, TIP or project, the MVEBs must be either approved or deemed adequate.  In this case, the budgets must be approved because this SIP revision is revising already approved budgets.  However, in reviewing such a submitted SIP it remains useful to apply the criteria used to make an adequacy finding.  The requirements for adequacy are set forth in 40 CFR 93.118(e)(4)(i)-(vi).  The criteria for adequacy and how they are met by the Pennsylvania submittal are found below in Table 1: Adequacy Criteria. The plan was properly submitted by Pennsylvania, the attainment plan was approved on August 28, 2012 (77 FR  51930), and the MVEBs were clearly and accurately identified and quantified. 

                          Table 1: Adequacy Criteria
                                   Criterion
                                   Submittal

(i) The submitted control strategy implementation plan revision or maintenance plan was endorsed by the Governor (or his or her designee) and was subject to a State public hearing;
   * Letter addressed to Shawn M. Garvin, Regional Administrator, EPA Region III from Michael L. Krancer, Secretary, Pennsylvania DEP
   * Public hearing documents were submitted 

(ii) Before the control strategy implementation plan or maintenance plan was submitted to EPA, consultation among federal, State, and local agencies occurred; full implementation plan documentation was provided to EPA; and EPA's stated concerns, if any, were addressed;
   * N/A, this revision does not accompany a control strategy implementation plan or maintenance plan

(iii) The motor vehicle emissions budget(s) is clearly identified and precisely quantified;
   * Appendix A-2 of the submittal provides detailed emission summary tables

(iv) The motor vehicle emissions budget(s), when considered together with all other emissions sources, is consistent with applicable requirements for reasonable further progress, attainment, or maintenance (whichever is relevant to the given implementation plan submission);
   * Attainment plan for the Philadelphia Area was already approved on August 28, 2012 (77 FR 51930), and this SIP revision shows that there have been no changes to any assumptions utilized in that attainment plan  
   * On May 16, 2012 (77 FR 28782), the Region published an FR notice indicating that the Philadelphia Area attained the 1997 PM2.5 NAAQS by the applicable attainment date of April 5, 2010.  The Philadelphia Area continues to meet the 1997 PM2.5 NAAQS

(v) The motor vehicle emissions budget(s) is consistent with and clearly related to the emissions inventory and the control measures in the submitted control strategy implementation plan revision or maintenance plan; and
   * The SIP revision shows no change in any assumptions utilized in the attainment plan, where the original budgets were submitted.  None of the control measures have changed.

(vi) Revisions to previously submitted control strategy implementation plans or maintenance plans explain and document any changes to previously submitted budgets and control measures; impacts on point and area source emissions; any changes to established safety margins (see § 93.101 for definition); and reasons for the changes (including the basis for any changes related to emission factors or estimates of vehicle miles traveled).
   * Changes in MVEBs are clearly documented and explained in the submittal.  The higher emissions are due to the use of MOVES2010a which is a more accurate emissions model and is based on more recent data on vehicle emissions than MOBILE6.2 

B.  STATE SUBMITTAL:

On January 31, 2013, Pennsylvania DEP submitted a SIP revision which included an update for the MVEBs for PM2.5 and NOx for the year 2009.  On January 31, 2013, Pennsylvania DEP submitted its formal, final SIP revision to update the SIP-approved MVEBs for the Philadelphia Area. The MVEBs were produced using the MOVES2010a model. The MVEBs were developed with guidance from the following EPA guidance documents: Policy Guidance on the Use of MOVES2010 for SIP Development, Transportation Conformity, and Other Purposes and Technical Guidance on the Use of MOVES2010 for Emission Inventory Preparation in State Implementation Plans and Transportation Conformity.  

I.  Methodology for Developing Data for Use in MOVES2010a

Pennsylvania DEP utilized MOVES2010a to provide emissions rates for emissions of PM2.5 as well as for precursor emissions.  The precursors for PM2.5 include volatile organic compounds (VOCs), nitrogen oxides (NOx), sulfur dioxide (SO2) and ammonia (NH3).  PPSUITE is a program that was utilized for the processing of highway information and to provide input files that are usable by the MOVES2010a model.  PPSUITE was run utilizing CENTRAL; CENTRAL is a program that provides a process for the proper function of PPSUITE and MOVES2010a.  The approved attainment demonstration is based on NOx being the only significant PM2.5 precursor from on-road sources; therefore, the attainment demonstration and this SIP revision establish budgets for NOx.  But Pennsylvania provided estimates for other insignificant precursors and carbon monoxide (CO) and PM10 as a courtesy.   

In PPSUITE, the Pennsylvania Department of Transportation (PennDOT) Roadway Management System (RMS) data was utilized for vehicle miles traveled (VMT) estimates.  The data available for the year 2008 was developed with respect to traffic signals.  Additionally, the highway data also included the average annual daily traffic (AADT) which includes vehicle volumes on state roadways; also, to include local roadway VMT, the VMT yielded by PennDOT's RMS was adjusted.  As shown in Table 2: VMT Growth, VMT actually decreased in all of the counties in the PA portion of the Philadelphia area from the 2002 base year to 2008. 

                              Table 2: VMT Growth
Year
Growth from 2002 
Annual Growth Rate from 2002
                                 Bucks County
                                                                           2002
                                                                            N/A
                                                                            N/A
                                                                           2009
                                                                          -2.0%
                                                                          -0.3%
                                Chester County
                                                                           2002
                                                                            N/A
                                                                            N/A
                                                                           2009
                                                                          -3.3%
                                                                           -0.5
                                Delaware County
                                                                           2002
                                                                            N/A
                                                                            N/A
                                                                           2009
                                                                         -1.30%
                                                                         -0.20%
                               Montgomery County
                                                                           2002
                                                                            N/A
                                                                            N/A
                                                                           2009
                                                                         -2.80%
                                                                         -0.40%
                              Philadelphia County
                                                                           2002
                                                                            N/A
                                                                            N/A
                                                                           2009
                                                                         -0.70%
                                                                         -0.10%

Before the VMT data is utilized in MOVES2010a, it is split for seasonal adjustments.  The seasonal factors utilized for data adjustments were obtained from PennDOT's 2002 Pennsylvania Traffic Data report and the 2008 Pennsylvania Traffic Data report.  Both documents were developed by PennDOT's Bureau of Planning and Research (BPR).  Seasonal and daily factors provided by BPR were developed with respect to statistical analyses of 2002 and 2008 traffic counts that were obtained by automatic traffic recorders (ATR) which are located within the pavement and are dispersed throughout roadways in Pennsylvania. 

PPSUITE also estimates hourly speed distributions based on AADT.  The daily RMS volumes are converted to hourly volumes by the use of vehicle pattern data which allows the variations in traffic volumes to be determined with respect to time.  The vehicle pattern data is obtained from PennDOT's 2002 Pennsylvania Traffic Data report and 2008 Pennsylvania Traffic Data report. 

Vehicle population was estimated in several ways.  Registration data for the years 2002 and 2008 was utilized to determine the vehicle population for light duty vehicles and school buses.  The data was then disaggregated by MOVES2010a and sectioned into source types by using population data.  Data from PennDOT and the National Transit Database (NTD) was utilized for the estimation of the transit bus population. The vehicle population of other heavy duty vehicles was estimated by PPSUITE via the analysis of annual VMT for each source type and ratios of VMT for the source type populations that are provided by MOVES2010a.  For the estimation of the 2009 vehicle fleet composition, the 2008 vehicle fleet composition was utilized and projected to 2009 by utilizing the highest growth rate for population and households while limiting the growth assumption such that it did not cause an exceedance of VMT with respect to VMT growth assumptions.  

VMT by source type was also utilized as a data input.  The total VMT was taken apart by MOVES2010a and was then aggregated again into one of the 13 vehicle source types.  The vehicle source type was calculated for each county and functional class via the use of the 2002 and 2008 RMS truck percentages, the 2008 PennDOT and NTD transit data and 2008 school bus registration data.  The remaining VMT distribution was determined via MOVES2010a .  

Each of the vehicle source types were also broken down with respect to the vehicle age distribution for each source type.  The distribution provides different percentages with respect to the age of the vehicle for each vehicle source type.  The 2002 vehicle age distribution was utilized for the 2002 MVEBs, while the 2010 vehicle age distribution was utilized for the 2009 MVEBs since 2010 registration data revealed that the fleet was significantly older than was previously thought.   Data for light duty vehicles was utilized for local inputs.  MOVES2010a default data was utilized for heavy duty vehicles. 

MOVES2010a also includes input parameters for inspection and maintenance (I/M) programs.  The defaults for an I/M program in MOVES2010a were modified to accurately represent the different I/M programs in different counties.  The I/M program for the Philadelphia Area covers the following counties: Bucks, Chester, Delaware, Philadelphia, and Montgomery Counties.  

Fuel supply data was provided by default data in MOVES2010a which was later updated by local volumetric fuel data.  MOVES2010a was utilized for the remaining fuel supply data.  The updated data included utilizing 8.7 Reid Vapor Pressure (RVP) for the summer months, 35% of the market share being conventional gasoline and  68% of the market share being composed of 10% ethanol for the year 2009, as well as the use of conventional gasoline for use throughout 2002.  

The meteorology data utilized included data retrieved from WeatherBank Inc.  MOVES2010a requires daily relative humidity and temperature data for entry into the model for annual analysis of emissions.  The data retrieved from WeatherBank Inc. was converted from minimum and maximum daily temperatures to hourly minimum and maximum hourly temperatures by EPA's data converters. 

Vehicle technology programs are also incorporated into MOVES2010a.  The current federal program incorporated into the model is the National Low Emission Vehicle (NLEV) Program.  The current state program for Pennsylvania incorporated into MOVES2010a is the Pennsylvania Clean Vehicles (PCV) Program.  This program is included in the modeling efforts for all years after 2008.  The PCV Program incorporated by reference the California Low Emission Vehicle Program (CA LEVII), therefore EPA provided input files to represent the CAL LEVII Program to be input into MOVES2010a.

II.  Running MOVES2010a

As stated in Section I, the data utilized to run MOVES2010a is a mixture of local and national data.  Local data is utilized for all inputs that have significant impact on the emissions rates that are calculated by MOVES2010a.  The local data utilized as inputs for MOVES2010a is categorized into five categories which include: traffic data, vehicle descriptions, fuel parameters, I/M programs, and environmental variables. The inputs for traffic data include vehicle type VMT, vehicle population, VMT fractions, road type distributions, and ramp fractions.  The inputs for vehicle descriptions include vehicle type mix, vehicle age distribution, average speeds and hourly distributions of different vehicles.  The inputs for fuel parameters include RVP, sulfur level, ethanol volume and refueling controls.  The inputs for I/M programs include start and model years, the frequency of tests, test standards, source types, stringency of tests, the waiver rate, and compliance rates.  The inputs for environmental variables include hourly temperatures and humidity.  

MOVES2010a inputs that were prepared by PPSUITE included vehicle type VMT, vehicle population, VMT fractions, average speed distributions, road type distribution and ramp fractions.  These files were input into the MOVES2010a county data importer.  Additional non-PPSUITE inputs included fuel and vehicle ages, as well as temperatures and I/M programs.  The county data importer was run in batch mode.  Running the county data importer converts input files into a MYSQL format which is accepted by MOVES2010a.  Afterwards, a MOVES run specification file (.mrs) was created.  This file includes options and different data locations for the execution of the model.  MOVES2010a can be executed to provide an emissions rate or an emissions inventory.  In this submittal, MOVES2010a was executed to provide an emissions inventory.  The emissions estimates of direct PM2.5 and NOx produced for the years 2002 and 2009 are provided in Table 3: Summary of MVEBs. This table also provides the comparison between the 2002 base year inventory and the 2009 MVEBs produced by MOVES2010a and MOBILE6.2.  After reviewing this submittal, EPA concurs with Pennsylvania that even though the emissions results produced by MOVES2010a are greater than those previously calculated using MOBILE6.2.  EPA's review of the SIP revision indicates these higher emissions result from improvements in the MOVES model rather than from unanticipated growth or changes in control measures.  The MOVES results are more accurate estimates of the emissions that actually occurred in 2002 and 2009, rather than an indication that emissions are increasing.  More importantly, the Philadelphia Area attained the 1997 PM2.5 NAAQS in 2009 and continues to attain that NAAQS now with emissions that are being released from all sources.  EPA determined on May 16, 2012 (77 FR 28782), that the Philadelphia Area attained the 1997 PM2.5 NAAQS by the applicable attainment date, April 5, 2010,  in accordance with section 179(c)(2) of the CAA.  The design values for the Philadelphia Area for the years 2007-2009, 2008-2010, and 2009-2011 are as follows: 13.7 micrograms per meter cubed (ug/m[3]), 13.8 ug/m[3], and 13.7 ug/m[3].  All of the design values are under the 1997 PM2.5 NAAQS which is 15 ug/m[3].  Also preliminary 2012 data shows that the Philadelphia Area continues to attain the standard.  Therefore, EPA finds this update to the MVEBs does not interfere with the Philadelphia Area's ability to continue to attain the1997 PM2.5 NAAQS.

                           Table 3: Summary of MVEBs
Model
                                   MOBILE6.2
                                  MOVES2010a
Year
                                                                           2002
                                                                           2009
                                                                           2002
                                                                           2009
PM2.5 (tpy)
                                                                         1032.8
                                                                          699.1
                                                                       2,904.60
                                                                        1,907.5
NOx (tpy)
                                                                       63,475.9
                                                                       36,317.7
                                                                      90,879.00
                                                                       57,218.3

C.  EPA EVALUATION AND CONCLUSION:

EPA thoroughly evaluated the submittal made by Pennsylvania through Pennsylvania DEP.  Our detailed review has led us to conclude that the development methodology of the MVEBs is consistent with applicable guidance documents intended to guide the development of on-road inventories and MVEBs.  We have also reviewed the available air quality data from the Philadelphia area.  The area attained the 1997 PM2.5 NAAQS by the attainment date of April 5, 2010 and continues to attain the 1997 PM2.5 NAAQS now. We also reviewed the MVEBs using the adequacy criteria set forth in 40 CFR 93.118(e)(4)(i)-(vi), and as documented above we found that the budgets meet all of the adequacy criteria.  Based on the results of our in depth review of the SIP revision, the area's continued attainment of the 1997 PM2.5 NAAQS and the results of our review of the MVEBs using the adequacy criteria in the transportation conformity rule, EPA is proposing to approve the SIP revision.