Technical SupportDocument (TSD) for the Redesignation Request and Maintenance Plan Forthe Johnstown, PA 1997 and 2006 

### PMz.s NonattainmentArea

Submitted December 2014 by the PennsylvaniaDepartment ofEnvironmental Protection

TSD Prepared February 2015 by Jessica L. Fry Office ofAir Monitoring and Analysis, 3AP40 U.S. Environmental ProtectionAgency, Region 3 1650 Arch Street Philadelphia, Pennsylvania 19103

Reviewed by Alice H. Chow, Associate Director Office ofAir Monitoring and Analysis (3AP40)

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### I. Introduction

The purpose ofthis document is to provide a technical summary ofthe Office ofAir Monitoring and Analysis (OAMA) review ofthe emissions inventories submitted with the Redesignation Request and Maintenance Plan for the Johnstown, PA 1997 and 2006 PM2.s NonattainmentArea (NAA) by the Pennsylvania Department ofEnvironmental Protection (PADEP). TheNAA consists ofCambria County and a portion ofIndiana County, Pennsylvania. This review does not determine the approvability ofthe redesignation request or maintenance plan. Emissions inventories in a redesignation request are used to showpermanent and enforceable emission reductions between the year the area was designated as a nonattainment area and the year the area came into attainment. In a maintenance plan, the emissions inventories are used to reflect the emissions during the time the area came into attainment and are then projected to showthat the area will remain in attainment. Any questions pertainingto this technical summary should be direGted to Alice H. Chow, Associate Director, Office ofAir Monitoring and Analysis, at 215-814-2144 or via email at chow.alice@epa.gov.


### II. Emissions Inventories for Redesignation Request
2005Nonattainment YearInventory

In aredesignation request, emissions inventories are used to support the State's claim that the areahas permanent and enforceable emissions reductions. In orderto do this, the state should estimatethe percent reduction (from the year that was used to determine the design value for designation and classification) achieved from federal and state control measures; this is usually termed as the nonattainment orbaseline year inventory. Forthe purpose ofthis plan, the year 2005 was used as the nonattainment year inventory. The 2005 nonattainment year inventory contains primary PM2

.semissions (including condensibles), S02,NOx,VOC, and NH3 emissions. This section will discuss the 2005 nonattainment year inventory that was used in the Johnstown Area, PA Redesignation Request and Maintenance Plan submitted by PADEP.
The NAA contains emissions from Cambria County and a portion oflndiana County that contains West Wheatfield Township, East Wheatfield Township, Center Township, Armagh Borough, and Homer City Borough. PADEP used emissions from EPA's 2005 NEI for their point, nonpoint, and nonroad nonattainment year inventory. To calculate nonpoint and nonroad values for the portion ofIndiana County included in the NAA, PADEP used county data apportioned bypopulation, ofwhich 21.1% ofthe population ofIndiana County is included in theNAA.

Forthe 2005 onroad inventory PADEP linearly interpolated MOVES 2010 emissions estimates from 2002 and 2007. This was done in order to make a more direct comparisonto the 2007 attainmentyear inventory which also used the MOVES 2010 model. EPA's 2005 NEI onroad emissions were generated using the MOBILE 6 model which was subsequently replaced bythe MOVES model.OAMA staffreviewed the files and the emission results provided by PADEP and found them to be acceptable.


### III. Emissions Inventories for Maintenance Plan

2007Attainment Year Inventory andMaintenancePlan Base YearInventory
Under section 172(c)(3) states are required to submit a comprehensive, accurate, current accounting ofactual emissions from all sources (point, nonpoint, nonroad, and onroad) in the nonattainment area. This inventory contains primary PM2.s emissions (including condensibles), S02,NOx, VOC, and NHJ. In a Maintenance Plan, states are required to submit an inventory used for the year ofattainment, which is called the attainment year inventory and can also be referred to as the maintenance planbase year inventory. This inventory is used as the basis for the projected inventories that are used to showthe area will remain in attainment. The base year inventory submitted by PADEP contains primary PM2

.semissions (including condensibles), S02, NOx,VOC, andNH3 emissions

. This section will discuss the 2007 emissions inventory that was used inthe Johnstown Redesignation Request and Maintenance Plan in orderto fulfill the 172(c)(3) and the attainment year emissions inventory requirements.

Forthe 2007 base year inventory for the point, nonpoint, and nonroad categories, PADEP submittedthe 2007 Version 3 Emissions Inventory developed through the Mid-Atlantic Regional AirManagementAssociation (MARAMA) regional planning process. Documentation ofthe development ofthe inventory canbe found in Technical SupportDocument for the Development of the 2007Emission Inventoryfor the RegionalAir QualityModeling in the NortheastIMidAtlanticRegion Version 3.3. January 23, 2012. To calculate nonpoint and nonroad values for the portion oflndiana County included in the NAA, PADEP used county data apportioned by population, ofwhich 21.1% ofthe population ofIndiana County is included in the NAA.

The 2007 point source inventory contained emissions for EGU and non-EGU sources in theNAA. EPA guidance for emissions inventory development provides that actual emissions shouldbe used for purposes ofthebase year inventory. PADEP developed their 2007 inventory by using emissions directly reported by the facilities. The PM emissions for the 2007 point
source inventory were augmented using condensable emission factors developed for MARAMA in 2008. This was done to fill in any missing condensable PM emissions from facilities.
The nonpoint source emissions inventory for 2007 was developed using 2007 specific activity data along with EPA emission factors and the most recently available emission calculation methodologies. PADEP used 2008 NEI data to fill in any missing categories in the 2007 inventory. To calculate values for the portion ofIndiana County included iri the NAA, PADEP used county data apportioned bypopulation.

For 2007 nonroad mobile sources, PADEP generated the emissions using EPA's NMIM2008 model. Since marine, air and rail/locomotive (MAR) emissions are not part ofthe NONROAD model, they were calculated separately outside ofthe NONROAD model. Aircraft emissions were developed using EPA's database to the supportthe 2008 NEI. PADEP used railroad emissions developed by the Eastern Regional Technical Advisory Committee (ERTAC).To calculate values for the portion ofIndiana County included in the NAA, PADEP used county data apportioned by population.
The 2007 onroad mobile source inventory was developed using EPA's highway mobile
source emissions model MOVES2010. PADEP used local activity to replace default inputs in the model where appropriate.

OAMA staffreviewed the files and the emission results provided by PADEP and found them to be acceptable.

2017and2025Projection Emission Inventories Projection inventories are used to showthat the areawill remain in attainment. PADEP used 2017 and 2025 emissionprojections developed through the MARAMA regional planning process for the interim and maintenance plan end year, respectively. Emission projections, emission methodologies and growth factors for 2017 and 2025 can be found in the Technical SupportDocument for the Development of the 

### 20131 201 7/2020 Emission Inventoriesfor RegionalAir QualityModeling in the Northeast /

Mid-Atlantic Region (MARAMA 2017 TSD) andthe Technical SupportDocument for the Development of the 

### 2025 Emission Inventory for PM2

.sNonattainment Counties in the MANE-VURegion, January 

### 2012 (MARAMA 2025 TSD), respectively.

PADEP apportioned the nonpoint and nonroad pa1iial county emissions in Indiana County apportioning (21.1% based on population) using the same methodology as the 2005 and 2007 inventories. Since the 2007 base year, the JohnstownNAA has experienced growth in the oil and gas sector due to Marcellus Shale drilling activity

. This will be discussed in the nonpoint emissions for 2017 and 2025.

ForEGU emissions, PADEP used growth factors based on the Annual Energy Outlook (AE02011) and applied them to the 2007 inventory. Non-EGU emissions projections were based onVersion 3.3 ofthe 2007 MANE-VU+VA inventory. MARAMA growth factors were developed using AEO fuel consumption forecasts, state-level employment projections, and other state-specific emissionprojection data. Nonpoint source emissions for 2017 and 2025 were developed similarly to the non-EGU point sources. Emissionprojections were based on Version 3.3 ofthe 2007 MANE-VU+VA inventory. MARAMA growth factors were developed using AEO fuel consumption forecasts, state-level employment projections, and other state-specific emissionprojection data. PADEP included emissions from the Marcellus Shale drilling activities into the nonpoint source inventory for 2017 and 2025. For compressor engines, PADEP used the 2013 Marcellus Shale Inventory submitted by natural gas producers as the basis for their projections. For other sources, where 2013 data was not available, PADEP used the 2012 Marcellus Shale Inventory as thebasis for projections. Unlike the other nonpoint sources in the NAA, PADEP apportioned the Marcellus Shale emissions based on land usage as opposed to population. Thejurisdictions in Indiana County that are included inthe NAA account for 12% ofthe land area in the county.Nonroad source emissions for 2017 and 2025 were developed using NMIM model runs which contain default assumptions for projected years. Aircraft emissions were projected by applying activity growth data reported in the Federal Aviation Administration's (FAA's) Terminal AreaForecast (TAF) system for 2009-2030 (FAA2010). Railroad emissions were based onthe MARAMA MANE-VU+Va inventory.
The 2017 and 2025 onroad mobile source inventory was developed using EPA's highway mobile source emissions model MOVES2010. PADEP used local activity to replace default inputs inthe model where appropriate

OAMA staffreviewed the methodologies provided by PADEP and found them to be acceptable.