Technical Support Document (TSD) for the Redesignation Request and Maintenance Plan Forthe Pittsburgh-BeaverValley, PA 2006 PM2

.sNonattainment Area

Submitted December 2014 by the PennsylvaniaDepartment ofEnvironmental Protection
TSD Prepared April 2015 by Jessica

### L. Fry Office ofAirMonitoring and Analysis, 3AP40 U.S. Environmental Protection Agency, Region 3 1650 Arch Street Philadelphia, Pennsylvania 19103

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

### 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 Pittsburgh-Beaver Valley, PA 2006 PM2

.s Nonattainment Area (NAA) bythe Pennsylvania Department ofEnvironmental Protection (PADEP). TheNAA consists ofportions ofAllegheny, Armstrong, Greene, and Lawrence Counties as well as the whole counties ofBeaver, Butler, Washington, and Westmoreland in Pennsylvania. This review does not determine the approvability ofthe redesignation request or maintenance plan. Emissions inventories in a redesignation request are used to show permanent and enforceable emission reductions between the year the area was designated as a nonattainment area and the yearthe 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 thenprojectedto showthat the area will remain in attainment. Any questions pertaining to this technical summary should be directed to Alice H. Chow, Associate Director, Office ofAir Monitoring and Analysis, at 215-814-2144 or viaemail 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 order to do this, the state should estimate the 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.s emissions (including condensibles), S02,NOx, VOC, and NH3 emissions. This section will discuss the 2005 nonattainment year inventory that was used in the PittsburghBeaver Valley Redesignation Request and Maintenance Plan submitted by PADEP.
The NAA contains emissions from Beaver, Butler, Washington, and Westmoreland and the partial counties ofAllegheny, Armstrong, Greene, and Lawrence. PADEP used emissions from EPA's 2005 NEI for their point, nonpoint, and nonroad nonattainment year inventory. To calculate nonpoint and nomoad values for the partial counties included in the NAA, PADEP used county data apportioned by population for Allegheny, Armstrong, Greene, and Lawrence Counties ofwhich98.47%, 3.96%, 4.06%, and 1.15% ofthepopulation, respectively is included intheNAA.
Forthe 2005 omoadinventory PADEP linearly interpolated MOVES 2010 emissions estimates from 2002 and 2007. This was done in order to make a more direct comparison to the 2007 attainment year inventory which also used the MOVES 2010 model. EPA's 2005 NEI onroad emissions were generated usingthe MOBILE 6 model which was subsequently replaced by the MOVES model.OAMA staffreviewedthe files and the emission results provided by PADEP and found themto be acceptable.


### III. Emissions Inventories for Maintenance Plan
2011Attainment YearInventory 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, and NH3 emissions. This sectionwill discuss the 2011 emissions inventory that was used in the Pittsburgh-BeaverValley Redesignation Request and Maintenance Plan in orderto fulfill the 172(c)(3) andthe attainment year emissions inventory requirements.

For the 20II base year inventory for the point, nonpoint, and nonroad categories, PADEP used EPA's 2011 National Emissions Inventory (NEI) V2. Documentation to support the NEI canbe found at http://www.epa.gov/ttn/chief/net/20IIinventory.html.
The 2011 onroad mobile source inventory was developed by PADEP using EPA's highway mobile source emissions model MOVES2010. PADEP used local activity to replace default inputs in the model where appropriate. Detailed road segment data was used to appropriately apportion emissions in the partial counties.
OAMA staffreviewed the files and the emissionresults provided by PADEP and found themto be acceptable.
2017and2025Projection Emission Inventories Projection inventories are usedto showthat the area will remain in attainment. PADEP used 2017 and 2025 emissionprojections developed through the MARAMA regional planning process for the interim and maintenanceplan end year, respectively. Typically projection inventories use the attainment year base year as the basis oftheirprojections, however PADEP used projections previously developed with a 2007 base year inventory. A comparison ofthe 2007 and 2011 year inventories shows that using the 2007 as a base year is a conservative approach, since emissions in 2007 were higherthan 20II emissions. Emissionprojections, emissionmethodologies and growth factors for 2017 and 2025 can be found in the Technical SupportDocument for the Developmentof the 20131 201712020 Emission Inventoriesfor RegionalAir QualityModeling in the Northeast/Mid-Atlantic Region (MARAMA 2017 TSD) and the Technical SupportDocument for the Development of the 2025 Emission Inventoryfor

### PM2.5Nonattainment Counties in the MANE-VURegion, January 2012 (MARAMA 2025 TSD), respectively.
PADEP apportioned the nonpoint and nonroadpartial county emissions in the nonattainment areausing the same methodology as the 2005 and 2007 inventories. Sincethe 2007 base year, the NAAhas 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 A1mual Energy Outlook (AE02011) and applied themto 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 employmentprojections, and other state-specific emissionprojection data. Nonpoint source emissions for 2017 and 2025 were developed similarly to the non-EGU point sources. Emission projections were based on Version 3.3 ofthe 2007 MANE-VU+VA inventory. MARAMA growth factors were developed using AEO fuel consumption forecasts, state-level employmentprojections, and other state-specific emission projection data. PADEP included emissions from the Marcellus Shale drilling activities into the nonpoint source inventory for 2017 and 2025. Forcompressor engines, PADEP used the 2013 Marcellus Shale Inventory submittedby natural gas producers as the basis for theirprojections. For other sources, where 2013 data was not available, PADEP used the 2012 Marcellus Shale Inventory as the basis for projections. Unlike other nonpoint sources in the NAA, PADEP apportioned the Marcellus Shale emissions based on land usage as opposed to population. Thejurisdictions in the NAA partial counties ofArmstrong, Greene, Lawrence and Allegheny account for 10 percent, 3percent, 3percent, and 2 percent 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 datareported inthe Federal Aviation Administration's (FAA's) Terminal Area Forecast (TAF) system for 2009-2030 (FAA2010). Railroad emissions were based on the MARAMA MANE-VU+Va inventory.
The 2017 and 2025 onroadmobile 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 methodologies provided by PADEP and found them to be acceptable.