Technical Support Document (TSD) for the Redesignation Request and Maintenance Plan Forthe Baltimore, MD 1997 PM2.s NonattaimnentArea

Submitted May 2013 TSD Prepared July 2014 by Jessica L. Fry Office ofAir Monitoring and Analysis, 3AP40 U.S. Enviromnental ProtectionAgency, Region 3 1650 Arch Street Philadelphia, Pennsylvania 19103

Reviewedby 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 withthe Redesignation Request and Maintenance Plan for the Baltimore, MD 1997 PM2

.sNonattainment Area. This plan was prepared by the Maryland Department ofthe Environment (MDE). The Baltimore Nonattainment Area is comprised ofAnne Arundel, Baltimore, Carroll, Harford, Howard, and Baltimore Counties in Maryland. This review does not determine the approvability ofthe redesignation request ormaintenance 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 thenprojected to show that 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 orvia email at chow.alice@epa.gov. 

### II. Emissions**Inven~ories** 

### for Redesignation Request 2002Base 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 is called the base year inventory and contains primary PM2

.s emissions (including condensibles), S02, NOx, VOC, and NH3. In December, 2012, EPA approved the 2002 emissions inventories submitted by Maryland with the attainment plan for the 1997 annual PM2

.sNAAQS to satisfy the requirements ofsection 172(c)(3) for the Baltimore Area. See (77 FR73313, December10, 2012). 

### III. Emissions Inventories for Maintenance Plan 2007Attainment YearInventory andMaintenance Plan Base YearInventory The inventory used for the year ofattainment is called the attainment year inventory and is also referred to as the maintenance plan base 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 contains primary PM2.s emissions (including condensibles), S02and NOx. MDE submitted VOC and NH3 emissions inthe appendices oftheirplan. This section will discuss the 2007 attainment year inventory that was used in the Baltimore, MD Redesignation Request and Maintenance Plan. For the 2007 attainment year inventory for the point, nonpoint, and nonroad categories, MOE submitted the 2007 Version 3 Emissions Inventory developed through the Mid-Atlantic Regional Air Management Association (MARAMA) regional planning process. Documentation ofthe development ofthe inventory canbe found in Technical SupportDocument for theDevelopment of the 2007Emission Inventory for the RegionalAir QualityModeling in the NortheastIMid-Atlantic Region Version 3.3. January 23, 2012. The 2007 point source inventory contained emissions for electric generating units (EGUs) and Non-EGU sources in the nonattainment area. EPA guidance for emissions inventory development provides that actual emissions should be used for purposes ofthe base year inventory. The point source inventory submitted was developed by MARAMA in consultation withMDE. 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. The 2007 nonroad emissions were generated using EPA'sNational Mobile Inventory Model 2008 (NMIM), which used the NONROAD 2008a emissions model. Marine, air and rail/locomotive (MAR) emissions are not part ofthe NMIM and were calculated separately using the most recent methodologies and inputs. The 2007 onroad mobile source inventory was developed byMichael Baker, Jr., Inc. using EPA'shighway mobile source emissions model MOVES2010a. A mix ofdefault and local data was used to develop the inventory. OAMA staffreviewed the files and the emission results provided by Maryland and found themto be acceptable. 

### III. Projection Emissions Inventories for Maintenance Plan 2017and2025Projection Emission Inventories Projection inventories are usedto showthatthe area will remain in attainment. MDE 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 canbe found in the Technical SupportDocument for the Development of the 2013/201712020Emission Inventoriesfor RegionalAir QualityModeling in the Northeast/Mid-Atlantic Region (MARAMA 2017 TSD) and the Technical SupportDocument for the Development of the 2025 Emission Inventory for PM2.5 Nonattainment Counties in the MANE- VURegion, January 2012 (MARAMA 2025 TSD), respectively. The 2017 and 2025 point source inventories were estimated by using appropriate growth/control factors and applying them to the 2007 inventory. The Department ofEnergy 2011 Annual Energy Outlook growth factors, delineated by region and fuel were used to develop the projected EGU emissions. Non-EGU emissions were developed using employment projections and other state specific emission data.Nonpoint emissions for 2017 and 2025 were also developed by applying the appropriate growth/control factors to the 2007 inventory. Nonroad source emissions for 2017 and 2025 were developed using growth factors from EPA'sNMIM2008 model. The 2007 onroad mobile source inventory was developed by Michael Baker, Jr., Inc. using EPA's highway mobile source emissions model MOVES2010a. A mix ofdefault and local datawas usedto develop the inventory. OAMA staffreviewedthe methodologies providedbyMaryland and found themto be acceptable.