Technical Support Document (TSD) for the 

Redesignation Request and Maintenance Plan 

For the Baltimore, MD 

1997 PM2.s Nonattaimnent Area 

Submitted May 2013 

TSD Prepared July 2014 by 

Jessica L. Fry 

Office of Air Monitoring and Analysis, 3AP40 

U.S. Enviromnental Protection Agency, Region 3 

1650 Arch Street 

Philadelphia, Pennsylvania 19103 

Reviewed by Alice H. Chow, Associate Director 

Office of Air Monitoring and Analysis (3AP40) 
I. Introduction 

The purpose of this document is to provide a technical summary of the Office of Air Monitoring 

and Analysis (OAMA) review of the emissions inventories submitted with the Redesignation 

Request and Maintenance Plan for the Baltimore, MD 1997 PM2.s Nonattainment Area. This 

plan was prepared by the Maryland Department of the Environment (MDE). The Baltimore 

Nonattainment Area is comprised of Anne Arundel, Baltimore, Carroll, Harford, Howard, and 

Baltimore Counties in Maryland. This review does not determine the approvability of the 

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 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 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 of Air Monitoring and Analysis, at 215-814-2144 or via email at 

chow.alice@epa.gov. 

II. Emissions Inven~ories for Redesignation Request 

2002 Base Year Inventory 

Under section 172(c)(3) states are required to submit a comprehensive, accurate, current 

accounting of actual 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.s NAAQS to satisfy the requirements of section 172(c)(3) for the Baltimore 

Area. See (77 FR 73313, December10, 2012). 

III. Emissions Inventories for Maintenance Plan 

2007 Attainment Year Inventory and Maintenance Plan Base Year Inventory 

The inventory used for the year of attainment 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 show the area will remain in attainment. The 

base year inventory contains primary PM2.s emissions (including condensibles), S02 and NOx. 

MDE submitted VOC and NH3 emissions in the appendices of their plan. 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 can be found in Technical Support Document for the 
Development of the 2007 Emission Inventory for the Regional Air Quality Modeling in the 

Northeast I Mid-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 of the 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's National Mobile Inventory 

Model 2008 (NMIM), which used the NONROAD 2008a emissions model. Marine, air and 

rail/locomotive (MAR) emissions are not part of the NMIM and were calculated separately using 

the most recent methodologies and inputs. 

The 2007 onroad mobile source inventory was developed by Michael Baker, Jr., Inc. 

using EPA's highway mobile source emissions model MOVES2010a. A mix of default and 

local data was used to develop the inventory. 

OAMA staff reviewed the files and the emission results provided by Maryland and found 

them to be acceptable. 

III. Projection Emissions Inventories for Maintenance Plan 

2017 and 2025 Projection Emission Inventories 

Projection inventories are used to show that the area will remain in attainment. MDE 

used 2017 and 2025 emission projections 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 

Support Document for the Development of the 2013/201712020 Emission Inventories for 

Regional Air Quality Modeling in the Northeast/Mid-Atlantic Region (MARAMA 2017 TSD) 

and the Technical Support Document for the Development of the 2025 Emission Inventory for 

P M2.5 Nonattainment Counties in the MANE-VU Region, 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 of Energy 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's NMIM2008 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 of default and 

local data was used to develop the inventory. 

OAMA staff reviewed the methodologies provided by Maryland and found them to be 

acceptable.