Technical Support Document (TSD) For 

Pennsylvania Portion of the Philadelphia-Wilmington, PA-NJ-DE

PM2.5 Nonattainment Area:

State Implementation Plan (SIP) Attainment Demonstration

and Base Year Inventory

Submitted April 2010 by the Pennsylvania 

Department of Environmental Protection 

TSD Prepared October 2011 by

Alice H. Chow

Office of Air Monitoring and Analysis, 3AP40

U.S. Environmental Protection Agency, Region 3

1650 Arch Street

Philadelphia, Pennsylvania 19103

/s/

____________________________________________

Reviewed by Andrew Hass, Acting Director

Office of Air Monitoring and Analysis (3AP40)

October 11, 2011

_________________

Date Signed

 
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 Pennsylvania Portion of the Philadelphia-Wilmington PM2.5 Nonattainment Area

State Implementation Plan (SIP), by the Pennsylvania Department of Environmental

Protection (PADEP). This review determines the approvability of the SIP Base Year 

Inventory and an evaluation of the methods used. A SIP Base Year Inventory is the 

starting point from which other SIP inventories are derived as well as serving as the 

benchmark for other SIP planning activities, such as the establishment of an emissions 

reduction credit program. On January 5, 2005 the Pennsylvania Portion of the 

Philadelphia-Wilmington area, comprised of Bucks, Chester, Delaware, Montgomery and 

Philadelphia counties, was designated as nonattainment for the PM2.5 NAAQS. Any

questions pertaining to this technical summary should be directed to Andrew Hass, 

Acting Director, Office of Air Monitoring and Analysis, at 215-814-2049 or via email at

hass.andrew@epa.gov. 

II. 2002 SIP Base Year Inventory

The SIP base year inventory is the primary inventory from which other 

inventories (3-year cycle inventories, reasonable further progress inventories, modeling

inventories) are derived. The Clean Air Act calls for State, local, and Tribal agencies to 

ensure that the base year inventory is comprehensive, accurate, and current for all actual 

emissions.1 The base year inventory includes emissions estimates from stationary point 

and nonpoint sources, onroad mobile sources, and nonroad mobile sources. For the PM2.5 

NAAQS, the pollutants to be inventoried are PM10, PM2.5, VOC, NOx, SO2 and NH3. 

For the NAAQS, emissions should be reported as actual annual emissions.

The Point Source data for 2002 is derived from the Air Information Management 

System /environment, Facility, Application, Compliance Tracking System 

(AIMS/eFACTS). The AIMS/eFACTS database is comprised of sources identified and 

inventoried by PADEP’s regional and central offices through permitting, field 

inspections, and surveys. Surveys are conducted annually as facilities must submit 

emission estimates for various operations, throughputs, work hours, as well as process 

data, such as combustion unit data and fuel characteristics. In 2002, PADEP noted that 

many facilities did not include condensable PM in their estimates of direct PM emissions. 

MANE-VU included both filterable and condensable PM estimates for their regional 

modeling efforts.

For the 2002 Nonpoint Source emissions, also known as “area sources,” PADEP 

provided an inventory that contained estimations of emissions by multiplying an emission 

 

1

“Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National Ambient 

Air Quality Standards (NAAQS) and Regional Haze Regulations” EPA-454/R-05-001, August 2005, 

updated November 2005.
factor by some known indicator or activity level for each category at the county level. 

These emissions are typically calculated on an annual basis because the activity data are 

generally only available on an annual basis. Nonpoint source estimates were provided by

SCC.

The Nonroad Mobile Source 2002 inventory was prepared with EPA’s 

NONROAD2005 model. NONROAD estimates fuel consumption and emissions of total 

volatile organic compounds (VOCs), oxides of nitrogen (NOx), carbon monoxide (CO), 

particulate matter (PM10), fine particulate matter (PM2.5) and sulfur dioxide (SO2) for all 

nonroad mobile source categories except for aircraft, locomotives, and commercial 

marine vessels. Revised allocation geographic files for NONROAD2005 model option 

files (average temperature, Reid Vapor Pressure) and revised housing unit data used for 

the model runs (to allocate residential lawn and garden equipment) were also discussed. 

The National Mobile Inventory Model (NMIM) was used to estimate emissions of 

ammonia from sources contained in the NONROAD model. PADEP provided emission 

estimates for locomotive engines and aircraft emissions separately. For locomotive 

engine emissions, PADEP obtained fuel usage from Norfolk Southern and Conrail for 

2002; emissions from all other railroad companies were projected emissions from a 1999 

survey using national fuel consumption information and EPA emission and conversion 

factors. 

Emissions from commercial aircraft and small airport operations for 2002 were 

estimated with the following methodologies: 

Small airports: PADEP used the EPA-approved Emissions and Dispersion 

Modeling System (EDMS) 4.20, the latest version available at the time the 

inventory was developed. PADEP estimated emissions using operations data 

obtained from the United States Department of Transportation, Federal Aviation 

Administration’s (FAA) Terminal Area Forecast for commercial aircraft 

operations. Using this operations data, emissions were modeled directly using the 

EDMS. Finally, Willow Grove Naval Air Station in Bucks County is a significant 

source of NOx but since the terrorist activity in September 2001, the Navy has not 

released any operations data to PADEP, therefore, its emissions were not included 

in the inventory.

Philadelphia International Airport: As part of the City of Philadelphia’s 

commitment to reduce delays at the Philadelphia International Airport (PHL), a 

major long-term project known as the Capacity Enhancement Program (CEP) was 

proposed to redesign runways, taxiways and terminals. This construction project 

would generate a large amount of direct and indirect emissions over time from 

excavation activities as well as less efficient aircraft operations (due to fewer 

runways). PADEP worked closely with the Philadelphia Division of Aviation to 

establish the 2002 base year using historical data and the most accurate operation 

data for emissions sources (aircraft type, arrivals, departures, etc.) for modeling 

with EDMS.

Commercial marine vessels emissions from the Port of Philadelphia were 

estimated using EPA’s “Commercial Marine Activity for Deep Sea Ports in the United 

States, Final Report,” as well as ship arrival information supplied by the Maritime 

Exchange for the Delaware River and Bay. By mutual agreement between Pennsylvania 

and New Jersey, downbound traffic north of the Pennsylvania-Delaware border is 
included in the Pennsylvania inventory and the upbound emissions traffic north of the 

border is in New Jersey’s inventory. In addition, hotelling emissions (emissions from 

auxiliary engines when docked) from larger vessels (tankers, cruise ships, etc.), ferries,

and tugboat emissions are included. All Nonroad mobile source emissions were provided 

by SCC and classification.

The Onroad Mobile Source 2002 emissions inventory was developed using the 

most current version of EPA’s highway mobile source emissions model MOBILE 6.2. 

PADEP also used PPSUITE, an enhanced version of the Post Processor for Air Quality

software systems used for previous inventory submissions in Pennsylvania. The 

Pennsylvania Department of Transportation (PennDOT) provided estimates of vehicle 

miles traveled (VMT) by vehicle type and roadway type. PADEP provided sample 

Mobile6.2 input files and estimate results for review. 

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

them to be approvable.