2008 Attainment Year State Implementation Plan 

Emissions Inventory for PM2.5, SO2 and NOx

New Castle County, Delaware

F I N A L R E P O R T

Submitted to:

U.S. Environmental Protection Agency

Region 3 – Philadelphia, PA

Prepared by:

Department of Natural Resources & Environmental Control

Division of Air Quality

Emission Inventory Development Program

655 S. Bay Road

Dover, DE 19901

October 2, 2012
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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ACKNOWLEDGEMENTS

Collin O’Mara

Secretary, Department of Natural Resources and Environmental Control

Ali Mirzakhalili, P.E.

Director, Division of Air Quality

Ronald A. Amirikian

Program Manager, Air Quality Planning Branch

Project Manager & Editor

David F. Fees, P.E.

Manager, Emission Inventory Development (EID) Program

Principal Contributors (EID Program)

Marian A. Hitch

Senior Environmental Compliance Specialist

John L. Outten

Senior Environmental Scientist

Jeffrey P. Bendelewski

Engineer

Mark A. Prettyman

Senior Environmental Scientist

The EID Program wishes to acknowledge the assistance of the staff of the Engineering and 

Compliance Branch within the Delaware Division of Air Quality for their assistance in review of 

emissions data reported by permitted facilities.
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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TABLE OF CONTENTS

Page

Acknowledgements ................................................................................ ii

List of Tables ......................................................................................... v

List of Figures......................................................................................... vi

Acronyms & Abbreviations ....................................................................... vii

SECTION 1 – OVERVIEW AND SUMMARY

1.1 Project Management ....................................................................... 1-2

1.1.1 Project Manager .............................................................. 1-2

1.1.2 Point Sources Technical Lead ............................................ 1-2

1.1.3 Point Sources Support ..................................................... 1-2

1.1.4 Non-point and Off-road Sources.................................................. 1-2

1.1.5 On-road Mobile Sources ..................................................... 1-3

1.2 Inventory Planning ....................................................................... 1-3

1.2.1 Inventory Parameters .............................................................. 1-3

1.2.2 Data Collection and Management ............................................ 1-4

1.3 Inventory Development .............................................................. 1-4

1.4 Emissions Summary ........................................................................ 1-5

1.5 References ................................................................................. 1-7

SECTION 2 – STATIONARY POINT SOURCES

2.1 Reporting Criteria ........................................................................ 2-1

2.2 Initial List of Facilities ............................................................... 2-2

2.3 Facilities Inventoried ........................................................................ 2-2

2.4 Survey Methods ........................................................................ 2-3

2.4.1 Electronic Reporting ............................................................... 2-4

2.4.2 Activity Data Reporting Forms ............................................. 2-4

2.4.3 Other Methods ............................................................... 2-4

2.5 Data Collection ........................................................................ 2-4

2.5.1 On-line Reporting ............................................................... 2-5

2.5.2 Activity Data Reporting Forms ............................................. 2-7

2.6 Inventory Tracking ........................................................................ 2-7

2.7 Administrative Review ............................................................... 2-8

2.7.1 Administrative Review of On-line Submissions ........................... 2-8

2.7.2 Administrative Review of Activity Data Reporting Forms .................. 2-9

2.8 Reported Data and Estimating Emissions ............................................. 2-9

2.8.1 Emission Estimation Methods ............................................. 2-10

2.9 Technical Review of Submitted Data and Information ........................ 2-11

2.9.1 Facility General ............................................................... 2-12

2.9.2 Group/Point (Emissions Unit) ............................................. 2-12

2.9.3 Process Unit ........................................................................ 2-12

2.9.4 Stack Parameters ............................................................... 2-13
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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TABLE OF CONTENTS – continued

Page

2.9.5 Process Unit Control Equipment ............................................. 2-13

2.9.6 Process Unit Emissions ...................................................... 2-14

2.9.7 A Multi-year Comparison of Facility Level Emissions .................. 2-14

2.10 Technical Review Using Database Queries, Reports and Spreadsheets ......... 2-14

2.11 PM2.5 Augmentation of Facility Reported Emissions.................................... 2-14

2.12 Review of NOx and SO2 Emissions from EGUs and Other Large Sources ......... 2-15

2.13 Methods for Correcting Erroneous Data ............................................. 2-16

2.14 Facility Site and Stack Coordinates ...................................................... 2-16

2.15 Database Management ............................................................... 2-16

2.16 Data Submission to EPA’s Emission Inventory System ........................... 2-17

2.17 Source Sector Discussions ............................................................... 2-17

2.17.1 Hot-mix Asphalt Plants ...................................................... 2-17

2.17.2 Electricity Generating Units ...................................................... 2-18

2.17.3 Emissions by Source Sector ...................................................... 2-19

2.18 Emissions by Facility ........................................................................ 2-19

2.18.1 Sources of PM2.5 Emissions ...................................................... 2-21

2.18.2 Sources of SO2 Emissions ...................................................... 2-22

2.18.3 Sources of NOx Emissions ...................................................... 2-23

2.19 Closed Facilities ........................................................................ 2-23

2.20 References ................................................................................. 2-25

SECTION 3 – STATIONARY NON-POINT SOURCES

3.1 Source Categories ........................................................................ 3-1

3.2 Emission Estimation Methodologies and Activity Data ........................... 3-2

3.3 Emissions Summary ........................................................................ 3-3

SECTION 4 – NON-ROAD MOBILE SOURCES

4.1 Source Categories ........................................................................ 4-1

4.2 Emission Estimation Methodologies ....................................................... 4-1

4.2.1 NONROAD Model Equipment ................................................... 4-2

4.2.2 Aircraft ................................................................................. 4-4

4.2.3 Locomotives ........................................................................... 4-6

4.2.4 Commercial Marine Vessels ...................................................... 4-8

4.3 2008 Emissions Summary ............................................................... 4-14

4.4 References .................................................................................... 4-14

SECTION 5 – ON-ROAD MOBILE SOURCES

5.1 Input Data Specific to New Castle County for 2008 .................................... 5-2

5.1.1 Vehicle Miles Traveled (VMT) Data ................................................... 5-2

5.1.2 Meteorological Data .............................................................................. 5-4
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TABLE OF CONTENTS – continued

Page

5.2.3 Fuel Data ........................................................................ 5-4

5.2.4 Vehicle Populations and Age Distributions .................................... 5-5

5.2.5 Vehicle Speeds ............................................................... 5-5

5.2.6 Northeast Ozone Transport Region Low Emission Vehicle Program ........ 5-6

5.2.7 Inspection and Maintenance (I/M) .............................................. 5-6

5.2 Running the MOVES Model ................................................................ 5-7

5.3 Controls ................................................................................. 5-8

5.4 Results ................................................................................. 5-8

5.5 References ................................................................................. 5-9

LIST OF TABLES

Page

SECTION 1

Table 1-1 2008 Demographic Data for New Castle County ........................... 1-4

Table 1-2 2008 PM2.5, SO2, and NOx Emissions by Source Sector ....................... 1-5

SECTION 2

Table 2-1 Inventory Methods ............................................................... 2-5

Table 2-2 i-STEPS® Emission Estimation Methods .................................... 2-10

Table 2-3 2008 PM2.5 and Precursor Emissions for New Castle County EGUs ......... 2-18

Table 2-4 2008 PM2.5 and Precursor Emissions by Industry Sector ..................... 2-19

Table 2-5 2008 PM2.5 and Precursor Emissions for New Castle County Facilities ..... 2-20

Table 2-6 2008 New Castle County Facility Ranking of PM2.5 Annual Emissions ..... 2-21

Table 2-7 2008 New Castle County Facility Ranking of SO2 Annual Emissions ...... 2-22

Table 2-8 2008 New Castle County Facility Ranking of NOx Annual Emissions ......2-24

Table 2-9 Reporting Facilities That Have Ceased Operations ........................... 2-25

SECTION 3

Table 3-1 Non-point Source Categories Inventoried .................................... 3-1

Table 3-2 Summary of 2008 Non-point Source Activity Data ........................... 3-4

Table 3-3 Summary of 2008 New castle County Emissions from Non-point Sources.. 3-7

SECTION 4

Table 4-1 SCCs Addressed by the NONROAD Model .................................... 4-2

Table 4-2 NONROAD Model Temperature and Fuel Characteristic

Input Values by Season for 2008 .................................... 4-3

Table 4-3 2008 Delaware-specific Geographic Allocation Factors .................. 4-4

Table 4-4 SCCs for Aircraft ............................................................... 4-5

Table 4-5 2008 LTO Data for New Castle County .................................... 4-6

Table 4-6 SCCs for Locomotives ...................................................... 4-7
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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LIST OF TABLES continued

Page

Table 4-7 2008 New Castle County Locomotive Fuel Consumption Data 

for Class I Line Haul Operations .................................... 4-7

Table 4-8 2008 Switchyard Activity and Estimated Fuel Consumption.................. 4-8

Table 4-9 U.S. EPA Marine Engine Category Definitions ........................... 4-8

Table 4-10 SCCs for Commercial Marine Vessels .................................... 4-8

Table 4-11 Waterway Segment Distances for the Delaware River Area .................. 4-10

Table 4-12 Vessel Types Calling on Delaware River Area Ports in 2008 ......... 4-11

Table 4-13 Average Propulsion Engine Power and the 2008 Number of Calls for

OGVs Calling on the Delaware River Area (DE, NJ, and PA) ...... 4-12

Table 4-14 Material Dredged in the New Castle County Portion 

of the Delaware River Area during 2008 ................................. 4-13

Table 4-15 Summary of 2008 New Castle County Emissions 

from Non-road Sources in tons/year .....................................4-14

SECTION 5

Table 5-1 SCC Included in On-road Mobile Inventory .................................... 5-1

Table 5-2 New Castle County VMT Fractions by Road Type ........................... 5-3

Table 5-3 New Castle County VMT Fractions by Vehicle Type .................. 5-3

Table 5-4 Monthly VMT Allocation Fractions ............................................. 5-4

Table 5-5 2008 Gasoline Fuel Parameters for New Castle County .................. 5-5

Table 5-6 2008 Vehicle Populations for New Castle County ........................... 5-5

Table 5-7 2008 Average Speed Matrix ...................................................... 5-6

Table 5-8 LEV Implementation Schedule in the Northeast OTR .................. 5-6

Table 5-9 New Castle County I/M Program Parameters.................................... 5-7

Table 5-10 2008 Annual On-road Mobile Emissions by Vehicle Type

for New Castle County ......................................................... 5-8

LIST OF FIGURES

Page

Figure 1-1 PM2.5 Emissions by Source Sector ................................................... 1-5

Figure 1-2 SO2 Emissions by Source Sector ................................................... 1-6

Figure 1-3 NOx Emissions by Source Sector ................................................... 1-6

Figure 2-1 2008 PM2.5 Annual Emissions by Facility .................................... 2-22

Figure 2-2 2008 SO2 Annual Emissions by Facility .................................... 2-23

Figure 2-3 2008 NOx Annual Emissions by Facility .................................... 2-24

Figure 3-1 200 New Castle County PM2.5 Emissions by Non-point Source Category... 3-4
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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ACRONYMS & ABBREVIATIONS

ACD administrative completeness determination

AERR Air Emissions Reporting Requirements

AMPD Air Markets Program Data (EPA)

AP-42 Compilation of Air Pollution Emission Factors (EPA)

ARP Delaware Accidental Release Prevention Program (DNREC)

ATP Anti-tampering Program

BOC Bureau of Census

C&D Chesapeake and Delaware

CARB California Air Resources Board

CBP County Business Patterns

CD compact disk

CDM county data manager

CDX central data exchange

CE control efficiency

CEM continuous emission monitor

CERS consolidated emissions reporting schema

CFR Code of Federal Register

CMV commercial marine vessel

CNG compressed natural gas

CO carbon monoxide

CROMERR Cross-media Electronic Reporting Rule

DAQ Delaware Division of Air Quality

DE Delaware

DE ANG Delaware Air National Guard

DE ARNG Delaware Army National Guard

DE DOL Delaware Department of Labor

DelDOT Delaware Department of Transportation

DMV Delaware Division of Motor Vehicles (DelDOT)

DNREC Department of Natural Resources and Environmental Control

DOE U.S. Department of Energy

DPC Delaware Population Consortium

DRBA Delaware River and Bay Authority

DSWC Division of Soil and Water Conservation (DNREC)

DVD digital video disk

DWT dead weight tonnage

E&C Engineering and Compliance Branch (DNREC-DAQ)

EDMS Emissions and Dispersion Modeling System (FAA)

EF emission factor

EGU electric generating unit

EIA Energy Information Administration (DOE)

EID Delaware Emission Inventory Development Program (DNREC-DAQ)

EIIP Emission Inventory Improvement Program

EIS Emission Inventory System

EPA U.S. Environmental Protection Agency
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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ACRONYMS & ABBREVIATIONS continued

ERTAC Eastern Regional Technical Advisory Committee

FAA Federal Aviation Administration

FHWA Federal Highway Administration

FIRE Factor Information Retrieval System

FP & GC fuel pressure and gas cap test

GAF geographic allocation factor

GHG greenhouse gas

GIS geographic information system

GSE ground support equipment

GTM gross ton-miles

GVWR gross vehicle weight rating

HAP hazardous air pollutant

hp horsepower

HPMS Highway Performance Monitoring System

IFO intermediate fuel oil

I/M Inspection and Maintenance

LEV low-emission vehicle

LPG liquefied petroleum gas

LTO landing/takeoff

MARAMA Mid-Atlantic Regional Air Management Association

MC method code (i-STEPS)

MMBtu million British thermal units

MOVES motor vehicle emission simulator

mph miles per hour

MY model year

NAAQS National Ambient Air Quality Standard

NAICS North American Industry Classification System

NCC New Castle County (Delaware)

NCDC National Climatic Data Center

NEI National Emissions Inventory

NH3 ammonia

NLEV national low emission vehicle

NOx oxides of nitrogen

OBD on-board diagnostics

OGV ocean-going vessel

OIT Office of Information Technology (DNREC)

OTR Ozone Transport Region

pdf portable document format

PEI Periodic Emissions Inventory

PM-CON condensable particulate matter

PM10-FIL filterable portion of PM10-PRI

PM2.5-FIL filterable portion of PM2.5-PRI

PM2.5-PRI particles with an aerodynamic diameter less than or equal to a nominal 

2.5 micrometers
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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ACRONYMS & ABBREVIATIONS continued

PM10-PRI particles with an aerodynamic diameter less than or equal to a nominal 

10 micrometers

ppm parts per million

POW Port of Wilmington

psi pounds per square inch

QA quality assurance

QC quality control

R&D research and development

RE rule effectiveness

RP rule penetration

rpm revolutions per minute

RSZ reduced speed zone

RVP Reid vapor pressure

SARA Superfund Amendments and Reauthorization Act

SCC source classification code

SEPTA Southeast Pennsylvania Transportation Authority

SIP State Implementation Plan 

SO2 sulfur dioxide

SQL structured query language

TIM time-in-mode

TPY tons per year

TRI Toxics Release Inventory

TV Title V permit classification

US United States

USACE U.S. Army Corps of Engineers

VMT vehicle miles traveled

VOC volatile organic compound

XML extensible markup language
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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SECTION 1

2008 PM2.5, SO2, AND NOX INVENTORY OVERVIEW AND SUMMARY

In 2006, the U.S. Environmental Protection Agency (EPA) promulgated a new 24-hour National 

Ambient Air Quality Standard (NAAQS) for particulate matter with an aerodynamic diameter 

less than or equal to a nominal 2.5 micrometers (PM2.5). Particles of this size are known as fine 

particulate matter. EPA established the standard at 35 μg/m3

. The previous 24-hour standard 

established by EPA in 1997 was set at 65 μg/m3.

New Castle County was designated non-attainment for the daily PM2.5 standard based on 2006-

2008 monitoring data. The 35 μg/m3 24-hour standard went into effect on December 14, 2009, 

following final non-attainment area boundary designations (EPA, 2009). New Castle County was 

included in the Philadelphia-Wilmington, PA-NJ-DE non-attainment area with an attainment 

date of December 14, 2012.

Particulate matter emitted from sources is known as primary particulate emissions. Primary 

emissions include filterable (PMx-FIL) and condensable (PM-CON) material. Filterable matter 

can be designated as PM-FIL, PM10-FIL, or PM2.5-FIL depending on particle size cut points. 

PM-CON is always considered smaller than 2.5 micrometers in diameter. The combination of 

PMx-FIL and PM-CON is known as primary particulate matter, or PMx-PRI. Throughout this 

report, the use of PM2.5 refers to primary fine particulate emissions. Particulate matter is also 

formed in the atmosphere through reactions that form sulfates and nitrates. These emissions are 

considered secondary emissions of particulate matter. Sulfur dioxide (SO2) and oxides of 

nitrogen (NOx) contribute to the formation of secondary PM emissions.

The Division of Air Quality (DAQ), within the Delaware Department of Natural Resources and 

Environmental Control (DNREC) established calendar year 2007 as the base year inventory for 

the 24-hour PM2.5 because (1) 2007 coincides with the three years of ambient monitoring data 

used to designate New Castle County as part of the Philadelphia non-attainment area, and (2) a 

2007 regional inventory had already been prepared for modeling and State Implementation Plan 

(SIP) purposes. This regional inventory, for which Delaware supplied Delaware-specific data for 

all source sectors, has undergone extensive quality assurance. Details of how the inventory was 

developed can be found in the regional report, Technical Support Document for the Development 

of the 2007 Emission Inventory for Regional Air Quality Modeling in the Northeast/Mid-Atlantic 

Region (MARAMA, 2007).

The DAQ established calendar year 2008 as the attainment year inventory for the 24-hour PM2.5 

because (1) 2008 coincides with the three years of ambient monitoring data used to demonstrate 

that New Castle County now attains the 24-hour PM2.5 standard, and (2) 2008 represents a 

Periodic Emissions Inventory (PEI) reporting year, for which Delaware has prepared a SIP 

quality inventory based on Delaware-specific data for all sources of criteria pollutants to include

PM2.5 emissions and emissions of NOx and SO2 as precursors to PM2.5. 

This report documents Delaware’s completed 2008 inventory of PM2.5 SO2, and NOx for New 

Castle County for all sources including the following four major source sectors: stationary point, 

stationary non-point, on-road mobile, and off-road mobile.
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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1.1 Project Management

The Emission Inventory Development (EID) Program within the Planning Branch of DAQ was 

responsible for preparing the 2008 PEI for criteria pollutants to include emissions PM2.5, SO2, 

and NOx summarized in this report. Internal planning began in September 2008, with focus on 

the 2008 point source inventory reporting cycle taking place in March/April of 2009. 

1.1.1 Project Manager

The overall project manager was David Fees, Managing Engineer for the EID Program. 

Responsibilities included identifying overall inventory goals, objectives, and deadlines, initiating 

inventory planning, approving estimation methodologies recommended by staff, reviewing 

emissions development work, and preparing inventory reports and documentation.

1.1.2 Point Sources Technical Lead

The point source technical planning and review was performed by John Outten, a senior

environmental scientist for the EID Program. Responsibilities included:

• Identifying point source inventory goals, objectives, and deadlines;

• Establishing the universe of facilities to inventory;

• Overseeing the development of the survey forms and instructions;

• Providing training and guidance to industry representatives;

• Setting up the on-line electronic reporting system and working with DNREC’s Office of 

Information Technology in preparing the on-line reporting capabilities;

• Performing a technical review of emissions data submitted by facilities;

• Working with facility representatives to correct errors;

• Managing the point source inventory database; and

• Overseeing quality control of point sources data.

1.1.3 Point Sources Support

Support of the point source inventory was performed by Marian Hitch, a senior environmental 

compliance specialist for the EID Program. Responsibilities included:

• Gathering facility general information on facilities to be surveyed;

• Assisting in developing survey forms and instructions;

• Preparing and mailing reporting packages;

• Receiving and organizing reports submitted by facilities;

• Performing an administrative review of all reports received;

• Tracking reporting status of each facility; and

• Preparing and organizing documentation for the point source inventory.

1.1.4 Non-point and Off-road Sources

Emission estimates of the many non-point and off-road source categories were prepared jointly 

by Jeffrey Bendelewski, an engineer for the EID program, and Mark Prettyman, a senior 

environmental scientist for the Planning Branch of DAQ. Their responsibilities included:
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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• Researching and recommending emission estimation methodologies;

• Defining all simplifying assumptions;

• Obtaining 2008 activity data, current emission factors, and applicable control information

• Using spreadsheets to calculate emissions;

• Downloading and using the EDMS model for developing aircraft emissions;

• Downloading and using the NONROAD model;

• Reviewing emission calculations for accuracy and completeness;

• Preparing report documents; and

• Compiling supporting documentation.

1.1.5 On-road Mobile Sources

Emission estimates of on-road mobile sources were prepared by John Outten, a senior

environmental scientist for the EID program. Responsibilities included:

• Downloading the MOVES model;

• Obtaining 2008 vehicle miles traveled (VMT), vehicle registration, and other mobile 

input data from the Delaware Department of Transportation;

• Obtaining other data for inclusion in the model inputs;

• Preparing the input files for running MOVES;

• Running MOVES and summarizing the model outputs;

• Reviewing emissions for accuracy and completeness;

• Preparing report documents; and

• Compiling supporting documentation.

1.2 Inventory Planning

Calendar year 2008 is a Periodic Emissions Inventory (PEI) year as defined by the Air Emissions 

Reporting Requirements (AERR) (EPA, 2008). The AERR specifies the emissions data for 

criteria pollutants that are required to be reported to EPA’s National Emission Inventory (NEI). 

A PEI requires the development of emission estimates from all sources within a state or local 

area for all criteria pollutants and their precursors. As such, the 2008 inventory can provide the 

necessary data for the PM2.5 24-hour NAAQS attainment year inventory. While not required, the 

DAQ also prepared 2008 emission estimates of air toxics and greenhouse gases from all sources.

1.2.1 Inventory Parameters

The inventory parameters defined by the 2008 PM2.5 Attainment Year SIP inventory include the 

following:

• Inventory year – 2008;

• Pollutants – PM2.5, and SO2 and NOx as precursors to PM2.5 (DNREC, 2012a);

• Source coverage – all sources, including point, non-point, mobile, and non-road sources;

• Spatial resolution – county level emissions;

• Geographic coverage –New Castle County; and

• Temporal resolution – annual emissions (DNREC, 2012b). 
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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1.2.2 Data Collection and Management

For all source categories the gathering of local activity data represented a major task spread over 

many months. For point sources, most facilities reported their emissions through the use of an 

on-line reporting system. Data entered into the on-line system were transferred to the DAQ iSTEPS® database for review and correction. 

Microsoft Excel spreadsheets were employed for managing activity data and calculating 

emissions from stationary non-point sources and some non-road categories. A consistent set of 

tabs within each source category spreadsheet included activity data, point source data (if 

applicable, for backouts), emission factors, controls, emission calculations, National Emission 

Inventory (NEI) input formats, and notes on QA/QC procedures. 

On-road mobile source emissions were calculated using the MOVES2010a model. Emissions for 

most of the non-road vehicles and equipment categories were calculated using the 

NONROAD2008a model. 

Emissions data were transferred from i-STEPS® (point sources), from the non-point and nonroad spreadsheets, and from the model outputs to staging tables in Microsoft Access databases. 

These databases were then converted to XML files via the EIS bridge tool, and then transmitted 

to the EIS via CDX web client by June 1, 2010 to meet the reporting requirements of the AERR.

1.3 Inventory Development

For point sources, the EID Program developed a set of criteria to use in establishing the universe 

of facilities required to report. These criteria are presented in detail in the point source section of 

this report. Reporting packages were sent to each facility meeting one or more of the reporting 

criteria. An extensive amount of review and follow up was performed on the point source data 

submitted by facilities. 

For non-point sources, the first main task involved gathering activity data for each source 

category. In many cases, these data were obtained from Delaware-specific sources. In some cases 

the activity data were developed through the allocation of a portion of a national activity dataset 

(i.e., national off-road equipment populations) to Delaware. Basic demographic data were also 

used for some source categories and are presented in Table 1-1. Once activity data were 

obtained, spreadsheets were developed to manage the data and combine the activity data with the 

selected emission factors to obtain uncontrolled emissions. Finally, for those sources where 

controls applied, emissions were adjusted to account for control efficiency, rule effectiveness, 

and rule penetration.

Table 1-1. 2008 Demographic Data for New Castle County

Demographic Parameter New Castle

Populationa 528,536

Householdsa 204,630

Land Area (square miles) 439

Annual VMT (million miles)b 5,273

 a DPC, 2009; b DelDOT, 2009.
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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For on-road mobile and off-road equipment, the MOVES and NONROAD models, respectively,

were used to develop emissions from these sources. In the use of these models, activity data were 

included in the model input files. For any type of data used by the model for which Delawarespecific data did not exist, the model used the system defaults. Details about Delaware-specific 

and default parameters are discussed in the on-road and non-road sections. The models account 

for controls, some of which reflect controls specific to Delaware.

1.4 Emissions Summary

The following emission summaries present the entire 2008 emission inventory for PM2.5, SO2, 

and NOx, for New Castle County broken down by source sector. Throughout this document, 

annual emissions are reported in tons per year (TPY). The totals may not match the sum of the 

individual values due to independent rounding.

Table 1-2. 2008 PM2.5, SO2, and NOx Emissions by Source Sector

Source 

Sector

Annual Emissions (TPY)

PM2.5 SO2 NOx

Point 1,109 10,576 5,589

Non-point 1,191 402 1,287

Non-road 312 1,067 4,317

On-road 282 94 9,311

All Sectors 2,894 12,139 20,504

Point

38%

Non-point

41%

On-road

10%

Non-road

11%

Figure 1-1. PM2.5 Emissions by Source Sector
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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Point

87%

Non-point

3%

On-road

1%

Non-road

9%

Figure 1-2. SO2 Emissions by Source Sector

Point

27%

Non-point

On-road 6%

46%

Non-road

21%

Figure 1-3. NOx Emissions by Source Sector
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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1.5 References

DPC, 2009. Delaware Population Consortium Annual Population Projections, downloaded from 

http://stateplanning.delaware.gov/information/dpc_projections.shtml, October 31, 2009.

DELDOT, 2009. 2008 Estimated VMT by County, by Functional Class, by Rural/Urban 

Designation, accessed DelDOT website July 10, 2009, per June 29, 2009 e-mail from 

Mike DuRoss, DelDOT Planning.

DNREC, 2012a.“Delaware Redesignation Request and Maintenance Plan Under the 2006 Daily 

PM2.5 National Ambient Air Quality Standard”, Section 7.2.1, Delaware Department of 

Natural Resources and Environmental Control, Division of Air Quality, September 2012.

DNREC, 2012b.“Delaware Redesignation Request and Maintenance Plan Under the 2006 Daily 

PM2.5 National Ambient Air Quality Standard”, Section 4.1, Delaware Department of 

Natural Resources and Environmental Control, Division of Air Quality, September 2012.

EPA, 2008. Final Rule: “Air Emission Reporting Requirements”, Federal Register – Vol. 73 No. 

243 page 76539, December 17, 2008.

EPA, 2009. Final Rule: “Air Quality Designations for the 2006 24-Hour Fine Particle (PM2.5)

National Ambient Air Quality Standards”, Federal Register – Vol. 74 No. 218 page 58688, 

November 13, 2009.
2-1

2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

SECTION 2

STATIONARY POINT SOURCES

The point source inventory represents facility-specific data for larger stationary sources.

Emissions data for all other source categories are reported at the county level. Point sources 

typically include large industrial, commercial and institutional facilities. Industrial manufacturing 

facilities comprise the majority of all reporting point sources. The institutional sector includes

hospitals, universities, prisons, military bases, landfills, and wastewater treatment plants. 

Unlike other source sector emissions which are estimated by DAQ, point source emissions data 

are submitted to DAQ by the facilities. Emissions are reported at the process level and include 

both confined (stack) emission points as well as unconfined (fugitive) emission sources. A key 

aspect of point source data is the inclusion of facility coordinates to accurately allocate emissions 

spatially within a county for purposes of performing air dispersion modeling.

The planning and execution of the point source inventory was accomplished in the following 

chronological order:

• Define the purpose of the inventory (defined in Section 1 of this report);

• Establish the reporting criteria and list of facilities to survey;

• Obtain inventory data from facilities;

• Perform administrative and technical review of data received from facilities;

• Seek resubmissions/corrections from facilities based on data review;

• Perform internal data augmentation (for PM2.5); and

• Prepare inventory data files, report, and supporting documentation.

Quality control/assurance is not listed in the chronology above since these activities were 

performed throughout the point source inventory development process. Quality control/assurance 

efforts are presented throughout this section. 

Since there may be overlap between point sources and stationary non-point source categories, 

one final activity required of the point source inventory staff is to provide point source back out 

data where appropriate. Point source back out data includes emissions, throughput, or employees, 

depending on the non-point source category methodology. 

2.1 Reporting Criteria

Based on the several purposes of the 2008 inventory (Ozone PEI, PM2.5 PEI, HAPs and GHG 

inventories, as well as the daily PM2.5 Attainment Year SIP inventory) the following criteria were 

established for defining the universe of facilities to be surveyed: 

• Facilities that held a Title V permit in 2008;

• Any facility falling into one of the following industry sectors;

o Hot-mix asphalt plants,
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

o Electric generating units (EGUs); 

o Facilities using anhydrous ammonia as a refrigerant; and

o Chrome plating operations;

• Any facility with emissions greater than 5 TPY for VOCs or 25 TPY for NOx in 2006 

or 2007, as previously reported to the DAQ inventory program; and

• Any facility that may be a significant source of emissions but for which DAQ does not 

have previous inventory data, or otherwise of particular interest.

2.2 Initial List of Facilities 

Once the reporting criteria were established, DAQ point source inventory staff compiled an 

initial list of facilities to be compared against the reporting criteria. All 133 facilities reporting 

statewide for the 2005 Periodic Emissions Inventory (PEI) were included in the initial list. All 

Title V (TV) permitted facilities are required to report emissions each year. The Engineering and 

Compliance Branch of DAQ provided a list of TV facilities as of the end of 2008, which 

contained one facility that had not reported for 2005.

The following additional data sources were reviewed to identify facilities that might have met 

one or more of the reporting criteria:

• Toxics Release Inventory (TRI, SARA 313) – 2006 and 2007 data;

• Hazardous Chemical Inventory (Tier II, SARA 312) – 2007 data;

• Accidental Release Prevention (ARP) Program facility list.

DAQ inventory staff reviewed the two most recent years of TRI data, and found that all facilities 

within TRI with more than five tons per year air releases of VOC compounds were already 

included in the initial list. The Tier II data and information from the ARP Program were 

reviewed mainly to identify facilities that used anhydrous ammonia; however, no additional 

facilities were added to the initial list as a result of this review.

Through a review of permit and compliance information, and conversations with the permitting 

group, one new asphalt plant and six other facilities of interest were added to the initial list. The

six facilities of interest were either new facilities needing baseline data, or facilities not recently 

inventoried, but nonetheless with the potential of having significant PM emissions.

The complete initial list included 142 facilities statewide. A spreadsheet was developed by DAQ 

point source staff containing a record of every facility included on the initial list of facilities. The 

spreadsheet includes the reason the facility was placed on the initial list. For facilities that were 

inventoried, the spreadsheet indicates which reporting criteria were met.

2.3 Facilities Inventoried

The facilities on the initial list were evaluated using the reporting criteria established in Section 

2.1. TV facilities are required to report regardless of the amount of emissions. Therefore, all 65 

TV facilities were included in the final list of point sources. The remaining 77 of the 142
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

facilities were evaluated against the other reporting criteria. As a result, 20 facilities were 

dropped from further consideration since no criterion was met.

Four facilities were identified as being closed prior to calendar year 2008. They were City of 

Lewes EGUs, Industraplate, Spatz Fiberglass and Tilcon-Horsepond Road. Prior to 2008, permits 

for the City of Seaford’s six EGUs had been modified to allow these units to operate only as 

emergency generators as defined by Delaware Regulation 1144 (DNREC, 2006). Therefore, this 

facility is no longer included in the point source inventory. One facility, Tilcon-Terminal 

Avenue, did not operate in 2008, and has since closed permanently.

Three facilities closed during 2008. Attempts were made to contact the companies. In phone 

conversations with Perma-Flex Rollers and PTFE Compounds, it was determined both facilities 

did not meet any of the reporting criteria for 2008. PTFE had closed after having minimal 

operations for the first six months of 2008. In July 2008 the facility moved their operations to 

New Jersey. The Perma-Flex Rollers site was used primarily for storage and warehousing and 

had little or no production during 2008. The third facility that closed in 2008, Pepsi Cola Bottling 

Company, used ammonia refrigeration, which would require reporting; however DAQ was 

unable to obtain any information related to potential ammonia emissions.

Through a review of emissions data from 2006 and 2007, recently reported TRI air emissions,

and inspection reports, eight facilities were determined to not meet either the VOC or NOx

emission thresholds, and thus were not included in the list of facilities to be inventoried.

Two facilities (the Port of Wilmington and VFL Technologies) that were added to the initial list 

as facilities of interest were not inventoried due to staff resources. DAQ staff did spend 

considerable time working with the Port of Wilmington to establish a set of stationary and 

mobile emission units, but due to time constraints, an inventory was not completed by the site.

Due to limited resources VFL Technologies was not contacted and did not submit an emissions 

inventory. VFL closed in 2010.

Finally, in 2007 SPI Polyols was sold to Croda-Uniqema, an adjacent and contiguous Synthetic 

Minor permitted facility. Starting with 2008, processes and emissions previously associated with 

SPI Polyols were reported by Croda.

The final list included 122 facilities inventoried statewide. Of these, 58 facilities in New Castle 

County reported emissions of particulate matter and/or particulate precursors (SO2, and NOx) and 

are included in the 2008 PM2.5 Attainment Year SIP inventory.

2.4 Survey Methods

In December 2008, the DAQ point source inventory staff began reviewing survey methods and 

preparing reporting packages to be e-mailed to each facility to be inventoried. DAQ used two 

primary methods to gather information from most facilities for the 2008 inventory. Facilities 

either used an on-line reporting system or submitted activity data reporting forms by e-mail or 

facsimile. These two methods are described in detail below.
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

2.4.1 Electronic Reporting

DAQ offers electronic reporting of emissions data through the Internet. For the 2008 reporting 

cycle, the Terminal Server Satellite i-STEPS application was updated with the latest FIRE and 

AP-42 emission factors. Satellite i-STEPS is capable of calculating emissions based on 

information supplied on process throughput, operating schedule, and controls. A database 

specific to each facility was generated based on previously submitted inventories and other 

information (i.e., permitting files). Information expected to remain the same from year to year 

was pre-populated in the database, while throughput and emissions data were zeroed out. 

Facilities were expected to update pre-populated information as necessary and enter 2008 data 

for fields that were zeroed out. 

2.4.2 Activity Data Reporting Forms

Instead of requiring on-line reporting for all facilities, DAQ provides smaller facilities with the 

option of completing fillable electronic activity data reporting forms that are e-mailed to the 

facility that can be e-mailed back to DAQ once completed. DAQ used these forms for 2008 to 

simplify the reporting process. The activity data supplied by facilities (i.e. operating schedule, 

monthly throughputs), were used by DAQ staff to calculate emissions based on EPA’s FIRE 

emission factors or material balance methodologies.

Activity data reporting forms applicable to the 2008 Attainment Year SIP inventory were 

developed for the following processes:

• Boilers;

• Stationary diesel engines; and

• Hot-mix asphalt production.

For facilities that used the activity data forms, DAQ already had detailed process and stack 

information on file.

2.4.3 Other Methods

In a limited number of cases where on-line reporting or the use of the activity data forms was not 

appropriate or useful, information was obtained from facilities via telephone, e-mail or facsimile.

Regardless of the survey methods used to obtain data from facilities, all data were entered into 

one database within i-STEPS.

2.5 Data Collection

Reporting packages were sent out in January and February 2009 to facilities identified as meeting 

one or more of the established reporting criteria. 

Table 2.1 provides the number of facilities inventoried by each survey method. 
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

Table 2-1. Inventory Methods 

Inventory Method Used

Number of 

Facilities

On-line reporting 71

Activity data report forms 48

Other methods 3

2.5.1 On-line Reporting

Terminal Server Satellite i-STEPS software reporting packages were e-mailed to 71 facilities

between February 10 and February 18, 2009. The reporting package contained a cover letter, 

instructions, and an Optical Media Certification Form. Two facilities (Micropore and CPI 

Packaging) that received reporting packages for on-line submissions were subsequently handled 

directly through e-mail and facsimile.

The instructions contained information on how to access the Terminal Server Satellite i-STEPS, 

user initials and passwords, DAQ contact information, information specific to the 2008

inventory, and a DAQ web page address where additional inventory documents were available. 

These documents included:

• Emission Inventory Definitions and Structure 

• Common Errors 

• Useful Web Pages 

• Uncontrolled Coal PMx Factors or Formula 

• Calculating PM10 and PM2.5 Emissions for #4, #5 and #6 Fuel Oils Using EPA FIRE 6.24 

Formulas 

• Regulated Pollutants 

• Web FIRE (Factor Information Retrieval System) 

• TANKS Software (EPA, 2005a)

• Emissions Factors / AP 42 

A database was customized for each facility based on the process structure previously established 

for the facility. For new facilities using Satellite i-STEPS, the reporting structure was created by 

DAQ point source inventory staff with input from the facility. The database was pre-populated 

with general information about the facility, as well as a few other data elements not expected to 

change from year to year, such as stack parameters and design capacity. Other data elements were 

left blank or zeroed out, such as annual process rate, percent sulfur and ash of fuel burned,

operating schedule, throughputs, capture and control efficiencies, and emission estimates.

Generally, it was the large, complex facilities with multiple processes that reported on-line. For 

facility representatives new to emissions inventory reporting or who had not reported in some 

time, DAQ inventory staff worked with them to understand the inventory structure. Assistance by 

phone or e-mail in completing the inventory was offered on an on-going basis for many facilities. 

Terminal Server Satellite i-STEPS® on-line reporting allowed point source inventory staff to 

work with a facility simultaneously on-line to resolve any issues a facility may have encountered.
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

The inventory information requested from facilities for the 2008 inventory is described in several 

EPA publications including Emission Inventory Requirements for Ozone State Implementation 

Plans and Emissions Inventory Guidance (EPA, 1991a) and Emissions Inventory Improvement 

Program (EIIP), Volume II (EPA, 1997). All emissions were reported at the process level.

Facilities were required to provide emission calculations and documentation in the Notes window

within Terminal Server Satellite i-STEPS or in writing when submitting their certified 

emissions.

Terminal Server Satellite i-STEPS® has built-in system checks for out of range values as well as 

relational errors. Field specific data entry checks were performed by the software at the time the 

data were entered or when an attempt was made to save the data. The system prompted the user 

to make the needed corrections. In most cases a record could not be saved until all edit checks 

were satisfied. System functions and checks include:

• Data can be entered through the use of look-up tables;

• Data entered directly must match information in the look-up table;

• Total percent quarterly throughputs must be between 95 and 101; 

• Alpha-numeric checks;

• Enforced relational database integrity;

• Mandatory field alerts;

• Stack assignment check (each process must have an assigned stack); and

• Automated emissions calculations.

Once a facility completed entering its data and information, the user had the ability to run the 

following reports:

• Group level emissions (facility summary);

• Process unit level emissions summary; and

• Detailed report (contains all entered and calculated data). 

Facilities used the three reports to verify data they entered and the emissions reported and/or 

calculated by the Terminal Server Satellite i-STEPS. Reports could be displayed to the screen or

created as an Adobe Acrobat pdf file which is then automatically e-mailed to the user. 

The process summary report provided emissions of each criteria pollutant for each process within 

an emissions unit. The detailed report lists the data following the Terminal Server Satellite iSTEPS structure and contains all information that the facility entered as well as information the 

system used to organize the inventory information or calculate emissions.

The facility summary report tabulates criteria pollutant emissions for each emission unit with a

facility total at the bottom. This report also served as the emission certification page and thus 

contains a signature area for the “Responsible Official”. When DAQ received a signed copy of 

this report, indicating the facility had completed the reporting process, DAQ set the Terminal 

Server Satellite i-STEPS to read-only for the facility.
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

EPA’s Cross-Media Electronic Reporting Rule (CROMERR), applies to states that choose to 

receive reports and documents from facilities through the Internet. The requirements of the rule 

provide for electronic reporting under authorized state and local government programs, apply to 

the governmental entities administering the authorized programs, and to facilities that submit 

data through the Internet to those governmental entities. If on-line reporting is offered by the 

state, an EPA-approved electronic signature process must be in place. Alternatively, on-line 

reporting can be followed up by the submission of a certified document (on diskette, compact 

disk (CD), digital video disk (DVD), facsimile, or paper report) containing the same information 

that was submitted on-line. 

Currently, the DAQ on-line reporting system does not have an approved electronic signature 

system. Therefore, DAQ is required to receive from reporting facilities a certified document in 

addition to the data submitted on-line. DAQ has created a detailed report that can be easily 

created in pdf format for use by a facility as the certified document of their on-line submission. 

The pdf file can be burned to a CD or DVD and sent to DAQ to meet the CROMERR 

requirements. A signed Optical Media Certification Form is mailed with the CD or DVD to 

DAQ.

2.5.2 Activity Data Reporting Forms

Activity data reporting form packages were e-mailed to 48 facilities, from January 13 through 

January 15, 2009. The reporting packages included a cover letter, general facility information 

page, and the appropriate activity data reporting form(s) for each facility. Reporting forms were 

in Microsoft Word format. The general facility information sheet contained pre-printed general 

information about the facility. This information included facility name, mailing address, contact 

name, NAICS codes, and phone and facsimile numbers. Facilities made corrections in the space 

provided on the facility general information page, added activity information to the activity report

forms, and returned these documents via e-mail or facsimile to DAQ.

Assistance in completing the activity reports was offered on an on-going basis. Assistance was 

provided by telephone and e-mail.

2.6 Inventory Tracking

A log book was maintained to record and track the reporting status of the 119 facilities receiving 

a reporting package. The log book contained the facility name and identification number, the 

facility contact, the date the reporting package was e-mailed to the facility, the original due date, 

an extension date, if given, the date the submission was received by DAQ, and notes regarding

phone or e-mail communications with the facility. 

In addition to the 2008 inventory log book, a Microsoft Excel spreadsheet was maintained to 

track each facility from the initial mailing through all tracking and review steps including the 

final QA/QC process. Communications with facilities are noted in the spreadsheet, especially 

when facilities failed to meet their deadlines. All facilities receiving reporting packages supplied 

either complete on-line submissions, or submitted activity forms via e-mail or facsimile.
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

2.7 Administrative Review

As soon as submissions were received, the review process began. The Administrative 

Completeness Determination (ACD) was performed as the first step in the review process. The 

ACD consisted of a one-page checklist which begins the audit trail associated with the review 

process. The ACD checklist was developed by the DAQ point source inventory staff over many 

years as a QA/QC tool for ozone SIP inventories. A checklist is completed and maintained in 

each facility file. An ACD is prepared for all facilities, whether Terminal Server Satellite iSTEPS or the activity data reporting forms were used to prepare their submission.

2.7.1 Administrative Review of On-line Submissions

The ACD performed on on-line submissions included the following steps:

Review cover letter - Facilities were asked to identify in their cover letter any operational 

changes and the impact such changes had on emissions. DAQ staff reviewed the cover letter 

noting any significant changes and highlighted it for future reference.

Emissions comparison - The 2008 facility-wide reported emissions for each criteria pollutant 

were compared to the most recent periodic emission inventory year which in most cases was 

2005. Annual emissions for other years were used when appropriate. Significant differences 

between the two years were identified, investigated, and documented. Reviewing past and 

present submissions, process additions and deletions were compared, identified and highlighted 

for further investigation. If sufficient information was not provided in the cover letter, the facility 

was contacted to explain the differences.

Accidental releases - Facilities were asked to identify accidental releases either through the 

assignment of a separate accidental release process or an explanation in their cover letter as to the

accounting of the release(s) in their inventory. Throughout 2008, DAQ staff compiled e-mails of 

accidental releases sent through DNREC’s Environmental Release Notification System list

server. This information was checked against accidental releases identified in the emission 

inventory reports. The Delaware City Refinery (Premcor) had the greatest number of reported 

accidental releases. DAQ requested and received a spreadsheet of detailed accidental release 

information from the refinery. DAQ compared this information to the release notification 

information and to emissions reported as accidental releases by the refinery.

Comments Spreadsheet – DAQ developed a Microsoft® Word document to list any data from 

individual facilities that had significant changes, such as significant decreases or increases in 

emissions, the reason for the changes in emissions, and a list of issues that needed to be 

addressed before the QA/QC process could be completed. This information was also listed on the 

facility’s ACD sheet.

Other ACD checks – DAQ staff verified that the emission certification report (facility summary) 

was signed by the Responsible Official. Any request for confidential business information was 

forwarded to the DAQ paralegal staff for review. The tracking spreadsheet was updated to 

include any communications with the facilities and to document when the ACD was completed 
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

for each facility and when all issues, if any, were resolved. The completed ACD, cover letter,

signed emissions summary page, submitted supporting calculation sheets, notes and other 

correspondence (i.e., e-mails) were placed in the facility file. 

2.7.2 Administrative Review of Activity Data Report Forms

Activity data report form information was used to update facility general information and 

calculate emissions. Information from the activity reports were entered into the Terminal Server 

Satellite i-STEPS database by DAQ staff. The database maintained an audit trail (user ID and 

date stamp) of data added to the system.

Activity data were used by the database to calculate emissions based on emission factors 

contained in the database. Fuel combustion throughputs for small boilers and generators were 

used in this way. Once emissions were estimated for a facility that reported activity data, the 

2008 emissions could be compared to data from previous years.

All Title V permitted facilities are required to submit a signed emissions certification report as 

part of their permit requirements. For those Title V facilities that reported activity data, the DAQ 

point source inventory staff generated the emissions summary page based on emissions 

calculated within i-STEPS and mailed it to the facility for signature by the Responsible Official. 

The ACD was not complete until the signed emissions summary page was returned to DAQ and 

the signature verified. The date the emissions summary page was mailed to a facility was 

documented within the tracking spreadsheet, as well as the due date for receiving the signed 

document. Finally, the actual date it was received was recorded.

The tracking spreadsheet was updated to include a record of communications with the facilities 

and to document when the ACD was completed for each facility and when all issues, if any, were 

resolved. The completed ACD, signed emissions summary page, notes and other correspondence 

(i.e., e-mails) were placed in the facility file.

2.8 Reported Data and Estimating Emissions

The 2008 stationary point source inventory included all criteria pollutants and their precursors 

(PM10-PRI, PM2.5-PRI, SO2, NOx, NH3, VOC, and CO), all hazardous air pollutants (HAPs), and 

the six greenhouse gases as defined by the Kyoto Protocol (UN, 1998). For the 2008 PM2.5 

Attainment Year SIP inventory, only emissions of PM2.5, SO2, and NOx from New Castle County 

facilities are included in this report.

If PM2.5 emissions were missing, DAQ augmented PM2.5 emissions within the point source 

inventory either by using standard emission factors based on throughput information provided by 

the facility, or as described in Section 2.11.

Emissions of sulfur dioxide were calculated using FIRE emission factors, except for large units 

that use CEMs to monitor SO2. Percent sulfur in the fuel is critical in calculating accurate SO2

emissions for combustion processes using emission factors. DAQ reviewed and worked with the 

facilities to resolve any issues associated with the reported percent sulfur. 
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

DAQ required facilities to report data to the process level, identified by an eight-digit Standard 

Classification Code (SCC). Key data reported included SCC identification, product or fuel 

throughput, operating schedule, control equipment information (type, capture efficiency and 

control efficiency), stack parameters (height, diameter, flow rate, velocity and temperature), and 

emission factors, if FIRE factors were not used. Data collected were consistent with EPA’s

Procedures Volume I (EPA, 1991b), the Air Emission Reporting Requirements (AERR) – Final 

Rule (EPA, 2008), Emissions Inventory Guidance for Implementation of Ozone and Particulate 

Matter National Air Quality Standards (NAAQS) and Regional Haze Regulations (EPA, 2005b)

(hereafter referred to as Emissions Inventory Guidance), and EIIP documents.

2.8.1 Emission Estimation Methods

Annual emissions could either be calculated within i-STEPS using uncontrolled emission 

factors, throughput data, and control data, or outside the system using mass balance, stack tests, 

or other means. Terminal Server Satellite i-STEPS allowed for the use of nine emission 

estimation methods, which are presented in Table 2-2.

Table 2-2. i-STEPS Emission Estimation Methods

i-STEPS

Method Code Basis for Emissions Estimate

1 Stack test dataa

2 Material balance

3

Use of emission factor outside of i-STEPS or use of 

EPA TANKS software

4 Best engineering judgment

5 State or local agency emission factor

6 New construction/not yet operational (zero emissions)

7 Source closed/operation ceased (zero emissions)

8 i-STEPS default emission factor 

9 Facility-supplied emission factor a includes Continuous and Predictive Emission Monitoring

Annual emissions are calculated by the database when Method Code (MC) 8 or 9 is designated.

The monthly fuel or process throughput rates obtained from the facility are summed to an annual 

rate and then applied to the relevant emission factor, either the system default (MC8) or one 

supplied by the facility (MC9). This calculation produces an annual emissions estimate in tons 

per year. Annual emissions may be calculated outside of i-STEPS with only the annual 

emissions entered in i-STEPS. Annual emissions calculated outside of i-STEPS are identified 

in the database by MC1 through MC4. Facilities were asked when deriving annual emissions

from stack tests to take into consideration operating conditions during the stack tests, such as 

load and control efficiency, and be aware when stack test conditions were not representative of 

operating conditions in 2008.

For MC8 or MC9, emissions are calculated by the database through the use of a default or 

facility-supplied emission factor using the following equation for pollutant x:
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

Ea = [(Qa) * (EFx) * (FP) / 2000] * (1-CEx)

where:

Ea = Annual emissions, tons per year

Qa = Annual process throughput

EFx = Emission factor for pollutant x

FP = Fuel parameter, such as percent sulfur or ash content

CEx = Overall capture and control efficiency

When a facility chooses MC8 for a process, i-STEPS automatically selects the emission factor

associated with the process SCC and calculates the emissions. For MC9, facilities were required 

to document facility-supplied emission factors. The emission factor must be documented by the 

facility or otherwise verified by DAQ. If not, DAQ replaced it with the current i-STEPS SCC 

emission factor. Facilities may choose to calculate emissions outside of i-STEPS and enter the 

emissions using MC3. If an emission factor is used by the facility to calculate the emissions, the 

factor must be documented by the facility or otherwise verified by DAQ. If not, DAQ changed 

the record to an MC8. 

2.9 Technical Review of Submitted Data and Information

Once issues from the completeness determination were resolved, the technical review would 

begin. The technical review was conducted through a series of database queries. The query 

results were exported to a spreadsheet for ease of review and to compare to previous years’ data. 

The spreadsheets allowed DAQ inventory staff to identify missing, suspicious or conflicting data. 

Any critical issues were identified and corrected in the database. Questionable data, missing 

information, and the correction of errors were handled in several ways. When a problem was

identified, such as missing data, a typographic error, or other simple errors in the data, a phone 

call or e-mail to the facility was usually sufficient to resolve and document the issue. Usually no 

other correspondence was needed.

The following information was included in the technical review:

• General facility information;

• Narrative descriptions of the following: group/point, process, SCC, SCC units, and 

pollutant;

• Design capacity and standard design capacity units;

• Operating schedule, percent quarterly throughputs, and fuel sulfur and ash content;

• Monthly and annual throughputs provided in the SCC units described;

• Process-level annual emissions for all pollutants for each process;

• Stack ID and parameters;

• Emission calculation method;

• Abatement equipment information, including capture and control efficiencies for each 

pollutant;

• Calculations and documentation entered by the facility into a Notes field; and

• A summary page of facility-wide annual emissions for each pollutant.
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

There were six general areas of data and information in the technical review, including facility 

general, group/point (emissions unit), process unit, stack information, process unit controls and

process unit emissions. The review of each section is described in detail below.

2.9.1 Facility General

The following facility general information was reviewed: facility name, facility site identification 

number, mailing address, year of inventory, North American Industry Classification System

(NAICS) code, contact person, and phone number. Any missing or questionable information, 

such as NAICS code or an incorrect inventory year, was noted and resolved. As an example, the 

NAICS code was compared to a brief description of the facility’s business activity supplied by 

the facility. DAQ had previously determined facility coordinates and thus this information only 

needed to be updated for newly inventoried facilities.

2.9.2 Group/Point (Emissions Unit)

Group information defines a piece of equipment, a group of related processes, or a particular 

activity at a facility. Design capacity, and annual and seasonal operating information were

reviewed individually and in context with other information in the Emissions Unit spreadsheet.

A description of the equipment or activity is provided along with the design capacity and design 

capacity units. If the design capacity is missing for combustion equipment, an attempt was made 

to determine the design capacity of the equipment by reviewing permits or contacting the facility. 

The operating schedule was reviewed for missing or inconsistent data. Hours per day and normal 

daily start and end times were also provided. The annual hours operated is calculated by iSTEPS from the hours per day, days per week and weeks per year the facility enters into the 

system. A facility could override this calculated value by entering the actual number of hours 

operated for the year, if the facility had accurate records.

The percent quarterly throughput was corroborated with operating information. i-STEPS

enforced a range of between 95 and 101 percent for the sum of the four quarterly throughputs. A 

review of the database indicated that all sums of the quarterly throughputs were within the range 

of 98 to 101 percent. When necessary, in order to be consistent with the EIS requirements (EPA, 

2009), the second quarter (March, April and May) and/or the fourth quarter (September, October 

and November) percent throughputs were adjusted so the sum of all four quarters would equal 

100 percent. The third quarter (summer season) was not adjusted, since it was assumed the 

facility would have provided an accurate summer season value. 

2.9.3 Process Unit 

Numerous database queries and spreadsheets were developed to review the process unit level 

data reported by facilities. The information was reviewed individually and in context with other 

information in this section and related sections such as the group/emissions unit and stack 

information. Process unit information includes the process description, stack identifier, Source 

Classification Code (SCC) and description, percent sulfur and ash (for combustion units), and 
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

monthly throughput for most processes. In a limited number of instances only annual throughput 

was provided.

The process description field is a text field that is used to describe a process in more detail than is

defined by the SCC description. A determination was made whether the process description 

provided by the facility was consistent with the SCC description. As an example, the process 

description may mention No.6 oil for a piece of combustion equipment; and therefore the SCC 

description must be for combustion equipment burning No.6 oil.

In most cases monthly throughputs were provided by facilities. i-STEPS sums the monthly 

throughputs and stores the value in the annual throughput field. In cases where there were

significant changes in the group-level emissions as compared to a previous year, the annual 

throughputs were compared to previous data. If the comparison of throughput explains the 

difference in emissions, such as fuel switching, or an increase or decrease in fuel usage, this was

noted on the Administrative Completeness Determination page and added to the tracking 

spreadsheet.

Each SCC has associated standard units as defined by EPA in its master list of SCCs and are 

contained within i-STEPS. Facilities are given the option within i-STEPS to change the units 

to make them appropriate to the data they are reporting. DAQ staff compared the SCC units as 

reported by the facility to the standard units. If the two values did not match, DAQ staff 

determined if the revised units were properly applied in the emission calculations.

2.9.4 Stack Parameters

Stack parameters and associated group and process unit information were reviewed. Each stack 

has an identification number and description assigned. The stack parameters include height above 

ground, diameter, exit gas temperature, velocity, and flow rate. If emissions were considered 

fugitive, then i-STEPS requires only a stack identification number, a release point type 

(fugitive) and a height value. A default of ten feet was used for stack height when no fugitive 

height was provided.

If no stack information was provided for a process unit, DAQ would use information provided 

for the process in previous years and make the appropriate link within i-STEPS between the 

stack and process unit records. If no previous year stack data existed in the database, a stack 

record was created and linked to the process based on permit file information or subsequent 

discussions with the facility. During data entry of the process unit record by facilities, Terminal 

Server Satellite i-STEPS flashes a warning message, if a stack is not identified for the process.

2.9.5 Process Unit Control Equipment

Control information for controlled processes was reviewed. A control device identification 

number, i-STEPS control device code, pollutant-specific capture and control efficiencies, and a 

description of the abatement equipment were reviewed. Control issues were flagged and 

resolved, if possible. Particulate, SO2, and NOx control devices were evaluated to determine if 

the control efficiency fell within a range expected for the identified control device. 
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

2.9.6 Process Unit Emissions

Process unit emissions and associated information by pollutant were reviewed. The EIS pollutant 

code, pollutant name, the emission estimation method code, emission factor, the overall capture 

and control efficiencies, and annual emissions in tons per year were compiled in spreadsheets.

The capture and control efficiencies were compared to the process unit control section. Issues 

associated with pollutant code or capture and control efficiencies were flagged, investigated, and 

resolved.

In the review a process was flagged if there was throughput or operating information that 

indicated a process was operating, but no emissions were provided. If emissions were expected, 

but not provided, the process unit emissions from the most recent year were checked. Usually, in 

cases such as this, the facility provided an explanation in the process unit or process emissions 

Notes field. An example of this would be when CEMs are used for NOx or SO2 emissions from

combustion sources that utilize more than one type of fuel. All NOx or SO2 emissions would be 

reported under the major fuel burned. The secondary fuel would have a throughput, but no 

process unit emissions.

2.9.7 A Multi-year Comparison of Facility Level Emissions

A spreadsheet of criteria pollutant facility-wide emissions in tons per year was created for the 

years 2002 through 2008. Any significant differences in the 2008 emissions compared to the 

previous years’ data were flagged. Fuel switching, production changes, or the addition of 

controls, were the most common reasons for the observed differences.

2.10 Technical Review Using Database Queries, Reports and Spreadsheets

Numerous database queries, reports and spreadsheets were created to identify information that 

appeared to be missing, in error or inconsistent with other related information. This included 

analysis of related operating schedule information. 

If an issue initially identified by DAQ or the facility, and subsequently corrected in the i-STEPS

database by DAQ, had a significant impact on the facility’s reported total emissions, DAQ 

requested documentation from the facility acknowledging the change in emissions. The 

documentation may be in the form of a letter, e-mail, or facsimile from the facility. Title V 

facilities were required to resubmit a new emissions summary report signed by the Responsible 

Official.

If issues were unable to be resolved with the facility, DAQ staff updated or modified the 

information submitted by the facility to the extent needed to develop emission estimates. This 

usually was acknowledged in correspondence with the facility.

2.11 PM2.5 Augmentation of Facility Reported Emissions

To insure PM2.5-PRI, PM2.5-FIL, and PM-CON were calculated properly for all combustion and 

non-combustion sources, numerous database queries and spreadsheets were developed to identify 
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

missing emissions or inconsistencies between the PM emission estimates for a given process. 

Missing emissions were determined as follows:

• With the exception of gaseous fuel fired external combustion processes, AP-42 PM2.5-FIL 

and PM-CON emission factors were available for nearly all external combustion 

processes. If filterable or condensable emissions were not reported by the facility, DAQ 

staff calculated these emissions using the AP-42 factors.

• For external combustion processes burning gaseous fuels, PM2.5-PRI was estimated using 

factors published in “Revision of the PM Emissions From Natural Gas Combustion in the 

Final Version of the 2002 NEI” (EPA, 2005c) and an EPA Excel file entitled “Ratios to 

Adjust PM” containing SCCs and PM2.5-PRI emission factors (EPA, 2005d). If PM2.5-PRI 

was not reported, DAQ staff estimated these emissions using these factors. Specific 

filterable and condensable factors are currently not available for gaseous fuels.

• If PM2.5-PRI was missing, DAQ equated it to the sum of PM2.5-FIL and PM-CON; 

• In instances where a facility reported only PM10 (PRI and/or FIL) DAQ assumed that 

PM2.5 conservatively equaled PM10.

Since primary emissions are the sum of the filterable and condensable components, queries and a 

spreadsheet were developed to insure that PM2.5-PRI matched the sum of its components. 

2.12 Review of NOx and SO2 Emissions from EGUs and Other Large Sources

In 2002 there were 21 electric generation units (EGUs) in New Castle County. The Madison 

Street combustion turbine closed in 2004. DAQ staff conducted a review of NOx and SO2

emissions for the 20 remaining EGUs in New Castle County. Most of these units report 

emissions based on continuous emissions monitoring (CEM) data to EPA through their Air 

Markets Program Data (AMPD) website (EPA, 2010). The website contains emissions data 

reported to EPA’s Acid Rain and NOx Budget Programs. DAQ staff compared AMPD 2008 

emissions to emissions reported to DAQ. 

There were 18 New Castle County EGUs listed in AMPD that had annual 2008 NOx and SO2

emissions that could be compared to annual emissions reported to DAQ. An additional two units 

reported 2008 emissions for six months (April – September). For those units that only reported 

six-month emissions, an annual estimate was needed to directly compare to the facility reported 

value. A NOx emission factor was calculated in pounds of NOx emissions per MMBtu using the 

six-month emission amount divided by the heat content of the fuel listed in AMPD for the six

months. Annual emissions were then calculated by applying this factor to the annual fuel heat 

content reported in i-STEPS.

There were five additional units (non-EGU) reporting annual emissions under the NOx Budget 

Program. These units were located at the Delaware City Refinery (Premcor) and were evaluated 

using the same methodology as above.

Differences in NOx emissions reported to DAQ compared to EPA’s AMPD data were expected 

for some units since the Acid Rain Program requires the use of the unit’s maximum load value as 

a default at times when the CEM is not functioning properly. DAQ staff worked with these 

facilities to determine the best estimate of actual NOx emissions for the inventory.
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

2.13 Methods for Correcting Erroneous Data

Questionable data, missing information, and the correction of errors were addressed in several 

ways. In all cases DAQ maintained a paper or electronic trail of changes made by staff or the 

facility. When a problem was identified, such as missing data, typographic error, or other simple 

errors in the data, a phone call or e-mail usually was sufficient to resolve and document the issue. 

Usually no other correspondence was needed.

If an issue had a significant impact on the facility’s initially reported total emissions, DAQ

requested documentation from the facility acknowledging the change in the emissions. The 

documentation may be in the form of a letter, e-mail, or facsimile from the facility. TV facilities 

were required to resubmit a new emissions summary report signed by the Responsible Official.

For submissions where there were extensive problems, a facility may have been asked to meet 

with DAQ staff to outline the issues and to develop ways to address the problems. Once issues 

had been discussed and resolved, the facility may have been asked to resubmit information 

through the on-line reporting system. DAQ staff would reopen the facility’s record within the 

Terminal Server Satellite i-STEPS on-line system to allow access for corrections and updates.

If issues were unable to be resolved with the facility, DAQ staff updated or modified the 

information submitted by the facility to the extent needed to develop emission estimates. This 

usually was acknowledged in correspondence with the facility.

2.14 Facility Site and Stack Coordinates

Facility and stack coordinates were verified during previous PEI inventories. Coordinates were 

verified through the use of high-resolution aerial photography that DNREC had previously 

placed in GIS. Existing site coordinates contained in i-STEPS were plotted and superimposed 

on the aerial photography. Staff from the Engineering and Compliance (E&C) Branch met with 

inventory staff and reviewed the resulting facility locations on the aerial photographs. E&C staff 

were knowledgeable enough with the layout of the facilities they permit to identify them on the 

photographs. Based on the permitting engineer’s advice, the facility point was moved, if 

necessary, to place it over the geographic center of emissions activity at the facility. For several 

facilities, ground reconnaissance was performed to verify a facility’s location.

Two New Castle County facilities, Corrado Construction and Micropore, were new to emissions 

reporting for 2008 and their coordinates were determined using Google Earth.

2.15 Database Management

The 2008 point source inventory database was managed using i-STEPS for Microsoft SQL

Server 5.0 data management system, associated utilities and applications including the Terminal 

Server Satellite i-STEPS on-line system and Microsoft Access. Microsoft Access was used to 

create queries and reports from the SQL tables. After the administrative review and a check of 

reasonableness of the facility-wide emissions were completed for most facilities, a copy of the
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

Terminal Server database was produced as an archive of data reported by the facilities. A second 

database was created as the 2008 production database for purposes of developing the several 

inventories required for 2008. This database was managed using the Agency i-STEPS.

DNREC’s Office of Information Technology (OIT) provides computer network support and

routine database management functions. Joseph Handley, Application Support Project Leader, of 

the OIT office served as liaison between DAQ inventory staff and OIT. Mr. Handley also helped 

with user network, Internet connectivity, and firewall issues.

i-STEPS utilizes relational databases and contains functions and utilities to maintain database 

integrity. There are field-sensitive look up tables, and data element and record validation routines 

that ensure valid data and enforce database integrity. The system has a record level audit trail 

that documents changes made to the records, identifies the user and the date the change was 

made. In addition, there are comment/note windows for each record where text can be added by 

the user and DAQ staff to clarify information provided or supply additional documentation.

2.16 Data Submission to EPA’s Emissions Inventory System

Emissions Inventory System (EIS) staging tables (EPA, 2009) in Microsoft Access format were 

generated from the i-STEPS database. EIS is the EPA’s air emissions inventory data 

management system. An application developed in conjunction with the Department’s

Information Technology staff was used to map information in the i-STEPS database to the EIS 

staging tables. EPA’s EIS Bridge Tool was then used to prepare emissions inventory data in the 

staging tables for submission to EIS. The EIS Bridge Tool transforms emissions inventory data 

into CERS XML files.

The XML files were submitted to the EIS QA environment to obtain several feedback reports 

that would identify errors and issues associated with the submitted files. All significant issues 

associated with mandatory and necessary fields were reviewed and resolved prior to submission 

of the XML files to the EIS Production environment. Emissions data submitted to the EIS 

Production environment are used by EPA to populate the National Emissions Inventory. 

Production submissions of the 2008 emissions data and facility information were initially made 

during May 2010 to meet the June 1, 2011 EPA reporting requirement, while final corrections 

and additions were sent to EIS between December 2010 and January 2011.

2.17 Source Sector Discussions

All New Castle County facilities associated with hot-mix asphalt production and electric 

generation are included in the 2008 PM2.5 Attainment Year SIP point source inventory. Details of 

these industry sectors are presented below.

2.17.1 Hot-mix Asphalt Plants

Hot-mix asphalt (also known as asphaltic concrete or blacktop) production facilities have been 

historically tracked and permitted by the Department as point sources. There were five facilities 
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

in New Castle County for 2008 and these are all included in the point source inventory. Delaware 

facilities employ both drum mixer and rotary dryer processes in the production of hot-mix 

asphalt. The appropriate SCCs were used to identify these processes. In 2008, all New Castle 

County facilities collectively emitted 12 tons PM2.5-PRI, two tons of SO2, and 13 tons of NOx.

The activity data forms were used to obtain throughput data from hot-mix asphalt plants. Data 

from the completed forms were entered into i-STEPS and EPA standard emission factors were 

used to calculated emissions within i-STEPS based on the SCC provided by the facility. In a 

few instance emissions were based on stack tests.

Many asphalt plants employ crushing operations powered by diesel engines. The emissions from

these diesel engines were estimated based on reported fuel usage and FIRE 6.24 emission factors. 

2.17.2 Electric Generating Units (EGUs)

New Castle County EGUs are represented by two large generating stations (Calpine Edge Moor and 

Calpine Hay Road), three Calpine peaking unit stations, and generators at the Delaware City 

Refinery (Premcor). In total, there are 20 EGUs located at six facilities in New Castle County 

included in the point source inventory. EGUs in Delaware include external combustion boilers and 

combustion turbines. Small diesel generators used by businesses and institutions for emergency 

backup power and load management are not included in this discussion, and are generally not 

reported to the point source inventory. 2008 PM2.5, SO2, and NOx emissions from New Castle 

County EGUs are presented in Table 2-3. Note that PM2.5 emissions given in the following tables 

represent primary emissions (i.e., filterable plus condensable).

Table 2-3. 2008 PM2.5 and Precursor Emissions for New Castle County EGUs

Annual Emissions, TPY

Facility Name Unit Description PM2.5 SO2 NOx

Calpine Christiana Turbine #11 < 1 < 1 1

Turbine #14 < 1 < 1 1

Calpine Delaware City Turbine #10 < 1 < 1 1

Calpine Edge Moor

Boiler #3 107 2,011 525

Boiler #4 242 4,923 1,292

Boiler #5 11 176 163

Turbine < 1 < 1 < 1

Calpine Hay Road

Turbine #1 7 2 65

Turbine #2 7 2 70

Turbine #3 7 1 47

Turbine #5 5 2 7

Turbine #6 5 2 7

Turbine #7 5 1 6

Calpine West Substation Turbine 1 1 1

Delaware City Refinery

Boiler #1 14 9 200

Boiler #2 11 15 41

Boiler #3 15 54 254

Boiler #4 3 11 184

Turbine #1 28 202 83

Turbine #2 13 49 47

Total 479 7,463 2,994
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

Emissions from New Castle County EGUs represent 71% and 54% of the county-wide point source 

emissions of SO2 and NOx, respectively. Most peaking units operate exclusively during the summer

to meet periods of high demand. Their operation may coincide with days when air quality is most 

likely to experience an exceedance of the daily fine particulate standard.

2.17.3 Emissions by Source Sector

Table 2-4 provides New Castle County total PM2.5-PRI, SO2, and NOx, emissions grouped by 

source sector as defined by the first three digits of the SCC codes assigned to each process. 

The source sectors include various combustion and manufacturing processing, material storage and 

transfer operations, and solid waste disposal. Combustion processes account for the majority of the 

particulate, SO2, and NOx emissions in New Castle County from the point source sector. 

Table 2-4. 2008 PM2.5 and Precursor Emissions by Industry Sector

SCC SCC Description

Annual Emissions, TPY

PM2.5 SO2 NOx

101 External Comb. Boilers - Utilities 402 7,199 2,659

102 External Comb. Boilers - Industrial 269 1,120 2,061

103 External Comb. Boilers – Commercial 1 28 51

105 Ex. Comb. Boilers - Space Heaters < 1 < 1 16

201 Internal Comb. Engines - Utilities 37 12 208

202 Internal Comb. Engines - Industrial 41 252 145

203 Internal Comb. Engines - Commercial < 1 < 1 4

270 Internal Comb. Engines – Off-road 1 12

301 Chemical Manufacturing 55 78 42

303 Primary Metal Production 56 42 190

304 Secondary Metal Production < 1

305 Mineral Products 16 2 13

306 Petroleum Industry 199 1782 164

307 Pulp, Paper and Wood Products < 1

308 Rubber and Misc. Plastics Products < 1 < 1 1

309 Fabricated Metal Products 1

385 Cooling Tower 15

399 Misc. Manufacturing < 1

402 Surface Coating Operations 7 < 1 5

406 Transport/Marketing of Petrol. Prod. < 1 < 1 1

501 Solid Waste Disposal - Government 1 7 2

502 Solid Waste Disposal – Comm./Inst. 8 24 11

503 Solid Waste Disposal - Industrial 2 28 4

682 Miscellaneous Processes < 1

Statewide Total 1,109 10,576 5,589

2.18 Emissions by Facility

Facility-level annual emissions for the 58 facilities included in the 2008 PM2.5 Attainment Year 

SIP inventory are provided in Tables 2-5. For recent facility name changes, the former name is 

included in parentheses.
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

Table 2-5. 2008 PM2.5 and Precursor Emissions for New Castle County Facilities

Annual Emissions, TPY

Facility Name PM2.5 SO2 NOx

A.I. DuPont Hospital 1 25 13

Amtrak Maintenance Facility < 1 < 1 4

Ashland Research Center (Hercules) 1 9 6

Astrazeneca Pharmaceuticals < 1 < 1 7

BASF (Ciba Specialty Chemicals) 2 < 1 10

Calpine – Christiana (Conectiv) < 1 < 1 2

Calpine - Delaware City (Conectiv) < 1 < 1 1

Calpine - Edge Moor (Conectiv) 360 7,110 1,980

Calpine - Hay Road (Conectiv) 36 10 202

Calpine - West Substation (Conectiv) 1 1

Christiana Hospital < 1 4 16

Christiana Materials 3 1 3

Chrysler (DaimlerChrysler) 3 24 34

Clean Earth of New Castle 8 24 11

Contractors Materials 2 < 1 2

Corrado Construction < 1 < 1 1

Croda (Uniqema) 1 7 49

Dassault Falcon Jet < 1 < 1 1

Delaware City Refinery (Premcor) 446 2,548 2,525

Delaware City Terminal (Premcor) < 1 < 1 < 1

Del. Correctional Center - Smyrna < 1 < 1 6

Delaware Recyclable Products 1 28 3

Diamond Materials 5 1 9

DSWA Cherry Island Landfill 1 7 1

DuPont - Chestnut Run 8 140 45

DuPont - Edge Moor 17 17 32

DuPont - Red Lion < 1 47 13

DuPont Building - Wilmington 3 57 19

DuPont Experimental Station 27 438 156

DuPont Stine-Haskell Lab 1 8 16

E-A-R Specialty Composites < 1 < 1 1

Eastern Shore Natural Gas – Del City < 1 < 1 4

Edgemoor Materials 2 < 1 3

Evraz Claymont Steel 64 42 190

FMC 17 < 1 30

Formosa Plastics 26 < 1 25

FP International < 1 < 1 1

General Motors 7 < 1 25

Honeywell International < 1 < 1

Johnson Controls Battery < 1 < 1 3

Kuehne Chemical < 1 < 1 1

MacDermid < 1 < 1 3

Magellan Terminals < 1 5 3

Medal Air Liquide < 1 < 1 4

Motech Americas (GE Energy) < 1 < 1 < 1

continued next page
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

Table 2-5. continued

Facility Name

Annual Emissions, TPY

PM2.5 SO2 NOx

Noramco < 1 < 1 1

NVF – Yorklyn < 1 < 1 < 1

Occidental Chemical < 1 < 1 < 1

Prince Minerals (American Minerals) < 1 < 1 < 1

Printpack < 1 < 1 2

Pure Green Industries < 1 < 1 1

Rohm & Haas Electronic Materials < 1 < 1 4

St. Francis Hospital < 1 < 1 4

Sunoco 66 17 83

University of Delaware - Newark < 1 3 22

Veterans Administration Hospital < 1 < 1 4

Wilmington Hospital < 1 < 1 7

Wilmington WWTP < 1 1 2

New Castle County Total 1,109 10,576 5,589

2.18.1 Sources of PM2.5 Emissions

The Delaware City Refinery is the largest source of PM2.5-PRI, emitting 446 tons in 2008. 56% 

of these emissions (263 tons) are associated with the catalytic cracker and coker CO boilers. The

Calpine Edge Moor/Hay Road complex is the second largest PM2.5-PRI source in Delaware. The 

coal-fired units at this facility have particulate controls, which have the ability to capture 

filterable particulates only. Calpine EM/HR emitted 396 tons of PM2.5-PRI of which 308 tons 

were condensables. All other facilities in New Castle County emitted less than 100 TPY of NOx

in 2008.

The top ten PM2.5 sources, representing 97% of county-wide annual PM2.5 emissions for 2008

from point sources in New Castle County, are presented in Table 2-6 and in Figure 2-1.

Table 2-6. 2008 New Castle County Facility Ranking of PM2.5 Annual Emissions

Facility Name Major Activity TPY

Delaware City Refinery / Terminal Petroleum Refinery 446

Calpine – Edge Moor/Hay Road Electricity Generation 396

Sunoco Petroleum Refinery 66

Evraz Claymont Steel Steel Manufacturing 64

DuPont Experimental Station R&D / Hazardous Waste Incinerator 27

Formosa Plastics PVC Manufacturing 26

DuPont Edge Moor Chemical Manufacturing 17

FMC Chemical Manufacturing 17

DuPont Chestnut Run Research & Development 8

Clean Earth of New Castle Contaminated Soil Remediation 8

All Other Facilities 34

County Total 1,109
2-22

2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

Figure 2-1. 2008 PM2.5 Annual Emissions by Facility

2.18.2 Sources of SO2 Emissions

The top three facilities account for 96% of the county-wide annual SO2 emissions from point 

sources in New Castle County. The top facility, Calpine Edge Moor/Hay Road power plants, 

burning coal in 2008 to generate electricity, accounted for 67% of county SO2 emissions. The

Delaware City Refinery accounted for another 25% of the county total SO2 emissions. The third

largest source of SO2 emissions is the DuPont Experimental Station, which utilizes residual oil in 

its several boilers. The top ten SO2 sources in New Castle County are presented in Table 2-7 and 

in Figure 2-2.

Table 2-7. 2008 New Castle County Facility Ranking of SO2 Annual Emissions

Facility Name Major Activity TPY

Calpine Edge Moor/Hay Road Electricity Generation 7,120

Delaware City Refinery Petroleum Refinery 2,548

DuPont Experimental Station R&D / Hazardous Waste Incinerator 438

DuPont Chestnut Run Research & Development 140

DuPont Building Wilmington Commercial Building 57

DuPont Red Lion Chemical Manufacturing 47

Evraz Claymont Steel Steel Manufacturing 42

Delaware Recyclable Products Construction Debris Landfill 28

A.I. DuPont Hospital Health Services 25

Clean Earth of New Castle Contaminated Soil Remediation 24

All Other Facilities 107

County Total 10,576
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

Figure 2-2. 2008 SO2 Annual Emissions by Facility

2.18.3 Sources of NOx Emissions

The largest source of NOx emissions in New Castle County for 2008 is the Delaware City

Refinery. A large majority of emissions (71%) from the refinery come from just a few processes, 

including the catalytic cracking unit, the fluidized coking unit, and four boilers used for 

electricity generation. The second largest source of NOx emissions is the Calpine Edge Moor/Hay 

Road electric generation complex. The refinery and Calpine EM/HR combined account for 84% 

of NOx emissions from point sources in New Castle County.

The top ten NOx sources, representing 95% of county-wide NOx emissions for 2008 from New 

Castle County point sources, are presented in Table 2-8 and in Figure 2-3.

2.19 Closed Facilities

Several facilities included in the 2008 PM2.5 Attainment Year SIP inventory have since 

permanently closed. Table 2-9 presents a list of closed facilities and the month and year operations 

ceased. For historical context, all New Castle County facilities that reported for 2002 and 2005 that 

have since closed are also included in Table 2-9.
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

Table 2-8. 2008 New Castle County Facility Ranking of NOx Annual Emissions

Facility Name Major Activity TPY

Delaware City Refinery Petroleum Refinery 2,525

Calpine Edge Moor/Hay Road Electricity Generation 2,182

Evraz Claymont Steel Steel Manufacturing 190

DuPont Experimental Station R&D / Hazardous Waste Incinerator 156

Sunoco Petroleum Refinery 83

Croda Chemical Manufacturing 49

DuPont Chestnut Run Research & Development 45

Chrysler Automobile Assembly 34

DuPont Edge Moor Chemical Manufacturing 32

General Motors Automobile Assembly 25

All Other Facilities 268

County Total 5,589

Figure 2-3. 2008 NOx Annual Emissions by Facility
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

Table 2-9. Reporting Facilities That Have Ceased Operations

Facility Name Date Closed

Metachem Products May 2002

Lafarge November 2002

Westvaco May 2003

Kaneka July 2003

VPI Film (VPI Mirrex) July 2003

Wilmington Piece Dye September 2003

General Chemical June 2004

Laidlaw September 2004

Conectiv - Madison Street December 2004

Industraplate March 2005

Ametek October 2005

Hardcore Composites January 2006

Spatz Fiberglass December 2007

PTFE July 2008

CPI (Unisource) October 2008

Occidental Chemical October 2008

Pepsi Cola Bottling November 2008

NVF Yorklyn March 2009

Chrysler (DaimlerChrysler) December 2009

Tilcon – Terminal Avenue June 2011

2.20 References

DNREC, 2006. Regulations Governing the Control of Air Pollution, Regulation No.1144 –

Control of Stationary Generator Emissions, Delaware Department of Natural Resources and 

Environmental Control, Division of Air Quality, Updated to November 2006.

EPA, 1991a. Emission Inventory Requirements for Ozone State Implementation Plans, EPA450/4-91-010, USEPA, Office of Air Quality Planning and Standards, Research Triangle 

Park, N.C., March 1991.

EPA, 1991b. Procedures for the Preparation of Emission Inventories for Carbon Monoxide and 

Precursors of Ozone, Volume I: General Guidance for Stationary Sources, EPA-450/4-91-

016, USEPA, Office of Air Quality Planning and Standards, Research Triangle Park, N.C., 

May 1991.

EPA, 1997. Emissions Inventory Improvement Plan (EIIP), Volume II: Point Sources Preferred 

and Alternative Methods, Chapter 1, EPA-454/R-97-004b, USEPA, Office of Air Quality 

Planning and Standards, Research Triangle Park, N.C., July 1997.

EPA, 2005a. TANKS Version 4.09D, Windows-based computer software program for estimating 

VOC emissions from storage tanks, 2005.
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2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

EPA, 2005b. 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, USEPA, Emissions Inventory Group Emissions, Monitoring and 

Analysis Division, Office of Air Quality Planning and Standards, Research Triangle Park, 

NC, November 2005.

EPA, 2005c. Revision of the PM Emissions From Natural Gas Combustion in the Final Version 

of the 2002 NEI, USEPA, Emissions Inventory Group, Office of Air Quality Planning and 

Standards, Research Triangle Park, NC, August 2005. ftp://ftp.epa.gov/EmisInventory/ 

2002finalnei/documentation/point/pm_adjustment_2002_nei.pdf

EPA, 2005d. 2002 Final NEI Documentation Containing Ratios to Adjust PM Values for 

Natural Gas Combustion, Excel file, Roy Huntley, August 2005., USEPA, Emissions 

Inventory Group, Office of Air Quality Planning and Standards, Research Triangle Park, 

NC, August 2005. ftp://ftp.epa.gov/EmisInventory/2002finalnei/documentation/point/aug 

mentation_point/ratios_to_adjust_pmvalues_in_nei_for_naturalgas_combustion082005.xls

EPA, 2008. Air Emission Reporting Requirements (AERR) – Final Rule, U.S. Environmental 

Protection Agency, 40 CFR Part 51, Vol. 73, No 2143, December 17, 2008.

EPA, 2009: 2008 National Emissions Inventory, Emissions Inventory System Implementation 

Plan, Section 7 Reporting Instruction for Point Emissions, Revised, August 3, 2009.

http://www.epa.gov/ttn/chief/net/neip/index.html.

EPA, 2010. CEM Data for the Acid Rain and NOx Budget Programs, Clean Air Markets 

Division, http://ampd.epa.gov/ampd/QueryToolie.html, Office of Air and Radiation, 

USEPA, accessed 2010.

UN, 1998. Kyoto Protocol to the United Nations Framework Convention on Climate Change, 

Annex A, United Nations, 1998.
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

3-1

SECTION 3

STATIONARY NON-POINT SOURCES

Stationary non-point sources represent a large and diverse set of individual emission source 

categories. A non-point source category is either represented by small facilities too numerous to 

individually inventory, such as commercial cooking at restaurants and fuel combustion at a variety 

of small businesses, or is a common activity, such as residential open burning. Emissions from the 

non-point source categories were estimated at the county level. 

3.1 Source Categories

There are a number of non-point source categories which contribute emissions of PM2.5, SO2, and 

NOx. These categories can be grouped into several category types. These include:

• Fuel Combustion – The combustion of fuels in industrial, commercial, institutional, 

and residential furnaces, engines, boilers, wood stoves, and fireplaces create emissions 

of PM2.5, SO2, and NOx.

• Open Burning – Open burning creates emissions of PM2.5, SO2, and NOx. Open 

burning categories include trash burning, prescribed burning, burning of land clearing 

debris, wildfires, and house and vehicle fires.

• Fugitive Dust – Primary crustal particulate is created from construction activities, 

agricultural production, and as a result of vehicle traffic. Fugitive dust is largely coarse 

material, with only a small percentage being fine particulate.

Individual facilities are typically grouped with other like sources into a source category. Source 

categories are grouped in such a way that emissions are estimated collectively using one 

methodology. For the 2008 inventory, the distinction between point and non-point was defined 

by an annual emission threshold based on recent point source data (see Section 2 for point source 

criteria). Table 3-1 lists the source categories for which PM2.5, SO2, and NOx for New Castle 

County were estimated.

Table 3-1. Non-point Source Categories Inventoried 

Agricultural Burning Residential Construction

Agricultural Production Residential Fuel Combustion

Commercial Construction Residential Open Burning

Commercial Cooking Residential Wood Combustion

Commercial Fuel Combustion Road Construction

Industrial Fuel Combustion Structure Fires

Land Clearing Debris Burning Vehicle Fires

Paved & Unpaved Road Dust Wildfires

Prescribed Burning
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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There were several source categories evaluated, but not included, in the non-point source inventory. 

These include:

• Crematories – While there are at least a dozen human/pet crematories and several 

laboratory animal incinerators in Delaware, DNREC was unable to locate emission 

factors for ozone precursors. Emissions from fuels used at these facilities are included in 

the commercial fuel combustion category.

• Feed Mills and Concrete Plants - These industry sectors were considered a source of 

particulate matter, both from material handling processes and fugitive dust (i.e., 

storage piles). Several large feed mills in Delaware already met the criteria for 

reporting as a Title V facility due to combustion emissions from process boilers and 

grain dryers. The lack of quality emissions data (i.e., emission factors) for feed mills 

persuaded DAQ from inventorying smaller feed mills. Lack of data was also the 

reason for not further considering concrete plants.

• Slash Burning - No activity for the burning of slash from logging for future 

silvicultural operations was identified. This was confirmed by the Delaware Division 

of Forestry. However, recently logged lands are occasionally converted to agriculture. 

This activity, previously reported as slash burning, is now reported under the land 

clearing debris burning category.

3.2 Emission Estimation Methodologies and Activity Data

The 2005 Delaware Periodic Emission Inventory served as the starting point for non-point source 

category selection and methodology development. One new category, agricultural burning, was 

added to the non-point sector. In 2007 agricultural burning was specifically delineated on the 

prescribed burning approval application form. This allowed DAQ to track the burning of woody 

debris specific to agricultural activities separate from other prescribed burning activities and other 

land clearing debris burning, (the latter is not permitted under Delaware Air Regulation 1113.)

New methods were applied to some existing source categories, and emission factors were updated 

where available. New methods and emission factors came primarily from current Emission 

Inventory Improvement Program, Volume III documents and documented projects performed by 

the California Air Resource Board (CARB). Other sources of information included the 

Compilation of Air Pollutant Emission Factors, Volume I (AP-42), the Factor Information Retrieval 

System (FIRE), and several projects performed by the Mid-Atlantic Regional Air Management 

Association (MARAMA) and EPA.

Emissions from most non-point source categories were estimated by multiplying an indicator of 

collective activity by a corresponding emission factor. An indicator is any parameter associated with 

the activity level of a source, such as production, employment, fuel usage, or population that can be 

correlated with the emissions from that source. The corresponding emission factors are per unit of 

production, per employee, per unit of commodity consumed, or per capita, respectively. The basic 

equation that was applied to emission development for most non-point source categories is as 

follows:
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

3-3

Emissions (E) = Activity Data (Q) x Emission Factor (EF)

If a source category had a regulatory control placed on it at the Federal or State level, the equation 

expands to the following:

E = Q x EF x [1 - (CE)(RE)(RP)]

where: CE = control efficiency

RE = rule effectiveness

RP = rule penetration

The control efficiency (CE) represents the typical emissions reduction achieved as compared to the 

otherwise uncontrolled emissions. A control may be a piece of equipment, such as a cyclone used to 

capture particulates, or it may be an operational control, such as low sulfur fuel.

Rule effectiveness (RE) reflects the ability of the regulatory program to achieve all emissions 

reductions that could have been achieved by full compliance with the applicable regulations at all 

sources at all times. If a rule is not being followed by all of the regulated community, then 

emissions will be higher than would otherwise be if there was 100% compliance. As an example, 

while the burning of trash is illegal under any circumstances in Delaware, the practice of burning 

household trash in backyard burn barrels still takes place in many rural areas of the State.

Rule penetration (RP) represents the percent of sources within a source category that are subject to 

the rule that requires control. As an example, while businesses and developers are prohibited from 

burning woody debris, Delaware residents may burn small piles of branches and limbs during 

certain times of the year. Therefore, RP is less than 100%. In the case of the burning of trash or 

leaves, no person or business is exempt, and thus RP is 100%.

A major portion of the work involved in creating the 2008 non-point source inventory was in 

collecting activity data for each source category. The activity data gathered was related to the type 

of emission factors available and, in many cases, obtained from local sources. Surveys, letters, emails, and phone calls to individual businesses to obtain representative data for a source category 

was a technique used for several source categories. The type of activity data and the data source for 

each category is provided in Table 3-2.

Point source backout was performed for the industrial and commercial fuel combustion categories

to avoid double counting of emissions between point and non-point sources. Point source fuel 

usage was backed out from fuel consumption data obtained from the U.S. Department of Energy’s 

(DOE) Energy Information Administration (EIA).

3.3 2008 Emissions Summary

Table 3-3 provides a summary of the 2008 annual (tons per year, TPY) emissions for each nonpoint source category for New Castle County. The totals may not match the sum of the 

individual values due to independent rounding.
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

3-4

Table 3-2. Summary of 2008 Non-point Source Activity Data

Source Category Activity Data Source of Activity Data

Agricultural Burning Acreage and vegetation type DAQ Area Source Compliance Program

Agricultural Production Planted and harvested crop acreage Delaware Department of Agriculture

Commercial Construction

Value of construction put in place; 

construction employment; 

construction businesses

US Census Bureau County Business 

Patterns; Delaware Department of 

Labor

Commercial Cooking Population Delaware Population Consortium

Commercial Fuel Combustion Fuel consumption DOE Energy Information Admin.

Industrial Fuel Combustion Fuel consumption DOE Energy Information Admin.

Land Clearing Debris Burning

Acreage disturbed during road, 

commercial, and residential 

construction

DAQ data calculated for the 

construction dust categories

Paved & Unpaved Road Dust Vehicle miles traveled Delaware Department of Transportation

Prescribed Burning Acreage and vegetation type DAQ Area Source Compliance Program

Residential Construction Residential building permits US Census Bureau

Residential Fuel Combustion Fuel consumption DOE Energy Information Admin.

Residential Open Burning Rural households US Census Bureau

Residential Wood Combustion Occupied households Delaware Population Consortium

Road Construction Highway capital outlays Federal Highway Administration

Structure Fires Number of structures fires

Delaware Fire Marshal and DAQ Area 

Source Compliance Program

Vehicle Fires Number of vehicle fires Delaware Fire Marshal

Wildfires Acreage and vegetation type Delaware Division of Forestry

Combustion processes and fugitive dust account for 84% of the direct particulate emissions in New 

Castle County from the non-point sector. Road dust and residential wood combustion are the two

largest non-point source category of direct PM2.5. Figure 3-1 presents the top eight PM2.5 non-point 

sources in New Castle County for 2008.

Figure 3-1. 2008 New Castle County PM2.5 Emissions by

Non-point Source Category
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

3-5

The important precursor pollutants to the formation of secondary fine particulate emissions are SO2

and NOx. The non-point sector is a small contributor of these pollutants to the overall county totals. 

Nearly all of the SO2 and NOx emissions result from the combustion of fossil fuels.

Table 3-3. Summary of 2008 New Castle County Emissions

from Non-point Sources

Source Categories

PM2.5 SO2 NOX

TPY TPY TPY

FUEL COMBUSTION

Commercial/Institutional 3 16 246

Industrial 3 34 445

Residential Fossil Fuel 20 339 535

Residential Wood 404 8 47

Fuel Combustion Total 429 399 1,273

OPEN BURNING

Agricultural Burning 4 --- 1

Land Clearing Debris Burning 0 --- 0

Prescribed Burning 43 3 11

Residential Open Burning 2 < 1 < 1

Structure Fires 3 --- < 1

Vehicle Fires 4 --- < 1

Wildfires 1 < 1 < 1

Open Burning Total 56 3 13

FUGITIVE DUST

Agricultural Production 48 --- ---

Commercial Construction 63 --- ---

Paved and Unpaved Road Dust 413 --- ---

Residential Construction 2 --- ---

Road Construction 51 --- ---

Fugitive Dust Total 576 --- ---

OTHER SOURCES

Commercial Cooking 131 --- ---

Other Sources Total 131 --- ---

NON-POINT SECTOR TOTAL 1,191 402 1,287
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

4-1

SECTION 4

NON-ROAD MOBILE SOURCES

Non-road mobile sources represent a large and diverse set of off-road vehicles and non-stationary 

equipment. Emission estimates of PM2.5, SO2, and NOx for this source sector account for exhaust 

emissions from engine fuel combustion.

4.1 Source Categories

Non-road vehicles and equipment are grouped into four source category types for the purpose of 

developing emission estimates. These include:

• Aircraft – Commercial, military, and private aircraft are considered under this source 

category.

• Locomotives – Commercial line haul and yard locomotives are considered under this 

source category.

• Commercial Marine Vessels (CMVs) – Various types of vessels that navigate the 

Delaware Bay and River and the Chesapeake and Delaware Canal are included under 

this source category. Recreational boats are included in the next category.

• Other Off-road Vehicles and Equipment – All other off-road emission sources are 

accounted for through the use of EPA’s NONROAD model. The NONROAD model 

compiles off-road equipment pertinent to Delaware into the following subcategories:

• Recreational (land-based);

• Construction;

• Industrial;

• Lawn and Garden;

• Agricultural;

• Commercial;

• Logging;

• Airport Ground Support;

• Recreational Marine; and

• Railway Maintenance.

Individual equipment SCCs covered in the NONROAD model are further broken down by the 

fuel type, including 2-stroke gasoline, 4-stroke gasoline, diesel, liquefied petroleum gas (LPG), 

and compressed natural gas (CNG). 

4.2 Emission Estimation Methodologies

The 2005 Delaware Periodic Emission Inventory served as the starting point for non-road source 

category selection and methodology development. No new sources were added to Delaware’s off-
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

4-2

road mobile source inventory. However, new versions of EPA’s NONROAD model and the Federal 

Aviation Administration’s (FAA) Emissions and Dispersion Modeling System (EDMS) were used 

for 2008. 

Similar to the estimation of stationary non-point emissions, off-road equipment emissions were

estimated by multiplying an indicator of collective activity within the inventory area for a source 

category by a corresponding emission factor. The indicators of activity for off-road sources include 

landing and take-offs (LTOs), vessel port-of-calls, time-in-mode (TIMs, which are pertinent to 

aircraft and CMVs), gross ton miles (locomotives), equipment populations and economic activity 

(both pertinent to NONROAD equipment) that can be correlated with the emissions from that 

source. The corresponding emission factors are amount of pollutant (either grams or pounds) per 

unit of fuel used (locomotives and military/commercial aircraft), per LTO (air taxi and general 

aviation) or per unit of power output in brake horsepower or kilowatt-hours (NONROAD 

equipment and CMVs, respectively).

A major portion of the work involved in creating the 2008 non-road source inventory was in 

collecting activity data for each source category. The activity data gathered was related to the type 

of emission factors available and, in many cases, obtained from local sources. More information 

about gathering activity data for each source category is presented below.

There are no point source data that must be backed out of the non-road mobile source sector. Even 

though larger airports may report as a point source, their reported point source emissions do not 

include ground support equipment or aircraft engine emissions. Also, aircraft emissions are 

estimated only for LTOs that take place at a Delaware airport. Emissions from aircraft that transit 

Delaware airspace are not included in Delaware’s inventory.

4.2.1 NONROAD Model Equipment

DAQ used NONROAD2008a to develop 2008 annual emission estimates for New Castle 

County. Most equipment covered by the NONROAD model is powered by diesel-fueled 

compression-ignition engines or gasoline-fueled spark-ignition engines. Engines fueled by 

compressed natural gas (CNG) and liquefied petroleum gas (LPG) engines are also included in 

the NONROAD model. Table 4-1 lists general SCCs addressed by the NONROAD model. 

Equipment categories are defined at the 7-digit SCC level (with recreational marine and railway 

maintenance being exceptions) and specific equipment are defined at the 10-digit SCC level.

To estimate pollutant emissions, the NONROAD model multiplies equipment populations and 

their associated activity by the appropriate emission factors. Geographic allocation factors 

(GAFs) are used to distribute national equipment populations to states/counties. These factors 

are based on surrogate indicators of equipment populations. For example, harvested cropland is 

the surrogate indicator used in allocating agricultural equipment. A national average engine 

activity (i.e., load factor times annual hours of use) is used in NONROAD.

To improve the accuracy of the model runs, default inputs were replaced in the NONROAD 

model option files for select parameters. In the options packet, inputs that can be replaced 

include: Reid vapor pressure (RVP), temperature, oxygenated fuel weight percent, and fuel 

sulfur levels. Local activity data inputs, such as equipment populations or activity (e.g., hours of 

use or load factors), can also replace default values in the model.
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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Table 4-1. SCCs Addressed by the NONROAD Model

Nonroad 

SCCs SCC Descriptions

Nonroad 

SCCs SCC Descriptions

2260xxxxxx

2260001xxx

2260002xxx

2260003xxx

2260004xxx

2260005xxx

2260006xxx

2260007xxx

2265xxxxxx

2265001xxx

2265002xxx

2265003xxx

2265004xxx

2265005xxx

2265006xxx

2265007xxx

2265008xxx

226501xxxx

2267xxxxxx

2267001xxx

2267002xxx

2267003xxx

2267004xxx

2267005xxx

2267006xxx

2267008xxx

2-stroke gasoline engines

 - recreational vehicles

 - construction equipment

 - industrial equipment

 - lawn & garden equipment

 - agricultural equipment

 - light commercial equipment

 - logging equipment 

4-stroke gasoline engines

 - recreational vehicles

 - construction equipment

 - industrial equipment

 - lawn & garden equipment

 - agricultural equipment

 - light commercial equipment

 - logging equipment 

 - airport service equipment

 - oil field equipment

LPG engines

 - recreational vehicles

 - construction equipment

 - industrial equipment

 - lawn & garden equipment

 - agricultural equipment

 - light commercial equipment

 - airport service equipment

2268xxxxxx

2268002xxx

2268003xxx

2268005xxx

2268006xxx

226801xxxx

2270xxxxxx

2270001xxx

2270002xxx

2270003xxx

2270004xxx

2270005xxx

2270006xxx

2270007xxx

2270008xxx

2270009xxx

227001xxxx

2282xxxxxx

2285xxx015

CNG engines

 - construction equipment

 - industrial equipment

 - agricultural equipment

 - light commercial equipment

 - oil field equipment

Diesel engines

 - recreational vehicles

 - construction equipment

 - industrial equipment

 - lawn & garden equipment

 - farm equipment

 - light commercial equipment

 - logging equipment 

 - airport service equipment

 - underground mining equipment

 - oil field equipment

Recreational marine equipment

Railway maintenance equipment

NONROAD model option files were prepared to account for temperatures and fuel 

characteristics representative of each county for each of the four seasons (winter, spring, 

summer, and fall). Temperature and fuel input values for each three-month period (DecemberFebruary, March-May, June-August, and September-November) were averaged to estimate 

seasonal values. Minimum, maximum, and average temperatures per month were obtained from 

the National Weather Service for the New Castle County Airport. Table 4-2 presents a summary 

of New Castle County temperature and gasoline fuel characteristics data used for each season. A 

sulfur content of 351 ppm for off-road diesel fuel was used for 2008 based on an EPA 

recommendation report (EPA, 2009a).

Table 4-2. NONROAD Model Temperature and Fuel Characteristic Input Values

by Season for 2008

County Season

Oxygen 

Weight % RVP psi

Gasoline 

Sulfur 

ppm

Temperature, oF

Minimum Maximum Average

New Castle Summer 3.55 6.82 39 66 86 76

New Castle Autumn 3.2 8.06 40.67 48 66 57

New Castle Winter 3.29 10.54 44 30 46 37

New Castle Spring 3.2 8.06 40.67 44 64 53

DAQ researched the availability of state and county-specific data to improve upon the default 

equipment populations and GAFs incorporated in the model. DAQ replaced the default 

equipment population of recreational marine equipment with Delaware-specific data. DAQ used 
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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recreational boat registration data provided by the Delaware Division of Fish and Wildlife 

(DNREC, 2009) to estimate the total recreational marine equipment population in use within 

Delaware waters. DAQ determined this to be a preferable approach to the NONROAD default 

approach of a top-down allocation of the national equipment population. However, registration 

data were not used to allocate recreational marine activity to the county level because residents 

may register their boats in one county, but use their boats in other parts of the State or 

neighboring counties. 

DAQ updated GAFs for numerous equipment categories. Table 4-3 provides a list of GAFs and 

the associated equipment populations that use the GAFs that were updated with 2008 Delawarespecific data. For golf carts, DAQ replaced the GAFs based on the number of golf courses in 

each county with the county total square kilometers of golf courses in each county. DAQ 

believes that golf cart usage is more directly related to the size of each golf course than to the 

number of courses that exist in each county. If an equipment population is not identified in Table 

4-3, then the model default GAFs were used in the 2008 runs. 

Table 4-3. 2008 Delaware-specific Geographic Allocation Factors

Geographic

Allocation Factor Data Source Equipment Population

Population DE Population Consortium

Aircraft NOx emissions Delaware 2008 inventory Airport ground support equipment

Dollar value of construction US Census Bureau and DE DOL Construction equipment

Harvested acres DE Department of Agriculture Agricultural equipment

Area of golf courses Delaware State Golf Association Golf carts

Wholesale businesses BOC County Business Patterns Commercial equipment

Single and duplex housing BOC FactFinder website Residential lawn & garden equipment

Landscaping businesses BOC County Business Patterns Commercial lawn & garden equipment

Manufacturing employees BOC County Business Patterns Industrial equipment

Snowfall Weather Warehouse website Snow blowers and snowmobiles

4.2.2 Aircraft

The aircraft source category includes emissions from commercial, air taxi, general aviation, and

military aircraft. These sub-categories are described as follows:

• Commercial aircraft are used for scheduled service transporting passengers, freight, or 

both;

• Air taxis are used for scheduled service carrying passengers and/or freight, but are 

smaller aircraft that operate on a more limited basis than the commercial carriers;

• General aviation includes other non-military aircraft used for recreational flying, 

business, personal transportation, and various other activities; and

• Military aircraft are used by the U.S. military in a wide range of missions.

Airport-specific emissions for all aircraft sub-categories were allocated to the county in which 

each airport is located. Where there are multiple airports in a given county, the emissions were 

summed to provide a county-level emissions estimate. Aircraft emissions are reported under the 

following SCCs:
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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Table 4-4. SCCs for Aircraft

SCC Descriptor 1 Descriptor 3 Descriptor 6 Descriptor 8

2275001000 Mobile Sources Aircraft Military Aircraft Total

2275020000 Mobile Sources Aircraft Commercial Aircraft Total: All Types

2275050000 Mobile Sources Aircraft General Aviation Total

2275060000 Mobile Sources Aircraft Air Taxi Total

DAQ estimated annual aircraft emissions using a combination of airport-specific activity data 

and Federal Aviation Administration (FAA)/EPA emission factors. Estimating aircraft 

emissions focuses on the “mixing zone,” which has a height (mixing height) equal to the 

thickness of the inversion layer. Air emissions within this zone are trapped by the inversion 

layer and ultimately affect ground-level pollutant concentrations. When aircraft are above the 

mixing zone, emissions tend to disperse and have no ground-level effects. The aircraft 

operations within the mixing zone are defined by the landing and take-off (LTO) cycle. Each 

LTO cycle consists of five specific operating modes:

• Approach – aircraft operates in this mode when it approaches the airport on 

its descent from the mixing height to when it lands on the runway.

• Taxi/idle-in – aircraft operates in this mode when it taxis from the runway to the gate 

and turns its engines off. 

• Taxi/idle-out – this period occurs from engine start-up to take-off as the aircraft taxis 

from the gate back out to the runway.

• Take-off – this mode is characterized primarily by full-throttle operation that typically 

lasts until the aircraft reaches between 500 and 1000 feet above ground, which is when 

engine power is reduced.

• Climb-out – this mode begins right after the take-off mode and lasts until the aircraft 

passes out of the mixing height.

The operation time in each of these modes is dependent on the aircraft category, local 

meteorological conditions, and operational considerations at a given airport. The time-in-mode 

(TIM) for the take-off operating mode is the least variable.

The following are the general steps to be used to estimate aircraft emissions:

• Determine the mixing height to be used to define the LTO cycle;

• Define the fleet make-up for each airport;

• Determine airport activity in terms of the number of LTOs by aircraft/engine type;

• Select emission factors for each engine model associated with the aircraft fleet;

• Estimate the TIM for the aircraft fleet at each airport;

• Calculate emissions based on aircraft LTOs, emission factors for each aircraft engine 

model, and estimated aircraft TIM; and

• Aggregate the emissions across aircraft.

DAQ contacted the New Castle County and Summit airports to request the number of aircraft 

LTOs for calendar year 2008 for each of the four aircraft types. Additionally, each airport was 
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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requested to provide LTOs by aircraft make and engine type; however this level of detail was not 

provided by the airports for 2008. DAQ assumed 2008 aircraft were of the same mix of 

aircraft/engine types as reported for 2002. Table 4-5 provides the LTO data by the four aircraft 

types for the two airports in New Castle County.

Table 4-5. 2008 LTO Data for New Castle County

Airport County Category LTOs

New Castle County New Castle Military 4,618

New Castle County New Castle Commercial 488

New Castle County New Castle Air Taxi 5,244

New Castle County New Castle General Aviation 40,342

Summit New Castle General Aviation 34,700

DNREC used these airport-specific LTO data to estimate commercial and military aircraft 

emissions using FAA’s Emissions and Dispersion Modeling System (EDMS), Version 5.1

(FAA, 2008). The model requires detailed inputs on aircraft operation by aircraft and engine 

type. DNREC matched the aircraft LTO data to the existing aircraft/engine types in EDMS, and 

used the default EDMS TIM data. A mixing height of 2,300 feet was used for both airports in 

New Castle County based on an isopleth chart of annual average morning mixing heights for the 

continental U.S. as provided in EPA’s Procedures Manual (EPA, 1992). The Delaware Army 

National Guard (DE ARNG) and the Delaware Air National Guard (DE ANG) operate units at 

the New Castle County Airport and contribute to the military LTOs at that airport.

EDMS generates emissions for SO2 and NOx in tons per year. EDMS does not estimate 

particulate emissions by aircraft/engine type. As such, DAQ used fleet average PM2.5 emission 

rates applied to total LTOs outside EDMS. The model also generates emissions for ground 

support equipment (GSE). However, DAQ used the GSE estimates generated from the 

NONROAD model, so these were subtracted from the EDMS results. EPA fleet average 

emission factors were applied to the LTO data to estimate annual general aviation and air taxi 

emissions.

4.2.3 Locomotives

Railroad locomotives are a combustion source of emissions with most significant emissions 

occurring where there is a concentration of railroad activity (such as a large switch yard). The 

primary fuel consumed by railroad locomotives is distillate oil (diesel fuel). Locomotives can 

perform two different types of operations: line haul and yard (or switch). Line haul locomotives 

generally travel between distant locations, such as from one city to another. Yard locomotives 

are primarily responsible for moving railcars within a particular railway yard. Locomotive 

emissions are reported under the SCCs provided in Table 4-6.

For line haul locomotives, DAQ calculated Class I operation emissions separately from Class 

II/III operations. Line haul locomotive emissions for passenger trains and commuter lines were 

estimated to be zero since rail service in Delaware (Amtrak and SEPTA) is electric powered. 

Fuel consumption was used to estimate locomotive engine emissions. Fuel consumption rates 

are usually known only for the entire interstate operating region, therefore, it is necessary to 

allocate the total amount of fuel consumed "system-wide" to Delaware and its counties.
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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Table 4-6. SCCs for Locomotives

SCC Descriptor 1 Descriptor 3 Descriptor 6 Descriptor 8

2285002006 Mobile Sources Railroad Equipment Diesel

Line Haul Locomotives: 

Class I Operations

2285002007 Mobile Sources Railroad Equipment Diesel

Line Haul Locomotives: 

Class II/Class III Operations

2285002010 Mobile Sources Railroad Equipment Diesel Yard Locomotives

Line Haul Locomotives – Class I Operations

Norfolk Southern and CSX Transportation operate Class I locomotives within New Castle 

County. DAQ contacted these companies to obtain estimates of fuel consumption or data to 

calculate fuel consumption (e.g., gross ton-miles (GTM) and gallons of fuel consumed per 

GTM). 

Norfolk Southern provided GTM data at the county level for each county in Delaware in which they 

operated. Norfolk Southern provided a fuel consumption index (GTM/fuel consumed) for the 

system that includes operations in Delaware. CSX provided GTM and fuel consumption data for 

New Castle County, the only county in which CSX operates in Delaware. The system-wide fuel 

consumption indices, county-specific GTM, and calculated county-level fuel consumption are 

provided in Table 4-7.

Table 4-7. 2008 New Castle County Locomotive Fuel Consumption Data for 

Class I Line Haul Operations

Class I Railroad

Gross Ton 

Miles (GMT)

System-wide 

GMT/Gallon 

Diesel

Fuel 

Consumed, 

gallons/year

Norfolk Southern 307,435,000 811.27 377,748

CSX Transportation 683,000,000 886.83 770,161

Line Haul Locomotives – Class II/III Operations

The Maryland & Delaware Railroad is the only Class II/III railroad that operates in New Castle 

County. The company provided 2008 statewide fuel consumption data. The Maryland & 

Delaware Railroad operates in New Castle and Sussex Counties. Track miles within each county 

were used to allocate statewide fuel consumption to each county. The Maryland & Delaware 

Railroad estimated 3,013 gallons of diesel fuel was used in New Castle County for 2008.

Yard Locomotives

Norfolk Southern, CSX Transportation, and Maryland & Delaware have yard operations within 

New Castle County. These companies provided the number of locomotives by switchyard 

location. Table 4-8 provides a summary of switchyard operations and fuel consumption. CSX 

and Maryland & Delaware provided Delaware-specific fuel consumption for 2008. An average 

switchyard engine fuel consumption estimate of 32,447 gallons per year was applied based on a 

recent regional study coordinated through the Eastern Regional Technical Advisory Committee 

(ERTAC, 2010).
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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Table 4-8. 2008 Switchyard Activity and 

Estimated Fuel Consumption

Class I Switchyard

No. of Yard 

Locomotives 

Fuel 

Consumed, 

gallons/year

Norfolk Southern 9 292,024

Maryland & Delaware 1 9,640

CSX Transportation 2 120,000

4.2.4 Commercial Marine Vessels

The CMV sector includes many types of vessels, such as large deep-draft vessels, barge 

towboats, harbor tugs, dredging vessels, ferries, excursion vessels, and commercial fishing 

vessels. In addition to the numerous vessel types, each vessel type engages in different activities 

such as hoteling, maneuvering within the port, and cruising.

In its 1999 final rule for commercial marine diesel engines, EPA defined three categories of 

marine diesel engines based on engine displacement, power and revolutions per minute (rpm) 

(EPA, 1999a). Table 4-9 presents the definitions for each category. 

Table 4-9. U.S. EPA Marine Engine Category Definitions

Category Displacement per cylinder

Power range 

(kW) RPM range

1 disp. < 5 liters and power > 37 kW 37 - 2,300 1,800 - 3,000

2 5 < displacement < 30 liters 1,500 - 8,000 750 - 1,500

3 displacement > 30 liters 2,500 - 80,000 60 - 900

The EPA classifies CMV emissions by fuel type (residual and diesel) and by mode of operation 

(port and underway). CMVs often burn multiple types of fuel and may burn different fuels for 

different operating modes or locations (i.e., near ports). DAQ used the port and underway SCCs 

to characterize the CMV emissions as listed in Table 4-10. The SCC classification is based on 

the most common type of fuel utilized by the vessel category. Ocean-going vessels (OGV) 

predominately burn intermediate fuel oil (IFO). DAQ placed emissions from OGVs burning IFO 

in the residual fuel SCC. This is consistent with how petroleum product sales data are reported 

by the Energy Information Administration and EPA’s classification of fuels (EPA 1999b).

Table 4-10. SCCs for Commercial Marine Vessels

SCC Descriptor 1 Descriptor 3 Descriptor 6 Descriptor 8

2280002100 Mobile Sources Marine Vessels, Commercial Diesel Port emissions

2280002200 Mobile Sources Marine Vessels, Commercial Diesel Underway emissions

2280003100 Mobile Sources Marine Vessels, Commercial Residual Port emissions

2280003200 Mobile Sources Marine Vessels, Commercial Residual Underway emissions

There are four activity modes for CMV; cruise, reduced speed zone (RSZ), maneuver, and hotel. 

Underway emissions are estimated as the combined activity of cruise and RSZ modes. Port 
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

4-9

emissions are estimated as the combined activity of maneuvering and hoteling modes. Emissions 

from ferries and dredging are considered port emissions since these vessels operate primarily 

within the port area.

DAQ calculated emissions for ocean-going vessels, towboats, tug-assist vessels, ferries and 

vessels associated with dredging operations. CMV engine emissions are assumed to be a function 

of the following:

• Mode of operation,

• Vessel type (bulk carrier, tanker, towboat, etc.);

• Vessel dead weight tonnage (DWT);

• Type of engine (2-stroke, 4-stroke, or steam); and

• Length of waterway segment.

Therefore, DAQ accounted for these variations when estimating CMV activity. The four modes 

of operation that are performed by vessels are defined below: 

Cruise - This mode is assumed to begin 25 miles out from the port breakwater until the 

vessel reaches the breakwater (EPA, 1999c). The breakwater is located at the mouth of the 

Delaware Bay. Cruise mode is not applicable to New Castle County. 

Reduced Speed Zone (RSZ) - This mode begins at the breakwater and continues until the 

vessel is one to two nautical miles from the berth or anchorage. The vessel is assumed to 

have a speed of twelve knots during this mode (EPA, 2009c). This mode is also referred to 

as transit, and escort for towboats and tug-assist vessels.

Maneuvering - This mode is defined as the time the vessel slows to below four knots until 

the dock lines are secure. This mode is also referred to as assist mode for tug-assist vessels.

Hoteling - This mode is defined as the time the vessel is at dock. During this mode, the 

vessel operates auxiliary engines for electrical power.

The waterway segment distances used to estimate activity and to allocate the activity to New 

Castle County were estimated from the Google Earth website in 2008 by tracing the shipping 

channel. Segment distances are shown in Table 4-11. The distance South is given to the 

breakwater at the mouth of the Delaware Bay. The distance north is given to the DelawarePennsylvania border. The distance for the C&D Canal East is given from the DelawareMaryland border to the entrance of the Delaware River (Reedy Point).

The engine activity for each mode is calculated using the following equation:

Activitymode = Power × LoadFactor ×Timemode ×Calls

where:

Activitymode = activity by mode (kilowatt-hours)

Power = rated engine power by vessel and engine type (kilowatts)

Load Factor = load factor of the engine by vessel type and mode 

Time = time in mode per call by vessel type (hours)
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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Calls = number of calls by vessel and engine type

Table 4-11. Waterway Segment Distances for the Delaware River Area

Waterway Segment Distance (mi.)

Point South

DE/PA Border 83.8

Oceanport 83.3

Port of Wilmington 76.1

Magellan Terminal 75.6

Delaware City Refinery 66.0

C&D Canal 62.6

Latitude 39o30' 57.7

New Castle Co/Kent Co 48.5

Kent Co/Sussex Co 15.9

Point North

Port of Wilmington 7.7

C&D Canal 21.2

Point East

C&D Canal 13.0

This calculation must be performed for both propulsion and auxiliary engines and for each mode. 

Both propulsion engines and auxiliary engines are operating during cruise, RSZ and 

maneuvering modes. Only auxiliary engines operate during hoteling. Once the activity is 

calculated, it is allocated to the county level using county allocation factors. 

This approach to calculating activity of CMVs was used for all vessel types except vessels 

involved in dredging activity. For dredging, the activity data used for emissions calculations was 

the volume of material dredged. Details on the sources and development of activity data are 

provided in the following subsections.

Ocean-Going Vessels

DAQ obtained vessel call data for ocean-going vessels (OGVs) during calendar year 2008 from 

the Marine Exchange for the Delaware River and Bay (ME, 2010). Data were obtained for 

vessels that called on ports in Delaware, New Jersey and Pennsylvania. The data for the entire 

port area is required since the majority of vessels pass through Delaware waters en route to other 

ports. The vessel call data included the vessel name, ship type, DWT, pier, and the date of the 

call. The ship types calling on the Delaware River Area ports in 2008 are shown in Table 4-12.

Vessels may shift between piers during the same call on the Delaware River area. DAQ adjusted 

the vessel call data to remove shifts between piers, where possible, to avoid double counting 

using a methodology recommended by the staff of the Marine Exchange. Data on the engine 

power and engine type (2-stroke, 4-stroke, and steam) used on OGVs were not available through 

the Marine Exchange. Therefore, DAQ assigned engine power and engine type based on average 

engine data obtained from other sources.

For propulsion engines, the average engine power and the engine type were obtained from the 

EPA report Commercial Marine Activity for Deep Sea Ports in the United States (Deep Sea 

Ports) (EPA, 1999c). This report presents data for vessels that called on the Delaware River area 
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

4-11

ports during calendar year 1996. Note that the Delaware River area includes ports in Delaware, 

New Jersey and Pennsylvania, which are located on the Delaware River. The number of calls by 

vessel and engine type is presented for specific DWT ranges. The average engine power is also 

given. 

Table 4-12. Vessel Types Calling on Delaware River Area Ports in 2008

Codes Main Vessel Type Additional Vessel Types Included w/ Main Type

BU Bulk Chemical (CH), Ore (OR)

CC Container Container/Bulk (CB), Part Container (PC)

GC General Cargo

MS Miscellaneous

Cable Ship (CL), Heavy Lift (HL), Livestock (LV), Tall 

Ship (TS)

PR Passenger

RF Refrigerated Cargo (Reefer) Container Reefer (CR)

RR Roll on-Roll off (RORO) RORO Container (RC)

TA Tanker Bulk Oil (BO), Gas Carrier (PG)

VE Vehicle Carrier

In order to calculate underway emissions, the number of calls (by vessel type and DWT range) 

had to be allocated to each port. The ports in Delaware include the Port of Wilmington, 

Magellan Terminal, Delaware City Refinery, and Oceanport. One port in New Jersey, Bermuda 

International on Salem Creek, is located adjacent to Delaware. All other ports in New Jersey and 

all ports in Pennsylvania are located north of the Delaware/Pennsylvania state line. Vessels 

calling on New Jersey and Pennsylvania ports must be included in underway emission 

calculations for Delaware since the vessels travel through the Delaware portion of the bay and 

river. 

Table 4-13 presents the assigned propulsion engine power and the number of calls by vessel 

type, DWT range and engine type for calls on the Delaware River area in 2008. In addition to 

vessels traveling in the Delaware River Bay and River, 424 OGVs traversed the C&D Canal to 

or from the Chesapeake Bay.

Towboats and Tug Assists

Towboats are used to transport non-self-propelled vessels, either dry cargo or tanker barges, 

throughout the Delaware River area, including the C&D Canal. DAQ obtained data on the 

number of towboat trips during calendar year 2008 from Waterborne Commerce of the United 

States (USACE, 2010a). DAQ subtracted the number of towboat trips for the Port of Wilmington 

(POW) and the C&D Canal from the number of trips on the Delaware River (PA to the Sea). For 

towboats traveling to and from the POW and traveling through the C&D Canal, DAQ assumed 

that half the vessels travel north and the other half travel south to/from the POW and the canal.

In 2008, 13,203 towboat trips transited Delaware waters on the Delaware River, with a trip 

defined as a one-way passage. 1,184 towboat trips entered or exited the Port of Wilmington, and 

3,597 towboat trips transited the C&D Canal.
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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Table 4-13. Average Propulsion Engine Power and the 2008 Number of Calls for 

OGVs Calling on the Delaware River Area (DE, NJ and PA)

Code DWT Range

Engine 

Type

Power 

(hp) Calls Code DWT Range

Engine

Type

Power 

(hp) Calls

BU < 25,000 2-stroke 9,665 41 RF 15,000-25,000 2-stroke 18,467 72

BU < 25,000 4-stroke 7,504 6 RR <15,000 2-stroke 8,280 13

BU 25,000 - 35,000 2-stroke 9,696 85 RR <15,000 4-stroke 8,553 13

BU 35,000 - 45,000 2-stroke 10,320 56 RR 15,000 - 30,000 2-stroke 12,852 16

BU > 45,000 2-stroke 16,328 90 RR >30,000 2-stroke 26,562 0

CC < 25,000 2-stroke 17,757 126 TA <30,000 2-stroke 10,008 75

CC < 25,000 4-stroke 10,898 67 TA <30,000 4-stroke 7,077 18

CC 25,000 - 35,000 2-stroke 16,327 145 TA <30,000 Steam 14,646 8

CC 35,000 - 45,000 2-stroke 34,467 117 TA 30,000 - 60,000 2-stroke 12,616 195

CC > 45,000 2-stroke 30,856 54 TA 30,000 - 60,000 4-stroke 15,360 13

GC < 15,000 2-stroke 5,784 45 TA 30,000 - 60,000 Steam 15,498 135

GC < 15,000 4-stroke 3,944 57 TA 60,000 - 90,000 2-stroke 16,026 69

GC 15,000 - 30,000 2-stroke 10,456 30 TA 60,000 - 90,000 4-stroke 14,305 10

GC 15,000 - 30,000 4-stroke 7,536 5 TA 90,000 - 120,000 2-stroke 15,451 302

GC 30,000 - 45,000 2-stroke 12,876 33 TA 90,000 - 120,000 Steam 23,923 7

GC > 45,000 2-stroke 12,170 2 TA 120,000 - 150,000 2-stroke 23,046 56

MS < 10,000 2-stroke 3,500 6 TA > 150,000 2-stroke 25,559 113

MS < 10,000 4-stroke 11,671 3 TA > 150,000 Steam 36,324 35

PR < 5,000 4-stroke 16,108 12 VE <12,500 2-stroke 11,877 13

PR 5,000 - 10,000 4-stroke 20,776 0 VE <12,500 4-stroke 13,150 3

PR 5,000 - 10,000 steam 40,649 1 VE 12,500 - 15,000 2-stroke 12,859 30

RF 5,000 - 10,000 2-stroke 9,706 115 VE 12,500 - 15,000 4-stroke 14,770 6

RF 5,000 - 10,000 4-stroke 6,837 20 VE 15,000 - 17,500 2-stroke 13,911 30

RF 10,000 - 15,000 2-stroke 12,500 173 VE > 17,500 2-stroke 15,224 51

RF 10,000 - 15,000 4-stroke 15,672 3

Tugs assist OGVs from the shipping channel to its intended berth and then back to the channel 

when the vessel leaves port. This activity is considered the maneuvering mode for OGVs. Two 

tugs are typically required to assist an OGV with a DWT greater than 20,000 tons; for smaller 

OGVs, one tug suffices (EPA, 2009b). The number of tug assists (3,428 in 2008) is directly 

related to the number of OGVs calling to a Delaware port. Note that a tug assisting a vessel to 

Bermuda International in New Jersey and the piers at the oil refineries in Marcus Hook, PA will 

require a tug to pick up the OGV in Delaware waters, thus tug assists are included for these 

docks. The tug meeting time to the docking time is usually within one hour (Anderson, 2010).

In addition to assisting OGVs to maneuver into port, tugboats escort gas carriers through the 

Delaware Bay and River (Andersen, 2010). Other vessels typically do not utilize an escort. Tug 

escort trips are included in the number of towboat trips transiting Delaware waters presented 

above. DNREC did not estimate emissions from hoteling of towboats and tugs due to lack of 

activity data.

Vessel speeds, average maneuvering and hoteling time, propulsion and auxiliary engine 

horsepower ratings, and engine load factors for OGVs, towboats, and tugs were obtained from 

EPA’s Deep Sea Ports (EPA, 1999c) and Preparing Port Emission Inventories (EPA, 2009b).
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

4-13

For RSZ mode, time-in-mode for each vessel was calculated based on vessel speeds and 

waterway segment distances provided in Table 4-11.

Dredging

Maintenance dredging is performed routinely on the Delaware River to keep the channels to their 

required depths. Dredging involves multiple vessels, including dredges, assist tugs, and generator 

barges that provide additional power. Estimating emissions from dredging vessel engine activity 

is time-consuming. Therefore, DAQ developed emissions based on the volume of material 

dredged during calendar year 2008 rather than engine activity in kilowatt-hours.

DAQ obtained the dredging activity data from both the USACE and from within DNREC. The 

amount of material dredged by USACE contractors was obtained from the USACE report on 

dredging contracts awarded for the year 2008 (USACE, 2010b). DAQ also contacted the 

Delaware Division of Soil and Water Conservation to obtain the amount of material dredged by 

the Division (DSWC, 2010). Table 4-14 presents the estimated amount of material dredged and 

the type of dredge used. DAQ assumed all the dredging activity is maintenance dredging. New 

cut dredging results in higher emissions, therefore this assumption may result in lower emission 

estimates than are actually occurring in the area.

Table 4-14. Material Dredged in the New Castle County Portion of the

Delaware River Area during 2008

Project Location

Type of 

Equipment

Total Material 

Dredged (cubic yards)

Philadelphia to the Sea Hydraulic Dredge 732,697

Chesapeake & Delaware Canal Hydraulic Dredge 600,000

Port of Wilmington Hydraulic Dredge 650,000

Premcor Berth Maintenance Hydraulic Dredge 230,000

Ferries 

The Three Forts Ferry was identified as the only ferry service in New Castle County. This ferry 

travels from either Delaware City, DE or Fort Mott, NJ to Fort Delaware located on Pea Patch 

Island in the Delaware River. Monthly trip count data for the ferry was obtained by contacting 

the Delaware River & Bay Authority (DRBA, 2010). The Three Forts Ferry made 2,280 oneway trips in 2008. The Delaware River and Bay Authority also provided the engine and time-inmode data for the Three Forts Ferry.

Spatial Allocation

DAQ developed county allocation factors for CMV activity data based on the location of the 

activity on the various waterways and length of the waterway segment. In developing county 

allocation factors, DAQ assumed that from latitude 39o

30' to 25 miles beyond the mouth of the 

Delaware Bay, the activity is split evenly between Delaware and New Jersey since the ship 

channel roughly corresponds to the boundary between the two states. Above latitude 39o30', all 

emissions are allocated to Delaware since the entire breadth of the river is under Delaware’s 
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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jurisdiction. Allocations were developed for each activity mode, since the activity takes place in 

different areas depending on the mode.

For OGV maneuvering and hoteling modes, the activity is allocated to the county in which the 

port is located. All the Delaware ports are located in New Castle County. Therefore, all 

maneuvering and hoteling activity was allocated to New Castle County. 

For the RSZ mode, county allocation factors were developed for the four ports in Delaware (Port 

of Wilmington, Magellan Terminal, Oceanport, and Delaware City Refinery), Bermuda 

International in New Jersey, and from the Pennsylvania-Delaware border to the breakwater 

(PA/DE to the Sea).

Allocating dredging to each county was based on the river miles in each county, and split 

between Delaware and New Jersey below latitude 39o

30'. While the Three Forts Ferry travels to 

Fort Mott on the New Jersey side of the Delaware River, at that latitude, Delaware’s 

jurisdictional waters extend the breadth of the river. Therefore, all activity for the Three Forts 

Ferry was allocated to New Castle County.

4.3 2008 Emissions Summary

Table 4-15 provides a summary of the 2008 annual (tons per year, TPY) New Castle County 

emissions for aircraft, locomotives, commercial marine vessels, and all equipment emissions 

estimated using EPA’s NONROAD model. The non-road sector is a significant contributor to 

PM2.5 emissions and emissions of NOx and SO2 as precursors to the secondary formation of 

PM2.5 in New Castle County. The totals may not match the sum of the individual values due to 

independent rounding.

Table 4-15. Summary of 2008 New Castle County Emissions from Non-road 

Sources in tons/year

Source Categories PM2.5 SO2 NOX

NONROAD Model Equipment 148 28 1,676

Aircraft 8 2 13

Locomotives 9 3 239

Commercial Marine Vessels 146 1,034 2,389

NON-ROAD SECTOR TOTAL 312 1,067 4,317

4.4 References

Anderson, 2010: Scott Anderson, Maritime Exchange for the Delaware River and Bay, 

Philadelphia PA, e-mail to David Fees, DNREC, on March 24, 2010.

DNREC, 2009: Delaware Department of Natural Resources and Environmental Control, 

Division of Fish and Wildlife, Delaware Annual Boating Statistics.

DRBA, 2010: Monthly trips data for the Three Forts Ferry, provided by J. Fred Coldren, 

Delaware River and Bay Authority, via e-mail to David Fees, DNREC, March 22, 2010. 
2008 NEW CASTLE COUNTY ATTAINMENT YEAR SIP EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

4-15

DSWC, 2010: Brian Kelly, Delaware Division of Soil and Water Conservation, e-mail to David 

Fees, DNREC, on February 23, 2010.

EPA, 1992: U.S. Environmental Protection Agency, Office of Air and Radiation, Procedures for 

Emission Inventory Preparation, Volume IV: Mobile Sources, EPA-450/4-81-026d 

(Revised), 1992. 

EPA, 1999a: Final Regulatory Impact Analysis: Control of Emissions from Marine Diesel 

Engines. U.S. Environmental Protection Agency, Office of Mobile Sources, Engine 

Programs and Compliance Division, EPA420-R-99-026, November 1999.

EPA, 1999b: In-Use Marine Diesel Fuel, U.S. Environmental Protection Agency, Office of 

Mobile Sources, Engine Programs and Compliance Division, EPA 420-R-99-027, August 

1999.

EPA, 1999c: Commercial Marine Activity for Deep Sea Ports in the United States. U.S. 

Environmental Protection Agency. Prepared by ARCADIS Geraghty & Miller, Inc. 

EPA420-R-99-020, September 1999.

EPA, 2009a: Suggested Nationwide Average Fuel Properties. Assessment and Standards 

Division, Office of Transportation and Air Quality, U.S. Environmental Protection 

Agency. EPA-420-B-09-018, April 2009.

EPA, 2009b: Current Methodologies in Preparing Mobile Source Port-Related Emission 

Inventories. U.S. Environmental Protection Agency. Prepared by ICF International, 09-024, 

April 2009.

ERTAC, 2010. “ERTAC Rail Emissions Inventory – Part 2: Class I Railyard Switcher 

Locomotives”, Eastern Regional Technical Advisory Committee, October 2010.

FAA, 2008: Federal Highway Administration, “Emissions and Dispersion Modeling System 

(EDMS) User’s Manual”, Version 5.1, FAA-AEE-07-01, Revision 5, September 19, 2008.

ME, 2010: “Ship Traffic: Delaware River Ports: 2008” [data files], from Scott Anderson, 

Maritime Exchange for the Delaware River and Bay, Philadelphia PA, via e-mail to David 

Fees, Division of Air Quality, DNREC, February 2010. 

USACE, 2010a: Waterborne Commerce of the United States – Calendar Year 2008 – Part 1 

Waterways and Harbors Atlantic Coast. Department of the Army Corps of Engineers, 

Institute of Water Resources, WR-WCUS-08-1, March 2010.

USACE, 2010b: “U.S. Army Corps of Engineers Dredging Contracts Awarded; Fiscal Year 2008

Awards”, U.S. Army Corps of Engineers, information retrieved in 2010 from 

http://www.iwr.usace.army.mil/ndc/dredge/pdf/awards08.pdf
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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SECTION 5

ON-ROAD MOBILE SOURCES

The 2008 on-road mobile source inventory is an estimate of vehicle emissions based on actual 

vehicle miles traveled (VMT) on Delaware roadways in 2008 using EPA’s Motor Vehicle 

Emission Simulator (MOVES) model. Vehicles include passenger cars, light-duty trucks, 

including sport utility vehicles, heavy-duty trucks, buses, and motorcycles. Emissions were 

calculated for vehicles fueled by gasoline or diesel. Controls as of 2008 were incorporated into 

the MOVES model inputs, and thus emissions account for controls. Engine exhaust emissions for 

PM2.5, SO2, and NOx, as well as for other criteria pollutants, air toxics, and greenhouse gases 

were calculated. In addition, particulate matter brake and tire wear emissions were separately 

calculated. Monthly emissions were calculated by roadway class, vehicle type, and county. 

The applicable Standard Classification Codes (SCCs) comprising vehicle type, roadway class, 

and emission process (exhaust, evaporative, brake wear, and tire wear) are shown in Table 5-1. 

As an example, the SCC applicable to exhaust emissions from a passenger car fueled by gasoline 

on an urban interstate would be 220100123X, with the “2201001” indicating that the vehicle is a 

light-duty gasoline vehicle, the “23” indicating the activity is occurring on an urban interstate, 

and the “X” indicating that the emissions are exhaust emissions.

Table 5-1. SCCs Included in On-road Mobile Inventory

SCC 

Digits

Applicable 

Portion of 

SCC Code

Portion that SCC 

Describes Description

1 - 7 2201001 Vehicle type Light-duty gasoline vehicles (passenger cars)

1 - 7 2201020 Vehicle type

Light-duty gasoline trucks 1 (0-6,000 lb gross vehicle 

weight rating [GVWR])

1 - 7 2201040 Vehicle type Light-duty gasoline trucks 2 (6,001-8,500 lb GVWR)

1 - 7 2201070 Vehicle type Heavy-duty gasoline vehicles (> 8,500 lb GVWR)

1 - 7 2201080 Vehicle type Motorcycles (gasoline)

1 - 7 2230001 Vehicle type Light-duty diesel vehicles (passenger cars)

1 - 7 2230060 Vehicle type Light-duty diesel trucks (0-8,500 lb GVWR)

1 - 7 2230071 Vehicle type

Class 2b heavy-duty diesel vehicles (8,501-10,000 lb 

GVWR)

1 - 7 2230072 Vehicle type

Class 3, 4, and 5 heavy-duty diesel vehicles (10,001-

19,500 lb GVWR)

1 - 7 2230073 Vehicle type

Class 6 and 7 heavy-duty diesel vehicles (19,501-

33,000 lb GVWR)

1 - 7 2230074 Vehicle type Class 8 heavy-duty diesel vehicles (> 33,000 lb GVWR)

1 - 7 2230075 Vehicle type Diesel buses

8 - 9 11 Roadway type Rural interstates

8 - 9 13 Roadway type Rural other principal arterials

8 - 9 15 Roadway type Rural minor arterials

8 - 9 17 Roadway type Rural major collectors

8 - 9 19 Roadway type Rural minor collectors

Continued next page
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

5-2

Table 5-1. continued

SCC 

Digits

Applicable 

Portion of 

SCC Code

Portion that SCC 

Describes Description

8 - 9 21 Roadway type Rural locals

8 - 9 23 Roadway type Urban interstates

8 - 9 25 Roadway type Urban other freeways and expressways

8 - 9 27 Roadway type Urban other principal arterials

8 - 9 29 Roadway type Urban minor arterials

8 - 9 31 Roadway type Urban collectors

8 - 9 33 Roadway type Urban locals

10 X Emission process Exhaust

10 V Emission process Evaporative

10 B Emission process Brake wear

10 T Emission process Tire wear

5.1 Input Data Specific to New Castle County for 2008

The 2008 inventory was the first year that DAQ used the MOVES model to develop on-road 

mobile emissions. The MOBILE6.2 model was used previously. The MOVES model allows for 

adjustments to a variety of model inputs, and as such, DAQ, with assistance from the Delaware 

Department of Transportation (DelDOT), put forth considerable effort in creating a suite of 

county-specific 2008 input data files. The New Castle County-specific input data types created 

for the 2008 inventory include VMT (by vehicle and roadway type), vehicle registration data 

(vehicle populations and age distributions), meteorological data (temperature and relative 

humidity), average speeds in the form of speed bin fractions (weekday versus weekend and by 

roadway type), fuel formulations and supply, and inspection and maintenance program 

specifications. Each of these input data sets are discussed separately below.

5.1.1 Vehicle Miles Traveled (VMT) Data

The activity data used for developing the on-road emission inventory is VMT. DelDOT provided 

2008 VMT data by roadway type for New Castle County. DelDOT is required to submit calendar 

year VMT data annually to the Federal Highway Administration’s (FHWA) Highway 

Performance Monitoring System (HPMS). The VMT is estimated based on data from permanent 

traffic count stations throughout the county. DelDOT’s traffic count program provides daily and 

seasonal variation data. Additional temporary stations provide shorter-term counts that are 

expanded with factors derived from appropriate permanent count stations. Counting and 

expansion activities are consistent with FHWA guidelines. The traffic data submitted to HPMS 

are considered the most accurate VMT totals for New Castle County.

Since the VMT provided by DelDOT is supplied by HPMS roadway type, the task of creating 

VMT by MOVES road type fractions only requires mapping the twelve HPMS road types to the 

four MOVES road types. The road type allocations for New Castle County for 2008 are provided 

in Table 5-2.
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

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Table 5-2. New Castle County VMT Fractions by Road Type

MOVES 

Road Type 

Code Road Type Description

VMT Fraction 

by Road Type

2 Rural Restricted Access 0.0000

3 Rural Unrestricted Access 0.1274

4 Urban Restricted Access 0.2813

5 Urban Unrestricted Access 0.5914

Total 1.0000

VMT Fractions by Vehicle Type

VMT by vehicle type data are not collected in Delaware, so an alternate procedure was 

developed using the local registration data in calculating the VMT mixes rather than using the 

default MOVES VMT distribution by vehicle type. This methodology uses national default 

MOVES mileage accumulation and diesel sales fraction data in combination with the Delaware 

county-specific registration data to develop estimates of VMT by vehicle type. The number of 

vehicles registered in Delaware by model year, vehicle type, and county was multiplied first by 

the MOBILE6.2 default gasoline or diesel sales fraction corresponding to that vehicle type and 

model year, and then by the average number of miles accumulated annually by vehicles of the 

same age and vehicle type in the MOBILE6.2 default mileage accumulation database. This 

provided an estimate of VMT by vehicle age and vehicle type. These VMT estimates were then 

summed for all years by vehicle type. The total VMT for each vehicle type was divided by the 

total calculated VMT to give VMT fractions by vehicle type. Table 5-3 presents the resulting 

VMT fractions by vehicle type for New Castle County.

Table 5-3. New Castle County VMT Fractions by Vehicle Type

MOVES 

Vehicle 

Type Code Vehicle Description

VMT 

Fraction by 

Vehicle Type

11 Motorcycle 0.0072

21 Passenger Car 0.4469

31 Passenger Truck 0.3738

32 Light Commercial Truck 0.1325

41 Intercity Bus 0.0031

42 Transit Bus 0.0011

43 School Bus 0.0018

51 Refuse Truck 0.0003

52 Single Unit Short-haul Truck 0.0078

53 Single Unit Long-haul Truck 0.0007

54 Motor Home 0.0003

61 Combination Short-haul Truck 0.0122

62 Combination Long-haul Truck 0.0123

Total 1.0000
2008 ATTAINMENT YEAR STATE IMPLEMENTATION PLAN EMISSIONS INVENTORY FOR PM2.5, SO2, & NOX

5-4

VMT Temporal Allocations

The MOVES model input files include allocations of VMT by month. Monthly allocation of 

VMT is accomplished through the use of permanent count station data provided by DelDOT. 

For 2008, DelDOT provided monthly VMT data from 27 permanent count stations throughout 

New Castle County. Each month’s data for all 27 count station were summed and divided by the 

sum of the annual VMT recorded by the 27 stations. The monthly VMT fractions created in this 

way are provided in Table 5-4.

Table 5-4. Monthly VMT Allocation Fractions

Month

VMT 

Fraction Month

VMT 

Fraction

January 0.0795 July 0.0877

February 0.0735 August 0.0905

March 0.0834 September 0.0819

April 0.0859 October 0.0795

May 0.0901 November 0.0784

June 0.0860 December 0.0836

5.1.2 Meteorological Data

Temperature and relative humidity are the meteorological data required for MOVES runs. 

Hourly data were obtained from the National Climatic Data Center (NCDC, 2010) from data 

collected at the New Castle County airport. These data were compiled as monthly averages of 

each hour of the day for input into the MOVES runs.

5.1.3 Fuel Data

The entire State receives Federal reformulated gasoline. However, the fuel parameters vary 

seasonally as well as by county, based on information from EPA’s Reformulated Gasoline Fuel 

Survey. This survey reports in-use gasoline parameters during winter and summer. New Castle 

County is well-represented in this survey, as the Philadelphia, PA-Wilmington, DE-Trenton, NJ 

area is one of the surveyed areas. Thus, it was felt that the parameters obtained from this study 

could be directly applied for use in the Delaware inventory. Fuel parameters were obtained from 

the survey for calendar year 2008 and obtained directly from EPA (EPA, 2009) since the Office 

of Transportation and Air Quality ceased posting such data on their RFG fuel survey data web 

page after 2006.

The MOVES model has nearly 9,000 choices in its library of fuel formulations. Summertime fuel 

survey data for 2008 from 21 gasoline stations located in New Castle County were averaged for 

Reid Vapor Pressure (RVP) to determine the fuel formulation that best matched in-use fuel 

characteristics in New Castle County. The summer fuel data were applied to the ozone season 

months of May through September. The summer fuel data were also applied to October as data 

indicated that fuel formulations are slow to switch to wintertime fuel. The winter fuel data were 

applied to January, February, and December, based on survey data. Fuel RVP for the remaining 

months (March, April, and November) were calculated using a straight line interpolation method
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between summer and winter fuel data. The resulting RVP and sulfur content for New Castle 

County by month are provided in Table 5-5. 

Table 5-5. 2008 Gasoline Fuel Parameters for New Castle County

Months

Reid Vapor 

Pressure (psi)

Sulfur Content 

(ppm)

Jan, Feb and Dec 13.4 51.8

Mar, Apr and Nov 10.6 52.4

May - Oct 6.86 53.1

 Source: EPA Reformulated Gasoline Survey, 2009.

5.1.4 Vehicle Populations and Age Distributions

Vehicle registration data were obtained from the Delaware Division of Motor Vehicles (DMV).

The data are a snapshot of DMV’s registration database as of July 1, 2008. The data show the 

number of vehicles registered by model year for each of the 16 MOBILE6.2 vehicle classes. The 

16 vehicle classes were converted to the 13 MOVES vehicle types using a converter provided by 

EPA. New Castle vehicle populations by MOVES vehicle type are provided in Table 5.6. 

Vehicle age distribution fractions were developed for each of the 13 vehicle types based on 

model year. Vehicle 30 years and older were lumped into one fraction.

Table 5-6. 2008 Vehicle Populations for New Castle County

Vehicle 

Code Vehicle Type

Number of 

Vehicles

11 Motorcycle 12,505

21 Passenger Vehicle 244,034

31 Passenger Truck 149,742

32 Light Commercial Truck 49,542

41 Intercity Bus 398

42 Transit Bus 244

43 School Bus 997

51 Refuse Truck 77

52 Single Unit Short-Haul Truck 3,103

53 Single Unit Long-Haul Truck 216

54 Motor Home 390

61 Combination Short-Haul Truck 1,211

62 Combination Long-Haul Truck 917

5.1.5 Vehicle Speeds

The MOVES model represents average vehicle speeds by roadway type through the use of speed 

bin fractions. There are 16 speed bins with the first representing speeds less than 2.5 miles per 

hour (mph), with each subsequent bin having a range of 5 mph (i.e., 42.5 mph – 47.5 mph). The 

final bin represents speeds equal to or greater than 72.5 mph. For 2008, DelDOT provided 

seasonal speed bin fractions for each of the four MOVES roadway types, for each hour of the

day, and for weekday and weekend driving patterns. DelDOT estimated speeds using the 

Peninsula travel demand model. The model accounts for traffic volumes and variations in travel 
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according to purpose, which impact average speeds. Table 5-7 summarizes the matrix of 

parameters that results in 12,288 records for speeds in New Castle County.

Table 5-7. 2008 Average Speed Matrix

Parameter

Number of 

Variables

Season 4

Hour 24

Roadway Type 4

Weekday/Weekend 2

Speed Bins 16

5.1.6 Northeast Ozone Transport Region Low Emission Vehicle Program

Delaware belongs to the Northeast Ozone Transport Region (OTR). The States in this region 

have adopted a low-emission vehicle program that began with the 1999 model year. The 

National LEV program (NLEV), which began with the 2001 model year, is the default modeled 

in MOVES. Therefore, to correctly model the Northeast Ozone Transport Region LEV program 

in place in Delaware, the early NLEV database was used in the MOVES run specification. The 

phase-in schedule of the Northeast Ozone Transport Region LEV program is shown in Table 5-8. 

This phase-in schedule was applied to gasoline-powered passenger cars, passenger trucks, and 

light commercial trucks under 8,501 GVWR. 

Table 5-8. LEV Implementation Schedule in the Northeast OTR

Model Year

Federal Tier I 

Standards

Transitional LEV 

Standards

LEV 

Standards

Tier 2 

Standards

1999 30% 40% 30%

2000 40% 60%

2001 - 2003 100%

2004 and later 100%

5.1.7 Inspection and Maintenance (I/M)

The I/M programs for New Castle County include a biennial onboard diagnostic testing program 

(OBD II) since 2002 for 1996 and later model year vehicles. Vehicle emission computer systems 

are checked for any diagnostic trouble codes present, a symptom of excess emissions which is a 

failing result for the vehicle. Older vehicles, starting with model year (MY) 1968, are given a 

curb idle test (MY 1968-1980) or a two-speed idle test (MY 1981- 1995). A tailpipe probe is 

inserted for 60 seconds to determine exhaust concentrations of hydrocarbons and carbon 

monoxide. Depending on the model year, vehicles with an excess emission concentration of 

either pollutant will fail the test. Older vehicles (MY 1975-1995) are also given a fuel system 

pressure test (FP) and a gas cap (GC) test. Air pressure is applied to the fuel system from the 

fuel inlet to the canister. After air pressure has been applied, pressure degradation is monitored. 
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Vehicles fail the fuel system pressure test if it cannot maintain the equivalent pressure of eight 

inches of water for up to two minutes after being pressurized to 14.0 ± 0.5 inches of water. A similar 

pressure test is applied to the vehicle’s gas cap.

Table 5-9. New Castle County I/M Program Parameters

Test Type IDLE 2500/IDLE FP & GC OBD I/M

Test Frequency Biennial Biennial Biennial Biennial

Program Type Test Only Test Only Test Only Test Only

Model Years 1968-1980 1981-1995 1975-1995 1996-2003

Compliance Factors

Passenger Vehicle 88.57 94.82 96.00 95.23

Passenger Truck 84.60 89.17 90.24 89.53

Light Comm. Truck 79.20 83.48 84.48 83.82

Vehicles Tested (gasoline only)

Passenger Vehicle Yes Yes Yes Yes

Passenger Truck Yes Yes Yes Yes

Light Comm. Truck 

(up to 8,500 GVWR) Yes Yes Yes Yes

School Bus No No No No

Single Unit

Short-Haul Truck No No No No

Single Unit

Long-Haul Truck No No No No

Refuse Truck No No No No

Combination

Short-Haul Truck No No No No

Combination

Long-Haul Truck No No No No

Motor Home No No No No

Intercity Bus No No No No

Transit Bus No No No No

Motorcycle No No No No

5.2 Running the MOVES Model

Running the MOVES model is accomplished through the development of (1) a run specification 

unique to a particular scenario of interest (2) the County Data Manager (CDM) that contains the 

various model inputs as described in Section 5.1 of this report, and (3) the form of the desired 

data output files. Unlike the MOBILE6 model that generated only emission factors that then 

were matched with the corresponding activity data, such as VMT, to develop emission estimates, 

the MOVES model, when executed in the Inventory Mode, provides final emissions.
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The run specification, or “runspec”, is where a user identifies the modeling scale (national, 

county, or project-level domain), and scenario parameters such as whether to run MOVES in 

inventory or lookup table mode, geographic boundaries (a county or multiple counties), time 

spans (year, month(s), hour(s) of the day, weekdays and weekends), fuel types, vehicle types, 

road types, and pollutants. The runspec is also where input data sets (other than the CDM) are 

identified. Two input data sets were prepared for 2008 MOVES runs, including the early NLEV 

program (see Section 5.1.6) and Stage 2 vapor recovery controls. All other inputs are provided in 

the CDM.

The CDM for New Castle for 2008 included county-specific data for all of the parameters 

provided in Section 5.1 of this report. Conversely, model default data were used for the 

following parameters: VMT daily and hourly fractions, ramp fractions, and diesel sales fractions

by vehicle type. In addition, speed bin profiles and road type VMT fractions were not vehicle 

type specific.

The MOVES emissions outputs were specified by county and month at the SCC level (see Table 

5-1). 

5.3 Controls

All MOVES-recognized on-road control measures known to be in place in Delaware in 2008 

were included in the MOVES emission inventory mode modeling. Local control programs 

include Delaware’s I/M program, the Federal reformulated gasoline program, and the Northeast 

Ozone Transport Region LEV program. The MOVES model internally includes all national 

control programs, such as the Tier 1 and Tier 2 gasoline fuel and light duty engine emission 

standards as well as the ultra-low sulfur diesel fuel and heavy duty engine standards.

Two Delaware control programs, the anti-tampering procedures (ATP) performed at the 

inspections lanes and the anti-idling regulation (DNREC, 2005) were not accounted for in the 

MOVES runs since the model does not provide for inputting these programs. For the ATP 

control program, vehicles that are tested are also checked to see if the catalytic converter, gas cap 

and fuel inlet restrictor are present. Vehicles will fail inspection if any of these devices are 

missing.

Regulation 1145, Excessive Idling of Heavy Duty Vehicles, is designed to eliminate emissions 

caused by extending idling. While MOVES delineates emissions processes for extended idling, 

currently the available control programs within MOVES do not account for anti-idling measures. 

Delaware currently has no off-model method to determine emission benefits from either ATP or 

Reg. 1145.

5.4 Results

The PM2.5 exhaust emissions are comprised of elemental carbon, organic carbon, and sulfates, 

while total PM2.5 shown in Table 5-10 includes exhaust, brake wear, and tire wear emissions. 

PM2.5 exhaust emissions account for 91.4% of total PM2.5 emissions.
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Table 5-10. 2008 Annual On-road Mobile Emissions by Vehicle Type

for New Castle County

Vehicle Type

Annual Emissions, TPY

PM2.5 SO2 NOx

Light-duty Gasoline Vehicles 49 31 2,188

Light-duty Gasoline Trucks 55 44 3,310

Heavy-duty Gasoline Vehicles 5 4 324

Motorcycles 2 1 40

Light-duty Diesel Vehicles 1 0 11

Light-duty Diesel Trucks 8 1 130

Heavy-duty Diesel Vehicles 142 12 2,879

Total 282 94 9,311

5.5 References

DNREC, 2005: Regulations Governing the Control of Air Pollution, Regulation 1145, Delaware 

Department of Natural Resources and Environmental Control, Division of Air Quality, 

April 11, 2005.

EPA, 2009: U.S. Environmental Protection Agency, “Reformulated Gasoline Parameters for 

2008” spreadsheet containing fuel survey data send via e-mail by Jamiee Dong, Office of 

Transportation and Air Quality, to Steven Potter, Bureau of Air Management, CT DEM, 

March 4, 2009.

NCDC, 2009: Annual Climatological Summary, National Climatic Data Center, Asheville, NC,

website accessed December 2009.