Technical Support Document (TSD) For 

Emissions Inventories for the Delaware Nonattainment Area

Particulate Matter (PM2.5) State Implementation Plan (SIP) Base Year
Inventory.

Submitted June 2007 by the 

Delaware Department of Natural Resources

And Environmental Control (DNREC)

TSD Prepared April, 2010

Janet C. Kremer

Office of Air Monitoring and Analysis, 3AP40

U.S. Environmental Protection Agency, Region 3

1650 Arch Street

Philadelphia, Pennsylvania 19103

/s/

____________________________________________

Reviewed by Walter Wilkie, Associate Director

Office of Air Monitoring and Analysis, 3AP40

June 16, 2010

_________________

Date Signed

        

Introduction

The purpose of this document is to provide a technical summary of the
Office of Air Monitoring and Analysis (OAMA) review of the emissions
inventories submitted with the Delaware Nonattainment Area PM2.5 SIP by
DNREC.  This review determines the approvability of the SIP Base Year
Inventory and an evaluation of the methods used for projection year
inventories.  A SIP Base Year Inventory is the starting point from which
other SIP inventories are derived as well as serving as the benchmark
for other SIP planning activities, such as the establishment of an
emissions reduction credit program.  Projection year inventories are
essentially used to track progress; the purpose of which is to
demonstrate a reduction in emissions of regulated sources from the Base
Year to a projected year.  The Delaware Nonattainment Area was
designated as a PM2.5 nonattainment area in 2004.  DNREC has submitted
the Delaware Nonattainment Area PM2.5 SIP and has requested EPA’s
approval.

Any questions pertaining to this technical summary should be directed to
Walter K. Wilkie, Associate Director, Office of Air Monitoring and
Analysis, at 215-814-2150 or via email at   HYPERLINK
"mailto:wilkie.walter@epa.gov"  wilkie.walter@epa.gov . 

II.	2002 SIP Base Year Inventory

The SIP base year inventory is the primary inventory from which other
inventories (3-year cycle inventories, reasonable further progress
inventories, modeling inventories) are derived.  The Clean Air Act calls
for State, local, and Tribal agencies to ensure that the base year
inventory is comprehensive, accurate, and current for all actual
emissions.  The base year inventory includes emissions estimates from
stationary point and nonpoint sources, onroad mobile sources, and
nonroad mobile sources.  For the PM2.5 NAAQS, the pollutants to be
inventoried are NH3, PM10, PM2.5, VOC, NOx and SO2.  For the NAAQS, NH3,
PM10, PM2.5, VOC, NOx and SO2 emissions should be reported as actual
annual emissions.  DNREC’s base year inventory is for 2002.  For the
Delaware SIP, the geographic coverage includes sources in New Castle
County.  A significant amount of documentation is required for these SIP
base year estimates which DNREC has provided.  

	DNREC’s Emission Inventory Development (EID) Program (which resides
within the Air Quality Management Section (AQMS)) was primarily
responsible for preparing the 2002 base year PM2.5 precursor inventory. 
The point source inventory represents facility-specific data for larger
stationary sources.  Point source emissions data are submitted to AQMS
by the facilities using Terminal Server Satellite i-STEPS software. 

i-STEPS are the point source emission inventory electronic data
management system. The criteria used to determine if a source would be a
part of the point source inventory was as follows: 

Facilities that held a Title V permit in 2002; 

Any facility with emissions of VOCs greater than 5 TPY for any of the
years 1999, 2000, or 2001, as previously reported to the AQMS inventory
program; 

Any facility falling into one of the following industry sectors: 

Hot-mix asphalt plants, 

Hospitals that use ethylene oxide for sterilization, 

Electric generating units (EGUs); and 

Facilities using anhydrous ammonia as a refrigerant; 

Any facility for which AQMS does not have previous inventory data that
appears may be a significant source. 

DNREC provided its 2002 actual annual emissions at the facility level
and at the process-level.  

	For the 2002 Nonpoint Source emissions, also known as “area
sources,” DNREC provided an inventory that contained estimations of
emissions by multiplying an emission factor by some known indicator or
activity level for each category at the county level.  These emissions
are calculated on an annual basis.  Various sources of emission factors
or methodologies were used, including EPA’s AP-42, the Factor
Information Retrieval System (FIRE), EPA’s Emissions Inventory
Improvement Program, Volume III, documented projects performed by the
California Air Resource Board, and projects performed by the
Mid-Atlantic Regional Air Management Association (MARAMA). Nonpoint
source estimates were provided by SCC.

	The Nonroad Mobile Source 2002 annual inventory was prepared with
EPA’s NONROAD2005 model by E.H. Pechan and Associates under contract
from the Mid Atlantic/Northeast Visibility Union (MANE-VU) using
Delaware specific inputs. NONROAD estimates fuel consumption and
emissions of total hydrocarbons, carbon monoxide, nitrogen oxides,
sulfur dioxide, and particulate matter for all nonroad mobile source
categories except for aircraft, locomotives, and commercial marine
vessels.  DNREC provided emission estimates for locomotive engines,
aircraft emissions and commercial marine vessels separately.  For line
haul locomotive and yard locomotive emissions, DNREC requested and
received estimates of fuel consumption or data to calculate fuel
consumption.  Some information was provided at county level for each
county in Delaware, while some was provided system-wide and needed to be
allocated to Delaware.  Track miles within each county were used to
allocate statewide fuel consumption to each county.  Paired with EPA
emission and conversion factors, DNREC calculated locomotive annual
emissions for the base year.  For aircraft emissions, DNREC took
airport-specific emissions for all aircraft sub-categories and allocated
them to the county in which each airport is located.  DNREC estimated
annual aircraft emissions using a combination of airport-specific
activity data and Federal Aviation Administration (FAA)/EPA emission
factors.  DNREC requested landing and take-off data from the Delaware
Aeronautics Administration and from individual airports, for each
sub-category of aircraft.  DNREC used these airport-specific LTO data to
estimate emissions using FAA’s Emissions and Dispersion Modeling
System (EDMS).  EDMS does not estimate particulate emissions by
aircraft/engine type.  DNREC used fleet average 

PM10 emission rates applied to total LTOs outside EDMS.  For commercial
marine vessels, there are many types of vessels that engage in many
different modes of activity, therefore DNREC used several different
sources to obtain data for each vessel type and activity.  Some of these
sources included the Marine Exchange of the Delaware River (ME, 2004),
the Commercial Marine Activity for Deep Sea Ports in the United States
(EPA, 1999), and the Waterborne Commerce of the United States (USACE,
2004a).  Annual emissions were calculated by vessel type, engine type,
and mode of operation using county level activity data.  All Nonroad
mobile source emissions were provided by SCC.

	The Onroad Mobile Source 2002 emissions inventory was developed using
the most current version of EPA’s highway mobile source emissions
model MOBILE 6.2 (M6.2) and link-level vehicle miles traveled (VMT) data
for each county from the Delaware Department of Transportation (DelDOT).
 The emission factors developed using M6.2, were by month, using monthly
temperature and fuel property data.  DNREC provided Mobile6.2 input and
output files for review.  DNREC provided annual mobile emissions values
in Tons Per Year (TPY) and were provided by SCC.

	DNREC also applied rule effectiveness and rule penetration for its 2002
PM2.5 SIP base year inventories.  Rule effectiveness reflects the actual
ability of a regulatory program to achieve the emission reductions
required by regulation (or perhaps voluntarily adopted).  DNREC applied
rule effectiveness and where applicable, provided a justification of a
higher percentage than EPA’s previous policy (which assumed an 80%
rule effectiveness for applicable sources unless otherwise specified). 
Rule penetration is an estimate of percentage of emissions in a source
category that are emitted at facilities subject to the requirements of a
rule.  DNREC applied rule penetration for its nonpoint sources where
applicable.

OAMA staff reviewed the results, procedures, and methodologies for the
SIP base year, and found them to be approvable.  

 “Emissions Inventory Guidance for Implementation of Ozone and
Particulate Matter National Ambient Air Quality Standards (NAAQS) and
Regional Haze Regulations” EPA-454/R-05-001, August 2005

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