Technical Support Document (TSD) For 


Emissions Inventories for the Delaware Nonattainment Area 


8 Hour Ozone State Implementation Plan (SIP) Base Year Inventory. 


Submitted June 2007 by the 


Delaware Department ofNatural Resources 


And Environmental Control 


TSD Prepared December, 2008 


Janet C. Kremer 


Air Quality Analysis Branch, 3AP22 


U.S. Environmental Protection Agency, Region 3 


1650 Arch Street 


Philadelphia, Pennsylvania 19103 


Reviewed by Walter Wilkie, Chief 


Air Quality Analysis Branch (3AP22) 


12 /11 )-u;; Or 

Date Si~ d 
II 

I. Introduction 

The purpose ofthis document is to provide a technical summary ofthe Air 

Quality Analysis Branch's (AQAB) review ofthe emissions inventories submitted with 

the Delaware Nonattainment Area 8 Hour Ozone State hnplementation Plan (SIP) by the 

Delaware Department o{Natural Resources and Environmental Control (DNREC). This 

review determines the approvability ofthe SIP Base Year Inventory and an evaluation of 

the methods used for proj ection 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 ofregulated 

sources from the Base Year to a projected year. The Delaware Nonattainment Area was 

designated as an 8 hour ozone nonattainment area with a Subpart 2 classification. 

Subpart 2 area(s) are required to submit initial SIP base year inventories to EPA by June 

15,2006; with the final Base Year inventory due with the SIP to EPA by June 15,2007. 

DNREC has submitted the Delaware Nonattainment Area 8 Hour Ozone SIP and has 

requested EPA's approval. 

Any questions pertaining to this technical summary should be directed to Walter 

K. Wilkie, Chief, Air Quality Analysis Branch, at 215-814-2150 or via email at 

wilkie. walter@epa.gov. 

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 8­

hour ozone NAAQS, the pollutants to be inventoried are VOC, NOx and CO (carbon 

monoxide). For the 8-hour ozone NAAQS, VOC, NOx and CO emissions should be 

reported as actual annual and actual summer weekday emissions (defined as an average 

day's emissions for a typical summer day during the ozone season). DNREC's base year 

inventory is for 2002. For the Delaware SIP, the geographic coverage includes sources in 

New Castle County, Kent County and Sussex 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 ozone 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. iI "Emissions Inventory Guidance/or Implementation o/Ozone and Particulate Matter National Ambient 

Air Quality Standards (NAAQS) and Regional Haze Regulations" EPA-4541R-05-001, August 2005 
STEPS is the point source emission inventory electronic data management system. The 

criteria used to detennine if a source would be a part of the point source inventory was as 

follows: 

• 	 Any Title V pennitted facilities 

• 	 In Kent County and New Castle County, any facility with emissions ofVOCs 

greater than 5 Tons Per Year (TPY) and 25 TPY or greater for NOx 

• 	 In Sussex County, any facility that with emissions of 100 TPY or greater of NO x 

orVOC 

• 	 all electric generating facilities 

DNREC provided its 2002 actual annual emissions and actual emissions for typical 

summer season(during peak ozone season-June, July, August) weekday emissions 

(SSWD) for NOx and VOC 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. Summer season weekday daily 

emissions were developed through the use of a temporal allocation factor (T AF) applied 

to the annual emissions. DNREC further converted these annual emissions to seasonal 

emissions, for ozone, the summer season is defined as peak ozone season months ofJune, 

July, and August. Various sources of emission factors or methodologies were used, 

including EPA's AP-42, the Factor Infonnation Retrieval System (FIRE), EPA's 

Emissions Inventory hnprovement Program, Volume III, documented projects perfonned 

by the California Air Resource Board, and projects perfonned 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 

AtlanticlNortheast Visibility Union (MANE-VU) using Delaware specific inputs. SSWD 

values were developed by summing the NONROAD2005 monthly emissions for June, 

July, and August and applying weekly allocation profiles. '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 

infonnation 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. To estimate SSWD emissions, DNREC assumed that locomotives operate 

evenly seven days a week. 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)IEPA 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). Temporal profiles were applied to get typical 

SSWD emissions. For commercial marine vessels, there are many types ofvessels that 

engage in many different modes of activity, therefore DNREC used several different 

sources to obtain data for each vessel type and activity. Some ofthese 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 ofoperation using county level activity data. SSWD 

daily emissions were calculated by multiplying the annual emissions by a TAP. 

All Nonroad mobile source emissions were provided by SCC. 

The Onroad Mobile Source 2002 emissions inventory was developed using the 

most current version ofEPA'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 ofTransportation(DelDOT). The emission factors developed 

using M6.2, were by month, using monthly temperature and fuel property data. Typical 

SSWD temporal adjustments were developed by county and roadway class. DNREC 

provided Mobile6.2 input and output files for review. DNREC provided annual mobile 

emissions values in Tons Per Year(TPY) and SSWD emissions in units oftons per 

summer day (TPD) and were provided by SCC. 

DNREC also applied rule effectiveness and rule penetration for its 2002 8-hour 

ozone 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 effectiven'ess 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. 

AQAB staff reviewed the results, procedures, and methodologies for the SIP base 

year, and found them to be approvable. 

II. 2008 and 2009 Projection Emission Inventories 

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

Projection inventories for the years 2008 and 2009 were used for the Delaware NAA SIP. 

The 2008 projected inventory is required for reasonable further progress (RFP) and the 

2009 projected inventory is required for the attainment year. In general, because the 

2008 milestone year is so close to the 2009 attainment year, the 2008 emission 

projections in this section are obtained by linear interpolating ofthe 2002 base year 

emissions and the 2009 projections, unless otherwise explained. This interpolation 

method assumes a linear growth in emission between ,2002 and 2009, wherever a growth 

factor is applied for the 2009 projection, and the same control efficiency (CE), rule 

effectiveness (RE) and rule penetration (RP) in 2008 and 2009 for the relevant controls. 
The EGU point source emissions for 2009 were projected, using growth factors 

from the Department ofEnergy. The source of data for determining growth was the 

Annual Energy Review 2004, and Energy Information Administration. Controls were 

applied on a unit by unit basis. . 

The non-EGU point and area source emissions for 2009 were developed by 

MACTEC Federal Programs (MACTEC) under a contract with MANE-VU. Projections 

were base on applying growth and control factors to the 2002 base year inventory. 

However, the 2009 non-EGU projections made by MACTEC have been updated in some 

cases for the following reasons: 

• Delaware 2002 base year emission updates; 

• Delaware specific growth factors; 

• Control factor (CE, RE, etc.) updates; 

• Additional controls 

DNREC used 2009 nonroad mobile emissions developed by MACT ABC. 

MACTEC developed the 2009 Nonroad Mobile Source inventories using EPA's National 

Mobile Inventory Model 2005 which includes the NONROAD2005 model. The 

NONROAD2005 model allows for the calculation ofpast year, present year, and future 

year inventories (up to the year 2050) to be generated. MACTEC used combined growth 

and control factors developed from emission projections for EPA's Clean Interstate Rule 

development effort. Delaware determined SSWD emissions by applying 2002 daily to 

annual emission ratios, assuming the daily to annual relations in 2009 will follow the 

same pattern as in 2002. These calculations were done by SCC, by county, and by 

pollutant. 

The 2008 2009 Onroad Mobile Source inventories were generated using EPA's 

MOBILE6.2 and 2009 VMT that was provided by DelDOT. On-road mobile source 

controls for 2009 were taking into account in the input files for M6.2 

AQAB staff reviewed the procedures, and found them to be reasonable for 

development ofthese inventories.