department of natural resources and environmental control

Division of Air and Waste Management

General notice

public NOTICE

Delaware State Implementation Plan for Attainment of the 8-Hour Ozone National Ambient Air Quality Standard, Revision for Establishment of 2008 and 2009 Mobile Source Emission Budgets

This document assigns the on-road mobile source emissions budgets for each county in Delaware as part of the Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE moderate non-attainment area for the 8 hour ozone National Ambient Air Quality Standard (NAAQ). S Section 176 of the Clean Air Act (42 USC 7506) and Title 40 Parts 51 and 93 of the Code of Federal Regulations are the basis for the authority to establish mobile emission budgets in the Delaware State Implementation Plan (SIP) to attain the ozone standard. The on-road mobile source emissions budgets will be made a part of the State Implementation Plan to attain the 8 hour ozone standard by the year 2009 and to reach further reasonable progress towards attaining the standard by 2008. Therefore, the tables below will assign budgets for each year and for each county. The mobile source emissions are projected for these years using the USEPA mobile emission model, “Mobile 6.2” for calculating emission factors and the “Peninsula Travel Demand Model” for calculating future vehicle miles traveled (VMT).

Mobile 6.2 calculates emission factors for each USEPA vehicle type traveling on designated federal highway classifications road types in Delaware. Depending on the county, Delaware has up to 11 different federal highway classifications for its roads. There are two pollutants that are calculated using the mobile computer model. Volatile organic compounds (VOC) and nitrogen oxide (NOx) emission factors are generated from the Mobile 6.2 computer model. These pollutants are modeled because they are the precursors to form ground level ozone. A sample emission factor output for New Castle County for nitrogen oxides is listed below, for the projection year of 2009.

New Castle County

Projected 2009 Mobile Emission Factors Nitrogen Oxides (NOx) Grams/Mile

USEPA Vehicle Type*

Federal Highway Class.	LDGV	LDGT 1-2	LDGT 3-4	HDGV	LDDV	LDDT	HDDV	MC
Other Principal Arterial-Rural	0.51	0.37	0.42	0.38	0.19	0.23	0.22	3.35
Minor Arterial-Rural	0.54	0.39	0.44	0.42	0.20	0.25	0.25	2.75
Major Collector-Rural	0.55	0.39	0.45	0.44	0.21	0.26	0.27	2.79
Minor Collector-Rural	0.57	0.41	0.47	0.48	0.22	0.28	0.30	2.90
Local-Rural	0.83	0.60	0.70	1.08	0.37	0.51	0.66	4.21
Interstate-Urban	0.52	0.38	0.43	0.39	0.19	0.23	0.23	3.19
Other Freeway & Expressways-Urban	0.51	0.38	0.42	0.39	0.19	0.23	0.23	3.41
Other Principal Arterial-Urban	0.55	0.39	0.45	0.44	0.21	0.26	0.27	2.79
Minor	0.57	0.41	0.47	0.48	0.22	0.28	0.31	2.90
Collector-Urban	0.57	0.41	0.47	0.49	0.22	0.28	0.31	2.91
Local	0.82	0.59	0.69	1.08	0.37	0.51	0.66	4.21

*Description of vehicle types is at the end of this document

A travel demand model for the State is maintained by the Delaware Department of Transportation. The model applies a variety of data regarding roadway network conditions, vehicular travel patterns, automobile ownership, and the location of population and employment sites. The model follows the “traditional four-step process” of trip generation, distribution, mode split, and assignment that is commonly used throughout the transportation planning industry. A similar table as above is generated for VMT according to USEPA vehicle type and federal highway classifications. The two matrices are incorporated to calculate tons per-day emissions for each pollutant.

There are numerous input criteria that go into the mobile model that affect the calculations. The major inputs are the vehicle emission control programs and clean fuel standards that are currently used or will be used for controlling and reducing vehicle emissions. They include: National Low Emission Vehicle Program and Tier 2 Motor Vehicle Controls (light duty vehicles), reformulated gas program, low sulfur gasoline program, ultra-low sulfur diesel fuel program, heavy duty engine control program beginning in 2007 reducing particulate matter and in 2010 reducing nitrogen oxides to their lowest levels. The State also has since 1983 inspected vehicles for tailpipe emissions. Currently as part of the vehicle emission inspection a vehicle on-board diagnostic system is checked for any diagnostic trouble codes which if present requires the vehicle to be repaired.

The following tables assign the on-road mobile emission budgets for milestone years of 2008 and 2009 for each county in Delaware.

2008 On-road Vehicle Mobile Emission Budgets for Delaware
(Emission in tons per day, VMT in miles per day)
Pollutant	Kent	New Castle	Sussex	DE Total
VOC	4.14	10.61	7.09	21.84
NOX	9.68	21.35	12.86	43.89
VMT	5,520,573	16,917,040	8,450,950	30,888,563

2009 On-road Vehicle Mobile Emission Budgets for Delaware
(Emission in tons per day, VMT in miles per day)
Pollutant	Kent	New Castle	Sussex	DE Total
VOC	3.95	9.89	7.05	20.89
NOX	9.04	19.23	11.93	40.2
VMT	5,703,033	17,122,179	8,541,828	31,367,040

Supporting documents, including Mobile 6.2 input, output and data files as well as spreadsheet calculation files, can be obtained by request in writing to Philip Wheeler, Air Quality Management Section, 156 South State Street, Dover, Delaware 19904 or e-mail Philip.Wheeler@state.de.us.

Description of Vehicle Types

LDGV	Light-Duty Gasoline Vehicles (Passenger Cars)
LDGT 1-2	Light-Duty Gasoline Trucks 1 (0-6,000 lbs. GVWR, 0-3,750 lbs. LVW) Light-Duty Gasoline Trucks 2 (0-6,000 lbs. GVWR, 3,751-5,750 lbs. LVW)
LDGT 3-4	Light-Duty Gasoline Trucks 3 (6,001-8,500 lbs. GVWR, 0-5,750 lbs. ALVW) Light-Duty Gasoline Trucks 4 (6,001-8,500 lbs. GVWR, 5,751 lbs. and greater ALVW)
HDGV	Heavy-Duty Gasoline Vehicles (8,501-80,000 lbs. GVWR)
LDDV	Light-Duty Diesel Vehicles (Passenger Cars)
LDDT	Light-Duty Diesel Trucks (0-8,500 lbs. GVWR)
HDDV	Heavy-Duty Diesel Vehicles (8,501-80,000 lbs. GVWR)
MC	Motorcycles