MWAQC PM 2.5 SIP March 7, 2008 3-1 3.0 2002 Base Year Inventory

3.1 Background and Requirements

The 2002 Base Year Inventory is documented in detail in Appendix B (2002 Base Year Emissions Inventory Document for Washington, DC-MD-VA PM 2.5 Nonattainment Area) of the

PM 2.5 SIP document. This inventory document was prepared for the District of Columbia, Maryland, and Virginia by the Metropolitan Washington Counc il of Governments (MWCOG) under the auspices of MWAQC. It is available for inspec tion along with rest of the PM 2.5 SIP

documents at the offices of the MWCOG and the District of Columbia, Maryland, and Virginia air management agencies in addition to the MWCOG Web site (http://sharepoint.mwcog.org/airquality).

The emissions inventory covers the Washington, DC-MD-VA PM 2.5 nonattainment area, Figure 1-1, which is classified as a nona ttainment area for the annual PM 2.5 standard by the Environmental Protection Agency (EPA). Th e 2002 emissions inventory is the baseline for tracking the progress for emissions in future years, such as the attainment year 2009. It also serves as the starting point for calculating the emissions reduction requi rement (for man-made sources of emissions) needed to meet the contingency requirements in case the PM 2.5 standards are not met in the attainment year 2009. Emissi ons reductions for attainment contingency are required for nonattainment areas by the Clean Air Act Amendments (CAAA) and EPA.

Appendix B (2002 Base Year Emissions Inve ntory Document for Washington, DC-MD-VA

PM 2.5 Nonattainment Area) of the PM 2.5 SIP document addresses emissions of PM 2.5- Direct, oxides of nitrogen (NO

x ), sulfur dioxide (SO 2 ), volatile organic compounds (VOCs), ammonia (NH 3 ), and PM 10- Direct on an annual basis. Included in the inventory are anthropogenic (manmade) sources, such as point, area, nonroad, and on-road mobile sources and biogenic (naturally occurring) sources of PM 2.5 precursors.

The 2002 base year annual inventories for PM 2.5 Direct, NO

x , SO 2 , VOCs, NH 3 , and PM 10 Direct can be seen in Tables 3-1 through 3-6.MWAQC PM 2.5 SIP March 7, 2008 3-2 Table 3-1

2002 Base Year Annual PM 2.5 -Direct Inventory (tons/year)

District of

Columbia Maryland Virginia Total a

Point 126.53 3,497.31 545.71 4,169.55

Area 495.07 7,479.48 5,692.32 13,666.87

Nonroad 298.71 1,007.45 1,312.15 2,618.31

On-Road 156.27 841.18 727.25 1,724.70

Biogenics 0.00 0.00 0.00 0.00

Total a 1,076.58 12,825.42 8,277.43 22,179.44

a Small discrepancies may result due to rounding.

Table 3-2

2002 Base Year Annual NO

x Inventory (tons/year)

District of

Columbia Maryland Virginia Total a

Point 1,317.46 45,829.43 14,195.67 61,342.56

Area 1,694.70 5,167.94 7,091.38 13,954.02

Nonroad 3,535.64 9,972.89 13,213.58 26,722.11

On-Road 8,827.37 47,640.16 41,107.78 97,575.31

Biogenics 25.91 430.75 301.22 757.88

Total a 15,401.08 109,041.17 75,909.63 200,351.88

a Small discrepancies may result due to rounding.MWAQC PM 2.5 SIP March 7, 2008 3-3 Table 3-3

2002 Base Year Annual SO 2 Inventory (tons/year)

District of

Columbia Maryland Virginia Total a

Point 2,467.55 164,784.06 37,400.23 204,651.84

Area 463.44 2,375.52 9,496.59 12,335.56

Nonroad 376.46 894.19 1,562.46 2,833.10

On-Road 289.88 1,734.88 1,515.22 3,539.98

Biogenics 0.00 0.00 0.00 0.00

Total a 3,597.33 169,788.65 49,974.50 223,360.49

a Small discrepancies may result due to rounding.

Table 3-4 2002 Base Year Annual VOCs Inventory (tons/year)

District of

Columbia Maryland Virginia Total a

Point 87.76 1,112.16 701.94 1,901.86

Area 6,313.88 31,667.71 34,395.80 72,377.39

Nonroad 2,042.83 14,224.36 14,225.08 30,492.27

On-Road 4,913.24 20,495.11 18,495.56 43,903.91

Biogenics 2,519.63 31,126.70 24,906.38 58,552.71

Total a 15,877.34 98,626.04 92,724.76 207,228.14

a Small discrepancies may result due to rounding.MWAQC PM 2.5 SIP March 7, 2008 3-4 Table 3-5

2002 Base Year Annual NH 3 Inventory (tons/year)

District of

Columbia Maryland Virginia Total a

Point 11.13 25.33 0.00 36.46

Area 12.59 3,113.84 543.72 3,670.14

Nonroad 0.00 0.00 0.00 0.00

On-Road 383.37 2,035.19 1,827.06 4,245.62

Biogenics 0.00 0.00 0.00 0.00

Total a 407.08 5,174.36 2,370.78 7,952.22

a Small discrepancies may result due to rounding.

Table 3-6

2002 Base Year Annual PM 10 -Direct Inventory (tons/year)

District of

Columbia Maryland Virginia Total a

Point 181.56 5,208.23 997.63 6,387.42

Area 2,680.45 23,359.83 26,571.31 52,611.59

Nonroad 310.18 1,057.65 1,380.70 2,748.53

On-Road 223.62 1,200.36 1,048.21 2,472.19

Biogenics 0.00 0.00 0.00 0.00

Total a 3,395.81 30,826.06 29,997.85 64,219.72

a Small discrepancies may result due to rounding.MWAQC PM 2.5 SIP March 7, 2008 3-5 3.2 Total Emissions by Source

3.2.1 Point Sources

For emissions inventory purposes, point sources are defined as stati onary, commercial, or industrial operations that emit more than 10 tons/year. Th e point source inventory consists of actual emissions for the base year 2002 and includ es sources within the geographical area of the Washington, DC-MD-VA PM 2.5 nonattainment area. The states of Maryland and Virginia and the District of Columbia are responsible for compiling and submitting point source emission

estimates.

In 2002, the State of Maryland also included a ll types of Andrews Ai r Force Base (AFB) emissions in their point source em issions. These sources are called quasi-point source emissions.

3.2.2 Area Sources

Area sources are sources of emissions that are too small to be inventoried individually and that collectively contribute significant emissions. Area sources incl ude smaller stationary point sources not included in the states' point source in ventories such as prin ting establishments, dry cleaners, and auto-refinishing companies as well as nonstationary sources such as evaporative emissions during transport of petroleum tank trucks and portable fuel containers.

Area source emissions typically are estimated by multiplying an emission factor by some known

indicator of collec tive activity for each source category at th e county level. An activity level is any parameter associated with the activity of a source, such as production rate or fuel consumption that may be correlated with the ai r pollutant emissions from that source. For example, the total amount of VOC emissions emitt ed by commercial aircraft can be calculated by multiplying the number of landing and takeo ff cycles (LTOs) by an EPA-approved emission factor per LTO cycle for each specific aircraft type.

Several approaches are available for estimating area source activity levels and emissions. These include apportioning statewide activity totals to the local inventory area and using emissions per employee (or other unit) factor s. For example, solvent evaporation from consumer and commercial products such as waxe s, aerosol products, and window cleaners cannot be routinely determined for many local sources. The per capit a emission factor assumes that emissions in a given area can be reasonably associated with population. This assumption is valid over broad areas for certain activities such as dry cleaning and small degreasing operations. For some other sources an employment-based factor is more appropriate as an activity surrogate.

3.2.3 Onroad Mobile Sources

Motor vehicles constitute onroad mobile sources . Emissions from mobile sources were derived from the use of the National Capital Region Tr ansportation Planning Boar d (TPB) travel demand forecasting procedure, which simulates vehicle tr avel across the region's transportation system. Travel was simulated on all highways in the regi on, including both volume and speed of travel for each hour of the day. An EPA emissions model, MOBILE 6.2.03, was used to determine the

emissions characteristics of the vehicle fleet in place in the year 2002. Input for this emissions model includes locally specific information such as age distribution of registered vehicles,MWAQC PM 2.5 SIP March 7, 2008 3-6 evaporation characteristics of motor fuel, and temperature data. The general equation for the

estimation of mobile sources is

Emissions = (Travel Component) x (Emission Factor).

Emissions accounted for in the mo bile source inventory include

Origin: Emissions include "cold st art" and "hot start" emissions occurring during the first few minutes of vehicle operation. Running: Emissions occurring on lo cal streets and on the region's network of arterial streets, freeways, and nonramp freeways. Running Loss: Emissions due to the heating of fuel and fuel lines. Crankcase: Emissions due to blow-by. Destination: Evaporative or "hot soak" emissions occurring at the conclusion of a vehicle trip afte r the engine is turned off. Diurnal: Evaporative emissions occurri ng when the vehicle is at rest due to temperature fluctuations. Resting Loss: Emissions due to the permeation of fuel through hoses and fittings.

Auto Access: Emissions attributable to au to trips to Metrorail stations or to park-and-ride lots.

Bus: Bus emissions, i.e., Metrobus, Ride-on, etc.

3.2.4 Nonroad Mobile Sources

Emissions for all nonroad vehicles and engi nes except airport [aircraft, ground support equipment (GSE), and auxiliary power units (APU s)], locomotives, and diesel marine vessels were calculated using EPA’s NONROAD2005 mode l version 2005a (February 8, 2006). This model was run with its associated gra phic user interface NONROAD2005.1.0 (June 12, 2006), reporting utility version 2005c (March 21, 2006), and all geographical allocation data files updated until February 1, 2006.

Emissions from the “nonroad vehicles and engines” category result from the use of fuel in a

diverse collection of vehicles and equipment, including vehicles and equipment in the following categories:

• Recreational vehicles, such as all-terra in vehicles and off-road motorcycles; • Logging equipment, such as chain saws; • Agricultural equipment, such as tractors; • Construction equipment, such as graders and back hoes; • Industrial equipment, such as fork lifts and sweepers; • Residential and commercial lawn and garden e quipment, such as leaf and snow blowers; and • Aircraft ground support equipment.

The nonroad model estimates emissions for each specific type of nonroad equipment by multiplying the following input data estimates:

• Equipment population for base year (or base year population grown to a future year),

distributed by age, power, fu el type, and application;MWAQC PM 2.5 SIP March 7, 2008 3-7 • Average load factor expressed as average fraction of available power; • Available power in horsepower; • Activity in hours of use per year; and

• Emission factor with deterior ation and/or new standards.

The emissions are then temporally and geograp hically allocated using appropriate allocation

factors.

Aircraft (military, commercial, general aviation, and air taxi) and auxili ary power units (APU) operated at airports along with locomotives a nd diesel marine vessels are also considered

nonroad sources and are include d in the nonroad category.

Metropolitan Washington Airports Authority (MWAA) provided a ll types of airport emissions for Dulles (Fairfax and Loudoun) and Reagan National (Arlington) airports, which are

documented in Air Pollution Emission Inventories for Washington Dulles International Airport and Ronald Reagan Washington National Airport for Calendar Years 2002, 2008, 2009 1 (see

Attachment B4 of the 2002 Base Year Invent ory document). Nonroad model-generated ground support equipment emissions for Loudoun and Arlington counties were replaced by emissions provided by MWAA. While MWAA GSE emissions for Dulles airport were equally divided between Fairfax and Loudoun counties, Reagan National emissions were put into Arlington County. Aircraft and APU emissions for other co unties were provided by th e respective states.

Emissions from locomotives and commercial dies el marine vessels were also provided by the

states.

3.2.5 Biogenic Sources

An important component of the inventory is bi ogenic emissions. Biogenic emissions are those resulting from natural sources. Biogenic emissions are primarily VOCs that are released from vegetation throughout the day. Biogenic emissions of NO

x include lightning and forest fires. EPA used a biogenic computer model (BEIS3.12) to estimate biogenic emissions for each county in the country for all 12 mont hs of the year 2002. Emissions data for Washington, DC PM 2.5 nonattainment-area counties were ac quired from the EPA Web site (ftp://ftp.epa.gov/EmisInventory/ 2002finalnei/biogenic_sector_da ta/). EPA has recommended that states use these emissions in case they do not have their own estim ated biogenic emissions. The Washington, DC-MD-VA PM 2.5 nonattainment area decided to use the inventories provided by the EPA.

3.3 Annual Inventories

The 2002 base year inventories for PM 2.5 -Direct, NO

x , SO 2 , VOCs, NH 3 , and PM 10 -Direct in Tables 3-1 through 3-6 are for the annual emission s. A summary of the annual inventories for

PM 2.5 Direct, NO

x , SO 2 , VOCs, NH 3 , and PM 10 Direct is also found in Ta ble 1-1 of Appendix B.

1 Metropolitan Washington Airports Authority, Air Pollution Emission Inventories for Washington Dulles International Airport and Ronald Reagan Washington National Airport for Calendar Years 2002, 2008, 2009, prepared by URS Corporation, Washington, DC., March 2006.