Technical Support Document (TSD) For

for Cecil County, Maryland,

located in the Philadelphia-Wilmington-Atlantic City, PA-NJ-DE

8 Hour Ozone Nonattainment Area:

State Jinpiementation Plan (SIP) Attainment Demonstration

and Base Year Inventory.

Submitted June 15, 2007 by the

Maryland Department ofthe Environment

TSD Prepared December, 2008

Alice H. Chow

Air Quality Analysis Branch, 3AP22

U.S. Environmental Protection Agency, Region 3

1650 Arch Street

Philadelphia, Permsylvania 19103

Reviewed by Walter Wilkie, Chief

Air Quality Analysis Branch (3AP22)

/2/’

Date Signed
Q

y 

nalysis Branch

s (AQAB) review ofthe emissions inventories submitted with the Cecil County, Maryland’s portion ofthe Philadelphia Nonattainment Area 8 Hour Ozone State Implementation Plan (SIP) by the Maryland Department ofthe Environment (MDE). 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. Cecil County, a part of the Philadelphia 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. Maryland Department of the Environment has submitted Cecil County as MDE’s portion ofthe Philadelphia 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.

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. 1The 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). MDE’s base year inventOry is for 2002. The Philadelphia Nonattainment Area (Philadelphia

— Wilmington

— Atlantic City, PA-DE-MD-NJ) includes Cecil County, MD.

A significant amount of documentation is required for these SiP base year estimates which MDE has provided.

In the MDE request, the base year used was 2002. MDE’s Air and Radiation

Management Administration (ARMA) is primarily responsible for compiling the Point

“Emissions Inventoty Guidancefor Implementation ofOzone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations” EPA-454/R-05-001, August 2005
For the 2002 Nonpoint Source emissions, also known as 

area sources,

ARMA

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 typically calculated on an annual basis because the activity data aregenerally only available on an annual basis. ARMA 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, EPA’s Emissions Inventory

Improvement Program, and EPA mobile source model. Nonpoint source estimates were

provided by SCC.

The Nonroad Mobile Source 2002 inventory was prepared with EPA’s

NONROAD2005 model, version as of 03/21/2006, and EPA emission factors.

NONROAD estimates fuel consumption and emissions oftotal hydrocarbons, carbon

monoxide, nitrogen oxides, sulfur dioxide, and particulate matter for all nonroad mobile

source categories except for aircraft, locomotives, and commercial marine vessels.

ARMA provided emission estimates for locomotive engines, aircraft emissions and

commercial marine vessels separately. For locomotive engine and line haul emissions,

ARMA requested and received fuel usage and track mileage data from all 13 railroads

operating in Maryland. Paired with EPA emission and conversion factors, ARMA

calculated locomotive emissions for the base year. For aircraft emissions, ARMA used

several sources of information: Federal Aviation Administration’s (FAA) Airport

Activity Statistics of Certificated Route Air Carriers; landing and takeoff cycle

information by airport in Maryland; Aviation Administration and the Federal Aviation

Administration Airport License Renewal Applications; and FAA’s Emissions &

Dispersion Modeling System (EDMS). For commercial marine vessels, ARMA used the

emission inventory prepared for the Maryland Port Administration by Edwards and

Kelcey (E&K). E&K analyzed the major categories of air emissions associated with ship

and port operations and ARMA allocated these cruising emissions to Cecil County. E&Kalso used EPA’s guidance, Analysis of Commercial Marine Vessels Emissions and Fuel

Consumption Data, (EPA-450-R-00-002), February 2000, to calculate emissions.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 and

traffic activity data from the Maryland State Highway Administration. ARMA also usedPPSUITE, an enhanced version ofthe Post Processor for Air Quality software systems.

ARMA provided Mobile6.2 input and output files for review. Mobile emissions valueswere given in units oftons per summer day and were provided by SCC.

ARMA 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
AQAB staffreviewed the results, procedures, and methodologies for the SIP base

year, and found them to be approvable.

III. 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 Cecil County SIP.

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

2009 projected inventory is required for the attainment year. Inventories were developed

for all emission sources for both years.

The Point Source emissions for 2008 and 2009 were projected, using growth

surrogates from EPA’s Economic Growth and Analysis System, Version 5.0 (EGAS 5.0).

The Nonpoint Source emissions for 2008 and 2009 were projected using growth

factors to account for population, household, vehicle miles travelled (VMT) and

employment data from the Baltimore Metropolitan Council, the Maryland Department of

Planning, and MDE Mobile Source Division.

For the 2008 and 2009 Nonroad Mobile Source inventories, ARMA used EPA’s

NONROAD2005 model to generate these future inventories. The NONROAD model

allows for the calculation of past year, present year, and future year inventories (up to the

year 2050) to be generated. Growth for locomotives and commercial marine vessels

came from employment data as surrogates; and, aircraft growth from small airports were

projected using EPA’s EGAS model.

The 2008 and 2009 Onroad Mobile Source inventories were generated using

EPA’s MOBILE6.2 and the Highway Performance Monitoring System (HPMS) vehicle

miles traveled growth rates. Input data was provided by the Baltimore Regional Transit

Board and Baltimore Metropolitan Council. ARMA then ran PPSUITE to calculate

VMT and speeds; the output is then run in MOBILE6.2 to calculate emissions.

AQAB staffreviewed the procedures, and found them to be reasonable for

development of these inventories.