Technical Support Document (TSD) For 

The Baltimore Nonattainment Area: 

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

Submitted June 6, 2008 by the 

Maryland Depruiment of the Environment 

TSD Prepared May 20 l 0 

Janet C. Kremer 

Office of Air Monitoring and Analysis, 3AP40 

U.S. Environmental Protection Agency, Region 3 

1650 Arch Street 

Philadelphia, Pennsylvania 19103 

Reviewed by Waltc1 Wilkie, Associate Director 

Office of Air Monitoring and Analysis, (3AP40) 

--:5~ I b , 000 

Date Signed 1 
I. Introduction 

The purpose ofthis document is to provide a technical summary of the Office of 

Air Monitoring and Analysis' (OAMA) review of the emissions inventories submitted 

with the Baltimore PM2.5 State Implementation Plan (SIP) by the Maryland Department 

of the Environment (MDE). This review determines the approvability ofthe SIP Base 

Year Inventory. 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. Maryland 

Department of the Environment has submitted Baltimore PM2.5 SIP and 2002 Base Year 

Inventory 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 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. 1 The base year inventory includes emissions estimates from stationary point 

and nonpoint sources, onroad mobile sources, and nonroad mobile sources. For PM2.5 

NAAQS, the pollutants to be inventoried are VOC, NOx, NH3, S02, PM10 and PM2.5. 

All emissions should be reported as actual annual emissions. MDE's base year inventory 

is for 2002. For the Baltimore SIP, the geographic coverage includes sources in Anne 

Arundel County, Baltimore County, Baltimore City, Carroll County, Harford County, and 

Howard County. 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 

Source data for 2002. ARMA uses several forms of source identification. The state's 

primary data source is from its permitting program, which includes permit applications 

and equipment registrations. ARMA also relies on its compliance program, which 

involves using information gathered from inspections and citizen complaints. ARMA 

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

For the 2002 Nonpoint Source emissions, also known as "area sources," ARMA 

provid.ed an inventory that contained estimations of emissions by multiplying an emis~ion 

factor by some known indicator or activity level for each category at the county level. 

These emissions are calculated on an annual basis because the activity data are generally 

only available on an annual basis. Various sources of emission factors or methodologies 

1 "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 
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 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. 

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 alll3 railroads 

operating in the Baltimore NAA. 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 Certiftcated Route Air Can-iers; 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 their relationship to air quality issues in the Baltimore NAA. 

E&K also 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 used 

PPSUITE, an enhanced version of the Post Processor for Air Quality softWare systems. 

ARMA provided Mobile6.2 input and output files for review. Mobile emissioD;S values 

were given in units of tons per year and were provided by sec. 

ARMA also applied rule effectiveness and rule penetration for its 2002 PM2.5 

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). ARMA 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. ARMA 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.