* \ *1 PROt^ DOCUMENTATION FOR THE 2008 MOBILE SOURCE NATIONAL EMISSIONS INVENTORY ------- ------- EPA-454/B-20-028 May 2011 DOCUMENTATION FOR THE 2008 MOBILE SOURCE NATIONAL EMISSIONS INVENTORY Prepared by: E.H. Pechan & Associates, Inc. 3622 Lyckan Parkway, Suite 2005 Durham, NC 27707 Prepared for: U.S. Environmental Protection Agency Office of Air Quality Planning and Standards Air Quality Assessment Division Emissions Inventory and Analysis Group Research Triangle Park, NC 27711 Contract No. EP-D-07-097 Work Order No. 4-02 U.S. Environmental Protection Agency Office of Air Quality Planning and Standards Air Quality Assessment Division Research Triangle Park, NC ------- [ This page intentionally left blank] ------- May 2011 CONTENTS Page TABLES iv ACRONYMS v 1.0 INTRODUCTION 1 1.1 WHAT IS THE PURPOSE OF THIS REPORT? 1 1.2 WHAT CATEGORIES ARE COVERED IN THIS REPORT? 1 1.3 IIOW IS THIS REPORT ORGANIZED? 2 2.0 SUMMARY OF 2008 NONROAD AND ONROAD MOBILE SOURCE METHODOLOGIES 3 2.1 WHAT ARE THE GENERAL METHODOLOGIES EPA USED TO DEVELOP PREVIOUS YEAR MOBILE SOURCE \EI" S? 3 2.2 WHAT IS THE BASIS FOR THE 2008 EMISSIONS DATA LOADED INTO THE EIS? 3 2.3 WHAT IS THE MAGNITUDE OF THE MOBILE SOURCE EMISSIONS ESTIMATED FOR 2008? 14 3.0 NATIONAL MOBILE INVENTORY MODEL (\ VIIVI) 16 3.1 BACKGROUND 16 3.2 THE \ VIIVI COUNTY DATABASE 16 3.2.1 Database Structure 16 3.2.2 EPA Default 2008 NCD Inputs 17 3.2.3 State/Local Agency-Submitted Inputs 19 4.0 POST-PROCESSING OF NMIM OUTPUT 23 4.1 POLLUTANT CODE REVISIONS 23 4.2 REMOVAL OF GROUND SUPPORT EQUIPMENT 23 4.3 STAGE II ONRO AD VEHICLE REFUELING 23 5.0 REFERENCES 24 APPENDIX A. TABLES UPDATED WITH EIS SUBMISSIONS A-l in ------- May 2011 TABLES Table 2-la. Methods Used to Develop Emission Estimates for Onroad Vehicle Sources 4 Table 2-lb. Methods Used to Develop Emission Estimates for Nonroad Mobile Sources 6 Table 2-2. Summary of Onroad and Nonroad 2008 NMIM Data Submissions 13 Table 2-3. 2008 Onroad Mobile NEI National Emission Totals 15 Table 2-4. 2008 Nonroad Mobile NEI National Emission Totals 15 Table 3-1. Tables in the NMIM County Database (NCD) 17 Table 3-2. Mapping of HPMS Vehicle Categories to NMIM/MOBILE6 and SCC-Level Vehicle Classes 20 Table 4-1. Pollutant Code Revisions 23 Table A-l. 2008 NMIM County Database Table Updates by Jurisdiction A-l Table A-2. Summary of 2008 NEI Vehicle Miles Traveled Data by Jurisdiction A-3 Table A-3. External Onroad Files Updated for the 2008 NEI A-5 Table A-4. NONROAD Model Parameters Provided by State Agencies A-7 ------- ACRONYMS AEO Annual Energy Outlook CAP criteria air pollutant CMV commercial marine vessel CNG compressed natural gas CO carbon monoxide DOE Department of Energy DOT Department of Transportation EDMS Emissions and Dispersion Modeling System EGAS Emissions Growth Analysis System EIA Energy Information Administration EIS Emissions Inventory System EPA Environmental Protection Agency ETBE ethyl tert-butyl ether ETOH ethanol FAA Federal Aviation Administration FHWA Federal Highway Administration FIPS Federal Information Processing System GIS geographic information system GSE ground support equipment HAPs hazardous air pollutants HC hydrocarbons HDDV heavy duty diesel vehicle HDGV heavy duty gasoline vehicle HHDDV heavy heavy-duty vehicle HPMS Highway Performance Monitoring System I/M inspection and maintenance LDDT light-duty diesel truck LDGT light-duty gasoline truck LDDV light-duty diesel vehicle LDGV light-duty gasoline vehicle LDV light-duty vehicle LEV low emission vehicle LHDDV light heavy-duty diesel vehicle LPG liquefied petroleum gas LTO landing/take-off MC motorcycle MTBE methyl tert-butyl ether NCD NMIM County Database NCDC National Climatic Data Center NEI National Emissions Inventory NGV natural gas vehicle nh3 ammonia NMIM National Mobile Inventory Model OTAQ Office of Transportation and Air Quality PADDs Petroleum Administration for Defense Districts ------- May 2011 PM particulate matter PM10 particulate matter less than or equal to 10 micrometers PM2.5 particulate matter less than or equal to 2.5 micrometers RVP Reid vapor pressure RFG reformulated gasoline see source classification code SIC standard industrial classification code SIP State Implementation Plan S/L/T State/Local/T rib al so2 sulfur dioxide STEEM Ship Traffic, Energy, and Environmental Model TAF Terminal Area Forecast TAME tertiary amyl methyl ether U.S. United States VMT vehicle miles traveled VOC volatile organic compound vi ------- May 2011 1.0 INTRODUCTION The National Emissions Inventory (NEI) is a comprehensive inventory covering criteria pollutants and hazardous air pollutants (HAPs) for the 50 United States (U.S.), Washington DC, Puerto Rico, and U.S. Virgin Islands. The NEI is developed by the U.S. Environmental Protection Agency (EPA)'s Emissions Inventory and Analysis Group in Research Triangle Park, North Carolina. The EPA is updating the NEI to a new computer system, the Emission Inventory System (EIS), which supports the collection and distribution of inventory information. The NEI is used to support air quality modeling, rule development, international reporting, air quality trends analysis, and other activities. To support these ends, the EPA compiles comprehensive emissions data in the NEI for criteria and HAPs for nonroad mobile, onroad mobile, point, and nonpoint sources. 1.1 WHAT IS THE PURPOSE OF THIS REPORT? This report summarizes the procedures EPA used to estimate annual emissions for the onroad mobile sector and a portion of the nonroad mobile source sector of EPA's 2008 general release NEI. The nonroad sector is comprised of nonroad engines characterized in EPA's National Mobile Inventory Model (NMIM), as well as other engines not modeled in NMIM, including aircraft, commercial marine vessel, and locomotive engines. This report only addresses those nonroad categories included in EPA's NMIM. Methodologies for other nonroad mobile source categories are documented in the following reports: Documentation for the Commercial Marine Vessel Component of the National Emissions Inventory Methodology (ERG, 2010); Documentation for Locomotive Component of the National Emissions Inventory Methodology (ERG, 2011a); and Documentation for Aircraft Component of the National Emissions Inventory Methodology (ERG, 2011b). 1.2 WHAT CATEGORIES ARE COVERED IN THIS REPORT? The onroad mobile source category includes motorized vehicles that are normally operated on public roadways. This includes passenger cars, motorcycles, minivans, sport-utility vehicles, light-duty trucks, heavy-duty trucks, and buses. The nonroad categories in NMIM include recreational marine and land-based vehicles, farm and construction machinery, industrial, commercial, logging, and lawn and garden equipment, and rail maintenance equipment. These equipment are powered by compression-ignition engines, which are typically diesel-fueled, as well as spark-ignition (gasoline-fueled) engines. Compressed natural gas (CNG) and liquefied petroleum gas (LPG) engines may also power certain types of nonroad equipment. Although included in NMIM, aircraft ground support equipment (GSE) emissions are modeled separately in the NEI (see Section 4.2 for details). 1 ------- May 2011 1.3 HOW IS THIS REPORT ORGANIZED? Section 2 provides an overview of the procedures used to develop the 2008 onroad and nonroad mobile source emission estimates, as well as a summary of methodologies used for developing pre-2008 year mobile source emission estimates. Section 3 presents a discussion of EPA's NMIM, as well as a description of the inputs used in the NMIM County Database (NCD). Section 4 describes the procedures used to process NMIM results for incorporation in the EIS. Section 5 presents the references cited in this document. Appendix A displays a detailed listing of the State/Local agency inputs incorporated into the NCD. 2 ------- May 2011 2.0 SUMMARY OF 2008 NONROAD AND ONROAD MOBILE SOURCE METHODOLOGIES This section provides an overview of the methods used to develop the EPA estimates in the 2008 NEI. Although the focus of this documentation is on describing the methodologies and data used to develop 2008 emission estimates, Section 2.1 of this document provides an overview of the methodologies used to develop pre-2008 year onroad and nonroad mobile source category emission estimates. 2.1 WHAT ARE THE GENERAL METHODOLOGIES EPA USED TO DEVELOP PREVIOUS YEAR MOBILE SOURCE NEI'S? Tables 2.1a and 2.1b summarize the year-specific emission estimation methodologies that EPA used to develop emission estimates for mobile source categories. Table 2.1a displays the onroad mobile source emission estimation methodologies, while Table 2.1b presents the nonroad methodologies. The entries in red boldface type summarize the 2008 NEI methods that are described in this report. 2.2 WHAT IS THE BASIS FOR THE 2008 EMISSIONS DATA LOADED INTO THE EIS? The EPA developed the EIS to support the development of the 2008 and future year NEIs. The EIS is a data repository that collects and combines data contributions from EPA and State/Local/Tribal (S/L/T) agencies into a cohesive data set in a transparent manner. One of the primary tenets of the NEI is that S/L/T agency data take preference over EPA developed data. Therefore, with some exceptions noted herein, EPA default mobile source data were replaced with S/L/T submitted data. For onroad and nonroad mobile source categories, EPA requested that S/L/T agencies submit model inputs for use in an EPA 2008 NEI run of NMIM. After EPA completed the NMIM runs for areas that submitted data, EPA then processed the emissions data for loading into the EIS for S/L/T agency review. If an agency submitted onroad emissions data rather than updated onroad NMIM inputs, then EPA compiled the vehicle miles traveled (VMT) from this submittal for use in EPA's NMIM run. As described in Section 3.2.3.1, this situation necessitated EPA efforts to allocate the SCC-level VMT in these submittals to the level of detail required by NMIM. Table 2-2 identifies the types of NMIM input updates that were provided by each State/Local agency. The "NCD Files" column indicates that an agency provided updates to the NCD. The NCD is the database that contains the input data needed by NMIM. The "Onroad SCC-based VMT" column is used to identify areas that supplied onroad emissions data to the EIS. In these cases, EPA extracted available SCC-based VMT data from these submittals, and further processed the VMT data for use in EPA onroad mobile source NMIM runs. 3 ------- May 2011 Table 2-1 a. Methods Used to Develop Emission Estimates for Onroad Vehicle Sources Base Year(s) Pollutant(s) Geographic Area Emission Estimation Method 2008 All Criteria, HAPs US, Puerto Rico, Virgin Islands 2005 All Criteria, HAPs 2002 All Criteria, HAPs 2001 2001 2001 2001 1999 1999 VOC, NOx, CO, S02, PM10, PM2.5 NH3 All Criteria All Criteria All Criteria VOC, NOx, CO, S02, PM10, PM2.5 US, Puerto Rico, Virgin Islands US, Puerto Rico, Virgin Islands California California AL; CO; ME; MA; MS; OR; UT; VA; WV; Maricopa County, AZ; Hamilton County, TN Rest of US AL; ME; MA; MS; UT; VA; WV; Maricopa County, AZ; Hamilton County, TN California Emission estimates for all pollutants were developed using EPA's National Mobile Inventory Model (NMIM), which uses MOBILE6 (specifically, M6203ChcOxFixNMIM.exe) to calculate onroad emission factors. Where States provided alternate onroad MOBILE6 inputs or VMT, these data replaced EPA default inputs. Default VMT is based on FHWA 2008 data and 2008 Census population estimates. Emission estimates for all pollutants were developed using EPA's NMIM, which uses MOBILE6 to calculate onroad emission factors. Where States provided alternate onroad MOBILE6 inputs or VMT, these data replaced EPA default inputs. Default VMT is based on FHWA 2005 data and 2005 Census population estimates. Emission estimates for all pollutants were developed using EPA's NMIM, which uses MOBILE6 to calculate onroad emission factors. Where States provided alternate onroad MOBILE6 inputs or VMT, these data replaced EPA default inputs. California-supplied emissions data which replaced default EPA emission estimates for this state. Default VMT is based on FHWA 2002 data and population data from 2000 Census. Emissions and VMT provided by California at county/vehicle type level; State- provided emissions expanded to county/SCC level by EPA Calculated at State/county/SCC level by month using MOBILE6 emission factors with State-provided VMT data State-provided VMT grown to 2001; emissions calculated by EPA using MOBILE6 emission factors Calculated at State/county/SCC level by month using MOBILE6 and FHWA- based VMT Calculated at State/county/SCC level by month using MOBILE6; State- provided VMT data used Emissions and VMT provided by California at county/vehicle type level; State- provided emissions expanded to county/SCC level by EPA 4 ------- May 2011 Table 2-1 a. Methods Used to Develop Emission Estimates for Onroad Vehicle Sources Base Year(s) Pollutant(s) Geographic Area Emission Estimation Method 1999 1999 1999 1999 1999 1999 1999 1997-1998 1990,1996 1991-1995 1988-1989 1979-1986 1978, 1987, 1990, 1996, 2000 1970,1975 NH3 PM10 Exhaust VOC, NOx, CO, S02, PM10 brake and tire wear, PM2.5, NH3 All Criteria All Criteria HAPs HAPs All Criteria HAPs All Criteria All Criteria All Criteria All Criteria All Criteria California Colorado Colorado Oregon Rest of US, Puerto Rico, and US Virgin Islands California Rest of US, Puerto Rico, and US Virgin Islands US US US US US US US Calculated at State/county/SCC level by month using MOBILE6 emission factors with State-provided VMT data PM10 emissions and VMT provided by State Calculated at State/county/SCC level by month using MOBILE6; State- provided VMT data used Emissions and VMT provided by Oregon at county/vehicle type level; State- provided emissions expanded to county/SCC level by EPA Calculated at State/county/SCC level by month using MOBILE6 and FHWA- based VMT HAP emissions and VMT provided by California at county/vehicle type level; emissions allocated to SCC level by EPA MOBILE6 emission factors calculated at State/county/SCC level by season; applied to FHWA-based VMT 2-step linear interpolation at State/count/SCC level based on 1996 and 1999 State/count/SCC level data MOBILE6 emission factors calculated at State/county/SCC level by season; applied to Federal Highway Administration (FHWA)-based vehicle miles traveled (VMT) Linear interpolation at State/count/SCC level based on 1990 and 1996 State/count/SCC level data Linear interpolation at State/count/SCC level based on 1987 and 1990 State/count/SCC level data Linear interpolation at State/count/SCC level based on 1978 and 1987 State/count/SCC level data Calculated at State/county/source classification code (SCC) level by month using MOBILE6, no State data incorporated Linear extrapolation at national vehicle type level based on 1978 and 1987 national data 5 ------- May 2011 Table 2-1 b. Methods Used to Develop Emission Estimates for Nonroad Mobile Sources Category Base Year Pollutant(s) Estimation Method* NONROAD Categories Nonroad Gasoline, Diesel, LPG, CNG 2008 VOC, NOx, CO, S02, PM10, PM2.5, NH3i & HAPs Emission estimates for NONROAD model engines were developed using EPA's National Mobile Inventory Model (NMIM), which incorporates NONROAD2008. Where states provided alternate NMIM nonroad inputs, these data replaced EPA default inputs. 2005 VOC, NOx, CO, S02, , PM-io, PM25, NH3, & HAPs Emission estimates for NONROAD model engines were developed using EPA's NMIM, which incorporates NONROAD2005. Where States provided alternate nonroad inputs, these data replaced EPA default inputs. 2002 VOC, NOx, CO, S02, PM10, PM25, NH3, & HAPs Emission estimates for NONROAD model engines were developed using EPA's NMIM, which incorporates NONROAD2004. Where states provided alternate nonroad inputs, these data replaced EPA default inputs. State-supplied emissions data also replaced default EPA emission estimates. 1999 VOC, NOx, CO, S02, PM-io, PM2 5 Using emission estimates from two emission inventories including: 1) a 1996 county-level inventory, developed using EPA's October 2001 draft NONROAD model; and 2) an updated 1999 national inventory, based on EPA's draft Lockdown C NONROAD model (dated May 2002). Using the 1996 county-level emission estimates, seasonal and daily county-to-national ratios were then developed for application to updated national estimates per season estimated from the Lockdown C model. Replaced State-submitted data for California for all NONROAD model categories; Pennsylvania for recreational marine and aircraft ground support equipment, and Texas for select equipment categories. 1996, 1997, 1998,2000 & 2001 VOC, NOx, CO, S02, PM-io, PM2 5 Using emission estimates from two emission inventories including: 1) a 1996 county-level inventory, developed using EPA's October 2001 draft NONROAD model; and 2) updated year- specific national and California inventories, based on EPA's draft Lockdown C NONROAD model (dated May 2002). Using the 1996 county-level emission estimates, seasonal and daily county-to- national ratios and California county-to-state ratios were then developed for application to updated national estimates per season estimated from the Lockdown C model. California results replace the diesel equipment emissions generated from prior application of county-to-national ratios. 6 ------- May 2011 Table 2-1 b. Methods Used to Develop Annual Emission Estimates for Nonroad Mobile Sources (Continued) Category Base Year Pollutant(s) Estimation Method* Nonroad Gasoline, Diesel, LPG, and CNG (Continued) 1991-1995 VOC, NOx, CO, S02, PM10, PM25, NH3 Using 1990 and 1996 county-level emissions inventories, estimated emissions using linear interpolation of national emissions between 1990 and 1996. From these emissions, calculated the average annual growth rate for each pollutant/SCC combination for each year, and then applied the growth factors to 1990 county-level emissions to estimate 1991-1995 emissions. 1990 VOC, NOx, CO, S02, PM-io, PM2 5 Using emission estimates from two emission inventories including: 1) a 1996 county-level inventory, developed using EPA's October 2001 draft NONROAD model; and 2) updated 1990 national inventory, based on EPA's draft Lockdown C NONROAD model (dated May 2002). Using the 1996 county-level emission estimates, seasonal and daily county-to-national ratios were then developed for application to updated national estimates per season estimated from the Lockdown C model. 1986, 1988, & 1989 VOC, NOx, CO, S02, PM-io, PM25, NH3 Using 1985 and 1990 county-level emissions inventories, estimated emissions using linear interpolation of national emissions between 1985 and 1990. From these emissions, calculated the average annual growth rate for each pollutant/SCC combination for each year, and then applied the growth factors to 1985 county-level emissions to estimate 1986-1989 emissions. 1987 VOC, NOx, CO, S02, PM-io, PM2 5 Using EPA's draft Lockdown C NONROAD model (dated May 2002), developed updated national emissions for 1987 by running 4 seasonal NONROAD model runs to estimate annual criteria pollutant emissions. Also performed national NONROAD model runs to estimate typical summer weekday emissions. 1985 VOC, NOx, CO, S02, PM-io, PM2 5 Using emission estimates from two emission inventories including: 1) a 1996 county-level inventory, developed using EPA's October 2001 draft NONROAD model; and 2) updated 1985 national inventory, based on EPA's draft Lockdown C NONROAD model (dated May 2002). Using the 1996 county-level emission estimates, seasonal and daily county-to-national ratios were then developed for application to updated national estimates per season estimated from the Lockdown C model. 1970, 1975, 1978, & 1980 VOC, NOx, CO, S02, PM-io, PM2 5 Using EPA's draft Lockdown C NONROAD model (dated May 2002), developed updated national emissions for all years by running 4 seasonal NONROAD model runs to estimate annual criteria pollutant emissions. Also performed national NONROAD model runs to estimate typical summer weekday emissions. 7 ------- May 2011 Table 2-1 b. Methods Used to Develop Annual Emission Estimates for Nonroad Mobile Sources (Continued) Category Base Year Pollutant(s) Estimation Method* Nonroad Gasoline, Diesel, LPG, and CNG (Continued) 1996, 1997, 1998, 1999, 2000,& 2001 nh3 Obtaining national fuel consumption estimates from the Lockdown C NONROAD model, multiplying by NH3 emission factors, and distributing to counties using 1996 inventory, based on October 2001 draft NONROAD. NH3 emissions for California were also recalculated using updated diesel fuel consumption values generated for California-specific runs, and assuming the 1996 county-level distribution. 1985 & 1990 nh3 Obtaining national fuel consumption estimates from the Lockdown C NONROAD model, multiplying by NH3 emission factors, and distributing to counties using 1996 inventory, based on October 2001 draft NONROAD. 1987 nh3 Obtaining 1987 national fuel consumption estimates from Lockdown C NONROAD model and multiplying by NH3 emission factors. 1970, 1975, 1978, & 1980 nh3 Obtaining national fuel consumption estimates from the Lockdown C NONROAD model and multiplying by NH3 emission factors. 1990, 1996, & 1999 HAPs Speciation profiles applied to county VOC and PM estimates. Metal HAPs were calculated using fuel and activity-based emission factors. Some state data were provided and replaced national estimates. (2003) Aircraft Commercial Aircraft 2008 Criteria and HAPs Federal Aviation Administration (FAA) Emissions and Dispersion Modeling System (EDMS) - Version 5.1.was run using BTS T-100 LTO data. (2009) 2002 and 2005 Criteria and HAPs Federal Aviation Administration (FAA) Emissions and Dispersion and Modeling System (EDMS) was run for criteria pollutants, VOC and PM emissions were speciated into HAP components. (2004) 1990, 1996, 1999, 2000, 2001 VOC, NOx, CO, SOx Input landing and take-off (LTO) data into FAA EDMS. National emissions were assigned to airports based on airport specific LTO data and BTS GIS data. State data replaced national estimates. (2003) 1970-1998 VOC, NOx, CO, SOx Estimated emissions for interim years using linear interpolation between available base years. (2003) 1990, 1996, 1999 HAPs Speciation profiles were applied to VOC estimates to get national HAP estimates. State data replaced national estimates. (2003) 8 ------- May 2011 Table 2-1 b. Methods Used to Develop Annual Emission Estimates for Nonroad Mobile Sources (Continued) Category Base Year Pollutant(s) Estimation Method* General Aviation, Air Taxis 2008 Criteria and HAPs Federal Aviation Administration (FAA) Emissions and Dispersion Modeling System (EDMS) - Version 5.1.was run using BTS T-100 LTO for aircraft identified as Air taxis. (2010) Used FAA LTO data from TAF and OTAQ provided activity data for smaller airports derived from FAA 5010 master plans. EPA approved generic emission factors for criteria estimates. Speciation profiles were applied to VOC and PM estimates to get national HAP estimates. (2010) 2005 VOC, NOx, CO, S02, PM-io, PM2 5 2002 emissions for approximately 4,000 largest airports were calculated via EDMS and SIP guidance and included in the 2005 NEI as point sources. Only airports in FAA's T100 and TAF databases were included. State point source submittals were incorporated. 1978, 1987, 1990, 1996, 1999, 2000, 2001,& 2002 VOC, NOx, CO, S02, PM10, PM2 5 Used FAA LTO data and EPA approved emission factors for criteria estimates. Speciation profiles were applied to VOC estimates to get national HAP estimates. State data replaced national estimates. (2004) 1970-1998 VOC, NOx, CO, SOx, PM10, PM2 5 Estimated emissions for interim years using linear interpolation between available base years. (2003) 1990, 1996, 1999,& 2002 HAPs Used FAA LTO data and EPA approved emission factors for criteria estimates. Speciation profiles were applied to VOC estimates to develop national HAP estimates. (2004) 1990, 1996, 1999,& 2002 Pb Used Department of Energy (DOE) aviation gasoline usage data with lead concentration of aviation gasoline. (2004) 1996 nh3 Applied NH3 emissions factors to 1996 national jet fuel and aviation gasoline consumption estimates. Military Aircraft 2008 VOC, NOx, CO, S02, PM-io, PM2.5 Used FAA LTO data as reported in TAF and EPA approved emission factors for criteria estimates. Representative HAP profiles were not readily available, therefore HAP estimates were not developed. (2010) 2005 VOC, NOx, CO, S02, PM-io, PM2 5 2002 emissions were included in the 2005 NEI as point sources similar to other TAF reported data. 1978, 1987, 1990, 1996, 1999, 2000, 2001,2002, 2008 VOC, NOx, CO, S02, PM-io, PM2.5 Used FAA LTO data as reported in TAF and EPA approved emission factors for criteria estimates. Representative HAP profiles were not readily available, therefore HAP estimates were not developed. 1970-1998 VOC, NOx, CO, SOx, PM-io, PM2.5 Estimated emissions for interim years using linear interpolation between available base years. (2003) 9 ------- May 2011 Table 2-1 b. Methods Used to Develop Annual Emission Estimates for Nonroad Mobile Sources (Continued) Category Base Year Pollutant(s) Estimation Method* Auxiliary Power Units and Ground Support Equipment 2008 VOC, NOx, CO, S02, PM-io, PM2.5i HAPs Federal Aviation Administration (FAA) Emissions and Dispersion and Modeling System (EDMS) - Version 5.1 .was run using BTS T-100 LTO data. (2009) 2002 and 2005 VOC, NOx, CO, S02, PM10, PM2.5, HAPs Computed via NONROAD2005 model runs 1985-2001 VOC, NOx, CO, S02, PM10, PM2 5 Grew 1996 emissions to each year using LTO operations data from the FAA. Estimation methods prior to 1996 reported in EPA, 1998. Unpaved Airstrips1 1985-2001 PM-io, PM2.5 Grew 1996 emissions to each year using SIC 45-Air Transportation growth factors, consistent with the current draft version of EGAS. Estimation methods prior to 1996 reported in EPA, 1998. Aircraft Refueling1 1985-2001 VOC Grew 1996 emissions to each year using SIC 45-Air Transportation growth factors, consistent with the current draft version of EGAS. Estimation methods prior to 1996 reported in EPA, 1998. Commercial Marine Vessel (CMV) All CMV Categories 2008 VOC, NOx, CO, SO2, PM-io, PM2.5 OTAQ provided CAP emission estimates for all CMV categories. Note that the SCCs for this category have changed such that the Diesel category refers to smaller vessels (Category 1 and 2) using distillate fuels and the Residual category refers to larger (Category 3) vessels using a blend of residual fuels. Emissions were allocated to segments using GIS shapefiles and adjusted based on limited state data (2010) 2008 HAPs OTAQ's 2008 estimates were speciated into HAP components using EPA profiles (2009) CMV Diesel 2002 and 2005 VOC, NOx, CO, S02, PM-io, PM2.5 2001 Estimates carried over. Used state data when provided. (2004) HAPs 1999 Estimates carried over. Used state data when provided. (2004) 1978, 1987, 1990, 1996, 1999, 2000, & 2001 VOC, NOx, CO, SOx, PM-io, & PM2.5 Used criteria emission estimates in the background document for marine diesel regulations for 2000. Adjusted 2000 criteria emission estimates for other used based on fuel usage. Emissions were disaggregated into port traffic and underway activities. Port emissions were assigned to specific ports based on amount of cargo handled. Underway emissions were allocated based on Army Corp of Engineering waterway data. State data replaced national estimates. (2003) 1970-1998 VOC, NOx, CO, SOx, PM-io, PM2 5 Estimated emissions for interim years using linear interpolation between available base years. (2003) 1990, 1996, 1999 HAPs VOC and PM emission estimates were speciated into HAP components. State data replaced national estimates. (2003) 1996 nh3 Applied NH3 emissions factors to 1996 distillate and residual fuel oil estimates (i.e., as reported in EIA, 1996). 1990-1995 nh3 Estimation methods reported in EPA, 1998. 10 ------- May 2011 Table 2-1 b. Methods Used to Develop Annual Emission Estimates for Nonroad Mobile Sources (Continued) Category Base Year Pollutant(s) Estimation Method* CMV Steam Powered 2005 VOC, NOx, CO, SOx, PM-io, & PM2 5, HAPs 2002 estimates grown to 2005 (2008). 2002 VOC, NOx, CO, SOx, PM-io, & PM2 5, HAPs 2002 based estimates were developed for port and underway category 3 (C3) vessels as part of a rulemaking effort. Emissions were developed separately for near port and underway emissions. For near port emissions, inventories for 2002 were developed for 89 deep water and 28 Great Lake ports in the U.S. The Waterway Network Ship Traffic, Energy, and Environmental Model (STEEM) was used to provide emissions from ships traveling in shipping lanes between and near individual ports (2008) 1978, 1987, 1990, 1996, 1999, 2000, & 2001 VOC, NOx, CO, SOx, PM-io, & PM2 5 Calculated criteria emissions based on EPA SIP guidance. Emissions were disaggregated into port traffic and underway activities. Port emissions were assigned to specific ports based on amount of cargo handled. Underway emissions were allocated based on Army Corp of Engineering waterway data. State data replaced national estimates. (2003) 1970-1998 VOC, NOx, CO, SOx, PM-io, PM2 5 Estimated emissions for interim years using linear interpolation between available base years. (2003) 1990, 1996, & 1999 HAPs VOC and PM emission estimates were speciated into HAP components. State data replaced national estimates. (2003) Military Marine 1997-2001 VOC, NOx, CO, S02, PM-io, PM2 5 Applied EGAS growth factors to 1996 emissions estimates for this category. CMV Coal/ CMV, Steam powered, CMV Gasoline2 1997-1998 VOC, NOx, CO, S02, PM-io, PM2 5 Applied EGAS growth factors to 1996 emissions estimates for this category. CM Coal, CMV, Steam powered, CMV Gasoline, Military Marine 1991-1995 VOC, NOx, CO, S02, PM-io, PM2 5 Estimation methods reported in EPA, 1998. Locomotives Class 1, II, III and Yard operations 2008 VOC, NOx, CO, PM-io, PM2 5 SOx & HAPs Criteria emission estimates were provided to EPA by ERTAC. These data were assigned to individual railway segments using DOT shapefiles and guidance from ERTAC. HAP emissions were calculated by applying speciation profiles to VOC and PM estimates. (2010) 11 ------- May 2011 Table 2-1 b. Methods Used to Develop Annual Emission Estimates for Category Base Year Pollutant(s) Estimation Method* Class 1, Class II, Commuter, Passenger, and Yard Locomotives 1978, 1987, 1990, 1996, 1999, 2000, 2000,2002,& 2005 VOC, NOx, CO, PM-IO, PM2 5 Criteria pollutants were estimated by using locomotive fuel use data from DOE EIA and available emission factors. County-level estimates were obtained by scaling the national estimates with the rail GIS data from DOT. State data replaced national estimates. (2004) 1978, 1987, 1990, 1996, 1999, 2000, 2001,2002, & 2005 so2 SOx emissions were calculated by using locomotive fuel use and fuel sulfur concentration data from EIA. County-level estimates were obtained by scaling the national estimates with the county level rail activity data from DOT. State data replaced national estimates. (2004) 1970-1998 VOC, NOx, CO, SOx, PM10, PM2 5 Estimated emissions for interim years using linear interpolation between available base years. (2003) 1990, 1996, 1999,& 2002 HAPs HAP emissions were calculated by applying speciation profiles to VOC and PM estimates. County-level estimates were obtained by scaling the national estimates with the county level rail activity from DOT. State data replaced national estimates. (2004) 1997-1998 nh3 Grew 1996 base year emissions using EGAS growth indicators. 1996 nh3 Applied NH3 emissions factors to diesel consumption estimates for 1996. 1990-1995 nh3 Estimation methods reported in EPA, 1998. Notes: * Dates included at the end of Estimation Method represent the year that the section was revised. 1 Emission estimates for unpaved airstrips and aircraft refueling are included in the nonpoint source NEI, since they represent non-engine emissions. 2 National Emission estimates for CMV Coal and CMV Gasoline were not developed, though states and local agencies may have submitted estimates for these source categories. EPA, 1998: U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Emission Factors and Inventory Group, National Air Pollutant Emission Trends, Procedures Document, 1900-1996, EPA-454/R-98-008. May 1998. 12 ------- May 2011 Table 2-2. Summary of Onroad and Nonroad 2008 NMIM Data Submissions Onroad SCC- Data Provided For NCD based State Name (all counties unless otherwise noted) Files VMT Alabama Alaska Arizona Maricopa County ¦/ Arkansas ¦/ California Colorado Connecticut Delaware Washington DC ¦/ Florida Georgia ¦/ Hawaii ¦/ Idaho ¦/ Illinois ¦/ Indiana Iowa Kansas ¦/ Kentucky Jefferson County ¦/ Louisiana ¦/ Maine ¦/ Maryland ¦/ Massachusetts ¦/ Michigan ¦/ Minnesota ¦/ Mississippi ¦/ Missouri ¦/ Montana Nebraska Nevada All counties except Clark and Washoe ¦/ New Hampshire ¦/ New Jersey New Mexico New York North Carolina ¦/ North Dakota Ohio ¦/ Oklahoma Oregon Pennsylvania ¦/ Rhode Island South Carolina ¦/ South Dakota Tennessee Davidson County ¦/ Texas ¦/ Utah Vermont ¦/ Virginia ¦/ Washington West Virginia 13 ------- May 2011 State Name Data Provided For (all counties unless otherwise noted) NCD Files Onroad SCC- based VMT Wisconsin ¦/ Wyoming Puerto Rico Virgin Islands The EPA developed the 2008 mobile source NEI in multiple phases. In the first phase, EPA ran NMIM for year 2008 for the entire country. This NMIM run used EPA default modeling inputs incorporated into "NCD20090327" (the naming convention reflects the NCD's lock-down date). These default inputs represented EPA's initial assumptions concerning key modeling parameters such as fuel blends, ambient temperatures, and onroad VMT. The 2008 mobile source emission estimates from this phase were listed in the EIS under the data set descriptions "EPA Nonroad using NCD20090327" and "EPA Onroad using NCD20090327." The EPA then discovered a need to update some of the fuel parameter values from the assumptions used in NCD20090327. Consequently, EPA developed an updated NCD reflecting the revised values, which was posted under the name "EPA NMIM Activity NCD20090531." This NCD was then posted for review/update by S/L/T agencies. For the second phase, EPA set a deadline of June 1, 2010 for agencies to submit changes to the NCD20090531 values for their areas. After obtaining any necessary clarification on these changes from S/L/T agencies, EPA modified the NCD to reflect S/L/T updates, ran NMIM for 2008 for the entire country, and processed annual NMIM emissions output for loading into the EIS. This 2008 mobile source NEI development phase resulted in the data sets "EPA Nonroad using NCD20100602" and "EPA Onroad using NCD20100602." In the third and final phase, agencies were afforded the opportunity to review EPA's emission estimates and provide additional revisions to NMIM inputs. After updating the NCD to reflect these revisions, EPA ran NMIM a final time and produced the data sets described as "EPA Nonroad using NCD20101201" and "EPA Onroad using NCD20101201." This data set only covers the geographical areas that submitted changes between July 2010 and November 2010.1 2.3 WHAT IS THE MAGNITUDE OF THE MOBILE SOURCE EMISSIONS ESTIMATED FOR 2008? Tables 2-3 and 2-4 display the national onroad and nonroad mobile source emission totals reflecting each area's latest emission estimates (i.e., emissions computed using NCD20101201 for areas for which agencies submitted changes between July 2010 and November 2010, and emissions computed using NCD20100602 for all other areas). These tables do not reflect any State/Local agency-submitted 2008 emissions data. 1 Although Lincoln County Nebraska data were provided in time for the June submittal deadline, EPA uploaded the NMIM results in the NCD20101201 data set rather than the NCD20100602 data set. 14 ------- May 2011 Table 2-3. 2008 Onroad Mobile NEI National Emission Totals Emissions Pollutant (tons) VOC 3,812,673 NOX 4,988,311 CO 41,373,673 PM10-PRI 147,328 PM25-PRI 94,372 so2 44,722 nh3 306,952 Table 2-4. 2008 Nonroad Mobile NEI National Emission Totals Emissions Pollutant (tons) VOC 2,492,230 NOX 1,882,841 CO 18,214,682 PM10-PRI 185,572 PM25-PRI 176,931 S02 32,214 NH3 2,093 15 ------- May 2011 3.0 NATIONAL MOBILE INVENTORY MODEL (NMIM) 3.1 BACKGROUND This subsection provides a brief overview of EPA's NMIM. Readers that are interested in a more detailed understanding of NMIM should refer to EPA's NMIM webpage for further model documentation: http://www.epa.gov/otaq/nmim.htm. The NMIM is a consolidated emissions modeling system that houses EPA's onroad mobile source (MOBILE6) and nonroad mobile source (NONROAD) emission models. It was developed to produce, in a consistent and automated way, national, county-level mobile source emission inventories. When national inventories have previously been constructed from MOBILE6 and NONROAD, the necessary input data have been widely scattered in disparate formats and have required additional specialized software to: convert these data into input files for MOBILE6 and NONROAD; run the models; integrate the results into a final inventory; and post-process the results into forms suitable for the national inventories. NMIM is designed to accomplish these tasks via a single package. Further details on EPA's MOBILE6 and NONROAD models are available from the following web pages: http://www.epa.gov/otaq/mobile.htm and http://www.epa.gov/otaq/nonrdmdl.htm, respectively. 3.2 THE NMIM COUNTY DATABASE 3.2.1 Database Structure The NCD contains all the county-specific information needed to run M0BILE6 and NONROAD. It also contains the ratios that are applied to M0BILE6/N0NR0AD outputs to estimate emissions of HAPs, dioxins/furans, and some metals. The NCD is a relational database management system available from www.mysql.com. Table 3-1 displays the tables that comprise the NCD. 3.2.1.1 EIS Interface To speed the interchange of mobile source activity data between S/L/T agencies and EPA, the EIS was designed to exclude NCD tables that should not generally be revised. Therefore, only the following tables were required to be included in an EIS mobile source activity data submission: baseyearvmt, county, countynrfile, countyvmtmonthallocation, countyyear, countyyearmonth, countyyearmonthhour, diesel, gasoline, natural gas, and state. A separate folder for the various external files was also required, along with a text file detailing changes that were made to each table. To facilitate interaction with S/L/T agencies on the 2008 NEI, the EPA provided NCD activity data in separate files by State. The EPA then reintegrated the updated data provided by S/L/T agencies into a single NCD for the 2008 NMIM run. The EPA's instructions for reporting NCD data to the EIS are available from http://www.epa.gov/ttn/chief/net/neip/section 9.pdf. 16 ------- May 2011 Table 3-1. Tables in the NMIM County Database (NCD) Table Contents BaseYearVMT VMT by year, county, M6Vclass, and HPMSRoadType. County For each county, Federal Information Processing System (FIPS) codes for the county and State, altitude, beginning and end of ozone season, Stage 2 information, Natural Gas Vehicle (NGV) fraction file name CountyMap The representing county for each county/county group, one for NONROAD and one for MOBILE6. CountyMonth Defines the set of possible county-month combinations. CountyMonthHour Monthly average hourly temperature and humidity table used if "Use Yearly Weather Data" option is not selected or data are not available for the requested year in the CountyYearMonthHour table. County NRFile References to external NONROAD files pertaining to a county. CountyVMTMonthAllocation Mileage allocation factors for the 12 months of the year, by county. CountyYear Stage2 percent input to the NONROAD model, plus external file references for MOBILE6 and NONROAD. CountyYearMonth Gasoline, diesel, and natural gas fuel IDs for each county for each year and month. CountyYearMonthHour Historical hourly temperature and relative humidity. DataSource Defines the data source identifiers used in other tables. Diesel Diesel sulfur content associated with each diesel ID. EmissionType Associates emission types (exhaust, evap, brake, tire) with EmissionTypelD used in other tables FileType Defines the set of valid external files and their 3-character extensions. Gasoline Detailed fuel properties associated with each gasoline ID. Hour Defines the hour identifiers. HPMSRoadType Defines the 12 HPMS road type identifiers. M6Vclass Defines the 28 vehicle classes used in MOBILE6. These are the valid combinations of M6Vtype and fuel. M6Vtype Defines the fuel-independent vehicle types used in MOBILE6. NaturalGas Natural gas sulfur content associated with each natural gas ID. PollutantCode Associates NIF pollutant codes and pollutant names with PollutantCodelD used in other tables. see Associates an SCC code and description for each SCCID, and ratios for NH3, PM25, and for converting between HC forms. SCCToxics SCC and fuel property-dependent ratios for calculating HAPs, dioxin/furans, and metals. State Associates State names and abbreviations with State FIPS codes used in other tables. VMTGrowth The annual VMT growth rate for a M6Vclass by county and year. VMTMonthAllocation Factors for allocating annual VMT to the 12 months, by M6Vtype and HPMSRoadType, used if there are no county-specific values in CountyVMTMonthAllocation. 3.2.2 EPA Default 2008 NCD Inputs This section describes how EPA developed default 2008 NCD inputs for the following: vehicle miles traveled; temperature and humidity; and gasoline and diesel fuel parameters. 3.2.2.1 Vehicle Miles Traveled The VMT data in the NCD is contained in the BaseYearVMT table. For each county in this table, VMT data are reported for each of the 12 Highway Performance Monitoring System (HPMS) functional roadway types and the 28 MOBILE6 vehicle classes, for a total of 336 records per county. 17 ------- May 2011 The EPA developed 2008 vehicle miles traveled (VMT) data by allocating Federal Highway Administration (FHWA) VMT data to the county/road type/vehicle class-level required by NMIM. The EPA initially developed 2008 VMT data in NCD20090327 by growing 2007 State- level VMT from FHWA's HPMS to 2008 using VMT growth factors (FHWA, 2007). The 2007 to 2008 growth factors were calculated from the 2007 and 2008 FHWA's Travel Volume Trends reports (FHWA, 2009a). For NCD20100602, 2008 HPMS State-level VMT totals by road type were allocated to the county/road type/vehicle class-level using VMT data submitted for earlier NEIs (FHWA, 2009b). For agencies that submitted data in 2005, the following formula was used: 2008 County VIVITvciass, Road Type ~~ 2008 State VMT * (2005 County VMTvaass, Road TyPJ2005 State VMT) An analogous formula was used for agencies that submitted 2002, but not 2005, VMT data. If a geographic area did not submit VMT data in either 2005 or 2002, then EPA allocated FHWA data from its HPMS urban and small urban area data sets, and the Highway Statistics rural VMT data by State and roadway class, to the county level using 2008 population data (Census, 2009a and 2009b). The HPMS data sets included VMT by roadway class for urban and small urban areas, which EPA then allocated to the counties included in these areas using population data. Rural VMT at the State and roadway class level was obtained from Highway Statistics and allocated to the rural counties in a State by roadway class using rural interstate mileage and rural population for the allocations. The EPA allocated the resulting VMT at the county and roadway class level to each of the 28 MOBILE6 vehicle types based on the default VMT allocations by vehicle type for 2008 in MOBILE6. See Section 3.2.2.1.2 of the 2005 Mobile NEI Version 2 report for a more detailed explanation of how these default allocations were performed (EPA/Pechan, 2008). 3.2.2.2 Temperature and Humidity NMIM requires that each county have both hourly average temperature and hourly relative humidity values for each month of the year. The NOx emission results from MOBILE6 are sensitive to humidity levels, and hourly humidity levels are the most accurate way to represent daily humidity. MOBILE6 allows users to supply daily temperatures as either minimum/maximum values or as hourly averages. Because MOBILE6 calculates emissions separately for each hour of the day, user-supplied minimum and maximum temperatures are used to internally derive hourly temperatures, using a default diurnal temperature profile. MOBILE6 also allows users to supply hourly relative humidity levels. The NCD contains a full set of default hourly average temperatures and hourly relative humidity values for each county for each month. These temperature and humidity values were derived from raw measurement data obtained from the National Climatic Data Center (NCDC). The procedures used to develop the default NMIM temperature and relative humidity values are discussed in more detail in the report, "Derivation of By-Month, By-County, By-Hour 18 ------- May 2011 Temperature and Relative Humidity with Monthly Data," by Air Improvement Resources, Inc. (AIR, 2004). 3.2.2.3 Gasoline The default year 2008 EPA gasoline parameters were generally developed by interpolating between historical 2005 values compiled in support of the 2005 NEI and 2012 values developed in support of modeling for the Renewable Fuel Standards established by the Energy Independence and Security Act of 2007 (RFS2) (EPA, 2009). The following identifies the instances where EPA deviated from this approach in developing NCD20090531 gasoline parameter values. For ethyl tert-butyl ether (ETBE), methyl tert-butyl ether (MTBE), and tertiary amyl methyl ether (TAME), EPA set 2008 year volume and market share values to zero.2 For gasoline sulfur, gasoline maximum sulfur, and benzene content, EPA set 2008 values to the 2012 RFS2 values. For the reformulated gasoline (RFG) and RVP Oxy Waiver fields, EPA retained the 2005 values for 2008. For ethanol volumes and market shares, EPA used one of two different interpolation procedures to estimate 2008 values. If RFG was used in the given area, then EPA added the 2005 NEI ETBE, MTBE, and TAME values to the 2005 NEI ethanol values before performing the interpolation. If RFG was not used, EPA did not include the 2005 values for ETBE, MTBE, and TAME in the interpolation procedure. Further details on the interpolation procedures are available in the NMIM ChangeLog under NCD20090531. 3.2.2.4 Diesel Diesel sulfur values were developed in support of the renewable fuel standard work performed as part of the 2002 Version 3 Modeling Platform (EPA, 2010). The year 2008 sulfur values were interpolated from 2005 values developed for the 2005 NEI and 2009 values developed from Annual Energy Outlook 2007 (additional details are provided in the ChangeLog under NCD20070727). 3.2.3 State/Local Agency-Submitted Inputs State/Local agencies were provided the opportunity to provide NCD input data to override EPA defaults. The EIS performed a number of automated checks on the agency submissions. As described below, it was necessary for EPA to perform detailed review/manipulation of some S/L agency data before incorporating the data into the NCD. 3.2.3.1 VMT If an agency submitted onroad mobile source emissions data, the SCC-level VMT data were extracted from the submission. Since NMIM maintains 28 vehicle classes and 12 road types (336 combinations total) to the SCC's 12 vehicle classes and 12 road types (144 combinations total), some effort was necessary to split SCC-level VMT to the level required by NMIM. Table 2 However, a MOBILE6 anomaly results in a national estimate of onroad MTBE emissions of 0.31 pounds. 19 ------- May 2011 3-2 shows the mapping between HPMS vehicle categories to both SCC and NMIM/MOBILE6- level vehicle classes. Table 3-2. Mapping of HPMS Vehicle Categories to NMIM/MOBILE6 and SCC- Level Vehicle Classes SCC-Level NMIM/MOBILE6 HPMS Vehicle Category Vehicle Classes Vehicle Classes Passenger Cars LDGV (2201001) LDDV (2230001) LDGV LDDV Motorcycles MC (2201080) MC Other 2-Axle 4-Tire Vehicles LDGT1 (2201020) LDGT1 LDGT2 LDGT2 (2201040) LDGT3 LDGT4 LDDT (2230060) LDDT12 LDDT34 HDGV (2201070) 2BHDDV (2230071) HDGV2B HDDV2B Single-Unit 2-Axle 6-Tire or More Trucks HDGV (2201070) HDGV3 HDGV4 HDGV5 HDGV6 HDGV7 LHDDV (2230072) HDDV3 HDDV4 HDDV5 MHDDV (2230073) HDDV6 HDDV7 Combination Trucks HDGV (2201070) HDGV8A HDGV8B HHDDV (2230074) HDDV8A HDDV8B Buses HDGV (2201070) BUS (2230075) HDGB HDDBT HDDBS If an agency had submitted VMT data to the 2005 or 2002 NEIs, the most recent NEI data submission was used to allocate the SCC-level VMT to the NMIM vehicle classes. In the case of Illinois and Texas there were county-SCC combinations for which VMT data were submitted in 2008 that did not appear in their 2005 submission. Therefore, EPA used default MOBILE6 data to allocate each State's SCC-level VMT data to the required NMIM vehicle classes. After performing the allocation to NMIM vehicle classes, the EPA compared the resulting VMT estimates to EPA's default VMT estimates. The EPA contacted agencies to confirm the validity of their SCC-level VMT data when estimates differed by more than 10 percent. In several cases, agencies submitted revised VMT data for use by EPA. Appendix Table A-2 summarizes the data sources/methods used to develop the VMT data incorporated into the 2008 NCD. 20 ------- May 2011 3.2.3.2 Temperature and Humidity Maryland was the only State that submitted temperature and humidity data updates. A review of the methodology used to generate the temperature data showed that there was no spatial interpolation performed between airports and neighboring counties, and that the documentation did not identify how monthly averaging was performed. The EPA decided not to incorporate Maryland's temperature/humidity data because of these concerns. 3.2.3.3 Gasoline Parameters The Gasolineld is a code used in the Gasoline table to identify a unique gasoline profile. A gasoline profile identifies the values for various fuel properties (e.g., the percent by volume of ethanol in the fuel). The EPA's instructions for reporting new gasoline profiles to the EIS identifies the naming convention for the Gasolineld field as SSNNNN, where SS indicates the State's Federal Information Processing System (FIPS) code and NNNNis a unique number chosen by the State. In cases where agencies submitted a new Gasolineld that did not follow this numbering convention, EPA revised the Gasolineld to match the convention, starting each State's new Gasolinelds with "0001" (e.g., two new submittals by Kansas would be assigned Gasolinelds 200001 and 200002). The countyyearmonth table was also revised to reflect the revised numbering. 3.2.3.4 CountyYear The countyyear table is one of the four tables that NMIM uses to determine which (if any) external files to use when preparing a run. The external files referenced in the countyyear table are all onroad-specific. The EPA used the description of changes provided in each agency's submission to identify the columns that should be updated in this table. See Appendix Table A-l for a list of agencies that supplied updates to the countyyear table. 3.2.3.5 CountyNRFile The CountyNRFile table is another of the tables NMIM uses to determine which (if any) external files to use when preparing a run. Files listed in this table are nonroad-specific. Appendix Table A-4 lists the State specific external files supplied by State agencies (no Local agencies submitted CountyNRfile updates)the last column in this table indicates if the file was new in 2008. 3.2.3.6 External Files External files were included if: (a) agencies noted them in their submission comments; (b) they were identified in the county, countyyear, countynrfile, or state tables; or (c) if the modified date on the file was later than the existing file in the NCD. In some cases, NMIM would output an error flag after running NMIM with the updated external files. When this occurred, EPA contacted the agency to identify the necessary fix. 21 ------- May 2011 In the case of Arkansas and Missouri, NMIM runs with updated external files resulted in atypically large increases in evaporative VOC emissions relative to previous runs before these updates. The EPA performed a sample county analysis in each State, and determined that the large increase occurred due to each State's updated registration distribution file. A review of the old and new files determined that the average age of vehicles was older in the updated files (on the order of 2-3 years). Based on this analysis, EPA determined that large evaporative VOC emission increases seen in other States (e.g., Georgia, Kansas, Minnesota, and Ohio) may also be attributable to similar registration distribution revisions. 22 ------- May 2011 4.0 POST-PROCESSING OF NMIM OUTPUT Because of specific design decisions in the EIS, it was necessary for EPA to post-process some of the NMIM output to be able to successfully post the data to the EIS. The following summarizes the NMIM post-processing procedures that EPA implemented for the 2008 NEI. 4.1 POLLUTANT CODE REVISIONS Table 4-1 lists the pollutant codes no longer considered valid in the EIS. To prepare the emissions for loading into the EIS, Pollutant 93 was changed to the valid code 7440382 (Arsenic). The mercury codes (200, 201, and 202) were summed together and reported under the code 7439976 (Mercury). SOA data were removed completely. Table 4-1. Pollutant Code Revisions Pollutant Code Pollutant Description Revision 93 Arsenic & compounds Updated to 7440382 (Arsenic) 200 Mercury (elemental gaseous) Combined into 7439976 (Mercury) 201 Mercury (divalent gaseous) 202 Mercury (particulate) SOA Secondary Organic Aerosols Removed 4.2 REMOVAL OF GROUND SUPPORT EQUIPMENT Airport GSE is a category computed by NMIM. The EPA used the Federal Aviation Administration (FAA)'s Emissions and Dispersion Modeling System (EDMS) - Version 5.1 to estimate aircraft emissions. This model also calculates GSE emissions using take-off and landing data. NMIM does not have this level of detail, so emissions for the three GSE SCCs (2265008005, 2267008005, and 2270008005) were removed before emissions were loaded into the EIS. Please see "Documentation for Aircraft Component of the National Emissions Inventory Methodology" for information on how EPA used the EDMS to calculate airport GSE emissions (ERG, 2011b). 4.3 STAGE II ONROAD VEHICLE REFUELING Stage II refueling data for onroad vehicles are categorized in the nonpoint source NEI rather than the mobile source NEI. Therefore, all NMIM onroad refueling emission type records were removed before loading the NMIM output to the EIS. The nonpoint source NEI documentation describes the development of Stage II onroad vehicle emission estimates (EPA, 2011). 23 ------- May 2011 5.0 REFERENCES AIR, 2004: "Derivation of By-Month, By-County, By-Hour Temperature and Relative Humidity with Monthly Data," by Air Improvement Resources, Inc. December 8, 2004. Census, 2009a: U.S Department of Commerce, Bureau of the Census, "Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2000 to July 1, 2008," data file NST-EST2008-01.csv, http://www.census.gov/popest/states/NST-ann-est.html downloaded on February 23, 2009. Census, 2009b: U.S Department of Commerce, Bureau of Census, "International Database - U.S. Virgin Island Total Midyear Population," http://www.census.gov/cgi- bin/ipc/idbsprd. downloaded on February 23, 2009. EPA, 2011: U.S. Environmental Protection Agency, "2008 National Emissions Inventory Data & Documentation," http://www.epa.gov/ttn/chief/net/2008inventory.html (see Nonpoint/Stage 2 Gasoline Refueling section), accessed March 2011. EPA, 2010: U.S. Environmental Protection Agency, "2002-Based Modeling Platform," http://www.epa.gOv/ttn/chief/emch/index.html#2002. last updated November 2010. EPA, 2009: U.S. Environmental Protection Agency, "Regulation of Fuels and Fuel Additives: Changes to Renewable Fuel Standard Program; Proposed Rule," http://www.epa.gov/otaq/renewablefuels/rfs2 1 -5.pdf. May 26, 2009. EPA/Pechan, 2008: U.S. Environmental Protection Agency, Office of Transportation and Air Quality, and E.H. Pechan & Associates, Inc., "Documentation for the 2005 Mobile National Emissions Inventory, Version 2," prepared for the U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, December 2008. ERG, 201 la: Eastern Research Group, "Documentation for Locomotive Component of the National Emissions Inventory Methodology," prepared under contract to E.H. Pechan & Associates, Inc., for U.S. Environmental Protection Agency, January 6, 2011. ERG, 201 lb: Eastern Research Group, "Documentation for Aircraft Component of the National Emissions Inventory Methodology," prepared under contract to E.H. Pechan & Associates, Inc., for U.S. Environmental Protection Agency, January 27, 2011. ERG, 2010: Eastern Research Group, "Documentation for the Commercial Marine Vessel Component of the National Emissions Inventory Methodology," prepared under contract to E.H. Pechan & Associates, Inc., for U.S. Environmental Protection Agency, March 30, 2010. 24 ------- May 2011 FHWA, 2009a: U.S. Department of Transportation, Federal Highway Administration, Office of Highway Policy Information, "2007 and 2008 Monthly Traffic Volume Trends," http://www.fhwa.dot.gov/ohim/tvtw/tvtpage.cfm. downloaded on February 19, 2009. FHWA, 2009b: U.S. Department of Transportation, Federal Highway Administration, HPMS 2008 Summary Data (summary_dvmt_2008.xls), HPMS 2008 Sample Data (Sample2008.csv and sample2008.schema), and HPMS2008 Universe Data (Universe2008.csv and Universe2008.schema) electronic files, 2009. FHWA, 2008: U.S. Department of Transportation, Federal Highway Administration, HPMS 2007 Summary Data (summary_dvmt_2007.xls), HPMS 2007 Sample Data (Sample2007.csv and sample2007.schema), and HPMS 2007 Universe Data (Universe2007.csv and Universe2007.schema), electronic files, December 1, 2008. 25 ------- May 2011 [This page intentionally left blank.] 26 ------- May 2011 APPENDIX A. TABLES UPDATED WITH EIS SUBMISSIONS This Appendix presents tables summarizing the 2008 NCD updates provided by State/Local agencies. Table A-l lists, for each jurisdiction, the specific NCD tables that were submitted. Table A-2 identifies the source of the VMT data incorporated into the 2008 NCD by jurisdiction. The "2008 VMT Allocation Data Source" column should be interpreted as follows: State 2002 indicates that State-supplied 2002 NEI VMT data was used to allocate 2008 VMT data. Local 2002 indicates that Local agency-supplied 2002 NEI VMT data were used to allocate 2008 VMT data. State 2005 indicates that State-supplied 2005 NEI VMT data was used to allocate 2008 VMT data. MOBILE6 indicates that the State or Local agency did not supply VMT updates in the 2002 or 2005 NEI so MOBILE6 default allocations were used to allocate 2008 VMT data. n/a indicates that agency-submitted VMT data were provided at the level of detail required by NMIM(i.e., it was not necessary for EPA to perform VMT allocations). Table A-3 lists the MOBILE6-specific external file types submitted by S/L agencies. Table A-4 displays the State agency-supplied external files used by NONROAD. The last column in this table identifies if the file was submitted for the 2008 NEI. Table A-1. 2008 NMIM County Database Table Updates by Jurisdiction Jurisdiction Base Year VMT County County NR File County VMT Month Allocation County Year County Year Month County Year Month Hour Diesel Gasoline Natural Gas State AL AK AZ AZ Maricopa County see1 AR ¦/ ¦/ CA see1* CO CT DE DC ¦/ ¦/ ~ FL GA ¦/ ¦/ ¦/ HI ¦/ ** ** ** ID see1 IL sec1 IN IA KS ¦/ ¦/ KY KY Jefferson County see1 LA ¦/ ¦/ ¦/ ¦/ ME ¦/ ¦/ ¦/ ¦/ ¦/ ~ A-l ------- May 2011 Jurisdiction Base Year VMT County County NR File County VMT Month Allocation County Year County Year Month County Year Month Hour Diesel Gasoline Natural Gas State MD ¦/ ¦/ ¦/ ¦/ ¦/ * * * ¦/ ¦/ ~ MA ¦/ ¦/ ~ Ml ¦/ ¦/ ¦/ ¦/ ¦/ MN ¦/ ¦/ ¦/ MS MO ¦/ ¦/ MT NE NV ¦/ ¦/ ¦/ ¦/ ¦/ ¦/ NH ¦/ ¦/ ¦/ NJ NM NY NC ¦/ ¦/ ¦/ ¦/ ND OH ¦/ ¦/ ¦/ OK OR PA ¦/ ¦/ ¦/ ¦/ ¦/ ~ Rl SC ¦/ SD TN TN Davidson County ¦/ TX see1 UT VT ¦/ ¦/ VA ¦/ ¦/ ¦/ WA WV Wl ¦/ ¦/ ¦/ ¦/ ¦/ WY PR VI 1 Jurisdiction supplied emissions data, EPA extracted SCC-level VMT data from this submittal. *Although CA submitted data, the submitted detail (i.e., SCC and pollutants) is substantially different from that used by other States. Therefore, the VMT submitted in CA's emissions file was not used in NMIM. ** Submitted revisions were inadvertently excluded. *** MD countyyearmonthhour changes not included due to differences in estimation methodology A-2 ------- May 2011 Table A-2. Summary of 2008 NEI Vehicle Miles Traveled Data by Jurisdiction Jurisdiction 2008 VMT Data Source Agency Provided Level of Detail 2008 VMT Allocation Data Source AL EPA State 2002 AK EPA MOBILE6 AZ Maricopa County Local see Local 2002 AZ - Rest of State EPA MOBILE6 AR State NMIM n/a CA EPA State 2005 CO EPA State 2005 CT EPA MOBILE6 DE EPA State 2005 DC State NMIM n/a FL EPA MOBILE6 GA State NMIM n/a HI State NMIM n/a ID State see State 2005 IL State see MOBILE6A IN EPA MOBILE6 IA EPA MOBILE6 KS State NMIM n/a KY Jefferson County Local see State 2002 KY - Rest of State EPA MOBILE6 LA State NMIM n/a ME State NMIM n/a MD State NMIM n/a MA EPA State 2002 Ml State NMIM n/a MN State NMIM n/a MS EPA State 2002 MO State NMIM n/a MT EPA MOBILE6 NE Lancaster County EPA State 2002 NE EPA MOBILE6 NV Clark County EPA State 2002 NV Washoe County EPA MOBILE6 NV - Rest of State State NMIM n/a NH State NMIM n/a NJ EPA State 2002 NM EPA MOBILE6 NY EPA State 2002 A-3 ------- May 2011 Jurisdiction 2008 VMT Data Source Agency Provided Level of Detail 2008 VMT Allocation Data Source NC State NMIM n/a ND EPA MOBILE6 OH State NMIM n/a OK EPA MOBILE6 OR EPA State 2002 PA State NMIM n/a Rl EPA State 2002 SC State NMIM n/a SD EPA MOBILE6 TN Davidson County Local NMIM n/a TN - Rest of State EPA State 2005 TX State see MOBILE6A UT EPA State 2005 VT State NMIM n/a VA State NMIM n/a WA EPA State 2002 WV EPA State 2005 Wl State NMIM n/a WY EPA MOBILE6 PR EPA MOBILE6 VI EPA MOBILE6 n/a- not applicable (data supplied at necessary NMIM-level of detail) A - Pre-2008 state supplied data were available (IL-2002; TX-2005), but could not be used as they did not cover all required categories. A-4 ------- May 2011 Table A-3. External Onroad Files Updated for the 2008 NEI Reg VMT By Trip Diesel Avg Speed Dist NLEV T2 Exh Phase T2 Evap Phase T2 Cert Jurisdiction ATP IM Dist Hour Length Fract Base File In File In File File AL AK AZ AR ¦/ CA CO CT DE DC ¦/ ~ ¦/ ¦/ ¦/ ¦/ FL GA ¦/ ¦/ HI ID IL IN IA KS ¦/ ¦/ KY KY Jefferson County LA ¦/ ~ ¦/ ME ¦/ ~ ¦/ ¦/ ¦/ ¦/ MD ¦/ ~ ¦/ ¦/ ¦/ ¦/ MA ~ ¦/ ¦/ ¦/ ¦/ ¦/ Ml ¦/ MN ¦/ MS MO ¦/ MT NE NV ¦/ NH ¦/ ~ ¦/ NJ NM NY NC ¦/ ~ ¦/ ¦/ ¦/ ND OH ¦/ ~ ¦/ OK OR PA ¦/ ~ ¦/ ¦/ ¦/ ¦/ ¦/ ¦/ ¦/ Rl SC SD TN TN Davidson County TX UT VT A-5 ------- May 2011 Jurisdiction ATP IM Reg Dist VMT By Hour Trip Length Diesel Fract Avg Speed Dist Base NLEV File T2 Exh Phase In File T2 Evap Phase In File T2 Cert File VA ~ ¦/ ¦/ WA WV Wl ~ ¦/ ¦/ WY PR VI A-6 ------- May 2011 Table A-4. NONROAD Model Parameters Provided by State Agencies State Description File Type Added in 2008 Colorado Oil production equipment allocations. oil Delaware Airport equipment allocations. air Delaware Golf equipment allocations. gc Delaware Household allocations. hou Delaware Logging equipment allocations. log Delaware Source populations. pop Delaware Recreational vehicle park allocations. rvp Illinois Nonroad activity act Illinois Growth rates. grw Illinois Source populations. pop Illinois Seasonal allocations. sea Illinois Inboard watercraft allocations. wib Illinois Outboard watercraft allocations. wob Indiana Nonroad activity act Indiana Growth rates. grw Indiana Source populations. pop Indiana Seasonal allocations. sea Indiana Inboard watercraft allocations. wib Indiana Outboard watercraft allocations. wob Iowa Nonroad activity act Iowa Seasonal allocations. sea Iowa Inboard watercraft allocations. wib Iowa Outboard watercraft allocations. wob Michigan Nonroad activity act Michigan Growth rates. grw Michigan Source populations. pop Michigan Seasonal allocations. sea Michigan Inboard watercraft allocations. wib Michigan Outboard watercraft allocations. wob Minnesota Nonroad activity act Minnesota Growth rates. grw ¦/ Minnesota Seasonal allocations. sea Minnesota Snowmobile populations. snm Minnesota Inboard watercraft allocations. wib Minnesota Outboard watercraft allocations. wob Nevada Census population cen Nevada Wholesale Establishments com Nevada Harvested acres frm Nevada Golf equipment allocations. gc ¦/ A-7 ------- May 2011 State Description File Type Added in 2008 Nevada Landscaping employment allocations wib ¦/ Nevada Oil production equipment allocations. oil ¦/ Nevada Recreational vehicle park allocations. rvp ¦/ Nevada Commercial snowblower allocations sea ¦/ Nevada Residential snowblower allocations sea ¦/ Nevada Snowmobile populations. snm ¦/ North Carolina Residential snowblower allocations sea Ohio Nonroad activity act Ohio Growth rates. grw Ohio Source populations. pop Ohio Seasonal allocations. sea Ohio Inboard watercraft allocations. wib Ohio Outboard watercraft allocations. wob Rhode Island Source populations. pop Washington Inboard watercraft allocations. wib Washington Outboard watercraft allocations. wob Wisconsin Nonroad activity act Wisconsin Growth rates. grw Wisconsin Source populations. pop Wisconsin Seasonal allocations. sea Wisconsin Inboard watercraft allocations. wib Wisconsin Outboard watercraft allocations. wob A-8 ------- United States Office of Air Quality Planning and Standards Publication No. EPA-454/B-20-028 Environmental Protection Air Quality Assessment Division May 2011 Agency Research Triangle Park, NC ------- |