***** E.O. 12866 Review –**  **Draft –**  **Do Not Cite, Quote, or Release During Review *****

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## CHAPTER: 5 **Emissions Impacts**  EO12866_GHG+Fuel Eff Stds for Med - Heavy- Duty Engines+Vehicles 2060 - AP61 FRM RIA_20110 722 _Ch 05 Emissions Inventory .docx 

### 5.1 **Executive Summary** Climate change is widel y viewed as the most significant long - term threat to the global environment. According to the Intergovernmental Panel on Climate Change, anthropogenic emissions of greenhouse gases (GHG) are very likely (90 to 99 percent probability) the cause of most of the observed global warming over the last 50 years. The primary GHGs of c oncern are carbon dioxide (CO 2 ), methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. 1 Mobile sources emitted 31 percent of all U.S. GHG in 2007 (transportation sources, which do not include certain off - highway sources, a ccount for 28 percent) and have been the fastest - growing source of U.S. GHG since 1990. 2 Mobile sources addressed in the recent endangerment finding under CAA section 202(a) -- light - duty vehicles, heav y- duty trucks, buses, and motorcycles -- accounted for 23 percent of all U.S. GHG in 2007. 3 Heav y- duty vehicles emit CO 2 , methane, nitrous oxide, and hydrofluorocarbons and are responsible for nearl y 19 percent of all mobile source GHGs (nearly 6% of all U.S. GHGs) and about 25 p ercent of S ection 202(a) mobile s ource GHGs . For heav y - duty vehicles in 2007 , CO 2 emissions represent ed more than 99 percent of all GHG emissions (including HFCs ) . 2 This final action estimates anticipated impacts from the EPA vehicle CO 2 emis sion standards. The emissions from the GHGs carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O) and h ydrofluorocarbons (HFCs) were quantified. In addition to reducing the emissions of greenhouse gases, this program would also influence the emissions of “crit eria” air pollutants, including carbon monoxide (CO), fine particulate matter ( PM 2.5 ) and sulfur dioxide (SO X) and the ozone precursors h ydrocarbons (VOC) and oxides of nitrogen (NO X) ; and several air toxics (including benzene, 1,3 - butadiene, form aldeh yde, acetaldeh yde, and acrolein). Downstream (tailpipe) e mission impacts were developed using EPA’s Motor Vehicle Emission Simulator (MOVES2010). Upstream (fuel production and distribution) emission changes resulting from the decreased fuel consumpti on predicted b y the downstream models were calculated using a spreadsheet model based on emission factors from GREET. 4 Based on these anal ys es, this program would lead to 76 million metric tons ( MMT ) of CO 2 equivalent ( CO 2 EQ ) of annual GHG reduction an d 6.0 billion gallons of fuel savings in the year 2030. The non - GHG impacts of the final rulemaking are driven b y the increased use of auxiliary power units (APUs) and reduced emissions from upstream fuel production and distribution. Emissions of certain pollutants are further reduced through improved aerody namics and tire rolling resistance. To a much smaller extent, rebound of vehicle miles trave led (VMT ) increases emissions of all pollutants proportional to the VMT rebound amount. Table 5 - 1 summarizes these non - GHG emissions impacts from the heav y - duty sector .**Regulatory Impact Analysis**

5 - 2 **Table 5**  **- 1**  **Impacts of Program on Heavy**  **- Duty**  **Non -**  **GHG Emissions (Short Tons per year)** POLLUTANT CALENDAR YEAR 2030 CHANG E VS.

2030 BASELINE Δ 1,3 - Butadiene

- 0.5 - 0.1% Δ Acetaldeh yde

- 1, 9 12 - 40.2 % Δ Acrolein

- 26 3 - 40.0 % Δ Benzene

- 359 - 15.0 % Δ Carbon Monoxide

- 55, 579 - 2.1% Δ Formaldeh yde

- 6, 2 8 2 - 46.2 % Δ Oxides of Nitrogen

- 245, 129 - 21.0 % Δ P articulate Matter (below 2.5 micrometers) 356 1.1 % Δ Oxides of S ulfur

- 6, 888 - 10.1 % Δ V olatile Organic Compounds

- 29, 932 - 16.0 % 

### 5.2 **Introduction 5.2.1**  **Scope of Analysis** The standards affect both diesel - and gasoline - fueled heav y- duty vehicles. This analysis accounts for the dire ct downstream/tailpipe reduction of GHG as well upstream (fuel production and distribution) reductions of GHGs and non - GHGs. Total GHG impacts will also be determined b y any VMT rebound effects, changes in fleet turnover, and changes in fuel consumption g lobally

due to reduced petroleum prices. See C hapter 9 for a further discussion of these aspects of the analysis. The agencies also expect this program to impact downstream and upstream emissions of non - GHG air pollutants. Emissions estimates for the four greenhouse gases carbon dioxide (CO 2 ), methane (C H 4 ), nitrous oxide (N 2 O ) , and hydrofluorocarbons (HFC) are presented herein. Inventories for the non - GHG pollutants 1,3 - butadiene, acetaldehyd e, acrolein, benzene, carbon monoxide (CO), formaldeh yde, oxid es of nitrogen (NO X), particulate matter below 2.5 micrometers (PM 2.5 ) , oxides of sulfur (SO X), and volatile organic compounds (VOC) are also presented. 

### 5.2.2 **Dow nstream Contributions**  The largest source of GHG and other air pollutant reductions from this pro gram is from tailpipe emissions produced during vehicle operation. Absolute reductions from tailpipe emissions are projected to grow over time as the fleet turns over to vehicles affected b y the standards, meaning the benefit of the program will continue to grow as long as the older vehicles in the fleet are replaced by newer, lower CO 2 - emitting vehicles.***** E.O. 12866 Review –**  **Draft –**  **Do Not Cite, Quote, or Release During Review *****

5 - 3 As described herein, the downstream reductions in emissions due to the program are anticipated to be achieved through improvements in engine efficiency , road load reduction, and APU use during extended idling . Changes in downstream GHG and other emissions at the fleet level will be affected b y whether the regulations affect the timing of fleet turnover and total VMT, as discussed in S ection VIII of the preambl e. If the regulations spur firms to increase their purchase of new vehicles before efficiency

standards are in place (“pre - buy”) or to delay their purchases once the standards are in place to avoid higher costs, then there will be a delay in achieving the full GHG and other emission reductions from improved fuel econom y across the fleet. If the lower permile costs associated with higher fuel economy lead to an increase in VMT (the “rebound effect”), then total emission reductions will also be reduced. C hapter 9 of this RIA provides more detail on how the rebound effect is calculated in EPA’s anal ys is. The anal ys is discussed in this chapter incorporates the rebound effect into the estimates, though fleet turnover impacts are not estimated. In addition, the agencies also recognize that this regulation w ould lower the world price of oil (the “monopsony” effect, further discussed in Chapter 9 of the RIA ). L owering oil prices could lead to an uptick in oil consumption globally , resulting in a corresponding increase in GHG emissions in other countries. This global increase in emissions could slightly offset some of the emission reductions achieved domestically as a result of the regulation. EPA does not provide quantitative estimates of the impact of the re gulation on global petroleum consumption and GHG emissions in this RIA . 

### 5.2.3 **Upstream Contributions** In addition to downstream emission reductions, reductions are expected in the emissions associated with the processes involved in getting fuel to the pump, inc luding the extraction and transportation of crude oil, the production , and the distribution of finished gasoline and diesel . Changes are anticipated in upstream emissions due to the expected reduction in the volume of fuel consumed. Less fuel consumed me ans less fuel transported, less fuel refined, and less crude oil extracted and transported to refineries. Thus, there should be reductions in the emissions associated with each of these steps in the fuel production and distribution process. Any changes i n downstream reductions associated with changes in fleet turnover, VMT, and global petroleum consumption should be reflected in a corresponding change in upstream emissions associated with petroleum processing and distribution. 

### 5.2.4 **Global Warming Potentials** Throughout this document, in order to refer to the four inventoried greenhouse gases on an equivalent basis, Global Warming Potentials (GWPs) are used. In simple terms, GWPs provide a common basis with which to combine several gases with different heat trapp ing abilities into a single inventory ( Table 5 - 2 ). When expressed in CO 2 EQ terms, each gas is weighted b y its heat trapping ability relative to that of carbon dioxide. The GWPs used in this**Regulatory Impact Analysis**

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chapter are drawn from publications b y the Intergovernmental Panel on Climate Change (IPCC). 5 The global warming potentials (GWP) used in this anal ys is are consistent with the 2007 Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). At this time, the 1996 IP CC Se cond Assessment Report (SAR) global warming potential values have been agreed upon as the official U.S. framework for addressing climate change and are used in the official U.S. greenhouse gas inventory submission to the United Nations climate change framework . This is consistent with the use of the SAR global warming potential values in current international agreements. **Table 5**  **- 2**  **Global Warming Potentials for the Inventory GHGs GAS**  **G LOBAL WARMING** 

**POTENTI AL**  **(CO 2**  **Equivalent)** CO 2 1 CH 4 25 N 2 O 298 HFC 1,430 

### 5.3 **Program Analysis and Modeling Methods 5.3.1**  **Models Used** The Motor Vehicle Emissions Simulator, more commonly called MOVES , EPA’s official mobile source emission inventory model, was the primary

tool used to calculate downstream emissions inventories . 6 The MOVES2010a version was used along with an internal 2010 - October - 6 default database. Some post - processing was done to MOVES output to ensure proper calculation of emissions inventories for each alternative . This program affects heavy- duty vehicles. In MOVES, which categorizes vehicle types by their use, these vehicle ty pes are represented by combination tractors, single unit tractors, refuse trucks, motor homes, transit buses, intercity buses, school buses , and light commercial trucks. Changes made to the default MOVES data for the baseline and the control case are described below in Section 5.3.2 . All the input data and MOVES run spec files can be found in the docket. 7 Upstre am emissions were calculated using the same tools as were used for the Renewable Fuel Standard 2 (RFS2) rule anal ys is . 8 The estimate of emissions associated with production of gasoline and diesel from crude oil is based on emission factors in the “Greenh ouse Gases, Regulated Emissions, and Energy Use in Transportation” model ( GREET ) developed b y DOE's Argonne National Lab, and are consistent with those used for the Li ght - Duty Greenhouse Gas rulemaking . 4 , 9 The actual calculation of the emission inventory impacts of the decreased gasoline production is done in EPA's spreadsheet model for upstream emission impacts. This***** E.O. 12866 Review –**  **Draft –**  **Do Not Cite, Quote, or Release During Review *****

5 - 5 model uses the decreased volumes of the crude based fuels and the various crude production and transport emission factors from GREET to estimate the net emissions impact of fuel use changes . As just noted, the anal ys is for this rulemaking assumes that all changes in volumes of fuel used affect only

gasoline and diesel, with no effects on use of ethanol, or other renewable fuels. 

### 5.3.2 **Calculation of Downstream**  **Emissions** 5.3.2.1 Baseline (reference case) The baseline, or reference case , assumes no action and assumes constant 2010 model year performance of the HD fleet , as described in RIA Chapter 2 . Since MOVES2 010 a vehicle sales and VMT inputs were developed from AEO2009 , EPA first updated these data using relative sales and activity growth projections from AEO201 1 . 10 The tables that were modified and included as user input tables for the baseline run were sourc etype ye ar and hpmsvty peyear. For HD pickups and vans, the agency updated sales projections for model years 2011 through 2018 using forecasts purchased from CSM Worldwide for the light - duty greenhouse gas rule. 11 This update was done through modifying the base population, along with the sales growth factors for model ye ars 2011 through 2018 , in the sourcetypeyear table . The sales growth factors for the other model years were updated from AEO2011 , as mentioned above. Also, extended idling PM rates were upd ated to match aged curb idling PM rates, a correction needed from the default emission rates. MOVES2010 a defaults , including all other emission rates, were used for all other parameters to estimate the baseline emissions inventories. F or combination trac tors and vocational vehicles, the aerodynamic drag and tire rolling resistance coefficients were the default MOVES values that represent a fleet - wide average rolling resistance and aerody namic drag (for each MOVES source/vehicle ty pe), which assumes only

a low level of adoption , if any , of low rolling resistance tires and advanced aerody namic features. It also assumes that these fleet - wide coefficients do not change with future model ye ars or by age . For extended idling emission inventories, MOVES defaults were post - processed to account for increased use of auxiliary power units (APUs ) for model ye ar 2010 and later, which is not assumed in default MOVES . For all alternatives , the agencies assumed that about 30 percent of all combination long - haul tractors between model years 2010 through 2013 use an APU during extended idling. For alternatives where combination long - haul tractors are regulated, the agencies assumed that 100 percent of those trucks model ye ar 2014 and later use APU s during extended idling. This assumption is based on the expectation that manufacturers will use APUs to meet the vehicle GHG standard for combination long - haul tractors. For alternatives where combination long - haul tractors are not regulated, the agencies assumed that 30 percent of those trucks model year 2014 and later use APUs during extended idling. A diesel fuel consumption rate of 0.2 gallons per hour for APUs and a factor 10.180 kg CO 2 per gallon diesel w ere assumed. EPA also considered that diesel APUs are regulated as non - road small engines for criteria (non - GHG) pollutants. Assuming that these APUs emit criteria pollutants at the EPA standard, Table 5 - 3 shows the emission rate of APUs , given an extended idle load demand of 4.5 kW (6 hp). 12 For SO 2 , which is not regulated through engines, but rather through fuel, the agency

assumed a diesel fuel sulfur level of 15 ppm and a diesel fuel density of 6.9**Regulatory Impact Analysis**

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lb/gal. Total extended idle emissions were calculated by multiplying by

the number of extended idle hours by

the emission rates in Table 5 - 3. **Table 5**  **- 3**  **Estimated E**  **mi ssion**  **R ates of non**  **- GHG**  **P ollutants from**  **APUs**

POLLUTANT EMI SSI ON RATE [ g/hr] CO 36 NO X 26.88 a VOC 6.72 a PM 1.8 SO 2 0.01 88 CH 4 0.0202 b Note: a NO X rate was estimated to be 80%, and NMHC 20% of the total NO X+NMH C rate (33.6 g/hr) , based on the 2004 model year heavy - duty engine standard. 13 VOC was estimated to be equal to NMHC for this analysis. b Extended idle methane (CH 4 ) emissions are assumed to be 0.3% of VOC emissions, based on existing MOVES methane - to - THC fractions for pre - DPF - equipped diesel engines. 

### 5.3.2.2 Control Case This case represents the final standard levels . The sales and VMT updates implemented in the baseline were also used in all the alternatives, including the control case, since the sales projections are projected for all future scenarios and are not affected b y this program . To account for improvements of engine and vehicle efficiency , EPA developed several user inputs to run the alternatives in MOVES. Since MOVES does not calculate emissions based on engine Federal Test Procedure ( FTP ) cycle results, EPA used the percent reduction in engine CO 2 emissions expected from the program to develop energy inputs for the control case runs. Also, EPA used the percent reduction in aerodynamic drag coefficient and tire rolling resistance coefficient expected from each alternative to develop road load inputs. Runs were post processed to calculate air toxics inventori es for diesel vehicles and emissions and fuel consumption from APUs . 

### 5.3.2.2.1 **Em ission**  **R ate and**  **R oad**  **L oad**  **I nputs**  The form of the fuel consumption and CO 2 emissions standards varies by regulatory category . Heavy- duty

engine standards are in terms of grams of CO 2 per brake horsepower - hour and gallons of fuel per 100 brake horsepower per hour. The form of the combination tractor and vocational vehicles is gallons per 1000 ton - mile and grams of CO 2 per ton - mile. For the vocational vehicles and combination tractors, the agencies have anal yz ed the impacts of the standards b y evaluating the technologies applied to the engines and vehicles separatel y. Table 5 - 4 **describes the improvem ents expected from the HD engine technologies wh**  **ich m ay be applied to**  **meet the standards. These values remain unchanged between proposal and final rule because no changes have been m**  **ade to the HD engine CO 2**  **and fuel consumption standards. The reductions from the baseline** 

**were applied to the appropriat e source bins in the MOVES emissionrate table**  **.******* E.O. 12866 Review –**  **Draft –**  **Do Not Cite, Quote, or Release During Review *****

5 - 7 Table 5 - 5 contains the combination long - haul tractor and vocational vehicle tire rolling resistance, coefficient of drag, and weight reductions expected from the technologies which coul d be used to meet the standards. The levels of reduction in the final rule are greater for the long - haul combination tractors’ rolling resistance and Cd due to the refined methodology of aggregating the three roof heights of sleeper cabs. In the NPRM, th e agencies assumed that manufacturers sold equal number of sleeper cabs with low, mid, and high roof heights. For the final rule, the agencies obtained sales distribution data from the manufacturers and attributed the reductions based on a sales mix assumption of 80 percent high roof, 15 percent mid roof, and 5 percent low roof sleeper cabs. The table also reflects the reduction in weight assumed in setting the final standards which was not evaluated in the NPRM. The value in the table reflects a 400 pound mass reduction. The short - haul combination tractors in the NPRM were evaluated using a day cab sales distribution assumption of equal number of each subcategory . For the final rule, the agencies used a sales mix of 10 percent Class 7 low roof, 10 perc ent Class 7 high roof, 45 percent Class 8 low roof, and 35 percent Class 8 high roof based on feedback from the manufacturers. The short - haul values in the table reflect a modeling assumption that 8 percent of all tractors would be considered vocational tractors and therefore will onl y be required to meet the vocational vehicle standards and not show any aerodynamic or weight improvement. The vocational tractor population (assumed to be 9,773 vehicles in 2014 based on confidential sales information shared by

a truck manufacturer) was applied entirely to short - haul tractor population which represents 19.7 percent of short - haul tractor population. The weight reduction applied to short - haul tractors is 321 pounds which is calculated from a 400 pound weight reduction reduced by 19.7 percent. The rolling resistance level in the NPRM was assumed to be reduced b y 10 percent due to the proposed vocational vehicle standards. However, the tire rolling resistance reduction in the final rule i s assumed to be 5 perce nt based on the data derived in the tire testing program conducted b y EPA. The reductions from the baseline summarized in Table 5 - 5 were applied to the corresponding source types in the MOVES sourceusetyp e table.

**Table 5**  **- 4**  **Estimated R**  **eductions in E**  **ngine CO 2**  **E mission**  **R ates from** **this Pr**  **ogram** GVWR CLASS FUEL MODEL YEARS CO 2 REDUCTI ON

FROM B ASELINE HHD (8a - 8b) Diesel 2014 - 2016 3% 2017+ 6% MHD (6 - 7) and LHD 4 - 5 Diesel 2014 - 2016 5% 2017+ 9% Gasoline 2016+ 5%**Regulatory Impact Analysis**

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**Table 5**  **- 5**  **Estimated R**  **eductions in R** **olling R**  **esistance and A**  **erodynamic D**  **rag C**  **oefficients from**  **R eference**  **C ase for Alternative**  **3 (** **M odel**  **Y ears 2014 and**  **Later )**  TRUCK TYPE REDUCTION IN TIRE ROLLING RESI STANCE COEFFI CI ENT FROM BASELINE REDUCTION IN AERODYNAMIC DRAG COEFFICIENT FROM BASELINE WEI GHT REDUCTION (LBS.) Combination long - haul 9.6 % 12.1 % 400 Combination short - haul 7.0% 5.9 % 321 V ocational vehicles (Single - unit trucks, refuse trucks, motor homes, buses, and light commercial trucks) 5.0 % 0% 0

The HD pickup truck standards are evaluated in terms of grams of CO 2 per mile or gallons of fuel per 100 miles. Since nearl y all HD pickup trucks and vans will be certified on a chas sis dy

namometer, the CO 2 reductions for these vehicles will not be represented as engine and road load reduction components , but total vehicle CO 2 reductions . Table 5 - 6 describes the estimated expected changes in engine and vehicle technologies from this final rulemaking, which were input into MOVES for estimating control case emissions inventories. Table 5 - 6 remains unchanged between proposal and final rule because no changes have been made to the HD pickup truck and van CO 2 and fuel consumption standards.

**Table 5**  **- 6**  **Estimated T**  **otal V**  **ehicle CO 2**  **R eductions for**  **HD P**  **ickup T**  **rucks and V**  **ans** GVWR CLASS FUEL MODEL YEARS CO 2 REDUCTI ON

FROM BASELINE LHD 2b - 3 Gasoline 2014 1 .5% 2015 2% 2016 4% 2017 6% 2018+ 10% Diesel 2014 2.3%

2015 3% 2016 6% 2017 9% 2018+ 15% Engine CO 2 reductions ( Table **5 -**  **4** ) and HD pickup/van total vehicle CO 2 reductions ( Table 5 - 6 ) were modified in the emissionrate table in MOVES. The percentage reductions were applied to the default energy rates. The improvements in tire rolling resistance and drag coefficient were modified in the***** E.O. 12866 Review –**  **Draft –**  **Do Not Cite, Quote, or Release During Review *****

5 - 9 sourceusetyp e table. The percentage reductions were applied to the road load coefficients. It was assumed that 100 percent of Class 7/8 combination long - haul tractors model year 2014 and later use APUs during extended idling. Emissions from APUs in the control case were calculated in the same way as the baseline (see Table 5 - 3 ) 

### 5.3.2.2.2 **VMT I** 

**nputs** The HPMSVty

pe table was modified to reflect VMT rebound. This table contains VMT growth factors from one calendar year to the next, starting from an absolute VMT estimate for calendar year 1999. For the control case, w e increased the HD pickup/van absolute VMT b y 1. 18 %, the vocational vehicle absolute VMT b y 1.33 %, and the combination tractor absolute VMT by 0. 50 % from baseline levels , based on the anal ys is in RIA Section 9.2. Si nce VMT growth is by

calendar year and not model ye ar, to ensure that onl y model years affected b y the program experienced VMT rebound, the results from the baseline run were used in the control case inventories for model years prior to the rules’ implementation. 

### 5.3.2.2.3 **Diesel A**  **ir T**  **oxics C**  **alculations** The composition of VOCs for heav y- duty diesel engines without model year 2007 and later emission controls versus those engines with such controls vary significantly . Thus, EPA developed one set of toxic to VOC ratio s for pre - 2007 diesel engines and another set for 2007 and later engines. Since light - duty diesels comprise a very

small portion of the fleet, the same ratios were applied to all diesel vehicle classes to streamline modeling. EPA relied on a database co mpiled for the Coordinating Research Council (CRC E - 75) and National Renewable Energy L aboratory

(NREL) to develop toxic to VOC ratios for pre 2007 model year engines. 14 This database was developed from a literature survey and included data from 13 different studies. The studies included in this database were conducted in a number of different countries, included heav y- duty and light - duty engines, a variety of diesel and biodiesel fuels, and a number of different operating modes and cycles. The methodolog y the y used to develop ratios is described in detail in their technical report. Data from tests using non conventional diesel fuel (Fischer - Tropsch, bioDiesel, ethanol - Diesel blends, emulsified fuel, European blends, and other obvious research fuels) were excluded, as were data from non - heavyduty engines. Toxic - to - VOC ratios for benzene, 1,3 - butadiene, formaldehyde, acetaldehyde, and acrolein were developed by EPA from the CRC E - 75 database. EPA relied on United States data from heav y- duty

diesel engin es running on conventional diesel fuels, collected on test cycles representative of real world operation. Some studies measured emissions over distance, while other studies measure emissions relative to engine work . For studies which measured emissions relative to distance, we calculated mean emissions per mile for toxics and VOC, then calculated a ratio of toxics to VOC. For studies which measured emissions relative to engine work , we calculated mean emissions per brake horsepower hour for toxics and VO C, then calculated a second ratio of toxics to VOC. We then calculated a composite ratio using sample size to weight the two ratios. The resulting ratios are provided in Table 5 - 7 .**Regulatory Impact Analysis**

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For model year 2007 and later heav y- duty diesel s , advanced emission controls change the composition of VOCs. For these engines, we relied on speciated emissions data from the Advanced Collaborative Emissions Study (ACES), directed b y the Health Effects Institute and Coordinating Research Council, with participation from a range of government and private sector sponsors. 15 Detailed emissions data from the study were provided to EPA at the request of the Coordinating Research Council. The data were collected on four engines on several test cycles with l ow sulfur diesel fuel. EPA used data from a 16 - hour transient cycle. Toxic to VOC ratios obtained from the ACES data are provided in Table 5 - 7 . Because diesel VOC estimates had not been updated in MOVES for model year 2007 and later heav y- duty diesel trucks, these data were also used to determine a VOC - to - total hydrocarbon (THC) ratio for those trucks. This ratio of 0.5327 was used in conjunction with the MOVES results for THC to estimate VOC emissions from model year 2007 and later heavy- duty diesel trucks. All model year APUs were treated like pre - 2007 engines with respect to toxics calculations because APUs are not equipped with the emission controls technology of model ye ar 2007 and later engines.

**Table 5**  **- 7**  **Air T**  **oxics R**  **atios P**  **ost -**  **P rocessed**  **A gainst**  **H ydrocarbon**  **R esults from** **MOVES** MODEL YEARS POLLUTANT RATIO to VOC Pre - 2007 engines and all model year APUs Benzene 0.0078

1,3 - butadiene 0.0029 Formaldeh yd e 0.0782 Acetaldeh yd e 0. 0356 Acrolein 0.0066 2007 and later engines Benzene 0.0129

1,3 - butadiene 0.0008 Formaldeh yd e 0.2174 Acetaldeh yd e 0.0693 Acrolein 0.0100 

### 5.3.3 **Calculation of Upstream Emissions** The term "upstream emissions" refers to air pollutant emissions generated from all crude oil extraction, transport, refining, and finished fuel transport, storage, and distribution ; this includes all stages prior to the final filling of vehicle fuel tanks at retail service stations. The details of the assumptions, data sources , and calculations that were used to estimate the emission impacts presented here can be found in the Technical Support Document and the docket memo, “ Calculation of Upstream Emi ssions for the GHG Vehicle Rule , ” initially created for use in the Li ght - Duty Greenhouse Gas rulemaking. 16 The agencies recognize the unique GHG emission characteristics associated with biofuels, and specificall y that in the context of biofuels, “upstream emissions ” include not only GHG emissions, but also any net biological seque stration that takes place. When considered on a lifecycle basis (including both tailpipe and upstream emissions), the net GHG emission impact of individual biofuels can vary significantl y from both petroleum - based fuels and from one***** E.O. 12866 Review –**  **Draft –**  **Do Not Cite, Quote, or Release During Review *****

5 - 11 biofuel to another. EP A’s Renewable Fuel Standard program, as modified by EI SA, examined these differences in lifecycle emissions in detail. For example, EPA found that with respect to aggregate lifecycle emissions including non - tailpipe GHG emissions (such as feedstock growth, transportation, fuel production, and land use), lifecycle GHG emissions in 2022 for biodiesel from soy , using certain advanced production technologies, are about 50 percent less than diesel from petroleum. The agencies note that to the extent future poli cy decisions involve upstream emissions, the agencies will need to consider the unique emission characteri stics associated with biofuels. More broadl y, the agencies recognize that biofuels, including biodiesel, will play an import ant role in reducing the n ation’s dependence on foreign oil, thereby increasing domestic energy security . The results of th e upstream analy sis are shown in Table 5 - 10 and Table 5 - 12 . 

### 5.3.4 **Calculation of HFC Emissions**  **A** EPA is finaliz ing as proposed air conditioning (AC) leakage standards for HD pickup trucks and vans and combination tractors to reduce HFC emissions. The Vintaging M odel, developed b y the EPA Office of Atmospheric programs, produces HFC inventories for several categori es of stationary

and mobiles sources. However, it does not include air conditioning sy stems in medium and heavy duty truck s within its inventory calculations. For this rulemaking , we conducted an anal ys is based on the inputs to the Vintaging M odel and th e inputs to the MOVES anal ys is discussed in Chapter 5.3.2.1 above. The general equation for calculating HFC emissions follows: HFC emissions Year x = AC Systems Year x x Average Charge Size x HFC loss rate We determined the number of functioning AC s ys tem s in each ye ar based on the projected sales of vehicles, the fraction of vehicles with AC sy stems, and the average lifetime of an air conditioning s ys tem. Sales were drawn from the MOVES anal ys is and we assumed that every vehicle had a functioning AC sy st em when sold based on feedback received from truck manufacturers. The Vintaging Model assumes that all light duty passenger vehicle AC s ys tems (in the U.S.) last exactly

12 years. 17 For lack of better information, we assumed that heav y duty vehicles AC s ys tems last for the same period of time as light duty vehicles. Light, medium and heav y duty vehicles use largel y the same components in their air conditioning s ys tems, which would indicate similar periods of durability .

A The U.S. has submitted a proposal to the Montreal Protocol which, if adopted, would phasedown production and consumption of HFCs.**Regulatory Impact Analysis**

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The charge size was determined using the Minnesota refrigerant leakage database. 18 EPA sorted the data based on AC charge size and evaluated only the largest 25 percent of AC sy stems. The average charge size is 1,025 grams of refrigerant. Due to the similarity

in sy stem design, we assumed that the light - duty vehicle emission rate in the Vintaging M odel was applicable to the current anal ys is, as shown in **Table 5**  **- 8**  . The Vintaging Model assumes that losses occur from three events: leak, service, and disposal. Although vehicle AC sy stems are serviced during discrete events and not usually every year, emissions from those events are averaged over the lifetime of the AC sy stem in the Vintaging model . L eak and service emissions are considered “annual losses” and are applied every year; disposal is considered an “end of life loss” and is applied only once for each vintage of vehicles. B **Table 5**  **- 8**  **Annual In -**  **use Vehicle HFC134a Em ission Rate from** **Vintaging Model**

KI ND OF LOSS LOSS F RACTION Leakage 8% Maintenance /Servicing 10% End of Life 43% Of note, the Vintaging M odel assumes that charge loss is replaced every year; i . e . , assuming an 18 percent rate of charge loss, a vehicle with a charge of 1 , 00 0 grams would lose a constant rate of 18 0 grams per year. While this loss rate is not accurate for any single vehicle, it is assumed accurate for the fleet as a whole. While other emissions, such as fugitive emissions at a production facility , leaks from cylinders in storage, etc., are not explicitly modeled, such emissions are accounted for within the average annual loss rate. EPA’s anal ys is of the MN database of MY 2010 vehicles suggests that many of the modeled vehicles likel y contain some of the technology required to meet the le akage standard, and as a consequence are leaking less. We assume that these improvements are independent of EPA regulation, rather than a preemptive response to regulation. Consequently , this rulemaking does not take credit for these emission reductions. EPA requested better information on HFC leakage rates in modern vehicles, with a particular emphasis on in - use vehicles , in the proposal, but did not receive any comments . Based on the MN 2010 database, we determined that it is possible to reduce the HFC emissions from these vehicles on average b y 13 percent. EPA calculated this based on the assumption that vehicles currentl y in the fleet which meet the 2014MY standard would not make any additional improvements to reduce leakage. We also assumed that the sy stems which currentl y have leakage rates above the standard will reduce their leakage to the standard level. We then applied the 13 perc ent reduction to the baseline 18 percent leakage rate to develop a 15 .6 percent leakage rate for 2014 MY and later vehicles to determine the reduction in emission rate which should be credited to this rulemaking . 19

B The U.S. EPA has reclamation requirements for refrigerants in place under Title VI of the Clean Air Act.***** E.O. 12866 Review –**  **Draft –**  **Do Not Cite, Quote, or Release During Review *****

5 - 13 We calculated our emission reductions based on the difference between the baseline case of 2010 vehicle technology (discussed above) and the control sce nario where the loss prevention technology

has been applied to 100 percent of the new HD pickup trucks and vans and Class 7/8 tractor s starting in 2014 model year, as required by the final standards. Total HFC reductions are 305 metric tons over the MY 20 10 baseline AC s ystem in 2030 and 417 metric tons in 2050. This is equivalent to a reduction of 122,338 metric tons of CO 2 e q in 2018 ; 436,483 metric tons of CO 2 e q emissions in 2030 ; and 596,396 metric tons CO 2 e q in 2050. 20 The difference in the emissions reductions between the final rule s and the proposal are due to changes in HD pickup truck and van and tractors sales projections, as detailed in above in Chapter 5 .3.2.1 . EPA reviewed a study conducted b y the Eastern Research Group (ERG) of R134a leaks in h eav y- d

uty v ehicles to California Air Resource s Board. 21 ERG delivered a presentation of the results during a CARB workshop held on January 6, 2011. The study

included a total of 70 medium - and heav y- duty vehicles and off - road equipment, of which18 of th e samples were HD tractors ranging between 1990 and 2008 model years. The mobile air conditioning capacity in the tractors ranged between 1,080 grams to 1,950 grams. The study measured HFC leakage during sample times which ranged between 0.3 and 0.6 year s. ERG then calculated an annualized in - use leakage rate with an assumed linear projection of measured leak rates to annual leak rates, which may

be an over - estimate. The annualize leakage rate for tractors ranged between nearl y 0 to nearly 1.5 grams leakage per gram of MAC capacity. These leakage rates did not include other leakage sources such as maintenance or end of life recovery . ERG found that the average of all MD and HD trucks and equipment which were 2006 MY or newer had an average leakage of 10 3 grams R134a per ye ar. Based on these results, the agency believes that our estimates for HFC reductions may understate the benefits of the program we are finalizing today . The agency

will continue to analyze this and other studies that may be conducted in the future. 

### 5.4 **Greenhouse Gas Emission Impacts**  After all the MOVES runs and post - processing was completed, baseline and control case inventories were totaled for all vehicle types and emission processes to estimate total downstream GHG impacts of the program . Table 5 - 9 summarizes these downstream GHG impacts and fuel savings from baseline to control case for calendar ye ar 2030. All emissions impacts reflect the heav y - duty sector onl y, and do not include emissions from light - duty vehicles or any other vehicle sector. **Table 5**  **- 9**  **Downstream GHG**  **I mpacts in 2030** 

POLLUTANT CALENDAR YEAR 2030 % CHANGE vs.

2030 BASELINE Δ CO 2 (metric tons) - 60, 710,570 - 10. 1 % Δ CH 4 (metric tons CO 2 EQ) - 785,4 4 9 - 53.8% Δ N 2 O (metric tons CO 2 EQ) 2, 8 51 0.4%**Regulatory Impact Analysis**

5 - 14 Δ HFC (metric tons CO 2 EQ) - 436,483 - 13% Δ Total CO 2 EQ (metric tons) - 61, 929,651 - 10.3 % Δ Gasoline Fuel (bil lion gallons) - 0. 3 4 9 - 6. 5 % Δ Diesel Fuel (billion gallons) - 5. 67 - 10 . 4 % Table 5 - 10 summarizes the upstream GHG impacts in 2030. The reductions in GHGs are proportional to the amount of fuel saved. **Table 5**  **- 10**  **Upstream GHG**  **I mpacts in 2030**  POLLUTANT CALENDAR YEAR 2030 % CHANGE vs.

2030 BASELINE CO 2 (metric tons) - 12, 241,470 - 10.2 % CH 4 (metric tons CO 2 EQ) - 1, 888, 769 - 10.2 % N 2 O (metric tons CO 2 EQ) - 59, 100 - 10.2 % Total CO 2 EQ (metric tons) - 14, 189,339 - 10.2 % 

### 5.5 **Non -**  **Greenhouse Gas Emission Impacts**  After all the MOVES runs and post - processing were completed, baseline and control case inventories were aggregated for all vehicle typ es and emission proces ses to estimate total downstream non - GHG impacts of the program . Table 5 - 11 summarizes these downstream non GHG impacts for calendar year 2030. The non - GHG impacts of the program are driven b y the increased use of APUs and, for certain pollutants, improved aerodyn amics and tire rolling resistance. Use of APUs increases PM 2.5 downstream inventories compared to the baseline case because APUs are not required to be equipped with diesel particulate filters, like the on - road engines are for model ye ar 2007 and later. To a much smaller extent, VMT rebound increases emissions of all pollutants proportional to the VMT rebound amount.

**Table 5**  **- 11**  **Downstream impacts for key non**  **- GHG pollutants**  **( S**  **hort tons)** POLLUTANT CALENDAR YEAR 2030 % CHANGE vs .

2030 BASELINE Δ 1,3 - Butadiene 0.4 0.1% Δ Acetaldeh yde - 1,908 - 40.5% Δ Acrolein - 263 - 40.2% Δ Benzene - 341 - 15.5% Δ Carbon Monoxide - 52, 299 - 2.0% Δ Formaldeh yde - 6,255 - 46.9% Δ Oxides of Nitrogen - 235, 0 52 - 22.0% Δ Particulate Matter (below 2.5 micrometer s) 1, 7 51 8. 4 % Δ Oxides of Sulfur - 42 3 - 8. 7 % Δ Volatile Organic Compounds - 25, 5 02 - 19.1%***** E.O. 12866 Review –**  **Draft –**  **Do Not Cite, Quote, or Release During Review *****

5 - 15 Non - GHG fuel production and distribution emission impacts of the program were estimated in conjunction with the development of life cycle GHG emission imp acts, and the GHG emission inventories discussed above. The basic calculation is a function of fuel volumes in the anal ys is year and the emission factors associated with each process or subprocess. In general this life cycle analy sis uses the same method ology as the Renewable Fuel Standard (RFS2) rule. It relies partially on the GREET model, developed by the Department of Energy ’s Argonne National Laboratory (ANL), but takes advantage of additional information and models to significantl y strengthen and e xpand on the GREET anal ys is. Updates and enhancements to the GREET model assumptions include updated crude oil and gasoline transport emission factors that account for recent EPA emission standards and modeling, such as the Tier 4 diesel truck standards published in 2001 and the locomotive and commercial marine standards finalized in 2008 22 . In addition, GREET does not include air toxics. Thus emission factors for the following air toxics were added: benzene, 1,3 - butadiene, formaldeh yde, acetaldehyde, and acrolein. These upstream toxics emission factors were calculated from the 2002 National Emissions Inventory (NEI), a risk and technology review for petroleum refineries, speciated emission profiles in EPA's SPECIATE database, or the Mobile Source Air T oxics rule (MSAT) inventory for benzene; these pollutant tons were divided by refinery energy use or gasoline distribution quantities published by the DOE Energy

Information Administration (EIA) to get emission factors in terms of grams per million BTU of finished gasoline and diesel . Results of these emission inventory impact calculations relative to the baseline for 2030 are shown in Table 5 - 12 for the criteria pollutants and individual air toxic pollutants. The program is projected to provide reductions in all pollutants associated with gasoline production and distribution as the projected fuel savings reduce the quantity of gasoline needed. **Table 5**  **- 12**  **Upstream I**  **mpacts for K**  **ey non -**  **GHG P**  **ollutants ( S**  **hort T**  **ons)** POLLUTANT CALENDAR YEAR 2030 % CHANGE vs.

2030 BASELINE Δ 1,3 - Butadiene - 0.9 - 10. 1 % Δ Acetaldeh yde - 3 - 10. 1 % Δ Acrolein - 0 .5 - 10. 1 % Δ Benzene - 19 - 9. 3 % Δ Carbon Monoxide - 3,3 31 - 10. 1 % Δ Formaldeh yd e - 26 - 10. 1 % Δ Oxides of Nitrogen - 9,975 - 10. 1 % Δ P articulate Matter (below 2.5 micrometers) - 1,3 79 - 10. 1 % Δ Oxides of S ulfur - 6, 395 - 10. 1 % Δ V olatile Organic Compounds - 4, 367 - 8. 2 %**Regulatory Impact Analysis**

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### 5.6 **Inventories Used for Air Quality Analyses** Th is section describes the processes used in calculating heavy- duty vehicle non - GHG inventories for the air quality (AQ) modeling analy sis. Air quality modeling requires significant lead time, and consequently the air quality

inventories were completed signi ficantly before the inventories presented in this final action . Air quality modeling was done for calendar ye ar 2030 . This section describes the differences in heav y- duty vehicle non - GHG emissions inventories between the final rule s and the air quali ty modeling. 

### 5.6.1 **Dow nstream Inventories**  The downstream emission inventories for 2030 presented in this chapter are slightly different from the emissions inventories used in the air quality modeling presented in Chapter 8 . Specificall y, since the air quality modeling required a significant lead time, the inventories used for this anal ys is were calculated from inputs developed for the proposal . 23 Differences between the final and the air quality inventories are due mostly to regional temperature effects . The inventories for the final rule s were run b y ye ar for the whole nation. This was sufficient for nationwide emissions estimates and assumes a uniform VMT - weighted average national temperature. The air quality inventories required a finer scale and were run by state and month. MOVES2010a was used in conjunction with an internal default database MOVESDB20100913, which contained performance updates from the MOVESDB20100826, the database originally released with MOVES2010a. Seasonal and regional variation s in temperature and humidity were accounted for. The national inventories included Puerto Rico and the U.S. Virgin Islands, but the air quality

inventories did not. The national inventories only included running exhaust, start exhaust, and extended idling e xhaust emissions processes, whereas the air quality inventories included other minor emissions processes, such as crankcase exhaust . The MOVES output for air quality modeling was stratified into Source Classification Codes, the basis for stratification o f inputs to the air quality modeling. The national inventories output was stratified b y source type (vehicle typ e). Table 5 - 13 shows the aggregated downstream emissions inventories in 2030 from the heav y- duty vehicle sector for both the air quality modeling and final rule. It should be noted that the air quality modeling inventories relied on state - supplied inventory projections for California. These projections do not reflect potential air quality

benefits of the standards bei ng finalized in this rule. Onroad emission changes for California from this rule would have included reductions in NO X , VOCs, and SO 2 as well as some smaller increases in direct PM. Although full - scale photochemical modeling is necessary to accurately project air quality impacts, it is likely

that the emissions changes in California would have resulted in a net benefit. As a result, the modeled inventory and air quality changes and the monetized benefits associated with this final action are likel y an underestimate. **Table 5**  **- 13**  **Comparison of Calendar Year 2030**  **Heavy -**  **Duty Vehicle Downstream**  **Final Rule National**

**Inventories and Inventories Used for Air Quality (AQ)**  **[Short tons]** REFERENCE CONTROL **POLLUTANT** Fi nal AQ Difference Final AQ Difference 1,3 - butadiene 305 364 19% 306 365 16%***** E.O. 12866 Review –**  **Draft –**  **Do Not Cite, Quote, or Release During Review *****

5 - 17 Acetaldeh yd e 4,716 5,229 11% 2,808 3,364 17% Acrolein 653 722 11% 391 465 16% Benzene 2,199 2,563 17% 1,858 2,231 17% CO 2,646,583 2,852,5 13 8% 2,594,341 2,803,402 7% Formaldeh yd e 13,344 14,577 9% 7,089 8,462 16% NO X 1,068,212 1,144,571 7% 832,813 927,099 10% PM 2.5 20,743 23,926 15% 22,503 24,158 7% SO 2 4,852 3,366 - 31% 4,424 3,061 - 45% VOC 133,377 146,416 10% 108,112 121,825 11% 

### 5.6.2 **Upstream Inventories** Petroleum production includes crude oil extraction and transport to refineries. As in the nationwide anal ys is presented in the propos al as well as th e s e final rule s , we assumed that (a) 50% of the change in gasoline and diesel supply was projected to come from domestic refineries, and (b) 10% of the change in crude being used b y domestic refineries would be domestic crude. Thus, using our assumption that 1.0 gallon less of gasoline equates to approximately 1.0 gallon less crude throughput, the reduction in crude extraction and transport would equal about 5% of the change in gasoline volume. To generate the emission inventory adjustment factors for air quality mo deling these reductions were applied to the projected crude supply to US refineries, per AEO 2009 (stimulus version). 24 The resulting estimates are shown in Table 5 - 14 . The percent reductions were applied to the NEI projected inventories for 2030. The 0.61% reduction was applied to all Source Classification Codes associated with petroleum extraction, and the 6.09% reduction was applied to all Source Classification Codes associated with gasoline and diesel refining. 25 **Table 5**  **- 14**  **Volum es and Reductions Associated with HD**  **National Program in 2030**  Crude Supply

to US Refineries, per AEO2010 228 bgal Reduction in Gasoli ne/Diesel Consumption 5.79 bgal Reduction in Domestic - Refined Ga soline/Diesel Vol 2.89 bgal Reduction in Domestic Refining of Crude (US & Imported Crude) 2.89 bgal Reduction in Domestic - Refined Gasoline/Diesel from Domestic Crude 0.29 bgal Reduction in Domestic Crude Production & Transport to refineries 0.29 bgal P ercent Reduction in Domestic Refining 1.27% Percent Reduction in Domestic Crude Production & Transport 0.13%**Regulatory Impact Analysis**

5 - 18

References 1 Intergovernmental Panel on Climate Change Working Group I. 2007. Climate Change 2007 - The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. 2 U.S. Environmental Protection Agency. 2009. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 - 2007. EPA 430 - R- 09 - 004. Available at http://epa.gov/climatechange/emissions /downloads09/GHG2007entire_report - 508.pdf 3 U.S. EPA. 2009 Technical Support Document for Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act. Washington, DC. pp. 180 - 194. Available at http://epa.gov/climatechange/endangerment/downloads/Endangerment%20TSD.pdf 4 Argonne National Laboratory. The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model versions 1.7 and 1.8. http://www.transportation.anl.gov/modeling_simulation/GREET/ . Docket ID: EPA - HQ - OAR - 2009 - 0472 - 0215 5 Intergovernmental Panel on C limate Change. Chapter 2. Changes in Atmospheric Constituents and in Radiative Forcing. September 2007. http://www.ipcc.ch/pdf/assessment - report/ar4/wg1/ar4 - wg1 - chapte r2.pdf . Docket ID: EPA - HQ - OAR - 2009 - 0472 - 0117 6 http://www.epa.gov/otaq/models/moves/index.htm 7 Memorandum to the Docket “Moves Inputs” Docket Number EPA - HQ - OAR - 2010 - 0162 Docket Identification Number EPA - HQ - OAR - 2010 - 0162 - 0153 8 U.S. EPA. Draft Regulat ory Im pact Analysis: Changes to Renewable Fuel Standard Program . Chapters 2 and 3.May 26, 2009. Docket ID: EPA - HQ - OAR - 2009 - 0472 - 0119 9 U.S. EPA. 2008. RFS2 Modified version of GREET1.7 Upstream Emissions Spreadsheet, October 31, 2008. Docket ID: EPA - HQ - OAR- 2009 - 0472 - 0191 10 Annual Energy Outlook 2011. http://www.eia.doe.gov/oiaf/aeo/ 11 Final Rulemaking to Establish Light - Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards, Joint Technical Support Document. EPA - 420 - R - 10 - 901, April 2010. http://www.epa.gov/otaq/climate/regulations/420r10901.pdf 12 Tier 4, less - than - 8 kW nonroad compression - ignition engine exhaust emissions standards assumed for APUs: http://www.epa.gov/otaq/standards/nonroad/nonroadci.htm 13 Heavy - duty highway compression ignition engine exhaust emission standards. For MY 2004, HD standard is 2.5 g/bhp - hr NO x+NMHC, with a limit of 0.5 g/bhp - hr NMHC. http://www.epa.gov/otaq/standards/heavy - duty/hdci exhaust.htm For MY 2004, HD standard is 2.5 g/bhp - hr NO x+NMHC, with a limit of 0.5 g/bhp - hr NMHC. 14 Hsu ,Y., and Mullen, M. 2007. Compilation of Diesel Emissions Speciation Data. Prepared by E. H. Pechan and Associates for the Coordinating Research Council. CRC Contract No. E - 75, October, 2007. Available at www.crcao.org . 15 Khalek, I., Bougher, T., and Merritt, P. M. 2009. Phase 1 of the Advanced Collaborative Emissions Study. Prepared by Southwest Research Institute for the Coordinating Research Council and the Health Effects Institute, June 2009. Available at www.crcao.org .***** E.O. 12866 Review –**  **Draft –**  **Do Not Cite, Quote, or Release During Review *****

5 - 19 16 Craig Harvey, EPA, “ Calculation of Upstream Emissions for the GHG Vehicle Rule .” 2009. Docket ID: EPA HQ - OAR - 2009 - 0472 - 0216 17 This is in agreement with the IPCC report IPCC/TEAP 2005 Safeguarding the Ozone Layer and the Global Climate System

– Issues Related to Hydrofluoroc arbons and Perfluorocarbons, which indicates lifetimes (worldwide) of 9 to 12 years. 18 The Minnesota refrigerant leakage data can be found at http://www.pca.state.mn.us/climatechange/mobileair.html#leakdata 19 Using 18% as the base emission rate may overstate the net emission reductions. However, recent number from the ERG Report to CARB studying the leakage rate of heavy - duty vehicles are actually much larger (range of near 0 to 150 percent annually), and places an 18 percent annual loss rate well within the literature. However, (a) the net im pact is very small, (b) these numbers have significant uncertainty, (c) it is unclear what the appropriate mo dification would be. No comments were recieved and EPA is not modifying the calculation methodology from the proposal. 20 Using a Global Warming Potential of 1,430 for HFC - 134a. 21 Eastern Research Group. “A Study of R134a Leaks in Heavy Duty Vehicles.” CARB Contract 06 - 342. Presented during CARB Seminar on January 6, 2011. 22 http://www.epa.gov/otaq/marine.htm , http://www.epa.gov/otaq/locomotives.htm 23 Proposed Relumading to Establish Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium - and Heavy - Duty Engines and Vehicles, Draft Regulato ry Im pact Analysis, Chapter 5. EPA - 420 - D - 10 - 901 , October 2010. http://www.epa.gov/otaq/climate/regulations/420d10901.pdf 24 Energy Information Administration. Annual Energy Outlook 2009. Supplemental Transportation Tables. April 2009. http://www.eia.doe.go v/oiaf/aeo/supplement/sup_tran.xls. EPA - HQ - OAR - 2009 - 0472 - 0121 25 U.S. EPA. 2009. “For LD GHG AQ Modeling, 2030 Control Case: Adjustments to Oil Refining, and Crude Production/Transport SCCs,” spreadsheet file: “Oil_Prod_Transp_Refine_2030_adjust.xls,” 11/6/2009.