***** EO12866 Review -**  **Draft -**  **Do Not Cite, Quote, or Release During Review ** ***

Page 1 of 88 **ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts**  **79, 80, 85, 86, 600, 1036, 1037,**  **1039, 1042, 1048, 1054, 1065, and**  **1066 [EPA** 

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**– 0135; FRL_XXXX**  **- X]**  **RIN 2060 -**  **AQ86 Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission**  **and Fuel Stand ards**  **AGENCY** : Environmental Protection Agency (EPA). **ACTION** : Final Rule. **SUMMARY** : This action establish es more stringent vehicle emissions standards and will reduce the sulfur content of gasoline beginning in 2017, as part of a sy stems approach to addressin g the impacts of motor vehicles and fuels on air quality and public health. The gasoline sulfur standard will make emission control sy stems more effective for both existing and new vehicles, and will enable more stringent vehicle emissions standards. The vehicle standards will reduce both tailpipe and evaporative emissions from passenger cars, light

- dut y trucks, medium

duty passenger vehicles, and some heav y - duty vehicles. This will result in significant reductions in pollutants such as ozone, particulat e matter, and air toxics across the country

and help state and local agencies in their efforts to attain and maintain health

- based National Ambient Air Quality Standards. Motor vehicles are an important source of exposure to air pollution both regionally and near roads. These vehicle standards are intended to harmonize with California’s Low Emission Vehicle program, thus creating a federal vehicle emissions program that will allow automakers to sell the same vehicles in all 50 states. The vehicle standards will be implemented over the same timeframe as the greenhouse gas/fuel efficiency standards for light

- dut y vehicles (promulgated b y EPA and the National Highway Safety Administration in 2012) , as part of a comprehensive approach toward regulating emissi ons from motor vehicles. **DATES** : This final rule is effective on **[Insert date 60 days after publication in the Federal Register]** 

. The incorporation by reference of certain publications listed in this regulation is approved by the Director of the **Federal Re gister**  as of **[Insert date 60**  **days after publication in the Federal Register]**  **.******* EO12866 Review -**  **Draft -**  **Do Not Cite, Quote, or Release During Review ** ***

Page 2 of 88 **ADDRESSES** : EPA has established a docket for this action under Docket ID No

. EPA

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– 0135. All documents in the docket are listed on the www.regulations.gov web site. Although listed in the index, some information is not publicly

available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copy righted material, is not placed on the Internet and will be publicly avail able onl y in hard copy form

. Publicly available docket materials are available either electronically in www.regulations.gov or in hard cop y at the Air and Radiation Docket and Information Center, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW, Wa shington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holiday s. The telephone number for the Public Reading Room is (202) 566

- 1744, and the telephone number for the Air Docket is (202) 566

- 1742. **FOR FURTHER INFORMATION CONTACT** : JoNell Iffland , Office of Transportation and Air Quality , Assessment and Standards Division (ASD) , Environmental Protection Agency , 2000 Traverwood Drive, Ann Arbor MI 48105; Telephone number: (734) 214

- 4 454 ; Fax number: ( 734) 214

- 4816; E

- mail address: iffland

. jonell @epa.gov. **SUPPLEMENTARY INFORMATION: I. General Information**  **A. Does this Action Apply to Me?** Entities potentially

affected by

this rule include gasoline refiners and importers, ethanol producers, ethanol denaturant producers, butane and pentane producers, gasoline additive manufacturers, transmix processors, terminals and fuel distributors, light

- duty

vehicle manufacturers, independent commercial importers, alternative fuel converters, and manufacturers and co nverters of vehicles between 8,500 and 14,000 lbs gross vehicle weight rating (GVWR). Potentially

regulated categories include: Category NAI CS a Code SI C b Code Examples of Potentially Affected Entities Industry 324110 2911 Petroleum refineries (including importers) Industry 325110 2869 Butane and pentane manufacturers Industry 325193 2869 Ethyl alcohol manufacturing Industry 324110,

211112 2911,

1321 Ethanol denaturant manufacturers Industry 211112 1321 Natural gas liquids extraction and fractionatio n Industry 325199 2869 Other basic organic chemical manufacturing***** EO12866 Review -**  **Draft -**  **Do Not Cite, Quote, or Release During Review ** ***

Page 3 of 88 Industry 486910 4613 Natural gas liquids pipelines, refined petroleum products pipelines Industry 424690 5169 Chemical and allied products merchant wholesalers Industry 325199 2869 Manuf acturers of gasoline additives Industry 424710 5171 Petroleum bulk stations and terminals. Industry 493190 4226 Other warehousing and storage

- bulk petroleum storage Industry 336111,

336112 3711 Li ght

- dut y vehicle and light

- dut y truck manufacturers Ind ustry 811111, 811112, 811198 7538,

7533, 7534 Independent commercial importers Industry 335312,

336312, 336322, 336399, 811198 3621,

3714, 3519, 3599, 7534 Alternative fuel converters Industry 333618,

336120, 336211, 336312 3699,

3711, 3713, 3714 On

- highway heavy

- dut y engine & vehicle (>8,500 lbs GVWR) manufacturers
a North American Industry Classification System (NAICS). b Standard Industrial Classification (SIC). This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated b y this action. This table lists the ty pes of entities that EPA is now aware could potentially be regulated b y this action. Other t ypes of entities not listed in the table could also be regulated. To determine wheth er your activities are regulated by this action, you should carefully examine the applicability criteria in 40 CFR parts 79, 80, 85, 86, 600, 1036, 1065, and 106 6 and the referenced regulations. If you have an y questions regarding the applicability

of thi s action to a particular entity , consult the person listed in the preceding **FOR FURTHER INFORMATION CONTACT** section. **B .**  **Did EPA Conduct a Peer Review before Issuing this Action**  **?** This regulatory

action was supported b y influential scientific information. T herefore, EPA conducted peer reviews in accordance with OMB’s Final In formation Qualit y Bulletin for Peer Review. EPA conducted several peer reviews in conne ction with data supporting the Tier 3 program, including new research on the effects of fuel prop erties changes (including sulfur effects) on***** EO12866 Review -**  **Draft -**  **Do Not Cite, Quote, or Release During Review ** ***

Page 4 of 88 exhaust and evaporative emissions of Tier 2 vehicles. The refinery

- by

- refinery cost model was also peer reviewed. The peer review reports are located in the docket for today 's action, as well as the agency 's r esponse to the peer review comments. **Table of Contents** 

## I. **Executive Summary and Program**  **Overview A.**  **Introduction** In this action, EPA is finalizing a major program designed to reduce air pollution from passenger cars and trucks. This program includes new stand ards for both vehicle emissions and the sulfur content of gasoline, considering the vehicle and its fuel as an integrated sy stem. We refer to this program as the “Tier 3” vehicle and fuel standards. This rule is part of a comprehensive approach to address the impacts of motor vehicles on air quality and public health. Over 149 million Americans are currentl y experiencing unhealthy levels of air pollution, which are linked with respiratory

and cardiovascular problems and other adverse health impacts that l ead to increased medication use, hospital admissions, emergency department visits, and premature mortality

. 1 Motor vehicles are a particularly important source of exposure to air pollution, especiall y in urban areas. By 201 8, we project that in many area s that are not attaining health

- based ambient air quality standards (i.e.,
“ nonattainment areas ”) , passenger cars and light trucks will contribute 10

- 25 percent of total nitrogen oxides (NO X ) emissions, 15

- 30 percent of total volatile organic compound (VOC ) emissions, and 5

- 10 percent of total direct particulate matter (PM 2.5 ) emissions. 2 These compounds form ozone, PM, and other air pollutants, whose health and environmental effects are described in more detail in Section II. Cars and light trucks also c ontinue to be a significant contributor to air pollution directly

near roads, with gasoline vehicles accounting for more than 50 percent of near

- road concentrations of some criteria and toxic pollutants. 3 More

1 Data come from Summary Nonattainment Area Population Exposure Report, current as of December 5 , 201 3 at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and cont ained in Docket EPA

- HQ

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- 0135. 2 Mobile source contributions derived from inventories developed for this rule

. For more information on these inventories see the Emissions Inventory Technical Support Document (TSD) for the final Tier 3 Rule, Docket ID No. EPA

- HQ

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- 20 11

- 01 35. 3 For example, see Fujita, E.M; Campbell, D.E.; Zielinska, B.; Arnott, W.P.; Chow , J.C. (2011) Concentrations of Air Toxics in Motor Vehicle

- Dominated Environments. Health Effects Institute Research Report 156. Available at http://www.healtheffects.orgPage 5 of 88

than 50 million people live, work, or go to s chool in close proximity to high

- traffic roadway s, and the average American spends more than one hour traveling along roads each day

. 4 , 5 Almost 90 percent of dail y trips use personal vehicles or other motor vehicles

. 6 The standards set forth in this rule w ill significantly reduce levels of multiple air pollutants (such as ambient levels of ozone, PM, nitrogen dioxide (NO 2 ), and mobile source air toxics (MSATs)) across the country , with immediate benefits from the gasoline sulfur control standards starting i n 2017. These reductions will help state and local agencies in their effort to attain and maintain health

- based National Ambient Air Quality Standards (NAAQS). Few other national strategies exist that will deliver the same magnitude of multi

- pollutant red uctions and associated public health protection that is projected to result from the Tier 3 standards. Without this action to reduce nationwide motor vehicle emissions, areas would have to adopt other , less cost

- effective measures to reduce emissions from other sources under their state or local authority. In the absence of additional controls, certain areas would continue to have ambient ozone concentrations exceeding the NAAQS in the future. See Section III.C for more details. The Clean Air Act authorizes EPA to establish emissions standards for motor vehicles to address air pollution that may reasonably

be anticipated to endanger public health or welfare (section 202). EPA also has authority to establish fuel controls to address such air pollution (section 211). These statutory authorities are described in Section II.A. The vehicle and gasoline sulfur standards we are finalizing represent a “sy stems approach” to reducing vehicle exhaust and evaporative emissions by addressing the vehicle and fue l as a s ys tem. The sy stems approach enables emission reductions that are both technologicall y feasible and cost

- effective beyond what would be possible looking at vehicle and fuel standards in isolation. We first applied such an approach with our Tier 2 v ehicle/gasoline sulfur standards

4 U.S. Census Bureau (2011). Current Housing Reports, Series H150/09, American Housing Survey for the United States: 2009. U.S. Government Printing Office, Washington, DC. Available at http://www.census.gov/hhes/www/housing/ahs/ahs09/ahs09.html

. (Note that this survey includes estimates of homes within 300 feet of highways with four or more lanes, railroads, and airports.) 5 Drago, R. (2011). Secondary activities in the 2006 American Time Use Survey. U.S. Bureau of Labor Stat istics Working Paper 446. Available at http://www.bls.gov 6 U.S. Department of Transportation, Bureau of Transportation Statistics (2003). National Household Travel Survey 2001 Highlights Report. Government Printing Office, Washington, DC. Available at http://www.bts.gov/publications/highlights_of_the_2001_national_household_travel_survey/Page 6 of 88

(finalized in 2000). 7 We believe that a similar approach for the Tier 3 standards is a cost
- effective way

to achieve substantial additional emissions reductions. The Tier 3 standards include new light

- and heav y - duty ve hicle emission standards for exhaust emissions of VOC (specifically , non - methane organic gases, or NMOG), NO X , and PM, as well as new evaporative emissions standards. The fully phased

- in standards for light

- dut y vehicle, light

- dut y truck, and medium

- duty passenger vehicle tailpipe emissions are an 80 percent reduction in fleet average NMOG+NO X compared to current standards, and a 70 percent reduction in per

vehicle PM standards. The fully phased

- in Tier 3 heavy

- dut y vehicle tailpipe emissions standards fo r NMOG+NO X and PM are on the order of 60 percent lower than current standards. Finally , the full y phased

- in evaporative emissions standards represent a 50 percent reduction from current standards. The vehicle emission standards, combined with the reductio n of gasoline sulfur content from the current 30 parts per million (ppm) average down to a 10 ppm average, will result in dramatic emissions reductions for NO X , VOC, direct PM 2.5 , carbon monoxide (CO) and air toxics. For example, in 2030, when Tier 3 vehi cles will make up the majority of the fleet as w ell as vehicle miles traveled, NO X and VOC emissions from o n - highway vehicles will be reduced b y about 21 percent , and CO emissions will be reduced b y about 24 percent. National e missions of many air toxics f

rom on - highway

vehicles will also be reduced b y 10 to nearl y 30 percent. Reductions will continue beyond 2030 as more of the fleet is composed of vehicles meeting the fully phased

- in Tier 3 standards . For example, the Tier 3 program w ill reduce on

- highway emissions of NO X and VOC nearl y 31 percent b y 2050, when vehicles meeting the full y phased

- in Tier 3 standards will comprise almost the entire fleet. Gasoline vehicles depend to a great degree on cataly tic converters to reduce levels of pollutants in the ir exhaust, including NMOG and NO X , as well as PM (specifically , the volatile hydrocarbon fraction), CO, and most air toxics. The catal yt ic converters become significantly less efficient when exposed to sulfur . The Tier 2 rulemaking required refiners to take steps to reduce sulfur levels in gasoline by approximately

90 percent, to an average of 30 ppm. As discussed in Section IV .A.6, subsequent research provides a compelling case that even this level of sulfur not only

degrades the emission performance o f vehicles on the road today , but also inhibits necessary further reductions in vehicle emissions performance to reach the Tier 3 standards. Thus, the 10 ppm average sulfur standard for Tier 3 is significant in two way s: it enables vehicles designed to the Tier 3 tailpipe exhaust standards to meet these standards in

- use for the duration of their useful life, and it facilitates immediate emission reductions from all the vehicles on the road at the

7 65 FR 6698 (February 10, 2000)Page 7 of 88

time the fuel sulfur controls are implemented. EPA is not the first regulatory agency to recognize the need for lower

- sulfur gasoline. Agencies in Europe and Japan have already imposed gasoline sulfur caps of 10 ppm, and the State of California is already averaging 10 ppm sulfur with a per gallon cap of 2 0 ppm. Other states are preempted b y the Clean Air Act from adopting new fuel programs to meet air quality objectives. Consequently , they could not receive the air quality benefits of lower sulfur gasoline without federal action. This action is one aspe ct of a comprehensive national program regulating emissions from motor vehicles. EPA’s final rule for reducing greenhouse gas (GHG) emissions from light

- dut y (LD) vehicles starting with model ye ar (MY) 2017 (referred to here as the “2017 LD GHG” standards ) is another aspect of this comprehensive program. 8 The Tier 3 program addresses interactions with the 2017 LD GHG rule in a manner that aligns implementation of the two actions, to achieve significant criteria pollutant and GHG emissions reductions while providing regulatory

certaint y and compliance efficiency. As vehicle manufacturers introduce new vehicle platforms for compliance with the GHG standards, they will be able to design them for compliance with the Tier 3 standards at the same time. The Tie r 3 standards are also closel y coordinated with California’s L ow Emission Vehicle (LEV ) III program to create a vehicle emissions program that will allow automakers to sell the same vehicles in all 50 states . (In December 2012 EPA approved a waiver of Cle an Air Act preemption for the California Air Resources Board’s (CARB’s) LEV III program with compliance beginning in 2015. Twelve states adopted the LEV III program under Section 177 of the Clean Air Act. 9 ) We have worked closel y with individual vehicle manufacturers and their trade associations, who have emphasized the importance of a harmonized national program. Together, the Tier 3, 2017 LD GHG, and LEV III standards will provide significant reductions in GHGs, criteria pollutants and air toxics from motor vehicles while streamlining programs and enabling manufacturers to design a single vehicle for nationwide sales, thus reducing their costs of compliance. In this way , the Tier 3 program responds to the May 21, 2010 Presidential Memorandum that reque sted that EPA develop a comprehensive approach toward regulating motor vehicles, including consideration of non

- GHG emissions standards. 10 As part of the s ys tems approach to this program, we have consider ed the ty pes of fuels on which vehicles will be operating in the future . In particular, the

8 EPA’s GHG standards are part of a joint National Program with the National Highway Traffic Safety Administration, which also set coo rdinated standards for Corporate Average Fuel Economy (CAFE). 7 7 FR 62623 ( October 1 5 , 201 2 ). 9 These states include Connecticut, Delaware, Maryland, Maine, Massachusetts, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Washington, and Vermont. 10 The Presidential Memorandum is found at: http://www.whitehouse.gov/the

- press office/presidential

- memorandum

- regarding

- fuel

- efficiency

- standards.Page 8 of 88

renewable fuels mandate that was revised b y the Energy Independence and Security Act (EISA) and is being implemented through the Renewable Fuel Standards program (RFS2) 11 is result ing in the use of signi ficant amounts of ethanol

- blended gasoline. We are updating the specifications of the emissions test fuel with which vehicles demonstrate compliance with emissions standards, in order to better reflect the ethanol content and other properties of gasoline that is in use today and is expected in future ye ars . S ection I provides an overview of the vehicle and fuel standards we are finalizing as well as the impacts of the standards. The public health issues and statutory requirements that have prompted this action are described in Section II, and our discussion of how the Tier 3 standards will reduce emissions and air pollution is presented in Section III. Details of the standards and how they will be implemented can be found in Sections IV through VI. Sections VII through X contain our discussion of the standards’ technological feasibility and cost s , benefits, and economic impacts. Sections XIthrough XIII address public participation, statutory and executive orders, and statutory provisions and legal authority under the Clean Air Act covered in this rulemaking. This final rule is based on extensive public input received in response to EPA’s Tier 3 proposal. The proposal was signed and posted on the EPA website on March 29, 2013, and publis hed in the Federal Register on May 21, 2013. EPA held two public hearings in Philadelphia and Chicago in April 2013. In response to stakeholder requests, EPA extended the public comment period to July 1, 2013. We received more than 200,000 public comments. A broad range of stakeholders provided comments, including state and local governments, auto manufacturers, emissions control suppliers, refiners, fuel distributors and others in the petroleum industry , renewable fuels providers, environmental organiz ations, consumer groups, labor groups, private citizens, and others. Some of the issues raised in comments included leadtime and the program’s start date, the vehicle manufacturers’ support for a 50

- state program harmonized with California, the need for and degree of gasoline sulfur control (including the level of the sulfur cap), the ethanol content of vehicle certification test fuel, and various details on the flexibilities and other program design features of both the vehicle and fuels standards. **B. Overvi**  **ew of the Tier 3 Program** In the 14 ye ars since EPA established the Tier 2 Vehicle Program, manufacturers of light

- duty vehicles and automotive technology suppliers have continued to develop a wide range of improved technologies capable of reducing vehicle emissions. The California LEV II program has been instrumental in the

11 75 FR 14670 (March 26, 2010)

.Page 9 of 88

continuous technology

improvements by

requiring year after ye ar reductions in fleet average h ydrocarbon levels, in addition to requiring the introduction of advanced exhaust and evaporative emission controls in partial zero emission vehicles (PZEVs). This technolog ical progress has made it possible for manufacturers to achieve emission reductions well beyond the requirements of the Tier 2 program if gasoline sulfur levels are lowered further. As a result, in conjunction with lower gasoline sulfur standards, we are establishing new Tier 3 standards for exhaust emissions of NMOG, NO X , and PM, as well as for evaporative hydrocarbon emissions. These vehicle emissions standards will phase i n beginning with MY 2017. The structure of the Tier 3 standards is very

similar to th at of the existing Tier 2 program. As with the Tier 2 program, the standards will apply to all light

- dut y vehicles (LDVs, or passenger cars), light

- dut y trucks (LDT1s, L DT2s, LDT3s, and LDT4s) and Med ium

- Duty Passenger Vehicles ( MDPVs). We also are establishing separate but closely related standards for heav y - dut y vehicles up to 14,000 lbs Gross Vehicle Weight Rating (GVWR). 12 We have concluded that the vehicle emissions standards, in conjunction with the reductions in fuel sulfur also required b y this action, are feasible across the fleet in the timeframe provided

. Auto manufacturers have stressed the importance of being able to design , produce , and sell a single fleet of vehicles in all 50 states that compl ies with both the Tier 3 and California LEV III program s , as well as the greenhouse gas (GHG) /Corporate Average Fuel Economy (CAFE) programs in the same timeframe. To that end, we worked closel y with the California Air Resources Board and vehicle manufacturers to align the two programs as closely as possible

. This c onsistency

among the federal and California programs means that manufacturers do not need to design unique versions of vehicles with diff erent emission control hardware and calibrations for different geographic areas. This allow s manufacturers to avoid the additional costs of parallel design, development, calibration, and manufacturing. We also have designed the Tier 3 program to be imple mented in the same timeframe as the GHG emissions and fuel economy standards for model years 2017

- 2025. We expect that in response to these programs, manufacturers will be developing entirely new powertrains for most of their vehicles. Because the Tier 3 standards will phase in over the same timeframe, manufacturers are in a better position to simultaneously respond to all of these requirements. Overall, the final Tier 3 program is very similar to the program we proposed. As discussed below and throughout this preamble, the program phases in

12 These heavy

- duty vehicles were not included in the Tier 2 program but were subject to standards in a subsequent rule cover ing the heavy

- duty sector (66 FR 5002, January 18, 2001).Page 10 of 88

over several ye ars
– with the primary vehicle emission standards starting in Model Year (MY) 2017 (2018 for heavier vehicles) and the gasoline sulfur control provisions beginning in 2017. As discussed above, we rece ived a large number and wide range of comments on the proposed rule. Several comments raise particularly significant issues concerning some fundamental components of the Tier 3 program, including when the vehicle

- related and fuel

- related requirements beg in. We briefl y discuss these key issues in this section, and in more detail later in this preamble. The Summary and Anal ys is of Comments document provides our responses to the comments we received; it is located in the docket for this rulemaking and also on EPA’s website at www.epa.gov/otaq/tier3.htm. 1. Major Public Comments and Key Changes from the Proposal
a. Start Date and Lead Time Issues (1) Gasoline Sulfur Control Program Many stakeholders commented on the proposed 2017 start date of the Tier 3 program, with state and NGO organizations supporting finalizing the standards as proposed. Conversel y, refiners, importers, and others in the fuel industry commented that they

believed the proposed start date would not provide a sufficient amount of lead time to meet the requirements of the Tier 3 program, and that EPA has historically

provided at least four years of lead time in previous fuels rulemakings. These commenters noted that five years of lead time is needed to allow for necessary

refinery changes to be made during a refinery ’s normal turnaround/shutdown schedule (these occur every four years, on average) and to allow adequate time for the permitting process. These commenters also stated that, given the proposed flexibility provisions for vehicles, that a 20 17 fuel program start date was not trul y needed to enable the vehicle technology. Further, these commenters stated that they believed insufficient lead time would drive up the costs for regulated entities as they would need to do unscheduled shutdowns to install and/or revamp equipment to meet the proposed standards. Lastl y, they stated that the uncertaint y regarding the potential availability of credits would make meeting a 2017 start date more challenging. As discussed in greater detail in Section V bel ow, we are finalizing the proposed start date of January 1, 2017. W e understand refiners’ concerns, including their concerns over the necessary capital investments and potential off

- cycle turnarounds/shutdowns to make refinery modifications for Tie r 3

. Especially in light of the additional flexibilities we are finalizing beyond those already in the proposal, we are confident that the program being finalized today addresses these concerns. The magnitude of the investments necessary to comply

with Tier 3 is much smaller than what was required for Tier 2 or ultra

- low sulfur diesel.Page 11 of 88

Considering all the flexibilities offered to regulated parties, there is, in effect, nearl y 6 years of lead time provided for those refineries that may need it. As dis cussed in Section V.D, we are finalizing a credit averaging, banking, and trading (ABT) program that will allow for a smooth transition from the Tier 2 to Tier 3 ABT programs (including provisions for earl y credit generation beginning in 2014). These earl y credit provisions, coupled with the ability to carry over credits from Tier 2 into Tier 3 (an additional flexibility being finalized today

that was not part of the proposal), will allow for early actions to reduce sulfur levels by some refineries to be u sed to delay

the need for actions at other refineries until 2020. This structure of the ABT program allows refiners and importers the flexibility to choose the most economical compliance strategy

– investment in technology , use of credits, or both

– for m eeting the Tier 3 average gasoline sulfur standard. In addition, approved small refiners and small volume refineries are given an additional three ye ars from the January

1, 2017, Tier 3 program start date to comply (January 1, 2020). We proposed that the Tier 2 ABT program would not only be separate from the Tier 3 ABT program, but that it would also end at the start of the Tier 3 program in 2017. The implications of this meant that any Tier 2 credits generated after 2012 would run the risk of expiring be fore the end of their full five

- ye ar life if they were not used before January

1, 2017. Commenters requested that EPA consider allowing such Tier 2 “banked” credits to receive their full five

- ye ar life. This would eliminate an y incentive refiners may hav e to use these credits prior to the end of the Tier 2 program to raise their in

- use sulfur levels. The ABT program that we are finalizing today

enables a seamless transition from Tier 2 to Tier 3, including an allowance for Tier 2 banked credits to be use d for their full five

- ye ar life or through December 31, 2019, whichever is earlier. Not only does this provision effectively provide more lead time and flexibility for refiners and importers, but we believe these banked credits will help to provide certai nty of the availability

of credits for refiners and importers who may want to rel y on them for compliance. Finally , as discussed in Section V.E.2, we are also finalizing hardship provisions that allow refiners to petition for delayed compliance , on a c ase - by

- case basis , for situations of extreme hardship or extreme unforeseen circumstances. These provisions, similar to those implemented in past fuel rulemakings , provide a safet y valve should all the other flexibilities provided prove insufficient. As part of these hardship provisions, we are finalizing the ability for refiners to carry

a deficit for up to 3 years, providing them with yet additional flexibility during the transition to Tier 3 should it prove necessary

.

(2) Vehicle Emission Control Program T here were no major concerns raised for the proposed MY 2017 start date for lighter light

- dut y vehicles, although commenters from the auto manufacturing industry raised concerns about the lead time we proposed for heavier light

- duty vehicles. Specifically , commenters pointed to the Clean Air Act requirement that,Page 12 of 88

for vehicles over 6,000 lbs GVWR, EPA emission standards provide at least four ye ars of lead time and three years of regulatory stability

. In light of this statutory

requirement, in addition to the primary declining fleet average standards starting in MY 2018 for heavier vehicles, EPA proposed an alternative phase

- in schedule for any manufacturer that prefers a longer lead time and annual stability

for these vehicles in lieu of the declining fleet average standards option. The commenters stated that the proposed alternative pathway would be too difficult to take advantage of in comparison to the primary program and thereb y failed to comply with the Clean Air Act. In considering these comments, EP A also considered that during the development of the Tier 3 program and in their comments, the same auto industry commenters consistentl y urged EPA to design the Tier 3 program to harmonize with the California LEV III standards as closel y and as earl y as p ossible. As discussed in detail below in Section IV.A, extensive data that EPA has generated or received continue to support the conclusion that the primary fleet

- average standards provide a compliance path that is feasible across the industry and that cl osely harmonizes with LEV III. EPA believes that we have reasonabl y resolved these somewhat competing concerns

-- early harmonization vs. additional lead time

-- by finalizing the primary

declining fleet average standards as proposed while also finalizing revised alternative phase

- in compliance schedules (see Section IV.A.2.c). In response to the comments on this topic, we have revised the alternative phase

- in schedules to reduce their associated burden for manufacturers, while still maintaining environme ntal benefits that are equivalent to the primary program. We also include provisions in the percent

- of

- sales phase

- in alternatives that allow manufacturers to exclude vehicle models that begin their 2019 model year production earl y in 2018, in order to provide four years of lead time. b. Emissions Test Fuel In

- use gasoline has changed considerably since EPA last revised specifications for the test gasoline used in emissions testing of light

- and heavy

duty vehicles. Perhaps most importantly , gasoline conta ining 10 percent ethanol by volume (E10) has replaced non

- oxygenated gasoline (E0) across the country . As a result, we are updating federal emissions test fuel specifications to better match in

use fuel. In the NPRM, EPA proposed that the specified gaso line for emissions testing be changed from E0 to E15 as a forward

- looking approach . Since then, several factors have led EPA to reconsider that approach , inclu ding minimal proliferation on a national scale of stations offering E15 and the complexities that E15 would introduce for long

- term harmonization with California’s use of E10 in their LEVIII program. We received comments from a broad set of stakeholders i ncluding the auto and oil industries, states, and NGOs with a general consensusPage 13 of 88

that E15 would not be appropriate as the official test fuel at this time. Ethanol industry commenters supported E15 certification fuel, but provided no timeline by which this blend level would be representative of in

- use fuel. In light of the comments received and EPA’s assessment of the current and projected levels of ethanol in gasoline in use, we are finalizing E10 as the new emissions test fuel. In deciding to finalize E10 test fuel, EPA considered whether to change the volatility of the test fuel, ty

picall y expressed as pounds per square inch (psi) Reid Vapor Pressure (RVP). As discussed in detail in Section IV.F, after considering technical and policy

implications as wel l as stakeholder comments, we have concluded that the most appropriate approach is to maintain an RVP of 9 psi for the E10 emissions test fuel at this time. EPA considered raising test fuel RVP to 10 psi, but decided to leave it unchanged at 9 psi based o n what would have been the associated increase in stringency of the Tier 3 evaporative standard with 10 psi and the loss of regulatory

harmony on evaporative emissions with California’s LEV III program. As a result, after reassessing market trends and co nsidering comments, EPA concludes that the most appropriate approach is to finalize an ethanol content of 10 percent and an RVP of 9 psi for emissions test gasoline. We will continue to monitor ethanol trends in the gasoline market, as discussed later in this preamble.
c. Gasoline Sulfur Caps As described in more detail in Section V.C. w e proposed two options for the Tier 3 per - gallon sulfur caps

— maintaining the Tier 2 refinery gate sulfur cap of 80 ppm (with a 95 ppm downstream sulfur cap ), and lowe ring to a 50 ppm refinery gate sulfur cap beginning January 1, 2020 (with a 65 ppm downstream cap). We received comments supporting lower per

- gallon caps which noted potential environmental benefits, greater certainty that vehicles would see lower and more uniform gasoline sulfur levels, and the ability to enable new vehicle technologies requiring very

low sulfur levels. Conversel y, comments received in support of maintaining the Tier 2 per

- gallon caps cited concerns on cost, flexibility for turnarounds/unplanned shutdowns (due to refinery fires, natural disasters, etc.), and gasoline suppl y and/or price impacts. Analy sis performed since the time of the proposal found that a lower refinery gate cap would likely

result in higher costs to the fuels industry and a decreased ability

to handle off

- spec product (potentially impacting gasoline supply and pricing), without an y significant increase in the nationwide emissions reductions provided b y the Tier 3 program. Thus, in today ’s action we are retaining the Tie r 2 per

- gallon sulfur caps. The 80 ppm refinery gate cap will provide refiners needed flexibility in allowing for naturally

- occurring fuel batch variability , as well as more certainty

that they will be able to continue producing and distributing gasoline during turnarounds/upsets to avoid a total shutdown. It willPage 14 of 88

also provide more certainty for transmix processors, additive manufacturers, and other downstream parties in producing gasoline. However, we do understand commenters’ concerns that retaining the Tier 2 sulfur caps might create regional differences in the benefits of the Tier 3 program. Therefore we will continue to monitor in

- use sulfur levels and their impact on vehicle emissions to ascertain whether a future reduction in th e per - gallon cap may be necessary

. d. Effect of Gasoline Sulfur on Tier 3 Vehicle Emissions The need for and level of gasoline sulfur control was a key issue raised in public comments. The petroleum industry raised concerns that there was insufficient basis for the proposed 10 ppm average sulfur level, while auto manufacturers and emissions control equipment manufacturers stressed that the feasibility of the Tier 3 vehicle standards was dependent on near

- zero gasoline sulfur levels. This issue is discussed i n detail below in Section IV.A.6. In sum, EPA believes that the range of studies conducted by EPA and others in recent y ears, along with the comments submitted by the auto industry

and emissions control manufacturers during the comment period and more rec entl y, strongl y reinforce our conclusion that the impact of gasoline sulfur poisoning on exhaust catal ys t performance is significant. Sulfur is a well

- known cataly st poison. The nature of sulfur’s interactions with active catal yt ic materials is complex and varies with catal ys t composition, exhaust gas composition , and exhaust temperature. Thus, even if a manufacturer were able to certify

a new vehicle to the new stringent standards, the manufacturer’s ability to maintain the emission performance of that vehicle in

- use is greatly jeopardized if the vehicle is being operated on gasoline sulfur levels greater than 10 ppm. Infact, d

ue to the variation in actual vehicle operation, any amount of gasoline sulfur will deteriorate cataly st efficiency

. V ehicle manufacturers and suppliers , both individually and through their trade associations, stressed the need for gasoline sulfur to be reduced to near zero levels in order for them to meet the proposed standards. However, we believe that a 10 ppm average sulfur level is sufficiently

low to enable compliance with the Tier 3 vehicle standards, and as described below and in Section V, reducing sulfur levels further would cause sulfur control costs to quickly

escalate. Taken together, this information provides a c ompelling argument that the fleetwide Tier 3 vehicle standards are achievable only with a reduction of gasoline sulfur content from the current 30 ppm average down to a 10 ppm average.Page 15 of 88 e. SFTP (US06) PM Standard for Light

- Dut y Vehicles The final Tier 3 vehi cle standards are largel y unchanged from their proposed levels. One change from the proposal is the PM emissions standards as measured on the US06 test cycle. The US06 cycle is part of the composite Supplemental Federal Test Procedure (SFTP) and simulate s aggressive driving. The US06 PM standards are part of the suite of Tier 3 tailpipe standards that limit emissions under a wide range of common vehicle driving conditions. Newer emissions test data presented in the NPRM, as well as more recent additiona l test data submitted in public comments, show that a numerically lower US06 PM standard is feasible and appropriatel y reflects the actual emissions performance achieved b y man y vehicles in the fleet today

while preventing increased emissions in the future

. Taken together, the test results clearl y show that most current light

- dut y vehicles

– regardless of engine technology , emission control strategy , or vehicle size

– are performing at much lower US06 emission levels than previousl y documented. Based on these newer data, we believe that it is appropriate to finalize a numericall y lower US06 PM emission standard for LDVs, LDTs, and MDPVs, and to set a single standard for both lighter and heavier vehicles in this vehicle segment. In general, the final US06 PM standard for these vehicles begins to phase in at a level of 10 mg/mi in MYs 2017 and 2018, stepping down to a level of 6 mg/mi in MY2019. See Section IV.A.4.b for additional discussion of the US06 standards and how they

will phase in. 2. Key Components of the Tier 3 Program
a. Tailpipe Standards for Light

- Dut y Vehicle, Light

- Duty Truck, and Medium

- Duty

Passenger Vehicle Tailpipe Emissions We are establishing a comprehensive program that include s new fleet

average standards for the sum of NMOG and NO X tailp ipe emissions (presented as NMOG+NO X ) a s well as new per

- vehicle standards for PM. 13 These standards, when applied in conjunction with reduced gasoline sulfur content, will result in very significant improvements in vehicle emissions from the levels of the Tier 2 program. For these pollutants, the standards are measured on test procedures that represent a range of vehicle operation, including the Federal Test Procedure (or FTP, simulating ty

pical driving) and the Supplemental Federal Test Procedure (or SFT P, a composite test simulating higher ambient temperatures, higher vehicle speeds, and quicker accelerations). In addition to the standards, we are extending the regulatory

useful life period during which the standards appl y (see Section

13 A discussion of the reasons for combining NMOG and NO X for this purpose is in Section IV.A.3.a below
.Page 16 of 88

IV .A.7.b below) and mak ing test fuel more representative of expected real

- world fuel (see Section I.B. 2.e below). The final standards are in most cases identical to those of California’s LEVIII program, which provides the 50

- state harmonization strongl y supported b y the a uto industry

. As proposed, the new Tier 3 FTP and SFTP NMOG+NO X standards are fleet

- average standards, meaning that a manufacturer calculate s the average emissions of the vehicles it sells in each model year and compare s that average to the applicabl e standard for that model year. The manufacturer certif ies each of its vehicles to a per

- vehicle “bin” standard (see Section IV.A.2) and sales

- weight s these values to calculate its fleet

- average NMOG+NO X emissions for each model ye ar. Table I

- 1 summarizes the fleet average standards for NMOG+NO X evaluated over the FTP. The standards for light

- dut y vehicles begin in MY 2017 at a level representing a 46 percent reduction from the Tier 2 requirements. For the light

- dut y fleet over 6000 lbs GVWR , and MDPVs , the standards appl y beginning in MY 2018. As shown, these fleet

- average standards decline during the first several years of the program, becoming increasingl y stringent until ultimately reaching an 81 percent red

uction when the transition is complete. The FTP NMOG+NO X program includes two separate sets of declining fleet

- average standards, with LDVs and small light trucks in one grouping and heavier light trucks and MDPVs in a second grouping, that converge at 30 milligram s per mile (mg/mi) in MY 2025 and later. As mentioned above, we are also providing alternative percent phase

- in schedules for this and the other light

- duty standards. **Table I**  **- 1**  **Tier 3 LDV, LDT, a**  **nd MDPV Fleet Average FTP NMOG+NO X**  **Standards (mg/mi)**

Model Year 2017 a 2018 2019 2020 2021 2022 2023 2024 2025 and later LDV/LDT1 b 86 79 72 65 58 51 44 37 30 LDT2,3,4 and MDPV 101 92 83 74 65 56 47 38 30

a For LDV and LDTs above 6000 lbs GVWR and M DPVs , the fleet average standards apply beginning in MY 2018. b These standards apply for a 150,000 mile useful life. Manufacturers can choose to certify some or all of their LDVs and LDT1s to a useful life of 120,000 miles. If a vehicle model is certifi ed to the shorter useful life, a proportionally lower numerical fleet

- average standard applies , calculated by multiplying the respective 150,000 mile standard by 0.85 and rounding to the nearest mg. See Section IV.A.7. c . Similarly , as proposed, the NMOG+N O X standards measured over the SFTP are fleet

- average standards, declining from MY 2017 until MY 2025, as shown in Table I

- 2 . In this case, the same standards appl y t o both lighter and heavierPage 17 of 88

vehicles in the light
- dut y fleet . In MY 2025, the SFTP NMOG+NO X standard reach es its final fleet average level of 50 mg/mi. **Table I**  **- 2**  **Tier 3 LDV, LDT, and MDPV Fleet Average SFTP NMOG+NO**  **X Standards (mg/mi)** 

Model Year 2017 a 20 18 2019 2020 2021 2022 2023 2024 2025 and later NMOG + NO X 103 97 90 83 77 70 63 57 50
a For LDVs and LDTs above 6000 lbs GVWR and MDPVs , the fleet average standards apply beginning in MY 2018. As proposed, m anufacturers can also earn credits if thei r fleet average NMOG+NO X performance is better than the applicable standard in any model year. Credits that have been previously banked or obtained from other manufacturers can be used, or credits can be tra ded to other manufacturers

. M anufacturers wou ld also be allowed to carry forward deficits in their credit balance. (S ee Section s IV .A.7. a and IV.A.7.m ). We are also establishing PM standards as part of th e Tier 3 program, for both the FTP and US06 cycles ( as described above, US06 is a component of the SFTP test). Research has demonstrated that the level of PM from gasoline light

duty vehicles is more significant than previousl y thought. 14 Although man y vehicles today

are performing at or near the levels of the new standards, the data indicate that i mprovements, especiall y in high

- load fuel control and in the durability of engine components, are possible. Under t ypical driving, as simulated by the FTP, the PM emissions of most current
- technology

gasoline vehicles are fairly low at certification and in use, well below the Tier 2 PM standards. At the same time we see considerable variation in PM emissions among vehicles of various makes, models, and designs. As a result, as proposed, we are setting the new FTP PM standard at a level that will ensure that all new vehicles perform at the level already being achieved b y well

- designed Tier 2 vehicles . The PM standards appl y to each vehicle separatel y (i.e., not as a fleet average). Also, in contrast to the declining NMOG+NO X standards, the PM standard on the FTP for certification testing is 3 mg/mi for all vehicles and for all model years. As for the NMOG+NO X standards, for vehicles over 6000 lbs

14 Nam , E.; Fulper, C.; Warila, J.; Somers, J.; Michaels, H.; Baldauf, R.; Rykowski, R.; and Scarbro, C. (2008). Analysis of Particulate Matter Emissions from Light

- Duty Gasoline Vehicles in Kansas City, EPA420

- R

- 08

- 010. Assessment and Standards Division Office of Transportation and Air Quality U.S. Environmental Protection Agency Ann Arbor, MI, April 2008.Page 18 of 88

GVWR, the FTP PM standard appl ies beginning in MY 2018. Manufacturers can phase in their vehicle models as a percent of U.S. sales through MY 2022. Most vehicles are already performing at this stringent PM level, and the primary intent of the standard is to bring all light

- duty vehicles to the ty

pical level of PM performance being demonstrated b y man y of today’ s vehicles

. As proposed, the Tier 3 program also includes a temporary in

- use FTP PM standard of 6 mg/mi for the testing of in

- use vehicles that appl ies during the percent phase

- in period onl y. This in

- use standard will address the in

- use variability and durability uncertainties that accompany the introduction of new technologies. Table I

- 3 presents the FTP certification and in

- use PM standards and the phase

- in percentages. **Table I**  **- 3**  **Phase -**  **In for Tier 3**  **FT P**  **PM Standards 2017**  **a 2018**  **2019 2020**  **2021 2022 and**  **later Phase**  **- In**  (percent of U.S. sales) 20 b 20 40 70 100 100 **Certification Standard (mg/mi)**  3 3 3 3 3 3 **In -**  **Use Standard (mg/mi)**  6 6 6 6 6 3

a For LDVs and LDT s above 6000 lbs GVWR and MDPVs , the FTP PM standards apply beginning in MY 2018. b Manufacturers comply in MY 2017 with 20 percent of their LDV and LDT fleet under 6,000 lbs GVWR, or a lt ernatively with 10 percent of their total LDV, LDT, and MDPV fleet. Finally , as discussed in Section I.B.1.e above, the Tier 3 program includes PM standards evaluated over the US06 driving cycle (the US06 is one part of the SFTP procedure) of 10 mg/mi through MY 2018 and of 6 mg/mi for 2019 and later model years, for li ght

- duty vehicles. As in the case of the FTP PM standards, the intent of the US06 PM standard is to bring the emission performance of all vehicles to that already being demonstrated b y man y vehicles in the current light

- duty fleet. b. Heav y - Duty

Vehicle Tailpipe Emissions Standards As discussed in detail in Section IV.B, we are setting Tier 3 exhaust emissions standards for complete heav y - dut y vehicles (HDVs) between 8,501 and 14,000 lb s GVWR. Vehicles in this GVWR range are often referred to as Class 2b (8, 501

- 10,000 lb s ) and Class 3 (10,001

- 14,000 lb s ) vehicles, and are t ypically heav y - dut y pickup trucks and work or shuttle vans. Most are built by companies with even larger light

- duty truck markets, and as such they frequentl y share major design characteri stics and emissions control technologies with their LDT counterparts. However, in contrast to the largel y gasoline

- fueled LDT fleet,Page 19 of 88

roughl y half of the heavy

- duty pickup and van fleet in the U.S. is diesel

- fueled

. This is an important consideration in s etting emissions standards, as diesel engine emissions control strategies differ from those of gasoline engines. As proposed, the key

elements of the Tier 3 program for HDVs parallel those being adopted for passenger cars and LDTs, with adjustments in stan dard levels, emission test requirement s, and implementation schedules appropriate to this sector. These key

elements include combined NMOG+NO X declining fleet average standard s , a phase

- in of PM standards, adoption of a new emissions test fuel for gasolin e - fueled vehicles, extension of the regulatory useful life to 150,000 miles or 15 years (whichever occurs first), and a first

- ever requirement for HDVs to meet standards over an SFTP drive cycle that address es real

- world driving modes not well

- represented by

the FTP cycle s . We are adopting the Class 2b and Class 3 fleet average NMOG+NO X standards shown in Table I

- 4 , as proposed . The standards become more stringent in successive model ye ars from 2018 to 2022, with voluntary standards made available in 2016 and 2017, all of which are set at levels that match those of California’s LEV III program for these classes of vehicles. Each covered HDV sold by a manufacturer in each model year contribute s to this fleet average based on the mg/mi NMOG+NO X standard leve l of the “bin” declared for it by the manufacturer , who chooses from a set of seven discrete Tier 3 bins specified in the regulations

. These bin standards then become the compliance standards for the vehicle over its useful life, with some adjustment pro vided for in

- use testing in the earl y m odel ye ars of the program. As proposed, m anufacturers can also earn credits for fleet average NMOG+NO X levels below the standard in an y model year. Tier 3 credits that were previously

banked, obtained from other manu facturers, or transferred across the Class 2b/Class 3 categories c an be used to help demonstrate compliance. Unused credits expire after 5 model years. Manufacturers w ill also be allowed to carry forward deficits in their credit balance for up to 3 model ye ars. **Table I**  **- 4**  **Tier 3 HDV Fleet Average**  **FT P**  **NMOG+NO X**  **Standards (mg/mi)**

Voluntary Required Program Model Year 2016 2017 2018 2019 2020 2021 2022 and later Class 2b 333 310 278 253 228 203 178 Class 3 54 8 508 451 400 349 298 247Page 20 of 88 We are adopting the proposed FTP PM standards of 8 mg/mi and 10 mg/mi for Class 2b and Class 3 HDVs, respectivel y, phasing in as an increasing percentage of a manufacturer’s sales per year. We are adopting the same phase

- in schedule as for the light

- dut y s ector during model ye ars 2018

- 2019

- 2020

- 2021: 20

- 40

- 70

- 100 percent, respectively , and a more flexible but equivalent alternative PM phase

- in is also being adopted . Tier 3 HDVs w ill also be subject to CO and formaldehyde exh aust emissions standards that are more stringent than the existing standards

. Finally , we are setting first

- ever nationwide SFTP standards for HDVs to ensure a robust overall control program that precludes high off

- FTP cycle emissions by having vehicle des igners consider them in their choice of compliance strategies. As for light

- dut y vehicles, we are requiring that SFTP compliance be based on a weighted composite of measured emissions from testing over the FTP cycle, the SC03 cycle, and an aggressive driv ing cycle, with the latter tailored to various HDV sub

- categories: the US06 cycle for most HDVs, the highway portion of the US06 cycle for low power

- to
- weight Class 2b HDVs, and the LA

- 92 (or “Unified”) cycle for Class 3 HDVs. The SFTP standards are the s ame as those adopted for California LEV III vehicles, and appl y to NMOG+NO X , PM, and CO emissions. The HDV program outlined above and described in detail in Section IV.B is substantially

what we proposed. Commenters generall y supported the scope, stringen cy , and implementation phase

- in of this program. However, some industry commenters requested changes to some specific provisions of the proposal, and the program we are adopting reflects improvements we have made in response. These are: (1) a limited al lowance for engine certification of Class 3 complete diesel vehicles to avoid a potential need for dual chassis

- and engine

- based certification and to better harmonize with LEV III, (2) relaxed interim in

- use testing standards to facilitate a smooth transi tion to the Tier 3 standards and to better harmonize with LEV III, (3) adoption of combined NMOG+NOx standards for the two highest (interim) bins, with a restriction placed on NOx levels in certification testing, to enhance the utility

of these bins and to better harmonize with LEV III, and (4) a provision in the percent

- of

- sales phase

- in alternative to allow manufacturers to exclude vehicle models that begin their 2019 model year production early in 2018, in order to provide four years of lead time. Comme nters also requested relaxed standards for testing at high altitudes and changes to the credits program structure for generation of earl y credits and use of LEV III

- based “vehicle emission credits”, but we did not adopt these for reasons explained in Secti on IV.B. Overall, we expect the Tier 3 program we are adopting for HDVs to result in substantial reductions in harmful emissions from this large fleet of work trucks and vans. The f

ull y - phased in Tier 3 standards levels for NMOG+NO X and PM are on the orde r of 60 percent lower than the current standards that took full effect in the 2009 model year.Page 21 of 88 c. Evaporative Emission Standards Gasoline vapor emissions from vehicle fuel sy stems occur when a vehicle is in operation, when it is parked, and when it is being r efueled. These evaporative emissions, which occur on a daily basis from gasoline

- powered vehicles, are primarily functions of temperature, fuel vapor pressure, and activity . EPA first instituted evaporative emission standards in the early 1970s to addres s emissions when vehicles are parked after being driven. These are commonly referred to as hot soak plus diurnal emissions. Over the subsequent years the test procedures have been modified and improved and the standards have become more numerically strin gent. We have addressed emissions which arose from new fuel s ys tem designs by putting in place new requirements such as running loss emission standards and test procedure provisions to address permeation emissions. Subsequently standards were put in plac e to control refueling emissions from all classes of gasoline

powered motor vehicles up to 10,000 lbs GVWR. Evaporative and refueling emission control sy stems have been in place for most of these vehicles for many ye ars . These controls have led to significant reductions , but evap orative and refueling emissions still constitute 30

- 40 percent of the summer on

- highway mobile source h ydrocarbon inventory

. These fuel vapor emissions are ozone and PM precursors, and also contain air toxics such as benzene. To control evaporative emiss ions, EPA is establishing more stringent standards that will require covered vehicles to have essentiall y zero fuel vapor emissions in use. These include more stringent evaporative emissions standards, new test procedures, and a new fuel/evaporative sy stem leak emission standard. The program also includes refueling emission standards for all complete heavy

- dut y gasoline vehicles (HDGVs) over 10,000 lbs GVWR. EPA is including phase

- in flexibilities as well as credit and allowance programs. The standards, harmonized with California’s “zero evap” standards, are designed to allow for a use of common technology

in vehicle models sold throughout the U.S. The level of the standard remains above zero to account for nonfuel background emissions from the vehicle h ardware. Requirements to meet the Tier 3 evaporative emission regulations phase in over a six model year period. We are finalizing three options for the 2017 model ye ar, but after that the sales percentage requirements are 60 percent for MYs 2018 and 2019 , 80 percent for model years 2020 and 2021, and 100 percent for model ye ars 2022 and later. In Table I

- 5 we present the Tier 3 evaporative hot soak plus diurnal emission standards by vehicle class. The standards are approximately a 50 percent reduction from the existing standards. To enhance flexibility and reduce costs, EPA is finalizing provisions that allow manufacturers to generate allowances through earl y certifications (basicall y before the 2017 model year) and to demonstrate compliance using averaging concepts. Manufacturers may comply on average within each of the four vehicle categories, but not across these categories. EPA is not making an y changes to the existing light

- duty running loss or refuelingPage 22 of 88

em ission standards, with the exception of the certification test fuel requirement discussed in Section I. B.2. below.

**Table I**  **- 5**  **Tier 3 Evaporative Emission Standards (g/test)**  Vehicle Class Highest Hot Soak + Diurnal Level (over both 2

- day

and 3

- day

diurnal tests) LDV, LDT1 0.300 LDT2 0.400 LDT3, LDT4, MDPV 0.500 HDGVs 0.600 Flexible Fuel Vehicles (FFVs) must meet the same evaporative emission standards as non

- FFVs using Tier 3 emissions certification test fue l. However, FFVs must meet the refueling emission standards using 10 psi RVP fuel to account for emissions resulting from commingling with non

- E85 blends that may be in the vehicle’s fuel tank. EPA is establishing the canister bleed emission test procedur e and emission standard to help ensure fuel vapor emissions are eliminated. Under this provision , manufacturers are required to measure diurnal emissions over the 2

- day diurnal test procedure from just the fuel tank and the evaporative emission canister a nd comply with a 0.020 gram per test (g/test) standard for all LDVs, LDTs, and MDPVs, without averaging. The corresponding canister bleed test standard for HDGVs is 0.030 g/test. The Tier 3 evaporative emission standards will be phased in over a period o f six model years between MY 2017 and MY 2022, with the leak test phasing in beginning in 2018. Data from in

- use evaporative emissions testing indicates that vapor leaks from vehicle fuel/evaporative sy stems are found in the fleet and that even very small leaks have the potential to make significant contributions to the mobile source VOC inventory . To help address this issue, we are also add ing a new standard and test procedure to control vapor leaks from vehicle fuel and vapor control s ystems. The standard will prohibit leaks with a cumulative equivalent diameter of 0.02 inches or greater. We are adding this simple and inexpensive test and emission standard to help ensure vehicles maintain zero fuel vapor emissions over their full useful life. New LDV, LDT, MDPV, and HDGV equal to or less than 14.000 lbs GVWR meeting the Tier 3 evaporative emission regulations are also required to meet the leak standard beginning in the 2018 model year. Manufacturers must comply with the leak standard phase

- in on the same percentage of sales schedule as that for the Tier 3 evaporative emission standard s . Manufacturers will comply with the leak emission standard during certification and in use. T he leak emission standard does not appl y t o HDGVs above 14,000 lbs GVWR.Page 23 of 88 EP A is also establishing new refueling emission control requirements for all complete HDGVs equal to or less than 14,000 lbs GVWR (i.e., Class 2b/3 HDGVs), starting in the 2018 model year , and for all larger complete HDGVs by the 2022 model year . The existi ng refueling emission control requirements apply to complete Class 2b HDGVs, and EPA is extend ing those requirements to other complete HDGVs, since the fuel and evaporative control sy stems on these vehicles are very similar to those on their lighter

- weight Class 2b counterparts.

d. Onboard Diagnostic S ys tems (OBD) EPA and CARB both have OBD regulations applicable to the vehicle classes covered b y the T ier 3 emission standards. In the past the requirements have been very similar, so most manufacturers have met CARB OBD requirements and, as permitted in our regulations, EPA has generally accepted compliance with CARB’s OBD requirements as satisfying EPA’s OBD requirements. Over the past several ye ars CARB has upgraded its requirements to help improve the eff ectiveness of OBD in ensuring good in

- use exhaust and evaporative s ys tem emissions performance. We have reviewed these provisions and agree with CARB that these revisions will help to improve in

- use emissions performance, while at the same time harmonizin g with the CARB program. Toward that end, we are adopt ing and incorporat ing by

reference the current CARB OBD regulations , effective for the 2017 MY , with a few minor differences including phase

- in flexibility provisions and specific additions to enhance the implementation of the leak standard. EPA is retain ing the provision that certifying with CARB’s program would permit manufacturers to seek a separate EPA certificate on that basis.
e. Emissions Test Fuel As described above, after reassessing market tre nds and considering comments, EPA is finalizing E10 as the ethanol blend level in emissions test gasoline for Tier 3 light

- duty and heav y - dut y gasoline vehicles. We will continue to monitor the in

- use gasoline supply and based on such review may initiate rulemaking action to revise the specifications for emissions test fuel to include a higher ethanol blend level. EPA is also making additional changes that are consistent with CARB’s LEV III emissions test fuel specifications, including new specifications for octane, distillation temperatures, aromatics, olefins, sulfur and benzene. (See Section IV.F below for a detailed discussion of all the revised emission test fuel parameters.) As discussed in Sections IV.A.7.d (tailpipe emission testing) and IV.C.5.b (evaporative emission testing), we are requiring certification of all Tier 3 light

- dut y and chassis

- certified heavy

- dut y gasoline vehicles on federal E10 test fuel. ThePage 24 of 88

new test fuel specifications will apply to new vehicle certification, assembly line, and in

- use testing. With a change in the ethanol content of the test fuel, EPA also needed to consider whether a change is warranted in the volatility of the test fuel, t ypically expressed as pounds per square inch (psi) Reid Vapor Pressure (RVP). As dis cussed in detail in Section IV.F below, after considering several technical and policy implications as well as stakeholder comments, EPA has concluded that the most appropriate approach is to maintain an RVP of 9 psi for the E10 certification fuel at this time. In addition to finalizing a new E1 0 emissions test fuel, we are also finalizing detailed specifications for the E85 emissions test fuel used for flexible fuel vehicle (FFV) certification, as discussed in Section IV. F

. 3

. 15 This will resolve uncertai nty and confusion in the certification of FFVs designed to operate on ethanol levels up to 83 percent. Furthermore, we allow vehicle manufacturers to request approval for an alternative certification fuel such as a high

- octane 30 percent ethanol b y volume blend (E30) for vehicles that may be optimize d for such fuel. f. Fuel Standards Under the Tier 3 fuel program, gasoline must contain no more than 10 ppm sulfur on an annual average basis beginn ing January 1, 2017. Similar to the Tier 2 gasoline program, the Tier 3 program will apply to gasoline in the U.S. and the U.S. territories of Puerto Rico and the Virgin Islands, excluding California. The program will result in gasoline that contains, on average, two

- thirds less sulfur than it does today . In addi tion, following discussions with numerous refiners and other segments of the fuel market (e.g., pipelines, terminals, marketers, ethanol industry representatives, transmix processors, additive manufacturers , etc. ), the Tier 3 fuel program contains consider able flexibility to ease both initial and long

- term implementation of the program. The program that we are finalizing today includes an averaging, banking, and trading (ABT) program that allow s refiners and importers to spread out their investments over n early a 6 year period through the use of an earl y credit program and then rel y on ongoing nationwide averaging to meet the 10 ppm sulfur standard. In addition there is a three

- ye ar delay for small refiners and “small volume refineries”. As a result of th e earl y credit program, we anticipate considerable reductions in gasoline sulfur levels prior to 2017, with a complete transition to the 10 ppm average occurring b y J anuary 1, 2020. For more information on the gasoline sulfur program flexibilities, refer to Section V.E.

15 Flexible fuel vehicles are currently required to meet emissions certification requirements using both E0 and E85 test fuels. However, there we re no detailed regulatory specifications regarding the composition of E85 test fuels before those finalized today

.Page 25 of 88 Under today ’s Tier 3 gasoline sulfur program, we are maintaining the current 80 ppm refinery

gate and 95 ppm downstream per

- gallon caps. We also evaluated and sought comment on the potential of lowering the per

- gallon caps

. While there are advantages and disadvantages with each of the sulfur cap options that we proposed, we believe that retaining the current Tier 2 sulfur caps is prudent at this time, as explained in more detail in Section V.C. Further, the stringency of the 10 ppm annual average standard will result in reduced gasoline sulfur levels nationwide. Today ’s program requires that manufacturers of gasoline additives that are used downstream of the refinery at less than 1 volume percent must limit the sulfur contribution to the finished gasoline from the use of their additive to less than 3 ppm when the additive is used at the maximum recommended treatment rate (see Section V.C.2)

. This requirement will preclude the unnecessary use of high sulfur content additives in gasoline

. The vehicle emissions standards finalized today are fuel

- neutral (i.e. , they are applicable regardless of the ty pe of fuel that the vehicle is designed to use). There currently

are no sulfur standards for the fuel used in compressed natural gas (CNG) an d liquid propane gas (LPG) vehicles. We requested comment on whether it is necessary

for EPA to establish sulfur standards for CNG and LPG to enable them meeting more stringent vehicle emissions standards. EPA is deferring finalizing in

- use sulfur requir ements for CNG/LPG in this final rule to provide additional time to work with stakeholders to collect data on current CNG/LPG sulfur content, to determine whether additional control of in

- use CNG/LPG sulfur content is needed, and to evaluate the feasibility and costs associated with potential additional sulfur controls (see Section V.J). Given that the information provided suggests that CNG/LPG sulfur levels tend to be low already, the vehicle emissions standards finalized today will apply to CNG/LPG vehic les in addition to vehicles fueled on gasoline, diesel fuel, or an y other fuel. The sulfur content of highway diesel fuel is already required to meet a 15 ppm sulfur cap , which is sufficient for diesel fuel v ehicles to meet the Tier 3 emissions standards. As the number of flex

- fuel vehicles (FFVs) in the in

- use fleet increases, it is becoming increasingl y i mportant that all fuels used in FFVs, not just gasoline, meet fuel quality

standards. A lack of clarity regarding the standards that appl y t o fuels used in FFVs could also act to impede the further expansion of ethanol blended fuels with concentrations greater than 15 volume percent, which is important to satisfying the requirements of the RFS2 program. Hen ce, we sought comment on appropriate regulatory

mechanism s to implement in

- use quality standards for E51

- 83 and E16

- 50 in the Tier 3 proposal. Additional work is needed on some issues that could not be accommodated within the timeline for this Tier 3 final rule. Therefore, we are choosing not to finalize these provisions at this time. We intend to finalize in

- use fuel quality standards for E51

- 83 and perhaps E16

- 50 as well in a follow

- up final rule.Page 26 of 88 g. Regulatory

Streamlining and Technical Amendments T his a ction also includes a number of items to help streamline the in

- use fuels regulations at 40 CFR part s 79 and 80. The majority of these items involve clarifying vague or inconsistent language, removal or updating of outdated provisions, and decreas ing in frequency and/or volume of reporting burden where data are no longer needed or are redundant with other EPA fuels programs. In general, we believe that these changes will reduce the burden on industry and allow the standards and resulting environmental benefits to be achieved as earl y as possible with no expected loss in environmental control. In some cases, these regulatory

streamlining items are non

- substantive amendments that correct minor errors or inconsistencies in the regulations. The regulatory

streamlining items that we are finalizing for the in

- use fuels regulations are changes that we believe are straightforward and should be made quickly

. Th is action also includes a variet y of technical amendments to certification

related requi rements for engine and vehicle emission standards ; adjusting the fuel econom y label provisions to correspond to the new Tier 3 standards , remov ing obsolete regulatory

text , and making several minor corrections and clarifications. Please refer to Section VIfor a complete discussion of technical amendments and regulatory streamlining provisions and issues. **C. What W**  **ill the Impacts of the Standards Be?**  The final Tier 3 vehicle and fuel standards together will reduce dramatically emissions of NO X , VOC, PM 2.5 , and air toxics. The gasoline sulfur standards, which will take effect in 2017, will provide large immediate reductions in emissions from existing gasoline vehicles and engines. NO X emissions are projected to be reduced b y about 260,000 tons, or about 10 percent of emissions from on

- highway vehicles, in 2018, and these emission reductions will increase over time as newer vehicles become a larger percentage of the fleet. In 2030, when 70 percent of the miles travelled are projected to be from vehicles that meet the full y phased

- in Tier 3 standards, we expect the NO X and VOC emissions to be reduced by about 330,000 tons and 170,000 tons, respectively , or 25 percent and 16 percent of emissions from on - highway

vehicles compared to their 2030 levels without the Tier 3 program. Emissions of CO are projected to decrease b y almost 3.5 million tons, or 24 percent of emissions from on

- highway vehicles. Emissions of many air toxics will also be reduced, including benzene, 1,3

- butadiene, acetaldehyde, formal deh yde, acrolein and ethanol, with reductions projected to rang e from 10 to nearly 30 percent of national emissions from on

- highway vehicles. We expect these reductions to continue beyond 2030 as more of the fleet continues to turn over to Tier 3 vehicl es; for example, by

2050, when nearl y all of the fleet will have turned over to vehiclesPage 27 of 88

meeting the fully

phased

- in Tier 3 standards, we estimate the Tier 3 program will reduce on

- highway

emissions of NO X and VOC nearly 31 percent from the level of emissi ons projected without Tier 3 controls. 16 These reductions in emissions of NO X , VOC, PM 2.5 and air toxics from the Tier 3 standards are projected to lead to significant decreases in ambient concentrations of ozone, PM 2.5 and air toxics (including notable nationwide reductions in benzene concentrations) b y 2030, and will immediately reduce ozone in 2017 when the sulfur controls take effect. Additional information on the emission and air quality

impacts of the final Tier 3 program is presented in Sections III.B and C. Exposure to ambient concentrations of ozone, PM 2.5 , and air toxics is linked to adverse human health impacts such as premature deaths as well as other important public health and environmental effects (see Section II.B). The final Tier 3 standards are expected to reduce these adverse impacts and yi eld significant benefits, including those we can monetize and those we are unable to quantify . We estimate that by

2030, the emission reductions of the Tier 3 standards will annually prevent b etween 660 and 1,500 PM

- related premature deaths, between 110 and 500 ozone - related premature deaths, 81,000 work day s lost, 210,000 school absence day s, and approximately 1.1 million minor restricted

- activit y days . The estimated annual monetized health b enefits of the Tier 3 standards in 2030 (201 1 $) is between $ 7.4 and $ 19 billion, assuming a 3

- percent discount rate (or between $ 6.7 billion and $ 18 billion assuming a 7

- percent discount rate). We project the final fuel standards to cost on average 0.65 ce nt (i.e., less than a penn y) per gallon of gasoline, and the final vehicle standards to have an average cost that increases in proportion to the increase in stringency during the phase

- in period, from $ 28 per vehicle in 2017 to $ 72 per vehicle in 2025, whe n the standards are fully phased in. We estimate the annual cost of the overall program in 2030 will be approximately $ 1.5 billion , and the 2030 benefits will be between 4.5 and 13 times the costs of the program. The estimated benefits in Table I

- 6 include all of the human health impacts we are able to quantify

and monetize at this time. However, the full complement of human health and welfare effects associated with PM, ozone and air toxics remain unquantified b ecause of current limitations in methods and/or available data. As a result, the health benefits quantified in this section are likel y underestimates of the total benefits attributable to the final standards. See Sections VII and VIII for detailed descriptions of the costs and benefits of this action

.

16 To estimate the benefits of the final Tier 3 rule, we performed air quality modeling for the year 2030.Page 28 of 88

**Table I**  **- 6**  **Summary of Estimated**  **Annual Benef i**  **ts and Costs Associated with the**  **Final Tier 3 Program (Billions, 201**  **1 $)**  **a Description**  **2030** Vehicle Program Costs F uels Program Costs Total Estimated Costs b $0.76 $0.70 $1.5 Total Estimated Health Benefits c,d,e,f 3 percent discount rate 7 percent discount rate $7.4

- $19 $6.7

- $18 Annual Net Benefits (Total Benefits

– Total Costs) 3 percent discount rate 7 percent discount rate $5.9

- $18 $5.2

- $17 Notes: a All estimates represent annual benefits and costs anticipated for the year 2030. Totals are rounded to two significant digits and may not sum due to rounding. b The calculation of annual c osts does not require amortization of costs over time. Therefore, the estimates of annual cost do not include a discount rate or rate of return assumption (see Section VII of the preamble for more information on vehicle and fuel costs). c Total includes oz one and PM 2.5 estimated benefits. Range was developed by adding the estimate from the Bell et al., 2004 ozone premature mortality function to PM 2.5 - related premature mortality derived from the American Cancer Society cohort study ( Krewski et al., 200 9 ) fo r the low estimate and ozone premature mortality derived from the Levy et al., 2005 study to PM 2.5 - related premature mo rtality derived from the Six

- Cities ( Lepeule et al., 20 12 ) study for the high estimate. d Annual benefits analysis results reflect the us e of a 3 percent and 7 percent discount rate in the valuation of premature mortality and nonfatal myocardial infarctions, consistent with EPA and OMB guidelines for preparing economic analyses. e Valuation of premature mortality based on long

- term PM exp osure assumes discounting over the SAB recommended 20

- year segmented lag structure described in the Regulatory Impact Analysis for the 20 12 PM National Ambient Air Quality Standards ( December, 2012 ). f Not all possible benefits are quantified and monetize d in this analysis; the total monetized benefits presented here may therefore be underestimated. Potential benefit categories that have not been quantified and monetized, due to current limitations in methods and/or data availability, are listed in Table VIII

- 2. For example, we have not quantified a number of known or suspected health and welfare effects linked with reductions in ozone and PM (e.g., reductions in heart rate variability, reduced material damage to structures and cultural monuments, and redu ced eutrophication in coastal areas). We are also unable to quantify health and welfare benefits associated with reductions in air toxics

. 

## II. **Why Is EP**

**A Ta**  **ki ng this**  **Action ?**  The Clean Air Act authorizes EPA to establish emissions standards for motor vehic les to address air pollution that may reasonably

be anticipated to endanger public health or welfare. EPA also has authority to establish fuel controls to address such air pollution. These statutory requirements are described in Section II.A.Page 29 of 88 Emissions fr om motor vehicles and their fuels contribute to ambient levels of ozone, PM, NO 2 , sulfur dioxide (SO 2 ) and CO, which are all pollutants for which EPA has established health

- based NAAQS. These pollutants are linked with respiratory

and/or cardiovascular pro blems and other adverse health impacts leading to increased medication use, hospital admissions, emergency department visits, and premature mortality . Over 149 million people currently live in areas designated nonattainment for one or more of the current NAAQS. 17 Motor vehicles also emit air toxics, and the most recent available data indicate that the majorit y of Americans continue to be exposed to ambient concentrations of air toxics at levels which have the potential to cause adverse health effects, in cluding cancer, immune s ys tem damage, and neurological, reproductive, developmental, respiratory , and other health problems. 18 A more detailed discussion of the health and environmental effects of these pollutants is included in Section II.B. Cars and light trucks also continue to be a significant contributor to air pollution directly

near roads, with gasoline vehicles accounting for more than 50 percent of near

- road concentrations of some criteria and toxic pollutants. 19 More than 50 million people live, work, or go to school in close proximity to high

- traffic roadway s, and the average American spends more than one hour traveling each day , with nearl y 90 percent of daily trips occurring b y personal vehicle. 20 , 21 , 22 , 23 , 24 Exposure to traffic

- related pollutants has been linked with adverse health impacts

17 Data come from Summary Nonattainment Area Population Exposure Report, current as of De cem ber 5 , 201 3 at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA

- HQ

- OAR

- 2011

- 0135. 18 U.S. EPA. (2011) Summary of Results for the 2005 National

- Scale Assessment. www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf. 19 For exam

ple, see Fujita, E.M; Campbell, D.E.; Zielinska, B.; Arnott, W.P.; Chow , J.C. (2011) Concentrations of Air Toxics in Motor Vehicle

- Dominated Environments. Health Effects Institute Research Report 156. Available at http://www.healtheffects.org 20 Rowangoul d, G.M. (2013) A census of the US near

- roadway population: public health and environmental justice considerations. Transportation Research Part D 25: 59

- 67. 21 U.S. Census Bureau ( 2011 ) . Current Housing Reports, Series H150/09, American Housing Survey fo r the United States: 2009. U.S. Government Printing Office, Washington, DC. Available at http://www.census.gov/hhes/www/housing/ahs/ahs09/ahs09.html 22 Drago, R. ( 2011 ) . Secondary activities in the 2006 American Time Use Survey. U.S. Bureau of Labor Stat istics Working Paper 446. Available at http://www.bls.gov 23 U.S. Department of Transportation, Bureau of Transportation Statistics. (2003) National Household Travel Survey 2001 Highlights Report. Government Pr inting Office, Washington, DC. Available at http://www.bts.gov/publications/highlights_of_the_2001_national_household_travel_survey/ 24 Santos, A.; McGuckin, N, Yukiko Nakamoto, H.; Gray, D.; Liss, S. (2011) Summary of Travel Trends: 2009 National Household Travel Survey. Federal Highway Administration report no FHWA

- PL

- 11

- 022. Available at http://nhts.ornl.gov/publications.shtml

.Page 30 of 88

such as respiratory

problems (particularly

in asthmatic children) and cardiovascular problems. In the absence of additional controls such as Tier 3 standards, many areas will continue to have ambient ozone and PM 2.5 concentrations exceeding the NAAQS in the future. States and local areas are required to adopt control measures to attain the NAAQS and, once attained, to demonstrate that control measures are in place sufficient to maintain the NAAQS for ten ye ars (and eight ye ars later, a similar demonstration is required for another ten

- ye ar period). The Tier 3 standards w ill be a critical part of many areas’ strategies to attain and maintain the NAAQS

. Maintaining the NAAQS has been challengi ng for some areas in the past, particularl y those where high population growth rates lead to significant annual increases in vehicle trips and vehicle miles traveled. Our air quality modeling for this final rule , which is described in more detail in Section III.C, projects that in 201 8 a significant number of counties outside CA will be within 10 percent of the 2008 ozone NAAQS, in the absence of additional controls. These counties in particular w ill benefit from the Tier 3 standards as they wor k to ensure long

- term maintenance of the NAAQS. Section III provides more detail on how we expect this action w ill reduce motor vehicle emissions and ambient levels of pollution. We project that the Tier 3 program w ill meaningfully reduce ozone concentrations as earl y as 2017 (the first ye ar of the program), and even more significantly in 2030. The estimated reductions are of significant enough magnitude to bring ozone levels in some counties from above the standard to below the standard, even without any additional controls. We also project that the Tier 3 standards w ill reduce ambient PM 2.5 concentrations. Without this action to reduce nationwide motor vehicle emissions, areas would have to adopt other measures to reduce emissions from other source s under their state or local authority . Few other measures exist for providing multi

- pollutant reductions of the same magnitude and cost

- effectiveness as those expec ted from the Tier 3 standards. Furthermore, most states do not have the authority to lowe r the sulfur in gasoline, which is needed to immediatel y reduce emissions from the existing fleet and also enable new vehicles to meet the Tier 3 emissions standards throughout their useful life. The projected reductions in ambient ozone and PM 2.5 that w i ll result from the Tier 3 standards w ill provide significant health benefits. We estimate that b y 2030, the standards w ill annually prevent between 660 and 1,500 PM

- rel ated premature deaths, between 110 and 500 ozone - related premature deaths, 81,000 work day s lost, 210,000 school absence day s, and approximately 1.1 million minor restricted

- activity

day s (see Section VIII for more details). This action will also reduce air toxics; for example, we project that in 2030, the Tier 3 standards will decrease amb ient benzene concentrations b y 10

- 25 percent in some urban areas.Page 31 of 88

Furthermore, the Tier 3 standards will reduce traffic

- associated pollution near major roads. EPA is finaliz ing Tier 3 vehicle and fuel standards as part of a comprehensive nationwide program for regulating all types of air pollution from motor vehicles. EPA recently finalized standards to reduce GHG emissions from light

- duty vehicles, starting with model year 2017. 25 The Tier 3 standards in this final rule , which address non

- GHGs, will be implemented on the same timeframe, thus allowing manufacturers to optimize their vehicle redesigns over both sets of standards. Furthermore, the Tier 3 vehicle and fuel standards are also closely aligned with California’s LEV III program, in such a way that manufacturers will be able to design a single vehicle for nationwide sales. This reduces the cost of compliance for auto manufacturers. This Tier 3 rulemaking responds to the President’s request in his May 2010 memorandum for EPA to review the adequac y of its existing non

- GHG standards for new motor vehicles and fuels, and to promulgate new standards, if necessary , as part of a comprehensive approach to regulating motor vehicles. 26 Based on our review, we have concluded that improved vehicle technology , combined with lower sulfur gasoline, make it feasible and cost

- effective to reduce emissions well below the current Tier 2 levels. These emission reductions are necessary to reduce air pollution that is (and projected to continue to be) at levels that e ndanger public health and welfare. **A. Basis for Action under the Clean Air Act**  1. Clean Air Act Section 202 We are setting motor vehicle emission standards under the authorit y of section 202 of the Clean Air Act. Section 202(a) provides EPA with general authori ty to prescribe vehicle standards, subject to any specific limitations elsewhere in the Act. EPA is setting standards for larger light

- dut y trucks and MDPVs under the general authority of section 202(a)(1) and under section 202(a)(3), which requires that standards applicable to emissions of hydrocarbons, NO X , CO and PM from heavy

- dut y vehicles 27 reflect the greatest degree of

25 77 FR 62623 (October 15, 2012). 26 The Presidential Memorandum is found at: http://www.whitehouse.gov/the

- press office/presidential

- memorandum

- regarding

- fuel

- efficiency

- standards. 27 LDTs that have gross vehicle weight ratings above 6000 lbs and all MDPVs are considered ‘‘heavy

- duty

vehicles’’ under the CAA. See section 202(b)(3)(C). For regulatory purposes, we generally refer to those LDTs which are above 6000 lbs GVWR an d at or below 8500 lbs GVWR as ‘‘heavy light

- duty trucks’’ made up of LDT3s and LDT4s , and we have defined MDPVs primarily as vehicles between 8500 and 10000 lbs GVWR designed primarily for the transportation of persons

. See 40 CFR 86.1803

- 01Page 32 of 88

emission reduction available for the model ye ar to which such standards apply , giving appropriate consideration to cost, energy , and safet y. In addition, section 202(k) provides EPA with authority to issue and revise regulations applicable to evaporative emissions of hydrocarbons from all gasoline

- fueled motor vehicles during: (1) operation, and (2) over 2 or more days of nonuse; under ozone - prone summertime conditions. Regulations under section 202(k) shall take effect as expeditiously

as possible and shall require the greatest degree of emission reduction achievable by means reasonably expected to be available for production during any model year to which the regulations appl y, giving appropriate consideration to fuel volatility , and to cost, energy , and safet y factors associated with the application of the appropriate technology . Further, section 206 and in particular section 206(d) o f the Clean Air Act authorizes EPA to establish methods and procedures for testing whether a motor vehicle or motor vehicle engine conforms with section 202 requirements. 2. Clean Air Act Section 211 We are adopt ing gasoline sulfur controls pursuant to our authority under section 211(c)(1) of the CAA. This section allows EPA to establish a fuel control if at least one of the following two criteria is met: (1) The emission products of the fuel cause or contribute to air pollution which may reasonabl y be anticip ated to endanger public health or welfare; or (2) the emission products of the fuel will impair to a significant degree the performance of any emissions control device or sy stem which is either in general use or which the Administrator finds has been devel oped to a point where in a reasonable time it will be in general use were the fuel control to be adopted. We are finalizing gasoline sulfur controls based on both of these criteria. Under the first criterion, we believe that gasoline with current levels of sulfur contributes to ambient levels of air pollution that endanger public health and welfare, as described in Section II.B. Under the second criterion, we believe that gasoline sulfur impairs the emissions control sy stems of vehicles, as discussed in Se ction III.A.2. **B. Overview of Public Health Impacts of Motor Vehicles and Fuels**  Motor vehicles emit pollutants that contribute to ambient concentration s of ozone, PM, NO 2, SO 2 , CO, and air toxics. Motor vehicles are significant contributors to emissions of VOC and NO X , which contribute to the formation of both ozone and PM 2.5 . Over 1 49 million people currentl y live in counties designated nonattainment for one or more of the NAAQS, and this figure does not include the people living in areas with a risk o f exceeding the NAAQS in thePage 33 of 88

future. 28 The majority

of Americans continue to be exposed to ambient concentrations of air toxics at levels which have the potential to cause adverse health effects. 29 Inaddition, populations who live, work, or attend school near major roads experience elevated exposure concentrations to a wide range of air pollutants. 30 EPA has already adopted many emission control programs that are expected to reduce ambient pollution concentration s. As a result of these programs, the number of areas that continue to violate the ozone and PM 2.5 NAAQS or have high levels of air toxics is expected to continue to decrease. However, the baseline air quality modeling completed for this rule predicts that without additional controls there will continue to be a need for reductions in ozone, PM 2.5 and air toxics concentrations in some locations in the future. Section III.C of this preamble presents the air quality

modeling results for this action

. 1. Ozone
a. Background Ground

- level ozone pollution is ty pically formed through reactions involving VOC and NO X in the lower atmosphere in the presence of sunlight. These pollutants, often referred to as ozone precursors, are emitted by many ty pes of pollution sources, such as highway and nonroad motor vehicl es and engines, power plants, chemical plants, refineries, makers of consumer and commercial products, industrial facilities, and smaller area sources. The science of ozone formation, transport, and accumulation is complex. Ground

- level ozone is produced and destroyed in a cyclical set of chemical reactions, man y of which are sensitive to temperature and sunlight. When ambient temperatures and sunlight levels remain high for several day s and the air is relativel y stagnant, ozone and its precursors can bu ild up and result in more ozone than ty pically occurs on a single high

- temperature day . Ozone and its precursors can be transported hundreds of miles downwind from precursor emissions, resulting in elevated ozone levels even in areas with low local VOC or NO X emissions.

28 Data come from Summary Nonattainment Area Population Exposure Report, current as of December 5, 2013 at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA

- HQ

- OAR

- 20 11

- 0 135. 29 U.S. EPA. (2011) Summary of Results for the 2005 National

- Scale Assessment. www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf. 30 Health Effects Institute Panel on the Health Effects of Traffic

- Related Air Pollution. (2010) Traffic

- related air pollution: a critical review of the literature on emissions, exposure , and health effects. HEI Special Report 17. Available at http://www.healtheffects.org]Page 34 of 88 b. Health Effects of Ozone This section provides a summary of the health effects associated with exposure to ambient concentrations of ozone . 31 The information in this section is based on the information and conclusions in the February 2013 Integrated Science Assessment for Ozone (Ozone I SA) prepared by EPA’s Office of Research and Development (ORD)

. 32 The Ozone I SA concludes that human exposures to ambient concentrations of ozone are associated with a number of adverse health effects and chara cterizes the weight of evidence for these health effects. 33 The discussion below highlights the Ozone I SA’s conclusions pertaining to health effects associated with both short

- term and long

- term periods of exposure to ozone. For short

- term exposure to ozo ne, the Ozone I SA concludes that respiratory effects, including lung function decrements, pulmonary inflammation, exacerbation of asthma, respiratory

- related hospital admissions, and mortality , are causally associated with ozone exposure. It also conclude s that cardiovascular effects, including decreased cardiac function and increased vascular disease, and total mortality are likely to be causall y associated with short

- term exposure to ozone and that evidence is suggestive of a causal relationship between central nervous sy stem effects and short

- term exposure to ozone. For long

- term exposure to ozone, the Ozone I SA concludes that respiratory effects, including new onset asthma, pulmonary inflammation and injury , are likely to be a causally

related with oz one exposure. The Ozone I SA characterizes the evidence as suggestive of a causal relationship for associations between long

- term ozone exposure and cardiovascular effects, reproductive and developmental effects, central nervous s ys tem effects and total mo rtalit y. The evidence is inadequate to infer a causal relationship between chronic ozone exposure and increased risk of lung cancer. Finally , interindividual variation in human responses to ozone exposure can result in some groups being at increased risk for detrimental effects in response to

31 Human exposure to ozone varies over time due to changes in ambient ozone concentration and because people move between locations which have notable different ozon e concentrations. Also, the amount of ozone delivered to the lung is not only influenced by the ambient concentrations but also by the individuals breathing route and rate. 32 U.S. EPA. Integrated Science Assessment of Ozone and Related Photochemical Oxid ants (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 10/076F, 2013. The ISA is available at http://cfpub.epa.gov/ncea/isa/recordisplay.cfm?deid=247492#Dow nload 33 The ISA evaluates evidence and draw s conclusions on the causa l relationship between relevant pollutant exposures and health effects, assigning one of five “weight of evidence” determinations: causal relationship, likely to be a causal relationship, suggestive of a causal relationship, inadequate to infer a causal r elationship, and not likely to be a causal relationship. For more information on these levels of evidence, please refer to Table II in the Preamble of the ISA.Page 35 of 88

exposure. The Ozone I SA identified several groups that are at increased risk for ozone - related health effects. These groups are people with asthma, children and older adults, individuals with reduced intake of certai n nutrients (i.e., Vitamins C and E), outdoor workers, and individuals having certain genetic variants related to oxidative metabolism or inflammation. Ozone exposure during childhood can have lasting effects through adulthood. Such effects include altere d function of the respiratory

and immune sy stems. Children absorb higher doses (normalized to lung surface area) of ambient ozone, compared to adults, due to their increased time spent outdoors, higher ventilation rates relative to body size, and a tendenc y to breathe a greater fraction of air through the mouth. Children also have a higher asthma prevalence compared to adults. Additional children’s vulnerability and susceptibility

factors are listed in Section XII.G.
c. Current and Projected Concentration s of Ozone Concentrations that exceed the level of the ozone NAAQS occur in many parts of the country , including major population centers such as Atlanta, Baltimore, Chicago, Dallas, Houston, New York, Philadelphia, and Washington, D.C

. In addition, our modeling without the Tier 3 controls projects that in the future we will continue to have man y countie s that will have ambient ozone concentrations above the level of the NAAQS (see Section III.C.1). States will need to meet the standard in the 2015

- 2032 time frame for the 2008 ozone NAAQS . The emission reductions and significant ambient ozone improvements from this rule, which will take effect starting in 2017, w ill be helpful to states as they work to attain and maintain the ozone NAAQS. The primary

and secondary

NAAQS for ozone are 8

- hour standards with a level of 0.075 ppm. The most recent revision to the ozone standards was in 2008; the previous 8

- hour ozone standards, set in 1997, had a level of 0.08 ppm. In 2004, the U.S. EPA designated nonattainm ent areas for the 1997 8

- hour ozone NAAQS. 34 , 35 As of December 5 , 201 3 , there were 39 ozone nonattainment areas for the 1997 ozone NAAQS composed of 2 16 full or partial counties w ith a total population of over 11 2 million. Nonattainment designations for th e 2008 ozone standard were finalized on April 30, 2012 and May 31, 2012. 36 As of December 5, 2013, there were 46 ozone nonattainment areas for the 2008 ozone NAAQS, composed of 227 full or partial counties, with a population of over 123 million. As

34 69 FR 23858 (April 30, 2004). 35 A nonattainment area is defined in the Clean Air Act (CAA) as an area that is violating an ambient standard or is contributing to a nearby area that is violating the standard. 36 77FR 30088 (May 21, 2012) and 77 FR 34221 (June 11, 2012)

.Page 36 of 88

of Dec ember 5 , 201 3 , over 13 5 million people are living in ozone nonattainment areas. 37 States with ozone nonattainment areas are required to take action to bring those areas into attainment. The attainment date assigned to an ozone nonattainment area is based on the area’s classification. Most ozone nonattainment areas we re required to attain the 1997 8

- hour ozone NAAQS in the 2007 to 2013 time frame and then to maintain it thereafter. 38 The attainment dates for areas designated nonattainment for the 2008 8

- h our ozone NAAQS are in the 2015 to 2032 timeframe, depending on the severity of the problem in each area. In addition, EPA is currentl y working on a review of the ozone NAAQS. If EPA revises the ozone standards pursuant to that review, the attainment dat es associated with areas designated nonattainment for that NAAQS would be 5 or more ye ars after the final rule is promulgated, depending on the severit y of the problem in each area. EPA has already adopted many emission control programs that are expecte d to reduce ambient ozone levels. As a result of these and other federal, state and local programs, 8

- hour ozone levels are expected to improve in the future. However, even with the implementation of all current state and federal regulations, there are p rojected to be counties violating the ozone NAAQS well into the future. Thus additional federal control programs, such as Tier 3, can assist areas with attainment dates in 201 8 and beyond in attaining the NAAQS as expeditiously as practicable and may

reli eve areas with already stringent local regulations from some of the burden associated with adopting additional local controls. 2. Particulate Matter
a. Background Particulate matter is a highly complex mixture of solid particles and liquid droplets distributed among numerous atmospheric gases which interact with solid and liquid phases. Particles range in size from those smaller than 1 nanometer (10 - 9 meter) to over 100 micrometer (μm, or 10 - 6 meter) in diameter (for reference, a ty pical strand of human hair is 7 0 μ m in diameter and a grain of salt is about 100 μm). Atmospheric particles can be grouped into several classes according to their

37 The 13 5 million total is calculated by summing, without double counting, the 1997 and 2008 ozone nonattainment populations contained in the Summary Nonattainment Area Population Exposure report (http://www.epa.gov/oar/oaqps/greenbk/popexp.html). If there is a population associated with both the 1997 and 2008 nonattainment areas, and they are not the same, then the larger of the two populations is included in the sum. 38 The Los Angeles South Coast Air Basin 8

- hour ozone nonattainment area and the San Joaquin Valley Air Basin 8

- hour ozone nonattainment area are designated as E xtreme and will have to attain before June 15, 2024. The Sacramento, Coachella Valley , Western Mojave and Houston 8

- hour ozone nonattainment areas are designated as S evere and will have to attain by June 15, 2019.Page 37 of 88

aerodynamic and ph ys ical sizes, including ultrafine particles (<0.1 μm), accumulation mode or ‘fine’ particles (<1 to 3 μm), and coarse particles (>1 to 3 μm). 39 For regulatory

purposes, fine particles are measured as PM 2.5 and inhalable or thoracic coarse particles are measured as PM 10

- 2.5 , corresponding to their size (diameter) range in micrometers. The EPA currently has stand ards that measure PM 2.5 and PM 10 . 40 Particles span man y sizes and shapes and may consist of hundreds of different chemicals. Particles are emitted directl y from sources and are also formed through atmospheric chemical reactions; the former are often refer red to as “primary” particles, and the latter as “secondary” particles. Particle concentration and composition varies by time of year and location , and in addition to differences in source emissions, is affected b y s everal weather

- related factors, such as temperature, clouds, humidity , and wind. A further layer of complexity comes from particles’ ability to shift between solid/liquid and gaseous phases, which is influenced b y concentration and meteorology, especiall y temperature. Fine particles are produc ed primaril y b y combustion processes and b y transformations of gaseous emissions (e.g., sulfur oxides (SO X ), oxides of nitrogen, and volatile organic compounds (VOC)) in the atmosphere. The chemical and phy sical properties of PM 2.5 may vary greatl y with ti me, region, meteorology, and source category . Thus, PM 2.5 may include a complex mixture of different components including sulfates, nitrates, organic compounds, elemental carbon and metal compounds. These particles can remain in the atmosphere for day s to weeks and travel hundreds to thousands of kilometers. b. Health Effects of PM Scientific studies show ambient PM is associated with a broad range of health effects. These health effects are discussed in detail in the December 2009 Integrated Science Assessme nt for Particulate Matter (PM I SA)

. 41 The PM ISA summarizes health effects evidence associated with both short

- and long

- term exposures to PM 2.5 , PM 10

- 2.5 , and ultrafine particles. The PM I SA concludes that human exposures to ambient PM 2.5 concentrations are associated with a number of adverse health effects and characterizes the weight of evidence for these health

39 U.S. EPA. (2009). Integrated Science Assess ment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 08/139F. Figure 3

- 1. 40 Regulatory definitions of PM size fractions, and information on reference and equivalent methods for measuring PM in ambient air, are provided in 40 CFR Parts 50, 53, and 58. With regard to national ambient air quality standards (NAAQS) which provide protection against health and welfare effects, the 24

- hour PM 10 standard provides protection against effects associated with sh ort
- term exposure to thoracic coarse particles (i.e., PM 10

- 2.5 ). 41 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 08/139F.Page 38 of 88

outcomes. 42 The discussion below highlights the PM I SA’s conclusions pertaining to health effects associated with both short

- and long

- term PM exposures. Further discussion of health effects associated with PM 2.5 can also be found in the rulemaking documents for the most recent review of the PM NAAQS completed in 2012

. 43 , 44 The EPA concludes that a causal relationship exists between both long

- and short

- term exposures to PM 2.5 and premature mortality and cardiovascular effects and a likel y causal relationship exists between long

- and short

- term PM 2.5 exposures and respiratory

effects. Further, there is evidence suggestive of a causal relationship between long

- term PM 2.5 exposures and other health effects, including developmental and reproductive effects (e.g., low birth weight, infant mortality) and carcinogenic, mutagenic, and genotoxic effects (e.g., lung cancer mortality). 45 As summarized in the Final PM NAAQS rule, and discussed extensively in the 2009 PM I SA, the scientific evidence available since the completion of the 2006 PM NAAQS review significantly strengthens the link between long

- and short

- term exposure to P M 2.5 and premature mortality, while providing indications that the magnitude of the PM 2.5 - mortality association with long

- term exposures may be larger than previousl y estimated. 46 , 47 The strongest evidence comes from recent studies investigating long

- term exposure to PM 2.5 and cardiovascular

- related mortality . The evidence supporting a causal relationship between long

- term PM 2.5 exposure and mortality

also includes consideration of new studies that demonstrated

42 The causal framework draw s upon the assessment and integration of evidence from across epidemiological, controlled human exposure, and toxicological studies, and the related uncertainties that ultimately influence our understanding of the evidence. This framework employs a five

- l evel hierarchy that classifies the overall weight of evidence and causality using the following categorizations: causal relationship, likely to be causal relationship, suggestive of a causal relationship, inadequate to infer a causal relationship, and not likely to be a causal relationship ( U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Wa shington, DC, EPA/600/R

- 08/139F, Table 1

– 3). 43 78 FR 3086 ( January 15, 201 3), pages 310 3

- 3104. 44 77 FR 38890 ( June 29, 2012 ), pages 38906

- 38911. 45 These causal inferences are based not only on the more expansive epidemiological evidence available in this review but also reflect considerat ion of important progress that has been made to advance our understanding of a number of potential biologic modes of action or pathways for PM

related cardiovascular and respiratory effects ( U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protecti on Agency, Wa shington, DC, EPA/600/R

- 08/139F, chapter 5). 46 78 FR 3103

- 3104 ( January 15, 2013 ). 47 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Wa shington, DC, EPA/600/R

- 08/13 9F, chapter 6 ( Section 6.5) and chapter 7 (Section 7.6).Page 39 of 88

an improvement in community health following reductions in ambient fine particles. 48 Several studies evaluated in the 2009 PM I SA have examined the association between cardiovascular effects and long

- term PM 2.5 exposures in multi

city studies conducted in the U.S. and Europe. While studies were not available in the 2006 PM NAAQS review with regard to long

- term exposure and cardiovascular

- related morbidity , studies published since then have provided new evidence linking long

- term exposure to PM 2.5 with an array of cardiovascular eff ects such as heart attacks, congestive heart failure, stroke, and mortality . This evidence is coherent with studies of short

- term exposure to PM 2.5 that have observed associations with a continuum of effects ranging from subtle changes in indicators of cardiovascular health to serious clinical events, such as increased hospitalizations and emergency department visits due to cardiovascular disease and cardiovascular mortality. 49 As detailed in the 2009 PM I SA, e xtended anal ys es of studies available in the 2 006 PM NAAQS review as well as epidemiological studies conducted in the U.S. and abroad published since then provide stronger evidence of respiratory

related morbidit y effects associated with long

- term PM 2.5 exposure. The strongest evidence for respir atory
- related effects is from studies that evaluated decrements in lung function growth (in children), increased respiratory s ymptoms, and asthma development. The strongest evidence from short

- term PM 2.5 exposure studies has been observed for increased re spiratory

- related emergency department visits and hospital admissions for chronic obstructive pulmonary disease (COPD) and respiratory

infections. 50 The body of scientific evidence detailed in the 2009 PM I SA is still limited with respect to associations be tween long

- term PM 2.5 exposures and developmental and reproductive effects as well as cancer, mutagenic, and genotoxic effects, but is somewhat expanded from the 2006 review . The strongest evidence for an association between PM 2.5 and developmental and reproductive effects comes from epidemiological studies of low birth weight and infant mortality , especiall y due to respiratory

causes during the post

- neonatal period (i.e., 1 month to 12 months of age). 51 With regard to cancer effects, ‘‘[m]ultiple epidemiologic studies have shown a consistent positive association between PM 2.5 and lung cancer mortality ,

48 78 FR 3103 ( January 15, 201 3). 49 78 FR 3103 ( January 15, 201 3). 50 78 FR 3103

- 3104 ( January 15, 201 3). 51 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Wa shington, DC, EPA/600/R

- 08/139F, chapter 2 (section 2.3.1 and 2.3.2) and chapter 7.Page 40 of 88

but studies have generally not reported associations between PM 2.5 and lung cancer incidence.’’ 53 Specific groups within the general population are at increased risk for experiencing adverse health effects related to PM exposures. 54 , 55 , 56 , 57 The evidence detailed in the 2009 PM ISA expands our understanding of previously identified at

risk populations and lifestages (i.e., children, older adults, and individuals with pre

existing heart and lung disease) and sup ports the identification of additional at

- risk populations (e.g., persons with lower socioeconomic status, genetic differences). Additionally , there is emerging, though still limited, evidence for additional potentially

at
- risk populations and lifestages , such as those with diabetes, people who are obese, pregnant women, and the developing fetus. 60 For PM 10

- 2.5 , the 2009 PM I SA conclude d that available evidence was suggestive of a causal relationship between short

- term exposures to PM 10

- 2.5 and cardiovascular effects (e.g., hospital admissions and ED visits, changes in cardiovascular function), respiratory effects (e.g, ED visits and hospital admissions, increase in markers of pulmonary inflammation), and premature mortality

. Data we re inadequate to draw conclusions regarding the relationships between long

- term exposure to PM 10

- 2. 5 and various health effects. 61 , 62 , 63 For ultrafine particles, th e 2009 PM I SA conclude d that the evidence wa s suggestive of a causal relationship between short

- term exposures and cardiovascular effects, including changes in heart rh ythm and vasomotor function (the ability of blood vessels to expand and contract) . It a lso conclude d that there wa s evidence suggestive of a causal relationship between short

- term exposure to ultrafine particles and respiratory

effects , including lung function and pulmonary inflammation, with limited and inconsistent evidence for increases i n ED visits and hospital admissions . Data we re inadequate to draw conclusions regarding the

53 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Env ironmental Protection Agency, Wa shington, DC, EPA/600/R

- 08/139F . pg 2

- 13 54 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 08/139F. Chapter 8 and Chapte r 2. 55 77 FR 38890 ( June 29, 2012 )

. 56 78 FR 3104 ( January 15, 201 3)

. 57 U.S. EPA. (2011)

. Policy Assessment for the Review of the PM NAAQS. U.S. Environmental Protection Agency, Wa shington, DC, EPA/452/R

- 11

- 003. section 2.2.1

. 60 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 08/139F. Chapter 8 and Chapter 2 (Section 2.4.1). 61 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 08/139F. Section 2.3.4 and Table 2

- 6. 62 78 FR 3167

- 8 ( January 15, 20 1 3). 63 77 FR 38947

- 51 (June 29, 2012).Page 41 of 88

relationship between short

- term exposure to ultrafine particle and additional health effects including premature mortality as well as long

- term exposure to ultrafin e particles and all health outcomes evaluated

. 64 , 65

c. Current and Projected Concentration s of PM 2.5 There are two primary NAAQS for PM 2.5 : an annual standard (12 .0 micrograms per cubic meter (μg/m 3 )) and a 24

- hour standard (35 μg/m 3 ) , and two secondary NAAQS for PM 2.5 : an annual standard (1 5 .0 μg/m 3 ) and a 24

- hour standard (35 μg/m 3 )

. The initial PM 2.5 standards were set in 1997 and revisions to the standards were finalized in 2006 and in December 2012. The December 2012 rule revised the level of the primary annual PM 2.5 standard from 15 .0 μg/m 3 to 12 .0 μg/m 3

. 66 There are man y areas of the country that are currently

in nonattainment for the annual and 24

- hour PM 2.5 NAAQS. Our modeling without the Tier 3 controls projects that in the future we will continue to have many areas that will have ambient PM 2.5 concentrations above the level of the NAAQS (see Section III.C.2). States will need to meet the 2006 24

- hour standard s in the 2015

- 2019 timeframe and the 2012 primary annual standard in the 2021

- 2025 timeframe. The emission reductions and improvements in ambient PM 2.5 concentrations from this action , which w ill take effect starting in 2017, w ill be helpful to state s as they work to attain and maintain the PM 2.5 NAAQS. In 2005 the EPA designated 39 nonattainment areas for the 1997 PM 2.5 NAAQS. 67 As of December 5 , 201 3 , over 68 million people lived in the 24 areas that are still designated as nonattainment for the 199 7 annual PM 2.5 NAAQS. These PM 2.5 nonattainment areas are comprised of 135 full or partial counties. EPA anticipates making initial area designation decision s for the 2012 primary annual PM 2.5 NAAQS in December 2014, with those designations likel y becomi ng effective in early

2015. 68 On November 13 , 2009 and February 3, 2011 , the EPA designat ed 32 nonattainment areas for the 2006 24

- hour PM 2.5 NAAQS. 69 As of December 5, 2013, 28 of these areas remain designated as nonattainment, and they are composed of 1 04 full or partial counties with a population of over 65 million.

64 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 08/139F. Section 2.3.5 and Table 2

- 6. 65 78 FR 3121 ( January 15, 201 3). 66 U.S. EPA (2012). National Ambient Air Quality Standards for Particulate Matter. http://www.epa.gov/PM/2012/finalrule.pdf . 78 FR 3164 67 70 FR 19844 (April 14, 2005). 68 U.S. EPA (2012). F act Sheet: Implementing the Standards. http://www.epa.gov/airquality/particlepollution/2012/decfsimp.pdf 69 74 FR 58688 (November 13, 2009) and 76 FR 6056 (February 3, 2011)

.Page 42 of 88

In total, there are currently 39 PM 2.5 nonattainment areas with a population of over 84 million people. 70 States with PM 2.5 nonattainment areas will be required to take action to bring tho se areas into attainment in the future. Designated nonattainment areas not currentl y attaining the 1997 annual PM 2.5 NAAQS are required to attain the NAAQS by 2015 and will be required to maintain the 1997 annual PM 2.5 NAAQS thereafter. The 2006 24

- hour PM 2.5 nonattainment areas are required to attain the 2006 24

- hour PM 2.5 NAAQS in the 201 5 to 2019 time frame and will be required to maintain the 2006 24

- hour PM 2.5 NAAQS thereafter. Areas to be designated nonattainment for the 2012 primary annual PM 2.5 NAAQS will likely be required to attain the 2012 NAAQS in the 202 1 to 2025 time frame. The Tier 3 standards finalized here begin taking effect in 2017. The EPA has already adopted many mobile source emission control programs that are expected to reduce ambient PM concentration s. As a result of these and other federal, state and local programs, the number of areas that fail to meet the PM 2.5 NAAQS in the future is expected to decrease. However, even with the implementation of all current state and federal regulations, there are projected to be counties violating the PM 2.5 NAAQS well into the future. Thus additional federal control programs, such as Tier 3, can assist areas with attainment dates in 2017 and beyond in attaining the NAAQS as expeditiously as practicable and may relieve areas with already stringent local regulations from some of the burden associated with adopting additional local controls. d. Current Concentrations of PM 10 In the December 2012 action in which the EPA promulgated the revised prim ary annual PM 2.5 NAAQS, the EPA also retained the existing primary and secondary 24

- hour PM 10 standards at 150 μg/m 3

. As of December 5 , 20 13, over 11 million people live in the 4 0 areas that are designated as nonattainment for the PM 10 NAAQS. There are 3 3 full or partial counties that make up the PM 10 nonattainment areas. 3. Oxides of Nitrogen and Sulfur
a. Background Nitrogen dioxide (NO 2 ) is a member of the NO X family of gases. Most NO 2 is formed in the air through the oxidation of nitric oxide (NO) emitted when fuel is

70 Data come from Summary Nonattainment Area Population Exposure Report, current a s of July 3 1, 201 3 at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA

- HQ

OAR

- 20 11

- 0 135.Page 43 of 88

burned at a high temperature. Sulfur dioxide (SO 2 ), a member of the sulfur oxide (SO X ) famil y of gases, is formed from burning fuels containing sulfur (e.g., coal or oil derived), extracting gasoline from oil, or extracting metals from ore. SO 2 and NO 2 and their gas phase oxidation products can dissolve in water droplets and further oxidize to form sulfuric and nitric acid which react with ammonia to form sulfates and nitrates, both of which are important components of ambient PM. The health effects of ambient PM are discussed in Section II.B.2.b of this preamble. NO X and VOC are the two major precursors of ozone. The health effects of ozone are covered in Section II.B.2.1.b. b. Health Effects of NO 2 The most recent review of the health effec ts of oxides of nitrogen completed by the EPA can be found in the 2008 Integrated Science Assessment for Nitrogen Oxides (NO X IS A)

. 71 The EPA concluded that the findings of epidemiologic, controlled human exposure, and animal toxicological studies provide evidence that is sufficient to infer a likely causal relationship between respiratory effects and short

- term NO 2 exposure. The 2008 NO X ISA conclude d that the strongest evidence for such a relationship comes from epidemiologic studies of respiratory effec ts including increased respiratory sy mptoms, emergency

department visits, and hospital admissions. Based on both short

- and long

- term exposure studies, the 2008 NO X ISA conclude d that individuals with preexisting pulmonary conditions (e.g., asthma or COPD ), children , and older adults are potentially at greater risk of NO 2 - related respiratory

effects. Based on findings from controlled human exposure studies , the 2008 NO X IS A also dr ew two broad conclusions regarding airway responsiveness following NO 2 expo sure. First, the NO X ISA conclude d that NO 2 exposure may

enhance the sensitivity

to allergen

- induced decrements in lung function and increase the allergen

- induced airway inflammatory

response following 30

- minute exposures of asthmatic adult s to NO 2 concentrations as low as 26 0 pp b

. Second, exposure to NO 2 has been found to enhance the inherent responsiveness of the airway

to subsequent nonspecific challenges in controlled human exposure studies of healthy

and asthmatic adult s. S mall but statistically significant increases in nonspecific airway

hyperresponsiveness were reported for asthmatic adults following 30

- minute exposures to 200

- 300 ppb NO 2 and following 1

- hour exposures of asthmatics to 1 00 pp b NO 2 . Enhanced airway responsiveness could have important clinical implications for asthmatics since transient increases in airway responsiveness following NO 2 exposure have the potential to increase sy mptoms and worsen asthma control. Together, the epidemiologic and experimental data sets form a plausible, c onsistent, and coherent description of a

71 U.S. EPA (2008). Integrated Science Assessment for Oxides of Nitrogen

– Health Criteria (Final Report). EPA/600/R

- 08/071. Washington, D C: U.S.EPA.Page 44 of 88

relationship between NO 2 exposures and an array of adverse health effects that range from the onset of respiratory s ymptoms to hospital admission. In evaluating a broader range of health effects, the 2008 NO X ISA concluded evidence was “suggestive but not sufficient to infer a causal relationship” between short

- term NO 2 exposure and premature mortality and between long

- term NO 2 exposure and respiratory effects. The latter was based largel y on associations observed between long

- term NO 2 exposure and decreases in lung function growth in children. Furthermore, the 2008 NO X ISA concluded that evidence was “inadequate to infer the presence or absence of a causal relationship” between short

- term NO 2 exposure and cardiova scular effects as well as between long

- term NO 2 exposure and cardiovascular effects, reproductive and developmental effects, premature mortality , and cancer. 72 The conclusions for these health effect categories were informed by uncertainties in the evidenc e base such as the independent effects of NO 2 exposure within the broader mixture of traffic

- related pollutants, limited evidence from experimental studies, and/or an overall limited literature base.
c. Health Effects of SO 2 In formation on the health effects of SO 2 can be found in the 2008 Integrated Science Assessment for Sulfur Oxides (SO 2 IS A)

. 73 Short

- term peaks of SO 2 have long been known to cause adverse respiratory health effects, particularl y among individuals with asthma. Inaddition to those with a sthma (both children and adults), potentially

sensitive groups include all children and the elderl y. During periods of elevated ventilation, asthmatics may experience s ymptomatic bronchoconstriction within minutes of exposure. Following an extensive evalu ation of health evidence from epidemiologic and laboratory studies, the EPA concluded that there is a causal relationship between respiratory health effects and short

- term exposure to SO 2 . Separately, based on an evaluation of the epidemiologic evidence o f associations between short

- term exposure to SO 2 and mortality , the EPA concluded that the overall evidence is suggestive of a causal relationship between short

- term exposure to SO 2 and mortality

. d. Current Concentration s of NO 2 The EPA most recentl y comple ted a review of the primary NAAQS for NO 2 in January

2010. There are two primary NAAQS for NO 2 : an annual standard (53 ppb) and a 1

- hour standard (100 ppb). The EPA promulgated area designations in

72 U.S. EPA (2008). Integrated Science Assessment for Oxides of Nitrogen

– Health Criteria (Final Report). EPA/600/R

- 08/071. Washington, DC: U.S.EPA. 73 U.S. EPA. (2008). Integrated Science Assessment (ISA) for Sulfur Oxides

– Health Criteria (F inal Report) . EPA/600/R

- 08/047F. Washington, DC: U.S. Environmental Protection Agency.Page 45 of 88

the Federal Register on February 17, 2012. In this init ial round of designations, all areas of the country

were designated as “unclassifiable/attainment” for the 2010 NO 2 NAAQS based on data from the existing air quality monitoring network. The EPA and state agencies are working to establish an expanded netwo rk of NO 2 monitors, expected to be deployed in the 2014

- 2017 time frame. Once three years of air qualit y data have been collected from the expanded network, the EPA will be able to evaluate NO 2 air quality in additional locations

. 74 , 75

e. Current Concentration s of S O 2 The EPA most recentl y completed a review of the primary SO 2 NAAQS in June 2010. The current primary NAAQS for SO 2 is a 1

- hour standard of 75 ppb. The EPA finalized the initial area designations for 29 nonattainment areas in 16 states in a notic e published in the Federal Register on August 5, 2013. In this first round of designations, EPA only designated nonattainment areas that were violating the standard based on existing air quality monitoring data provided b y the states. The Agency

did not h ave sufficient information to designate any area as “attainment” or make final decisions about areas for which additional modeling or monitoring is needed (78 FR 47191, August 5, 2013). EPA anticipates designating areas for the revised SO2 standard in mul tiple rounds

. 4. Carbon Monoxide Carbon monoxide (CO) is a colorless, odorless gas emitted from combustion processes. Nationally

and, particularl y in urban areas, the majority of CO emissions to ambient air come from mobile sources.
a. Health Effects of Carbon Monoxide In formation on the health effects of CO can be found in the January 2010 Integrated Science Assessment for Carbon Monoxide (CO I SA)

. 76 The CO ISA concludes that ambient concentrations of CO are associated with a number of

74 U.S. EPA. (201 2 ). Fact Sheet

– Air Quality Designations for the 2010 Primary Nitrogen Dioxide (NO 2 ) National Ambient A ir Quality Standards. http://www.epa.gov/airqua lity/nitrogenoxides/designations/pdfs/20120120FS.pdf 75 U.S. Environmental Protection Agency (2013). Revision to Ambient Nitrogen Dioxide Monitoring Requirements. March 7, 2013. http://www.epa.gov/airquality/nitrogenoxides/pdfs/20130307fr.pdf 76 U.S. EPA, (2010). Integrated Science Assessment for Carbon Monoxide (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 09/019F, 2010. Available at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=218686.Page 46 of 88

adverse health effects. 77 This section provides a summary of the health effects associated with exposure to ambient concentrations of CO. 78 Controlled human exposure studies of subjects with coronary artery disease show a decrease in the time to onset of exercise

- induced angina ( chest pain) and electrocardiogram changes following CO exposure. In addition, epidemiologic studies show associations between short

- term CO exposure and cardiovascular morbidity , particularly

increased emergency

room visits and hospital admissions for cor onary heart disease (including ischemic heart disease, m yocardial infarction, and angina). Some epidemiologic evidence is also available for increased hospital admissions and emergency room visits for congestive heart failure and cardiovascular disease as a whole. The CO IS A concludes that a causal relationship is likely to exist between short

- term exposures to CO and cardiovascular morbidity

. It also concludes that available data are inadequate to conclude that a causal relationship exists between long

- term exposures to CO and cardiovascular morbidity

. Animal studies show various neurological effects with in

- utero CO exposure. Controlled human exposure studies report central nervous s ys tem and behavioral effects following low

- level CO exposures , altho ugh the findings have not been consistent across all studies . The CO IS A concludes the evidence is suggestive of a causal relationship with both short

- and long

- term exposure to CO and central nervous s ys tem effects. A number of studies cited in the CO IS A have evaluated the role of CO exposure in birth outcomes such as preterm birth or cardiac birth defects. The epidemiologic studies provide limited evidence of a CO

- induced effect on preterm births and birth defects, with weak evidence for a decrease in birth weight. Animal toxicological studies have found perinatal CO exposure to affect birth weight, as well as other developmental outcomes. The CO ISA concludes the evidence is suggestive of a causal relationship between long

- term exposures to CO and de velopmental effects and birth outcomes. Epidemiologic studies provide evidence of associations between ambient CO concentrations and respiratory morbidity

such as changes in pulmonary

77 The ISA evaluates the hea lth evidence associated with different health effects, assigning one of five “weight of evidence” determinations: causal relationship, likely to be a causal relationship, suggestive of a causal relationship, inadequate to infer a causal relationship, and not likely to be a causal relationship. For definitions of these levels of evidence, please refer to Section 1.6 of the ISA. 78 Personal exposure includes contributions from many sources, and in many different environments. Total personal exposure to CO includes both ambient and nonambient components; and both components may contribute to adverse health effects.Page 47 of 88

function, respiratory

s ymptoms, and hospital admissions. A limited numb er of epidemiologic studies considered copollutants such as ozone, SO 2 , and PM in two

pollutant models and found that CO risk estimates were generally robust, although this limited evidence makes it difficult to disentangle effects attributed to CO itself from those of the larger complex air pollution mixture. Controlled human exposure studies have not extensively evaluated the effect of CO on respiratory morbidity

. Animal studies at levels of 50

- 100 ppm CO show preliminary evidence of altered pulmonary

v ascular remodeling and oxidative injury . The CO ISA concludes that the evidence is suggestive of a causal relationship between short

- term CO exposure and respiratory

morbidity, and inadequate to conclude that a causal relationship exists between long

- term exposure and respiratory morbidity

. Finally , the CO IS A concludes that the epidemiologic evidence is suggestive of a causal relationship between short

- term concentrations of CO and mortality

. Epidemiologic studies provide evidence of an association between short

- term exposure to CO and mortality , but limited evidence is available to evaluate cause

specific mortality outcomes associated with CO exposure. In addition, the attenuation of CO risk estimates which was often observed in copollutant models contributes to the uncertainty as to whether CO is acting alone or as an indicator for other combustion

- related pollutants. The CO IS A also concludes that there is not likely to be a causal relationship between relevant long

- term exposures to CO and mortality

. b. Current Concentration s of C O There are two NAAQS for C O: an 8

- hour standard (9 ppm ) and a 1

- hour standard (35 ppm ). The primary NAAQS for C O w ere re tain ed in August 2011

. T here are currently

no CO nonattainment areas ; as of September 27, 2010, all CO n onattainment areas were redesignated to maintenance areas . The designations were based on the existing community - wide monitoring network. EPA is making changes to the ambient air monitoring requirements for CO. The new requirements are expected to resul t in approximately 52 CO monitors operating near roads within 52 urban areas b y J anuary 2015 (76 FR 54294, August 31, 2011). 5. Mobile Source Air Toxics Li ght

- dut y vehicle emissions contribute to ambient levels of air toxics known or suspected as human or animal carcinogens, or that have noncancer health effects. The population experiences an elevated risk of cancer and other noncancer health effects from exposure to the class of pollutants known collectively as “air toxics.” 79 These compounds include, but are not limited to, benzene, 1,3

- butadiene,

79 U.S. EPA. (2011) Summary of Results for the 2005 National

- Scale Assessment. www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf.Page 48 of 88

formaldeh yde, acetaldehyde, acrolein, polycyclic organic matter, and naphthalene. These compounds were identified as national or regional risk drivers or contributors in the 2005 National

- scale Air Toxics Assess ment and have significant inventory contributions from mobile sources. 80

a. Health Effects of Air Toxics i. Benzene The EPA’s Integrated Risk Information Sy stem ( IRI S ) database lists benzene as a known human carcinogen (causing leukemia) b y all routes of exposure, and concludes that exposure is associated with additional health effects, including genetic changes in both humans and animals and increased proliferation of bone marrow cells in mice. 81 , 82 , 83 EPA states in its IRI S database that data indicate a causal r elationship between benzene exposure and acute l ymphocy tic leukemia and suggest a relationship between benzene exposure and chronic non

ly mphocy tic leukemia and chronic l ymphocy tic leukemia. EPA’s IRI S documentation for benzene also lists a range of 2.2 x 10 - 6 to 7.8 x 10 - 6 as the unit risk estimate (URE) for benzene. 84 , 85 The International Agency for Research on Carcinogens (IARC) has determined that benzene is a human carcinogen and the U.S. Department of Health and Human Services (DHHS) has characterized benzene as a known human carcinogen. 86 , 87 A number of adverse noncancer health effects including blood disorders, such as preleukemia and aplastic anemia, have also been associated with long

- term

80 U.S. EPA ( 2011) 2005 National

- Scale Air Toxics Assessment. http://www.epa.gov/ttn/atw/nata2005. 81 U.S. EPA. (2000). Integrated Risk Information System File for Benzene. This material is available electronically at: http://www.epa.gov/iris/subst/0276.htm

. 82 International Agency for Research on Cancer, IARC monographs on the evaluation of carcinogenic risk of chemicals to humans, Volume 29, Some industrial chemicals and dyestuffs, International Agency for Resear ch on Cancer, World Health Organization, Lyon, France 1982. 83 Irons, R.D.; Stillman, W.S.; Colagiovanni, D.B.; Henry, V.A. (1992). Synergistic action of the benzene metabolite hydroquinone on myelopoietic stimulating activity of granulocyte/macrophage col ony - stimulating factor in vitro, Proc. Natl. Acad. Sci. 89:3691

- 3695. 84 A unit risk estimate is defined as the increase in the lifetime risk of an individual who is exposed for a lifetime to 1 μg/m3 benzene in air. 85 U.S. EPA. (2000). Integrated Risk Info rmation System File for Benzene. This material is available electronically at: http://www.epa.gov/iris/subst/0276.htm

. 86 International Agency for Research on Cancer (IARC). (1987). Monographs on the evaluation of carcinogenic risk of chemicals to humans, Volume 29, Supplement 7, Some industrial chemicals and dyestuffs, World Health Organization, Lyon, France. 87 U.S. Department of Health and Human Services National Toxicology Program. (2011). 12th Rep ort on Carcinogens

. Available at: http://ntp.niehs.nih.gov/?objectid=03C9AF75

- E1BF

- FF40

- DBA9EC0928DF8B15.Page 49 of 88

exposure to benzene. 88 , 89 The most sensitive noncancer eff ect observed in humans, based on current data, is the depression of the absolute ly mphocy te count in blood. 90 , 91 EPA’s inhalation reference concentration (RfC) for benzene is 30 μg/m 3

. The RfC is based on suppressed absolute l ymphocy te counts seen in human s under occupational exposure conditions. In addition, recent work, including studies sponsored b y the Health Effects Institute, provides evidence that biochemical responses are occurring at lower levels of benzene exposure than previously known. 92 , 93 , 94 , 95 EPA’s IRI S program has not yet evaluated these new data. EPA does not currently

have an acute reference concentration for benzene. The Agency for Toxic Substances and Disease Registry (ATSDR) Minimal Risk L evel (MRL) for acute exposure to benzene is 29 μ g/m 3 for 1

- 14 day s exposure. 96 , 97

ii. Formaldehyde In 1991, EPA concluded that formaldeh yde is a carcinogen based on nasal tumors in animal bioassays. 98 An Inhalation Unit Risk for cancer and a Reference Dose for oral noncancer effects were developed by the Agen cy

and posted on the IR IS database. Since that time, the National Toxicology Program (NTP) and

88 Aksoy, M. (1989). Hematotoxicity and carcinogenicity of benzene. Environ. Health Perspect. 82: 193

- 197. 89 Goldstein, B.D. (1988). Benzene tox icity. Occupational medicine. State of the Art Reviews. 3: 541

- 554

. 90 Rothman, N., G.L. Li, M. Dosemeci, W.E. Bechtold, G.E. Marti, Y.Z. Wang, M. Linet, L.Q. Xi, W. Lu, M.T. Smith, N. Titenko

- Holland, L.P. Zhang, W. Blot, S.N. Yin, and R.B. Hayes. (1996 ). Hematotoxicity among Chinese workers heavily exposed to benzene. Am. J. Ind. Med. 29: 236

- 246. 91 U.S . EPA. (2002). Toxicological Revie w of Benzene (Noncancer Effects). Environmental Protection Agency , Integrated Risk Information System (IRIS), Resear ch and Development, National Center for Environmental Assessment, Washington DC. This material is available electronically at http://www.epa.gov/iris/subst/0276.htm

. 92 Qu, O.; Shore, R.; Li, G.; Jin, X .; Chen, C.L.; Cohen, B.; Melikian, A.; Eastmond, D.; Rappaport, S.; Li, H.; Rupa, D.; Suramaya, R.; Songnian, W.; Huifant, Y.; Meng, M.; Winnik, M.; Kw ok, E.; Li, Y.; Mu, R.; Xu, B.; Zhang, X.; Li, K. (2003). HEI Report 115, Validation & Evaluation of Biomarkers in Workers Exposed to Benzene in China. 93 Qu, Q., R. Shore, G. Li, X. Jin, L.C. Chen, B. Cohen, et al. (2002). Hematological changes among Chinese workers with a broad range of benzene exposures. Am. J. Industr. Med. 42: 275

- 285. 94 Lan, Qing, Zhang, L., Li, G., Vermeulen, R., et al. (2004). Hematotoxically in Workers Exposed to Low Levels of Benzene. Science 306: 1774

- 1776. 95 Turtletaub, K.W. and Mani, C. (2003). Benzene metabolism in rodents at doses relevant to human exposure from Urban Air. Research Reports Health Effect Inst. Report No.113. 96 U.S. Agency for Toxic Substances and Disease Registry (ATSDR). (2007). Toxicological profile for benzene. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. http://www.atsdr.cdc.gov/ToxProfiles/tp3.pdf. 97 A minimal risk level (MRL) is defined as an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse noncancer health effects over a specified durat ion of exposure. 98 EPA. Integrated Risk Information System. Formaldehyde (CASRN 50

- 00

- 0) http://www.epa.gov/iris/subst/0419/htmPage 50 of 88

International Agency

for Research on Cancer (IARC) have concluded that formaldeh yde is a known human carcinogen. 99 , 100 , 101 The conclusions b y IAR C and NTP reflect th e results of epidemiologic research published since 1991 in combination with previous animal, human and mechanistic evidence. Research conducted b y the National Cancer Institute reported an increased risk of nasophary ngeal cancer and specific ly mphohemato poietic malignancies among workers exposed to formaldeh yde. 102 , 103 , 104 A National Institute of Occupational Safet y and Health study of garment workers also reported increased risk of death due to leukemia among workers exposed to formaldeh yde. 105 Extended follow

- up of a cohort of British chemical workers did not report evidence of an increase in nasophary ngeal or ly mphohematopoietic cancers, but a continuing statistically significant excess in lung cancers was reported. 106 Finally , a study of embalmers reported fo rmaldehyde exposures to be associated with an increased risk of myeloid leukemia but not brain cancer. 107 Health effects of formaldehyde in addition to cancer were reviewed b y the Agency for Toxics Substances and Disease Registry in 1999 108 and supplemented in

99 National Toxicology Program, U.S. Department of Health and Human Services (HHS), 12th Report on Carcinogens, June 10, 2011 100 I ARC Monographs on the Evaluation of Carcinogenic Risks to Humans Volume 88 (2006): Formaldehyde, 2

- Butoxyethanol and 1

- tert
- Butoxypropan

- 2

- ol 101 IARC Mongraphs on the Evaluation of Carcinogenic Risks to Humans Volume 100F (2012): Formaldehyde 102 Hauptmann, M ..; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Blair, A. 2003. Mortality from lymphohematopoetic malignancies among workers in formaldehyde industries. Journal of the National Cancer Institute 95: 1615

- 1623. 103 Hauptmann, M..; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Blair, A. 2004. Mortality from solid cancers among workers in formaldehyde industries. American Journal of Epidemiology 159: 1117

- 1130. 104 Beane Freeman, L. E.; Blair, A.; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Hoover, R. N.; Hau ptmann, M. 2009. Mortality from lymphohematopoietic malignancies among workers in formaldehyde industries: The National Cancer Institute cohort. J. National Cancer Inst. 101: 751

- 761. 105 Pinkerton, L. E. 2004. Mortality among a cohort of garment workers exposed to formaldehyde: an update. Occup. Environ. Med. 61: 193

- 200. 106 Coggon, D, EC Harris, J Poole, KT Palmer. 2003. Extended follow

- up of a cohort of British chemical workers exposed to formaldehyde. J National Cancer Inst. 95:1608

- 1615. 107 Hauptmann, M,; Stewart P. A.; Lubin J. H.; Beane Freeman, L. E.; Hornung, R. W.; Herrick, R. F.; Hoover, R. N.; Fraumeni, J. F.; Hayes, R. B. 2009. Mortality from lymphohematopoietic malignancies and brain cancer among embalmers exposed to formaldehyde. Journal of th e National Cancer Institute 101:1696

- 1708. 108 AT SDR. 1999. Toxicological Profile for Formaldehyde, U.S. Department of Health and Human Services (HHS), July 1999.Page 51 of 88

2010, 109 and by

the World Health Organization. 110 These organizations reviewed the literature concerning effects on the eyes and respiratory s ys tem, the primary point of contact for inhaled formaldeh yd e, including sensory irritation of eyes and respiratory tract, pulmonary function, nasal histopathology , and immune s ystem effects. In addition, research on reproductive and developmental effects and neurological effects were discussed. EPA released a draft Toxicological Review of Formaldehyde

– Inhalation Assessment through the IRI S program for peer review by the National Research Council (NRC) and public comment in June 2010. 111 The draft assessment reviewed more recent research from animal and human studies on cancer and other health effects. The NRC rele ased their review report in April 2011. 112 The EPA is currentl y revising the draft assessment in response to this review.

iii. Acetaldehyde Acetaldeh yd e is classified in EPA’s IRI S database as a probable human carcinogen, based on nasal tumors in rats, and is c onsidered toxic by the inhalation, oral, and intravenous routes. 113 The URE in IRI S for acetaldehyde is 2.2 × 10 - 6 per μg/m 3

. 114 Acetaldeh yde is reasonabl y anticipated to be a human carcinogen by the U.S. DHHS in the 12 th Report on Carcinogens and is classif ied as possibly carcinogenic to humans (Group 2B) b y the IARC. 115 , 116 EPA is currentl y conducting a reassessment of cancer risk from inhalation exposure to acetaldehyde.

109 AT SDR. 2010. Addendum to theToxicological Profile for Formaldehyde

. U.S. Department of Health and Human Services (HHS), October 2010. 110 IPCS. 2002. Concise International Chemical Assessment Document 40. Formaldehyde. World Health Organization. 111 EPA (U.S. Environmental Protection Agency). 2010. Toxicological Review of Formaldehyde (CAS No. 50

- 00

- 0)

– Inhalation Assessment: In Support of Summary Information on the Integrated Risk Information System (IRIS). External Review Draft. EPA/635/R

- 10/002A. U.S. Environmental Protection Agency, Washington DC [online]. Available: http://cfpub.epa.gov/ncea/i rs_drats/recordisplay.cfm?deid=223614 112 NRC (National Research Council). 2011. Review of the Environmental Protection Agency’s Draft IRIS Assessment of Formaldehyde. Washington DC: National Academies Press. http://books.nap.edu/openbook.php?record_id=1314 2 113 U.S. EPA (1991). Integrated Risk Information System File of Acetaldehyde. Research and Development, National Center for Environmental Assessment, Washington, DC. This material is available electronically at http://www.epa.gov/iris/subst/0290.htm

. 114 U .S. EPA (1991). Integrated Risk Information System File of Acetaldehyde. This material is available electronically at http://www.epa.gov/iris/subst/0290.htm. 115 NTP. (2011). Report on Carcinogens, T we lfth Edition. Research Triangle Park, NC: U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program. 499 pp.Page 52 of 88 The primary

noncancer effects of exposure to acetaldehyde vapors include irritation of th e eyes, skin, and respiratory tract. 117 In short

- term (4 week) rat studies, degeneration of olfactory epithelium was observed at various concentration levels of acetaldeh yde exposure. 118 , 119 Data from these studies were used b y EPA to develop an inhalation ref erence concentration of 9 μg/m 3 . Some asthmatics have been shown to be a sensitive subpopulation to decrements in functional expiratory volume (FEV1 test) and bronchoconstriction upon acetaldehyde inhalation. 120 The agency is currentl y conducting a reasses sment of the health hazards from inhalation exposure to acetaldeh yd e.

iv. Acrolein EPA most recently

evaluated the toxicological and health effects literature related to acrolein in 2003 and concluded that the human carcinogenic potential of acrolein could not be determined because the available data were inadequate. No information was available on the carcinogenic effects of acrolein in humans and the animal data provided inadequate evidence of carcinogenicity

. 121 The IARC determined in 1995 that acrolein w as not classifiable as to its carcinogenicity in humans. 122 Lesions to the lungs and upper respiratory tract of rats, rabbits, and hamsters have been observed after subchronic exposure to acrolein. 123 The Agency has

116 International Agency for Research on Cancer (IARC). (1999). Re

- evaluation of some organic chemicals, hydrazine, and hydrogen peroxide. IARC Monographs on the E valuation of Carcinogenic Risk of Chemical to Humans, Vol 71. Lyon, France. 117 U.S. EPA (1991). Integrated Risk Information System File of Acetaldehyde. This material is available electronically at http://www.epa.gov/iris/subst/0290.htm. 118 U.S. EPA. (200 3). Integrated Risk Information System File of Acrolein. Research and Development, National Center for Environmental Assessment, Washington, DC. This material is available electronically at http://www.epa.gov/iris/subst/0364.htm

. 119 Appleman, L.M., R.A. W outersen, and V.J. Feron. (1982). Inhalation toxicity of acetaldehyde in rats. I. Acute and subacute studies. Toxicology. 23: 293

- 297. 120 Myou, S.; Fujimura, M.; Nishi K.; Ohka, T.; and Matsuda, T. (1993) Aerosolized acetaldehyde induces histamine

- mediate d bronchoconstriction in asthmatics. Am. Rev. Respir.Dis.148(4 Pt 1): 940

- 943. 121 U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Research and Development, National Center for Environmental Assessment, Washington, DC. This materia l is available at http://www.epa.gov/iris/subst/0364.htm

. 122 International Agency for Research on Cancer (IARC). (1995). Monographs on the evaluation of carcinogenic risk of chemicals to humans, Volume 63. Dry cleaning, some chlorinated solvents and other industrial chemicals, World Health Organization, Lyon, France. 123 U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Office of Research and Development, National Center for Environmental Assessment, Washington, DC. This material is available at http://www.epa.gov/iris/subst/0364.htm.Page 53 of 88

developed an RfC for acrolein of 0.02 μg/m 3 and an RfD of 0.5 μg/kg

- day

. 124 EPA is considering updating the acrolein assessment with data that have become available since the 2003 assessment was completed. Acrolein is extremely

acrid and irritating to humans when inhaled, with acute exposure resul ting in upper respiratory tract irritation, mucus hy persecretion and congestion. The intense irritancy of this carbonyl has been demonstrated during controlled tests in human subjects, who suffer intolerable eye and nasal mucosal sensory

reactions within minutes of exposure. 125 These data and additional studies regarding acute effects of human exposure to acrolein are summarized in EPA’s 2003 IRI S Human Health Assessment for acrolein. 126 Studies in humans indicate that levels as low as 0.09 ppm (0.21 mg/m 3 ) for five minutes may elicit subjective complaints of eye irritation with increasing concentrations leading to more extensive eye, nose and respiratory s ymptoms. Acute exposures in animal studies report bronchial hyper

- responsiveness. Based on animal data (more pronounced respiratory

irritancy in mice with allergic airway disease in comparison to non
- diseased mice 127 ) and demonstration of similar effects in humans (e.g., reduction in respiratory

rate), individuals with compromised respiratory function (e.g., emph ys ema, asthma) are expected to be at increased risk of developing adverse responses to strong respiratory irritants such as acrolein. EPA does not currentl y have an acute reference concentration for acrolein. The available health effect reference va lues for acrolein have been summarized by EPA and include an ATSDR MRLfor acute exposure to acrolein of 7 μg/m 3 for 1

- 14 day s exposure; and Reference Exposure Level (REL) values from the California Office of Environmental Health Hazard Assessment (OEHHA) for one

- hour and 8

- hour exposures of 2.5 μg/m 3 and 0.7 μg/m 3 , respectively. 128

124 U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Office of Research and Development, National Center for Environmental Assessment, Washington, DC. This material is available at http://www.epa.gov/iris/subst/0364.htm. 125 U.S. EPA. (2003) Toxicological review of acrolein in support of summary information on Integrated Risk Information System (IRIS) National Center for Environmental Assessment, Washington, DC. EPA/635/R

- 03/003. p. 1 0. Available online at: http://www.epa.gov/ncea/iris/toxreviews/0364tr.pdf

. 126 U.S. EPA. (2003) Toxicological review of acrolein in support of summary information on Integrated Risk Information System (IRIS) National Center for Environmental Assessment, Wa shington, DC. EPA/635/R

- 03/003. Available online at: http://www.epa.gov/ncea/iris/toxreviews/0364tr.pdf

. 127 Morris JB, Symanowicz PT, Olsen JE, et al. (2003). Immediate sensory nerve

- mediated respiratory responses to irritants in healthy and allergic airway - diseased mice. J Appl Physiol 94(4):1563

- 1571. 128 U.S. EPA. (2009). Graphical Arrays of Chemical

- Specific Health Effect Reference Values for Inhalation Exposures (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 09/061, 2009 . http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=211003Page 54 of 88 v. 1,3

-Butadiene EPA has characterized 1,3

- butadiene as carcinogenic to humans by inhalation. 129 , 130 The IARC has determined that 1,3

- butadiene is a human carcinogen and the U.S. DHHS h as characterized 1,3

- butadiene as a known human carcinogen. 131 , 132 , 133 There are numerous studies consistently demonstrating that 1,3

- butadiene is metabolized into genotoxic metabolites by experimental animals and humans. The specific mechanisms of 1,3

- butadie ne - induced carcinogenesis are unknown; however, the scientific evidence strongly suggests that the carcinogenic effects are mediated b y genotoxic metabolites. Animal data suggest that females may be more sensitive than males for cancer effects associated with 1,3

- butadiene exposure; there are insufficient data in humans from which to draw conclusions about sensitive subpopulations. The URE for 1,3

- butadiene is 3 × 10 - 5 per μg/m 3

. 134 1,3

- butadiene also causes a variety of reproductive and developmental effe cts in mice; no human data on these effects are available. The most sensitive effect was ovarian atroph y observed in a lifetime bioassay of female mice. 135 Based on this critical effect and the benchmark concentration methodology , an RfC for chronic health effects was calculated at 0.9 ppb (approximately 2 μg/m 3 ). vi. Ethanol

129 U.S. EPA. (2002). Health Assessment of 1,3

- Butadiene. Office of Research and Development, National Center for Environmental Assessment, Washington Office, Washington, DC. Report No. EPA600

- P

- 98

- 001F. This document is available electronically at http://www.epa.gov/iris/supdocs/buta

- sup.pdf

. 130 U.S. EPA. (2002). “Full IRIS Summary for 1,3

- butadiene (CASRN 106

- 99

- 0)” Environmental Protection Agency, Integrated Risk Information System (IRIS), Res earch and Development, National Center for Environmental Assessment, Washington, DC http://www.epa.gov/iris/subst/0139.htm. 131 International Agency for Research on Cancer (IARC). (1999). Monographs on the evaluation of carcinogenic risk of chemicals to hum ans, Volume 71, Re

- evaluation of some organic chemicals, hydrazine and hydrogen peroxide and Volume 97 (in preparation), World Health Organization, Lyo n, France. 132 International Agency for Research on Cancer (IARC). (2008). Monographs on the evaluation of carcinogenic risk of chemicals to humans, 1,3

- Butadiene, Ethylene Oxide and Vinyl Halides (Vinyl Fluoride, Vinyl Chloride and Vinyl Bromide) Volume 97, World Health Organization, Lyon, France. 133 NTP. (2011). Report on Carcinogens, T we lfth Edition. Resear ch Triangle Park, NC: U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program. 499 pp. 134 U.S. EPA. (2002). “Full IRIS Summary for 1,3

- butadiene (CASRN 106

- 99

- 0)” Environmental Protection Agency, Integrated Risk Info rmation System (IRIS), Research and Development, National Center for Environmental Assessment, Washington, DC http://www.epa.gov/iris/subst/0139.htm. 135 Bevan, C.; Stadler, J.C.; Elliot, G.S.; et al. (1996). Subchronic toxicity of 4

- vinylcyclohexene in rat s and mice by inhalation. Fundam. Appl. Toxicol. 32:1

- 10.Page 55 of 88 EPA is planning to develop an assessment of the health effects of exposure to ethanol, a compound which is not currentl y listed on EPA’s IRI S database. Extensive health effects data are available for ingestion of ethanol, while data on inhalation exposure effects are sparse. In developing the assessment, EPA is evaluating pharmacokinetic models as a means of extrapolating across species (animal to human) and across exposure routes (oral t o inhalation) to better characterize the health hazards and dose

- response relationships for low levels of ethanol exposure in the environment.

vii. Polycyclic Organic Matter The term pol yc yclic organic matter (POM) defines a broad class of compounds that includ es the polycyclic aromatic hydrocarbon compounds (PAHs). One of these compounds, naphthalene, is discussed separately below. POM compounds are formed primarily from combustion and are present in the atmosphere in gas and particulate form. Cancer is the major concern from exposure to POM. Epidemiologic studies have reported an increase in lung cancer in humans exposed to diesel exhaust, coke oven emissions, roofing tar emissions, and cigarette smoke; all of these mixtures contain POM compounds. 136 , 137 Anima l studies have reported respiratory

tract tumors from inhalation exposure to benzo[a]py rene and alimentary

tract and liver tumors from oral exposure to benzo[a]py rene. 138 In 1997 EPA classified seven PAHs (benzo[a]py rene, benz[a]anthracene, chry sene, benzo[ b]fluoranthene, benzo[k]fluoranthene, dibenz[a,h]anthracene, and indeno[1,2,3

- cd]py

rene) as Group B2, probable human carcinogens. 139 Since that time, studies have found that maternal exposures to PAHs in a population of pregnant women were associated with s everal adverse birth outcomes, including low birth weight and reduced length at birth, as well as impaired cognitive development in preschool children (3 ye ars of age). 140 , 141 These and similar studies

136 Agency for Toxic Substances and Disease Registry (ATSDR). (1995). Toxicological profile for Polycyclic Aromatic Hydrocarbons (PAHs). Atlanta, GA: U.S. Department of Health and Human Services, Pub lic Health Service. Available electronically at http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=122&tid=25. 137 U.S. EPA (2002). Health Assessment Document for Diesel Engine Exhaust . EPA/600/8

- 90/057F Office of Research and Development, Washington DC. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=29060

. 138 International Agency for Research on Cancer (IARC). (2012). Monographs on the Evaluation of the Carcinogenic Risk of Chemic als for Humans, Chemical Agents and Related Occupations. Vol. 100F. Lyon, France. 139 U.S. EPA (1997). Integrated Risk Information System File of indeno(1,2,3

- cd)pyrene. Research and Development, National Center for Environmental Assessment, Washington, DC . This material is available electronically at http://www.epa.gov/ncea/iris/subst/0457.htm. 140 Perera , F.P.; Rauh, V.; Tsai, W

- Y.; et al. (2002). Effect of transplacental exposure to environmental pollutants on birth outcomes in a multiethnic population. E nviron Health Perspect. 111: 201

- 205.Page 56 of 88

are being evaluated as a part of the ongoing IRIS assessme nt of health effects associated with exposure to benzo[a]py rene. viii. Naphthalene Naphthalene is found in small quantities in gasoline and diesel fuels. Naphthalene emissions have been measured in larger quantities in both gasoline and diesel exhaust compared with evaporative emissions from mobile sources, indicating it is primarily

a product of combustion. Acute (short

- term) exposure of humans to naphthalene by inhalation, ingestion, or dermal contact is associated with hemoly tic anemia and damage to the live r and the nervous s ys tem. 142 Chronic (long term) exposure of workers and rodents to naphthalene has been reported to cause cataracts and retinal damage. 143 EPA released an external review draft of a reassessment of the inhalation carcinogenicity of naphthale ne based on a number of recent animal carcinogenicity studies. 144 The draft reassessment completed external peer review. 145 Based on external peer review comments received, a revised draft assessment that considers all routes of exposure, as well as cancer a nd noncancer effects, is under development. The external review draft does not represent official agency opinion and was released solel y for the purposes of external peer review and public comment. The National Toxicology Program listed naphthalene as "r easonabl y anticipated to be a human carcinogen" in 2004 on the basis of bioassay s reporting clear evidence of carcinogenicity in rats and some evidence of carcinogenicity

in mice. 146 California EPA has released a new risk assessment for

141 Perera, F.P.; Rauh, V.; Whyatt, R.M.; Tsai, W.Y.; Tang, D.; Diaz, D.; Hoepner, L.; Barr, D.; Tu, Y.H.; Camann, D.; Kinney, P. (2006). Effect of prenatal exposure to airborne polycyclic aromatic hydrocarbons on neuro development in the first 3 years of life among inner

- city children. Environ Health Perspect 114: 1287

- 1292. 142 U. S. EPA. 1998. Toxicological Review of Naphthalene (Reassessment of the Inhalation Cancer Risk), Environmental Protection Agency, Integrated Risk Information System, Research and Development, National Center for Environmental Assessment, Washington, DC. This material is available electronically at http://www.epa.gov/iris/subst/0436.htm

. 143 U. S. EPA. 1998. Toxicological Review of Naphthalene (Reassessment of the Inhalation Cancer Risk), Environmental Protection Agency, Integrated Risk Information System, Research and Development, National Center for Environmental Assessment, Washington, DC. This material is available electronically at http://www.epa.gov/iris/subst/0436.htm

. 144 U. S. EPA. (1998). Toxicological Review of Naphthalene (Reassessment of the Inhalation Cancer Risk), Environmental Protection Agency, Integrated Risk Information System, Research and Development, National Center for Env ironmental Assessment, Washington, DC. This material is available electronically at http://www.epa.gov/iris/subst/0436.htm

. 145 Oak Ridge Institute for Science and Education. (2004). External Peer Review for the IRIS Reassessment of the Inhalation Carci nogenicity of Naphthalene. August 2004. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=84403

. 146 NT P. (2011). Report on Carcinogens, T we lfth Edition. Research Triangle Park, NC: U.S. Department of Health and Human Services, Public Health Service, N ational Toxicology Program. 499 pp.Page 57 of 88

naphthalene, and the IAR C has reevaluated naphthalene and re

- classified it as Group 2B: possibly

carcinogenic to humans. 147 Naphthalene also causes a number of chronic non

- cancer effects in animals, including abnormal cell changes and growth in respiratory and nasal tissues. 148 The current EPA IRIS assessment includes noncancer data on h yperplasia and metaplasia in nasal tissue that form the basis of the inhalation RfC of 3 μg/m 3

. 149 The ATSDR MRLfor acute exposure to naphthalene is 0.6 mg/kg/day

.

ix. Other Air Toxics In addition t o the compounds described above, other compounds in gaseous hydrocarbon and PM emissions from motor vehicles will be affected b y this action

. Mobile source air toxic compounds that will potentially be impacted include ethylbenzene, propionaldehyde, toluen e, and xylene. Information regarding the health effects of these compounds can be found in EPA’s IRI S database. 150 b. Current Concentration s of Air Toxics The most recent available data indicate that the majority of Americans continue to be exposed to ambient concentrations of air toxics at levels which have the potential to cause adverse health effects. 151 Th e levels of air toxics to which people are exposed vary

depending on where people live and work and the kinds of activities in which they

engage, as disc ussed in detail in U.S. EPA’s most recent Mobile Source Air Toxics Rule. 152 According to the National Air Toxic Assessment (NATA) for 2005, 153 mobile sources were responsible for 43 percent of outdoor toxic emissions and over 50 percent of the cancer risk and noncancer hazard associated with primary emissions. Mobile sources are also large contributors to precursor emissions which react to form secondary concentrations of

147 International Agency for Research on Cancer (IARC). (2002). Monographs on the Evaluation of the Carcinogenic Risk of Chemicals for Humans. Vol. 82. Lyon, France. 148 U. S. EPA. (1998). Toxicological Review of Naphth alene, Environmental Protection Agency, Integrated Risk Information System, Research and Development, National Center for Environmental Assessment, Washington, DC. This material is available electronically at http://www.epa.gov/iris/subst/0436.htm 149 U.S. EPA. (1998). Toxicological Review of Naphthalene. Environmental Protection Agency, Integrated Risk Information System (IRIS), Research and Development, National Center for Environmental Assessment, Washington, DC http://www.epa.gov/iris/subst/0436.htm. 150 U.S. EPA Integrated Risk Information System (IRIS) database is available at: www.epa.gov/iris 151 U.S. EPA. (2011) Summary of Results for the 2005 National

- Scale Assessment. www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf. 152 U. S. Environmental Prot ection Agency (2007). Control of Hazardous Air Pollutants from Mobile Sources; Final Rule. 72 FR 8434, February 26, 2007. 153 U. S. EPA. (2011). 2005 National

- Scale Air Toxics Assessment. http://www.epa.gov/ttn/atw/nata2005/.Page 58 of 88

air toxics. Formaldeh yde is the largest contributor to cancer risk of all 80 pollutants quantitatively

assessed in the 2005 NATA. Mobile sources were responsible for over 40 percent of primary emissions of this pollutant in 2005, and are major contributors to formaldehyde precursor emissions. Benzene is also a large contributor to cancer risk, and mobile sources account for over 70 percent of ambient exposure. Over the years, EPA has implemented a number of mobile source and fuel controls which have resulted in VOC reductions, which also reduced formaldeh yd e, benzene and other air toxic e missions. 6. Near

- Roadway

Pollution Locations in close proximity to major roadway s generall y have elevated concentrations of man y air pollutants emitted from motor vehicles. Hundreds of such studies have been published in peer

- reviewed journals, concluding that concentrations of CO, NO, NO 2 , benzene, aldeh ydes, particulate matter, black carbon, and man y other compounds are elevated in ambient air within approximately

300

- 600 meters (about 1,000

- 2,000 feet) of major roadways. Highest concentrations of most po llutants emitted directly by motor vehicles are found at locations within 50 meters (about 165 feet) of the edge of a roadway ’s traffic lanes. A recent large

- scale review of air quality measurements in vicinity of major roadway s between 1978 and 2008 concluded that the pollutants with the steepest concentration gradients in vicinities of roadway s were CO, ultrafine particles, metals, elemental carbon (EC), NO, NO X , and several VOCs. 154 These pollutants showed a large reduction in concentrations within 100 me ters downwind of the roadway . Pollutants that showed more gradual reductions with distance from roadway s included benzene, NO 2 , PM 2.5 , and PM 10 . In the review article, results varied based on the method of statistical anal ys is used to determine the trend

. For pollutants with relatively high background concentrations relative to near - road concentrations, detecting concentration gradients can be difficult. For example, many

aldehydes have high background concentrations as a result of photochemical breakdown of precursors from many different organic compounds. This can make detection of gradients around roadway s and other primary emission sources difficult. However, several studies have measured aldeh ydes in multiple weather conditions, and found higher co ncentrations of many carbonyls downwind

154 Karner, A.A.; Eisinger, D.S.; Niemeier, D.A. (2010). Near

- roadway air quality: synthesizing the findings from real

- wo rld data. Environ Sci Technol 44: 5334

- 5344.Page 59 of 88

of roadway s. 155 , 156 These findings suggest a substantial roadway source of these carbon yl s. In the past 15 years, many studies have been published with results reporting that populations who live, work, or go to school near high

- traffic roadway s experience higher rates of numerous adverse health effects, compared to populations far away

from major roads. 157 Inaddition, numerous studies have found adverse health effects associated with spending time in traffic, su ch as commuting or walking along high

- traffic roadways. 158 , 159 , 160 , 161 The health outcomes with the strongest evidence linking them with traffic

- associated air pollutants are respiratory effects, particularly in asthmatic children, and cardiovascular effects. Num erous reviews of this body of health literature have been published as well. In 2010, an expert panel of the Health Effects Institute (HEI) published a review of hundreds of exposure, epidemiology , and toxicology studies. 162 The panel rated how the evidenc e for each t ype of health outcome supported a conclusion of a causal association with traffic

- associated air pollution as either “sufficient,” “suggestive but not sufficient,” or “inadequate and insufficient.” The panel categorized evidence of a causal a ssociation for exacerbation of childhood asthma as “sufficient.” The panel categorized evidence of a causal association for new onset asthma as between “sufficient” and as “suggestive but not sufficient.” “Suggestive of a causal association” was how the panel categorized evidence

155 Liu, W.; Zhang, J.; Kwon, J.l; et l. (2006). Concentrations and source characteristics of airborne carbonyl comp ounds measured outside urban residences. J Air Waste Manage Assoc 56: 1196

- 1204. 156 Cahill, T.M.; Charles, M.J.; Seaman, V.Y. (2010). Development and application of a sensitive method to determine concentrations of acrolein and other carbonyls in ambient air. Health Effects Institute Research Report 149. Available at http://dx.doi.org 157 In the widely

- used PubMed database of health publications, between January 1, 1990 and August 18, 2011, 605 publications contained the keywords “traffic, pollution, epidemi ology,” with approximately half the studies published after 2007. 158 Laden, F.; Hart, J.E.; Smith, T.J.; Davis, M.E.; Garshick, E. (2007) Cause

- specific mortality in the unionized U.S. trucking industry. Environmental Health Perspect 115:1192

- 1196. 159 Pet ers, A.; von Klot, S.; Heier, M.; Trentinaglia, I.; Hörmann, A.; Wichmann, H.E.; Löwel, H. (2004) Exposure to traffic and the onset of myocardial infarction. New England J Med 351: 1721

- 1730. 160 Zanobetti, A.; Stone, P.H.; Spelzer, F.E.; Schwartz, J.D.; C oull, B.A.; Suh, H.H.; Nearling, B.D.; Mittleman, M.A.; Verrier, R.L.; Gold, D.R. (2009) T

- wave alternans, air pollution and traffic in high

- risk subjects. Am J Cardiol 104: 665

- 670. 161 Dubowsky Adar, S.; Adamkiewicz, G.; Gold, D.R.; Schwartz, J.; Coull, B.A.; Suh, H. (2007) Ambient and microenvironmental particles and exhaled nitric oxide before and after a group bus trip. Environ Health Perspect 115: 507

- 512. 162 Health Effects Institute Panel on the Health Effects of Traffic

- Related Air Pollution. (2010 ). Traffic

- related air pollution: a critical review of the literature on emissions, exposure, and health effects. HEI Special Report 17. Available at http://www.healtheffects.orgPage 60 of 88

linking traffic

- associated air pollutants with exacerbation of adult respiratory sy mptoms and lung function decrement. It categorized as “inadequate and insufficient” evidence of a causal relationship between traffic

- related air pollution and health care utilization for respiratory problems, new onset adult asthma, chronic obstructive pulmonary

disease (COPD), nonasthmatic respiratory allergy , and cancer in adults and children. Other literature reviews have been published with c onclusions similar to the HEI panel’s. 163 , 164 , 165 Health outcomes with few publications suggest the possibility of other effects still lacking sufficient evidence to draw definitive conclusions. Among these outcomes with a small number of positive studies are neurological impacts (e.g., autism and reduced cognitive function) and reproductive outcomes (e.g., preterm birth, low birth weight). 166 , 167 , 168 , 169 In addition to health outcomes, particularl y cardiopulmonary effects, conclusions of numerous studies suggest mechanisms by which traffic

- related air pollution affects health. Numerous studies indicate that near

- roadway exposures may increase s ys temic inflammation, affecting organ s ys tems, including blood vessels and lungs. 170 , 171 , 172 , 173 Long

- term exposures in near

- road env ironments have

163 Boothe, V.L.; Shendell, D.G. (2008). Potential health effects associate d with residential proximity to freeways and primay roads: review of scientific literature, 1999

- 2006. J Environ Health 70: 33

- 41. 164 Salam, M.T.; Islam, T.; Gilliland, F.D. (2008). Recent evidence for adverse effects of residential proximity to traffic sources on asthma. Curr Opin Pulm Med 14: 3

- 8. 165 Raaschou

-Nielsen, O.; Reynolds, P. (2006). Air pollution and childhood cancer: a review of the epidemiological literature. Int J Cancer 118: 2920

- 9. 166 Volk, H.E.; Hertz

- Picciotto, I.; Delwiche, L.; et a l. (2011). Residential proximity to freeways and autism in the CHARGE study. Environ Health Perspect 119: 873

- 877. 167 Franco

- Suglia, S.; Gryparis, A.; Wright, R.O.; et al. (2007). Association of black carbon with cognition among children in a prospective birth cohort study. Am J Epidemiol. doi: 10.1093/aje/kwm308. [Online at http://dx.doi.org] 168 Power, M.C.; Weisskopf, M.G.; Alexeef, S.E.; et al. (2011). Traffic

- related air pollution and cognitive function in a cohort of older men. Environ Health Perspe ct 2011: 682

- 687. 169 Wu, J.; Wilhelm, M.; Chung, J.; et al. (2011). Comparing exposure assessment methods for traffic

- related air pollution in and adverse pregnancy outcome study. Environ Res 111: 685

- 6692. 170 Riediker, M. (2007). Cardiovascular effects of fine particulate matter components in highway patrol officers. Inhal Toxicol 19: 99

- 105. doi: 10.1080/08958370701495238 Available at http://dx.doi.org 171 Alexeef, S.E.; Coull, B.A.; Gryparis, A.; et al. (2011). Medium

- term exposure to traffic

- related a ir pollution and markers of inflammation and endothelial function. Environ Health Perspect 119: 481

- 486. doi:10.1289/ehp.1002560 Available at http://dx.doi.org 172 Eckel. S.P.; Berhane, K.; Salam, M.T.; et al. (2011). Traffic

- related pollution exposure and exhaled nitric oxide in the Children’s Health Study. Environ Health Perspect (IN PRESS). doi:10.1289/ehp.1103516

. Available at http://dx.doi.org 173 Zhang, J.; McCreanor, J.E.; Cullinan, P.; et al. (2009). Health effects of real

- world exposure diesel exhaust in persons with asthma. Res Rep Health Effects Inst 138. [Online at http://www.healtheffects.org]Page 61 of 88

been associated with inflammation

- associated conditions, such as atherosclerosis and asthma. 174 , 175 , 176 Several studies suggest that some factors may increase susceptibility

to the effects of traffic

- associated air pollution. Several studies have found stronger respiratory

associations in children experiencing chronic social stress, such as in violent neighborhoods or in homes with high family stress. 177 , 178 , 179 The risks associated with residence, workplace, or schools near major roads are of potentially

high public health significance due to the large population in such locations. According to the 2009 American Housing Survey , over 22 million homes (17.0 percent of all U.S. housing units) were located within 300 feet of an airport, railroad, or hi ghway with four or more lanes. This corresponds to a population of more than 50 million U.S. residents in close proximity to high

- traffic roadway s or other transportation sources. Based on 2010 Census data, a 2013 publication estimated that 19% of the U.S . population (over 59 million people) lived within 500 meters of roads with at least 25,000 annual average daily traffic (AADT), while about 3.2% of the population lived within 100 meters (about 300 feet) of such roads. 180 Another 2013 study estimated that 3.7% of the U.S. population (about 11.3 million people) lived within 150 meters (about 500 feet) of interstate highway s, or other freeway s and expressway s. 181 As discussed in Section III, on average, populations near major roads have higher fractions of min ority residents and lower socioeconomic status. Furthermore, on average, Americans

174 Adar, S.D.; Klein, R.; Klein, E.K.; et al. (2010). Air pollution and the microvasculatory: a cross

sectional assessment of in vivo retinal images in the population

- based Multi

- Ethnic Study of Atherosclerosis. PLoS Med 7(11): E1000372. doi:10.1371/journal.pmed.1000372

. Available at http://dx.doi.org 175 Kan, H.; Heiss, G.; Rose, K.M.; et al. (2008). Proxpective analysis of traffic exposure as a risk f actor for incident coronary heart disease: the Atherosclerosis Risk in Communities (ARIC) study. Environ Health Perspect 116: 1463

- 1468. doi:10.1289/ehp.11290

. Available at http://dx.doi.org 176 McConnell, R.; Islam, T.; Shankardass, K.; et al. (2010). C hildhood incident asthma and traffic

related air pollution at home and school. Environ Health Perspect 1021

- 1026. 177 Islam, T.; Urban, R.; Gauderman, W.J.; et al. (2011). Parental stress increases the detrimental effect of traffic exposure on children’s lung function. Am J Respir Crit Care Med (In press) 178 Clougherty, J.E.; Levy, J.I.; Kubzansky, L.D.; et al. (2007). Synergistic effects of traffic

- related air pollution and exposure to violence on urban asthma etiology. Environ Health Perspect 115: 1140

- 1 146. 179 Chen, E.; Schrier, H.M.; Strunk, R.C.; et al. (2008). Chronic traffic

- related air pollution and stress interact to predict biologic and clinical outcomes in asthma. Environ Health Perspect 116: 970

- 5. 180 Rowangould, G.M. (2013) A census of the US n ear - roadway population: public health and environmental justice considerations. Transportation Research Part D 25: 59

- 67. 181 Boehmer, T.K.; Foster, S.L.; Henry, J.R.; Woghiren

- Akinnifesi, E.L.; Yip, F.Y. (2013) Residential proximity to major highways

– Un ited States, 2010. Morbidity and Mortality Weekly Report 62(3);46

- 50.Page 62 of 88

spend more than an hour traveling each day , bringing nearl y all residents into a high

- exposure microenvironment for part of the day

. In light of these concerns , EPA has required and is working with states to ensure that air quality

monitors be placed near high

- traffic roadway s for determining NAAQS compliance for CO, NO 2 , and PM 2.5 ( in addition to those existing monitors located in neighborhoods and other locations farther a way from pollution sources )

. Near

- roadway monitors for NO 2 begin operation between 2014 and 2017 in Core Based Statistical Areas (CBSAs) with population of at least 500,000 . Monitors for CO and PM 2.5 begin operation between 2015 and 2017. The se monitors will further our understanding of exposure in these locations. EPA continues to research near

- road air quality , including the t ypes of pollutants found in high concentrations near major roads and health problems associated with the mixture of p ollutants near roads. 7. Environmental Impacts of Motor Vehicles and Fuels
a. Plant and Ecosy stem Effects of Ozone The welfare effects of ozone can be observed across a variet y of scales, i.e. subcellular , c ellular, leaf, whole plant, population and ecos ys t em. Ozone effects that begin at small spatial scales, such as the leaf of an individual plant, when they occur at sufficient magnitudes (or to a sufficient degree) can result in effects being propagated along a continuum to larger and larger spatial scale s. For example, effects at the individual plant level, such as altered rates of leaf gas exchange, growth and reproduction can , when widespread, result in broad changes in ecos ys tems, such as productivity , carbon storage, water cycling, nutrient cycling, and community

composition. Ozone can produce both acute and chronic injury in sensitive species depending on the concentration level and the duration of the exposure. 182 Inthose sensitive species, o zone effects also tend to accumulate over the growing sea son of

182 O nly a small percentage of all the plant species growing within the U.S. (over 43,000 species have been catalogued in the USDA PLANTS database ) have been studied with respect to ozone sensitivity (U.S. EPA. Review of the National Ambient Air Quality Standards for Ozone: Policy Assessment of Scientific and Technical Information. OAQPS Staff Paper. U.S. Environmental Protection Agency, Washington, DC, EPA

- 452/R

- 07

- 007, 2007. p .7

- 7)

. T hus, ozone im pacts could be occurring in areas where plant species sensitive to ozone have not yet been studied or identified. In addition, the concentration at which ozone levels overwhelm a plant’s ability to detoxify or compensate for oxidant exposur e varies ( U.S. EPA. Welfare Risk and Exposure Assessment for Ozone. Second External Review Draft. EPA

- 452/P

- 14

- 003a, 2014. Figure 6

- 2, p. 6

- 5). Thus, whether a plant is classified as sensitive or tolerant depends in part on the exposure levels being consi dered.Page 63 of 88

the plant, so that even low concentrations experienced for a longer duration have the potential to create chronic stress on vegetation. Ozone damage to sensitive species includes visible injury to leaves and impaired photosy nthesis, both of which can lead to reduced plant growth and reproduction, resulting in reduced crop yields, forestry production, and use of sensitive ornamentals in landscaping. In addition, the impairment of photosynthesis, the process b y which the plant makes carboh ydrat es (its source of energy and food), can lead to a subsequent reduction in root growth and carboh ydrate storage below ground, resulting in other, more subtle plant and ecos ys tems impacts. These latter impacts include increased susceptibility of plants to i nsect attack, disease, harsh weather, interspecies competition and overall decreased plant vigor. The adverse effects of ozone on areas with sensitive species could potentiall y lead to species shifts and loss from th e affected ecos ys tems, resulting in a loss or reduction in associated ecosy stem goods and services. Lastl y, visible ozone injury to leaves can result in a loss of aesthetic value in areas of special scenic significance like national parks and wilderness a reas. T he Integrated Science Assessment (I SA) for Ozone presents more detailed information on how ozone effects vegetation and ecosy stems. 183 The ISA concludes that ambient concentrations of ozone are associated with a number of adverse welfare effects an d characterizes the weight of evidence for different effects associated with ozone. 184 The I SA concludes that visible foliar injury effects on vegetation, reduced vegetation growth, reduced productivity in terrestrial ecos ys tems, reduced yi eld and quality o f agricultural crops, and alteration of below

ground biogeochemical cycles are causally associated with exposure to ozone. It also concludes that reduced carbon sequestration in terrestrial ecos ys tems, alteration of terrestrial ecos ys tem water cycling, an d alteration of terrestrial community composition are likely

to be caus all y associated with exposure to ozone. b. Visibility Visibility can be defined as the degree to which the atmosphere is transparent to visible light. 185 Visibility impairment is caus ed b y light scattering

183 U.S. EPA. Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 10/076F, 2013. The ISA is available at http://cfpub.epa.gov/ncea/isa/recordisplay. cfm?deid=247492#Dow nload
184 The Ozone ISA evaluates the evidence associated with different ozone related health and welfare effects, assigning one of five “weight of evidence” determinations: causal relationship, likely to be a causal relationship, sugges tive of a causal relationship, inadequate to infer a causal relationship, and not likely to be a causal relationship. For more information on these levels of evidence, please refer to Table II of the ISA. 185 National Research Council, (1993). Protecting Visibility in National Parks and Wilderness Areas. National Academy of Sciences Committee on Haze in National Parks and Wilderness Areas.Page 64 of 88

and absorption b y suspended particles and gases. Visibility is important because it has direct significance to people’s enjo ym ent of daily activities in all parts of the country . Individuals value good visibility for the well

- being it provides them directly , where they

live and work, and in places where they enjoy recreational opportunities. Visibility

is also highly

valued in significant natural areas, such as national parks and wilderness areas, and special emphasis is given to p rotecting visibility in these areas. For more information on visibility see the final 2009 PM ISA. 186 EPA is working to address visibility impairment. In 1999 , EPA finalized the regional haze program to protect the visibility in Mandatory

Class I Federal areas. 187 There are 156 national parks, forests and wilderness areas categorized as Mandatory

Class I Federal areas. 188 These areas are defined in CAA section 162 as those national parks exceeding 6,000 acres, wilderness areas and memorial parks exceeding 5,0 00 acres, and all international parks which were in existence on August 7, 1977. EPA has also concluded that PM 2.5 causes adverse effects on visibility in other areas that are not protected b y the Regional Haze Rule, depending on PM 2.5 concentrations and other factors that control their visibility impact effectiveness such as dry

chemical composition and relative humidity (i.e., an indicator of the water composition of the particles). EPA revised the PM 2.5 standards in December 2012 and established a targe t level of protection that is expected to be met through attainment of the existing secondary standards for PM 2.5 .

National Academy Press, Washington, DC. This book can be view ed on the National Academy Press Website at http://www.nap.edu/books/0309048443/html/ 186 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R

- 08/139F. 187 64 FR 35714 (July 1, 1999). 188 62 FR 38680

- 38681 (July 18, 1997).Page 65 of 88 i. Current Visibility Levels As mentioned in Section II.B.2.c , millions of people live in nonattainment areas for the PM 2.5 NAAQS. These populations, as well as large numbers of individuals who travel to these areas, are likel y to experience visibility impairment. In addition, while visibility trends have improved in mandatory class I federal areas, the most recent data show that these areas continue to suffer from visibility impairment. In summary, visibility impairment is experienced throughout the U.S., in multi

- state regions, urban areas, and remote mandatory class I federal areas.
c. Atmospheric Dep osition Wet and dry

deposition of ambient particulate matter delivers a complex mixture of metals (e.g., mercury , zinc, lead, nickel, aluminum, cadmium), organic compounds (e.g., pol yc yclic organic matter, dioxins, furans) and inorganic compounds (e.g., ni trate, sulfate) to terrestrial and aquatic ecosy stems. The chemical form of the compounds deposited depends on a variety of factors including ambient conditions (e.g., temperature, humidity , oxidant levels) and the sources of the material. Chemical and p hy sical transformations of the compounds occur in the atmosphere as well as the media onto which they deposit. These transformations in turn influence the fate, bioavailability and potential toxicity

of these compounds. Atmospheric deposition has been id entified as a key component of the environmental and human health hazard posed by several pollutants including mercury , dioxin and PCBs. 189 Adverse impacts on water quality can occur when atmospheric contaminants deposit to the water surface or when material deposited on the land enters a waterbody through runoff. Potential impacts of atmospheric deposition to waterbodies include those related to both nutrient and toxic inputs. Adverse effects to human health and welfare can occur from the addition of exces s nitrogen via atmospheric deposition. The nitrogen

- nutrient enrichment contributes to toxic algae blooms and zones of depleted ox ygen, which can lead to fish kills, frequently in coastal waters. Deposition of heav y metals or other toxics may lead to the human ingestion of contaminated fish, impairment of drinking water, damage to freshwater and marine ecos ys tem components, and limits to recreational uses. Several studies have been conducted in U.S. coastal waters and in the Great Lakes Region in which the role of ambient PM deposition and runoff is investigated. 190 , 191 , 192 , 193 , 194

189 U.S. EPA. (2000). Deposition of Air Pollutants to the Great Waters: Third Report to Congress. Office of Air Quality Planning and Standards. EPA

- 453/R

- 00

- 0005. 190 U.S. EPA. (2004). National Coastal Condition Report II. Office of Research and Development/ Office of Water. EPA

- 620/R

- 03/002.Page 66 of 88 Atmospheric deposition of nitrogen and sulfur contributes to acidification, altering biogeochemistry

and affecting animal and plant life in terrestrial and aquatic ecosy stems across th e United States. The sensitivity of terrestrial and aquatic ecosy stems to acidification from nitrogen and sulfur deposition is predominantly

governed by

geology

. Prolonged exposure to excess nitrogen and sulfur deposition in sensitive areas acidifies lak es, rivers and soils. Increased acidity in surface waters creates inhospitable conditions for biota and affects the abundance and nutritional value of preferred prey species, threatening biodiversity and ecos ys tem function. Over time, acidifying depositi on also removes essential nutrients from forest soils, depleting the capacity of soils to neutralize future acid loadings and negativel y affecting forest sustainability. Major effects include a decline in sensitive forest tree species, such as red spruce ( Picea rubens ) and sugar maple ( Acer saccharum ), and a loss of biodiversity of fishes, zooplankton, and macro invertebrates

. In addition to the role nitrogen deposition play s in acidification, nitrogen deposition also leads to nutrient enrichment and altered biogeochemical cycling. In aquatic s ys tems increased nitrogen can alter species assemblages and cause eutrophication. In terrestrial sy stems nitrogen loading can lead to loss of nitrogen sensitive lichen species, decreased biodiversity of grasslands, meadows and other sensitive habitats, and increased potential for invasive species. For a broader explanation of the topics treated here, refer to the description in Section 6.3.2 of the RIA. Adverse impacts on soil chemistry and plant life have been obse rved for areas heavil y influenced by atmospheric deposition of nutrients, metals and acid species, resulting in species shifts, loss of biodiversity , forest decline, damage to forest productivit y and reductions in ecosystem services. Potential impacts als o include adverse effects to human health through ingestion of contaminated vegetation or livestock (as in the case for dioxin deposition), reduction in crop yi eld, and limited use of land due to contamination.

191 Gao, Y., E.D. Nelson, M.P. Field, et al. (2002). Characterization of atmospheric trace elements on PM 2.5 particulate matter over the New York

- New Jersey harbor estuary. Atmos. Environ. 36: 1077

- 1086. 192 Kim , G., N. Hussain, J.R. Scudlark, and T.M. Church. (2000). Factors influencing the atmospheric depositional fluxes of stable Pb, 210Pb, and 7Be into Chesapeake Bay. J. Atmos. Chem. 36: 65

- 79. 193 Lu, R., R.P. Turco, K. Stolzenbach, et al. (2003). Dry deposition of airborne trace metals on the Los Angeles Basin and adjacent coastal waters. J. Geophys. Res. 108(D2, 4074): AAC 11

- 1 to 11

- 24. 194 Marvin, C.H., M.N. Charlton, E.J. Reiner, et al. (2002). Surficial sediment contamination in Lakes Eri e and Ontario: A comparative analysis. J. Great Lakes Res. 28(3): 437

- 450.Page 67 of 88 Atmospheric deposition of pollutants can re duce the aesthetic appeal of buildings and culturall y i mportant articles through soiling, and can contribute directly (or in conjunction with other pollutants) to structural damage by means of corrosion or erosion. Atmospheric deposition may affect materi als principally by promoting and accelerating the corrosion of metals, by degrading paints, and by deteriorating building materials such as concrete and limestone. Particles contribute to these effects because of their electroly tic, hygroscopic, and acidi c properties, and their ability

to adsorb corrosive gases (principall y sulfur dioxide). i. Current Nitrogen and Sulfur Deposition Over the past two decades, the EPA has undertaken numerous efforts to reduce nitrogen and sulfur deposition across the U.S. An aly ses of long

- term monitoring data for the U.S. show that deposition of both nitrogen and sulfur compounds has decreased over the last 1 9 ye ars. 195 The data show that reductions were more substantial for sulfur compounds than for nitrogen compounds. In th e eastern U.S., where data are most abundant, total sulfur deposition decreased by about 44 percent between 1990 and 2007, while total nitrogen deposition decreased by 25 percent over the same time frame. 196 These numbers are generated b y the U.S. national monitoring network and they likel y underestimate nitrogen deposition because neither ammonia nor organic nitrogen is measured. Although total nitrogen and sulfur deposition has decreased over time, many areas continue to be negativel y impacted b y depositi on. Deposition of inorganic nitrogen and sulfur species routinely measured in the U.S. between 2005 and 2007 were as high as 9.6 kilograms of nitrogen per hectare (kg N/ha) averaged over three ye ars and 20.8 kilograms of sulfur per hectare (kg S/ha) avera ged over three years. 197 d. Environmental Effects of Air Toxics Emissions from producing, transporting and combusting fuel contribute to ambient levels of pollutants that contribute to adverse effects on vegetation. Volatile organic compounds, some of which are considered air toxics, have long

195 U.S. EPA. (2013). U.S. EPA’s Report on the Environment. Data accessed online November 25, 2013 at: http://cfpub.epa.gov/eroe/index.cfm? fuseaction=detail.viewInd&lv=list.listBy SubTopic&r=216610 &subtop=341&ch=46

. 196 U.S. EPA. (2012). U.S. EPA’s Report on the Environment. Data accessed online February 15, 2012 at: http://cfpub.epa.gov/eroe/index.cfm? fuseaction=detail.viewPDF&ch=46&lShowInd=0&subtop=341 &lv=list.listByChapter&r=216 610. 197 U.S. EPA. (2012). U.S. EPA's Report on the Environment. Data accessed online February 15, 2012 at: http://cfpub.epa.gov/eroe/index.cfm? fuseaction=detail.viewPDF&ch=46&lShowInd=0&subtop=341 &lv=list.listByChapter&r=216610.Page 68 of 88

been suspected to play

a role in vegetation damage. 198 In laboratory experiments, a wide range of tolerance to VOCs has been observed. 199 Decreases in harvested seed pod weight have been reported for the more sensitive pl ants, and some studies have reported effects on seed germination, flowering and fruit ripening. Effects of individual VOCs or their role in conjunction with other stressors (e.g., acidification, drought, temperature extremes) have not been well studied. Ina recent study of a mixture of VOCs including ethanol and toluene on herbaceous plants, significant effects on seed production, leaf water content and photosy nthetic efficiency were reported for some plant species. 200 Research suggests an adverse impact of vehicle exhaust on plants, which has in some cases been attributed to aromatic compounds and in other cases to nitrogen oxides. 201 , 202 , 203 

## III. **How Wo**  **uld This**  **Rule Reduce Emissions and**  **Air Pollution?**  **A. Effects of the Vehicle and Fuel Changes on Mobile Source Emissi**  **ons** The Tier 3 vehicle and fuel standards will significantly reduce the tailpipe and evaporative emissions of light

- and heav y - duty vehicles in several ways, as described in this section. In addition, the gasoline sulfur standard will reduce emissions of SO 2 from existing gasoline

- powered vehicles and equipment. As described in Section II, all of these emission reductions will in turn improve air quality nationwide and reduce the health effects associated with air pollution from mobile sources. As with the Tier 2 program, EPA is implement ing closely

- coordinated requirements for both automakers and refiners in the same rulemaking action. The Tier 3 vehicle emission standards and gasoline sulfur standards represent a “sy stems

198 U.S. EPA. (1991). Effe cts of organic chemicals in the atmosphere on terrestrial plants. EPA/600/3

- 91/001. 199 Cape JN, ID Leith, J Binnie, J Content, M Donkin, M Skewes, DN Price AR Brown, AD Sharpe. (2003). Effects of VOCs on herbaceous plants in an open

- top chamber experiment. Environ. Pollut. 124:341

- 343. 200 Cape JN, ID Leith, J Binnie, J Content, M Donkin, M Skewes, DN Price AR Brown, AD Sharpe. (2003). Effects of VOCs on herbaceous plants in an open

- top chamber experiment. Environ. Pollut. 124:341

- 343. 201 Viskari E

- L. (2000). Epicuticular wax of Norway spruce needles as indicator of traffic pollutant deposition. Water, Air, and Soil Pollut. 121:327

- 337. 202 Ugrekhelidze D, F Korte, G Kvesitadze. (1997). Uptake and transformation of benzene and toluene by plant leaves. Ecotox. Environ. Safety 37:24

- 29. 203 Kammerbauer H, H Selinger, R Rommelt, A Ziegler

- Jons, D Knoppik, B Hock. (1987). Toxic components of motor vehicle emissions for the spruce Picea abies. Environ. Pollut. 48:235

- 243.Page 69 of 88

approach” to reducing vehicle

- r elated exhaust and evaporative emissions. By recognizing the relationships among the various sources of emissions addressed by this action , we have been able to integrate the provisions into a single, coordinated program. 1. How Do Vehicles Produce the Emi ssions Addressed in this Action ? The degree to which vehicles produce exhaust and evaporative emissions depends on the design and functionality of the engine and the associated exhaust and evaporative emission controls, in concert with the properties of t he fuel on which the vehicle is operating. In the following paragraphs, we discuss how light

and heav y - dut y vehicles produce each of these t yp es of emissions, both from the tailpipe and from the fuel sy stem.
a. Tailpipe (Exhaust) Emissions The pollutants emitted at the vehicle’s tailpipe and their quantities depend on how the fuel is combusted in the engine and how the resulting gases are treated in the exhaust sy stem. Historically , much of tailpipe emission control has focused on hydrocarbon compounds ( HC) and NO X . The portion of hydrocarbons that is methane is minimally

reactive in forming ozone. Thus, for emission control purposes, the focus is generall y on non - methane hydrocarbons (NMHC), which are also expressed as non

- methane organic gases (NMOG) in order to account for oxygenates (usually

ethanol) now usually

present in the fuel. Tailpipe hydrocarbon emissions also include several toxic pollutants, including benzene, acetaldehyde, and formaldehyde. To varying degrees, the mass emissions of thes e pollutants are reduced along with other hydrocarbons by the catal yt ic converter and improved engine controls. Li ght

- and heav y - dut y gasoline vehicles also emit PM and CO. PM forms directly as a combustion product (as elemental carbon or soot) and indi rectly as semi

- volatile hydrocarbon compounds that form particles in the exhaust sy stem or soon after exiting the tailpipe. CO is a product of incomplete fuel combustion. When operating properl y, modern exhaust emission controls (centering on the catal yt i c convertor) can reduce much of the HC (including toxics), NO X and CO exiting the engine. However, tailpipe emissions are increased during periods of vehicle startup, as catal yt ic convertors must warm up to be effective; during subsequent operation due to the interference of sulfur in the gasoline; during high load operating events, as the catal ys t is overwhelmed or its operation is modified to protect against permanent damage; and as a vehicle ages, as the cataly st degrades in performance due to the effec ts of high temperature operation and contaminants in the fuel and lubricating oil.Page 70 of 88 b. Evaporative Emissions Gasoline vehicles also produce vapors in the fuel tank and fuel s ys tem that can be released as evaporative emissions. These vapors are primaril y the lighter, more volatile hydrocarbon compounds in gasoline. As discussed in Section IV below, vehicle evaporative (“evap”) control sy stems are designed to block or capture vapors as they

are generated. Vapors are generated in the vehicle fuel tank and fuel sy stem (and released to the atmosphere if not adequatel y controlled) as fuel heats up due to ambient temperature increase and/or vehicle operation. Fuel vapors are also released when they permeate through elastomers in the fuel s ys tem , when they leak at connections or due to damaged components, and during refueling events. In general, the evap emission controls on current vehicles (and that will be improved under this action ) consist of a canister filled with activated charcoal and connected b y hoses to the fuel s ys tem. The hoses direct generated vapors to the canister, which collects the vapors on the carbon and stores them until the sy stem experiences a “purge” event. During purge, the engine draws fresh air through the canister, carrying vapors re leased by the carbon to the engine to be combusted and restoring the capacity of the canister. Evaporative emissions occur when vapors are emitted to the atmosphere because the evap s ys tem is compromised, the carbon canister is overwhelmed, or vapors perm eate or leak. As such, evaporative emission controls also involve proper material selection for fuel sy stem components, careful design of these components, and onboard diagnostics to check the sy stem for failure. 2. How W ill the Changes to Gasoline Sulfur Content Affect Vehicle Emissions? Gasoline vehicles rel y on highl y efficient aftertreatment catalysts to control tailpipe emissions of harmful pollutants like CO and NO X , as well as VOCs that include air toxics and precursor compounds to ozone and seconda ry PM in the atmosphere. These cataly sts utilize finely

- dispersed precious metals that are susceptible to deactivation by sulfur compounds in the exhaust. Studies have repeatedly

demonstrated that the presence of even a tiny amount of sulfur in fuel has a measurable impact on the ability of the cataly st to control emissions, and that emission levels of most pollutants, especially NOx, are very

sensitive to fuel sulfur. 204 , 205

204 The Effects of Ultra

- Lo w Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In

- Use Fleet , EPA

- 420

- R

- 1 4

- 00 2.Page 71 of 88 Sulfur naturally

occurs in crude oil and is carried through the refining process i nto gasoline

. EPA’s Tier 2 rulemaking for light

- dut y vehicles, published in 2000, required refiners to reduce sulfur levels in gasoline to an average of 30 ppm , a reduction of about 90 percent from the in

- use baseline . At the time , there were indications that sulfur reductions below 30 ppm may provide additional emission benefits. However, the data was insufficient to quantify the benefits to the existing fleet, and the Tier 2 vehicle standards could be achieved without lowering sulfur below 30 ppm

. 206 As discussed in Section IV.A.6, subsequent research provides a compelling case that even this level of sulfur degrades the emission performance of vehicles on the road today

and inhibits necessary

further reductions in vehicle emissions performance, which dep end on optimum cataly st performance to reach emission targets. A study conducted by EPA and the auto industry in support of the Mobile Source Air Toxics (MSAT) rule found significant reductions in NO X , CO and total HC when nine Tier 2 vehicles were tested on ultra

- low sulfur fuel. 207 Inparticular, the study found a 32 percent de crease in NO X when sulfur was reduced from 32 ppm to 6 ppm (equivalent to a 25% decrease if sulfur levels were reduced from 30 to 10 ppm, assuming a linear effect) . Another recent study by Umicore showed reductions of 41 percent for NO X and 17 percent for hydrocarbons on a PZEV operating on fuel with 33 ppm and 3 ppm fuel (equivalent to reductions of 27% and 11%, respectively , if sulfur levels were reduced from 30 to 10 ppm, assumin g a linear effect). 208 A larger study of Tier 2 vehicles recentl y completed by EPA confirmed these results, showing significant reductions in FTP

- composite NO X (14 percent), CO (10 percent) and total HC (15 percent) on the 5 ppm fuel, relative to 28 ppm fu el (equivalent to 12%, 9%, and 13% reduction, respectivel y, if sulfur levels were reduced from 30 to 10 ppm, assuming a linear effect)

. 209 For NO X , the majority of overall reductions were driven by large reductions on warmed

- up periods of the tes t cycle (Ba g 2), which showed a 52% reduction using 5 ppm fuel relative to 28 ppm fuel (equivalent to 45% reduction if sulfur levels were reduced from 30 to 10 ppm, assuming a linear effect) , consistent with the role of sulfur in catal ys t degradation

205 Durbin, T., “The Effect of Fuel Sulfur on NH3 and Other Emissions from 2000

- 2001 Model Year Vehicles”, May 2003. Published as Report E

- 60 by the Coordinating Research Coun cil, Alpharetta, GA. 206 65 FR 6698 (February 10, 2000) 207 Regulatory Impact Analysis for the Control of Hazardous Air Pollutants from Mobile Sources Final Rule, EPA 420

- R

- 07

- 002, Chapter 6 208 Ball D., Clark D., Moser D. (2011) , Effects of Fuel Sulfur on FTP N Ox Emissions from a PZEV 4 Cylinder Application. SAE 2011 World Congress Paper 2011

- 01

- 0300 209 The Effects of Ultra

- Lo w Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In

- Use Fleet , EPA

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discussed above. For additional details regarding these results, please see Section IV .A.6.c. Our application of these study results assumes a linear effect of sulfur level on catal ys t efficiency

between the high and low sulfur test fuels. This is reasonable given that the mass flow rate of sulfur in exhaust gas changes in proportion to its concentration in the fuel, and that the chemical kinetics of adsorption of sulfur to the precious metal sites is approximately first order

. Linearity of effect is also supported by

p ast studies with multiple fuel sulfur levels such as the CRC E

- 60 and 200 0 AAM/AIAM/Oil Industry emission test program s . 210 , 211 Based on these analy ses , the benefits of the Tier 3 sulfur standard are significant in two way s: they enable vehicles designed to the Tier 3 tailpipe exhaust standards to meet these standards for the duration of their useful life, and they facilitate immediate emission reductions from all the vehicles on the road at the time the sulfur controls are implemented. **B. How W**  **ill Emissions Be**  **Reduced?** The Tier 3 standards will reduce emissions of VOC, NO X (including NO 2 ), direct PM 2.5 , CO, SO 2 , and air toxics. The sulfur standards will reduce emissions from the on

- road fleet immediately upon implementation in calendar ye ar 2017. The vehicle standards will begin to reduce emissions as the cleaner cars and trucks begin to enter the fleet in model year 2017 and model year 2018, respectively . The magnitude of reduction will grow as more Tier 3 vehicles enter the fleet. We present emission redu ctions in calendar ye ar 2018 to reflect the earl y reductions expected from the Tier 3 standards, and in calendar year 2030 , when 70 percent of the miles travelled are from vehicles that meet the fully phased

- in Tier 3 standards

. Although 2030 is the farth est year that is feasible for air qualit y modeling, the full reduction of the vehicle program will be realized after 2030, when the fleet has fully turned over to vehicles that meet the full y phased

- in Tier 3 standards; thus we present emission reductions projected in 2050 as well (see Chapter 7 of the RIA)

. Emission reductions are estimated on an annual basis, for all 50 U.S. states plus the District of Columbia, Puerto Rico and the U.S. Virgin Islands. The reductions were estimated using a version of EPA’s MOVES model updated for this anal ys is, as described in detail in Chapter 7 of the RIA. This version of MOVES includes our most recent data on how vehicle emissions are affected b y changes in

210 Durbin, T., “The Effect of Fuel Sulfur on NH3 and Other Emissions from 2000

- 2001 Model Year Vehicles”, May 2003. Published as Report E

- 60 by the Coordinating Research Council, Alpharetta, GA. 211 “AAM/AIAM/Oil Industry Low Sulfur & Oxygenate Test Program”, 2000, last accessed on 01/15/14 at the follow ing URL: http://www.arb.ca.gov/fuels/gasoline/carfg3/aam_prstn.pdf

.Page 73 of 88

sulfur, ethanol, RVP, and other fuel properties. We estimated emission reductions compared to a reference case that assumed renewable fuel volumes and ethanol blends based on the U.S. Energy Information Administration’s Annual Energy Outlook 2013 (AEO2013). 212 As described in Chapter 7 of the RIA, the reference an d control scenarios based on AEO2013 reflect a mix of E10 , E15 , and E85 in both 2018 and 2030. The reference case assumed an average sulfur level of 30 ppm (10 ppm in California) and continuation of the Tier 2 vehicle program indefinitely , with the except ion of California and Section 177 states that have adopted the LEV III program. The anal ys is described here account s for the following national onroad rules:

 Tier 2 Motor Vehicle Emissions Standards and Gasoline Sulfur

Control Requirements (65 FR 6698, Feb ruary 10, 2000)

 Heav y - Duty

Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements (66 FR 5002, January 18, 2001)

 Mobile Source Air Toxics Rule (72 FR 8428, February 26, 2007)

 Regulation of Fuels and Fuel Additives: Changes to Rene wable Fuel Standard Program (75 FR 14670, March 26, 2010)

 Li ght

- Dut y Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards for 2012

- 2016 (75 FR 25324, May

7, 2010)

 Greenhouse Gas Emissions Standards and Fuel Efficiency Stan dards for Medium

- and Heav y - Duty Engines and Vehicles ( 76 FR 57106 , September 15, 201 1 )

 2017 and Later Model Year Light

- Dut y Vehicle Greenhouse Gas Emissions and Corporate Average Fuel Econom y Standards (77 FR 62623, October 15, 2012 ) The anal ys is also acc ounts for many other national rules and standards. In addition, the modeling accounts for state and local rules including California’s most recent Low Emission Vehicle (LEV III) program adopted in California and twelve other states (also referred to as Se ction 177 states), 213 local fuel standards,

212 U.S. Energy Information Administration, Annual Energy Outlook (April 15, 2013) 213 These states include Connecticut, Delaware, Maryland, Maine, Massachusetts, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Washington, and Vermont.Page 74 of 88

Inspection/Maintenance programs, Stage II refueling controls, the National L ow Emission Vehicle Program (NLEV), and the S ection 177 states LEV and LEV II programs. See the Tier 3 emissions modeling TSD for more de tail. A summary

of emission reductions projected to result from Tier 3, relative to the reference case, is shown in calendar years 201 8 and 2030 for NO X , VOC, direct PM 2.5 , CO, SO 2 , and total air toxics in Table III

- 1

. For man y pollutants, the immediate reductions in 201 8 are significant; for example, combined NO X and VOC emissions will be reduced b y over 300,000 tons. By 2030, combined NO X and VOC emissions will be reduced b y roughl y 500,000 tons, one quarter of th e onroad inventory . Man y of the modeled air toxics will be significantl y reduced as well, including benzene, 1,3

- butadiene, acetaldehyde, acrolein and ethanol (ranging from 10 to nearl y 30 percent of the national onroad inventory by 2030). The relative r eduction in overall emissions will continue to increase beyond 2030 as more of the fleet continues to turn over to Tier 3 vehicles; for example, b y 2050, when nearly

all of the fleet will have turned over to vehicles meeting the fully phased

- in Tier 3 stan dards, we estimate the Tier 3 program will reduce onroad emissions of NO X and VOC nearl y 31 percent from the level of emissions projected without Tier 3 controls. **Table III**  **- 1**  **Estimated Emission Reductions from the Tier 3 Standards** 

**(Annual U.S. short tons)** 20 18 2030 Tons % of

Onroad Inventory Tons % of

Onroad Inventory NO X 264,369 10% 328,509 25% VOC 47,504 3% 167,591 16% CO 278,879 2% 3,458,041 24% Direct PM 2.5 130 0.1% 7,892 10% Benzene 1,916 6% 4,762 26% SO 2 14,813 56% 12,399 56% 1,3

- Butadiene 257 5% 677 29% Formaldeh yd e 513 2% 1,277 10% Acetaldeh yd e 600 3% 2,067 21% Acrolein 40 3% 127 15% Ethanol 2,704 2% 19,950 16%Page 75 of 88 Reductions for each pollutant are discussed in the following sections, f ocusing on the contribution of program elements to the total reductions summarized above. 1. NO X The Tier 3 sulfur standards will significantly reduce NO X emissions immediately

upon implementation of the program. As discussed above, recent research on the impact of sulfur on Tier 2 technology vehicles shows the potential for significant reductions in NO X emissions from the existing fleet of Tier 2 vehicles b y lowering sulfur levels to 10 ppm. Prior research shows that NO X emissions will also be expected to decrease from the fleet of older (pre

- Tier 2) light

- duty vehicles as well as heavy

- dut y gasoline vehicles, 214 although to a lesser extent than for Tier 2 vehicles. Table III

- 2 shows the reduction in NO X emissions, in annual short tons, projected in calendar ye ars 2018 and 2030. The reductions are split into those attributable to the introduction of low sulfur fuel in the pre

- Tier 3 fleet (defined for this analy sis as model years prior to 2017); and reductions attributable to vehicle standards enabled b y low sulfur fuel (model ye ar 2017 and later). As shown, upon implementation of the Tier 3 sulfur standards, total onroad NO X emissions are projected to drop 10 percent. This is primarily due to large reductions from Tier 2 gasoline vehicles, which contribute about one

- quarter of the NO X emissions from the on

- road fleet in 201 8 . The relative reduction grows as cleaner vehicles turn over into the fleet. By

2030, we project that the reduction in overall onroad NO X inventory will be 25 percent. **Table III**  **- 2**  **Projected NO X**  **Reductions from Tier 3 Program (Annual U.S. Tons)**  **2018 2030**  **Total reduction 264,369**  **328,509** Reduction from pre

- Tier 3 fleet due to sulfur standard 242,4 34 56,324 Reduction from Tier 3 fleet due to vehicle and sulfur standards 21,934 272,185
**Percent reduction in onroad NO**  **X emissions**  **10% 25%** 

214 Rao, V. (2001) , Fuel Sulfur Effects on Exhaust Emissions: Recommendations for MOBILE6, EPA

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- 039Page 76 of 88 2. VOC Table III

- 3 shows the reduction in VOC emissions, in annual short tons, projected in calendar ye ars 2018 and 2030 resulting from the Tier 3 standards. In 2018 , as with NO X , we project reductions from the pre

- Tier 3 fleet with the fuel standards. By

2030 , the reduction in overall onroad VOC emissions will be 16 percent, the majority

of this from the vehicles meeting the full y phased

- in Tier 3 standards . The evaporative standards are projected to account for roughly one third of the overall vehicle program reduction in 2030. **Table III**  **- 3**  **Projected VOC Reductions from Tier 3 Program (Annual U.S. Tons)**  **2018 2030**  **Total reduction 47,504**  **167,591** Reduction from pre

- Tier 3 fleet due to sulfur standard 38,786 11,249 Reduction from Tier 3 fleet due to vehicle and sulfur standards 8,7 18 156,343

Exhaust 43,009 105,253 Evaporative 4,495 62,339 **Percent reduction in onroad VOC emissions**  **3% 16%** 
3. CO Table III

- 4 shows the reductions for CO, broken down by pre - and post

- Tier 3 in the manner described f or NO X and VOC above. In contrast to NOx and VOC, the immediate CO reductions in the onroad fleet from sulfur control in 2018 are small, based on research showing that fuel sulfur level has a minimal impact on CO emissions from Tier 2 vehicles . The CO ex haust standards are projected to reduce onroad CO emissions by

24 percent in 2030. **Table III**  **- 4**  **Projected CO Reductions from Tier 3 Program (Annual U.S. Tons) 2018**  **2030 Total reduction**  **278,879 3,458,041**  Re duction from pre

- Tier 3 fleet due to sulfur standard 122,171 17,734
Reduction from Tier 3 fleet due to vehicle and sulfur standards 156,708 3,440,307
**Percent reduction in onroad CO emissions**  **2% 24%** Page 77 of 88 4. Direct PM 2.5 Reductions in direct emissions of PM 2.5 are projected to result solely from the vehicle tailpipe standards, so meaningful reductions are realized mainly as the fleet turns over. By

2030, we project a reduction of about 7,900 tons annually , which represents approximately 10 percent of the onroad direct PM 2.5 inventory. T he relative reduction in onroad emissions is projected to grow to 28 percent in 2050 , when nearl y all of the fleet will have turned over to vehicles meeting the fully phased

- in Tier 3 standards . Reductions in NO X and VOC emission s will also reduce secondary

PM formation, which is quantified as part of the air quality anal ys is described in Section III.C. 5. Air Toxics Emissions of air toxics also will be reduced b y the sulfur, exhaust and evaporative standards. Air toxics are gener ally a subset of compounds making up VOC, so the reduction trends tend to track the VOC reductions presented above , for most air toxics. Table III

- 5 presents reductions for certain key air toxics, and Table III

- 6 presents reductions for the sum of 71 different toxic compounds. **Table III**  **- 5**  **Reductions for Certain Individual Compounds (Annual U.S. Tons)**

Tons Reduced in 201 8 % Reduction

in Onroad Emissions Tons Reduced

in 2030 % Reduction in

Onroad Emissions Benzene 1,916 6% 4,762 26% Acetaldeh yd e 600 3% 2,067 21% Formaldeh yd e 513 2% 1,277 10% 1,3

- Butadiene 257 5% 677 29% Acrolein 40 3% 127 15% Naphthalene 99 3% 269 15% Ethanol 2, 704 2% 19,950 16% The totals shown in Table III

- 6 represent the sum of 71 species including the toxics in Table III

- 5 , 15 polycyclic aromatic h ydrocarbon (PAH) compounds in gas an d particle phase, and additional gaseous compounds such as toluene, x yl enes, sty rene, hexane, 2,2,4

- trimethylpentane, n

- hexane, and propionaldeh yde ( see Appendix 7A of the RIA). As shown, in 2030 , the overall onroad inventory of total toxics will be reduc ed b y 15 percent, with nearl y one half of the vehicle program reductions coming from the evaporative standards. **Table III**  **- 6**  **Reductions in Total Mobile Source Air Toxics (Annual U.S. Tons) 2018**  **2030**Page 78 of 88

**Total r eduction**  **15,583 64,558**  Reduction from pre

- Tier 3 fleet due to sulfur standard 11,981 3,517 Reduction from Tier 3 fleet due to vehicle and sulfur standards 3,602 61,041

Exhaust 13,340 34,595 Evaporative 2,243 29,963 **Percent reduction in onroad toxics**  **emissions 3%**  **15%**
6. SO 2 SO 2 emissions from mobile sources are a direct function of sulfur in the fuel, and reducing sulfur in gasoline w ill result in immediate reductions in SO 2 from the on and off

- road fleet. The reductions, shown in Table III

- 7 , are a function of the sulfur level and fuel consumption. This is reflected in the relative contribution of on - road vehicles and off

- road equipment, where off

- road gasoline consumption accounts for approximately 5 percent of ov erall gasoline use. 215 **Table III**  **- 7**  **Projected SO 2**  **Reductions from Tier 3 Program (Annual U.S. Tons) 2018**  **2030 Total reduction**  **15,565 13,261**  Reduction from onroad vehicles due to sulfur standard 14,813 12,399
Reduction from off

- road equipment due to sulfur standard 752 862
**Percent reduction in onroad SO**  **2 emissions**  **56% 56%** 
7. Greenhouse Gases Reductions in nitrous oxide (N 2 O) emissions and methane (CH 4 ) emissions, both potent greenhouse gas emissions, are project ed for gasoline cars and trucks as a result of the sulfur and tailpipe standards. A study conducted by

the University of California

- Riverside found a 29 percent reduction in N 2 O emissions over the FTP when sulfur was reduced from 30 to 5 ppm, 216 whi le EPA research described in

215 U.S. Energy Information Administration , Annual Energy Outlook 2013 (April 15, 2013) 216 Huai, et al. (2004) , Estimates of the emission rates of nitrous oxide from light

- duty vehicles using different chassis dynamometer test cycles , Atmospheric Environment 6621

- 6629Page 79 of 88

Section IV.A.6 on sulfur effects found a 26 percent reduction in CH 4 emissions when sulfur was reduced from 28 to 5 ppm

. 217 Several studies have established correlations between reductions in tailpipe NO X emissions and reductio ns in N 2 O from gasoline cars and trucks, 218 , 219 , 220 , 221 as well as correlations between reductions in tailpipe HC emissions and reductions in CH 4 . 222 , 223 Studies by

Winer, et al (2005) and Behrentz et al (2004) reported N 2 O: NO X ratio s of 0.06 and 0.095, respectivel y , and supported the application of N 2 O: NO X ratios to NO X emissions as a reasonable method for estimating N 2 O emission inventories. CARB has also used N 2 O : NO X ratio to develop the N 2 O emissions inventories for the LEV III program, based on a regression anal ys is suggesting N 2 O : NO X ratio of 0.04, on average. 224 As detailed in Chapter 7.3 of the RIA , the N 2 O reductions are estimated b y employing two different methodologies, resulting in a range of reductions. The first method applies the relationship betwe en N 2 O and NO X from a regression model 225 to NO X inventories from both Tier 3 and pre

- Tier 3 vehicles. The second method applies the regression of N 2 O and NO X onl y to Tier 3 vehicles and uses the UC Riverside sulfur results to estimate the N 2 O reductions fr om pre - Tier 3 vehicles. Using a 100

- year global warming potential of 298 for N 2 O according to the 2007 IPCC AR4 , 226 the estimated N 2 O reduction is 2.2 million metric tons of carbon

217 The Ef

fects of Ultra

- Lo w Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In

- Use Fleet , EPA

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- 00 2, 218 Michaels, H. (1998) Emissions of Nitrous Oxide from Highway Mobile Sources , U.S. EPA EPA420

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- 009 219 Behrentz, et al. (2004), Measurements of n itrous oxide emissions from light

- duty motor vehicles: a pilot study , Atmospheric Environment 4291

- 4303 220 Meffert, et. al (2000) Analysis of Nitrous Oxide Emissions from Light Duty Passenger Cars, SAE 2000

- 01

- 1952 221 Winer, et al. (2005) Estimates of Nitro us Oxide Emissions and the Effects of Catalyst Com position and Aging , State of California Air Resources Board 02

- 313 222 Meszler, D. (2004), Light Duty Vehicle Methane and Nitrous Oxide Emissions: Greenhouse Gas Im pacts , Study for Northeast States Center for a Clean Air Future 223 Graham, L. , Greenhouse Gas Emissions from 1997

- 2005 Model Year Light Duty Vehicles , Environment Canada ERMD Report #04

- 44 224 LEV III Moblie Source Emissions Inventory Technical Support Document

– Appendix T , January 2012, last access ed on 01/15/14 at the following URL: http://www.arb.ca.gov/regact/2012/leviiighg2012/levappt.pdf 225 U.S. EPA, 2014, Memorandum to Docket: Regression Analysis of Nitrous Oxide and Ox ides of Nitrogen from Motor Vehicles

. 226 The global warming potentials (GWP) used in this rule are consistent with the 100

- year time frame values in the 2007 Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). At this time, the 1996 IPCC Second Assessment Report (SAR) 100

- year GWP values are used in the official U.S. greenhouse gas inventory submission to the United Nations Framew ork Convention on Climate Change (per the reporting requirements under that internationalPage 80 of 88

dioxide equivalent (MMTCO 2 e) in 2018 , growing to the range between 3.8 to 4. 0 MMTCO 2 e in 2030. For 2018, there was an agreement between the two methodologies described above, resulting in a single estimate. MOVES can be used to directly

estimate CH 4 reductions from the sulfur and vehicle standards, estimating an additional 0.1 M MTCO 2 e reduction in 2018 , growing to 0.3 MMTCO2e in 2030. The total GHG reduction from the Tier 3 rule is 2.3 MMTCO 2 e in 2018 , and between 4.1 and 4.3 MMTCO 2 e in 2030. These reductions will be partially offset by CO 2 emissions associated with higher en ergy

use required in the process of removing sulfur within the refinery

. As an extension of our refinery

- by

- refinery cost modeling described in Section VII.B., we calculated the CO 2 emission impacts of Tier 3 gasoline sulfur control. We estimated refinery - specific changes in process energy and then applied emission factors that correspond to those changes, on a refinery

- by

- refinery basis. As described in Chapter 4.5 of the RIA, the results showed an increase of up to 1.9 MMTCO 2 e in 2018 and 1.6 MMTCO 2 e i n 2030 for all U.S. refineries complying with the lower sulfur standards assuming that the sulfur standards are fully phased

in. In 2018 , the combined impact of CH 4 and N 2 O emission reductions from the vehicles and CO 2 emission increases from the refineri es shows a slight net decrease on a CO 2 equivalent basis. While still small, this net decrease grows to a range between 2.5 to 2.7 MMTCO 2 e by 2030. We do not expect the Tier 3 vehicle standards to result in any discernible changes in vehicle CO 2 emission s or fuel economy. Emissions of the pollutants that are controlled b y the Tier 3 program

– NMOG, NO X , and PM

– are not a function of the amount of fuel consumed, since manufacturers need to design their cataly tic emission control sy stems to reduce these e missions regardless of their engine

- out levels. **C. How W**  **ill Air Pollution Be Reduced?**  Reductions in emissions of NO X , VOC, PM 2.5 and air toxics expected as a result of the Tier 3 standards are projected to lead to significant improvements in air quality

. The air quality

modeling predicts significant improvements in ozone concentrations due to the Tier 3 st ` andards. Ambient PM 2.5 and NO 2 concentrations are also expected to improve as a result of the Tier 3 program. Decreases in ambient concentrations of air toxics are projected with the Tier 3 standards, including notable nationwide reductions in benzene concentrations. Our air quality modeling also predicts improvements in visibility and sulfur deposition, as well as substantial decreases in nitrogen deposition as a result of the Tier 3 standards. The

convention , which were last updated in 2006). N 2 O has a 100

- year GWP of 298 and CH 4 has a 100

- year GWP of 25 according to the 2007 IPCC AR4

.Page 81 of 88

results of our air quality

modeling of the impacts of the Tier 3 rule are summarized in the following section. 1. Ozone The air qualit y modeling done for this action projects that in 201 8 , with all current and required controls in effect but excluding the emissions changes expected to occur as a result of the Tier 3 standards or an y other additional controls, at least 19 counties, with a projected population of over 37 million peopl e, would have projected design values above the level of the 2008 8

- hour ozone standard of 75 ppb

. In 2030 the modeling projects that in the absence of Tier 3 standards or any other additional controls there w ill be 6 counties with a population of o ver 19 million people with projected design values above the level of the 2008 8

- hour ozone standard of 75 ppb

. An additional 37 million people will be living in the 43 counties that will be close to (within 10% of) the level of the ozone standard. Air quality modeling indicates that this action will meaningfully decrease ozone design value concentrations in many areas of the country , including those that are projected to be exceeding, or close to exceeding, the ozone standard. In 201 8 , the majority

of the design value decreases are between 0.5 and 1.0 ppb. In 2030, the Tier 3 rule will result in larger decreases in ozone design values, with the majority of counties projecting decreases of between 0

. 5 and 1. 0 ppb, and over 2 5 0 more counties with decrea ses greater than 1. 0 ppb. Since the Tier 3 standards go into effect during the period when some areas are still working to attain the ozone NAAQS, the projected air quality changes will help st ate and local agencies in their effort to attain and maintain the ozone standard.

2. Particulate Matter The air qual ity

modeling conducted for this action projects that in 20 18 , with all current controls in effect but excluding the emissions changes expected to occur as a result of Tier 3 standards or an y other addit ional controls, at least 14 counties, with a projected population of over 20 million people, would have projected design values above the level of the annual standard of 12 μg/m 3 and at least 24 counties, with a projected population of over 18 million peop le, would have projected design values above the level of the 24

- hour standard of 35 μg/m 3. In 2030, the modeling projects that in the absence of Tier 3 standards or any other additional controls there will be 1 3 counties, with a projected populatio n of over 2 1 million people, with projected design values above the level of the annual standard of 12 μg/m 3 and 18 counties, with a projected population of over 12 million people, with projected design values above the level of the 24

- hour standard of 35 μg/m 3

. Since the Tier 3 standards go into effect during the period when some areas are still working to attain the 2006 and 2012 PM 2.5 NAAQS, the projected air qualityPage 82 of 88

changes will be useful to state and local agencies in their effort to attain and mainta in the PM 2.5 standard s . The Tier 3 standards will reduce 24

- hour and annual PM 2.5 design values due to projected tailpipe reductions in primary PM 2.5 , SO 2 , NO X and VOCs from reductions in fuel sulfur and engine controls

. In 2018 the standards will have a small impact on annual PM 2.5 design values in the majority of modeled counties

. However, in over 200 counties annual PM 2. 5 design values are projected to decrease by greater than 0.0 1 μg/m 3 . In 2030 annual PM 2.5 design values in the majority of mode led counties will decrease b y between 0.01 and 0.05 μg/m 3 and in over 1 4 0 additional counties design values are projected to decrease b y greater than 0.05 μg/m 3

. Inaddition, in 2018 24

- hour PM 2.5 design values in over 200 counties are projected to decrea se b y between 0.05 and 0.15 μg/m 3 and in 2030 24

- hour PM 2.5 design values in over 180 counties decrease b y at least 0. 15 μg/m 3

. 3. Nitrogen Dioxide Although our modeling indicates that b y 2030 the majority of the country will experience decreases of less th an 0. 1 ppb in their annual NO 2 concentrations due to this rule , annual NO 2 concentrations are projected to decrease b y more than 0 .3 ppb in most urban areas. These emissions reductions would also likely decrease 1

- hour NO 2 concentrations and help any pote ntial nonattainment areas to attain and maintain the standard. Additional information on the emissions reductions that are projected with this rule is available in Section 7.2.1 of the RIA. 4. Air Toxics Our modeling indicates that the impacts of final Tier 3 standards include notable nationwide reductions in benzene and generall y small decreases in ambient concentrations of other air toxics, mainly in urban areas. Although reductions are greater in 2030 (when 70 percent of the miles travelled are from vehicles that meet the fully phased

- in Tier 3 standards ) than in 201 7 (the first year of the final program), our modeling projects there w ill be small immediate reductions in ambient concentrations of air toxics due to the Tier 3 sulfur controls. Further more, the full reduction of the vehicle program w ill be realized after 2030, when the fleet has fully turned over to vehicles meeting the full y phased

- in Tier 3 standards . Air toxics pollutants dominated by primary emissions (or a decay

product of a direc tly emitted pollutant) , such as benzene, are impacted more than air toxics that primarily result from photochemical transformation. Specificall y, in 2030, our modeling projects that the Tier 3 rule w ill decrease ambient benzene concentrations across much of the country on the order of 1 to 5 percent, with reductions ranging from 10 to 25 percent in some urban areas. Our modeling also shows reductions of 1,3

- butadiene and acrolein concentrations in 2030 ranging between 1 and 25 percent and 1 and 10 percentPage 83 of 88

respectivel y , with 1,3

- butadiene decreases of at least 0.005 μg/m3 in urban areas. These toxics are national risk drivers and the reductions in ambient concentrations from this rule w ill result in reductions in risks from cancer and noncancer health eff ects. In some parts of the country (mainl y urban areas), ethanol and formaldeh yde concentrations are projected to decrease on the order of 1 to 10 percent and 1 to 2.5 percent respectively in 2030 as a result of the Tier 3 rule. Decreases in ethanol conc entrations are expected due to reductions in VOC as a result of the Tier 3 standards. Changes in ambient acetaldehyde concentrations are generall y less than 1 percent across the U.S., although the Tier 3 rule may decrease acetaldeh yde concentrations in som e urban areas by 1 to 2.5 percent in 2030. Changes in ambient naphthalene concentrations are generally between 1 and 10 percent in 2030 with absolute decreases of up to 0.005 μg/m3

. Although the reductions in ambient air toxics concentrations expected from the Tier 3 standards are generall y small, they are projected to benefit the majority of the U.S. population. As shown in Table III

- 8 , over 75 percent of the total U.S. population is projected to experience a decrease in ambient benzene and 1,3

- butadiene concentrations of at least 1 percent. Over 60 percent of the U.S population is projected to experience at least a 1 percent decrease in ambient ethanol and acrolein concentrations, and over 35 percent would experi ence a similar decrease in ambient formaldehyde concentrations with the Tier 3 standards. **Table III**  **- 8**  **Percent of Total Population Experiencing Changes in Annual Am**  **bient Concentrations of Toxic Pollutants in 2030 as a Result of the**  **Tier 3 Standards**  Percent Change Benzene Acrolein 1,3

- Butadiene Formaldeh yd e Ethanol Acetaldeh yd e Naphthalene ≤
- 50 > - 50 to ≤
- 25 > - 25 to ≤
- 10 2.29% 0.75% 19.07% 10.74% > - 10 to ≤
- 5 20.63% 12.72% 27.29% 5.39% 31.56% > - 5 to ≤
- 2.5 27.50% 25.17% 15.37% 0.60% 24.08% 20.58% > - 2.5 to ≤
- 1 28.60% 24.62% 18.33% 35.34% 34.10% 11.77% 14.98% > - 1 to < 1 20.97% 36.74% 19.93% 64.06% 36.43% 88.23% 22.14% ≥ 1 to < 2.5 ≥ 2.5 to < 5 ≥ 5 to < 10 ≥ 10 to < 25 ≥ 25 to < 50 ≥ 50Page 84 of 88 In addition, as described in Section 7.2.4.4.2 of the RIA, o ur modeling p rojects that acrolein concentrations would decrease to levels below the inhalation reference concentration for acrolein ( 0.02 μg/m3 ) for over 5 million people in 2030 , meaning that as a result of the Tier 3 standards, 5 million fewer Americans will be expo sed to ambient levels of acrolein high enough to present a potent ial for adverse health effects. 5. Visibility Air quality

modeling conducted for this final action was used to project visibility conditions in 137 mandatory class I federal areas across the U .S. The results show that in 2030 all the modeled areas w ill continue to have annual average deciview levels above background and the Tier 3 rule w ill improve visibility in all these areas. 227 The average visibility at all modeled mandatory class I federal areas on the 20 percent worst day s is projected to improve by 0.02 deciviews, or 0.16 percent, in 2030. Section 7.2.5.5 of the RIA contains more detail on the visibility portion of the air quality modeling. 6. Nitrogen and Sulfur Deposition Our air qualit y modeling projects substantial decreases in nitrogen deposition as a result of the Tier 3 standards. The standards w ill result in annual percent decreases of greater than 2.5 percent in most major urban areas and greater than 5 percent in a few areas. In addition, smaller decreases, in the 1 to 2.5 percent range, w ill occur over much of the rest of the country . The impacts of the Tier 3 standards on sulfur deposition are smaller, ranging from no change to decreases of over 2.5 percent in some areas. For maps of 2030 deposition impacts and additional information on these impacts see Section 7.2.5.6 of the RIA. 7. Environmental Justice Environmental justice (EJ) is a principle asserting that all people deserve fair treatment and meaningful involvement with respect to environmental laws, regulations, and policies. EPA seeks to provide the same degree of protection from environmental health hazards for all people. As referenced below, numerous studies have found that some environmental hazards are more prevalent in areas with high population fractions of racial/ethnic minorities and people with low

227 The level of visibility impairment in an area is based on the light

- extinction coefficient and a unitless visibility index , called a “deciview , ” which is used in the valuation of visibility. The deciview metric provides a scale for perceived visual changes over the entire range of conditions, from clear to hazy. Under many scenic conditions, the average person can generally perceive a change of one deciview. The higher the deciview value, the worse the visibility. Thus, an im provement in visibility is a decrease in deciview value.Page 85 of 88

socioeconomic status (SES), as would be expected on the basis of those areas’ share of the general population. As discussed in Section II of this document, concentrations of many air pollutants are elevated near high

- traffic roadway s. If minority populations and low

- income populations disproportionately live near such roads, then an issue of EJ may be present. Such disparities may be due to multiple factors. 228 Peop le with low SES often live in neighborhoods with multiple stressors and health risk factors, including reduced health insurance coverage rates, higher smoking and drug use rates, limited access to fresh food, visible neighborhood violence, and elevated rat es of obesit y and some diseases such as asthma, diabetes, and ischemic heart disease. Although questions remain, several studies find stronger associations between air pollution and health in locations with such chronic neighborhood stress, suggesting that populations in these areas may be more susceptible to the effects of air pollution. 229 , 230 , 231 , 232 Household

- level stressors such as parental smoking and relationship stress also may increase susceptibility

to the adverse effects of air pollution. 233 , 234 To address the existing conditions in areas near major roadway s, in comparison with other locations, we reviewed existing scholarl y literature examining the topic, and conducted our own evaluation of two national datasets:

228 Depro, B.; Timmins, C. (2008) Mobility and environmental equity: do housing choices determ ine exposure to air pollution? North Caroline State University Center for Environmental and Resource Economic Policy 229 Clougherty, J.E.; Kubzansky, L.D. (2009) A framework for examining social stress and susceptibility to air pollution in respiratory heal th. Environ Health Perspect 117: 1351

- 1358. Doi:10.1289/ehp.0900612 [Online at http://dx.doi.org] 230 Clougherty, J.E.; Levy, J.I.; Kubzansky, L.D.; Ryan, P.B.; Franco Suglia, S.; Jacobson Canner, M.; Wright, R.J. (2007) Synergistic effects of traffic

- related air pollution and exposure to violence on urban asthma etiology. Environ Health Perspect 115: 1140

- 1146. doi:10.1289/ehp.9863 [Online at http://dx.doi.org] 231 Finkelstein, M.M.; Jerrett, M.; DeLuca, P.; Finkelstein, N.; Verma, D.K.; Chapman, K.; Sear s, M.R. (2003) Relation between income, air pollution and mortality: a cohort study. Canadian Med Assn J 169: 397

- 402. 232 Shankardass, K.; McConnell, R.; Jerrett, M.; Milam, J.; Richardson, J.; Berhane, K. (2009) Parental stress increases the effect of tr affic

- related air pollution on childhood asthma incidence. Proc Natl Acad Sci 106: 12406

- 12411. doi:10.1073/pnas.0812910106 [Online at http://dx.doi.org] 233 Lewis, A.S.; Sax, S.N.; Wason, S.C.; Campleman, S.L (2011) Non

- chemical stressors and cumulative r isk assessment: an overvie w of current initiatives and potential air pollutant interactions. Int J Environ Res Public Health 8: 2020

- 2073. Doi:10.3390/ijerph8062020 [Online at http://dx.doi.org] 234 Rosa, M.J.; Jung, K.H.; Perzanowski, M.S.; Kelvin, E.A. ; Darling, K.W.; Camann, D.E.; Chillrud, S.N.; Whyatt, R.M.; Kinney, P.L.; Perera, F.P.; Miller, R.L (2010) Prenatal exposure to polycyclic aromatic hydrocarbons, environmental tobacco smoke and asthma. Respir Med (In press). doi:10.1016/j.rmed.2010.11.0 22 [Online at http://dx.doi.org]Page 86 of 88

the U.S. Census Bureau’s American Housing Survey for calendar year 2009 and the U.S. Department of Education’s database of school locations. Existing publications that address EJ issues generally report that populations living near major roadways (and other types of transportation infrastructure) tend to be composed of larger fractions of nonwhite residents. People living in neighborhoods near such sources of air pollution also tend to be lower in income than people living elsewhere. Numerous studies evaluating the demographics and socioeconomic status of populations or schools near roadway s have found that they include a greater percentage of minority residents, as well as lower SES (indicated by variables such as median household income). Locations in these studies include Los Angeles, CA ; Seattle, WA ; Way ne County , MI ; Orange Count y, FL ; and the State of California 235 , 236 , 237 , 238 , 239 , 240 More recentl y, three publications report nationwide anal ys es that compare the demographic patterns of people who do or do not live near major roadway s. 241 , 242 , 243 All three of these studies found that people living near major roadway s are more likel y to be minorities or low in SES. They also found that the outcomes of their analy ses varied between regions within the U.S. However, only one such study

looked at whether such c onclusions were confounded b y living in a location with higher population density and how demographics differ between

235 Marshall, J.D. (2008) Environmental inequality: air pollution exposures in California’s South Coast Air Basin. 236 Su, J.G.; Larson, T.; Gould, T.; Cohen, M.; Buzzelli, M. (2010) Transboundary air pollution and environment al justice: Vancouver and Seattle compared. GeoJournal 57: 595

- 608. doi:10.1007/s10708

- 009

- 9269

- 6 [Online at http://dx.doi.org] 237 Chakraborty, J.; Zandbergen, P.A. (2007) Children at risk: measuring racial/ethnic disparities in potential exposure to a ir pollution at school and home. J Epidemiol Community Health 61: 1074

- 1079. doi: 10.1136/jech.2006.054130 [Online at http://dx.doi.org] 238 Green, R.S.; Smorodinsky, S.; Kim, J.J.; McLaughlin, R.; Ostro, B. (2003) Proximity of California public schools t o busy roads. Environ Health Perspect 112: 61

- 66. doi:10.1289/ehp.6566 [http://dx.doi.org] 239 Wu, Y; Batterman, S.A. (2006) Proximity of schools in Detroit, Michigan to automobile and truck traffic. J Exposure Sci & Environ Epidemiol. doi:10.1038/sj.j es.7500484 [Online at http://dx.doi.org] 240 Su, J.G.; Jerrett, M.; de Nazelle, A.; Wolch, J. (2011) Does exposure to air pollution in urban parks have socioeconomic, racial, or ethnic gradients? Environ Res 111: 319

- 328. 241 Rowangould, G.M. (2013) A census of the US near

- roadway population: public health and environmental justice considerations. Transportation Research Part D; 59

- 67. 242 Tian, N.; Xue, J.; Barzyk. T.M. (2013) Evaluating socioeconomic and racial differences in traffic

related metrics in the United States using a GIS approach. J Exposure Sci Environ Epidemiol 23: 215

- 222. 243 Boehmer, T.K.; Foster, S.L.; Henry, J.R.; Woghiren

- Akinnifesi, E.L.; Yip, F.Y. (2013) Residential proximity to major highways

– United States, 2010. Morbidity and Morta lity Weekly Report 62(3): 46

- 50.Page 87 of 88

locations nationwide. In general, it found that higher density areas have higher proportions of low income and minority residents. We an alyzed two national databases that allowed us to evaluate whether homes and schools were located near a major road. One database, the American Housing Survey

(AHS), includes descriptive statistics of over 70,000 housing units across the nation. The study is conducted every two years by

the U.S. Census Bureau. We anal yz ed data from the 2009 AHS. The second database we anal yz ed was the U.S. Department of Education’s Common Core of Data, which includes enrollment and location information for schools across the U.S. In anal yz ing the 2009 AHS, we focused on whether or not a housing unit was located within 300 feet of “4

- or - more lane highway , railroad, or airport.” 244 We analyzed whether there were differences between houses and householders in such locations and those not in them. 245 We include d other variables, such as land use category , region of country , and housing t ype. We found that ho m es with a nonwhite householder were 22

- 34 percent more likely to be located within 300 feet of these large transportation facilities, while ho mes with a Hispanic householder were 17

- 33 percent more likely . Households near large transportation facilities were, on average, lower in income and educational attainment, more likely to be a rental property

and located in an urban area. In examining schools near major roadway s, we examined the Common Core of Data (CCD) from the U.S. Department of Education, which includes information on all public elementary and secondary

schools and school districts nationwide. 246 To determine schoo l proximities to major roadway s, we used a geographic information system (GI S) to map each school and roadway s based on the U.S. Census’s TIGER roadway file. 247 We found that minority students were overrepresented at schools within 200 meters of the largest roadway s, and that schools within 200 meters of the largest roadway s also had higher than expected numbers of students eligible for free or reduced

- price lunches. For example, Black students represent 21.57 percent of students at schools located within 2 00 meters of a primary

road, whereas Black students represent 16.62 percent of students in all U.S. schools. Hispanic students represent 30.13 percent of students at schools

244 This variable primarily represents roadway proximity. According to the Central Intelligence Agency’s World Factbook, in 2010, the United States had 6,506,204 km or roadw ays, 224,792 km of railways, and 15,079 airports. H ighways thus represent the overwhelming majority of transportation facilities described by this factor in the AHS. 245 Bailey, C . (2011) Demographic and Social Patterns in Housing Units Near Large Highways and other Transportation Sources . Memo randum to docket. 246 http://nces.ed.gov/ccd/ 247 Pedde, M.; Bailey, C. (2011) Identification of S chools within 200 M eters of U.S. P rimary and S econdary Roads. Memorandum to the docket.Page 88 of 88

located within 200 meters of a primary road, whereas Hispanic students represent 21.93 percent of students in all U.S. schools. Overall, there is substantial evidence that people who live or attend school near major roadway s are more likely to be of a minority

race, Hispanic ethnicity , and/or low SES. The emission reductions from this rule will result in widespread air quality

improvements, but the impact on pollution levels in close proximity to roadway s will be most direct. Thus, this rule is likely to help in mitigating th e disparity in racial, ethnic, and economically

- based exposures.