[Federal Register: October 5, 2001 (Volume 66, Number 194)] [Proposed Rules] [Page 51097-51146] From the Federal Register Online via GPO Access [wais.access.gpo.gov] [DOCID:fr05oc01-53] [[Page 51097]] ----------------------------------------------------------------------- Part II Environmental Protection Agency ----------------------------------------------------------------------- 40 CFR Part 89, 90, 91, etc. Control of Emissions From Nonroad Large Spark Ignition Engines and Recreational Engines (Marine and Land-Based); Proposed Rule [[Page 51098]] ----------------------------------------------------------------------- ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 89, 90, 91, 94, 1048, 1051, 1065, and 1068 [AMS-FRL-7058-8] RIN 2060-AI11 Control of Emissions From Nonroad Large Spark Ignition Engines and Recreational Engines (Marine and Land-Based) AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of proposed rulemaking. ----------------------------------------------------------------------- SUMMARY: In this action, we are proposing emission standards for several groups of nonroad engines that cause or contribute to air pollution but that have yet to be regulated by EPA. These engines include large spark-ignition engines such as those used in forklifts and airport tugs; recreational vehicles using spark-ignition engines such as off-highway motorcycles, all-terrain vehicles, and snowmobiles; and recreational marine diesel engines. Nationwide, engines and vehicles in these various categories contribute to ozone, CO, and PM nonattainment. These pollutants cause a range of adverse health effects, especially in terms of respiratory impairment and related illnesses. The proposed standards will help states achieve air quality standards. In addition, the proposed standards will help reduce acute exposure to CO, air toxics, and PM for operators and other people close to the emission source. They will also help address other environmental problems, such as visibility impairment in our national parks. We expect that manufacturers will be able to maintain or even improve the performance of their products when producing engines and equipment meeting the proposed standards. In fact, many engines will substantially reduce their fuel consumption, partially or completely offsetting any costs associated with the emission standards. Overall, we estimate the gasoline-equivalent fuel savings associated with the anticipated changes in technology resulting from this rule would be about 730 million gallons per year once the program is fully phased in. The proposal also has several provisions to address the unique limitations of small-volume manufacturers. DATES: Comments: Send written comments on this proposed rule by December 19, 2001. See Section X.B for more information about written comments. Hearings: We will hold a public hearing in the Washington, DC area on October 24. We will hold a second public hearing on October 30 in Denver, CO. See Section X.B for more information about public hearings. ADDRESSES: Comments: You may send written comments in paper form or by e-mail. We must receive them by the date indicated under DATES above. Send paper copies of written comments (in duplicate if possible) to the contact person listed below. You may also submit comments via e-mail to ``NRANPRM@epa.gov.'' In your correspondence, refer to Docket A-2000-01. See Section X.B for more information on comment procedures. Docket: EPA's Air Docket makes materials related to this rulemaking available for review in Public Docket No. A-2000-01 at the following address: U.S. Environmental Protection Agency (EPA), Air Docket (6102), Room M-1500 (on the ground floor in Waterside Mall), 401 M Street, SW., Washington, DC 20460 between 8 a.m. to 5:30 p.m., Monday through Friday, except on government holidays. You can reach the Air Docket by telephone at (202) 260-7548, and by facsimile (202) 260-4400. We may charge a reasonable fee for copying docket materials, as provided in 40 CFR part 2. Hearings: We will hold a public hearing on October 24, 2001 at Washington Dulles Airport Marriott, Dulles, VA 20166 (703-471-9500). We will hold a second public hearing October 30, 2001 at Doubletree Hotel, 3203 Quebec Street, Denver, CO 80207 (303-321-3333). If you want to testify at a hearing, notify the contact person listed below at least ten days before the date of the hearing. See Section X.B for more information on the public-hearing procedures. FOR FURTHER INFORMATION CONTACT: Margaret Borushko, U.S. EPA, National Vehicle and Fuels Emission Laboratory, 2000 Traverwood, Ann Arbor, MI 48105; Telephone (734) 214-4334; Fax: (734) 214-4816; E-mail: borushko.margaret@epa.gov. SUPPLEMENTARY INFORMATION: Regulated Entities This proposed action would affect companies that manufacture or introduce into commerce any of the engines or vehicles that would be subject to the proposed standards. These include: spark-ignition industrial engines such as those used in forklifts and airport tugs; recreational vehicles such as off-highway motorcycles, all-terrain vehicles, and snowmobiles; and recreational marine diesel engines. This proposed action would also affect companies buying engines for installation in nonroad equipment. There are also proposed requirements that apply to those who rebuild any of the affected nonroad engines. Regulated categories and entities include: ------------------------------------------------------------------------ NAICS Examples of potentially Category codes a SIC codes regulated entities ------------------------------------------b----------------------------- Industry............... 333618 3519 Manufacturers of new nonroad SI engines, new marine engines. Do............... 333111 3523 Manufacturers of farm equipment. Do............... 333112 3531 Manufacturers of construction equipment, recreational marine vessels. Do............... 333924 3537 Manufacturers of industrial trucks. Do............... 811310 7699 Engine repair and maintenance. Do............... 336991 .......... Motorcycles and motorcycle parts manufacturers. Do............... 336999 .......... Snowmobiles and all- terrain vehicle manufacturers. Do............... 421110 .......... Independent Commercial Importers of Vehicles and Parts. ------------------------------------------------------------------------ a North American Industry Classification System (NAICS). b Standard Industrial Classification (SIC) system code. This list is not intended to be exhaustive, but rather provides a guide regarding entities likely to be regulated by this action. To determine whether particular activities may be regulated by this action, you should carefully examine the proposed regulations. You may direct questions regarding the applicability of this action to the person listed in FOR FURTHER INFORMATION CONTACT. [[Page 51099]] Obtaining Electronic Copies of the Regulatory Documents The preamble, regulatory language, Draft Regulatory Support Document, and other rule documents are also available electronically from the EPA Internet Web site. This service is free of charge, except for any cost incurred for internet connectivity. The electronic version of this proposed rule is made available on the day of publication on the primary web site listed below. The EPA Office of Transportation and Air Quality also publishes Federal Register notices and related documents on the secondary web site listed below. 1. http://www.epa.gov/docs/fedrgstr/EPA-AIR/ (either select desired date or use Search feature) 2. http://www.epa.gov/otaq/ (look in What's New or under the specific rulemaking topic) Please note that due to differences between the software used to develop the documents and the software into which the document may be downloaded, format changes may occur. Table of Contents I. Introduction A. Overview B. How Is This Document Organized? C. What Categories of Vehicles and Engines Are Covered in This Proposal? D. What Requirements Are We Proposing? E. Why Is EPA Taking This Action? F. Putting This Proposal Into Perspective II. Public Health and Welfare Effects of Emissions From Covered Engines A. Background B. What Are the Public Health and Welfare Effects Associated With Emissions From Nonroad Engines Subject to the Proposed Standards? C. What Is the Inventory Contribution From the Nonroad Engines and Vehicles That Would Be Subject to This Proposal? D. Regional and Local-Scale Public Health and Welfare Effects III. Nonroad: General Concepts A. Scope of Application B. Emission Standards and Testing C. Demonstrating Compliance D. Other Concepts IV. Large SI Engines A. Overview B. Large SI Engines Covered by This Proposal C. Proposed Standards D. Proposed Testing Requirements and Supplemental Emission Standards E. Special Compliance Provisions F. Technological Feasibility of the Standards V. Recreational Marine Diesel Engines A. Overview B. Engines Covered by This Proposal C. Proposed Standards for Marine Diesel Engines D. Proposed Testing Requirements E. Special Compliance Provisions F. Technical Amendments G. Technological Feasibility VI. Recreational Vehicles and Engines A. Overview B. Engines Covered by this Proposal C . Proposed Standards D. Proposed Testing Requirements E. Special Compliance Provisions F. Technological Feasibility of the Standards VII. General Nonroad Compliance Provisions A. Miscellaneous Provisions (Part 1068, Subpart A) B. Prohibited Acts and Related Requirements (Part 1068, Subpart B) C. Exemptions (Part 1068, Subpart C) D. Imports (Part 1068, Subpart D) E. Selective Enforcement Audit (Part 1068, Subpart E) F. Defect Reporting and Recall (Part 1068, Subpart F) G. Public Hearings (Part 1068, Subpart G) VIII. General Test Procedures A. General Provisions B. Laboratory Testing Equipment C. Laboratory Testing Procedures IX. Projected Impacts A. Environmental Impact B. Economic Impact C. Cost per Ton of Emissions Reduced D. Additional Benefits X. Public Participation A. How Do I Submit Comments? B. Will There Be a Public Hearing? XI. Administrative Requirements A. Administrative Designation and Regulatory Analysis (Executive Order 12866) B. Regulatory Flexibility Act C. Paperwork Reduction Act D. Intergovernmental Relations E. National Technology Transfer and Advancement Act F. Protection of Children (Executive Order 13045) G. Federalism (Executive Order 13132) H. Energy Effects (Executive Order 13211) I. Plain Language I. Introduction A. Overview Air pollution is a serious threat to the health and well-being of millions of Americans and imposes a large burden on the U.S. economy. Ground-level ozone, carbon monoxide, and particulate matter are linked to potentially serious respiratory health problems, especially respiratory effects and environmental degradation, including visibility impairment in our precious national parks. Over the past quarter century, state and federal representatives have established emission- control programs that significantly reduce emissions from individual sources. Many of these sources now pollute at only a small fraction of their precontrol rates. This proposal further addresses these air- pollution concerns by proposing national emission standards for several types of nonroad engines and vehicles that are currently unregulated. These include industrial spark-ignition engines such as those used in forklifts and airport tugs; recreational vehicles such as off-highway motorcycles, all-terrain vehicles, and snowmobiles; and recreational marine diesel engines.\1\ The proposed standards are a continuation of the process of establishing standards for nonroad engines and vehicles, as required by Clean Air Act section 213(a)(3). All the nonroad engines subject to this proposal are still unregulated emission sources. --------------------------------------------------------------------------- \1\ Diesel-cycle engines, referred to simply as ``diesel engines'' in this document, may also be referred to as compression- ignition (or CI) engines. These engines typically operate on diesel fuel, but other fuels may also be used. Otto-cycle engines (referred to here as spark-ignition or SI engines) typically operate on gasoline, liquefied petroleum gas, or natural gas. --------------------------------------------------------------------------- Nationwide, these engines are a significant source of mobile-source air pollution. They currently account for about 13 percent of mobile- source hydrocarbon (HC) emissions, 6 percent of mobile-source carbon monoxide (CO) emissions, 3 percent of mobile-source oxides of nitrogen ( NOX) emissions, and 1 percent of mobile-source particulate matter (PM) emissions.\2\ The proposed standards will reduce exposure to these emissions and help avoid a range of adverse health effects associated with ambient ozone, CO, and PM levels, especially in terms of respiratory impairment and related illnesses. In addition, the proposed standards will help reduce acute exposure to CO, air toxics, and PM for persons who operate or who work with or are otherwise active in close proximity to these engines. They will also help address other environmental problems associated with these engines, such as visibility impairment in our national parks and other wilderness areas where recreational vehicles and marine engines are often used. --------------------------------------------------------------------------- \2\ While we characterize emissions of hydrocarbons, this can be used as a surrogate for volatile organic compounds (VOC), which is a broader group of compounds. --------------------------------------------------------------------------- This proposal follows a final finding published on December 7, 2000 (65 FR 76790). Under this finding, EPA found that industrial spark- ignition (SI) engines rated above 19 kilowatts (kW), as well as all land-based recreational nonroad spark-ignition engines, cause or contribute to air quality nonattainment in more than one ozone or carbon monoxide (CO) nonattainment area. We also found that particulate matter (PM) emissions from these engines cause or contribute to air pollution that may reasonably be anticipated to endanger public health or welfare. This proposal also follows EPA's Advance Notice of Proposed [[Page 51100]] Rulemaking (ANRPM) published on December 7, 2000 (65 FR 76797). In that Advance Notice, we provided an initial overview of possible regulatory strategies for the nonroad vehicles and engines and invited early input to the process of developing standards. We received comments on the Advance Notice from a wide variety of stakeholders, including the engine industry, the equipment industry, various governmental bodies, environmental groups, and the general public. The Advance Notice, the related comments, and other new information provide the framework for this proposal. B. How Is This Document Organized? This proposal covers engines and vehicles that vary in design and use, and many readers may be interested in only one or two of the applications. For the purpose of this proposal, we have chosen to group engines by common application (e.g., recreational land-based engines, marine engines, large spark-ignition engines used in commercial applications). We have attempted to organize the document in a way that allows each reader to focus on the applications of particular interest. The Air Quality discussion in Section II is general in nature, however, and applies to all the categories covered by this proposal. The next four sections contain our proposal for the nonroad engines that are the subject of this action. Sections III contains some general concepts that are relevant to all of the nonroad engines covered by this proposal. Section IV through VI present information specific to each of the nonroad applications covered by the proposal, including standards, effective dates, testing information, and other specific requirements. Sections VII and VIII describe a wide range of compliance and testing provisions that apply generally to engines and vehicles from all the nonroad engine and vehicle categories included in this proposal. Several of these provisions apply not only to manufacturers, but also to equipment manufacturers installing certified engines, remanufacturing facilities, operators, and others. Therefore, all affected parties should read the information contained in this section. Section IX summarizes the projected impacts and a discussion of the benefits of this proposal. Finally, Sections X and XI contain information about public participation, how we satisfied our administrative requirements, and the statutory provisions and legal authority for this proposal. The remainder of this Section I summarizes important background information about this proposal, including the engines covered, the proposed standards, and why we are proposing them. C. What Categories of Vehicles and Engines Are Covered in This Proposal? This proposal presents regulatory strategies for new nonroad vehicles and engines that have yet to be regulated under EPA's nonroad engine programs. This proposal covers the following engines: Land-based spark-ignition recreational engines, including those used in snowmobiles, off-highway motorcycles, and all-terrain vehicles. For the purpose of this proposal, we are calling this group of engines ``recreational vehicles,'' even though all-terrain vehicles can be used for commercial purposes. Land-based spark-ignition engines rated over 19 kW, including engines used in forklifts, generators, airport tugs, and various farm, construction, and industrial equipment. This category also includes auxiliary marine engines, but does not include engines used in recreational vehicles. For the purpose of this proposal, we are calling this group of engines ``Large SI engines.'' Recreational marine diesel engines. This proposal covers new engines that are used in the United States, whether they are made domestically or imported.\3\ A more detailed discussion of the meaning of the terms ``new,'' ``imported,'' as well as other terms that help define the scope of application of this proposal, is contained in Section III of this preamble. --------------------------------------------------------------------------- \3\ For this proposal, we consider the United States to include the States, the District of Columbia, the Commonwealth of Puerto Rico, the Commonwealth of the Northern Mariana Islands, Guam, American Samoa, the U.S. Virgin Islands, and the Trust Territory of the Pacific Islands. --------------------------------------------------------------------------- We intended to include in this proposal emission standards for two additional vehicle categories: new exhaust emission standards for highway motorcycles and new evaporative emission standards for marine vessels powered by spark-ignition engines. Proposals for these two categories are not included in the September 14 deadline mandated by the courts, as is the case for the remaining contents that appear in today's proposed rule. We are committed to issue proposals regarding these categories within the next two to three months. Interested parties will have an opportunity to comment on issues associated with the proposed standards for these two categories during the public review period that will begin after a subsequent proposal or proposals are issued. D. What Requirements Are We Proposing? The fundamental requirement for engines under Clean Air Act section 213 is to meet EPA's emission standards. The Act requires that standards achieve the greatest degree of emission reduction achievable through the application of technology that will be available, giving appropriate consideration to cost, noise, energy, and safety factors. Other requirements such as applying for certification, labeling engines, and meeting warranty requirements define a process for implementing the proposed program in an effective way. With regard to Large SI engines, we are proposing a two-phase program. The first phase of the standards, to go into effect in 2004, are the same as those recently adopted by the California Air Resources Board. These standards will reduce combined HC and NOX emissions by nearly 75 percent, based on a steady-state test. In 2007, we propose to supplement these standards by setting limits that would require optimizing the same technologies but would be based on a transient test cycle. New requirements for evaporative emissions and engine diagnostics would also start in 2007. For recreational vehicles, we are proposing emission standards for snowmobiles separately from off-highway motorcycles and all-terrain vehicles. For snowmobiles, we are proposing a first phase of standards for HC and CO emissions based on the use of clean carburetion or 2- stroke electronic fuel injection (EFI) technology, and a second phase of emission standards for snowmobiles that would involve significant use of direct fuel injection 2-stroke technology, as well as possible limited conversion to 4-stroke engines. For off highway motorcycles and all-terrain vehicles, we are proposing standards that would result in a 50-percent reduction and is based mainly on moving these engines from 2-stroke to 4-stroke technology. In addition, we are proposing a second phase of standards for all-terrain vehicles that would require some catalyst use. We are also proposing voluntary Blue Sky Series emission standards for recreational marine diesel engines and industrial spark-ignition engines. Blue Sky Series emission standards are intended to encourage the introduction and more widespread use of low-emission technologies. Manufacturers could be motivated to exceed emission [[Page 51101]] requirements either to gain early experience with certain technologies or as a response to market demand or local government programs. For recreational vehicles, we are proposing separate voluntary standards based more on providing consumers with an option of buying low-emission models. E. Why Is EPA Taking This Action? There are important public health and welfare reasons supporting the standards proposed in this document. As described in Section II.B, these engines contribute to air pollution which causes public health and welfare problems. Emissions from these engines contribute to ground level ozone and ambient CO and PM levels. Exposure to ground level ozone, CO, and PM can cause serious respiratory problems. These emissions also contribute to other serious environmental problems, including visibility impairment. We believe existing technology that can be applied to these engines would reduce emissions of these harmful pollutants. Manufacturers can reduce 2-stroke engine emissions by improving fuel management and calibration. In addition, many of the existing 2-stroke engines in these categories can be converted to 4-stroke technology. Finally, there are modifications that can be made to 4-stroke engines, often short of requiring catalysts, that can reduce emissions even further. F. Putting This Proposal Into Perspective This proposal should be considered in the broader context of EPA's nonroad emission-control programs; state-level programs, particularly in California; and international efforts. Each of these are described in more detail below. 1. EPA's Nonroad Emission-Control Programs a. EPA's nonroad process. Clean Air Act section 213(a)(1) directs us to study emissions from nonroad engines and vehicles to determine, among other things, whether these emissions ``cause, or significantly contribute to, air pollution that may reasonably be anticipated to endanger public health or welfare.'' Section 213(a)(2) further required us to determine whether emissions of CO, VOC, and NOX from all nonroad engines significantly contribute to ozone or CO emissions in more than one nonattainment area. If we determine that emissions from all nonroad engines were significant contributors, section 213(a)(3) then requires us to establish emission standards for classes or categories of new nonroad engines and vehicles that in our judgment cause or contribute to such pollution. We may also set emission standards under section 213(a)(4) regulating any other emissions from nonroad engines that we find contribute significantly to air pollution. We completed the Nonroad Engine and Vehicle Emission Study, required by Clean Air Act section 213(a)(1), in November 1991.\4\ On June 17, 1994, we made an affirmative determination under section 213(a)(2) that nonroad emissions are significant contributors to ozone or CO in more than one nonattainment area. We also determined that these engines make a significant contribution to PM and smoke emissions that may reasonably be anticipated to endanger public health or welfare. In the same document, we set a first phase of emission standards (now referred to as Tier 1 standards) for land-based nonroad diesel engines rated at or above 37 kW. We recently added a more stringent set of Tier 2 and Tier 3 emission levels for new land-based nonroad diesel engines at or above 37 kW and adopted Tier 1 standards for land-based nonroad diesel engines less than 37 kW. Our other emission-control programs for nonroad engines are listed in Table I.F- 1. This proposal takes another step toward the comprehensive nonroad engine emission-control strategy envisioned in the Act by proposing an emission-control program for the remaining unregulated nonroad engines. --------------------------------------------------------------------------- \4\ This study is available in docket A-92-28. Table I.F-1.--EPA's Nonroad Emission-Control Programs ---------------------------------------------------------------------------------------------------------------- Engine category Final rulemaking Date ---------------------------------------------------------------------------------------------------------------- Land-based diesel engines 56 FR 31306 June 17, 1994. 37 kW--Tier 1. Spark-ignition engines 19 60 FR 34581 July 3, 1995. kW--Phase 1. Spark-ignition marine................ 61 FR 52088 October 4, 1996. Locomotives.......................... 63 FR 18978 April 16, 1998. Land-based diesel engines--Tier 1 and 63 FR 56968 October 23, 1998. Tier 2 for engines 37 kW. --Tier 2 and Tier 3 for engines 37 kW Commercial marine diesel............. 64 FR 73300 December 29, 1999. Spark-ignition engines 19 64 FR 15208 March 30, 1999. kW (Non-handheld)--Phase 2. Spark-ignition engines 19 65 FR 24268 April 25, 2000. kW (Handheld)--Phase 2. ---------------------------------------------------------------------------------------------------------------- b. National standards for marine engines. In the October 1996 final rule for spark-ignition marine engines, we set standards only for outboard and personal watercraft engines. We decided not to finalize emission standards for sterndrive or inboard marine engines at that time. Uncontrolled emission levels from sterndrive and inboard marine engines were already significantly lower than the outboard and personal watercraft engines. We did, however, leave open the possibility of revisiting the need for emission standards for sterndrive and inboard engines in the future. In December 1999, we published emission standards for commercial marine diesel engines. To allow more time to evaluate the potential impact of the proposed emission limits on the recreational vessel industry, we did not include recreational propulsion marine diesel engines in that rulemaking. c. National standards for land-based spark-ignition engines. The standards we have set to date for land-based, spark-ignition nonroad engines apply to engines typically used in lawn and garden applications. In adopting these emission standards, we decided not to include engines rated over 19 kW or any engines used in recreational vehicles. The proposed emission-control program in this document addresses these remaining unregulated engines. 2. State Initiatives Under Clean Air Act section 209, California has the authority to regulate emissions from new motor vehicles and new motor vehicle engines. California may also regulate emissions from nonroad engines, with the exception of [[Page 51102]] new engines used in locomotives and new engines used in farm and construction equipment rated under 130 kW.\5\ So far, the California Air Resources Board (California ARB) has adopted requirements for four groups of nonroad engines: (1) Diesel- and Otto-cycle small off-road engines rated under 19 kW; (2) new land-based nonroad diesel engines rated over 130 kW; (3) land-based nonroad recreational engines, including all-terrain vehicles, snowmobiles, off-highway motorcycles, go-carts, and other similar vehicles; and (4) new nonroad SI engines rated over 19 kW. They have approved a voluntary registration and control program for existing portable equipment. --------------------------------------------------------------------------- \5\ The Clean Air Act limits the role states may play in regulating emissions from new motor vehicles and nonroad engines. California is permitted to establish emission standards for new motor vehicles and most nonroad engines; other states may adopt California's programs (sections 209 and 177 of the Act). --------------------------------------------------------------------------- Other states may adopt emission standards set by California ARB, but are otherwise preempted from setting emission standards for new engines or vehicles. In contrast, there is generally no federal preemption of state initiatives related to the way individuals use individual engines or vehicles. a. Industrial SI engines. California ARB in 1998 adopted requirements that apply to new nonroad engines rated over 25 hp produced for California starting in 2001. These standards phase in over three years, during which manufacturers show only that engines meet the standards before they start in service. Beginning in 2004, the standards apply to 100 percent of engines sold in California, including a requirement to show that an engine meets emission standards throughout its useful life. As described above, these standards do not apply to engines under 130 kW used in farm or construction equipment. Texas has adopted the California ARB emission standards statewide starting in 2004. b. Off-highway motorcycles and all-terrain vehicles. California established standards for off-highway motorcycles and all-terrain vehicles which took effect in January 1997 (1999 for vehicles with engines of 90 cc or less). The standards are 1.2 g/km HC and 15.0 g/km CO and are based on the highway motorcycle chassis test procedures. Manufacturers may certify all-terrain vehicles to optional standards, which are based on the utility engine test procedure.\6\ These standards are 12 g/hp-hr HC+NOX and 300 g/hp-hr CO, for all- terrain vehicles with engine displacements less than 225 cubic centimeters (cc) and 10 g/hp-hr NC+NOX and 300 g/hp-hr CO, for all-terrain vehicles with engine displacement greater than 225 cc. The utility engine test procedure is the procedure over which Small SI engines are tested. The stringency level of the standards was based on the emissions performance of 4-stroke engines and advanced 2-stroke engines equipped with a catalytic converter. California anticipated that the standards would be met initially through the use of high performance 4-stroke engines. --------------------------------------------------------------------------- \6\ Notice to Off-Highway Recreational Vehicle Manufacturers and All Other Interested Parties Regarding Alternate Emission Standards for All-Terrain Vehicles, Mail Out #95-16, April 28, 1995, California ARB (Docket A-2000-01, document II-D-06). --------------------------------------------------------------------------- California revisited the program in the 1997 time frame because a lack of certified product from manufacturers was reportedly creating economic hardship for dealerships. The number of certified off-highway motorcycle models was particularly inadequate.\7\ In 1998, California revised the program, allowing the use of uncertified products in off- highway vehicle recreation areas with regional/seasonal use restrictions. Currently, noncomplying vehicles can be legally sold in California and used in attainment areas year-round and in nonattainment areas during months when exceedances of the state ozone standard are not expected. For enforcement purposes, certified and uncertified products are identified respectively with green and red stickers. Only about one-third of off-highway motorcycles sold in California are certified. --------------------------------------------------------------------------- \7\ Initial Statement of Reasons, Public Hearing to Consider Amendments to the California Regulations for New 1997 and Later Off- highway Recreational Vehicles and Engines, California ARB, October 23, 1998 (Docket A-2000-01, II-D-08). --------------------------------------------------------------------------- 3. Actions in Other Countries a. European action--Recreational Marine Engines. The European Commission has proposed emission standards for recreational marine engines, including both diesel and gasoline engines. These requirements would apply to all new engines sold in member countries. The numerical emission standards for recreational diesel marine engines, shown in Table I.F-2, consist of the Annex VI NOX standard for small marine diesel engines, the rough equivalent of Nonroad Diesel Tier 1 emission standards for HC and CO. Emission testing is to be conducted using the ISO D2 duty cycle for constant-speed engines and the ISO E5 duty cycle for all other engines. Table I.F-2 also presents average baseline emissions based on data that we have collected. These data are presented in Chapter 4 of the Draft Regulatory Support Document. We have received comment that we should apply these standards in the U.S., but the proposed European emission standards for recreational marine diesel engines may not result in a decrease in emissions, and may even allow an increase in emissions from engines operated in the U.S. Table I.F-2.--Proposed European Emission Standards for Recreational Marine Diesel Engines ------------------------------------------------------------------------ Emission Baseline standard emissions Pollutant (g/k W- (g/k W- hr) hr) ------------------------------------------------------------------------ NOX............................................... 9.8 8.9 PM................................................ 1.4 0.2 HC................................................ \a\ 1.5 0.3 CO................................................ 5.0 1.3 ------------------------------------------------------------------------ \a\ Increases slightly with increasing engine power rating. b. International Maritime Organization--CI Marine Engines. In response to growing international concern about air pollution and in recognition of the highly international nature of maritime transportation, the International Maritime Organization developed a program to reduce NOX and SOx emissions from marine vessels. No restrictions on PM, HC, or CO emissions were considered. The NOX provisions, contained in Regulation 13 of Annex VI to the International Convention on the Prevention of Pollution from Ships (MARPOL 73/78), specify that each diesel engine with a power output of more than 130 kW installed on a ship constructed on or after January 1, 2000, or that undergoes a major conversion on or after January 1, 2000, must meet the NOX emission standards in Table I.F-3.\8\ The Annex does not distinguish between marine diesel engines installed on recreational or commercial vessels; all marine diesel engines above 130 kW would be subject to the standards regardless of their use. --------------------------------------------------------------------------- \8\ Additional information about the MARPOL Annex VI NOX standards can be found in the documents for our commercial marine diesel standards, which can be found on our website (http://www.epa.gov/otaq/marine.htm). That website also contains facts sheets and other information about the Annex. Table I.F-3.--MARPOL Annex VI NOX Standards ------------------------------------------------------------------------ NOX (g/kW- Engine speed (n = engine speed, rpm) hr) ------------------------------------------------------------------------ n 130 rpm.................................................. 17.0 130 rpmn2000 rpm................................ 45*n(-0.2) [[Page 51103]] n 2000......................................... 9.8 ------------------------------------------------------------------------ After several years of negotiation, the Member States of the International Maritime Organization adopted a final version of Annex VI on September 26, 1997. As stipulated in Article 6 of the Agreement, the Annex will go into force when fifteen States, the combined merchant fleets of which constitute not less than 50 percent of the gross tonnage of the world's merchant shipping, have ratified it. As of today, three countries have ratified the Annex (Norway, Sweden, Singapore), representing about 7 percent of the world fleet. Pending entry into force, ship owners and vessel manufacturers are expected to install compliant engines on relevant ships beginning with the date specified in Regulation 13, January 1, 2000. In addition, ship owners are expected to bring existing engines into compliance if the engines undergo a major conversion on or after that date.\9\ As defined in Regulation 13 of Annex VI, a major conversion is defined to include those situations when the engine is replaced by a new engine, it is substantially modified, or its maximum continuous rating is increased by more than 10 percent. To facilitate this process, and to allow engine manufacturers to certify their engines before the Annex goes into force, we set up a process for manufacturers to obtain a Statement of Voluntary Compliance.\10\ This document will be exchangeable for an Engine International Air Pollution Prevention (EIAPP) certificate once the Annex goes into effect for the United States. --------------------------------------------------------------------------- \9\ As defined in Regulation 13 of Annex VI, a major conversion means the engine is replaced by a new engine, it is substantially modified, or its maximum continuous rating is increased by more than 10 percent. \10\ For more information about our voluntary certification program, see ``guidance for Certifying to MARPOL Annex VI,'' VPCD- 99-02. This letter is available on our website: http://www.epa.gov/ otaq/regs/nonroad/marine/ci/imolettr.pdf. --------------------------------------------------------------------------- II. Public Health and Welfare Effects of Emissions From Covered Engines A. Background This proposal contains regulatory strategies for three sets of new nonroad vehicles and engines that cause or contribute to air pollution but that have not been regulated under EPA's nonroad engine programs. The three sets of nonroad vehicles and engines are: Large Industrial Spark Ignition Engines. These are spark- ignition nonroad engines rated over 19 kW used in commercial applications. These include engines used in forklifts, electric generators, airport tugs, and a variety of other construction, farm, and industrial equipment. Many of these engines, such as those used in farm and construction equipment, are operated outdoors, predominantly during warmer weather and often in or near heavily-populated urban areas where they contribute to ozone formation and ambient CO and PM levels. These engines are also often operated in factories, warehouses, and large retail outlets throughout the year, where they contribute to high exposure levels to personnel who work with or near this equipment as well as to ozone formation and ambient CO and PM levels. For the purpose of this proposal, we are calling these ``Large SI engines.'' Nonroad Spark-Ignition Recreational Engines. These are spark-ignition nonroad engines used primarily in recreational applications. These include off-highway motorcycles, all-terrain- vehicles and snowmobiles. Some of these engines, particularly those used on all-terrain vehicles, are increasingly used for commercial purposes within urban areas, especially for mowing lawns and hauling loads. These vehicles are typically used in suburban and rural areas, where they contribute to ozone formation and ambient CO, and PM levels. All these vehicles, and snowmobiles in particular, contribute to visibility impairment problems in our national and state parks. For the purpose of this proposal, we are calling this group of engines ``recreational vehicles.'' Marine Engines. These are marine diesel engines that are used on recreational vessels such as yachts, cruisers, and other types of pleasure craft. Recreational marine engines are primarily used in warm weather and therefore contribute to ozone formation and PM levels, especially in marinas, which are often located in nonattainment areas. Nationwide, these engines and vehicles are a significant source of mobile-source air pollution. As described in Section II.C, below, they currently account for about 13 percent of national mobile-source HC emissions, 6 percent of mobile-source CO emissions, 3 percent of mobile-source NOX emissions, and 1 percent of mobile-source PM emissions. Recreational vehicles by themselves account for nearly 10 percent of national mobile-source HC emissions and about 3 percent of national mobile-source CO emissions. Within national parks, snowmobiles are significant contributors to ambient concentrations of fine particulate matter, a leading component of visibility impairment. By reducing these emissions, the proposed standards would provide assistance to states facing ozone and CO air quality problems, which can cause a range of adverse health effects, especially in terms of respiratory impairment and related illnesses. States are required to develop plans to address visibility impairment in national parks, and the reductions proposed in this rule would assist states in those efforts. In addition, the proposed standards would help reduce acute exposure to CO and air toxics for forklift operators, snowmobile users, national and state park attendants, and other people who may be at particular risk because they operate or work or are otherwise active for long periods of time in close proximity to this equipment. Emissions from these vehicles and equipment can be very high on a per engine basis. In addition, the equipment (e.g., forklifts) is often used in enclosed areas. Similarly, exposure can be intensified for snowmobile riders who follow a group of other rides along a trail, since those riders are exposed to the emissions of all the other snowmobiles riding ahead. As summarized below and explained in greater detail in the Draft Regulatory Support Document for this proposal, CO emissions have been directly associated with cardisvascular and other health problems, and many types of hydrocarbons are also air toxics. The standards proposed in this document would require the use of cleaner emission-control technologies. For Large SI engines, we are proposing a two-phase program that will take fuel effects into account. The first phase consists of one set of standards that would apply to all engines regardless of fuel (i.e., gasoline, LPG, CNG). These standards are identical to those recently adopted by California Air Resources Board (CARB) and are based on a steady-state test. The second phase of standards is more stringent than the California standards. The numerical limits differ depending on fuel type and would require optimizing the same emission-control technologies used in Phase 1 but would be based on a transient duty test cycle. These standards would also include new requirements for evaporative emissions and engine diagnostics. For marine engines, we are proposing to set new standards that would require recreational diesel marine engines to adopt the emission- control technology [[Page 51104]] that will be in use on commercial diesel marine engines. For nonroad recreational vehicles, we are proposing standards that would require snowmobiles to use cleaner 2-stroke technologies (e.g., clean carburetion, electronic fuel injection). For off-highway motorcycles and all-terrain vehicles, we are proposing standards that would effectively require manufacturers to use more 4-stroke technology for most engines. A second phase of proposed standards for all-terrain vehicles is based on catalyst technology. When the proposed emission standards are fully implemented in 2020, we expect a 79 percent reduction in HC emissions, 75 percent reduction in NOX emissions, and 56 percent reduction in CO emissions from these engines, equipment, and vehicles (see Section IX below for more details). These emission reductions will reduce ambient concentrations of ozone, CO, and PM fine, which is a health concern and contributes to visibility impairment. The standards will also reduce personal exposure for people who operate or who work with or are otherwise in close proximity to these engines and vehicles. For the nonroad engines covered by this proposal, the Agency has already established in several previous actions that they cause or contribute to ozone or carbon monoxide pollution in more than one nonattainment area. In three actions in 1996, 1999, and 2000, we made separate determinations that each category of nonroad engines covered by this proposal specifically contributes to ozone and CO nonattainment, and to adverse health effects associated with ambient concentrations of PM. These actions are summarized in Table II.A-1. In addition, pursuant to Section 213(a)(4) of the Act, we are proposing to find that nonroad engines, including construction equipment, farm tractors, boats, planes, locomotives, marine engines, and recreational vehicles (e.g., off-highway motorcycles, all-terrain-vehicles, and snowmobiles), significantly contribute to regional haze, and that these engines, particularly snowmobiles, are significant emitters of pollutants that are known to impair visibility in federal Class I areas. The discussion pertaining to this proposed finding is in Section II.D.1, below. Table II.A-1.--Summary of Nonroad Air Quality Findings ---------------------------------------------------------------------------------------------------------------- Source Date of finding Pollutants covered Emissions determined to contribute ---------------------------------------------------------------------------------------------------------------- CI Marine..................... December 29, 1999, 64 Ozone, PM............ HC+NOX, PM, CO. FR 73300. Large SI...................... December 7, 2000, 65 Ozone, CO, PM........ HC+NOX, CO, PM. FR 76790. Recreational Vehicles......... December 7, 2000, 65 Ozone, CO, PM........ HC+NOX, CO, PM. FR 76790. ---------------------------------------------------------------------------------------------------------------- B. What Are the Public Health and Welfare Effects Associated With Emissions From Nonroad Engines Subject to the Proposed Standards? The engines and vehicles that would be subject to the proposed standards generate emissions of HC, CO, PM and air toxics that contribute to ozone and CO nonattainment as well as adverse health effects associated with ambient concentrations of PM and air toxics. Elevated emissions from those recreational vehicles that operate in national parks (e.g., snowmobiles) contribute to visibility impairment. This section summarizes the general health effects of these substances. National inventory estimates are set out in Section II.B, and estimates of the expected impact of the proposed control programs are described in Section IX. Interested readers are encouraged to refer to the Draft Regulatory Support Document for this proposal for more in-depth discussions. 1. Health and Welfare Effects Associated With Ground Level Ozone and Its Precursors Volatile organic compounds (VOC) and NOX are precursors in the photochemical reaction which forms tropospheric ozone. Ground- level ozone, the main ingredient in smog, is formed by complex chemical reactions of VOCs and NOX in the presence of heat and sunlight. Hydrocarbons (HC) are a large subset of VOC, and to reduce mobile-source VOC levels we set maximum emissions limits for hydrocarbon and particulate matter emissions. A large body of evidence shows that ozone can cause harmful respiratory effects including chest pain, coughing, and shortness of breath, which affect people with compromised respiratory systems most severely. When inhaled, ozone can cause acute respiratory problems; aggravate asthma; cause significant temporary decreases in lung function of 15 to over 20 percent in some healthy adults; cause inflammation of lung tissue; produce changes in lung tissue and structure; may increase hospital admissions and emergency room visits; and impair the body's immune system defenses, making people more susceptible to respiratory illnesses. Children and outdoor workers are likely to be exposed to elevated ambient levels of ozone during exercise and, therefore, are at a greater risk of experiencing adverse health effects. Beyond its human health effects, ozone has been shown to injure plants, which has the effect of reducing crop yields and reducing productivity in forest ecosystems. There is strong and convincing evidence that exposure to ozone is associated with exacerbation of asthma-related symptoms. Increases in ozone concentrations in the air have been associated with increases in hospitalization for respiratory causes for individuals with asthma, worsening of symptoms, decrements in lung function, and increased medication use, and chronic exposure may cause permanent lung damage. The risk of suffering these effects is particularly high for children and for people with compromised respiratory systems. Ground level ozone today remains a pervasive pollution problem in the United States. In 1999, 90.8 million people (1990 census) lived in 31 areas designated nonattainment under the 1-hour ozone NAAQS.\73\ This sharp decline from the 101 nonattainment areas originally identified under the Clean Air Act Amendments of 1990 demonstrates the effectiveness of the last decade's worth of emission-control programs. However, elevated ozone concentrations remain a serious public health concern throughout the nation. --------------------------------------------------------------------------- \73\ National Air Quality and Emissions Trends Report, 1999, EPA, 2001, at Table A-19. This document is available at http:// www.epa.gov/oar/aqtrnd99/. The data from the Trends report are the most recent EPA air quality data that have been quality assured. A copy of this table can also be found in Docket No. A-2000-01, Document No. II-A-64. --------------------------------------------------------------------------- Over the last decade, declines in ozone levels were found mostly in urban areas, where emissions are heavily influenced by controls on mobile sources and their fuels. Twenty-three metropolitan areas have realized a decline in ozone levels since 1989, but at the same time ozone levels in 11 metropolitan areas with 7 million [[Page 51105]] people have increased.\74\ Regionally, California and the Northeast have recorded significant reductions in peak ozone levels, while four other regions (the Mid-Atlantic, the Southeast, the Central and Pacific Northwest) have seen ozone levels increase. --------------------------------------------------------------------------- \74\ National Air Quality and Emissions Trends Report, 1998, March, 2000, at 28. This document is available at http:// www.epa.gov/oar/aqtrnd98/. Relevant pages of this report can be found in Memorandum to Air Docket A-2000-01 from Jean Marie Revelt, September 5, 2001, Document No. II-A-63. --------------------------------------------------------------------------- The highest ambient concentrations are currently found in suburban areas, consistent with downwind transport of emissions from urban centers. Concentrations in rural areas have risen to the levels previously found only in cities. Particularly relevant to this proposal, ozone levels at 17 of our National Parks have increased, and in 1998, ozone levels in two parks, Shenandoah National Park and the Great Smoky Mountains National Park, were 30 to 40 percent higher than the ozone NAAQS over part of the last decade.\75\ --------------------------------------------------------------------------- \75\ National Air Quality and Emissions Trends Report, 1998, March, 2000, at 32. This document is available at http:// www.epa.gov/oar/aqtrnd98/. Relevant pages of this report can be found in Memorandum to Air Docket A-2000-01 from Jean Marie Revelt, September 5, 2001, Document No. II-A-63. --------------------------------------------------------------------------- To estimate future ozone levels, we refer to the modeling performed in conjunction with the final rule for our most recent heavy-duty highway engine and fuel standards.\76\ We performed ozone air quality modeling for the entire Eastern U.S. covering metropolitan areas from Texas to the Northeast.\77\ This ozone air quality model was based upon the same modeling system as was used in the Tier 2 air quality analysis, with the addition of updated inventory estimates for 2007 and 2030. The results of this modeling were examined for those 37 areas in the East for which EPA's modeling predicted exceedances in 2007, 2020, and/or 2030 and the current 1-hour design values are above the standard or within 10 percent of the standard. This photochemical ozone modeling for 2020 predicts exceedances of the 1-hour ozone standard in 32 areas with a total of 89 million people (1999 census) after accounting for light- and heavy-duty on-highway control programs.\78\ We expect the NOX and HC control strategies contained in this proposal for nonroad engines will further assist state efforts already underway to attain and maintain the 1-hour ozone standard. --------------------------------------------------------------------------- \76\ Additional information about this modeling can be found in our Regulatory Impact Analysis: Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements, document EPA420-R-00-026, December 2000. Docket No. 1-2000-01, Document No. II-A-13. This document is also available at http://www.epa.gov/otaq/diesel.htm#documents. \77\ We also performed ozone air quality modeling for the western United States but, as described further in the air quality technical support document, model predictions were well below corresponding ambient concentrations for out heavy-duty engine standards and fuel sulfur control rulemaking. Because of poor model performance for this region of the country, the results of the Western ozone modeling were not relied on for that rule. \78\ Regulatory Impact Analysis: Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements, US EPA, EPA420-R-00-026, December 2000, at II-14, Table II.A-2. Docket No. A-2000-01, Document Number II-A-13. This document is also available at http://www.epa.gov/otaq/diesel.htm#documents. --------------------------------------------------------------------------- In addition to the health effects described above, there exists a large body of scientific literature that shows that harmful effects can occur from sustained levels of ozone exposure much lower than 0.125 ppm.\79\ Studies of prolonged exposures, those lasting about 7 hours, show health effects from prolonged and repeated exposures at moderate levels of exertion to ozone concentrations as low as 0.08 ppm. The health effects at these levels of exposure include transient pulmonary function responses, transient respiratory symptoms, effects on exercise performance, increased airway responsiveness, increased susceptibility to respiratory infection, increased hospital and emergency room visits, and transient pulmonary respiratory inflammation. --------------------------------------------------------------------------- \79\ Additional information about these studies can be found in Chapter 2 of ``Regulatory Impact Analysis: Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements,'' December 2000, EPA420-R-00-026. Docket No. A-2000- 01, Document Number II-A-13. This document is also available at http://www.epa.gov/otaq/diesel.htm#documents. --------------------------------------------------------------------------- Prolonged and repeated ozone concentrations at these levels are common in areas throughout the country, and are found both in areas that are exceeding, and areas that are not exceeding, the 1-hour ozone standard. Areas with these high concentrations are more widespread than those in nonattainment for that 1-hour ozone standard. Monitoring data indicate that 333 counties in 33 states exceed these levels in 1997- 99.\80\ The Agency's most recent photochemical ozone modeling forecast that 111 million people are predicted to live in areas that are at risk of exceeding these moderate ozone levels for prolonged periods of time in 2020 after accounting for expected inventory reductions due to controls on light- and heavy-duty on-highway vehicles.\81\ --------------------------------------------------------------------------- \80\ A copy of these data can be found in Air Docket A-2000-01, Document No. II-A-80. \81\ Memorandum to Docket A-99-06 from Eric Ginsburg, EPA, ``Summary of Model-Adjusted Ambient Concentrations for Certain Levels of Ground-Level Ozone over Prolonged Periods,'' November 22, 2000, at Table C, Control Scenario--2020 Populations in Eastern Metropolitan Counties with Predicted Daily 8-Hour Ozone greater than or equal to 0.080 ppm. Docket A-2000-01, Document Number II-B-13. --------------------------------------------------------------------------- 2. Health Effects Associated With Carbon Monoxide Carbon monoxide (CO) is a colorless, odorless gas produced through the incomplete combustion of carbon-based fuels. Carbon monoxide enters the bloodstream through the lungs and reduces the delivery of oxygen to the body's organs and tissues. The health threat from CO is most serious for those who suffer from cardiovascular disease, particularly those with angina or peripheral vascular disease. Healthy individuals also are affected, but only at higher CO levels. Exposure to elevated CO levels is associated with impairment of visual perception, work capacity, manual dexterity, learning ability and performance of complex tasks. High concentrations of CO generally occur in areas with elevated mobile-source emissions. Peak concentrations typically occur during the colder months of the year when mobile-source CO emissions are greater and nighttime inversion conditions are more frequent. This is due to the enhanced stability in the atmospheric boundary layer, which inhibits vertical mixing of emissions from the surface. The current primary NAAQS for CO are 35 parts per million for the one-hour average and 9 parts per million for the eight-hour average. These values are not to be exceeded more than once per year. Air quality carbon monoxide value is estimated using EPA guidance for calculating design values. In 1999, 30.5 million people (1990 census) lived in 17 areas designated nonattainment under the CO NAAQS.\82\ --------------------------------------------------------------------------- \82\ National Air Quality and Emissions Trends Report, 1999, EPA, 2001, at Table A-19. This document is available at http:// www.epa.gov/oar/aqtrnd99/. The data from the Trends report are the most recent EPA air quality data that have been quality assured. A copy of this table can also be found in Docket No. A-2000-01, Document No. II-A-64. --------------------------------------------------------------------------- Snowmobiles, which have relatively high per engine CO emissions, can be a significant source of ambient CO levels in CO nonattainment areas. Several states that contain CO nonattainment areas also have large populations of registered snowmobiles. This is shown in Table II.B-1. A review of snowmobile trail maps indicates that snowmobiles are used in these CO nonattainment [[Page 51106]] areas or in adjoining counties.\83\ These include the Mt. Spokane and Riverside trails near the Spokane, Washington CO nonattainment area; the Larimer trails near the Fort Collins, Colorado CO nonattainment area; and the Hyatt Lake, Lake of the Woods, and Cold Springs trails near the Klamath Falls and Medford, Oregon CO nonattainment area. There are also trails in Missoula County, Montana that demonstrate snowmobile use in the Missoula, Montana CO nonattainment area. While Colorado has a large snowmobile population, the snowmobile trails are fairly distant from the Colorado Springs CO nonattainment areas. EPA requests comment on the volume and nature of snowmobile use in these and other CO nonattainment areas. Of particular interest is information about the number of trails in and around CO nonattainment areas, the magnitude of snowmobile use on those trails, and the extent to which snowmobiles are used off-trail.\84\ --------------------------------------------------------------------------- \83\ St. Paul, Minnesota was recently reclassified as being in attainment but is still considered a maintenance area. There is also a significant population of snowmobiles in Minnesota, with snowmobile trails in Washington County. \84\ The trail maps consulted for this proposal can be found in Docket No. A-2000-01, Document No. II-A-65. Table II.B-1.--Snowmobile Use in Selected CO Nonattainment Areas ---------------------------------------------------------------------------------------------------------------- 1998 State City and State CO nonattainment classification snowmobile population \a\ ---------------------------------------------------------------------------------------------------------------- Fairbanks, AK............................ Serious.............................................. 12,997 Spokane, WA.............................. Serious.............................................. 32,274 Colorado Springs, CO..................... Moderate............................................. 28,000 Fort Collins, CO......................... Moderate............................................. Klamath Falls, OR........................ Moderate............................................. 13,426 Medford, OR.............................. Moderate............................................. Missoula, MT............................. Moderate............................................. 14,361 ---------------------------------------------------------------------------------------------------------------- \a\ Source: Letter from International Snowmobile Manufacturers Association to US-EPA, July 8, 1999, Docket A- 2000-01, Document No. II-G. Exceedances of the 8-hour CO standard were recorded in three of these seven CO nonattainment areas located in the northern portion of the country over the five year period from 1994 to 1999: Fairbanks, AK; Medford, OR; and Spokane, WA.\85\ Given the variability in CO ambient concentrations due to weather patterns such as inversions, the absence of recent exceedances for some of these nonattainment areas should not be viewed as eliminating the need for further reductions to consistently attain and maintain the standard. A review of CO monitor data in Fairbanks from 1986 to 1995 shows that while median concentrations have declined steadily, unusual combinations of weather and emissions have resulted in elevated ambient CO concentrations well above the 8-hour standard of 9 ppm. Specifically, a Fairbanks monitor recorded average 8-hour ambient concentrations at 16 ppm in 1988, around 9 ppm from 1990 to 1992, and then a steady increase in CO ambient concentrations at 12, 14 and 16 ppm during some extreme cases in 1993, 1994 and 1995, respectively.\86\ --------------------------------------------------------------------------- \85\ Technical Memorandum to Docket A-2000-01 from Drew Kodjak, Attorney-Advisor, Office of Transportation and Air Quality, ``Air Quality Information for Selected CO Nonattainment Areas,'' July 27, 2001, Docket Number A-2000-01, Document Number II-B-18. \86\ Air Quality Criteria for Carbon Monoxide, US EPA, EPA 600/ P-99/001F, June 2000, at 3-38, Figure 3-32 (Federal Bldg, AIRS Site 020900002). Air Docket A-2000-01, Document Number II-A-29. This document is also available at http://www.epa.gov/ncea/ coabstract.htm. --------------------------------------------------------------------------- Nationally, significant progress has been made over the last decade to reduce CO emissions and ambient CO concentrations. Total CO emissions from all sources have decreased 16 percent from 1989 to 1998, and ambient CO concentrations decreased by 39 percent. During that time, while the mobile source CO contribution of the inventory remained steady at about 77 percent, the highway portion decreased from 62 percent of total CO emissions to 56 percent while the nonroad portion increased from 17 percent to 22 percent.\87\ Over the next decade, we would expect there to be a minor decreasing trend from the highway segment due primarily to the more stringent standards for certain light-duty trucks (LDT2s).\88\ CO standards for passenger cars and other light-duty trucks and heavy-duty vehicles did not change as a result of other recent rulemakings). As described in Section II.C, below, the engines subject to this rule currently account for about 7 percent of the mobile source CO inventory; this is expected to increase to 10 percent by 2020 without the emission controls proposed in this action. --------------------------------------------------------------------------- \87\ National Air Quality and Emissions Trends Report, 1998, March, 2000; this document is available at http://www.epa.gov/oar/ aqtrnd98/. National Air Pollutant Emission Trends, 1900-1998 (EPA- 454/R-00-002), March, 2000. These documents are available at Docket No. A-2000-01, Document No. II-A-72. See also Air Quality Criteria for Carbon Monoxide, US EPA, EPA 600/P-99/001F, June 2000, at 3-10. Air Docket A-2000-01, Document Number II-A-29. This document is also available at http://www.epa.gov/ncea/coabstract.htm. \88\ LDT2s are light light-duty trucks greater than 3750 lbs. loaded vehicle weight, up through 6000 gross vehicle weight rating. --------------------------------------------------------------------------- The state of Alaska recently submitted draft CO attainment SIPs to the Agency for the Fairbanks CO nonattainment area. Fairbanks is located in a mountain valley with a much higher potential for air stagnation than cities within the contiguous United States. Nocturnal inversions that give rise to elevated CO concentrations can persist 24- hours a day due to the low solar elevation, particularly in December and January. These inversions typically last from 2 to 4 days (Bradley et al., 1992), and thus inversions may continue during hours of maximum CO emissions from mobile sources. Despite the fact that snowmobiles are largely banned in CO nonattainment areas by the state, the state estimated that snowmobiles contributed 0.3 tons/day in 1995 to Fairbanks' CO nonattainment area or 1.2 percent of a total inventory of 23.3 tons per day in 2001.\89\ While Fairbanks has made significant progress in reducing ambient CO concentrations, existing climate conditions make achieving and maintaining attainment challenging. Fairbanks failed to attain the CO NAAQS by the applicable deadline of [[Page 51107]] December 21, 2000, and EPA approved a one-year extension in May of 2001.\90\ --------------------------------------------------------------------------- \89\ Draft Anchorage Carbon Monoxide Emission Inventory and Year 2000 Attainment Projections, Air Quality Program, May 2001, Docket Number A-2000-01, Document II-A-40; Draft Fairbanks 1995-2001 Carbon Monoxide Emissions Inventory, June 1, 2001, Docket Number A-2000-01, Document II-A-39. \90\ 66 FR 28836, May 25, 2001. Clean Air Act Promulgation of Attainment Date Extension for the Fairbanks North Star Borough Carbon Monoxide Nonattainment Area, AK, Direct Final Rule. --------------------------------------------------------------------------- In addition to the health effects that can result from exposure to carbon monoxide, this pollutant also can contribute to ground level ozone formation.\91\ Recent studies in atmospheric chemistry in urban environments suggest CO can react with hydrogen-containing radicals, leaving fewer of these to combine with non-methane hydrocarbons and thus leading to increased levels of ozone. Few analyses have been performed that estimate these effects, but a study of an ozone episode in Atlanta, GA in 1988 found that CO accounted for about 17.5 percent of the ozone formed (compared to 82.5 percent for volatile organic compounds). While different cities may have different results, the effects of CO emissions on ground level ozone are not insignificant. The engines that are the subject of the proposed standards are contributors to these effects in urban areas, particularly because their per engine emissions are so high. For example, CO emissions from an off-highway motorcycle are high relative to a passenger car, (32 g/ mi compared to 4.2 g/mi). The CO controls contained in this proposal will further assist state efforts already underway to attain and maintain the CO NAAQS. --------------------------------------------------------------------------- \91\ U.S. EPA, Air Quality Criteria for Carbon Monoxide, EPA 600/P-99.001F, June 2000, Section 3.2.3. Air Docket A-2000-01, Document Number II-A-29. This document is also available at http:// www.epa.gov/ncea/coabstract.htm. --------------------------------------------------------------------------- 3. Health and Welfare Effects Associated With Particulate Matter Nonroad engines and vehicles that would be subject to the proposed standards contribute to ambient particulate matter (PM) levels in two ways. First, they contribute through direct emissions of particulate matter. Second, they contribute to indirect formation of PM through their emissions of organic carbon, especially HC. Organic carbon accounts for between 27 and 36 percent of fine particle mass depending on the area of the country. Particulate matter represents a broad class of chemically and physically diverse substances. It can be principally characterized as discrete particles that exist in the condensed (liquid or solid) phase spanning several orders of magnitude in size. All particles equal to and less than 10 microns are called PM10. Fine particles can be generally defined as those particles with an aerodynamic diameter of 2.5 microns or less (also known as PM2.5), and coarse fraction particles are those particles with an aerodynamic diameter greater than 2.5 microns, but equal to or less than a nominal 10 microns. Particulate matter, like ozone, has been linked to a range of serious respiratory health problems. Scientific studies suggest a likely causal role of ambient particulate matter (which is attributable to several sources including mobile sources) in contributing to a series of health effects.\92\ The key health effects categories associated with ambient particulate matter include premature mortality, aggravation of respiratory and cardiovascular disease (as indicated by increased hospital admissions and emergency room visits, school absences, work loss days, and restricted activity days), aggravated asthma, acute respiratory symptoms, including aggravated coughing and difficult or painful breathing, chronic bronchitis, and decreased lung function that can be experienced as shortness of breath. Observable human noncancer health effects associated with exposure to diesel PM include some of the same health effects reported for ambient PM such as respiratory symptoms (cough, labored breathing, chest tightness, wheezing), and chronic respiratory disease (cough, phlegm, chronic bronchitis and suggestive evidence for decreases in pulmonary function). Symptoms of immunological effects such as wheezing and increased allergenicity are also seen. Exposure to fine particles is closely associated with such health effects as premature mortality or hospital admissions for cardiopulmonary disease. --------------------------------------------------------------------------- \92\ EPA (1996) Review of the National Ambient Air Quality Standards for Particulate Matter: Policy Assessment of Scientific and Technical Information OAQPS Staff Paper. EPA-452/R-96-013. Docket Number A-99-06, Documents Nos. II-A-18, 19, 20, and 23. The particulate matter air quality criteria documents are also available at http://www.epa.gov/ncea/partmatt.htm. --------------------------------------------------------------------------- PM also causes adverse impacts to the environment. Fine PM is the major cause of reduced visibility in parts of the United States, including many of our national parks. Other environmental impacts occur when particles deposit onto soils, plants, water or materials. For example, particles containing nitrogen and sulphur that deposit on to land or water bodies may change the nutrient balance and acidity of those environments. Finally, PM causes soiling and erosion damage to materials, including culturally important objects such as carved monuments and statues. It promotes and accelerates the corrosion of metals, degrades paints, and deteriorates building materials such as concrete and limestone. The NAAQS for PM10 were established in 1987. According to these standards, the short term (24-hour) standard of 150 g/m3 is not to be exceeded more than once per year on average over three years. The long-term standard specifies an expected annual arithmetic mean not to exceed 50 g/ m3 over three years. The most recent PM10 monitoring data indicate that 14 designated PM10 nonattainment areas with a projected population of 23 million violated the PM10 NAAQS in the period 1997-99. In addition, there are 25 unclassifiable areas that have recently recorded ambient concentrations of PM10 above the PM10 NAAQS.\93\ --------------------------------------------------------------------------- \93\ EPA adopted a policy in 1996 that allows areas with PM10 exceedances that are attributable to natural events to retain their designation as unclassifiable if the State is taking all reasonable measures to safeguard public health regardless of the sources of PM10 emissions. --------------------------------------------------------------------------- Current 1999 PM2.5 monitored values, which cover about a third of the nation's counties, indicate that at least 40 million people live in areas where long-term ambient fine particulate matter levels are at or above 16 g/m3 (37 percent of the population in the areas with monitors).\94\ This 16 g/ m3 threshold is the low end of the range of long term average PM2.5 concentrations in cities where statistically significant associations were found with serious health effects, including premature mortality.\95\ To estimate the number of people who live in areas where long-term ambient fine particulate matter levels are at or above 16 g/m3 but for which there are no monitors, we can use modeling. According to our national modeled predictions, there were a total of 76 million people (1996 population) living in areas with modeled annual average PM2.5 concentrations at or above 16 g/m3 (29 percent of the population).\96\ --------------------------------------------------------------------------- \94\ Memorandum to Docket A-99-06 from Eric O. Ginsburg, Senior Program Advisor, ``Summary of 1999 Ambient Concentrations of Fine Particulate Matter,'' November 15, 2000. Air Docket A-2000-01, Document No. II-B-12. \95\ EPA (1996) Review of the National Ambient Air Quality Standards for Particulate Matter: Policy Assessment of Scientific and Technical Information OAQPS Staff Paper. EPA-452/R-96-013. Docket Number A-99-06, Documents Nos. II-A-18, 19, 20, and 23. The particulate matter air quality criteria documents are also available at http://www.epa.gov/ncea/partmatt.htm. \96\ Memorandum to Docket A-99-06 from Eric O. Ginsburg, Senior Program Advisor, ``Summary of Absolute Modeled and Model-Adjusted Estimates of Fine Particulate Matter for Selected Years,'' December 6, 2000. Air Docket A-2000-01, Document No. II-B-14. --------------------------------------------------------------------------- To estimate future PM2.5 levels, we refer to the modeling performed in [[Page 51108]] conjunction with the final rule for our most recent heavy-duty highway engine and fuel standards, using EPA's Regulatory Model System for Aerosols and Deposition (REMSAD).\97\ The most appropriate method of making these projections relies on the model to predict changes between current and future states. Thus, we have estimated future conditions only for the areas with current PM2.5 monitored data (which cover about a third of the nation's counties). For these counties, REMSAD predicts the current level of 37 percent of the population living in areas where fine PM levels are at or above 16 g/ m3 to increase to 49 percent in 2030.\98\ --------------------------------------------------------------------------- \97\ Additional information about the Regulatory Model System for Aerosols and Deposition (REMSAD) and our modeling protocols can be found in our Regulatory Impact Analysis: Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements, document EPA420-R-00-026, December 2000. Docket No. A- 2000-01, Document No. A-II-13. This document is also available at http://www.epa.gov/otaq/disel.htm#documents. \98\ Technical Memorandum, EPA Air Docket A-99-06, Eric O. Ginsburg, Senior Program Advisor, Emissions Monitoring and Analysis Division, OAQPS, Summary of Absolute Modeled and Model-Adjusted Estimates of Fine Particulate Matter for Selected Years, December 6, 2000, Table P-2. Docket Number 2000-01, Document Number II-B-14. --------------------------------------------------------------------------- Emissions of HCs from snowmobiles contribute to secondary formation of fine particulate matter which can cause a variety of adverse health and welfare effects, including visibility impairment discussed in Section II.D.1(b) below. For 20 counties across nine states, snowmobile trails are found within or near counties that registered ambient PM 2.5 concentrations at or above 15 g/m3, the level of the revised national ambient air quality standard for fine particles.\99\ Fine particles may remain suspended for days or weeks and travel hundreds to thousands of kilometers, and thus fine particles emitted or created in one county may contribute to ambient concentrations in a neighboring county.\100\ These counties are listed in Table II.B-2. To obtain the information about snowmobile trails contained in Table II.B-2, we consulted snowmobile trail maps that were supplied by various states.\101\ --------------------------------------------------------------------------- \99\ Memo to file from Terence Fitz-Simons, OAQPS, Scott Mathias, OAQPS, Mike Rizzo, Region 5, ``Analyses of 1999 PM Data for the PM NAAQS Review,'' November 17, 2000, with attachment B, 1999 PM2.5 Annual Mean and 98th Percentile 24-Hour Average Concentrations. Docket No. A-2000-01, Document No. II-B-17. \100\ Review of the National Ambient Air Quality Standards for Particulate Matter: Policy Assessment for Scientific and Technical Information, OAQPS Staff Paper, EPA-452/R-96-013, July, 1996, at IV- 7. \101\ The trail maps consulted for this proposal can be found in Docket No. A-2000-01, Document No. II-A-65. Table II.B-2.--Counties With Annual PM2.5 Levels Above 16 g/m\3\ and Snowmobile Trails ---------------------------------------------------------------------------------------------------------------- State and PM2.5 exceedance county County with snowmobile trails Proximity to PM2.5 exceedance county ---------------------------------------------------------------------------------------------------------------- Ohio: Mahoning............................ Mahoning..................... Trumbull............................ Trumbull..................... Summit.............................. Summit....................... Montgomery.......................... Montgomery................... Portage............................. Portage...................... Franklin............................ Delaware..................... Borders North. Marshall/Ohio (WV).................. Belmont...................... Borders West. Montana............................... Lincoln...................... Lincoln California: Tulane.............................. Tulane....................... Butte............................... Butte........................ Fresno.............................. Fresno....................... Kern................................ Kern......................... Minnesota: Washington.......................... Washington................... Wright.............................. Wright....................... Wisconsin: Waukesha............................ Waukesha..................... Milwaukee........................... Milwaukee.................... Oregon: Jackson............................. Douglas...................... Borders NNE. Klamath............................. Douglas...................... Borders North. Pennsylvania: Washington.............. Layette...................... Borders East. Somerset..................... Illinois: Rock Island................. Rock Island Henry........................ Borders East. Iowa: Rock Island (IL)................ Dubuque...................... Borders West. ---------------------------------------------------------------------------------------------------------------- We expect the PM control strategies contained in this proposal would further assist state efforts already underway to attain and maintain the PM NAAQS. 4. Health Effects Associated With Air Toxics In addition to the human health and welfare impacts described above, emissions from the engines covered by this proposal also contain several other substances that are known or suspected human or animal carcinogens, or have serious noncancer health effects. These include benzene, 1,3-butadiene, formaldehyde, acetaldehyde, and acrolein. The health effects of these air toxics are described in more detail in Chapter 1 of the Draft Regulatory Support Document for this rule. Additional information can also be found in the Technical Support [[Page 51109]] Document for our final Mobile Source Air Toxics rule.102 --------------------------------------------------------------------------- \102\ See our Mobile Source Air Toxics final rulemaking, 66 FR 17230, March 29, 2001, and the Technical Support Document for that rulemaking. Docket No. A-2000-01, Documents Nos. II-A-42 and II-A- 30. --------------------------------------------------------------------------- The hydrocarbon controls contained in this proposal are expected to reduce exposure to air toxics and therefore may help reduce the impact of these engines on cancer and noncancer health effects. C. What Is the Inventory Contribution From the Nonroad Engines and Vehicles That Would Be Subject to This Proposal? The contribution of emissions from the nonroad engines and vehicles that would be subject to the proposed standards to the national inventories of pollutants that are associated with the health and public welfare effects described in Section II.B are considerable. To estimate nonroad engine and vehicle emission contributions, we used the latest version of our NONROAD emissions model. This model computes nationwide, state, and county emission levels for a wide variety of nonroad engines, and uses information on emission rates, operating data, and population to determine annual emission levels of various pollutants. A more detailed description of the model and our estimation methodology can be found in the Chapter 6 of the Draft Regulatory Support Document. Baseline emission inventory estimates for the year 2000 for the categories of engines and vehicles covered by this proposal are summarized in Table II.C-1. This table shows the relative contributions of the different mobile-source categories to the overall national mobile-source inventory. Of the total emissions from mobile sources, the categories of engines and vehicles covered by this proposal contribute about 13 percent, 3 percent, 6 percent, and 1 percent of HC, NOX, CO, and PM emissions, respectively, in the year 2000. The results for industrial SI engines indicate they contribute approximately 3 percent to HC, NOX, and CO emissions from mobile sources. The results for land-based recreational engines reflect the impact of the significantly different emissions characteristics of two-stroke engines. These engines are estimated to contribute 10 percent of HC emissions and 3 percent of CO from mobile sources. Recreational CI marine contribute less than 1 percent to NOX mobile source inventories. When only nonroad emissions are considered, the engines and vehicles that would be subject to the proposed standards would account for a larger share. Our draft emission projections for 2020 for the nonroad engines and vehicles subject to this proposal show that emissions from these categories are expected to increase over time if left uncontrolled. The projections for 2020 are summarized in Table II.C-2 and indicate that the categories of engines and vehicles covered by this proposal are expected to contribute 33 percent, 9 percent, 9 percent, and 2 percent of HC, NOX, CO, and PM emissions in the year 2020. Population growth and the effects of other regulatory control programs are factored into these projections. The relative importance of uncontrolled nonroad engines is higher than the projections for 2000 because there are already emission control programs in place for the other categories of mobile sources which are expected to reduce their emission levels. The effectiveness of all control programs is offset by the anticipated growth in engine populations. Table II.C-1.--Modeled Annual Emission Levels for Mobile-Source Categories in 2000 [Thousand short tons] -------------------------------------------------------------------------------------------------------------------------------------------------------- NOX HC CO PM --------------------------------------------------------------------------------------- Category Percent Percent Percent Percent Tons of mobile Tons of mobile Tons of mobile Tons of mobile source source source source -------------------------------------------------------------------------------------------------------------------------------------------------------- Total for engines subject to proposed standards................. 343 2.6 985 12.9 4,870 6.3 8.3 1.2 ======================================================================================= Highway Motorcycles............................................. 8 0.1 84 1.1 329 0.4 0.4 0.1 Nonroad Industrial SI > 19 kW................................... 306 2.3 247 3.2 2,294 3.0 1.6 0.2 Recreational SI................................................. 13 0.1 737 9.7 2,572 3.3 5.7 0.8 Recreation Marine CI............................................ 24 0.2 1 0.0 4 0.0 1 0.1 Marine SI Evap.................................................. 0 0.0 89 1.2 0 0.0 0 0.0 Marine SI Exhaust............................................... 32 0.2 708 9.3 2,144 2.8 38 5.4 Nonroad SI 19 kW............................................... 106 0.8 1,460 19.1 18,359 23.6 50 7.2 Nonroad CI...................................................... 2,625 19.5 316 4.1 1,217 1.6 253 36.2 Commercial Marine CI............................................ 977 7.3 30 0.4 129 0.2 41 5.9 Locomotive...................................................... 1,192 8.9 47 0.6 119 0.2 30 4.3 --------------------------------------------------------------------------------------- Total Nonroad................................................... 5,275 39 3,635 48 26,838 35 420 60 Total Highway................................................... 7,981 59 3,811 50 49,811 64 240 34 Aircraft........................................................ 178 1 183 2 1,017 1 39 6 --------------------------------------------------------------------------------------- Total Mobile Sources............................................ 13,434 100 7,629 100 77,666 100 699 100 ======================================================================================= Total Man-Made Sources.......................................... 24,538 ......... 18,575 ......... 99,745 ......... 3,095 ......... ======================================================================================= Mobile Source percent of Total Man-Made Sources................. 55 ......... 41 ......... 78 ......... 23 ......... -------------------------------------------------------------------------------------------------------------------------------------------------------- [[Page 51110]] Table II.C-2.--Modeled Annual Emission Levels for Mobile-Source Categories in 2020 [Thousand short tons] -------------------------------------------------------------------------------------------------------------------------------------------------------- NOX HC CO PM --------------------------------------------------------------------------------------- Category Percent Percent Percent Percent Tons of mobile Tons of mobile Tons of mobile Tons of mobile source source source source -------------------------------------------------------------------------------------------------------------------------------------------------------- Total for engines subject to proposed standards................. 552 8.9 2,055 33.4 8,404 9.4 11.4 1.8 ======================================================================================= Highway Motorcyles.............................................. 14 0.2 144 2.3 569 0.6 0.8 0.1 Nonroad Industrial SI > 19 kW................................... 486 7.8 348 5.7 2,991 3.3 2.4 0.4 Recreational SI................................................. 27 0.4 1,706 27.7 5,407 3.3 7.5 1.2 Recreation Marine CI............................................ 39 0.6 1 0.0 6 0.0 1.5 0.2 Marine SI Evap.................................................. 0 0.0 102 1.4 0 0.0 0 0.0 Marine SI Exhaust............................................... 58 0.9 284 4.6 1,985 2.2 28 4.4 Nonroad SI 19 kW............................................... 106 1.7 986 16.0 27,352 30.5 77 12.2 Nonroad CI...................................................... 1,791 28.8 142 2.3 1,462 1.6 261 41.3 Commercial Marine CI............................................ 819 13.2 35 0.6 160 0.2 46 7.3 Locomotive...................................................... 611 9.8 35 0.6 119 0.1 21 3.3 --------------------------------------------------------------------------------------- Total Nonroad................................................... 3,937 63 3,639 59 39,482 44 444 70 Total Highway................................................... 2,050 33 2,278 37 48,903 54 145 23 Aircraft........................................................ 232 4 238 4 1,387 2 43 7 --------------------------------------------------------------------------------------- Total Mobile Sources............................................ 6,219 100 6,155 100 89,772 100 632 100 ======================================================================================= Total Man-Made Sources.......................................... 16,195 ......... 16,215 ......... 113,440 ......... 3,016 ......... ======================================================================================= Mobile Source percent of Total Man-Made Sources................. 38 ......... 38 ......... 79 ......... 21 ......... -------------------------------------------------------------------------------------------------------------------------------------------------------- D. Regional and Local-Scale Public Health and Welfare Effects The previous section describes national-scale adverse public health effects associated with the nonroad engines and vehicles covered by this proposal. This section describes significant adverse health and welfare effects arising from the usage patterns of snowmobiles, Large SI engines, and gasoline marine engines on the regional and local scale. Studies suggest that emissions from these engines can be concentrated in specific areas, leading to elevated ambient concentrations of particular pollutants and associated elevated personal exposures to operators and by-standers. Recreational vehicles, and particularly snowmobiles, are typically operating in rural areas such as national parks and wilderness areas, and emissions from these vehicles contribute to ambient particulate matter which is a leading component of visibility impairment. 1. Health and Welfare Effects Related to Snowmobiles In this section, we describe more localized human health and welfare effects associated with snowmobile emissions: visibility impairment and personal exposure to air toxics and CO. We describe the contribution of snowmobile HC emissions to secondary formation of fine particles, which are the leading component of visibility impairment and adverse health effects related to ambient PM2.5 concentrations greater than 16 ug/m3. We also discuss personal exposure to CO emissions and air toxics. Gaseous air toxics are components of hydrocarbons, and CO personal exposure measurements suggest that snowmobile riders and bystanders are exposed to unhealthy levels of gaseous air toxics (e.g., benzene) and CO. a. Nonroad Engines and Regional Haze. The Clean Air Act established special goals for improving visibility in many national parks, wilderness areas, and international parks. In the 1977 amendments to the Clean Air Act, Congress set as a national goal for visibility the ``prevention of any future, and the remedying of any existing, impairment of visibility in mandatory class I Federal areas which impairment results from manmade air pollution'' (CAA section 169A(a)(1)). The Amendments called for EPA to issue regulations requiring States to develop implementation plans that assure ``reasonable progress'' toward meeting the national goal (CAA Section 169A(a)(4)). EPA issued regulations in 1980 to address visibility problems that are ``reasonably attributable'' to a single source or small group of sources, but deferred action on regulations related to regional haze, a type of visibility impairment that is caused by the emission of air pollutants by numerous emission sources located across a broad geographic region. At that time, EPA acknowledged that the regulations were only the first phase for addressing visibility impairment. Regulations dealing with regional haze were deferred until improved techniques were developed for monitoring, for air quality modeling, and for understanding the specific pollutants contributing to regional haze. In the 1990 Clean Air Act amendments, Congress provided additional emphasis on regional haze issues (see CAA section 169B). In 1999 EPA finalized a rule that calls for States to establish goals and emission reduction strategies for improving visibility in all 156 mandatory Class I national parks and wilderness areas. In that rule, EPA also encouraged the States to work together in developing and implementing their air quality plans. The regional haze program is designed to improve visibility and air quality in our most treasured natural areas. At the same time, control strategies designed to improve visibility in the national parks and wilderness areas will improve visibility over broad geographic areas. Regional haze is caused by the emission from numerous sources located over a wide geographic area. Such sources include, but are not limited to, major and minor stationary sources, mobile sources, and area sources. Visibility impairment is caused by pollutants (mostly fine particles and precursor gases) directly emitted to the [[Page 51111]] atmosphere by several activities (such as electric power generation, various industry and manufacturing processes, truck and auto emissions, construction activities, etc.). These gases and particles scatter and absorb light, removing it from the sight path and creating a hazy condition. Some fine particles are formed when gases emitted to the air form particles as they are carried downwind (examples include sulfates, formed from sulfur dioxide, and nitrates, formed from nitrogen oxides). These activities generally span broad geographic areas and fine particles can be transported great distances, sometimes hundreds or thousands of miles. Consequently, visibility impairment is a national problem. Without the effects of pollution a natural visual range is approximately 140 miles in the West and 90 miles in the East. However, fine particles have significantly reduced the range that people can see and in the West the current range is 33-90 miles and in the East it is only 14 to 24 miles. Because of evidence that fine particles are frequently transported hundreds of miles, all 50 states, including those that do not have Class I areas, will have to participate in planning, analysis and, in many cases, emission control programs under the regional haze regulations. Even though a given State may not have any Class I areas, pollution that occurs in that State may contribute to impairment in Class I areas elsewhere. The rule encourages states to work together to determine whether or how much emissions from sources in a given state affect visibility in a downwind Class I area. The regional haze program calls for states to establish goals for improving visibility in national parks and wilderness areas to improve visibility on the haziest 20 percent of days and to ensure that no degradation occurs on the clearest 20 percent of days. The rule requires states to develop long-term strategies including enforceable measures designed to meet reasonable progress goals. Under the regional haze program, States can take credit for improvements in air quality achieved as a result of other Clean Air Act programs, including national mobile-source programs. Nonroad engines (including construction equipment, farm tractors, boats, planes, locomotives, recreational vehicles, and marine engines) contribute significantly to regional haze. This is because there are nonroad engines in all of the states, and their emissions contain precursors of fine PM and organic carbon that are transported and contribute to the formation of regional haze throughout the country and in Class I areas specifically. As illustrated in Table II.D-1, nonroad engines are expected to contribute 15 percent of national VOC emissions, 23 percent of national NOX emissions, 6 percent of national SOx emissions, and 14 percent of national PM10 emissions. Snowmobiles alone are estimated to emit 208,926 tons of total hydrocarbons (THC), 1,461 tons of NOX, 2,145 tons of SOx, and 5,082 tons of PM in 2007. Table II.D-1.--National Emissions of Various Pollutants--2007 [Thousands short tons] -------------------------------------------------------------------------------------------------------------------------------------------------------- VOC NOX SOX PM10 Source ----------------------------------------------------------------------------------------------- Tons Percent Tons Percent Tons Percent Tons Percent -------------------------------------------------------------------------------------------------------------------------------------------------------- Heavy-Duty Highway...................................... 413 3 2,969 14 24 0 115 4 Light-Duty Highway...................................... 2,596 18 2,948 14 24 0 82 3 Nonroad................................................. 2,115 15 4,710 23 1,027 6 407 14 Electric General........................................ 35 0 4,254 21 10,780 63 328 12 Point................................................... 1,639 11 3,147 15 3,796 22 1,007 36 Area.................................................... 7,466 52 2,487 12 1,368 8 874 31 ------------ ------------ ------------ ------------ Total............................................. 14,265 20,516 17,019 2,814 -------------------------------------------------------------------------------------------------------------------------------------------------------- b. Snowmobiles and Visibility Impairment. As noted above, EPA issued regulations in 1980 to address Class I area visibility impairment that is ``reasonably attributable'' to a single source or small group of sources. In 40 CFR Part 51.301 of the visibility regulations, visibility impairment is defined as ``any humanly perceptible change in visibility (light extinction, visual range, contrast, coloration) from that which would have existed under natural conditions.'' States are required to develop implementation plans that include long-term strategies for improving visibility in each class I area. The long-term strategies under the 1980 regulations should consist of measures to reduce impacts from local sources and groups of sources that contribute to poor air quality days in the class I area. Types of impairment covered by these regulations includes layered hazes and visible plumes. While these kinds of visibility impairment can be caused by the same pollutants and processes as those that cause regional haze, they generally are attributed to a smaller number of sources located across a smaller area. The Clean Air Act and associated regulations call for protection of visibility impairment in class I areas from localized impacts as well as broader impacts associated with regional haze. Visibility and particle monitoring data are available for 8 Class I areas where snowmobiles are commonly used. These are: Acadia, Boundary Waters, Denali, Mount Rainier, Rocky Mountain, Sequoia and Kings Canyon, Voyageurs, and Yellowstone.\103\ Visibility and fine particle data for these parks are set out in Table II.D-2. This table shows the number of monitored days in the winter that fell within the 20-percent haziest days for each of these eight parks. Monitors collect data two days a week for a total of about 104 days of monitored values. Thus, for a particular site, a maximum of 21 worst possible days of these 104 days with monitored values constitute the set of 20-percent haziest days during a year which are tracked as the primary focus of regulatory efforts.\104\ With the exception of Denali in Alaska, we defined the snowmobile season as January 1 through March 15 and December 15 through December 31 of the same calendar year, consistent with the methodology used in the Regional Haze Rule, which is calendar-year based. For Denali in [[Page 51112]] Alaska, the snowmobile season is October 1 to April 30. The Agency would be interested in comments from the public on the start and end dates for the typical snowmobile season at each of these national parks. --------------------------------------------------------------------------- \103\ No data were available at five additional parks where snowmobiles are also commonly used: Black Canyon of the Gunnison, CO, Grant Teton, WY, Northern Cascades, WA, Theodore Roosevelt, ND, and Zion, UT. \104\ Letter from Debra C. Miller, Data Analyst, National Park Service, to Drew Kodjak, August 22, 2001. Docket No. A-2000-01, Document Number. II-B-28. Table II.D-2.--Winter Days That Fall Within the 20 Percent Haziest Days at National Parks Used by Snowmobiles ---------------------------------------------------------------------------------------------------------------- Number of sampled wintertime days within 20 percent haziest days NPS Unit State(s) (maximum of 21 sampled days) --------------------------------------- 1996 1997 1998 1999 ---------------------------------------------------------------------------------------------------------------- Acadia NP........................ ME................................... 4 4 2 1 Denali NP and Preserve........... AK................................... 10 10 12 9 Mount Rainier NP................. WA................................... 1 3 1 1 Rocky Mountain NP................ CO................................... 2 1 2 1 Sequoia and Kings Canyon NP...... CA................................... 4 9 1 8 Voyageurs NP (1989-1992)......... MN................................... 1989 1990 1991 1992 3 4 6 8 --Boundary Waters USFS Wilderness MN................................... 2 5 1 5 Area (close to Voyaguers with recent data). Yellowstone NP................... ID, MT, WY........................... 0 2 0 0 ---------------------------------------------------------------------------------------------------------------- Source: Letter from Debra C. Miller, Data Analyst, National Park Service, to Drew Kodjak, August 22, 2001. Docket No. A-2000-01, Document Number. II-B-28. The information presented in Table II.D-2 shows that visibility data support a conclusion that there are at least eight Class I Areas (7 in National Parks and one in a Wilderness Area) frequented by snowmobiles with one or more wintertime days within the 20-percent haziest days of the year. For example, Rocky Mountain National Park in Colorado was frequented by about 27,000 snowmobiles during the 1998- 1999 winter. Of the monitored days characterized as within the 20- percent haziest monitored days, two (2) of those days occurred during the wintertime when snowmobile emissions such as hydrocarbons contributed to visibility impairment. According to the National Park Service, ``[s]ignificant differences in haziness occur at all eight sites between the averages of the clearest and haziest days. Differences in mean standard visual range on the clearest and haziest days fall in the approximate range of 115-170 km.'' \105\ --------------------------------------------------------------------------- \105\ Letter from Debra C. Miller, Data Analyst, National Park Service, to Drew Kodjak, August 22, 2001. Docket No. A-2000-01, Document Number. II-B-28. --------------------------------------------------------------------------- Ambient concentrations of fine particles are the primary pollutant responsible for visibility impairment. Five pollutants are largely responsible for the chemical composition of fine particles: sulfates, nitrates, organic carbon particles, elemental carbon, and crustal material. Hydrocarbon emissions from automobiles, trucks, snowmobiles, and other industrial processes are common sources of organic carbon. The organic carbon fraction of fine particles ranges from 47 percent in Western areas such as Denali National Park, to 28 percent in Rocky Mountain National Park, to 13 percent in Acadia National Park.\106\ --------------------------------------------------------------------------- \106\ Letter from Debra C. Miller, Data Analyst, National Park Service, to Drew Kodjak, August 22, 2001. Docket No. A-2000-01, Document Number. II-B-28. --------------------------------------------------------------------------- The contribution of snowmobiles to elemental carbon and nitrates is small. Their contribution to sulfates is a function of fuel sulfur and is small and will decrease even more as the sulfur content of their fuel decreases due to our recently finalized fuel sulfur requirements. In the winter months, however, hydrocarbon emissions from snowmobiles can be significant, as indicated in Table II.D-3, and these HC emissions can contribute significantly to the organic carbon fraction of fine particles which are largely responsible for visibility impairment. This is because they are typically powered by two-stroke engines that emit large amounts of hydrocarbons. In Yellowstone, a park with high snowmobile usage during the winter months, snowmobile hydrocarbon emissions can exceed 500 tons per year, as much as several large stationary sources. Other parks with less snowmobile traffic are less impacted by these hydrocarbon emissions.\107\ --------------------------------------------------------------------------- \107\ Technical Memorandum, Aaron Worstell, Environmental Engineer, National Park Service, Air Resources Division, Denver, Colorado, particularly Table 1. Docket No. A-2000-01, Document Number II-G-178. --------------------------------------------------------------------------- Table II.D-3 shows modeled tons of four pollutants during the winter season in five Class I national parks for which we have estimates of snowmobile use. The national park areas outside of Denali in Alaska are open to snowmobile operation in accordance with special regulations (36 CFR Part 7). Denali National Park permits snowmobile operation by local rural residents engaged in subsistence uses (36 CFR Part 13). Emission calculations are based on an assumed 2 hours of use per snowmobile visit at 16 hp with the exception of Yellowstone where 4 hours of use at 16 hp was assumed. The emission factors used to estimate these emissions are identical to those used by the NONROAD model. Two-stroke snowmobile emission factors are: 111 g/hp-hr HC, 296 g/hp-hr CO, 0.86 g/hp-hr NOX, and 2.7 g/hp-hr PM. These emission factors are based on several engine tests performed by the International Snowmobile Manufacturers Association (ISMA) and the Southwest Research Institute (SwRI). These emission factors are still under review, and the emissions estimates may change pending the outcome of that review. [[Page 51113]] Table II.D-3.--Winter Season Snowmobile Emissions [Tons; 1999 Winter Season] ---------------------------------------------------------------------------------------------------------------- NPS unit HC CO NOX PM ---------------------------------------------------------------------------------------------------------------- Denali NP & Preserve............................................ >9.8 >26.1 >0.08 >0.24 Grand Teton NP.................................................. 13.7 36.6 0.1 0.3 Rocky Mountain NP............................................... 106.7 284.7 0.8 2.6 Voyageurs NP.................................................... 138.5 369.4 1.1 3.4 Yellowstone NP.................................................. 492.0 1,311.9 3.8 12.0 ---------------------------------------------------------------------------------------------------------------- Source: Letter from Aaron J. Worstell, Environmental Engineer, National Park Service, Air Resources Division, to Drew Kodjak, August 21, 2001, particularly Table 1. Docket No. A-2000-01, Document No. II-G-178. Inventory analysis performed by the National Park Service for Yellowstone National Park suggests that snowmobile emissions can be a significant source of total annual mobile source emissions for the park year round. Table II.D-4 shows that in the 1998 winter season snowmobiles contributed 64 percent, 39 percent, and 30 percent of HC, CO, and PM emissions.\108\ It should be noted that the snowmobile emission factors used to estimate these contributions are currently under review, and the snowmobile emissions may be revised down. However, when the emission factors used by EPA in its NONROAD model are used, the contribution of snowmobiles to total emissions in Yellowstone remains significant: 59 percent, 33 percent, and 45 percent of HC, CO and PM emissions. The University of Denver used remote-sensing equipment to estimate snowmobile HC emissions at Yellowstone during the winter of 1998-1999, and estimated that snowmobiles contribute 77% of annual hydrocarbon emissions at the park.\109\ The portion of wintertime emissions attributable to snowmobiles is even higher, since all snowmobile emissions occur during the winter months. --------------------------------------------------------------------------- \108\ National Park Service, February 2000. Air Quality Concerns Related to Snowmobile Usage in National Parks. Air Docket A-2000-01, Document No. II-A-44. \109\ G. Bishop, et al., Snowmobile Contributions to Mobile Source Emissions in Yellowstone National Park, Environmental Science and Technology, Vol. 35, No. 14, at 2873. Docket No. A-2000-01, Document No. II-A-47. Table II.D-4.--1998 Annual HC Emissions (tpy), Yellowstone National Park -------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------- HC CO NOX PM -------------------------------------------------------------------------------------------------------------------------------------------------------- Source: Coaches............................................... 2.69 0% 24.29 1% 0.42 0% 0.01 0% Autos................................................. 307.17 33% 2,242.12 54% 285.51 88% 12.20 60% RVs................................................... 15.37 2% 269.61 6% 24.33 7% 0.90 4% Snowmobiles........................................... 596.22 64% 1,636.44 39% 1.79 1% 6.07 30% Buses................................................. 4.96 1% 18.00 0% 13.03 4% 1.07 5% ------------ ------------ ------------ ------------ Total........................................... 926.4 4,190.46 325.08 20.25 -------------------------------------------------------------------------------------------------------------------------------------------------------- Source: National Park Service, February 2000. Air Quality Concerns Related to Snowmobile Usage in National Parks. Air Docket A-2000-01, Document No. II- A-44. The information presented in this discussion indicates that snowmobiles are significant emitters of pollutants that are known to contribute to visibility impairment in some Class I areas. Annual and particularly wintertime hydrocarbon emissions from snowmobiles are high in the five parks considered in Table II.D-4, with two parks having HC emissions nearly as high as Yellowstone (Rocky Mountain and Voyageurs). The proportion of snowmobile emissions to emissions from other sources affecting air quality in these parks is likely to be similar to that in Yellowstone. c. Snowmobiles and personal exposure to air toxics and CO. Snowmobile users can be exposed to high air toxic and CO emissions, both because they sit very close to the vehicle's exhaust port and because it is common for them to ride their vehicles on groomed trails where they travel fairly close behind other snowmobiles. Because of these riding patterns, snowmobilers breathe exhaust emissions from their own vehicle, the vehicle directly in front, as well as those farther up the trail. This can lead to relatively high personal exposure levels of harmful pollutants. A study of snowmobile rider CO exposure conducted at Grand Teton National Park showed that a snowmobiler riding at distances of 25 to 125 feet behind another snowmobiler and traveling at speeds from 10 to 40 mph can be exposed to average CO levels ranging from 0.5 to 23 ppm, depending on speed and distance. The highest CO level measured in this study was 45 ppm, as compared to the current 1-hour NAAQS for CO of 35 ppm.\110\ While exposure levels can be less if a snowmobile drives 15 feet off the centerline of the lead snowmobile, the exposure levels are still of concern. This study led to the development of an empirical model for predicting CO exposures from riding behind snowmobiles. --------------------------------------------------------------------------- \110\ Snook and Davis, 1997, ``An Investigation of Driver Exposure to Carbon Monoxide While Traveling Behind Another Snowmobile.'' Docket No. A-2000-01, Document Number II-A-35. --------------------------------------------------------------------------- Hydrocarbon speciation for snowmobile emissions was performed for the State of Montana in a 1997 report.\111\ Using the empirical model for CO from the Grand Teton exposure study with benzene emission rates from the State of Montana's emission study, benzene exposures for riders driving behind a single snowmobile were predicted to range from 1.2E+02 to 1.4E+03 g/m3. Using the same model to predict exposures when riding at the end of a line of six snowmobiles spaced 25 feet apart yielded exposure predictions of 3.5E+03, 1.9E+03, [[Page 51114]] 1.3E+03, and 1.2E+03 g/m3 benzene. at 10, 20, 30, and 40 mph, respectively. --------------------------------------------------------------------------- \111\ Emissions from Snowmobile Engines Using Bio-based Fuels and Lubricants, Southwest Research Institute, August, 1997, at 22. Docket No. A-2000-01, Document Number II-A-50. --------------------------------------------------------------------------- The cancer risk posed to those exposed to benzene emissions from snowmobiles must be viewed within the broader context of expected lifetime benzene exposure. Observed monitoring data and predicted modeled values demonstrate that a significant cancer risk already exists from ambient concentrations of benzene for a large portion of the US population. The Agency's 1996 National-Scale Air Toxics Assessment of personal exposure to ambient concentrations of air toxic compounds emitted by outside sources (e.g. cars and trucks, power plants) found that benzene was among the five air toxics that appear to pose the greatest risk to people nationwide. This national assessment found that for approximately 50% of the US population in 1996, the inhalation cancer risks associated with benzene exceeded 10 in one million. Modeled predictions for ambient benzene from this assessment correlated well with observed monitored concentrations of benzene ambient concentrations. Specifically, the draft National-Scale Assessment predicted nationwide annual average benzene exposures from outdoor sources to be 1.4 g/m3.\112\ In comparison, snowmobile riders and those directly exposed to snowmobile exhaust emissions had predicted benzene levels two to three orders of magnitude greater than the 1996 national average benzene concentrations.\113\ These elevated levels are also known as air toxic ``hot spots,'' which are of particular concern to the Agency. Thus, total annual average exposures to typical ambient benzene concentrations combined with elevated short-term exposures to benzene from snowmobiles may pose a significant risk of adverse public health effects to snowmobile riders and those exposed on a frequent basis to exhaust benzene emissions from snowmobiles. We request comment on this issue. --------------